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Sample records for metal-molecule interfaces trends

  1. Resolving metal-molecule interfaces at single-molecule junctions

    PubMed Central

    Komoto, Yuki; Fujii, Shintaro; Nakamura, Hisao; Tada, Tomofumi; Nishino, Tomoaki; Kiguchi, Manabu

    2016-01-01

    Electronic and structural detail at the electrode-molecule interface have a significant influence on charge transport across molecular junctions. Despite the decisive role of the metal-molecule interface, a complete electronic and structural characterization of the interface remains a challenge. This is in no small part due to current experimental limitations. Here, we present a comprehensive approach to obtain a detailed description of the metal-molecule interface in single-molecule junctions, based on current-voltage (I-V) measurements. Contrary to conventional conductance studies, this I-V approach provides a correlated statistical description of both, the degree of electronic coupling across the metal-molecule interface, and the energy alignment between the conduction orbital and the Fermi level of the electrode. This exhaustive statistical approach was employed to study single-molecule junctions of 1,4-benzenediamine (BDA), 1,4-butanediamine (C4DA), and 1,4-benzenedithiol (BDT). A single interfacial configuration was observed for both BDA and C4DA junctions, while three different interfacial arrangements were resolved for BDT. This multiplicity is due to different molecular adsorption sites on the Au surface namely on-top, hollow, and bridge. Furthermore, C4DA junctions present a fluctuating I-V curve arising from the greater conformational freedom of the saturated alkyl chain, in sharp contrast with the rigid aromatic backbone of both BDA and BDT. PMID:27221947

  2. Resolving metal-molecule interfaces at single-molecule junctions

    NASA Astrophysics Data System (ADS)

    Komoto, Yuki; Fujii, Shintaro; Nakamura, Hisao; Tada, Tomofumi; Nishino, Tomoaki; Kiguchi, Manabu

    2016-05-01

    Electronic and structural detail at the electrode-molecule interface have a significant influence on charge transport across molecular junctions. Despite the decisive role of the metal-molecule interface, a complete electronic and structural characterization of the interface remains a challenge. This is in no small part due to current experimental limitations. Here, we present a comprehensive approach to obtain a detailed description of the metal-molecule interface in single-molecule junctions, based on current-voltage (I-V) measurements. Contrary to conventional conductance studies, this I-V approach provides a correlated statistical description of both, the degree of electronic coupling across the metal-molecule interface, and the energy alignment between the conduction orbital and the Fermi level of the electrode. This exhaustive statistical approach was employed to study single-molecule junctions of 1,4-benzenediamine (BDA), 1,4-butanediamine (C4DA), and 1,4-benzenedithiol (BDT). A single interfacial configuration was observed for both BDA and C4DA junctions, while three different interfacial arrangements were resolved for BDT. This multiplicity is due to different molecular adsorption sites on the Au surface namely on-top, hollow, and bridge. Furthermore, C4DA junctions present a fluctuating I-V curve arising from the greater conformational freedom of the saturated alkyl chain, in sharp contrast with the rigid aromatic backbone of both BDA and BDT.

  3. Determination of energy level alignment at metal/molecule interfaces by in-device electrical spectroscopy

    NASA Astrophysics Data System (ADS)

    Gobbi, M.; Pietrobon, L.; Atxabal, A.; Bedoya-Pinto, A.; Sun, X.; Golmar, F.; Llopis, R.; Casanova, F.; Hueso, L. E.

    2014-06-01

    The energetics of metal/molecular semiconductor interfaces plays a fundamental role in organic electronics, determining the performance of very diverse devices. So far, information about the energy level alignment has been most commonly gained by spectroscopy techniques that typically require experimental conditions far from the real device operation. Here we demonstrate that a simple three-terminal device allows the acquisition of spectroscopic information about the metal/molecule energy alignment in real operative condition. As a proof of principle, we employ the proposed device to measure the energy barrier height between different clean metals and C60 molecules and we recover typical results from photoemission spectroscopy. The device is designed to inject a hot electron current directly into the molecular level devoted to charge transport, disentangling the contributions of both the interface and the bulk to the device total resistance, with important implications for spintronics and low-temperature physics.

  4. Determination of energy level alignment at metal/molecule interfaces by in-device electrical spectroscopy.

    PubMed

    Gobbi, M; Pietrobon, L; Atxabal, A; Bedoya-Pinto, A; Sun, X; Golmar, F; Llopis, R; Casanova, F; Hueso, L E

    2014-01-01

    The energetics of metal/molecular semiconductor interfaces plays a fundamental role in organic electronics, determining the performance of very diverse devices. So far, information about the energy level alignment has been most commonly gained by spectroscopy techniques that typically require experimental conditions far from the real device operation. Here we demonstrate that a simple three-terminal device allows the acquisition of spectroscopic information about the metal/molecule energy alignment in real operative condition. As a proof of principle, we employ the proposed device to measure the energy barrier height between different clean metals and C60 molecules and we recover typical results from photoemission spectroscopy. The device is designed to inject a hot electron current directly into the molecular level devoted to charge transport, disentangling the contributions of both the interface and the bulk to the device total resistance, with important implications for spintronics and low-temperature physics. PMID:24946715

  5. Global trends in infectious diseases at the wildlife–livestock interface

    PubMed Central

    Wiethoelter, Anke K.; Beltrán-Alcrudo, Daniel; Kock, Richard; Mor, Siobhan M.

    2015-01-01

    The role and significance of wildlife–livestock interfaces in disease ecology has largely been neglected, despite recent interest in animals as origins of emerging diseases in humans. Scoping review methods were applied to objectively assess the relative interest by the scientific community in infectious diseases at interfaces between wildlife and livestock, to characterize animal species and regions involved, as well as to identify trends over time. An extensive literature search combining wildlife, livestock, disease, and geographical search terms yielded 78,861 publications, of which 15,998 were included in the analysis. Publications dated from 1912 to 2013 and showed a continuous increasing trend, including a shift from parasitic to viral diseases over time. In particular there was a significant increase in publications on the artiodactyls–cattle and bird–poultry interface after 2002 and 2003, respectively. These trends could be traced to key disease events that stimulated public interest and research funding. Among the top 10 diseases identified by this review, the majority were zoonoses. Prominent wildlife–livestock interfaces resulted largely from interaction between phylogenetically closely related and/or sympatric species. The bird–poultry interface was the most frequently cited wildlife–livestock interface worldwide with other interfaces reflecting regional circumstances. This review provides the most comprehensive overview of research on infectious diseases at the wildlife–livestock interface to date. PMID:26195733

  6. Global trends in infectious diseases at the wildlife-livestock interface.

    PubMed

    Wiethoelter, Anke K; Beltrán-Alcrudo, Daniel; Kock, Richard; Mor, Siobhan M

    2015-08-01

    The role and significance of wildlife-livestock interfaces in disease ecology has largely been neglected, despite recent interest in animals as origins of emerging diseases in humans. Scoping review methods were applied to objectively assess the relative interest by the scientific community in infectious diseases at interfaces between wildlife and livestock, to characterize animal species and regions involved, as well as to identify trends over time. An extensive literature search combining wildlife, livestock, disease, and geographical search terms yielded 78,861 publications, of which 15,998 were included in the analysis. Publications dated from 1912 to 2013 and showed a continuous increasing trend, including a shift from parasitic to viral diseases over time. In particular there was a significant increase in publications on the artiodactyls-cattle and bird-poultry interface after 2002 and 2003, respectively. These trends could be traced to key disease events that stimulated public interest and research funding. Among the top 10 diseases identified by this review, the majority were zoonoses. Prominent wildlife-livestock interfaces resulted largely from interaction between phylogenetically closely related and/or sympatric species. The bird-poultry interface was the most frequently cited wildlife-livestock interface worldwide with other interfaces reflecting regional circumstances. This review provides the most comprehensive overview of research on infectious diseases at the wildlife-livestock interface to date. PMID:26195733

  7. Phospholipids at the Interface: Current Trends and Challenges

    PubMed Central

    Pichot, Roman; Watson, Richard L.; Norton, Ian T.

    2013-01-01

    Phospholipids are one of the major structural elements of biological membranes. Due to their amphiphilic character, they can adopt various molecular assemblies when dispersed in water, such as bilayer vesicles or micelles, which give them unique interfacial properties and render them very attractive in terms of foam or emulsion stabilization. This article aims at reviewing the properties of phospholipids at the air/water and oil/water interfaces, as well as the recent advances in using these natural components as stabilizers, alone or in combination with other compounds such as proteins. A discussion regarding the challenges and opportunities offered by phospholipids-stabilized structure concludes the review. PMID:23736688

  8. P300 brain computer interface: current challenges and emerging trends

    PubMed Central

    Fazel-Rezai, Reza; Allison, Brendan Z.; Guger, Christoph; Sellers, Eric W.; Kleih, Sonja C.; Kübler, Andrea

    2012-01-01

    A brain-computer interface (BCI) enables communication without movement based on brain signals measured with electroencephalography (EEG). BCIs usually rely on one of three types of signals: the P300 and other components of the event-related potential (ERP), steady state visual evoked potential (SSVEP), or event related desynchronization (ERD). Although P300 BCIs were introduced over twenty years ago, the past few years have seen a strong increase in P300 BCI research. This closed-loop BCI approach relies on the P300 and other components of the ERP, based on an oddball paradigm presented to the subject. In this paper, we overview the current status of P300 BCI technology, and then discuss new directions: paradigms for eliciting P300s; signal processing methods; applications; and hybrid BCIs. We conclude that P300 BCIs are quite promising, as several emerging directions have not yet been fully explored and could lead to improvements in bit rate, reliability, usability, and flexibility. PMID:22822397

  9. Non-traditional approaches to solid-electrolyte interfaces: Trends and prospects

    NASA Astrophysics Data System (ADS)

    Duke, C. B.

    1980-12-01

    This paper is a synopsis of the "summing-up" lecture presented at the International Conference on Non-Traditional Approaches to the Study of the Solid-Electrolyte Interface. The major issue addressed at this conference was the determination of the structure of the solid-electrolyte interface at the microscopic level (e.g., elemental composition, atomic geometry) as opposed to the phenomenological level (e.g., average local electrostatic potentials and dielectric functions). Studies reported at the conference and in the recent literature may be collected into three groups: (1) the development of new experimental methods to determine the interface structure, (2) the construction of new theoretical models either to interpret the experimental measurements or to predict interface structure, and (3) the study of new materials for electrodes, electrolytes, and complete electrochemical cells. In each of these three areas major trends in current research are delineated. Current work is compared with the goal, articulated by the conference organizers, of achieving an experimental determination of the microscopic structure of the solid-electrolyte interface via in situ methods. This comparison suggests that whereas the reproducibility of the preparation and characterization of these interfaces seem adequate for the intended purpose, suitable in situ structure-sensitive experimental methods have not yet been demonstrated. It is proposed that the status of the characterization of solid-electrolyte interfaces today is roughly comparable to that of solidvacuum interfaces in the early 1970's. Examination of the history of the development of solid-vacuum interface characterization from this perspective further suggests that improved collaboration between theorists and experimentalists as well as more substantial investments in new apparatus and computation for data analysis will be required if the goal of the characterization at a microscopic level of the solid

  10. Electrical and Spectroscopic Characterization of Metal-Molecule-Metal Junctions

    NASA Astrophysics Data System (ADS)

    Mayer, Theresa

    2005-03-01

    Considerable attention has been devoted to developing an understanding of the mechanisms that dominate electrical transport in metal- molecule-metal junctions comprised of single and small ensembles of molecules. In this talk, we will present an overview of recent research on the electrical and spectroscopic characterization of molecular junctions inserted along the length of sub-40-nm diameter Au and Pd metal nanowires (i.e., in-wire junctions) fabricated by template-directed synthesis. In particular, we will show results that investigate the relationship between the temperature dependent (10 -- 300 K) current-voltage (I-V) characteristics and the vibrational spectra measured by inelastic electron tunneling (IET) spectroscopy for candidate molecular wires and bistable switching molecules. The two types of molecular wire junctions that were studied incorporate a self assembled monolayer of dithiolated oligo(phenylene- ethynylene) (OPE) molecules or their -NO2 derivatives. The I-V of these junctions are stable and reproducible between +/-1V. Temperature independent I-V are measured for both types of junctions, which is indicative of coherent tunneling transport. Moreover, strong vibrations associated with υ(18b) and υ(19a) ring modes were observed in both junctions. In contrast, measurements of molecular junctions that incorporate SAMs based on aniline derivatives show reproducible bistable switching with an on-off ratio of >10:1 at 1V. Differences are observed in the vibrational spectra that depend on the state of the junction.

  11. Electrical characterization of metal-molecule-silicon junctions

    NASA Astrophysics Data System (ADS)

    Wang, W.; Lee, T.; Kamdar, M.; Reed, M. A.; Stewart, M. P.; Hwang, J.-J.; Tour, J. M.

    2003-04-01

    Direct assembly of molecules onto silicon surfaces is of particular interest for potential employment in hybrid organic-semiconductor devices. In this study, aryl diazonium salts are used to assemble covalently bound molecular groups onto a hydride-passivated, oxide-free n-type Si(111) surface. The reaction of 4-(trimethylsilylethynyl)benzenediazonium tetrafluoroborate generates a molecular layer of 4-(trimethylsilylethynyl)phenylene (TMS-EP) on the Si surface. The monolayer modifies the electrical properties of the interface and exhibits nonlinear current-voltage characteristics, as compared with the ohmic behavior observed from metal- n ++-Si(111) junctions. Results of current-voltage measurements at variable temperatures (from 300 to 10 K) on samples made with the TMS-EP molecules do not show significant thermally-activated transport, indicating tunneling is the dominant transport mechanism for this device structure. The measured data is compared to a tunneling model.

  12. Roles of lattice cooling on local heating in metal-molecule-metal junctions

    NASA Astrophysics Data System (ADS)

    Tsutsui, Makusu; Taniguchi, Masateru; Yokota, Kazumichi; Kawai, Tomoji

    2010-03-01

    We report a quantitative assessment of the efficacy of lattice cooling on mitigating local heating in a current-carrying single molecule wire connected to gold nanoelectrodes by comparative analyses of high-field effective temperatures at different ambient temperatures. We find substantial local heating in benzenedithiol single molecule junctions raising the local temperatures by ˜320 K from the ambient to ˜400 K at 0.85 V. The intense self-heating are attributable to decreased thermal conductance at low temperatures that leads to deteriorated heat transfer at metal-molecule contacts, thereby manifesting a critical role of lattice cooling for alleviating metal-molecule-metal junction overheating.

  13. Current trends in hardware and software for brain-computer interfaces (BCIs)

    NASA Astrophysics Data System (ADS)

    Brunner, P.; Bianchi, L.; Guger, C.; Cincotti, F.; Schalk, G.

    2011-04-01

    A brain-computer interface (BCI) provides a non-muscular communication channel to people with and without disabilities. BCI devices consist of hardware and software. BCI hardware records signals from the brain, either invasively or non-invasively, using a series of device components. BCI software then translates these signals into device output commands and provides feedback. One may categorize different types of BCI applications into the following four categories: basic research, clinical/translational research, consumer products, and emerging applications. These four categories use BCI hardware and software, but have different sets of requirements. For example, while basic research needs to explore a wide range of system configurations, and thus requires a wide range of hardware and software capabilities, applications in the other three categories may be designed for relatively narrow purposes and thus may only need a very limited subset of capabilities. This paper summarizes technical aspects for each of these four categories of BCI applications. The results indicate that BCI technology is in transition from isolated demonstrations to systematic research and commercial development. This process requires several multidisciplinary efforts, including the development of better integrated and more robust BCI hardware and software, the definition of standardized interfaces, and the development of certification, dissemination and reimbursement procedures.

