WorldWideScience

Sample records for biomolecular arraying applications

  1. Application of Nanodiamonds in Biomolecular Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Ping Cheng

    2010-03-01

    Full Text Available The combination of nanodiamond (ND with biomolecular mass spectrometry (MS makes rapid, sensitive detection of biopolymers from complex biosamples feasible. Due to its chemical inertness, optical transparency and biocompatibility, the advantage of NDs in MS study is unique. Furthermore, functionalization on the surfaces of NDs expands their application in the fields of proteomics and genomics for specific requirements greatly. This review presents methods of MS analysis based on solid phase extraction and elution on NDs and different application examples including peptide, protein, DNA, glycan and others. Owing to the quick development of nanotechnology, surface chemistry, new MS methods and the intense interest in proteomics and genomics, a huge increase of their applications in biomolecular MS analysis in the near future can be predicted.

  2. Biomolecular logic systems: applications to biosensors and bioactuators

    Science.gov (United States)

    Katz, Evgeny

    2014-05-01

    The paper presents an overview of recent advances in biosensors and bioactuators based on the biocomputing concept. Novel biosensors digitally process multiple biochemical signals through Boolean logic networks of coupled biomolecular reactions and produce output in the form of YES/NO response. Compared to traditional single-analyte sensing devices, biocomputing approach enables a high-fidelity multi-analyte biosensing, particularly beneficial for biomedical applications. Multi-signal digital biosensors thus promise advances in rapid diagnosis and treatment of diseases by processing complex patterns of physiological biomarkers. Specifically, they can provide timely detection and alert to medical emergencies, along with an immediate therapeutic intervention. Application of the biocomputing concept has been successfully demonstrated for systems performing logic analysis of biomarkers corresponding to different injuries, particularly exemplified for liver injury. Wide-ranging applications of multi-analyte digital biosensors in medicine, environmental monitoring and homeland security are anticipated. "Smart" bioactuators, for example for signal-triggered drug release, were designed by interfacing switchable electrodes and biocomputing systems. Integration of novel biosensing and bioactuating systems with the biomolecular information processing systems keeps promise for further scientific advances and numerous practical applications.

  3. Biomolecular crystals for material applications and a mechanistic study of an iron oxide nanoparticle synthesis

    Science.gov (United States)

    Falkner, Joshua Charles

    The three projects within this work address the difficulties of controlling biomolecular crystal formats (i.e. size and shape), producing 3-D ordered composite materials from biomolecular crystal templates, and understanding the mechanism of a practical iron oxide synthesis. The unifying thread consistent throughout these three topics is the development of methods to manipulate nanomaterials using a bottom-up approach. Biomolecular crystals are nanometer to millimeter sized crystals that have well ordered mesoporous solvent channels. The overall physical dimensions of these crystals are highly dependent on crystallization conditions. The controlled growth of micro- and nanoprotein crystals was studied to provide new pathways for creating smaller crystalline protein materials. This method produced tetragonal hen egg-white lysozyme crystals (250--100,000 nm) with near monodisperse size distributions (membranes or templates. In this work, the porous structure of larger cowpea mosaic virus crystals was used to template metal nanoparticle growth within the body centered cubic crystalline network. The final composite material was found to have long range ordering of palladium and platinum nonocrystal aggregates (10nm) with symmetry consistent to the virus template. Nanoparticle synthesis itself is an immense field of study with an array of diverse applications. The final piece of this work investigates the mechanism behind a previously developed iron oxide synthesis to gain more understanding and direction to future synthesis strategies. The particle growth mechanism was found to proceed by the formation of a solvated iron(III)oleate complex followed by a reduction of iron (III) to iron (II). This unstable iron(II) nucleates to form a wustite (FeO) core which serves as an epitaxial surface for the magnetite (Fe3O4) shell growth. This method produces spherical particles (6-60nm) with relative size distributions of less than 15%.

  4. Recent applications of AC electrokinetics in biomolecular analysis on microfluidic devices.

    Science.gov (United States)

    Sasaki, Naoki

    2012-01-01

    AC electrokinetics is a generic term that refers to an induced motion of particles and fluids under nonuniform AC electric fields. The AC electric fields are formed by application of AC voltages to microelectrodes, which can be easily integrated into microfluidic devices by standard microfabrication techniques. Moreover, the magnitude of the motion is large enough to control the mass transfer on the devices. These advantages are attractive for biomolecular analysis on the microfluidic devices, in which the characteristics of small space and microfluidics have been mainly employed. In this review, I describe recent applications of AC electrokinetics in biomolecular analysis on microfluidic devices. The applications include fluid pumping and mixing by AC electrokinetic flow, and manipulation of biomolecules such as DNA and proteins by various AC electrokinetic techniques. Future prospects for highly functional biomolecular analysis on microfluidic devices with the aid of AC electrokinetics are also discussed.

  5. Surface-plasmon-enhanced fluorescence from periodic quantum dot arrays through distance control using biomolecular linkers

    International Nuclear Information System (INIS)

    We have developed a protein-enabled strategy to fabricate quantum dot (QD) nanoarrays where up to a 15-fold increase in surface-plasmon-enhanced fluorescence has been achieved. This approach permits a comprehensive control both laterally (via lithographically defined gold nanoarrays) and vertically (via the QD-metal distance) of the collectively behaving assemblies of QDs and gold nanoarrays by way of biomolecular recognition. Specifically, we demonstrated the spectral tuning of plasmon resonant metal nanoarrays and self-assembly of protein-functionalized QDs in a stepwise fashion with a concomitant incremental increase in separation from the metal surface through biotin-streptavidin spacer units.

  6. Markov propagation of allosteric effects in biomolecular systems: application to GroEL–GroES

    OpenAIRE

    Chennubhotla, Chakra; Bahar, Ivet

    2006-01-01

    We introduce a novel approach for elucidating the potential pathways of allosteric communication in biomolecular systems. The methodology, based on Markov propagation of ‘information' across the structure, permits us to partition the network of interactions into soft clusters distinguished by their coherent stochastics. Probabilistic participation of residues in these clusters defines the communication patterns inherent to the network architecture. Application to bacterial chaperonin complex ...

  7. Rational Design of Biomolecular Templates for Synthesizing Multifunctional Noble Metal Nanoclusters toward Personalized Theranostic Applications.

    Science.gov (United States)

    Yu, Yong; Mok, Beverly Y L; Loh, Xian Jun; Tan, Yen Nee

    2016-08-01

    Biomolecule-templated or biotemplated metal nanoclusters (NCs) are ultrasmall (<2 nm) metal (Au, Ag) particles stabilized by a certain type of biomolecular template (e.g., peptides, proteins, and DNA). Due to their unique physiochemical properties, biotemplated metal NCs have been widely used in sensing, imaging, delivery and therapy. The overwhelming applications in these individual areas imply the great promise of harnessing biotemplated metal NCs in more advanced biomedical aspects such as theranostics. Although applications of biotemplated metal NCs as theranostic agents are trending, the rational design of biomolecular templates suitable for the synthesis of multifunctional metal NCs for theranostics is comparatively underexplored. This progress report first identifies the essential attributes of biotemplated metal NCs for theranostics by reviewing the state-of-art applications in each of the four modalities of theranostics, namely sensing, imaging, delivery and therapy. To achieve high efficacy in these modalities, we elucidate the design principles underlying the use of biomolecules (proteins, peptides and nucleic acids) to control the NC size, emission color and surface chemistries for post-functionalization of therapeutic moieties. We then propose a unified strategy to engineer biomolecular templates that combine all these modalities to produce multifunctional biotemplated metal NCs that can serve as the next-generation personalized theranostic agents.

  8. Surface-enhanced Raman spectroscopy bioanalytical, biomolecular and medical applications

    CERN Document Server

    Procházka, Marek

    2016-01-01

    This book gives an overview of recent developments in RS and SERS for sensing and biosensing considering also limitations, possibilities and prospects of this technique. Raman scattering (RS) is a widely used vibrational technique providing highly specific molecular spectral patterns. A severe limitation for the application of this spectroscopic technique lies in the low cross section of RS. Surface-enhanced Raman scattering (SERS) spectroscopy overcomes this problem by 6-11 orders of magnitude enhancement compared with the standard RS for molecules in the close vicinity of certain rough metal surfaces. Thus, SERS combines molecular fingerprint specificity with potential single-molecule sensitivity. Due to the recent development of new SERS-active substrates, labeling and derivatization chemistry as well as new instrumentations, SERS became a very promising tool for many varied applications, including bioanalytical studies and sensing. Both intrinsic and extrinsic SERS biosensing schemes have been employed to...

  9. Scanning probe and micropatterning approaches for biomolecular screening applications

    CERN Document Server

    Wilde, L M

    2002-01-01

    Force mapping using atomic force microscopy (AFM) allows for the simultaneous acquisition of topography and probe-sample interaction data. For example, AFM probes functionalised with an antigen can be employed to map the spatial distribution of recognition events on a substrate functionalised with the complementary specific antibody. However, this technique is currently limited to the detection of a single receptor-ligand species. Were the detection of multiple receptor-ligand interactions possible, AFM force mapping would offer greater scope as a sensitive tool for bioassay and screening applications. This thesis outlines developments in probe and substrate immobilisation methods to facilitate this process. We have developed an immobilisation strategy, which allows two antigen species, human serum albumin (HSA) and the beta subunit of human chorionic gonadotropin (beta hCG) to be simultaneously present on an AFM probe. Single point force spectroscopy results have revealed the ability of such probes to discri...

  10. Tailored surface-enhanced Raman nanopillar arrays fabricated by laser-assisted replication for biomolecular detection using organic semiconductor lasers.

    Science.gov (United States)

    Liu, Xin; Lebedkin, Sergei; Besser, Heino; Pfleging, Wilhelm; Prinz, Stephan; Wissmann, Markus; Schwab, Patrick M; Nazarenko, Irina; Guttmann, Markus; Kappes, Manfred M; Lemmer, Uli

    2015-01-27

    Organic semiconductor distributed feedback (DFB) lasers are of interest as external or chip-integrated excitation sources in the visible spectral range for miniaturized Raman-on-chip biomolecular detection systems. However, the inherently limited excitation power of such lasers as well as oftentimes low analyte concentrations requires efficient Raman detection schemes. We present an approach using surface-enhanced Raman scattering (SERS) substrates, which has the potential to significantly improve the sensitivity of on-chip Raman detection systems. Instead of lithographically fabricated Au/Ag-coated periodic nanostructures on Si/SiO2 wafers, which can provide large SERS enhancements but are expensive and time-consuming to fabricate, we use low-cost and large-area SERS substrates made via laser-assisted nanoreplication. These substrates comprise gold-coated cyclic olefin copolymer (COC) nanopillar arrays, which show an estimated SERS enhancement factor of up to ∼ 10(7). The effect of the nanopillar diameter (60-260 nm) and interpillar spacing (10-190 nm) on the local electromagnetic field enhancement is studied by finite-difference-time-domain (FDTD) modeling. The favorable SERS detection capability of this setup is verified by using rhodamine 6G and adenosine as analytes and an organic semiconductor DFB laser with an emission wavelength of 631.4 nm as the external fiber-coupled excitation source.

  11. Overcoming the solubility limit with solubility-enhancement tags: successful applications in biomolecular NMR studies

    International Nuclear Information System (INIS)

    Although the rapid progress of NMR technology has significantly expanded the range of NMR-trackable systems, preparation of NMR-suitable samples that are highly soluble and stable remains a bottleneck for studies of many biological systems. The application of solubility-enhancement tags (SETs) has been highly effective in overcoming solubility and sample stability issues and has enabled structural studies of important biological systems previously deemed unapproachable by solution NMR techniques. In this review, we provide a brief survey of the development and successful applications of the SET strategy in biomolecular NMR. We also comment on the criteria for choosing optimal SETs, such as for differently charged target proteins, and recent new developments on NMR-invisible SETs.

  12. Advances in biomolecular surface meshing and its applications to mathematical modeling

    Institute of Scientific and Technical Information of China (English)

    CHEN MinXin; LU BenZhuo

    2013-01-01

    In the field of molecular modeling and simulation,molecular surface meshes are necessary for many problems,such as molecular structure visualization and analysis,docking problem and implicit solvent modeling and simulation.Recently,with the developments of advanced mathematical modeling in the field of implicit solvent modeling and simulation,providing surface meshes with good qualities efficiently for large real biomolecular systems becomes an urgent issue beyond its traditional purposes for visualization and geometry analyses for molecular structure.In this review,we summarize recent works on this issue.First,various definitions of molecular surfaces and corresponding meshing methods are introduced.Second,our recent meshing tool,TMSmesh,and its performances are presented.Finally,we show the applications of the molecular surface mesh in implicit solvent modeling and simulations using boundary element method (BEM) and finite element method (FEM).

  13. Global analysis of time-resolved fluorescence microspectroscopy and applications in biomolecular studies

    NARCIS (Netherlands)

    Laptenok, S.

    2009-01-01

    Understanding the properties of biomolecular networks is of central importance in life sciences. Optical microscopy has been very useful to determine the sub-cellular localisation of proteins but it cannot reveal whether proteins interact with one another. Micro-spectroscopic techniques (combining m

  14. Antenna Arrays and Automotive Applications

    CERN Document Server

    Rabinovich, Victor

    2013-01-01

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

  15. Acoustic array systems theory, implementation, and application

    CERN Document Server

    Bai, Mingsian R; Benesty, Jacob

    2013-01-01

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

  16. PUPIL: A Software Integration System for Multi-Scale QM/MM-MD Simulations and Its Application to Biomolecular Systems.

    Science.gov (United States)

    Torras, Juan; Roberts, Benjamin P; Seabra, Gustavo M; Trickey, Samuel B

    2015-01-01

    PUPIL (Program for User Package Interfacing and Linking) implements a distinctive multi-scale approach to hybrid quantum mechanical/molecular mechanical molecular dynamics (QM/MM-MD) simulations. Originally developed to interface different external programs for multi-scale simulation with applications in the materials sciences, PUPIL is finding increasing use in the study of complex biological systems. Advanced MD techniques from the external packages can be applied readily to a hybrid QM/MM treatment in which the forces and energy for the QM region can be computed by any of the QM methods available in any of the other external packages. Here, we give a survey of PUPIL design philosophy, main features, and key implementation decisions, with an orientation to biomolecular simulation. We discuss recently implemented features which enable highly realistic simulations of complex biological systems which have more than one active site that must be treated concurrently. Examples are given.

  17. Design of Flow Systems for Improved Networking and Reduced Noise in Biomolecular Signal Processing in Biocomputing and Biosensing Applications

    Directory of Open Access Journals (Sweden)

    Arjun Verma

    2016-07-01

    Full Text Available We consider flow systems that have been utilized for small-scale biomolecular computing and digital signal processing in binary-operating biosensors. Signal measurement is optimized by designing a flow-reversal cuvette and analyzing the experimental data to theoretically extract the pulse shape, as well as reveal the level of noise it possesses. Noise reduction is then carried out numerically. We conclude that this can be accomplished physically via the addition of properly designed well-mixing flow-reversal cell(s as an integral part of the flow system. This approach should enable improved networking capabilities and potentially not only digital but analog signal-processing in such systems. Possible applications in complex biocomputing networks and various sense-and-act systems are discussed.

  18. Design of Flow Systems for Improved Networking and Reduced Noise in Biomolecular Signal Processing in Biocomputing and Biosensing Applications.

    Science.gov (United States)

    Verma, Arjun; Fratto, Brian E; Privman, Vladimir; Katz, Evgeny

    2016-07-05

    We consider flow systems that have been utilized for small-scale biomolecular computing and digital signal processing in binary-operating biosensors. Signal measurement is optimized by designing a flow-reversal cuvette and analyzing the experimental data to theoretically extract the pulse shape, as well as reveal the level of noise it possesses. Noise reduction is then carried out numerically. We conclude that this can be accomplished physically via the addition of properly designed well-mixing flow-reversal cell(s) as an integral part of the flow system. This approach should enable improved networking capabilities and potentially not only digital but analog signal-processing in such systems. Possible applications in complex biocomputing networks and various sense-and-act systems are discussed.

  19. Design of Flow Systems for Improved Networking and Reduced Noise in Biomolecular Signal Processing in Biocomputing and Biosensing Applications.

    Science.gov (United States)

    Verma, Arjun; Fratto, Brian E; Privman, Vladimir; Katz, Evgeny

    2016-01-01

    We consider flow systems that have been utilized for small-scale biomolecular computing and digital signal processing in binary-operating biosensors. Signal measurement is optimized by designing a flow-reversal cuvette and analyzing the experimental data to theoretically extract the pulse shape, as well as reveal the level of noise it possesses. Noise reduction is then carried out numerically. We conclude that this can be accomplished physically via the addition of properly designed well-mixing flow-reversal cell(s) as an integral part of the flow system. This approach should enable improved networking capabilities and potentially not only digital but analog signal-processing in such systems. Possible applications in complex biocomputing networks and various sense-and-act systems are discussed. PMID:27399702

  20. Grid computing and biomolecular simulation.

    Science.gov (United States)

    Woods, Christopher J; Ng, Muan Hong; Johnston, Steven; Murdock, Stuart E; Wu, Bing; Tai, Kaihsu; Fangohr, Hans; Jeffreys, Paul; Cox, Simon; Frey, Jeremy G; Sansom, Mark S P; Essex, Jonathan W

    2005-08-15

    Biomolecular computer simulations are now widely used not only in an academic setting to understand the fundamental role of molecular dynamics on biological function, but also in the industrial context to assist in drug design. In this paper, two applications of Grid computing to this area will be outlined. The first, involving the coupling of distributed computing resources to dedicated Beowulf clusters, is targeted at simulating protein conformational change using the Replica Exchange methodology. In the second, the rationale and design of a database of biomolecular simulation trajectories is described. Both applications illustrate the increasingly important role modern computational methods are playing in the life sciences.

  1. Variational Methods for Biomolecular Modeling

    CERN Document Server

    Wei, Guo-Wei

    2016-01-01

    Structure, function and dynamics of many biomolecular systems can be characterized by the energetic variational principle and the corresponding systems of partial differential equations (PDEs). This principle allows us to focus on the identification of essential energetic components, the optimal parametrization of energies, and the efficient computational implementation of energy variation or minimization. Given the fact that complex biomolecular systems are structurally non-uniform and their interactions occur through contact interfaces, their free energies are associated with various interfaces as well, such as solute-solvent interface, molecular binding interface, lipid domain interface, and membrane surfaces. This fact motivates the inclusion of interface geometry, particular its curvatures, to the parametrization of free energies. Applications of such interface geometry based energetic variational principles are illustrated through three concrete topics: the multiscale modeling of biomolecular electrosta...

  2. Biomolecular EPR spectroscopy

    CERN Document Server

    Hagen, Wilfred Raymond

    2008-01-01

    Comprehensive, Up-to-Date Coverage of Spectroscopy Theory and its Applications to Biological SystemsAlthough a multitude of books have been published about spectroscopy, most of them only occasionally refer to biological systems and the specific problems of biomolecular EPR (bioEPR). Biomolecular EPR Spectroscopy provides a practical introduction to bioEPR and demonstrates how this remarkable tool allows researchers to delve into the structural, functional, and analytical analysis of paramagnetic molecules found in the biochemistry of all species on the planet. A Must-Have Reference in an Intrinsically Multidisciplinary FieldThis authoritative reference seamlessly covers all important bioEPR applications, including low-spin and high-spin metalloproteins, spin traps and spin lables, interaction between active sites, and redox systems. It is loaded with practical tricks as well as do's and don'ts that are based on the author's 30 years of experience in the field. The book also comes with an unprecedented set of...

  3. Stable isotope applications in biomolecular structure and mechanisms. A meeting to bring together producers and users of stable-isotope-labeled compounds to assess current and future needs

    Energy Technology Data Exchange (ETDEWEB)

    Trewhella, J.; Cross, T.A.; Unkefer, C.J. [eds.

    1994-12-01

    Knowledge of biomolecular structure is a prerequisite for understanding biomolecular function, and stable isotopes play an increasingly important role in structure determination of biological molecules. The first Conference on Stable Isotope Applications in Biomolecular Structure and Mechanisms was held in Santa Fe, New Mexico, March 27--31, 1994. More than 120 participants from 8 countries and 44 institutions reviewed significant developments, discussed the most promising applications for stable isotopes, and addressed future needs and challenges. Participants focused on applications of stable isotopes for studies of the structure and function of proteins, peptides, RNA, and DNA. Recent advances in NMR techniques neutron scattering, EPR, and vibrational spectroscopy were highlighted in addition to the production and synthesis of labeled compounds. This volume includes invited speaker and poster presentations as well as a set of reports from discussion panels that focused on the needs of the scientific community and the potential roles of private industry, the National Stable Isotope Resource, and the National High Magnetic Field Laboratory in serving those needs. This is the leading abstract. Individual papers are processed separately for the database.

  4. Stable isotope applications in biomolecular structure and mechanisms. A meeting to bring together producers and users of stable-isotope-labeled compounds to assess current and future needs

    International Nuclear Information System (INIS)

    Knowledge of biomolecular structure is a prerequisite for understanding biomolecular function, and stable isotopes play an increasingly important role in structure determination of biological molecules. The first Conference on Stable Isotope Applications in Biomolecular Structure and Mechanisms was held in Santa Fe, New Mexico, March 27--31, 1994. More than 120 participants from 8 countries and 44 institutions reviewed significant developments, discussed the most promising applications for stable isotopes, and addressed future needs and challenges. Participants focused on applications of stable isotopes for studies of the structure and function of proteins, peptides, RNA, and DNA. Recent advances in NMR techniques neutron scattering, EPR, and vibrational spectroscopy were highlighted in addition to the production and synthesis of labeled compounds. This volume includes invited speaker and poster presentations as well as a set of reports from discussion panels that focused on the needs of the scientific community and the potential roles of private industry, the National Stable Isotope Resource, and the National High Magnetic Field Laboratory in serving those needs. This is the leading abstract. Individual papers are processed separately for the database

  5. Application of isothermal titration calorimetry for characterizing thermodynamic parameters of biomolecular interactions: peptide self-assembly and protein adsorption case studies.

    Science.gov (United States)

    Kabiri, Maryam; Unsworth, Larry D

    2014-10-13

    The complex nature of macromolecular interactions usually makes it very hard to identify the molecular-level mechanisms that ultimately dictate the result of these interactions. This is especially evident in the case of biological systems, where the complex interaction of molecules in various situations may be responsible for driving biomolecular interactions themselves but also has a broader effect at the cell and/or tissue level. This review will endeavor to further the understanding of biomolecular interactions utilizing the isothermal titration calorimetry (ITC) technique for thermodynamic characterization of two extremely important biomaterial systems, viz., peptide self-assembly and nonfouling polymer-modified surfaces. The advantages and shortcomings of this technique will be presented along with a thorough review of the recent application of ITC to these two areas. Furthermore, the controversies associated with the enthalpy-entropy compensation effect as well as thermodynamic equilibrium state for such interactions will be discussed.

  6. Piezoresistive Foam Sensor Arrays for Marine Applications

    CERN Document Server

    Dusek, Jeff E; Lang, Jeffrey H

    2016-01-01

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

  7. Development of Cellulose-Based, Nanostructured, Conductive Paper for Biomolecular Extraction and Energy Storage Applications

    OpenAIRE

    Razaq, Aamir

    2011-01-01

    Conductive paper materials consisting of conductive polymers and cellulose are promising for high-tech applications (energy storage and biosciences) due to outstanding aspects of environmental friendliness, mechanical flexibility, electrical conductivity and efficient electroactive behavior. Recently, a conductive composite paper material was developed by covering the individual nanofibers of cellulose from the green algae Cladophora with a polypyrrole (PPy) layer. The PPy-Cladophora cellulos...

  8. Biosensors with Built-In Biomolecular Logic Gates for Practical Applications

    Directory of Open Access Journals (Sweden)

    Yu-Hsuan Lai

    2014-08-01

    Full Text Available Molecular logic gates, designs constructed with biological and chemical molecules, have emerged as an alternative computing approach to silicon-based logic operations. These molecular computers are capable of receiving and integrating multiple stimuli of biochemical significance to generate a definitive output, opening a new research avenue to advanced diagnostics and therapeutics which demand handling of complex factors and precise control. In molecularly gated devices, Boolean logic computations can be activated by specific inputs and accurately processed via bio-recognition, bio-catalysis, and selective chemical reactions. In this review, we survey recent advances of the molecular logic approaches to practical applications of biosensors, including designs constructed with proteins, enzymes, nucleic acids, nanomaterials, and organic compounds, as well as the research avenues for future development of digitally operating “sense and act” schemes that logically process biochemical signals through networked circuits to implement intelligent control systems.

  9. Biomolecular urease thin films grown by laser techniques for blood diagnostic applications

    International Nuclear Information System (INIS)

    Matrix assisted pulsed laser evaporation (MAPLE) was used for growing urease thin films designed for bio-sensor applications in clinical diagnostics. The targets exposed to laser radiation were made from a frozen composite manufactured by dissolving biomaterials in distilled water. We used a UV KrF* (λ = 248 nm, τFWHM ≅ 30 ns, ν = 10 Hz) excimer source for multipulse laser irradiation of the frozen targets cooled with Peltier elements. The laser source was operated at an incident fluence of 0.4 J/cm2. Urease activity and kinetics were assayed by the Worthington method that monitors urea hydrolysis by coupling ammonia production to a glutamate dehydrogenase reaction. A decrease in absorbance was measured at 340 nm and correlated with the enzymatic activity of urease. We show that the urease films obtained by MAPLE techniques remain active up to three months after deposition.

  10. Applicability of carbon and boron nitride nanotubes as biosensors: Effect of biomolecular adsorption on the transport properties of carbon and boron nitride nanotubes

    Science.gov (United States)

    Zhong, Xiaoliang; Mukhopadhyay, Saikat; Gowtham, S.; Pandey, Ravindra; Karna, Shashi P.

    2013-04-01

    The effect of molecular adsorption on the transport properties of single walled carbon and boron nitride nanotubes (CNTs and BNNTs) is investigated using density functional theory and non-equilibrium Green's function methods. The calculated I-V characteristics predict noticeable changes in the conductivity of semiconducting BNNTs due to physisorption of nucleic acid base molecules. Specifically, guanine which binds to the side wall of BNNT significantly enhances its conductivity by introducing conduction channels near the Fermi energy of the bioconjugated system. For metallic CNTs, a large background current masks relatively small changes in current due to the biomolecular adsorption. The results therefore suggest the suitability of BNNTs for biosensing applications.

  11. Biomolecular Science (Fact Sheet)

    Energy Technology Data Exchange (ETDEWEB)

    2012-04-01

    A brief fact sheet about NREL Photobiology and Biomolecular Science. The research goal of NREL's Biomolecular Science is to enable cost-competitive advanced lignocellulosic biofuels production by understanding the science critical for overcoming biomass recalcitrance and developing new product and product intermediate pathways. NREL's Photobiology focuses on understanding the capture of solar energy in photosynthetic systems and its use in converting carbon dioxide and water directly into hydrogen and advanced biofuels.

  12. Conducting polymer based biomolecular electronic devices

    Indian Academy of Sciences (India)

    B D Malhotra; Rahul Singhal

    2003-08-01

    Biomolecular electronics is rapidly evolving from physics, chemistry, biology, electronics and information technology. Organic materials such as proteins, pigments and conducting polymers have been considered as alternatives for carrying out the functions that are presently being performed by semiconductor silicon. Conducting polymers such as polypyrroles, polythiophenes and polyanilines have been projected for applications for a wide range of biomolecular electronic devices such as optical, electronic, drug-delivery, memory and biosensing devices. Our group has been actively working towards the application of conducting polymers to Schottky diodes, metal–insulator–semiconductor (MIS) devices and biosensors for the past 10 years. This paper is a review of some of the results obtained at our laboratory in the area of conducting polymer biomolecular electronics.

  13. A novel array antenna for MSAT applications

    Science.gov (United States)

    Bodnar, Donald G.; Rainer, B. Keith; Rahmat-Samii, Yahya

    1989-01-01

    The issue of reducing the cost of phased array vehicle antennas through the use of a lens feeding arrangement instead of phase shifters at each element is addressed. In particular, the economic viability of a mobile satellite system (MSAT) is largely dependent on the efficient use of the allocated scarce spectrum and orbit as well as the satellite power. the type of vehicle antenna used will play a critical role in achieving this efficiency. A standard design approach for an electronically steered array uses phase shifters at each element to provide beam steering. A method for reducing the required number of phase shifters by using an R-KR lens feed network is outlined. The authors briefly discuss the phase shifter approach to beam steering, examine various lens feed techniques, and describe the R-KR lens approach. The lens feed network architecture is examined, a computer model for simulation of the array is presented, and the results of analysis of a suggested design for the MSAT application are given. In addition, satellite acquisition and tracking considerations are investigated.

  14. Polymeric Cantilever Arrays for Biosensing Applications

    DEFF Research Database (Denmark)

    Calleja, M.; Tamayo, J.; Johansson, Alicia;

    2003-01-01

    We report the fabrication of arrays of polymeric cantilevers for biochemistry applications. The cantilevers are fabricated in the polymer SU-8. The use of a polymer as the component material for the cantilevers provides the sensors with very high sensitivity due to convenient mechanical material...... properties. The fabrication process is based on spin coating of the photosensitive polymer and near-ultraviolet exposure. The method allows obtaining well-controlled and uniform mechanical properties of the cantilevers. The elastic constant of the cantilevers was measured, and their dynamic response...... was studied. Characterization of the devices shows that they are suitable for both static and dynamic measurements for biochemical detection in either air or liquid environments. The sensor was applied to monitoring of the immobilization process of cystamine on a gold-coated SU-8 cantilever....

  15. Programming in Biomolecular Computation:

    DEFF Research Database (Denmark)

    Hartmann, Lars; Jones, Neil; Simonsen, Jakob Grue;

    2011-01-01

    Our goal is to provide a top-down approach to biomolecular computation. In spite of widespread discussion about connections between biology and computation, one question seems notable by its absence: Where are the programs? We identify a number of common features in programming that seem...... conspicuously absent from the literature on biomolecular computing; to partially redress this absence, we introduce a model of computation that is evidently programmable, by programs reminiscent of low-level computer machine code; and at the same time biologically plausible: its functioning is defined...... by a single and relatively small set of chemical-like reaction rules. Further properties: the model is stored-program: programs are the same as data, so programs are not only executable, but are also compilable and interpretable. It is universal: all computable functions can be computed (in natural ways...

  16. Silver nanorod arrays for photocathode applications

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-10-16

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

  17. APPLICATION OF MICROPHONE ARRAYS FOR DISTANT SPEECH CAPTURE

    Directory of Open Access Journals (Sweden)

    M. B. Stolbov

    2015-07-01

    Full Text Available Application of microphone arrays and beamforming techniques for speech information collection has significant advantages compared to systems operating with a single microphone. This paper presents a brief overview of microphone array systems for collecting distant speech information. The paper is based on an analysis of publications on the use of microphone arrays for speech information collection tasks, as well as on the author’s experience in the development and practical application of planar microphone arrays. The paper describes the main stages of the development of systems for remote capture of audio information. It provides a review of the main applications of microphone arrays, the basic types of microphone arrays and their features. The bulk of the paper deals with planar microphone arrays. We analyze the work of microphone arrays in different acoustic environments. The paper contains the basic equations for calculating the parameters of equidistant planar microphone arrays. Some methods of designing non-equidistant arrays are also mentioned (a list of references is included. We also provide a list of basic digital signal processing algorithms for planar microphone arrays, as well as a list of references on processing algorithms in the frequency domain. The paper includes a list of foreign companies offering systems based on microphone arrays for a wide range of tasks associated with the processing of speech and audio signals. We describe some state-of-the-art speech information collection systems based on microphone arrays. Some promising directions for the development of speech information collection systems using microphone arrays are described in conclusion. The material of the review is usable in designing of microphone arrays for specific practical applications.

  18. The research progress of tiling array technology and applications

    Institute of Scientific and Technical Information of China (English)

    LANG XianYu; WANG Jun; CHI XueBin

    2008-01-01

    Tiling array technology was improved from microarray technology. Over the past five years, tiling array has become an important tool for gathering genome information. Its features of high density and high throughput allow people to probe into life from the whole-genome level. This paper is a survey of tiling array technology and its applications. In addition, some typical algorithms for identifying expressed probe signals are described and compared.

  19. Science Letters: Demonstration of a new biosensing concept for immunodiagnostic applications based on change in surface conductance of antibodies after biomolecular interactions

    Institute of Scientific and Technical Information of China (English)

    VASHIST Sandeep Kumar; KAUR Inderpreet; BAJPAI Ram Prakash; BHARADWAJ Lalit Mohan; TEWARI Rupinder; RAITERI Roberto

    2006-01-01

    We report an important observation that the surface conductivity of antibody layer immobilized on polylysine-coated glass substrate decreases upon the formation of complex with their specific antigens. This change in conductivity has been observed for both monoclonal and polyclonal antibodies. The conductance of monoclonal mouse IgG immobilized on polylysine-coated glass substrate changed from 1.02×l0-8 Ω-1 to 1.41×l0-11 Ω-1 at 10 V when complex is formed due to the specific biomolecular interactions with rabbit anti-mouse IgG F(ab')2. Similar behavior was observed when the same set up was tested in two clinical assays: (1) anti-Leishmania antigen polyclonal antibodies taken from Kala Azar positive patient serum interacting with Leishmania promastigote antigen, and (2) anti-p21 polyclonal antibodies interacting with p21 antigen. The proposed concept can represent a new immunodiagnostic technique and may have wide ranging applications in biosensors and nanobiotechnology too.

  20. Application of Array Measurement in Blind Identification

    Institute of Scientific and Technical Information of China (English)

    王勇; 孙连明; 刘文江

    2003-01-01

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

  1. Design of an active array filtenna for radar applications

    NARCIS (Netherlands)

    Cifola, L.; Gerini, G.; Berg, S. van den; Water, F. van de

    2014-01-01

    A novel design of an S-band active array antenna with enhanced frequency selectivity properties, for radar applications, is presented. The array unit cell consists of a stacked-patch radiator, characterized by an operational bandwidth of [2.8 - 3.4] GHz. A microstrip two-pole band pass filter is con

  2. Ordered Au Nanodisk and Nanohole Arrays: Fabrication and Applications

    KAUST Repository

    Zheng, Yue Bing

    2010-01-01

    We have utilized nanosphere lithography (NSL) to fabricate ordered Au nanodisk and nanohole arrays on substrates and have studied the localized surface plasmon resonance (LSPR) of the arrays. Through these investigations, we demonstrate that the angle- dependent behavior of the LSPR in the Au nanodisk arrays enables real-time observation of exciton-plasmon couplings. In addition, we show that the NSL-fabricated Au nanohole arrays can be applied as templates for patterning micro-/nanoparticles under capillary force. The unique structural and plasmonic characteristics of the Au nanodisk and nano- hole arrays, as well as the low-cost and high-throughput NSL-based nanofabrication technique, render these arrays excellent platforms for numerous engineering applications. © 2010 by ASME.

  3. Programming in Biomolecular Computation

    DEFF Research Database (Denmark)

    Hartmann, Lars; Jones, Neil; Simonsen, Jakob Grue

    2010-01-01

    Our goal is to provide a top-down approach to biomolecular computation. In spite of widespread discussion about connections between biology and computation, one question seems notable by its absence: Where are the programs? We introduce a model of computation that is evidently programmable......, by programs reminiscent of low-level computer machine code; and at the same time biologically plausible: its functioning is defined by a single and relatively small set of chemical-like reaction rules. Further properties: the model is stored-program: programs are the same as data, so programs are not only...... in a strong sense: a universal algorithm exists, that is able to execute any program, and is not asymptotically inefficient. A prototype model has been implemented (for now in silico on a conventional computer). This work opens new perspectives on just how computation may be specified at the biological level....

  4. Interleaved Array Antennas for FMCW Radar Applications

    NARCIS (Netherlands)

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

    2009-01-01

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

  5. Broadband-antireflective hybrid nanopillar array for photovoltaic application

    International Nuclear Information System (INIS)

    Subwavelength structures such as nanopillars, nanoholes, and nanodomes have recently attracted considerable attention as antireflective structures for solar cells. Recent studies on the optical property of nanopillar array revealed that the reflection minimum is related to the diameter, the pitch, and the height of nanopillars. Here, we investigate the “hybrid” nanopillar array, which is composed of different diameters of nanopillars. Finite differential time domain simulations revealed that the photogeneration in a hybrid nanopillar array is spatially heterogeneous: carriers are generated mainly in the narrower pillars for short-wavelength incident light and in the thicker pillars for long-wavelength light, respectively. Hybrid silicon nanopillar arrays fabricated by using electron beam lithography and dry etching show excellent broadband antireflection property. Hybrid nanopillar array is thus highly promising for next-generation antireflection for photovoltaic applications

  6. Applications of field-programmable gate arrays in scientific research

    CERN Document Server

    Sadrozinski, Hartmut F W

    2011-01-01

    Focusing on resource awareness in field-programmable gate array (FPGA) design, Applications of Field-Programmable Gate Arrays in Scientific Research covers the principle of FPGAs and their functionality. It explores a host of applications, ranging from small one-chip laboratory systems to large-scale applications in ""big science."" The book first describes various FPGA resources, including logic elements, RAM, multipliers, microprocessors, and content-addressable memory. It then presents principles and methods for controlling resources, such as process sequencing, location constraints, and in

  7. Progress on conformal microwave array applicators for heating chestwall disease

    Science.gov (United States)

    Stauffer, P. R.; Maccarini, P. F.; Juang, T.; Jacobsen, S. K.; Gaeta, C. J.; Schlorff, J. L.; Milligan, A. J.

    2007-02-01

    Previous studies have reported the computer modeling, CAD design, and theoretical performance of single and multiple antenna arrays of Dual Concentric Conductor (DCC) square slot radiators driven at 915 and 433 MHz. Subsequently, practical CAD designs of microstrip antenna arrays constructed on thin and flexible printed circuit board (PCB) material were reported which evolved into large Conformal Microwave Array (CMA) sheets that could wrap around the surface of the human torso for delivering microwave energy to large areas of superficial tissue. Although uniform and adjustable radiation patterns have been demonstrated from multiple element applicators radiating into simple homogeneous phantom loads, the contoured and heterogeneous tissue loads typical of chestwall recurrent breast cancer have required additional design efforts to achieve good coupling and efficient heating from the increasingly larger conformal array applicators used to treat large area contoured patient anatomy. Thus recent work has extended the theoretical optimization of DCC antennas to improve radiation efficiency of each individual aperture and reduce mismatch reflections, radiation losses, noise, and cross coupling of the feedline distribution network of large array configurations. Design improvements have also been incorporated into the supporting bolus structure to maintain effective coupling of DCC antennas into contoured anatomy and to monitor and control surface temperatures under the entire array. New approaches for non-invasive monitoring of surface and sub-surface tissue temperatures under each independent heat source are described that make use of microwave radiometry and flexible sheet grid arrays of thermal sensors. Efforts to optimize the clinical patient interface and move from planar rectangular shapes to contoured vest applicators that accommodate entire disease in a larger number of patients are summarized. By applying heat more uniformly to large areas of contoured anatomy

  8. Microwave array applicator for radiometry-controlled superficial hyperthermia

    Science.gov (United States)

    Stauffer, Paul R.; Jacobsen, Svein; Neuman, Daniel

    2001-06-01

    Hyperthermia therapy has been shown clinically effective for a variety of skin diseases but current heating equipment is inadequate for most patients. This effort describes the design and performance of a flexible microstrip array applicator intended for heating large regions of tissue over contoured anatomy while at the same time monitoring temperature of the underlying tissue by non-invasive radiometric sensing of blackbody radiation from the heated volume. For this dual purpose applicator, an array of broadband Archimedean spiral receive antennas is integrated into an array of Dual Concentric Conductor heating apertures. Applicator heating uniformity is assessed with electric field scans in homogenous muscle phantoms and with measured temperature distributions in clinical treatments of chestwall recurrence of breast carcinoma. The data demonstrate precisely controlled heating out to the perimeter of large (40 x 13 cm2) multiaperture conformal array applicators. Capabilities of the radiometry system are assessed by correlation of brightness temperatures measured in phantom loads of known temperature distribution as seen through an intervening 5 mm thick water bolus at constant 40°C. The radiometer demonstrates excellent sensitivity and an accuracy of +0.1-0.45°C for temperature measurements up to 5 cm deep in phantom when using a one dimensional weighting function analysis and up to 6 independent 500 MHz bandwidths within the 1-4 GHz range. The data clearly indicate that both heating and radiometric thermometry are possible using the same thin and flexible printed circuit board microstrip array applicator. Once development is complete, this dual mode conformal array applicator with multiplexed radiometric display system should provide significantly improved uniformity and ease of heating large area superficial tissue disease.

  9. Nanostructure arrays in free-space: optical properties and applications

    International Nuclear Information System (INIS)

    Dielectric and metallic gratings have been studied for more than a century. Nevertheless, novel optical phenomena and fabrication techniques have emerged recently and have opened new perspectives for applications in the visible and infrared domains. Here, we review the design rules and the resonant mechanisms that can lead to very efficient light–matter interactions in sub-wavelength nanostructure arrays. We emphasize the role of symmetries and free-space coupling of resonant structures. We present the different scenarios for perfect optical absorption, transmission or reflection of plane waves in resonant nanostructures. We discuss the fabrication issues, experimental achievements and emerging applications of resonant nanostructure arrays. (review article)

  10. Event Detection and Sub-state Discovery from Bio-molecular Simulations Using Higher-Order Statistics: Application To Enzyme Adenylate Kinase

    OpenAIRE

    Ramanathan, Arvind; Savol, Andrej J.; Agarwal, Pratul K.; Chennubhotla, Chakra S.

    2012-01-01

    Biomolecular simulations at milli-second and longer timescales can provide vital insights into functional mechanisms. Since post-simulation analyses of such large trajectory data-sets can be a limiting factor in obtaining biological insights, there is an emerging need to identify key dynamical events and relating these events to the biological function online, that is, as simulations are progressing. Recently, we have introduced a novel computational technique, quasi-anharmonic analysis (QAA)...

  11. Nano-arrays of SAM by dip-pen nanowriting (DPN) technique for futuristic bio-electronic and bio-sensor applications

    Energy Technology Data Exchange (ETDEWEB)

    Agarwal, Pankaj B., E-mail: pankaj@ceeri.ernet.i [Central Electronics Engineering Research Institute, Pilani - 333 031, (Council of Scientific and Industrial Research, Delhi) (India); Kumar, A. [Central Electronics Engineering Research Institute, Pilani - 333 031, (Council of Scientific and Industrial Research, Delhi) (India); Saravanan, R. [Vellore Institute of Technology University, Vellore - 632 014 (India); Sharma, A.K.; Shekhar, Chandra [Central Electronics Engineering Research Institute, Pilani - 333 031, (Council of Scientific and Industrial Research, Delhi) (India)

    2010-11-30

    Nano-arrays of bio-molecules have potential applications in many areas namely, bio-sensors, bio/molecular electronics and virus detection. Spot array, micro-contact printing and photolithography are used for micron size array fabrications while Dip-Pen Nanowriting (DPN) is employed for submicron/nano size arrays. We have fabricated nano-dots of 16-MHA (16-mercaptohexadecanoic acid) self-assembled monolayer (SAM) on gold substrate by DPN technique with different dwell time under varying relative humidity. These patterns were imaged in the same system in LFM (Lateral Force Microscopy) mode with fast scanning speed (5 Hz). The effect of humidity on size variation of nano-dots has been studied. During experiments, relative humidity (RH) was varied from 20% to 60%, while the temperature was kept constant {approx} 25 {sup o}C. The minimum measured diameter of the dot is {approx} 294 nm at RH = 20% for a dwell time of 2 s. The thickness of the 16-MHA dots, estimated in NanoRule image analysis software is {approx} 2 nm, which agrees well with the length of single MHA molecule (2.2 nm). The line profile has been used to estimate the size and thickness of dots. The obtained results will be useful in further development of nano-array based bio-sensors and bio-electronic devices.

  12. Simulation and Data Processing for Ultrasonic Phased-Arrays Applications

    Science.gov (United States)

    Chaffaï-Gargouri, S.; Chatillon, S.; Mahaut, S.; Le Ber, L.

    2007-03-01

    The use of phased-arrays techniques has considerably contributed to extend the domain of applications and the performances of ultrasonic methods on complex configurations. Their adaptability offers a great freedom for conceiving the inspection leading to a wide range of functionalities gathering electronic commutation, applications of different delay laws and so on. This advantage allows to circumvent the difficulties encountered with more classical techniques especially when the inspection is assisted by simulation at the different stages : probe design (optimization of the number and characteristics of the elements), evaluation of the performances in terms of flaw detection (zone coverage) and characterization, driving the array (computation of adapted delay laws) and finally analyzing the results (versatile model-based imaging tools allowing in particular to locate the data in the real space). The CEA is strongly involved in the development of efficient simulation-based tools adapted to these needs. In this communication we present the recent advances done at CEA in this field and show several examples of complex NDT phased arrays applications. On these cases we show the interest and the performances of simulation-helped array design, array-driving and data analysis.

  13. Micro and Nanotechnologies Enhanced Biomolecular Sensing

    Directory of Open Access Journals (Sweden)

    Tza-Huei Wang

    2013-07-01

    Full Text Available This editorial summarizes some of the recent advances of micro and nanotechnology-based tools and devices for biomolecular detection. These include the incorporation of nanomaterials into a sensor surface or directly interfacing with molecular probes to enhance target detection via more rapid and sensitive responses, and the use of self-assembled organic/inorganic nanocomposites that inhibit exceptional spectroscopic properties to enable facile homogenous assays with efficient binding kinetics. Discussions also include some insight into microfluidic principles behind the development of an integrated sample preparation and biosensor platform toward a miniaturized and fully functional system for point of care applications.

  14. Optimized shapes of magnetic arrays for drug targeting applications

    Science.gov (United States)

    Barnsley, Lester C.; Carugo, Dario; Stride, Eleanor

    2016-06-01

    Arrays of permanent magnet elements have been utilized as light-weight, inexpensive sources for applying external magnetic fields in magnetic drug targeting applications, but they are extremely limited in the range of depths over which they can apply useful magnetic forces. In this paper, designs for optimized magnet arrays are presented, which were generated using an optimization routine to maximize the magnetic force available from an arbitrary arrangement of magnetized elements, depending on a set of design parameters including the depth of targeting (up to 50 mm from the magnet) and direction of force required. A method for assembling arrays in practice is considered, quantifying the difficulty of assembly and suggesting a means for easing this difficulty without a significant compromise to the applied field or force. Finite element simulations of in vitro magnetic retention experiments were run to demonstrate the capability of a subset of arrays to retain magnetic microparticles against flow. The results suggest that, depending on the choice of array, a useful proportion of particles (more than 10% ) could be retained at flow velocities up to 100 mm s-1 or to depths as far as 50 mm from the magnet. Finally, the optimization routine was used to generate a design for a Halbach array optimized to deliver magnetic force to a depth of 50 mm inside the brain.

  15. Terahertz integrated antenna arrays for imaging applications

    OpenAIRE

    Alonso del Pino, María

    2013-01-01

    Terahertz is the portion of the spectrum that covers a frequency range between 300 GHz - 3 THz. This frequency band has proven its potential for imaging applications thanks to the good compromise between spatial resolution and penetration; however, this push towards high frequencies contains many technological difficulties in all the subsystems involved in the signal generation, transmission and detection. The power budget restrictions and high losses that sources and receivers currently suff...

  16. Highly Integrated Application Specific MMICS for Active Phased Array Radar Applications

    NARCIS (Netherlands)

    Bogaart, F.L.M. van den

    2000-01-01

    Application specific MMIC solutions for active array radar, developed at TNO-FEL. are presented. The use and application of these MMICs in their respective radar systems will be shown. These MMICs address the needs for current and future phased-array topologies as for example the concept of "smart s

  17. Parallel scanning probe arrays: their applications

    Directory of Open Access Journals (Sweden)

    Chang Liu

    2008-01-01

    Full Text Available Since the invention of the scanning tunneling microscope (STM1 and the atomic force microscope (AFM2, the field of scanning probe microscopy (SPM instruments has grown steadily and has had a profound influence in materials research, chemistry, biology, nanotechnology, and electronics3,4. Today, scanning probe instruments are used for metrology, characterization5, detection6, manipulation7, patterning8,9, and material modification. A wide range of scanning probe applications are available, taking advantage of various modes of tip–substrate interactions, including force, optics10,11, electrochemistry12, electromagnetics, electrostatics, thermal and mass transfer13,14, and vibration15,16.

  18. Application of Dense Array Analysis to Strong Motion Data Recorded at The SMART-1 Array

    Science.gov (United States)

    Francois, C.

    2003-12-01

    This paper is part of a project to design an optimal strong motion dense array in New Zealand. The overall project looks at developing a dense network of strong motion seismometers in order to measure directly the rupture process of major seismogenic sources such as the Alpine Fault and strands of the Marlborough Fault System defining the South Island sector of the Australia-Pacific plate boundary zone. This work shows the application of dense array analysis to a set of seismic data recorded at the SMART-1 array in Taiwan (data kindly provided by the Institute of Earth Sciences, Academia Sinica Data Management Center for Strong Motion Seismology - Taiwan). The data have been processed and analysed applying modified MUSIC algorithm with higher computing capabilities giving higher resolution results. The SMART-1 array is an ideal dense array of 37 strong motion instruments set up in the following configuration: 3 concentric circles of radii 200m, 1 km and 2km, and one central station. The studied event called Event 5 was recorded on January 29th 1981 and had a magnitude 6. Event 5 is an ideal case study as its epicentral distance (about 30 km) is comparable to epicentral distances for expected events on the Alpine Fault or on the Hope Fault in New Zealand. Event 5 has been previously widely analysed using strong motion array studies and aftershocks studies but with disagreeing results; this new study hopes to bring new insights in the debate. Using simple fault and velocity models, this latest analysis of Event 5 has given the following rupture properties. It has confirmed one of the hypotheses that the fault ruptured from southeast to northwest. The higher resolution of the computation has improved the location of the hypocentre depth and the location of the propagating rupture front. This allowed resolving changes of velocities in the rupture process and locating asperities in the fault plane. Contrary to the previous array studies, the inferred size of the fault

  19. Low Power Systolic Array Based Digital Filter for DSP Applications

    Directory of Open Access Journals (Sweden)

    S. Karthick

    2015-01-01

    Full Text Available Main concepts in DSP include filtering, averaging, modulating, and correlating the signals in digital form to estimate characteristic parameter of a signal into a desirable form. This paper presents a brief concept of low power datapath impact for Digital Signal Processing (DSP based biomedical application. Systolic array based digital filter used in signal processing of electrocardiogram analysis is presented with datapath architectural innovations in low power consumption perspective. Implementation was done with ASIC design methodology using TSMC 65 nm technological library node. The proposed systolic array filter has reduced leakage power up to 8.5% than the existing filter architectures.

  20. Field emitter arrays for plasma and microwave source applications

    Science.gov (United States)

    Jensen, K. L.

    1999-05-01

    Field emitter arrays (FEAs) stand to strongly impact device performance when physical size, weight, power consumption, beam current, and/or high pulse repetition frequencies are an issue. FEAs are capable of instant ON/OFF performance, high brightness, high current density, large transconductance to capacitance ratio, and low voltage operation characteristics. Advanced microwave power tubes, and in particular, inductive output amplifiers, are by far the most technically challenging use to date. Other important uses include, e.g., electron sources for micropropulsion systems-Hall thrusters-and tethers for satellites, and (the most widely pursued application) field emission displays. The characteristics of field emitters that make them attractive to such applications shall be surveyed. A thorough analytical model of a field emitter array, beginning with a review of the nature of field emission and continuing with an analytical model of a single emitter and the operation of an array of emitters, shall be presented. In particular, attention shall be directed towards those features of FEAs that render them attractive as cold cathode candidates for electron beam generation. Tip characteristics, such as emission distribution, and array operation, such as space charge effects, will be analyzed in the context of the model. Finally, restricting attention to microwave applications, the performance of a tapered-helix inductive output amplifier to highlight the advantages of high frequency emission gating of the electron beam in a power tube shall be investigated.

  1. The Applicability of Incoherent Array Processing to IMS Seismic Array Stations

    Science.gov (United States)

    Gibbons, S. J.

    2012-04-01

    nuclear tests but, due to signal incoherence, failed to contribute to the automatic event detections. It is demonstrated that the smoothed incoherent slowness estimates for the MJAR Pn phases for both tests indicate unambiguously the correct type of phase and a backazimuth estimate within 5 degrees of the great-circle backazimuth. The detection part of the algorithm is applicable to all IMS arrays, and spectrogram-based processing may offer a reduction in the false alarm rate for high frequency signals. Significantly, the local maxima of the scalar functions derived from the transformed spectrogram beams provide good estimates of the signal onset time. High frequency energy is of greater significance for lower event magnitudes and in, for example, the cavity decoupling detection evasion scenario. There is a need to characterize propagation paths with low attenuation of high frequency energy and situations in which parameter estimation on array stations fails.

  2. Analysis of Camera Arrays Applicable to the Internet of Things.

    Science.gov (United States)

    Yang, Jiachen; Xu, Ru; Lv, Zhihan; Song, Houbing

    2016-03-22

    The Internet of Things is built based on various sensors and networks. Sensors for stereo capture are essential for acquiring information and have been applied in different fields. In this paper, we focus on the camera modeling and analysis, which is very important for stereo display and helps with viewing. We model two kinds of cameras, a parallel and a converged one, and analyze the difference between them in vertical and horizontal parallax. Even though different kinds of camera arrays are used in various applications and analyzed in the research work, there are few discussions on the comparison of them. Therefore, we make a detailed analysis about their performance over different shooting distances. From our analysis, we find that the threshold of shooting distance for converged cameras is 7 m. In addition, we design a camera array in our work that can be used as a parallel camera array, as well as a converged camera array and take some images and videos with it to identify the threshold.

  3. Design of nested Halbach cylinder arrays for magnetic refrigeration applications

    Energy Technology Data Exchange (ETDEWEB)

    Trevizoli, Paulo V., E-mail: trevizoli@polo.ufsc.br; Lozano, Jaime A.; Peixer, Guilherme F.; Barbosa Jr, Jader R.

    2015-12-01

    We present an experimentally validated analytical procedure to design nested Halbach cylinder arrays for magnetic cooling applications. The procedure aims at maximizing the magnetic flux density variation in the core of the array for a given set of design parameters, namely the inner diameter of the internal magnet, the air gap between the magnet cylinders, the number of segments of each magnet and the remanent flux density of the Nd{sub 2}Fe{sub 14}B magnet grade. The design procedure was assisted and verified by 3-D numerical modeling using a commercial software package. An important aspect of the optimal design is to maintain an uniform axial distribution of the magnetic flux density in the region of the inner gap occupied by the active magnetocaloric regenerator. An optimal nested Halbach cylinder array was manufactured and experimentally evaluated for the magnetic flux density in the inner gap. The analytically calculated magnetic flux density variation agreed to within 5.6% with the experimental value for the center point of the magnet gap. - Highlights: • An analytical procedure to design nested Halbach cylinder arrays is proposed. • An optimal magnet configuration was built based on the analytical procedure. • The procedure was validated with 3D COMSOL simulations and experimental data.

  4. Analysis of Camera Arrays Applicable to the Internet of Things.

    Science.gov (United States)

    Yang, Jiachen; Xu, Ru; Lv, Zhihan; Song, Houbing

    2016-01-01

    The Internet of Things is built based on various sensors and networks. Sensors for stereo capture are essential for acquiring information and have been applied in different fields. In this paper, we focus on the camera modeling and analysis, which is very important for stereo display and helps with viewing. We model two kinds of cameras, a parallel and a converged one, and analyze the difference between them in vertical and horizontal parallax. Even though different kinds of camera arrays are used in various applications and analyzed in the research work, there are few discussions on the comparison of them. Therefore, we make a detailed analysis about their performance over different shooting distances. From our analysis, we find that the threshold of shooting distance for converged cameras is 7 m. In addition, we design a camera array in our work that can be used as a parallel camera array, as well as a converged camera array and take some images and videos with it to identify the threshold. PMID:27011189

  5. Analysis of Camera Arrays Applicable to the Internet of Things

    Directory of Open Access Journals (Sweden)

    Jiachen Yang

    2016-03-01

    Full Text Available The Internet of Things is built based on various sensors and networks. Sensors for stereo capture are essential for acquiring information and have been applied in different fields. In this paper, we focus on the camera modeling and analysis, which is very important for stereo display and helps with viewing. We model two kinds of cameras, a parallel and a converged one, and analyze the difference between them in vertical and horizontal parallax. Even though different kinds of camera arrays are used in various applications and analyzed in the research work, there are few discussions on the comparison of them. Therefore, we make a detailed analysis about their performance over different shooting distances. From our analysis, we find that the threshold of shooting distance for converged cameras is 7 m. In addition, we design a camera array in our work that can be used as a parallel camera array, as well as a converged camera array and take some images and videos with it to identify the threshold.

  6. Microfabricated Chemical Gas Sensors and Sensor Arrays for Aerospace Applications

    Science.gov (United States)

    Hunter, Gary W.

    2005-01-01

    Aerospace applications require the development of chemical sensors with capabilities beyond those of commercially available sensors. In particular, factors such as minimal sensor size, weight, and power consumption are particularly important. Development areas which have potential aerospace applications include launch vehicle leak detection, engine health monitoring, and fire detection. Sensor development for these applications is based on progress in three types of technology: 1) Micromachining and microfabrication (Microsystem) technology to fabricate miniaturized sensors; 2) The use of nanocrystalline materials to develop sensors with improved stability combined with higher sensitivity; 3) The development of high temperature semiconductors, especially silicon carbide. This presentation discusses the needs of space applications as well as the point-contact sensor technology and sensor arrays being developed to address these needs. Sensors to measure hydrogen, hydrocarbons, nitrogen oxides (NO,), carbon monoxide, oxygen, and carbon dioxide are being developed as well as arrays for leak, fire, and emissions detection. Demonstrations of the technology will also be discussed. It is concluded that microfabricated sensor technology has significant potential for use in a range of aerospace applications.

  7. Biomolecular detection employing the Interferometric Reflectance Imaging Sensor (IRIS).

    Science.gov (United States)

    Lopez, Carlos A; Daaboul, George G; Ahn, Sunmin; Reddington, Alexander P; Monroe, Margo R; Zhang, Xirui; Irani, Rostem J; Yu, Chunxiao; Genco, Caroline A; Cretich, Marina; Chiari, Marcella; Goldberg, Bennett B; Connor, John H; Ünlü, M Selim

    2011-01-01

    The sensitive measurement of biomolecular interactions has use in many fields and industries such as basic biology and microbiology, environmental/agricultural/biodefense monitoring, nanobiotechnology, and more. For diagnostic applications, monitoring (detecting) the presence, absence, or abnormal expression of targeted proteomic or genomic biomarkers found in patient samples can be used to determine treatment approaches or therapy efficacy. In the research arena, information on molecular affinities and specificities are useful for fully characterizing the systems under investigation. Many of the current systems employed to determine molecular concentrations or affinities rely on the use of labels. Examples of these systems include immunoassays such as the enzyme-linked immunosorbent assay (ELISA), polymerase chain reaction (PCR) techniques, gel electrophoresis assays, and mass spectrometry (MS). Generally, these labels are fluorescent, radiological, or colorimetric in nature and are directly or indirectly attached to the molecular target of interest. Though the use of labels is widely accepted and has some benefits, there are drawbacks which are stimulating the development of new label-free methods for measuring these interactions. These drawbacks include practical facets such as increased assay cost, reagent lifespan and usability, storage and safety concerns, wasted time and effort in labelling, and variability among the different reagents due to the labelling processes or labels themselves. On a scientific research basis, the use of these labels can also introduce difficulties such as concerns with effects on protein functionality/structure due to the presence of the attached labels and the inability to directly measure the interactions in real time. Presented here is the use of a new label-free optical biosensor that is amenable to microarray studies, termed the Interferometric Reflectance Imaging Sensor (IRIS), for detecting proteins, DNA, antigenic material

  8. Abstractions for biomolecular computations

    CERN Document Server

    Okunoye, Babatunde O

    2008-01-01

    Deoxyribonucleic acid is increasingly being understood to be an informational molecule, capable of information processing.It has found application in the determination of non-deterministic algorithms and in the design of molecular computing devices. This is a theoretical analysis of the mathematical properties and relations of the molecules which constituting DNA, which explains in part why DNA is a successful computing molecule.

  9. Two dimensional coupled oscillators array with rhombus structure and its application in active antenna array

    Institute of Scientific and Technical Information of China (English)

    ZHAI LongJun; JIANG YongHua; LIU LongHe

    2008-01-01

    Beam scanning and forming can be achieved by coupled oscillators array without phase shifter. Active antenna array based on coupled oscillators array has the virtue of low cost, high integration, and high efficiency. Traditional two dimensional coupled oscillators array has been arranged on rectangular lattices, and phase difference of adjacent elements is limited to [-90°, 90°]. Therefore, the beam scanning range is limited to [-30°, 30°] from normal for half wavelength element spacing. A new two dimensional coupled oscillators array with rhombus structure is presented. Phase control method and phase error of the array are also provided. Stability of the array is analyzed, and stable condition is given. When this coupled oscillators array with rhombus structure is used in active antenna array, theoretical results show that phase difference of adjacent elements reach the limit of [-180°,180°] along the horizontal and vertical directions. Therefore, it has wider beam scanning range than that of a rectangular lattice structure.

  10. Application of cooled IR focal plane arrays in thermographic cameras

    Science.gov (United States)

    Vollheim, B.; Gaertner, M.; Dammass, G.; Krausz, M.

    2016-05-01

    The usage of cooled IR Focal Plane Array detectors in thermographic or radiometric thermal imaging cameras, respectively, leads to special demands on these detectors, which are discussed in this paper. For a radiometric calibration of wide temperature measuring ranges from -40 up to 2,000 °C, a linear and time-stable response of the photodiode array has to be ensured for low as well as high radiation intensities. The maximum detectable photon flux is limited by the allowed shift of the photodiode's bias that should remain in the linear part of the photodiode's I(V) curve even for the highest photocurrent. This limits the measurable highest object temperature in practice earlier than the minimum possible integration time. Higher temperature measuring ranges are realized by means of neutral or spectral filters. Defense and Security applications normally provide images at the given ambient temperature with small hot spots. The usage of radiometric thermal imagers for thermography often feature larger objects with a high temperature contrast to the background. This should not generate artifacts in the image, like pixel patterns or stripes. Further issues concern the clock regime or the sub-frame capabilities of the Read-Out-Circuit and the frame rate dependency of the signal. We will briefly describe the demands on the lens design for thermal imaging cameras when using cooled IR Focal Plane Array detectors with large apertures.

  11. Micro- and nanodevices integrated with biomolecular probes

    Science.gov (United States)

    Alapan, Yunus; Icoz, Kutay; Gurkan, Umut A.

    2016-01-01

    Understanding how biomolecules, proteins and cells interact with their surroundings and other biological entities has become the fundamental design criterion for most biomedical micro- and nanodevices. Advances in biology, medicine, and nanofabrication technologies complement each other and allow us to engineer new tools based on biomolecules utilized as probes. Engineered micro/nanosystems and biomolecules in nature have remarkably robust compatibility in terms of function, size, and physical properties. This article presents the state of the art in micro- and nanoscale devices designed and fabricated with biomolecular probes as their vital constituents. General design and fabrication concepts are presented and three major platform technologies are highlighted: microcantilevers, micro/nanopillars, and microfluidics. Overview of each technology, typical fabrication details, and application areas are presented by emphasizing significant achievements, current challenges, and future opportunities. PMID:26363089

  12. An Array Library for Microsoft SQL Server with Astrophysical Applications

    Science.gov (United States)

    Dobos, L.; Szalay, A. S.; Blakeley, J.; Falck, B.; Budavári, T.; Csabai, I.

    2012-09-01

    Today's scientific simulations produce output on the 10-100 TB scale. This unprecedented amount of data requires data handling techniques that are beyond what is used for ordinary files. Relational database systems have been successfully used to store and process scientific data, but the new requirements constantly generate new challenges. Moving terabytes of data among servers on a timely basis is a tough problem, even with the newest high-throughput networks. Thus, moving the computations as close to the data as possible and minimizing the client-server overhead are absolutely necessary. At least data subsetting and preprocessing have to be done inside the server process. Out of the box commercial database systems perform very well in scientific applications from the prospective of data storage optimization, data retrieval, and memory management but lack basic functionality like handling scientific data structures or enabling advanced math inside the database server. The most important gap in Microsoft SQL Server is the lack of a native array data type. Fortunately, the technology exists to extend the database server with custom-written code that enables us to address these problems. We present the prototype of a custom-built extension to Microsoft SQL Server that adds array handling functionality to the database system. With our Array Library, fix-sized arrays of all basic numeric data types can be created and manipulated efficiently. Also, the library is designed to be able to be seamlessly integrated with the most common math libraries, such as BLAS, LAPACK, FFTW, etc. With the help of these libraries, complex operations, such as matrix inversions or Fourier transformations, can be done on-the-fly, from SQL code, inside the database server process. We are currently testing the prototype with two different scientific data sets: The Indra cosmological simulation will use it to store particle and density data from N-body simulations, and the Milky Way Laboratory

  13. Biomolecular simulation on thousands of processors

    Science.gov (United States)

    Phillips, James Christopher

    Classical molecular dynamics simulation is a generally applicable method for the study of biomolecular aggregates of proteins, lipids, and nucleic acids. As experimental techniques have revealed the structures of larger and more complex biomolecular machines, the time required to complete even a single meaningful simulation of such systems has become prohibitive. We have developed the program NAMD to simulate systems of 50,000--500,000 atoms efficiently with full electrostatics on parallel computers with 1000 and more processors. NAMD's scalability is achieved through latency tolerant adaptive message-driven execution and measurement-based load balancing. NAMD is implemented in C++ and uses object-oriented design and threads to shield the basic algorithms from the necessary complexity of high-performance parallel execution. Apolipoprotein A-I is the primary protein constituent of high density lipoprotein particles, which transport cholesterol in the bloodstream. In collaboration with A. Jonas, we have constructed and simulated models of the nascent discoidal form of these particles, providing theoretical insight to the debate regarding the lipid-bound structure of the protein. Recently, S. Sligar and coworkers have created 10 nm phospholipid bilayer nanoparticles comprising a small lipid bilayer disk solubilized by synthetic membrane scaffold proteins derived from apolipoprotein A-I. Membrane proteins may be embedded in the water-soluble disks, with various medical and technological applications. We are working to develop variant scaffold proteins that produce disks of greater size, stability, and homogeneity. Our simulations have demonstrated a significant deviation from idealized cylindrical structure, and are being used in the interpretation of small angle x-ray scattering data.

