WorldWideScience

Sample records for biomolecular arraying applications

  1. Nanoarchitectonics of biomolecular assemblies for functional applications

    Science.gov (United States)

    Avinash, M. B.; Govindaraju, T.

    2014-10-01

    The stringent processes of natural selection and evolution have enabled extraordinary structure-function properties of biomolecules. Specifically, the archetypal designs of biomolecules, such as amino acids, nucleobases, carbohydrates and lipids amongst others, encode unparalleled information, selectivity and specificity. The integration of biomolecules either with functional molecules or with an embodied functionality ensures an eclectic approach for novel and advanced nanotechnological applications ranging from electronics to biomedicine, besides bright prospects in systems chemistry and synthetic biology. Given this intriguing scenario, our feature article intends to shed light on the emerging field of functional biomolecular engineering.

  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. Nanopatterned structures for biomolecular analysis toward genomic and proteomic applications

    Science.gov (United States)

    Chou, Chia-Fu; Gu, Jian; Wei, Qihuo; Liu, Yingjie; Gupta, Ravi; Nishio, Takeyoshi; Zenhausern, Frederic

    2005-01-01

    We report our fabrication of nanoscale devices using electron beam and nanoimprint lithography (NIL). We focus our study in the emerging fields of NIL, nanophotonics and nanobiotechnology and give a few examples as to how these nanodevices may be applied toward genomic and proteomic applications for molecular analysis. The examples include reverse NIL-fabricated nanofluidic channels for DNA stretching, nanoscale molecular traps constructed from dielectric constrictions for DNA or protein focusing by dielectrophoresis, multi-layer nanoburger and nanoburger multiplets for optimized surface-plasma enhanced Raman scattering for protein detection, and biomolecular motor-based nanosystems. The development of advanced nanopatterning techniques promises reliable and high-throughput manufacturing of nanodevices which could impact significantly on the areas of genomics, proteomics, drug discovery and molecular clinical diagnostics.

  4. 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%.

  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. 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...

  8. 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...

  9. 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.

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

    Science.gov (United States)

    Zhou, Pei; Wagner, Gerhard

    2010-01-01

    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. PMID:19731047

  11. 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).

  12. Phase sensitive spectral domain interferometry for label free biomolecular interaction analysis and biosensing applications

    Science.gov (United States)

    Chirvi, Sajal

    Biomolecular interaction analysis (BIA) plays vital role in wide variety of fields, which include biomedical research, pharmaceutical industry, medical diagnostics, and biotechnology industry. Study and quantification of interactions between natural biomolecules (proteins, enzymes, DNA) and artificially synthesized molecules (drugs) is routinely done using various labeled and label-free BIA techniques. Labeled BIA (Chemiluminescence, Fluorescence, Radioactive) techniques suffer from steric hindrance of labels on interaction site, difficulty of attaching labels to molecules, higher cost and time of assay development. Label free techniques with real time detection capabilities have demonstrated advantages over traditional labeled techniques. The gold standard for label free BIA is surface Plasmon resonance (SPR) that detects and quantifies the changes in refractive index of the ligand-analyte complex molecule with high sensitivity. Although SPR is a highly sensitive BIA technique, it requires custom-made sensor chips and is not well suited for highly multiplexed BIA required in high throughput applications. Moreover implementation of SPR on various biosensing platforms is limited. In this research work spectral domain phase sensitive interferometry (SD-PSI) has been developed for label-free BIA and biosensing applications to address limitations of SPR and other label free techniques. One distinct advantage of SD-PSI compared to other label-free techniques is that it does not require use of custom fabricated biosensor substrates. Laboratory grade, off-the-shelf glass or plastic substrates of suitable thickness with proper surface functionalization are used as biosensor chips. SD-PSI is tested on four separate BIA and biosensing platforms, which include multi-well plate, flow cell, fiber probe with integrated optics and fiber tip biosensor. Sensitivity of 33 ng/ml for anti-IgG is achieved using multi-well platform. Principle of coherence multiplexing for multi

  13. Bioactive membranes for bone regeneration applications: effect of physical and biomolecular signals on mesenchymal stem cell behavior.

    Science.gov (United States)

    Tejeda-Montes, Esther; Smith, Katherine H; Rebollo, Elena; Gómez, Raúl; Alonso, Matilde; Rodriguez-Cabello, J Carlos; Engel, Elisabeth; Mata, Alvaro

    2014-01-01

    This study focuses on the in vitro characterization of bioactive elastin-like recombinamer (ELR) membranes for bone regeneration applications. Four bioactive ELRs exhibiting epitopes designed to promote mesenchymal stem cell adhesion (RGDS), endothelial cell adhesion (REDV), mineralization (HAP), and both cell adhesion and mineralization (HAP-RGDS) were synthesized using standard recombinant protein techniques. The materials were then used to fabricate ELR membranes incorporating a variety of topographical micropatterns including channels, holes and posts. Primary rat mesenchymal stem cells (rMSCs) were cultured on the different membranes and the effects of biomolecular and physical signals on cell adhesion, morphology, proliferation, and differentiation were evaluated. All results were analyzed using a custom-made MATLAB program for high throughput image analysis. Effects on cell morphology were mostly dependent on surface topography, while cell proliferation and cell differentiation were largely dependent on the biomolecular signaling from the ELR membranes. In particular, osteogenic differentiation (evaluated by staining for the osteoblastic marker osterix) was significantly enhanced on cells cultured on HAP membranes. Remarkably, cells growing on membranes containing the HAP sequence in non-osteogenic differentiation media exhibited significant up-regulation of the osteogenic marker as early as day 5, while those growing on fibronectin-coated glass in osteogenic differentiation media did not. These results are part of our ongoing effort to develop an optimized molecularly designed periosteal graft. PMID:24035887

  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. 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.

  17. 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

  18. Photodamage and the importance of photoprotection in biomolecular-powered device applications.

    Science.gov (United States)

    Vandelinder, Virginia; Bachand, George D

    2014-01-01

    In recent years, an enhanced understanding of the mechanisms underlying photobleaching and photoblinking of fluorescent dyes has led to improved photoprotection strategies, such as reducing and oxidizing systems (ROXS) that reduce blinking and oxygen scavenging systems to reduce bleaching. Excitation of fluorescent dyes can also result in damage to catalytic proteins (e.g., biomolecular motors), affecting the performance of integrated devices. Here, we characterized the motility of microtubules driven by kinesin motor proteins using various photoprotection strategies, including a microfluidic deoxygenation device. Impaired motility of microtubules was observed at high excitation intensities in the absence of photoprotection as well as in the presence of an enzymatic oxygen scavenging system. In contrast, using a polydimethylsiloxane (PDMS) microfluidic deoxygenation device and ROXS, not only were the fluorophores slower to bleach but also moving the velocity and fraction of microtubules over time remained unaffected even at high excitation intensities. Further, we demonstrate the importance of photoprotection by examining the effect of photodamage on the behavior of a switchable mutant of kinesin. Overall, these results demonstrate that improved photoprotection strategies may have a profound impact on functional fluorescently labeled biomolecules in integrated devices. PMID:24350711

  19. 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...

  20. 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.

  1. 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

  2. Biomolecular motors

    Directory of Open Access Journals (Sweden)

    Henry Hess

    2005-12-01

    Here, we give a brief introduction to molecular motors, with an emphasis on motor proteins, describe the challenges in interfacing these bionanomachines with an artificial environment, and provide examples of emerging applications.

  3. The Applicability of Incoherent Array Processing to IMS Seismic Arrays

    Science.gov (United States)

    Gibbons, Steven J.

    2014-03-01

    significant sidelobes. The detection part of the algorithm is applicable to all IMS arrays, with spectrogram-based processing offering a potential reduction in the false alarm rate for high-frequency signals. Significantly, the local maxima of the scalar functions derived from the transformed spectrogram beams are robust estimates of the signal onset time. High-frequency energy is of greater importance for lower event magnitudes and in the cavity decoupling detection evasion scenario. There is a need to characterize both propagation paths with low attenuation of high-frequency energy and situations in which parameter estimation on array stations fails.

  4. Overcoming the Solubility Limit with Solubility-Enhancement Tags: Successful Applications in Biomolecular NMR Studies

    OpenAIRE

    Zhou, Pei; Wagner, Gerhard

    2010-01-01

    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 techniq...

  5. 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...

  6. 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.

  7. 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.

  8. 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.

  9. 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...

  10. 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.

  11. Mission applications for advanced photovoltaic solar arrays

    International Nuclear Information System (INIS)

    The compatibility of the advanced photovoltaic solar array (APSA) for future space missions was examined by considering the impact on the spacecraft system in general. The lightweight flexible blanket array system (> 130 w/kG) was compared to rigid arrays and an RTG (radio-isotope thermoelectric generator) static power source for a wide range of assumed future Earth orbiting and interplanetary mission applications. The study approach was to establish assessment criteria and a rating scheme, identify a reference mission set, perform the power system assessment for each mission, and develop conclusions and recommendations to guide future APSA technology development. This paper discusses the three selected power sources, the assessment criteria and rating definitions, the reference missions, and presents the assessment results in a tabular format

  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; Rasmussen, Peter; Lechuga, L.; Boisen, Anja

    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...

  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. Mode-Locked Laser Arrays for WDM Applications

    Science.gov (United States)

    Forouhar, S.

    1997-01-01

    Colliding pulse mode-locked laser arrays are being developed at 20 GHz for WDM applications. Arrays with 5 wavelengths in the EDFA gain bandwidth have already been demonstrated, with the final goal being a packaged, 10 wavelength mode-locked laser array.

  17. 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.

  18. 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....

  19. Mixture of experts models to exploit global sequence similarity on biomolecular sequence labeling

    OpenAIRE

    2009-01-01

    Background Identification of functionally important sites in biomolecular sequences has broad applications ranging from rational drug design to the analysis of metabolic and signal transduction networks. Experimental determination of such sites lags far behind the number of known biomolecular sequences. Hence, there is a need to develop reliable computational methods for identifying functionally important sites from biomolecular sequences. Results We present a mixture of experts approach to b...

  20. 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

  1. 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.

  2. 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

  3. Optimized shapes of magnetic arrays for drug targeting applications

    OpenAIRE

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

    2016-01-01

    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 ...

  4. 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)...

  5. 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.

  6. 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)

  7. A mechanical Turing machine: blueprint for a biomolecular computer.

    Science.gov (United States)

    Shapiro, Ehud

    2012-08-01

    We describe a working mechanical device that embodies the theoretical computing machine of Alan Turing, and as such is a universal programmable computer. The device operates on three-dimensional building blocks by applying mechanical analogues of polymer elongation, cleavage and ligation, movement along a polymer, and control by molecular recognition unleashing allosteric conformational changes. Logically, the device is not more complicated than biomolecular machines of the living cell, and all its operations are part of the standard repertoire of these machines; hence, a biomolecular embodiment of the device is not infeasible. If implemented, such a biomolecular device may operate in vivo, interacting with its biochemical environment in a program-controlled manner. In particular, it may 'compute' synthetic biopolymers and release them into its environment in response to input from the environment, a capability that may have broad pharmaceutical and biological applications. PMID:22649583

  8. An analytic performance model of disk arrays and its application

    Science.gov (United States)

    Lee, Edward K.; Katz, Randy H.

    1991-01-01

    As disk arrays become widely used, tools for understanding and analyzing their performance become increasingly important. In particular, performance models can be invaluable in both configuring and designing disk arrays. Accurate analytic performance models are desirable over other types of models because they can be quickly evaluated, are applicable under a wide range of system and workload parameters, and can be manipulated by a range of mathematical techniques. Unfortunately, analytical performance models of disk arrays are difficult to formulate due to the presence of queuing and fork-join synchronization; a disk array request is broken up into independent disk requests which must all complete to satisfy the original request. We develop, validate, and apply an analytic performance model for disk arrays. We derive simple equations for approximating their utilization, response time, and throughput. We then validate the analytic model via simulation and investigate the accuracy of each approximation used in deriving the analytical model. Finally, we apply the analytical model to derive an equation for the optimal unit of data striping in disk arrays.

  9. 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...

  10. 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.

  11. 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

  12. Large-Array Signal Processing for Deep-Space Applications

    Science.gov (United States)

    Lee, C. H.; Vilnrotter, V.; Satorius, E.; Ye, Z.; Fort, D.; Cheung, K.-M.

    2002-04-01

    This article develops the mathematical models needed to describe the key issues in using an array of antennas for receiving spacecraft signals for DSN applications. The detrimental effects of nearby interfering sources, such as other spacecraft transmissions or natural radio sources within the array's field of view, on signal-to noise ratio (SNR) are determined, atmospheric effects relevant to the arraying problem developed, and two classes of algorithms (multiple signal classification (MUSIC) plus beam forming, and an eigen-based solution) capable of phasing up the array with maximized SNR in the presence of realistic disturbances are evaluated. It is shown that, when convolutionally encoded binary-phase shift keying (BPSK) data modulation is employed on the spacecraft signal, previously developed data pre-processing techniques that partially reconstruct the carrier can be of great benefit to array performance, particularly when strong interfering sources are present. Since this article is concerned mainly with demonstrating the required capabilities for operation under realistic conditions, no attempt has been made to reduce algorithm complexity; the design and evaluation of less complex algorithms with similar capabilities will be addressed in a future article. The performances of the candidate algorithms discussed in this article have been evaluated in terms of the number of symbols needed to achieve a given level of combining loss for different numbers of array elements, and compared on this common basis. It is shown that even the best algorithm requires approximately 25,000 symbols to achieve a combining loss of less than 0.5 dB when 128 antenna elements are employed, but generally 50,000 or more symbols are needed. This is not a serious impediment to successful arraying with high data-rate transmission, but may be of some concern with missions exploring near the edge of our solar system or beyond, where lower data rates may be required.

  13. 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.

  14. Storing and analysing biomolecular contacts

    OpenAIRE

    Walter, Peter

    2011-01-01

    Biomolecular contacts play a crucial role in all areas of life. In particular, protein-protein (PP) interactions are essential for most processes in biological cells. Antigen-antibody recognition, enzyme substrate binding, hormone receptor binding, RNA splicing, DNA replication and signal transduction are just some examples for the rich variety of PP interactions. In the last years modern proteomic methods have helped to get a better understanding of the complexity within living cell and orga...

  15. Models for solvated biomolecular structures

    OpenAIRE

    Cerutti, David

    2007-01-01

    Methods for estimating the structure and energetics of water around biomolecules are presented with the objective of improving the treatment of the biomolecular simulation environment as well as facilitating the use of complex, rigorous water models in the context of structure prediction problems that demand cheap solutions. Salt solutions around biomolecules are studied using an implicit solvent model with explicitly represented ions, revealing that the structure of the ion atmosphere is muc...

  16. 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

  17. 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.

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

    International Nuclear Information System (INIS)

    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 Nd2Fe14B 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

  19. 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

  20. 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

  1. 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.

  2. 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.

  3. 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.

  4. Micro- and nanodevices integrated with biomolecular probes.

    Science.gov (United States)

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

    2015-12-01

    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

  5. 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

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

    Science.gov (United States)

    Trevizoli, Paulo V.; Lozano, Jaime A.; Peixer, Guilherme F.; Barbosa, Jader R., Jr.

    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 Nd2Fe14B 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.

  7. 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...

  8. 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

  9. 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

  10. Biomolecular structure refinement using the GROMOS simulation software

    Energy Technology Data Exchange (ETDEWEB)

    Schmid, Nathan; Allison, Jane R.; Dolenc, Jozica; Eichenberger, Andreas P.; Kunz, Anna-Pitschna E.; Gunsteren, Wilfred F. van, E-mail: wfvgn@igc.phys.chem.ethz.ch [Swiss Federal Institute of Technology ETH, Laboratory of Physical Chemistry (Switzerland)

    2011-11-15

    For the understanding of cellular processes the molecular structure of biomolecules has to be accurately determined. Initial models can be significantly improved by structure refinement techniques. Here, we present the refinement methods and analysis techniques implemented in the GROMOS software for biomolecular simulation. The methodology and some implementation details of the computation of NMR NOE data, {sup 3}J-couplings and residual dipolar couplings, X-ray scattering intensities from crystals and solutions and neutron scattering intensities used in GROMOS is described and refinement strategies and concepts are discussed using example applications. The GROMOS software allows structure refinement combining different types of experimental data with different types of restraining functions, while using a variety of methods to enhance conformational searching and sampling and the thermodynamically calibrated GROMOS force field for biomolecular simulation.

  11. Microoptical array projectors for free-form screen applications.

    Science.gov (United States)

    Sieler, M; Fischer, S; Schreiber, P; Dannberg, P; Bräuer, A

    2013-11-18

    The system design of front-projection systems for free-form screens utilizing conventional single-aperture optical layouts always requires a trade-off between system complexity and achievable luminous output. This article presents novel slide pre-processing algorithms based on array projection technology that are able to resolve the design drawbacks for both free-form as well as strongly-inclined planar screen applications by breaking the common contradiction between system simplicity and flux. Starting from describing common design strategies and their drawbacks, the theoretical basics of the novel concept are investigated and applied to raytracing simulations. Experimental results are shown and evaluated regarding their optical performance. PMID:24514382

  12. 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.

  13. 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...

  14. Crystalline colloidal array hydrogel materials: From synthesis to applications

    Science.gov (United States)

    Liu, Lei

    This dissertation is focused on the synthesis, characterization, and applications of crystalline colloidal array (CCA) hydrogel materials. CCA are three dimensional periodic structures formed by the electrostatic self-assembly of monodisperse macroionic colloidal spheres in an aqueous medium. CCA dispersions efficiently Bragg diffract light in the near UV to near IR spectral region, and are useful in areas of optical device fabrication, chemical sensing devices, and novel separation materials. We developed methodologies to synthesize monodisperse colloidal silica spheres via hydrolysis and condensation of tetraethoxysilane in nonionic reverse microemulsion systems. We examined the effects of reaction parameters and surfactant hydrophilic-lipophilic-balance (HLB) number on the final particle size and size distribution. We developed a unique multi-step growth technique by which the final particle diameter can be continuously selected with extremely narrow size distributions over a broad size range. We also developed methodologies to surface functionalize silica spheres to increase the particle surface charge density by two orders of magnitude. The resulting dispersions readily self-assemble into CCA and Bragg diffract light over a broad concentration range. In addition, we discovered an anomalously intense secondary diffraction phenomenon from CCA which occurs due to the superimposed Bragg diffraction from numerous lattice planes. This was quantitatively modeled by using dynamical diffraction and light scattering theory. We extended the microemulsion synthesis methodologies to fabricate monodisperse SiOsb2/CdS composite spheres with well-controlled and complex morphologies. By controlling the co-precipitation process, CdS could be incorporated into silica spheres as quantum dots, as large inclusions, as surface patches and welds, or as shells or cores. Further processing of these materials by selectively etching out CdS templates also generated a series of porous

  15. [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

  16. 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

  17. 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.

  18. 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

  19. 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.

  20. 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 ...

  1. 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

  2. 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

  3. 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.

  4. 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.

  5. ANTENNA ARRAY WITH ELECTRONIC BEAM STEERING FOR TELECOMMUNICATION APPLICATIONS

    OpenAIRE

    Ali Akbarian, Hadi; Volskiy, Vladimir; Vandenbosch, Guy

    2010-01-01

    Electronically controlled beam steering array antennas highly increase the performance of telecommunication links by improving the link budget. Moreover, digital (baseband) beam steering includes the possibility of having multiple beams simultaneously and of communicating with more than one user at the same time. The basics of digital beam forming are explained in this paper. A 1x2 prototype array with digital beam steering is introduced and measurement results are shown.

  6. Self-assembled arrays of peptide nanotubes by vapour deposition.

    Science.gov (United States)

    Adler-Abramovich, Lihi; Aronov, Daniel; Beker, Peter; Yevnin, Maya; Stempler, Shiri; Buzhansky, Ludmila; Rosenman, Gil; Gazit, Ehud

    2009-12-01

    The use of bionanostructures in real-world applications will require precise control over biomolecular self-assembly and the ability to scale up production of these materials. A significant challenge is to control the formation of large, homogeneous arrays of bionanostructures on macroscopic surfaces. Previously, bionanostructure formation has been based on the spontaneous growth of heterogenic populations in bulk solution. Here, we demonstrate the self-assembly of large arrays of aromatic peptide nanotubes using vapour deposition methods. This approach allows the length and density of the nanotubes to be fine-tuned by carefully controlling the supply of the building blocks from the gas phase. Furthermore, we show that the nanotube arrays can be used to develop high-surface-area electrodes for energy storage applications, highly hydrophobic self-cleaning surfaces and microfluidic chips. PMID:19893524

  7. Application of Seismic Array Processing to Earthquake Early Warning

    Science.gov (United States)

    Meng, L.; Allen, R. M.; Ampuero, J. P.

    2013-12-01

    Earthquake early warning (EEW) systems that can issue warnings prior to the arrival of strong ground shaking during an earthquake are essential in mitigating seismic hazard. Many of the currently operating EEW systems work on the basis of empirical magnitude-amplitude/frequency scaling relations for a point source. This approach is of limited effectiveness for large events, such as the 2011 Tohoku-Oki earthquake, for which ignoring finite source effects may result in underestimation of the magnitude. Here, we explore the concept of characterizing rupture dimensions in real time for EEW using clusters of dense low-cost accelerometers located near active faults. Back tracing the waveforms recorded by such arrays allows the estimation of the earthquake rupture size, duration and directivity in real-time, which enables the EEW of M > 7 earthquakes. The concept is demonstrated with the 2004 Parkfield earthquake, one of the few big events (M>6) that have been recorded by a local small-scale seismic array (UPSAR array, Fletcher et al, 2006). We first test the approach against synthetic rupture scenarios constructed by superposition of empirical Green's functions. We find it important to correct for the bias in back azimuth induced by dipping structures beneath the array. We implemented the proposed methodology to the mainshock in a simulated real-time environment. After calibrating the dipping-layer effect with data from smaller events, we obtained an estimated rupture length of 9 km, consistent with the distance between the two main high frequency subevents identified by back-projection using all local stations (Allman and Shearer, 2007). We proposed to deploy small-scale arrays every 30 km along the San Andreas Fault. The array processing is performed in local processing centers at each array. The output is compared with finite fault solutions based on real-time GPS system and then incorporated into the standard ElarmS system. The optimal aperture and array geometry is

  8. 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

  9. Flourescence from Gas-Phase Biomolecular Ions

    DEFF Research Database (Denmark)

    Nielsen, Steen Brøndsted

    2013-01-01

    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 difficul...