  14. Current trends in hardware and software for brain-computer interfaces (BCIs).

    PubMed

    Brunner, P; Bianchi, L; Guger, C; Cincotti, F; Schalk, G

    2011-04-01

    A brain-computer interface (BCI) provides a non-muscular communication channel to people with and without disabilities. BCI devices consist of hardware and software. BCI hardware records signals from the brain, either invasively or non-invasively, using a series of device components. BCI software then translates these signals into device output commands and provides feedback. One may categorize different types of BCI applications into the following four categories: basic research, clinical/translational research, consumer products, and emerging applications. These four categories use BCI hardware and software, but have different sets of requirements. For example, while basic research needs to explore a wide range of system configurations, and thus requires a wide range of hardware and software capabilities, applications in the other three categories may be designed for relatively narrow purposes and thus may only need a very limited subset of capabilities. This paper summarizes technical aspects for each of these four categories of BCI applications. The results indicate that BCI technology is in transition from isolated demonstrations to systematic research and commercial development. This process requires several multidisciplinary efforts, including the development of better integrated and more robust BCI hardware and software, the definition of standardized interfaces, and the development of certification, dissemination and reimbursement procedures. PMID:21436536

  15. Spelling with non-invasive Brain-Computer Interfaces--current and future trends.

    PubMed

    Cecotti, Hubert

    2011-01-01

    Brain-Computer Interfaces (BCIs) have become a large research field that include challenges mainly in neuroscience, signal processing, machine learning and user interface. A non-invasive BCI can allow the direct communication between humans and computers by analyzing electrical brain activity, recorded at the surface of the scalp with electroencephalography. The main purpose for BCIs is to enable communication for people with severe disabilities. Spelling is one of the first BCI application, it corresponds to the main communication mean for people who are unable to speak. While spelling can be the most basic application it remains a benchmark for communication applications and one challenge in the BCI community for some patients. This paper proposes a review of the current main strategies, and their limitations, for spelling words. It includes recent BCIs based on P300, steady-state visual evoked potentials and motor imagery. By considering some challenges in BCI spellers and virtual keyboards, some pragmatic issues are pointed out to eliminate false hopes about BCI for both disabled and healthy people. PMID:21911058

  16. Metal-molecule contacts and charge transport across monomolecular layers: measurement and theory.

    PubMed

    Kushmerick, J G; Holt, D B; Yang, J C; Naciri, J; Moore, M H; Shashidhar, R

    2002-08-19

    Charge transport studies across molecular length scales under symmetric and asymmetric metal-molecule contact conditions using a simple crossed-wire tunnel junction technique are presented. It is demonstrated that oligo(phenylene ethynylene), a conjugated organic molecule, acts like a molecular wire under symmetric contact conditions, but exhibits characteristics of a molecular diode when the connections are asymmetric. To understand this behavior, we have calculated current-voltage (I-V) characteristics using extended Huckel theory coupled with a Green's function approach. The experimentally observed I-V characteristics are in excellent qualitative agreement with the theory. PMID:12190491

  17. Investigation of inelastic electron tunneling spectra of metal-molecule-metal junctions fabricated using direct metal transfer method

    SciTech Connect

    Jeong, Hyunhak; Hwang, Wang-Taek; Kim, Pilkwang; Kim, Dongku; Jang, Yeonsik; Min, Misook; Park, Yun Daniel; Lee, Takhee; Xiang, Dong; Song, Hyunwook; Jeong, Heejun

    2015-02-09

    We measured the inelastic electron tunneling spectroscopy (IETS) characteristics of metal-molecule-metal junctions made with alkanethiolate self-assembled monolayers. The molecular junctions were fabricated using a direct metal transfer method, which we previously reported for high-yield metal-molecule-metal junctions. The measured IETS data could be assigned to molecular vibration modes that were determined by the chemical structure of the molecules. We also observed discrepancies and device-to-device variations in the IETS data that possibly originate from defects in the molecular junctions and insulating walls introduced during the fabrication process and from the junction structure.

  18. Accurate characterization and understanding of interface trap density trends between atomic layer deposited dielectrics and AlGaN/GaN with bonding constraint theory

    SciTech Connect

    Ramanan, Narayanan; Lee, Bongmook; Misra, Veena

    2015-06-15

    Many dielectrics have been proposed for the gate stack or passivation of AlGaN/GaN based metal oxide semiconductor heterojunction field effect transistors, to reduce gate leakage and current collapse, both for power and RF applications. Atomic Layer Deposition (ALD) is preferred for dielectric deposition as it provides uniform, conformal, and high quality films with precise monolayer control of film thickness. Identification of the optimum ALD dielectric for the gate stack or passivation requires a critical investigation of traps created at the dielectric/AlGaN interface. In this work, a pulsed-IV traps characterization method has been used for accurate characterization of interface traps with a variety of ALD dielectrics. High-k dielectrics (HfO{sub 2}, HfAlO, and Al{sub 2}O{sub 3}) are found to host a high density of interface traps with AlGaN. In contrast, ALD SiO{sub 2} shows the lowest interface trap density (<2 × 10{sup 12 }cm{sup −2}) after annealing above 600 °C in N{sub 2} for 60 s. The trend in observed trap densities is subsequently explained with bonding constraint theory, which predicts a high density of interface traps due to a higher coordination state and bond strain in high-k dielectrics.

  19. Modeling light-induced charge transfer dynamics across a metal-molecule-metal junction: bridging classical electrodynamics and quantum dynamics.

    PubMed

    Hu, Zixuan; Ratner, Mark A; Seideman, Tamar

    2014-12-14

    We develop a numerical approach for simulating light-induced charge transport dynamics across a metal-molecule-metal conductance junction. The finite-difference time-domain method is used to simulate the plasmonic response of the metal structures. The Huygens subgridding technique, as adapted to Lorentz media, is used to bridge the vastly disparate length scales of the plasmonic metal electrodes and the molecular system, maintaining accuracy. The charge and current densities calculated with classical electrodynamics are transformed to an electronic wavefunction, which is then propagated through the molecular linker via the Heisenberg equations of motion. We focus mainly on development of the theory and exemplify our approach by a numerical illustration of a simple system consisting of two silver cylinders bridged by a three-site molecular linker. The electronic subsystem exhibits fascinating light driven dynamics, wherein the charge density oscillates at the driving optical frequency, exhibiting also the natural system timescales, and a resonance phenomenon leads to strong conductance enhancement. PMID:25494729

  20. Modeling light-induced charge transfer dynamics across a metal-molecule-metal junction: Bridging classical electrodynamics and quantum dynamics

    NASA Astrophysics Data System (ADS)

    Hu, Zixuan; Ratner, Mark A.; Seideman, Tamar

    2014-12-01

    We develop a numerical approach for simulating light-induced charge transport dynamics across a metal-molecule-metal conductance junction. The finite-difference time-domain method is used to simulate the plasmonic response of the metal structures. The Huygens subgridding technique, as adapted to Lorentz media, is used to bridge the vastly disparate length scales of the plasmonic metal electrodes and the molecular system, maintaining accuracy. The charge and current densities calculated with classical electrodynamics are transformed to an electronic wavefunction, which is then propagated through the molecular linker via the Heisenberg equations of motion. We focus mainly on development of the theory and exemplify our approach by a numerical illustration of a simple system consisting of two silver cylinders bridged by a three-site molecular linker. The electronic subsystem exhibits fascinating light driven dynamics, wherein the charge density oscillates at the driving optical frequency, exhibiting also the natural system timescales, and a resonance phenomenon leads to strong conductance enhancement.

  1. Modeling light-induced charge transfer dynamics across a metal-molecule-metal junction: Bridging classical electrodynamics and quantum dynamics

    SciTech Connect

    Hu, Zixuan; Ratner, Mark A.; Seideman, Tamar

    2014-12-14

    We develop a numerical approach for simulating light-induced charge transport dynamics across a metal-molecule-metal conductance junction. The finite-difference time-domain method is used to simulate the plasmonic response of the metal structures. The Huygens subgridding technique, as adapted to Lorentz media, is used to bridge the vastly disparate length scales of the plasmonic metal electrodes and the molecular system, maintaining accuracy. The charge and current densities calculated with classical electrodynamics are transformed to an electronic wavefunction, which is then propagated through the molecular linker via the Heisenberg equations of motion. We focus mainly on development of the theory and exemplify our approach by a numerical illustration of a simple system consisting of two silver cylinders bridged by a three-site molecular linker. The electronic subsystem exhibits fascinating light driven dynamics, wherein the charge density oscillates at the driving optical frequency, exhibiting also the natural system timescales, and a resonance phenomenon leads to strong conductance enhancement.

  2. Chemically Designed Molecular Interfaces in Cross-Linked Poly(ethylene glycol)/Silica Nanocomposites Reveal Strong Size-Dependent Trends in Gas Permeability

    NASA Astrophysics Data System (ADS)

    Su, Norman; Urban, Jeffrey

    2015-03-01

    Polymer nanocomposite membranes can exhibit gas separation performance that surpasses conventional polymeric membranes. While promising, the optimization of nanocomposite membranes requires a fundamental understanding of the transport mechanism and interfacial effects between the inorganic and polymer phase that is currently limited to empirical relationships. Synthesized nanocomposites often consist of poorly distributed and polydisperse inorganic nanomaterials. It is known that polymer dynamics can change drastically upon introduction of an inorganic phase, which can dramatically alter molecular transport behavior. Here, we systematically explore the role of nanoparticle sizes from 12 to 130 nm on polymer dynamics and permeability in a series of cross-linked poly(ethylene glycol)/silica nanocomposite membranes. The nanocomposites are well-dispersed and display excellent homogeneity throughout. Size-dependent broadening of the Tg indicates strong attractive interactions especially at high surface area loadings, which lead to deviations in permeability not captured by Maxwell's model. Chemical modifications of silica at this interface can yield significantly different polymer dynamics than previously observed with enhanced transport and mechanical properties.

  3. Energy level alignment and quantum conductance of functionalized metal-molecule junctions: Density functional theory versus GW calculations

    SciTech Connect

    Jin, Chengjun; Markussen, Troels; Thygesen, Kristian S.; Strange, Mikkel; Solomon, Gemma C.

    2013-11-14

    We study the effect of functional groups (CH{sub 3}*4, OCH{sub 3}, CH{sub 3}, Cl, CN, F*4) on the electronic transport properties of 1,4-benzenediamine molecular junctions using the non-equilibrium Green function method. Exchange and correlation effects are included at various levels of theory, namely density functional theory (DFT), energy level-corrected DFT (DFT+Σ), Hartree-Fock and the many-body GW approximation. All methods reproduce the expected trends for the energy of the frontier orbitals according to the electron donating or withdrawing character of the substituent group. However, only the GW method predicts the correct ordering of the conductance amongst the molecules. The absolute GW (DFT) conductance is within a factor of two (three) of the experimental values. Correcting the DFT orbital energies by a simple physically motivated scissors operator, Σ, can bring the DFT conductances close to experiments, but does not improve on the relative ordering. We ascribe this to a too strong pinning of the molecular energy levels to the metal Fermi level by DFT which suppresses the variation in orbital energy with functional group.

  4. Understanding long-term baseflow water quality trends using a synoptic survey of the ground water-surface water interface, central Wisconsin.

    PubMed

    Browne, Bryant A; Guldan, Nathan M

    2005-01-01

    The relationship between stream water quality and landscape activities is difficult to evaluate where the principal source of stream flow is ground water seepage because the average travel time from ground water recharge areas to stream discharge positions can be on the order of decades. We tested the idea that past and future baseflow water quality can be predicted based on a synoptic survey of ground water recharge age-dates (based on chlorofluorocarbon [CFC] measurements) and water quality measurements obtained at the ground water-surface water interface. In this study we (i) characterize the discharge-weighted age distribution and water quality of ground water seepage into the Little Plover River (LPR); (ii) use this information to backcast and forecast baseflow NO(3)(-) concentrations; and (iii) evaluate NO(3)(-) backcasts against historical baseflow data (1960 to 2000). The discharge-weighted apparent CFC age of ground water seepage into the LPR was 23.7 (+/-7) yr. Baseflow backcasts matched the four decade rise of baseflow NO(3)(-) from 2 to 8 mg L(-1). Baseflow forecasts included three scenarios. Scenario A projects the historical rise of NO(3)(-) in the LPR basin's ground water recharge through 2050. Scenario B projects a leveling off of NO(3)(-) in ground water recharge in the year 2000. Scenario C projects a leveling off in the year 1985. Under Scenario A, LPR baseflow NO(3)(-) will increase steadily from 8 to 19 mg L(-1) between 2000 and 2050. Under scenarios B and C baseflow NO(3)(-) will plateau at 13 mg L(-1) in 2030 and at 10 mg L(-1) in 2010, respectively. The approach developed in this study can be used to (i) reconstruct historical baseflow water quality patterns in the absence of long-term monitoring data and (ii) project the effects of potential management decision on future water quality. PMID:15843645

  5. Productivity issues at organizational interfaces

    NASA Technical Reports Server (NTRS)

    Holland, A. W.

    1985-01-01

    The need for close interdependence between large numbers of diverse and specialized work groups makes the Space Program extremely vulnerable to loss of productivity at organizational interfaces. Trends within the program also suggest that the number and diversity of interfaces will grow in the near term. Continued maintenance of R&D excellence will require that interface performance issues be included in any future productivity improvement effort. The types and characteristics of organizational interfaces are briefly presented, followed by a review of factors which impact their productivity. Approaches to assessing and improving interface effectiveness are also discussed.

  6. Enterprise Trends

    ERIC Educational Resources Information Center

    Technology & Learning, 2007

    2007-01-01

    Education research experts Eduventures released a report in February 2007 on where U.S. districts are headed with large system management. "Trends in K-12 Enterprise Management: Are Districts Ready to Cross the Chasm?" provides a detailed assessment of the themes and the trends that are driving the market for K-12 enterprise management systems.…

  7. Instructional Time Trends. Education Trends

    ERIC Educational Resources Information Center

    Woods, Julie Rowland

    2015-01-01

    For more than 30 years, Education Commission of the States has tracked instructional time and frequently receives requests for information about policies and trends. In this Education Trends report, Education Commission of the States addresses some of the more frequent questions, including the impact of instructional time on achievement, variation…

  8. Program Trends.

    ERIC Educational Resources Information Center

    Moss, Jeffrey W.; And Others

    1989-01-01

    Articles by Moss, Van Huss, Raynor, Lynch, and Sullivan discuss the trends in all areas of vocational education. Includes information on how new technologies, life-styles, and job demands have changed or should change vocational education. (JOW)

  9. Nationwide Trends

    MedlinePlus

    ... Charts Emerging Trends and Alerts Alcohol Club Drugs Cocaine Hallucinogens Heroin Inhalants Marijuana MDMA (Ecstasy/Molly) Methamphetamine ... includes ecstasy and LSD) in the past month. Cocaine use has gone down in the last few ...