  14. Low Average Sidelobe Slot Array Antennas for Radiometer Applications

    Science.gov (United States)

    Rengarajan, Sembiam; Zawardzki, Mark S.; Hodges, Richard E.

    2012-01-01

    In radiometer applications, it is required to design antennas that meet low average sidelobe levels and low average return loss over a specified frequency bandwidth. It is a challenge to meet such specifications over a frequency range when one uses resonant elements such as waveguide feed slots. In addition to their inherent narrow frequency band performance, the problem is exacerbated due to modeling errors and manufacturing tolerances. There was a need to develop a design methodology to solve the problem. An iterative design procedure was developed by starting with an array architecture, lattice spacing, aperture distribution, waveguide dimensions, etc. The array was designed using Elliott s technique with appropriate values of the total slot conductance in each radiating waveguide, and the total resistance in each feed waveguide. Subsequently, the array performance was analyzed by the full wave method of moments solution to the pertinent integral equations. Monte Carlo simulations were also carried out to account for amplitude and phase errors introduced for the aperture distribution due to modeling errors as well as manufacturing tolerances. If the design margins for the average sidelobe level and the average return loss were not adequate, array architecture, lattice spacing, aperture distribution, and waveguide dimensions were varied in subsequent iterations. Once the design margins were found to be adequate, the iteration was stopped and a good design was achieved. A symmetric array architecture was found to meet the design specification with adequate margin. The specifications were near 40 dB for angular regions beyond 30 degrees from broadside. Separable Taylor distribution with nbar=4 and 35 dB sidelobe specification was chosen for each principal plane. A non-separable distribution obtained by the genetic algorithm was found to have similar characteristics. The element spacing was obtained to provide the required beamwidth and close to a null in the E

  15. Biomolecular Detection employing the Interferometric Reflectance Imaging Sensor (IRIS)

    OpenAIRE

    Carlos A Lopez; George G Daaboul; Ahn, Sunmin; Reddington, Alexander P.; Monroe, Margo R.; Zhang, Xirui; Irani, Rostem J.; Yu, Chunxiao; Genco, Caroline A.; Cretich, Marina; Chiari, Marcella; Goldberg, Bennett B.; Connor, John H.; Ünlü, M. Selim

    2011-01-01

    The sensitive measurement of biomolecular interactions has use in many fields and industries such as basic biology and microbiology, environmental/agricultural/biodefense monitoring, nanobiotechnology, and more. For diagnostic applications, monitoring (detecting) the presence, absence, or abnormal expression of targeted proteomic or genomic biomarkers found in patient samples can be used to determine treatment approaches or therapy efficacy. In the research arena, information on molecular aff...

  16. Event Detection and Sub-state Discovery from Bio-molecular Simulations Using Higher-Order Statistics: Application To Enzyme Adenylate Kinase

    Science.gov (United States)

    Ramanathan, Arvind; Savol, Andrej J.; Agarwal, Pratul K.; Chennubhotla, Chakra S.

    2012-01-01

    Biomolecular simulations at milli-second and longer timescales can provide vital insights into functional mechanisms. Since post-simulation analyses of such large trajectory data-sets can be a limiting factor in obtaining biological insights, there is an emerging need to identify key dynamical events and relating these events to the biological function online, that is, as simulations are progressing. Recently, we have introduced a novel computational technique, quasi-anharmonic analysis (QAA) (PLoS One 6(1): e15827), for partitioning the conformational landscape into a hierarchy of functionally relevant sub-states. The unique capabilities of QAA are enabled by exploiting anharmonicity in the form of fourth-order statistics for characterizing atomic fluctuations. In this paper, we extend QAA for analyzing long time-scale simulations online. In particular, we present HOST4MD - a higher-order statistical toolbox for molecular dynamics simulations, which (1) identifies key dynamical events as simulations are in progress, (2) explores potential sub-states and (3) identifies conformational transitions that enable the protein to access those sub-states. We demonstrate HOST4MD on micro-second time-scale simulations of the enzyme adenylate kinase in its apo state. HOST4MD identifies several conformational events in these simulations, revealing how the intrinsic coupling between the three sub-domains (LID, CORE and NMP) changes during the simulations. Further, it also identifies an inherent asymmetry in the opening/closing of the two binding sites. We anticipate HOST4MD will provide a powerful and extensible framework for detecting biophysically relevant conformational coordinates from long time-scale simulations. PMID:22733562

  17. Acoustic Eaton lens array and its fluid application

    CERN Document Server

    Kim, Sang-Hoon; Das, Mukunda P

    2016-01-01

    A principle of an acoustic Eaton Lens array and its application as a removable tsunami wall is proposed theoretically. The lenses are made of expandable rubber balloons and create a stop-band by the rotating the incoming tsunami wave and reduce the pressure by canceling each other. The diameter of each lens is larger than the wavelength of the tsunami near the coast, that is, order of a kilometer. The impedance matching on the border of the lenses results in little reflection. Before a tsunami, the balloons are buried underground in shallow water near the coast in folded or rounded form. Upon sounding of the tsunami alarm, water and air are pumped into the balloons, which expand and erect the wall above the sea level within a few hours. After the tsunami, the water and air are released from the balloons, which are then buried underground for reuse. Electricity is used to power the entire process.

  18. Application of multiplicative array techniques for multibeam sounder systems

    Digital Repository Service at National Institute of Oceanography (India)

    Chakraborty, B.

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

  19. Integrative NMR for biomolecular research.

    Science.gov (United States)

    Lee, Woonghee; Cornilescu, Gabriel; Dashti, Hesam; Eghbalnia, Hamid R; Tonelli, Marco; Westler, William M; Butcher, Samuel E; Henzler-Wildman, Katherine A; Markley, John L

    2016-04-01

    NMR spectroscopy is a powerful technique for determining structural and functional features of biomolecules in physiological solution as well as for observing their intermolecular interactions in real-time. However, complex steps associated with its practice have made the approach daunting for non-specialists. We introduce an NMR platform that makes biomolecular NMR spectroscopy much more accessible by integrating tools, databases, web services, and video tutorials that can be launched by simple installation of NMRFAM software packages or using a cross-platform virtual machine that can be run on any standard laptop or desktop computer. The software package can be downloaded freely from the NMRFAM software download page ( http://pine.nmrfam.wisc.edu/download_packages.html ), and detailed instructions are available from the Integrative NMR Video Tutorial page ( http://pine.nmrfam.wisc.edu/integrative.html ). PMID:27023095

  20. Biconical Ring Antenna Array for Wide Band Applications

    Directory of Open Access Journals (Sweden)

    C.SUBBA RAO

    2012-02-01

    Full Text Available Circular or ring arrays are conformal to the cylindrical surfaces unlike the linear arrays and can be mounted on moving objects. Biconical antenna is simple in construction and exhibits broad band characteristics. This antenna presents broad band radiation characteristics. In this paper circular or ring array of biconical antenna is proposed and its characteristics are analyzed for frequency band of 0.1 to 1GHz range. Radiation characteristicsof the array with excitation phase change are presented. Simulated results of the radiation characteristics of the circular array are analyzed.

  1. Start Up Application Concerns with Field Programmable Gate Arrays (FPGAs)

    Science.gov (United States)

    Katz, Richard B.

    1999-01-01

    This note is being published to improve the visibility of this subject, as we continue to see problems surface in designs, as well as to add additional information to the previously published note for design engineers. The original application note focused on designing systems with no single point failures using Actel Field Programmable Gate Arrays (FPGAs) for critical applications. Included in that note were the basic principles of operation of the Actel FPGA and a discussion of potential single-point failures. The note also discussed the issue of startup transients for that class of device. It is unfortunate that we continue to see some design problems using these devices. This note will focus on the startup properties of certain electronic components, in general, and current Actel FPGAs, in particular. Devices that are "power-on friendly" are currently being developed by Actel, as a variant of the new SX series of FPGAs. In the ideal world, electronic components would behave much differently than they do in the real world, The chain, of course, starts with the power supply. Ideally, the voltage will immediately rise to a stable V(sub cc) level, of course, it does not. Aside from practical design considerations, inrush current limits of certain capacitors must be observed and the power supply's output may be intentionally slew rate limited to prevent a large current spike on the system power bus. In any event, power supply rise time may range from less than I msec to 100 msec or more.

  2. [Advances in biomolecular machine: methane monooxygenases].

    Science.gov (United States)

    Lu, Jixue; Wang, Shizhen; Fang, Baishan

    2015-07-01

    Methane monooxygenases (MMO), regarded as "an amazing biomolecular machine", catalyze the oxidation of methane to methanol under aerobic conditions. MMO catalyze the oxidation of methane elaborately, which is a novel way to catalyze methane to methanol. Furthermore, MMO can inspire the biomolecular machine design. In this review, we introduced MMO including structure, gene and catalytic mechanism. The history and the taxonomy of MMO were also introduced. PMID:26647577

  3. Microwave spectroscopy of biomolecular building blocks.

    Science.gov (United States)

    Alonso, José L; López, Juan C

    2015-01-01

    Microwave spectroscopy, considered as the most definitive gas phase structural probe, is able to distinguish between different conformational structures of a molecule, because they have unique spectroscopic constants and give rise to distinct individual rotational spectra.Previously, application of this technique was limited to molecular specimens possessing appreciable vapor pressures, thus discarding the possibility of studying many other molecules of biological importance, in particular those with high melting points, which had a tendency to undergo thermal reactions, and ultimately degradation, upon heating.Nowadays, the combination of laser ablation with Fourier transform microwave spectroscopy techniques, in supersonic jets, has enabled the gas-phase study of such systems. In this chapter, these techniques, including broadband spectroscopy, as well as results of their application into the study of the conformational panorama and structure of biomolecular building blocks, such as amino acids, nucleic bases, and monosaccharides, are briefly discussed, and with them, the tools for conformational assignation - rotational constants, nuclear quadrupole coupling interaction, and dipole moment. PMID:25721775

  4. Field Emitter Arrays for a Free Electron Laser Application

    CERN Document Server

    Shing-Bruce-Li, Kevin; Ganter, Romain; Gobrecht, Jens; Raguin, Jean Yves; Rivkin, Leonid; Wrulich, Albin F

    2004-01-01

    The development of a new electron gun with the lowest possible emittance would help reducing the total length and cost of a free electron laser. Field emitter arrays (FEAs) are an attractive technology for electron sources of ultra high brightness. Indeed, several thousands of microscopic tips can be deposited on a 1 mm diameter area. Electrons are then extracted by applying voltage to a first grid layer close to the tip apexes, the so called gate layer, and focused by a second grid layer one micrometer above the tips. The typical aperture diameter of the gate and the focusing layer is in the range of one micrometer. One challenge for such cathodes is to produce peak currents in the ampere range since the usual applications of FEAs require less than milliampere. Encouraging peak current performances have been obtained by applying voltage pulses at low frequency between gate and tips. In this paper we report on different tip materials available on the market: diamond FEAs from Extreme Devices Inc., ZrC single ...

  5. Analysis of Cylindrical Dipole Arrays for Smart Antenna Application

    Institute of Scientific and Technical Information of China (English)

    CAOXiangyu; GAOJun; K.M.Luk; LIANGChanghong

    2005-01-01

    A locally Conformal finite difference time domain (CFDTD) algorithm is studied and applied to model the radiation pattern of a linear dipole arrays mounted on a finite solid conducting cylinder. The numerical result shows that is in good agreement with the moment methods. Finally, the algorithm is applied to study smart antenna used in base station antenna. Several linear arrays mounted with uniform distribution on the cylinder are analyzed. The effects of the number of linear arrays on producing reasonably omnidirectional radiation pattern in the horizontal plane are investigated. It is shown that eight column dipole arrays may be a good choice for economical and practical considerations, and the omnidirection radiation characteristic can be better if the distance from the array axis to the cylinder surface is reduced.

  6. Scanning probe and optical tweezer investigations of biomolecular interactions

    Energy Technology Data Exchange (ETDEWEB)

    Rigby-Singleton, Shellie

    2002-07-01

    A complex array of intermolecular forces controls the interactions between and within biological molecules. The desire to empirically explore the fundamental forces has led to the development of several biophysical techniques. Of these, the atomic force microscope (AFM) and the optical tweezers have been employed throughout this thesis to monitor the intermolecular forces involved in biomolecular interactions. The AFM is a well-established force sensing technique capable of measuring biomolecular interactions at a single molecule level. However, its versatility has not been extrapolated to the investigation of a drug-enzyme complex. The energy landscape for the force induced dissociation of the DHFR-methotrexate complex was studied. Revealing an energy barrier to dissociation located {approx}0.3 nm from the bound state. Unfortunately, the AFM has a limited range of accessible loading rates and in order to profile the complete energy landscape alternative force sensing instrumentation should be considered, for example the BFP and optical tweezers. Thus, this thesis outlines the development and construction an optical trap capable of measuring intermolecular forces between biomolecules at the single molecule level. To demonstrate the force sensing abilities of the optical set up, proof of principle measurements were performed which investigate the interactions between proteins and polymer surfaces subjected to varying degrees of argon plasma treatment. Complementary data was gained from measurements performed independently by the AFM. Changes in polymer resistance to proteins as a response to changes in polymer surface chemistry were detected utilising both AFM and optical tweezers measurements. Finally, the AFM and optical tweezers were employed as ultrasensitive biosensors. Single molecule investigations of the antibody-antigen interaction between the cardiac troponin I marker and its complementary antibody, reveals the impact therapeutic concentrations of heparin

  7. Integrated Spintronic Platforms for Biomolecular Recognition Detection

    Science.gov (United States)

    Martins, V. C.; Cardoso, F. A.; Loureiro, J.; Mercier, M.; Germano, J.; Cardoso, S.; Ferreira, R.; Fonseca, L. P.; Sousa, L.; Piedade, M. S.; Freitas, P. P.

    2008-06-01

    This paper covers recent developments in magnetoresistive based biochip platforms fabricated at INESC-MN, and their application to the detection and quantification of pathogenic waterborn microorganisms in water samples for human consumption. Such platforms are intended to give response to the increasing concern related to microbial contaminated water sources. The presented results concern the development of biological active DNA chips and protein chips and the demonstration of the detection capability of the present platforms. Two platforms are described, one including spintronic sensors only (spin-valve based or magnetic tunnel junction based), and the other, a fully scalable platform where each probe site consists of a MTJ in series with a thin film diode (TFD). Two microfluidic systems are described, for cell separation and concentration, and finally, the read out and control integrated electronics are described, allowing the realization of bioassays with a portable point of care unit. The present platforms already allow the detection of complementary biomolecular target recognition with 1 pM concentration.

  8. A cylindrical-section ultrasound phased-array applicator for hyperthermia cancer therapy.

    Science.gov (United States)

    Ebbini, E S; Umemura, S I; Ibbini, M; Cain, C A

    1988-01-01

    A phased-array applicator geometry for deep localized hyperthermia is presented. The array consists of rectangular transducer elements forming a section of a cylinder that conforms to the body portals in the abdominal and pelvic regions. Focusing and scanning properties of the cylindrical-section array are investigated in homogeneous lossy media using appropriate computer simulations. The characteristic focus of this array is shown to be spatially limited in both transverse and longitudinal directions with intensity gain values suitable for deep hyperthermia applications. The ability of the cylindrical-section phased array to generate multiple foci using the field conjugation method is examined. The effect of the grating lobes on the power deposition pattern of the scanned field is shown to be minimal. Steady-state temperature distributions are simulated using a three-dimensional thermal model of the normal tissue layers surrounding a tumor of typical volume. The advantages and the limitations of this array configuration are discussed. PMID:18290188

  9. Array processors: an introduction to their architecture, software, and applications in nuclear medicine

    International Nuclear Information System (INIS)

    Array processors are ''number crunchers'' that dramatically enhance the processing power of nuclear medicine computer systems for applicatons dealing with the repetitive operations involved in digital image processing of large segments of data. The general architecture and the programming of array processors are introduced, along with some applications of array processors to the reconstruction of emission tomographic images, digital image enhancement, and functional image formation

  10. Enhancing resolution properties of array antennas via field extrapolation: application to MIMO systems

    Science.gov (United States)

    Reggiannini, Ruggero

    2015-12-01

    This paper is concerned with spatial properties of linear arrays of antennas spaced less than half wavelength. Possible applications are in multiple-input multiple-output (MIMO) wireless links for the purpose of increasing the spatial multiplexing gain in a scattering environment, as well as in other areas such as sonar and radar. With reference to a receiving array, we show that knowledge of the received field can be extrapolated beyond the actual array size by exploiting the finiteness of the interval of real directions from which the field components impinge on the array. This property permits to increase the performance of the array in terms of angular resolution. A simple signal processing technique is proposed allowing formation of a set of beams capable to cover uniformly the entire horizon with an angular resolution better than that achievable by a classical uniform-weighing half-wavelength-spaced linear array. Results are also applicable to active arrays. As the above approach leads to arrays operating in super-directive regime, we discuss all related critical aspects, such as sensitivity to external and internal noises and to array imperfections, and bandwidth, so as to identify the basic design criteria ensuring the array feasibility.

  11. High NA diffractive array illuminators and application in a multi-spot scanning microscope

    NARCIS (Netherlands)

    Hulsken, B.; Vossen, D.; Stallinga, S.

    2012-01-01

    Array illuminators generating spots with high NA at high efficiency are presented. They are designed via application of high-NA scalar optics methods, and implemented as periodic binary phase structures. These array illuminators are used in a multi-spot scanning microscope for scanning large sample

  12. Flourescence from Gas-Phase Biomolecular Ions

    DEFF Research Database (Denmark)

    Nielsen, Steen Brøndsted

    2013-01-01

    from experiments on dye-derivatised biomolecular ions that provide important information on folding/unfolding processes and local structural changes are presented. Examples included here are a model DNA duplex, the Trp-cage protein, polyproline peptides, and the cytochrome c heme protein. The chapter......This chapter deals with measurements of fluorescence from electronically excited biomolecular ions where there are no interactions with an external environment. Biomolecules with no natural fluorophores are labelled with a dye for such experiments. First, some of the advantages, but also...

  13. Manufacture of a 2D optical fiber array coupler with micrometer precision for laser radar applications

    International Nuclear Information System (INIS)

    This article presents the manufacture of a 2D-fiber array coupler using UV-LIGA technology for the precise positioning of a two-dimensional (2D) optical fiber array. The precision of the alignment of the eight-by-eight fiber array was demonstrated to be less than 2 μm. The average concentricity error of the fibers to the positioning holes of the array coupler had a minimum and maximum error of 1.7 µm and 6.5 μm, respectively. The 2D fiber array coupler can fulfill the coupling and transmission requirements of 2D light spots for laser radar applications. The method developed here can easily be extended to the manufacture of larger arrays. (paper)

  14. Role of biomolecular logic systems in biosensors and bioactuators

    Science.gov (United States)

    Mailloux, Shay; Katz, Evgeny

    2014-09-01

    An overview of recent advances in biosensors and bioactuators based on biocomputing systems is presented. Biosensors digitally process multiple biochemical signals through Boolean logic networks of coupled biomolecular reactions and produce an output in the form of a YES/NO response. Compared to traditional single-analyte sensing devices, the biocomputing approach enables high-fidelity multianalyte biosensing, which is particularly beneficial for biomedical applications. Multisignal digital biosensors thus promise advances in rapid diagnosis and treatment of diseases by processing complex patterns of physiological biomarkers. Specifically, they can provide timely detection and alert medical personnel of medical emergencies together with immediate therapeutic intervention. Application of the biocomputing concept has been successfully demonstrated for systems performing logic analysis of biomarkers corresponding to different injuries, particularly as exemplified for liver injury. Wide-ranging applications of multianalyte digital biosensors in medicine, environmental monitoring, and homeland security are anticipated. "Smart" bioactuators, for signal-triggered drug release, for example, were designed by interfacing switchable electrodes with biocomputing systems. Integration of biosensing and bioactuating systems with biomolecular information processing systems advances the potential for further scientific innovations and various practical applications.

  15. Plasmonic nanopatch array for optical integrated circuit applications.

    Science.gov (United States)

    Qu, Shi-Wei; Nie, Zai-Ping

    2013-01-01

    Future plasmonic integrated circuits with the capability of extremely high-speed data processing at optical frequencies will be dominated by the efficient optical emission (excitation) from (of) plasmonic waveguides. Towards this goal, plasmonic nanoantennas, currently a hot topic in the field of plasmonics, have potential to bridge the mismatch between the wave vector of free-space photonics and that of the guided plasmonics. To manipulate light at will, plasmonic nanoantenna arrays will definitely be more efficient than isolated nanoantennas. In this article, the concepts of microwave antenna arrays are applied to efficiently convert plasmonic waves in the plasmonic waveguides into free-space optical waves or vice versa. The proposed plasmonic nanoantenna array, with nanopatch antennas and a coupled wedge plasmon waveguide, can also act as an efficient spectrometer to project different wavelengths into different directions, or as a spatial filter to absorb a specific wavelength at a specified incident angle. PMID:24201454

  16. Plasmonic nanopatch array for optical integrated circuit applications.

    Science.gov (United States)

    Qu, Shi-Wei; Nie, Zai-Ping

    2013-11-08

    Future plasmonic integrated circuits with the capability of extremely high-speed data processing at optical frequencies will be dominated by the efficient optical emission (excitation) from (of) plasmonic waveguides. Towards this goal, plasmonic nanoantennas, currently a hot topic in the field of plasmonics, have potential to bridge the mismatch between the wave vector of free-space photonics and that of the guided plasmonics. To manipulate light at will, plasmonic nanoantenna arrays will definitely be more efficient than isolated nanoantennas. In this article, the concepts of microwave antenna arrays are applied to efficiently convert plasmonic waves in the plasmonic waveguides into free-space optical waves or vice versa. The proposed plasmonic nanoantenna array, with nanopatch antennas and a coupled wedge plasmon waveguide, can also act as an efficient spectrometer to project different wavelengths into different directions, or as a spatial filter to absorb a specific wavelength at a specified incident angle.

  17. Plasmonic nanopatch array for optical integrated circuit applications

    Science.gov (United States)

    Qu, Shi-Wei; Nie, Zai-Ping

    2013-01-01

    Future plasmonic integrated circuits with the capability of extremely high-speed data processing at optical frequencies will be dominated by the efficient optical emission (excitation) from (of) plasmonic waveguides. Towards this goal, plasmonic nanoantennas, currently a hot topic in the field of plasmonics, have potential to bridge the mismatch between the wave vector of free-space photonics and that of the guided plasmonics. To manipulate light at will, plasmonic nanoantenna arrays will definitely be more efficient than isolated nanoantennas. In this article, the concepts of microwave antenna arrays are applied to efficiently convert plasmonic waves in the plasmonic waveguides into free-space optical waves or vice versa. The proposed plasmonic nanoantenna array, with nanopatch antennas and a coupled wedge plasmon waveguide, can also act as an efficient spectrometer to project different wavelengths into different directions, or as a spatial filter to absorb a specific wavelength at a specified incident angle. PMID:24201454

  18. A head and neck hyperthermia applicator: Theoretical antenna array design

    NARCIS (Netherlands)

    Paulides, M.M.; Bakker, J.F.; Zwamborn, A.P.M.; Rhoon, G.C. van

    2007-01-01

    Purpose: Investigation into the feasibility of a circular array of dipole antennas to deposit RF-energy centrally in the neck as a function of: 1) patient positioning, 2) antenna ring radius, 3) number of antenna rings, 4) number of antennas per ring and 5) distance between antenna rings. Materials

  19. A head and neck hyperthermia applicator: Theoretical antenna array design

    NARCIS (Netherlands)

    M.M. Paulides (Margarethus); J.F. Bakker (Jurriaan); A.P.M. Zwamborn; G.C. van Rhoon (Gerard)

    2007-01-01

    textabstractPurpose: Investigation into the feasibility of a circular array of dipole antennas to deposit RF-energy centrally in the neck as a function of: (1) patient positioning, (2) antenna ring radius, (3) number of antenna rings, (4) number of antennas per ring and (5) distance between antenna

  20. Sunflower array antenna for multi-beam satellite applications

    NARCIS (Netherlands)

    Vigano, M.C.

    2011-01-01

    Saving space on board, reducing costs and improving the antenna performances are tasks of outmost importance in the field of satellite communication. In this work it is shown how a non-uniformly spaced, direct radiating array designed according to the so called ‘sunflower’ law is able to satisfy str

  1. Microstrip Yagi array antenna for mobile satellite vehicle application

    Science.gov (United States)

    Huang, John; Densmore, Arthur C.

    1991-01-01

    A novel antenna structure formed by combining the Yagi-Uda array concept and the microstrip radiator technique is discussed. This antenna, called the microstrip Yagi array, has been developed for the mobile satellite (MSAT) system as a low-profile, low-cost, and mechanically steered medium-gain land-vehicle antenna. With the antenna's active patches (driven elements) and parasitic patches (reflector and director elements) located on the same horizontal plane, the main beam of the array can be tilted, by the effect of mutual coupling, in the elevation direction providing optimal coverage for users in the continental United States. Because the parasitic patches are not connected to any of the lossy RF power distributing circuit the antenna is an efficient radiating system. With the complete monopulse beamforming and power distributing circuits etched on a single thin stripline board underneath the microstrip Yagi array, the overall L-band antenna system has achieved a very low profile for vehicle's rooftop mounting, as well as a low manufacturing cost. Experimental results demonstrate the performance of this antenna.

  2. Advances in integrative modeling of biomolecular complexes

    NARCIS (Netherlands)

    Karaca, E.; Bonvin, A.M.J.J.

    2013-01-01

    High-resolution structural information is needed in order to unveil the underlying mechanistic of biomolecular function. Due to the technical limitations or the nature of the underlying complexes, acquiring atomic resolution information is difficult for many challenging systems, while, often, low-re

  3. Radiometric packaging of uncooled microbolometer FPA arrays for space applications

    Science.gov (United States)

    García-Blanco, S.; Cote, P.; Leclerc, M.; Blanchard, N.; Desroches, Y.; Caron, J.-S.; Ngo Phong, L.; Chateauneuf, F.; Pope, T.

    2009-02-01

    INO has extensive experience in the design and fabrication of focal plane arrays (FPAs) of uncooled microbolometers. In particular, the FPA of 512×3 microbolometers, developed in collaboration with the Canadian Space Agency (CSA), has been selected for use in the NIRST (New Infrared Sensor Technology) radiometer of the SAC-D Aquarius mission. The FPA has been designed for pushbroom scanning of the Earth to provide radiometric data in the mid- and long-wave infrared for the monitoring of fires as well as thermal mapping of ocean temperature. Uncooled microbolometer detectors are suited for space applications due to their low power consumption while still exhibiting adequate performance. Furthermore, the spectral range of their response could be tuned from the mid- to the far-infrared to meet different mission requirements. In order to ensure that the detector receives only the thermal contribution from the desired target and to minimize radiometric error due to variation of the temperature of the surrounding during the measurements, a radiometric package is required. In a radiometric package the detector environment is thermally stabilized by means of a temperature controlled radiation shield. The radiation shield should also be designed to prevent stray radiation from reaching the detector. Under the Space Technology Development Program of the CSA, INO has designed, assembled and tested a radiometric package in order to characterize its performance and compatibility with the space environment. The operating spectral band is defined by the spectral characteristics of a bandpass filter placed in front of the FPA. For typical space missions, the package must pass standard environmental tests without degradation of its performance (thermal cycling from -55 to +85 °C according to MIL-STD-810, random acceleration up to 14 G RMS from 20-2000 Hz and shock up to 75 G). In order to ensure reliability in those conditions while maintaining optimum performance, an adequate

  4. Null-steering techniques for application to large array antennas

    Science.gov (United States)

    Hockham, G. A.; Cho, C.; Parr, J. C.; Wolfson, R. I.

    A multimode waveguide can be employed to design an antenna which produces a beam for each propagating mode. A dual-beam waveguide slot array is particularly attractive. The antenna is compact, highly efficient, and has lower sidelobe-level performance than can be achieved with conventional monopulse techniques. Adaptive phase steering for jammer nulling is considered, taking into account a large phased array using a series feed system. The considered configuration was selected for computer simulation. A description is presented of a multiple beam antenna with independent steerable nulls. The multiple beam low-sidelobe antenna configuration has the ability to provide a radiation pattern with multiple and independently-located nulls, with minimal effect on the sidelobes of the unperturbed pattern.

  5. Applications of trimode waveguide feeds in adaptive virtual array antennas

    Science.gov (United States)

    Allahgholi Pour, Z.; Shafai, Lotfollah

    2015-03-01

    This paper presents the formation of an adaptive virtual array antenna in a symmetric parabolic reflector antenna illuminated by trimode circular waveguide feeds with different mode alignments. The modes of interest are the TE11, TE21, and TM01 type modes. The terms TE and TM stand for the transverse electric and transverse magnetic modes, respectively. By appropriately exciting these modes and varying the mode orientations inside the primary feed, the effective source of radiation is displaced on the reflector aperture, while the resulting secondary patterns remain axial. Different antenna parameters such as gain, cross polarization, and phase center locations are investigated. It is demonstrated that the extra third mode facilitates the formation of symmetric virtual array antennas with reasonable cross polarization discriminations at the diagonal plane.

  6. Application of Seismic Array Processing to Tsunami Early Warning

    Science.gov (United States)

    An, C.; Meng, L.

    2015-12-01

    Tsunami wave predictions of the current tsunami warning systems rely on accurate earthquake source inversions of wave height data. They are of limited effectiveness for the near-field areas since the tsunami waves arrive before data are collected. Recent seismic and tsunami disasters have revealed the need for early warning to protect near-source coastal populations. In this work we developed the basis for a tsunami warning system based on rapid earthquake source characterisation through regional seismic array back-projections. We explored rapid earthquake source imaging using onshore dense seismic arrays located at regional distances on the order of 1000 km, which provides faster source images than conventional teleseismic back-projections. We implement this method in a simulated real-time environment, and analysed the 2011 Tohoku earthquake rupture with two clusters of Hi-net stations in Kyushu and Northern Hokkaido, and the 2014 Iquique event with the Earthscope USArray Transportable Array. The results yield reasonable estimates of rupture area, which is approximated by an ellipse and leads to the construction of simple slip models based on empirical scaling of the rupture area, seismic moment and average slip. The slip model is then used as the input of the tsunami simulation package COMCOT to predict the tsunami waves. In the example of the Tohoku event, the earthquake source model can be acquired within 6 minutes from the start of rupture and the simulation of tsunami waves takes less than 2 min, which could facilitate a timely tsunami warning. The predicted arrival time and wave amplitude reasonably fit observations. Based on this method, we propose to develop an automatic warning mechanism that provides rapid near-field warning for areas of high tsunami risk. The initial focus will be Japan, Pacific Northwest and Alaska, where dense seismic networks with the capability of real-time data telemetry and open data accessibility, such as the Japanese HiNet (>800

  7. Plasmonic nanopatch array for optical integrated circuit applications

    OpenAIRE

    Shi-Wei Qu; Zai-Ping Nie

    2013-01-01

    Future plasmonic integrated circuits with the capability of extremely high-speed data processing at optical frequencies will be dominated by the efficient optical emission (excitation) from (of) plasmonic waveguides. Towards this goal, plasmonic nanoantennas, currently a hot topic in the field of plasmonics, have potential to bridge the mismatch between the wave vector of free-space photonics and that of the guided plasmonics. To manipulate light at will, plasmonic nanoantenna arrays will def...

  8. Phased-array radar design application of radar fundamentals

    CERN Document Server

    Jeffrey, Thomas

    2009-01-01

    Phased-Array Radar Design is a text-reference designed for electrical engineering graduate students in colleges and universities as well as for corporate in-house training programs for radar design engineers, especially systems engineers and analysts who would like to gain hands-on, practical knowledge and skills in radar design fundamentals, advanced radar concepts, trade-offs for radar design and radar performance analysis.

  9. Analysis of Camera Arrays Applicable to the Internet of Things

    OpenAIRE

    Jiachen Yang; Ru Xu; Zhihan Lv; Houbing Song

    2016-01-01

    The Internet of Things is built based on various sensors and networks. Sensors for stereo capture are essential for acquiring information and have been applied in different fields. In this paper, we focus on the camera modeling and analysis, which is very important for stereo display and helps with viewing. We model two kinds of cameras, a parallel and a converged one, and analyze the difference between them in vertical and horizontal parallax. Even though different kinds of camera arrays are...

  10. Transition metal bioconjugates with an organometallic link between the metal and the biomolecular scaffold

    OpenAIRE

    Monney, Angèle; Albrecht, Martin

    2013-01-01

    This overview compiles recent advances in the synthesis and application of organometallic bioconjugates that comprise a metal–carbon linkage between the metal and the biomolecular scaffold. This specific area of bioorganometallic chemistry has been spurred by the discovery of naturally occurring bioorganometallic compounds and afforded organometallic bioconjugates from transition metals binding to amino acids, nucleic acids and other biomolecules. These artificial bioorganometallic compounds ...

  11. Computer Programming and Biomolecular Structure Studies: A Step beyond Internet Bioinformatics

    Science.gov (United States)

    Likic, Vladimir A.

    2006-01-01

    This article describes the experience of teaching structural bioinformatics to third year undergraduate students in a subject titled "Biomolecular Structure and Bioinformatics." Students were introduced to computer programming and used this knowledge in a practical application as an alternative to the well established Internet bioinformatics…

  12. Two Elements Elliptical Slot CDRA Array with Corporate Feeding For X-Band Applications

    Directory of Open Access Journals (Sweden)

    Abdulkareem S. Abdullah

    2014-06-01

    Full Text Available In this paper, a compact two-element cylindrical dielectric resonator antenna (CDRA array with corporate feeding is proposed for X-band applications. The dielectric resonator antenna (DRA array is excited by a microstrip feeder using an efficient aperture-coupled method. The designed array antenna is analyzed using a CST microwave studio. The fabricated sample of the proposed CDRA antenna array showed bandwidth extending from 10.42GHz to 12.84GHz (20.8%. The achieved array gain has a maximum of 9.29dBi at frequency of 10.7GHz. This is about 2.06dBi enhancement of the gain in comparison with a single pellet CDRA. The size of the whole antenna structure is about 5050mm2.

  13. A Novel Compact Wideband TSA Array for Near-Surface Ice Sheet Penetrating Radar Applications

    Science.gov (United States)

    Zhang, Feng; Liu, Xiaojun; Fang, Guangyou

    2014-03-01

    A novel compact tapered slot antenna (TSA) array for near-surface ice sheet penetrating radar applications is presented. This TSA array is composed of eight compact antenna elements which are etched on two 480mm × 283mm FR4 substrates. Each antenna element is fed by a wideband coplanar waveguide (CPW) to coupled strip-line (CPS) balun. The two antenna substrates are connected together with a metallic baffle. To obtain wideband properties, another two metallic baffles are used along broadsides of the array. This array is fed by a 1 × 8 wideband power divider. The measured S11 of the array is less than -10dB in the band of 500MHz-2GHz, and the measured gain is more than 6dBi in the whole band which agrees well with the simulated results.

  14. A Comparative Performance Analysis of Two Printed Circular Arrays for Power-Based Vehicle Localization Applications

    Directory of Open Access Journals (Sweden)

    Mohammad S. Sharawi

    2012-01-01

    Full Text Available A comparative study of the performance characteristics of a printed 8-element V-shaped circular antenna array and an 8-element Yagi circular array operating at 2.45 GHz for vehicular direction finding applications is presented. Two operating modes are investigated; switched and phased modes. The arrays were fabricated on FR-4 substrates with 0.8 mm thickness. Measured and simulated results were compared. Radiation gain patterns were measured on a 1 m diameter ground plane that resembles the rooftop of a vehicle. The HPBW of the Yagi was found to be about 3° narrower than its V-shaped counterpart when measured above a reflecting ground plane and operated in switched mode. The printed V-shaped antenna array offers 2.5 dB extra gain compared to the printed Yagi array.

  15. Control of zinc oxide nanowire array properties with electron-beam lithography templating for photovoltaic applications

    International Nuclear Information System (INIS)

    Hydrothermally synthesized zinc oxide nanowire arrays have been used as nanostructured acceptors in emerging photovoltaic (PV) devices. The nanoscale dimensions of such arrays allow for enhanced charge extraction from PV active layers, but the device performance critically depends on the nanowire array pitch and alignment. In this study, we templated hydrothermally-grown ZnO nanowire arrays via high-resolution electron-beam-lithography defined masks, achieving the dual requirements of high-resolution patterning at a pitch of several hundred nanometers, while maintaining hole sizes small enough to control nanowire array morphology. We investigated several process conditions, including the effect of annealing sputtered and spincoated ZnO seed layers on nanowire growth, to optimize array property metrics—branching from individual template holes and off-normal alignment. We found that decreasing template hole size decreased branching prevalence but also reduced alignment. Annealing seed layers typically improved alignment, and sputtered seed layers yielded nanowire arrays superior to spincoated seed layers. We show that these effects arose from variation in the size of the template holes relative to the ZnO grain size in the seed layer. The quantitative control of branching and alignment of the nanowire array that is achieved in this study will open new paths toward engineering more efficient electrodes to increase photocurrent in nanostructured PVs. This control is also applicable to inorganic nanowire growth in general, nanomechanical generators, nanowire transistors, and surface-energy engineering. (paper)

  16. Design of a Compact Wideband Antenna Array for Microwave Imaging Applications

    Directory of Open Access Journals (Sweden)

    J. Puskely

    2013-12-01

    Full Text Available In the paper, wideband antenna arrays aimed at microwave imaging applications and SAR applications operating at Ka band were designed. The antenna array feeding network is realized by a low-loss SIW technology. Moreover, we have replaced the large feed network comprised of various T and Y junctions by a simple broadband network of compact size to more reduce losses in the substrate integrated waveguide and also save space on the PCB. The designed power 8-way divider is complemented by a wideband substrate integrated waveguide to a grounded coplanar waveguide transition and directly connected to the antenna elements. The measured results of antenna array are consistent with our simulation. Obtained results of the developed array demonstrated improvement compared to previously developed binary feed networks with microstrip or SIW splitters.

  17. The application of taylor weighting, digital phase shifters, and digital attenuators to phased-array antennas.

    Energy Technology Data Exchange (ETDEWEB)

    Brock, Billy C.

    2008-03-01

    Application of Taylor weighting (taper) to an antenna aperture can achieve low peak sidelobes, but combining the Taylor weighting with quantized attenuators and phase shifters at each radiating element will impact the performance of a phased-array antenna. An examination of array performance is undertaken from the simple point of view of the characteristics of the array factor. Design rules and guidelines for determining the Taylor-weighting parameters, the number of bits required for the digital phase shifter, and the dynamic range and number of bits required for the digital attenuator are developed. For a radar application, when each element is fed directly from a transmit/receive module, the total power radiated by the array will be reduced as a result of the taper. Consequently, the issue of whether to apply the taper on both transmit and receive configurations, or only on the receive configuration is examined with respect to two-way sidelobe performance.

  18. Target localization techniques for vehicle-based electromagnetic induction array applications

    Science.gov (United States)

    Miller, Jonathan S.; Schultz, Gregory M.; Shubitidze, Fridon; Marble, Jay A.

    2010-04-01

    State-of-the-art electromagnetic induction (EMI) arrays provide significant capability enhancement to landmine, unexploded ordnance (UXO), and buried explosives detection applications. Arrays that are easily configured for integration with a variety of mobile platforms offer improved safety and efficiency to personnel conducting detection operations including site remediation, explosive ordnance disposal, and humanitarian demining missions. We present results from an evaluation of two vehicle-based frequency domain EMI arrays. Our research includes implementation of a simple circuit model to estimate target location from sensor measurements of the scattered vertical magnetic field component. Specifically, we characterize any conductive or magnetic target using a set of parameters that describe the eddy current and magnetic polarizations induced about a set of orthogonal axes. Parameter estimations are based on the fundamental resonance mode of a series inductance and resistance circuit. This technique can be adapted to a variety of EMI array configurations, and thus offers target localization capabilities to a number of applications.

  19. New Applications of Electrochemically Produced Porous Semiconductors and Nanowire Arrays

    Directory of Open Access Journals (Sweden)

    Leisner Malte

    2010-01-01

    Full Text Available Abstract The growing demand for electro mobility together with advancing concepts for renewable energy as primary power sources requires sophisticated methods of energy storage. In this work, we present a Li ion battery based on Si nanowires, which can be produced reliable and cheaply and which shows superior properties, such as a largely increased capacity and cycle stability. Sophisticated methods based on electrochemical pore etching allow to produce optimized regular arrays of nanowires, which can be stabilized by intrinsic cross-links, which serve to avoid unwanted stiction effects and allow easy processing.

  20. Large-area nanogap plasmon resonator arrays for plasmonics applications

    Science.gov (United States)

    Jin, Mingliang; van Wolferen, Henk; Wormeester, Herbert; van den Berg, Albert; Carlen, Edwin T.

    2012-07-01

    Large-area (~8000 mm2) Au nanogap plasmon resonator array substrates manufactured using maskless laser interference lithography (LIL) with high uniformity are presented. The periodically spaced subwavelength nanogap arrays are formed between adjacent nanopyramid (NPy) structures with precisely defined pitch and high length density (~1 km cm-2), and are ideally suited as scattering sites for surface enhanced Raman scattering (SERS), as well as refractive index sensing. The two-dimensional grid arrangement of NPy structures renders the excitation of the plasmon resonators minimally dependent on the incident polarization. The SERS average enhancement factor (AEF) has been characterized using over 30 000 individual measurements of benzenethiol (BT) chemisorbed on the Au NPy surfaces. From the 1(a1), βCCC + νCS ring mode (1074 cm-1) of BT on surfaces with pitch λg = 200 nm, AEF = 0.8 × 106 and for surfaces with λg = 500 nm, AEF = 0.3 × 107 from over 99% of the imaged spots. Maximum AEFs > 108 have been measured in both cases.

  1. Perspective: Coarse-grained models for biomolecular systems

    Science.gov (United States)

    Noid, W. G.

    2013-09-01

    By focusing on essential features, while averaging over less important details, coarse-grained (CG) models provide significant computational and conceptual advantages with respect to more detailed models. Consequently, despite dramatic advances in computational methodologies and resources, CG models enjoy surging popularity and are becoming increasingly equal partners to atomically detailed models. This perspective surveys the rapidly developing landscape of CG models for biomolecular systems. In particular, this review seeks to provide a balanced, coherent, and unified presentation of several distinct approaches for developing CG models, including top-down, network-based, native-centric, knowledge-based, and bottom-up modeling strategies. The review summarizes their basic philosophies, theoretical foundations, typical applications, and recent developments. Additionally, the review identifies fundamental inter-relationships among the diverse approaches and discusses outstanding challenges in the field. When carefully applied and assessed, current CG models provide highly efficient means for investigating the biological consequences of basic physicochemical principles. Moreover, rigorous bottom-up approaches hold great promise for further improving the accuracy and scope of CG models for biomolecular systems.

  2. MPBEC, a Matlab Program for Biomolecular Electrostatic Calculations

    Science.gov (United States)

    Vergara-Perez, Sandra; Marucho, Marcelo

    2016-01-01

    One of the most used and efficient approaches to compute electrostatic properties of biological systems is to numerically solve the Poisson-Boltzmann (PB) equation. There are several software packages available that solve the PB equation for molecules in aqueous electrolyte solutions. Most of these software packages are useful for scientists with specialized training and expertise in computational biophysics. However, the user is usually required to manually take several important choices, depending on the complexity of the biological system, to successfully obtain the numerical solution of the PB equation. This may become an obstacle for researchers, experimentalists, even students with no special training in computational methodologies. Aiming to overcome this limitation, in this article we present MPBEC, a free, cross-platform, open-source software that provides non-experts in the field an easy and efficient way to perform biomolecular electrostatic calculations on single processor computers. MPBEC is a Matlab script based on the Adaptative Poisson-Boltzmann Solver, one of the most popular approaches used to solve the PB equation. MPBEC does not require any user programming, text editing or extensive statistical skills, and comes with detailed user-guide documentation. As a unique feature, MPBEC includes a useful graphical user interface (GUI) application which helps and guides users to configure and setup the optimal parameters and approximations to successfully perform the required biomolecular electrostatic calculations. The GUI also incorporates visualization tools to facilitate users pre- and post-analysis of structural and electrical properties of biomolecules.

  3. Transition-edge sensor imaging arrays for astrophysics applications

    Science.gov (United States)

    Burney, Jennifer Anne

    Many interesting objects in our universe currently elude observation in the optical band: they are too faint or they vary rapidly and thus any structure in their radiation is lost over the period of an exposure. Conventional photon detectors cannot simultaneously provide energy resolution and time-stamping of individual photons at fast rates. Superconducting detectors have recently made the possibility of simultaneous photon counting, imaging, and energy resolution a reality. Our research group has pioneered the use of one such detector, the Transition-Edge Sensor (TES). TES physics is simple and elegant. A thin superconducting film, biased at its critical temperature, can act as a particle detector: an incident particle deposits energy and drives the film into its superconducting-normal transition. By inductively coupling the detector to a SQUID amplifier circuit, this resistance change can be read out as a current pulse, and its energy deduced by integrating over the pulse. TESs can be used to accurately time-stamp (to 0.1 [mu]s) and energy-resolve (0.15 eV at 1.6 eV) near-IR/visible/near-UV photons at rates of 30~kHz. The first astronomical observations using fiber-coupled detectors were made at the Stanford Student Observatory 0.6~m telescope in 1999. Further observations of the Crab Pulsar from the 107" telescope at the University of Texas McDonald Observatory showed rapid phase variations over the near-IR/visible/near-UV band. These preliminary observations provided a glimpse into a new realm of observations of pulsars, binary systems, and accreting black holes promised by TES arrays. This thesis describes the development, characterization, and preliminary use of the first camera system based on Transition-Edge Sensors. While single-device operation is relatively well-understood, the operation of a full imaging array poses significant challenges. This thesis addresses all aspects related to the creation and characterization of this cryogenic imaging

  4. Improvements in continuum modeling for biomolecular systems

    CERN Document Server

    Qiao, Yu

    2015-01-01

    Modeling of biomolecular systems plays an essential role in understanding biological processes, such as ionic flow across channels, protein modification or interaction, and cell signaling. The continuum model described by the Poisson-Boltzmann (PB)/Poisson-Nernst-Planck (PNP) equations has made great contributions towards simulation of these processes. However, the model has shortcomings in its commonly used form and cannot capture (or cannot accurately capture) some important physical properties of biological systems. Considerable efforts have been made to improve the continuum model to account for discrete particle interactions and to make progress in numerical methods to provide accurate and efficient simulation. This review will summarize recent main improvements in continuum modeling for biomolecular systems, with focus on the size-modified models, the coupling of the classical density functional theory and PNP equations, the coupling of polar and nonpolar interactions, and numerical progress.

  5. A statistical mechanical description of biomolecular hydration

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-02-01

    We present an efficient and accurate theoretical description of the structural hydration of biological macromolecules. The hydration of molecules of almost arbitrary size (tRNA, antibody-antigen complexes, photosynthetic reaction centre) can be studied in solution and in the crystal environment. The biomolecular structure obtained from x-ray crystallography, NMR, or modeling is required as input information. The structural arrangement of water molecules near a biomolecular surface is represented by the local water density analogous to the corresponding electron density in an x-ray diffraction experiment. The water-density distribution is approximated in terms of two- and three-particle correlation functions of solute atoms with water using a potentials-of-mean-force expansion.

  6. Visualization of confocal microscopic biomolecular data

    Science.gov (United States)

    Liu, Zhanping; Moorhead, Robert J., II

    2005-04-01

    Biomolecular visualization facilitates insightful interpretation of molecular structures and complex mechanisms underlying bio-chemical processes. Effective visualization techniques are required to deal with confocal microscopic biomolecular data in which intricate structures, fine features, and obscure patterns might be overlooked without sophisticated data processing and image synthesis. This paper presents major challenges in visualizing confocal microscopic biomolecular data, followed by a survey of related work. We then introduce a case study conducted to investigate the interaction between two proteins contained in a budding yeast saccharomyces cerevisiae by embedding custom modules in Amira. The multi-channel confocal microscopic volume data was first processed using an exponential operator to correct z-drop artifacts introduced during data acquisition. Channel correlation was then exploited to extract the overlap between the proteins as a new channel to represent the interaction while a statistical method was employed to compute the intensity of interaction to locate hot spots. To take advantage of crisp surface representation of region boundaries by iso-surfaces and visually pleasing translucent delineation of dense volumes by volume rendering, we adopted hybrid rendering that incorporates these two methods to display clear-cut protein boundaries, amorphous interior materials, and the scattered interaction in the same view volume with suppressed and highlighted parts selected by the user. The highlighted overlap helped biologists learn where the interaction happens and how it spreads, particularly when the volume was investigated in an immersive Cave Automatic Virtual Environment (CAVE) for intuitive comprehension of the data.

  7. Glycan Arrays: From Basic Biochemical Research to Bioanalytical and Biomedical Applications

    Science.gov (United States)

    Geissner, Andreas; Seeberger, Peter H.

    2016-06-01

    A major branch of glycobiology and glycan-focused biomedicine studies the interaction between carbohydrates and other biopolymers, most importantly, glycan-binding proteins. Today, this research into glycan-biopolymer interaction is unthinkable without glycan arrays, tools that enable high-throughput analysis of carbohydrate interaction partners. Glycan arrays offer many applications in basic biochemical research, for example, defining the specificity of glycosyltransferases and lectins such as immune receptors. Biomedical applications include the characterization and surveillance of influenza strains, identification of biomarkers for cancer and infection, and profiling of immune responses to vaccines. Here, we review major applications of glycan arrays both in basic and applied research. Given the dynamic nature of this rapidly developing field, we focus on recent findings.

  8. Halbach arrays consisting of cubic elements optimised for high field gradients in magnetic drug targeting applications

    International Nuclear Information System (INIS)

    A key challenge in the development of magnetic drug targeting (MDT) as a clinically relevant technique is designing systems that can apply sufficient magnetic force to actuate magnetic drug carriers at useful tissue depths. In this study an optimisation routine was developed to generate designs of Halbach arrays consisting of multiple layers of high grade, cubic, permanent magnet elements, configured to deliver the maximum pull or push force at a position of interest between 5 and 50 mm from the array, resulting in arrays capable of delivering useful magnetic forces to depths past 20 mm. The optimisation routine utilises a numerical model of the magnetic field and force generated by an arbitrary configuration of magnetic elements. Simulated field and force profiles of optimised arrays were evaluated, also taking into account the forces required for assembling the array in practice. The resultant selection for the array, consisting of two layers, was then constructed and characterised to verify the simulations. Finally the array was utilised in a set of in vitro experiments to demonstrate its capacity to separate and retain microbubbles loaded with magnetic nanoparticles against a constant flow. The optimised designs are presented as light-weight, inexpensive options for applying high-gradient, external magnetic fields in MDT applications. (paper)

  9. Halbach arrays consisting of cubic elements optimised for high field gradients in magnetic drug targeting applications.

    Science.gov (United States)

    Barnsley, Lester C; Carugo, Dario; Owen, Joshua; Stride, Eleanor

    2015-11-01

    A key challenge in the development of magnetic drug targeting (MDT) as a clinically relevant technique is designing systems that can apply sufficient magnetic force to actuate magnetic drug carriers at useful tissue depths. In this study an optimisation routine was developed to generate designs of Halbach arrays consisting of multiple layers of high grade, cubic, permanent magnet elements, configured to deliver the maximum pull or push force at a position of interest between 5 and 50 mm from the array, resulting in arrays capable of delivering useful magnetic forces to depths past 20 mm. The optimisation routine utilises a numerical model of the magnetic field and force generated by an arbitrary configuration of magnetic elements. Simulated field and force profiles of optimised arrays were evaluated, also taking into account the forces required for assembling the array in practice. The resultant selection for the array, consisting of two layers, was then constructed and characterised to verify the simulations. Finally the array was utilised in a set of in vitro experiments to demonstrate its capacity to separate and retain microbubbles loaded with magnetic nanoparticles against a constant flow. The optimised designs are presented as light-weight, inexpensive options for applying high-gradient, external magnetic fields in MDT applications. PMID:26458056

  10. Multi-lead ECG electrode array for clinical application of electrocardiographic inverse problem.

    Science.gov (United States)

    Hintermuller, Christoph; Fischer, Gerald; Seger, Michael; Pfeifer, Bernhard; Hanser, Friedrich; Modre, Robert; Tilg, Bernhard

    2004-01-01

    Methods for noninvasive imaging of electric function of the heart might become clinical standard procedure the next years. Thus, the overall procedure has to meet clinical requirements as easy and fast application. In this study we propose a new electrode array which improves the information content in the ECG map, considering clinical constraints such as easy to apply and compatibility with routine leads. A major challenge is the development of an electrode array which yields a high information content even for a large interindividual variation in torso shape. For identifying regions of high information content we introduce the concept of a locally applied virtual electrode array. As a result of our analysis we constructed a new electrode array consisting of two L-shaped regular spaced parts and compared it to the electrode array we use for clinical studies upon activation time imaging. We assume that one side effect caused by the regular shape and spacing of the new array be that the reconstruction of electrodes placed on the patients back is simplified. It may be sufficient to record a few characteristic electrode positions and merge them with a model of the posterior array.

  11. Characterization of InGaAs linear array for applications to remote sensing

    Science.gov (United States)

    Garcia, Christopher S.; Refaat, Tamer F.; Farnsworth, Glenn R.; Abedin, M. N.; Elsayed-Ali, Hani E.

    2005-05-01

    An Indium Gallium Arsenide linear photodiode array in the 1.1-2.5 μm spectral range was characterized. The array has 1024X1 pixels with a 25 μm pitch and was manufactured by Sensors Unlimited, Inc. Characterization and analysis of the electrical and optical properties of a camera system were carried out at room temperature to obtain detector performance parameters. The signal and noise were measured while the array was uniformly illuminated at varying exposure levels. A photon transfer curve was generated by plotting noise as a function of average signal to obtain the camera gain constant. The spectral responsivity was also measured, and the quantum efficiency, read noise and full-well capacity were determined. This paper describes the characterization procedure, analyzes the experimental results, and discusses the applications of the InGaAs linear array to future earth and planetary remote sensing mission.

  12. Parameterizing Quasiperiodicity: Generalized Poisson Summation and Its Application to Modified-Fibonacci Antenna Arrays

    CERN Document Server

    Galdi, V; Pierro, V; Pinto, I M; Felsen, L B; Galdi, Vincenzo; Castaldi, Giuseppe; Pierro, Vincenzo; Pinto, Innocenzo M.; Felsen, Leopold B.

    2005-01-01

    The fairly recent discovery of "quasicrystals", whose X-ray diffraction patterns reveal certain peculiar features which do not conform with spatial periodicity, has motivated studies of the wave-dynamical implications of "aperiodic order". Within the context of the radiation properties of antenna arrays, an instructive novel (canonical) example of wave interactions with quasiperiodic order is illustrated here for one-dimensional (1-D) array configurations based on the "modified-Fibonacci" sequence, with utilization of a two-scale generalization of the standard Poisson summation formula for periodic arrays. This allows for a "quasi-Floquet" analytic parameterization of the radiated field, which provides instructive insights into some of the basic wave mechanisms associated with quasiperiodic order, highlighting similarities and differences with the periodic case. Examples are shown for quasiperiodic infinite and spatially-truncated arrays, with brief discussion of computational issues and potential application...

  13. Hydrothermal synthesis of porous Co(OH)2 nanoflake array film and its supercapacitor application

    Indian Academy of Sciences (India)

    Z Chen; Y Chen; C Zuo; S Zhou; A G Xiao; A X Pan

    2013-04-01

    Porous -Co(OH)2 nanoflake array film is prepared by a facile hydrothermal synthesis method. The -Co(OH)2 nanoflake array film exhibits a highly porous net-like structure composed of interconnected nanoflakes with a thickness of 15 nm. The pseudo-capacitive behaviour of the Co(OH)2 nanoflake array film is investigated by cyclic voltammograms (CV) and galvanostatic charge–discharge tests in 2MKOH. The -Co(OH)2 nanoflake array film exhibits high capacitances of 1017 F g-1 at 2Ag-1 and 890 F g-1 at 40Ag-1 as well as rather good cycling stability for supercapacitor application. The porous architecture is responsible for the enhancement of the electrochemical properties because it provides fast ion and electron transfer, large reaction surface area and good strain accommodation.

  14. Investigation of the Sequential Rotation Technique and its Application in Phased Arrays

    DEFF Research Database (Denmark)

    Larsen, Niels Vesterdal

    2007-01-01

    This report documents the investigations of the sequential rotation technique in application to phased array antennas. A spherical wave expansion for the far field of sequentially phased arrays is derived for general antenna elements. This model is approximate in that it assumes that the element...... patterns are identical and it does not included the effects of mutual coupling between the elements. For this reason it is compared with more accurate numerical models which include the coupling effects. The results show that the sequential rotation technique generally improves the performance...... of the phased array also when it is scanned off bore sight. For array topologies where the elements are not positioned rotationally symmetric the performance of the sequential rotation is to some extent impaired by the mutual coupling and non-identical element patterns. These effects are not evident from...

  15. Analysis, Implementation, and Application of Acoustic and Seismic Arrays

    OpenAIRE

    J.Z. Stafsudd; Asgari, Shadnaz; Chen, Chiao-en; Hudson, Ralph E.; Lorenzelli, F.; Yao, K.; Taciroglu, Ertugrul

    2006-01-01

    In this paper, we consider the analysis, implementation, and application of wideband sources using both seismic and acoustic sensors. We use the approximate maximum likelihood (AML) algorithm to perform acoustic direction of arrival (DOA). For non-uniform noise spectra, whitening filtering was applied to the received acoustic signals before the AML operation. For short-range seismic DOA applications, one method was based on eigen-decomposition of the covariance matrix and a second method was ...

  16. Biomolecular interactions: essential instrumentation methods.

    Science.gov (United States)

    Messina, Paula Veronica; Ruso, Juan Manuel

    2013-01-01

    The main goal of this review is to outline the basic principles and applications of the broad range of modern biophysical technical methods used to study the different aspects of protein–ligand interactions by discussing such aspects as newer systems, unusual approaches and highly used techniques.

  17. Preparation, Applications, and Digital Simulation of Carbon Interdigitated Array Electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Fei; Kolesov, Grigory; Parkinson, Bruce A.

    2014-12-16

    Carbon interdigitated array (IDA) electrodes with features sizes down to 1.2 μm were fabricated by controlled pyrolysis of patterned photoresist. Cyclic voltam-metry of reversible redox species produced the expected steady-state currents. The collection efficiency depends on the IDA electrode spacing, which ranged from around 2.7 to 16.5 μm, with the smaller dimensions achieving higher collection efficiencies of up to 98%. The signal amplification because of redox cycling makes it possible to detect species at relatively low concentrations (10–5 molar) and the small spacing allows detection of transient electrogenerated species with much shorter lifetimes (submillisecond). Digital simulation software that accounts for both the width and height of electrode elements as well as the electrode spacing was developed to model the IDA electrode response. The simulations are in quantitative agreement with experimental data for both a simple fast one electron redox reaction and an electron transfer with a following chemical reaction at the IDAs with larger gaps whereas currents measured for the smallest IDA electrodes, that were larger than the simulated currents, are attributed to convection from induced charge electrokinetic flow. This work was supported as part of the Center for Molecular Electrocatalysis, an Energy Frontier Research Center funded by the Department of Energy, Office of Science Office of Basic Energy Sciences.

  18. Barcoded microchips for biomolecular assays.

    Science.gov (United States)

    Zhang, Yi; Sun, Jiashu; Zou, Yu; Chen, Wenwen; Zhang, Wei; Xi, Jianzhong Jeff; Jiang, Xingyu

    2015-01-20

    Multiplexed assay of analytes is of great importance for clinical diagnostics and other analytical applications. Barcode-based bioassays with the ability to encode and decode may realize this goal in a straightforward and consistent manner. We present here a microfluidic barcoded chip containing several sets of microchannels with different widths, imitating the commonly used barcode. A single barcoded microchip can carry out tens of individual protein/nucleic acid assays (encode) and immediately yield all assay results by a portable barcode reader or a smartphone (decode). The applicability of a barcoded microchip is demonstrated by human immunodeficiency virus (HIV) immunoassays for simultaneous detection of three targets (anti-gp41 antibody, anti-gp120 antibody, and anti-gp36 antibody) from six human serum samples. We can also determine seven pathogen-specific oligonucleotides by a single chip containing both positive and negative controls.

  19. Ion cyclotron and lower hybrid arrays applicable to current drive in fusion reactors

    Science.gov (United States)

    Bosia, G.; Helou, W.; Goniche, M.; Hillaret, J.; Ragona, R.

    2014-02-01

    This paper presents concepts for Ion Cyclotron and Lower Hybrid Current Drive arrays applicable to fusion reactors and based on periodically loaded line power division. It is shown that, in large arrays, such as the ones proposed for fusion reactor applications, these schemes can offer, in principle, a number of practical advantages, compared with currently adopted ones, such as in-blanket operation at significantly reduced power density, lay out suitable for water cooling, single ended or balanced power feed, simple and load independent impedance matching In addition, a remote and accurate real time measurement of the complex impedance of all array elements as well as detection, location, and measurement of the complex admittance of a single arc occurring anywhere in the structure is possible.

  20. Hexabundles: imaging fiber arrays for low-light astronomical applications

    DEFF Research Database (Denmark)

    Bland-Hawthorn, Joss; Bryant, Julia; Robertson, Gordon;

    2011-01-01

    We demonstrate for the first time an imaging fibre bundle (“hexabundle”) that is suitable for low-light applications in astronomy. The most successful survey instruments at optical-infrared wavelengths today have obtained data on up to a million celestial sources using hundreds of multimode fibre...

  1. Application of Uncooled Monolithic Thermoelectric Linear Arrays to Imaging Radiometers

    Science.gov (United States)

    Kruse, Paul W.

    Introduction Identification of Incipient Failure of Railcar Wheels Technical Description of the Model IR 1000 Imaging Radiometer Performance of the Model IR 1000 Imaging Radiometer Initial Application Summary Imaging Radiometer for Predictive and Preventive Maintenance Description Operation Specifications Summary References INDEX CONTENTS OF VOLUMES IN THIS SERIES

  2. Hexabundles: imaging fibre arrays for low-light astronomical applications

    DEFF Research Database (Denmark)

    Bland-Hawthorn, Joss; Bryant, Julie; Robertson, Gordon;

    2010-01-01

    We demonstrate for the first time an imaging fibre bundle (“hexabundle”) that is suitable for low-light applications in astronomy. The most successful survey instruments at optical-infrared wavelengths today have obtained data on up to a million celestial sources using hundreds of multimode fibre...

  3. A light writable microfluidic "flash memory": optically addressed actuator array with latched operation for microfluidic applications.

    Science.gov (United States)

    Hua, Zhishan; Pal, Rohit; Srivannavit, Onnop; Burns, Mark A; Gulari, Erdogan

    2008-03-01

    This paper presents a novel optically addressed microactuator array (microfluidic "flash memory") with latched operation. Analogous to the address-data bus mediated memory address protocol in electronics, the microactuator array consists of individual phase-change based actuators addressed by localized heating through focused light patterns (address bus), which can be provided by a modified projector or high power laser pointer. A common pressure manifold (data bus) for the entire array is used to generate large deflections of the phase change actuators in the molten phase. The use of phase change material as the working media enables latched operation of the actuator array. After the initial light "writing" during which the phase is temporarily changed to molten, the actuated status is self-maintained by the solid phase of the actuator without power and pressure inputs. The microfluidic flash memory can be re-configured by a new light illumination pattern and common pressure signal. The proposed approach can achieve actuation of arbitrary units in a large-scale array without the need for complex external equipment such as solenoid valves and electrical modules, which leads to significantly simplified system implementation and compact system size. The proposed work therefore provides a flexible, energy-efficient, and low cost multiplexing solution for microfluidic applications based on physical displacements. As an example, the use of the latched microactuator array as "normally closed" or "normally open" microvalves is demonstrated. The phase-change wax is fully encapsulated and thus immune from contamination issues in fluidic environments. PMID:18305870

  4. A light writable microfluidic "flash memory": optically addressed actuator array with latched operation for microfluidic applications.