  10. 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)

  11. 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

  12. An Efficient Beam Steerable Antenna Array Concept for Airborne Applications

    Directory of Open Access Journals (Sweden)

    H. Aliakbarian

    2014-04-01

    Full Text Available Deployment of a satellite borne, steerable antenna array with higher directivity and gain in Low Earth Orbit makes sense to reduce ground station complexity and cost, while still maintaining a reasonable link budget. The implementation comprises a digitally beam steerable phased array antenna integrated with a complete system, comprising the antenna, hosting platform, ground station, and aircraft based satellite emulator to facilitate convenient aircraft based testing of the antenna array and ground-space communication link. This paper describes the design, development and initial successful interim testing of the various subsystems. A two element prototype used in this increases the signal-to-noise ratio (SNR by 3 dB which is corresponding to more than 10 times better bit error rate (BER.

  13. Decoupling of Multifrequency Dipole Antenna Arrays for Microwave Imaging Applications

    Directory of Open Access Journals (Sweden)

    R. Gonzalo

    2010-01-01

    Full Text Available The mutual coupling between elements of a multifrequency dipole antenna array is experimentally investigated by S-parameter measurements and planar near-field scanning of the radiated field. A multifrequency array with six dipoles is analyzed. In order to reduce the coupling between dipoles, a planar metasurface is placed atop the array acting as superstrate. The mutual coupling of the antenna elements in the absence and presence of the superstrate is presented comparatively. Between 3 and 20 dB mutual coupling reduction is achieved when the superstrate is used. By scanning the field radiated by the antennas and far-field measurements of the radiation pattern, it is observed that the superstrate confines the radiated power, increases the boresight radiation, and reduces the endfire radiation.

  14. 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 ...

  15. 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…

  16. 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.

  17. 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

  18. CdZnTe array detectors for synchrotron radiation applications

    International Nuclear Information System (INIS)

    An X-ray linear-array detector was fabricated using high-pressure Bridgman-grown CdZnTe. The detector area was 175 x 800 μm and the pitch size was 250 μm. The measured dark current for the test 16-element detector was as low as 0.1 pA at 800 V cm-1 with excellent uniformity. Energy spectra were measured using a 57Co radiation source. Both a small-pixel effect and charge sharing were observed. For the arrays, an average 5.8% full width a half-maximum (FWHM) at the 122 keV photopeak was obtained with a standard deviation of 0.2%. A large-area detector (1 x 1 cm) of the same material before fabrication exhibited a low-energy tail at the photopeak, which limits the photopeak FWHM to 8%, typically due to hole trapping. At energies below 60 keV, charge sharing between elements was observed. The charge sharing was greatly reduced by providing a path to ground for unwanted charges. A prototype readout electronic system for an eight-channel array detector was developed. A readout system intended for a multielement solid-state detector system was also used. The array detector will be used for high-energy diffraction and Compton scattering measurements at the Advanced Photon Source. (au)

  19. 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

  20. 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.

  1. Advanced array techniques for unattended ground sensor applications

    Energy Technology Data Exchange (ETDEWEB)

    Followill, F.E.; Wolford, J.K.; Candy, J.V.

    1997-05-06

    Sensor arrays offer opportunities to beam form, and time-frequency analyses offer additional insights to the wavefield data. Data collected while monitoring three different sources with unattended ground sensors in a 16-element, small-aperture (approximately 5 meters) geophone array are used as examples of model-based seismic signal processing on actual geophone array data. The three sources monitored were: (Source 01). A frequency-modulated chirp of an electromechanical shaker mounted on the floor of an underground bunker. Three 60-second time-windows corresponding to (a) 50 Hz to 55 Hz sweep, (b) 60 Hz to 70 Hz sweep, and (c) 80 Hz to 90 Hz sweep. (Source 02). A single transient impact of a hammer striking the floor of the bunker. Twenty seconds of data (with the transient event approximately mid-point in the time window.(Source 11)). The transient event of a diesel generator turning on, including a few seconds before the turn-on time and a few seconds after the generator reaches steady-state conditions. The high-frequency seismic array was positioned at the surface of the ground at a distance of 150 meters (North) of the underground bunker. Four Y-shaped subarrays (each with 2-meter apertures) in a Y-shaped pattern (with a 6-meter aperture) using a total of 16 3-component, high-frequency geophones were deployed. These 48 channels of seismic data were recorded at 6000 and 12000 samples per second on 16-bit data loggers. Representative examples of the data and analyses illustrate the results of this experiment.

  2. 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

  3. 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...

  4. 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.

  5. A passive array antenna system for microwave imaging applications

    International Nuclear Information System (INIS)

    In this paper a 3-GHz imaging system based on a modulated scattering technique (MST) is described. By using a probe made of an array of (passive) dipoles rotating around a test area, it is possible to efficiently measure field-scattered data under approximately transverse-magnetic illumination conditions. In the paper, the functional description of system is provided together with some preliminary validation tests

  6. Application of Seismic Array Processing to Earthquake Early Warning

    OpenAIRE

    L. Meng; Allen, R. M.; Ampuero, J.-P.

    2014-01-01

    Earthquake early warning (EEW) systems that issue warnings prior to the arrival of strong shaking are essential in mitigating earthquake hazard. Currently operating EEW systems work on point‐source assumptions and are of limited effectiveness for large events, for which ignoring finite‐source effects result in magnitude underestimation. Here, we explore the concept of characterizing rupture dimensions in real time for EEW using small‐aperture seismic arrays located near active faults. Back tr...

  7. 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...

  8. Biomolecular localization: Applications in tissue engineering

    Science.gov (United States)

    Znidarsic, William John

    A carrier material designed for in vivo implantation of cells can be chemically modified to present ligands that interact with cell surface receptors and guide new tissue formation. This study presents a versatile technique for modification of alginate matrices that relies upon molecular coating of nanoparticle surfaces, using a layer-by-layer deposition technique, followed by dispersion of these particles with the alginate gel matrix. The deposition technique results in nanoparticle coatings that present a variety of biological information including organic molecules (e.g. amines, polyacrylic acid (PAA), phosphoproteins, collagen, albumin, and growth factors) and inorganic calcium phosphate (e.g. hydroxyapatite). Results show that incorporation of coated nanoparticles can stimulate cell proliferation when compared with incorporation of un-coated particles and/or free molecules. Because cells incorporated within the volume of the alginate matrix present cell surface receptors that are spatially distributed on the nano-scale, the observed stimulation in proliferation may be a result of changes in local concentration of molecules that are coated on the nanoparticles rather than added in "free form". In the repair of maxillofacial defects, alginate gels are used clinically for the delivery and localization of stem cells. Similar techniques for three-dimensional localization of biomolecules within these constructs may possibly prove beneficial in stimulating positive biological outcomes in vivo.

  9. 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.

  10. 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.

  11. 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.

  12. Membrane-based biomolecular smart materials

    International Nuclear Information System (INIS)

    Membrane-based biomolecular materials are a new class of smart material that feature networks of artificial lipid bilayers contained within durable synthetic substrates. Bilayers contained within this modular material platform provide an environment that can be tailored to host an enormous diversity of functional biomolecules, where the functionality of the global material system depends on the type(s) and organization(s) of the biomolecules that are chosen. In this paper, we review a series of biomolecular material platforms developed recently within the Leo Group at Virginia Tech and we discuss several novel coupling mechanisms provided by these hybrid material systems. The platforms developed demonstrate that the functions of biomolecules and the properties of synthetic materials can be combined to operate in concert, and the examples provided demonstrate how the formation and properties of a lipid bilayer can respond to a variety of stimuli including mechanical forces and electric fields

  13. 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.

  14. Micromachining microcarrier-based biomolecular encoding for miniaturized and multiplexed immunoassay.

    Science.gov (United States)

    Zhi, Zheng-liang; Morita, Yasutaka; Hasan, Quamrul; Tamiya, Eiichi

    2003-08-15

    Micromachining techniques, which originated in the microelectronics industry, have been employed to manufacture microparticles bearing an engraved dot-type signature for biomolecular encoding. These metallic microstructures are photolithographically defined and manufactured in a highly reproducible manner. In addition, the code introduced on the particle face is a straightforward visible feature that is easily recognizable with the use of optical microscopy. The number of distinct codes theoretically could be many thousands, depending on the coding element numbers. Such microparticles are, thus, with appropriate surface organic functionalizations, ideal for encoding biomolecular libraries and serving as a platform for developing high-throughput multiplexed bioassay schemes based on suspension array technology. As proof of this statement, we demonstrated that encoded microparticles tagged with antibodies to human immunoglobulin classes are capable, using imaging detection as the interrogating approach, of high sensitivity and high specificity, as well as multiplexed detection of the respective antigens in a microliter-sample volume. PMID:14651038

  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. 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.

  17. 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.

  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. Solution processed semiconductor alloy nanowire arrays for optoelectronic applications

    Science.gov (United States)

    Shimpi, Paresh R.

    In this dissertation, we use ZnO nanowire as a model system to investigate the potential of solution routes for bandgap engineering in semiconductor nanowires. Excitingly, successful Mg-alloying into ZnO nanowire arrays has been achieved using a two-step sequential hydrothermal method at low temperature (post-annealing process. Evidently, both room temperature and 40 K photoluminescence (PL) spectroscopy revealed enhanced and blue-shifted near-band-edge ultraviolet (NBE UV) emission in the Mg-alloyed ZnO (ZnMgO) nanowire arrays, compared with ZnO nanowires. The specific template of densely packed ZnO nanowires is found to be instrumental in achieving the Mg alloying in low temperature solution process. By optimizing the density of ZnO nanowires and precursor concentration, 8-10 at.% of Mg content has been achieved in ZnMgO nanowires. Post-annealing treatment is conducted in oxygen-rich and oxygen-deficient environment at different temperatures and time durations on silicon and quartz substrates in order to study the structural and optical property evolution in ZnMgO nanowire arrays. Vacuum annealed ZnMgO nanowires on both substrates retained their hexagonal structures and PL results showed the enhanced but red-shifted NBE UV emission compared to ZnO nanowires with visible emission nearly suppressed, suggesting the reduced defects concentration and improvement in crystallinity of the nanowires. On the contrast, for ambient annealed ZnMgO nanowires on silicon substrate, as the annealing temperature increased from 400°C to 900°C, intensity of visible emission peak across blue-green-yellow-red band (˜400-660 nm) increased whereas intensity of NBE UV peak decreased and completely got quenched. This might be due to interface diffusion of oxidized Si (SiOx) and formation of (Zn,Mg)1.7SiO4 epitaxially overcoated around individual ZnMgO nanowire. On the other hand, ambient annealed ZnMgO nanowires grown on quartz showed a ˜6-10 nm blue-shift in NBE UV emission

  20. 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.

  1. 5x1 Linear Antenna Array for 60 GHz Beam Steering Applications

    OpenAIRE

    Kyrö, Mikko; Titz, Diane; Kolmonen, Veli-Matti; Ranvier, Sylvain; Pons, Patrick; Luxey, Cyril; Vainikainen, Pertti

    2011-01-01

    This paper presents a design process and simulation results of a 5 x 1 linear antenna array with phase shifters for 60 GHz beam steering applications. The antenna array has been designed using a membrane process in order to achieve high radiation efficiency and good radiation characteristics. The same process can be used to manufacture Micro-Electro-Mechanical Systems (MEMS) switches and phase shifters. The maximum gain of the developed antenna array is 9.0 dBi and the radiation efficiency is...

  2. Modelling and Simulation of Solar Photovoltaic array for Battery charging Application using Matlab-Simulink.

    OpenAIRE

    P. Sathya; G.Aarthi*1

    2013-01-01

    This paper presents a model of solar photovoltaic array for charging a battery in Matlab/simulink. This model is used to extract the parameters of a solar module under continuous irradiation. An array of PV modules created and tested for continuous solar insolation. The output from this array system is provided as input to the Boost converter to produce a regulated output of 24V. Regulated output from the converter is used for charging a battery which can be used for powering any application....

  3. New template based nanoelectrode arrays for organic/inorganic photovoltaic applications

    Energy Technology Data Exchange (ETDEWEB)

    Gu, Diefeng; Baumgart, Helmut; Namkoong, Gon [Department of Electrical Engineering, Old Dominion University, Norfolk, Virginia 23529 (United States); Applied Research Center, Newport News, Virginia 23606 (United States)

    2011-03-15

    In this Letter, we report on a new nanofabrication technology to yield highly arrayed nanoelectrodes for organic-inorganic solar cells that promise new levels of performance and efficiency. This technology efficiently controls the effective area of highly arrayed nanoelectrodes and allows for the maximum incorporation of organic materials within the voids. Particularly the 3D parameters such as thickness, spacing, and height of the nanostructures are controlled non-lithographically by atomic layer deposition technology. New template based device structure with nanoelectrode arrays for organic/inorganic photovoltaic applications. (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  4. Silicon nanopillar arrays with SiO2 overlayer for biosensing application

    OpenAIRE

    Choudhury, B. Dev; Casquel del Campo, Rafael; Bañuls, María José; Sanza Gutierrez, Francisco Javier; Laguna Heras, Maria Fe; Holgado Bolaños, Miguel; Puchades, Rosa; Maquieira, Ángel; Angulo Barrios, Carlos; Anand, S.

    2014-01-01

    We present the fabrication of silicon dioxide (SiO2) coated silicon nanopillar array structures and demonstrate their application as sensitive optical biosensors. Colloidal lithography, plasma dry etching and deposition processes are used to fabricate SiO2 coated Si nanopillar arrays with two different diameters and periods. Proof of concept bio recognition experiments are carried out with the bovine serum albumin (BSA)/antiBSA model system using Fourier transform visible and IR spectrometry ...

  5. ZnO nanowire array-templated LbL self-assembled polyelectrolyte nanotube arrays and application for charged drug delivery

    International Nuclear Information System (INIS)

    Vertically oriented and robust polyelectrolyte nanotube arrays with high density, large area and high uniformity were successfully grown on substrates by a ZnO nanowire array-templated layer-by-layer (LbL) self-assembly approach for the first time, and were further used to deliver charged drugs, showing that they not only possess pH-responsive loading property, but also significantly enhance the loading capacity and sustained release time. This work could be extended to fabricate polyelectrolyte nanotube arrays with different polyelectrolyte combinations, including weak polyelectrolyte/weak polyelectrolyte, weak polyelectrolyte/strong polyelectrolyte and strong polyelectrolyte/strong polyelectrolyte. With the great versatility to use various substrates and building blocks, the polyelectrolyte nanotube arrays may have great potential for broad applications such as biosensor arrays, bioreactor arrays and optoelectronics. (paper)

  6. Large Ka-Band Slot Array for Digital Beam-Forming Applications

    Science.gov (United States)

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

    2011-01-01

    This work describes the development of a large Ka Band Slot Array for the Glacier and Land Ice Surface Topography Interferometer (GLISTIN), a proposed spaceborne interferometric synthetic aperture radar for topographic mapping of ice sheets and glaciers. GLISTIN will collect ice topography measurement data over a wide swath with sub-seasonal repeat intervals using a Ka-band digitally beamformed antenna. For technology demonstration purpose a receive array of size 1x1 m, consisting of 160x160 radiating elements, was developed. The array is divided into 16 sticks, each stick consisting of 160x10 radiating elements, whose outputs are combined to produce 16 digital beams. A transmit array stick was also developed. The antenna arrays were designed using Elliott's design equations with the use of an infinite-array mutual-coupling model. A Floquet wave model was used to account for external coupling between radiating slots. Because of the use of uniform amplitude and phase distribution, the infinite array model yielded identical values for all radiating elements but for alternating offsets, and identical coupling elements but for alternating positive and negative tilts. Waveguide-fed slot arrays are finding many applications in radar, remote sensing, and communications applications because of their desirable properties such as low mass, low volume, and ease of design, manufacture, and deployability. Although waveguide-fed slot arrays have been designed, built, and tested in the past, this work represents several advances to the state of the art. The use of the infinite array model for the radiating slots yielded a simple design process for radiating and coupling slots. Method of moments solution to the integral equations for alternating offset radiating slots in an infinite array environment was developed and validated using the commercial finite element code HFSS. For the analysis purpose, a method of moments code was developed for an infinite array of subarrays. Overall

  7. Application of phased array techniques to coarse grain components inspection

    International Nuclear Information System (INIS)

    Ultrasonic inspection of cast stainless steel components from primary and auxiliary cooling circuits of 'French Nuclear Power Plant has to face with major difficulties due to the coarse grained structure of these materials. Attenuation losses and structural noise are encountered, which limits the performances of defect detection ability, mostly in terms of degraded signal-to-noise ratio and poor sensitivity. To overcome such problems, theoretical and experimental studies have been achieved at the French Atomic Energy Commission, with support from the French Institute for Radiological Protection and Nuclear Safety. Experimental studies have been performed over stainless steel specimen of known coarse structure (equi-axial grains and/or elongated grains), containing artificial reflectors (cylindrical holes and electro-eroded surface breaking notches). Those mock-ups have been inspected using contact probes of different array designs (linear or matrix splitting), and using pulse echo or dual-element techniques. Such arrays allow to control the ultrasonic beam so as to investigate different inspection angles and focusing depths. Experiments were carried out using oblique longitudinal waves, using delay laws computed by a specific model, taking account of acoustical and geometrical properties of the probes and the inspected component. In addition, specific reconstruction techniques have been investigated to enhance the signal-to-noise ratio as well as spatial resolution. These techniques are based on beam-forming summation and multi-angle inspections. Experimental results show that such techniques allow to reduce the speckle noise and to optimise the beam resolution. Those increased performances allow to detect and to size small planar defects located at the inner wall of a thick specimen, using corner and tip diffraction echoes. (authors)

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

    Science.gov (United States)

    Geissner, Andreas; Seeberger, Peter H

    2016-06-12

    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. PMID:27306309

  9. 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.

  10. 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)

  11. 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.

  12. 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 ...

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

    OpenAIRE

    J. Puskely; Mikulasek, T.; Z. Raida

    2013-01-01

    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 wideb...

  14. Multi-walled carbon nanotube arrays for gas sensing applications

    International Nuclear Information System (INIS)

    Vertically aligned multi-walled carbon nanotube (MWCNT) arrays fabricated by xylene pyrolysis in anodized aluminum oxide (AAO) templates without the use of a catalyst were integrated into a resistive sensor design. Steady state sensitivities as high as 5% and 10% for 100 ppm of NH3 and NO2, respectively, at a flow rate of 750 sccm were observed. A thin layer of amorphous carbon (5-50 nm), formed on both sides of the template during xylene pyrolysis, was part of the sensor design. The thickness of the conducting amorphous carbon layers was found to play a crucial role in determining the sensitivity of the resistive sensor. A study was undertaken to elucidate (i) the dependence of sensitivity on the thickness of amorphous carbon layers, (ii) the effect of UV light on gas desorption characteristics and (iii) the dependence of room temperature sensitivity on different NH3 flow rates. Variations in sensor resistance with exposure to oxidizing and reducing gases are explained on the basis of charge transfer between the analytes and the CNTs which were modeled as p-type semiconductors

  15. 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.

  16. 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.

  17. Perspective: Markov models for long-timescale biomolecular dynamics

    International Nuclear Information System (INIS)

    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

  18. 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.

  19. Biomolecular Assembly of Gold Nanocrystals

    Energy Technology Data Exchange (ETDEWEB)

    Micheel, Christine Marya

    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.

  20. Analyzing biomolecular interactions by variable angle ellipsometry

    Science.gov (United States)

    Wu, Jiun-Yan; Lee, Chih-Kung; Lee, J. H.; Shiue, Shuen-Chen; Lee, Shu-Sheng; Lin, Shiming

    2001-10-01

    In this paper, an innovative ellipsometer is developed and applied to metrology of the biomolecular interaction on a protein biochip. Both the theory, optical and opto-mechanical configurations of this newly developed ellipsometer and methodologies adopted in system design to improve the system performance are presented. It will be shown that by measuring the ellipsometric parameters, the corresponding concentration variation in biochemical reaction can be calculated according to stoichiometry analysis. By applying the variable angle ellipsometry to analysis of a multi-layered sample, the thickness and concentration are resolved. It is believed that the newly developed ellipsometer biosensor is able to undertake an accurate measurement on biomedical interaction.

  1. 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.

  2. 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.

  3. 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...

  4. 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...

  5. 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.

  6. Energy dissipation in biomolecular machines

    Energy Technology Data Exchange (ETDEWEB)

    Lervik, Anders

    2012-07-01

    The operation of a molecular pump, the calcium pump of sarcoplasmic reticulum is studied using mesoscopic non-equilibrium thermodynamics and molecular dynamics. The mesoscopic non-equilibrium thermodynamic description of the pump is compared to the description obtained in the framework of Hill for kinetic enzyme cycles. By comparing these two descriptions at isothermal conditions, they are found to be equivalent. This supports the validity of the mesoscopic approach. An extension of the mesoscopic non-equilibrium framework to also include a heat flux and the corresponding temperature difference is proposed. This can be used to model phenomena such as non-shivering thermogenesis, a process which lack a theoretical description in the kinetic cycle picture. Further, the heat transfer in the calcium pump is studied using molecular dynamics. This is done in order to obtain phenomenological parameters that can be used for the modeling of thermogenesis. A non-stationary non-equilibrium molecular dynamics approach is developed, which may be used to study heat transfer between a small object and the surrounding solvent. This methodology is applied to the calcium pump solvated in water. It is found that the thermal conductivity of the protein is low (0.2 W K-1 m-1) compared to water (0.6 WK-1 m-1). This means that the protein may sustain a large temperature gradient across its structure. The simulations also show that the protein-water surface is important for the heat transfer. The time scale for vibrational energy relaxation is found to be of order 10/100 ps which strengthens the local equilibrium assumption of mesoscopic non-equilibrium thermodynamics. Mesoscopic non-equilibrium thermodynamics is also applied to calculate the thermodynamic efficiency of the calcium pump embedded in lipid bilayers of varying length and from different tissues. This is done in order to show the applicability of mesoscopic non-equilibrium thermodynamics to interpret experimental data. The

  7. 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

  8. 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

  9. 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.

  10. 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

  11. 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...

  12. Multi-Wavelength Mode-Locked Laser Arrays for WDM Applications

    Science.gov (United States)

    Davis, L.; Young, M.; Dougherty, D.; Keo, S.; Muller, R.; Maker, P.

    1998-01-01

    Multi-wavelength arrays of colliding pulse mode-locked (CPM) lasers have been demonstrated for wavelength division multiplexing (WDM) applications. The need for increased bandwidth is driving the development of both increased speed in time division multiplexing (TDM) and more channels in WDM for fiber optic communication systems.

  13. 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.

  14. 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.