  10. Active colloids at fluid interfaces.

    PubMed

    Malgaretti, P; Popescu, M N; Dietrich, S

    2016-05-01

    If an active Janus particle is trapped at the interface between a liquid and a fluid, its self-propelled motion along the interface is affected by a net torque on the particle due to the viscosity contrast between the two adjacent fluid phases. For a simple model of an active, spherical Janus colloid we analyze the conditions under which translation occurs along the interface and we provide estimates of the corresponding persistence length. We show that under certain conditions the persistence length of such a particle is significantly larger than the corresponding one in the bulk liquid, which is in line with the trends observed in recent experimental studies. PMID:27025167

  11. Environmental Trends.

    ERIC Educational Resources Information Center

    Council on Environmental Quality, Washington, DC.

    This document consists of data which highlight trends in all sectors relevant to environmental policy. These data are presented in the form of charts and maps contained in 13 sections under the following headings: people and the land; critical areas (wetlands, wild areas, parks, historic places, and risk zones); human settlements; transportation;…

  12. Food Trends.

    ERIC Educational Resources Information Center

    Schwenk, Nancy E.

    1991-01-01

    An overall perspective on trends in food consumption is presented. Nutrition awareness is at an all-time high; consumption is influenced by changes in disposable income, availability of convenience foods, smaller household size, and an increasing proportion of ethnic minorities in the population. (18 references) (LB)

  13. Hybridization of organic molecular orbitals with substrate states at interfaces: PTCDA on silver.

    PubMed

    Ziroff, J; Forster, F; Schöll, A; Puschnig, P; Reinert, F

    2010-06-11

    We demonstrate the application of orbital k-space tomography for the analysis of the bonding occurring at metal-organic interfaces. Using angle-resolved photoelectron spectroscopy, we probe the spatial structure of the highest occupied molecular orbital and the former lowest unoccupied molecular orbital (LUMO) of one monolayer 3, 4, 9, 10-perylene-tetracarboxylic-dianhydride (PTCDA) on Ag(110) and (111) surfaces and, in particular, the influence of the hybridization between the orbitals and the electronic states of the substrate. We are able to quantify and localize the substrate contribution to the LUMO and thus prove the metal-molecule hybrid character of this complex state. PMID:20867234

  14. Global trends

    NASA Technical Reports Server (NTRS)

    Megie, G.; Chanin, M.-L.; Ehhalt, D.; Fraser, P.; Frederick, J. F.; Gille, J. C.; Mccormick, M. P.; Schoebert, M.; Bishop, L.; Bojkov, R. D.

    1990-01-01

    Measuring trends in ozone, and most other geophysical variables, requires that a small systematic change with time be determined from signals that have large periodic and aperiodic variations. Their time scales range from the day-to-day changes due to atmospheric motions through seasonal and annual variations to 11 year cycles resulting from changes in the sun UV output. Because of the magnitude of all of these variations is not well known and highly variable, it is necessary to measure over more than one period of the variations to remove their effects. This means that at least 2 or more times the 11 year sunspot cycle. Thus, the first requirement is for a long term data record. The second related requirement is that the record be consistent. A third requirement is for reasonable global sampling, to ensure that the effects are representative of the entire Earth. The various observational methods relevant to trend detection are reviewed to characterize their quality and time and space coverage. Available data are then examined for long term trends or recent changes in ozone total content and vertical distribution, as well as related parameters such as stratospheric temperature, source gases and aerosols.

  15. Hyperbolic interfaces.

    PubMed

    Giomi, Luca

    2012-09-28

    Fluid interfaces, such as soap films, liquid droplets, or lipid membranes, are known to give rise to several special geometries, whose complexity and beauty continue to fascinate us, as observers of the natural world, and challenge us as scientists. Here I show that a special class of surfaces of constant negative Gaussian curvature can be obtained in fluid interfaces equipped with an orientational ordered phase. These arise in various soft and biological materials, such as nematic liquid crystals, cytoskeletal assemblies, or hexatic colloidal suspensions. The purely hyperbolic morphology originates from the competition between surface tension, that reduces the area of the interface at the expense of increasing its Gaussian curvature, and the orientational elasticity of the ordered phase, that in turn suffers for the distortion induced by the underlying curvature. PMID:23030106

  16. Hyperbolic Interfaces

    NASA Astrophysics Data System (ADS)

    Giomi, Luca

    2012-09-01

    Fluid interfaces, such as soap films, liquid droplets, or lipid membranes, are known to give rise to several special geometries, whose complexity and beauty continue to fascinate us, as observers of the natural world, and challenge us as scientists. Here I show that a special class of surfaces of constant negative Gaussian curvature can be obtained in fluid interfaces equipped with an orientational ordered phase. These arise in various soft and biological materials, such as nematic liquid crystals, cytoskeletal assemblies, or hexatic colloidal suspensions. The purely hyperbolic morphology originates from the competition between surface tension, that reduces the area of the interface at the expense of increasing its Gaussian curvature, and the orientational elasticity of the ordered phase, that in turn suffers for the distortion induced by the underlying curvature.

  17. Future trends.

    PubMed

    Friedberg, Richard C; Weiss, Ronald L

    2007-12-01

    Several current forces have set anticipated future changes in health care in motion, or, at least, have set the stage for change. End-consumer demand increasingly drives the market; as a result, entire businesses are transforming or emerging anew to meet these demands. In general, consumers demand high quality at reasonable cost, to be delivered as fast as possible with minimal inconvenience. The health care consumer takes this expectation further, to include the desire for all helpful information regarding one's health to be made readily available for him/her to make the best decision and minimize morbidity, mortality, misdiagnosis, and inconvenience. This article addresses the impact upon the laboratory by considering four key interrelated dynamics that affect these trends: market, medicine, technology, and information systems. PMID:17950906

  18. Fertilizer trends

    SciTech Connect

    Donaldson, R.

    1992-12-31

    This fourteenth edition of Fertilizer Trends presents historical fertilizer market data to aid industry, government, and financial market analysis and planners in their study of fertilizer and agricultural market cycles, market planning, and investment decisions. A 27-year summary of the US fertilizer market is presented in graphic and tabular form. Production, use, and trade data are included for each plant nutrient and sulfur. Canadian statistics have been included because of the important role of the Canadian fertilizer industry in the US fertilizer market. World production and consumption of nitrogen, phosphate, and potash are included because of the strong influence of world markets on the domestic market. Planted acreage and plant nutrient application rates for the major crops have been included to illustrate their effect on fertilizer use. Retail prices of the leading US fertilizer materials also are given.

  19. Fertilizer trends

    SciTech Connect

    Donaldson, R.

    1992-01-01

    This fourteenth edition of Fertilizer Trends presents historical fertilizer market data to aid industry, government, and financial market analysis and planners in their study of fertilizer and agricultural market cycles, market planning, and investment decisions. A 27-year summary of the US fertilizer market is presented in graphic and tabular form. Production, use, and trade data are included for each plant nutrient and sulfur. Canadian statistics have been included because of the important role of the Canadian fertilizer industry in the US fertilizer market. World production and consumption of nitrogen, phosphate, and potash are included because of the strong influence of world markets on the domestic market. Planted acreage and plant nutrient application rates for the major crops have been included to illustrate their effect on fertilizer use. Retail prices of the leading US fertilizer materials also are given.

  20. Soft Interfaces

    NASA Astrophysics Data System (ADS)

    Gilles de Gennes, Pierre; Edwards, Introduction By Sam

    1997-04-01

    Paul Adrien Maurice Dirac, one of the greatest physicists of the twentieth century, died in 1984. Dirac's college, St. John's of Cambridge, generously endowed annual lectures to be held at Cambridge University in his memory. This volume contains a much expanded version of the 1994 Dirac Lecture by Nobel Laureate Pierre Gilles de Gennes. The book presents an impressionistic tour of the physics of soft interfaces. Full of insight and interesting asides, it not only provides an accessible introduction to this topic, but also lays down many markers and signposts that will be of interest to researchers in physics or chemistry. Features discussions of wetting and dewetting, the dynamics of different types of interface and adhesion and polymer/polymer welding.

  1. Beating the Stoner criterion using molecular interfaces

    NASA Astrophysics Data System (ADS)

    Ma'Mari, Fatma Al; Moorsom, Timothy; Teobaldi, Gilberto; Deacon, William; Prokscha, Thomas; Luetkens, Hubertus; Lee, Steve; Sterbinsky, George E.; Arena, Dario A.; MacLaren, Donald A.; Flokstra, Machiel; Ali, Mannan; Wheeler, May C.; Burnell, Gavin; Hickey, Bryan J.; Cespedes, Oscar

    2015-08-01

    Only three elements are ferromagnetic at room temperature: the transition metals iron, cobalt and nickel. The Stoner criterion explains why iron is ferromagnetic but manganese, for example, is not, even though both elements have an unfilled 3d shell and are adjacent in the periodic table: according to this criterion, the product of the density of states and the exchange integral must be greater than unity for spontaneous spin ordering to emerge. Here we demonstrate that it is possible to alter the electronic states of non-ferromagnetic materials, such as diamagnetic copper and paramagnetic manganese, to overcome the Stoner criterion and make them ferromagnetic at room temperature. This effect is achieved via interfaces between metallic thin films and C60 molecular layers. The emergent ferromagnetic state exists over several layers of the metal before being quenched at large sample thicknesses by the material's bulk properties. Although the induced magnetization is easily measurable by magnetometry, low-energy muon spin spectroscopy provides insight into its distribution by studying the depolarization process of low-energy muons implanted in the sample. This technique indicates localized spin-ordered states at, and close to, the metal-molecule interface. Density functional theory simulations suggest a mechanism based on magnetic hardening of the metal atoms, owing to electron transfer. This mechanism might allow for the exploitation of molecular coupling to design magnetic metamaterials using abundant, non-toxic components such as organic semiconductors. Charge transfer at molecular interfaces may thus be used to control spin polarization or magnetization, with consequences for the design of devices for electronic, power or computing applications (see, for example, refs 6 and 7).

  2. Beating the Stoner criterion using molecular interfaces.

    PubMed

    Ma'Mari, Fatma Al; Moorsom, Timothy; Teobaldi, Gilberto; Deacon, William; Prokscha, Thomas; Luetkens, Hubertus; Lee, Steve; Sterbinsky, George E; Arena, Dario A; MacLaren, Donald A; Flokstra, Machiel; Ali, Mannan; Wheeler, May C; Burnell, Gavin; Hickey, Bryan J; Cespedes, Oscar

    2015-08-01

    Only three elements are ferromagnetic at room temperature: the transition metals iron, cobalt and nickel. The Stoner criterion explains why iron is ferromagnetic but manganese, for example, is not, even though both elements have an unfilled 3d shell and are adjacent in the periodic table: according to this criterion, the product of the density of states and the exchange integral must be greater than unity for spontaneous spin ordering to emerge. Here we demonstrate that it is possible to alter the electronic states of non-ferromagnetic materials, such as diamagnetic copper and paramagnetic manganese, to overcome the Stoner criterion and make them ferromagnetic at room temperature. This effect is achieved via interfaces between metallic thin films and C60 molecular layers. The emergent ferromagnetic state exists over several layers of the metal before being quenched at large sample thicknesses by the material's bulk properties. Although the induced magnetization is easily measurable by magnetometry, low-energy muon spin spectroscopy provides insight into its distribution by studying the depolarization process of low-energy muons implanted in the sample. This technique indicates localized spin-ordered states at, and close to, the metal-molecule interface. Density functional theory simulations suggest a mechanism based on magnetic hardening of the metal atoms, owing to electron transfer. This mechanism might allow for the exploitation of molecular coupling to design magnetic metamaterials using abundant, non-toxic components such as organic semiconductors. Charge transfer at molecular interfaces may thus be used to control spin polarization or magnetization, with consequences for the design of devices for electronic, power or computing applications (see, for example, refs 6 and 7). PMID:26245580

  3. Googling trends in conservation biology.

    PubMed

    Proulx, Raphaël; Massicotte, Philippe; Pépino, Marc

    2014-02-01

    Web-crawling approaches, that is, automated programs data mining the internet to obtain information about a particular process, have recently been proposed for monitoring early signs of ecosystem degradation or for establishing crop calendars. However, lack of a clear conceptual and methodological framework has prevented the development of such approaches within the field of conservation biology. Our objective was to illustrate how Google Trends, a freely accessible web-crawling engine, can be used to track changes in timing of biological processes, spatial distribution of invasive species, and level of public awareness about key conservation issues. Google Trends returns the number of internet searches that were made for a keyword in a given region of the world over a defined period. Using data retrieved online for 13 countries, we exemplify how Google Trends can be used to study the timing of biological processes, such as the seasonal recurrence of pollen release or mosquito outbreaks across a latitudinal gradient. We mapped the spatial extent of results from Google Trends for 5 invasive species in the United States and found geographic patterns in invasions that are consistent with their coarse-grained distribution at state levels. From 2004 through 2012, Google Trends showed that the level of public interest and awareness about conservation issues related to ecosystem services, biodiversity, and climate change increased, decreased, and followed both trends, respectively. Finally, to further the development of research approaches at the interface of conservation biology, collective knowledge, and environmental management, we developed an algorithm that allows the rapid retrieval of Google Trends data. PMID:24033767

  4. TMS communications software. Volume 1: Computer interfaces

    NASA Technical Reports Server (NTRS)

    Brown, J. S.; Lenker, M. D.

    1979-01-01

    A prototype bus communications system, which is being used to support the Trend Monitoring System (TMS) as well as for evaluation of the bus concept is considered. Hardware and software interfaces to the MODCOMP and NOVA minicomputers are included. The system software required to drive the interfaces in each TMS computer is described. Documentation of other software for bus statistics monitoring and for transferring files across the bus is also included.

  5. TMS communications hardware. Volume 1: Computer interfaces

    NASA Technical Reports Server (NTRS)

    Brown, J. S.; Weinrich, S. S.

    1979-01-01

    A prototpye coaxial cable bus communications system was designed to be used in the Trend Monitoring System (TMS) to connect intelligent graphics terminals (based around a Data General NOVA/3 computer) to a MODCOMP IV host minicomputer. The direct memory access (DMA) interfaces which were utilized for each of these computers are identified. It is shown that for the MODCOMP, an off-the-shell board was suitable, while for the NOVAs, custon interface circuitry was designed and implemented.

  6. Drivers, Trends and Mitigation

    SciTech Connect

    Blanco, Arthur S.; Gerlagh, Reyer; Suh, Sangwon; Barrett, John A.; de Coninck, Heleen; Diaz Morejon, Cristobal Felix; Mathur, Ritu; Nakicenovic, Nebojsa; Ahenkorah, Alfred Ofosu; Pan, Jiahua; Pathak, Himanshu; Rice, Jake; Richels, Richard G.; Smith, Steven J.; Stern, David; Toth, Ferenc L.; Zhou, Peter

    2014-12-01

    Chapter 5 analyzes the anthropogenic greenhouse gas (GHG) emission trends until the present and the main drivers that explain those trends. The chapter uses different perspectives to analyze past GHG-emissions trends, including aggregate emissions flows and per capita emissions, cumulative emissions, sectoral emissions, and territory-based vs. consumption-based emissions. In all cases, global and regional trends are analyzed. Where appropriate, the emission trends are contextualized with long-term historic developments in GHG emissions extending back to 1750.

  7. TMS communications software. Volume 2: Bus interface unit

    NASA Technical Reports Server (NTRS)

    Gregor, P. J.

    1979-01-01

    A data bus communication system to support the space shuttle's Trend Monitoring System (TMS) and to provide a basis for evaluation of the bus concept is described. Installation of the system included developing both hardware and software interfaces between the bus and the specific TMS computers and terminals. The software written for the microprocessor-based bus interface units is described. The software implements both the general bus communications protocol and also the specific interface protocols for the TMS computers and terminals.