    Science.gov (United States)

    Hua, Zhishan; Pal, Rohit; Srivannavit, Onnop; Burns, Mark A; Gulari, Erdogan

    2008-03-01

    This paper presents a novel optically addressed microactuator array (microfluidic "flash memory") with latched operation. Analogous to the address-data bus mediated memory address protocol in electronics, the microactuator array consists of individual phase-change based actuators addressed by localized heating through focused light patterns (address bus), which can be provided by a modified projector or high power laser pointer. A common pressure manifold (data bus) for the entire array is used to generate large deflections of the phase change actuators in the molten phase. The use of phase change material as the working media enables latched operation of the actuator array. After the initial light "writing" during which the phase is temporarily changed to molten, the actuated status is self-maintained by the solid phase of the actuator without power and pressure inputs. The microfluidic flash memory can be re-configured by a new light illumination pattern and common pressure signal. The proposed approach can achieve actuation of arbitrary units in a large-scale array without the need for complex external equipment such as solenoid valves and electrical modules, which leads to significantly simplified system implementation and compact system size. The proposed work therefore provides a flexible, energy-efficient, and low cost multiplexing solution for microfluidic applications based on physical displacements. As an example, the use of the latched microactuator array as "normally closed" or "normally open" microvalves is demonstrated. The phase-change wax is fully encapsulated and thus immune from contamination issues in fluidic environments.

  5. Silicon Nanoridge Array Waveguides for Nonlinear and Sensing Applications

    CERN Document Server

    Puckett, Matthew W; Vallini, Felipe; Shahin, Shiva; Monifi, Faraz; Barrina, Peter N; Mehravar, Soroush; Kieu, Khanh; Fainman, Yeshaiahu

    2015-01-01

    We fabricate and characterize waveguides composed of closely spaced and longitudinally oriented silicon ridges etched into silicon-on-insulator wafers. Through both guided mode and bulk measurements, we demonstrate that the patterning of silicon waveguides on such a deeply subwavelength scale is desirable for nonlinear and sensing applications alike. The proposed waveguide geometry simultaneously exhibits comparable propagation loss to similar schemes proposed in literature, an enhanced effective third-order nonlinear susceptibility, and high sensitivity to perturbations in its environment.

  6. Precise calibration of a GNSS antenna array for adaptive beamforming applications.

    Science.gov (United States)

    Daneshmand, Saeed; Sokhandan, Negin; Zaeri-Amirani, Mohammad; Lachapelle, Gérard

    2014-05-30

    The use of global navigation satellite system (GNSS) antenna arrays for applications such as interference counter-measure, attitude determination and signal-to-noise ratio (SNR) enhancement is attracting significant attention. However, precise antenna array calibration remains a major challenge. This paper proposes a new method for calibrating a GNSS antenna array using live signals and an inertial measurement unit (IMU). Moreover, a second method that employs the calibration results for the estimation of steering vectors is also proposed. These two methods are applied to the receiver in two modes, namely calibration and operation. In the calibration mode, a two-stage optimization for precise calibration is used; in the first stage, constant uncertainties are estimated while in the second stage, the dependency of each antenna element gain and phase patterns to the received signal direction of arrival (DOA) is considered for refined calibration. In the operation mode, a low-complexity iterative and fast-converging method is applied to estimate the satellite signal steering vectors using the calibration results. This makes the technique suitable for real-time applications employing a precisely calibrated antenna array. The proposed calibration method is applied to GPS signals to verify its applicability and assess its performance. Furthermore, the data set is used to evaluate the proposed iterative method in the receiver operation mode for two different applications, namely attitude determination and SNR enhancement.

  7. LEO resistant PI-B-PDMS block copolymer films for solar array applications

    NARCIS (Netherlands)

    Lonkhuyzen, H. van; Bongers, E.; Fischer, H.R.; Dingemans, T.J.; Semprimoschnig, C.

    2013-01-01

    Due to their low atomic oxygen erosion yields PI-b-PDMS block copolymer films have considerable potential for application onto space exposed surfaces of satellites in low earth orbit. On solar arrays these materials might be used as electrical electrical insulation film, flexprint outer layer, elect

  8. Precise Calibration of a GNSS Antenna Array for Adaptive Beamforming Applications

    Directory of Open Access Journals (Sweden)

    Saeed Daneshmand

    2014-05-01

    Full Text Available The use of global navigation satellite system (GNSS antenna arrays for applications such as interference counter-measure, attitude determination and signal-to-noise ratio (SNR enhancement is attracting significant attention. However, precise antenna array calibration remains a major challenge. This paper proposes a new method for calibrating a GNSS antenna array using live signals and an inertial measurement unit (IMU. Moreover, a second method that employs the calibration results for the estimation of steering vectors is also proposed. These two methods are applied to the receiver in two modes, namely calibration and operation. In the calibration mode, a two-stage optimization for precise calibration is used; in the first stage, constant uncertainties are estimated while in the second stage, the dependency of each antenna element gain and phase patterns to the received signal direction of arrival (DOA is considered for refined calibration. In the operation mode, a low-complexity iterative and fast-converging method is applied to estimate the satellite signal steering vectors using the calibration results. This makes the technique suitable for real-time applications employing a precisely calibrated antenna array. The proposed calibration method is applied to GPS signals to verify its applicability and assess its performance. Furthermore, the data set is used to evaluate the proposed iterative method in the receiver operation mode for two different applications, namely attitude determination and SNR enhancement.

  9. Development of arrays of transition edge sensors for application in X-ray astronomy

    NARCIS (Netherlands)

    Bruijn, Marcel P.; Bergmann Tiest, Wouter M.; Hoevers, Henk F.C.; Krouwer, Eric; Kuur, van der Jan; Ridder, Marcel L.; Moktadir, Zakaria; Wiegerink, Remco; Gelder, van Dick; Elwenspoek, Miko

    2003-01-01

    The development of an array of voltage biased superconducting transition edge microcalorimeters is described. This work is directed to an application in future X-ray Astronomy missions, such as Constellation-X (USA) and the X-ray Evolving Universe Spectroscopy Mission (XEUS, Europe). After several y

  10. Biomolecular Assembly of Gold Nanocrystals

    Energy Technology Data Exchange (ETDEWEB)

    Micheel, Christine Marya [Univ. of California, Berkeley, CA (United States)

    2005-05-20

    Over the past ten years, methods have been developed to construct discrete nanostructures using nanocrystals and biomolecules. While these frequently consist of gold nanocrystals and DNA, semiconductor nanocrystals as well as antibodies and enzymes have also been used. One example of discrete nanostructures is dimers of gold nanocrystals linked together with complementary DNA. This type of nanostructure is also known as a nanocrystal molecule. Discrete nanostructures of this kind have a number of potential applications, from highly parallel self-assembly of electronics components and rapid read-out of DNA computations to biological imaging and a variety of bioassays. My research focused in three main areas. The first area, the refinement of electrophoresis as a purification and characterization method, included application of agarose gel electrophoresis to the purification of discrete gold nanocrystal/DNA conjugates and nanocrystal molecules, as well as development of a more detailed understanding of the hydrodynamic behavior of these materials in gels. The second area, the development of methods for quantitative analysis of transmission electron microscope data, used computer programs written to find pair correlations as well as higher order correlations. With these programs, it is possible to reliably locate and measure nanocrystal molecules in TEM images. The final area of research explored the use of DNA ligase in the formation of nanocrystal molecules. Synthesis of dimers of gold particles linked with a single strand of DNA possible through the use of DNA ligase opens the possibility for amplification of nanostructures in a manner similar to polymerase chain reaction. These three areas are discussed in the context of the work in the Alivisatos group, as well as the field as a whole.

  11. Simulation of Parallel Logical Operations with Biomolecular Computing

    Directory of Open Access Journals (Sweden)

    Mahnaz Kadkhoda

    2008-01-01

    Full Text Available Biomolecular computing is the computational method that uses the potential of DNA as a parallel computing device. DNA computing can be used to solve NP-complete problems. An appropriate application of DNA computation is large-scale evaluation of parallel computation models such as Boolean Circuits. In this study, we present a molecular-based algorithm for evaluation of Nand-based Boolean Circuits. The contribution of this paper is that the proposed algorithm has been implemented using only three molecular operations and the number of passes in each level is decreased to less than half of previously addressed in the literature. Thus, the proposed algorithm is much easier to implement in the laboratory.

  12. Perspective: Markov Models for Long-Timescale Biomolecular Dynamics

    CERN Document Server

    Schwantes, Christian R; Pande, Vijay S

    2014-01-01

    Molecular dynamics simulations have the potential to provide atomic-level detail and insight to important questions in chemical physics that cannot be observed in typical experiments. However, simply generating a long trajectory is insufficient, as researchers must be able to transform the data in a simulation trajectory into specific scientific insights. Although this analysis step has often been taken for granted, it deserves further attention as large-scale simulations become increasingly routine. In this perspective, we discuss the application of Markov models to the analysis of large-scale biomolecular simulations. We draw attention to recent improvements in the construction of these models as well as several important open issues. In addition, we highlight recent theoretical advances that pave the way for a new generation of models of molecular kinetics.

  13. Freestanding membrane composed of micro-ring array with ultrahigh sidewall aspect ratio for application in lightweight cathode arrays

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Lanlan [State Key Laboratory for Manufacturing Systems Engineering, Xi’an Jiaotong University, Xi’an 710049 (China); Liu, Hongzhong, E-mail: hzliu@mail.xjtu.edu.cn [State Key Laboratory for Manufacturing Systems Engineering, Xi’an Jiaotong University, Xi’an 710049 (China); Jiang, Weitao, E-mail: wtjiang@mail.xjtu.edu.cn [State Key Laboratory for Manufacturing Systems Engineering, Xi’an Jiaotong University, Xi’an 710049 (China); Gao, Wei [Key Laboratory of Mechanics on Western Disasters and Environment, Lanzhou University, Lanzhou 730000 (China); Chen, Bangdao [State Key Laboratory for Manufacturing Systems Engineering, Xi’an Jiaotong University, Xi’an 710049 (China); Li, Xin [Department of Microelectronics, Xi’an Jiaotong University, Xi’an 710049 (China); Ding, Yucheng [State Key Laboratory for Manufacturing Systems Engineering, Xi’an Jiaotong University, Xi’an 710049 (China); An, Ningli [Department of Packaging Engineering, Xi’an University of Technology, Xi’an 710048 (China)

    2014-12-15

    Graphical abstract: A freestanding multilayer ultrathin nano-membrane (FUN-membrane) with a micro-ring array (MRA), in which the dimension of each micro-ring is 3 μm in diameter, 2 μm in height and sub-100 nm in sidewall thickness is successfully fabricated, as shown in the SEM image of figure (a). Due to the MRA with ultrahigh aspect ratio of dielectric-metal sidewall, the FUN-membrane can be transferred to either rigid or flexible substrate to be used as the cathode for lightweight display panel, as shown in the schematic of figure (b). - Highlights: • Exploring a new fabrication method for the freestanding ultrathin nano-membrane (FUN-membrane). • FUN-membrane is composed of micro-ring array with ultrahigh aspect ratio of the insulator-metal sidewall. • The sharp metal edge of each micro-ring is preferred to be served as the micro-emitter. - Abstract: A freestanding multilayer ultrathin nano-membrane (FUN-membrane) with a micro-ring array (MRA) is successfully fabricated through the controllable film deposition. Each micro-ring of FUN-membrane is 3 μm in diameter, 2 μm in height and sub-100 nm in sidewall thickness, demonstrating an ultrahigh sidewall aspect ratio of 20:1. In our strategy, a silica layer (200 nm in thickness), a chromium transition layer (5 nm-thick) and a gold layer (40 nm-thick), were in sequence deposited on patterned photoresist. After removal of the photoresist by lift-off process, a FUN-membrane with MRA was peeled off from the substrate, where the gold layer acted as a protecting layer to prevent the MRA from fracture. The FUN-membrane was then transferred to a flexible polycarbonate (PC) sheet coated with indium tin oxide (ITO) layer, which was then used as a flexible and lightweight cathode. Remarkably, the field emission effect of the fabricated FUN-membrane cathode performs a high field-enhancement factor of 1.2 × 10{sup 4} and a low turn-on voltage of 2 V/μm, indicating the advantages of the sharp metal edge of MRA. Due

  14. Application of a Halbach magnetic array for long-range cell and particle separations in biological samples

    Science.gov (United States)

    Kang, Joo H.; Driscoll, Harry; Super, Michael; Ingber, Donald E.

    2016-05-01

    Here, we describe a versatile application of a planar Halbach permanent magnet array for an efficient long-range magnetic separation of living cells and microparticles over distances up to 30 mm. A Halbach array was constructed from rectangular bar magnets using 3D-printed holders and compared to a conventional alternating array of identical magnets. We theoretically predicted the superiority of the Halbach array for a long-range magnetic separation and then experimentally validated that the Halbach configuration outperforms the alternating array for isolating magnetic microparticles or microparticle-bound bacterial cells at longer distances. Magnetophoretic velocities (ymag) of magnetic particles (7.9 μm diameter) induced by the Halbach array in a microfluidic device were significantly higher and extended over a larger area than those induced by the alternating magnet array (ymag = 178 versus 0 μm/s at 10 mm, respectively). When applied to 50 ml tubes (˜30 mm diameter), the Halbach array removed >95% of Staphylococcus aureus bacterial cells bound with 1 μm magnetic particles compared to ˜70% removed using the alternating array. In addition, the Halbach array enabled manipulation of 1 μm magnetic beads in a deep 96-well plate for ELISA applications, which was not possible with the conventional magnet arrays. Our analysis demonstrates the utility of the Halbach array for the future design of devices for high-throughput magnetic separations of cells, molecules, and toxins.

  15. Development of macropore arrays in silicon and related technologies for X-ray imaging applications

    OpenAIRE

    Badel, Xavier

    2003-01-01

    Digital devices have started to replace photographic film inX-ray imaging applications. As compared to photographic films,these devices are more convenient to obtain images and tohandle, treat and store these images. The goal of the presentstudy is to develop macropore arrays and related silicontechnologies in order to fabricate X-ray imaging detectors formedical applications, and in particular for dentistry. Althougha few detectors are already available on the market, theirperformances, such...

  16. Nanotube-Based Chemical and Biomolecular Sensors

    Institute of Scientific and Technical Information of China (English)

    J.Koh; B.Kim; S.Hong; H.Lim; H.C.Choi

    2008-01-01

    We present a brief review about recent results regarding carbon nanotube (CNT)-based chemical and biomolecular sensors. For the fabrication of CNT-based sensors, devices containing CNT channels between two metal electrodes are first fabricated usually via chemical vapor deposition (CVD) process or "surface programmed assembly" method. Then, the CNT surfaces are often functionalized to enhance the selectivity of the sensors. Using this process, highly-sensitive CNT-based sensors can be fabricated for the selective detection of various chemical and biological molecules such as hydrogen, ammonia, carbon monoxide, chlorine gas, DNA, glucose, alcohol, and proteins.

  17. Azurin for Biomolecular Electronics: a Reliability Study

    Science.gov (United States)

    Bramanti, Alessandro; Pompa, Pier Paolo; Maruccio, Giuseppe; Calabi, Franco; Arima, Valentina; Cingolani, Roberto; Corni, Stefano; Di Felice, Rosa; De Rienzo, Francesca; Rinaldi, Ross

    2005-09-01

    The metalloprotein azurin, used in biomolecular electronics, is investigated with respect to its resilience to high electric fields and ambient conditions, which are crucial reliability issues. Concerning the effect of electric fields, two models of different complexity agree indicating an unexpectedly high robustness. Experiments in device-like conditions confirm that no structural modifications occur, according to fluorescence spectra, even after a 40-min exposure to tens of MV/m. Ageing is then investigated experimentally, at ambient conditions and without field, over several days. Only a small conformational rearrangement is observed in the first tens of hours, followed by an equilibrium state.

  18. Scalable Molecular Dynamics for Large Biomolecular Systems

    Directory of Open Access Journals (Sweden)

    Robert K. Brunner

    2000-01-01

    Full Text Available We present an optimized parallelization scheme for molecular dynamics simulations of large biomolecular systems, implemented in the production-quality molecular dynamics program NAMD. With an object-based hybrid force and spatial decomposition scheme, and an aggressive measurement-based predictive load balancing framework, we have attained speeds and speedups that are much higher than any reported in literature so far. The paper first summarizes the broad methodology we are pursuing, and the basic parallelization scheme we used. It then describes the optimizations that were instrumental in increasing performance, and presents performance results on benchmark simulations.

  19. Built-In Self-Test Circuits for Silicon Phased Array Applications /

    OpenAIRE

    Inac, Ozgur

    2013-01-01

    The thesis presents built-in self-test circuits for phased array applications, and the characterization of a 45 nm CMOS SOI technology for millimeter-wave systems. First, an X-Band phased-array RF integrated circuit with built-in self-test (BIST) capabilities is presented. The BIST is accomplished using a miniature capacitive coupler at the input of each channel and an on-chip I/Q vector receiver. Systematic effects introduced with BIST system are covered in detail and are calibrated out of t...

  20. Systematic evaluation of bundled SPC water for biomolecular simulations.

    Science.gov (United States)

    Gopal, Srinivasa M; Kuhn, Alexander B; Schäfer, Lars V

    2015-04-01

    molecules between the active site and the bulk. Our results form a basis for assessing the accuracy that can be expected from bundled SPC water models. At the same time, this study also highlights the importance of evaluating beforehand the effects of water bundling on the biomolecular system of interest for a particular multiscale simulation application.

  1. ssDNA-Functionalized Nanoceria: A Redox-Active Aptaswitch for Biomolecular Recognition.

    Science.gov (United States)

    Bülbül, Gonca; Hayat, Akhtar; Andreescu, Silvana

    2016-04-01

    Quantification of biomolecular binding events is a critical step for the development of biorecognition assays for diagnostics and therapeutic applications. This paper reports the design of redox-active switches based on aptamer conjugated nanoceria for detection and quantification of biomolecular recognition. It is shown that the conformational transition state of the aptamer on nanoceria, combined with the redox properties of these particles can be used to create surface based structure switchable aptasensing platforms. Changes in the redox properties at the nanoceria surface upon binding of the ssDNA and its target analyte enables rapid and highly sensitive measurement of biomolecular interactions. This concept is demonstrated as a general applicable method to the colorimetric detection of DNA binding events. An example of a nanoceria aptaswitch for the colorimetric sensing of Ochratoxin A (OTA) and applicability to other targets is provided. The system can sensitively and selectivity detect as low as 0.15 × 10(-9) m OTA. This novel assay is simple in design and does not involve oligonucleotide labeling or elaborate nanoparticle modification steps. The proposed mechanism discovered here opens up a new way of designing optical sensing methods based on aptamer recognition. This approach can be broadly applicable to many bimolecular recognition processes and related applications. PMID:26844813

  2. Bio-molecular sensors based on guided mode resonance filters

    Science.gov (United States)

    Saleem, M. R.; Ali, R.; Honkanen, S.; Turunen, J.

    2016-08-01

    In this work a low surface roughness and homogenous, high refractive index, and amorphous TiO2 layer on corrugated structures of diffractive optical element is coated by Atomic Layer Deposition (ALD) for biosensors. The design of Guided Mode Resonance Filters (GMRFs) is based on refractive indices and thicknesses of the waveguide biomolecular layers. The designed spectral shifts are calculated by Fourier Modal Method (FMM) and depend on the magnitude of the variations in refractive index of the biomolecular layer on waveguide structures. Furthermore, the sensitivity of the biomolecular sensors depends on the thickness of biomolecular layer and periodicity of the structures. The waveguide structures designed for larger periods show an enhancement in the sensitivity (nm/RIU) of the biomolecular sensor at longer wavelengths. The periodicities of nanophotonic structures are varied from 300 to 500 nm in design calculations with predominance of increase in effective index of the structure to support leaky waveguide modes.

  3. Graphical Environment Tools for Application to Gamma-Ray Energy Tracking Arrays

    Energy Technology Data Exchange (ETDEWEB)

    Todd, Richard A. [RIS Corp.; Radford, David C. [ORNL Physics Div.

    2013-12-30

    Highly segmented, position-sensitive germanium detector systems are being developed for nuclear physics research where traditional electronic signal processing with mixed analog and digital function blocks would be enormously complex and costly. Future systems will be constructed using pipelined processing of high-speed digitized signals as is done in the telecommunications industry. Techniques which provide rapid algorithm and system development for future systems are desirable. This project has used digital signal processing concepts and existing graphical system design tools to develop a set of re-usable modular functions and libraries targeted for the nuclear physics community. Researchers working with complex nuclear detector arrays such as the Gamma-Ray Energy Tracking Array (GRETA) have been able to construct advanced data processing algorithms for implementation in field programmable gate arrays (FPGAs) through application of these library functions using intuitive graphical interfaces.

  4. Microelectrode Arrays with Overlapped Diffusion Layers as Electroanalytical Detectors: Theory and Basic Applications

    Directory of Open Access Journals (Sweden)

    Peter Tomčík

    2013-10-01

    Full Text Available This contribution contains a survey of basic literature dealing with arrays of microelectrodes with overlapping diffusion layers as prospective tools in contemporary electrochemistry. Photolithographic thin layer technology allows the fabrication of sensors of micrometric dimensions separated with a very small gap. This fact allows the diffusion layers of single microelectrodes to overlap as members of the array. Various basic types of microelectrode arrays with interacting diffusion layers are described and their analytical abilities are accented. Theoretical approaches to diffusion layer overlapping and the consequences of close constitution effects such as collection efficiency and redox cycling are discussed. Examples of basis applications in electroanalytical chemistry such as amperometric detectors in HPLC and substitutional stripping voltammetry are also given.

  5. Clinical prototype of a plastic water-equivalent scintillating fiber dosimeter array for QA applications

    International Nuclear Information System (INIS)

    A clinical prototype of a scintillating fiber dosimeter array for quality assurance applications is presented. The array consists of a linear array of 29 plastic scintillation detectors embedded in a water-equivalent plastic sheet coupled to optical fibers used to guide optical photons to a charge coupled device (CCD) camera. The CCD is packaged in a light-tight, radiation-shielded housing designed for convenient transport. A custom designed connector is used to ensure reproducible mechanical positioning of the optical fibers relative to the CCD. Profile and depth dose characterization measurements are presented and show that the prototype provides excellent dose measurement reproducibility (±0.8%) in-field and good accuracy (±1.6% maximum deviation) relative to the dose measured with an IC10 ionization chamber

  6. Development of Microfabricated Chemical Gas Sensors and Sensor Arrays for Aerospace Applications

    Science.gov (United States)

    Hunter, G. W.; Neudeck, P. G.; Fralick, G.; Thomas, V.; Liu, C. C.; Wu, W. H.; Ward, B.; Makel, D.

    2002-01-01

    Aerospace applications require the development of chemical sensors with capabilities beyond those of commercially available sensors. In particular, factors such as minimal sensor size, weight, and power consumption are particularly important. Development areas which have potential aerospace applications include launch vehicle leak detection, engine health monitoring, fire detection, and environmental monitoring. Sensor development for these applications is based on progress in three types of technology: 1) Micromachining and microfabrication (Microsystem) technology to fabricate miniaturized sensors. 2) The use of nanocrystalline materials to develop sensors with improved stability combined with higher sensitivity. 3) The development of high temperature semiconductors, especially silicon carbide. However, due to issues of selectivity and cross-sensitivity, individual sensors are limited in the amount of information that they can provide in environments that contain multiple chemical species. Thus, sensor arrays are being developed to address detection needs in such multi-species environments. This paper discusses the needs of space applications as well as the point-contact sensor technology and sensor arrays being developed to address these needs. Sensors to measure hydrogen, hydrocarbons, hydrazine, nitrogen oxides (NO,), carbon monoxide, oxygen, and carbon dioxide are being developed as well as arrays for leak, fire, and emissions detection. Demonstrations of the technology will also be discussed. It is concluded that microfabricated sensor technology has significant potential for use in a range of aerospace applications.

  7. Application of unified array calculus to connect 4-D spacetime sensing with string theory and relativity

    Science.gov (United States)

    Rauhala, U. A.

    2013-12-01

    Array algebra of photogrammetry and geodesy unified multi-linear matrix and tensor operators in an expansion of Gaussian adjustment calculus to general matrix inverses and solutions of inverse problems to find all, or some optimal, parametric solutions that satisfy the available observables. By-products in expanding array and tensor calculus to handle redundant observables resulted in general theories of estimation in mathematical statistics and fast transform technology of signal processing. Their applications in gravity modeling and system automation of multi-ray digital image and terrain matching evolved into fast multi-nonlinear differential and integral array calculus. Work since 1980's also uncovered closed-form inverse Taylor and least squares Newton-Raphson-Gauss perturbation solutions of nonlinear systems of equations. Fast nonlinear integral matching of array wavelets enabled an expansion of the bundle adjustment to 4-D stereo imaging and range sensing where real-time stereo sequence and waveform phase matching enabled data-to-info conversion and compression on-board advanced sensors. The resulting unified array calculus of spacetime sensing is applicable in virtually any math and engineering science, including recent work in spacetime physics. The paper focuses on geometric spacetime reconstruction from its image projections inspired by unified relativity and string theories. The collinear imaging equations of active object space shutter of special relativity are expanded to 4-D Lorentz transform. However, regular passive imaging and shutter inside the sensor expands the law of special relativity by a quantum geometric explanation of 4-D photogrammetry. The collinear imaging equations provide common sense explanations to the 10 (and 26) dimensional hyperspace concepts of a purely geometric string theory. The 11-D geometric M-theory is interpreted as a bundle adjustment of spacetime images using 2-D or 5-D membrane observables of image, string and

  8. Microphone array signal processing with application in three-dimensional spatial hearing.

    Science.gov (United States)

    Bai, Mingsian R; Lin, Chenpang

    2005-04-01

    Microphone arrays are known to enhance the directionality and signal-to-noise ratio (SNR) over single-channel sensors. This is considered beneficial in many applications such as video-conferencing systems and hearing aids. However, this advantage comes at the price of the sensation of spatial hearing. The spatial cues due to diffractions of the head and torso are lost if the array is not fitted in the ears. In this paper we present a system that incorporates binaural hearing synthesis into array signal processing, in an attempt to recover the three-dimensional sound image that a human listener would naturally perceive. In the system, the superdirective beamformer is exploited to estimate the direction of arrival (DOA) of the incoming sound. The spatial sound image is restored by steering the beam to the direction found in the DOA session and filtering the array output with the corresponding Head Related Transfer Functions (HRTF). The algorithms have been implemented in real-time fashion using a digital signal processor. Objective and subjective experiments were performed to validate the proposed system. The experimental results showed that the accurate localization of the sound source is achievable using the array system. PMID:15898652

  9. Coassembly of aromatic dipeptides into biomolecular necklaces.

    Science.gov (United States)

    Yuran, Sivan; Razvag, Yair; Reches, Meital

    2012-11-27

    This paper describes the formation of complex peptide-based structures by the coassembly of two simple peptides, the diphenylalanine peptide and its tert-butyl dicarbonate (Boc) protected analogue. Each of these peptides can self-assemble into a distinct architecture: the diphenylalanine peptide into tubular structures and its analogue into spheres. Integrated together, these peptides coassemble into a construction of beaded strings, where spherical assemblies are connected by elongated elements. Electron and scanning force microscopy demonstrated the morphology of these structures, which we termed "biomolecular necklaces". Additional experiments indicated the reversibility of the coassembly process and the stability of the structures. Furthermore, we suggest a possible mechanism of formation for the biomolecular necklaces. Our suggestion is based on the necklace model for polyelectrolyte chains, which proposes that a necklace structure appears as a result of counterion condensation on the backbone of a polyelectrolyte. Overall, the approach of coassembly, demonstrated using aromatic peptides, can be adapted to any peptides and may lead to the development and discovery of new self-assembled architectures formed by peptides and other biomolecules. PMID:23061818

  10. Improvements in continuum modeling for biomolecular systems

    Science.gov (United States)

    Yu, Qiao; Ben-Zhuo, Lu

    2016-01-01

    Modeling of biomolecular systems plays an essential role in understanding biological processes, such as ionic flow across channels, protein modification or interaction, and cell signaling. The continuum model described by the Poisson- Boltzmann (PB)/Poisson-Nernst-Planck (PNP) equations has made great contributions towards simulation of these processes. However, the model has shortcomings in its commonly used form and cannot capture (or cannot accurately capture) some important physical properties of the biological systems. Considerable efforts have been made to improve the continuum model to account for discrete particle interactions and to make progress in numerical methods to provide accurate and efficient simulations. This review will summarize recent main improvements in continuum modeling for biomolecular systems, with focus on the size-modified models, the coupling of the classical density functional theory and the PNP equations, the coupling of polar and nonpolar interactions, and numerical progress. Project supported by the National Natural Science Foundation of China (Grant No. 91230106) and the Chinese Academy of Sciences Program for Cross & Cooperative Team of the Science & Technology Innovation.

  11. Biomolecular detection with a thin membrane transducer.

    Science.gov (United States)

    Cha, Misun; Shin, Jaeha; Kim, June-Hyung; Kim, Ilchaek; Choi, Junbo; Lee, Nahum; Kim, Byung-Gee; Lee, Junghoon

    2008-06-01

    We present a thin membrane transducer (TMT) that can detect nucleic acid based biomolecular reactions including DNA hybridization and protein recognition by aptamers. Specific molecular interactions on an extremely thin and flexible membrane surface cause the deflection of the membrane due to surface stress change which can be measured by a compact capacitive circuit. A gold-coated thin PDMS membrane assembled with metal patterned glass substrate is used to realize the capacitive detection. It is demonstrated that perfect match and mismatch hybridizations can be sharply discriminated with a 16-mer DNA oligonucleotide immobilized on the gold-coated surface. While the mismatched sample caused little capacitance change, the perfectly matched sample caused a well-defined capacitance decrease vs. time due to an upward deformation of the membrane by a compressive surface stress. Additionally, the TMT demonstrated the single nucleotide polymorphism (SNP) capabilities which enabled a detection of mismatching base pairs in the middle of the sequence. It is intriguing that the increase of capacitance, therefore a downward deflection due to tensile stress, was observed with the internal double mismatch hybridization. We further present the detection of thrombin protein through ligand-receptor type recognition with 15-mer thrombin aptamer as a receptor. Key aspects of this detection such as the effect of concentration variation are investigated. This capacitive thin membrane transducer presents a completely new approach for detecting biomolecular reactions with high sensitivity and specificity without molecular labelling and optical measurement. PMID:18497914

  12. Electrochemical sensor for multiplex screening of genetically modified DNA: identification of biotech crops by logic-based biomolecular analysis.

    Science.gov (United States)

    Liao, Wei-Ching; Chuang, Min-Chieh; Ho, Ja-An Annie

    2013-12-15

    Genetically modified (GM) technique, one of the modern biomolecular engineering technologies, has been deemed as profitable strategy to fight against global starvation. Yet rapid and reliable analytical method is deficient to evaluate the quality and potential risk of such resulting GM products. We herein present a biomolecular analytical system constructed with distinct biochemical activities to expedite the computational detection of genetically modified organisms (GMOs). The computational mechanism provides an alternative to the complex procedures commonly involved in the screening of GMOs. Given that the bioanalytical system is capable of processing promoter, coding and species genes, affirmative interpretations succeed to identify specified GM event in terms of both electrochemical and optical fashions. The biomolecular computational assay exhibits detection capability of genetically modified DNA below sub-nanomolar level and is found interference-free by abundant coexistence of non-GM DNA. This bioanalytical system, furthermore, sophisticates in array fashion operating multiplex screening against variable GM events. Such a biomolecular computational assay and biosensor holds great promise for rapid, cost-effective, and high-fidelity screening of GMO.

  13. A Compact Two-Level Sequentially Rotated Circularly Polarized Antenna Array for C-Band Applications

    Directory of Open Access Journals (Sweden)

    Stefano Maddio

    2015-01-01

    Full Text Available A compact circular polarized antenna array with a convenient gain/bandwidth/dimension trade-off is proposed for applications in the C-band. The design is based on the recursive application of the sequential phase architecture, resulting in a 4 × 4 array of closely packed identical antennas. The 16 antenna elements are disc-based patches operating in modal degeneration, tuned to exhibit a broad while imperfect polarization. Exploiting the compact dimension of the patches and a space-filling design for the feeding network, the entire array is designed to minimize the occupied area. A prototype of the proposed array is fabricated with standard photoetching procedure in a single-layer via less printed board of overall area 80 × 80 mm2. Adequate left-hand polarization is observed over a wide bandwidth, demonstrating a convenient trade-off between bandwidth and axial ratio. Satisfying experimental results validate the proposed design, with a peak gain of 12.6 dB at 6.7 GHz maintained within 3 dB for 1 GHz, a very wide 10 dB return loss bandwidth of 3 GHz, and a 4 dB axial ratio bandwidth of 1.82 GHz, meaning 31% of fractional bandwidth.

  14. A NEW FABRICATION PROCESS FOR A FLEXIBLE SKIN WITH TEMPERATURE SENSOR ARRAY AND ITS APPLICATIONS

    Institute of Scientific and Technical Information of China (English)

    LEE Gwo-Bin; HUANG Fu-Chun; Lee Chia-Yen; Mian Jiun-Jih

    2004-01-01

    This paper reports a novel technique for fabrication of a flexible skin with a temperature sensor array (40 × 1 sensors). A simplified MEMS technology using platinum resistors as sensing materials, which are sandwiched between two polyimide layers as flexible substrates is developed. The two polyimide layers are deposited on top of a thin aluminum layer, which serves as a sacrificial layer such that the flexible skin can be released by metal etching and peeled off easily. The flexible skin with a temperature sensor array has a high mechanical flexibility and can be handily attached on a highly curved surface to detect tiny temperature distribution inside a small area. The sensor array shows a linear output and has a sensitivity of 7.SmV/℃ (prior to amplifiers) at a drive current of 1 mA. To demonstrate its applications, two examples have been demonstrated, including measurement of temperature distribution around a micro heater of a micro PCR (polymerase chain reaction) chip for DNA amplification and detection of separation point for flow over a circular cylinder. The development of the flexible skin with a temperature sensor array may be crucial for measuring temperature distribution on any curved surface in the fields of aerodynamics, space exploration, auto making and biomedical applications etc.

  15. DESIGN OF HYBRID COUPLER CONNECTED SQUARE ARRAY PATCH ANTENNA FOR Wi-Fi APPLICATIONS

    Directory of Open Access Journals (Sweden)

    A. Sahaya Anselin Nisha

    2012-01-01

    Full Text Available Microstrip patch antennas being popular because of light weight, low volume, thin profile configuration which can be made conformal. Wireless communication systems applications circular polarization antenna is placing vital role. In this study we introduce a new technique to produce circular polarization. Hybrid coupler is directly connected to microstrip antenna to get circular polarization. Also gain is further increased by introducing antenna array technique. Each square in array having length of 4.6mm patch is having thickness of 0.381mm and the dielectric material used FR4. The designed antenna having high gain of 6.26dB and directivity of 5.11dB at the resonant frequency of 3.7GHz. Simulation results shows that the designed antenna characteristic is suitable for Wi-Fi applications.

  16. High-performance large format impurity band conductor focal plane arrays for astronomy applications

    Science.gov (United States)

    Mills, Robert; Edwards, John; Beuville, Eric; Toth, Andrew; Corrales, Elizabeth; Therrien, Neil; Kissel, Jeff; Finger, Gert

    2010-08-01

    Raytheon Vision Systems (RVS) has developed a family of high performance large format infrared detector arrays whose detectors are most effective for the detection of long and very long wavelength infrared energy. This paper describes the state of the art in mega-pixel Si:As Impurity Band Conduction (IBC) arrays and relevant system applications that offers unique off-the-shelf solutions to the astronomy community. Raytheon's Aquarius-1k, developed in collaboration with ESO, is a 1024 × 1024 pixel high performance array with a 30μm pitch that features high quantum efficiency IBC detectors, low noise, low dark current, and on-chip clocking for ease of operation. This large format array was designed for ground-based astronomy applications but lends itself for space based platforms too. The detector has excellent sensitivity out to 27μm wavelength. The readout circuit has several programmable features such as low gain for a well capacity of 11 × 106e-, high gain for a well capacity of 106e- and a programmable number of outputs (16 or 64). Programmable integration time and integration modes, like snapshot, rolling and non-destructive integrations, allow the Aquarius to be used for a wide variety of applications and performance. A very fast full frame rate of 120Hz is achieved with 64 outputs (32 outputs per side) and a programmable centered windowing will accommodate a wide range of readout rates. The multiplexer and packaging design utilizes two alignment edges on the SCA which can be butted on two sides for expansion to 2k × 1k and wider focal planes. Data is shown on several focal plane arrays to demonstrate that very low noise and high quantum efficiency performance has been achieved. This array leverages over thirty years of experience in both ground and space based astronomy sensor applications. The technology has been successfully demonstrated on programs such as NASA's Spitzer Space Telescope and Japan's Akari Space Telescope, and will be used on the Mid

  17. A 400 KHz line rate 2048 pixel modular SWIR linear array for earth observation applications

    Science.gov (United States)

    Anchlia, Ankur; Vinella, Rosa M.; Wouters, Kristof; Gielen, Daphne; Hooylaerts, Peter; Deroo, Pieter; Ruythooren, Wouter; van der Zanden, Koen; Vermeiren, Jan; Merken, Patrick

    2015-10-01

    In this paper, we report about a family of linear imaging FPAs sensitive in the [0.9 - 1.7um] band, developed for high speed applications such as LIDAR, wavelength references and OCT analyzers and also for earth observation applications. Fast linear FPAs can also be used in a wide variety of terrestrial applications, including high speed sorting, electro- and photo-luminesce and medical applications. The arrays are based on a modular ROIC design concept: modules of 512 pixels are stitched during fabrication to achieve 512, 1024 and 2048 pixel arrays. In principle, this concept can be extended to any multiple of 512 pixels, the limiting factor being the pixel yield of long InGaAs arrays and the CTE differences in the hybrid setup. Each 512-pixel module has its own on-chip digital sequencer, analog readout chain and 4 output buffers. This modular concept enables a long-linear array to run at a high line rate of 400 KHz irrespective of the array length, which limits the line rate in a traditional linear array. The pixel has a pitch of 12.5um. The detector frontend is based on CTIA (Capacitor Trans-impedance Amplifier), having 5 selectable integration capacitors giving full well from 62x103e- (gain0) to 40x106e- (gain4). An auto-zero circuit limits the detector bias non-uniformity to 5-10mV across broad intensity levels, limiting the input referred dark signal noise to 20e-rms for Tint=3ms at room temperature. An on-chip CDS that follows the CTIA facilitates removal of Reset/KTC noise, CTIA offsets and most of the 1/f noise. The measured noise of the ROIC is 35e-rms in gain0. At a master clock rate of 60MHz and a minimum integration time of 1.4us, the FPAs reach the highest line rate of 400 KHz.

  18. High-performance SPAD array detectors for parallel photon timing applications

    Science.gov (United States)

    Rech, I.; Cuccato, A.; Antonioli, S.; Cammi, C.; Gulinatti, A.; Ghioni, M.

    2012-02-01

    Over the past few years there has been a growing interest in monolithic arrays of single photon avalanche diodes (SPAD) for spatially resolved detection of faint ultrafast optical signals. SPADs implemented in planar technologies offer the typical advantages of microelectronic devices (small size, ruggedness, low voltage, low power, etc.). Furthermore, they have inherently higher photon detection efficiency than PMTs and are able to provide, beside sensitivities down to single-photons, very high acquisition speeds. In order to make SPAD array more and more competitive in time-resolved application it is necessary to face problems like electrical crosstalk between adjacent pixel, moreover all the singlephoton timing electronics with picosecond resolution has to be developed. In this paper we present a new instrument suitable for single-photon imaging applications and made up of 32 timeresolved parallel channels. The 32x1 pixel array that includes SPAD detectors represents the system core, and an embedded data elaboration unit performs on-board data processing for single-photon counting applications. Photontiming information is exported through a custom parallel cable that can be connected to an external multichannel TCSPC system.

  19. Biomolecular Structure Determination with Divide and Concur

    Science.gov (United States)

    Kallus, Yoav; Elser, Veit

    2009-03-01

    Divide and concur (D-C) is a general computational approach, designed for the solution of highly frustrated problems. Recently applied to the problems of disk packing, the kissing number problem, and 3-SAT, it was competitive or outperformed special-purpose methods.ootnotetextS. Gravel and V. Elser, Phys. Rev. E 78, 036706 (2008) We present a method for applying the D-C framework to the problem of biomolecular structure determination. From a list of geometric constraints on groups of atoms in the molecule, we construct a deterministic iterative map that efficiently searches for structures simultaneously satisfying all constraints. As our method eschews an energy function and its minimization to focus on geometric constraints, it can very naturally integrate with the geometric constraints due to chemistry and physics, experimental constraints due to NMR data or many other experimental or biological hints. We present some results of our method.

  20. Biomolecular Markers in Cancer of the Tongue

    Directory of Open Access Journals (Sweden)

    Daris Ferrari

    2009-01-01

    Full Text Available The incidence of tongue cancer is increasing worldwide, and its aggressiveness remains high regardless of treatment. Genetic changes and the expression of abnormal proteins have been frequently reported in the case of head and neck cancers, but the little information that has been published concerning tongue tumours is often contradictory. This review will concentrate on the immunohistochemical expression of biomolecular markers and their relationships with clinical behaviour and prognosis. Most of these proteins are associated with nodal stage, tumour progression and metastases, but there is still controversy concerning their impact on disease-free and overall survival, and treatment response. More extensive clinical studies are needed to identify the patterns of molecular alterations and the most reliable predictors in order to develop tailored anti-tumour strategies based on the targeting of hypoxia markers, vascular and lymphangiogenic factors, epidermal growth factor receptors, intracytoplasmatic signalling and apoptosis.

  1. Nonequilibrium phase transitions in biomolecular signal transduction

    Science.gov (United States)

    Smith, Eric; Krishnamurthy, Supriya; Fontana, Walter; Krakauer, David

    2011-11-01

    We study a mechanism for reliable switching in biomolecular signal-transduction cascades. Steady bistable states are created by system-size cooperative effects in populations of proteins, in spite of the fact that the phosphorylation-state transitions of any molecule, by means of which the switch is implemented, are highly stochastic. The emergence of switching is a nonequilibrium phase transition in an energetically driven, dissipative system described by a master equation. We use operator and functional integral methods from reaction-diffusion theory to solve for the phase structure, noise spectrum, and escape trajectories and first-passage times of a class of minimal models of switches, showing how all critical properties for switch behavior can be computed within a unified framework.

  2. Low cost, high concentration ratio solar cell array for space applications

    Science.gov (United States)

    Patterson, R. E.; Rauschenbach, H. S.; Cannady, M. D.; Whang, U. S.; Crabtree, W. L.

    1981-01-01

    A miniaturized Cassegrainian-type concentrator solar array concept for space applications is described. In-orbit cell operating temperatures near 80 C are achieved with purely passive cell cooling and a net concentration ratio of 100. A multiplicity of miniaturized, rigid solar cell concentrator subassemblies are electrically interconnected in conventional fashion and mounted into rigid frames to form concentrator solar panel assemblies approximately 14-mm thick. A plurality of such interconnected panels forms a stowable and deployable solar cell blanket. It is projected that for 20% efficient silicon cells an array of 500 kW beginning-of-life output capability, including orbiter cradle structures, can be transported by a single shuttle orbiter flight into low earth orbit. In-orbit array specific performance is calculated to be approximately 100 W/sq m and 20 W/kg, including all stowage, deployment and array figure control equipment designed for a 30-year orbital life. Higher efficiency gallium arsenide and multiple band gap solar cells will improve these performance factors correspondingly.

  3. Pointing-Vector and Velocity Based Frequency Predicts for Deep-Space Uplink Array Applications

    Science.gov (United States)

    Tsao, P.; Vilnrotter, Victor A.; Jamnejad, V.

    2008-01-01

    Uplink array technology is currently being developed for NASA's Deep Space Network (DSN) to provide greater range and data throughput for future NASA missions, including manned missions to Mars and exploratory missions to the outer planets, the Kuiper belt, and beyond. Here we describe a novel technique for generating the frequency predicts that are used to compensate for relative Doppler, derived from interpolated earth position and spacecraft ephemerides. The method described here guarantees velocity and range estimates that are consistent with each other, hence one can always be recovered from the other. Experimental results have recently proven that these frequency predicts are accurate enough to maintain the phase of a three element array at the EPOXI spacecraft for three hours. Previous methods derive frequency predicts directly from interpolated relative velocities. However, these velocities were found to be inconsistent with the corresponding spacecraft range, meaning that range could not always be recovered accurately from the velocity predicts, and vice versa. Nevertheless, velocity-based predicts are also capable of maintaining uplink array phase calibration for extended periods, as demonstrated with the EPOXI spacecraft, however with these predicts important range and phase information may be lost. A comparison of the steering-vector method with velocity-based techniques for generating precise frequency predicts specifically for uplink array applications is provided in the following sections.

  4. Simulation and Application of Dynamic Inspection Modes Using Ultrasonic Phased Arrays

    Science.gov (United States)

    Mahaut, Steve; Chatillon, Sylvain; Raillon-Picot, Raphaële; Calmon, Pierre

    2004-02-01

    NDT techniques using phased arrays are more and more applied in different industrial contexts. Their main advantage is the adaptability to the testing configuration : ability to steer and to focus the beam inside the inspected component taking account the geometry and the constitutive materials, high acquisition rates without raster scanning pattern of the probe using electronic commutation, sectorial scanning inspection to fully insonify the specimen, etc. Optimal use of phased arrays requires simulation tools accounting for the actual testing configuration. For several years, such tools have been developed at the French Atomic Energy Commission. Delay laws, beam forming and echo formation (interaction of the beam with defects or specimen boundaries) models are used to design the arrays, to conceive and to evaluate the performances of methods in realistic and complex configurations. Recently, works have been made to extend the simulation skills to advanced inspection modes : electronic commutation with separate Transmission/Reception patterns, non-symmetric Transmit/Receive delay laws, sectorial scanning inspections. This paper presents some examples of simulation and application of such inspections carried out over complex specimen. These examples demonstrate the interest for simulation tools in terms of prediction, optimization and interpretation of phased arrays techniques.

  5. Monolithic arrays of silicon drift detectors for medical imaging applications and related CMOS readout electronics

    Energy Technology Data Exchange (ETDEWEB)

    Fiorini, C. [Politecnico di Milano, Dipartimento di Elettronica e Informazione, Milan (Italy) and INFN, Sezione di Milano, Milan (Italy)]. E-mail: carlo.fiorini@polimi.it; Longoni, A. [Politecnico di Milano, Dipartimento di Elettronica e Informazione, Milan (Italy); INFN, Sezione di Milano, Milan (Italy); Porro, M. [Politecnico di Milano, Dipartimento di Ingegneria Nucleare, Milan (Italy); INFN, Sezione di Milano, Milan (Italy); Perotti, F. [Istituto di Astrofisica Spaziale e Fisica Cosmica - INAF, Milan (Italy); Lechner, P. [PNSensors, Munich (Germany); Strueder, L. [MPI fuer Extraterrestrische Physik Halbleiterlabor, Munich (Germany)

    2006-05-01

    Monolithic arrays of Silicon Drift Detectors (SDDs) have been recently proposed to be used with scintillators for high-position-resolution {gamma}-ray imaging applications. Thanks to the low electronics noise due to the small value of the output capacitance, the SDD offers better performances with respect to conventional photodiodes of the same geometry. We show the results achieved with a small monolithic array of SDDs, each one with a front-end JFET integrated at its center, used as photodetector in a first prototype of Anger Camera. An intrinsic resolution better than 200 {mu}m has been achieved with this prototype. Moreover, we describe a new monolithic array of SDDs composed of 77 single hexagonal units, each one with an active area of 8.7 mm{sup 2}, for a total active area of the device of 6.7 cm{sup 2}. Finally, the basic principles and the first results of the CMOS readout chip specifically designed for the readout of the signals from SDDs arrays are presented.

  6. Monolithic arrays of silicon drift detectors for medical imaging applications and related CMOS readout electronics

    International Nuclear Information System (INIS)

    Monolithic arrays of Silicon Drift Detectors (SDDs) have been recently proposed to be used with scintillators for high-position-resolution γ-ray imaging applications. Thanks to the low electronics noise due to the small value of the output capacitance, the SDD offers better performances with respect to conventional photodiodes of the same geometry. We show the results achieved with a small monolithic array of SDDs, each one with a front-end JFET integrated at its center, used as photodetector in a first prototype of Anger Camera. An intrinsic resolution better than 200 μm has been achieved with this prototype. Moreover, we describe a new monolithic array of SDDs composed of 77 single hexagonal units, each one with an active area of 8.7 mm2, for a total active area of the device of 6.7 cm2. Finally, the basic principles and the first results of the CMOS readout chip specifically designed for the readout of the signals from SDDs arrays are presented

  7. System-Level Integrated Circuit (SLIC) Technology Development for Phased Array Antenna Applications

    Science.gov (United States)

    Windyka, John A.; Zablocki, Ed G.

    1997-01-01

    This report documents the efforts and progress in developing a 'system-level' integrated circuit, or SLIC, for application in advanced phased array antenna systems. The SLIC combines radio-frequency (RF) microelectronics, digital and analog support circuitry, and photonic interfaces into a single micro-hybrid assembly. Together, these technologies provide not only the amplitude and phase control necessary for electronic beam steering in the phased array, but also add thermally-compensated automatic gain control, health and status feedback, bias regulation, and reduced interconnect complexity. All circuitry is integrated into a compact, multilayer structure configured for use as a two-by-four element phased array module, operating at 20 Gigahertz, using a Microwave High-Density Interconnect (MHDI) process. The resultant hardware is constructed without conventional wirebonds, maintains tight inter-element spacing, and leads toward low-cost mass production. The measured performances and development issues associated with both the two-by-four element module and the constituent elements are presented. Additionally, a section of the report describes alternative architectures and applications supported by the SLIC electronics. Test results show excellent yield and performance of RF circuitry and full automatic gain control for multiple, independent channels. Digital control function, while suffering from lower manufacturing yield, also proved successful.

  8. Application of Field Programmable Gate Arrays in Instrumentation and Control Systems of Nuclear Power Plants

    International Nuclear Information System (INIS)

    Field programmable gate arrays (FPGAs) are gaining increased attention worldwide for application in nuclear power plant (NPP) instrumentation and control (I&C) systems, particularly for safety and safety related applications, but also for non-safety ones. NPP operators and equipment suppliers see potential advantages of FPGA based digital I&C systems as compared to microprocessor based applications. This is because FPGA based systems can be made simpler, more testable and less reliant on complex software (e.g. operating systems), and are easier to qualify for safety and safety related applications. This publication results from IAEA consultancy meetings covering the various aspects, including design, qualification, implementation, licensing, and operation, of FPGA based I&C systems in NPPs

  9. Mechanical design of a low concentration ratio solar array for a space station application

    Science.gov (United States)

    Biss, M. S.; Hsu, L.

    1983-01-01

    This paper describes a preliminary study and conceptual design of a low concentration ratio solar array for a space station application with approximately a 100 kW power requirement. The baseline design calls for a multiple series of inverted, truncated, pyramidal optical elements with a geometric concentration ratio (GCR) of 6. It also calls for low life cycle cost, simple on-orbit maintainability, 1984 technology readiness date, and gallium arsenide (GaAs) of silicon (Si) solar cell interchangeability. Due to the large area needed to produce the amount of power required for the baseline space station, a symmetrical wing design, making maximum use of the commonality of parts approach, was taken. This paper will describe the mechanical and structural design of a mass-producible solar array that is very easy to tailor to the needs of the individual user requirement.

  10. Recent applications of phased array inspection for turbine components and welded structures

    International Nuclear Information System (INIS)

    The paper presents recent development and field applications of phased array technology for the following turbine components [low-pressure rotors]: ABB - GEC ALSTOM: rotor steeple, welded rotor, blade roots of 900 MW and 160 MW turbines; Siemens - Parson: rotor steeple, blade roots, disk bore, anti-rotating hole, for 580 MW turbines (nuclear and thermal design); GE : rotor disk rim attachment of 850 MW turbine and Westinghouse: blade roots of 1,250 MW turbine. Capability demonstration on EDM notches, service-induced cracks and 'crack-like' 3-D EDM notches for different items is also discussed. The lab results contributed to a reliable detection and sizing capability for in-situ inspection. Practical aspects of field inspection are illustrated and commented. The paper also presents some examples of weld inspection of SG manway welds, as an extension of phased array technology in weld inspection domain. (author)

  11. Application-specific coarse-grained reconfigurable array: architecture and design methodology

    Science.gov (United States)

    Zhou, Li; Liu, Dongpei; Zhang, Jianfeng; Liu, Hengzhu

    2015-06-01

    Coarse-grained reconfigurable arrays (CGRAs) have shown potential for application in embedded systems in recent years. Numerous reconfigurable processing elements (PEs) in CGRAs provide flexibility while maintaining high performance by exploring different levels of parallelism. However, a difference remains between the CGRA and the application-specific integrated circuit (ASIC). Some application domains, such as software-defined radios (SDRs), require flexibility with performance demand increases. More effective CGRA architectures are expected to be developed. Customisation of a CGRA according to its application can improve performance and efficiency. This study proposes an application-specific CGRA architecture template composed of generic PEs (GPEs) and special PEs (SPEs). The hardware of the SPE can be customised to accelerate specific computational patterns. An automatic design methodology that includes pattern identification and application-specific function unit generation is also presented. A mapping algorithm based on ant colony optimisation is provided. Experimental results on the SDR target domain show that compared with other ordinary and application-specific reconfigurable architectures, the CGRA generated by the proposed method performs more efficiently for given applications.

  12. Bio-Inspired Pressure Sensitive Foam Arrays for use in Hydrodynamic Sensing Applications

    Science.gov (United States)

    Dusek, Jeff; Triantafyllou, Michael; Lang, Jeffrey

    2015-11-01

    Shallow, turbid, and highly dynamic coastal waters provide a challenging environment for safe and reliable operation of marine vehicles faced with a distinct environmentally driven perceptual deficit. In nature, fish have solved this perplexing sensory problem and exhibit an intimate knowledge of the near-body flow field. This enhanced perception is mediated by the ability to discern and interpret hydrodynamic flow structures through the velocity and pressure sensing capabilities of the fish's lateral line. Taking cues from biological sensory principles, highly conformal pressure sensor arrays have been developed utilizing a novel piezoresistive carbon black-PDMS foam active material. By leveraging the low Young's modulus and watertight structure of closed-cell PDMS (silicone) foam, the sensor arrays are well suited for hydrodynamic sensing applications and prolonged exposure to fluid environments. Prototype arrays were characterized experimentally using hydrodynamic stimuli inspired by biological flows, and were found to exhibit a high degree of sensitivity while improving on the flexibility, robustness, and cost of existing pressure sensors.

  13. A 28 GHz FR-4 Compatible Phased Array Antenna for 5G Mobile Phone Applications

    DEFF Research Database (Denmark)

    Ojaroudiparchin, Naser; Shen, Ming; Pedersen, Gert F.

    2015-01-01

    The design of a 28 GHz phased array antenna for future fifth generation (5G) mobile-phone applications has been presented in this paper. The proposed antenna can be implemented using low cost FR-4 substrates, while maintaining good performance in terms of gain and efficiency. This is achieved by ...... the gains are higher than 13 dB. In addition, the simulated and measured results show that the antenna has the S11 response less than -10 dB in the frequency range of 27 to 29 GHz....

  14. Standing-wave excited soft x-ray photoemission microscopy: application to Co microdot magnetic arrays

    Energy Technology Data Exchange (ETDEWEB)

    Gray, Alexander; Kronast, Florian; Papp, Christian; Yang, See-Hun; Cramm, Stefan; Krug, Ingo P.; Salmassi, Farhad; Gullikson, Eric M.; Hilken, Dawn L.; Anderson, Erik H.; Fischer, Peter; Durr, Hermann A.; Schneider, Claus M.; Fadley, Charles S.

    2010-10-29

    We demonstrate the addition of depth resolution to the usual two-dimensional images in photoelectron emission microscopy (PEEM), with application to a square array of circular magnetic Co microdots. The method is based on excitation with soft x-ray standing-waves generated by Bragg reflection from a multilayer mirror substrate. Standing wave is moved vertically through sample simply by varying the photon energy around the Bragg condition. Depth-resolved PEEM images were obtained for all of the observed elements. Photoemission intensities as functions of photon energy were compared to x-ray optical calculations in order to quantitatively derive the depth-resolved film structure of the sample.

  15. A multiscale modeling approach for biomolecular systems

    Energy Technology Data Exchange (ETDEWEB)

    Bowling, Alan, E-mail: bowling@uta.edu; Haghshenas-Jaryani, Mahdi, E-mail: mahdi.haghshenasjaryani@mavs.uta.edu [The University of Texas at Arlington, Department of Mechanical and Aerospace Engineering (United States)

    2015-04-15

    This paper presents a new multiscale molecular dynamic model for investigating the effects of external interactions, such as contact and impact, during stepping and docking of motor proteins and other biomolecular systems. The model retains the mass properties ensuring that the result satisfies Newton’s second law. This idea is presented using a simple particle model to facilitate discussion of the rigid body model; however, the particle model does provide insights into particle dynamics at the nanoscale. The resulting three-dimensional model predicts a significant decrease in the effect of the random forces associated with Brownian motion. This conclusion runs contrary to the widely accepted notion that the motor protein’s movements are primarily the result of thermal effects. This work focuses on the mechanical aspects of protein locomotion; the effect ATP hydrolysis is estimated as internal forces acting on the mechanical model. In addition, the proposed model can be numerically integrated in a reasonable amount of time. Herein, the differences between the motion predicted by the old and new modeling approaches are compared using a simplified model of myosin V.

  16. SU-E-T-343: Valencia Applicator Commissioning Using a Micro-Chamber Array

    Energy Technology Data Exchange (ETDEWEB)

    Carmona-Meseguer, V; Palomo-Llinares, R; Candela-Juan, C; Gimeno-Olmos, J; Lliso-Valverde, F [Hospital La Fe, Valencia (Spain); Garcia-Martinez, T [Hospital de La Ribera, Alzira, Valencia (Spain); Richart-Sancho, J [Clinica Benidorm, Benidorm, Alicante (Spain); Granero, D [ERESA-Hospital General Universitario, Mislata, Valencia (Spain); Ballester, F [University of Valencia, Burjassot, Valencia (Spain); Perez-Calatayud, J [Hospital La Fe, Valencia (Spain); Clinica Benidorm, Benidorm, Alicante (Spain)

    2014-06-01

    Purpose: In the commissioning and QA of surface isotope-based applicators, source-indexer distance (SID) has a great influence in the flatness, symmetry and output. To these purposes, methods described in the literature are the use of a special insert at the entrance of dwell chamber or radiochromic films. Here we present the experience with a micro-chamber array to perform the commissioning and QA of Valencia applicators. Methods: Valencia applicators have been used, the classic and the new extra-shielded version. A micro-chamber array has been employed, 1000 SRS (PTW), with 977 liquid filled, 2.3×2.3×0.5 mm{sup 3} sized ion chambers covering 11×11 cm{sup 2}, which spacing is 2.5 mm in the central 5.5×5.5 cm{sup 2}, dedicated mainly in principle, in conjunction with Octavius 4D (PTW), to IMRT, VMAT, SBRT verifications. Verisoft software that allows for 3D and planar analysis has been used to evaluate the results. Applicators were located on the surface of the array. To verify the SID, measurements corresponding to the reference value, SID ± 1 mm and SID ± 2 mm were acquired (integration time was fixed in order to discard the influence of the source entrance/exit). Once SID was determined, standard protocol treatments corresponding to 3 Gy and 7 Gy were acquired in order to establish typical patient dose distribution. Results: The method is fast and sensitive. The SID obtained was 1321 mm which is the nominal value included in the applicator manual. For example at 1319 mm an asymmetry of ±8% with respect to the central value was measured, along with a central deviation of −4% referred to 1321 mm. Conclusion: A practical method for the commissioning and QA of Valencia applicators has been described. It has been shown that it is an efficient and accurate tool for these purposes as well as for the verification of the absolute output constancy.

  17. The fidelity of dynamic signaling by noisy biomolecular networks.

    Directory of Open Access Journals (Sweden)

    Clive G Bowsher

    Full Text Available Cells live in changing, dynamic environments. To understand cellular decision-making, we must therefore understand how fluctuating inputs are processed by noisy biomolecular networks. Here we present a general methodology for analyzing the fidelity with which different statistics of a fluctuating input are represented, or encoded, in the output of a signaling system over time. We identify two orthogonal sources of error that corrupt perfect representation of the signal: dynamical error, which occurs when the network responds on average to other features of the input trajectory as well as to the signal of interest, and mechanistic error, which occurs because biochemical reactions comprising the signaling mechanism are stochastic. Trade-offs between these two errors can determine the system's fidelity. By developing mathematical approaches to derive dynamics conditional on input trajectories we can show, for example, that increased biochemical noise (mechanistic error can improve fidelity and that both negative and positive feedback degrade fidelity, for standard models of genetic autoregulation. For a group of cells, the fidelity of the collective output exceeds that of an individual cell and negative feedback then typically becomes beneficial. We can also predict the dynamic signal for which a given system has highest fidelity and, conversely, how to modify the network design to maximize fidelity for a given dynamic signal. Our approach is general, has applications to both systems and synthetic biology, and will help underpin studies of cellular behavior in natural, dynamic environments.

  18. Metal-modified and vertically aligned carbon nanotube sensors array for landfill gas monitoring applications

    Energy Technology Data Exchange (ETDEWEB)

    Penza, M; Rossi, R; Alvisi, M [ENEA, Department of Physical Technologies and New Materials, PO Box 51 Br-4, I-72100 Brindisi (Italy); Serra, E, E-mail: michele.penza@enea.it [ENEA, Department of Physical Technologies and New Materials, Via Anguillarese 301, I-00060 Rome (Italy)

    2010-03-12

    -modified CNT-chemoresistor array demonstrates high sensitivity by providing minimal sub-ppm level detection, e.g., download up to 100 ppb NO{sub 2}, at the sensor temperature of 150 deg. C. The gas sensitivity of the CNT sensor array depends on operating temperature, showing a lower optimal temperature of maximum sensitivity for the metal-decorated CNT sensors compared to unmodified CNT sensors. Results indicate that the recovery mechanisms in the CNT chemiresistors can be altered by a rapid heating pulse from room temperature to about 110 deg. C. A comparison of the NO{sub 2} gas sensitivity for the chemiresistors based on disorderly networked CNTs and vertically aligned CNTs is also reported. Cross-sensitivity towards relative humidity of the CNT sensors array is investigated. Finally, the sensing properties of the metal-decorated and vertically aligned CNT sensor arrays are promising to monitor gas events in the LFG for practical applications with low power consumption and moderate sensor temperature.

  19. A Reconfigurable Systolic Array Architecture for Multicarrier Wireless and Multirate Applications

    Directory of Open Access Journals (Sweden)

    H. Ho

    2009-01-01

    Full Text Available A reconfigurable systolic array (RSA architecture that supports the realization of DSP functions for multicarrier wireless and multirate applications is presented. The RSA consists of coarse-grained processing elements that can be configured as complex DSP functions that are the basic building blocks of Polyphase-FIR filters, phase shifters, DFTs, and Polyphase-DFT circuits. The homogeneous characteristic of the RSA architecture, where each reconfigurable processing element (PE cell is connected to its nearest neighbors via configurable switch (SW elements, enables array expansion for parallel processing and facilitates time sharing computation of high-throughput data by individual PEs. For DFT circuit configurations, an algorithmic optimization technique has been employed to reduce the overall number of vector-matrix products to be mapped on the RSA. The hardware complexity and throughput of the RSA-based DFT structures have been evaluated and compared against several conventional modular FFT realizations. Designs and circuit implementations of the PE cell and several RSAs configured as DFT and Polyphase filter circuits are also presented. The RSA architecture offers significant flexibility and computational capacity for applications that require real time reconfiguration and high-density computing.

  20. Generation of a genomic tiling array of the human Major Histocompatibility Complex (MHC and its application for DNA methylation analysis

    Directory of Open Access Journals (Sweden)

    Ottaviani Diego

    2008-05-01

    Full Text Available Abstract Background The major histocompatibility complex (MHC is essential for human immunity and is highly associated with common diseases, including cancer. While the genetics of the MHC has been studied intensively for many decades, very little is known about the epigenetics of this most polymorphic and disease-associated region of the genome. Methods To facilitate comprehensive epigenetic analyses of this region, we have generated a genomic tiling array of 2 Kb resolution covering the entire 4 Mb MHC region. The array has been designed to be compatible with chromatin immunoprecipitation (ChIP, methylated DNA immunoprecipitation (MeDIP, array comparative genomic hybridization (aCGH and expression profiling, including of non-coding RNAs. The array comprises 7832 features, consisting of two replicates of both forward and reverse strands of MHC amplicons and appropriate controls. Results Using MeDIP, we demonstrate the application of the MHC array for DNA methylation profiling and the identification of tissue-specific differentially methylated regions (tDMRs. Based on the analysis of two tissues and two cell types, we identified 90 tDMRs within the MHC and describe their characterisation. Conclusion A tiling array covering the MHC region was developed and validated. Its successful application for DNA methylation profiling indicates that this array represents a useful tool for molecular analyses of the MHC in the context of medical genomics.

  1. Natural Migration of Scattered Surface Waves from Correlated Ambient Noise: Applications on Long Beach Array and US-Array

    Science.gov (United States)

    AlTheyab, A.; Workman, E. J.; Lin, F. C.; Schuster, G. T.

    2014-12-01

    Correlation of ambient seismic noise gives traces that are an approximation to the time-derivative of the Green's function between two recording stations. These empirical Greens functions often contain the incident surface-waves and backscattered waves, which can be migrated to image near-surface discontinuities and scatterers. Traditional migration approaches require an approximation of the near-surface velocity field and proper modeling of elastic waves to estimate the Green's functions from the source and receiver positions to every image-point. With dense passive seismic array acquisition and ambient noise cross-correlations, each station can be considered as both a virtual source and a receiver and near-surface scatterers can be imaged across the array using only the empirical Green's functions. This new imaging approach is referred to as natural migration because the Green's functions needed for migration are naturally estimated from the crosscorrelograms of recorded traces. The advantages of natural migration are that it does not require estimation of the near-surface velocity or modeling of elastic waves. In addition, natural migration simultaneously images both low- and higher-order scattering and mode converted waves. The disadvantage is that the image resolution is dependent on the distribution of seismic receivers. To validate this concept, natural migration is applied to crosscorrelograms of passive data recorded by the Long Beach array and the USArray. The resulting migration images highlight known discontinuities from tomography and correlate to prominent geological boundaries at two very different scales: (1) tectonic scale such as the edge of the Atlantic Plain Province in southeastern US and (2) regional scale structure in Long Beach, California. The migration images can be used along with tomography methods to improve structure sharpness in a model construction.