  15. 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

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

    International Nuclear Information System (INIS)

    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 × 104 and a low turn-on voltage of 2 V/μm, indicating the advantages of the sharp metal edge of MRA. Due to the

  17. 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

  18. Optimization of the creation of specific circuits on gate arrays MHS 2 microns for space applications

    International Nuclear Information System (INIS)

    Improving behaviour of gate array against total dose can be reached in three ways: improving technology, optimising cell library and developing specialized CAD tools. These two last items are the purpose of collaboration between MATRA MHS and MATRA ESPACE concerning MATRA MHS 2 μm 2 metal gate array family. This work leads to define a tolerant library up to 100 Krads. All total dose and SEU sensitive cells have been withdrawn from standard library and replaced by more efficient logical equivalents. To complete this work, a design rule set for space applications has been released and propapagation delay derating versus total dose was modelised inside logic simulator

  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. 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. PMID:23893064

  1. 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.

  2. 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

  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. 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.

  5. 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.

  6. 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.

  7. 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.

  8. Ensemble based convergence assessment of biomolecular trajectories

    CERN Document Server

    Lyman, E; Lyman, Edward; Zuckerman, Daniel M.

    2006-01-01

    Assessing the convergence of a biomolecular simulation is an essential part of any computational investigation. This is because many important quantities (e.g., free energy differences) depend on the relative populations of different conformers; insufficient convergence translates into systematic errors. Here we present a simple method to self-consistently assess the convergence of a simulation. Standard clustering methods first generate a set of reference structures to any desired precision. The trajectory is then classified by proximity to the reference structures, yielding a one-dimensional histogram of structurally distinct populations. Comparing ensembles of different trajectories (or different parts of the same trajectory) built with the same reference structures provides a sensitive, quantitative measure of convergence. Please note: this is a preliminary manuscript, and should be read as such. Comments are most welcome, especially regarding pertinent prior work.

  9. 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.

  10. The design and application of large area intensive lens array focal spots measurement system

    Science.gov (United States)

    Chen, Bingzhen; Yao, Shun; Yang, Guanghui; Dai, Mingchong; Wang, Zhiyong

    2014-12-01

    Concentrating Photovoltaic (CPV) modules are getting thinner and using smaller cells now days. Correspondingly, large area intensive lens arrays with smaller unit dimension and shorter focal length are wanted. However, the size and power center of lens array focal spots usually differ from the design value and are hard to measure, especially under large area situation. It is because the machining error and deformation of material of the lens array are hard to simulate in the optical design process. Thus the alignment error between solar cells and focal spots in the module assembly process will be hard to control. Under this kind of situation, the efficiency of CPV module with thinner body and smaller cells is much lower than expected. In this paper, a design of large area lens array focal spots automatic measurement system is presented, as well as its prototype application results. In this system, a four-channel parallel light path and its corresponding image capture and process modules are designed. These modules can simulate focal spots under sunlight and have the spots image captured and processed using charge coupled devices and certain gray level algorithm. Thus the important information of focal spots such as spot size and location will be exported. Motion control module based on grating scale signal and interval measurement method are also employed in this system in order to get test results with high speed and high precision on large area lens array no less than 1m×0.8m. The repeatability of the system prototype measurement is +/-10μm with a velocity of 90 spot/min. Compared to the original module assembled using coordinates from optical design, modules assembled using data exported from the prototype is 18% higher in output power, reaching a conversion efficiency of over 31%. This system and its design can be used in the focal spot measurement of planoconvex lens array and Fresnel lens array, as well as other kinds of large area lens array application

  11. Ultra Wide Wavelength Multiplexing/Demultiplexing Conventional Arrayed Waveguide Grating (AWG Devices for Multi Band Applications

    Directory of Open Access Journals (Sweden)

    Abd El–Naser A. Mohamed

    2012-03-01

    Full Text Available This paper has proposed new materials based conventional arrayed waveguide grating (AWG devices such as pure silica glass (SiO2, Lithium niobate (LiNbO3 , and gallium aluminum arsenide (Ga(1-xAl(xAs materials for multiplexing and demultiplexing applications in interval of 1.45 μm to 1.65 μm wavelength band, which including the short, conventional, long, and ultra long wavelength band. Moreover we have taken into account a comparison between these new materials within operating design parameters of conventional AWG devices such as diffraction order, length difference of adjacent waveguides, focal path length, free spectral range or region, maximum number of input/output wavelength channels, and maximum number of arrayed waveguides. As well as we have employed these materials based AWG to include Multi band applications under the effect of ambient temperature variations.

  12. 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.

  13. 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.

  14. 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.

    and other steering angles suppoet the use of such an array for bathymetric applications. The half-power beam widths at different steering angles are found to be comparable with the computed values of the half-power beam widths of a linear array of equivalent...

  15. Extracting Biomolecular Interactions Using Semantic Parsing of Biomedical Text

    OpenAIRE

    Garg, Sahil; Galstyan, Aram; Hermjakob, Ulf; Marcu, Daniel

    2015-01-01

    We advance the state of the art in biomolecular interaction extraction with three contributions: (i) We show that deep, Abstract Meaning Representations (AMR) significantly improve the accuracy of a biomolecular interaction extraction system when compared to a baseline that relies solely on surface- and syntax-based features; (ii) In contrast with previous approaches that infer relations on a sentence-by-sentence basis, we expand our framework to enable consistent predictions over sets of sen...

  16. 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.

  17. 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.

  18. 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

  19. Effects of design on cost of flat-plate solar photovoltaic arrays for terrestrial central station power applications

    Science.gov (United States)

    Tsou, P.; Stolte, W.

    1978-01-01

    The paper examines the impact of module and array designs on the balance-of-plant costs for flat-plate terrestrial central station power applications. Consideration is given to the following types of arrays: horizontal, tandem, augmented, tilt adjusted, and E-W tracking. The life-cycle cost of a 20-year plant life serves as the costing criteria for making design and cost tradeoffs. A tailored code of accounts is developed for determining consistent photovoltaic power plant costs and providing credible photovoltaic system cost baselines for flat-plate module and array designs by costing several varying array design approaches.

  20. Biomolecular surface construction by PDE transform.

    Science.gov (United States)

    Zheng, Qiong; Yang, Siyang; Wei, Guo-Wei

    2012-03-01

    This work proposes a new framework for the surface generation based on the partial differential equation (PDE) transform. The PDE transform has recently been introduced as a general approach for the mode decomposition of images, signals, and data. It relies on the use of arbitrarily high-order PDEs to achieve the time-frequency localization, control the spectral distribution, and regulate the spatial resolution. The present work provides a new variational derivation of high-order PDE transforms. The fast Fourier transform is utilized to accomplish the PDE transform so as to avoid stringent stability constraints in solving high-order PDEs. As a consequence, the time integration of high-order PDEs can be done efficiently with the fast Fourier transform. The present approach is validated with a variety of test examples in two-dimensional and three-dimensional settings. We explore the impact of the PDE transform parameters, such as the PDE order and propagation time, on the quality of resulting surfaces. Additionally, we utilize a set of 10 proteins to compare the computational efficiency of the present surface generation method and a standard approach in Cartesian meshes. Moreover, we analyze the present method by examining some benchmark indicators of biomolecular surface, that is, surface area, surface-enclosed volume, solvation free energy, and surface electrostatic potential. A test set of 13 protein molecules is used in the present investigation. The electrostatic analysis is carried out via the Poisson-Boltzmann equation model. To further demonstrate the utility of the present PDE transform-based surface method, we solve the Poisson-Nernst-Planck equations with a PDE transform surface of a protein. Second-order convergence is observed for the electrostatic potential and concentrations. Finally, to test the capability and efficiency of the present PDE transform-based surface generation method, we apply it to the construction of an excessively large biomolecule, a

  1. 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

  2. Platinum nanowire microelectrode arrays for neurostimulation applications: Fabrication, characterization, and in-vitro retinal cell stimulation

    Science.gov (United States)

    Whalen, John J., III

    Implantable electrical neurostimulating devices are being developed for a number of applications, including artificial vision through retinal stimulation. The epiretinal prosthesis will use a two-dimensional array microelectrodes to address individual cells of the retina. MEMS fabrication processes can produce arrays of microelectrodes with these dimensions, but there are two critical issues that they cannot satisfy. One, the stimulating electrodes are the only part of the implanted electrical device that penetrate through the water impermeable package, and must do so without sacrificing hermeticity. Two, As electrode size decreases, the current density (A cm-2 ) increases, due to increased electrochemical impedance. This reduces the amount of charge that can be safely injected into the tissue. To date, MEMS processing method, cannot produce electrode arrays with good, prolonged hermetic properties. Similarly, MEMS approaches do not account for the increased impedance caused by decreased surface area. For these reasons there is a strong motivation for the development of a water-impermeable, substrate-penetrating electrode array with low electrochemical impedance. This thesis presents a stimulating electrode array fabricated from platinum nanowires using a modified electrochemical template synthesis approach. Nanowires are electrochemically deposited from ammonium hexachloroplatinate solution into lithographically patterned nanoporous anodic alumina templates to produce microarrays of platinum nanowires. The platinum nanowires penetrating through the ceramic aluminum oxide template serve as parallel electrical conduits through the water impermeable, electrically insulating substrate. Electrode impedance can be adjusted by either controlling the nanowire hydrous platinum oxide content or by partially etching the alumina template to expose additional surface area. A stepwise approach to this project was taken. First, the electrochemistry of ammonium

  3. 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)

  4. 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.

  5. 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.

  6. 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.

  7. Pyroelectric ceramics and thin films for applications in uncooled infra-red sensor arrays

    International Nuclear Information System (INIS)

    Pyroelectric infra-red detector arrays provide an attractive solution to the problem of collecting spatial information in the far IR. They are only sensitive to changes in the IR flux and are well suited to sensing movements of people. The applications of low cost arrays with limited (a few hundred) elements for people sensing and radiometry will be illustrated. The performances of uncooled pyroelectric arrays are ultimately driven by the materials used. For this reason, continuous improvements in materials technology and figures-of-merit (FoM) are important. The performance of dense, bulk pyroelectric ceramics has not increased for several years, but nevertheless it is possible to obtain significant improvements in performance through the use of tape-cast, functionally gradient materials (FGMs) in which controlled porosity is used to control the permittivity and heat capacity of the material. A model for the performance of such a material will be presented, and compared with experimentally determined properties of FGMs based on a modified-PZT pyroelectric ceramic. The use of ferroelectric thin films is offering considerable potential for low cost and high performance. It will be shown that the introduction of controlled amounts of porosity can have a significant positive effect on the relevant pyroelectric FoM

  8. 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.

  9. Improved performance of high average power semiconductor arrays for applications in diode pumped solid state lasers

    International Nuclear Information System (INIS)

    The average power performance capability of semiconductor diode laser arrays has improved dramatically over the past several years. These performance improvements, combined with cost reductions pursued by LLNL and others in the fabrication and packaging of diode lasers, have continued to reduce the price per average watt of laser diode radiation. Presently, we are at the point where the manufacturers of commercial high average power solid state laser systems used in material processing applications can now seriously consider the replacement of their flashlamp pumps with laser diode pump sources. Additionally, a low cost technique developed and demonstrated at LLNL for optically conditioning the output radiation of diode laser arrays has enabled a new and scalable average power diode-end-pumping architecture that can be simply implemented in diode pumped solid state laser systems (DPSSL's). This development allows the high average power DPSSL designer to look beyond the Nd ion for the first time. Along with high average power DPSSL's which are appropriate for material processing applications, low and intermediate average power DPSSL's are now realizable at low enough costs to be attractive for use in many medical, electronic, and lithographic applications

  10. 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.

  11. 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

  12. 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.

  13. 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.

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

    Science.gov (United States)

    Penza, M.; Rossi, R.; Alvisi, M.; Serra, E.

    2010-03-01

    providing minimal sub-ppm level detection, e.g., download up to 100 ppb NO2, at the sensor temperature of 150 °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 °C. A comparison of the NO2 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.

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

    International Nuclear Information System (INIS)

    by providing minimal sub-ppm level detection, e.g., download up to 100 ppb NO2, 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 NO2 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.

  16. 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.

  17. 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.

  18. New product development with the innovative biomolecular sublingual immunotherapy formulations for the management of allergic rhinitis

    Directory of Open Access Journals (Sweden)

    Frati F

    2014-09-01

    helper 2, and T helper 3 cells by polymerase chain reaction array on mRNA extracted from Waldeyer's ring tissue (adenoids. Sublingual immunotherapy with a defined content of major allergens in micrograms induced a strong downregulation of genes involved in T helper 2 and T helper 1 activation and function, allowing the definition of the immunologic effect as "bio-homeostatic". This clinical and immunological model must be implemented with respect to other allergens, thus expanding the application of a treatment with a unique disease-modifying capacity. Keywords: allergen immunotherapy, allergy, component resolved diagnosis, major allergens, allergen molecules

  19. High Power Laser Diode Arrays for 2-Micron Solid State Coherent Lidars Applications

    Science.gov (United States)

    Amzajerdian, Farzin; Meadows, Byron; Kavaya, Michael J.; Singh, Upendra; Sudesh, Vikas; Baker, Nathaniel

    2003-01-01

    Laser diode arrays are critical components of any diode-pumped solid state laser systems, constraining their performance and reliability. Laser diode arrays (LDAs) are used as the pump source for energizing the solid state lasing media to generate an intense coherent laser beam with a high spatial and spectral quality. The solid state laser design and the characteristics of its lasing materials define the operating wavelength, pulse duration, and power of the laser diodes. The pump requirements for high pulse energy 2-micron solid state lasers are substantially different from those of more widely used 1-micron lasers and in many aspects more challenging [1]. Furthermore, the reliability and lifetime demanded by many coherent lidar applications, such as global wind profiling from space and long-range clear air turbulence detection from aircraft, are beyond the capability of currently available LDAs. In addition to the need for more reliable LDAs with longer lifetime, further improvement in the operational parameters of high power quasi-cw LDAs, such as electrical efficiency, brightness, and duty cycle, are also necessary for developing cost-effective 2-micron coherent lidar systems for applications that impose stringent size, heat dissipation, and power constraints. Global wind sounding from space is one of such applications, which is the main driver for this work as part of NASA s Laser Risk Reduction Program. This paper discusses the current state of the 792 nm LDA technology and the technology areas being pursued toward improving their performance. The design and development of a unique characterization facility for addressing the specific issues associated with the LDAs for pumping 2-micron coherent lidar transmitters and identifying areas of technological improvement will be described. Finally, the results of measurements to date on various standard laser diode packages, as well as custom-designed packages with potentially longer lifetime, will be reported.

  20. 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

  1. 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

  2. Ex vivo evaluation of a microneedle array device for transdermal application.

    Science.gov (United States)

    Indermun, Sunaina; Choonara, Yahya E; Kumar, Pradeep; du Toit, Lisa C; Modi, Girish; van Vuuren, Sandy; Luttge, Regina; Pillay, Viness

    2015-12-30

    A new approach of transdermal drug delivery is the use of microneedles. This promising technique offers the potential to be broadly used for drug administration as it enables the dramatic increase in permeation of medicaments across the stratum corneum. The potential of microneedles has evolved to spawn a plethora of potential transdermal applications. In order to advance the microneedle capabilities and possibly revolutionize advanced drug delivery, this study introduces a novel transdermal electro-modulated hydrogel-microneedle array (EMH-MNA) device composed of a nano-porous, embeddable ceramic microneedle array as well as an optimized EMH for the electro-responsive delivery of indomethacin through the skin. The ex vivo permeation as well as drug release experiments were performed on porcine skin tissue to ascertain the electro-responsive capabilities of the device. In addition, the microbial permeation ability of the microneedles across the viable epidermis in both microneedle-punctured skin as well as hypodermic needle-punctured skin was determined. Ex vivo evaluation of the EMH-MNA device across porcine skin demonstrated that without electro-stimulation, significantly less drug release was obtained (±0.4540mg) as compared to electro-stimulation (±2.93mg). PMID:26453791

  3. 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)

  4. 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.

  5. Interference mitigation for simultaneous transmit and receive applications on digital phased array systems

    Science.gov (United States)

    Snow, Trevor M.

    As analog-to-digital (ADC) and digital-to-analog conversion (DAC) technologies become cheaper and digital processing capabilities improve, phased array systems with digital transceivers at every element will become more commonplace. These architectures offer greater capability over traditional analog systems and enable advanced applications such as multiple-input, multiple-output (MIMO) communications, adaptive beamforming, space-time adaptive processing (STAP), and MIMO for radar. Capabilities for such systems are still limited by the need for isolating self-interference from transmitters at co-located receivers. The typical approach of time-sharing the antenna aperture between transmitters and receivers works but leaves the receivers blind for a period of time. For full-duplex operation, some systems use separate frequency bands for transmission and reception, but these require fixed filtering which reduces the system's ability to adapt to its environment and is also an inefficient use of spectral resources. To that end, tunable, high quality-factor filters are used for sub-band isolation and protect receivers while allowing open reception at other frequencies. For more flexibility, another emergent area of related research has focused on co-located spatial isolation using multiple antennas and direct injection of interference cancellation signals into receivers, which enables same-frequency full-duplex operation. With all these methods, self-interference must be reduced by an amount that prevents saturation of the ADC. Intermodulation products generated in the receiver in this process can potentially be problematic, as certain intermodulation products may appear to come from a particular angle and cohere in the beamformer. This work explores various digital phased array architectures and the how the flexibility afforded by an all-digital beamforming architecture, layered with other methods of isolation, can be used to reduce self-interference within the system

  6. 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

  7. 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 of...

  8. 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.

  9. 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.

  10. A carbon nanotube field emission multipixel x-ray array source for microradiotherapy application

    OpenAIRE

    Wang, Sigen; Calderon, Xiomara; Peng, Rui; Schreiber, Eric C.; Zhou, Otto; Chang, Sha

    2011-01-01

    The authors report a carbon nanotube (CNT) field emission multipixel x-ray array source for microradiotherapy for cancer research. The developed multipixel x-ray array source has 50 individually controllable pixels and it has several distinct advantages over other irradiation source including high-temporal resolution (millisecond level), the ability to electronically shape the form, and intensity distribution of the radiation fields. The x-ray array was generated by a CNT cathode array (5×10)...

  11. Synthesis and Characterization of Nanoporous Alumina Films and their Application to Nanorod Array Fabrication

    Science.gov (United States)

    Abolhassani Monfared, Negar

    The purpose of this study is to synthesize and characterize the nanoporous structures that can be obtained by the anodization of thin film aluminum sputter deposited on a silicon wafer substrate. This study also investigated the application of nanoporous alumina to fabricate nanorod arrays by using preceramic polymers. Although there are many studies on the effect of anodizing conditions on anodized alumina, there are a few studies on anodizing of thin film aluminum. Anodized thin film of aluminum supported on silicon could have several applications that involve integrating the nanoporous structures into chemical and biological sensors and as templates for creating hierarchically complex nanostructures that are integrated with microelectronic circuits. In this study the different attributes of anodizing parameters in the synthesis of nanoporous structures on thin film aluminum compared to the results of studies on aluminum bulk is investigated. These differences can be due to attributes of the material, the resistance of the substrate and the reactions of substrate during anodizing. In this study the effects of different anodizing parameters and the contribution of each parameter were investigated using statistical approaches for quantification of pore sizes, their distributions and pore densities. This approach has never been previously used for studying the aluminum anodization. Until now, studies have always been based on average of the structure parameters with the hypothesis of homogeneity and uniformity of the structure which is not the case for anodization of thin film aluminum. To investigate the relative effect of each parameter, the Taguchi method and signal-to-noise calculation were applied. A new fabrication method for making nanorod arrays was introduced. In this method, nanoporous alumina was used as a casting mold for being filled by a preceramic polymer. KDT Ceraset polysilazane 20 (PSZ) and KDT Ceraset polyureasilazane (PUSZ) were two preceramic

  12. 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.

  13. 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

  14. 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

  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. 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.

  17. 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

  18. 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.

  19. Photovoltaic solar array technology required for three wide scale generating systems for terrestrial applications: rooftop, solar farm, and satellite

    Science.gov (United States)

    Berman, P. A.

    1972-01-01

    Three major options for wide-scale generation of photovoltaic energy for terrestrial use are considered: (1) rooftop array, (2) solar farm, and (3) satellite station. The rooftop array would use solar cell arrays on the roofs of residential or commercial buildings; the solar farm would consist of large ground-based arrays, probably in arid areas with high insolation; and the satellite station would consist of an orbiting solar array, many square kilometers in area. The technology advancement requirements necessary for each option are discussed, including cost reduction of solar cells and arrays, weight reduction, resistance to environmental factors, reliability, and fabrication capability, including the availability of raw materials. The majority of the technology advancement requirements are applicable to all three options, making possible a flexible basic approach regardless of the options that may eventually be chosen. No conclusions are drawn as to which option is most advantageous, since the feasibility of each option depends on the success achieved in the technology advancement requirements specified.

  20. 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).

  1. Unconventional XAS applications in Physical Science using Pixel Array X-ray Detector

    International Nuclear Information System (INIS)

    Fluorescence x-ray yield is a conventional technique which increases sensitivity of x-ray absorption spectroscopy (XAS). Combining high brilliance x-ray sources and state-of-the-art pixel array detector (PAD) opened up unconventional application channels in condensed matter science. PAD is a segmented detector fabricated onto a mono domain single crystal by lithography. Our Ge PAD consists of 10x10 segments with almost 100% packing ratio. The local structure of photo-induced phase transition of Fe(II) spin-crossover complex under visible light irradiation was studied. We find that the coordination symmetry is retained upon the diamagnetic (S=0)↔paramagnetic (S=2) transformation. In the application to high-temperature superconducting (La,Sr)2CuO4 thin film single crystals, the EXAFS results show that the local structure (CuO6 octahedron) is tetragonally deformed in accordance with the epitaxial strain. High-quality data without the effect of substrates were obtained by real-time monitoring segmented fluorescence signals

  2. ECL gate array with integrated PLL-based clock recovery and synthesis for high-speed data and telecom applications

    Science.gov (United States)

    Rosky, David S.; Coy, Bruce H.; Friedmann, Marc D.

    1992-03-01

    A 2500 gate mixed signal gate array has been developed that integrates custom PLL-based clock recovery and clock synthesis functions with 2500 gates of configurable logic cells to provide a single chip solution for 200 - 1244 MHz fiber based digital interface applications. By customizing the digital logic cells, any of the popular telecom and datacom standards may be implemented.

  3. 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....

  4. Dynamic application of microprojection arrays to skin induces circulating protein extravasation for enhanced biomarker capture and detection.