  8. Media independent interface. Interface control document

    NASA Technical Reports Server (NTRS)

    1987-01-01

    A Media Independent Interface (MII) is specified, using current standards in the industry. The MII is described in hierarchical fashion. At the base are IEEE/International Standards Organization (ISO) documents (standards) which describe the functionality of the software modules or layers and their interconnection. These documents describe primitives which are to transcent the MII. The intent of the MII is to provide a universal interface to one or more Media Access Contols (MACs) for the Logical Link Controller and Station Manager. This interface includes both a standardized electrical and mechanical interface and a standardized functional specification which defines the services expected from the MAC.

  9. Marketing Trends to Watch

    ERIC Educational Resources Information Center

    Circle, Alison

    2009-01-01

    This article identifies 13 cultural trends that libraries can turn into opportunites to reach patrons. These trends include: Twitter, online reputation management, value added content, mobile marketing, and emotional connection.

  10. Trends in Education.

    ERIC Educational Resources Information Center

    School Planning & Management, 2002

    2002-01-01

    Several architects, planners, administrators, and contractors answer questions about trends related to school construction, interior design, business, security, and technology. Trends concern funding issues, specialized designs, planning for safety, technological integration, and equity in services. (EV)

  11. Media independent interface

    NASA Technical Reports Server (NTRS)

    1987-01-01

    The work done on the Media Independent Interface (MII) Interface Control Document (ICD) program is described and recommendations based on it were made. Explanations and rationale for the content of the ICD itself are presented.

  12. NASA trend analysis procedures

    NASA Technical Reports Server (NTRS)

    1993-01-01

    This publication is primarily intended for use by NASA personnel engaged in managing or implementing trend analysis programs. 'Trend analysis' refers to the observation of current activity in the context of the past in order to infer the expected level of future activity. NASA trend analysis was divided into 5 categories: problem, performance, supportability, programmatic, and reliability. Problem trend analysis uncovers multiple occurrences of historical hardware or software problems or failures in order to focus future corrective action. Performance trend analysis observes changing levels of real-time or historical flight vehicle performance parameters such as temperatures, pressures, and flow rates as compared to specification or 'safe' limits. Supportability trend analysis assesses the adequacy of the spaceflight logistics system; example indicators are repair-turn-around time and parts stockage levels. Programmatic trend analysis uses quantitative indicators to evaluate the 'health' of NASA programs of all types. Finally, reliability trend analysis attempts to evaluate the growth of system reliability based on a decreasing rate of occurrence of hardware problems over time. Procedures for conducting all five types of trend analysis are provided in this publication, prepared through the joint efforts of the NASA Trend Analysis Working Group.

  13. Trends in transport aircraft avionics

    NASA Technical Reports Server (NTRS)

    Berkstresser, B. K.

    1973-01-01

    A survey of avionics onboard present commercial transport aircraft was conducted to identify trends in avionics systems characteristics and to determine the impact of technology advances on equipment weight, cost, reliability, and maintainability. Transport aircraft avionics systems are described under the headings of communication, navigation, flight control, and instrumentation. The equipment included in each section is described functionally. However, since more detailed descriptions of the equipment can be found in other sources, the description is limited and emphasis is put on configuration requirements. Since airborne avionics systems must interface with ground facilities, certain ground facilities are described as they relate to the airborne systems, with special emphasis on air traffic control and all-weather landing capability.

  14. Water at Interfaces.

    PubMed

    Björneholm, Olle; Hansen, Martin H; Hodgson, Andrew; Liu, Li-Min; Limmer, David T; Michaelides, Angelos; Pedevilla, Philipp; Rossmeisl, Jan; Shen, Huaze; Tocci, Gabriele; Tyrode, Eric; Walz, Marie-Madeleine; Werner, Josephina; Bluhm, Hendrik

    2016-07-13

    The interfaces of neat water and aqueous solutions play a prominent role in many technological processes and in the environment. Examples of aqueous interfaces are ultrathin water films that cover most hydrophilic surfaces under ambient relative humidities, the liquid/solid interface which drives many electrochemical reactions, and the liquid/vapor interface, which governs the uptake and release of trace gases by the oceans and cloud droplets. In this article we review some of the recent experimental and theoretical advances in our knowledge of the properties of aqueous interfaces and discuss open questions and gaps in our understanding. PMID:27232062

  15. Trends in Educational Technology.

    ERIC Educational Resources Information Center

    Ely, Donald P.

    Based on the findings of a content analysis of representative literature on educational technology, this report examines the trends in educational technology from October 1, 1990 through September 30, 1991. Ten trends for 1991 are identified and discussed: (1) the creation of technology-based teaching/learning products is based largely on…

  16. General Achievement Trends: Maryland

    ERIC Educational Resources Information Center

    Center on Education Policy, 2009

    2009-01-01

    This general achievement trends profile includes information that the Center on Education Policy (CEP) and the Human Resources Research Organization (HumRRO) obtained from states from fall 2008 through April 2009. Included herein are: (1) Bullet points summarizing key findings about achievement trends in that state at three performance…

  17. General Achievement Trends: Arkansas

    ERIC Educational Resources Information Center

    Center on Education Policy, 2009

    2009-01-01

    This general achievement trends profile includes information that the Center on Education Policy (CEP) and the Human Resources Research Organization (HumRRO) obtained from states from fall 2008 through April 2009. Included herein are: (1) Bullet points summarizing key findings about achievement trends in that state at three performance…

  18. General Achievement Trends: Idaho

    ERIC Educational Resources Information Center

    Center on Education Policy, 2009

    2009-01-01

    This general achievement trends profile includes information that the Center on Education Policy (CEP) and the Human Resources Research Organization (HumRRO) obtained from states from fall 2008 through April 2009. Included herein are: (1) Bullet points summarizing key findings about achievement trends in that state at three performance…

  19. General Achievement Trends: Nebraska

    ERIC Educational Resources Information Center

    Center on Education Policy, 2009

    2009-01-01

    This general achievement trends profile includes information that the Center on Education Policy (CEP) and the Human Resources Research Organization (HumRRO) obtained from states from fall 2008 through April 2009. Included herein are: (1) Bullet points summarizing key findings about achievement trends in that state at three performance…

  20. General Achievement Trends: Colorado

    ERIC Educational Resources Information Center

    Center on Education Policy, 2009

    2009-01-01

    This general achievement trends profile includes information that the Center on Education Policy (CEP) and the Human Resources Research Organization (HumRRO) obtained from states from fall 2008 through April 2009. Included herein are: (1) Bullet points summarizing key findings about achievement trends in that state at three performance…

  1. General Achievement Trends: Iowa

    ERIC Educational Resources Information Center

    Center on Education Policy, 2009

    2009-01-01

    This general achievement trends profile includes information that the Center on Education Policy (CEP) and the Human Resources Research Organization (HumRRO) obtained from states from fall 2008 through April 2009. Included herein are: (1) Bullet points summarizing key findings about achievement trends in that state at three performance…

  2. General Achievement Trends: Hawaii

    ERIC Educational Resources Information Center

    Center on Education Policy, 2009

    2009-01-01

    This general achievement trends profile includes information that the Center on Education Policy (CEP) and the Human Resources Research Organization (HumRRO) obtained from states from fall 2008 through April 2009. Included herein are: (1) Bullet points summarizing key findings about achievement trends in that state at three performance…

  3. General Achievement Trends: Kentucky

    ERIC Educational Resources Information Center

    Center on Education Policy, 2009

    2009-01-01

    This general achievement trends profile includes information that the Center on Education Policy (CEP) and the Human Resources Research Organization (HumRRO) obtained from states from fall 2008 through April 2009. Included herein are: (1) Bullet points summarizing key findings about achievement trends in that state at three performance…

  4. General Achievement Trends: Florida

    ERIC Educational Resources Information Center

    Center on Education Policy, 2009

    2009-01-01

    This general achievement trends profile includes information that the Center on Education Policy (CEP) and the Human Resources Research Organization (HumRRO) obtained from states from fall 2008 through April 2009. Included herein are: (1) Bullet points summarizing key findings about achievement trends in that state at three performance…

  5. General Achievement Trends: Texas

    ERIC Educational Resources Information Center

    Center on Education Policy, 2009

    2009-01-01

    This general achievement trends profile includes information that the Center on Education Policy (CEP) and the Human Resources Research Organization (HumRRO) obtained from states from fall 2008 through April 2009. Included herein are: (1) Bullet points summarizing key findings about achievement trends in that state at three performance…

  6. General Achievement Trends: Oregon

    ERIC Educational Resources Information Center

    Center on Education Policy, 2009

    2009-01-01

    This general achievement trends profile includes information that the Center on Education Policy (CEP) and the Human Resources Research Organization (HumRRO) obtained from states from fall 2008 through April 2009. Included herein are: (1) Bullet points summarizing key findings about achievement trends in that state at three performance…

  7. General Achievement Trends: Virginia

    ERIC Educational Resources Information Center

    Center on Education Policy, 2009

    2009-01-01

    This general achievement trends profile includes information that the Center on Education Policy (CEP) and the Human Resources Research Organization (HumRRO) obtained from states from fall 2008 through April 2009. Included herein are: (1) Bullet points summarizing key findings about achievement trends in that state at three performance…

  8. Trends Shaping Education 2010

    ERIC Educational Resources Information Center

    OECD Publishing (NJ3), 2010

    2010-01-01

    "Trends Shaping Education 2010" brings together evidence showing the effects on education of globalisation, social challenges, changes in the workplace, the transformation of childhood, and ICT. To make the content accessible, each trend is presented on a double page, containing an introduction, two charts with brief descriptive text and a set of…

  9. General Achievement Trends: Tennessee

    ERIC Educational Resources Information Center

    Center on Education Policy, 2009

    2009-01-01

    This general achievement trends profile includes information that the Center on Education Policy (CEP) and the Human Resources Research Organization (HumRRO) obtained from states from fall 2008 through April 2009. Included herein are: (1) Bullet points summarizing key findings about achievement trends in that state at three performance…

  10. Microconical interface fitting and interface grasping tool

    NASA Technical Reports Server (NTRS)

    Gernhardt, Michael L. (Inventor); Wightman, William D. (Inventor); Johnston, Alistair P. (Inventor)

    1994-01-01

    A small and light weight microconical interface fitting may be attached to the surface of a space vehicle or equipment to provide an attachment device for an astronaut or robot to capture the space vehicle or equipment. The microconical interface fitting of the present invention has an axisymmetrical conical body having a base portion with a torque reaction surface for preventing rotation of the interface grasping tool; a cavitated, sunken or hollowed out intermediate locking portion which has a cavity shaped for receiving the latches of the grasping tool and an upper guiding portion for guiding the grasping tool into axial alignment with the microconical interface fitting. The capture is accomplished with an interface grasping tool. The grasping tool comprises an outer sleeve with a handle attached, an inner sleeve which may be raised and lowered within the outer sleeve with a plurality of latches supported at the lower end and a cam to raise and lower the inner sleeve. When the inner sleeve is at its lowest position, the latches form the largest diameter opening for surrounding the microconical fitting and the latches form the smallest diameter or a locking, grasping position when raised to the highest position within the outer sleeve. The inner sleeve may be at an intermediate, capture position which permits the latches to be biased outwardly when contacting the microconical fitting under very low forces to grasp the fitting and permits capture (soft docking) without exact alignment of the fitting and the tool.

  11. Turbomachine Interface Sealing

    NASA Technical Reports Server (NTRS)

    Hendricks, Robert C.; Chupp, Raymond E.; Lattime, Scott B.; Steinetz, Bruce M.

    2005-01-01

    Sealing interfaces and coatings, like lubricants, are sacrificial, giving up their integrity for the benefit of the component. Clearance control is a major issue in power systems turbomachine design and operational life. Sealing becomes the most cost-effective way to enhance system performance. Coatings, films, and combined use of both metals and ceramics play a major role in maintaining interface clearances in turbomachine sealing and component life. This paper focuses on conventional and innovative materials and design practices for sealing interfaces.

  12. The kinked interface crack

    NASA Astrophysics Data System (ADS)

    Heitzer, Joerg

    1992-05-01

    Two methods for the numerical solution of the integral equation describing the kinked interface crack, one proposed by Erdogan et al. (1973) and the other by Theokaris and Iokimidis (1979), are examined. The method of Erdogan et al. is then used to solve the equation in order to determine the kinking angle of the interface crack. Results are presented for two material combinations, aluminum/epoxy and glass/ceramic, under uniaxial tension in the direction normal to the interface.

  13. Persistent interface fluid syndrome.

    PubMed

    Hoffman, Richard S; Fine, I Howard; Packer, Mark

    2008-08-01

    We present an unusual case of persistent interface fluid that would not resolve despite normal intraocular pressure and corneal endothelial replacement with Descemet-stripping endothelial keratoplasty. Dissection, elevation, and repositioning of the laser in situ keratomileusis flap were required to resolve the interface fluid. Circumferential corneal graft-host margin scar formation acting as a mechanical strut may have been the cause of the intractable interface fluid. PMID:18655997

  14. Popeye Project: ROV interface

    SciTech Connect

    Scates, C.R.; Hernandez, D.A.; Hickok, D.D.

    1996-12-31

    This paper discusses the Remote Operated Vehicle (ROV) interface with the Popeye Project Subsea System. It describes the ROV-related plans, design philosophies, intervention tasks, tooling/equipment requirements, testing activities, and offshore installation experiences. Early identification and continuous consideration of the ROV interfaces significantly improved the overall efficiency of equipment designs and offshore operations. The Popeye Project helped advance the technology and standardization of ROV interfaces for deep water subsea production systems.

  15. Multimodal neuroelectric interface development

    NASA Technical Reports Server (NTRS)

    Trejo, Leonard J.; Wheeler, Kevin R.; Jorgensen, Charles C.; Rosipal, Roman; Clanton, Sam T.; Matthews, Bryan; Hibbs, Andrew D.; Matthews, Robert; Krupka, Michael

    2003-01-01

    We are developing electromyographic and electroencephalographic methods, which draw control signals for human-computer interfaces from the human nervous system. We have made progress in four areas: 1) real-time pattern recognition algorithms for decoding sequences of forearm muscle activity associated with control gestures; 2) signal-processing strategies for computer interfaces using electroencephalogram (EEG) signals; 3) a flexible computation framework for neuroelectric interface research; and d) noncontact sensors, which measure electromyogram or EEG signals without resistive contact to the body.

  16. Subsea production systems -- Trends in the nineties

    SciTech Connect

    Jones, J.W.

    1995-12-31

    This paper describes recent subsea production system experience, with focus on cost reduction trends which are expected to continue throughout the remainder of the decade. First, the system configuration trend from large, heavy, multi-well integrated drilling template and production/injection manifold systems to small, lightweight, ``minitemplate`` systems or clustered well manifolds with individual satellite wells is addressed. Second, several equipment technology trends are addressed including towed flowline bundles with integral manifolds, development of improved reservoir management/data acquisition tools, subsea pressure boosting to extend the reach of subsea systems, emergence of the rental tool market and ``tool pools``, ``horizontal`` trees for certain applications, and standardization of subsea components and interfaces. This paper concludes that subsea production systems have successfully demonstrated their overall reliability, and have established a proven track record over the past thirty years of field experience. System configuration and equipment technology trends in the nineties are now improving the profitability and capability of subsea production systems. Subsea production system examples are cited along with generic costs to illustrate the effectiveness of these cost reduction trends. 12 figs.