  2. The detection of specific biomolecular interactions with micro-Hall magnetic sensors

    Science.gov (United States)

    Manandhar, Pradeep; Chen, Kan-Sheng; Aledealat, Khaled; Mihajlović, Goran; Yun, C. Steven; Field, Mark; Sullivan, Gerard J.; Strouse, Geoffrey F.; Bryant Chase, P.; von Molnár, Stephan; Xiong, Peng

    2009-09-01

    The detection of reagent-free specific biomolecular interactions through sensing of nanoscopic magnetic labels provides one of the most promising routes to biosensing with solid-state devices. In particular, Hall sensors based on semiconductor heterostructures have shown exceptional magnetic moment sensitivity over a large dynamic field range suitable for magnetic biosensing using superparamagnetic labels. Here we demonstrate the capability of such micro-Hall sensors to detect specific molecular binding using biotin-streptavidin as a model system. We apply dip-pen nanolithography to selectively biotinylate the active areas of InAs micro-Hall devices with nanoscale precision. Specific binding of complementarily functionalized streptavidin-coated superparamagnetic beads to the Hall crosses occurs via molecular recognition, and magnetic detection of the assembled beads is achieved at room temperature using phase sensitive micro-Hall magnetometry. The experiment constitutes the first unambiguous demonstration of magnetic detection of specific biomolecular interactions with semiconductor micro-Hall sensors, and the selective molecular functionalization and resulting localized bead assembly demonstrate the possibility of multiplexed sensing of multiple target molecules using a single device with an array of micro-Hall sensors.

  3. Biomolecular Modification of Inorganic Crystal Growth

    Energy Technology Data Exchange (ETDEWEB)

    De Yoreo, J J

    2007-04-27

    The fascinating shapes and hierarchical designs of biomineralized structures are an inspiration to materials scientists because of the potential they suggest for biomolecular control over materials synthesis. Conversely, the failure to prevent or limit tissue mineralization in the vascular, skeletal, and urinary systems is a common source of disease. Understanding the mechanisms by which organisms direct or limit crystallization has long been a central challenge to the biomineralization community. One prevailing view is that mineral-associated macromolecules are responsible for either inhibiting crystallization or initiating and stabilizing non-equilibrium crystal polymorphs and morphologies through interactions between anionic moieties and cations in solution or at mineralizing surfaces. In particular, biomolecules that present carboxyl groups to the growing crystal have been implicated as primary modulators of growth. Here we review the results from a combination of in situ atomic force microscopy (AFM) and molecular modeling (MM) studies to investigate the effect of specific interactions between carboxylate-rich biomolecules and atomic steps on crystal surfaces during the growth of carbonates, oxalates and phosphates of calcium. Specifically, we how the growth kinetics and morphology depend on the concentration of additives that include citrate, simple amino acids, synthetic Asp-rich polypeptides, and naturally occurring Asp-rich proteins found in both functional and pathological mineral tissues. The results reveal a consistent picture of shape modification in which stereochemical matching of modifiers to specific atomic steps drives shape modification. Inhibition and other changes in growth kinetics are shown to be due to a range of mechanisms that depend on chemistry and molecular size. Some effects are well described by classic crystal growth theories, but others, such as step acceleration due to peptide charge and hydrophylicity, were previously unrealized

  4. LDRD final report on Bloch Oscillations in two-dimensional nanostructure arrays for high frequency applications.

    Energy Technology Data Exchange (ETDEWEB)

    Lyo, Sungkwun Kenneth; Pan, Wei; Reno, John Louis; Wendt, Joel Robert; Barton, Daniel Lee

    2008-09-01

    We have investigated the physics of Bloch oscillations (BO) of electrons, engineered in high mobility quantum wells patterned into lateral periodic arrays of nanostructures, i.e. two-dimensional (2D) quantum dot superlattices (QDSLs). A BO occurs when an electron moves out of the Brillouin zone (BZ) in response to a DC electric field, passing back into the BZ on the opposite side. This results in quantum oscillations of the electron--i.e., a high frequency AC current in response to a DC voltage. Thus, engineering a BO will yield continuously electrically tunable high-frequency sources (and detectors) for sensor applications, and be a physics tour-de-force. More than a decade ago, Bloch oscillation (BO) was observed in a quantum well superlattice (QWSL) in short-pulse optical experiments. However, its potential as electrically biased high frequency source and detector so far has not been realized. This is partially due to fast damping of BO in QWSLs. In this project, we have investigated the possibility of improving the stability of BO by fabricating lateral superlattices of periodic coupled nanostructures, such as metal grid, quantum (anti)dots arrays, in high quality GaAs/Al{sub x}Ga{sub 1-x}As heterostructures. In these nanostructures, the lateral quantum confinement has been shown theoretically to suppress the optical-phonon scattering, believed to be the main mechanism for fast damping of BO in QWSLs. Over the last three years, we have made great progress toward demonstrating Bloch oscillations in QDSLs. In the first two years of this project, we studied the negative differential conductance and the Bloch radiation induced edge-magnetoplasmon resonance. Recently, in collaboration with Prof. Kono's group at Rice University, we investigated the time-domain THz magneto-spectroscopy measurements in QDSLs and two-dimensional electron systems. A surprising DC electrical field induced THz phase flip was observed. More measurements are planned to investigate this

  5. Low-cost silver capped polystyrene nanotube arrays as super-hydrophobic substrates for SERS applications

    International Nuclear Information System (INIS)

    In this paper, we describe the fabrication, simulation and characterization of dense arrays of freestanding silver capped polystyrene nanotubes, and demonstrate their suitability for surface enhanced Raman scattering (SERS) applications. Substrates are fabricated in a rapid, low-cost and scalable way by melt wetting of polystyrene (PS) in an anodized alumina (AAO) template, followed by silver evaporation. Scanning electron microscopy reveals that substrates are composed of a dense array of freestanding polystyrene nanotubes topped by silver nanocaps. SERS characterization of the substrates, employing a monolayer of 4-aminothiophenol (4-ABT) as a model molecule, exhibits an enhancement factor of ∼1.6 × 106, in agreement with 3D finite difference time domain simulations. Contact angle measurements of the substrates revealed super-hydrophobic properties, allowing pre-concentration of target analyte into a small volume. These super-hydrophobic properties of the samples are taken advantage of for sensitive detection of the organic pollutant crystal violet, with detection down to ∼400 ppt in a 2 μl aliquot demonstrated. (paper)

  6. Patterning of visible/infrared dual-band microstrip filter arrays for multispectral imaging application

    International Nuclear Information System (INIS)

    Visible/infrared dual-band microstrip filter arrays have been developed to be integrated with 512 × 512 PtSi CCD imaging sensor chips for multispectral imaging when it operates in the front-illumination mode. A high visible transmittance and high infrared reflectance ZAO (ZnO:Al) based coating for visible passband and an interference absorbing filter film for a mid-infrared passband have been designed and deposited on sapphire substrates. An effective double-layer lift-off technique that is compatible with high temperature deposition has been developed to create thick microstrip infrared film. The infrared passband film using germanium and yttrium fluoride as high and low refractive indices materials have been deposited by ion-beam-assisted electron beam evaporation. Tested optical performance results reveal that the visible and near-infrared transmittance of the infrared passband film is very low, which makes it ideal for mid-infrared imaging. Environmental durability testing shows that the microstrip arrays have good mechanical and thermal performances for practical applications

  7. A MEMS-based solid propellant microthruster array for space and military applications

    Science.gov (United States)

    Chaalane, A.; Chemam, R.; Houabes, M.; Yahiaoui, R.; Metatla, A.; Ouari, B.; Metatla, N.; Mahi, D.; Dkhissi, A.; Esteve, D.

    2015-12-01

    Since combustion is an easy way to achieve large quantities of energy from a small volume, we developed a MEMS based solid propellant microthruster array for small spacecraft and micro-air-vehicle applications. A thruster is composed of a fuel chamber layer, a top-side igniter with a micromachined nozzle in the same silicon layer. Layers are assembled by adhesive bonding to give final MEMS array. The thrust force is generated by the combustion of propellant stored in a few millimeter cube chamber. The micro-igniter is a polysilicon resistor deposited on a low stress SiO2/SiNx thin membrane to ensure a good heat transfer to the propellant and thus a low electric power consumption. A large range of thrust force is obtained simply by varying chamber and nozzle geometry parameters in one step of Deep Reactive Ion Etching (DRIE). Experimental tests of ignition and combustion employing home made (DB+x%BP) propellant composed of a DoubleBase and Black-Powder. A temperature of 250 °C, enough to propellant initiation, is reached for 40 mW of electric power. A combustion rate of about 3.4 mm/s is measured for DB+20%BP propellant and thrust ranges between 0.1 and 3,5 mN are obtained for BP ratio between 10% and 30% using a microthruster of 100 μm of throat wide.

  8. Genome-wide computational prediction of tandem gene arrays: application in yeasts

    Directory of Open Access Journals (Sweden)

    Durrens Pascal

    2010-01-01

    Full Text Available Abstract Background This paper describes an efficient in silico method for detecting tandem gene arrays (TGAs in fully sequenced and compact genomes such as those of prokaryotes or unicellular eukaryotes. The originality of this method lies in the search of protein sequence similarities in the vicinity of each coding sequence, which allows the prediction of tandem duplicated gene copies independently of their functionality. Results Applied to nine hemiascomycete yeast genomes, this method predicts that 2% of the genes are involved in TGAs and gene relics are present in 11% of TGAs. The frequency of TGAs with degenerated gene copies means that a significant fraction of tandem duplicated genes follows the birth-and-death model of evolution. A comparison of sequence identity distributions between sets of homologous gene pairs shows that the different copies of tandem arrayed paralogs are less divergent than copies of dispersed paralogs in yeast genomes. It suggests that paralogs included in tandem structures are more recent or more subject to the gene conversion mechanism than other paralogs. Conclusion The method reported here is a useful computational tool to provide a database of TGAs composed of functional or nonfunctional gene copies. Such a database has obvious applications in the fields of structural and comparative genomics. Notably, a detailed study of the TGA catalog will make it possible to tackle the fundamental questions of the origin and evolution of tandem gene clusters.

  9. A Tutorial on Optical Feeding of Millimeter-Wave Phased Array Antennas for Communication Applications

    Directory of Open Access Journals (Sweden)

    Ivan Aldaya

    2015-01-01

    Full Text Available Given the interference avoidance capacity, high gain, and dynamical reconfigurability, phased array antennas (PAAs have emerged as a key enabling technology for future broadband mobile applications. This is especially important at millimeter-wave (mm-wave frequencies, where the high power consumption and significant path loss impose serious range constraints. However, at mm-wave frequencies the phase and amplitude control of the feeding currents of the PAA elements is not a trivial issue because electrical beamforming requires bulky devices and exhibits relatively narrow bandwidth. In order to overcome these limitations, different optical beamforming architectures have been presented. In this paper we review the basic principles of phased arrays and identify the main challenges, that is, integration of high-speed photodetectors with antenna elements and the efficient optical control of both amplitude and phase of the feeding current. After presenting the most important solutions found in the literature, we analyze the impact of the different noise sources on the PAA performance, giving some guidelines for the design of optically fed PAAs.

  10. The Application of Seismic Array Techniques to Image UXO-Contaminated Littoral Environments

    Science.gov (United States)

    Gritto, R.; Korneev, V.; Nihei, K.; Johnson, L.

    2004-12-01

    We investigate the application of seismic array techniques to increase the energy radiation and resolution of seismic waves in littoral areas to improve the success rate of detecting UXO in contaminated underwater sites. The investigation is carried out based on numerical modeling, including 2-D finite difference modeling and 3-D analytical solutions of the problem. In addition to various UXO orientations, we also modeled the presence of clutter in the subsurface. An array of 31 source and receiver elements was located floating in the water as well as sited on the seafloor, which allowed the comparison between single source-receiver combinations and beam-forming techniques. The numerical forward modeling involved noise-free and noisy data as well as interferences by free surface reflections (off the water-air interface), which produced the strongest phases on the seismograms. The inversion of the scattered seismic energy was performed using a 2-D eikonal solver (curved rays), which stacked and located the recorded amplitudes in space to determine the location of the UXO. The inversion also included the determination of the best fitting velocity model for the bay mud. The results of the 2-D modeling indicated that a single, horizontally oriented, UXO could be well detected as a function of depth and horizontal location. In the case of the source-receiver array being placed on the seafloor, the edges of the UXO were resolved indicating its horizontal extent, while the top of the UXO was correctly located. The cases of a second, vertically oriented, UXO and clutter located 0.1 m next to the first UXO, produced similar results. In each case the two objects produced slight interference in the backscattered seismic signal, yet the resolution of the seismic wave was still good enough to resolve the two objects from each other. The introduction of a rippled water-seafloor interface during the forward modeling didn't change the results for the case of a floating source

  11. In situ monitoring of biomolecular processes in living systems using surface-enhanced Raman scattering

    Science.gov (United States)

    Altunbek, Mine; Kelestemur, Seda; Culha, Mustafa

    2015-12-01

    Surface-enhanced Raman scattering (SERS) continues to strive to gather molecular level information from dynamic biological systems. It is our ongoing effort to utilize the technique for understanding of the biomolecular processes in living systems such as eukaryotic and prokaryotic cells. In this study, the technique is investigated to identify cell death mechanisms in 2D and 3D in vitro cell culture models, which is a very important process in tissue engineering and pharmaceutical applications. Second, in situ biofilm formation monitoring is investigated to understand how microorganisms respond to the environmental stimuli, which inferred information can be used to interfere with biofilm formation and fight against their pathogenic activity.

  12. Ultra-high-aspect-orthogonal and tunable three dimensional polymeric nanochannel stack array for BioMEMS applications

    Science.gov (United States)

    Heo, Joonseong; Kwon, Hyukjin J.; Jeon, Hyungkook; Kim, Bumjoo; Kim, Sung Jae; Lim, Geunbae

    2014-07-01

    Nanofabrication technologies have been a strong advocator for new scientific fundamentals that have never been described by traditional theory, and have played a seed role in ground-breaking nano-engineering applications. In this study, we fabricated ultra-high-aspect (~106 with O(100) nm nanochannel opening and O(100) mm length) orthogonal nanochannel array using only polymeric materials. Vertically aligned nanochannel arrays in parallel can be stacked to form a dense nano-structure. Due to the flexibility and stretchability of the material, one can tune the size and shape of the nanochannel using elongation and even roll the stack array to form a radial-uniformly distributed nanochannel array. The roll can be cut at discretionary lengths for incorporation with a micro/nanofluidic device. As examples, we demonstrated ion concentration polarization with the device for Ohmic-limiting/overlimiting current-voltage characteristics and preconcentrated charged species. The density of the nanochannel array was lower than conventional nanoporous membranes, such as anodic aluminum oxide membranes (AAO). However, accurate controllability over the nanochannel array dimensions enabled multiplexed one microstructure-on-one nanostructure interfacing for valuable biological/biomedical microelectromechanical system (BioMEMS) platforms, such as nano-electroporation.Nanofabrication technologies have been a strong advocator for new scientific fundamentals that have never been described by traditional theory, and have played a seed role in ground-breaking nano-engineering applications. In this study, we fabricated ultra-high-aspect (~106 with O(100) nm nanochannel opening and O(100) mm length) orthogonal nanochannel array using only polymeric materials. Vertically aligned nanochannel arrays in parallel can be stacked to form a dense nano-structure. Due to the flexibility and stretchability of the material, one can tune the size and shape of the nanochannel using elongation and even

  13. Nanoscale field effect transistor for biomolecular signal amplification

    CERN Document Server

    Chen, Yu; Hong, Mi K; Erramilli, Shyamsunder; Rosenberg, Carol; Mohanty, Pritiraj

    2008-01-01

    We report amplification of biomolecular recognition signal in lithographically defined silicon nanochannel devices. The devices are configured as field effect transistors (FET) in the reversed source-drain bias region. The measurement of the differential conductance of the nanowire channels in the FET allows sensitive detection of changes in the surface potential due to biomolecular binding. Narrower silicon channels demonstrate higher sensitivity to binding due to increased surface-to-volume ratio. The operation of the device in the negative source-drain region demonstrates signal amplification. The equivalence between protein binding and change in the surface potential is described.

  14. Applications of tensor (multiway array) factorizations and decompositions in data mining

    DEFF Research Database (Denmark)

    Mørup, Morten

    2011-01-01

    Tensor (multiway array) factorization and decomposition has become an important tool for data mining. Fueled by the computational power of modern computer researchers can now analyze large-scale tensorial structured data that only a few years ago would have been impossible. Tensor factorizations...... have several advantages over two-way matrix factorizations including uniqueness of the optimal solution and component identification even when most of the data is missing. Furthermore, multiway decomposition techniques explicitly exploit the multiway structure that is lost when collapsing some...... of the modes of the tensor in order to analyze the data by regular matrix factorization approaches. Multiway decomposition is being applied to new fields every year and there is no doubt that the future will bring many exciting new applications. The aim of this overview is to introduce the basic concepts...

  15. Fiber Bragg Grating Array as a Quasi Distributed Temperature Sensor for Furnace Boiler Applications

    Science.gov (United States)

    Reddy, P. Saidi; Prasad, R. L. N. Sai; Sengupta, D.; Shankar, M. Sai; Srimannarayana, K.; Kishore, P.; Rao, P. Vengal

    2011-10-01

    This paper presents the experimental work on distributed temperature sensing making use of Fiber Bragg grating (FBG) array sensor for possible applications in the monitoring of temperature profile in high temperature boilers. A special sensor has been designed for this purpose which consists of four FBGs (of wavelengths λB1 = 1547.28 nm, λB2 = 1555.72 nm, λB3 = 1550.84 nm, λB4 = 1545.92 nm) written in hydrogen loaded fiber in line with a spacing of 15 cm between them. All the FBGs are encapsulated inside a stainless steel tube for avoiding micro cracks using rigid probe technique. The spatial distribution of temperature profile inside a prototype boiler has been measured experimentally both in horizontal and vertical directions employing the above sensor and the results are presented.

  16. Isolation Improvement of a Microstrip Patch Array Antenna for WCDMA Indoor Repeater Applications

    Directory of Open Access Journals (Sweden)

    Hongmin Lee

    2012-01-01

    Full Text Available This paper presents the isolation improvement techniques of a microstrip patch array antenna for the indoor wideband code division multiple access (WCDMA repeater applications. One approach is to construct the single-feed switchable feed network structure with an MS/NRI coupled-line coupler in order to reduce the mutual coupling level between antennas. Another approach is to insert the soft surface unit cells near the edges of the microstrip patch elements in order to reduce backward radiation waves. In order to further improve the isolation level, the server antenna and donor antenna are installedinorthogonal direction. The fabricated antenna exhibits a gain over 7 dBi and higher isolation level between server and donor antennas below −70 dB at WCDMA band.

  17. Planar Array Sensor for High-speed Component Distribution Imaging in Fluid Flow Applications

    Directory of Open Access Journals (Sweden)

    Uwe Hampel

    2007-10-01

    Full Text Available A novel planar array sensor based on electrical conductivity measurements ispresented which may be applied to visualize surface fluid distributions. The sensor ismanufactured using printed-circuit board fabrication technology and comprises of 64 x 64interdigital sensing structures. An associated electronics measures the electricalconductivity of the fluid over each individual sensing structure in a multiplexed manner byapplying a bipolar excitation voltage and by measuring the electrical current flowing from adriver electrode to a sensing electrode. After interrogating all sensing structures, a two-dimensional image of the conductivity distribution over a surface is obtained which in turnrepresents fluid distributions over sensor’s surface. The employed electronics can acquire upto 2500 frames per second thus being able to monitor fast transient phenomena. The systemhas been evaluated regarding measurement accuracy and depth sensitivity. Furthermore, theapplication of the sensor in the investigation of two different flow applications is presented.

  18. Performance measurement of low concentration ratio solar array for space application

    Science.gov (United States)

    Mills, M. W.

    1984-01-01

    The measured performance of a silicon and a gallium arsenide low concentration ratio solar array (LCRSA) element is presented. The element characteristics measured in natural sunlight are off pointing performance and response to mechanical distortions. Laboratory measurements of individual silicon and gallium-arsenide solar cell assemblies are also made. The characteristics measured in the laboratory involved responses to temperature and intensity variations as well as to the application of reverse bias potentials. The element design details covered include the materials, the solar cells, and the rationale for selecting these specific characteristics. The measured performance characteristics are contrasted with the predicted values for both laboratory testing and high altitude natural sunlight testing. Excellent agreement between analytical predictions and measured performance is observed.

  19. New CMOS readout circuit with background suppression and CDS for infrared focal plane array applications

    Institute of Scientific and Technical Information of China (English)

    LI Xin-yi; ZHAO Yi-qiang; YAO Su-ying

    2009-01-01

    A high injection, large dynamic range, stable detector bias, small area and low power consumption CMOS readout circuit with background current suppression and correlated double sampling (CDS) for a high-resolution infrared focal plane array applications is proposed. The detector bias error in this structure is less than 0.1 mV. The input resistance is ideally zero, which is important to obtain high injection efficiency. Unit-cell occupies 10 μm × 15 μm area and consumes less than 0.4 mW power. Charge storage capacity is 3 × 108 electrons. The function and performance of the proposed readout circuit have been verified by experimental results.

  20. Photon counting pixel and array in amorphous silicon technology for large area digital medical imaging applications

    Science.gov (United States)

    Yazdandoost, Mohammad Y.; Shin, Kyung W.; Safavian, Nader; Taghibakhsh, Farhad; Karim, Karim S.

    2010-04-01

    A single photon counting Voltage Controlled Oscillator (VCO) based pixel architecture in amorphous silicon (a-Si) technology is reported for large area digital medical imaging. The VCO converts X-ray generated input charge into an output oscillating frequency signal. Experimental results for an in-house fabricated VCO circuit in a-Si technology are presented and external readout circuits to extract the image information from the VCO's frequency output are discussed. These readout circuits can be optimized to reduce the fixed pattern noise and fringing effects in an imaging array containing many such VCO pixels. Noise estimations, stability simulations and measurements for the fabricated VCO are presented. The reported architecture is particularly promising for large area photon counting applications (e.g. low dose fluoroscopy, dental computed tomography (CT)) due to its very low input referred electronic noise, high sensitivity and ease of fabrication in low cost a-Si technology.

  1. Application of Correlation and Coherency Methods to Naqu Seismic Array Design

    Institute of Scientific and Technical Information of China (English)

    Hao Chunyue; Zheng Zhong

    2006-01-01

    The waveform data recorded during the site survey of the Naqu seismic array in Aug. 2004 were processed by the author. According to the relativity of site pairs in time and frequency domains, the reference values of the inner ring and outer ring were determined. The author evaluated the array deployed for site survey as the primary array, and the results show that the resolution of the primary array is high enough to locate earthquakes precisely.

  2. An application of ultrasonic phased array imaging in electron beam welding inspection

    Institute of Scientific and Technical Information of China (English)

    周琦; 刘方军; 李志军; 李旭东; 齐铂金

    2002-01-01

    The basic principle and features of ultrasonic phased array imaging are discussed in this paper. Through the ultrasonic phased array technology, the electron beam welding defects and frozen keyholes characterization and imaging were realized. The ultrasonic phased array technology can detect kinds of defects in electron beam welding (EBW) quickly and easily.

  3. Biomolecular detection using a metal semiconductor field effect transistor

    Science.gov (United States)

    Estephan, Elias; Saab, Marie-Belle; Buzatu, Petre; Aulombard, Roger; Cuisinier, Frédéric J. G.; Gergely, Csilla; Cloitre, Thierry

    2010-04-01

    In this work, our attention was drawn towards developing affinity-based electrical biosensors, using a MESFET (Metal Semiconductor Field Effect Transistor). Semiconductor (SC) surfaces must be prepared before the incubations with biomolecules. The peptides route was adapted to exceed and bypass the limits revealed by other types of surface modification due to the unwanted unspecific interactions. As these peptides reveal specific recognition of materials, then controlled functionalization can be achieved. Peptides were produced by phage display technology using a library of M13 bacteriophage. After several rounds of bio-panning, the phages presenting affinities for GaAs SC were isolated; the DNA of these specific phages were sequenced, and the peptide with the highest affinity was synthesized and biotinylated. To explore the possibility of electrical detection, the MESFET fabricated with the GaAs SC were used to detect the streptavidin via the biotinylated peptide in the presence of the bovine Serum Albumin. After each surface modification step, the IDS (current between the drain and the source) of the transistor was measured and a decrease in the intensity was detected. Furthermore, fluorescent microscopy was used in order to prove the specificity of this peptide and the specific localisation of biomolecules. In conclusion, the feasibility of producing an electrical biosensor using a MESFET has been demonstrated. Controlled placement, specific localization and detection of biomolecules on a MESFET transistor were achieved without covering the drain and the source. This method of functionalization and detection can be of great utility for biosensing application opening a new way for developing bioFETs (Biomolecular Field-Effect Transistor).

  4. Time-resolved methods in biophysics. 9. Laser temperature-jump methods for investigating biomolecular dynamics.

    Science.gov (United States)

    Kubelka, Jan

    2009-04-01

    Many important biochemical processes occur on the time-scales of nanoseconds and microseconds. The introduction of the laser temperature-jump (T-jump) to biophysics more than a decade ago opened these previously inaccessible time regimes up to direct experimental observation. Since then, laser T-jump methodology has evolved into one of the most versatile and generally applicable methods for studying fast biomolecular kinetics. This perspective is a review of the principles and applications of the laser T-jump technique in biophysics. A brief overview of the T-jump relaxation kinetics and the historical development of laser T-jump methodology is presented. The physical principles and practical experimental considerations that are important for the design of the laser T-jump experiments are summarized. These include the Raman conversion for generating heating pulses, considerations of size, duration and uniformity of the temperature jump, as well as potential adverse effects due to photo-acoustic waves, cavitation and thermal lensing, and their elimination. The laser T-jump apparatus developed at the NIH Laboratory of Chemical Physics is described in detail along with a brief survey of other laser T-jump designs in use today. Finally, applications of the laser T-jump in biophysics are reviewed, with an emphasis on the broad range of problems where the laser T-jump methodology has provided important new results and insights into the dynamics of the biomolecular processes.

  5. Tests of operating conditions for metrological application of HTS Josephson arrays

    International Nuclear Information System (INIS)

    We report on an experimental study of metrological properties of High Temperature Superconductor arrays, made of shunted bicrystal YBCO Josephson junctions, to assess their accuracy. A detailed analysis of measurement errors is presented, mainly based on a direct comparison of an HTS array against a low temperature array. Owing to the high sensitivity of the comparison, we were able to measure the changes in the HTS array voltage on a step at nanovolt level. A precise estimate of the dependence of the HTS array step width on operating conditions was obtained. Differences were observed with respect to the results provided by the usual, low sensitivity, techniques, confirming that the method we adopted is necessary in the study of HTS arrays for metrology. The high sensitivity analysis was applied in the derivation of the temperature dependence of the critical current as well, providing some insights on the behaviour of the HTS array

  6. Facing and Overcoming Sensitivity Challenges in Biomolecular NMR Spectroscopy

    DEFF Research Database (Denmark)

    Ardenkjær-Larsen, Jan Henrik; Boebinger, Gregory S.; Comment, Arnaud;

    2015-01-01

    In the Spring of 2013, NMR spectroscopists convened at the Weizmann Institute in Israel to brainstorm on approaches to improve the sensitivity of NMR experiments, particularly when applied in biomolecular settings. This multi‐author interdisciplinary Review presents a state‐of‐the‐art description...

  7. The HADDOCK web server for data-driven biomolecular docking

    NARCIS (Netherlands)

    de Vries, S.J.; van Dijk, M.; Bonvin, A.M.J.J.

    2010-01-01

    Computational docking is the prediction or modeling of the three-dimensional structure of a biomolecular complex, starting from the structures of the individual molecules in their free, unbound form. HADDOC K is a popular docking program that takes a datadriven approach to docking, with support for

  8. From dynamics to structure and function of model biomolecular systems

    NARCIS (Netherlands)

    Fontaine-Vive-Curtaz, F.

    2007-01-01

    The purpose of this thesis was to extend recent works on structure and dynamics of hydrogen bonded crystals to model biomolecular systems and biological processes. The tools that we have used are neutron scattering (NS) and density functional theory (DFT) and force field (FF) based simulation method

  9. Large Format Si:As IBC Array Performance for NGST and Future IR Space Telescope Applications

    Science.gov (United States)

    Ennico, Kimberly; Johnson, Roy; Love, Peter; Lum, Nancy; McKelvey, Mark; McCreight, Craig; McMurray, Robert, Jr.; DeVincenzi, D. (Technical Monitor)

    2002-01-01

    A mid-IR (5-30micrometer) instrument aboard a cryogenic space telescope can have an enormous impact in resolving key questions in astronomy and cosmology. A space platform's greatly reduced thermal backgrounds (compared to airborne or ground-based platforms), allow for more sensitive observations of dusty young galaxies at high redshifts, star formation of solar-type stars in the local universe, and formation and evolution of planetary disks and systems. The previous generation's largest, in sensitive IR detectors at these wavelengths are 256x256 pixel Si:As Impurity Band Conduction (IBC) devices built by Raytheon Infrared Operations (RIO) for the Space Infrared Telescope Facility/Infrared Array Camera (SIRTF)/(IRAC) instrument. RIO has successfully enhanced these devices, increasing the pixel count by a factor of 16 while matching or exceeding SIRTF/IRAC device performance. NASA-ARC in collaboration with RIO has tested the first high performance large format (1024x 1024) Si:As IBC arrays for low background applications, such as for the middle instrument on Next Generation Space Telescope (NGST) and future IR Explorer missions. These hybrid devices consist of radiation hard SIRTF/IRAC-type Si:As IBC material mated to a readout multiplexer that has been specially processed for operation at low cryogenic temperatures (below 10K), yielding high device sensitivity over a wavelength range of 5-28 micrometers. We present laboratory testing results from these benchmark, devices. Continued development in this technology is essential for conducting large-area surveys of the local and early universe through observation and for complementing future missions such as NGST, Terrestrial Planet Finder (TPF), and Focal Plane Instruments and Requirement Science Team (FIRST).

  10. An L-Band, Circularly Polarised, Dual-Feed, Cavity-Backed Annular Slot Antenna For Phased-Array Applications

    DEFF Research Database (Denmark)

    Larsen, Niels Vesterdal; Breinbjerg, Olav

    2006-01-01

    The results of a parametric study for the development of an L-band, circularly polarised, dual-feed, cavity-backed annular slot antenna is presented. The study included detailed numerical simulations and measurements on a prototype with different ground planes, to assess the antenna’s applicability...... as an element in a small phased array antenna....

  11. A self-regulating biomolecular comparator for processing oscillatory signals.

    Science.gov (United States)

    Agrawal, Deepak K; Franco, Elisa; Schulman, Rebecca

    2015-10-01

    While many cellular processes are driven by biomolecular oscillators, precise control of a downstream on/off process by a biochemical oscillator signal can be difficult: over an oscillator's period, its output signal varies continuously between its amplitude limits and spends a significant fraction of the time at intermediate values between these limits. Further, the oscillator's output is often noisy, with particularly large variations in the amplitude. In electronic systems, an oscillating signal is generally processed by a downstream device such as a comparator that converts a potentially noisy oscillatory input into a square wave output that is predominantly in one of two well-defined on and off states. The comparator's output then controls downstream processes. We describe a method for constructing a synthetic biochemical device that likewise produces a square-wave-type biomolecular output for a variety of oscillatory inputs. The method relies on a separation of time scales between the slow rate of production of an oscillatory signal molecule and the fast rates of intermolecular binding and conformational changes. We show how to control the characteristics of the output by varying the concentrations of the species and the reaction rates. We then use this control to show how our approach could be applied to process different in vitro and in vivo biomolecular oscillators, including the p53-Mdm2 transcriptional oscillator and two types of in vitro transcriptional oscillators. These results demonstrate how modular biomolecular circuits could, in principle, be combined to build complex dynamical systems. The simplicity of our approach also suggests that natural molecular circuits may process some biomolecular oscillator outputs before they are applied downstream. PMID:26378119

  12. Interacting with the biomolecular solvent accessible surface via a haptic feedback device

    Directory of Open Access Journals (Sweden)

    Hayward Steven

    2009-10-01

    Full Text Available Abstract Background From the 1950s computer based renderings of molecules have been produced to aid researchers in their understanding of biomolecular structure and function. A major consideration for any molecular graphics software is the ability to visualise the three dimensional structure of the molecule. Traditionally, this was accomplished via stereoscopic pairs of images and later realised with three dimensional display technologies. Using a haptic feedback device in combination with molecular graphics has the potential to enhance three dimensional visualisation. Although haptic feedback devices have been used to feel the interaction forces during molecular docking they have not been used explicitly as an aid to visualisation. Results A haptic rendering application for biomolecular visualisation has been developed that allows the user to gain three-dimensional awareness of the shape of a biomolecule. By using a water molecule as the probe, modelled as an oxygen atom having hard-sphere interactions with the biomolecule, the process of exploration has the further benefit of being able to determine regions on the molecular surface that are accessible to the solvent. This gives insight into how awkward it is for a water molecule to gain access to or escape from channels and cavities, indicating possible entropic bottlenecks. In the case of liver alcohol dehydrogenase bound to the inhibitor SAD, it was found that there is a channel just wide enough for a single water molecule to pass through. Placing the probe coincident with crystallographic water molecules suggests that they are sometimes located within small pockets that provide a sterically stable environment irrespective of hydrogen bonding considerations. Conclusion By using the software, named HaptiMol ISAS (available from http://www.haptimol.co.uk, one can explore the accessible surface of biomolecules using a three-dimensional input device to gain insights into the shape and water

  13. Biomolecular transport and separation in nanotubular networks.

    Energy Technology Data Exchange (ETDEWEB)

    Stachowiak, Jeanne C.; Stevens, Mark Jackson (Sandia National Laboratories, Albuquerque, NM); Robinson, David B.; Branda, Steven S.; Zendejas, Frank; Meagher, Robert J.; Sasaki, Darryl Yoshio; Bachand, George David (Sandia National Laboratories, Albuquerque, NM); Hayden, Carl C.; Sinha, Anupama; Abate, Elisa; Wang, Julia; Carroll-Portillo, Amanda (Sandia National Laboratories, Albuquerque, NM); Liu, Haiqing (Sandia National Laboratories, Albuquerque, NM)

    2010-09-01

    Cell membranes are dynamic substrates that achieve a diverse array of functions through multi-scale reconfigurations. We explore the morphological changes that occur upon protein interaction to model membrane systems that induce deformation of their planar structure to yield nanotube assemblies. In the two examples shown in this report we will describe the use of membrane adhesion and particle trajectory to form lipid nanotubes via mechanical stretching, and protein adsorption onto domains and the induction of membrane curvature through steric pressure. Through this work the relationship between membrane bending rigidity, protein affinity, and line tension of phase separated structures were examined and their relationship in biological membranes explored.

  14. Study and operating conditions of HTS Josephson arrays for metrological application

    International Nuclear Information System (INIS)

    We report an experimental study of metrological properties of high-temperature superconductor arrays, made of shunted bicrystal YBCO Josephson junctions. The work is mainly based on a direct comparison against a low temperature array. Owing to the high sensitivity of the measurements, we observed at nanovolt level the changes in the HTS array voltage on a step. A precise estimate of the dependence of the HTS array step width on operating conditions was obtained. Differences were observed with respect to the results of low sensitivity techniques, confirming that our method is necessary in the study of HTS arrays for metrology. The high sensitivity analysis was also applied in the derivation of the temperature dependence of the critical current, providing insights on the behavior of the HTS array

  15. Engineering intracellular active transport systems as in vivo biomolecular tools.

    Energy Technology Data Exchange (ETDEWEB)

    Bachand, George David; Carroll-Portillo, Amanda

    2006-11-01

    Active transport systems provide essential functions in terms of cell physiology and metastasis. These systems, however, are also co-opted by invading viruses, enabling directed transport of the virus to and from the cell's nucleus (i.e., the site of virus replication). Based on this concept, fundamentally new approaches for interrogating and manipulating the inner workings of living cells may be achievable by co-opting Nature's active transport systems as an in vivo biomolecular tool. The overall goal of this project was to investigate the ability to engineer kinesin-based transport systems for in vivo applications, specifically the collection of effector proteins (e.g., transcriptional regulators) within single cells. In the first part of this project, a chimeric fusion protein consisting of kinesin and a single chain variable fragment (scFv) of an antibody was successfully produced through a recombinant expression system. The kinesin-scFv retained both catalytic and antigenic functionality, enabling selective capture and transport of target antigens. The incorporation of a rabbit IgG-specific scFv into the kinesin established a generalized system for functionalizing kinesin with a wide range of target-selective antibodies raised in rabbits. The second objective was to develop methods of isolating the intact microtubule network from live cells as a platform for evaluating kinesin-based transport within the cytoskeletal architecture of a cell. Successful isolation of intact microtubule networks from two distinct cell types was demonstrated using glutaraldehyde and methanol fixation methods. This work provides a platform for inferring the ability of kinesin-scFv to function in vivo, and may also serve as a three-dimensional scaffold for evaluating and exploiting kinesin-based transport for nanotechnological applications. Overall, the technology developed in this project represents a first-step in engineering active transport system for in vivo

  16. Dual-frequency dual-polarized stacked patch microstrip arrays: An investigation of their suitability for soil-moisture remote-sensing applications

    Science.gov (United States)

    Kona, Keerti Sruta

    The objective of this research is to develop design and analysis procedures for dual-frequency dual-polarized microstrip arrays applicable to future spaceborne remote sensing missions. In particular this thesis focuses on two main applications: Application 1. Design of light-weight L-band standalone planar array for soil moisture and sea-surface salinity measurements. We then investigate the possibility of a stacked patch array topology with L-band array elements for use as feed to 12m offset reflector. Application 2. Development of feed array concept for 30m symmetric reflector. The principal contributions of this research has been investigation of novel dual-band and dual-polarization array designs that can comply with the demanding specifications. Novel probe feeding methods for microstrip elements to achieve the best array performance are identified. Most importantly, "proof-of-concept" scaled models of the array designs were experimentally and numerically verified for a given set of specifications. A sixteen element microstrip stacked patch array with combined L-band active (radar) and passive (radiometer) frequencies for use in airborne sensors operating on standalone aircrafts has been optimized, fabricated and tested for application 1. Sub-cell FDTD method was applied for accurately modeling thin radomes and multilayer dielectrics covering such aperture type antennas in space applications. From the design and performance study of the L-band array, we have shown that it is feasible to use optimized stacked patch arrays as alternatives to conventionally used feed horns for offset reflectors. For application 2, a dual-stack patch array feed is identified that can synthesize long rectangular apertures with matched beams for two frequencies on the reflector surface. An experimental prototype scaled feed was designed, built and also integrated with a scaled 3.65m reflector antenna thus demonstrating the overall system feasibility.

  17. Real-Time, Label-Free Detection of Biomolecular Interactions in Sandwich Assays by the Oblique-Incidence Reflectivity Difference Technique

    Directory of Open Access Journals (Sweden)

    Yung-Shin Sun

    2014-12-01

    Full Text Available One of the most important goals in proteomics is to detect the real-time kinetics of diverse biomolecular interactions. Fluorescence, which requires extrinsic tags, is a commonly and widely used method because of its high convenience and sensitivity. However, in order to maintain the conformational and functional integrality of biomolecules, label-free detection methods are highly under demand. We have developed the oblique-incidence reflectivity difference (OI-RD technique for label-free, kinetic measurements of protein-biomolecule interactions. Incorporating the total internal refection geometry into the OI-RD technique, we are able to detect as low as 0.1% of a protein monolayer, and this sensitivity is comparable with other label-free techniques such as surface plasmon resonance (SPR. The unique advantage of OI-RD over SPR is no need for dielectric layers. Moreover, using a photodiode array as the detector enables multi-channel detection and also eliminates the over-time signal drift. In this paper, we demonstrate the applicability and feasibility of the OI-RD technique by measuring the kinetics of protein-protein and protein-small molecule interactions in sandwich assays.

  18. Mass-sensing BioCD Protein Array towards Clinical Application: Prostate Specific Antigen Detection in Patient Sera

    CERN Document Server

    Wang, Xuefeng; Nolte, David D; Ratliff, Timothy L

    2009-01-01

    Mass-sensing biosensor arrays for protein detection require no fluorophores or enzyme labels. However, few mass biosensor protein arrays have demonstrated successful application in high background samples, such as serum. In this paper, we test the BioCD as a mass biosensor based on optical interferometry of antibodies covalently attached through Schiff-base reduction. We use the BioCD to detect prostate specific antigen (PSA, a biomarker of prostate cancer) in patient sera in a 96-well anti-PSA microarray. We have attained a 4 ng/ml detection limit in full serum and have measured PSA concentrations in three patient sera.

  19. Characterization of Acousto-Electric Cluster and Array Levitation and its Application to Evaporation

    Science.gov (United States)

    Robert E. Apfel; Zheng, Yibing

    2000-01-01

    An acousto-electric levitator has been developed to study the behavior of liquid drop and solid particle clusters and arrays. Unlike an ordinary acoustic levitator that uses only a standing acoustic wave to levitate a single drop or particle, this device uses an extra electric static field and the acoustic field simultaneously to generate and levitate charged drops in two-dimensional arrays in air without any contact to a solid surface. This cluster and array generation (CAG) instrument enables us to steadily position drops and arrays to study the behavior of multiple drop and particle systems such as spray and aerosol systems relevant to the energy, environmental, and material sciences.

  20. Dense nanoimprinted silicon nanowire arrays with passivated axial p-i-n junctions for photovoltaic applications

    Science.gov (United States)

    Zhang, Peng; Liu, Pei; Siontas, Stylianos; Zaslavsky, A.; Pacifici, D.; Ha, Jong-Yoon; Krylyuk, S.; Davydov, A. V.

    2015-03-01

    We report on the fabrication and photovoltaic characteristics of vertical arrays of silicon axial p-i-n junction nanowire (NW) solar cells grown by vapor-liquid-solid (VLS) epitaxy. NW surface passivation with silicon dioxide shell is shown to enhance carrier recombination time, open-circuit voltage (VOC), short-circuit current density (JSC), and fill factor (FF). The photovoltaic performance of passivated individual NW and NW arrays was compared under 532 nm laser illumination with power density of ˜10 W/cm2. Higher values of VOC and FF in the NW arrays are explained by enhanced light trapping. In order to verify the effect of NW density on light absorption and hence on the photovoltaic performance of NW arrays, dense Si NW arrays were fabricated using nanoimprint lithography to periodically arrange the gold seed particles prior to epitaxial growth. Compared to sparse NW arrays fabricated using VLS growth from randomly distributed gold seeds, the nanoimprinted NW array solar cells show a greatly increased peak external quantum efficiency of ˜8% and internal quantum efficiency of ˜90% in the visible spectral range. Three-dimensional finite-difference time-domain simulations of Si NW periodic arrays with varying pitch (P) confirm the importance of high NW density. Specifically, due to diffractive scattering and light trapping, absorption efficiency close to 100% in the 400-650 nm spectral range is calculated for a Si NW array with P = 250 nm, significantly outperforming a blanket Si film of the same thickness.

  1. Gold planar wire array radiation sources at university scale generators and their applications

    International Nuclear Information System (INIS)

    Various configurations of planar wires arrays (PWA) made from wires in a broad range of atomic numbers up to 74 (W) have been extensively tested on Zebra generator at the University of Nevada, Reno. In this work, we present the results of our experiments with PWA made of the wires with an even higher atomic number, specifically 79 (Au). Two different configurations (single and double PWAs) are considered. The diagnostic set included: x-ray detectors, laser shadowgraphy, time-gated and time-integrated x-ray pinhole cameras, time-integrated spatially resolved and time-gated spatially integrated x-ray spectrometers, and a bolometer. The total x-ray yield was measured along and perpendicular to the load plane and reached the highest value measured on Zebra so far for the single PWA (perpendicular to the plane, 32 kJ). Theoretical tools included non-LTE kinetic and wire ablation dynamic models. The full set of data using aforementioned diagnostics is analyzed and specific implosion and radiative characteristics of Au PWAs. The application of gold PWAs in compact hohlraum configurations on Zebra is highlighted. VisRad (Prism Computational Sciences), a 3-D view factor code, is used to simulate the multi-dimensional radiation environment with a special emphasis on radiation temperature calculations and uniformity at the re-emission target surface. (author)

  2. Quasi-distributed fiber bragg grating array sensor for furnace applications

    Science.gov (United States)

    Reddy, P. Saidi; Sai Prasad, R. L. N.; Sen Gupta, D.; Sai Shankar, M.; Srimannarayana, K.; Ravinder Reddy, P.

    2012-05-01

    An experimental work on distributed temperature sensing making use of the fiber Bragg grating (FBG) array sensor for possible applications in the monitoring of the temperature profile in high temperature boilers is presented. A special sensor has been designed for this purpose which consists of four FBGs (of wavelengths λ B1 =1545.8 nm, λ B2 =1547 nm, λ B3 =1550.8 nm, λ B4 =1555.5 nm at 30 °C) written in the hydrogen-loaded fiber in line. All the FBGs are encapsulated inside a stainless steel tube using the rigid probe technique for avoiding micro cracks. The spatial distribution of the temperature profile inside a prototype boiler was measured experimentally both in horizontal and vertical directions employing the above sensor, and the results are presented. Further, the finite element simulation has been carried out by using ANSYS R11 software to predict temperature contours in the boiler, and the experimental and predicted results were found to be closely matching.

  3. Phased array UT application for boiling water reactor vessel bottom head

    International Nuclear Information System (INIS)

    Stress Corrosion Cracking (SCC) on welds of reactor internals is one of the most important issues in nuclear plants since 1990's. Demands to inspect the reactor internals are increasing. This paper focuses on the development and the application of the phased array ultrasonic testing (PAUT) for the reactor internals located in Boiling Water Reactor (BWR) vessel bottom head (e.g., shroud support). The Toshiba PAUT technologies and technique has been developed and applied to in-Vessel inspections (IVIs) as our universal nondestructive testing (NDT) technologies. Though it was difficult to detect and size cracks in Alloy 182 welds (i.e. weld metal of the shroud support and a CRD stub tube), the efficiency of the PAUT techniques is shown in recent IVI activities. For example the PAUT techniques are applied to crack depth sizing in the weld between the CRD stub tube and RPV bottom build-up in recent years. An immersion technique by the PAUT enables to perform the UT examination on a complex geometric surface to be inspected. The PAUT techniques are developed to detect and size flaws on the shroud support Alloy 182 welds. The techniques include detection from the outside and the inside of RPV. These techniques are applied to the simulated shroud support mockups with SCC-simulated flaws. The examination result is proven to have a good agreement with their actual. As a result, the efficiency of the PAUT techniques is confirmed. (author)

  4. Tricobalt tetroxide nanoplate arrays on flexible conductive fabric substrate: Facile synthesis and application for electrochemical supercapacitors

    Science.gov (United States)

    Nagaraju, Goli; Ko, Yeong Hwan; Yu, Jae Su

    2015-06-01

    Tricobalt tetroxide (Co3O4) nanoplate arrays (NPAs) were synthesized on flexible conductive fabric substrate (FCFs) by a facile two-electrode system based electrochemical deposition method, followed by a simple heat treatment process. Initially, cobalt hydroxide (Co(OH)2) NPAs were electrochemically deposited on FCFs by applying an external voltage of -1.5 V for 30 min. Then, the Co3O4 NPAs on FCFs was obtained by thermal treatment of as-deposited Co(OH)2 NPAs on FCFs at 200 °C for 2 h. From the analysis of morphological and crystal properties, the Co3O4 NPAs were well integrated and uniformly covered over the entire surface of substrate with good crystallinity in the cubic phase. Additionally, the fabricated sample was directly used as a binder-free electrode to examine the feasibility for electrochemical supercapacitors using cyclic voltammetry and galvanic charge-discharge measurements in 1 M KOH electrolyte solution. The Co3O4 NPAs coated FCFs electrode exhibited a maximum specific capacitance of 145.6 F/g at a current density of 1 A/g and an excellent rate capability after 1000 cycles at a current density of 3 A/g. This facile fabrication method for integrating the Co3O4 nanostructures on FCFs could be a promising approach for advanced flexible electronic and energy-storage device applications.

  5. Metal capped polystyrene nanotubes arrays as super-hydrophobic substrates for SERS applications

    Science.gov (United States)

    Lovera, Pierre; Creedon, Niamh; Alatawi, Hanan; O'Riordan, Alan

    2014-05-01

    We present a low-cost and rapid fabrication and characterisations of polymer nanotubes based substrates inspired by a Gecko's foot, and demonstrate its suitability for Surface Enhanced Raman Scattering (SERS) applications. Substrates are fabricated in a simple, scalable and cost efficient way by melt wetting of polystyrene (PS) in an anodised alumina (AAO) template, followed by silver or gold evaporation. Scanning electron microscopy reveals the substrates are composed of a dense array of free-standing polystyrene nanotubes topped by silver nanocaps. The gaps (electromagnetic hot spots) between adjacent nanotubes are measured to be 30nm +/-15nm. SERS characterisation of the substrates, employing a monolayer of 4-aminothiophenol (4-ABT) as a model molecule, exhibits an enhancement factor of ~1.6 × 106. This value is consistent with the one obtained from 3D-Finite Difference Time Domain (3D-FDTD) simulations of a simplified version of the sample. The contact angle of the substrates is measured to be 150°, making them super-hydrophobic. This later property renders the samples compatible to very low sample volumes and highly sensitive detection (down to 408ppt) of the environmental pollutant crystal violet in water is demonstrated.

  6. Development and application of functional gene arrays for microbial community analysis

    Institute of Scientific and Technical Information of China (English)

    Z.L.HE; J.D.VAN NOSTRAND; L.Y.WU; J.Z.ZHOU

    2008-01-01

    Functional gene markers can provide important information about functional gene diversity and potential activity of microbial communities.Although microarray technology has been successfully applied to study gene expression for pure cultures,simple,and artificial microbial communities,adapting such a technology to analyze complex microbial communities still presents a lot of challenges in terms of design,sample preparation,and data analysis.This work is focused on the development and application of functional gene arrays (FGAs) to target key functional gene markers for microbial community studies.A few key issues specifically related to FGAs,such as oligonucleotide probe design,nucleic acid extraction and purification,data analysis,specificity,sensitivity,and quantitative capability are discussed in detail.Recent studies have demonstrated that FGAs can provide specific,sensitive,and potentially quantitative information about microbial communities from a variety of natural environments and controlled ecosystems.This technology is expected to revolutionize the analysis of microbial communities,and link microbial structure to ecosystem functioning.

  7. Application of the FD-TD method to the electromagnetic modeling of patch antenna arrays

    Energy Technology Data Exchange (ETDEWEB)

    Pasik, M.F. [Sandia National Labs., Albuquerque, NM (United States); Aguirre, G.; Cangellaris, A.C. [Univ. of Arizona, Tucson, AZ (United States). Dept. of Electrical and Computer Eengineering, Center for Electronic Packaging Research

    1996-01-10

    FD-TD method and the Berenger Perfectly Matched Layer (PML) absorbing condition are applied to the modeling of a 32-element patch array. Numerical results for the return loss at the array feed are presented and compared to measured results for the purpose of model validation.

  8. Assessment of SEPS solar array technology for orbital service module application

    Science.gov (United States)

    1978-01-01

    Work performed in the following assessment areas on the SEPS solar array is reported: (1) requirements definition, (2) electrical design evaluation, (3) mechanical design evaluation, and (4) design modification analysis. General overall assessment conclusions are summarized. There are no known serious design limitations involved in the implementation of the recommended design modifications. A section of orbiter and array engineering drawings is included.

  9. Embroidered electrochemical sensors for biomolecular detection.

    Science.gov (United States)

    Liu, Xiyuan; Lillehoj, Peter B

    2016-05-24

    Electrochemical sensors are powerful analytical tools which possess the capacity for rapid detection of biomarkers in clinical specimens. While most electrochemical sensors are fabricated on rigid substrates, there is a growing need for sensors that can be manufactured on inexpensive and flexible materials. Here, we present a unique embroidered electrochemical sensor that is capable of quantitative analytical measurements using raw biofluid samples. Conductive threads immobilized with enzyme probes were generated using a simple and robust fabrication process and used to fabricate flexible, mechanically robust electrodes on textiles. For proof of concept, measurements were performed to detect glucose and lactate in buffer and whole blood samples, which exhibited excellent specificity and accuracy. We also demonstrate that our embroidered biosensor can be readily fabricated in two-dimensional (2D) arrays for multiplexed measurements. Lastly, we show that this biosensor exhibits good resiliency against mechanical stress and superior repeatability, which are important requirements for flexible sensor platforms. PMID:27156700

  10. A New Dual Polarized Aperture-Coupled Printed Array for SAR Applications

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    This paper presents a new design of dual polarized aperture-coupled printed antenna array. The finite-difference time-domain (FDTD) analysis of an aperture-coupled microstrip element is performed, and the effects of antenna parameters on its characteristics are obtained to guide the design of the printed array. Then an 8 × 2 dual polarized array design in X-band is introduced with configuration plots. In order to improve its isolation and cross polarization, an outphase-displacement feeding technique is adopted in the feed network. Also, the round bends are used instead of conventional right-angle bends so as to achieve better VSWR performance.Experimental results are presented, indicating the validity of the design. This dual polarized array can be applied as a sub-array of spaceborne SAR systems.

  11. In Vivo application and localization of transcranial focused ultrasound using dual-mode ultrasound arrays.

    Science.gov (United States)

    Haritonova, Alyona; Liu, Dalong; Ebbini, Emad S

    2015-12-01

    Focused ultrasound (FUS) has been proposed for a variety of transcranial applications, including neuromodulation, tumor ablation, and blood-brain barrier opening. A flurry of activity in recent years has generated encouraging results demonstrating its feasibility in these and other applications. To date, monitoring of FUS beams has been primarily accomplished using MR guidance, where both MR thermography and elastography have been used. The recent introduction of real-time dual-mode ultrasound array (DMUA) systems offers a new paradigm in transcranial focusing. In this paper, we present first experimental results of ultrasound-guided transcranial FUS (tFUS) application in a rodent brain, both ex vivo and in vivo. DMUA imaging is used for visualization of the treatment region for placement of the focal spot within the brain. This includes the detection and localization of pulsating blood vessels at or near the target point(s). In addition, DMUA imaging is used to monitor and localize the FUS-tissue interactions in real time. In particular, a concave (40 mm radius of curvature), 32-element, 3.5-MHz DMUA prototype was used for imaging and tFUS application in ex vivo and in vivo rat models. The ex vivo experiments were used to evaluate the point spread function of the transcranial DMUA imaging at various points within the brain. In addition, DMUA-based transcranial ultrasound thermography measurements were compared with thermocouple measurements of subtherapeutic tFUS heating in rat brain ex vivo. The ex vivo setting was also used to demonstrate the capability of DMUA to produce localized thermal lesions. The in vivo experiments were designed to demonstrate the ability of the DMUA to apply, monitor, and localize subtherapeutic tFUS patterns that could be beneficial in transient blood-brain barrier opening. The results show that although the DMUA focus is degraded due to the propagation through the skull, it still produces localized heating effects within a sub

  12. Synthesis of Millimeter-Scale Carbon Nanotube Arrays and Their Applications on Electrochemical Supercapacitors

    Science.gov (United States)

    Cui, Xinwei

    This research is aimed at synthesizing millimeter-scale carbon nanotube arrays (CNTA) by conventional chemical vapor deposition (CCVD) and water-assisted chemical vapor deposition (WACVD) methods, and exploring their application as catalyst supports for electrochemical supercapacitors. The growth mechanism and growth kinetics of CNTA under different conditions were systematically investigated to understand the relationship among physical characteristics of catalyst particles, growth parameters, and carbon nanotube (CNT) structures within CNTAs. Multiwalled CNT (MWCNT) array growth demonstrates lengthening and thickening stages in CCVD and WACVD. In CCVD, the lengthening and thickening were found to be competitive. By investigating catalyst particles after different pretreatment conditions, it has been found that inter-particle spacing plays a significant role in influencing CNTA height, CNT diameter and wall number. In WACVD, a long linear lengthening stage has been found. CNT wall number remains constant and catalysts preserve the activity in this stage, while MWCNTs thicken substantially and catalysts deactivate following the previously proposed radioactive decay model in the thickening stage of WACVD. Water was also shown to preserve the catalyst activity by significantly inhibiting catalyst-induced and gas phase-induced thickening processes in WACVD. Mn3O4 nanoparticles were successfully deposited and uniformly distributed within millimeter-long CNTAs by dip-casting method from non-aqueous solutions. After modification with Mn3O4 nanoparticles, CNTAs have been changed from hydrophobic to hydrophilic without their alignment and integrity being destroyed. The hydrophilic Mn 3O4/CNTA composite electrodes present ideal capacitive behavior with high reversibility. This opens up a new route of utilizing ultra-long CNTAs, based on which a scalable and cost-effective method was developed to fabricate composite electrodes using millimeter-long CNTAs. To improve the

  13. Combining vibrational biomolecular spectroscopy with chemometric techniques for the study of response and sensitivity of molecular structures/functional groups mainly related to lipid biopolymer to various processing applications.

    Science.gov (United States)

    Yu, Gloria Qingyu; Yu, Peiqiang

    2015-09-01

    The objectives of this project were to (1) combine vibrational spectroscopy with chemometric multivariate techniques to determine the effect of processing applications on molecular structural changes of lipid biopolymer that mainly related to functional groups in green- and yellow-type Crop Development Centre (CDC) pea varieties [CDC strike (green-type) vs. CDC meadow (yellow-type)] that occurred during various processing applications; (2) relatively quantify the effect of processing applications on the antisymmetric CH3 ("CH3as") and CH2 ("CH2as") (ca. 2960 and 2923 cm(-1), respectively), symmetric CH3 ("CH3s") and CH2 ("CH2s") (ca. 2873 and 2954 cm(-1), respectively) functional groups and carbonyl C=O ester (ca. 1745 cm(-1)) spectral intensities as well as their ratios of antisymmetric CH3 to antisymmetric CH2 (ratio of CH3as to CH2as), ratios of symmetric CH3 to symmetric CH2 (ratio of CH3s to CH2s), and ratios of carbonyl C=O ester peak area to total CH peak area (ratio of C=O ester to CH); and (3) illustrate non-invasive techniques to detect the sensitivity of individual molecular functional group to the various processing applications in the recently developed different types of pea varieties. The hypothesis of this research was that processing applications modified the molecular structure profiles in the processed products as opposed to original unprocessed pea seeds. The results showed that the different processing methods had different impacts on lipid molecular functional groups. Different lipid functional groups had different sensitivity to various heat processing applications. These changes were detected by advanced molecular spectroscopy with chemometric techniques which may be highly related to lipid utilization and availability. The multivariate molecular spectral analyses, cluster analysis, and principal component analysis of original spectra (without spectral parameterization) are unable to fully distinguish the structural differences in the

  14. Combining vibrational biomolecular spectroscopy with chemometric techniques for the study of response and sensitivity of molecular structures/functional groups mainly related to lipid biopolymer to various processing applications.

    Science.gov (United States)

    Yu, Gloria Qingyu; Yu, Peiqiang

    2015-09-01

    The objectives of this project were to (1) combine vibrational spectroscopy with chemometric multivariate techniques to determine the effect of processing applications on molecular structural changes of lipid biopolymer that mainly related to functional groups in green- and yellow-type Crop Development Centre (CDC) pea varieties [CDC strike (green-type) vs. CDC meadow (yellow-type)] that occurred during various processing applications; (2) relatively quantify the effect of processing applications on the antisymmetric CH3 ("CH3as") and CH2 ("CH2as") (ca. 2960 and 2923 cm(-1), respectively), symmetric CH3 ("CH3s") and CH2 ("CH2s") (ca. 2873 and 2954 cm(-1), respectively) functional groups and carbonyl C=O ester (ca. 1745 cm(-1)) spectral intensities as well as their ratios of antisymmetric CH3 to antisymmetric CH2 (ratio of CH3as to CH2as), ratios of symmetric CH3 to symmetric CH2 (ratio of CH3s to CH2s), and ratios of carbonyl C=O ester peak area to total CH peak area (ratio of C=O ester to CH); and (3) illustrate non-invasive techniques to detect the sensitivity of individual molecular functional group to the various processing applications in the recently developed different types of pea varieties. The hypothesis of this research was that processing applications modified the molecular structure profiles in the processed products as opposed to original unprocessed pea seeds. The results showed that the different processing methods had different impacts on lipid molecular functional groups. Different lipid functional groups had different sensitivity to various heat processing applications. These changes were detected by advanced molecular spectroscopy with chemometric techniques which may be highly related to lipid utilization and availability. The multivariate molecular spectral analyses, cluster analysis, and principal component analysis of original spectra (without spectral parameterization) are unable to fully distinguish the structural differences in the

  15. The interplay of intrinsic and extrinsic bounded noises in biomolecular networks.

    Directory of Open Access Journals (Sweden)

    Giulio Caravagna

    Full Text Available After being considered as a nuisance to be filtered out, it became recently clear that biochemical noise plays a complex role, often fully functional, for a biomolecular network. The influence of intrinsic and extrinsic noises on biomolecular networks has intensively been investigated in last ten years, though contributions on the co-presence of both are sparse. Extrinsic noise is usually modeled as an unbounded white or colored gaussian stochastic process, even though realistic stochastic perturbations are clearly bounded. In this paper we consider Gillespie-like stochastic models of nonlinear networks, i.e. the intrinsic noise, where the model jump rates are affected by colored bounded extrinsic noises synthesized by a suitable biochemical state-dependent Langevin system. These systems are described by a master equation, and a simulation algorithm to analyze them is derived. This new modeling paradigm should enlarge the class of systems amenable at modeling. We investigated the influence of both amplitude and autocorrelation time of a extrinsic Sine-Wiener noise on: (i the Michaelis-Menten approximation of noisy enzymatic reactions, which we show to be applicable also in co-presence of both intrinsic and extrinsic noise, (ii a model of enzymatic futile cycle and (iii a genetic toggle switch. In (ii and (iii we show that the presence of a bounded extrinsic noise induces qualitative modifications in the probability densities of the involved chemicals, where new modes emerge, thus suggesting the possible functional role of bounded noises.

  16. Physics at the biomolecular interface fundamentals for molecular targeted therapy

    CERN Document Server

    Fernández, Ariel

    2016-01-01

    This book focuses primarily on the role of interfacial forces in understanding biological phenomena at the molecular scale. By providing a suitable statistical mechanical apparatus to handle the biomolecular interface, the book becomes uniquely positioned to address core problems in molecular biophysics. It highlights the importance of interfacial tension in delineating a solution to the protein folding problem, in unravelling the physico-chemical basis of enzyme catalysis and protein associations, and in rationally designing molecular targeted therapies. Thus grounded in fundamental science, the book develops a powerful technological platform for drug discovery, while it is set to inspire scientists at any level in their careers determined to address the major challenges in molecular biophysics. The acknowledgment of how exquisitely the structure and dynamics of proteins and their aqueous environment are related attests to the overdue recognition that biomolecular phenomena cannot be effectively understood w...

  17. Single-Molecule Pull-down FRET (SiMPull-FRET) to dissect the mechanisms of biomolecular machines

    Science.gov (United States)

    Kahlscheuer, Matthew L.; Widom, Julia; Walter, Nils G.

    2016-01-01

    Spliceosomes are multi-megadalton RNA-protein complexes responsible for the faithful removal of non-coding segments (introns) from pre-messenger RNAs (pre-mRNAs), a process critical for the maturation of eukaryotic mRNAs for subsequent translation by the ribosome. Both the spliceosome and ribosome, as well as many other RNA and DNA processing machineries, contain central RNA components that endow biomolecular complexes with precise, sequence-specific nucleic acid recognition and versatile structural dynamics. Single molecule fluorescence (or Förster) resonance energy transfer (smFRET) microscopy is a powerful tool for the study of local and global conformational changes of both simple and complex biomolecular systems involving RNA. The integration of biochemical tools such as immunoprecipitation with advanced methods in smFRET microscopy and data analysis has opened up entirely new avenues towards studying the mechanisms of biomolecular machines isolated directly from complex biological specimens such as cell extracts. Here we detail the general steps for using prism-based total internal reflection fluorescence (TIRF) microscopy in exemplary single molecule pull-down FRET (SiMPull-FRET) studies of the yeast spliceosome and discuss the broad application potential of this technique. PMID:26068753

  18. Dense nanoimprinted silicon nanowire arrays with passivated axial p-i-n junctions for photovoltaic applications

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Peng; Liu, Pei; Siontas, Stylianos; Zaslavsky, A.; Pacifici, D. [Department of Physics and School of Engineering, Brown University, Providence, Rhode Island 02912 (United States); Ha, Jong-Yoon; Krylyuk, S. [Institute for Research in Electronics and Applied Physics, University of Maryland, College Park, Maryland 20742 (United States); Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States); Davydov, A. V. [Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States)

    2015-03-28

    We report on the fabrication and photovoltaic characteristics of vertical arrays of silicon axial p-i-n junction nanowire (NW) solar cells grown by vapor-liquid-solid (VLS) epitaxy. NW surface passivation with silicon dioxide shell is shown to enhance carrier recombination time, open-circuit voltage (V{sub OC}), short-circuit current density (J{sub SC}), and fill factor (FF). The photovoltaic performance of passivated individual NW and NW arrays was compared under 532 nm laser illumination with power density of ∼10 W/cm{sup 2}. Higher values of V{sub OC} and FF in the NW arrays are explained by enhanced light trapping. In order to verify the effect of NW density on light absorption and hence on the photovoltaic performance of NW arrays, dense Si NW arrays were fabricated using nanoimprint lithography to periodically arrange the gold seed particles prior to epitaxial growth. Compared to sparse NW arrays fabricated using VLS growth from randomly distributed gold seeds, the nanoimprinted NW array solar cells show a greatly increased peak external quantum efficiency of ∼8% and internal quantum efficiency of ∼90% in the visible spectral range. Three-dimensional finite-difference time-domain simulations of Si NW periodic arrays with varying pitch (P) confirm the importance of high NW density. Specifically, due to diffractive scattering and light trapping, absorption efficiency close to 100% in the 400–650 nm spectral range is calculated for a Si NW array with P = 250 nm, significantly outperforming a blanket Si film of the same thickness.