    Science.gov (United States)

    Coffey, Jacob W; Meliga, Stefano C; Corrie, Simon R; Kendall, Mark A F

    2016-04-01

    Surface modified microprojection arrays are a needle-free alternative to capture circulating biomarkers from the skin in vivo for diagnosis. The concentration and turnover of biomarkers in the interstitial fluid, however, may limit the amount of biomarker that can be accessed by microprojection arrays and ultimately their capture efficiency. Here we report that microprojection array insertion induces protein extravasation from blood vessels and increases the concentration of biomarkers in skin, which can synergistically improve biomarker capture. Regions of blood vessels in skin were identified in the upper dermis and subcutaneous tissue by multi-photon microscopy. Insertion of microprojection array designs with varying projection length (40-190 μm), density (5000-20,408 proj.cm(-2)) and array size (4-36 mm(2)) did not affect the degree of extravasation. Furthermore, the location of extravasated protein did not correlate with projection penetration to these highly vascularised regions, suggesting extravasation was not caused by direct puncture of blood vessels. Biomarker extravasation was also induced by dynamic application of flat control surfaces, and varied with the impact velocity, further supporting this conclusion. The extravasated protein distribution correlated well with regions of high mechanical stress generated during insertion, quantified by finite element models. Using this approach to induce extravasation prior to microprojection array-based biomarker capture, anti-influenza IgG was captured within a 2 min application time, demonstrating that extravasation can lead to rapid biomarker sampling and significantly improved microprojection array capture efficiency. These results have broad implications for the development of transdermal devices that deliver to and sample from the skin. PMID:26826791

  5. 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

  6. 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

  7. 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

  8. Optical absorption enhancement in submicrometre crystalline silicon films with nanotexturing arrays for solar photovoltaic applications

    International Nuclear Information System (INIS)

    Optical absorption enhancement in submicrometre silicon films with three types of nanotexturing arrays, i.e. a column-shaped nanohole (CLNH), and a cone-shaped nanohole (CNNH) and an inverted cone-shaped nanohole (I-CNNH) array, is studied via simulation. The ultimate efficiency, which is a function of the type of array, film thickness, array period and filling fraction, is optimized. We find that in all the CNNH (or I-CNNH) arrays with the same film thickness and the same period, the ones having a filling fraction equal to the critical value of 1 − π/12 correspond to the highest ultimate efficiencies. For a given type of array and film thickness, the ultimate efficiency is optimized over the array period and filling fraction, which is defined as the optimized ultimate efficiency (OUE). In the three types of nanotextured silicon films with the same thickness in the range 250–2000 nm, the CNNH arrays show the highest optimized ultimate efficiency (OUE); however, the CLNH arrays show the highest OUEs when the film thickness is equal to 125 and 62.5 nm, and when the film thickness is in the range 500–2000 nm, the I-CNNH arrays show the lowest OUEs. The OUEs of 250 nm, 500 nm, 1000 nm and 2000 nm thick CNNH array textured silicon films are 19.88%, 28.51%, 34.06% and 39.53%, respectively. For the CNNH array, when the film thickness is reduced from 2000 nm to one-eighth, the OUE is only reduced to half its value. (paper)

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

    Science.gov (United States)

    Caravagna, Giulio; Mauri, Giancarlo; d'Onofrio, Alberto

    2013-01-01

    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. PMID:23437034

  10. Spatially encoded strategies in the execution of biomolecular-oriented 3D NMR experiments

    International Nuclear Information System (INIS)

    Three-dimensional nuclear magnetic resonance (3D NMR) provides one of the foremost analytical tools available for the elucidation of biomolecular structure, function and dynamics. Executing a 3D NMR experiment generally involves scanning a series of time-domain signals S(t3), as a function of two time variables (t1, t2) which need to undergo parametric incrementations throughout independent experiments. Recent years have witnessed extensive efforts towards the acceleration of this kind of experiments. Among the different approaches that have been proposed counts an 'ultrafast' scheme, which distinguishes itself from other propositions by enabling-at least in principle-the acquisition of the complete multidimensional NMR data set within a single transient. 2D protein NMR implementations of this single-scan method have been demonstrated, yet its potential for 3D acquisitions has only been exemplified on model organic compounds. This publication discusses a number of strategies that could make these spatial encoding protocols compatible with 3D biomolecular NMR applications. These include a merging of 2D ultrafast NMR principles with temporal 2D encoding schemes, which can yield 3D HNCO spectra from peptides and proteins within ∼100 s timescales. New processing issues that facilitate the collection of 3D NMR spectra by relying fully on spatial encoding principles are also assessed, and shown capable of delivering HNCO spectra within 1 s timescales. Limitations and prospects of these various schemes are briefly addressed

  11. Group transfer theory of single molecule imaging experiments in the F-ATPase biomolecular motor

    Science.gov (United States)

    Volkan-Kacso, Sandor; Marcus, Rudolph

    I describe a chemo-mechanical theory to treat single molecule imaging and ``stalling'' experiments on the F-ATPase enzyme. This enzyme is an effective stepping biomolecular rotary motor with a rotor shaft and a stator ring. Using group transfer theoretical approach the proposed structure-based theory couples the binding transition of nucleotides in the stator subunits and the physics of torsional elasticity in the rotor. The twisting of the elastic rotor domain acts as a perturbation upon the driving potential, the Gibbs free energy. In the theory, without the use of adjustastable parameters, we predict the rate and equilibrium constant dependence of steps such as ATP binding and phosphate release as a function of manipulated rotor angle. Then we compare these predictions to available data from stalling experiments. Besides treating experiments, the theory can provide guides for atomistic simulations, which could calculate the reorganization parameter and the torsional spring constant. The framework is generic and I discuss its application to other single molecule experiments, such as controlled rotation and other biomolecular motors, including motor-DNA complexes and linear motors.[PNAS, Early Edition, Oct. 19, 2015, doi: 10.1073/pnas.1518489112

  12. 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.

  13. 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.

  14. Evaluation of solar cells and arrays for potential solar power satellite applications

    Science.gov (United States)

    Almgren, D. W.; Csigi, K.; Gaudet, A. D.

    1978-01-01

    Proposed solar array designs and manufacturing methods are evaluated to identify options which show the greatest promise of leading up to the develpment of a cost-effective SPS solar cell array design. The key program elements which have to be accomplished as part of an SPS solar cell array development program are defined. The issues focussed on are: (1) definition of one or more designs of a candidate SPS solar array module, using results from current system studies; (2) development of the necessary manufacturing requirements for the candidate SPS solar cell arrays and an assessment of the market size, timing, and industry infrastructure needed to produce the arrays for the SPS program; (3) evaluation of current DOE, NASA and DOD photovoltaic programs to determine the impacts of recent advances in solar cell materials, array designs and manufacturing technology on the candidate SPS solar cell arrays; and (4) definition of key program elements for the development of the most promising solar cell arrays for the SPS program.

  15. 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.

  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. Quantifying Modularity in the Evolution of Biomolecular Systems

    OpenAIRE

    2004-01-01

    Functional modules are considered the primary building blocks of biomolecular systems. Here we study to what extent functional modules behave cohesively across genomes:That is, are functional modules also evolutionary modules? We probe this question by analyzing for a large collection of functional modules the phyletic patterns of their genes across 110 genomes. The majority of functional modules display limited evolutionary modularity. This result confirms certain comparative genome analyses...

  18. The biomolecular and ultrastructural basis of epidermolysis bullosa:

    OpenAIRE

    Ciolan, Maria; Olariu, Liviu; Solovan, Caius

    2005-01-01

    Transmission electron microscopy, immunoelectron microscopy, immunofluorescence and antigenic mapping have improved our understanding of the dermo-epidermal junction. We have reviewed some ultrastructural and biomolecular aspects related to the dermo-epidermal junction. In part, they are implicated in the pathogenesis of a group of hereditary disorders characterized by skin fragility, collectively known as epidermolysis bullosa (EB). These disorders could benefit in the near future from a gen...

  19. A mechanical Turing machine: blueprint for a biomolecular computer

    OpenAIRE

    Shapiro, Ehud

    2012-01-01

    We describe a working mechanical device that embodies the theoretical computing machine of Alan Turing, and as such is a universal programmable computer. The device operates on three-dimensional building blocks by applying mechanical analogues of polymer elongation, cleavage and ligation, movement along a polymer, and control by molecular recognition unleashing allosteric conformational changes. Logically, the device is not more complicated than biomolecular machines of the living cell, and a...

  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. 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. Design of Field Programmable Gate Array Based Emulators for Motor Control Applications

    Directory of Open Access Journals (Sweden)

    Ahmed Ben Achballah

    2012-01-01

    Full Text Available Problem statement: Field Programmable Gate Array (FPGA circuits play a significant role in major recent embedded process control designs. However, exploiting these platforms requires deep hardware conception skills and remains an important time consuming stage in a design flow. High Level Synthesis technique avoids this bottleneck and increases design productivity as witnessed by industry specialists. Approach: This study proposes to apply this technique for the conception and implementation of a Real Time Direct Current Machine (RTDCM emulator for an embedded control application. Results: Several FPGA-based configuration scenarios are studied. A series of tests including design and timing-precision analysis were conducted to discuss and validate the obtained hardware architectures. Conclusion/Recommendations: The proposed methodology has accelerated the design time besides it has provided an extra time to refine the hardware core of the DCM emulator. The high level synthesis technique can be applied to the control field especially to test with low cost and short delays newest algorithms and motor models.

  3. A Ku band 5 bit MEMS phase shifter for active electronically steerable phased array applications

    International Nuclear Information System (INIS)

    The design, fabrication and measurement of a 5 bit Ku band MEMS phase shifter in different configurations, i.e. a coplanar waveguide and microstrip, are presented in this work. The development architecture is based on the hybrid approach of switched and loaded line topologies. All the switches are monolithically manufactured on a 200 µm high resistivity silicon substrate using 4 inch diameter wafers. The first three bits (180°, 90° and 45°) are realized using switched microstrip lines and series ohmic MEMS switches whereas the fourth and fifth bits (22.5° and 11.25°) consist of microstrip line sections loaded by shunt ohmic MEMS devices. Individual bits are fabricated and evaluated for performance and the monolithic device is a 5 bit Ku band (16–18 GHz) phase shifter with very low average insertion loss of the order of 3.3 dB and a return loss better than 15 dB over the 32 states with a chip area of 44 mm2. A total phase shift of 348.75° with phase accuracy within 3° is achieved over all of the states. The performance of individual bits has been optimized in order to achieve an integrated performance so that they can be implemented into active electronically steerable antennas for phased array applications. (paper)

  4. A Ku band 5 bit MEMS phase shifter for active electronically steerable phased array applications

    Science.gov (United States)

    Sharma, Anesh K.; Gautam, Ashu K.; Farinelli, Paola; Dutta, Asudeb; Singh, S. G.

    2015-03-01

    The design, fabrication and measurement of a 5 bit Ku band MEMS phase shifter in different configurations, i.e. a coplanar waveguide and microstrip, are presented in this work. The development architecture is based on the hybrid approach of switched and loaded line topologies. All the switches are monolithically manufactured on a 200 µm high resistivity silicon substrate using 4 inch diameter wafers. The first three bits (180°, 90° and 45°) are realized using switched microstrip lines and series ohmic MEMS switches whereas the fourth and fifth bits (22.5° and 11.25°) consist of microstrip line sections loaded by shunt ohmic MEMS devices. Individual bits are fabricated and evaluated for performance and the monolithic device is a 5 bit Ku band (16-18 GHz) phase shifter with very low average insertion loss of the order of 3.3 dB and a return loss better than 15 dB over the 32 states with a chip area of 44 mm2. A total phase shift of 348.75° with phase accuracy within 3° is achieved over all of the states. The performance of individual bits has been optimized in order to achieve an integrated performance so that they can be implemented into active electronically steerable antennas for phased array 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. 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.

  7. 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)

  8. 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.

  9. Progress in developing focal-plane-multiplexer readout for large CdZnTe arrays for nuclear medicine applications

    International Nuclear Information System (INIS)

    We report on the construction and initial testing of a 48 x 48 CdZnTe array with 125 μm pixel spacing and multiplexer readout. Large portions of the array function well but there was a loss of pixels near one corner of the array due to non-interconnecting indium bumps. This problem is readily correctable. Excellent single-pixel spectra were obtained with a 99mTc source using an adjustment technique that accounts for energy deposited in neighboring pixels. A point-spread function (PSF) taken at 140 keV yielded a spatial resolution of 230 μm, much better than required for nuclear medicine applications. No problems were found that are not readily correctable or of much less significance for CdZnTe arrays having larger pixel spacing. We are now constructing 64 x 64 CdZnTe arrays with 380 μm pixel spacing for use in an ultra-high resolution brain SPECT imaging system. (orig.)

  10. Angular super-resolution with array antennas: Application to seeker-heads

    Science.gov (United States)

    Nickel, U.

    1986-07-01

    Monopulse seeker-heads can give large errors due to closely spaced targets or even completely wrong directions in the case of cross-eye deception. The effective countermeasure against these errors is resolution enhancement. Super-resolution methods offer the possibility to resolve targets closer than the antenna beamwidth. Such methods are favorable for seeker-head applications, because the target separation as well as the signal-to-noise ratio increases as the missile approaches the target. All effective super-resolution methods require an antenna array with access to the single element outputs. Thus mechanical scanning is replaced by electronic scanning. Depending on the type of missile, sometimes antenna pattern restrictions have to be tolerated. Among all super-resolution methods the parametric target model fitting (PTMF) method seems to be most appropriate for this application. This method tries to fit a completely parameterized target model directly to the measured data. It can be rather easily computed, and it is the only method which can resolve completely correlated targets, which arise in the case of multipath and cross-eye deception. For seeker-heads with few antenna elements an implementation with digital signal processor chips is most suited. Computer simulations and experiments with measured data using the DESAS test equipment show that two targets separated at 0.3 beamwidth can be resolved in azimuth and elevation and that the switch from conventional monopulse to two-target estimation (super-resolution), which is crucial for the approaching missile, can be done by a reliable automatic test procedure.

  11. 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.

  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. Hydrothermal-synthesized mesoporous nickel oxide nanowall arrays with enhanced electrochromic application

    International Nuclear Information System (INIS)

    Highlights: • Mesoporous NiO nanowall arrays are prepared by a hydrothermal method. • Mesoporous structure is favorable for fast ion/electron transfer. • Mesoporous NiO nanowall arrays show fast switching speed and high color contrast. -- Abstract: Mesoporous NiO nanowall arrays are prepared by a facile hydrothermal synthesis method in combination with a following annealing process. The as-prepared NiO nanowalls have average diameters of ∼10 nm and composed of interconnected nanoparticles ranging from 5 to 30 nm. The NiO nanowall arrays show a hierarchical porous structure from mesopores of 5–20 nm to macropores of 30–200 nm. The electrochromic performances of the NiO nanowall arrays are characterized by means of UV–vis spectroscopy and cyclic voltammetry (CV) measurements. The mesoporous NiO nanowall arrays exhibit much better electrochromic performance with faster switching speed and higher color contrast than the dense NiO film. The mesoporous NiO nanowall arrays show a transmittance variation with 77% at 550 nm, and the coloration and bleaching times are 2 s and 2.5 s, respectively. The improved electrochromic performances are due to the porous morphological characteristics, which provide fast ion and electron transfer resulting in fast reaction kinetics and high color contrast

  14. 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...

  15. 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

  16. 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.

  17. 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...

  18. 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...

  19. 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.

  20. 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

  1. Experiment and Modeling of Spatially Indexed Microbead Arrays for High-Throughput Screening Applications

    Science.gov (United States)

    Leary, Thomas; Maldarelli, Charles; Couzis, Alexander

    2011-11-01

    The development of platforms for multiplexed, high throughput screening of the binding interactions of target biomolecules against a library of potential binding probes enables progress in many areas in medicine and biology. Formats in which probes are linked to microbeads arrayed in a microfluidic channel offer high sensitivity, reduced reagent consumption and are easily parallelized for multiplexed detection. This presentation describes a microfluidically assembled microbead array in which beads are streamed through a channel with an array of wells inscribed in the floor of the channel. The beads are captured in the wells via gravity. We demonstrate that an array of beads displaying different receptors can be assembled in this format, indexed by sequential depostion and used for a prototype assay. Solutions for a two dimensional mass transfer model of the conjugation of the probe to the receptor on the bead surface identify kinetically limited regimes which are used to measure the binding kinetics of the prototype assay.

  2. 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...

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

    International Nuclear Information System (INIS)

    Self-assembly of silicon nanowire (SiNW) arrays is studied using SF6/O2 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 200–1100 nm 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. (physics of gases, plasmas, and electric discharges)

  4. Hyper-hemispheric lens distortion model for 3D-imaging SPAD-array-based applications

    Science.gov (United States)

    Pernechele, Claudio; Villa, Federica A.

    2015-09-01

    Panoramic omnidirectional lenses have the typical draw-back effect to obscure the frontal view, producing the classic "donut-shape" image in the focal plane. We realized a panoramic lens in which the frontal field is make available to be imaged in the focal plane together with the panoramic field, producing a FoV of 360° in azimuth and 270° in elevation; it have then the capabilities of a fish eye plus those of a panoramic lens: we call it hyper-hemispheric lens. We built and test an all-spherical hyper-hemispheric lens. The all-spherical configuration suffer for the typical issues of all ultra wide angle lenses: there is a large distortion at high view angles. The fundamental origin of the optical problems resides on the fact that chief rays angles on the object side are not preserved passing through the optics preceding the aperture stop (fore-optics). This effect produce an image distortion on the focal plane, with the focal length changing along the elevation angles. Moreover, the entrance pupil is shifting at large angle, where the paraxial approximation is not more valid, and tracing the rays appropriately require some effort to the optical designer. It has to be noted here as the distortion is not a source-point-aberrations: it is present also in well corrected optical lenses. Image distortion may be partially corrected using aspheric surface. We describe here how we correct it for our original hyper-hemispheric lens by designing an aspheric surface within the optical train and optimized for a Single Photon Avalanche Diode (SPAD) array-based imaging applications.

  5. 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...

  6. Analytical Model of Non-Imaging Planar Concentrator for the Application in Dense-Array Concentrator Photovoltaic System

    OpenAIRE

    Wong, Chee Woon; Chong, Kok Keong; Yew, Tiong Keat

    2014-01-01

    Instead of using numerical simulation method that is relatively slow if accuracy is required, an analytical model has been proposed to analyze the optical characteristic of Non-Imaging Planar Concentrator (NIPC) for the application in dense-array concentrator photovoltaic (DACPV) system. Several trigonometry equations have been solved to determine the maximum solar concentration ratio, uniform illumination area and energy within the uniform area by varying the focal distance. The concentratio...

  7. Recent Advances in Genetic Technique of Microbial Report Cells and Their Applications in Cell Arrays

    OpenAIRE

    Kim, Do Hyun; Kim, Moon Il; Park, Hyun Gyu

    2015-01-01

    Microbial cell arrays have attracted consistent attention for their ability to provide unique global data on target analytes at low cost, their capacity for readily detectable and robust cell growth in diverse environments, their high degree of convenience, and their capacity for multiplexing via incorporation of molecularly tailored reporter cells. To highlight recent progress in the field of microbial cell arrays, this review discusses research on genetic engineering of reporter cells, tech...

  8. 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 ...

  9. 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...

  10. 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.

  11. 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).

  12. 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)

  13. 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.

  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. Near-infrared fluorophores as biomolecular probes

    Science.gov (United States)

    Patonay, Gabor; Beckford, Garfield; Strekowski, Lucjan; Henary, Maged; Merid, Yonathan

    2010-02-01

    Near-Infrared (NIR) fluorescence has been valuable in analytical and bioanalytical chemistry. NIR probes and labels have been used for several applications, including hydrophobicity of protein binding sites, DNA sequencing, immunoassays, CE separations, etc. The NIR region (700-1100 nm) has advantages for the spectroscopist due to the inherently lower background interference from the biological matrix and the high molar absorptivities of NIR chromophores. During the studies we report here several NIR dyes were prepared to determine the role of the hydrophobicity of NIR dyes and their charge in binding to amino acids and proteins, e.g., serum albumins. We synthesized NIR dye homologs containing the same chromophore but substituents of varying hydrophobicity. Hydrophobic moieties were represented by alkyl and aryl groups. These NIR dyes of varying hydrophobicity exhibited varying degrees of H-aggregation in aqueous solution indicating that the degree of H-aggregation could be used as an indicator to predict binding characteristics to serum albumins. In order to understand what factors may be important in the binding process, spectral behavior of these varying hydrophobicity dyes were examined in the presence of amino acids. Typical dye structures that exhibit large binding constants to biomolecules were compared in order to optimize applications utilizing non-covalent interactions.

  16. 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.

  17. 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

  18. ACEMD: Accelerating bio-molecular dynamics in the microsecond time-scale

    CERN Document Server

    Harvey, M J; De Fabritiis, G

    2009-01-01

    The high arithmetic performance and intrinsic parallelism of recent graphical processing units (GPUs) can offer a technological edge for molecular dynamics simulations. ACEMD is a production-class bio-molecular dynamics (MD) simulation program designed specifically for GPUs which is able to achieve supercomputing scale performance of 40 nanoseconds/day for all-atom protein systems with over 23,000 atoms. We illustrate the characteristics of the code, its validation and performance. We also run a microsecond-long trajectory for an all-atom molecular system in explicit TIP3P water on a single workstation computer equipped with just 3 GPUs. This performance on cost effective hardware allows ACEMD to reach microsecond timescales routinely with important implications in terms of scientific applications.

  19. 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.

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

    International Nuclear Information System (INIS)

    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)5]2 and [d(C5G5)]2. We find that this method can accurately reproduce the hydration patterns of A-DNA observed in neutron diffraction experiments on oriented DNA fibers

  1. 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)

  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. 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.

  4. 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.

  5. 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).

  6. 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.

  7. Development and characterization of a TES optical imaging array for astrophysics applications

    Energy Technology Data Exchange (ETDEWEB)

    Burney, J. E-mail: burney@stanford.edu; Bay, T.J.; Brink, P.L.; Cabrera, B.; Castle, J.P.; Romani, R.W.; Tomada, A.; Nam, S.W.; Miller, A.J.; Martinis, J.; Wang, E.; Kenny, T.; Young, B.A

    2004-03-11

    Our research group has successfully developed photon detectors capable of both time-stamping and energy-resolving individual photons at very high rates in a wide band from the near-IR through optical and into the near-UV. We have fabricated 32-pixel arrays of these Transition-Edge Sensor (TES) devices and have mounted them in an adiabatic demagnetization refrigerator equipped with windows for direct imaging. We have characterized single pixel behavior; we have also begun operating multiple pixels simultaneously, starting the scaling process towards use of the full array. We emphasize the development of a metalized mask for our array that blocks photons from hitting the inter-pixel areas and reflects them onto the TESs. We also present calibration data on detector resolution, electronics noise, and optical alignment.