  17. TSF Interface Package

    SciTech Connect

    2004-03-01

    A collection of packages of classes for interfacing to sparse and dense matrices, vectors and graphs, and to linear operators. TSF (via TSFCore, TSFCoreUtils and TSFExtended) provides the application programmer interface to any number of solvers, linear algebra libraries and preconditioner packages, providing also a sophisticated technique for combining multiple packages to solve a single problem. TSF provides a collection of abstract base classes that define the interfaces to abstract vector, matrix and linear soerator objects. By using abstract interfaces, users of TSF are not limiting themselves to any one concrete library and can in fact easily combine multiple libraries to solve a single problem.

  18. Trends in stratospheric temperature

    NASA Technical Reports Server (NTRS)

    Schoeberl, M. R.; Newman, P. A.; Rosenfield, J. E.; Angell, J.; Barnett, J.; Boville, B. A.; Chandra, S.; Fels, S.; Fleming, E.; Gelman, M.

    1989-01-01

    Stratospheric temperatures for long-term and recent trends and the determination of whether observed changes in upper stratospheric temperatures are consistent with observed ozone changes are discussed. The long-term temperature trends were determined up to 30mb from radiosonde analysis (since 1970) and rocketsondes (since 1969 and 1973) up to the lower mesosphere, principally in the Northern Hemisphere. The more recent trends (since 1979) incorporate satellite observations. The mechanisms that can produce recent temperature trends in the stratosphere are discussed. The following general effects are discussed: changes in ozone, changes in other radiatively active trace gases, changes in aerosols, changes in solar flux, and dynamical changes. Computations were made to estimate the temperature changes associated with the upper stratospheric ozone changes reported by the Solar Backscatter Ultraviolet (SBUV) instrument aboard Nimbus-7 and the Stratospheric Aerosol and Gas Experiment (SAGE) instruments.

  19. A modern trends retrospective.

    PubMed

    Wallach, Edward E

    2011-06-01

    Editorship of the Modern Trends section has been a great ride. The section raised the level of interest and readership of Fertility and Sterility, while providing important, up-to-date material for students, scientists and practitioners. PMID:21496803

  20. Skin Cancer Trends

    MedlinePlus

    ... Indian/Alaska Native men. Remained level among Asian/Pacific Islander men. Women Increased significantly by 1.4% ... Indian/Alaska Native women. Remained level among Asian/Pacific Islander women. Mortality Trends From 2003 to 2012 ...

  1. Breast Cancer Trends

    MedlinePlus

    ... significantly by 1.1% per year among Asian/Pacific Islander women. Mortality Trends From 2003 to 2012 ... significantly by 1.4% per year among Asian/Pacific Islander women. Data source: Ryerson AB, Eheman CR, ...

  2. Lung Cancer Trends

    MedlinePlus

    ... significantly by 1.8% per year among Asian/Pacific Islander men. Women Decreased significantly by 0.9% ... Indian/Alaska Native women. Remained level among Asian/Pacific Islander women. Mortality Trends From 2003 to 2012 ...

  3. TREND DATA 1971 - 1995

    EPA Science Inventory

    Trend Data provides information up to 25 years of Veteran Data. Included are social and economic information about veterans, demographical and geographical veteran information, statistical information by veteran program areas and veteran survey information as well as references t...

  4. Ovarian Cancer Trends

    MedlinePlus

    ... year among Hispanic women. Remained level among American Indian/Alaska Native women. Decreased significantly by 0.9% per year among Asian/Pacific Islander women. Mortality Trends From 2003 to 2012 in the United ...

  5. Ozone Trend Detectability

    NASA Technical Reports Server (NTRS)

    Campbell, J. W. (Editor)

    1981-01-01

    The detection of anthropogenic disturbances in the Earth's ozone layer was studied. Two topics were addressed: (1) the level at which a trend in total ozoning is detected by existing data sources; and (2) empirical evidence in the prediction of the depletion in total ozone. Error sources are identified. The predictability of climatological series, whether empirical models can be trusted, and how errors in the Dobson total ozone data impact trend detectability, are discussed.

  6. Thread Pool Interface (TPI)

    Energy Science and Technology Software Center (ESTSC)

    2008-04-01

    Thread Pool Interface (TpI) provides a simple interface for running functions written in C or C++ in a thread-parallel mode. Application or library codes may need to perform operations thread-parallel on machines with multicore processors. the TPI library provides a simple mechanism for managing thread activation, deactivation, and thread-parallel execution of application-provided subprograms.

  7. Interface Conductance Modal Analysis

    NASA Astrophysics Data System (ADS)

    Gordiz, Kiarash; Henry, Asegun

    2015-03-01

    Reliably and quantitatively calculating the conductance of phonons across an interface between two materials has been one of the major unresolved questions in thermal transport physics for the last century. Theories have been presented in this regard, but their predictive power is limited. A new formalism to extract the modal contributions to thermal interface conductance with full inclusion of temperature dependent anharmonicity and all of the atom level topography is presented. The results indicate that when two materials are joined a new set of vibrational modes are required to correctly describe the transport across the interface. The new set of vibrational modes is inconsistent with the physical picture described by phonon gas model (PGM), because some of the most important modes are localized and non-propagating and therefore do not have a well-defined velocity nor do they impinge on the interface. Among these new modes, certain classifications emerge, as most modes extend at least partially into the other material. Localized interfacial modes are also present and exhibit a high conductance contribution on a per mode basis by strongly coupling to other types of vibrational modes. We apply our formalism to different interfaces and present thermal interface conductance accumulation functions, two-dimensional cross-correlation matrices, and a quantitative determination of the contributions arising from inelastic effects. The provided new perspective on interface thermal transport can open new gates towards deeper understanding of phonon-phonon and electron-phonon interactions around interfaces.

  8. Interface colloidal robotic manipulator

    DOEpatents

    Aronson, Igor; Snezhko, Oleksiy

    2015-08-04

    A magnetic colloidal system confined at the interface between two immiscible liquids and energized by an alternating magnetic field dynamically self-assembles into localized asters and arrays of asters. The colloidal system exhibits locomotion and shape change. By controlling a small external magnetic field applied parallel to the interface, structures can capture, transport, and position target particles.

  9. Designing the Instructional Interface.

    ERIC Educational Resources Information Center

    Lohr, L. L.

    2000-01-01

    Designing the instructional interface is a challenging endeavor requiring knowledge and skills in instructional and visual design, psychology, human-factors, ergonomic research, computer science, and editorial design. This paper describes the instructional interface, the challenges of its development, and an instructional systems approach to its…

  10. Trends in groundwater quality

    NASA Astrophysics Data System (ADS)

    Loftis, Jim C.

    1996-02-01

    The term trend takes on a variety of meanings for groundwater quality in both a temporal and spatial context. Most commonly, trends are thought of as changes over time at either a regional or localized spatial scale. Generally water quality managers are most interested in changes associated with some form of human activity. Carefully defining what is meant by trend is a critical step in trend analysis and may be accomplished by formulating a statistical model which includes a trend component. Although there are a great many regional groundwater studies which provide a snapshot description of water quality conditions over an area at one point in time, there are relatively few which consider changes over time and fewer still which include a statistical analysis of long-term trend. This review covers both regional and localized studies of groundwater quality around the world, including a few snapshots, but focusing primarily on those studies which include an evaluation of temporal changes in groundwater quality. The studies include national assessments, agricultural case studies (the largest group, mostly regional in scope), urban case studies, and point source and hazardous waste case studies.

  11. Interfaces in Perovskite Heterostructures

    SciTech Connect

    Christen, Hans M; Kim, Dae Ho; Rouleau, Christopher M

    2008-01-01

    Recent advances in film synthesis have made it possible to investigate the properties of well-controlled interfaces in perovskite metal-oxides. A review of published experimental data and computational results indicate that so far most interfaces that have been analyzed in ferroelectric materials - while necessary to impose large lattice strain on the polar material - contribute little to the ferroelectricity and may instead be detrimental to the desired properties. In contrast, a very different situation arises at interfaces that show changes in the electronic configuration as a consequence of a compositional discontinuity. Data is shown for LaMnO3/SrTiO 3 superlattices as an example of electronic effects that produce enhanced properties, further illustrating the richness of interfacial properties that can be obtained at interfaces (as shown in numerous published results for different but related interfaces).

  12. Trends in Programming Languages for Neuroscience Simulations

    PubMed Central

    Davison, Andrew P.; Hines, Michael L.; Muller, Eilif

    2009-01-01

    Neuroscience simulators allow scientists to express models in terms of biological concepts, without having to concern themselves with low-level computational details of their implementation. The expressiveness, power and ease-of-use of the simulator interface is critical in efficiently and accurately translating ideas into a working simulation. We review long-term trends in the development of programmable simulator interfaces, and examine the benefits of moving from proprietary, domain-specific languages to modern dynamic general-purpose languages, in particular Python, which provide neuroscientists with an interactive and expressive simulation development environment and easy access to state-of-the-art general-purpose tools for scientific computing. PMID:20198154

  13. Operator interface for vehicles

    DOEpatents

    Bissontz, Jay E

    2015-03-10

    A control interface for drivetrain braking provided by a regenerative brake and a non-regenerative brake is implemented using a combination of switches and graphic interface elements. The control interface comprises a control system for allocating drivetrain braking effort between the regenerative brake and the non-regenerative brake, a first operator actuated control for enabling operation of the drivetrain braking, and a second operator actuated control for selecting a target braking effort for drivetrain braking. A graphic display displays to an operator the selected target braking effort and can be used to further display actual braking effort achieved by drivetrain braking.

  14. Interface Structure of MoO3 on Organic Semiconductors

    NASA Astrophysics Data System (ADS)

    White, Robin T.; Thibau, Emmanuel S.; Lu, Zheng-Hong

    2016-02-01

    We have systematically studied interface structure formed by vapor-phase deposition of typical transition metal oxide MoO3 on organic semiconductors. Eight organic hole transport materials have been used in this study. Ultraviolet photoelectron spectroscopy and X-ray photoelectron spectroscopy are used to measure the evolution of the physical, chemical and electronic structure of the interfaces at various stages of MoO3 deposition on these organic semiconductor surfaces. For the interface physical structure, it is found that MoO3 diffuses into the underlying organic layer, exhibiting a trend of increasing diffusion with decreasing molecular molar mass. For the interface chemical structure, new carbon and molybdenum core-level states are observed, as a result of interfacial electron transfer from organic semiconductor to MoO3. For the interface electronic structure, energy level alignment is observed in agreement with the universal energy level alignment rule of molecules on metal oxides, despite deposition order inversion.

  15. Blind predictions of protein interfaces by docking calculations in CAPRI.

    PubMed

    Lensink, Marc F; Wodak, Shoshana J

    2010-11-15

    Reliable prediction of the amino acid residues involved in protein-protein interfaces can provide valuable insight into protein function, and inform mutagenesis studies, and drug design applications. A fast-growing number of methods are being proposed for predicting protein interfaces, using structural information, energetic criteria, or sequence conservation or by integrating multiple criteria and approaches. Overall however, their performance remains limited, especially when applied to nonobligate protein complexes, where the individual components are also stable on their own. Here, we evaluate interface predictions derived from protein-protein docking calculations. To this end we measure the overlap between the interfaces in models of protein complexes submitted by 76 participants in CAPRI (Critical Assessment of Predicted Interactions) and those of 46 observed interfaces in 20 CAPRI targets corresponding to nonobligate complexes. Our evaluation considers multiple models for each target interface, submitted by different participants, using a variety of docking methods. Although this results in a substantial variability in the prediction performance across participants and targets, clear trends emerge. Docking methods that perform best in our evaluation predict interfaces with average recall and precision levels of about 60%, for a small majority (60%) of the analyzed interfaces. These levels are significantly higher than those obtained for nonobligate complexes by most extant interface prediction methods. We find furthermore that a sizable fraction (24%) of the interfaces in models ranked as incorrect in the CAPRI assessment are actually correctly predicted (recall and precision ≥50%), and that these models contribute to 70% of the correct docking-based interface predictions overall. Our analysis proves that docking methods are much more successful in identifying interfaces than in predicting complexes, and suggests that these methods have an excellent

  16. Scalable coherent interface

    SciTech Connect

    Alnaes, K.; Kristiansen, E.H. ); Gustavson, D.B. ); James, D.V. )

    1990-01-01

    The Scalable Coherent Interface (IEEE P1596) is establishing an interface standard for very high performance multiprocessors, supporting a cache-coherent-memory model scalable to systems with up to 64K nodes. This Scalable Coherent Interface (SCI) will supply a peak bandwidth per node of 1 GigaByte/second. The SCI standard should facilitate assembly of processor, memory, I/O and bus bridge cards from multiple vendors into massively parallel systems with throughput far above what is possible today. The SCI standard encompasses two levels of interface, a physical level and a logical level. The physical level specifies electrical, mechanical and thermal characteristics of connectors and cards that meet the standard. The logical level describes the address space, data transfer protocols, cache coherence mechanisms, synchronization primitives and error recovery. In this paper we address logical level issues such as packet formats, packet transmission, transaction handshake, flow control, and cache coherence. 11 refs., 10 figs.

  17. TSF Interface Package

    Energy Science and Technology Software Center (ESTSC)

    2004-03-01

    A collection of packages of classes for interfacing to sparse and dense matrices, vectors and graphs, and to linear operators. TSF (via TSFCore, TSFCoreUtils and TSFExtended) provides the application programmer interface to any number of solvers, linear algebra libraries and preconditioner packages, providing also a sophisticated technique for combining multiple packages to solve a single problem. TSF provides a collection of abstract base classes that define the interfaces to abstract vector, matrix and linear soeratormore » objects. By using abstract interfaces, users of TSF are not limiting themselves to any one concrete library and can in fact easily combine multiple libraries to solve a single problem.« less

  18. Implantable microscale neural interfaces.

    PubMed

    Cheung, Karen C

    2007-12-01

    Implantable neural microsystems provide an interface to the nervous system, giving cellular resolution to physiological processes unattainable today with non-invasive methods. Such implantable microelectrode arrays are being developed to simultaneously sample signals at many points in the tissue, providing insight into processes such as movement control, memory formation, and perception. These electrode arrays have been microfabricated on a variety of substrates, including silicon, using both surface and bulk micromachining techniques, and more recently, polymers. Current approaches to achieving a stable long-term tissue interface focus on engineering the surface properties of the implant, including coatings that discourage protein adsorption or release bioactive molecules. The implementation of a wireless interface requires consideration of the necessary data flow, amplification, signal processing, and packaging. In future, the realization of a fully implantable neural microsystem will contribute to both diagnostic and therapeutic applications, such as a neuroprosthetic interface to restore motor functions in paralyzed patients. PMID:17252207

  19. Some fighter aircraft trends

    NASA Technical Reports Server (NTRS)

    Spearman, L.

    1985-01-01

    Some basic trends in fighters are traced from the post World II era. Beginning with the first operational jet fighter, the P-80, the characteristics of subsequent fighter aircraft are examined for performance, mission capability, effectiveness, and cost. Characteristics presented include: power loading, wing loading, maximum speed, rate of climb, turn rate, weight and weight distribution, cost and cost distribution. The characteristics of some USSR aircraft are included for comparison. The trends indicate some of the rationale for certain fighter designs and some likely characteristics to be sought in future fighter aircraft designs.