  19. Association of Biomolecular Resource Facilities Survey: Service Laboratory Funding

    OpenAIRE

    Ogorzalek Loo, Rachel; Nicolet, Charles M.; Niece, Ronald L.; Young, Mary; Simpson, John T.

    2009-01-01

    In 2007, The Association of Biomolecular Resource Facilities (ABRF) Survey Committee surveyed the ABRF membership and scientists at-large concerning the current state of funding in service-oriented laboratories. Questions pertained to services offered, cost recovery, capital equipment funding, and future outlook. The web-based survey, available for 3 weeks, achieved participation from 209 respondents in 13 countries, 77% of which represented academic laboratories. Most respondents (75%) direc...

  20. Dynamic Presentation of Immobilized Ligands Regulated through Biomolecular Recognition

    OpenAIRE

    Liu, Bo; Liu, Yang; Riesberg, Jeremiah J.; Shen, Wei

    2010-01-01

    To mimic the dynamic regulation of signaling ligands immobilized on extracellular matrices or on the surfaces of neighboring cells for guidance of cell behavior and fate selection, we have harnessed biomolecular recognition in combination with polymer engineering to create dynamic surfaces on which the accessibility of immobilized ligands to cell surface receptors can be reversibly interconverted under physiological conditions. The cell-adhesive RGD peptide is chosen as a model ligand. RGD is...

  1. WO3 thin film based multiple sensor array for electronic nose application

    International Nuclear Information System (INIS)

    Multiple sensor array comprising 16 x 2 sensing elements were realized using RF sputtered WO3 thin films. The sensor films were modified with a thin layer of sensitizers namely Au, Ni, Cu, Al, Pd, Ti, Pt. The resulting sensor array were tested for their response towards different gases namely H2S, NH3, NO and C2H5OH. The sensor response values measured from the response curves indicates that the sensor array generates a unique signature pattern (bar chart) for the gases. The sensor response values can be used to get both qualitative and quantitative information about the gas

  2. Application of different spatial sampling patterns for sparse-array transducer design

    DEFF Research Database (Denmark)

    Nikolov, Svetoslav; Jensen, Jørgen Arendt

    2000-01-01

    In the last years the efforts of many researchers have been focused ondeveloping 3D real-time scanners. The use of 2D phased-array transducers makes it possible to steer the ultrasonicbeam in all directions in the scanned volume. An unacceptably large amount oftransducer channels (more than $4000...... of the ultrasound fields show a decrease of the grating-lobe level of 10 dB for the diagonally optimized 2D array transducers compared to the the previuosly designed 2D arrays which didn't consider the diagonals....

  3. WO{sub 3} thin film based multiple sensor array for electronic nose application

    Energy Technology Data Exchange (ETDEWEB)

    Ramgir, Niranjan S., E-mail: niranjanpr@yahoo.com, E-mail: deepakcct1991@gmail.com; Goyal, C. P.; Datta, N.; Kaur, M.; Debnath, A. K.; Aswal, D. K.; Gupta, S. K. [Thin Film Devices Section, Technical Physics Division, Bhabha Atomic Research Centre, Mumbai–400085 (India); Goyal, Deepak, E-mail: niranjanpr@yahoo.com, E-mail: deepakcct1991@gmail.com [Thin Film Devices Section, Technical Physics Division, Bhabha Atomic Research Centre, Mumbai–400085 (India); Centre for Converging Technologies, University of Rajasthan, Jaipur-302004 (India)

    2015-06-24

    Multiple sensor array comprising 16 x 2 sensing elements were realized using RF sputtered WO{sub 3} thin films. The sensor films were modified with a thin layer of sensitizers namely Au, Ni, Cu, Al, Pd, Ti, Pt. The resulting sensor array were tested for their response towards different gases namely H{sub 2}S, NH{sub 3}, NO and C{sub 2}H{sub 5}OH. The sensor response values measured from the response curves indicates that the sensor array generates a unique signature pattern (bar chart) for the gases. The sensor response values can be used to get both qualitative and quantitative information about the gas.

  4. Applications of Flexible Ultrasonic Transducer Array for Defect Detection at 150 °C

    OpenAIRE

    Jiunn-Woei Liaw; Jing-Chi Tzeng; Chun-Hsiung Chiu; Jeanne-Louise Shih; Kuo-Ting Wu; Cheng-Kuei Jen

    2013-01-01

    In this study, the feasibility of using a one dimensional 16-element flexible ultrasonic transducer (FUT) array for nondestructive testing at 150 °C is demonstrated. The FUT arrays were made by a sol-gel sprayed piezoelectric film technology; a PZT composite film was sprayed on a titanium foil of 75 µm thickness. Since the FUT array is flexible, it was attached to a steel pipe with an outer diameter of 89 mm and a wall thickness of 6.5 mm at 150 °C. Using the ultras...

  5. Retroactivity in the Context of Modularly Structured Biomolecular Systems

    Science.gov (United States)

    Pantoja-Hernández, Libertad; Martínez-García, Juan Carlos

    2015-01-01

    Synthetic biology has intensively promoted the technical implementation of modular strategies in the fabrication of biological devices. Modules are considered as networks of reactions. The behavior displayed by biomolecular systems results from the information processes carried out by the interconnection of the involved modules. However, in natural systems, module wiring is not a free-of-charge process; as a consequence of interconnection, a reactive phenomenon called retroactivity emerges. This phenomenon is characterized by signals that propagate from downstream modules (the modules that receive the incoming signals upon interconnection) to upstream ones (the modules that send the signals upon interconnection). Such retroactivity signals, depending of their strength, may change and sometimes even disrupt the behavior of modular biomolecular systems. Thus, analysis of retroactivity effects in natural biological and biosynthetic systems is crucial to achieve a deeper understanding of how this interconnection between functionally characterized modules takes place and how it impacts the overall behavior of the involved cell. By discussing the modules interconnection in natural and synthetic biomolecular systems, we propose that such systems should be considered as quasi-modular. PMID:26137457

  6. Fano-resonance boosted cascaded field enhancement in a plasmonic nanoparticle-in-cavity nanoantenna array and its SERS application

    CERN Document Server

    Zhu, Zhendong; You, Oubo; Li, Qunqing; Fan, Shoushan

    2015-01-01

    Cascaded optical field enhancement (CFE) can be realized in some specially designed multiscale plasmonic nanostructures, where the generation of extremely strong field at nanoscale volume is crucial for many applications, for example, surface enhanced Raman spectroscopy (SERS). Here, we propose a strategy of realizing a high-quality plasmonic nanoparticle-in-cavity (PIC) nanoantenna array, where strong coupling between a nanoparticle dark mode with a high order nanocavity bright mode can produce Fano resonance at a target wavelength. The Fano resonance can effectively boost the CFE in the PIC, with a field enhancement factor up to 5X10^2. A cost-effective and reliable nanofabrication method is developed with room temperature nanoimprinting lithography to manufacture high-quality PIC arrays. This technique guarantees the generation of only one gold nanoparticle at the bottom of each nanocavity, which is crucial for the generation of the expected CFE. As a demonstration of the performance and application of the...

  7. Application of Novel Printed Dipole Antenna to Design Broadband Planar Phased Array

    Directory of Open Access Journals (Sweden)

    Jie Xu

    2014-01-01

    Full Text Available A broadband planar phased array consisting of 22 linear printed dipole antennas (PDA is presented in this paper. The element is designed by a coax probe feeding mechanism with a ground plate configuration. The PDA with two arms placed on both sides of a substrate is realized. The inner conductor of the coaxial cable is connected to the PDA’s upper arm, and the outer conductor is connected to the PDA’s lower arm, so it eliminates the balun. The impedance bandwidth of the PDA array can be improved by increasing mutual coupling effect between the adjacent array elements. A dielectric layer, which is integrated on the surface of the antenna, is designed and fabricated to improve the impedance bandwidth and to shield the array. The measured results indicate the active VSWR is less than 3 over the frequency range of 4–20 GHz.

  8. Arc arrays: studies of high resolution techniques for multibeam bathymetric applications

    Digital Repository Service at National Institute of Oceanography (India)

    Chakraborty, B.; Schenke, H.W.

    arrayof 15 degrees arc. The superiorityof the high resolution methods is seen by examining the patterns of the 15 degrees arc array under multiple source/interference conditions, i.e. the situation for rough terrain or artefactcreating conditions...

  9. Synthesis of ZnO nanosheet arrays with exposed (100) facets for gas sensing applications.

    Science.gov (United States)

    Xiao, Chuanhai; Yang, Tianye; Chuai, Mingyan; Xiao, Bingxin; Zhang, Mingzhe

    2016-01-01

    ZnO nanosheet (NS) arrays have been synthesized by a facile ultrathin liquid layer electrodeposition method. The ion concentration and electrode potential play important roles in the formation of ZnO NS arrays. Studies on the structural information indicate that the NSs are exposed with (100) facets. The results of Raman and PL spectra indicate that there existed a large amount of oxygen vacancies in the NSs. The gas sensing performances of the ZnO NS arrays are investigated: the ZnO NS arrays exhibited high gas selectivity and quick response/recovery for detecting NO2 at a low working temperature. High binding energies between NO2 molecules and exposed ZnO(100) facets lead to large surface reconstructions, which is responsible for the intrinsic NO2 sensing properties. In addition, the highly exposed surface and a large amount of oxygen vacancies existing in the NSs also make a great contribution to the gas sensing performance.

  10. Self-Assembled Wire Arrays and ITO Contacts for Silicon Nanowire Solar Cell Applications

    Institute of Scientific and Technical Information of China (English)

    YANG Cheng; ZHANG Gang; LEE Dae-Young; LI Hua-Min; LIM Young-Dae; Y00 Won Jong; PARK Young-Jun; KIM Jong-Min

    2011-01-01

    Self-assembly of silicon nanowire(SiNW)arrays is studied using SF6/02 plasma treatment. The self-assembly method can be applied to single- and poly-crystalline Si substrates. Plasma conditions can control the length and diameter of the SiNW arrays. Lower reflectance of the wire arrays over the wavelength range 200-1100nm is obtained. The conducting transparent indium-tin-oxide(ITO) electrode can be fully coated on the self-assembled SiNW arrays by sputtering. The ITO-coated SiNW solar cells show the same low surface light reflectance and a higher carrier collection efficiency than SiNW solar cells without ITO coating. An efficiency enhancement of around 3 times for ITO coated SiNW solar cells is demonstrated via experiments.

  11. Periodically Aligned Si Nanopillar Arrays as Efficient Antireflection Layers for Solar Cell Applications

    Directory of Open Access Journals (Sweden)

    Li Xiaocheng

    2010-01-01

    Full Text Available Abstract Periodically aligned Si nanopillar (PASiNP arrays were fabricated on Si substrate via a silver-catalyzed chemical etching process using the diameter-reduced polystyrene spheres as mask. The typical sub-wavelength structure of PASiNP arrays had excellent antireflection property with a low reflection loss of 2.84% for incident light within the wavelength range of 200–1,000 nm. The solar cell incorporated with the PASiNP arrays exhibited a power conversion efficiency (PCE of ~9.24% with a short circuit current density (JSC of ~29.5 mA/cm2 without using any extra surface passivation technique. The high PCE of PASiNP array-based solar cell was attributed to the excellent antireflection property of the special periodical Si nanostructure.

  12. High Resolution, Radiation Tolerant Focal Plane Array for Lunar And Deep Space Applications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Aerius Photonics and its partners propose the development of a high resolution, radiation hardened 3-D FLASH Focal Plane Array (FPA), with performance expected to...

  13. Fano-resonance boosted cascaded field enhancement in a plasmonic nanoparticle-in-cavity nanoantenna array and its SERS application

    OpenAIRE

    Zhu, Zhendong; Bai, Benfeng; You, Oubo; Li, Qunqing; Fan, Shoushan

    2015-01-01

    Cascaded optical field enhancement (CFE) can be realized in some specially designed multiscale plasmonic nanostructures, where the generation of extremely strong field at nanoscale volume is crucial for many applications, for example, surface enhanced Raman spectroscopy (SERS). Here, we propose a strategy of realizing a high-quality plasmonic nanoparticle-in-cavity (PIC) nanoantenna array, where strong coupling between a nanoparticle dark mode with a high order nanocavity bright mode can prod...

  14. Application of Gas Sensor Arrays in Assessment of Wastewater Purification Effects

    OpenAIRE

    Łukasz Guz; Grzegorz Łagód; Katarzyna Jaromin-Gleń; Zbigniew Suchorab; Henryk Sobczuk; Andrzej Bieganowski

    2014-01-01

    A gas sensor array consisting of eight metal oxide semiconductor (MOS) type gas sensors was evaluated for its ability for assessment of the selected wastewater parameters. Municipal wastewater was collected in a wastewater treatment plant (WWTP) in a primary sedimentation tank and was treated in a laboratory-scale sequential batch reactor (SBR). A comparison of the gas sensor array (electronic nose) response to the standard physical-chemical parameters of treated wastewater was performed. To ...

  15. A paper-supported graphene-ionic liquid array for e-nose application.

    Science.gov (United States)

    Zhu, X; Liu, D; Chen, Q; Lin, L; Jiang, S; Zhou, H; Zhao, J; Wu, J

    2016-02-18

    A flexible graphene sensor array has been fabricated by in situ reduction of a graphene oxide (GO) array patterned on a paper chip. To achieve cross-reactive sensing and gas discrimination ability, the surface of each reduced GO (rGO) spot was modified with different types of ionic liquids (ILs), which could significantly alter the semiconductor properties and consequently the gas sensing behaviour of the paper-supported rGO sensor. PMID:26794831

  16. Reconfigurable Plasma Antenna Array by Using Fluorescent Tube for Wi-Fi Application

    OpenAIRE

    H. Ja’afar; M. T. Ali; Dagang, A N; I. P. Ibrahim; N. A. Halili; H. M. Zali

    2016-01-01

    This paper presents a new design of reconfigurable plasma antenna array using commercial fluorescent tube. A round shape reconfigurable plasma antenna array is proposed to collimate beam radiated by an omnidirectional antenna (monopole antenna) operates at 2.4GHz in particular direction. The antenna design is consisted of monopole antenna located at the center of circular aluminum ground. The monopole antenna is surrounded by a cylindrical shell of conducting plasma. The plasma shield consist...

  17. Increase Jc by Improving the Array of Nb3Sn strands for Fusion Application

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Xuan Peng

    2012-12-17

    During Phase I, our efforts were focusing on improving the array of subelement in the tube type strands by hardening the Sn core and the subelement matrix to effectively increase the Jc of the strands. Below is a summary of the results. 1) We were unsuccessful in improving the array using a Cu-Sn matrix approach. 2) We slightly improved the array using Sn with 1.5at%Ti doped core, and a 217-subelement restacked strand was made and drawn down without any breakage. 3) We greatly improved the array using the Glidcop Al-15 to replace the pure Cu sheath in the subelement, and a 217-subelement restacked strand was made and drawn down. Both strands have very good drawability and the array showed good improvement. 4) We also improved the array using improved wire drawing techniques using Hyper Tech’s new caterpillar wire drawing machines to enable straight wire drawing for the entire wire drawing process. 5) The 919-subelement restack strand shows its non-Cu Jc over 2100 A/mm2 at 12 T/4.2 K and AC loss of 508 mJ/cm3.

  18. High efficiency and dual polarized array antenna for satellite communication application

    Science.gov (United States)

    Liu, Ningmin

    2009-12-01

    In this paper, we describe a flat plate array for the satellite communication receiver, with small aperture, high efficiency and low cross polarization levels. The radiating element used is circular waveguide which is probe-fed using a stripline distribution networks providing uniform excitations to the 4×4 array. The networks are placed one behind the other for dual polarized purposes. The array is composed of 2×1 subarrays. The overall array thickness is about 1λ ( λ is the wavelength of the center frequency), and the array aperture is about 3.2λ. Simulated results on a Ku-band prototype are discussed. The bandwidth (VSWR below 2.0) is about 500MHz, cross-polarized radiation from both ports is below -35dB, the isolation between the ports is below -25dB, and the gain of the 4×4 array is about 20dBi. Simulated efficiency is about 75% (including the stripline feed networks).

  19. Microstructure and magnetic properties of micro NiFe alloy arrays for MEMS application

    International Nuclear Information System (INIS)

    NiFe alloy arrays with various geometry sizes and shapes were designed, fabricated and investigated. Electrodeposition was introduced as a highly effective integrated method to fabricate the alloy film. The influence of dimensional size and geometry shape of the array unit was discussed. With decreasing size, the soft magnetic properties of the samples are improved with a 78.6% decrease of coercivity and an 65.0% decrease of squareness ratio. Compared with square and rectangular arrays, circular arrays exhibit smaller coercivity, higher permeability and smaller squareness ratio. Additionally, different compositional arrays were also tested for their crystal structures. It is found that the alloy with a content of Ni80Fe20 can achieve a face-centered cubic structure and realize the best soft magnetic properties. A coercivity of 0.383 Oe, a squareness ratio of 4.21 × 10−4 and a saturation magnetization of 4.2 T have been successfully achieved in circular arrays within an area of 2000 × 2000 µm2. (paper)

  20. Controlled growth of standing Ag nanorod arrays on bare Si substrate using glancing angle deposition for self-cleaning applications

    Science.gov (United States)

    Singh, Dhruv P.; Singh, J. P.

    2014-03-01

    A facile approach to manipulate the hydrophobicity of surface by controlled growth of standing Ag nanorod arrays is presented. Instead of following the complicated conventional method of the template-assisted growth, the morphology or particularly average diameter and number density (nanorods cm-2) of nanorods were controlled on bare Si substrate by simply varying the deposition rate during glancing angle deposition. The contact angle measurements showed that the evolution of Ag nanorods reduces the surface energy and makes an increment in the apparent water contact angle compared to the plain Ag thin film. The contact angle was found to increase for the Ag nanorod samples grown at lower deposition rates. Interestingly, the morphology of the nanorod arrays grown at very low deposition rate (1.2 Å sec-1) results in a self-cleaning superhydrophobic surface of contact angle about 157° and a small roll-off angle about 5°. The observed improvement in hydrophobicity with change in the morphology of nanorod arrays is explained as the effect of reduction in solid fraction within the framework of Cassie-Baxter model. These self-cleaning Ag nanorod arrays could have a significant impact in wide range of applications such as anti-icing coatings, sensors and solar panels.

  1. Computational Studies on Biomolecular Diffusion and Electrostatics

    OpenAIRE

    Wang, Nuo

    2015-01-01

    As human understandings of physics, chemistry and biology converge and the development of computers proceeds, computational chemistry or computational biophysics has become a substantial field of research. It serves to explore the fundamentals of life and also has extended applications in the field of medicine. Among the many aspects of computational chemistry, this Ph. D. work focuses on the numerical methods for studying diffusion and electrostatics of biomolecules at the nanoscale. Diffusi...

  2. Application of simple array method in one-way traffic synthetic asessment

    Institute of Scientific and Technical Information of China (English)

    PEI Yu-long; LIU Guang-ping

    2005-01-01

    One-Way Traffic synthetic assessing can not only determine the assessment method, but can also provide an opportunity for further study of road systems. Comparing three Road Traffic Planning methods, which are Value Analysis method, Simple Array method and Step Analysis method, this paper concludes that Simple Array method has one prominent merit, avoiding the complicated relationship of various factors and simplifying the complex problem. Therefore Simple Array method is firstly presented in this paper to be the assessing measure to assess the One-Way Traffic Planning project. Although this assessing method cannot wholly give way to man's will, through consistently testing on qualitative factors and with the decision-making results of a multiprogram, this method is still an effective method. Using an example of Harbin One-Way Traffic planning, with seven assessing indexes including economic benefit index, Simple Array method is applied to synthetically assessing the program. This fully reflects the general function of One-Way Traffic planning program and objectively evaluates the program. It also proves that, as the method of One-Way Traffic synthetic assessing, Simple Array method is rational and practical.

  3. Multi-layer hierarchical array fabricated with diatom frustules for highly sensitive bio-detection applications

    International Nuclear Information System (INIS)

    Diatoms have delicate porous structures which are very beneficial in improving the absorbing ability in the bio-detection field. In this study, multi-layered hierarchical arrays were fabricated by packing Nitzschia soratensis (N. soratensis) frustules into Cosinodiscus argus (C. argus) frustules to achieve advanced sensitivity in bio-detection chips. Photolithographic patterning was used to obtain N. soratensis frustule arrays, and the floating behavior of C. argus frustules was employed to control their postures for packing N. soratensis frustule array spots. The morphology of the multi-layer C. argus–N. soratensis package array was investigated by scanning electron microscopy, demonstrating that the overall and sub-structures of the diatom frustules were retained. The signal enhancing effect of multi-layer C. argus–N. soratensis packages was demonstrated by fluorescent antibody test results. The mechanism of the enhancement was also analyzed, indicating that both complex hierarchical frustule structures and optimized posture of C. argus frustules were important for improving bio-detection sensitivities. The technique for fabricating multi-layer diatom frustules arrays is also useful for making multi-functional biochips and controllable drug delivery systems. (paper)

  4. Low concentration ratio solar array for low Earth orbit multi-100 kW application

    Science.gov (United States)

    Nalbandian, S. J.

    1982-01-01

    An ongoing preliminary design effort directed toward a low-concentration-ratio photovoltaic array system based on 1984 technology and capable of delivering multi-hundred kilowatts (300 kW to 1000 kW range) in low earth orbit is described. The array system consists of two or more array modules each capable of delivering between 80 kW to 172 kW using silicon solar cells or gallium arsenide solar cells respectively. The array module deployed area is 1320 square meters and consists of 4356 pryamidal concentrator elements. The module, when stowed in the Space Shuttle's payload bay, has a stowage volume of a cube with 3.24 meters on a side. The concentrator elements are sized for a geometric concentration ratio (GCR) of six with an aperture area of 0.5 meters x 0.5 meters. The structural analysis and design trades leading to the baseline design are discussed. The configuration, as well as optical, thermal and electrical performance analyses that support the design and overall performance estimates for the array are described.

  5. Enhanced semiempirical QM methods for biomolecular interactions

    Directory of Open Access Journals (Sweden)

    Nusret Duygu Yilmazer

    2015-01-01

    Full Text Available Recent successes and failures of the application of ‘enhanced’ semiempirical QM (SQM methods are reviewed in the light of the benefits and backdraws of adding dispersion (D and hydrogen-bond (H correction terms. We find that the accuracy of SQM-DH methods for non-covalent interactions is very often reported to be comparable to dispersion-corrected density functional theory (DFT-D, while computation times are about three orders of magnitude lower. SQM-DH methods thus open up a possibility to simulate realistically large model systems for problems both in life and materials science with comparably high accuracy.

  6. Enhanced semiempirical QM methods for biomolecular interactions.

    Science.gov (United States)

    Yilmazer, Nusret Duygu; Korth, Martin

    2015-01-01

    Recent successes and failures of the application of 'enhanced' semiempirical QM (SQM) methods are reviewed in the light of the benefits and backdraws of adding dispersion (D) and hydrogen-bond (H) correction terms. We find that the accuracy of SQM-DH methods for non-covalent interactions is very often reported to be comparable to dispersion-corrected density functional theory (DFT-D), while computation times are about three orders of magnitude lower. SQM-DH methods thus open up a possibility to simulate realistically large model systems for problems both in life and materials science with comparably high accuracy. PMID:25848495

  7. A low power 10 V programmable array based on Nb x Si1-x Josephson junctions for metrology applications

    Science.gov (United States)

    Knipper, Richard; Anders, Solveig; Schubert, Marco; Peiselt, Katja; Scheller, Thomas; Franke, Dirk; Dellith, Jan; Meyer, Hans-Georg

    2016-09-01

    Josephson junctions generate, when subjected to microwave irradiation, voltages with a very high precision and are used in metrology applications. So-called PJVS (programmable Josephson voltage-standards) are capable of generating both AC and DC voltages of up to 10 V. Our work addresses a full fabrication scenario for 10 V PJVS arrays driven at 70 GHz to be used in low microwave-power conditions as in, but not limited to GUNN diodes or cryocooler applications. Nb x Si1-x in its function as a barrier material was characterised with AFM, RBS and reflectometry in order to establish a reliable technological foundation. A 10 V PJVS array driven with microwave power below 50 mW is further presented, which was achieved by optimising the fabrication technology regarding the degree of homogeneity of the Josephson junctions composition and thickness. Control over these parameters is crucial in choosing a stable and well-suited characteristic voltage (I c R n product) and critical current density j c. With this, a low-power operation of a PJVS array is possible without the need for liquid helium cooling, which is currently limiting the availability of PJVS based metrology.

  8. A scalable multi-chip architecture to realise large-format microshutter arrays for coded aperture applications

    Science.gov (United States)

    McNie, Mark E.; King, David O.; Smith, Gilbert W.; Stone, Steven M.; Brown, Alan G.; Gordon, Neil T.; Slinger, Christopher W.; Cannon, Kevin; Riches, Stephen; Rogers, Stanley

    2009-08-01

    Coded aperture imaging has been used for astronomical applications for several years. Typical implementations used a fixed mask pattern and are designed to operate in the X-Ray or gamma ray bands. Recently applications have emerged in the visible and infra red bands for low cost lens-less imaging systems and system studies have shown that considerable advantages in image resolution may accrue from the use of multiple different images of the same scene - requiring a reconfigurable mask. Previously we reported on the realization of a 2x2cm single chip mask in the mid-IR based on polysilicon micro-opto-electro-mechanical systems (MOEMS) technology and its integration with ASIC drive electronics using conventional wire bonding. The MOEMS architecture employs interference effects to modulate incident light - achieved by tuning a large array of asymmetric Fabry-Perot optical cavities via an applied voltage and uses a hysteretic row/column scheme for addressing. In this paper we present the latest transmission results in the mid-IR band (3-5μm) and report on progress in developing a scalable architecture based on a tiled approach using multiple 2 x 2cm MOEMS chips with associated control ASICs integrated using flip chip technology. Initial work has focused on a 2 x 2 tiled array as a stepping stone towards an 8 x 8 array.

  9. Application of a sensor array based on capillary-attached conductive gas sensors for odor identification

    International Nuclear Information System (INIS)

    An electronic nose based on an array of capillary-attached conductive gas sensors was fabricated. The identification ability of the developed structure was investigated by employing different categories of simple and complex odor databases. Feature data sets were generated from the dynamic and steady state responses of the sensor array to the applied odor databases. Combinations of different feature extraction and classification methods were used to detect target gases. Validation of each technique was evaluated. Achievements of the study proved high classification rates of the fabricated e-nose in odor identification. It was indicated that gas identification is possible by applying the early selected portion of transient responses of the developed sensor array. The ability of the mentioned structure in analyzing gas mixtures was also investigated. The results presented high accuracy in the classification of gas mixtures

  10. Application of ultrasonic phased array technique for inspection of stud bolts in nuclear reactor vessel

    International Nuclear Information System (INIS)

    The stud bolt is one of crucial parts for safety of reactor vessels in nuclear power plants. Cracks initiation and propagation were reported in stud bolts using closure of reactor vessel and head. Stud bolts are inspected by ultrasonic technique during overhaul periodically for the prevention of stud bolt failure and radioactive leakage from nuclear reactor. In conventional ultrasonic testing for inspection of stud bolts, crack was detected by using shadow effect. It take too much time to inspect stud bolt by using conventional ultrasonic technique. In addition, there were numerous spurious signal reflected from every thread. In this study, the advanced ultrasonic phased array technique was introduced for inspect stud bolts. The phased array technique provide fast inspection and high detectability of defects. There are sector scanning and linear scanning method in phased array technique, and these scanning methods were applied to inspect stud bolt and detectability was investigated.

  11. Arrays of microscopic magnetic traps for cold atoms and their applications in atom optics

    Institute of Scientific and Technical Information of China (English)

    印建平; 高伟建; 胡建军

    2002-01-01

    A single microscopic magnetic trap for neutral atoms using planar current-carrying wires was proposed and studiedtheoretically by Weinstein et al. In this paper, we propose three structures of composite current-carrying wires to provide1D, 2D and 3D arrays of microscopic magnetic traps for cold alkali atoms. The spatial distributions of magnetic fieldsgenerated by these structures are calculated and the field gradient and curvature in each single microtrap are analysed.Our study shows that arrays of microscopic magnetic traps can be used to provide 1D, 2D or 3D atomic magneticlattices, and even to realize 1D, 2D and 3D arrays of magneto-optical traps, and so on.

  12. Complementary bipolar application specific analog semicustom array, intended to implement front-end units

    CERN Document Server

    Atkin, E; Kondratenko, S; Maslennikov, V; Meshcheriakov, V; Mishin, Yu; Volkov, Yu

    2002-01-01

    The structure of an analog semicustom array, intended to implement front-end electronics ICs on its basis, is considered. The features of this array are: implementation with an inexpensive bipolar process despite containing an equal number of NPN and PNP structures with well matched characteristics, supply voltages from 1.5 V to 15 V, transistor current gains Bst~100 and unity gain frequencies Ft > 3 GHz at collector currents of (100...300) mu A, high- and low-ohmic resistors, MOS capacitors, minimum two variable plating levels available. Specific circuit diagrams and parameters of the front-end electronics ICs, created on the basis of the considered array, are presented. The results of their tests are given. (4 refs).

  13. Flexible complementary metal oxide semiconductor microelectrode arrays with applications in single cell characterization

    Science.gov (United States)

    Pajouhi, H.; Jou, A. Y.; Jain, R.; Ziabari, A.; Shakouri, A.; Savran, C. A.; Mohammadi, S.

    2015-11-01

    A highly flexible microelectrode array with an embedded complementary metal oxide semiconductor (CMOS) instrumentation amplifier suitable for sensing surfaces of biological entities is developed. The array is based on ultrathin CMOS islands that are thermally isolated from each other and are interconnected by meandered nano-scale wires that can adapt to cellular surfaces with micro-scale curvatures. CMOS temperature sensors are placed in the islands and are optimally biased to have high temperature sensitivity. While no live cell thermometry is conducted, a measured temperature sensitivity of 0.15 °C in the temperature range of 35 to 40 °C is achieved by utilizing a low noise CMOS lock-in amplifier implemented in the same technology. The monolithic nature of CMOS sensors and amplifier circuits and their versatile flexible interconnecting wires overcome the sensitivity and yield limitations of microelectrode arrays fabricated in competing technologies.

  14. Cellular automata modelling of biomolecular networks dynamics.

    Science.gov (United States)

    Bonchev, D; Thomas, S; Apte, A; Kier, L B

    2010-01-01

    The modelling of biological systems dynamics is traditionally performed by ordinary differential equations (ODEs). When dealing with intracellular networks of genes, proteins and metabolites, however, this approach is hindered by network complexity and the lack of experimental kinetic parameters. This opened the field for other modelling techniques, such as cellular automata (CA) and agent-based modelling (ABM). This article reviews this emerging field of studies on network dynamics in molecular biology. The basics of the CA technique are discussed along with an extensive list of related software and websites. The application of CA to networks of biochemical reactions is exemplified in detail by the case studies of the mitogen-activated protein kinase (MAPK) signalling pathway, the FAS-ligand (FASL)-induced and Bcl-2-related apoptosis. The potential of the CA method to model basic pathways patterns, to identify ways to control pathway dynamics and to help in generating strategies to fight with cancer is demonstrated. The different line of CA applications presented includes the search for the best-performing network motifs, an analysis of importance for effective intracellular signalling and pathway cross-talk. PMID:20373215

  15. Relaxing the electrostatic screening effect by patterning vertically-aligned silicon nanowire arrays into bundles for field emission application

    Energy Technology Data Exchange (ETDEWEB)

    Hung, Yung-Jr, E-mail: yungjrhung@gmail.com [Department of Electronic Engineering, National Taiwan University of Science and Technology, No. 43, Sec. 4, Keelung Rd., Taipei 106, Taiwan, ROC (China); Department of Photonics, National Sun Yat-sen University, No. 70, Lienhai Rd., Kaohsiung 80424, Taiwan, ROC (China); Graduate Institute of Electro-Optical Engineering, National Taiwan University of Science and Technology, No. 43, Sec. 4, Keelung Rd., Taipei 106, Taiwan, ROC (China); Lee, San-Liang [Department of Electronic Engineering, National Taiwan University of Science and Technology, No. 43, Sec. 4, Keelung Rd., Taipei 106, Taiwan, ROC (China); Graduate Institute of Electro-Optical Engineering, National Taiwan University of Science and Technology, No. 43, Sec. 4, Keelung Rd., Taipei 106, Taiwan, ROC (China); Beng, Looi Choon [Faculty of Engineering, Multimedia University, Jalan Multimedia, 63100 Cyberjaya, Selangor (Malaysia); Chang, Hsuan-Chen [Department of Electronic Engineering, National Taiwan University of Science and Technology, No. 43, Sec. 4, Keelung Rd., Taipei 106, Taiwan, ROC (China); Graduate Institute of Electro-Optical Engineering, National Taiwan University of Science and Technology, No. 43, Sec. 4, Keelung Rd., Taipei 106, Taiwan, ROC (China); Huang, Yung-Jui [Graduate Institute of Electro-Optical Engineering, National Taiwan University of Science and Technology, No. 43, Sec. 4, Keelung Rd., Taipei 106, Taiwan, ROC (China); Lee, Kuei-Yi; Huang, Ying-Sheng [Department of Electronic Engineering, National Taiwan University of Science and Technology, No. 43, Sec. 4, Keelung Rd., Taipei 106, Taiwan, ROC (China); Graduate Institute of Electro-Optical Engineering, National Taiwan University of Science and Technology, No. 43, Sec. 4, Keelung Rd., Taipei 106, Taiwan, ROC (China)

    2014-04-01

    Top-down fabrication strategies are proposed and demonstrated to realize arrays of vertically-aligned silicon nanowire bundles and bundle arrays of carbon nanotube–silicon nanowire (CNT–SiNW) heterojunctions, aiming for releasing the electrostatic screening effect and improving the field emission characteristics. The trade-off between the reduction in the electrostatic screening effect and the decrease of emission sites leads to an optimal SiNW bundle arrangement which enables the lowest turn-on electric field of 1.4 V/μm and highest emission current density of 191 μA/cm{sup 2} among all testing SiNW samples. Benefiting from the superior thermal and electrical properties of CNTs and the flexible patterning technologies available for SiNWs, bundle arrays of CNT–SiNW heterojunctions show improved and highly-uniform field emission with a lower turn-on electric field of 0.9 V/μm and higher emission current density of 5.86 mA/cm{sup 2}. The application of these materials and their corresponding fabrication approaches is not limited to the field emission but can be used for a variety of emerging fields like nanoelectronics, lithium-ion batteries, and solar cells. - Highlights: • Aligned silicon nanowire (SiNW) bundle arrays are realized with top-down methods. • Growing carbon nanotubes atop SiNW bundle arrays enable uniform field emission. • A turn-on field of 0.9 V/μm and an emission current of > 5 mA/cm{sup 2} are achieved.

  16. Optimal Design of Low-Density SNP Arrays for Genomic Prediction: Algorithm and Applications.

    Science.gov (United States)

    Wu, Xiao-Lin; Xu, Jiaqi; Feng, Guofei; Wiggans, George R; Taylor, Jeremy F; He, Jun; Qian, Changsong; Qiu, Jiansheng; Simpson, Barry; Walker, Jeremy; Bauck, Stewart

    2016-01-01

    Low-density (LD) single nucleotide polymorphism (SNP) arrays provide a cost-effective solution for genomic prediction and selection, but algorithms and computational tools are needed for the optimal design of LD SNP chips. A multiple-objective, local optimization (MOLO) algorithm was developed for design of optimal LD SNP chips that can be imputed accurately to medium-density (MD) or high-density (HD) SNP genotypes for genomic prediction. The objective function facilitates maximization of non-gap map length and system information for the SNP chip, and the latter is computed either as locus-averaged (LASE) or haplotype-averaged Shannon entropy (HASE) and adjusted for uniformity of the SNP distribution. HASE performed better than LASE with ≤1,000 SNPs, but required considerably more computing time. Nevertheless, the differences diminished when >5,000 SNPs were selected. Optimization was accomplished conditionally on the presence of SNPs that were obligated to each chromosome. The frame location of SNPs on a chip can be either uniform (evenly spaced) or non-uniform. For the latter design, a tunable empirical Beta distribution was used to guide location distribution of frame SNPs such that both ends of each chromosome were enriched with SNPs. The SNP distribution on each chromosome was finalized through the objective function that was locally and empirically maximized. This MOLO algorithm was capable of selecting a set of approximately evenly-spaced and highly-informative SNPs, which in turn led to increased imputation accuracy compared with selection solely of evenly-spaced SNPs. Imputation accuracy increased with LD chip size, and imputation error rate was extremely low for chips with ≥3,000 SNPs. Assuming that genotyping or imputation error occurs at random, imputation error rate can be viewed as the upper limit for genomic prediction error. Our results show that about 25% of imputation error rate was propagated to genomic prediction in an Angus population. The

  17. Formation of organic crystalline nanopillar arrays and their application to organic photovoltaic cells.

    Science.gov (United States)

    Hirade, Masaya; Nakanotani, Hajime; Yahiro, Masayuki; Adachi, Chihaya

    2011-01-01

    To enhance the performance of organic photovoltaic (OPV) cells, preparation of organic nanometer-sized pillar arrays is fascinating because a significantly large area of a donor/acceptor heterointerface having continuous conduction path to both anode and cathode electrodes can be realized. In this study, we grew cupper phthalocyanine (CuPc) crystalline nanopillar arrays by conventional thermal gradient sublimation technique using a few-nanometer-sized trigger seeds composed of a CuPc and 3,4,9,10-perylene-tetracarboxylic-dianhydride (PTCDA) stacked layer. We optimized the pillar density by tuning crystal growth condition in order to apply it to OPV cells.

  18. Formation of organic crystalline nanopillar arrays and their application to organic photovoltaic cells.

    Science.gov (United States)

    Hirade, Masaya; Nakanotani, Hajime; Yahiro, Masayuki; Adachi, Chihaya

    2011-01-01

    To enhance the performance of organic photovoltaic (OPV) cells, preparation of organic nanometer-sized pillar arrays is fascinating because a significantly large area of a donor/acceptor heterointerface having continuous conduction path to both anode and cathode electrodes can be realized. In this study, we grew cupper phthalocyanine (CuPc) crystalline nanopillar arrays by conventional thermal gradient sublimation technique using a few-nanometer-sized trigger seeds composed of a CuPc and 3,4,9,10-perylene-tetracarboxylic-dianhydride (PTCDA) stacked layer. We optimized the pillar density by tuning crystal growth condition in order to apply it to OPV cells. PMID:21194207

  19. Digitalization decoupling method and its application to the phased array in MRI

    Institute of Scientific and Technical Information of China (English)

    SONG Xiaoyu; WANG Weidong; ZHANG Bida; LEI Ming; BAO Shanglian

    2003-01-01

    A general network decoupling method for phased array radio frequency coil used in magnetic resonance imaging is developed. A more flexible digital approach further simplifies the method, which has an even higher signal-to-noise ratio. The performance of the digitalized decoupling method was confirmed by the calculated result by using a high frequency structure simulation software with the method of finite element for a tree-port phased array RF coil. The consistence was well established between the theoretical and simulated results.

  20. Application of highly-ordered TiO2 nanotube-arrays in heterojunction dye-sensitized solar cells

    Science.gov (United States)

    Paulose, Maggie; Shankar, Karthik; Varghese, Oomman K.; Mor, Gopal K.; Grimes, Craig A.

    2006-06-01

    Highly-ordered TiO2 nanotube arrays are made by potentiostatic anodization of a titanium film in a fluoride containing electrolyte. Here we describe the application of this unique material architecture in both front-side and back-side illuminated dye-sensitized solar cells (DSSCs). The back-side illuminated solar cells are based on the use of 6.2 µm long (110 nm pore diameter, 20 nm wall thickness) highly-ordered nanotube-array films made by anodization of a 250 µm thick Ti foil in a KF electrolyte. Front-side illuminated solar cells use a negative electrode composed of optically transparent nanotube arrays, approximately 3600 nm in length (46 nm pore diameter, 17 nm wall thickness), grown on a fluorine doped tin oxide coated glass substrate by anodic oxidation of a previously deposited RF-sputtered titanium thin film in a HF electrolyte. After crystallization by oxygen annealling the nanotube-arrays are treated with TiCl4 to enhance photocurrent amplitudes. The arrays are then sensitized by a self-assembled monolayer of bis(tetrabutylammonium)-cis-(dithiocyanato)-N, N'- bis(4-carboxylato-4'-carboxylic acid-2, 2'-bipyridine)ruthenium(II) (commonly called 'N719'). Superior photoresponse is obtained using acetonitrile as the dye solvent. Voltage decay measurements indicate that the highly-ordered TiO2 nanotube-arrays, in comparison with nanoparticulate systems, provide excellent pathways for electron percolation with superior electron lifetimes. The front-side illuminated DSSCs, show a typical AM 1.5 photocurrent of 10.3 mA cm-2, open circuit voltage of 0.84 V, 0.54 fill factor, and 4.7% efficiency although the transparent nanotube-array negative electrode is only 360 nm thick. The back-side illuminated DSSCs show an AM 1.5 short-circuit current density of 10.6 mA cm-2, 0.82 V open circuit potential and a 0.51 fill factor yielding a solar conversion efficiency of 4.4%.

  1. Polymer packaging for arrayed ionic polymer–metal composites and its application to micro air vehicle control surface

    International Nuclear Information System (INIS)

    In this study, ionic polymer–metal composite (IPMC) actuators arrayed in horizontal as well as vertical directions were investigated for more effective actuation performance. A very thin polymer packaging structure named 'glove' was designed and fabricated, and the IPMC package, composed of the glove and the arrayed IPMCs, was applied to the multifunctional control surface of a micro air vehicle (MAV). The IPMC package is light and space-saving, and therefore appropriate for the application of a MAV which has a limitation in weight and size. A wind tunnel test was performed to demonstrate the capability of the IPMC package for the control surface of a MAV and it was confirmed that the package generates enough force to maneuver a MAV

  2. Fabrication of flexible MoS2 thin-film transistor arrays for practical gas-sensing applications.

    Science.gov (United States)

    He, Qiyuan; Zeng, Zhiyuan; Yin, Zongyou; Li, Hai; Wu, Shixin; Huang, Xiao; Zhang, Hua

    2012-10-01

    By combining two kinds of solution-processable two-dimensional materials, a flexible transistor array is fabricated in which MoS(2) thin film is used as the active channel and reduced graphene oxide (rGO) film is used as the drain and source electrodes. The simple device configuration and the 1.5 mm-long MoS(2) channel ensure highly reproducible device fabrication and operation. This flexible transistor array can be used as a highly sensitive gas sensor with excellent reproducibility. Compared to using rGO thin film as the active channel, this new gas sensor exhibits much higher sensitivity. Moreover, functionalization of the MoS(2) thin film with Pt nanoparticles further increases the sensitivity by up to ∼3 times. The successful incorporation of a MoS(2) thin-film into the electronic sensor promises its potential application in various electronic devices. PMID:22778003

  3. Fabrication, Modification, and Emerging Applications of TiO2 Nanotube Arrays by Electrochemical Synthesis: A Review

    Directory of Open Access Journals (Sweden)

    Jian-Ying Huang

    2013-01-01

    Full Text Available Titania nanotube arrays (TNAs as a hot nanomaterial have a unique highly ordered array structure and good mechanical and chemical stability, as well as excellent anticorrosion, biocompatible, and photocatalytic performance. It has been fabricated by a facile electrochemical anodization in electrolytes containing small amounts of fluoric ions. In combination with our research work, we review the recent progress of the new research achievements of TNAs on the preparation processes, forming mechanism, and modification. In addition, we will review the potential and significant applications in the photocatalytic degradation of pollutants, solar cells, water splitting, and other aspects. Finally, the existing problems and further prospects of this renascent and rapidly developing field are also briefly addressed and discussed.

  4. Biomolecular ion detection using high-temperature superconducting MgB2 strips

    Science.gov (United States)

    Zen, N.; Shibata, H.; Mawatari, Y.; Koike, M.; Ohkubo, M.

    2015-06-01

    Superconducting strip ion detectors (SSIDs) are promising for realization of ideal ion detection with 100% efficiency and nanosecond-scale time response in time-of-flight mass spectrometry. We have detected single biomolecular ions in the keV range using a 10-nm-thick and 250-nm-wide strip of a high temperature superconductor, magnesium diboride (MgB2), at temperatures of up to 13 K. The output pulse shape is explained remarkably well using circuit simulations and time-dependent Ginzburg-Landau simulations coupled with a heat diffusion equation. The simulations show that the hot spot model is applicable to the proposed MgB2-SSIDs and the normal region expansion is completed within 16 ps, which corresponds to a maximum length of 1010 nm.

  5. A program to calculate non-bonded interaction energy in biomolecular aggregates.

    Science.gov (United States)

    Sundaram, K; Prasad, C V

    1982-02-01

    This paper describes a program to calculate intermolecular as well as intramolecular electronic potential energy resulting from non-bonded interactions. The underlying theory is obtained by the application of Rayleigh-Schroedinger perturbation theory to non-overlap regions of a molecular system. The rigorous theoretical expressions for the energy terms are simplified by approximations consistent with those commonly employed in semi-empirical molecular orbital theories. The program is particularly suited for the study of biomolecular assemblies, and in situations where insight into contributions to total energy from various component interaction types is desired. The inclusion of the non-additive dispersion effects in this approach makes it especially interesting for the study of cooperative phenomena in the light of a recent finding [1]. PMID:7067416

  6. Prussian Blue-coated interdigitated array electrodes for possible analytical application

    NARCIS (Netherlands)

    Hartmann, M.; Grabner, E.W.; Bergveld, P.

    1991-01-01

    Thin films of iron(III) hexacyanoferrate(II) (Prussian Blue) were electrochemically deposited on interdigitated array (IDA) electrodes, yielding systems which can be considered as chemiresistors in sensing alkali metal ion concentrations in an adjacent electrolyte. This is due to the fact that the c

  7. Continuous CWB GPS Array in Taiwan and Applications to Monitoring Seismic Activity

    Directory of Open Access Journals (Sweden)

    Tzay-Chyn Shin

    2011-01-01

    Full Text Available GPS observations have revealed important information for studying active tectonics and plate motion and are a useful tool for monitoring crustal deformation. The CWB continuous GPS array consists of approximately 150 stations with dense spatial coverage throughout Taiwan and can be used not only to monitor crustal deformation and seismic activity, but also to analyze the earthquake precursors in Taiwan.

  8. Study of the characteristics of a scintillation array and single pixels for nuclear medicine imaging applications

    Institute of Scientific and Technical Information of China (English)

    ZHU Jie; MA Hong-Guang; MA Wen-Yan; ZENG Hui; WANG Zhao-Min; XU Zi-Zong

    2009-01-01

    By using a pixelized Nal(T1) crystal array coupled to a R2486 PSPMT, the characteristics of the array and of a single pixel, such as the light output, energy resolution, peak-to-valley ratio (P/V) and imaging performance of the detector were studied. The pixel size of the NaI(TI) scintillation pixel array is 2 min×2 mm×5 mm. There are in total 484 pixels in a 22~22 matrix. In the pixel spectrum an average peak-to-valley ratio (P/V) of 16 was obtained. In the image of all the pixels, good values for the Peak-to-Valley ratios could be achieved, namely a mean of 17, a maximum of 45 and the average peak FWHM (the average value of intrinsic spatial resolution) of 2.3 mm. However, the PSPMT non-uniform response and the scintillation pixels array inhomogeneities degrade the imaging performance of the detector.

  9. A transparency model and its applications for simulation of reflector arrays and sound transmission (A)

    DEFF Research Database (Denmark)

    Christensen, Claus Lynge; Rindel, Jens Holger

    2006-01-01

    The paper describes a new method for simulating the frequency-dependent reflection and transmission of reflector arrays, and the frequency-dependent airborne sound insulation between rooms by means of a room acoustic computer model. The method makes use of a transparency method in the ray-tracing...

  10. The Largest Multi-Planar Wire Arrays on Zebra with LCM and their Applications

    Science.gov (United States)

    Safronova, A. S.; Kantsyrev, V. L.; Weller, M. E.; Shlyaptseva, V. V.; Shrestha, I. K.; Lorance, M. Y.; Stafford, A.; Schultz, K. A.; Coverdale, C. A.; Chuvatin, A. S.

    2015-11-01

    Two new approaches of i) simultaneous study of implosion and radiative characteristics of different materials in wire array Z-pinch plasma in one shot [Safronova et al, PoP 21, 031205 (2014)] and ii) investigation of larger sized wire arrays (to enhance energy coupling to plasmas and provide better diagnostic access) were further developed in experiments with 1.7 MA Zebra with a Load Current Multiplier. In particular, the largest multi-Planar Wire Arrays with two outer planes from alloyed Al wires placed as far from each other as at 19 mm (compare with 6 and 9 mm studied before) and with a modified central plane from Ni-60 (mostly Cu), were investigated. Though K-shell Al and L-shell Cu plasmas have similar temperatures and densities, the ablation dynamics and radiation of Al and Cu planes is somewhat different, which was investigated in detail using the full set of diagnostics and modeling. Advantages of using such wire arrays at higher currents to study plasma flow and radiation from different materials and jets are highlighted. This work was supported by NNSA under DOE Cooperative Agreement DE-NA0001984 and in part by DE-NA0002075. SNL is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Company, for the U.S. DOE under Contract DE-AC04-94AL85000.

  11. Application of HEMT for multiplexing large arrays of high impedance LTDs

    Energy Technology Data Exchange (ETDEWEB)

    Benoit, A.; Camus, Ph. E-mail: camus@grenoble.cnrs.fr; Cavanna, A.; Elhdiy, A.; Jin, Y.; Leclercq, S

    2004-03-11

    The development of large arrays of detectors requires using a proximate electronics at low temperatures for signal multiplexing and amplification. We report the use of commercial High Electronic Mobility Transistors (HEMT) for multiplexing signals from high impedance LTD arrays (typ. 10-100 M{omega}). The electronic architecture is based on HEMTs cooled at 0.1 K for the multiplexer and a JFET amplifier cooled at 100 K with <1 nV/Hz{sup 1/2} noise figure. For this time-multiplexing scheme, a capacitor is used to integrate the signal between measurements. Two main solutions are compared for the detectors polarization: the first uses a classical resistive method; the second uses a common capacitor allowing to polarize the detectors individually. The multiplexing ratio is mainly limited by the amplifier noise to about 20 detectors per amplifier with a pixel sampling rate of about 60 Hz. A specific development of HEMT arrays with Quantum Point Contacts (QPC-HEMT) with very small grid-to-channel capacitor ({approx}1 fF) allows minimizing the transient effects and realizing a close integration with the LTD arrays.

  12. Biological applications of an LCoS-BASED PROGRAMMABLE ARRAY MICROSCOPE (PAM)

    NARCIS (Netherlands)

    Hagen, G.M.; Caarls, W.; Thomas, M.; Hill, A.; Lidke, K.A.; Rieger, B.; Fritsch, C.; Van Geest, B.; Jovin, T.M.; Arndt-Jovin, D.J.

    2007-01-01

    We report on a new generation, commercial prototype of a programmable array optical sectioning fluorescence microscope (PAM) for rapid, light efficient 3D imaging of living specimens. The stand-alone module, including light source(s) and detector(s), features an innovative optical design and a ferro

  13. Broadband High Efficiency Fractal-Like and Diverse Geometry Silicon Nanowire Arrays for Photovoltaic Applications

    Science.gov (United States)

    AL-Zoubi, Omar H.

    Solar energy has many advantages over conventional sources of energy. It is abundant, clean and sustainable. One way to convert solar energy directly into electrical energy is by using the photovoltaic solar cells (PVSC). Despite PVSC are becoming economically competitive, they still have high cost and low light to electricity conversion efficiency. Therefore, increasing the efficiency and reducing the cost are key elements for producing economically more competitive PVSC that would have significant impact on energy market and saving environment. A significant percentage of the PVSC cost is due to the materials cost. For that, thin films PVSC have been proposed which offer the benefits of the low amount of material and fabrication costs. Regrettably, thin film PVSC show poor light to electricity conversion efficiency because of many factors especially the high optical losses. To enhance conversion efficiency, numerous techniques have been proposed to reduce the optical losses and to enhance the absorption of light in thin film PVSC. One promising technique is the nanowire (NW) arrays in general and the silicon nanowire (SiNW) arrays in particular. The purpose of this research is to introduce vertically aligned SiNW arrays with enhanced and broadband absorption covering the entire solar spectrum while simultaneously reducing the amount of material used. To this end, we apply new concept for designing SiNW arrays based on employing diversity of physical dimensions, especially radial diversity within certain lattice configurations. In order to study the interaction of light with SiNW arrays and compute their optical properties, electromagnetic numerical modeling is used. A commercial numerical electromagnetic solver software package, high frequency structure simulation (HFSS), is utilized to model the SiNW arrays and to study their optical properties. We studied different geometries factors that affect the optical properties of SiNW arrays. Based on this study, we

  14. Development of an array of transition edge sensors for application in X-ray astronomy

    NARCIS (Netherlands)

    Bruijn, Marcel P.; Baars, Norman H.R.; Bergmann Tiest, Wouter M.; Germeau, Alexander; Hoevers, Henk F.C.; Korte, de Piet A.J.; Mels, Wim A.; Ridder, Marcel L.; Krouwer, Eric; Baar, van John J.; Wiegerink, Remco J.

    2004-01-01

    We report on the development activities towards a cryogenic array of micro-calorimeters, based on voltage-biased Ti/Au transition edge thermometers. Fabrication issues are discussed along the lines of two fabrication routes. One route utilizes bulk micromachining in [1 1 0] Si wafers, the other rout

  15. Engineering biomolecular microenvironments for cell instructive biomaterials.

    Science.gov (United States)

    Custódio, Catarina A; Reis, Rui L; Mano, João F

    2014-06-01

    Engineered cell instructive microenvironments with the ability to stimulate specific cellular responses are a topic of high interest in the fabrication and development of biomaterials for application in tissue engineering. Cells are inherently sensitive to the in vivo microenvironment that is often designed as the cell "niche." The cell "niche" comprising the extracellular matrix and adjacent cells, influences not only cell architecture and mechanics, but also cell polarity and function. Extensive research has been performed to establish new tools to fabricate biomimetic advanced materials for tissue engineering that incorporate structural, mechanical, and biochemical signals that interact with cells in a controlled manner and to recapitulate the in vivo dynamic microenvironment. Bioactive tunable microenvironments using micro and nanofabrication have been successfully developed and proven to be extremely powerful to control intracellular signaling and cell function. This Review is focused in the assortment of biochemical signals that have been explored to fabricate bioactive cell microenvironments and the main technologies and chemical strategies to encode them in engineered biomaterials with biological information.

  16. Recent CSMIP/CALTRANS Downhole Array Data and their Application in Site Specific Analysis

    Science.gov (United States)

    Haddadi, H. R.; Graizer, V.; Shakal, T.; Hipely, P.

    2002-12-01

    The California Strong Motion Instrumentation Program (CSMIP) operates 13 downhole geotechnical arrays throughout the state of California, 8 of them instrumented with the support and cooperation of California Department of Transportation (Caltrans). More than 60 low amplitude recordings from earthquakes with 2.4arrays. The strongest acceleration of 0.5g was recorded at the La Cienega array in Los Angeles area during the M4.2 earthquake of 9/9/2001. This is a relatively small event with the epicentral distance of 2.7 km and depth of 7.9 km (almost vertical wave incidence). This case presents an opportunity to trace the incident and reflected phases of shear wave recorded at different elevations of the array. The structure of shallow ground layers is evaluated based on those phases and shows good agreement with the downhole profile of US Geological Survey and Caltrans. At the La Cienega site the shear wave velocity increases gradually from 163 m/s at the ground surface to 653 m/s at depth of 250 m. Due to vertical propagation of waves, the one dimensional wave propagation program SHAKE91 can be used to model ground motion in the layers. The earthquake ground motion at depth of 252 m is considered as the input, and the ground motion is computed at the surface, and at depths of 18 m and 100 m using SHAKE91 program. The recorded motion at the depth of 252 m consists of the two main phases: incident wave and reflected wave from the ground surface. The incident wave is used as an input ground motion in order to prevent coupling effect. Output motions are in good agreement with the actual recordings at the ground surface, 18 m and 100 m depths. The earthquake ground motion recorded at geotechnical arrays show that the incident and reflected phases of P- waves overlap in some cases (because of higher P-wave velocity the arrival time of reflected phase cannot be visually identified) and additional analysis is necessary to distinguish the arrival

  17. Theoretical description of biomolecular hydration - Application to A-DNA

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, A.E.; Hummer, G. [Los Alamos National Laboratory, NM (United States); Soumpasis, D.M. [Max Planck Inst. for Biophysical Chemistry, Goettingen (Germany)

    1994-12-31

    The local density of water molecules around a biomolecule is constructed from calculated two- and three-points correlation functions of polar solvents in water using a Potential-of-Mean-Force (PMF) expansion. As a simple approximation, the hydration of all polar (including charged) groups in a biomolecule is represented by the hydration of water oxygen in bulk water, and the effect of non-polar groups on hydration are neglected, except for excluded volume effects. Pair and triplet correlation functions are calculated by molecular dynamics simulations. We present calculations of the structural hydration for ideal A-DNA molecules with sequences [d(CG){sub 5}]{sub 2} and [d(C{sub 5}G{sub 5})]{sub 2}. We find that this method can accurately reproduce the hydration patterns of A-DNA observed in neutron diffraction experiments on oriented DNA fibers.

  18. Protein hydrogels with engineered biomolecular recognition

    Science.gov (United States)

    Mi, Lixin

    water soluble and swelling. The RGD cell adhesion tripeptide has been inserted into the polyelectrolyte region by site-directed mutagenesis. Two dimensional human foreskin fibroblast cultures have shown that the RGD-containing protein surface is bioactive in promoting cell attachment, cell signaling, and cytoskeleton organization. The protein and the cell recognize and interact at molecular level. Collectively, these findings indicate that this bioactive protein hydrogel system is a promising biomaterial for mammalian cell culture. This research may provide insights for the rational development of bioactive ECM for specific cell and tissue engineering applications.

  19. Studies on a 120 degrees segmented circular array for multi-beam multi-frequency bathymetric application

    Digital Repository Service at National Institute of Oceanography (India)

    Chakraborty, B.

    size. The present study of the mutual interaction effect between the array elements reveals that the interaction effects are relatively less for a 120 degrees segmented circular array. Furthermore, the 120 degrees segmented circular array geometry...

  20. Field application of phased array ultrasonic testing for structural weld overlay on dissimilar welds of pressurizer nozzles

    International Nuclear Information System (INIS)

    Weld overlay was first used in power plants in the US in the early 1980s as an interim method of repairing the welds of flawed piping joints. Weld overlaid piping joints in nuclear power plants must be examined periodically using ultrasonic examination technology. Portable phased array ultrasonic technology has recently become available. Currently, the application of preemptive weld overlays as a mitigation technique and/as a method to improve the examination surface condition for more complex configurations is becoming more common. These complex geometries may require several focused conventional transducers for adequate inspection of the overlay, the original weld, and the base material. Alternatively, Phased array ultrasonic probes can be used to generate several inspection angles simultaneously at various focal depths to provide better and faster coverage than that possible by conventional methods. Thus, this technology can increase the speed of examinations, save costs, and reduce radiation exposure. In this paper, we explain the general sequence of the inspection of weld overlay and the results of signal analysis for some PAUT (phased array ultrasonic testing) signals detected in on-site inspections

  1. Application of Celluspots peptide arrays for the analysis of the binding specificity of epigenetic reading domains to modified histone tails

    Directory of Open Access Journals (Sweden)

    Dhayalan Arunkumar

    2011-08-01

    Full Text Available Abstract Background Epigenetic reading domains are involved in the regulation of gene expression and chromatin state by interacting with histones in a post-translational modification specific manner. A detailed knowledge of the target modifications of reading domains, including enhancing and inhibiting secondary modifications, will lead to a better understanding of the biological signaling processes mediated by reading domains. Results We describe the application of Celluspots peptide arrays which contain 384 histone peptides carrying 59 post translational modifications in different combinations as an inexpensive, reliable and fast method for initial screening for specific interactions of reading domains with modified histone peptides. To validate the method, we tested the binding specificities of seven known epigenetic reading domains on Celluspots peptide arrays, viz. the HP1ß and MPP8 Chromo domains, JMJD2A and 53BP1 Tudor domains, Dnmt3a PWWP domain, Rag2 PHD domain and BRD2 Bromo domain. In general, the binding results agreed with literature data with respect to the primary specificity of the reading domains, but in almost all cases we obtained additional new information concerning the influence of secondary modifications surrounding the target modification. Conclusions We conclude that Celluspots peptide arrays are powerful screening tools for studying the specificity of putative reading domains binding to modified histone peptides.

  2. Field application of phased array ultrasonic testing for structural weld overlay on dissimilar welds of pressurizer nozzles

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jin Hoi; Kim, Yong Sik [Korea Hydro and Nuclear Power Company Ltd., Central Research Institute, Daejeon (Korea, Republic of)

    2015-08-15

    Weld overlay was first used in power plants in the US in the early 1980s as an interim method of repairing the welds of flawed piping joints. Weld overlaid piping joints in nuclear power plants must be examined periodically using ultrasonic examination technology. Portable phased array ultrasonic technology has recently become available. Currently, the application of preemptive weld overlays as a mitigation technique and/as a method to improve the examination surface condition for more complex configurations is becoming more common. These complex geometries may require several focused conventional transducers for adequate inspection of the overlay, the original weld, and the base material. Alternatively, Phased array ultrasonic probes can be used to generate several inspection angles simultaneously at various focal depths to provide better and faster coverage than that possible by conventional methods. Thus, this technology can increase the speed of examinations, save costs, and reduce radiation exposure. In this paper, we explain the general sequence of the inspection of weld overlay and the results of signal analysis for some PAUT (phased array ultrasonic testing) signals detected in on-site inspections.

  3. Concept, Design, and Prototyping of XSAS: A High Power Extendable Solar Array for CubeSat Applications

    Science.gov (United States)

    Senatore, Patrick; Klesh, Andrew; Zurbuchen, Thomas H.; McKague, Darren; Cutler, James

    2010-01-01

    CubeSats have proven themselves as a reliable and cost-effective method to perform experiments in space, but they are highly constrained by their specifications and size. One such constraint is the average continuous power, about 5 W, which is available to the typical CubeSat. To improve this constraint, we have developed the eXtendable Solar Array System (XSAS), a deployable solar array prototype in a CubeSat package, which can provide an average 23 W of continuous power. The prototype served as a technology demonstrator for the high risk mechanisms needed to release, deploy, and control the solar array. Aside from this drastic power increase, it is in the integration of each mechanism, their application within the small CubeSat form-factor, and the inherent passive control benefit of the deployed geometry that make XSAS a novel design. In this paper, we discuss the requirements and design process for the XSAS system and mechanical prototype, and provide qualitative and quantitative results from numerical simulations and prototype tests. We also discuss future work, including an upcoming NASA zero-gravity flight campaign, to further improve on XSAS and prepare it for future launch opportunities.

  4. Silicon Detector Arrays with Absolute Quantum Efficiency over 50% in the Far Ultraviolet for Single Photon Counting Applications

    CERN Document Server

    Nikzad, Shouleh; Greer, Frank; Jones, Todd; Jacquot, Blake; Monacos, Steve; Blacksberg, J; Hamden, Erika; Schiminovich, David; Martin, Chris; Morrissey, Patrick

    2011-01-01

    We have used Molecular Beam Epitaxy (MBE)-based delta doping technology to demonstrate near 100% internal quantum efficiency (QE) on silicon electron-multiplied Charge Coupled Devices (EMCCDs) for single photon counting detection applications. Furthermore, we have used precision techniques for depositing antireflection (AR) coatings by employing Atomic Layer Deposition (ALD) and demonstrated over 50% external QE in the far and near-ultraviolet in megapixel arrays. We have demonstrated that other device parameters such as dark current are unchanged after these processes. In this paper, we report on these results and briefly discuss the techniques and processes employed.

  5. Antennas for Terahertz Applications: Focal Plane Arrays and On-chip Non-contact Measurement Probes

    Science.gov (United States)

    Trichopoulos, Georgios C.