  8. P(VDF-TrFE) ferroelectric nanotube array for high energy density capacitor applications.

    Science.gov (United States)

    Li, Xue; Lim, Yee-Fun; Yao, Kui; Tay, Francis Eng Hock; Seah, Kar Heng

    2013-01-14

    Poly(vinylidene-fluoride-co-trifluoroethylene) (P(VDF-TrFE)) ferroelectric nanotube arrays were fabricated using an anodized alumina membrane (AAM) as a template and silver electrodes were deposited on both the outer and inner sides of the nanotubes by an electroless plating method. The nanotubes have the unique structure of being sealed at one end and linked at the open end, thus preventing electrical shorting between the inner and outer electrodes. Compared with a P(VDF-TrFE) film with a similar overall thickness, the idealized nanotube array has a theoretical capacitance that is 763 times larger due to the greatly enlarged contact area between the electrodes and the polymer dielectric. A capacitance that is 95 times larger has been demonstrated experimentally, thus indicating that such nanotube arrays are promising for realizing high density capacitance and high power dielectric energy storage. PMID:23171985

  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. 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.

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

    International Nuclear Information System (INIS)

    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/cm2 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/cm2. 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/cm2 are achieved

  12. 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

  13. 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.

  14. Conformal GaP layers on Si wire arrays for solar energy applications

    OpenAIRE

    Tamboli, Adele C.; Malhotra, Manav; Kimball, Gregory M.; Turner-Evans, Daniel B.; Atwater, Harry A.

    2010-01-01

    We report conformal, epitaxial growth of GaP layers on arrays of Si microwires. Silicon wires grown using chlorosilane chemical vapor deposition were coated with GaP grown by metal-organic chemical vapor deposition. The crystalline quality of conformal, epitaxial GaP/Si wire arrays was assessed by transmission electron microscopy and x-ray diffraction. Hall measurements and photoluminescence show p- and n-type doping with high electron mobility and bright optical emission. GaP pn homojunction...

  15. 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

  16. Application of the Solubility Parameter Concept to the Design of Chemiresistor Arrays

    Energy Technology Data Exchange (ETDEWEB)

    Eastman, M.P.; Hughes, R.C.; Jenkins, M.W.; Patel, S.V.; Ricco, A.J.; Yelton, G.

    1999-01-11

    Arrays of unheated chemically sensitive resistors (chemiresistors) can serve as extremely small, low-power-consumption sensors with simple read-out electronics. We report here results on carbon-loaded polymer composites, as well as polymeric ionic conductors, as chemiresistor sensors. We use the volubility parameter concept to understand and categorize the chemiresistor responses and, in particular, we compare chemiresistors fabricated from polyisobutylene (PIB) to results from PIB-coated acoustic wave sensors. One goal is to examine the possibility that a small number of diverse chemiresistors can sense all possible solvents-the "Universal Solvent Sensor Array". keywords: chemiresistor, volubility parameter, chemical sensor

  17. 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%.

  18. 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.

  19. 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

  20. 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

  1. Fabrication of large area nanoprism arrays and their application for surface enhanced Raman spectroscopy

    International Nuclear Information System (INIS)

    This work demonstrates the fabrication of metallic nanoprism (triangular nanostructure) arrays using a low-cost and high-throughput process. In the method, the triangular structure is defined by the shadow of a pyramid during angle evaporation of a metal etching mask. The pyramids were created by nanoimprint lithography in polymethylmethacrylate (PMMA) using a mould having an inverse-pyramid-shaped hole array formed by KOH wet etching of silicon. Silver and gold nanoprism arrays with a period of 200 nm and an edge length of 100 nm have been fabricated and used as effective substrates for surface enhanced Raman spectroscopy (SERS) detection of rhodamine 6G (R6G) molecules. Numerical calculations confirmed the great enhancement of electric field near the sharp nanoprism corners, as well as the detrimental effect of the chromium adhesion layer on localized surface plasmon resonance. The current method can also be used to fabricate non-equilateral nanoprism and three-dimensional (3D) nanopyramid arrays, and it can be readily extended to other metals

  2. 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...

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

    International Nuclear Information System (INIS)

    By using a pixelized Nal (Tl) 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 mm x 2 mm x 5 mm. There are in total 484 pixels in a 22 x 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. (authors)

  4. 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.

    . This geometry is tested using the Bartlett method for varying arc and linear arrays of 30 - elements. We also examine `high resolution techniques' such as the Maximum LIkelihood (ML) method and the Maximum Entropy (ME) methods (different orders), for 16-element...

  5. 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.

  6. 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.

  7. 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.

  8. Biomolecular interaction analysis for carbon nanotubes and for biocompatibility prediction.

    Science.gov (United States)

    Chen, Xiaoping; Fang, Jinzhang; Cheng, Yun; Zheng, Jianhui; Zhang, Jingjing; Chen, Tao; Ruan, Benfang Helen

    2016-07-15

    The interactions between carbon nanotubes (CNTs) and biologics have been commonly studied by various microscopy and spectroscopy methods. We tried biomolecular interaction analysis to measure the kinetic interactions between proteins and CNTs. The analysis demonstrated that wheat germ agglutinin (WGA) and other proteins have high affinity toward carboxylated CNT (f-MWCNT) but essentially no binding to normal CNT (p-MWCNT). The binding of f-MWCNT-protein showed dose dependence, and the observed kinetic constants were in the range of 10(-9) to 10(-11) M with very small off-rates (10(-3) to 10(-7) s(-1)), indicating a relatively tight and stable f-MWCNT-protein complex formation. Interestingly in hemolysis assay, p-MWCNT showed good biocompatibility, f-MWCNT caused 30% hemolysis, but WGA-coated f-MWCNT did not show hemolysis. Furthermore, the f-MWCNT-WGA complex demonstrated enhanced cytotoxicity toward cancer cells, perhaps through the glycoproteins expressed on the cells' surface. Taken together, biomolecular interaction analysis is a precise method that might be useful in evaluating the binding affinity of biologics to CNTs and in predicting biological actions. PMID:27108187

  9. 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

  10. PREFACE: Radiation Damage in Biomolecular Systems (RADAM07)

    Science.gov (United States)

    McGuigan, Kevin G.

    2008-03-01

    The annual meeting of the COST P9 Action `Radiation damage in biomolecular systems' took place from 19-22 June 2007 in the Royal College of Surgeons in Ireland, in Dublin. The conference was structured into 5 Working Group sessions: Electrons and biomolecular interactions Ions and biomolecular interactions Radiation in physiological environments Theoretical developments for radiation damage Track structure in cells Each of the five working groups presented two sessions of invited talks. Professor Ron Chesser of Texas Tech University, USA gave a riveting plenary talk on `Mechanisms of Adaptive Radiation Responses in Mammals at Chernobyl' and the implications his work has on the Linear-No Threshold model of radiation damage. In addition, this was the first RADAM meeting to take place after the Alexander Litvenenko affair and we were fortunate to have one of the leading scientists involved in the European response Professor Herwig Paretzke of GSF-Institut für Strahlenschutz, Neuherberg, Germany, available to speak. The remaining contributions were presented in the poster session. A total of 72 scientific contributions (32 oral, 40 poster), presented by 97 participants from 22 different countries, gave an overview on the current progress in the 5 different subfields. A 1-day pre-conference `Early Researcher Tutorial Workshop' on the same topic kicked off on 19 June attended by more than 40 postgrads, postdocs and senior researchers. Twenty papers, based on these reports, are included in this volume of Journal of Physics: Conference Series. All the contributions in this volume were fully refereed, and they represent a sample of the courses, invited talks and contributed talks presented during RADAM07. The interdisciplinary RADAM07 conference brought together researchers from a variety of different fields with a common interest in biomolecular radiation damage. This is reflected by the disparate backgrounds of the authors of the papers presented in these proceedings

  11. 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

  12. Broadband high efficiency silicon nanowire arrays with radial diversity within diamond-like geometrical distribution for photovoltaic applications.

    Science.gov (United States)

    Al-Zoubi, Omar H; Said, Tarek M; Alher, Murtadha Abdulmueen; El-Ghazaly, Samir; Naseem, Hameed

    2015-07-27

    In this study we report novel silicon nanowire (SiNW) array structures that have near-unity absorption spectrum. The design of the new SiNW arrays is based on radial diversity of nanowires with periodic diamond-like array (DLA) structures. Different array structures are studied with a focus on two array structures: limited and broad diversity DLA structures. Numerical electromagnetic modeling is used to study the light-array interaction and to compute the optical properties of SiNW arrays. The proposed arrays show superior performance over other types of SiNW arrays. Significant enhancement of the array absorption is achieved over the entire solar spectrum of interest with significant reduction of the amount of material. The arrays show performance independent of angle of incidence up to 70 degrees, and polarization. The proposed arrays achieved ultimate efficiency as high as 39% with filling fraction as low as 19%. PMID:26367679

  13. 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.

  14. 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.

  15. High-density ordered Ag@Al2O3 nanobowl arrays in applications of surface-enhanced Raman spectroscopy

    Science.gov (United States)

    Kang, Mengyang; Zhang, Xiaoyan; Liu, Liwei; Zhou, Qingwei; Jin, Mingliang; Zhou, Guofu; Gao, Xingsen; Lu, Xubing; Zhang, Zhang; Liu, Junming

    2016-04-01

    In this paper, we demonstrate a high-performance surface-enhanced Raman scattering (SERS) substrate based on high-density ordered Ag@Al2O3 nanobowl arrays. By ion beam etching (IBE) the anodized aluminum oxide (AAO) and subsequent Ag coating, ordered Ag@Al2O3 nanobowl arrays were created on the Si substrate. Unlike the ‘hot spots’ generated between adjacent metallic nanostructures, the Ag@Al2O3 nanobowl introduced ‘hot spots’ on the metal boundary of its hemispherical cavity. Based on the analysis of SERS signals, the optimized SERS substrate of Ag@Al2O3 nanobowl arrays had both high sensitivity and large-area uniformity. A detection limit as low as 10-10 M was obtained using chemisorbed p-thiocresol (p-Tc) molecules, and the SERS signal was highly reproducible with a small standard deviation. The method opens up a new way to create highly sensitive SERS sensors with high-density ‘hot spots’, and it could play an important role in device design and corresponding biological and food safety monitoring applications.

  16. 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

  17. 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.

  18. Electrical crosstalk in front-illuminated photodiode array with different guard ring designs for medical CT applications

    International Nuclear Information System (INIS)

    This paper presents electrical crosstalk studies on front-illuminated photodiode arrays for medical computed tomography (CT) applications. Crosstalk is an important factor to the system noise and image quality. The electrical crosstalk depends on silicon substrate properties and photodiode structures. The photodiode samples employed in this paper are planar processed on high-resistivity n-type silicon substrate, resulting in a p+/n-/n+ diode structure. Two types of guard ring structures are designed and applied to the same geometry of two-dimensional photodiode arrays. One structure is an n guard ring in the gap area between pixels, and the other structure is an additional p+ guard ring around each pixel together with the n guard ring. A 10 μm light spot with wavelength of 525 nm is used to scan across the surface of the photodiode array in the electrical crosstalk measurements. The electrical currents of two neighbor pixels are measured and the results are compared between two guard ring designs. The design with the p+ guard ring structure gives better electrical crosstalk suppression. Moreover, the measurement results show much smaller influence on surrounding pixels with the p+ guard ring structure in the case of disconnected pixel. Besides the electrical crosstalk, the light sensitivity within the gap area is also discussed between two guard ring designs.

  19. Electrical crosstalk in front-illuminated photodiode array with different guard ring designs for medical CT applications

    Energy Technology Data Exchange (ETDEWEB)

    Ji Fan [Detection Technology Inc., Espoo (Finland); Helsinki University of Technology, Espoo (Finland)], E-mail: ji.fan@deetee.com; Juntunen, Mikko; Hietanen, Iiro [Detection Technology Inc., Espoo (Finland)

    2009-08-01

    This paper presents electrical crosstalk studies on front-illuminated photodiode arrays for medical computed tomography (CT) applications. Crosstalk is an important factor to the system noise and image quality. The electrical crosstalk depends on silicon substrate properties and photodiode structures. The photodiode samples employed in this paper are planar processed on high-resistivity n-type silicon substrate, resulting in a p+/n-/n+ diode structure. Two types of guard ring structures are designed and applied to the same geometry of two-dimensional photodiode arrays. One structure is an n guard ring in the gap area between pixels, and the other structure is an additional p+ guard ring around each pixel together with the n guard ring. A 10 {mu}m light spot with wavelength of 525 nm is used to scan across the surface of the photodiode array in the electrical crosstalk measurements. The electrical currents of two neighbor pixels are measured and the results are compared between two guard ring designs. The design with the p+ guard ring structure gives better electrical crosstalk suppression. Moreover, the measurement results show much smaller influence on surrounding pixels with the p+ guard ring structure in the case of disconnected pixel. Besides the electrical crosstalk, the light sensitivity within the gap area is also discussed between two guard ring designs.

  20. 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

  1. 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.

  2. 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.

  3. Approach to fabricating Co nanowire arrays with perpendicular anisotropy: Application of a magnetic field during deposition

    International Nuclear Information System (INIS)

    Cobalt (Co) nanowire arrays were electrodeposited into the pores of polycarbonate membranes. A magnetic field parallel or perpendicular to the membrane plane was applied during deposition to control the wire growth. X-ray diffraction, transmission electron microscopy, and vibrating sample magnetometer were employed to investigate the structure as well as the magnetic properties of the nanowire arrays. The results show that the magnetic field applied during deposition strongly influences the growth of Co nanowires, inducing variations in their crystalline structure and magnetic properties. The sample deposited with the field perpendicular to the membrane plane exhibits a perpendicular magnetic anisotropy with greatly enhanced coercivity and squareness as a result of the preferred growth of Co grains with the c axis perpendicular to the film plane. In contrast, the deposition in a parallel magnetic field forces Co grains to grow with the c axis parallel to the film plane, resulting in in-plane anisotropy. [copyright] 2001 American Institute of Physics

  4. Approach to fabricating Co nanowire arrays with perpendicular anisotropy: Application of a magnetic field during deposition

    Science.gov (United States)

    Ge, Shihui; Li, Chao; Ma, Xiao; Li, Wei; Xi, Li; Li, C. X.

    2001-07-01

    Cobalt (Co) nanowire arrays were electrodeposited into the pores of polycarbonate membranes. A magnetic field parallel or perpendicular to the membrane plane was applied during deposition to control the wire growth. X-ray diffraction, transmission electron microscopy, and vibrating sample magnetometer were employed to investigate the structure as well as the magnetic properties of the nanowire arrays. The results show that the magnetic field applied during deposition strongly influences the growth of Co nanowires, inducing variations in their crystalline structure and magnetic properties. The sample deposited with the field perpendicular to the membrane plane exhibits a perpendicular magnetic anisotropy with greatly enhanced coercivity and squareness as a result of the preferred growth of Co grains with the c axis perpendicular to the film plane. In contrast, the deposition in a parallel magnetic field forces Co grains to grow with the c axis parallel to the film plane, resulting in in-plane anisotropy.

  5. An electrical impedance tomography system for gynecological application GIT with a tiny electrode array

    International Nuclear Information System (INIS)

    The paper describes the development of an electrical impedance tomography (EIT) system for gynecologic research. The GIT (gynecological impedance tomography) system has 48 electrodes and is embedded on a small space (30 mm diameter and 20 mm height) inside of the vaginal probe. The system provides real-time (one shot per second) 3D visualization of the spatial distribution of the static electrical properties of the cervix tissue. History, advantages, disadvantages and aspects of the system development are also described. The algorithm for the tiny measuring array organization is given. New details of the backprojection method on the non-regular electrode array are discussed. Some pictures reconstructed from numerical simulated data are offered. 3D visualization of the test object and cervix is presented. (paper)

  6. Plasmon enhanced broadband optical absorption in ultrathin silicon nanobowl array for photoactive devices applications

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Rui-Nan; Peng, Kui-Qing, E-mail: kq-peng@bnu.edu.cn; Hu, Bo; Hu, Ya; Zhang, Fu-Qiang [Department of Physics and Beijing Key Laboratory of Energy Conversion and Storage Materials, Beijing Normal University, Beijing 100875 (China); Lee, Shuit-Tong [Institute of Functional Nano and Soft Materials (FUNSOM) and Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, Suzhou 215123 (China)

    2015-07-06

    Both photonic and plasmonic nanostructures are key optical components of photoactive devices for light harvesting, enabling solar cells with significant thickness reduction, and light detectors capable of detecting photons with sub-band gap energies. In this work, we study the plasmon enhanced broadband light absorption and electrical properties of silicon nanobowl (SiNB) arrays. The SiNB-metal photonic-plasmonic nanostructure-based devices exhibited superior light-harvesting ability across a wide range of wavelengths up to the infrared regime well below the band edge of Si due to effective optical coupling between the SiNB array and incident sunlight, as well as electric field intensity enhancement around metal nanoparticles due to localized surface plasmon resonance. The photonic-plasmonic nanostructure is expected to result in infrared-light detectors and high-efficiency solar cells by extending light-harvesting to infrared frequencies.

  7. Verification and application of beam steering Phased Array UT technique for complex structures

    International Nuclear Information System (INIS)

    Phased Array Ultrasonic Testing (PAUT) techniques for complex geometries are greatly progressing. We developed an immersion PAUT which is suitable for complex surface profiles such as nozzles and deformed welded areas. Furthermore, we have developed a shape adaptive beam steering technique for 3D complex surface structures with conventional array probe and flexible coupling gel which makes the immersion beam forming technique usable under dry conditions. This system consists of 3 steps. Step1 is surface profile measurement which based on 3D Synthesis Aperture Focusing Technique (SAFT), Step2 is delay law calculation which could take into account the measured 3D surface profiles and steer a shape adjusted ultrasonic beam, Step3 is shape adjusted B-scope construction. In this paper, verification results of property of this PAUT system using R60 curved specimen and nozzle shaped specimen which simulated actual BWR structure. (author)

  8. Efficient broadband light absorption in elliptical nanohole arrays for photovoltaic application.

    Science.gov (United States)

    Xia, Zihuan; Qin, Xuefei; Wu, Yonggang; Pan, Yongdong; Zhou, Jian; Zhang, Zongyi

    2015-12-15

    We propose a perpendicular elliptical silicon nanohole (PE-SiNH) array for light absorption in thin film silicon solar cells. Our analysis shows that this architecture is capable of increasing the absorption of a thin film silicon solar cell by 11.3% in comparison to that of the optimal circular SiNH array. The process of breaking the mirror symmetries is responsible for the increase of the coupled modes. The PE-SiNH structures show additional near-zero spatial Fourier components compared with the circular SiNH structure, which helps to couple more incident light into slow Bloch modes. The mode interaction between adjacent elliptical nanoholes is in favor of the coupling of the incident light into channeling modes and, therefore, enhances light absorption in the short wavelength region. PMID:26670519

  9. 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...

  10. New CdTe photoconductor array detector for x-ray applications

    International Nuclear Information System (INIS)

    A CdTe photoconductor array x-ray detector was grown using molecular beam epitaxy (MBE) on a Si(100) substrate. The temporal response of the photoconductor arrays is as fast as 21 ps rise time and 38 ps full width half-maximum (FWHM). The spatial resolution of the photoconductor was good enough to provide 75 μm FWHM using a 50 μm synchrotron x-ray beam. A substantial number of x-ray photons are absorbed effectively within the MBE CdTe layer as observed from the linear response up to 15 keV. These results demonstrate that MBE grown CdTe is a suitable choice of the detector materials to meet the requirements for x-ray detectors

  11. 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.

  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 of Field Programmable Gate Array (FPGA) Based Emulators for Motor Control Applications

    OpenAIRE

    Ahmed Ben Achballah; Slim Ben Othman; Slim Ben Saoud

    2013-01-01

    Problem statement: Field Programmable Gate Array (FPGA) circuits play a significant role in major recent embedded process control designs. However, exploiting these platforms requires deep hardware conception skills and remains an important time consuming stage in a design flow. High Level Synthesis technique avoids this bottleneck and increases design productivity as witnessed by industry specialists. Approach: This study proposes to apply this technique for the conception and implementation...

  14. 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...

  15. 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...

  16. 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...

  17. 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.

  18. 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

  19. FUNDAMENTAL AREAS OF PHENOMENOLOGY (INCLUDING APPLICATIONS): Talbot Effect in Three Waveguide Arrays

    Science.gov (United States)

    Li, Zhi; Zhou, Hai-Feng; Yang, Jian-Yi; Jiang, Xiao-Qing

    2008-09-01

    By taking the coupling between the non-neighbourhood waveguides into account, the coupling characteristic of three waveguide arrays is analysed. The strong coupling equation of three waveguides is dealt with Laplace transform and LU decomposition. The general field evolution equation is obtained by inversion of the Laplace transform. The results show that the self-imaging conditions (Talbot effect) do not satisfy in general. The theoretical predictions are in good agreement with the BPM simulations.

  20. Applications of Generalized Cascade Scattering Matrix on the Microwave Circuits and Antenna Arrays

    OpenAIRE

    2015-01-01

    The ideal lossless symmetrical reciprocal network (ILSRN) is constructed and introduced to resolve the complex interconnections of two arbitrary microwave networks. By inserting the ILSRNs, the complex interconnections can be converted into the standard one-by-one case without changing the characteristics of the previous microwave networks. Based on the algorithm of the generalized cascade scattering matrix, a useful derivation on the excitation coefficients of antenna arrays is firstly propo...

  1. A new generation of multichannel seismic apparatus and its practical application in standalone and array monitoring

    Czech Academy of Sciences Publication Activity Database

    Brož, Milan; Štrunc, Jaroslav

    2011-01-01

    Roč. 8, č. 3 (2011), s. 345-352. ISSN 1214-9705 R&D Projects: GA ČR GA103/07/1522 Institutional research plan: CEZ:AV0Z30460519 Keywords : analog-to-digital converter * seismic array * weak event Subject RIV: DC - Siesmology, Volcanology, Earth Structure Impact factor: 0.530, year: 2011 http://www.irsm.cas.cz/abstracts/AGG/03_11/16_Broz.pdf

  2. 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...