  20. Ozone trends: A review

    NASA Astrophysics Data System (ADS)

    Staehelin, J.; Harris, N. R. P.; Appenzeller, C.; Eberhard, J.

    2001-05-01

    Ozone plays a very important role in our atmosphere because it protects any living organisms at the Earth's surface against the harmful solar UVB and UVC radiation. In the stratosphere, ozone plays a critical role in the energy budget because it absorbs both solar UV and terrestrial IR radiation. Further, ozone in the tropopause acts as a strong greenhouse gas, and increasing ozone trends at these altitudes contribute to climate change. This review contains a short description of the various techniques that provided atmospheric ozone measurements valuable for long-term trend analysis. The anthropogenic emissions of substances that deplete ozone (chlorine- and bromine-containing volatile gases) have increased from the 1950s until the second half of the 1980s. The most severe consequence of the anthropogenic release of ozone-depleting substances is the "Antarctic ozone hole." Long-term observations indicate that stratospheric ozone depletion in the southern winter-spring season over Antarctica started in the late 1970s, leading to a strong decrease in October total ozone means. Present values are only approximately half of those observed prior to 1970. In the Arctic, large ozone depletion was observed in winter and spring in some recent years. Satellite and ground-based measurements show no significant trends in the tropics but significant long-term decreasing trends in the northern and southern midlatitudes (of the order of 2-4% per decade in the period from 1970 to 1996 and an acceleration in trends in the 1980s). Ozone at northern midlatitudes decreased by -7.4±2% per decade at 40 km above mean sea level, while ozone loss was small at 30 km. Large trends were found in the lower stratosphere, -5.1±1.8% at 20 km and -7.3±4.6% at 15 km, where the bulk of the ozone resides. The possibility of a reduction in the observed trends has been discussed recently, but it is very hard to distinguish this from the natural variability. As a consequence of the Montreal Protocol

  1. Polarizable Ions at Interfaces

    NASA Astrophysics Data System (ADS)

    Levin, Yan

    2009-04-01

    A nonperturbative theory is presented which allows us to calculate the solvation free energy of polarizable ions near water-vapor and water-oil interfaces. The theory predicts that larger halogen anions are adsorbed at the interface, while the alkali metal cations are repelled from it. The density profiles calculated theoretically are similar to those obtained using molecular dynamics simulations with polarizable force fields.

  2. Performance Application Programming Interface

    Energy Science and Technology Software Center (ESTSC)

    2005-10-31

    PAPI is a programming interface designed to provide the tool designer and application engineer with a consistent interface and methodology for use of the performance counter hardware found in most major microprocessors. PAPI enables software engineers to see, in near real time, the relation between software performance and processor events. This release covers the hardware dependent implementation of PAPI version 3 for the IBM BlueGene/L (BG/L) system.

  3. VIRTUAL FRAME BUFFER INTERFACE

    NASA Technical Reports Server (NTRS)

    Wolfe, T. L.

    1994-01-01

    Large image processing systems use multiple frame buffers with differing architectures and vendor supplied user interfaces. This variety of architectures and interfaces creates software development, maintenance, and portability problems for application programs. The Virtual Frame Buffer Interface program makes all frame buffers appear as a generic frame buffer with a specified set of characteristics, allowing programmers to write code which will run unmodified on all supported hardware. The Virtual Frame Buffer Interface converts generic commands to actual device commands. The virtual frame buffer consists of a definition of capabilities and FORTRAN subroutines that are called by application programs. The virtual frame buffer routines may be treated as subroutines, logical functions, or integer functions by the application program. Routines are included that allocate and manage hardware resources such as frame buffers, monitors, video switches, trackballs, tablets and joysticks; access image memory planes; and perform alphanumeric font or text generation. The subroutines for the various "real" frame buffers are in separate VAX/VMS shared libraries allowing modification, correction or enhancement of the virtual interface without affecting application programs. The Virtual Frame Buffer Interface program was developed in FORTRAN 77 for a DEC VAX 11/780 or a DEC VAX 11/750 under VMS 4.X. It supports ADAGE IK3000, DEANZA IP8500, Low Resolution RAMTEK 9460, and High Resolution RAMTEK 9460 Frame Buffers. It has a central memory requirement of approximately 150K. This program was developed in 1985.

  4. Interfaces: nanometric dielectrics

    NASA Astrophysics Data System (ADS)

    Lewis, T. J.

    2005-01-01

    The incorporation of nanometric size particles in a matrix to form dielectric composites shows promise of materials (nanodielectrics) with new and improved properties. It is argued that the properties of the interfaces between the particles and the matrix, which will themselves be of nanometric dimensions, will have an increasingly dominant role in determining dielectric performance as the particle size decreases. The forces that determine the electrical and dielectric properties of interfaces are considered, with emphasis on the way in which they might influence composite behaviour. A number of examples are given in which interfaces at the nanometric level exercise both passive and active control over dielectric, optical and conductive properties. Electromechanical properties are also considered, and it is shown that interfaces have important electrostrictive and piezoelectric characteristics. It is demonstrated that the process of poling, namely subjecting macroscopic composite materials to electrical stress and raised temperatures to create piezoelectric materials, can be explained in terms of optimizing the collective response of the nanometric interfaces involved. If the electrical and electromechanical features are coupled to the long-established electrochemical properties, interfaces represent highly versatile active elements with considerable potential in nanotechnology.

  5. MER SPICE Interface

    NASA Technical Reports Server (NTRS)

    Sayfi, Elias

    2004-01-01

    MER SPICE Interface is a software module for use in conjunction with the Mars Exploration Rover (MER) mission and the SPICE software system of the Navigation and Ancillary Information Facility (NAIF) at NASA's Jet Propulsion Laboratory. (SPICE is used to acquire, record, and disseminate engineering, navigational, and other ancillary data describing circumstances under which data were acquired by spaceborne scientific instruments.) Given a Spacecraft Clock value, MER SPICE Interface extracts MER-specific data from SPICE kernels (essentially, raw data files) and calculates values for Planet Day Number, Local Solar Longitude, Local Solar Elevation, Local Solar Azimuth, and Local Solar Time (UTC). MER SPICE Interface was adapted from a subroutine, denoted m98SpiceIF written by Payam Zamani, that was intended to calculate SPICE values for the Mars Polar Lander. The main difference between MER SPICE Interface and m98SpiceIf is that MER SPICE Interface does not explicitly call CHRONOS, a time-conversion program that is part of a library of utility subprograms within SPICE. Instead, MER SPICE Interface mimics some portions of the CHRONOS code, the advantage being that it executes much faster and can efficiently be called from a pipeline of events in a parallel processing environment.

  6. Serial interface controller

    SciTech Connect

    Kandasamy, A.

    1995-04-14

    The idea of building a Serial Interface Controller (SIC) proposed by Paul O`Connor, Instrumentation Division, BNL is to determine the feasibility of incorporating a Serial Interface Controlled CMOS IC`s for charge amplification, shaping, analog storage and multiplexing used in particle detectors for high energy physics experiments. The serial data pumped into the CMOS ICs will be used to control many circuit parameters like digitally controlled gain, shaping time, precision preamplifier calibration circuits and many other parameters like timing discriminators mode of operation. The SIC board built will be tested on a Serial Interface Controlled Digital - to - Analog Convertor, which follows either Motorola`s SPI/QSPI or National Semiconductors Microwire interface technique. The DAC chosen for this was MAXIM`s MAX537, a Quad, 12-bit DAC. The function of this controller can be achieved by using some on-shelf micro-controllers like the Motorola`s MC68HC11, which offers dedicated SPI ports. The drawback encountered in using this controller is the overhead involved in putting together an user interface where the user can dynamically change its settings and load the SIC device. This is very critical in testing fewer number of CMOS IC`s having SIC. The SIC board described here takes care of this dynamic user interface issue.

  7. Enrollment and Budget Trends.

    ERIC Educational Resources Information Center

    Connecticut Community Coll. System, Hartford.

    This document discusses Fall 2001 enrollment and budget trends for Connecticut Community Colleges. It provides a map of the geographic planning regions as well as the geographic distribution of credit enrollments for the regions. The document shows the total credit enrollment for Fall 2001 was 42,642 students, which consisted of 28% full time and…

  8. Marketing for Camp Trends.

    ERIC Educational Resources Information Center

    Biddle, Alicia

    1998-01-01

    To effectively market a camp, current trends and issues must be considered: specialty programming, the Americans With Disabilities Act, competing recreational programs, changes in the school year, programming for seniors, and accountability. Camps should have a marketing strategy that includes public relations, a marketing plan, a pricing…

  9. Today's Recruitment Trends.

    ERIC Educational Resources Information Center

    Sugarman, Joe

    1996-01-01

    Five trends in the creation of college student recruitment publications are identified: (1) using market research and marketing principles; (2) targeting specific groups; (3) honesty about campus personality and reputation; (4) cost-effectiveness; and (5) creativity in using effective copy and design. (MSE)

  10. The Top Ten Trends.

    ERIC Educational Resources Information Center

    Bassi, Laurie J.; And Others

    1996-01-01

    Trends shaping the workplace are increased skill requirements; more educated, diverse work force; continued corporate restructuring; change in size and composition of training departments; instructional technology advances; new training delivery methods; focus on performance improvement; integrated high-performance work systems; companies becoming…

  11. Trends in nuclear astrophysics

    NASA Astrophysics Data System (ADS)

    Schatz, Hendrik

    2016-06-01

    Nuclear astrophysics is a vibrant field at the intersection of nuclear physics and astrophysics that encompasses research in nuclear physics, astrophysics, astronomy, and computational science. This paper is not a review. It is intended to provide an incomplete personal perspective on current trends in nuclear astrophysics and the specific role of nuclear physics in this field.

  12. Trends in Copyright.

    ERIC Educational Resources Information Center

    Becker, Gary H.

    1993-01-01

    Reviews trends in copyright law, including changes resulting from technological advances that include audio and video tape recordings, motion pictures, photocopying equipment, CD-ROM, and multimedia; amendments to the law, including administrative issues; compensation to authors of computer software programs; court cases; and a movement toward…

  13. Population Trends and Prospects.

    ERIC Educational Resources Information Center

    Mauldin, W. Parker

    1980-01-01

    Future trends in population are described as they relate to developed and developing nations. It is suggested that for the next 20 years there will be a decrease in population growth rates for all areas of the world except Africa. (Author/SA)

  14. Five Trends for Schools

    ERIC Educational Resources Information Center

    Lapkoff, Shelley; Li, Rose Maria

    2007-01-01

    The authors look at important demographic trends that will have an effect on schools, including roller-coaster enrollments and increasing diversity. For example, compared with 10 years ago, the average child entering a U.S. school today is less likely to live in a family with two married parents but is more likely to have a living grandparent,…

  15. Trends in Education.

    ERIC Educational Resources Information Center

    Snyder, Thomas D.

    This paper describes trends in public elementary and secondary education in the United States. The data were obtained from the "Condition of Education" and the "Digest of Education Statistics," which are prepared annually by the National Center for Education Statistics. Information is presented on the following areas: enrollment, minority…

  16. Children's Books: Current Trends.

    ERIC Educational Resources Information Center

    Nist, Joan Stidham

    A major trend in children's literature is the growing academic recognition of the field--indicated by the large number of new texts that have been published since 1975. Scholarly periodicals in the field have likewise grown since the 1970s. Library science, elementary education and English literature have fostered the development of children's…

  17. INTERNATIONAL LEGISLATIVE TRENDS

    EPA Science Inventory

    This paper will attempt to provide a pollution prevention legislative overview of where we have been, where we are, and some thoughts on pollution prevention legislative trends for the future. overnments have an important role to play by setting the regulatory framework, but clea...

  18. Trends Reshaping Colleges.

    ERIC Educational Resources Information Center

    Campbell, Dale F.; Peek, Roger C.

    2002-01-01

    Examines current educational trends in the community colleges, based on critical issues addressed at the 2002 Community College Futures Assembly (CCFA) in Orlando, Florida. Describes the CCFA as an independent policy forum, sponsored by the University of Florida, that convenes annually. Discusses the top three critical issues presented: the needs…

  19. Trends in Biomedical Education.

    ERIC Educational Resources Information Center

    Peppas, Nicholas A.; Mallinson, Richard G.

    1982-01-01

    An analysis of trends in biomedical education within chemical education is presented. Data used for the analysis included: type/level of course, subjects taught, and textbook preferences. Results among others of the 1980 survey indicate that 28 out of 79 schools responding offer at least one course in biomedical engineering. (JN)

  20. Trends & Indicators: Enrollment Period

    ERIC Educational Resources Information Center

    Harney, John O.

    2011-01-01

    Since New England Board of Higher Education (NEBHE) began publishing tables and charts exploring "Trends & Indicators" in New England higher education more than a half-century ago, few figures have grabbed as much attention as college "enrollment" data. These local, state, regional and national data go beyond simple headcounts of students going to…

  1. Ten Top Tech Trends

    ERIC Educational Resources Information Center

    McLester, Susan

    2008-01-01

    In this article, the author discusses the major technical issues, products, and practices of the day. The top ten tech trends are listed and discussed. These include: (1) data mining; (2) cyberbullying; (3) 21st century skills; (4) digital content; (5) learning at leisure; (6) personal responders; (7) mobile tools; (8) bandwidth; (9) open-source…

  2. Mechanics of load transfer at the interface. [from matrix to fiber of composites

    NASA Technical Reports Server (NTRS)

    Chamis, C. C.

    1974-01-01

    The mechanism of load transfer from matrix to fiber though the interface and, as a consequence, the effects of the interface on composite structural integrity are discussed. Specifically, the present work deals with the role of interfacial bonding in composite strength, the dependence of fracture surface on interface bond strength, and methods of measuring and predicting the stress at the interface, the microresidual stress, and load condition effects on the interface bond. The possibility of designing composites with specified bond properties is examined. Many of these effects are illustrated graphically to indicate general trends and to illustrate significant points. The discussion is based on theoretical considerations and is supplemented with pertinent experimental data.

  3. Approach and landing test network interface processor interface control document

    NASA Technical Reports Server (NTRS)

    1976-01-01

    The design requirements are established for all external or interproject interfaces to the Network Interface Processor located in Building 30 at the Lyndon B. Johnson Space Center, Houston, Texas. In addition to external interfaces, software/hardware and special interfaces are also described.

  4. Environmental materials and interfaces

    SciTech Connect

    Not Available

    1991-11-01

    A workshop that explored materials and interfaces research needs relevant to national environmental concerns was conducted at Pacific Northwest Laboratory. The purposes of the workshop were to refine the scientific research directions being planned for the Materials and Interface Program in the Molecular Science Research Center (MSRC) and further define the research and user equipment to the included as part of the proposed Environmental and Molecular Science Laboratory (EMSL). Three plenary information sessions served to outline the background, objectives, and status of the MSRC and EMSL initiatives; selected specific areas with environmentally related materials; and the status of capabilities and facilities planned for the EMSL. Attention was directed to four areas where materials and interface science can have a significant impact on prevention and remediation of environmental problems: in situ detection and characterization of hazardous wastes (sensors), minimization of hazardous waste (separation membranes, ion exchange materials, catalysts), waste containment (encapsulation and barrier materials), and fundamental understanding of contaminant transport mechanisms. During all other sessions, the participants were divided into three working groups for detailed discussion and the preparation of a written report. The working groups focused on the areas of interface structure and chemistry, materials and interface stability, and materials synthesis. These recommendations and suggestions for needed research will be useful for other researchers in proposing projects and for suggesting collaborative work with MSRC researchers. 1 fig.