    The terahertz (THz) band provides unique sensing opportunities that enable several important applications such as biomedical imaging, remote non-destructive inspection of packaged goods, and security screening. THz waves can penetrate most materials and can provide unique spectral information in the 0.1--10 THz band with high resolution. In contrast, other imaging modalities, like infrared (IR), suffer from low penetration depths and are thus not attractive for non-destructive evaluation. However, state-of-the-art THz imaging systems typically employ mechanical raster scans using a single detector to acquire two-dimensional images. Such devices tend to be bulky and complicated due to the mechanical parts, and are thus rather expensive to develop and operate. Thus, large-format (e.g. 100x100 pixels) and all-electronics based THz imaging systems are badly needed to alleviate the space, weight and power (SWAP) factors and enable cost effective utilization of THz waves for sensing and high-data-rate communications. In contrast, photonic sensors are very compact because light can couple directly to the photodiode without residing to radiation coupling topologies. However, in the THz band, due to the longer wavelengths and much lower photon energies, highly efficient antennas with optimized input impedance have to be integrated with THz sensors. Here, we implement novel antenna engineering techniques that are optimized to take advantage of recent technological advances in solid-state THz sensing devices. For example, large-format focal plane arrays (FPAs) have been the Achilles' heel of THz imaging systems. Typically, optical components (lenses, mirrors) are employed in order to improve the optical performance of FPAs, however, antenna sensors suffer from degraded performance when they are far from the optical axis, thus minimizing the number of useful FPA elements. By modifying the radiation pattern of FPA antennas we manage to alleviate the off-axis aberration

  6. Microfabrication technology for large LEKID arrays : from NIKA2 to future applications

    CERN Document Server

    Goupy, J; Benoit, A; Bourrion, O; Calvo, M; Catalano, A; Coiffard, G; Hoarau, C; Leclercq, S; Sueur, H Le; Macias-Perez, J; Monfardini, A; Peck, I; Schuster, K

    2016-01-01

    The Lumped Element Kinetic Inductance Detectors (LEKID)demonstrated full maturity in the NIKA (New IRAM KID Arrays)instrument. These results allow directly comparing LEKID performance with other competing technologies (TES, doped silicon) in the mm and sub-mm range. A continuing effort is ongoing to improve the microfabrication technologies and concepts in order to satisfy the requirements of new instruments. More precisely, future satellites dedicated to CMB (Cosmic Microwave Background) studies will require the same focal plane technology to cover, at least, the frequency range of 60 to 600 GHz. Aluminium LEKID developed for NIKA have so far demonstrated, under real telescope conditions, performance approaching photon-noise limitation in the band 120-300 GHz. By implementing superconducting bi-layers we recently demonstrated LEKID arrays working in the range 80-120 GHz and with sensitivities approaching the goals for CMB missions. NIKA itself (350 pixels) is followed by a more ambitious project requiring se...

  7. RF MEMS Phase Shifters and their Application in Phase Array Antennas

    Science.gov (United States)

    Scardelletti, Maximilian; Ponchak, George E.; Zaman, Afroz J.; Lee, Richard Q.

    2005-01-01

    Electronically scanned arrays are required for space based radars that are capable of tracking multiple robots, rovers, or other assets simultaneously and for beam-hopping communication systems between the various assets. ^Traditionally, these phased array antennas used GaAs Monolithic Microwave Integrated Circuit (MMIC) phase shifters, power amplifiers, and low noise amplifiers to amplify and steer the beam, but the development of RF MEMS switches over the past ten years has enabled system designers to consider replacing the GaAs MMIC phase shifters with RF Micro-Electro Mechanical System (MEMS) phase shifters. In this paper, the implication of replacing the relatively high loss GaAs MMICs with low loss MEMS phase shifters is investigated.

  8. A CMB-based approach to mapping gravitational-wave backgrounds: application to pulsar timing arrays

    CERN Document Server

    Gair, Jonathan R; Taylor, Stephen; Mingarelli, Chiara M F

    2014-01-01

    We describe an alternative approach to the analysis of gravitational-wave backgrounds, based on the formalism used to characterise the polarisation of the cosmic microwave background. An arbitrary background can be decomposed into modes whose angular dependence on the sky is given by gradients and curls of spherical harmonics. We derive the pulsar timing overlap reduction function for individual modes, which are given by simple combinations of spherical harmonics evaluated at the pulsar locations. We show how these can be used to recover the components of an arbitrary background, giving explicit results for both isotropic and anisotropic uncorrelated backgrounds. We also find that the response of a pulsar timing array to curl modes is identically zero, so half of the gravitational-wave sky will never be observed using pulsar timing, no matter how many pulsars are included in the array. An isotropic uncorrelated background can be accurately represented using only three components, and so a search of this type ...

  9. Application of neural networks to digital pulse shape analysis for an array of silicon strip detectors

    Science.gov (United States)

    Flores, J. L.; Martel, I.; Jiménez, R.; Galán, J.; Salmerón, P.

    2016-09-01

    The new generation of nuclear physics detectors that used to study nuclear reactions is considering the use of digital pulse shape analysis techniques (DPSA) to obtain the (A,Z) values of the reaction products impinging in solid state detectors. This technique can be an important tool for selecting the relevant reaction channels at the HYDE (HYbrid DEtector ball array) silicon array foreseen for the Low Energy Branch of the FAIR facility (Darmstadt, Germany). In this work we study the feasibility of using artificial neural networks (ANNs) for particle identification with silicon detectors. Multilayer Perceptron networks were trained and tested with recent experimental data, showing excellent identification capabilities with signals of several isotopes ranging from 12C up to 84Kr, yielding higher discrimination rates than any other previously reported.

  10. Binary cobalt ferrite nanomesh arrays as the advanced binder-free electrode for applications in oxygen evolution reaction and supercapacitors

    Science.gov (United States)

    Liu, Li; Zhang, Huijuan; Mu, Yanping; Bai, Yuanjuan; Wang, Yu

    2016-09-01

    The porous CoFe2O4nanomesh arrays are successfully synthesized on nickel foam substrate through a high temperature and pressure hydrothermal method, following by the thermal post-treatment in air. The CoFe2O4 nanomesh arrays own numerous pores and large specific surface area, which is in favor of exposing more active sites. In consideration of the structural preponderances and versatility of the materials, the CoFe2O4 nanomesh arrays have been researched as the binder-free electrode materials for electrocatalysis and supercapacitors. When the CoFe2O4nanomesh arrays on nickel foam (CoFe2O4 NM-As/Ni) directly act as the free-binder catalyst toward catalyzing the oxygen evolution reaction (OER) of electrochemical water splitting, CoFe2O4 NM-As/Ni exhibits an admirable OER property with a low onset potential of 1.47 V(corresponding to the onset overpotential of 240 mV), a minimal overpotential (η10 = 253 mV), a small Tafel slope (44 mV dec-1), large anodic currents and long-term durability for 35 h in alkaline media. In addition, as an electrode of supercapacitors, CoFe2O4 NM-As/Ni obtains a desired specific capacitance (1426 F/g at the current density of 1 A/g), remarkable rate capability (1024 F/g at the current density of 20 A/g) and eminent capacitance retention (92.6% after 3000 cycles). The above results demonstrate the CoFe2O4 NM-As/Ni possesses great potential application in electrocatalysis and supercapacitors.

  11. HgCdTe e-APD detector arrays with single photon sensitivity for space lidar applications

    Science.gov (United States)

    Sun, Xiaoli; Abshire, James B.; Beck, Jeffrey D.

    2014-05-01

    A multi-element HgCdTe electron initiated avalanche photodiode (e-APD) array has been developed for space lidar. The detector array was fabricated with 4.3μm cutoff HgCdTe with a spectral response from 0.4 to 4.3 μm. We have demonstrated a 4x4 e-APD array with 80 μm square elements followed by a custom cryogenic CMOS read-out integrated circuit (ROIC). The device operates at 77K inside a small closed-cycle cooler-Dewar with the support electronics integrated in a field programmable gate array. Measurements showed a unity gain quantum efficiency of about 90% at 1.5-1.6 μm wavelength. The bulk dark current of the HgCdTe e-APD at 77K was less than 50,000 input referred electrons/s at 12 V APD bias where the APD gain was 620 and the measured noise equivalent power (NEP) was 0.4 fW/Hz1/2. The electrical bandwidth of the device was about 6 MHz, mostly limited by the ROIC, but sufficient for the lidar application. Although the devices were designed for low bandwidth pulse detections, the high gain and low dark current enabled them to be used for single photon detections. Because the APD was biased below the break-down voltage, the output is linear to the input signal and there were no nonlinear effect such as dead-time and afterpulsing, and no need for gated operation. A new series of HgCdTe e-APDs have also been developed with a much wider bandwidth ROIC and higher APD gain, which is expected to give a much better performance in single photon detections.

  12. Application of custom-designed oligonucleotide array CGH in 145 patients with autistic spectrum disorders

    OpenAIRE

    Wiśniowiecka-Kowalnik, Barbara; Kastory-Bronowska, Monika; Bartnik, Magdalena; Derwińska, Katarzyna; Dymczak-Domini, Wanda; Szumbarska, Dorota; Ziemka, Ewa; Szczałuba, Krzysztof; Sykulski, Maciej; Gambin, Tomasz; Gambin, Anna; Shaw, Chad A.; Mazurczak, Tadeusz; Obersztyn, Ewa; Bocian, Ewa

    2012-01-01

    Autism spectrum disorders (ASDs) are a heterogeneous group of neurodevelopmental disorders, including childhood autism, atypical autism, and Asperger syndrome, with an estimated prevalence of 1.0–2.5% in the general population. ASDs have a complex multifactorial etiology, with genetic causes being recognized in only 10–20% of cases. Recently, copy-number variants (CNVs) have been shown to contribute to over 10% of ASD cases. We have applied a custom-designed oligonucleotide array comparative ...

  13. Design, Fabrication, and Packaging of an Integrated, Wirelessly-Powered Optrode Array for Optogenetics Application

    OpenAIRE

    Wen eLi; Ki Yong eKwon; Hyung-Min eLee; Maysam eGhovanloo; Arthur eWeber

    2015-01-01

    The recent development of optogenetics has created an increased demand for advancing engineering tools for optical modulation of neural circuitry. This paper details the design, fabrication, integration, and packaging procedures of a wirelessly-powered, light emitting diode (LED) coupled optrode neural interface for optogenetic studies. The LED-coupled optrode array employs microscale LED (μLED) dies and polymer-based microwaveguides to deliver light into multi-level cortical networks, coup...

  14. Design, fabrication, and packaging of an integrated, wirelessly-powered optrode array for optogenetics application

    OpenAIRE

    Kwon, Ki Yong; Lee, Hyung-Min; Ghovanloo, Maysam; Weber, Arthur; Li, Wen

    2015-01-01

    The recent development of optogenetics has created an increased demand for advancing engineering tools for optical modulation of neural circuitry. This paper details the design, fabrication, integration, and packaging procedures of a wirelessly-powered, light emitting diode (LED) coupled optrode neural interface for optogenetic studies. The LED-coupled optrode array employs microscale LED (μLED) chips and polymer-based microwaveguides to deliver light into multi-level cortical networks, coupl...

  15. Optical Analysis of a Linear-Array Thermal Radiation Detector for Geostationary Earth Radiation Budget Applications

    OpenAIRE

    Sanchez, Maria Cristina

    1998-01-01

    The Thermal Radiation Group, a laboratory in the Department of Mechanical Engineering at Virginia Polytechnic Institute and State University, is currently working to develop a new technology for thermal radiation detectors. The Group is also studying the viability of replacing current Earth Radiation Budget radiometers with this new concept. This next-generation detector consists of a thermopile linear array thermal radiation detector. The principal objective of t...

  16. In situ fabrication of cleavable peptide arrays on polydimethylsiloxane and applications for kinase activity assays

    International Nuclear Information System (INIS)

    Highlights: • A novel approach for in situ fabrication of cleavable peptide arrays on polydimethylsiloxane (PDMS). • The first report of peptide synthesis on PDMS. • Use of the PDMS peptide array for developing sensitive chip-based kinase activity bioassays. • The on-chip synthesized peptides can be cleaved for MS detection. - Abstract: Polydimethylsiloxane (PDMS) is widely used for microfabrication and bioanalysis; however, its surface functionalization is limited due to the lack of active functional groups and incompatibility with many solvents. We presented a novel approach for in situ fabrication of cleavable peptide arrays on polydimethylsiloxane (PDMS) viatert-butyloxycarbonyl (t-Boc)/trifluoroacetic acid (TFA) chemistry using gold nanoparticles (AuNPs) as the anchor and a disulfide/amine terminated hetero-polyethylene glycol as the cleavable linker. The method was fine tuned to use reagents compatible with the PDMS. Using 5-mer pentapeptide, Trp5, as a model, step-by-step covalent coupling during the reaction cycles was monitored by Attenuated total reflectance-Fourier transform infrared spectrometer (ATR-FTIR), X-ray photoelectron spectroscopy (XPS), or atomic force microscopy (AFM), and further confirmed by mass spectrometry (MS) detection of the cleaved peptides. Using such a method, heptapeptides of the PKA substrate, LRRASLG (Kemptide), and its point mutated analogs were fabricated in an array format for comparative studies of cAMP-dependent protein kinase (PKA) activity. Based on on-chip detection, Kemptide sequence exhibited the highest phosphorylation activity, which was detected to a 1.5-time lesser extent for the point mutated sequence (LRRGSLG) containing the recognition motif (RRXS), and was nearly undetectable for another point mutated sequence (LRLASLG) that lacked the recognition motif. These results indicate that the reported fabrication method is able to yield highly specific peptide sequences on PDMS, leading to a highly motif

  17. High-frequency Ultrasound Doppler System for Biomedical Applications with a 30 MHz Linear Array

    Science.gov (United States)

    Xu, Xiaochen; Sun, Lei; Cannata, Jonathan M.; Yen, Jesse T.; Shung, K. Kirk

    2008-01-01

    In this paper, we report the development of the first high-frequency (HF) pulsed-wave Doppler system using a 30 MHz linear array transducer to assess the cardiovascular functions in small animal. This array based pulsed-wave Doppler system included a 16-channel HF analog beamformer, a HF pulsed-wave Doppler module, timing circuits, HF bipolar pulsers, and analog front-ends. The beamformed echoes acquired by the 16 channel analog beamformer, were directly fed to the HF pulsed-wave Doppler module. Then the in-phase and quadrature-phase (IQ) audio Doppler signals were digitized by either a sound card or a Gage digitizer and stored in a PC. The Doppler spectrogram was displayed on a PC in real time. The two-way beam-widths were determined to be 160 μm to 320 μm when the array was electronically focused at different focal points at depths from 5–10 mm. A micro flow phantom, consisting of a polyimide tube with inner diameter of 127 μm, and the wire phantom were used to evaluate and calibrate the system. The results show that the system is capable of detecting motion velocity of the wire phantom as low as 0.1 mm/s, and detecting blood-mimicking flow velocity in the 127 μm tube lower than 7 mm/s. The system was subsequently used to measure the blood flow in vivo in two mouse abdominal superficial vessels with diameters of approximately 200 μm, and a mouse aorta close to the heart. These results demonstrated that this system may become an indispensable part of the current HF array based imaging systems for small animal studies. PMID:17993243

  18. Digital Radiography Using Digital Detector Arrays Fulfills Critical Applications for Offshore Pipelines

    OpenAIRE

    Lopes RicardoTadeu; Pereira MarcelodosSantos; Barbosa Rabello JoséMaurício; Zscherpel Uwe; Moreira EdsonVasques

    2010-01-01

    Digital radiography in the inspection of welded pipes to be installed under deep water offshore gas and oil pipelines, like a presalt in Brazil, in the paper has been investigated. The aim is to use digital radiography for nondestructive testing of welds as it is already in use in the medical, aerospace, security, automotive, and petrochemical sectors. Among the current options, the DDA (Digital Detector Array) is considered as one of the best solutions to replace industrial films, as well a...

  19. In situ fabrication of cleavable peptide arrays on polydimethylsiloxane and applications for kinase activity assays

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Huang-Han, E-mail: z10008047@email.ncku.edu.tw; Hsiao, Yu-Chieh, E-mail: s10076221@hotmail.com; Li, Jie-Ren, E-mail: jierenli@mail.ncku.edu.tw; Chen, Shu-Hui, E-mail: shchen@mail.ncku.edu.tw

    2015-03-20

    Highlights: • A novel approach for in situ fabrication of cleavable peptide arrays on polydimethylsiloxane (PDMS). • The first report of peptide synthesis on PDMS. • Use of the PDMS peptide array for developing sensitive chip-based kinase activity bioassays. • The on-chip synthesized peptides can be cleaved for MS detection. - Abstract: Polydimethylsiloxane (PDMS) is widely used for microfabrication and bioanalysis; however, its surface functionalization is limited due to the lack of active functional groups and incompatibility with many solvents. We presented a novel approach for in situ fabrication of cleavable peptide arrays on polydimethylsiloxane (PDMS) viatert-butyloxycarbonyl (t-Boc)/trifluoroacetic acid (TFA) chemistry using gold nanoparticles (AuNPs) as the anchor and a disulfide/amine terminated hetero-polyethylene glycol as the cleavable linker. The method was fine tuned to use reagents compatible with the PDMS. Using 5-mer pentapeptide, Trp{sub 5}, as a model, step-by-step covalent coupling during the reaction cycles was monitored by Attenuated total reflectance-Fourier transform infrared spectrometer (ATR-FTIR), X-ray photoelectron spectroscopy (XPS), or atomic force microscopy (AFM), and further confirmed by mass spectrometry (MS) detection of the cleaved peptides. Using such a method, heptapeptides of the PKA substrate, LRRASLG (Kemptide), and its point mutated analogs were fabricated in an array format for comparative studies of cAMP-dependent protein kinase (PKA) activity. Based on on-chip detection, Kemptide sequence exhibited the highest phosphorylation activity, which was detected to a 1.5-time lesser extent for the point mutated sequence (LRRGSLG) containing the recognition motif (RRXS), and was nearly undetectable for another point mutated sequence (LRLASLG) that lacked the recognition motif. These results indicate that the reported fabrication method is able to yield highly specific peptide sequences on PDMS, leading to a highly motif

  20. Development of an application specific scintimammography detector based on a crystal scintillator array and a PSPMT

    CERN Document Server

    Majewski, S; Goode, A; Kross, B J; Steinbach, D; Weisenberger, A; Williams, M; Wojci, R

    1998-01-01

    We report the results of studies conducted with small field of view scintimammography camera based on a position-sensitive photomultiplier tube (5'' Hamamatsu R3292) and several pixelized crystal scintillator arrays made of YAP, CsI(Na) and NaI(Tl) scintillators. Laboratory tests and pre-clinical phantom studies were conducted to compare and optimize the performances of the prototypes with special emphasis on spatial resolution (approx 2-3mm) and sufficient energy resolution for scatter rejection.

  1. Knowledge based cluster ensemble for cancer discovery from biomolecular data.

    Science.gov (United States)

    Yu, Zhiwen; Wongb, Hau-San; You, Jane; Yang, Qinmin; Liao, Hongying

    2011-06-01

    The adoption of microarray techniques in biological and medical research provides a new way for cancer diagnosis and treatment. In order to perform successful diagnosis and treatment of cancer, discovering and classifying cancer types correctly is essential. Class discovery is one of the most important tasks in cancer classification using biomolecular data. Most of the existing works adopt single clustering algorithms to perform class discovery from biomolecular data. However, single clustering algorithms have limitations, which include a lack of robustness, stability, and accuracy. In this paper, we propose a new cluster ensemble approach called knowledge based cluster ensemble (KCE) which incorporates the prior knowledge of the data sets into the cluster ensemble framework. Specifically, KCE represents the prior knowledge of a data set in the form of pairwise constraints. Then, the spectral clustering algorithm (SC) is adopted to generate a set of clustering solutions. Next, KCE transforms pairwise constraints into confidence factors for these clustering solutions. After that, a consensus matrix is constructed by considering all the clustering solutions and their corresponding confidence factors. The final clustering result is obtained by partitioning the consensus matrix. Comparison with single clustering algorithms and conventional cluster ensemble approaches, knowledge based cluster ensemble approaches are more robust, stable and accurate. The experiments on cancer data sets show that: 1) KCE works well on these data sets; 2) KCE not only outperforms most of the state-of-the-art single clustering algorithms, but also outperforms most of the state-of-the-art cluster ensemble approaches.

  2. Programming in Biomolecular Computation: Programs, Self-Interpretation and Visualisation

    Directory of Open Access Journals (Sweden)

    J.G. Simonsen

    2011-01-01

    Full Text Available Our goal is to provide a top-down approach to biomolecular computation. In spite of widespread discussion about connections between biology and computation, one question seems notable by its absence: Where are the programs? We identify a number of common features in programming that seem conspicuously absent from the literature on biomolecular computing; to partially redress this absence, we introduce a model of computation that is evidently programmable, by programs reminiscent of low-level computer machine code; and at the same time biologically plausible: its functioning is defined by a single and relatively small set of chemical-like reaction rules. Further properties: the model is stored-program: programs are the same as data, so programs are not only executable, but are also compilable and interpretable. It is universal: all computable functions can be computed (in natural ways and without arcane encodings of data and algorithm; it is also uniform: new ``hardware'' is not needed to solve new problems; and (last but not least it is Turing complete in a strong sense: a universal algorithm exists, that is able to execute any program, and is not asymptotically inefficient.

  3. Application of Gas Sensor Arrays in Assessment of Wastewater Purification Effects

    Directory of Open Access Journals (Sweden)

    Łukasz Guz

    2014-12-01

    Full Text Available A gas sensor array consisting of eight metal oxide semiconductor (MOS type gas sensors was evaluated for its ability for assessment of the selected wastewater parameters. Municipal wastewater was collected in a wastewater treatment plant (WWTP in a primary sedimentation tank and was treated in a laboratory-scale sequential batch reactor (SBR. A comparison of the gas sensor array (electronic nose response to the standard physical-chemical parameters of treated wastewater was performed. To analyze the measurement results, artificial neural networks were used. E-nose—gas sensors array and artificial neural networks proved to be a suitable method for the monitoring of treated wastewater quality. Neural networks used for data validation showed high correlation between the electronic nose readouts and: (I chemical oxygen demand (COD (r = 0.988; (II total suspended solids (TSS (r = 0.938; (III turbidity (r = 0.940; (IV pH (r = 0.554; (V nitrogen compounds: N-NO3 (r = 0.958, N-NO2 (r = 0.869 and N-NH3 (r = 0.978; (VI and volatile organic compounds (VOC (r = 0.987. Good correlation of the abovementioned parameters are observed under stable treatment conditions in a laboratory batch reactor.

  4. Single-layer graphene-TiO2 nanotubes array heterojunction for ultraviolet photodetector application

    Science.gov (United States)

    Zhang, Deng-Yue; Ge, Cai-Wang; Wang, Jiu-Zhen; Zhang, Teng-Fei; Wu, Yu-Cheng; Liang, Feng-Xia

    2016-11-01

    In this work, we reported on the fabrication of a single-layer graphene (SLG)-TiO2 nanotube arrays (NTs) heterostructures ultraviolet photodetector (UVPD) by transferring chemical vapor deposition derived MLG on the surface of anodic TiO2NTs array. Through varying the annealing atmosphere and anodization time in the TiO2 synthesis procedure, the electronic and optoelectronic properties of the as-fabricated Schottky junction UVPD were studied. It was revealed that the anodic TiO2NTs annealed in air showed a better rectifying behavior and was highly sensitive to UV light irradiation. Further investigation found that the device performance of the UVPD can be readily modulated by the anodization time, and the anodic TiO2NTs with a medium tube length of 9.6 μm exhibits the highest device performance. These results demonstrated that the present SLG-TiO2NTs array hetero-junction UVPD will be highly promising for fabricating high-performance optoelectronic device and system in the future.

  5. Extension of the GLYCAM06 Biomolecular Force Field to Lipids, Lipid Bilayers and Glycolipids.

    Science.gov (United States)

    Tessier, Matthew B; Demarco, Mari L; Yongye, Austin B; Woods, Robert J

    2008-01-01

    GLYCAM06 is a generalisable biomolecular force field that is extendible to diverse molecular classes in the spirit of a small-molecule force field. Here we report parameters for lipids, lipid bilayers and glycolipids for use with GLYCAM06. Only three lipid-specific atom types have been introduced, in keeping with the general philosophy of transferable parameter development. Bond stretching, angle bending, and torsional force constants were derived by fitting to quantum mechanical data for a collection of minimal molecular fragments and related small molecules. Partial atomic charges were computed by fitting to ensemble-averaged quantum-computed molecular electrostatic potentials.In addition to reproducing quantum mechanical internal rotational energies and experimental valence geometries for an array of small molecules, condensed-phase simulations employing the new parameters are shown to reproduce the bulk physical properties of a DMPC lipid bilayer. The new parameters allow for molecular dynamics simulations of complex systems containing lipids, lipid bilayers, glycolipids, and carbohydrates, using an internally consistent force field. By combining the AMBER parameters for proteins with the GLYCAM06 parameters, it is also possible to simulate protein-lipid complexes and proteins in biologically relevant membrane-like environments. PMID:22247593

  6. Glad nanostructured arrays with enhanced carrier collection and light trapping for photoconductive and photovoltaic device applications

    Science.gov (United States)

    Cansizoglu, Hilal

    Solar energy harvesting has been of great interest for researchers over the past 50 years. Main emphasis has been on developing high quality materials with low defect density and proper band gaps. However, high cost of bulk materials and insufficient light absorption in thin films led to utilization of semiconductor nanostructures in photovoltaics and photonics. Light trapping abilities of nanostructures can provide high optical absorption whereas core/shell nanostructured arrays can allow enhanced charge carrier collection. However, most of the nanofabrication methods that can produce uniform nanostructure geometries are limited in materials, dimensions, and not compatible with industrial production systems. Therefore, it is essential to develop innovative low-cost fabrication approaches that can address these issues. The primary goal of this project is to investigate light trapping and carrier collection properties of glancing angle deposited (GLAD) nanostructured arrays for high-efficiency, low-cost photoconductive and photovoltaic devices using characterization techniques including scanning electron microscopy (SEM), transmission electron microscopy (TEM), ultraviolet-visible-near infrared (UV-vis-NIR) spectroscopy and time resolved photocurrent measurements. Indium sulfide (In2S3) has been chosen as a model material system in this study. GLAD nanostructured arrays of vertical rods, screws, springs, zigzags and tilted rods were fabricated and characterized. A strong dependence of optical absorption on the shapes of nanostructures is observed from UV-vis-NIR spectroscopy. A simulation study using finite difference time domain (FDTD) shows that introducing 3D geometry results in diffuse scattering of light and leads to high optical absorption. Monte Carlo simulations were conducted to determine a simple and scalable fabrication technique for conformal and uniform shell coatings. The results suggest that an atomic flux with angular distribution, which can be

  7. Cryogenic phased-array for high resolution magnetic resonance imaging (MRI); assessment of clinical and research applications

    Science.gov (United States)

    Ip, Flora S.

    Magnetic Resonance (MR) imaging is one of the most powerful tools in diagnostic medicine for soft tissue imaging. Image acquisition techniques and hardware receivers are very important in achieving high contrast and high resolution MR images. An aim of this dissertation is to design single and multi-element room and cryogenic temperature arrays and make assessments of their signal-to-noise ratio (SNR) and SNR gain. In this dissertation, four sets of MR receiver coils are built. They are the receiver-only cryo-coils that are not commercially available. A tuning and matching circuit is attached to each coil. The tuning and matching circuits are simple; however, each device component has to operate at a high magnetic field and cryogenic temperature environment. Remote DC bias of the varactor controls the tuning and matching outside the scanner room. Active detuning of the resonator is done by two p-i-n junction (PIN) diodes. Cooling of the receiver is done by a customized liquid nitrogen cryostat. The first application is to build a 3-Tesla 2x1 horseshoe counter-rotating current (CRC) cryogenic array to image the tibia in a human body. With significant increase in SNR, the surface coil should deliver high contrast and resolution images that can show the trabecular bone and bone marrow structure. This structural image will be used to model the mechanical strength of the bone as well as bone density and chance of fracture. The planar CRC is a unique design of this surface array. The second application is to modify the coil design to 7-Tesla to study the growth of infant rhesus monkey eyes. Fast scan MR images of the infant monkey heads are taken for monitoring shapes of their eyeballs. The monkeys are induced with shortsightedness by eye lenses, and they are scanned periodically to get images of their eyeballs. The field-of-view (FOV) of these images is about five centimeters and the area of interest is two centimeters deep from the surface. Because of these reasons

  8. Heterogeneous flammulina velutipes-like CdTe/TiO{sub 2} nanorod array: A promising composite nanostructure for solar cell application

    Energy Technology Data Exchange (ETDEWEB)

    Luo Bingwei [Beijing Key Laboratory of Special Functional Materials and Film, School of Chemistry and Environment, Beihang University, Beijing 100191 (China); Deng Yuan, E-mail: dengyuan@buaa.edu.cn [Beijing Key Laboratory of Special Functional Materials and Film, School of Chemistry and Environment, Beihang University, Beijing 100191 (China); Wang Yao; Zhang Zhiwei; Tan Ming [Beijing Key Laboratory of Special Functional Materials and Film, School of Chemistry and Environment, Beihang University, Beijing 100191 (China)

    2012-03-15

    Highlights: Black-Right-Pointing-Pointer Core-shell CdTe/TiO{sub 2} nanorod arrays have been prepared via hydrothermal growth and magnetron sputtering method. Black-Right-Pointing-Pointer CdTe nanograins covered on the surface of the TiO{sub 2} nanorod arrays constructing a flammulina velutipe like type-II heterostructure. Black-Right-Pointing-Pointer The spectrum absorption region and the open circuit photocurrent are greatly increased. - Abstract: Core-shell heterogeneous CdTe/TiO{sub 2} nanorod arrays have been prepared by a two-step synthesis route through combined hydrothermal growth and magnetron sputtering. The composition and microstructure of the arrays were investigated by powder X-ray diffraction (XRD), scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM), which show that CdTe nanograins coated on the surface of the single-crystalline TiO{sub 2} nanorod arrays to form a type-II heterostructure. Compared with TiO{sub 2} nanorod arrays, the spectrum absorption region of CdTe/TiO{sub 2} core-shell nanostructure is broadened from ultraviolet light to visible light. The photoelectrodes of CdTe/TiO{sub 2} nanorod arrays show better photoelectric properties than those of bare TiO{sub 2} nanorod arrays. The output power of CdTe/TiO{sub 2} nanorod arrays is 25 times higher than that of a bare TiO{sub 2} nanorod array. These results indicate that the photoelectrode of CdTe/TiO{sub 2} nanorod array has a promising application in solar cell.

  9. Triple Band Parasitic Array Antenna for C-X-Ku-Band Application Using Out-of-Phase Coupling Approach

    Directory of Open Access Journals (Sweden)

    Anubhuti Khare

    2014-01-01

    Full Text Available Triple band parasitic array antenna for C-X-Ku-band application is presented. The proposed antenna is designed using the concept of parasitic array and out-of-phase coupling approach. The objects of research are to optimize total inductance of geometry by using out-of-phase inductance approach. The out of phase inductance of geometry consists of using two U-patches novel director on the left side of geometry, appropriate dimension of ground plan, and gap coupling between parasitic and active patches. The dimension of the ground plan geometry is 0.5λ mil × 0.5154λ mil. The usable impedance bandwidth of design antenna is “5.8 GHz to 18 GHz” (102% impedance bandwidth and gain enhancement is up to 11.8 dBi. The proposed antenna can be used for X-Ku band and C-band applications. Both simulated and measured results are presented, which are in good agreement. The proposed antenna was fabricated with a thin copper layer printed on a thin lossy FR4 substrate for low-cost production.

  10. Application of TMA (Tissue micro-array) in the observation of apoptotic cascade in postradiation damage in avian medicine

    International Nuclear Information System (INIS)

    The study of apoptotic cascade by the use of relatively new technique in avian medicine: TMA may help in early detection and prevention of acquired immunodeficiency caused by the influence of a variety of pathogenic and non-pathogenic environmental factors, which may result in severe economical losses in conditions of intensive poultry farming. There has not been any report of applying this method in veterinary medicine. Tissue micro-array (TMA) technology allows rapid visualization of molecular targets in thousands of tissue specimens at a time, either at the DNA, RNA or protein level. The technique facilitates rapid translation of molecular discoveries to clinical applications. This technology has a number of advantages compared with conventional techniques: speed and high throughput, standardization and experimental uniformity, ease of use, all histochemical and molecular detection techniques can be used, decreased assay volume, preservation of original block, and conservation of valuable tissue etc. The aim of the present work were the study of immunosuppression and apoptotic cascade and possibilities of application of tissue micro-array in chicken in experimental condition and diagnostics in avian medicine in general. The selection of samples from avian primary immune organs: thymus and Bursa Fabric was done after gamma irradiation and infectious bursal virus infection (IBDV). (authors)

  11. Strong adhesion and friction coupling in hierarchical carbon nanotube arrays for dry adhesive applications.

    Science.gov (United States)

    Hu, Shihao; Xia, Zhenhai; Gao, Xiaosheng

    2012-04-01

    The adhesion and friction coupling of hierarchical carbon nanotube arrays was investigated with a hierarchical multiscale modeling approach. At device level, vertically aligned carbon nanotube (VA-CNT) arrays with laterally distributed segments on top were analyzed via finite element methods to determine the macroscopic adhesion and friction force coupling. At the nanoscale, molecular dynamics simulation was performed to explore the origin of the adhesion enhancement due to the existence of the laterally distributed CNTs. The results show interfacial adhesion force is drastically promoted by interfacial friction force when a single lateral CNT is being peeled from an amorphous carbon substrate. By fitting with experiments, we find that under shearing loadings the maximum interfacial adhesion force is increased by a factor of ~5, compared to that under normal loadings. Pre-existing surface asperities of the substrate have proven to be the source of generating large interfacial friction, which in turn results in an enhanced adhesion. The critical peeling angles derived from the continuum and nano- levels are comparable to those of geckos and other synthetic adhesives. Our analysis indicates that the adhesion enhancement factor of the hierarchically structured VA-CNT arrays could be further increased by uniformly orienting the laterally distributed CNTs on top. Most importantly, a significant buckling of the lateral CNT at peeling front is captured on the molecular level, which provides a basis for the fundamental understanding of local deformation, and failure mechanisms of nanofibrillar structures. This work gives an insight into the durability issues that prevent the success of artificial dry adhesives.

  12. Application of the MNA design method to a nonlinear turbofan engine. [multivariable Nyquist array method

    Science.gov (United States)

    Leininger, G. G.

    1981-01-01

    Using nonlinear digital simulation as a representative model of the dynamic operation of the QCSEE turbofan engine, a feedback control system is designed by variable frequency design techniques. Transfer functions are generated for each of five power level settings covering the range of operation from approach power to full throttle (62.5% to 100% full power). These transfer functions are then used by an interactive control system design synthesis program to provide a closed loop feedback control using the multivariable Nyquist array and extensions to multivariable Bode diagrams and Nichols charts.

  13. Miniaturization high-resolution NUV-VIS-NIR imaging spectrometer array for FAST SAT applications

    Energy Technology Data Exchange (ETDEWEB)

    Torr, D.G. [Science and Engineering Associates Inc., Albuquerque, NM (United States)]|[Univ. of Alabama, Huntsville, AL (United States); Zukic, M.; Feng, C.; Ahmad, A.; Swift, W. [Univ. of Alabama, Huntsville, AL (United States)

    1994-12-31

    The authors report here the design of an instrument needed to study processes relevant to the natural destruction of ozone in the upper atmosphere. They report the design of a miniature Imaging Spectrometer Array (ISA) for observations of the daytime and nighttime mesosphere, capable of operating in a spectral range extending from the near-ultraviolet (NUV) to the near-infrared (NIR). The instrument comprises an array of f/2 all-reflective imaging spectrometers with a 6{degree} field of view. The design comprises an offset single aspheric toroidal telescope mirror, a slit, an offset aspheric toroidal collimator, a plane reflective grating and a camera with three offset decentered aspheric mirrors. The optical system has a 75 mm effective focal length and ca. 7.5 {micro}m spot size. The slit image curvature distortion for the system is <7.5 {micro}m. Sampling of the image plane is provided by a 1317x1035 spatial x spectral pixel CCD array with 6.8 {micro}m x 6.8 {micro}m pixel size. Three modules of the array cover the wavelength range 260 to 400 and 550 to 870 nm at 0.3 nm spectral resolution. One high resolution module covers the range 306 to 310 at 0.05 nm resolution. The readout electronics software allows the 1317 spatial pixels to be summed into any number of selectable bin sizes incurring a single read per bin. Since much of the full slit sensitivity is attributable to the large (6{degree}) field of view, the slit could be slanted with respect to the vertical, in order to enhance the sensitivity per vertical spatial bin, at the cost of some horizontal smearing. The instrument offers a powerful means for conducting comprehensive spectroscopy studies of the lower thermosphere and mesosphere, since the overall performance is better than that of the Imaging Spectrometric Observatory (ISO) flown on the ATLAS 1 shuttle mission in 1992. The weight and size reduction from the ISO to the ISA are approximately 270 kg to <15 kg, and 20 cu ft to 1 cu ft respectively.

  14. Application of Global Dynamic Reconfiguration in Artificial Neural Network System based on Field Programmable Gate Array

    Institute of Scientific and Technical Information of China (English)

    LI Wei; WANG Wei; MA Yi-mei; WANG Jin-hai

    2008-01-01

    Presented is a global dynamic reconfiguration design of an artificial neural network based on field programmable gate array(FPGA). Discussed are the dynamic reconfiguration principles and methods. Proposed is a global dynamic reconfiguration scheme using Xilinx FPGA and platform flash. Using the revision capabilities of Xilinx XCF32P platform flash, an artificial neural network based on Xilinx XC2V30P Virtex-Ⅱ can be reconfigured dynamically from back propagation(BP) learning algorithms to BP network testing algorithms. The experimental results indicate that the scheme is feasible, and that, using dynamic reconfiguration technology, FPGA resource utilization can be reduced remarkably.

  15. Fabrication, characterization and applications of flexible vertical InGaN micro-light emitting diode arrays.

    Science.gov (United States)

    Tian, Pengfei; McKendry, Jonathan J D; Gu, Erdan; Chen, Zhizhong; Sun, Yongjian; Zhang, Guoyi; Dawson, Martin D; Liu, Ran

    2016-01-11

    Flexible vertical InGaN micro-light emitting diode (micro-LED) arrays have been fabricated and characterized for potential applications in flexible micro-displays and visible light communication. The LED epitaxial layers were transferred from initial sapphire substrates to flexible AuSn substrates by metal bonding and laser lift off techniques. The current versus voltage characteristics of flexible micro-LEDs degraded after bending the devices, but the electroluminescence spectra show little shift even under a very small bending radius 3 mm. The high thermal conductivity of flexible metal substrates enables high thermal saturation current density and high light output power of the flexible micro-LEDs, benefiting the potential applications in flexible high-brightness micro-displays and high-speed visible light communication. We have achieved ~40 MHz modulation bandwidth and 120 Mbit/s data transmission speed for a typical flexible micro-LED. PMID:26832299

  16. SAW synthesis with IDTs array and the inverse filter: toward a versatile SAW toolbox for microfluidics and biological applications

    CERN Document Server

    Riaud, Antoine; Thomas, Jean-Louis; Matar, Olivier Bou

    2016-01-01

    Surface acoustic waves (SAWs) are versatile tools to manipulate fluids at small scales for microfluidics and bio- logical applications. A non-exhaustive list of operations that can be performed with SAW includes sessile droplet displacement, atomization, division and merging but also the actuation of fluids embedded in microchannels or the manipulation of suspended particles. However, each of these operations requires a specific design of the wave generation system, the so-called interdigitated transducers (IDTs). Depending on the application, it might indeed be necessary to generate focused or plane, propagating or standing, aligned or shifted waves. Furthermore, the possibilities offered by more complex wave-fields such as acoustical vortices for particle tweezing and liquid twisting cannot be explored with classical IDTs. In this paper, we show that the inverse filter technique coupled with an interdigitated transducers array (IDTA) enables to synthesize all classical wave-fields used in microfluidics and ...

  17. Fabrication, characterization and applications of flexible vertical InGaN micro-light emitting diode arrays.

    Science.gov (United States)

    Tian, Pengfei; McKendry, Jonathan J D; Gu, Erdan; Chen, Zhizhong; Sun, Yongjian; Zhang, Guoyi; Dawson, Martin D; Liu, Ran

    2016-01-11

    Flexible vertical InGaN micro-light emitting diode (micro-LED) arrays have been fabricated and characterized for potential applications in flexible micro-displays and visible light communication. The LED epitaxial layers were transferred from initial sapphire substrates to flexible AuSn substrates by metal bonding and laser lift off techniques. The current versus voltage characteristics of flexible micro-LEDs degraded after bending the devices, but the electroluminescence spectra show little shift even under a very small bending radius 3 mm. The high thermal conductivity of flexible metal substrates enables high thermal saturation current density and high light output power of the flexible micro-LEDs, benefiting the potential applications in flexible high-brightness micro-displays and high-speed visible light communication. We have achieved ~40 MHz modulation bandwidth and 120 Mbit/s data transmission speed for a typical flexible micro-LED.

  18. An Electronic-Nose Sensor Node Based on a Polymer-Coated Surface Acoustic Wave Array for Wireless Sensor Network Applications

    OpenAIRE

    Kea-Tiong Tang; Cheng-Han Li; Shih-Wen Chiu

    2011-01-01

    This study developed an electronic-nose sensor node based on a polymer-coated surface acoustic wave (SAW) sensor array. The sensor node comprised an SAW sensor array, a frequency readout circuit, and an Octopus II wireless module. The sensor array was fabricated on a large K 2 128° YX LiNbO3 sensing substrate. On the surface of this substrate, an interdigital transducer (IDT) was produced with a Cr/Au film as its metallic structure. A mixed-mode frequency readout application specific integrat...

  19. Microfabrication Technology for Large Lekid Arrays: From Nika2 to Future Applications

    Science.gov (United States)

    Goupy, J.; Adane, A.; Benoit, A.; Bourrion, O.; Calvo, M.; Catalano, A.; Coiffard, G.; Hoarau, C.; Leclercq, S.; Le Sueur, H.; Macias-Perez, J.; Monfardini, A.; Peck, I.; Schuster, K.

    2016-08-01

    The lumped element kinetic inductance detectors (LEKID) demonstrated full maturity in the New IRAM KID Arrays (NIKA) instrument. These results allow directly comparing LEKID performance with other competing technologies (TES, doped silicon) in the mm and sub-mm range. A continuing effort is ongoing to improve the microfabrication technologies and concepts in order to satisfy the requirements of new instruments. More precisely, future satellites dedicated to cosmic microwave background (CMB) studies will require the same focal plane technology to cover, at least, the frequency range of 60-600 GHz. Aluminium LEKID developed for NIKA have so far demonstrated, under real telescope conditions, a performance approaching photon noise limitation in the band 120-300 GHz. By implementing superconducting bi-layers, we recently demonstrated LEKID arrays working in the range 80-120 GHz and with sensitivities approaching the goals for CMB missions. NIKA itself (350 pixels) is followed by a more ambitious project requiring several thousand (3000-5000) pixels. NIKA2 has been installed in October 2015 at the IRAM 30-m telescope. We will describe in detail the technological improvements that allowed a relatively harmless tenfold up-scaling in pixels count without degrading the initial sensitivity. In particular, we will briefly describe a solution to simplify the difficult fabrication step linked to the slot-line propagation mode in coplanar waveguide.

  20. Development and application of a novel genome-wide SNP array reveals domestication history in soybean.

    Science.gov (United States)

    Wang, Jiao; Chu, Shanshan; Zhang, Huairen; Zhu, Ying; Cheng, Hao; Yu, Deyue

    2016-02-09

    Domestication of soybeans occurred under the intense human-directed selections aimed at developing high-yielding lines. Tracing the domestication history and identifying the genes underlying soybean domestication require further exploration. Here, we developed a high-throughput NJAU 355 K SoySNP array and used this array to study the genetic variation patterns in 367 soybean accessions, including 105 wild soybeans and 262 cultivated soybeans. The population genetic analysis suggests that cultivated soybeans have tended to originate from northern and central China, from where they spread to other regions, accompanied with a gradual increase in seed weight. Genome-wide scanning for evidence of artificial selection revealed signs of selective sweeps involving genes controlling domestication-related agronomic traits including seed weight. To further identify genomic regions related to seed weight, a genome-wide association study (GWAS) was conducted across multiple environments in wild and cultivated soybeans. As a result, a strong linkage disequilibrium region on chromosome 20 was found to be significantly correlated with seed weight in cultivated soybeans. Collectively, these findings should provide an important basis for genomic-enabled breeding and advance the study of functional genomics in soybean.

  1. Design and optimization of arrays of neodymium iron boron-based magnets for magnetic tweezers applications.

    Science.gov (United States)

    Zacchia, Nicholas A; Valentine, Megan T

    2015-05-01

    We present the design methodology for arrays of neodymium iron boron (NdFeB)-based magnets for use in magnetic tweezers devices. Using finite element analysis (FEA), we optimized the geometry of the NdFeB magnet as well as the geometry of iron yokes designed to focus the magnetic fields toward the sample plane. Together, the magnets and yokes form a magnetic array which is the basis of the magnetic tweezers device. By systematically varying 15 distinct shape parameters, we determined those features that maximize the magnitude of the magnetic field gradient as well as the length scale over which the magnetic force operates. Additionally, we demonstrated that magnetic saturation of the yoke material leads to intrinsic limitations in any geometric design. Using this approach, we generated a compact and light-weight magnetic tweezers device that produces a high field gradient at the image plane in order to apply large forces to magnetic beads. We then fabricated the optimized yoke and validated the FEA by experimentally mapping the magnetic field of the device. The optimization data and iterative FEA approach outlined here will enable the streamlined design and construction of specialized instrumentation for force-sensitive microscopy. PMID:26026529

  2. Fabrication and Electrochemical Characterization of Micro- and Nanoelectrode Arrays for Sensor Applications

    Energy Technology Data Exchange (ETDEWEB)

    Said, Nur Azura Mohd; Twomey, Karen; Ogurtsov, Vladimir I; Herzog, Gregoire [Tyndall National Institute, Lee Maltings, University College Cork, Cork (Ireland); Arrigan, Damien W M, E-mail: gregoire.herzog@tyndall.ie [Nanochemistry Research Institute, Department of Chemistry, Curtin University, Perth (Australia)

    2011-08-17

    This paper describes the fabrication of microelectrode arrays, with two different geometries: disc (Designs d1 and d2) and band (Designs b1, b2 and b3) using three critical dimensions (100 nm, 1 {mu}m and 10 {mu}m) leading to 5 different designs, fabricated by the combination of UV photolithographic and e-beam lithographic techniques. Three silicon nitride layer thicknesses (200, 300 and 500 nm) were chosen to determine an optimized transducer design and fabrication process. Cyclic voltammetry characterisation using a simple redox probe ion, ferreocenecarboxylic acid in phosphate buffered saline electrolyte solution, demonstrated steady-state voltammetric curves for d1, d2, b1 and b2. A good agreement between experimental and theoretical data is found for devices d1, d2, b1 and b2. The experimental current for b3, on the other hand, is much lower compared to the calculated one- perhaps due to the overlapping of the diffusion layers of neighbouring microelectrodes in the array.

  3. Reconfigurable Plasma Antenna Array by Using Fluorescent Tube for Wi-Fi Application

    Directory of Open Access Journals (Sweden)

    H. Ja’afar

    2016-06-01

    Full Text Available This paper presents a new design of reconfigurable plasma antenna array using commercial fluorescent tube. A round shape reconfigurable plasma antenna array is proposed to collimate beam radiated by an omnidirectional antenna (monopole antenna operates at 2.4GHz in particular direction. The antenna design is consisted of monopole antenna located at the center of circular aluminum ground. The monopole antenna is surrounded by a cylindrical shell of conducting plasma. The plasma shield consists of 12 commercial fluorescent tubes aligned in series containing a mixture of Argon gas and mercury vapor which upon electrification forms plasma columns. The plasma behaves as a conductor and acts as a reflector in radiation, in the condition where plasma frequency,ωp is higher than operating frequency. From this concepts, when all plasma elements are activated or switched to ON, the radiation signal from monopole antenna will trapped inside the plasma blanket and meanwhile when one or more plasma elements is deactivated (switched OFF, the radiation from monopole antenna will escape. This antenna has the capability to change its patterns with beam direction at 0°, 30°, 60°, 90°, 120°, 150°, 180°, 210°, 240°, 270°, 300° and 330° at frequency 2.4 GHz. The proposed antenna has been successfully fabricated and measured with conclusive results.

  4. Design and optimization of arrays of neodymium iron boron-based magnets for magnetic tweezers applications

    International Nuclear Information System (INIS)

    We present the design methodology for arrays of neodymium iron boron (NdFeB)-based magnets for use in magnetic tweezers devices. Using finite element analysis (FEA), we optimized the geometry of the NdFeB magnet as well as the geometry of iron yokes designed to focus the magnetic fields toward the sample plane. Together, the magnets and yokes form a magnetic array which is the basis of the magnetic tweezers device. By systematically varying 15 distinct shape parameters, we determined those features that maximize the magnitude of the magnetic field gradient as well as the length scale over which the magnetic force operates. Additionally, we demonstrated that magnetic saturation of the yoke material leads to intrinsic limitations in any geometric design. Using this approach, we generated a compact and light-weight magnetic tweezers device that produces a high field gradient at the image plane in order to apply large forces to magnetic beads. We then fabricated the optimized yoke and validated the FEA by experimentally mapping the magnetic field of the device. The optimization data and iterative FEA approach outlined here will enable the streamlined design and construction of specialized instrumentation for force-sensitive microscopy

  5. Matched field noise suppression: Principle with application to towed hydrophone line array

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Discrete noise source suppression in underwater acoustic channel has attracted great attention in recent years. The paper proposes a new principle for dealing with the problem. This new principle is called matched field noise suppression (MFNS). Based on a previous work of the authors group, a full understanding about how a discrete noise source shows effects on the performance of a towed hydrophone line array has been obtained. In light of that finding, MFNS is proposed, which explores and utilizes the characteristics of the noise transmission channel to achieve much greater suppression of the noise in comparison with existing approaches. MFNS combines the concept of matched field processing (MFP) and optimal sensor array processing (OSAP) together to suppress the discrete noise source and to maintain an optimal beam for receiving far-field wanted plane wave signals. A MFNS beam-former is deduced in constraint with signal plane-wave response being unit and noise matched field response being zero. A closed-form solution of the weight vector for the beam-former is given. Computer simulation results agree well to the theoretical analysis.

  6. Monolithic integrated four DFB lasers array with a polymer-based combiner for WDM applications

    Science.gov (United States)

    Toussaere, E.; Bouadma, N.; Zyss, J.

    1998-01-01

    Compact and low cost integrated photonic components will be of significant importance for a wider penetration of optical technologies into private customer access systems. Hybrid semiconductor/polymer integrated technologies are very promising to achieve this goal by virtue of the highly flexible nature of polymers at both molecular and material scale, of their compatibility with processing steps used in semiconductor technologies, and of their reasonably low cost. One example is an integrated semiconductor 4-wavelength laser array with a polymer based 1-4 passive optical combiner on the same substrate. The polymer waveguide structure is a polysulfone material stripe embedded in PMMA cladding layers, and the laser structure is a buried ridge stripe (BRS). The optical coupling between the active and passive elements is a butt-joint coupling via a reactive ion beam etched (RIBE) semiconductor mirror facet. Such a photonic integration simplifies the optical coupling between a laser array and single mode fibers, while reducing the packaging cost. This optical device has been achieved with interesting performances such as small dimension size (1.2 × 0.5 mm), low laser threshold current, and output powers for each laser from the polymeric waveguide port of at least 1.5 mW without additional on-chip optical amplification.

  7. Evaluation of Emerging Energy-Efficient Heterogeneous Computing Platforms for Biomolecular and Cellular Simulation Workloads

    Science.gov (United States)

    Stone, John E.; Hallock, Michael J.; Phillips, James C.; Peterson, Joseph R.; Luthey-Schulten, Zaida; Schulten, Klaus

    2016-01-01

    Many of the continuing scientific advances achieved through computational biology are predicated on the availability of ongoing increases in computational power required for detailed simulation and analysis of cellular processes on biologically-relevant timescales. A critical challenge facing the development of future exascale supercomputer systems is the development of new computing hardware and associated scientific applications that dramatically improve upon the energy efficiency of existing solutions, while providing increased simulation, analysis, and visualization performance. Mobile computing platforms have recently become powerful enough to support interactive molecular visualization tasks that were previously only possible on laptops and workstations, creating future opportunities for their convenient use for meetings, remote collaboration, and as head mounted displays for immersive stereoscopic viewing. We describe early experiences adapting several biomolecular simulation and analysis applications for emerging heterogeneous computing platforms that combine power-efficient system-on-chip multi-core CPUs with high-performance massively parallel GPUs. We present low-cost power monitoring instrumentation that provides sufficient temporal resolution to evaluate the power consumption of individual CPU algorithms and GPU kernels. We compare the performance and energy efficiency of scientific applications running on emerging platforms with results obtained on traditional platforms, identify hardware and algorithmic performance bottlenecks that affect the usability of these platforms, and describe avenues for improving both the hardware and applications in pursuit of the needs of molecular modeling tasks on mobile devices and future exascale computers.

  8. The biomolecular corona of nanoparticles in circulating biological media

    Science.gov (United States)

    Pozzi, D.; Caracciolo, G.; Digiacomo, L.; Colapicchioni, V.; Palchetti, S.; Capriotti, A. L.; Cavaliere, C.; Zenezini Chiozzi, R.; Puglisi, A.; Laganà, A.

    2015-08-01

    When nanoparticles come into contact with biological media, they are covered by a biomolecular `corona', which confers a new identity to the particles. In all the studies reported so far nanoparticles are incubated with isolated plasma or serum that are used as a model for protein adsorption. Anyway, bodily fluids are dynamic in nature so the question arises on whether the incubation protocol, i.e. dynamic vs. static incubation, could affect the composition and structure of the biomolecular corona. Here we let multicomponent liposomes interact with fetal bovine serum (FBS) both statically and dynamically, i.e. in contact with circulating FBS (~40 cm s-1). The structure and composition of the liposome-protein corona, as determined by dynamic light scattering, electrophoretic light scattering and liquid chromatography tandem mass spectrometry, were found to be dependent on the incubation protocol. Specifically, following dynamic exposure to FBS, multicomponent liposomes were less enriched in complement proteins and appreciably more enriched in apolipoproteins and acute phase proteins (e.g. alpha-1-antitrypsin and inter-alpha-trypsin inhibitor heavy chain H3) that are involved in relevant interactions between nanoparticles and living systems. Supported by our results, we speculate that efficient predictive modeling of nanoparticle behavior in vivo will require accurate knowledge of nanoparticle-specific protein fingerprints in circulating biological media.When nanoparticles come into contact with biological media, they are covered by a biomolecular `corona', which confers a new identity to the particles. In all the studies reported so far nanoparticles are incubated with isolated plasma or serum that are used as a model for protein adsorption. Anyway, bodily fluids are dynamic in nature so the question arises on whether the incubation protocol, i.e. dynamic vs. static incubation, could affect the composition and structure of the biomolecular corona. Here we let

  9. Biomolecular Simulation of Base Excision Repair and Protein Signaling

    Energy Technology Data Exchange (ETDEWEB)

    Straatsma, TP; McCammon, J A; Miller, John H; Smith, Paul E; Vorpagel, Erich R; Wong, Chung F; Zacharias, Martin W

    2006-03-03

    The goal of the Biomolecular Simulation of Base Excision Repair and Protein Signaling project is to enhance our understanding of the mechanism of human polymerase-β, one of the key enzymes in base excision repair (BER) and the cell-signaling enzymes cyclic-AMP-dependent protein kinase. This work used molecular modeling and simulation studies to specifically focus on the • dynamics of DNA and damaged DNA • dynamics and energetics of base flipping in DNA • mechanism and fidelity of nucleotide insertion by BER enzyme human polymerase-β • mechanism and inhibitor design for cyclic-AMP-dependent protein kinase. Molecular dynamics simulations and electronic structure calculations have been performed using the computer resources at the Molecular Science Computing Facility at the Environmental Molecular Sciences Laboratory.

  10. Insights into cancer severity from biomolecular interaction mechanisms

    Science.gov (United States)

    Raimondi, Francesco; Singh, Gurdeep; Betts, Matthew J.; Apic, Gordana; Vukotic, Ranka; Andreone, Pietro; Stein, Lincoln; Russell, Robert B.

    2016-01-01

    To attain a deeper understanding of diseases like cancer, it is critical to couple genetics with biomolecular mechanisms. High-throughput sequencing has identified thousands of somatic mutations across dozens of cancers, and there is a pressing need to identify the few that are pathologically relevant. Here we use protein structure and interaction data to interrogate nonsynonymous somatic cancer mutations, identifying a set of 213 molecular interfaces (protein-protein, -small molecule or –nucleic acid) most often perturbed in cancer, highlighting several potentially novel cancer genes. Over half of these interfaces involve protein-small-molecule interactions highlighting their overall importance in cancer. We found distinct differences in the predominance of perturbed interfaces between cancers and histological subtypes and presence or absence of certain interfaces appears to correlate with cancer severity. PMID:27698488

  11. Structure and Interactions of Isolated Biomolecular Building Blocks.

    Science.gov (United States)

    de Vries, Mattanjah

    2006-03-01

    We investigate biomolecular building blocks and their clusters with each other and with water on a single molecular level. The motivation is the need to distinguish between intrinsic molecular properties and those that result from the biological environment. This is achieved by a combination of laser desorption and jet cooling, applied to aromatic amino acids, small peptides containing those, nucleobases and nucleosides. This approach is coupled with a number of laser spectroscopic techniques, including resonant multi-photon ionization, spectral hole burning and infra-red ion-dip spectroscopy. We will discuss examples illustrating how information can be obtained on spatial structure of individual biomolecules, including peptide conformations and details of DNA base-pairing.

  12. Characterization of an advanced focal plane for multispectral linear array (MLA) application

    Science.gov (United States)

    King, P.; Botts, S.; Orias, G.; Yang, H. B.

    1984-01-01

    It is pointed out that the MLA instrument represents the next generation in the Landsat series of earth resources satellites. The MLA sensor concept utilizes a pushbroom scan mode to eliminate electromechanical scan mirrors, and the lower reliabililty and higher power dissipation which accompany their employment. The pushbroom scanner makes use of a linear array which consists generally of thousands of detectors oriented perpendicular to the along-track direction of the satellite. Test techniques have been developed for the measurement of the module parameters which are critical to MLA focal plane performance. These measurements include the determination of infrared responsivity, linearity over the dynamic range, temporal noise, and fixed pattern effects on each detector element of each module tested. Tests related to spectral response, crosstalk, and spot scan profiles are also conducted. A description is provided of the test equipment involved.

  13. Design of primary optics for LED chip array in road lighting application.

    Science.gov (United States)

    Wang, Shang; Wang, Kai; Chen, Fei; Liu, Sheng

    2011-07-01

    In this study, we proposed an effective optical design method to solve the problem of prescribed illuminance for LED chip array packaging (LCAP). With this method, light energy redistribution can be obtained by optimizing meshing parameters on the target. Not only can it deal with light controlling of extended source, but also improve the uniformity of both illuminance and luminance for road lighting as well. As an example, we designed a 16W LED packaging with a smooth primary freeform lens for general road lighting. The simulation results demonstrated that optical performance of this lens can meet the requirements of Commission Internationale del'Eclairage (CIE) quite well. Longitudinal and overall uniformities are 0.7 and 0.5 respectively, and relative optical efficiency of luminaire can be enhanced 19.6% in theory compared with traditional optics. PMID:21747539

  14. Optical characterization of nonimaging dish concentrator for the application of dense-array concentrator photovoltaic system.

    Science.gov (United States)

    Tan, Ming-Hui; Chong, Kok-Keong; Wong, Chee-Woon

    2014-01-20

    Optimization of the design of a nonimaging dish concentrator (NIDC) for a dense-array concentrator photovoltaic system is presented. A new algorithm has been developed to determine configuration of facet mirrors in a NIDC. Analytical formulas were derived to analyze the optical performance of a NIDC and then compared with a simulated result obtained from a numerical method. Comprehensive analysis of optical performance via analytical method has been carried out based on facet dimension and focal distance of the concentrator with a total reflective area of 120 m2. The result shows that a facet dimension of 49.8 cm, focal distance of 8 m, and solar concentration ratio of 411.8 suns is the most optimized design for the lowest cost-per-output power, which is US$1.93 per watt.

  15. Scalable stacked array piezoelectric deformable mirror for astronomy and laser processing applications.

    Science.gov (United States)

    Wlodarczyk, Krystian L; Bryce, Emma; Schwartz, Noah; Strachan, Mel; Hutson, David; Maier, Robert R J; Atkinson, David; Beard, Steven; Baillie, Tom; Parr-Burman, Phil; Kirk, Katherine; Hand, Duncan P

    2014-02-01

    A prototype of a scalable and potentially low-cost stacked array piezoelectric deformable mirror (SA-PDM) with 35 active elements is presented in this paper. This prototype is characterized by a 2 μm maximum actuator stroke, a 1.4 μm mirror sag (measured for a 14 mm × 14 mm area of the unpowered SA-PDM), and a ±200 nm hysteresis error. The initial proof of concept experiments described here show that this mirror can be successfully used for shaping a high power laser beam in order to improve laser machining performance. Various beam shapes have been obtained with the SA-PDM and examples of laser machining with the shaped beams are presented.

  16. Application of silicon zig-zag wall arrays for anodes of Li-ion batteries

    Science.gov (United States)

    Li, G. V.; Rumyantsev, A. M.; Levitskii, V. S.; Beregulin, E. V.; Zhdanov, V. V.; Terukov, E. I.; Astrova, E. V.

    2016-01-01

    Cyclic tests of anodes based on zigzag wall arrays fabricated by the electrochemical etching and post-anodization treatment of silicon have been performed. Compared with anodes based on nanowires and planar thin films, these structures have several advantages. An ex situ analysis of the morphology and structural transformations in a material subjected to cyclic lithiation was conducted by electron microscopy and micro-Raman spectroscopy. The effect of geometrical parameters and a cycling mode on the degradation rate was studied. It is shown that a significant rise in the cycle life of the anode can be obtained by the restriction of the inserted amount of lithium. The anode, subjected to galvanostatic cycling at a rate С/2.8 at a limited charge capacity of 1000 mA · h g-1, demonstrates no degradation after 1200 cycles.

  17. Application of multiparameter coincidence spectrometry using a Ge detectors array to neutron activation analysis

    CERN Document Server

    Hatsukawa, Y; Hayakawa, T; Toh, Y; Shinohara, N

    2002-01-01

    The method of multiparameter coincidence spectrometry based on gamma-gamma coincidence is widely used for the nuclear structure studies, because of its high sensitivity to gamma-rays. In this study, feasibility of the method of multiparameter coincidence spectrometry for analytical chemistry was examined. Two reference igneous rock samples (JP-1, JB-1a) issued by the Geological Survey of Japan were irradiated at a research reactor, and the gamma-rays from the radioisotopes produced via neutron capture reactions were measured using an array of 12 Ge detectors with BGO Compton suppressors, GEMINI. Simultaneously 24 elements were analyzed without chemical separation. The observed smallest component was Eu contained in JP-1 with abundance of 4 ppb.

  18. Enhanced extraordinary optical transmission (EOT) through arrays of bridged nanohole pairs and their sensing applications

    KAUST Repository

    Yue, Weisheng

    2014-01-01

    Extraordinary optical transmission (EOT) through arrays of gold nanoholes was studied with light across the visible to the near-infrared spectrum. The EOT effect was found to be improved by bridging pairs of nanoholes due to the concentration of the electromagnetic field in the slit between the holes. The geometrical shape and separation of the holes in these pairs of nanoholes affected the intensity of the transmission and the wavelength of resonance. Changing the geometrical shapes of these nanohole pairs from triangles to circles to squares leads to increased transmission intensity as well as red-shifting resonance wavelengths. The performance of bridged nanohole pairs as a plasmonic sensor was investigated. The bridged nanohole pairs were able to distinguish methanol, olive oil and microscope immersion oil for the different surface plasmon resonance in transmission spectra. Numerical simulation results were in agreement with experimental observations. © 2014 the Partner Organisations.

  19. Nanotube Arrays in Porous Anodic Alumina Membranes

    Institute of Scientific and Technical Information of China (English)

    Liang LI; Naoto KOSHIZAKI; Guanghai LI

    2008-01-01

    This review summarizes the various techniques developed for fabricating nanotube arrays in porous anodic alumina membranes (AAMs). After a brief introduction to the fabrication process of AAMs, taking carbons, metals, semiconductors, organics, biomoleculars, and heterojunctions as typical examples, attention will be focused on the recently established methods to fabricate nanotubes in AAM, including electrochemical deposition, surface sol-gel, modified chemical vapor deposition, atomic layer deposition, and layer-by-layer growth. Every method is demonstrated by one or two reported results. Finally, this review is concluded with some perspectives on the research directions and focuses on the AAM-based nanotubes fields.

  20. MCT-Based LWIR and VLWIR 2D Focal Plane Detector Arrays for Low Dark Current Applications at AIM

    Science.gov (United States)

    Hanna, S.; Eich, D.; Mahlein, K.-M.; Fick, W.; Schirmacher, W.; Thöt, R.; Wendler, J.; Figgemeier, H.

    2016-09-01

    We present our latest results on n-on- p as well as on p-on- n low dark current planar mercury cadmium telluride (MCT) photodiode technology long wavelength infrared (LWIR) and very long wavelength infrared (VLWIR) two-dimensional focal plane arrays (FPAs) with quantum efficiency (QE) cut-off wavelength >11 μm at 80 K and a 512 × 640 pixel format FPA at 20 μm pitch stitched from two 512 × 320 pixel photodiode arrays. Significantly reduced dark currents as compared with Tennant's "Rule 07" are demonstrated in both polarities while retaining good detection efficiency ≥60% for operating temperatures between 30 K and 100 K. This allows for the same dark current performance at 20 K higher operating temperature than with previous AIM INFRAROT-MODULE GmbH (AIM) technology. For p-on- n LWIR MCT FPAs, broadband photoresponse nonuniformity of only about 1.2% is achieved at 55 K with low defective pixel numbers. For an n-on- p VLWIR MCT FPA with 13.6 μm cut-off at 55 K, excellent photoresponse nonuniformity of about 3.1% is achieved at moderate defective pixel numbers. This advancement in detector technology paves the way for outstanding signal-to-noise ratio performance infrared detection, enabling cutting-edge next-generation LWIR/VLWIR detectors for space instruments and devices with higher operating temperature and low size, weight, and power for field applications.