  3. 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

  4. Application of the solubility parameter concept to the design of chemiresistor arrays

    Energy Technology Data Exchange (ETDEWEB)

    Hughes, R.C.; Yelton, W.G.; Ricco, A.J.; Patel, S.V.; Jenkins, M.W. [Sandia National Labs., Albuquerque, NM (United States); Eastman, M.P. [Northern Arizona Univ., Flagstaff, AZ (United States). Dept. of Chemistry

    1998-04-01

    Arrays of unheated chemically sensitive resistors (chemiresistors) can serve as extremely small, low power consumption sensors with simple read out electronics. Most work has focused on the exotic polymeric organic metals, but here the authors report new results on carbon loaded polymer composites, as well as polymeric ionic conductors. They use the solubility parameter concept to understand and categorize the chemiresistor responses and, in particular, they compare chemiresistors fabricated from polyisobutylene (PIB) to results from PIB coated acoustic wave sensors.

  5. Optimum Design of a 4x4 Planar Butler Matrix Array for WLAN Application

    OpenAIRE

    Bhowmik, Wriddhi; Srivastava, Shweta

    2010-01-01

    In recent years, high-speed wireless communication is in vogue. In wireless communication systems, multipath fading, delay and interference occurres by reflection or diffraction. In a high-speed wireless communication, it becomes a necessary to separate desired signal from delay or interference signal. Thus to overcome these problems Smart antenna systems have been developed. Basically there are two types of smart antenna systems, one is Switched beam system and another Adaptive array system....

  6. 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.

  7. Low Frequency Phased Array Application for Crack Detection in Cast Austenitic Piping

    International Nuclear Information System (INIS)

    As part of a multi-year program funded by the United States Nuclear Regulatory Commission (US NRC) to address nondestructive examination (NDE) reliability of inservice inspection (ISI) programs, studies conducted at the Pacific Northwest National Laboratory (PNNL) in Richland, Washington, have focused on assessing novel NDE approaches for the inspection of coarse-grained, cast stainless steel reactor components. The primary objective of this work is to provide information to the US NRC on the utility, effectiveness and reliability of ultrasonic testing (UT) as related to the ISI of primary piping components in US commercial nuclear power plants. This paper describes progress, recent developments and results from an assessment of a portion of the work relating to the ultrasonic low frequency phased array inspection technique. Westinghouse Owner's Group (WOG) cast stainless steel pipe segments with thermal and mechanical fatigue cracks, PNNL samples containing thermal fatigue cracks and several blank vintage specimens having very coarse grains that are representative of early centrifugally cast piping installed in PWRs, were used for assessing the inspection method. The phased array approach was implemented using an R/D Tech Tomoscan III system operating at 1.0 MHz and 500 kHz, providing composite volumetric images of the samples. Several dual, transmit-receive, custom designed low-frequency arrays were employed in laboratory trials. Results from laboratory studies for assessing detection, localization and length sizing effectiveness are discussed.

  8. 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.

  9. Application of Stacking Technique in ANA: Method and Practice with PKU Seismological Array

    Science.gov (United States)

    Liu, J.; Tang, Y.; Ning, J.; Chen, Y. J.

    2010-12-01

    Cross correlation of ambient noise records is now routinely used to get dispersion curve and then do seismic tomography; however little attention has been paid to array techniques. We will present a spacial-stacking method to get high resolution dispersion curves and show practices with the observation data of PKU seismological array. Experiential Green Functions are generally obtained by correlation between two stations, and then the dispersion curves are obtained from the analysis of FTAN. Popular method to get high resolution dispersion curves is using long time records. At the same time, if we want to get effectual signal, the distance between the two stations must be at least 3 times of the longest wavelength. So we need both long time records and appropriate spaced stations. Now we use a new method, special-stacking, which allows shorter observation period and utilizes observations of a group of closely distributed stations to get fine dispersion curves. We correlate observations of every station in the station group with those of a far station, and then stack them together. However we cannot just simply stack them unless the stations in the station group at a circle, of which the center is the far station owing to dispersion characteristics of the Rayleigh waves. Thus we do antidispersion on the observation data of every station in the array, then do stacking. We test the method using the theoretical seismic surface wave records which obtained by qseis06 compiled by Rongjiang Wang both with and without noise. For the cases of three imaginary stations (distance is 1 degree) have the same underground structure and without noise, result is that the center station had the same dispersion with and without spacial-stacking. Then we add noise to the theoretical records. The center station's dispersion curves obtained by our method are much closer to the dispersion curve without noise than contaminated ones. We can see that our method has improved the resolution of

  10. 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

  11. 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.

  12. 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

  13. Pushing back the frontiers of mercury speciation using a combination of biomolecular and isotopic signatures: challenge and perspectives.

    Science.gov (United States)

    Pedrero, Zoyne; Donard, Olivier F X; Amouroux, David

    2016-04-01

    Mercury (Hg) pollution is considered a major environmental problem due to the extreme toxicity of Hg. However, Hg metabolic pathways in biota remain elusive. An understanding of these pathways is crucial to elucidating the (eco)toxic effects of Hg and its biogeochemical cycle. The development of a new analytical methodology based on both speciation and natural isotopic fractionation represents a promising approach for metabolic studies of Hg and other metal(loid)s. Speciation provides valuable information about the reactivity and potential toxicity of metabolites, while the use of natural isotopic signature analysis adds a complementary dynamic dimension that allows the life history of the target element to be probed, the source of the target element (i.e., the source of pollution) to be identified, and reactions to be tracked. The resulting combined (bio)molecular and isotopic signature affords precious insight into the behavior of Hg in biota and Hg detoxification mechanisms. In the long term, this highly innovative methodology could be used in life and environmental science studies of metal(loid)s to push back the frontiers of our knowledge in this field. This paper summarizes the current status of the application of Hg speciation and the isotopic signature of Hg at the biomolecular level in living organisms, and discusses potential future uses of this combination of techniques. Graphical Abstract Application of Hg speciation and the isotopic signature of Hg to enhance our understanding of the roles of Hg in metabolic, toxicological, and environmental processes. PMID:26753975

  14. Heterogeneous flammulina velutipes-like CdTe/TiO2 nanorod array: A promising composite nanostructure for solar cell application

    International Nuclear Information System (INIS)

    Highlights: ► Core–shell CdTe/TiO2 nanorod arrays have been prepared via hydrothermal growth and magnetron sputtering method. ► CdTe nanograins covered on the surface of the TiO2 nanorod arrays constructing a flammulina velutipe like type-II heterostructure. ► The spectrum absorption region and the open circuit photocurrent are greatly increased. - Abstract: Core–shell heterogeneous CdTe/TiO2 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 TiO2 nanorod arrays to form a type-II heterostructure. Compared with TiO2 nanorod arrays, the spectrum absorption region of CdTe/TiO2 core–shell nanostructure is broadened from ultraviolet light to visible light. The photoelectrodes of CdTe/TiO2 nanorod arrays show better photoelectric properties than those of bare TiO2 nanorod arrays. The output power of CdTe/TiO2 nanorod arrays is 25 times higher than that of a bare TiO2 nanorod array. These results indicate that the photoelectrode of CdTe/TiO2 nanorod array has a promising application in solar cell.

  15. Minimal metabolic pathway structure is consistent with associated biomolecular interactions.

    Science.gov (United States)

    Bordbar, Aarash; Nagarajan, Harish; Lewis, Nathan E; Latif, Haythem; Ebrahim, Ali; Federowicz, Stephen; Schellenberger, Jan; Palsson, Bernhard O

    2014-01-01

    Pathways are a universal paradigm for functionally describing cellular processes. Even though advances in high-throughput data generation have transformed biology, the core of our biological understanding, and hence data interpretation, is still predicated on human-defined pathways. Here, we introduce an unbiased, pathway structure for genome-scale metabolic networks defined based on principles of parsimony that do not mimic canonical human-defined textbook pathways. Instead, these minimal pathways better describe multiple independent pathway-associated biomolecular interaction datasets suggesting a functional organization for metabolism based on parsimonious use of cellular components. We use the inherent predictive capability of these pathways to experimentally discover novel transcriptional regulatory interactions in Escherichia coli metabolism for three transcription factors, effectively doubling the known regulatory roles for Nac and MntR. This study suggests an underlying and fundamental principle in the evolutionary selection of pathway structures; namely, that pathways may be minimal, independent, and segregated. PMID:24987116

  16. Ion irradiation and biomolecular radiation damage II. Indirect effect

    CERN Document Server

    Wang, Wei; Su, Wenhui

    2010-01-01

    It has been reported that damage of genome in a living cell by ionizing radiation is about one-third direct and two-thirds indirect. The former which has been introduced in our last paper, concerns direct energy deposition and ionizing reactions in the biomolecules; the latter results from radiation induced reactive species (mainly radicals) in the medium (mainly water) surrounding the biomolecules. In this review, a short description of ion implantation induced radical formation in water is presented. Then we summarize the aqueous radical reaction chemistry of DNA, protein and their components, followed by a brief introduction of biomolecular damage induced by secondary particles (ions and electron). Some downstream biological effects are also discussed.

  17. Computational and theoretical aspects of biomolecular structure and dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, A.E.; Berendzen, J.; Catasti, P., Chen, X. [and others

    1996-09-01

    This is the final report for a project that sought to evaluate and develop theoretical, and computational bases for designing, performing, and analyzing experimental studies in structural biology. Simulations of large biomolecular systems in solution, hydrophobic interactions, and quantum chemical calculations for large systems have been performed. We have developed a code that implements the Fast Multipole Algorithm (FMA) that scales linearly in the number of particles simulated in a large system. New methods have been developed for the analysis of multidimensional NMR data in order to obtain high resolution atomic structures. These methods have been applied to the study of DNA sequences in the human centromere, sequences linked to genetic diseases, and the dynamics and structure of myoglobin.

  18. 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

  19. 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)

  20. 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.

  1. Fabrication of polyaniline/graphene/titania nanotube arrays nanocomposite and their application in supercapacitors

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Hua; Gan, Mengyu; Ma, Li, E-mail: mlsys607@126.com; Yu, Lei; Hu, Haifeng; Yang, Fangfang; Li, Yanjun; Ge, Chengqiang

    2015-05-05

    Highlights: • The PANI/graphene/TiO{sub 2} nanotube arrays were fabricated firstly. • The composite shows a high specific capacitance and superior rate capability. • A high capacity retention rate of 91% after 1000 cycles can be achieved. • The composite possesses a novel three-dimensional (3D) highly ordered nanostructure. • TiO{sub 2} NTs enhance the adhesion between PANI and substrate. - Abstract: Polyaniline/graphene/titania nanotube arrays (PGTNs) nanocomposite as a supercapacitor electrode is fabricated by in-situ polymerization for the first time. Herein, the PGTNs possesses a novel three-dimensional (3D) highly ordered hybrid nanostructure consisting of coaxial polyaniline (PANI)/TiO{sub 2} nanotube arrays and graphene coated with PANI on the surface of TiO{sub 2} in some degree. The synthesized three-dimensional PGTNs is characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and Raman spectroscopy, and its electrochemical performance is measured by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and galvanostatic charge/discharge. The maximum specific capacitance of PGTNs is as high as 933 F g{sup −1} at current density of 0.75 A g{sup −1} and the specific capacitance retains 91% of the initial after constant charge–discharge 1000 cycles. The improved electrochemical performance is due to the 3D nanostructure, which effectively prevents the mechanical deformation during the fast charge/discharge process and favors the diffusion of the electrolyte ions into the inner region of active materials. The composite electrode material is very promising for the next generation of high-performance electrochemical supercapacitors.

  2. Integration of biomolecular logic gates with field-effect transducers

    International Nuclear Information System (INIS)

    Highlights: → Enzyme-based AND/OR logic gates are integrated with a capacitive field-effect sensor. → The AND/OR logic gates compose of multi-enzyme system immobilised on sensor surface. → Logic gates were activated by different combinations of chemical inputs (analytes). → The logic output (pH change) produced by the enzymes was read out by the sensor. - Abstract: The integration of biomolecular logic gates with field-effect devices - the basic element of conventional electronic logic gates and computing - is one of the most attractive and promising approaches for the transformation of biomolecular logic principles into macroscopically useable electrical output signals. In this work, capacitive field-effect EIS (electrolyte-insulator-semiconductor) sensors based on a p-Si-SiO2-Ta2O5 structure modified with a multi-enzyme membrane have been used for electronic transduction of biochemical signals processed by enzyme-based OR and AND logic gates. The realised OR logic gate composes of two enzymes (glucose oxidase and esterase) and was activated by ethyl butyrate or/and glucose. The AND logic gate composes of three enzymes (invertase, mutarotase and glucose oxidase) and was activated by two chemical input signals: sucrose and dissolved oxygen. The developed integrated enzyme logic gates produce local pH changes at the EIS sensor surface as a result of biochemical reactions activated by different combinations of chemical input signals, while the pH value of the bulk solution remains unchanged. The pH-induced charge changes at the gate-insulator (Ta2O5) surface of the EIS transducer result in an electronic signal corresponding to the logic output produced by the immobilised enzymes. The logic output signals have been read out by means of a constant-capacitance method.

  3. Controlled synthesis of ZnO branched nanorod arrays by hierarchical solution growth and application in dye-sensitized solar cells

    International Nuclear Information System (INIS)

    We demonstrate the controlled synthesis of ZnO branched nanorod arrays on fluorine-doped SnO2-coated glass substrates by the hierarchical solution growth method. In the secondary growth, the concentration of Zn(NO3)2/hexamethylenetetramine plays an important role in controlling the morphology of the branched nanorod arrays, besides that of diaminopropane used as a structure-directing agent to induce the growth of branches. The population density and morphology of the branched nanorod arrays depend on those of the nanorod arrays obtained from the primary growth, which can be modulated though the concentration of Zn(NO3)2/hexamethylenetetramine in the primary growth solution. The dye-sensitized ZnO branched nanorod arrays exhibit much stronger optical absorption as compared with its corresponding primary nanorod arrays, suggesting that the addition of the branches improves light harvesting. The dye-sensitized solar cell based on the optimized ZnO branched nanorod array reaches a conversion efficiency of 1.66% under the light radiation of 1000 W/m2. The branched nanorod arrays can also be applied in other application fields of ZnO.

  4. 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

  5. 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 ...

  6. 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.

  7. 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.

  8. Preparation, characterization, and application of titanium nano-tube array in dye-sensitized solar cells

    OpenAIRE

    Ho, Shih-Yu; Su, Chaochin; Cheng, Chieh-Chung; Kathirvel, Sasipriya; Li, Chung-Yen; Li, Wen-Ren

    2012-01-01

    The vertically orientated TiO2 nanotube array (TNA) decorated with TiO2 nano-particles was successfully fabricated by electrochemically anodizing titanium (Ti) foils followed by Ti-precursor post-treatment and annealing process. The TNA morphology characterized by SEM and TEM was found to be filled with TiO2 nano-particles interior and exterior of the TiO2 nano-tubes after titanium (IV) n-butoxide (TnB) treatment, whereas TiO2 nano-particles were only found inside of TiO2 nano-tubes upon tita...

  9. 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.

  10. 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...

  11. Super phase array

    Energy Technology Data Exchange (ETDEWEB)

    Wee, W H; Pendry, J B [Condensed Matter Theory Group Department of Physics Imperial College London London SW7 2AZ (United Kingdom)], E-mail: w.wee07@imperial.ac.uk

    2010-03-15

    For a long time phase arrays have been used in a variety of wave transmission applications because of their simplicity and versatility. Conventionally there is a trade-off between the compactness of a phase array and its directivity. In this paper we demonstrate how by embedding a normal phase array within a superlens (made of negative refractive index material) we can overcome this constraint and create compact phase arrays with a virtual extent much larger than the physical size of the array. In this paper we also briefly discuss the apparent unphysical field divergences in superlenses and how to resolve this issue.

  12. Super phase array

    International Nuclear Information System (INIS)

    For a long time phase arrays have been used in a variety of wave transmission applications because of their simplicity and versatility. Conventionally there is a trade-off between the compactness of a phase array and its directivity. In this paper we demonstrate how by embedding a normal phase array within a superlens (made of negative refractive index material) we can overcome this constraint and create compact phase arrays with a virtual extent much larger than the physical size of the array. In this paper we also briefly discuss the apparent unphysical field divergences in superlenses and how to resolve this issue.

  13. 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.

  14. 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

  15. 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.

    2016-02-01

    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.

  16. 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.

  17. 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.

  18. 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

  19. 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.

  20. 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.

  1. 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.

  2. Current Approach in Surface Plasmons for Thin Film and Wire Array Solar Cell Applications

    Directory of Open Access Journals (Sweden)

    Keya Zhou

    2015-07-01

    Full Text Available Surface plasmons, which exist along the interface of a metal and a dielectric, have been proposed as an efficient alternative method for light trapping in solar cells during the past ten years. With unique properties such as superior light scattering, optical trapping, guide mode coupling, near field concentration, and hot-electron generation, metallic nanoparticles or nanostructures can be tailored to a certain geometric design to enhance solar cell conversion efficiency and to reduce the material costs. In this article, we review current approaches on different kinds of solar cells, such as crystalline silicon (c-Si and amorphous silicon (a-Si thin film solar cells, organic solar cells, nanowire array solar cells, and single nanowire solar cells.

  3. A Complete Charge Recycling TCAM with Checkerboard Array Arrangement for Low Power Applications

    Science.gov (United States)

    Dosaka, Katsumi; Ogawa, Daisuke; Kusumoto, Takahito; Miyama, Masayuki; Matsuda, Yoshio

    Architecture of a low power Ternary Content Addressable Memory (TCAM) is proposed. The TCAM is a powerful engine for search and sort processing, but it has two serious problems, large power consumption and large power line noise. To solve these problems, we have developed a charge recycling scheme for match lines and search lines. A combination of the newly introduced PMOS CAM cell together with the conventional NMOS CAM cell realizes match line charge recycling. A checkerboard arrangement of the NMOS and the PMOS cell array enables search line charge recycling. By using these technologies, the power consumption of the TCAM can be reduced to 50% of conventional designs, and as a result, the power line noise is also reduced. An experimental chip has been fabricated in 180-nm 6-metal process. The power consumption of this chip is 6.3fJ/bit/search, which is half of the conventional scheme.

  4. 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.

  5. Micro/nano-scale fabrication of integrated polymer optical wire circuit arrays for optical printed circuit board (O-PCB) application

    Science.gov (United States)

    Lee, El-Hang; Lee, Seung G.; Park, Se G.; Kim, Kyong H.; Kang, Jin K.; Chin, In J.; Kwon, Y. K.; Choi, Young W.

    2005-02-01

    We report on the results of our study on the micro/nano-scale design, fabrication and integration of waveguide arrays for optical printed circuit boards (O-PCBs) and VLSI micro/nano-photonic applications. The O-PCBs are designed to perform the functions of transporting, switching, routing and distributing optical signals on flat modular boards or substrates. We have assembled O-PCBs using optical waveguide arrays and circuits made of polymer materials and have examined information handling performances. We also designed power beam splitters and waveguide filters, using nano-scale photonic band-gap crystals, for VLSI photonic integration application. We discuss potential applications of polymer optical waveguide devices and arrays for O-PCB and VLSI micro/nano-photonics for computers, telecommunications, and transportation systems.

  6. 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

  7. Emergent properties of nanosensor arrays: applications for monitoring IgG affinity distributions, weakly affined hypermannosylation, and colony selection for biomanufacturing.

    Science.gov (United States)

    Reuel, Nigel F; Grassbaugh, Brittany; Kruss, Sebastian; Mundy, J Zachary; Opel, Cary; Ogunniyi, Adebola O; Egodage, Kamal; Wahl, Ramon; Helk, Bernhard; Zhang, Jingqing; Kalcioglu, Z Ilke; Tvrdy, Kevin; Bellisario, Darin O; Mu, Bin; Blake, Steven S; Van Vliet, Krystyn J; Love, J Christopher; Wittrup, Karl Dane; Strano, Michael S

    2013-09-24

    It is widely recognized that an array of addressable sensors can be multiplexed for the label-free detection of a library of analytes. However, such arrays have useful properties that emerge from the ensemble, even when monofunctionalized. As examples, we show that an array of nanosensors can estimate the mean and variance of the observed dissociation constant (KD), using three different examples of binding IgG with Protein A as the recognition site, including polyclonal human IgG (KD μ = 19 μM, σ(2) = 1000 mM(2)), murine IgG (KD μ = 4.3 nM, σ(2) = 3 μM(2)), and human IgG from CHO cells (KD μ = 2.5 nM, σ(2) = 0.01 μM(2)). Second, we show that an array of nanosensors can uniquely monitor weakly affined analyte interactions via the increased number of observed interactions. One application involves monitoring the metabolically induced hypermannosylation of human IgG from CHO using PSA-lectin conjugated sensor arrays where temporal glycosylation patterns are measured and compared. Finally, the array of sensors can also spatially map the local production of an analyte from cellular biosynthesis. As an example, we rank productivity of IgG-producing HEK colonies cultured directly on the array of nanosensors itself. PMID:23909808

  8. 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 ...

  9. 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.

  10. 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

  11. 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

  12. 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.

  13. 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.

  14. 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.

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

    Directory of Open Access Journals (Sweden)

    Wen Li

    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.

  16. Bilayer-metal assisted chemical etching of silicon microwire arrays for photovoltaic applications

    Science.gov (United States)

    Wu, R. W.; Yuan, G. D.; Wang, K. C.; Wei, T. B.; Liu, Z. Q.; Wang, G. H.; Wang, J. X.; Li, J. M.

    2016-02-01

    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.

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

    Directory of Open Access Journals (Sweden)

    Ricardo Tadeu Lopes

    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.

  18. 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.

  19. Conjugated polymer–silicon nanowire array hybrid Schottky diode for solar cell application

    International Nuclear Information System (INIS)

    The hybrid Schottky diode based on silicon nanowire arrays (SiNWs) and poly(3,4-ethylenedioxythiophene)/poly(styrenesulfonate) (PEDOT:PSS) has been fabricated for high performance solar cells. The length of SiNWs on a silicon substrate, which is prepared by metal-assisted chemical etching, can be tuned by adjusting the length of the etching time. In addition, the average distances between the adjacent silicon nanowires can be controlled by changing the immersing time in a saturated PCl5 solution. The hybrid devices are made from the SiNWs with different wire lengths and various distances between adjacent wires by spin-casting PEDOT:PSS on the silicon substrates. It is found that the length and density play leading roles in the electric output characteristics. The device made from SiNWs with optimum morphology can achieve a power conversion efficiency of 7.3%, which is much improved in comparison with that of the planar one. The measurement of the transient photovoltage decay and the analysis of the current versus voltage curve indicate that the charge recombination process is a dominant factor on the device performance. (paper)

  20. 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.