  5. [Emergency Department Interfaces].

    PubMed

    Fleischmann, Thomas

    2016-01-01

    Emergency Departments ED may be an exceptionally good example of an interface within a hospital. EDs have no patients of their own but pass them over to other institutions, either to specialist departments within the hospital or to primary care providers. Moreover, many doctors, nurses, attendants and institutions take part in the care of emergency department patients, and thus the number of its interfaces is very high. The characteristics of working in an ED, for example shortage of time, high work load, taking care of several patients at the same time and frequently crowding, may compromise the transfer of information via interfaces, sometimes including even vital data. The best way to secure handoff of information may be the formalization and standardization of this process, assuring patient safety and quality of care. Further study is required. PMID:26710198

  6. High temperature interface superconductivity

    DOE PAGESBeta

    Gozar, A.; Bozovic, I.

    2016-01-20

    High-Tc superconductivity at interfaces has a history of more than a couple of decades. In this review we focus our attention on copper-oxide based heterostructures and multi-layers. We first discuss the technique, atomic layer-by-layer molecular beam epitaxy (ALL-MBE) engineering, that enabled High-Tc Interface Superconductivity (HT-IS), and the challenges associated with the realization of high quality interfaces. Then we turn our attention to the experiments which shed light on the structure and properties of interfacial layers, allowing comparison to those of single-phase films and bulk crystals. Both ‘passive’ hetero-structures as well as surface-induced effects by external gating are discussed. Here, wemore » conclude by comparing HT-IS in cuprates and in other classes of materials, especially Fe-based superconductors, and by examining the grand challenges currently laying ahead for the field.« less

  7. High temperature interface superconductivity

    NASA Astrophysics Data System (ADS)

    Gozar, A.; Bozovic, I.

    2016-02-01

    High-Tc superconductivity at interfaces has a history of more than a couple of decades. In this review we focus our attention on copper-oxide based heterostructures and multi-layers. We first discuss the technique, atomic layer-by-layer molecular beam epitaxy (ALL-MBE) engineering, that enabled High-Tc Interface Superconductivity (HT-IS), and the challenges associated with the realization of high quality interfaces. Then we turn our attention to the experiments which shed light on the structure and properties of interfacial layers, allowing comparison to those of single-phase films and bulk crystals. Both 'passive' hetero-structures as well as surface-induced effects by external gating are discussed. We conclude by comparing HT-IS in cuprates and in other classes of materials, especially Fe-based superconductors, and by examining the grand challenges currently laying ahead for the field.

  8. Magnetic multilayer interface anisotropy

    SciTech Connect

    Pechan, M.J.

    1992-01-01

    Ni/Mo and Ni/V multilayer magnetic anisotropy has been investigated as a function of Ni layer thickness, frequency and temperature. Variable frequency ferromagnetic resonance (FMR) measurements show, for the first time, significant frequency dependence associated with the multilayer magnetic anisotropy. The thickness dependence allows one to extract the interface contribution from the total anisotropy. Temperature dependent FMR (9 GHz) and room temperature magnetization indicate that strain between Ni and the non-magnetic layers is contributing significantly to the source of the interface anisotropy and the state of the interfacial magnetization. In order to examine the interface properties of other transition metal multilayer systems, investigations on Fe/Cu are underway and CoCr/Ag is being proposed. ESR measurements have been reported on Gd substituted YBaCuO superconductors and a novel quasi-equilibrium method has been developed to determine quickly and precisely the ransition temperature.

  9. The interplay between interface structure, energy level alignment and chemical bonding strength at organic-metal interfaces.

    PubMed

    Willenbockel, M; Lüftner, D; Stadtmüller, B; Koller, G; Kumpf, C; Soubatch, S; Puschnig, P; Ramsey, M G; Tautz, F S

    2015-01-21

    What do energy level alignments at metal-organic interfaces reveal about the metal-molecule bonding strength? Is it permissible to take vertical adsorption heights as indicators of bonding strengths? In this paper we analyse 3,4,9,10-perylene-tetracarboxylic acid dianhydride (PTCDA) on the three canonical low index Ag surfaces to provide exemplary answers to these questions. Specifically, we employ angular resolved photoemission spectroscopy for a systematic study of the energy level alignments of the two uppermost frontier states in ordered monolayer phases of PTCDA. Data are analysed using the orbital tomography approach. This allows the unambiguous identification of the orbital character of these states, and also the discrimination between inequivalent species. Combining this experimental information with DFT calculations and the generic Newns-Anderson chemisorption model, we analyse the alignments of highest occupied and lowest unoccupied molecular orbitals (HOMO and LUMO) with respect to the vacuum levels of bare and molecule-covered surfaces. This reveals clear differences between the two frontier states. In particular, on all surfaces the LUMO is subject to considerable bond stabilization through the interaction between the molecular π-electron system and the metal, as a consequence of which it also becomes occupied. Moreover, we observe a larger bond stabilization for the more open surfaces. Most importantly, our analysis shows that both the orbital binding energies of the LUMO and the overall adsorption heights of the molecule are linked to the strength of the chemical interaction between the molecular π-electron system and the metal, in the sense that stronger bonding leads to shorter adsorption heights and larger orbital binding energies. PMID:25475998

  10. Urban water interfaces

    NASA Astrophysics Data System (ADS)

    Gessner, M. O.; Hinkelmann, R.; Nützmann, G.; Jekel, M.; Singer, G.; Lewandowski, J.; Nehls, T.; Barjenbruch, M.

    2014-06-01

    Urban water systems consist of large-scale technical systems and both natural and man-made water bodies. The technical systems are essential components of urban infrastructure for water collection, treatment, storage and distribution, as well as for wastewater and runoff collection and subsequent treatment. Urban aquatic ecosystems are typically subject to strong human influences, which impair the quality of surface and ground waters, often with far-reaching impacts on downstream aquatic ecosystems and water users. The various surface and subsurface water bodies in urban environments can be viewed as interconnected compartments that are also extensively intertwined with a range of technical compartments of the urban water system. As a result, urban water systems are characterized by fluxes of water, solutes, gases and energy between contrasting compartments of a technical, natural or hybrid nature. Referred to as urban water interfaces, boundaries between and within these compartments are often specific to urban water systems. Urban water interfaces are generally characterized by steep physical and biogeochemical gradients, which promote high reaction rates. We hypothesize that they act as key sites of processes and fluxes with notable effects on overall system behaviour. By their very nature, urban water interfaces are heterogeneous and dynamic. Therefore, they increase spatial heterogeneity in urban areas and are also expected to contribute notably to the temporal dynamics of urban water systems, which often involve non-linear interactions and feedback mechanisms. Processes at and fluxes across urban water interfaces are complex and less well understood than within well-defined, homogeneous compartments, requiring both empirical investigations and new modelling approaches at both the process and system level. We advocate an integrative conceptual framework of the urban water system that considers interfaces as a key component to improve our fundamental

  11. Breastfeeding trends in Singapore.

    PubMed

    Chua, S; Viegas, O A; Counsilman, J J; Ratnam, S S

    1989-01-01

    About 60% of well-to-do mothers in Singapore initiate breastfeeding. This value compares favourably with the 36% recently recorded for poor mothers, but is still unacceptably low compared to the 85-95% of well-to-do mothers and 90% of poor mothers who breastfed in the 1950s and 1960s. There has been a general decline in the incidence of breastfeeding over the last 35 years. Differences between the well-to-do and poor groups were initially small. A pronounced decline in the incidence of breastfeeding among the well-to-do mothers followed; a reversal in this downward trend in well-to-do mothers over the past 10 years has narrowed, and indeed reversed, the difference between the two groups. Similar trends can be found for the duration of breastfeeding. Whilst the overall decline probably reflects increasing affluence and 'Westernization' of the population the variation between these two economic groups is probably a result of differences in education. Among the three major ethnic communities, Chinese favoured breastfeeding least and Malays favoured it most. The differences are believed to be related to cultural differences and the ability of traditional practices and beliefs among the ethnic groups to resist the modern trend towards bottlefeeding. PMID:2919314

  12. Ozone and temperature trends

    NASA Technical Reports Server (NTRS)

    Stolarski, Richard S.; Fioletov, Vitali; Bishop, Lane; Godin, Sophie; Bojkov, Rumen D.; Kirchhoff, Volker; Chanin, Marie-Lise; Zawodny, Joseph M.; Zerefos, Christos S.; Chu, William

    1991-01-01

    An update of the extensive reviews of the state of knowledge of measured ozone trends published in the Report of the International Ozone Trends Panel is presented. The update contains a review of progress since these reports, including reviewing of the ozone records, in most cases through March 1991. Also included are some new, unpublished reanalyses of these records including a complete reevaluation of 29 stations located in the former Soviet Union. The major new advance in knowledge of the measured ozone trend is the existence of independently calibrated satellite data records from the Total Ozone Mapping Spectrometer (TOMS) and Stratospheric Aerosol and Gas Experiment (SAG) instruments. These confirm many of the findings, originally derived from the Dobson record, concerning northern mid-latitude changes in ozone. We now have results from several instruments, whereas the previously reported changes were dependent on the calibration of a single instrument. This update will compare the ozone records from many different instruments to determine whether or not they provide a consistent picture of the ozone change that has occurred in the atmosphere. The update also briefly considers the problem of stratospheric temperature change. As in previous reports, this problem received significantly less attention, and the report is not nearly as complete. This area needs more attention in the future.

  13. Nonlinear optics at interfaces

    SciTech Connect

    Chen, C.K.

    1980-12-01

    Two aspects of surface nonlinear optics are explored in this thesis. The first part is a theoretical and experimental study of nonlinear intraction of surface plasmons and bulk photons at metal-dielectric interfaces. The second part is a demonstration and study of surface enhanced second harmonic generation at rough metal surfaces. A general formulation for nonlinear interaction of surface plasmons at metal-dielectric interfaces is presented and applied to both second and third order nonlinear processes. Experimental results for coherent second and third harmonic generation by surface plasmons and surface coherent antiStokes Raman spectroscopy (CARS) are shown to be in good agreement with the theory.

  14. Modal Interfaces in Hawaii

    NASA Technical Reports Server (NTRS)

    Wright, E. Alvey

    1974-01-01

    Hawaii, an archipelago where transportation distances are short but the interfaces are many, seeks elimination of modal changes by totally-submerged hydrofoil craft operating at the water surface directly between tourist resort destinations, by dual mode rapid transit vehicles operating directly between the deplaning bridges at Honolulu International Airport and hotel porte-cochere at Waikiki, by demand responsive vehicles for collection and distribution operating on fixed guideways for line haul, and by roll-on/roll-off inter-island ferries for all models of manually operated ground vehicles. The paper also describes facilitation of unavoidable interfaces by innovative sub-systems.

  15. Interfacing to accelerator instrumentation

    SciTech Connect

    Shea, T.J.

    1995-12-31

    As the sensory system for an accelerator, the beam instrumentation provides a tremendous amount of diagnostic information. Access to this information can vary from periodic spot checks by operators to high bandwidth data acquisition during studies. In this paper, example applications will illustrate the requirements on interfaces between the control system and the instrumentation hardware. A survey of the major accelerator facilities will identify the most popular interface standards. The impact of developments such as isochronous protocols and embedded digital signal processing will also be discussed.

  16. Optical encryption interface

    NASA Technical Reports Server (NTRS)

    Jackson, Deborah J. (Inventor)

    1998-01-01

    An analog optical encryption system based on phase scrambling of two-dimensional optical images and holographic transformation for achieving large encryption keys and high encryption speed. An enciphering interface uses a spatial light modulator for converting a digital data stream into a two dimensional optical image. The optical image is further transformed into a hologram with a random phase distribution. The hologram is converted into digital form for transmission over a shared information channel. A respective deciphering interface at a receiver reverses the encrypting process by using a phase conjugate reconstruction of the phase scrambled hologram.

  17. Profile Interface Generator

    Energy Science and Technology Software Center (ESTSC)

    2013-11-09

    The Profile Interface Generator (PIG) is a tool for loosely coupling applications and performance tools. It enables applications to write code that looks like standard C and Fortran functions calls, without requiring that applications link to specific implementations of those function calls. Performance tools can register with PIG in order to listen to only the calls that give information they care about. This interface reduces the build and configuration burden on application developers and allowsmore » semantic instrumentation to live in production codes without interfering with production runs.« less

  18. Profile Interface Generator

    SciTech Connect

    2013-11-09

    The Profile Interface Generator (PIG) is a tool for loosely coupling applications and performance tools. It enables applications to write code that looks like standard C and Fortran functions calls, without requiring that applications link to specific implementations of those function calls. Performance tools can register with PIG in order to listen to only the calls that give information they care about. This interface reduces the build and configuration burden on application developers and allows semantic instrumentation to live in production codes without interfering with production runs.

  19. Unstable nonlocal interface dynamics.

    PubMed

    Nicoli, Matteo; Cuerno, Rodolfo; Castro, Mario

    2009-06-26

    Nonlocal effects occur in many nonequilibrium interfaces, due to diverse physical mechanisms like diffusive, ballistic, or anomalous transport, with examples from flame fronts to thin films. While dimensional analysis describes stable nonlocal interfaces, we show the morphologically unstable condition to be nontrivial. This is the case for a family of stochastic equations of experimental relevance, paradigmatically including the Michelson-Sivashinsky system. For a whole parameter range, the asymptotic dynamics is scale invariant with dimension-independent exponents reflecting a hidden Galilean symmetry. The usual Kardar-Parisi-Zhang nonlinearity, albeit irrelevant in that parameter range, plays a key role in this behavior. PMID:19659099

  20. Direct Manipulation Interfaces.

    ERIC Educational Resources Information Center

    Hutchins, Edwin L.; And Others

    This paper presents a cognitive account of both the advantages and disadvantages of direct manipulation interfaces, i.e., the use of icons to manipulate and interact directly with data rather than writing programs or calling on a set of statistical subroutines. Two underlying phenomena that give rise to the sensation of directness are identified.…

  1. Interfacing with a DMM.

    ERIC Educational Resources Information Center

    Beatty, Jim

    1985-01-01

    Suggests purchasing a digital multimer (DMM) with an IEEE-488 option to interface an instrument to a microcomputer, indicating that a DMM is well protected from overloads and is easy to connect. An example of its use in an experiment involving hydrolysis of tertiary butyl alcohol (with program listing) is given. (JN)

  2. A Thermistor Interface.

    ERIC Educational Resources Information Center

    Kamin, Gary D.; Dowden, Edward

    1987-01-01

    Describes the use of a precalibrated stainless steel thermistor, interfaced with an Apple computer, in chemistry experiments. Discusses the advantages of "instant" temperature readings in experiments requiring that readings be taken at certain intervals. Outlines such an experiment which investigates freezing point depressions. (TW)

  3. Photochemistry at Interfaces

    SciTech Connect

    Eisenthal, Kenneth B

    2015-02-24

    We have advanced our capabilities to investigate ultrafast excited state dynamics at a liquid interface using a pump to excite molecules to higher electronic states and then probe the subsequent time evolution of the interfacial molecules with femtosecond time delayed vibrational SFG.