  1. Development of a SNP array and its application to genetic mapping and diversity assessment in pepper (Capsicum spp.)

    Science.gov (United States)

    Cheng, Jiaowen; Qin, Cheng; Tang, Xin; Zhou, Huangkai; Hu, Yafei; Zhao, Zicheng; Cui, Junjie; Li, Bo; Wu, Zhiming; Yu, Jiping; Hu, Kailin

    2016-01-01

    The development and application of single nucleotide polymorphisms (SNPs) is in its infancy for pepper. Here, a set of 15,000 SNPs were chosen from the resequencing data to develop an array for pepper with 12,720 loci being ultimately synthesized. Of these, 8,199 (~64.46%) SNPs were found to be scorable and covered ~81.18% of the whole genome. With this array, a high-density interspecific genetic map with 5,569 SNPs was constructed using 297 F2 individuals, and genetic diversity of a panel of 399 pepper elite/landrace lines was successfully characterized. Based on the genetic map, one major QTL, named Up12.1, was detected for the fruit orientation trait. A total of 65 protein-coding genes were predicted within this QTL region based on the current annotation of the Zunla-1 genome. In summary, the thousands of well-validated SNP markers, high-density genetic map and genetic diversity information will be useful for molecular genetics and innovative breeding in pepper. Furthermore, the mapping results lay foundation for isolating the genes underlying variation in fruit orientation of Capsicum. PMID:27623541

  2. An Electronic-Nose Sensor Node Based on a Polymer-Coated Surface Acoustic Wave Array for Wireless Sensor Network Applications

    Directory of Open Access Journals (Sweden)

    Kea-Tiong Tang

    2011-04-01

    Full Text Available This study developed an electronic-nose sensor node based on a polymer-coated surface acoustic wave (SAW sensor array. The sensor node comprised an SAW sensor array, a frequency readout circuit, and an Octopus II wireless module. The sensor array was fabricated on a large K2 128° YX LiNbO3 sensing substrate. On the surface of this substrate, an interdigital transducer (IDT was produced with a Cr/Au film as its metallic structure. A mixed-mode frequency readout application specific integrated circuit (ASIC was fabricated using a TSMC 0.18 μm process. The ASIC output was connected to a wireless module to transmit sensor data to a base station for data storage and analysis. This sensor node is applicable for wireless sensor network (WSN applications.

  3. Morphological and Structural Control of Organic Monolayer Colloidal Crystal Based on Plasma Etching and Its Application in Fabrication of Ordered Gold Nanostructured Arrays

    Directory of Open Access Journals (Sweden)

    Guangqiang Liu

    2016-09-01

    Full Text Available The organic monolayer colloidal crystals, which are usually prepared by self-assembling, could be used as templates, due to their interstitial geometry, for the periodically arranged nanostructured arrays, which have important applications in many fields, such as photonic crystals, information storage, super-hydrophobicity, biological and chemical sensing. Obviously, the structures of the obtained arrays mainly depend on those of the templates. However, the self-assembled monolayer colloidal crystal is exclusive in structure and for its hexagonal close-packed colloidal arrangement, leading to the limitation of the monolayer colloidal crystal as the template for the nanostructured arrays. Therefore, structural diversity is important in order for colloidal crystals to be used as the templates for various nanostructured arrays. Recently, there have been some reports on the morphological and structural manipulation of the organic monolayer colloidal crystals. In this review article, we focus on the recent progress in morphological and structural manipulation of polystyrene monolayer colloidal crystals based on plasma etching, and its application in the fabrication of the ordered gold nanostructured arrays with different structures, mainly including close-packed monolayer colloidal crystal and its transferrable property; structural manipulation based on plasma etching; and fabrication of gold nanostructured arrays based on varied monolayer colloidal crystals as template.

  4. System integration and radiation pattern measurements of a phased array antenna employing an integrated photonic beamformer for radio astronomy applications.

    Science.gov (United States)

    Burla, Maurizio; Roeloffzen, Chris G H; Zhuang, Leimeng; Marpaung, David; Khan, Muhammad Rezaul; Maat, Peter; Dijkstra, Klaas; Leinse, Arne; Hoekman, Marcel; Heideman, René

    2012-03-01

    In this paper we describe the system integration and the experimental demonstration of a photonically beamformed four-element receiving array antenna for radio astronomy applications. To our knowledge, the work described here is the first demonstration of the squint-free, continuously tunable beamsteering capability offered by an integrated photonic beamformer based on optical ring resonator true-time-delay units, with measured radiation patterns. The integrated beamformer is realized in a low loss, complementary metal-oxide-semiconductor (CMOS) compatible optical waveguide technology. The measurements show a wideband, continuous beamsteering operation over a steering angle of 23.5 degrees and an instantaneous bandwidth of 500 MHz limited only by the measurement setup. PMID:22410879

  5. Comprehensive scaling study of NbO2 insulator-metal-transition selector for cross point array application

    Science.gov (United States)

    Cha, Euijun; Park, Jaehyuk; Woo, Jiyong; Lee, Daeseok; Prakash, Amit; Hwang, Hyunsang

    2016-04-01

    The transition metal oxide, NbO2, which exhibits an insulator to metal transition (IMT) is regarded as a promising selector device to be integrated with a resistive memory for cross point array application. In this study, we comprehensively investigated the scaling of an NbO2 selector using a mushroom device structure. A thorough understanding of the scaling behavior of forming voltage (Vf), threshold voltage (Vth), and current (Ith) is essential to evaluate the potential of voltage as well as current scaling and selectivity of NbO2 selector. Importantly, by analyzing the scaling trend of threshold current, we believed that the IMT behavior is strongly affected by filamentary conducting path formed during the forming process. The findings provide the promise to maximize the selector device performance by minimizing the conducting path inside the NbO2 layer.

  6. Application of multielectrode array (MEA) chips for the evaluation of mixtures neurotoxicity

    International Nuclear Information System (INIS)

    Cortical neurons grown on multielectrode array (MEA) chips have been shown to be a valuable alternative method to study electrophysiological properties of the central nervous system neurons and to perform functional toxicological screening. Here we studied the effects of binary mixtures on neuronal networks cultured on MEAs. We have considered compounds with similar and different mode-of-action (MoA) to characterize and assess their combined effects. Individual and binary mixture dose–response curves based on spontaneous neuronal activity have been generated and the IC50 has been considered as the end-point for neurotoxicity assessment. The two classical approaches of mixtures toxicity studies: concentration addition (CA) and independent action (IA) have been applied to compare calculated and experimental results. Nuclear magnetic resonance (NMR) spectroscopy has been employed to confirm no chemical reaction or complexation between mixtures components. The results suggest that both CA and IA are able to predict the toxicity of the mixture and that the combination of in vitro test methods with theoretical dose–response models has a strong potential as an alternative tool for the prediction of mixtures neurotoxicity.

  7. Two-Stage Chaos Optimization Search Application in Maximum Power Point Tracking of PV Array

    Directory of Open Access Journals (Sweden)

    Lihua Wang

    2014-01-01

    Full Text Available In order to deliver the maximum available power to the load under the condition of varying solar irradiation and environment temperature, maximum power point tracking (MPPT technologies have been used widely in PV systems. Among all the MPPT schemes, the chaos method is one of the hot topics in recent years. In this paper, a novel two-stage chaos optimization method is presented which can make search faster and more effective. In the process of proposed chaos search, the improved logistic mapping with the better ergodic is used as the first carrier process. After finding the current optimal solution in a certain guarantee, the power function carrier as the secondary carrier process is used to reduce the search space of optimized variables and eventually find the maximum power point. Comparing with the traditional chaos search method, the proposed method can track the change quickly and accurately and also has better optimization results. The proposed method provides a new efficient way to track the maximum power point of PV array.

  8. A Partially Magnetized Ferrite LTCC-Based SIW Phase Shifter for Phased Array Applications

    KAUST Repository

    Ghaffar, Farhan A.

    2015-06-01

    The theory and design of a half-mode substrate-integrated waveguide ferrite low-temperature cofired ceramic-based phase shifter are presented in this paper. Unlike typical ferrite-based designs, the biasing is done through embedded windings in a multi-layer substrate that not only obviates the requirement of bulky electromagnets, but also prevents loss of bias fields at the air-to-ferrite interface. The phase shifter is operated in the partially magnetized state of ferrite substrate. Through the combined effect of embedded windings, half-mode waveguide operation, and partially magnetized state, the required bias fields have been reduced by 90% as compared with conventional ferrite-based designs employing electromagnets. A complete analytical model, backed up by electromagnetic simulations and measured results from a prototype, is presented in this paper. The fabricated prototype demonstrates a phase shift of 83.2° at a center frequency of 13.1 GHz and a figure of merit of 83.2°/dB. As a proof-of-concept, the proposed phase shifter design is monolithically integrated with a two-element antenna array to demonstrate a measured beam steering of 30°. The phase shifter design is highly efficient in terms of required bias fields, and it has a small form factor and can be easily integrated with other electronic components and systems. © 1965-2012 IEEE.

  9. Digital Radiography Using Digital Detector Arrays Fulfills Critical Applications for Offshore Pipelines

    Directory of Open Access Journals (Sweden)

    Lopes RicardoTadeu

    2010-01-01

    Full Text Available Digital radiography in the inspection of welded pipes to be installed under deep water offshore gas and oil pipelines, like a presalt in Brazil, in the paper has been investigated. The aim is to use digital radiography for nondestructive testing of welds as it is already in use in the medical, aerospace, security, automotive, and petrochemical sectors. Among the current options, the DDA (Digital Detector Array is considered as one of the best solutions to replace industrial films, as well as to increase the sensitivity to reduce the inspection cycle time. This paper shows the results of this new technique, comparing it to radiography with industrial films systems. In this paper, 20 test specimens of longitudinal welded pipe joints, specially prepared with artificial defects like cracks, lack of fusion, lack of penetration, and porosities and slag inclusions with varying dimensions and in 06 different base metal wall thicknesses, were tested and a comparison of the techniques was made. These experiments verified the purposed rules for parameter definitions and selections to control the required digital radiographic image quality as described in the draft international standard ISO/DIS 10893-7. This draft is first standard establishing the parameters for digital radiography on weld seam of welded steel pipes for pressure purposes to be used on gas and oil pipelines.

  10. Development of high resolution arrayed waveguide grating spectrometers for astronomical applications: first results

    CERN Document Server

    Gatkine, Pradip; Hu, Yiwen; Zhu, Tiecheng; Meng, Yang; Bland-Hawthorn, Joss; Dagenais, Mario

    2016-01-01

    Astrophotonics is the next-generation approach that provides the means to miniaturize near-infrared (NIR) spectrometers for upcoming large telescopes and make them more robust and inexpensive. The target requirements for our spectrograph are: a resolving power of about 3000, wide spectral range (J and H bands), free spectral range of about 30 nm, high on-chip throughput of about 80% (-1dB) and low crosstalk (high contrast ratio) between adjacent on-chip wavelength channels of less than 1% (-20dB). A promising photonic technology to achieve these requirements is Arrayed Waveguide Gratings (AWGs). We have developed our first generation of AWG devices using a silica-on-silicon substrate with a very thin layer of silicon-nitride in the core of our waveguides. The waveguide bending losses are minimized by optimizing the geometry of the waveguides. Our first generation of AWG devices are designed for H band and have a resolving power of around 1500 and free spectral range of about 10 nm around a central wavelength ...

  11. Design, Fabrication, and Packaging of an Integrated, Wirelessly-Powered Optrode Array for Optogenetics Application

    Directory of Open Access Journals (Sweden)

    Wen eLi

    2015-05-01

    Full Text Available The recent development of optogenetics has created an increased demand for advancing engineering tools for optical modulation of neural circuitry. This paper details the design, fabrication, integration, and packaging procedures of a wirelessly-powered, light emitting diode (LED coupled optrode neural interface for optogenetic studies. The LED-coupled optrode array employs microscale LED (μLED dies and polymer-based microwaveguides to deliver light into multi-level cortical networks, coupled with microelectrodes to record spontaneous changes in neural activity. An integrated, implantable, switched-capacitor based stimulator (SCS system provides high instantaneous power to the μLEDs through an inductive link to emit sufficient light and evoke neural activities. The presented system is mechanically flexible, biocompatible, miniaturized, and lightweight, suitable for chronic implantation in small freely behaving animals. The design of this system is scalable and its manufacturing is cost effective through batch fabrication using microelectromechanical systems (MEMS technology. It can be adopted by other groups and customized for specific needs of individual experiments.

  12. Rapid Progress of a Thermal Arrayed Waveguide Grating Module for Dense Wavelength Division Multiplexing Applications

    Directory of Open Access Journals (Sweden)

    Abd ElñNaser A. Mohamed

    2011-09-01

    Full Text Available In the present paper, we have proposed a thermal planar arrayed waveguide grating (AWG module for dense wavelength division multiplexing (DWDM which is composed of one of the following material as a core such as Pure silica glass (SiO2, Lithium niobate (LiNbO3, and gallium aluminum arsenide (Ga(1 xAl(xAs/Polyhexafluoro isopropyl 2-fluoroacrylate dibutyl phathalate (PHFIP 2-FA-DBP used as over cladding material/Polyhexafluoro isopropyl 2-fluoroacrylate (PHFIP 2-FA used as under cladding material, hybrid materials on a silicon substrate has parametrically investigated over wide range of the affecting parameters. multiplexing technique is processed where multi channels in ultra dense wavelength division multiplexing in a thermal AWG module. We have theoretically investigated the temperature dependent wavelength shift of the AWG depends on the refractive indices of the materials and the size of the waveguide. A thermalization of the AWG can be realized by selecting proper values of the material and structural parameters of the device. We have taken into account the increased number of transmitted channels within DWDM technique over a thermal planar AWG of hybrid materials. The thermal effects of different hybrid materials employed in the fabrication of AWG are studied deeply and parametrically for the good performance of such AWG.

  13. Multichannel quartz crystal microbalance array: Fabrication, evaluation, application in biomarker detection.

    Science.gov (United States)

    Tao, Wenyan; Lin, Peng; Ai, Yanqing; Wang, Hairui; Ke, Shanming; Zeng, Xierong

    2016-02-01

    A multichannel quartz crystal microbalance array (MQCM) with three pairs of gold electrodes was fabricated for detection of two biomarkers: acetone and nitric oxide (NO). The gold electrodes were deposited symmetrically on an AT-cut 10 MHz circular quartz plate using photolithography, sputtering, and lift-off technologies. The effect of gold layer thickness on MQCM performance was investigated and the optimized thickness was 101 nm. The simulation values of the electric parameters C0, Cq, Lq, and Rq in the Butterworth-Van Dike equivalent circuit for the MQCM device were 97 pF, 1.3 pF, 1.05 mH, and 9.8 Ω, respectively. Simulation values were in the theoretical range, which indicated that the fabricated MQCM device had good resonance performance. Two types of nanocomposites, titanium dioxide-multiwalled carbon nanotubes and cobalt (II)phthalocyanine-silica, were synthesized as sensing materials. The sensing mechanism is based on coordination adsorption of target molecules onto the sensing material, resulting in a resonant frequency shift of modified QCM sensor. A linear range from 4.33 to 129.75 ppmv for acetone was obtained and one from 5.75 to 103.45 ppbv for NO. PMID:26582433

  14. Dislocation dynamics. II. Applications to the formation of persistent slip bands, planar arrays, and dislocation cells

    International Nuclear Information System (INIS)

    The dynamic organization of dislocations into spatially heterogeneous substructures is demonstrated by applying the principles of dislocation dynamics that were outlined in the preceding paper. Here it is shown that the formation of persistent slip bands is a consequence of the competition between dipole formation and annihilation of dislocations of opposite Burgers vectors in the absence of temperature-enhanced climb recovery under cyclic stress conditions. Planar arrays, which are also uniaxial structures, are shown to arise from enhanced dislocation multiplication and the formation of stable dipole configurations along a slip plane at lower temperatures where climb is unimportant. Biaxial dislocation systems experience additional degrees of freedom compared with uniaxial systems because of available motion along additional slip systems. It is demonstrated that for a system of orthogonal slip directions at high temperatures in which climb and glide motion are competitive, dislocation cellular structures form as a result of immobile dipole and junction formation and by the internal elastic strain energy minimization caused by long-range self-shielding. It is shown that the internal elastic strain energy is reduced by the self-organization process. However, the short-range nonlinear processes (i.e., dipole and junction formation) are shown not to allow absolute elastic energy minimization

  15. Parameter allocation of parallel array bistable stochastic resonance and its application in communication systems

    Science.gov (United States)

    Liu, Jian; Wang, You-Guo; Zhai, Qi-Qing; Liu, Jin

    2016-10-01

    In this paper, we propose a parameter allocation scheme in a parallel array bistable stochastic resonance-based communication system (P-BSR-CS) to improve the performance of weak binary pulse amplitude modulated (BPAM) signal transmissions. The optimal parameter allocation policy of the P-BSR-CS is provided to minimize the bit error rate (BER) and maximize the channel capacity (CC) under the adiabatic approximation condition. On this basis, we further derive the best parameter selection theorem in realistic communication scenarios via variable transformation. Specifically, the P-BSR structure design not only brings the robustness of parameter selection optimization, where the optimal parameter pair is not fixed but variable in quite a wide range, but also produces outstanding system performance. Theoretical analysis and simulation results indicate that in the P-BSR-CS the proposed parameter allocation scheme yields considerable performance improvement, particularly in very low signal-to-noise ratio (SNR) environments. Project supported by the National Natural Science Foundation of China (Grant No. 61179027), the Qinglan Project of Jiangsu Province of China (Grant No. QL06212006), and the University Postgraduate Research and Innovation Project of Jiangsu Province (Grant Nos. KYLX15_0829, KYLX15_0831).

  16. Miniaturizable Ion-Selective Arrays Based on Highly Stable Polymer Membranes for Biomedical Applications

    Science.gov (United States)

    Mir, Mònica; Lugo, Roberto; Tahirbegi, Islam Bogachan; Samitier, Josep

    2014-01-01

    Poly(vinylchloride) (PVC) is the most common polymer matrix used in the fabrication of ion-selective electrodes (ISEs). However, the surfaces of PVC-based sensors have been reported to show membrane instability. In an attempt to overcome this limitation, here we developed two alternative methods for the preparation of highly stable and robust ion-selective sensors. These platforms are based on the selective electropolymerization of poly(3,4-ethylenedioxythiophene) (PEDOT), where the sulfur atoms contained in the polymer covalently interact with the gold electrode, also permitting controlled selective attachment on a miniaturized electrode in an array format. This platform sensor was improved with the crosslinking of the membrane compounds with poly(ethyleneglycol) diglycidyl ether (PEG), thus also increasing the biocompatibility of the sensor. The resulting ISE membranes showed faster signal stabilization of the sensor response compared with that of the PVC matrix and also better reproducibility and stability, thus making these platforms highly suitable candidates for the manufacture of robust implantable sensors. PMID:24999717

  17. Synthesis, characterization and application of electroless metal assisted silicon nanowire arrays

    Science.gov (United States)

    Sahoo, Sumanta Kumar; Marikani, Arumugam

    2015-12-01

    Vertically aligned silicon nanowire arrays (SiNWs) have been synthesized by electroless metal deposition process. The fabricated SiNWs have an average diameter of 75 nm and 3.5-4.0 μm length, as confirmed from scanning electron microscopy. A characteristic asymmetric peak broadening at 520 cm-1 from Raman spectroscopy was obtained for the SiNWs as compared to the bulk silicon crystal due to phonon confinement. The as-prepared SiNWs exhibit good electron field-emission properties with turn-on field of about 8.26 V μm-1 at a current density of 4.9 μA cm-2. The SiNWs was functionalized by coating with a thin gold metallic film for 60 s, and then used as bio-probe for the detection of bovine serum albumin (BSA) protein molecules. From the linear sweep voltammetry analysis, the Au coated SiNWs, exhibit linear response to the BSA analyte with increase in concentration. The minimum detection limit of the protein molecule was calculated of about 1.16 μM by the as-synthesized SiNWs probe.

  18. Digital Radiography Using Digital Detector Arrays Fulfills Critical Applications for Offshore Pipelines

    Science.gov (United States)

    Moreira, EdsonVasques; Barbosa Rabello, JoséMaurício; Pereira, MarcelodosSantos; Lopes, RicardoTadeu; Zscherpel, Uwe

    2010-12-01

    Digital radiography in the inspection of welded pipes to be installed under deep water offshore gas and oil pipelines, like a presalt in Brazil, in the paper has been investigated. The aim is to use digital radiography for nondestructive testing of welds as it is already in use in the medical, aerospace, security, automotive, and petrochemical sectors. Among the current options, the DDA (Digital Detector Array) is considered as one of the best solutions to replace industrial films, as well as to increase the sensitivity to reduce the inspection cycle time. This paper shows the results of this new technique, comparing it to radiography with industrial films systems. In this paper, 20 test specimens of longitudinal welded pipe joints, specially prepared with artificial defects like cracks, lack of fusion, lack of penetration, and porosities and slag inclusions with varying dimensions and in 06 different base metal wall thicknesses, were tested and a comparison of the techniques was made. These experiments verified the purposed rules for parameter definitions and selections to control the required digital radiographic image quality as described in the draft international standard ISO/DIS 10893-7. This draft is first standard establishing the parameters for digital radiography on weld seam of welded steel pipes for pressure purposes to be used on gas and oil pipelines.

  19. Bilayer–metal assisted chemical etching of silicon microwire arrays for photovoltaic applications

    Directory of Open Access Journals (Sweden)

    R. W. Wu

    2016-02-01

    Full Text Available Silicon microwires with lateral dimension from 5 μm to 20 μm and depth as long as 20 μm are prepared by bilayer metal assisted chemical etching (MaCE. A bilayer metal configuration (Metal 1 / Metal 2 was applied to assist etching of Si where metal 1 acts as direct catalyst and metal 2 provides mechanical support. Different metal types were investigated to figure out the influence of metal catalyst on morphology of etched silicon. We find that silicon microwires with vertical side wall are produced when we use Ag/Au bilayer, while cone–like and porous microwires formed when Pt/Au is applied. The different micro-/nano-structures in as-etched silicon are demonstrated to be due to the discrepancy of work function of metal catalyst relative to Si. Further, we constructed a silicon microwire arrays solar cells in a radial p–n junction configurations in a screen printed aluminum paste p–doping process.

  20. Solar array deployment mechanism

    Science.gov (United States)

    Calassa, Mark C.; Kackley, Russell

    1995-05-01

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

  1. Fabrication of Ni-Ti-O nanotube arrays by anodization of NiTi alloy and their potential applications

    Science.gov (United States)

    Hang, Ruiqiang; Liu, Yanlian; Zhao, Lingzhou; Gao, Ang; Bai, Long; Huang, Xiaobo; Zhang, Xiangyu; Tang, Bin; Chu, Paul K.

    2014-12-01

    Nickel-titanium-oxide (Ni-Ti-O) nanotube arrays (NTAs) prepared on nearly equiatomic NiTi alloy shall have broad application potential such as for energy storage and biomedicine, but their precise structure control is a great challenge because of the high content of alloying element of Ni, a non-valve metal that cannot form a compact electronic insulating passive layer when anodized. In the present work, we systemically investigated the influence of various anodization parameters on the formation and structure of Ni-Ti-O NTAs and their potential applications. Our results show that well controlled NTAs can be fabricated during relatively wide ranges of the anodization voltage (5-90 V), electrolyte temperature (10-50°C) and electrolyte NH4F content (0.025-0.8 wt%) but within a narrow window of the electrolyte H2O content (0.0-1.0 vol%). Through modulating these parameters, the Ni-Ti-O NTAs with different diameter (15-70 nm) and length (45-1320 nm) can be produced in a controlled manner. Regarding potential applications, the Ni-Ti-O NTAs may be used as electrodes for electrochemical energy storage and non-enzymic glucose detection, and may constitute nanoscaled biofunctional coating to improve the biological performance of NiTi based biomedical implants.

  2. Differential geometry-based solvation and electrolyte transport models for biomolecular modeling: a review

    OpenAIRE

    Wei, Guo Wei; Baker, Nathan A.

    2014-01-01

    This chapter reviews the differential geometry-based solvation and electrolyte transport for biomolecular solvation that have been developed over the past decade. A key component of these methods is the differential geometry of surfaces theory, as applied to the solvent-solute boundary. In these approaches, the solvent-solute boundary is determined by a variational principle that determines the major physical observables of interest, for example, biomolecular surface area, enclosed volume, el...

  3. Modeling Structural Dynamics of Biomolecular Complexes by Coarse-Grained Molecular Simulations.

    Science.gov (United States)

    Takada, Shoji; Kanada, Ryo; Tan, Cheng; Terakawa, Tsuyoshi; Li, Wenfei; Kenzaki, Hiroo

    2015-12-15

    Due to hierarchic nature of biomolecular systems, their computational modeling calls for multiscale approaches, in which coarse-grained (CG) simulations are used to address long-time dynamics of large systems. Here, we review recent developments and applications of CG modeling methods, focusing on our methods primarily for proteins, DNA, and their complexes. These methods have been implemented in the CG biomolecular simulator, CafeMol. Our CG model has resolution such that ∼10 non-hydrogen atoms are grouped into one CG particle on average. For proteins, each amino acid is represented by one CG particle. For DNA, one nucleotide is simplified by three CG particles, representing sugar, phosphate, and base. The protein modeling is based on the idea that proteins have a globally funnel-like energy landscape, which is encoded in the structure-based potential energy function. We first describe two representative minimal models of proteins, called the elastic network model and the classic Go̅ model. We then present a more elaborate protein model, which extends the minimal model to incorporate sequence and context dependent local flexibility and nonlocal contacts. For DNA, we describe a model developed by de Pablo's group that was tuned to well reproduce sequence-dependent structural and thermodynamic experimental data for single- and double-stranded DNAs. Protein-DNA interactions are modeled either by the structure-based term for specific cases or by electrostatic and excluded volume terms for nonspecific cases. We also discuss the time scale mapping in CG molecular dynamics simulations. While the apparent single time step of our CGMD is about 10 times larger than that in the fully atomistic molecular dynamics for small-scale dynamics, large-scale motions can be further accelerated by two-orders of magnitude with the use of CG model and a low friction constant in Langevin dynamics. Next, we present four examples of applications. First, the classic Go̅ model was used to

  4. Optimizing Chemical Sensor Array Sizes

    International Nuclear Information System (INIS)

    Optimal selection of array sensors for a chemical sensing application is a nontrivial task. It is commonly believed that ''more is better'' when choosing the number of sensors required to achieve good chemical selectivity. However, cost and system complexity issues point towards the choice of small arrays. A quantitative array optimization is carried out to explore the selectivity of arrays of partially-selective chemical sensors as a function of array size. It is shown that modest numbers (dozens) of target analytes are completely distinguished with a range of arrays sizes. However, the array selectivity and the robustness against sensor sensitivity variability are significantly degraded if the array size is increased above a certain number of sensors, so that relatively small arrays provide the best performance. The results also suggest that data analyses for very large arrays of partially-selective sensors will be optimized by separately anal yzing small sensor subsets

  5. Nanowire array chips for molecular typing of rare trafficking leukocytes with application to neurodegenerative pathology

    Science.gov (United States)

    Kwak, Minsuk; Kim, Dong-Joo; Lee, Mi-Ri; Wu, Yu; Han, Lin; Lee, Sang-Kwon; Fan, Rong

    2014-05-01

    Despite the presence of the blood-brain barrier (BBB) that restricts the entry of immune cells and mediators into the central nervous system (CNS), a small number of peripheral leukocytes can traverse the BBB and infiltrate into the CNS. The cerebrospinal fluid (CSF) is one of the major routes through which trafficking leukocytes migrate into the CNS. Therefore, the number of leukocytes and their phenotypic compositions in the CSF may represent important sources to investigate immune-to-brain interactions or diagnose and monitor neurodegenerative diseases. Due to the paucity of trafficking leucocytes in the CSF, a technology capable of efficient isolation, enumeration, and molecular typing of these cells in the clinical settings has not been achieved. In this study, we report on a biofunctionalized silicon nanowire array chip for highly efficient capture and multiplexed phenotyping of rare trafficking leukocytes in small quantities (50 microliters) of clinical CSF specimens collected from neurodegenerative disease patients. The antibody coated 3D nanostructured materials exhibited vastly improved rare cell capture efficiency due to high-affinity binding and enhanced cell-substrate interactions. Moreover, our platform creates multiple cell capture interfaces, each of which can selectively isolate specific leukocyte phenotypes. A comparison with the traditional immunophenotyping using flow cytometry demonstrated that our novel silicon nanowire-based rare cell analysis platform can perform rapid detection and simultaneous molecular characterization of heterogeneous immune cells. Multiplexed molecular typing of rare leukocytes in CSF samples collected from Alzheimer's disease patients revealed the elevation of white blood cell counts and significant alterations in the distribution of major leukocyte phenotypes. Our technology represents a practical tool for potentially diagnosing and monitoring the pathogenesis of neurodegenerative diseases by allowing an effective

  6. High linearity SPAD and TDC array for TCSPC and 3D ranging applications

    Science.gov (United States)

    Villa, Federica; Lussana, Rudi; Bronzi, Danilo; Dalla Mora, Alberto; Contini, Davide; Tisa, Simone; Tosi, Alberto; Zappa, Franco

    2015-01-01

    An array of 32x32 Single-Photon Avalanche-Diodes (SPADs) and Time-to-Digital Converters (TDCs) has been fabricated in a 0.35 μm automotive-certified CMOS technology. The overall dimension of the chip is 9x9 mm2. Each pixel is able to detect photons in the 300 nm - 900 nm wavelength range with a fill-factor of 3.14% and either to count them or to time stamp their arrival time. In photon-counting mode an in-pixel 6-bit counter provides photon-numberresolved intensity movies at 100 kfps, whereas in photon-timing mode the 10-bit in-pixel TDC provides time-resolved maps (Time-Correlated Single-Photon Counting measurements) or 3D depth-resolved (through direct time-of-flight technique) images and movies, with 312 ps resolution. The photodetector is a 30 μm diameter SPAD with low Dark Count Rate (120 cps at room temperature, 3% hot-pixels) and 55% peak Photon Detection Efficiency (PDE) at 450 nm. The TDC has a 6-bit counter and a 4-bit fine interpolator, based on a Delay Locked Loop (DLL) line, which makes the TDC insensitive to process, voltage, and temperature drifts. The implemented sliding-scale technique improves linearity, giving 2% LSB DNL and 10% LSB INL. The single-shot precision is 260 ps rms, comprising SPAD, TDC and driving board jitter. Both optical and electrical crosstalk among SPADs and TDCs are negligible. 2D fast movies and 3D reconstructions with centimeter resolution are reported.

  7. The Xsense project: The application of an intelligent sensor array for high sensitivity handheld explosives detectors

    DEFF Research Database (Denmark)

    Kostesha, Natalie; Schmidt, Michael Stenbæk; Bosco, Filippo;

    2011-01-01

    Multiple independent sensors are used in security and military applications in order to increase sensitivity, selectivity and data reliability. The Xsense project has been initiated at the Technical University of Denmark in collaboration with a number of partners in an effort to produce a handhel...

  8. Advances and Applications of Antibody Arrays - Proteomic Profiling of Pancreatic Disease

    OpenAIRE

    Sandström Gerdtsson, Anna

    2013-01-01

    Recombinant antibody microarrays have advanced into indispensable tools for large-scale, high-throughput multiplexed serum proteomics. This thesis, based upon five original papers, deals with the development of an in-house designed antibody microarray platform, and its applications for serum profiling of pancreatic disease. Pancreatic cancer is the 4th deadliest cancer, with a 5-year survival rate of only 6%. In order to increase the survival of this deadly disease, novel diagnostic bioma...

  9. Ultra high brightness laser diode arrays for pumping of compact solid state lasers and direct applications

    Science.gov (United States)

    Kohl, Andreas; Fillardet, Thierry; Laugustin, Arnaud; Rabot, Olivier

    2012-10-01

    High Power Laser Diodes (HPLD) are increasingly used in different fields of applications such as Industry, Medicine and Defense. Our significant improvements of performances (especially in power and efficiency) and a reproducible manufacturing process have led to reliable, highly robust components. For defense and security applications these devices are used predominantly for pumping of solid state lasers (ranging, designation, countermeasures, and sensors). Due to the drastically falling price per watt they are more and more replacing flash lamps as pump sources. By collimating the laser beam even with a bar to bar pitch of only 400μm. cutting edge brightness of our stacks.is achieved Due the extremely high brightness and high power density these stacks are an enabling technology for the development of compact highly efficient portable solid state lasers for applications as telemeters and designators on small platforms such as small UAVs and handheld devices. In combination with beam homogenizing optics their compact size and high efficiency makes these devices perfectly suited as illuminators for portable active imaging systems. For gated active imaging systems a very short pulse at high PRF operation is required. For this application we have developed a diode driver board with an efficiency several times higher than that of a standard driver. As a consequence this laser source has very low power consumption and low waste heat dissipation. In combination with its compact size and the integrated beam homogenizing optics it is therefore ideally suited for use in portable gated active imaging systems. The kWatt peak power enables a range of several hundred meters. The devices described in this paper mostly operate at wavelength between 800 nm and 980nm. Results from diodes operating between 1300 nm and 1550 nm are presented as well.

  10. HIGH-CURRENT COLD CATHODE FIELD EMISSION ARRAY FOR ELECTRON LENS APPLICATION

    Energy Technology Data Exchange (ETDEWEB)

    Hirshfield, Jay L

    2012-12-28

    During Phase I, the following goals were achieved: (1) design and fabrication of a novel, nano-dimensional CNT field emitter assembly for high current density application, with high durability; (2) fabrication of a ceramic based micro channel plate (MCP) and characterization of its secondary electron emission; and (3) characterizing the CNT/MCP cathode for high field emission and durability. As a result of these achievements, a relatively high current density of ~ 1.2 A/cm2 from a CNT cathode and single channel MCP were measured. The emission current was also extremely stable with a peak-to-peak variation of only 1.8%. The emission current could be further enhanced to meet requirements for electron lens applications by increasing the number of MCP channels. A calculation for maximum possible current density with a 1200 channel/cm2 MCP, placed over a cathode with 1200 uniformly functioning CNTs, would be ~1.46 kA/cm2, neglecting space charge limitations. Clearly this level of emission is far greater than what is needed for the electron lens application, but it does offer a highly comforting margin to account for sub-standard emitters and/or to allow the lesser challenge of building a cathode with fewer channels/cm2. A satisfactory goal for the electron lens application would be a controllable emission of 2-4 mA per channel in an ensemble of 800-1200 uniformly-functioning channels/cm2, and a cathode with overall area of about 1 cm2.

  11. Optimizing laser beam profiles using micro-lens arrays for efficient material processing: applications to solar cells

    Science.gov (United States)

    Hauschild, Dirk; Homburg, Oliver; Mitra, Thomas; Ivanenko, Mikhail; Jarczynski, Manfred; Meinschien, Jens; Bayer, Andreas; Lissotschenko, Vitalij

    2009-02-01

    High power laser sources are used in various production tools for microelectronic products and solar cells, including the applications annealing, lithography, edge isolation as well as dicing and patterning. Besides the right choice of the laser source suitable high performance optics for generating the appropriate beam profile and intensity distribution are of high importance for the right processing speed, quality and yield. For industrial applications equally important is an adequate understanding of the physics of the light-matter interaction behind the process. In advance simulations of the tool performance can minimize technical and financial risk as well as lead times for prototyping and introduction into series production. LIMO has developed its own software founded on the Maxwell equations taking into account all important physical aspects of the laser based process: the light source, the beam shaping optical system and the light-matter interaction. Based on this knowledge together with a unique free-form micro-lens array production technology and patented micro-optics beam shaping designs a number of novel solar cell production tool sub-systems have been built. The basic functionalities, design principles and performance results are presented with a special emphasis on resilience, cost reduction and process reliability.

  12. Properties and Application Prospects of Frequency Diverse Array:an Overview%频控阵特征及应用前景综述

    Institute of Scientific and Technical Information of China (English)

    张希会; 王文钦

    2016-01-01

    频控阵是近年来提出的一种新体制阵列技术。与传统相控阵不同的是,频控阵通过在不同通道附加很小的频偏,使其波束图在远场成为随位置、角度和时间变化的函数。频控阵这种新波束的特征产生许多新的功能,具有很多独特的应用优势和广阔的发展应用前景。首先介绍了频控阵发展历程和基本原理,然后分析了频控阵技术实现难点,最后指出了频控阵可能的应用和发展方向。%Frequency diverse array( FDA) is a new array technique proposed in recent years. Unlike con-ventional phased array,frequency diverse array uses a very small frequency shift across its array elements to provide a beam pattern which focuses direction changes as a function of the range,angle and time in the far-field. This new beam property offers many promising advantages for communication,radar,interference countermeasure applications and so on. This paper introduces the development progress and principle of fre-quency diverse array,analyzes the existing technical challenges of frequency diverse array and finally dis-cusses the promising applications and future developments.

  13. Function of Amphiphilic Biomolecular Machines: Elastic Protein-based Polymers

    Science.gov (United States)

    Urry, Dan W.

    2000-03-01

    Elastic protein-based polymers function as biomolecular machines due to inverse temperature transitions of hydrophobic folding and assembly. The transitions occur either on raising the temperature from below to above the transition temperature, Tt, or on isothermally lowering Tt from above to below an operating temperature. The inverse temperature transition involves a decrease in entropy of the polymer component of the system on raising the temperature and a larger increase in solvent entropy on hydrophobic association. Tt depends on the quantity of hydrophobic hydration that undergoes transition to bulk water. Designed amphiphilic polymers perform free energy transductions involving the intensive variables of mechanical force, pressure, temperature, chemical potential, electrochemical potential and electromagnetic radiation and define a set of five axioms for their function as machines. The physical basis for these diverse energy conversions is competition for hydration between apolar (hydrophobic) and polar (e.g., charged) moieties. The effectiveness of these Tt-type entropic elastic protein-based machines is due to repeating peptide sequences that form regular, dynamic repeating structures and exhibit damping of backbone torsional oscillations on extension.

  14. [Biobanking and Biomolecular Resources Research Infrastructure (BBMRI). Implications for pathology].

    Science.gov (United States)

    Viertler, C; Zatloukal, K

    2008-11-01

    High quality human biological samples (e.g. blood, tissue or DNA) with associated, well documented clinical and research data are key resources for advancement of life sciences, biotechnology, clinical medicine, drug development and also molecular pathology. Millions of samples of diseased tissues have been collected in the context of routine histopathological diagnosis and are stored in the archives of hospitals and institutes of pathology. A concerted effort is necessary to overcome the current fragmentation of the European biobanking community in order to tap the full research potential of existing biobanks. A pan-European research infrastructure for biobanking and biomolecular resources (BBMRI) is currently in its planning phase. The mission is to link and provide access to local biobanks of different formats, including tissue collections, harmonize standards, establish operational procedures which properly consider ethical, legal, societal aspects, and to secure sustainable funding. Pathology plays a key role in development and administration of tissue banks and is, thus, a major partner for collaboration, expertise and construction of this pan-European research infrastructure.

  15. A programmable biomolecular computing machine with bacterial phenotype output.

    Science.gov (United States)

    Kossoy, Elizaveta; Lavid, Noa; Soreni-Harari, Michal; Shoham, Yuval; Keinan, Ehud

    2007-07-23

    The main advantage of autonomous biomolecular computing devices over electronic computers is their ability to interact directly with biological systems. No interface is required since all components of molecular computers, including hardware, software, input, and output are molecules that interact in solution along a cascade of programmable chemical events. Here, we demonstrate for the first time that the output of a computation preduced by a molecular finite automaton can be a visible bacterial phenotype. Our 2-symbol-2-state finite automaton utilized linear double-stranded DNA inputs that were prepared by inserting a string of six base pair symbols into the lacZ gene on the pUC18 plasmid. The computation resulted in a circular plasmid that differed from the original pUC18 by either a 9 base pair (accepting state) or 11 base pair insert (unaccepting state) within the lacZ alpha region gene. Upon transformation and expression of the resultant plasmids in E. coli, the accepting state was represented by production of functional beta-galactosidase and formation of blue colonies on X-gal medium. In contrast, the unaccepting state was represented by white colonies due to a shift in the open reading frame of lacZ. PMID:17562552

  16. Stochastic Simulation of Biomolecular Networks in Dynamic Environments.

    Directory of Open Access Journals (Sweden)

    Margaritis Voliotis

    2016-06-01

    Full Text Available Simulation of biomolecular networks is now indispensable for studying biological systems, from small reaction networks to large ensembles of cells. Here we present a novel approach for stochastic simulation of networks embedded in the dynamic environment of the cell and its surroundings. We thus sample trajectories of the stochastic process described by the chemical master equation with time-varying propensities. A comparative analysis shows that existing approaches can either fail dramatically, or else can impose impractical computational burdens due to numerical integration of reaction propensities, especially when cell ensembles are studied. Here we introduce the Extrande method which, given a simulated time course of dynamic network inputs, provides a conditionally exact and several orders-of-magnitude faster simulation solution. The new approach makes it feasible to demonstrate-using decision-making by a large population of quorum sensing bacteria-that robustness to fluctuations from upstream signaling places strong constraints on the design of networks determining cell fate. Our approach has the potential to significantly advance both understanding of molecular systems biology and design of synthetic circuits.

  17. Design and fabrication of a micro PZT cantilever array actuator for applications in fluidic systems

    DEFF Research Database (Denmark)

    Kim, H.; In, C.; Yoon, Gil Ho;

    2005-01-01

    behavior predicted. The calculated value of the tip deflection was 15 pm at 5 V. The fabrication process from SIMOX (Separation by oxygen ion implantation) wafer is presented in detail with the PZT film deposition process. The PZT films are characterized by investigating the ferroelectric properties......, dielectric constant, and dielectric loss. Tip deflections of 12 mu m at 5 V are measured, which agreed well with the predicted value. The 18 mu l/s leakage rate of air was observed at a pressure difference of 1000 Pa. Micro cooler is introduced, and its possible application to micro compressor is discussed....

  18. Dynamic strain detection using a fiber Bragg grating sensor array for geotechnical applications

    Science.gov (United States)

    Schmidt-Hattenberger, Cornelia; Naumann, M.; Borm, Gunter

    2003-03-01

    In recent years fiber Bragg gratings have been successfully introduced as sensors for strain, temperature and pressure variations. Their performance and reliability has been proven in many practical applications including strain monitoring in civil engineering and tunneling, downhole monitoring in oil reservoirs and flow assurance monitoring in pipelines. The gratings have great potential to at as true structurally integrated sensor elements. They can be embedded in typical structural or reinforcing elements of civil and geotechnical buildings. Several methods of interrogation schemes are established depending on the desired accuracy and resolution of the measurement. The most important methods are the linear discriminator, the tunable Fbry-Perot filter technique, and several interferometer setups.

  19. Radio frequency interference noise reduction using a field programmable gate array for SQUID applications

    International Nuclear Information System (INIS)

    It is important to remove large environmental noise in superconducting quantum interference device (SQUID) measurement without magnetic shielding. Active noise control (ANC) is one of the effective methods to reduce environmental noise. Recently, SQUIDs have been used in various applications at high frequencies, such as nuclear quadrupole resonance (NQR). The NQR frequency from explosives is in the range 0.5-5 MHz. In this case, an NQR sensor is exposed to AM radio frequency interference (RFI). The feasibility of the ANC system for RFI that used digital signal processing was studied. Our investigation showed that this digital ANC system can be applied to SQUID measurements for RFI suppression

  20. A Quick-responsive DNA Nanotechnology Device for Bio-molecular Homeostasis Regulation

    Science.gov (United States)

    Wu, Songlin; Wang, Pei; Xiao, Chen; Li, Zheng; Yang, Bing; Fu, Jieyang; Chen, Jing; Wan, Neng; Ma, Cong; Li, Maoteng; Yang, Xiangliang; Zhan, Yi

    2016-01-01

    Physiological processes such as metabolism, cell apoptosis and immune responses, must be strictly regulated to maintain their homeostasis and achieve their normal physiological functions. The speed with which bio-molecular homeostatic regulation occurs directly determines the ability of an organism to adapt to conditional changes. To produce a quick-responsive regulatory system that can be easily utilized for various types of homeostasis, a device called nano-fingers that facilitates the regulation of physiological processes was constructed using DNA origami nanotechnology. This nano-fingers device functioned in linked open and closed phases using two types of DNA tweezers, which were covalently coupled with aptamers that captured specific molecules when the tweezer arms were sufficiently close. Via this specific interaction mechanism, certain physiological processes could be simultaneously regulated from two directions by capturing one biofactor and releasing the other to enhance the regulatory capacity of the device. To validate the universal application of this device, regulation of the homeostasis of the blood coagulant thrombin was attempted using the nano-fingers device. It was successfully demonstrated that this nano-fingers device achieved coagulation buffering upon the input of fuel DNA. This nano-device could also be utilized to regulate the homeostasis of other types of bio-molecules. PMID:27506964

  1. Nanoscale Biomolecular Detection Limit for Gold Nanoparticles Based on Near-Infrared Response

    Directory of Open Access Journals (Sweden)

    Mario D’Acunto

    2012-01-01

    Full Text Available Gold nanoparticles have been widely used during the past few years in various technical and biomedical applications. In particular, the resonance optical properties of nanometer-sized particles have been employed to design biochips and biosensors used as analytical tools. The optical properties of nonfunctionalized gold nanoparticles and core-gold nanoshells play a crucial role for the design of biosensors where gold surface is used as a sensing component. Gold nanoparticles exhibit excellent optical tunability at visible and near-infrared frequencies leading to sharp peaks in their spectral extinction. In this paper, we study how the optical properties of gold nanoparticles and core-gold nanoshells are changed as a function of different sizes, shapes, composition, and biomolecular coating with characteristic shifts towards the near-infrared region. We show that the optical tenability can be carefully tailored for particle sizes falling in the range 100–150 nm. The results should improve the design of sensors working at the detection limit.

  2. Solving the 0/1 Knapsack Problem by a Biomolecular DNA Computer

    Directory of Open Access Journals (Sweden)

    Hassan Taghipour

    2013-01-01

    Full Text Available Solving some mathematical problems such as NP-complete problems by conventional silicon-based computers is problematic and takes so long time. DNA computing is an alternative method of computing which uses DNA molecules for computing purposes. DNA computers have massive degrees of parallel processing capability. The massive parallel processing characteristic of DNA computers is of particular interest in solving NP-complete and hard combinatorial problems. NP-complete problems such as knapsack problem and other hard combinatorial problems can be easily solved by DNA computers in a very short period of time comparing to conventional silicon-based computers. Sticker-based DNA computing is one of the methods of DNA computing. In this paper, the sticker based DNA computing was used for solving the 0/1 knapsack problem. At first, a biomolecular solution space was constructed by using appropriate DNA memory complexes. Then, by the application of a sticker-based parallel algorithm using biological operations, knapsack problem was resolved in polynomial time.

  3. Potential-of-mean-force description of ionic interactions and structural hydration in biomolecular systems

    Energy Technology Data Exchange (ETDEWEB)

    Hummer, G.; Garcia, A.E. [Los Alamos National Lab., NM (United States). Theoretical Biology and Biophysics Group; Soumpasis, D.M. [Max-Planck-Inst for Biophysical Chemistry, Goettingen (Germany). Biocomputation Group

    1994-10-01

    To understand the functioning of living organisms on a molecular level, it is crucial to dissect the intricate interplay of the immense number of biological molecules. Most of the biochemical processes in cells occur in a liquid environment formed mainly by water and ions. This solvent environment plays an important role in biological systems. The potential-of-mean-force (PMF) formalism attempts to describe quantitatively the interactions of the solvent with biological macromolecules on the basis of an approximate statistical-mechanical representation. At its current status of development, it deals with ionic effects on the biomolecular structure and with the structural hydration of biomolecules. The underlying idea of the PMF formalism is to identify the dominant sources of interactions and incorporate these interactions into the theoretical formalism using PMF`s (or particle correlation functions) extracted from bulk-liquid systems. In the following, the authors shall briefly outline the statistical-mechanical foundation of the PMF formalism and introduce the PMF expansion formalism, which is intimately linked to superposition approximations for higher-order particle correlation functions. The authors shall then sketch applications, which describe the effects of the ionic environment on nucleic-acid structure. Finally, the authors shall present the more recent extension of the PMF idea to describe quantitatively the structural hydration of biomolecules. Results for the interface of ice and water and for the hydration of deoxyribonucleic acid (DNA) will be discussed.

  4. Computational Recipe for Efficient Description of Large-Scale Conformational Changes in Biomolecular Systems.

    Science.gov (United States)

    Moradi, Mahmoud; Tajkhorshid, Emad

    2014-07-01

    Characterizing large-scale structural transitions in biomolecular systems poses major technical challenges to both experimental and computational approaches. On the computational side, efficient sampling of the configuration space along the transition pathway remains the most daunting challenge. Recognizing this issue, we introduce a knowledge-based computational approach toward describing large-scale conformational transitions using (i) nonequilibrium, driven simulations combined with work measurements and (ii) free energy calculations using empirically optimized biasing protocols. The first part is based on designing mechanistically relevant, system-specific reaction coordinates whose usefulness and applicability in inducing the transition of interest are examined using knowledge-based, qualitative assessments along with nonequilirbrium work measurements which provide an empirical framework for optimizing the biasing protocol. The second part employs the optimized biasing protocol resulting from the first part to initiate free energy calculations and characterize the transition quantitatively. Using a biasing protocol fine-tuned to a particular transition not only improves the accuracy of the resulting free energies but also speeds up the convergence. The efficiency of the sampling will be assessed by employing dimensionality reduction techniques to help detect possible flaws and provide potential improvements in the design of the biasing protocol. Structural transition of a membrane transporter will be used as an example to illustrate the workings of the proposed approach.

  5. The calibration of cellphone camera-based colorimetric sensor array and its application in the determination of glucose in urine.

    Science.gov (United States)

    Jia, Ming-Yan; Wu, Qiong-Shui; Li, Hui; Zhang, Yu; Guan, Ya-Feng; Feng, Liang

    2015-12-15

    In this work, a novel approach that can calibrate the colors obtained with a cellphone camera was proposed for the colorimetric sensor array. The variations of ambient light conditions, imaging positions and even cellphone brands could all be compensated via taking the black and white backgrounds of the sensor array as references, thereby yielding accurate measurements. The proposed calibration approach was successfully applied to the detection of glucose in urine by a colorimetric sensor array. Snapshots of the glucose sensor array by a cellphone camera were calibrated by the proposed compensation method and the urine samples at different glucose concentrations were well discriminated with no confusion after a hierarchical clustering analysis. PMID:26275712

  6. GLYCAM06: a generalizable biomolecular force field. Carbohydrates.

    Science.gov (United States)

    Kirschner, Karl N; Yongye, Austin B; Tschampel, Sarah M; González-Outeiriño, Jorge; Daniels, Charlisa R; Foley, B Lachele; Woods, Robert J

    2008-03-01

    A new derivation of the GLYCAM06 force field, which removes its previous specificity for carbohydrates, and its dependency on the AMBER force field and parameters, is presented. All pertinent force field terms have been explicitly specified and so no default or generic parameters are employed. The new GLYCAM is no longer limited to any particular class of biomolecules, but is extendible to all molecular classes in the spirit of a small-molecule force field. The torsion terms in the present work were all derived from quantum mechanical data from a collection of minimal molecular fragments and related small molecules. For carbohydrates, there is now a single parameter set applicable to both alpha- and beta-anomers and to all monosaccharide ring sizes and conformations. We demonstrate that deriving dihedral parameters by fitting to QM data for internal rotational energy curves for representative small molecules generally leads to correct rotamer populations in molecular dynamics simulations, and that this approach removes the need for phase corrections in the dihedral terms. However, we note that there are cases where this approach is inadequate. Reported here are the basic components of the new force field as well as an illustration of its extension to carbohydrates. In addition to reproducing the gas-phase properties of an array of small test molecules, condensed-phase simulations employing GLYCAM06 are shown to reproduce rotamer populations for key small molecules and representative biopolymer building blocks in explicit water, as well as crystalline lattice properties, such as unit cell dimensions, and vibrational frequencies. PMID:17849372

  7. Tactile Sensing System Based on Arrays of Graphene Woven Microfabrics: Electromechanical Behavior and Electronic Skin Application.

    Science.gov (United States)

    Yang, Tingting; Wang, Wen; Zhang, Hongze; Li, Xinming; Shi, Jidong; He, Yijia; Zheng, Quan-shui; Li, Zhihong; Zhu, Hongwei

    2015-11-24

    Nanomaterials serve as promising candidates for strain sensing due to unique electromechanical properties by appropriately assembling and tailoring their configurations. Through the crisscross interlacing of graphene microribbons in an over-and-under fashion, the obtained graphene woven fabric (GWF) indicates a good trade-off between sensitivity and stretchability compared with those in previous studies. In this work, the function of woven fabrics for highly sensitive strain sensing is investigated, although network configuration is always a strategy to retain resistance stability. The experimental and simulation results indicate that the ultrahigh mechanosensitivity with gauge factors of 500 under 2% strain is attributed to the macro-woven-fabric geometrical conformation of graphene, which induces a large interfacial resistance between the interlaced ribbons and the formation of microscale-controllable, locally oriented zigzag cracks near the crossover location, both of which have a synergistic effect on improving sensitivity. Meanwhile, the stretchability of the GWF could be tailored to as high as over 40% strain by adjusting graphene growth parameters and adopting oblique angle direction stretching simultaneously. We also demonstrate that sensors based on GWFs are applicable to human motion detection, sound signal acquisition, and spatially resolved monitoring of external stress distribution. PMID:26468735

  8. Tactile Sensing System Based on Arrays of Graphene Woven Microfabrics: Electromechanical Behavior and Electronic Skin Application.

    Science.gov (United States)

    Yang, Tingting; Wang, Wen; Zhang, Hongze; Li, Xinming; Shi, Jidong; He, Yijia; Zheng, Quan-shui; Li, Zhihong; Zhu, Hongwei

    2015-11-24

    Nanomaterials serve as promising candidates for strain sensing due to unique electromechanical properties by appropriately assembling and tailoring their configurations. Through the crisscross interlacing of graphene microribbons in an over-and-under fashion, the obtained graphene woven fabric (GWF) indicates a good trade-off between sensitivity and stretchability compared with those in previous studies. In this work, the function of woven fabrics for highly sensitive strain sensing is investigated, although network configuration is always a strategy to retain resistance stability. The experimental and simulation results indicate that the ultrahigh mechanosensitivity with gauge factors of 500 under 2% strain is attributed to the macro-woven-fabric geometrical conformation of graphene, which induces a large interfacial resistance between the interlaced ribbons and the formation of microscale-controllable, locally oriented zigzag cracks near the crossover location, both of which have a synergistic effect on improving sensitivity. Meanwhile, the stretchability of the GWF could be tailored to as high as over 40% strain by adjusting graphene growth parameters and adopting oblique angle direction stretching simultaneously. We also demonstrate that sensors based on GWFs are applicable to human motion detection, sound signal acquisition, and spatially resolved monitoring of external stress distribution.

  9. A 34K SNP genotyping array for Populus trichocarpa: design, application to the study of natural populations and transferability to other Populus species

    Energy Technology Data Exchange (ETDEWEB)

    Geraldes, Armando [University of British Columbia, Vancouver; Hannemann, Jan [University of Victoria, Canada; Grassa, Chris [University of British Columbia, Vancouver; Farzaneh, Nima [University of British Columbia, Vancouver; Porth, Ilga [University of British Columbia, Vancouver; McKown, Athena [University of British Columbia, Vancouver; Skyba, Oleksandr [University of British Columbia, Vancouver; Li, Eryang [University of British Columbia, Vancouver; Mike, Fujita [University of British Columbia, Vancouver; Friedmann, Michael [University of British Columbia, Vancouver; Wasteneys, Geoffrey [University of British Columbia, Vancouver; Guy, Robert [University of British Columbia, Vancouver; El-Kassaby, Yousry [University of British Columbia, Vancouver; Mansfield, Shawn [University of British Columbia, Vancouver; Cronk, Quentin [University of British Columbia, Vancouver; Ehlting, Juergen [University of Victoria, Canada; Douglas, Carl [University of British Columbia, Vancouver; DiFazio, Stephen P [West Virginia University, Morgantown; Slavov, Gancho [West Virginia University, Morgantown; Ranjan, Priya [ORNL; Muchero, Wellington [ORNL; Gunter, Lee E [ORNL; Wymore, Ann [ORNL; Tuskan, Gerald A [ORNL; Martin, Joel [U.S. Department of Energy, Joint Genome Institute; Schackwitz, Wendy [U.S. Department of Energy, Joint Genome Institute; Pennacchio, Christa [U.S. Department of Energy, Joint Genome Institute; Rokhsar, Daniel [U.S. Department of Energy, Joint Genome Institute

    2013-01-01

    Genetic mapping of quantitative traits requires genotypic data for large numbers of markers in many individuals. Despite the declining costs of genotyping by sequencing, for most studies, the use of large SNP genotyping arrays still offers the most cost-effective solution for large-scale targeted genotyping. Here we report on the design and performance of a SNP genotyping array for Populus trichocarpa (black cottonwood). This genotyping array was designed with SNPs pre-ascertained in 34 wild accessions covering most of the species range. Due to the rapid decay of linkage disequilibrium in P. trichocarpa we adopted a candidate gene approach to the array design that resulted in the selection of 34,131 SNPs, the majority of which are located in, or within 2 kb, of 3,543 candidate genes. A subset of the SNPs (539) was selected based on patterns of variation among the SNP discovery accessions. We show that more than 95% of the loci produce high quality genotypes and that the genotyping error rate for these is likely below 2%, indicating that high-quality data are generated with this array. We demonstrate that even among small numbers of samples (n=10) from local populations over 84% of loci are polymorphic. We also tested the applicability of the array to other species in the genus and found that due to ascertainment bias the number of polymorphic loci decreases rapidly with genetic distance, with the largest numbers detected in other species in section Tacamahaca (P. balsamifera and P. angustifolia). Finally, we provide evidence for the utility of the array for intraspecific studies of genetic differentiation and for species assignment and the detection of natural hybrids.

  10. Transparent, well-aligned TiO(2) nanotube arrays with controllable dimensions on glass substrates for photocatalytic applications.

    Science.gov (United States)

    Tan, Lee Kheng; Kumar, Manippady K; An, Wen Wen; Gao, Han

    2010-02-01

    Transparent, well-aligned TiO(2) nanotube arrays (NTAs) with controllable dimensions are grown on glass substrates via atomic layer deposition (ALD) of TiO(2) onto free-standing porous anodic alumina (PAA) templates. Photodegradation of aqueous methylene blue (MB) solution and solid stearic acid (SA) film using TiO(2) NTAs of various wall thicknesses are investigated. The Pd functionalized TiO(2) NTAs, with a wall thickness of 15 nm and height of 200 nm, has the highest photodegradation efficiency at 76% after 4 h of UV irradiation. These functionalized NTAs are able to photodegrade MB molecules completely as no obvious demethylated byproducts are observed during the process. It also demonstrates excellent photocatalytic activity for solid contaminants such as SA film. By using the ALD technique, the nanotube wall thickness can be precisely controlled so that it is sufficiently thin to be transparent while sufficiently thick for excellent photocatalytic performances. The transparent TiO(2) NTAs on glass substrates with excellent photocatalytic properties might have potential applications in self-cleaning coating, transparent electronics, and solar cells.

  11. Design and Imaging Application of Room-Temperature Terahertz Detector with Micro-Bolometer Focal Plane Array

    Institute of Scientific and Technical Information of China (English)

    Jun Wang; Jun Gou; Zhi-Ming Wu; Ya-Dong Jiang

    2016-01-01

    Abstract'Room-temperature terahertz (THz) detectors indicate a great potential in the imaging application because of their real-time, compact bulk, and wide spectral band responding characteristics. THz detectors with different dimensions based on a micro-bridge structure have been designed and fabricated to get optimized micro-bolometer parameters from the test results of membrane deformation. A nanostructured titanium (Ti) thin film absorber is integrated in the micro-bridge structure of the VOx micro-bolometer by a combined process of magnetron sputtering and reactive ion etching (RIE), and its improvement of THz absorption is verified by an optical characteristics mesurement. Continuous-wave THz detection and imaging are demonstrated by using a 2.52 THz far infrared CO2 laser and a 320×240 vanadium oxide micro-bolometer focal plane array with an optimized cell structure. With this detecting system, THz imaging of metal concealed in a wiping cloth and an envelope is demonstrated, respectively.

  12. Preparation and Application of TiO2 Nanotube Array Gas Sensor for SF6-Insulated Equipment Detection: a Review.

    Science.gov (United States)

    Zhang, Xiaoxing; Gui, Yingang; Dong, Xingchen

    2016-12-01

    Since Zwilling and co-workers first introduced the electrochemical anodization method to prepare TiO2 nanotubes in 1999, it has attracted a lot of researches due to its outstanding gas response and selectivity, making it widely used in gas detection field. This review presents an introduction to the sensor applications of TiO2 nanotube arrays (TNTAs) in sulfur hexafluoride (SF6)-insulated equipment, which is used to evaluate and diagnose the insulation status of SF6-insulated equipment by detecting their typical decomposition products of SF6: sulfur dioxide (SO2), thionyl fluoride (SOF2), and sulfuryl fluoride (SO2F2). The synthesis and sensing properties of TiO2 nanotubes are discussed first. Then, it is followed by discussing the theoretical sensing to the typical SF6 decomposition products, SO2, SOF2, and SO2F2, which analyzes the sensing mechanism at the molecular level. Finally, the gas response of pure and modified TiO2 nanotubes sensor to SO2, SOF2, and SO2F2 is provided according to the change of resistance in experimental observation. PMID:27316743

  13. Preparation and Application of TiO2 Nanotube Array Gas Sensor for SF6-Insulated Equipment Detection: a Review

    Science.gov (United States)

    Zhang, Xiaoxing; Gui, Yingang; Dong, Xingchen

    2016-06-01

    Since Zwilling and co-workers first introduced the electrochemical anodization method to prepare TiO2 nanotubes in 1999, it has attracted a lot of researches due to its outstanding gas response and selectivity, making it widely used in gas detection field. This review presents an introduction to the sensor applications of TiO2 nanotube arrays (TNTAs) in sulfur hexafluoride (SF6)-insulated equipment, which is used to evaluate and diagnose the insulation status of SF6-insulated equipment by detecting their typical decomposition products of SF6: sulfur dioxide (SO2), thionyl fluoride (SOF2), and sulfuryl fluoride (SO2F2). The synthesis and sensing properties of TiO2 nanotubes are discussed first. Then, it is followed by discussing the theoretical sensing to the typical SF6 decomposition products, SO2, SOF2, and SO2F2, which analyzes the sensing mechanism at the molecular level. Finally, the gas response of pure and modified TiO2 nanotubes sensor to SO2, SOF2, and SO2F2 is provided according to the change of resistance in experimental observation.

  14. Development of an informatics infrastructure for data exchange of biomolecular simulations: Architecture, data models and ontology.

    Science.gov (United States)

    Thibault, J C; Roe, D R; Eilbeck, K; Cheatham Iii, T E; Facelli, J C

    2015-01-01

    Biomolecular simulations aim to simulate structure, dynamics, interactions, and energetics of complex biomolecular systems. With the recent advances in hardware, it is now possible to use more complex and accurate models, but also reach time scales that are biologically significant. Molecular simulations have become a standard tool for toxicology and pharmacology research, but organizing and sharing data - both within the same organization and among different ones - remains a substantial challenge. In this paper we review our recent work leading to the development of a comprehensive informatics infrastructure to facilitate the organization and exchange of biomolecular simulations data. Our efforts include the design of data models and dictionary tools that allow the standardization of the metadata used to describe the biomedical simulations, the development of a thesaurus and ontology for computational reasoning when searching for biomolecular simulations in distributed environments, and the development of systems based on these models to manage and share the data at a large scale (iBIOMES), and within smaller groups of researchers at laboratory scale (iBIOMES Lite), that take advantage of the standardization of the meta data used to describe biomolecular simulations. PMID:26387907

  15. Well-Oriented NanoWell Array Metrics for Digital NanoBioChip

    Science.gov (United States)

    Lee, Heayeon; Lee, Bongkuk; Kawai, Tomoji

    2008-03-01

    Recently many researchers have sought new paradigm for nanobiochip that can be miniaturized and integrated to produce intelligent analysis systems in numerous biotechnology. We have been tried to develop biocompatible materials based nanopatterning, self-assembly array to address challenging problem in nanobioscience. In this time, we describe the nanometrics geometry of a well-oriented nanowell (ONW) array derived from nanofabrication technology which can easily be employed for digital detection with a high S/N ratio, miniaturization, integrated assays and single molecule analysis. We fabricated the self-organized nanopatterning of copolymer as a platform of biomolecular nanoarry using nanolithography. We also present a strong specific antibody-antigen interaction on lipid-membrane modified gold surface using ONW. We believe these findings can be related to various nanobiochip applications. References 1. H.Y. Lee, T. Kawai, K.Y.Suh et al, Advanced Materials, In press (2007). 2. H.Y. Lee, T. Kawai et al, Appl. Phys. Lett. 89, (2006) 113901.