  1. The application of scintillating fiber optics in a diode array digital radiography system

    International Nuclear Information System (INIS)

    This paper presents research to evaluate the use of scintillating fiber optics (SFO) to replace traditional phosphor screens as an imaging detector in a digital radiographic system. A SFO-based detector was constructed for a Diode Array Digital Radiography (DADR) system. System image quality was evaluated with five characterization criteria: spatial resolution, signal-to noise ratio (SNR), large-area contrast detectability, responsivity, and inspection task performance. It has been concluded from this evaluation that the spatial resolution, SNR and large-area contrast detectability to that observed with phosphor screens. Spatial resolution is typically 8-9 line-pairs/mm (lp/mm) for SFO, while the phosphor screen resolution typically 2-6 lp/mm. However, responsivity (i.e., the system sensitivity), with SFO is much lower than measured with phosphor screens. In this energy range, although the x-ray absorption efficiency of SFO is high, the overall efficiency is low than for phosphor screens. By adjusting the gains of an image intensifier and an electronic amplifier, and adequately large signal output for a feasible x-ray dose input was obtained with the SFO system. The SFO system has produced images of electronic assemblies and met the requirements of the ASTM 801E No. 4. The experimental results indicate that the SFO detector is comparable to phosphor screens at low x-ray energies (p)

  2. 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

  3. 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.

  4. Arrays of high quality SAM-based junctions and their application in molecular diode based logic

    Science.gov (United States)

    Wan, Albert; Suchand Sangeeth, C. S.; Wang, Lejia; Yuan, Li; Jiang, Li; Nijhuis, Christian A.

    2015-11-01

    This paper describes a method to fabricate a microfluidic top-electrode that can be utilized to generate arrays of self-assembled monolayer (SAM)-based junctions. The top-electrodes consist of a liquid-metal of GaOx/EGaIn mechanically stabilized in microchannels and through-holes in polydimethylsiloxane (PDMS); these top-electrodes form molecular junctions by directly placing them onto the SAM supported by template-stripped (TS) Ag or Au bottom-electrodes. Unlike conventional techniques to form multiple junctions, our method does not require lithography to pattern the bottom-electrode and is compatible with TS bottom-electrodes, which are ultra-flat with large grains, free from potential contamination of photoresist residues, and do not have electrode-edges where the molecules are unable to pack well. We formed tunneling junctions with n-alkanethiolate SAMs in yields of ~80%, with good reproducibility and electrical stability. Temperature dependent J(V) measurements indicated that the mechanism of charge transport across the junction is coherent tunneling. To demonstrate the usefulness of these junctions, we formed molecular diodes based on SAMs with Fc head groups. These junctions rectify currents with a rectification ratio R of 45. These molecular diodes were incorporated in simple electronic circuitry to demonstrate molecular diode-based Boolean logic.This paper describes a method to fabricate a microfluidic top-electrode that can be utilized to generate arrays of self-assembled monolayer (SAM)-based junctions. The top-electrodes consist of a liquid-metal of GaOx/EGaIn mechanically stabilized in microchannels and through-holes in polydimethylsiloxane (PDMS); these top-electrodes form molecular junctions by directly placing them onto the SAM supported by template-stripped (TS) Ag or Au bottom-electrodes. Unlike conventional techniques to form multiple junctions, our method does not require lithography to pattern the bottom-electrode and is compatible with TS

  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. Self-assembling biomolecular catalysts for hydrogen production

    Science.gov (United States)

    Jordan, Paul C.; Patterson, Dustin P.; Saboda, Kendall N.; Edwards, Ethan J.; Miettinen, Heini M.; Basu, Gautam; Thielges, Megan C.; Douglas, Trevor

    2016-02-01

    The chemistry of highly evolved protein-based compartments has inspired the design of new catalytically active materials that self-assemble from biological components. A frontier of this biodesign is the potential to contribute new catalytic systems for the production of sustainable fuels, such as hydrogen. Here, we show the encapsulation and protection of an active hydrogen-producing and oxygen-tolerant [NiFe]-hydrogenase, sequestered within the capsid of the bacteriophage P22 through directed self-assembly. We co-opted Escherichia coli for biomolecular synthesis and assembly of this nanomaterial by expressing and maturing the EcHyd-1 hydrogenase prior to expression of the P22 coat protein, which subsequently self assembles. By probing the infrared spectroscopic signatures and catalytic activity of the engineered material, we demonstrate that the capsid provides stability and protection to the hydrogenase cargo. These results illustrate how combining biological function with directed supramolecular self-assembly can be used to create new materials for sustainable catalysis.

  7. 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.

  8. 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

  9. SWISS-PROT: connecting biomolecular knowledge via a protein database.

    Science.gov (United States)

    Gasteiger, E; Jung, E; Bairoch, A

    2001-07-01

    With the explosive growth of biological data, the development of new means of data storage was needed. More and more often biological information is no longer published in the conventional way via a publication in a scientific journal, but only deposited into a database. In the last two decades these databases have become essential tools for researchers in biological sciences. Biological databases can be classified according to the type of information they contain. There are basically three types of sequence-related databases (nucleic acid sequences, protein sequences and protein tertiary structures) as well as various specialized data collections. It is important to provide the users of biomolecular databases with a degree of integration between these databases as by nature all of these databases are connected in a scientific sense and each one of them is an important piece to biological complexity. In this review we will highlight our effort in connecting biological information as demonstrated in the SWISS-PROT protein database. PMID:11488411

  10. Deterministic characterization of phase noise in biomolecular oscillators

    International Nuclear Information System (INIS)

    On top of the many external perturbations, cellular oscillators also face intrinsic perturbations due the randomness of chemical kinetics. Biomolecular oscillators, distinct in their parameter sets or distinct in their architecture, show different resilience with respect to such intrinsic perturbations. Assessing this resilience can be done by ensemble stochastic simulations. These are computationally costly and do not permit further insights into the mechanistic cause of the observed resilience. For reaction systems operating at a steady state, the linear noise approximation (LNA) can be used to determine the effect of molecular noise. Here we show that methods based on LNA fail for oscillatory systems and we propose an alternative ansatz. It yields an asymptotic expression for the phase diffusion coefficient of stochastic oscillators. Moreover, it allows us to single out the noise contribution of every reaction in an oscillatory system. We test the approach on the one-loop model of the Drosophila circadian clock. Our results are consistent with those obtained through stochastic simulations with a gain in computational efficiency of about three orders of magnitude

  11. 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; Kim, J.

    2005-01-01

    , 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....

  12. Integration of polymer-based optical waveguide arrays and micro/nano-photonic devices for optical printed circuit board (O-PCB) application

    Science.gov (United States)

    Lee, El-Hang; Lee, Seung Gol; O, Beom Hoan; Park, Se-Geun; Kim, Kyong Heon; Kang, Jin Ku; Choi, Young Wan

    2005-03-01

    We report, in the form of review, on the results of our study on the fabrication and assembly of polymer-based optical waveguide arrays and micro/nano-photonic devices for optical printed circuit boards (O-PCBs) application. The O-PCBs are designed to perform the functions of transporting, switching, routing and distributing optical signals on flat modular boards, substrates or chips. We have assembled and constructed O-PCBs using optical waveguide arrays and circuits made of polymer materials and have examined their information handling performances. We also designed power beam splitters and waveguide filters using nano-scale photonic band-gap crystals. We discuss scientific and technological issues concerning the processes of miniaturization, interconnection and integration of polymer optical waveguide devices and arrays for the O-PCBs as applicable to board-to-board, chip-to-chip, and intra-chip integration for computers, telecommunications, and transportation systems.

  13. 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

  14. 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.

  15. 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.

  16. Energy deposition patterns within limb models heated with a mini annular phased array (MAPA) applicator

    International Nuclear Information System (INIS)

    A series of experiments has been carried out in order to characterize a MAPA applicator prior to possible clinical implementation. The energy deposition patterns were determined in several human limb models of different complexities. The maximum energy deposition observed in a homogeneous cylindrical phantom was found to be at the middle of the applicator. For more realistically shaped, homogeneous limb models, the point of maximum energy deposition was shifted towards a smaller cross-sectional region; this was also the case for isolated human legs. Furthermore, significant heating was observed in the bone of the isolated legs. Such phenomena illustrate the limitation of using classical 2-D numerical models for predicting the energy deposition patterns in heterogeneous bodies

  17. 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

  18. 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...

  19. 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.

  20. 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.

  1. 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.

  2. 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

  3. Developments of large-area APD arrays for future applications to PET technology

    International Nuclear Information System (INIS)

    Silicon avalanche photodiodes (APD) are solid-state devices which have internal gain. Since the good features of both photodiodes (PDs) and photomultiplier tubes (PMTs) are shared in a single device, APD offers new design for physics experiments and devices for nuclear medicine. In particular, thanks to its high quantum efficiency (QE) and low noise, reverse-type APDs generally show much better energy resolution than traditional PMTs when coupled to various scintillators. Most recently, we have developed various large area reverse-type APDs with Hamamatsu Photonics, up to 32 x 32 mm2 square area. Such large dimensions have been awaited by researchers world-wide, and further extend the potential of APDs for various application such as in space science and nuclear medicine. For example, the use of APDs in space experiments is now validated thanks to successful launch of the Cute 1.7+APD II, which has measured both electron/proton distributions in Low Earth Orbit at E >9 keV. Moreover, the mission successfully demonstrated an active gain control system to keep the APD gain stable under moderate temperature variations. In other aspects, an APD is a compact, high performance light sensor that could be used in the strong magnetic field MRIs. An ultimate spatial resolution as better as sub-mm will be possible by adopting small pixel, high density APD pixels. Future PET detectors with time-of-flight (TOF) capability may be expected thanks to very fast time response of the APD devices. As a first step, we have developed a versatile APD-based positron emission tomography (PET) modules for future applications in high resolution, fast medical imaging. We will also discuss future use of digital (Geiger-mode) APDs, such as multi-pixel photon counter (MPPCs) in similar medical imaging applications. (author)

  4. Molecular Occupancy of Nanodot Arrays.

    Science.gov (United States)

    Cai, Haogang; Wolfenson, Haguy; Depoil, David; Dustin, Michael L; Sheetz, Michael P; Wind, Shalom J

    2016-04-26

    Single-molecule nanodot arrays, in which a biomolecule of choice (protein, nucleic acid, etc.) is bound to a metallic nanoparticle on a solid substrate, are becoming an increasingly important tool in the study of biomolecular and cellular interactions. We have developed an on-chip measurement protocol to monitor and control the molecular occupancy of nanodots. Arrays of widely spaced nanodots and nanodot clusters were fabricated on glass surfaces by nanolithography and functionalized with fluorescently labeled proteins. The molecular occupancy was determined by monitoring individual fluorophore bleaching events, while accounting for fluorescence quenching effects. We found that the occupancy can be interpreted as a packing problem, and depends on nanodot size and binding ligand concentration, where the latter is easily adjusted to compensate the flexibility of dimension control in nanofabrication. The results are scalable with nanodot cluster size, extending to large area close packed arrays. As an example, the nanoarray platform was used to probe the geometric requirement of T-cell activation at the single-molecule level. PMID:26966946

  5. 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.

  6. 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

  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 handheld...... sensor for trace detection of explosives. We are using micro- and nano technological approaches for integrating four sensing principles into a single device. At the end of the project, the consortium aims at having delivered a sensor platform consisting of four independent detector principles capable of...... nanostructured sensors and sensor design....

  8. Low-voltage current-mode CMOS building blocks for field programmable analog arrays and application

    International Nuclear Information System (INIS)

    The role of analog integrated circuits in modem electronic systems remains important, even though digital circuits dominate the market for VLSI solutions. Analog systems have always played an essential role in interfacing digital electronics to the real world in applications such as analog signal processing and signal conditioning .Industrial process and motion control and biomedical measurements . In addition, analog solutions are becoming increasingly competitive with digital circuits for dense, low-power, high-speed applications in low-precision signal-processing. Because of the wide variety of analog functions required in electronic systems and the complexity of the signals (frequency, time, signal levels, parasitic), analog system design is very specialized and supported by a diverse set of CAD tools that are more difficult to integrate than those required for digital design. The drive towards shorter design cycles for analog integrated circuits has demanded the development of high performance analog circuits that are re configurable and suitable for CAD methodologies. the researcher here try to contribute in this filed

  9. Duplication and Divergence Effect on Network Motifs in Undirected Bio-Molecular Networks.

    Science.gov (United States)

    Pei Wang; Jinhu Lu; Xinghuo Yu; Zengrong Liu

    2015-06-01

    Duplication and divergence are two basic evolutionary mechanisms of bio-molecular networks. Real-world bio-molecular networks and their statistical characteristics can be well mimicked by artificial algorithms based on the two mechanisms. Bio-molecular networks consist of network motifs, which act as building blocks of large-scale networks. A fundamental question is how network motifs are evolved from long time evolution and natural selection. By considering the effect of various duplication and divergence strategies, we find that the underlying duplication scheme of the real-world undirected bio-molecular networks would rather follow the anti-preference strategy than the random one. The anti-preference duplication mechanism and the dimerization processes can lead to the formation of various motifs, and robustly conserve proper quantities of motifs in the artificial networks as that in the real-world ones. Furthermore, the anti-preference mechanism and edge deletion divergence can robustly preserve the sparsity of the networks. The investigations reveal the possible evolutionary mechanisms of network motifs in real-world bio-molecular networks, and have potential implications in the design, synthesis and reengineering of biological networks for biomedical purpose. PMID:25203993

  10. 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

  11. Diode Laser Arrays

    Science.gov (United States)

    Botez, Dan; Scifres, Don R.

    1994-08-01

    This book provides a comprehensive overview of the fundamental principles and applications of semiconductor diode laser arrays. All of the major types of arrays are discussed in detail, including coherent, incoherent, edge- and surface-emitting, horizontal- and vertical-cavity, individually addressed, lattice- matched and strained-layer systems. The initial chapters cover such topics as lasers, amplifiers, external-cavity control, theoretical modeling, and operational dynamics. Spatially incoherent arrays are then described in detail, and the uses of vertical-cavity surface emitter and edge-emitting arrays in parallel optical-signal processing and multi-channel optical recording are discussed. Researchers and graduate students in solid state physics and electrical engineering studying the properties and applications of such arrays will find this book invaluable.

  12. 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

  13. Soft Supercharging of Biomolecular Ions in Electrospray Ionization Mass Spectrometry

    Science.gov (United States)

    Chingin, Konstantin; Xu, Ning; Chen, Huanwen

    2014-06-01

    The charge states of biomolecular ions in ESI-MS can be significantly increased by the addition of low-vapor supercharging (SC) reagents into the spraying solution. Despite the considerable interest from the community, the mechanistic aspects of SC are not well understood and are hotly debated. Arguments that denaturation accounts for the increased charging observed in proteins sprayed from aqueous solutions containing SC reagent have been published widely, but often with incomplete or ambiguous supporting data. In this work, we explored ESI MS charging and SC behavior of several biopolymers including proteins and DNA oligonucleotides. Analytes were ionized from 100 mM ammonium acetate (NH4Ac) aqueous buffer in both positive (ESI+) and negative (ESI-) ion modes. SC was induced either with m-NBA or by the elevated temperature of ESI capillary. For all the analytes studied we, found striking differences in the ESI MS response to these two modes of activation. The data suggest that activation with m-NBA results in more extensive analyte charging with lower degree of denaturation. When working solution with m-NBA was analyzed at elevated temperatures, the SC effect from m-NBA was neutralized. Instead, the net SC effect was similar to the SC effect achieved by thermal activation only. Overall, our observations indicate that SC reagents enhance ESI charging of biomolecules via distinctly different mechanism compared with the traditional approaches based on analyte denaturation. Instead, the data support the hypothesis that the SC phenomenon involves a direct interaction between a biopolymer and SC reagent occurring in evaporating ESI droplets.

  14. 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...

  15. 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

  16. Gold mesoflower arrays with sub-10 nm intraparticle gaps for highly sensitive and repeatable surface enhanced Raman spectroscopy

    International Nuclear Information System (INIS)

    Self-assembling Au mesoflower arrays are prepared using a polymethylmethacrylate (PMMA) template on an iron substrate via a combined top-down/bottom-up nanofabrication strategy. The PMMA template with the holes around 300–500 nm in diameter is first fabricated by using polymer blend lithography on iron substrates, and the highly homogeneous Au mesoflower arrays with less than 10 nm intraparticle gaps are subsequently obtained by an in situ galvanic reaction between HAuCl4 solution and the iron substrate under optimal stirring of the solution as well as reaction time. Owing to the unique mesostructures and uniformity, Raman measurements show that the gold mesoflower arrays obtained demonstrated a strong and reproducible surface enhanced Raman scattering (SERS) enhancement on the order of ∼107–108. The development of a SERS substrate based on the Au mesoflowers with high spatial density of hot spots, relatively low cost and facial synthesis provides a novel strategy for applications in chemical and biomolecular sensing. (paper)

  17. 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

  18. Architecture of transcriptional regulatory circuits is knitted over the topology of bio-molecular interaction networks

    DEFF Research Database (Denmark)

    Soberano de Oliveira, Ana Paula; Patil, Kiran Raosaheb; Nielsen, Jens

    2008-01-01

    use the topology of bio-molecular interaction networks in order to constrain the solution space. Such approaches systematically integrate the existing biological knowledge with the 'omics' data. Results: Here we introduce a hypothesis-driven method that integrates bio-molecular network topology with...... transcriptome data, thereby allowing the identification of key biological features (Reporter Features) around which transcriptional changes are significantly concentrated. We have combined transcriptome data with different biological networks in order to identify Reporter Gene Ontologies, Reporter Transcription...... Factors, Reporter Proteins and Reporter Complexes, and use this to decipher the logic of regulatory circuits playing a key role in yeast glucose repression and human diabetes. Conclusion: Reporter Features offer the opportunity to identify regulatory hot-spots in bio-molecular interaction networks that...

  19. 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.

  20. 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.

  1. Application of RP-HPLC-diode array detector after SPE to the determination of pesticides in pepper samples.

    Science.gov (United States)

    Tuzimski, Tomasz

    2012-01-01

    The application of HPLC-diode array detector (DAD) after SPE for identification and quantitative analysis of pesticides in red and green pepper samples is demonstrated. An HPLC procedure on an RP column (C18) was developed for analysis of selected pesticides from different chemical groups: metamitron, metalaxyl, linuron, and prometryn. Average recoveries for C18 Polar Plus cartridges and solvents by the proposed RP-HPLC-DAD method after SPE are presented. Average recoveries from the spiked samples and the SDs were 22.5 +/- 2.2, 138.0 +/- 4.1, 78.6 +/- 2.8, and 109.2 +/- 2.3% for metamitron, metalaxyl, linuron, and prometryn, respectively, at concentrations of 7 microg/g in the plant material. The efficiency of the SPE procedure was evaluated using real food samples. The quantities of prometryn, linuron, metalaxyl, and metamitron determined were in the ranges of 0.02-2.24 microg/g (n = 24), 0.08-1.01 microg/g (n = 9), 1.61-2.28 microg/g (n=4), and 0.05-1.07 microg/g (n = 3), respectively, in plant material sampled in 2011. The method was validated for precision, repeatability, and accuracy. PMID:23175966

  2. 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.

  3. An application of neural network for Structural Health Monitoring of an adaptive wing with an array of FBG sensors

    International Nuclear Information System (INIS)

    This paper presents an application of neural networks to determinate the level of activation of shape memory alloy actuators of an adaptive wing. In this concept the shape of the wing can be controlled and altered thanks to the wing design and the use of integrated shape memory alloy actuators. The wing is assumed as assembled from a number of wing sections that relative positions can be controlled independently by thermal activation of shape memory actuators. The investigated wing is employed with an array of Fibre Bragg Grating sensors. The Fibre Bragg Grating sensors with combination of a neural network have been used to Structural Health Monitoring of the wing condition. The FBG sensors are a great tool to control the condition of composite structures due to their immunity to electromagnetic fields as well as their small size and weight. They can be mounted onto the surface or embedded into the wing composite material without any significant influence on the wing strength. The paper concentrates on analysis of the determination of the twisting moment produced by an activated shape memory alloy actuator. This has been analysed both numerically using the finite element method by a commercial code ABAQUS (registered) and experimentally using Fibre Bragg Grating sensor measurements. The results of the analysis have been then used by a neural network to determine twisting moments produced by each shape memory alloy actuator.

  4. 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

  5. Field application of smart SHM using field programmable gate array technology to monitor an RC bridge in New Mexico

    International Nuclear Information System (INIS)

    In this paper, an innovative field application of a structural health monitoring (SHM) system using field programmable gate array (FPGA) technology and wireless communication is presented. The new SHM system was installed to monitor a reinforced concrete (RC) bridge on Interstate 40 (I-40) in Tucumcari, New Mexico. This newly installed system allows continuous remote monitoring of this bridge using solar power. Details of the SHM component design and installation are discussed. The integration of FPGA and solar power technologies make it possible to remotely monitor infrastructure with limited access to power. Furthermore, the use of FPGA technology enables smart monitoring where data communication takes place on-need (when damage warning signs are met) and on-demand for periodic monitoring of the bridge. Such a system enables a significant cut in communication cost and power demands which are two challenges during SHM operation. Finally, a three-dimensional finite element (FE) model of the bridge was developed and calibrated using a static loading field test. This model is then used for simulating damage occurrence on the bridge. Using the proposed automation process for SHM will reduce human intervention significantly and can save millions of dollars currently spent on prescheduled inspection of critical infrastructure worldwide

  6. Development of the microphone array measurement technique for application to cryogenic wind tunnels; Entwicklung der Mikrofonarraymesstechnik fuer die experimentelle Anwendung in kryogenen Windkanaelen

    Energy Technology Data Exchange (ETDEWEB)

    Ahlefeldt, Thomas

    2013-02-01

    The present work deals with the development of the microphone array measurement technique for application to cryogenic wind tunnels at temperatures down to 100 K. In contrast to conventional wind tunnels, in cryogenic wind tunnels the Reynolds number can be changed independent of the Mach number. Therefore the applicability of the microphone array measurement technique to cryogenic wind tunnels allows the independent investigation of Mach and Reynolds number effects for aeroacoustic sources. For this purpose two microphone arrays suitable for cryogenic application have been developed. A small array was used for a validation experiment using a single-rod configuration as an aeroacoustic noise source; the experience gained therefrom being then used to develop a larger array. This array was used to finally demonstrate the applicability of the measuring technology to an airplane half model. For the development of both arrays several factors had to be considered, such as, for example, the contraction arising from the low temperatures and the influence of the temperature on the microphone frequency response. In the validation experiment, acoustic array measurements have been performed using the small microphone array with 21 microphones in a cryogenic wind tunnel for various Mach and Reynolds numbers, using a single-rod configuration. The aeroacoustic source induced by the rod could be identified by the microphone.array at ambient as well as at cryogenic temperatures. The radiated sound powers were compared with predictions from two models: one model was based on a dimensional analysis of the measured data without taking into consideration the Reynolds number. The measured data with this model could be better fitted by a speed law with the exponent 6.7 rather than the expected 6.0. The second model was based on an analytical model for sound radiation from a single-rod configuration which took into account variables dependent on the Reynolds number. The comparison with

  7. General model for lipid-mediated two-dimensional array formation of membrane proteins: Application to bacteriorhodopsin

    DEFF Research Database (Denmark)

    Sabra, Mads Christian; Uitdehaag, J.C.M.; Watts, A

    1998-01-01

    Based on experimental evidence for 2D array formation of bacteriorhodopsin, we propose a general model for lipid-mediated 2D array formation of membrane proteins in lipid bilayers. The model includes two different lipid Species; "annular" lipids and "neutral" lipids, and one protein species. The ...

  8. 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

  9. From Correlation to Causality: Statistical Approaches to Learning Regulatory Relationships in Large-Scale Biomolecular Investigations.

    Science.gov (United States)

    Ness, Robert O; Sachs, Karen; Vitek, Olga

    2016-03-01

    Causal inference, the task of uncovering regulatory relationships between components of biomolecular pathways and networks, is a primary goal of many high-throughput investigations. Statistical associations between observed protein concentrations can suggest an enticing number of hypotheses regarding the underlying causal interactions, but when do such associations reflect the underlying causal biomolecular mechanisms? The goal of this perspective is to provide suggestions for causal inference in large-scale experiments, which utilize high-throughput technologies such as mass-spectrometry-based proteomics. We describe in nontechnical terms the pitfalls of inference in large data sets and suggest methods to overcome these pitfalls and reliably find regulatory associations. PMID:26731284

  10. 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

  11. 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

  12. 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.

  13. 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

  14. 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.

  15. ZnO dense nanowire array on a film structure in a single crystal domain texture for optical and photoelectrochemical applications

    International Nuclear Information System (INIS)

    A single crystal domain texture quality (a unique in-plane and out-of-plane crystalline orientation over a large area) ZnO nanostructure of a dense nanowire array on a thick film has been homogeneously synthesized on a-plane sapphire substrates over large areas through a one-step chemical vapor deposition (CVD) process. The growth mechanism is clarified: a single crystal [0 2-bar 1] oriented ZnAl2O4 buffer layer was formed at the ZnO film and the a-plane sapphire substrate interface via a diffusion reaction process during the CVD process, providing improved epitaxial conditions that enable the synthesis of the high crystalline quality ZnO nanowire array on a film structure. The high optoelectronic quality of the ZnO nanowire array on a film sample is evidenced by the free exitonic emissions in the low-temperature photoluminescence spectroscopy. A carrier density of ∼1017 cm−3 with an n-type conductivity of the ZnO nanowire array on a film sample is obtained by electrochemical impedance analysis. Finally, the ZnO nanowire array on a film sample is demonstrated to be an ideal template for a further synthesis of a single crystal quality ZnO–ZnGa2O4 core–shell nanowire array on a film structure. The fabricated ZnO–ZnGa2O4 sample revealed an enhanced anticorrosive ability and photoelectrochemical performance when used as a photoanode in a photoelectrochemical water splitting application. (paper)

  16. Development of a biomolecular assay for postmortem diagnosis of Taenia saginata Cysticercosis.

    Science.gov (United States)

    Chiesa, Francesco; Dalmasso, Alessandra; Bellio, Alberto; Martinetti, Manuela; Gili, Stefano; Civera, Tiziana

    2010-10-01

    Bovine cysticercosis is caused by the larval stage of the human tapeworm Taenia saginata. According to European data on meat inspection, the prevalence ranges from 0.007% to 6.8%, but the real prevalence is considered to be at least 10 times higher. Laboratory confirmation of the etiological agent is based on gross, stereomicroscopic, and histological examination of submitted specimens. False identifications may occur, possibly because of death and degeneration of cysts, or because taeniid larvae and other tissue parasites, such as Sarcocystis spp., may cause similar macroscopic morphological lesions. Therefore, tests that can warrant sure identification of taeniid lesions and calcified cysts in the muscle are needed. The focus of our study was to develop a suitable postmortem test that could be applied on putative lesions by T. saginata cysticerci, as ambiguously diagnosed after routine meat inspection. In particular, we proposed a biomolecular assay targeting the mitochondrial cytochrome c oxidase subunit I gene (COI). For developing the polymerase chain reaction assay, viable cysts of Cysticercus bovis (n = 10) were used as positive reference samples, and those of Echinococcus granulosus (n = 3), Cysticercus tenuicollis (n = 3), and Sarcocystis spp. (n = 4) as reference negative controls. Further, to evaluate the applicability of the proposed assay, 171 samples of bovine muscular tissue, obtained from local slaughterhouses and containing lesions recognized as T. saginata cysticerci by macroscopic examination, were tested. The proposed test confirmed the diagnosis at postmortem inspection in 94.7% (162/171) of samples. In conclusion, the assay developed in this study, amplifying a short fragment from the mitochondrial gene COI, showed to be suitable for samples containing both viable and degenerating T. saginata cysticerci, yielding an unequivocal diagnosis. PMID:20618079

  17. 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

  18. 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

  19. 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

  20. Genetic optimisation of a plane array geometry for beamforming. Application to source localisation in a high speed train

    Science.gov (United States)

    Le Courtois, Florent; Thomas, Jean-Hugh; Poisson, Franck; Pascal, Jean-Claude

    2016-06-01

    Thanks to its easy implementation and robust performance, beamforming is applied for source localisation in several fields. Its effectiveness depends greatly on the array sensor configuration. This paper introduces a criterion to improve the array beampattern and increase the accuracy of sound source localisation. The beamwidth and the maximum sidelobe level are used to quantify the spatial variation of the beampattern through a new criterion. This criterion is shown to be useful, especially for the localisation of moving sources. A genetic algorithm is proposed for the optimisation of microphone placement. Statistical analysis of the optimised arrays provides original results on the algorithm performance and on the optimal microphone placement. An optimised array is tested to localise the sound sources of a high speed train. The results show an accurate separation.

  1. 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.

  2. 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

  3. 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.

  4. 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

  5. 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...

  6. 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

  7. AfricaArray International Geophysics Field School: Applications of Near Surface Geophysics to challenges encountered in mine planning

    Science.gov (United States)

    Webb, S. J.; Jones, M. Q.; Durrheim, R. J.; Nyblade, A.; Snyman, Q.

    2012-12-01

    Hard rock exploration and mining presents many opportunities for the effective use of near surface geophysics. For over 10 years the AfricaArray international geophysics field school has been hosted at a variety of mines in South Africa. While the main objective of the field school is practical training for the next generation of geophysicists, being hosted at a mine has allowed us to investigate applications of near surface geophysics in the early stages of mine planning and development as geophysics is often cheaper and faster than drilling. Several applications include: detailed delineation of dykes and stringer dykes, physical property measurements on drill core for modeling and marker horizons, determination of overburden thickness, locations of water and faults. Dolerite dykes are usually magnetic and are associated with loss of ground (i.e. where the dyke replaces the ore and thus reduces the amount of ore available) and safety/stability concerns. Thus the accurate mapping of dykes and narrow stringers that are associated with them are crucial to the safe planning of a mine. We have acquired several case studies where ground magnetic surveys have greatly improved on the resolution and detail of airborne magnetic surveys in regions of complicated dyke swarms. In many cases, thin stringer dykes of less than 5 cm have been detected. Physical property measurements of these dykes can be used to distinguish between different ages of dykes. It is important to accurately determine overburden thickness when planning an open pit mine as this directly affects the cost of development. Depending on the nature of the overburden, both refraction seismic and or DC resistivity can provide continuous profiling in the area of interest that fills in gaps between boreholes. DC resistivity is also effective for determining water associated with dykes and structures that may affect mine planning. The field school mainly addresses the training of a variety of students. The core

  8. Aligators for arrays

    OpenAIRE

    Henzinger, Thomas A.; Hottelier, Thibaud; Kovács, Laura; Rybalchenko, Andrey

    2010-01-01

    This paper presents Aligators, a tool for the generation of universally quantified array invariants. Aligators leverages recurrence solving and algebraic techniques to carry out inductive reasoning over array content. The Aligators’ loop extraction module allows treatment of multi-path loops by exploiting their commutativity and serializability properties. Our experience in applying Aligators on a collection of loops from open source software projects indicates the applicability of recurren...

  9. Controllable synthesis of mesoporous Co{sub 3}O{sub 4} nanoflake array and its application for supercapacitor

    Energy Technology Data Exchange (ETDEWEB)

    Xiao, Anguo, E-mail: hixiaoanguo@126.com; Zhou, Shibiao; Zuo, Chenggang; Zhuan, Yongbing; Ding, Xiang

    2014-12-15

    Graphical abstract: Electrodeposited mesoporous Co{sub 3}O{sub 4} nanoflake arrays exhibit porous structure composed of mesoporous nanoflakes and high supercapacitor performance. - Highlights: • Mesoporous Co{sub 3}O{sub 4} nanoflake arrays are prepared via electrodeposition method. • Mesoporous nanowall arrays are favorable for fast ion/electron transfer. • Mesoporous Co{sub 3}O{sub 4} nanoflake arrays show excellent supercapacitor performance. - Abstract: A mesoporous Co{sub 3}O{sub 4} nanoflake array grown on carbon cloth is prepared by a facile electrodeposition method with a following annealing process. The as-prepared Co{sub 3}O{sub 4} nanoflake possesses a continuous mesopores ranging from 2 to 5 nm and grows tightly on the substrate forming a porous net-like structure with macropores of 20–200 nm. The electrochemical performance of the mesoporous Co{sub 3}O{sub 4} nanoflake arrays as pseudocapcitor electrode are investigated by cyclic voltammograms and galvanostatic charge/discharge tests in 2 M KOH. The as-prepared Co{sub 3}O{sub 4} array exhibits a high discharge capacitance and excellent rate capability with 450 F g{sup −1}, 436 F g{sup −1}, 408 F g{sup −1}, 380 F g{sup −1}and 363 F g{sup −1} at 1, 2, 4, 10, and 20 A g{sup −1}, respectively. The specific capacitance of 81% is maintained from 1 A g{sup −1} to 20 A g{sup −1}. The electrode also shows rather good cycling stability and exhibits a specific capacitance of 414 F g{sup −1} after 5000 cycles.

  10. 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.

  11. Electrocatalytic applications of a vertical Au nanorod array using ultrathin Pt/Ru/Pt layer-by-layer coatings

    International Nuclear Information System (INIS)

    This study compared the electro-oxidation of carbon monoxide adlayers formed on a codeposited and a layer-by-layer deposited Pt/Ru thin overlayer on a Au surface. Vertical arrays of smooth and nanoporous Au nanorods were used as a platform for the Pt/Ru overlayer-coating. The vertical arrays of Au nanorods served as high surface area templates, where the surface area could be controlled as a function of the rod length in a given geometrical surface area. A coating of the Au nanorod arrays with Pt/Ru via Cu underpotential deposition (UPD) steps allowed control of the overlayer thickness with an ultrathin film nature. The electronic modification of the Pt overlayer with a Ru underlayer became increasingly weaker with increasing Pt overlayer thickness. The thick Pt overlayer exhibited CO electro-oxidation that was similar to the electro-oxidation profile on the Pt bulk surface. Coating of the Au nanorod arrays with Pt/Ru through Cu UPD steps demonstrated an optimal electronic response between the Pt outer overlayer and the underlying Ru layer. It is expected that an ultrathin overlayer-coating strategy can be expanded to nanoporous Au nanorod arrays. These finding will facilitate better design of highly active Pt/Ru composite nanostructures for electrocatalysis

  12. 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.

  13. 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...

  14. Synthesis of CdS nanorod arrays and their applications in flexible piezo-driven active H2S sensors

    International Nuclear Information System (INIS)

    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. (paper)

  15. Application of finite-difference time domain to dye-sensitized solar cells: The effect of nanotube-array negative electrode dimensions on light absorption

    Energy Technology Data Exchange (ETDEWEB)

    Ong, Keat G. [Department of Biomedical Engineering, Michigan Technological University, Houghton, MI 49931 (United States); Varghese, Oomman K.; Mor, Gopal K.; Shankar, Karthik; Grimes, Craig A. [The Pennsylvania State University, 217 Materials Research Laboratory, University Park, PA 16802 (United States)

    2007-02-15

    We examine the light absorbing behavior of dye-sensitized solar cells (DSCs) having cathodes (negative electrodes) comprised of highly ordered TiO{sub 2} nanotube arrays using the electromagnetic computational technique, finite-difference time domain (FDTD). The highly ordered nanotube arrays, grown using anodic oxidation of titanium foils or thin films, feature an open end with the other end fixed on a dense oxide layer (barrier layer). The numerical simulation model is comprised of nanotube arrays on a transparent conducting glass substrate under front-side illumination. In the FDTD analysis, a transverse electromagnetic (TEM) wave is incident onto a N719 dye-coated nanotube array initially passing through the barrier layer; light that emerges from the nanotubes is reflected by a perfectly conducting layer (perfect electric conductor-PEC) boundary that simulates the effect of the DSC platinum counter electrode. An observation plane placed between the electromagnetic source and DSC detects the intensity of both the incident wave and the wave returning back from the DSC structure. The absorbance and transmittance spectra are determined in the wavelength range 300-700nm as a function of nanotube-array dimensions including length, pore size, barrier layer thickness, and surface roughness while keeping the wall thickness constant at 12nm. The validity of the computational simulations is experimentally verified. A significant increase in the light absorption by the dye-coated nanotubes was observed for increasing nanotube length; smaller pore sizes, and increased surface roughness. Changes in the barrier layer thickness had a negligible effect on the absorbance spectrum. Our efforts demonstrate FDTD to be a broadly applicable technique capable of guiding design of an optimal DSC architecture. (author)

  16. Patterning with particles using three-dimensional interdigitated array electrodes with negative dielectrophoresis and its application to simple immunosensing

    International Nuclear Information System (INIS)

    Island organization of particles have been fabricated in a microfluidic device consisted of upper and lower conductive indium-tin-oxide (ITO) substrates with interdigitated microband array (IDA) electrode used as the template based on a dielectrophoresis (DEP). Grid formation of electrodes was fabricated by rotating the upper template ITO-IDA by 90° relative to the lower ITO-IDA. A suspension of polystyrene particles with a 3-μm diameter was introduced into the device. AC electric signal (typically 20 V peak-to-peak, 1.0 MHz) was then applied to the bands on the upper and lower IDA, resulting in the formation of island patterns at the intersections with low electric fields. When the AC voltage with same frequency and same phase was applied to the bands on upper and lower IDA, particles were accumulated at the intersections consisted of the bands applied voltage and bands connected to the ground because the relatively lower electric fields were produced at those intersections; on contrast, the application of the AC voltage with different frequencies to the bands allowed to the formation of second pattern due to the generation of the strong electric field at the intersections applied the AC voltage with different frequencies. Moreover, it is possible to convert the second patterns reversibly by choosing the band applying the different frequencies. The particles forming the patterns were immobilized in a photoreactive hydrogel polymer. The well-ordered particles embedded in the flexible hydrogel sheet firmly were obtained by ultraviolet irradiation to the entire device with patterns. The accumulated particles were fixed through the immunoreactions between the antibody immobilized on the particle surface and analytes in the solution. The presence of the specific antigens allowed to the fixed complexes of particles. It is noted that the time required for single sensing is as short as 5 min and separation steps are eliminated in the presented procedure, while we decide

  17. Tuning of structural, optical, and magnetic properties of ultrathin and thin ZnO nanowire arrays for nano device applications

    Science.gov (United States)

    Shrama, Satinder K.; Saurakhiya, Neelam; Barthwal, Sumit; Kumar, Rudra; Sharma, Ashutosh

    2014-03-01

    One-dimensional (1-D) ultrathin (15 nm) and thin (100 nm) aligned 1-D (0001) and ([InlineEquation not available: see fulltext.]) oriented zinc oxide (ZnO) nanowire (NW) arrays were fabricated on copper substrates by one-step electrochemical deposition inside the pores of polycarbonate membranes. The aspect ratio dependence of the compressive stress because of the lattice mismatch between NW array/substrate interface and crystallite size variations is investigated. X-ray diffraction results show that the polycrystalline ZnO NWs have a wurtzite structure with a = 3.24 Å, c = 5.20 Å, and [002] elongation. HRTEM and SAED pattern confirmed the polycrystalline nature of ultrathin ZnO NWs and lattice spacing of 0.58 nm. The crystallite size and compressive stress in as-grown 15- and 100-nm wires are 12.8 nm and 0.2248 GPa and 22.8 nm and 0.1359 GPa, which changed to 16.1 nm and 1.0307 GPa and 47.5 nm and 1.1677 GPa after annealing at 873 K in ultrahigh vacuum (UHV), respectively. Micro-Raman spectroscopy showed that the increase in E2 (high) phonon frequency corresponds to much higher compressive stresses in ultrathin NW arrays. The minimum-maximum magnetization magnitude for the as-grown ultrathin and thin NW arrays are approximately 8.45 × 10-3 to 8.10 × 10-3 emu/g and approximately 2.22 × 10-7 to 2.190 × 10-7 emu/g, respectively. The magnetization in 15-nm NW arrays is about 4 orders of magnitude higher than that in the 100 nm arrays but can be reduced greatly by the UHV annealing. The origin of ultrathin and thin NW array ferromagnetism may be the exchange interactions between localized electron spin moments resulting from oxygen vacancies at the surfaces of ZnO NWs. The n-type conductivity of 15-nm NW array is higher by about a factor of 2 compared to that of the 100-nm ZnO NWs, and both can be greatly enhanced by UHV annealing. The ability to tune the stresses and the structural and relative occupancies of ZnO NWs in a wide range by annealing has important

  18. Tuning of structural, optical, and magnetic properties of ultrathin and thin ZnO nanowire arrays for nano device applications

    OpenAIRE

    Shrama, Satinder K; Saurakhiya, Neelam; Barthwal, Sumit; Kumar, Rudra; Sharma, Ashutosh

    2014-01-01

    One-dimensional (1-D) ultrathin (15 nm) and thin (100 nm) aligned 1-D (0001) and ( 000 1 ¯ ) oriented zinc oxide (ZnO) nanowire (NW) arrays were fabricated on copper substrates by one-step electrochemical deposition inside the pores of polycarbonate membranes. The aspect ratio dependence of the compressive stress because of the lattice mismatch between NW array/substrate interface and crystallite size variations is investigated. X-ray diffraction results show that the polycrystalline ZnO NWs ...

  19. 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)

  20. 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.

  1. 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.

  2. 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

  3. 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

  4. 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.

  5. Distributed Phased Arrays and Wireless Beamforming Networks

    OpenAIRE

    David Jenn; Yong Loke; Tong Chin Hong Matthew; Yeo Eng Choon; Ong Chin Siang; Yeo Siew Yam

    2009-01-01

    Distributed phased arrays have advantages over conventional arrays in many radar and communication applications. Additional advantages are realized by replacing the microwave beamforming circuit by a wireless network, thus forming a wirelessly networked distributed sensor array. This article examines various aspects of a distributed phased array that incorporates wireless beamforming. First, the fundamental array theory and digital signal processing are reviewed. Basic equations are presented...

  6. Aligators for Arrays (Tool Paper)

    Science.gov (United States)

    Henzinger, Thomas A.; Hottelier, Thibaud; Kovács, Laura; Rybalchenko, Andrey

    This paper presents Aligators, a tool for the generation of universally quantified array invariants. Aligators leverages recurrence solving and algebraic techniques to carry out inductive reasoning over array content. The Aligators' loop extraction module allows treatment of multi-path loops by exploiting their commutativity and serializability properties. Our experience in applying Aligators on a collection of loops from open source software projects indicates the applicability of recurrence and algebraic solving techniques for reasoning about arrays.

  7. 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...

  8. 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

  9. 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

  10. 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

  11. 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

  12. 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...

  13. 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)

  14. 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...

  15. 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...

  16. Evaluation of stochastic effects on biomolecular networks using the generalised Nyquist stability criterion

    OpenAIRE

    Kim, J; Bates, D. G.; Postlethwaite, I.

    2008-01-01

    Abstract—Stochastic differential equations are now commonly used to model biomolecular networks in systems biology, and much recent research has been devoted to the development of methods to analyse their stability properties. Stability analysis of such systems may be performed using the Laplace transform, which requires the calculation of the exponential matrix involving time symbolically. However, the calculation of the symbolic exponential matrix is not feasible for problems of even mod...

  17. 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...

  18. The Shadow Map: A General Contact Definition for Capturing the Dynamics of Biomolecular Folding and Function

    OpenAIRE

    Jeffrey K Noel; Whitford, Paul C.; Onuchic, José N.

    2012-01-01

    Structure-based models (SBMs) are simplified models of the biomolecular dynamics that arise from funneled energy landscapes. We recently introduced an all-atom SBM that explicitly represents the atomic geometry of a biomolecule. While this initial study showed the robustness of the all-atom SBM Hamiltonian to changes in many of the energetic parameters, an important aspect, which has not been explored previously, is the definition of native interactions. In this study, we propose a general de...

  19. A Review of Salam Phase Transition in Protein Amino Acids: Implication for Biomolecular Homochirality

    OpenAIRE

    Bai, Fan; Wang, Wenqing

    2002-01-01

    The origin of chirality, closely related to the evolution of life on the earth, has long been debated. In 1991, Abdus Salam suggested a novel approach to achieve biomolecular homochirality by a phase transition. In his subsequent publication, he predicted that this phase transition could eventually change D-amino acids to L-amino acids as C -H bond would break and H atom became a superconductive atom. Since many experiments denied the configuration change in amino acids, Salam hypothesis arou...

  20. Affinity capillary electrophoresis and density functional theory employed for characterization of (bio)molecular interactions

    Czech Academy of Sciences Publication Activity Database

    Kašička, Václav; Ehala, Sille; Růžička, Martin; Dybal, Jiří; Toman, Petr

    Salzburg: Society of Analytical Chemistry, 2014. OR28. [ISC 2014. International Symposium on Chromatography /30./. 14.09.2014-18.09.2014, Salzburg] R&D Projects: GA ČR(CZ) GAP206/12/0453; GA ČR(CZ) GA13-17224S Institutional support: RVO:61388963 ; RVO:61389013 Keywords : affinity capillary electrophoresis * density functional theory * biomolecular complexes Subject RIV: CB - Analytical Chemistry, Separation