  16. Volumetric CT with sparse detector arrays (and application to Si-strip photon counters)

    Science.gov (United States)

    Sisniega, A.; Zbijewski, W.; Stayman, J. W.; Xu, J.; Taguchi, K.; Fredenberg, E.; Lundqvist, Mats; Siewerdsen, J. H.

    2016-01-01

    Novel x-ray medical imaging sensors, such as photon counting detectors (PCDs) and large area CCD and CMOS cameras can involve irregular and/or sparse sampling of the detector plane. Application of such detectors to CT involves undersampling that is markedly different from the commonly considered case of sparse angular sampling. This work investigates volumetric sampling in CT systems incorporating sparsely sampled detectors with axial and helical scan orbits and evaluates performance of model-based image reconstruction (MBIR) with spatially varying regularization in mitigating artifacts due to sparse detector sampling. Volumetric metrics of sampling density and uniformity were introduced. Penalized-likelihood MBIR with a spatially varying penalty that homogenized resolution by accounting for variations in local sampling density (i.e. detector gaps) was evaluated. The proposed methodology was tested in simulations and on an imaging bench based on a Si-strip PCD (total area 5 cm  ×  25 cm) consisting of an arrangement of line sensors separated by gaps of up to 2.5 mm. The bench was equipped with translation/rotation stages allowing a variety of scanning trajectories, ranging from a simple axial acquisition to helical scans with variable pitch. Statistical (spherical clutter) and anthropomorphic (hand) phantoms were considered. Image quality was compared to that obtained with a conventional uniform penalty in terms of structural similarity index (SSIM), image uniformity, spatial resolution, contrast, and noise. Scan trajectories with intermediate helical width (~10 mm longitudinal distance per 360° rotation) demonstrated optimal tradeoff between the average sampling density and the homogeneity of sampling throughout the volume. For a scan trajectory with 10.8 mm helical width, the spatially varying penalty resulted in significant visual reduction of sampling artifacts, confirmed by a 10% reduction in minimum SSIM (from 0.88 to 0.8) and a 40

  17. Bridging Nano- and Microtribology in Mechanical and Biomolecular Layers

    Science.gov (United States)

    Tomala, Agnieszka; Göçerler, Hakan; Gebeshuber, Ille C.

    The physical and chemical composition of surfaces determine various important properties of solids such as corrosion rates, adhesive properties, frictional properties, catalytic activity, wettability, contact potential and - finally and most importantly - failure mechanisms. Very thin, weak layers (of man-made and biological origin) on much harder substrates that reduce friction are the focus of the micro- and nanotribological investigations presented in this chapter.Biomolecular layers fulfil various functions in organs of the human body. Examples comprise the skin that provides a protective physical barrier between the body and the environment, preventing unwanted inward and outward passage of water and electrolytes, reducing penetration by destructive chemicals, arresting the penetration of microorganisms and external antigens and absorbing radiation from the sun, or the epithelium of the cornea that blocks the passage of foreign material, such as dust, water and bacteria, into the eye and that contributes to the lubrication layer that ensures smooth movement of the eyelids over the eyeballs.Monomolecular thin films, additive-derived reaction layers and hard coatings are widely used to tailor tribological properties of surfaces. Nanotribological investigations on these substrates can reveal novel properties regarding the orientation of chemisorbed additive layers, development of rubbing films with time and the relation of frictional properties to surface characteristics in diamond coatings.Depending on the questions to be answered with the tribological research, various micro- and nanotribological measurement methods are applied, including scanning probe microscopy (AFM, FFM), scanning electron microscopy, microtribometer investigations, angle-resolved photoelectron spectroscopy and optical microscopy. Thoughts on the feasibility of a unified approach to energy-dissipating systems and how it might be reached (touching upon new ways of scientific publishing

  18. Computational methods to study the structure and dynamics of biomolecules and biomolecular processes from bioinformatics to molecular quantum mechanics

    CERN Document Server

    2014-01-01

    Since the second half of the 20th century machine computations have played a critical role in science and engineering. Computer-based techniques have become especially important in molecular biology, since they often represent the only viable way to gain insights into the behavior of a biological system as a whole. The complexity of biological systems, which usually needs to be analyzed on different time- and size-scales and with different levels of accuracy, requires the application of different approaches, ranging from comparative analysis of sequences and structural databases, to the analysis of networks of interdependence between cell components and processes, through coarse-grained modeling to atomically detailed simulations, and finally to molecular quantum mechanics. This book provides a comprehensive overview of modern computer-based techniques for computing the structure, properties and dynamics of biomolecules and biomolecular processes. The twenty-two chapters, written by scientists from all over t...

  19. Micromachined electrode array

    Energy Technology Data Exchange (ETDEWEB)

    Okandan, Murat (Edgewood, NM); Wessendorf, Kurt O. (Albuquerque, NM)

    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.

  20. 1K X 1K Si:As IBC detector arrays for JWST MIRI and other applications

    Science.gov (United States)

    Love, Peter J.; Hoffman, Alan W.; Lum, Nancy A.; Ando, Ken J.; Ritchie, William D.; Therrien, Neil J.; Toth, Andrew G.; Holcombe, Roger S.

    2004-09-01

    1K × 1K Si:As Impurity Band Conduction (IBC) arrays have been developed by Raytheon Vision Systems (RVS) for the James Webb Space Telescope (JWST) Mid-Infrared Instrument (MIRI). The devices are also suitable for other low-background applications. The Si:As IBC detectors respond out to ~28 microns, covering an important mid-IR region beyond the 1-5 micron range covered by the JWST NIRCam and NIRSpec instruments. Due to high terrestrial backgrounds at the longer mid-IR wavelengths, it is very difficult to conduct ground-based observations at these wavelengths. Hence, the MIRI instrument on JWST can provide science not obtainable from the ground. A mid-infrared instrument aboard a cryogenic space telescope can have an enormous impact in resolving key questions in astronomy and cosmology. The greatly reduced thermal backgrounds achievable on a space platform (compared to airborne or ground-based platforms) allow for more sensitive observations of dusty young galaxies at high redshifts, star formation of solar-type stars in the local universe, and formation and evolution of planetary disks and systems. We describe results of the development of a new 1024 × 1024 Si:As IBC array with 25-micron pixels that responds with high quantum efficiency over the wavelength range 5 to 28 microns. The previous generation's largest, most sensitive IR detectors at these wavelengths were the 256 × 256/30-micron pitch Si:As IBC devices built by Raytheon for the SIRTF/IRAC instrument. JWST MIRI detector requirements will be reviewed and some model results for IBC device performance will be presented. The IBC detector architecture will be described and the SB305 Readout Integrated Circuit (ROIC), developed specifically for JWST MIRI, will be discussed. The SB305 ROIC utilizes a PMOS Source Follower per Detector (SFD) input circuit with a well capacity of about 2 × 105 electrons. The read noise is expected to be less than 20 e- rms with Fowler-8 sampling at an operating temperature of 7

  1. Fabrication of heterogeneous nanomaterial array by programmable heating and chemical supply within microfluidic platform towards multiplexed gas sensing application.

    Science.gov (United States)

    Yang, Daejong; Kang, Kyungnam; Kim, Donghwan; Li, Zhiyong; Park, Inkyu

    2015-01-01

    A facile top-down/bottom-up hybrid nanofabrication process based on programmable temperature control and parallel chemical supply within microfluidic platform has been developed for the all liquid-phase synthesis of heterogeneous nanomaterial arrays. The synthesized materials and locations can be controlled by local heating with integrated microheaters and guided liquid chemical flow within microfluidic platform. As proofs-of-concept, we have demonstrated the synthesis of two types of nanomaterial arrays: (i) parallel array of TiO2 nanotubes, CuO nanospikes and ZnO nanowires, and (ii) parallel array of ZnO nanowire/CuO nanospike hybrid nanostructures, CuO nanospikes and ZnO nanowires. The laminar flow with negligible ionic diffusion between different precursor solutions as well as localized heating was verified by numerical calculation and experimental result of nanomaterial array synthesis. The devices made of heterogeneous nanomaterial array were utilized as a multiplexed sensor for toxic gases such as NO2 and CO. This method would be very useful for the facile fabrication of functional nanodevices based on highly integrated arrays of heterogeneous nanomaterials. PMID:25634814

  2. Multiple Features Based Approach to Extract Bio-molecular Event Triggers Using Conditional Random Field

    Directory of Open Access Journals (Sweden)

    Amit Majumder

    2012-11-01

    Full Text Available The purpose of Biomedical Natural Language Processing (BioNLP is to capture biomedical phenomena from textual data by extracting relevant entities, information and relations between biomedical entities (i.e. proteins and genes. In general, in most of the published papers, only binary relations were extracted. In a recent past, the focus is shifted towards extracting more complex relations in the form of bio-molecular events that may include several entities or other relations. In this paper we propose an approach that enables event trigger extraction of relatively complex bio-molecular events. We approach this problem as a detection of bio-molecular event trigger using the well-known algorithm, namely Conditional Random Field (CRF. We apply our experiments on development set. It shows the overall average recall, precision and F-measure values of 64.27504%, 69.97559% and 67.00429%, respectively for the event detection.

  3. Protein Functionalized Nanodiamond Arrays

    Directory of Open Access Journals (Sweden)

    Liu YL

    2010-01-01

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

  4. Introduction to adaptive arrays

    CERN Document Server

    Monzingo, Bob; Haupt, Randy

    2011-01-01

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

  5. Combinatorial aspects of covering arrays

    Directory of Open Access Journals (Sweden)

    Charles J. Colbourn

    2004-11-01

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

  6. iBIOMES: managing and sharing biomolecular simulation data in a distributed environment.

    Science.gov (United States)

    Thibault, Julien C; Facelli, Julio C; Cheatham, Thomas E

    2013-03-25

    Biomolecular simulations, which were once batch queue or compute limited, have now become data analysis and management limited. In this paper we introduce a new management system for large biomolecular simulation and computational chemistry data sets. The system can be easily deployed on distributed servers to create a mini-grid at the researcher's site. The system not only offers a simple data deposition mechanism but also a way to register data into the system without moving the data from their original location. Any registered data set can be searched and downloaded using a set of defined metadata for molecular dynamics and quantum mechanics and visualized through a dynamic Web interface.

  7. Low concentration ratio solar array for low Earth orbit multi-100kW application. Volume 2: Drawings

    Science.gov (United States)

    Nalbandian, S. J.; French, E. P.

    1982-01-01

    A preliminary design effort directed toward a low concentration ratio photovoltaic array system based on 1984 technology and capable of delivering multi-hundred kilowatts (300 kW to 100 kW range) in low Earth orbit. The array system consists of two or more array modules each capable of delivering between 113 kW to 175 kW using silicon solar cells or gallium arsenide solar cells, respectively. The array module deployed area is 1320 square meters and consists of 4356 pyramidal concentrator elements. The module, when stowed in the Space Shuttle's payload bay, has a stowage volume of a cube with 3.24 meters on a side. The concentrator elements are sized for a geometric concentration ratio (GCR) of six with an aperture area of 0.5 meters x 0.5 meters. Drawings for the preliminary design configuration and for the test hardware that was fabricated for design evaluation and test are provided.

  8. Low-crosstalk operation of directly modulated DFB laser array TOSA for 112-Gbit/s application.

    Science.gov (United States)

    Kanazawa, Shigeru; Kobayashi, Wataru; Ueda, Yuta; Fujisawa, Takeshi; Ohno, Tetsuichiro; Yoshimatsu, Toshihide; Ishii, Hiroyuki; Sanjoh, Hiroaki

    2016-06-13

    A directly modulated DFB laser (DML) array transmitter optical sub-assembly (TOSA) operating at 112 Gbit/s was fabricated for the first time. The DML array chip, which was integrated with a GND pad, and the DML array sub-assembly were designed to suppress the adjacent electrical crosstalk of the DML array TOSA. The 3-dB bandwidths of the fabricated TOSA exceeded 18 GHz. The electrical crosstalk of the TOSA was suppressed to less than -20 dB below 18GHz. Under simultaneous 4-channel 28-Gbit/s (112 Gbit/s) operation, the OTU4 mask margins were degraded by a maximum of only 6% compared with those under discrete operation. Error-free transmissions over a 10-km single-mode fiber were demonstrated for all the lanes under 112-Gbit/s operation. PMID:27410371

  9. Design and Application of Wuhan Ionospheric Oblique Backscattering Sounding System with the Addition of an Antenna Array (WIOBSS-AA)

    Science.gov (United States)

    Cui, Xiao; Chen, Gang; Wang, Jin; Song, Huan; Gong, Wanlin

    2016-01-01

    The Wuhan Ionospheric Oblique Backscattering Sounding System with the addition of an antenna array (WIOBSS-AA) is the newest member of the WIOBSS family. It is a multi-channel radio system using phased-array antenna technology. The transmitting part of this radio system applies an array composed of five log-periodic antennas to form five beams that span an area to the northwest of the radar site. The hardware and the antenna array of the first multi-channel ionosonde in the WIOBSS family are introduced in detail in this paper. An ionospheric detection experiment was carried out in Chongyang, Hubei province, China on 16 March 2015 to examine the performance of WIOBSS-AA. The radio system demonstrated its ability to obtain ionospheric electron density information over a wide area. The observations indicate that during the experiment, the monitored large-area ionospheric F2-layer was calm and electron density increased with decreasing latitude. PMID:27314360

  10. Design and Application of Wuhan Ionospheric Oblique Backscattering Sounding System with the Addition of an Antenna Array (WIOBSS-AA).

    Science.gov (United States)

    Cui, Xiao; Chen, Gang; Wang, Jin; Song, Huan; Gong, Wanlin

    2016-01-01

    The Wuhan Ionospheric Oblique Backscattering Sounding System with the addition of an antenna array (WIOBSS-AA) is the newest member of the WIOBSS family. It is a multi-channel radio system using phased-array antenna technology. The transmitting part of this radio system applies an array composed of five log-periodic antennas to form five beams that span an area to the northwest of the radar site. The hardware and the antenna array of the first multi-channel ionosonde in the WIOBSS family are introduced in detail in this paper. An ionospheric detection experiment was carried out in Chongyang, Hubei province, China on 16 March 2015 to examine the performance of WIOBSS-AA. The radio system demonstrated its ability to obtain ionospheric electron density information over a wide area. The observations indicate that during the experiment, the monitored large-area ionospheric F2-layer was calm and electron density increased with decreasing latitude. PMID:27314360

  11. Coherent-subspace array processing based on wavelet covariance: an application to broad-band, seismo-volcanic signals

    Science.gov (United States)

    Saccorotti, G.; Nisii, V.; Del Pezzo, E.

    2008-07-01

    Long-Period (LP) and Very-Long-Period (VLP) signals are the most characteristic seismic signature of volcano dynamics, and provide important information about the physical processes occurring in magmatic and hydrothermal systems. These events are usually characterized by sharp spectral peaks, which may span several frequency decades, by emergent onsets, and by a lack of clear S-wave arrivals. These two latter features make both signal detection and location a challenging task. In this paper, we propose a processing procedure based on Continuous Wavelet Transform of multichannel, broad-band data to simultaneously solve the signal detection and location problems. Our method consists of two steps. First, we apply a frequency-dependent threshold to the estimates of the array-averaged WCO in order to locate the time-frequency regions spanned by coherent arrivals. For these data, we then use the time-series of the complex wavelet coefficients for deriving the elements of the spatial Cross-Spectral Matrix. From the eigenstructure of this matrix, we eventually estimate the kinematic signals' parameters using the MUltiple SIgnal Characterization (MUSIC) algorithm. The whole procedure greatly facilitates the detection and location of weak, broad-band signals, in turn avoiding the time-frequency resolution trade-off and frequency leakage effects which affect conventional covariance estimates based upon Windowed Fourier Transform. The method is applied to explosion signals recorded at Stromboli volcano by either a short-period, small aperture antenna, or a large-aperture, broad-band network. The LP (0.2 2s) of the explosion recordings from the broad-band network. Source locations obtained this way are fully compatible with those retrieved from application of more traditional (and computationally expensive) time-domain techniques, such as the Radial Semblance method.

  12. Output-input ratio in thermally fluctuating biomolecular machines.

    Science.gov (United States)

    Kurzynski, Michal; Torchala, Mieczyslaw; Chelminiak, Przemyslaw

    2014-01-01

    Biological molecular machines are proteins that operate under isothermal conditions and hence are referred to as free energy transducers. They can be formally considered as enzymes that simultaneously catalyze two chemical reactions: the free energy-donating (input) reaction and the free energy-accepting (output) one. Most if not all biologically active proteins display a slow stochastic dynamics of transitions between a variety of conformational substates composing their native state. This makes the description of the enzymatic reaction kinetics in terms of conventional rate constants insufficient. In the steady state, upon taking advantage of the assumption that each reaction proceeds through a single pair (the gate) of transition conformational substates of the enzyme-substrates complex, the degree of coupling between the output and the input reaction fluxes has been expressed in terms of the mean first-passage times on a conformational transition network between the distinguished substates. The theory is confronted with the results of random-walk simulations on the five-dimensional hypercube. The formal proof is given that, for single input and output gates, the output-input degree of coupling cannot exceed unity. As some experiments suggest such exceeding, looking for the conditions for increasing the degree of coupling value over unity challenges the theory. Performed simulations of random walks on several model networks involving more extended gates indicate that the case of the degree of coupling value higher than 1 is realized in a natural way on critical branching trees extended by long-range shortcuts. Such networks are scale-free and display the property of the small world. For short-range shortcuts, the networks are scale-free and fractal, representing a reasonable model for biomolecular machines displaying tight coupling, i.e., the degree of coupling equal exactly to unity. A hypothesis is stated that the protein conformational transition networks, as

  13. Design and implementation of a space domain spherical microphone array with application to source localization and separation.

    Science.gov (United States)

    Bai, Mingsian R; Yao, Yueh Hua; Lai, Chang-Sheng; Lo, Yi-Yang

    2016-03-01

    In this paper, four delay-and-sum (DAS) beamformers formulated in the modal domain and the space domain for open and solid spherical apertures are examined through numerical simulations. The resulting beampatterns reveal that the mainlobe of the solid spherical DAS array is only slightly narrower than that of the open array, whereas the sidelobes of the modal domain array are more significant than those of the space domain array due to the discrete approximation of continuous spherical Fourier transformation. To verify the theory experimentally, a three-dimensionally printed spherical array on which 32 micro-electro-mechanical system microphones are mounted is utilized for localization and separation of sound sources. To overcome the basis mismatch problem in signal separation, source localization is first carried out using minimum variance distortionless response beamformer. Next, Tikhonov regularization (TIKR) and compressive sensing (CS) are employed to extract the source signal amplitudes. Simulations and experiments are conducted to validate the proposed spherical array system. Objective perceptual evaluation of speech quality test and a subjective listening test are undertaken in performance evaluation. The experimental results demonstrate better separation quality achieved by the CS approach than by the TIKR approach at the cost of computational complexity.

  14. Design and implementation of a space domain spherical microphone array with application to source localization and separation.

    Science.gov (United States)

    Bai, Mingsian R; Yao, Yueh Hua; Lai, Chang-Sheng; Lo, Yi-Yang

    2016-03-01

    In this paper, four delay-and-sum (DAS) beamformers formulated in the modal domain and the space domain for open and solid spherical apertures are examined through numerical simulations. The resulting beampatterns reveal that the mainlobe of the solid spherical DAS array is only slightly narrower than that of the open array, whereas the sidelobes of the modal domain array are more significant than those of the space domain array due to the discrete approximation of continuous spherical Fourier transformation. To verify the theory experimentally, a three-dimensionally printed spherical array on which 32 micro-electro-mechanical system microphones are mounted is utilized for localization and separation of sound sources. To overcome the basis mismatch problem in signal separation, source localization is first carried out using minimum variance distortionless response beamformer. Next, Tikhonov regularization (TIKR) and compressive sensing (CS) are employed to extract the source signal amplitudes. Simulations and experiments are conducted to validate the proposed spherical array system. Objective perceptual evaluation of speech quality test and a subjective listening test are undertaken in performance evaluation. The experimental results demonstrate better separation quality achieved by the CS approach than by the TIKR approach at the cost of computational complexity. PMID:27036243

  15. 3D MR angiography of the entire aorta: modified application of the body-phased array coil for a single-shot technique

    International Nuclear Information System (INIS)

    Objective: Evaluation of different contrast-enhanced MR angiography imaging protocols for visualization of the entire aorta in breath-hold technique. Methods and patients: Three different CE (0.15 mmol/kg) MRA protocols were evaluated by phantom and patient studies: (1) two separate MRA with conventional application of the body-phased array coil; (2) a single-shot MRA with modified application of the body-phased array coil; (3) a single-shot MRA with the body coil. Duplex sonography, CTA and DSA were used as standard of reference. Results: In all examinations the entire aorta could be visualized. The best SNR was acquired with protocol (1). The SNR of protocol (2) was reduced if the sagittal body diameter of the patient was greater than 20 cm and decreased significantly with diameters over 30 cm. By the use of protocol (3) the SNR was notably poor. The quality scored for the visualization of the entire aorta was 97.5% (protocol 1); 92.5% (protocol 2); and 80.0% (protocol 3). Conclusion: In most cases the modified application of the body-phased array coil allows the imaging of the entire aorta as a single-shot 3D CE MRA in diagnostic quality

  16. A 2x2 multi-chip reconfigurable MOEMS mask: a stepping stone to large format microshutter arrays for coded aperture applications

    Science.gov (United States)

    McNie, Mark E.; Brown, Alan G.; King, David O.; Smith, Gilbert W.; Gordon, Neil T.; Riches, Stephen; Rogers, Stanley

    2010-08-01

    Coded aperture imaging has been used for astronomical applications for several years. Typical implementations used a fixed mask pattern and are designed to operate in the X-Ray or gamma ray bands. Recently applications have emerged in the visible and infra red bands for low cost lens-less imaging systems and system studies have shown that considerable advantages in image resolution may accrue from the use of multiple different images of the same scene - requiring a reconfigurable mask. Previously reported work focused on realising a 2x2cm single chip mask in the mid-IR based on polysilicon micro-optoelectro- mechanical systems (MOEMS) technology and its integration with ASIC drive electronics using conventional wire bonding. It employs interference effects to modulate incident light - achieved by tuning a large array of asymmetric Fabry-Perot optical cavities via an applied voltage and uses a hysteretic row/column scheme for addressing. In this paper we report on the latest results in the mid-IR for the single chip reconfigurable MOEMS mask, trials in scaling up to a mask based on a 2x2 multi-chip array and report on progress towards realising a large format mask comprising 44 MOEMS chips. We also explore the potential of such large, transmissive IR spatial light modulator arrays for other applications and in the current and alternative architectures.

  17. Real-time PCR array as a universal platform for the detection of genetically modified crops and its application in identifying unapproved genetically modified crops in Japan.

    Science.gov (United States)

    Mano, Junichi; Shigemitsu, Natsuki; Futo, Satoshi; Akiyama, Hiroshi; Teshima, Reiko; Hino, Akihiro; Furui, Satoshi; Kitta, Kazumi

    2009-01-14

    We developed a novel type of real-time polymerase chain reaction (PCR) array with TaqMan chemistry as a platform for the comprehensive and semiquantitative detection of genetically modified (GM) crops. Thirty primer-probe sets for the specific detection of GM lines, recombinant DNA (r-DNA) segments, endogenous reference genes, and donor organisms were synthesized, and a 96-well PCR plate was prepared with a different primer-probe in each well as the real-time PCR array. The specificity and sensitivity of the array were evaluated. A comparative analysis with the data and publicly available information on GM crops approved in Japan allowed us to assume the possibility of unapproved GM crop contamination. Furthermore, we designed a Microsoft Excel spreadsheet application, Unapproved GMO Checker version 2.01, which helps process all the data of real-time PCR arrays for the easy assumption of unapproved GM crop contamination. The spreadsheet is available free of charge at http://cse.naro.affrc.go.jp/jmano/index.html .

  18. A Novel Miniaturized Dual Slant-Polarized UWB Antenna Array with Excellent Pattern Symmetry Property for MIMO Applications

    Directory of Open Access Journals (Sweden)

    Zhi Zeng

    2015-01-01

    Full Text Available A novel miniaturized 1 × 10 uniform linear dual slant-polarized UWB antenna array for MIMO base station is presented. The antenna array operates in the frequency band from 1710 to 2690 MHz with a 17.3–18.7 dBi gain in a size of 105 × 1100 × 37 mm. The array element is composed of two single-polarized dipoles evolved from bow-tie antenna with slots on them, which miniaturize the size of the antenna. The 10 array elements are fed through an air dielectric strip-line power splitter. Two parameters, the beam tracking and the beam squint, are presented to quantitatively describe the pattern symmetry property of the antenna. The simulated and measured radiation performances are studied and compared. The results show that the pattern symmetry property of the single antenna element has been improved about 24% compared with the former study, and the antenna array also provides excellent pattern symmetry property.

  19. Controllable Synthesis of Copper Oxide/Carbon Core/Shell Nanowire Arrays and Their Application for Electrochemical Energy Storage

    Directory of Open Access Journals (Sweden)

    Jiye Zhan

    2015-10-01

    Full Text Available Rational design/fabrication of integrated porous metal oxide arrays is critical for the construction of advanced electrochemical devices. Herein, we report self-supported CuO/C core/shell nanowire arrays prepared by the combination of electro-deposition and chemical vapor deposition methods. CuO/C nanowires with diameters of ~400 nm grow quasi-vertically to the substrates forming three-dimensional arrays architecture. A thin carbon shell is uniformly coated on the CuO nanowire cores. As an anode of lithium ion batteries, the resultant CuO/C nanowire arrays are demonstrated to have high specific capacity (672 mAh·g−1 at 0.2 C and good cycle stability (425 mAh·g−1 at 1 C up to 150 cycles. The core/shell arrays structure plays positive roles in the enhancement of Li ion storage due to fast ion/electron transfer path, good strain accommodation and sufficient contact between electrolyte and active materials.

  20. Conformation of bovine submaxillary mucin layers on hydrophobic surface as studied by biomolecular probes

    DEFF Research Database (Denmark)

    Pakkanen, Kirsi I.; Madsen, Jan Busk; Lee, Seunghwan

    2015-01-01

    In the present study, the conformational changes of bovine submaxillary mucin (BSM) adsorbed on a hydrophobic surface (polystyrene (PS)) as a function of concentration in bulk solution (up to 2mg/mL) have been investigated with biomolecular probe-based approaches, including bicinchoninic acid (BC...

  1. Optical Coherence Tomography and Biomolecular Imaging with Coherent Raman Scattering Microscopy

    DEFF Research Database (Denmark)

    Andersson-Engels, Stefan; Andersen, Peter E.

    2014-01-01

    The Special Section on Selected Topics in Biophotonics: Optical Coherence Tomography and Biomolecular Imaging with Coherent Raman Scattering Microscopy comprises two invited review papers and several contributed papers from the summer school Biophotonics ’13, as well as contributed papers within...

  2. Flexible retinal electrode array

    Energy Technology Data Exchange (ETDEWEB)

    Okandan, Murat (Albuquerque, NM); Wessendorf, Kurt O. (Albuquerque, NM); Christenson, Todd R. (Albuquerque, NM)

    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.

  3. Plasmonic spectrum on 1D and 2D periodic arrays of rod-shape metal nanoparticle pairs with different core patterns for biosensor and solar cell applications

    Science.gov (United States)

    Kumara, N. T. R. N.; Chou Chau, Yuan-Fong; Huang, Jin-Wei; Huang, Hung Ji; Lin, Chun-Ting; Chiang, Hai-Pang

    2016-11-01

    Simulations of surface plasmon resonance (SPR) on the near field intensity and absorption spectra of one-dimensional (1D) and two-dimensional (2D) periodic arrays of rod-shape metal nanoparticle (MNP) pairs using the finite element method (FEM) and taking into account the different core patterns for biosensor and solar cell applications are investigated. A tunable optical spectrum corresponding to the transverse SPR modes is observed. The peak resonance wavelength (λ res) can be shifted to red as the core patterns in rod-shape MNPs have been changed. We find that the 2D periodic array of core–shell MNP pairs (case 2) exhibit a red shifted SPR that can be tuned the gap enhancement and absorption efficiency simultaneously over an extended wavelength range. The tunable optical performances give us a qualitative idea of the geometrical properties of the periodic array of rod-shape MNP pairs on SPRs that can be as a promising candidate for plasmonic biosensor and solar cell applications.

  4. Switched-beam array of dielectric rod antenna with RF-MEMS switch for millimeter-wave applications

    Science.gov (United States)

    Rousstia, M. W.; Reniers, A. C. F.; Herben, M. H. A. J.

    2015-03-01

    A conformal dielectric rod antenna array with operating frequency of 11.2 GHz is investigated, designed, and measured. This antenna array is combined with a single pole double throw radio frequency microelectromechanical systems (RF-MEMS) switch to realize switched-beam performance. Moreover, this antenna array exhibits uniform radiation performance for different scan angles with no grating lobes. The characterization and measurement of the antenna system have been performed. The measured radiation pattern of the antenna in the anechoic chamber is in good agreement with the simulated antenna pattern. The measured antenna with the RF-MEMS switch has 13.5 dBi realized gain, -15 dB sidelobe level, 22° half-power beamwidth, and 7.3% (fractional) bandwidth (or 800 MHz) at 11.2 GHz.

  5. Synthesis of CdS nanorod arrays and their applications in flexible piezo-driven active H2S sensors.

    Science.gov (United States)

    Wang, Penglei; Deng, Ping; Nie, Yuxin; Zhao, Yayu; Zhang, Yan; Xing, Lili; Xue, Xinyu

    2014-02-21

    A flexible piezo-driven active H2S sensor has been fabricated from CdS nanorod arrays. By coupling the piezoelectric and gas sensing properties of CdS nanorods, the piezoelectric output generated by CdS nanorod arrays acts not only as a power source, but also as a response signal to H2S. Under externally applied compressive force, the piezoelectric output of CdS nanorod arrays is very sensitive to H2S. Upon exposure to 600 ppm H2S, the piezoelectric output of the device decreased from 0.32 V (in air) to 0.12 V. Such a flexible device can be driven by the tiny mechanical energy in our living environment, such as human finger pinching. Our research can stimulate a research trend on designing new material systems and device structures for high-performance piezo-driven active gas sensors.

  6. Application of radial basis function networks for solar-array modelling and maximum power-point prediction

    Energy Technology Data Exchange (ETDEWEB)

    Al-Amoudi, A.; Zhang, L. [University of Leeds (United Kingdom). School of Electronic and Electrical Engineering

    2000-09-01

    A neural-network-based approach for solar array modelling is presented. The logic hidden unit of the proposed network consists of a set of nonlinear radial basis functions (RBFs) which are connected directly to the input vector. The links between hidden and output units are linear. The model can be trained using a random set of data collected from a real photovoltaic (PV) plant. The training procedures are fast and the accuracy of the trained models is comparable with that of the conventional model. The principle and training procedures of the RBF-network modelling when applied to emulate the I/V characteristics of PV arrays are discussed. Simulation results of the trained RBF networks for modelling a PV array and predicting the maximum power points of a real PV panel are presented. (author)

  7. Fabrication and characterization of well-aligned zinc oxide nanowire arrays and their realizations in Schottky-device applications

    Energy Technology Data Exchange (ETDEWEB)

    Wong, Kin Mun; Grote, Fabian; Sun, Hui; Lei, Yong [Institute of Materials Physics, Center for Nanotechnology, University of Muenster (Germany); Wen, Liaoyong; Fang, Yaoguo [Institute of Nanochemistry and Nanobiology, Shanghai University, Shanghai 201800 (China)

    2011-07-01

    Highly ordered arrays of vertical zinc oxide (ZnO) nanowires (NWs) or nanopores were fabricated in our group by first thermal evaporating a thin film of gold on the ultrathin alumina membrane (UTAM). The UTAM was then utilized as a substrate for the growth of the ordered arrays using a chemical vapour deposition (CVD) process. Alternatively, a modified CVD process was also used to fabricate ultra-long ZnO NWs with the length of the nanowire exceeding 100 micrometres. Subsequently, densely packed arrays of ZnO NWs Schottky diodes were synthesized by transferring the long NWs on a substrate using a dry contact printing method and the electrical contacts were made on the NWs with a photolithographic process. The interesting electrical properties of the ZnO NWs, diodes or other metal oxide NWs such as the field emission, electron transport and piezoelectric properties were characterized by current-voltage or by other appropriate measurements.

  8. Photovoltaic array performance model.

    Energy Technology Data Exchange (ETDEWEB)

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

    2004-08-01

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

  9. Design and validation of a large-format transition edge sensor array magnetic shielding system for space application

    Science.gov (United States)

    Bergen, A.; van Weers, H. J.; Bruineman, C.; Dhallé, M. M. J.; Krooshoop, H. J. G.; ter Brake, H. J. M.; Ravensberg, K.; Jackson, B. D.; Wafelbakker, C. K.

    2016-10-01

    The paper describes the development and the experimental validation of a cryogenic magnetic shielding system for transition edge sensor based space detector arrays. The system consists of an outer mu-metal shield and an inner superconducting niobium shield. First, a basic comparison is made between thin-walled mu-metal and superconducting shields, giving an off-axis expression for the field inside a cup-shaped superconductor as a function of the transverse external field. Starting from these preliminary analytical considerations, the design of an adequate and realistic shielding configuration for future space flight applications (either X-IFU [D. Barret et al., e-print arXiv:1308.6784 [astro-ph.IM] (2013)] or SAFARI [B. Jackson et al., IEEE Trans. Terahertz Sci. Technol. 2, 12 (2012)]) is described in more detail. The numerical design and verification tools (static and dynamic finite element method (FEM) models) are discussed together with their required input, i.e., the magnetic-field dependent permeability data. Next, the actual manufacturing of the shields is described, including a method to create a superconducting joint between the two superconducting shield elements that avoid flux penetration through the seam. The final part of the paper presents the experimental verification of the model predictions and the validation of the shield's performance. The shields were cooled through the superconducting transition temperature of niobium in zero applied magnetic field (<10 nT) or in a DC field with magnitude ˜100 μT, applied either along the system's symmetry axis or perpendicular to it. After cool-down, DC trapped flux profiles were measured along the shield axis with a flux-gate magnetometer and the attenuation of externally applied AC fields (100 μT, 0.1 Hz, both axial and transverse) was verified along this axis with superconducting quantum interference device magnetometers. The system's measured on-axis shielding factor is greater than 106, well exceeding

  10. Single-molecule protein arrays enabled by scanning probe block copolymer lithography

    OpenAIRE

    Chai, Jinan; Wong, Lu Shin; Giam, Louise; Mirkin, Chad A.

    2011-01-01

    The ability to control the placement of individual protein molecules on surfaces could enable advances in a wide range of areas, from the development of nanoscale biomolecular devices to fundamental studies in cell biology. Such control, however, remains a challenge in nanobiotechnology due to the limitations of current lithographic techniques. Herein we report an approach that combines scanning probe block copolymer lithography with site-selective immobilization strategies to create arrays o...

  11. Simple and cost-effective fabrication of microvalve arrays in PDMS using laser cut molds with application to C. elegans manipulation in microfluidics

    International Nuclear Information System (INIS)

    We present a new fabrication protocol for fabricating pneumatically controlled microvalve arrays (consisting of 100 s of microvalves) in PDMS substrates. The protocol utilizes rapid and cost-effective fabrication of molds using laser cutting of adhesive vinyl tapes and replica molding of PDMS. Hence the protocol is fast, simple and avoids cleanroom use. The results show that effective doormat-style microvalves can be easily fabricated in arrays by manipulating the stiffness of the actuating membrane through varying the valve-chamber area/shape. Three frequently used valve-chamber shapes (circle, square and capsule) were tested and all showed advantages in different situations. Circular valve chambers were best for small valves, square valves were best for medium-sized valves, and the capsule valves were best for larger valves. An application of this protocol has been demonstrated in the fabrication of a microfluidic 32-well plate for high-throughput manipulation of C. elegans for biomedical research. (paper)

  12. Nonlinear waveform analysis for water-layer response and its application to high-frequency receiver function analysis using OBS array

    Science.gov (United States)

    Akuhara, Takeshi; Mochizuki, Kimihiro; Kawakatsu, Hitoshi; Takeuchi, Nozomu

    2016-07-01

    Determination of a response of the seawater column to teleseismic plane wave is important to suppress adverse effects of water reverberations in calculating receiver functions (RFs) using ocean-bottom seismometer (OBS) records. We present a novel nonlinear-waveform analysis method using the simulated annealing algorithm to determine such a water-layer response recorded by an OBS array. We then demonstrate its usefulness for the RF estimation through its application to synthetic and observed data. Synthetic experiments suggest that the water-layer response constrained in this way has a potential to improve RFs of OBS records drastically even in the high-frequency range (to 4 Hz). By applying it to data observed by the OBS array around the Kii Peninsula, southwestern Japan, we identified a low-velocity zone at the top of the subducting Philippine Sea plate. This zone may represent the incoming fluid-rich sediment layer that has been reported by active source seismic survey.

  13. Simple and cost-effective fabrication of microvalve arrays in PDMS using laser cut molds with application to C. elegans manipulation in microfluidics

    Science.gov (United States)

    Samuel, R.; Thacker, C. M.; Maricq, A. V.; Gale, B. K.

    2014-09-01

    We present a new fabrication protocol for fabricating pneumatically controlled microvalve arrays (consisting of 100 s of microvalves) in PDMS substrates. The protocol utilizes rapid and cost-effective fabrication of molds using laser cutting of adhesive vinyl tapes and replica molding of PDMS. Hence the protocol is fast, simple and avoids cleanroom use. The results show that effective doormat-style microvalves can be easily fabricated in arrays by manipulating the stiffness of the actuating membrane through varying the valve-chamber area/shape. Three frequently used valve-chamber shapes (circle, square and capsule) were tested and all showed advantages in different situations. Circular valve chambers were best for small valves, square valves were best for medium-sized valves, and the capsule valves were best for larger valves. An application of this protocol has been demonstrated in the fabrication of a microfluidic 32-well plate for high-throughput manipulation of C. elegans for biomedical research.

  14. Micro-structured electrode arrays : high-frequency discharges at atmospheric pressure—characterization and new applications

    NARCIS (Netherlands)

    Baars-Hibbe, Lutz; Schrader, Christian; Sichler, Philipp; Cordes, Thorben; Gericke, Karl-Heinz; Büttgenbach, Stephanus; Draeger, Siegfried

    2004-01-01

    Micro-structured electrode (MSE) arrays allow to generate large-area uniform glow discharges over a wide pressure range up to atmospheric pressure. The electrode dimensions in the µm-range realized by means of modern micro-machining and galvanic techniques are small enough to generate sufficiently h

  15. Array analysis using circular-wave-front geometry: an application to locate the nearby seismo-volcanic source

    OpenAIRE

    Almendros, J.; University of Granada, Spain; Ibanez, J.; University of Granada, Spain; Alguacil, G.; University of Granada, Spain; Del Pezzo, E.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia

    1999-01-01

    The zero-lag cross-correlation technique, used for array analysis in the hypothesis of plane waves, has been modified to allow the wave front to be circular. Synthetic tests have been performed to check the capability of the method

  16. Application of waveform stacking to the Tainan and Ilan low-cost local early warning (EEW) arrays in Taiwan

    Science.gov (United States)

    Yung, T. C.; Ting-Li, L.; Yih-Min, W.

    2014-12-01

    Taiwan has been constantly threatened by large, damaging earthquakes. Nowadays, EEWS is a useful tool for seismic hazard mitigation, and it is practical in Japan, Taiwan, Mexico, and the southern California (Kanamori, 1997). There are two types of EEWS. Generally, the front-type warning has higher accuracy than the on-site one because of the use of more stations and longer time window. On the other hand, the on-site type warning has the shorter reporting time, but lower accuracy because of using only one single or couple stations. Based on the on-site process, we installed two local early warning arrays in Ilan and Tainan city of the newly established EEW network and adopted the waveform stacking method to enhance the coherent part of early arrivals. We selected 15 events in 2013 of Central Weather Bureau earthquake catalog, and used the MPd method to estimate the magnitude. Since the EEW network is newly established and the accelerometers (named as Palert) are all installed on the building wall instead of the free surface, the present Pdattenuation relationships have to modify to account for the building effect to get the new regression equation. We show that the accuracy of magnitude estimation (MPd) for the on-site EEW mode by using the array stacking method can be significantly improved. Since the station density of the Palert network is high, more arrays can be formed especially in the metropolitan areas. Key words: EEW, EEW array, waveform stacking.

  17. Array tomography: imaging stained arrays.

    Science.gov (United States)

    Micheva, Kristina D; O'Rourke, Nancy; Busse, Brad; Smith, Stephen J

    2010-11-01

    Array tomography is a volumetric microscopy method based on physical serial sectioning. Ultrathin sections of a plastic-embedded tissue are cut using an ultramicrotome, bonded in an ordered array to a glass coverslip, stained as desired, and imaged. The resulting two-dimensional image tiles can then be reconstructed computationally into three-dimensional volume images for visualization and quantitative analysis. The minimal thickness of individual sections permits high-quality rapid staining and imaging, whereas the array format allows reliable and convenient section handling, staining, and automated imaging. Also, the physical stability of the arrays permits images to be acquired and registered from repeated cycles of staining, imaging, and stain elution, as well as from imaging using multiple modalities (e.g., fluorescence and electron microscopy). Array tomography makes it possible to visualize and quantify previously inaccessible features of tissue structure and molecular architecture. However, careful preparation of the tissue is essential for successful array tomography; these steps can be time-consuming and require some practice to perfect. In this protocol, tissue arrays are imaged using conventional wide-field fluorescence microscopy. Images can be captured manually or, with the appropriate software and hardware, the process can be automated. PMID:21041399

  18. Array tomography: production of arrays.

    Science.gov (United States)

    Micheva, Kristina D; O'Rourke, Nancy; Busse, Brad; Smith, Stephen J

    2010-11-01

    Array tomography is a volumetric microscopy method based on physical serial sectioning. Ultrathin sections of a plastic-embedded tissue are cut using an ultramicrotome, bonded in an ordered array to a glass coverslip, stained as desired, and imaged. The resulting two-dimensional image tiles can then be reconstructed computationally into three-dimensional volume images for visualization and quantitative analysis. The minimal thickness of individual sections permits high-quality rapid staining and imaging, whereas the array format allows reliable and convenient section handling, staining, and automated imaging. Also, the physical stability of the arrays permits images to be acquired and registered from repeated cycles of staining, imaging, and stain elution, as well as from imaging using multiple modalities (e.g., fluorescence and electron microscopy). Array tomography makes it possible to visualize and quantify previously inaccessible features of tissue structure and molecular architecture. However, careful preparation of the tissue is essential for successful array tomography; these steps can be time consuming and require some practice to perfect. This protocol describes the sectioning of embedded tissues and the mounting of the serial arrays. The procedures require some familiarity with the techniques used for ultramicrotome sectioning for electron microscopy. PMID:21041397

  19. Far-infrared imaging antenna arrays

    OpenAIRE

    Neikirk, Dean P.; Rutledge, David B.; Muha, Michael S.; Park, Hyeon; Yu, Chang-Xuan

    1982-01-01

    A far-infrared imaging antenna array has been demonstrated for the first time. The array is a line of evaporated silver bow-tie antennas on a fused-quartz substrate with bismuth-microbolometer detectors. The measured optical transfer function shows that the system is diffraction limited. This imaging array should find direct application in fusion plasma diagnostics. If the microbolometers can be replaced by more sensitive diode detectors, the array should also find application in radiometry a...

  20. Cantilever array sensors

    Directory of Open Access Journals (Sweden)

    Hans Peter Lang

    2005-04-01

    Full Text Available Miniaturized microfabricated sensors have enormous potential in gas detection, biochemical analysis, medical applications, quality and process control, and product authenticity issues. Here, we highlight an ultrasensitive mechanical way of converting (bio-chemical or physical processes into a recordable signal using microfabricated cantilever arrays.

  1. A Fabrication Route for Arrays of Ultra-low-Noise MoAu Transition Edge Sensors on Thin Silicon Nitride for Space Applications

    OpenAIRE

    Glowacka, D. M.; Crane, M.; Goldie, D. J.; Withington, S.

    2014-01-01

    We describe a process route to fabricate arrays of Ultra-low-Noise MoAu Transition Edge Sensors (TESs). The low thermal conductance required for space applications is achieved using 200 nm-thick Silicon Nitride (SiNx ) patterned to form long-thin legs with widths of 2.1 {\\mu}m. Using bilayers formed on SiNx islands from films with 40 nm-thick Mo and Au thicknesses in the range 30 to 280 nm deposited by dc-sputtering in ultra-high vacuum we can obtain tunable transition temperatures in the ran...

  2. Integration of lateral flow and micro array technologies for multiplex immunoassay: application to the determination of drugs of abuse

    International Nuclear Information System (INIS)

    We report on a lateral flow micro array that combines multi-spot immunochip technology and immunochromatography. It can serve as a tool for the simultaneous detection of multiple analytes. The test zone of the nitrocellulose support comprises a micro array spotted with up to 32 antigens that can capture labeled gold-antibodies after lateral flow. The detection limits and detectable concentration ranges of the assay were characterized. The method was applied to the determination of drugs of abuse (and their metabolites) in urine, specifically of morphine, amphetamine, methamphetamine, and benzoylecgonine. The assay format is rapid (10 min), and has both a low relative standard deviation (-1 for drugs of abuse) are comparable to those of conventional single-analyte strip methods. (author)

  3. Controllable hydrothermal synthesis of rutile TiO{sub 2} hollow nanorod arrays on TiCl{sub 4} pretreated Ti foil for DSSC application

    Energy Technology Data Exchange (ETDEWEB)

    Xi, Min [Key Laboratory of Renewable Energy, Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640 (China); Zhang, Yulan; Long, Lizhen [Key Laboratory of Renewable Energy, Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Li, Xinjun, E-mail: lixj@ms.giec.ac.cn [Key Laboratory of Renewable Energy, Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640 (China)

    2014-11-15

    Rutile TiO{sub 2} nanorod arrays (TNRs) were achieved by hydrothermal process on TiCl{sub 4} pretreated Ti foil. Subsequently, TNRs were hydrothermally etched in HCl solution to form hollow TiO{sub 2} nanorod arrays (H-TNRs). The TiCl{sub 4} pretreatment plays key roles in enhancement of Ti foil corrosion resistance ability and crystal nucleation introduction for TNRs growth. TNRs with desired morphology can be obtained by controlling TiCl{sub 4} concentration and the amount of tetrabutyl titanate (TTB) accordingly. TNRs with the length of ∼1.5 μm and diameter of ∼200 nm, obtained on 0.15 M TiCl{sub 4} pretreated Ti foil with 0.6 mL TTB, exhibits relatively higher photocurrent. The increased pore volume of the H-TNRs has contributed to the increased surface area which is benefit for Dye-Sensitized Solar Cells (DSSC) application. And the 180 °C-H-TNRs photoanode obtained from the 0.15-TiCl{sub 4}-TNRs sample demonstrated 128.9% enhancement of photoelectric efficiency of DSSC compared to that of the original TNR photoanode. - Graphical abstract: Rutile hollow TiO{sub 2} nanorod array photoanode obtained from original TiO{sub 2} nanorod array photoanode by hydrothermal etching demonstrates enhanced photoelectric efficiency of DSSC. - Highlights: • TiO{sub 2} nanorods are prepared via hydrothermal process on TiCl{sub 4}-pretreated Ti foil. • Hollow TiO{sub 2} nanorods are obtained by hydrothermal etching of TiO{sub 2} nanorods. • TiCl{sub 4} pretreatment plays a key role in protecting Ti foil from chemical corrosion. • Hollow TiO{sub 2} nanorods photoanode shows enhanced photoelectric efficiency for DSSC.

  4. Understanding and optimizing microstrip patch antenna cross polarization radiation on element level for demanding phased array antennas in weather radar applications

    Science.gov (United States)

    Vollbracht, D.

    2015-11-01

    The antenna cross polarization suppression (CPS) is of significant importance for the accurate calculation of polarimetric weather radar moments. State-of-the-art reflector antennas fulfill these requirements, but phased array antennas are changing their CPS during the main beam shift, off-broadside direction. Since the cross polarization (x-pol) of the array pattern is affected by the x-pol element factor, the single antenna element should be designed for maximum CPS, not only at broadside, but also for the complete angular electronic scan (e-scan) range of the phased array antenna main beam positions. Different methods for reducing the x-pol radiation from microstrip patch antenna elements, available from literature sources, are discussed and summarized. The potential x-pol sources from probe fed microstrip patch antennas are investigated. Due to the lack of literature references, circular and square shaped X-Band radiators are compared in their x-pol performance and the microstrip patch antenna size variation was analyzed for improved x-pol pattern. Furthermore, the most promising technique for the reduction of x-pol radiation, namely "differential feeding with two RF signals 180° out of phase", is compared to single fed patch antennas and thoroughly investigated for phased array applications with simulation results from CST MICROWAVE STUDIO (CST MWS). A new explanation for the excellent port isolation of dual linear polarized and differential fed patch antennas is given graphically. The antenna radiation pattern from single fed and differential fed microstrip patch antennas are analyzed and the shapes of the x-pol patterns are discussed with the well-known cavity model. Moreover, two new visual based electromagnetic approaches for the explanation of the x-pol generation will be given: the field line approach and the surface current distribution approach provide new insight in understanding the generation of x-pol component in microstrip patch antenna radiation

  5. Background Noise Reduction in Wind Tunnels using Adaptive Noise Cancellation and Cepstral Echo Removal Techniques for Microphone Array Applications

    OpenAIRE

    Spalt, Taylor B

    2010-01-01

    Two experiments were conducted to investigate Adaptive Noise Cancelling and Cepstrum echo removal post-processing techniques on acoustic data from a linear microphone array in an anechoic chamber. A point source speaker driven with white noise was used as the primary signal. The first experiment included a background speaker to provide interference noise at three different Signal-to-Noise Ratios to simulate noise propagating down a wind tunnel circuit. The second experiment contained only the...

  6. Hierarchical-Multiplex DNA Patterns Mediated by Polymer Brush Nanocone Arrays That Possess Potential Application for Specific DNA Sensing.

    Science.gov (United States)

    Liu, Wendong; Liu, Xueyao; Ge, Peng; Fang, Liping; Xiang, Siyuan; Zhao, Xiaohuan; Shen, Huaizhong; Yang, Bai

    2015-11-11

    This paper provides a facile and cost-efficient method to prepare single-strand DNA (ssDNA) nanocone arrays and hierarchical DNA patterns that were mediated by poly(2-hydroxyethyl methacrylate) (PHEMA) brush. The PHEMA brush nanocone arrays with different morphology and period were fabricated via colloidal lithography. The hierarchical structure was prepared through the combination of colloidal lithography and traditional photolithography. The DNA patterns were easily achieved via grafting the amino group modified ssDNA onto the side chain of polymer brush, and the anchored DNA maintained their reactivity. The as-prepared ssDNA nanocone arrays can be applied for target DNA sensing with the detection limit reaching 1.65 nM. Besides, with the help of introducing microfluidic ideology, the hierarchical-multiplex DNA patterns on the same substrate could be easily achieved with each kind of pattern possessing one kind of ssDNA, which are promising surfaces for the preparation of rapid, visible, and multiplex DNA sensors.

  7. Effect of a light guide plate with lenticular-arrayed surface on optical output for backlight and illumination application

    Science.gov (United States)

    Teng, Tun-Chien; Tseng, Li-Wei

    2013-09-01

    In this paper, we investigated the optical output characteristic of the light guide plate (LGP) with microstructures engraved by a CO2 laser, which is for edge-lit backlight of liquid crystal display or illumination. Especially, the laser-engraving method is suitable for the slim large-sized LGP used in LED TV backlight, and the engraved microstructure has polished surface to contribute to better optical efficiency. For seeking higher optical efficiency, we adopted a LGP with lenticular-arrayed surface (LAS LGP) as the experimental substrate. In order to investigate the effect of the lenticular-arrayed surface on optical output characteristic for the different kinds of the engraved microstructures, we used the laser to directly engrave the flat surface (opposite to the lenticular-arrayed surface) of the LAS LGP with different kinds of microstructures as experimental samples; each sample has one kind of the engraved microstructures on its flat surface. Similarly, we also engraved the same kinds of the microstructures on the flat LGP as a controlled group for comparison. The cross-section profiles of the engraved microstructures on both LAS LGP and flat LGP were measured by a laser confocal microscope. All the samples were further measured for spatial and angular luminance by the BM7 and Conoscope, respectively. In addition, both the experimental data and simulation results were demonstrated and compared to each other in this paper.

  8. Electrode array for neural stimulation

    Energy Technology Data Exchange (ETDEWEB)

    Wessendorf, Kurt O. (Albuquerque, NM); Okandan, Murat (Edgewood, NM); Stein, David J. (Albuquerque, NM); Yang, Pin (Albuquerque, NM); Cesarano, III, Joseph (Albuquerque, NM); Dellinger, Jennifer (Albuquerque, NM)

    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. Constructing Bio-molecular Databases on a DNA-based Computer

    CERN Document Server

    Chang, Weng-Long; Ho,; Guo, Minyi

    2007-01-01

    Codd [Codd 1970] wrote the first paper in which the model of a relational database was proposed. Adleman [Adleman 1994] wrote the first paper in which DNA strands in a test tube were used to solve an instance of the Hamiltonian path problem. From [Adleman 1994], it is obviously indicated that for storing information in molecules of DNA allows for an information density of approximately 1 bit per cubic nm (nanometer) and a dramatic improvement over existing storage media such as video tape which store information at a density of approximately 1 bit per 1012 cubic nanometers. This paper demonstrates that biological operations can be applied to construct bio-molecular databases where data records in relational tables are encoded as DNA strands. In order to achieve the goal, DNA algorithms are proposed to perform eight operations of relational algebra (calculus) on bio-molecular relational databases, which include Cartesian product, union, set difference, selection, projection, intersection, join and division. Fu...

  10. PREFACE: India-Japan Workshop on Biomolecular Electronics & Organic Nanotechnology for Environment Preservation

    Science.gov (United States)

    Onoda, Mitsuyoshi; Malhotra, Bansi D.

    2012-04-01

    The 'India-Japan Workshop on Biomolecular Electronics & Organic Nanotechnology for Environment Preservation' (IJWBME 2011) will be held on 7-10 December 2011 at EGRET Himeji, Himeji, Hyogo, Japan. This workshop was held for the first time on 17-19 December 2009 at NPL, New Delhi. Keeping in mind the importance of organic nanotechnology and biomolecular electronics for environmental preservation and their anticipated impact on the economics of both the developing and the developed world, IJWBME 2009 was jointly organized by the Department of Biological Functions, Graduate School of Life Sciences and Systems Engineering, the Kyushu Institute of Technology (KIT), Kitakyushu, Japan, and the Department of Science & Technology Centre on Biomolecular Electronics (DSTCBE), National Physical Laboratory (NPL). Much progress in the field of biomolecular electronics and organic nanotechnology for environmental preservation is expected for the 21st Century. Organic optoelectronic devices, such as organic electroluminescent devices, organic thin-film transistors, organic sensors, biological systems and so on have especially attracted much attention. The main purpose of this workshop is to provide an opportunity for researchers interested in biomolecular electronics and organic nanotechnology for environmental preservation, to come together in an informal and friendly atmosphere and exchange technical knowledge and experience. We are sure that this workshop will be very useful and fruitful for all participants in summarizing the recent progress in biomolecular electronics and organic nanotechnology for environmental preservation and preparing new ground for the next generation. Many papers have been submitted from India and Japan and more than 30 papers have been accepted for presentation. The main topics of interest are as follows: Bioelectronics Biomolecular Electronics Fabrication Techniques Self-assembled Monolayers Nano-sensors Environmental Monitoring Organic Devices

  11. Biochemical filter with sigmoidal response: increasing the complexity of biomolecular logic.

    Science.gov (United States)

    Privman, Vladimir; Halámek, Jan; Arugula, Mary A; Melnikov, Dmitriy; Bocharova, Vera; Katz, Evgeny

    2010-11-11

    The first realization of a designed, rather than natural, biochemical filter process is reported and analyzed as a promising network component for increasing the complexity of biomolecular logic systems. Key challenge in biochemical logic research has been achieving scalability for complex network designs. Various logic gates have been realized, but a "toolbox" of analog elements for interconnectivity and signal processing has remained elusive. Filters are important as network elements that allow control of noise in signal transmission and conversion. We report a versatile biochemical filtering mechanism designed to have sigmoidal response in combination with signal-conversion process. Horseradish peroxidase-catalyzed oxidation of chromogenic electron donor by H(2)O(2) was altered by adding ascorbate, allowing to selectively suppress the output signal, modifying the response from convex to sigmoidal. A kinetic model was developed for evaluation of the quality of filtering. The results offer improved capabilities for design of scalable biomolecular information processing systems.

  12. Effect of antibody modifications on its biomolecular binding as determined by surface plasmon resonance.

    Science.gov (United States)

    Vashist, Sandeep Kumar

    2012-02-01

    A surface plasmon resonance (SPR)-based procedure was developed to determine the effect of antibody modifications on its biomolecular binding behavior. Mouse immunoglobulin G (IgG) was immobilized on a protein A-functionalized gold-coated SPR chip. Goat anti-mouse IgG and its various commercially available modifications (i.e., conjugated with atto 550, atto 647, tetramethylrhodamine isothiocyanate [TRITC], horseradish peroxidase [HRP], or biotin) were employed in exactly the same concentration for the detection of mouse IgG. The various modifications of goat anti-mouse IgG decreased its biomolecular binding to mouse IgG in the order of unmodified>HRP-labeled>atto 550-labeled>biotinylated>TRITC-labeled>atto 647-labeled. PMID:22093612

  13. Bridge- and Solvent-Mediated Intramolecular Electronic Communications in Ubiquinone-Based Biomolecular Wires

    OpenAIRE

    Liu, Xiao-Yuan; Ma, Wei; Zhou, Hao; Cao, Xiao-Ming; Long, Yi-Tao

    2015-01-01

    Intramolecular electronic communications of molecular wires play a crucial role for developing molecular devices. In the present work, we describe different degrees of intramolecular electronic communications in the redox processes of three ubiquinone-based biomolecular wires (Bis-CoQ0s) evaluated by electrochemistry and Density Functional Theory (DFT) methods in different solvents. We found that the bridges linkers have a significant effect on the electronic communications between the two pe...

  14. Extension of the GLYCAM06 Biomolecular Force Field to Lipids, Lipid Bilayers and Glycolipids

    OpenAIRE

    Tessier, Matthew B; DeMarco, Mari L.; Yongye, Austin B.; Woods, Robert J.

    2008-01-01

    GLYCAM06 is a generalisable biomolecular force field that is extendible to diverse molecular classes in the spirit of a small-molecule force field. Here we report parameters for lipids, lipid bilayers and glycolipids for use with GLYCAM06. Only three lipid-specific atom types have been introduced, in keeping with the general philosophy of transferable parameter development. Bond stretching, angle bending, and torsional force constants were derived by fitting to quantum mechanical data for a c...

  15. Atomic force microscopy of self-assembled biomolecular structures and their interaction with metallic nanoparticles.

    OpenAIRE

    Gysemans, Maarten

    2009-01-01

    We applied AFM to study biomolecular wires, both out of interest in thei r biological functions and in the framework of nanotechnology based fabr ication. We have focused on two different kinds of protein wires: Insuli n fibrils and microtubules. Microtubules are an important constituent of the cytoskeleton and fulfill multiple vital functions in the cell. Insu lin fibrils on the other hand are amyloid fibrils without a clear biolog ical role, but with intriguing polymerization properties tha...

  16. Assembly of single wall carbon nanotube-metal nanohybrids using biomolecular components

    Science.gov (United States)

    Kim, Sang Nyon; Slocik, Joseph M.; Naik, Rajesh R.

    2010-08-01

    Biomaterials such as nucleic acids and proteins can be exploited to create higher order structures. The biomolecular components such as DNA and peptides have been used to assemble nanoparticles with high fidelity. Here, we use DNA and peptides, and their preferential interaction with inorganic and carbon nanomaterials to form homogeneous hybrids. The enhanced binding of Pt ions to both DNA and peptide functionalized nanoparticles mediates the assembly of carbon nanotubes functionalized with DNA with peptide coated gold nanoparticles.

  17. Repeatable, accurate, and high speed multi-level programming of memristor 1T1R arrays for power efficient analog computing applications

    Science.gov (United States)

    Merced-Grafals, Emmanuelle J.; Dávila, Noraica; Ge, Ning; Williams, R. Stanley; Strachan, John Paul

    2016-09-01

    Beyond use as high density non-volatile memories, memristors have potential as synaptic components of neuromorphic systems. We investigated the suitability of tantalum oxide (TaOx) transistor-memristor (1T1R) arrays for such applications, particularly the ability to accurately, repeatedly, and rapidly reach arbitrary conductance states. Programming is performed by applying an adaptive pulsed algorithm that utilizes the transistor gate voltage to control the SET switching operation and increase programming speed of the 1T1R cells. We show the capability of programming 64 conductance levels with algorithm is also utilized to program 16 conductance levels on a population of cells in the 1T1R array showing robustness to cell-to-cell variability. In general, the proposed algorithm results in approximately 10× improvement in programming speed over standard algorithms that do not use the transistor gate to control memristor switching. In addition, after only two programming pulses (an initialization pulse followed by a programming pulse), the resulting conductance values are within 12% of the target values in all cases. Finally, endurance of more than 106 cycles is shown through open-loop (single pulses) programming across multiple conductance levels using the optimized gate voltage of the transistor. These results are relevant for applications that require high speed, accurate, and repeatable programming of the cells such as in neural networks and analog data processing.

  18. Repeatable, accurate, and high speed multi-level programming of memristor 1T1R arrays for power efficient analog computing applications

    Science.gov (United States)

    Merced-Grafals, Emmanuelle J.; Dávila, Noraica; Ge, Ning; Williams, R. Stanley; Strachan, John Paul

    2016-09-01

    Beyond use as high density non-volatile memories, memristors have potential as synaptic components of neuromorphic systems. We investigated the suitability of tantalum oxide (TaOx) transistor-memristor (1T1R) arrays for such applications, particularly the ability to accurately, repeatedly, and rapidly reach arbitrary conductance states. Programming is performed by applying an adaptive pulsed algorithm that utilizes the transistor gate voltage to control the SET switching operation and increase programming speed of the 1T1R cells. We show the capability of programming 64 conductance levels with programming speed and programming error. The algorithm is also utilized to program 16 conductance levels on a population of cells in the 1T1R array showing robustness to cell-to-cell variability. In general, the proposed algorithm results in approximately 10× improvement in programming speed over standard algorithms that do not use the transistor gate to control memristor switching. In addition, after only two programming pulses (an initialization pulse followed by a programming pulse), the resulting conductance values are within 12% of the target values in all cases. Finally, endurance of more than 106 cycles is shown through open-loop (single pulses) programming across multiple conductance levels using the optimized gate voltage of the transistor. These results are relevant for applications that require high speed, accurate, and repeatable programming of the cells such as in neural networks and analog data processing.

  19. ArrayMining: a modular web-application for microarray analysis combining ensemble and consensus methods with cross-study normalization

    Directory of Open Access Journals (Sweden)

    Krasnogor Natalio

    2009-10-01

    Full Text Available Abstract Background Statistical analysis of DNA microarray data provides a valuable diagnostic tool for the investigation of genetic components of diseases. To take advantage of the multitude of available data sets and analysis methods, it is desirable to combine both different algorithms and data from different studies. Applying ensemble learning, consensus clustering and cross-study normalization methods for this purpose in an almost fully automated process and linking different analysis modules together under a single interface would simplify many microarray analysis tasks. Results We present ArrayMining.net, a web-application for microarray analysis that provides easy access to a wide choice of feature selection, clustering, prediction, gene set analysis and cross-study normalization methods. In contrast to other microarray-related web-tools, multiple algorithms and data sets for an analysis task can be combined using ensemble feature selection, ensemble prediction, consensus clustering and cross-platform data integration. By interlinking different analysis tools in a modular fashion, new exploratory routes become available, e.g. ensemble sample classification using features obtained from a gene set analysis and data from multiple studies. The analysis is further simplified by automatic parameter selection mechanisms and linkage to web tools and databases for functional annotation and literature mining. Conclusion ArrayMining.net is a free web-application for microarray analysis combining a broad choice of algorithms based on ensemble and consensus methods, using automatic parameter selection and integration with annotation databases.

  20. Repeatable, accurate, and high speed multi-level programming of memristor 1T1R arrays for power efficient analog computing applications.

    Science.gov (United States)

    Merced-Grafals, Emmanuelle J; Dávila, Noraica; Ge, Ning; Williams, R Stanley; Strachan, John Paul

    2016-09-01

    Beyond use as high density non-volatile memories, memristors have potential as synaptic components of neuromorphic systems. We investigated the suitability of tantalum oxide (TaOx) transistor-memristor (1T1R) arrays for such applications, particularly the ability to accurately, repeatedly, and rapidly reach arbitrary conductance states. Programming is performed by applying an adaptive pulsed algorithm that utilizes the transistor gate voltage to control the SET switching operation and increase programming speed of the 1T1R cells. We show the capability of programming 64 conductance levels with programming speed and programming error. The algorithm is also utilized to program 16 conductance levels on a population of cells in the 1T1R array showing robustness to cell-to-cell variability. In general, the proposed algorithm results in approximately 10× improvement in programming speed over standard algorithms that do not use the transistor gate to control memristor switching. In addition, after only two programming pulses (an initialization pulse followed by a programming pulse), the resulting conductance values are within 12% of the target values in all cases. Finally, endurance of more than 10(6) cycles is shown through open-loop (single pulses) programming across multiple conductance levels using the optimized gate voltage of the transistor. These results are relevant for applications that require high speed, accurate, and repeatable programming of the cells such as in neural networks and analog data processing.