  4. Videodisc-Computer Interfaces.

    ERIC Educational Resources Information Center

    Zollman, Dean

    1984-01-01

    Lists microcomputer-videodisc interfaces currently available from 26 sources, including home use systems connected through remote control jack and industrial/educational systems utilizing computer ports and new laser reflective and stylus technology. Information provided includes computer and videodisc type, language, authoring system, educational…

  5. the EXFOR interface

    Energy Science and Technology Software Center (ESTSC)

    2011-03-10

    The x4i package is an interface to the EXFOR nuclear data library. It simplifies retrieval of EXFOR entries and can automatically parse them, allowing one to extract cross-section (and other) data in a simple, plot-able format. x4i also understands and can parse the entire reaction string, allowing one to build a strategy for processing the data

  6. Virtual interface environment

    NASA Technical Reports Server (NTRS)

    Fisher, Scott S.

    1988-01-01

    A head-mounted, wide-angle, stereoscopic display system controlled by operator position, voice and gesture is under development for use as a multipurpose interface environment. Initial applications of the system are in telerobotics, data-management and human factors research. System configuration and research directions are described.

  7. Construction Trends Dictate Vital Skills.

    ERIC Educational Resources Information Center

    Polivchak, Philip

    1989-01-01

    Vocational education can provide opportunities for students by anticipating trends. Four trends in the construction industry are (1) remodeling, (2) building and apartment maintenance, (3) quality, and (4) smart houses. (JOW)

  8. The NASA trend analysis program

    NASA Technical Reports Server (NTRS)

    Crawford, J. Larry; Weinstock, Robert

    1990-01-01

    The four main areas of the NASA trend analysis program (problem/reliability, performance, supportability, and programmatic trending) are defined and illustrated with examples from Space Shuttle applications. Emphasis is on the programmatic-trending component of the program and several of the statistical techniques used. Also described is the NASA safety, reliability, maintainability, and quality assurance management information center, used to focus management attention on key near-term launch concerns and long-range mission trend issues.

  9. SCADA -- AM/FM interface: Platforms, technology

    SciTech Connect

    Gilbert, R.F. )

    1994-05-01

    Efficient utility operations is enhanced by close interoperation between automated mapping/facility management (AM/FM) and supervisory control and data acquisition (SCADA) systems. Important benefits of such integration are improvements in service quality and reduced maintenance costs. Development of an AM/FM -- SCADA interface to provide automatic database and display generation for SCADA through AM/FM functions is continuing by Valmet Automation. To minimize or eliminate vendor-dependence, the AM/FM-SCADA interface is compliant with the Electric Power Research Institute's (EPRI) utility communication architecture (UCA). The utility industry is changing at an unprecedented rate. To remain a leader, or even to keep pace, utilities must be flexible and innovative. Competition forces companies to become more streamlined and efficient. These forces make the requirements for automation go beyond simple SCADA. Among several developing trends in the industry is the emergence of AM/FM. Collectively, these trends indicate the need to increase efficiency in the design, operation and maintenance of the transmission and distribution system. To accomplish its mission, SCADA and AM/FM must be a highly integrated system to provide timely information to its users. Open systems, the client-server paradigm and better information integration tools facilitate meeting these needs. UCA specification provides the technological glue, to achieve application integration between heterogeneous systems.

  10. Unsupervised Discovery of Subspace Trends.

    PubMed

    Xu, Yan; Qiu, Peng; Roysam, Badrinath

    2015-10-01

    This paper presents unsupervised algorithms for discovering previously unknown subspace trends in high-dimensional data sets without the benefit of prior information. A subspace trend is a sustained pattern of gradual/progressive changes within an unknown subset of feature dimensions. A fundamental challenge to subspace trend discovery is the presence of irrelevant data dimensions, noise, outliers, and confusion from multiple subspace trends driven by independent factors that are mixed in with each other. These factors can obscure the trends in conventional dimension reduction & projection based data visualizations. To overcome these limitations, we propose a novel graph-theoretic neighborhood similarity measure for detecting concordant progressive changes across data dimensions. Using this measure, we present an unsupervised algorithm for trend-relevant feature selection, subspace trend discovery, quantification of trend strength, and validation. Our method successfully identified verifiable subspace trends in diverse synthetic and real-world biomedical datasets. Visualizations derived from the selected trend-relevant features revealed biologically meaningful hidden subspace trend(s) that were obscured by irrelevant features and noise. Although our examples are drawn from the biological domain, the proposed algorithm is broadly applicable to exploratory analysis of high-dimensional data including visualization, hypothesis generation, knowledge discovery, and prediction in diverse other applications. PMID:26353189

  11. NATIONAL STATUS AND TRENDS PROGRAM

    EPA Science Inventory

    Since 1984, the National Status and Trends (NS&T) Program has monitored, on a national scale, spatial and temporal trends of chemical contamination and biological responses to that contamination. Temporal trends are being monitored through the Mussel Watch project that analyzes m...

  12. Trends in Neurocognitive Aging

    PubMed Central

    Grady, Cheryl

    2013-01-01

    Preface The availability of neuroimaging technology has spurred a marked increase in the human cognitive neuroscience literature, including the study of cognitive aging. Although there is a growing consensus that the aging brain retains considerable plasticity of function, currently measured primarily by means of functional magnetic resonance imaging, it is less clear how age differences in brain activity relate to cognitive performance. The field also is hampered by the complexity of the aging process itself and the large number of factors that are influenced by age. In this review, current trends and unresolved issues in the cognitive neuroscience of aging are discussed. PMID:22714020

  13. Trends in Environmental Analysis

    SciTech Connect

    Koester, C J; Moulik, A

    2005-03-31

    This article discusses developments in environmental analytical chemistry that occurred in the years of 2003 and 2004. References were found by searching the ''Science Citation Index and Current Contents''. As in our review of two years ago (A1), techniques are highlighted that represent current trends and state-of-the-art technologies in the sampling, extraction, separation, and detection of trace concentrations, low-part-per-billion and less, of organic, inorganic, and organometallic contaminants in environmental samples. New analytes of interest are also reviewed, the detections of which are made possible by recently developed analytical instruments and methods.

  14. Nuclear power attitude trends

    SciTech Connect

    Nealey, S.M.

    1981-11-01

    The increasing vulnerability of nuclear power to political pressures fueled by public concerns, particularly about nuclear plant safety and radioactive waste disposal, has become obvious. Since Eisenhower's Atoms-for-Peace program, utility and government plans have centered on expansion of nuclear power generating capability. While supporters have outnumbered opponents of nuclear power expansion for many years, in the wake of the Three Mile Island (TMI) accident the margin of support has narrowed. The purpose of this paper is to report and put in perspective these long-term attitude trends.

  15. Trends in PET imaging

    SciTech Connect

    Moses, William W.

    2000-11-01

    Positron Emission Tomography (PET) imaging is a well established method for obtaining information on the status of certain organs within the human body or in animals. This paper presents an overview of recent trends PET instrumentation. Significant effort is being expended to develop new PET detector modules, especially those capable of measuring depth of interaction. This is aided by recent advances in scintillator and pixellated photodetector technology. The other significant area of effort is development of special purpose PET cameras (such as for imaging breast cancer or small animals) or cameras that have the ability to image in more than one modality (such as PET / SPECT or PET / X-Ray CT).

  16. PREFACE: Water at interfaces Water at interfaces

    NASA Astrophysics Data System (ADS)

    Gallo, P.; Rovere, M.

    2010-07-01

    This special issue is devoted to illustrating important aspects and significant results in the field of modeling and simulation of water at interfaces with solutes or with confining substrates, focusing on a range of temperatures from ambient to supercooled. Understanding the behavior of water, in contact with different substrates and/or in solutions, is of pivotal importance for a wide range of applications in physics, chemistry and biochemistry. Simulations of confined and/or interfacial water are also relevant for testing how different its behavior is with respect to bulk water. Simulations and modeling in this field are of particular importance when studying supercooled regions where water shows anomalous properties. These considerations motivated the organization of a workshop at CECAM in the summer of 2009 which aimed to bring together scientists working with computer simulations on the properties of water in various environments with different methodologies. In this special issue, we collected a variety of interesting contributions from some of the speakers of the workshop. We have roughly classified the contributions into four groups. The papers of the first group address the properties of interfacial and confined water upon supercooling in an effort to understand the relation with anomalous behavior of supercooled bulk water. The second group deals with the specific problem of solvation. The next group deals with water in different environments by considering problems of great importance in technological and biological applications. Finally, the last group deals with quantum mechanical calculations related to the role of water in chemical processes. The first group of papers is introduced by the general paper of Stanley et al. The authors discuss recent progress in understanding the anomalies of water in bulk, nanoconfined, and biological environments. They present evidence that liquid water may display 'polymorphism', a property that can be present in

  17. Easy-to-use interface

    SciTech Connect

    Blattner, M M; Blattner, D O; Tong, Y

    1999-04-01

    Easy-to-use interfaces are a class of interfaces that fall between public access interfaces and graphical user interfaces in usability and cognitive difficulty. We describe characteristics of easy-to-use interfaces by the properties of four dimensions: selection, navigation, direct manipulation, and contextual metaphors. Another constraint we introduced was to include as little text as possible, and what text we have will be in at least four languages. Formative evaluations were conducted to identify and isolate these characteristics. Our application is a visual interface for a home automation system intended for a diverse set of users. The design will be expanded to accommodate the visually disabled in the near future.

  18. Interface Configuration Experiment: Preliminary results

    SciTech Connect

    Concus, P.; Finn, R.; Weislogel, M.

    1993-09-01

    The Interface Configuration Experiment (ICE) was carried out on USML-1 to investigate liquid-gas interfaces in certain rotationally-symmetric containers having prescribed, mathematically derived shapes. These containers have the property that they admit an entire continuum of distinct equilibrium rotationally-symmetric interfaces for a given liquid volume and contact angle. Furthermore, it can be shown that none of these interfaces can be stable. It was found, after the containers were filled in orbit, that an initial equilibrium interface from the symmetric continuum reoriented, when perturbed, to a stable interface that was not rotationally symmetric, in accordance with the mathematical theory.

  19. Interface Configuration Experiment: Preliminary Results

    NASA Technical Reports Server (NTRS)

    Concus, Paul; Finn, Robert; Weislogel, Mark

    1994-01-01

    The Interface Configuration Experiment (ICE) was carried out on USML-1 to investigate liquid-gas interfaces in certain rotationally-symmetric containers having prescribed, mathematically derived shapes. These containers have the property that they admit an entire continuum of distinct equilibrium rotationally-symmetric interfaces for a given liquid volume and contact angle. Furthermore, it can be shown that none of these interfaces can be stable. It was found, after the containers were filled in orbit, that an initial equilibrium interface from the symmetric continuum re-oriented, when perturbed, to a stable interface that was not rotationally symmetric, in accordance with the mathematical theory.

  20. Global trends, needs, issues.

    PubMed

    Kieffer, R G

    1998-01-01

    Worldwide, Pharmaceutical Plant Management struggles with the competing priorities of lowering costs, rising customer expectations, more demanding government regulations, and the need to reduce cycle times especially in the introduction of new products. All of this takes place in an environment of global competition, regulatory harmonization, mergers and downsizing, and employee insecurity. Employees are expected to do more with less, work with more sophisticated equipment and processes, take more personal responsibility for quality and productivity, work in teams, etc. In summary, we are talking about CHANGE, the speed of which will accelerate in the years to come. This presentation will discuss how some pharmaceutical plants are addressing these challenges. Examples will be given in the areas of validation, process reengineering, risk analysis, role of the quality function and people. It is my contention that most of the global trends today are insufficient to meet the challenges that we face. I hope that this presentation will generate some ideas on what the global trends should be. PMID:9752708

  1. Thyra Abstract Interface Package

    Energy Science and Technology Software Center (ESTSC)

    2005-09-01

    Thrya primarily defines a set of abstract C++ class interfaces needed for the development of abstract numerical atgorithms (ANAs) such as iterative linear solvers, transient solvers all the way up to optimization. At the foundation of these interfaces are abstract C++ classes for vectors, vector spaces, linear operators and multi-vectors. Also included in the Thyra package is C++ code for creating concrete vector, vector space, linear operator, and multi-vector subclasses as well as other utilitiesmore » to aid in the development of ANAs. Currently, very general and efficient concrete subclass implementations exist for serial and SPMD in-core vectors and multi-vectors. Code also currently exists for testing objects and providing composite objects such as product vectors.« less

  2. Popeye Project: ROV interfaces

    SciTech Connect

    Scates, C.R.; Hickok, D.D.; Hernandez, D.A.

    1997-04-01

    The Popeye Project in the Gulf of Mexico helped advance the technology and standardization of ROV interfaces for deepwater subsea production systems. Some of the many successful ROV operations during installation and completion were {open_quotes}first-of-it`s-kind{close_quotes} activities-enabled by many technical advances. The use and reliance upon ROV systems for support of deepwater drilling and installation operations significantly increased in the past 10 years. Shell Offshore Inc.`s (SOI) confidence in this increased capability was an important factor in many of the design decisions which characterized the innovative system. Technology advancements, which depended on effective ROV intervention, were implemented with no significant difficulties. These advancements, in particular the flying leads and seabed position methods, are available to the industry for other deepwater subsea systems. In addition, several Popeye ROV interfaces have helped advance the subsea standardization initiative; e.g., hot stabs, torque-tool end effectors, and paint color.

  3. Object oriented programming interfaces for accelerator control

    SciTech Connect

    Hoff, L.T.

    1997-07-01

    Several years ago, the AGS controls group was given the task of developing software for the RHIC accelerator. Like the AGS, the RHIC control system needs to control and monitor equipment distributed around a relatively large geographic area. A local area network connects this equipment to a collection of UNIX workstations in a central control room. Similar software had been developed for the AGS about a decade earlier, but isn`t well suited for RHIC use for a number of reasons. Rather than adapt the AGS software for RHIC use, the controls group opted to start with a clean slate. To develop software that would address the shortcomings of the AGS software, while preserving the useful features that evolved through years of use. A current trend in control system design is to provide an object oriented programming interface for application developers. This talk will discuss important aspects and features of object oriented application programming interfaces (APIs) for accelerator control systems, and explore why such interfaces are becoming the norm.

  4. Standard interface file handbook

    SciTech Connect

    Shapiro, A.; Huria, H.C. )

    1992-10-01

    This handbook documents many of the standard interface file formats that have been adopted by the US Department of Energy to facilitate communications between and portability of, various large reactor physics and radiation transport software packages. The emphasis is on those files needed for use of the VENTURE/PC diffusion-depletion code system. File structures, contents and some practical advice on use of the various files are provided.

  5. Virtual button interface

    DOEpatents

    Jones, J.S.

    1999-01-12

    An apparatus and method of issuing commands to a computer by a user interfacing with a virtual reality environment are disclosed. To issue a command, the user directs gaze at a virtual button within the virtual reality environment, causing a perceptible change in the virtual button, which then sends a command corresponding to the virtual button to the computer, optionally after a confirming action is performed by the user, such as depressing a thumb switch. 4 figs.

  6. Virtual button interface

    DOEpatents

    Jones, Jake S.

    1999-01-01

    An apparatus and method of issuing commands to a computer by a user interfacing with a virtual reality environment. To issue a command, the user directs gaze at a virtual button within the virtual reality environment, causing a perceptible change in the virtual button, which then sends a command corresponding to the virtual button to the computer, optionally after a confirming action is performed by the user, such as depressing a thumb switch.

  7. SNE Industrial Fieldbus Interface

    NASA Technical Reports Server (NTRS)

    Lucena, Angel; Raines, Matthew; Oostdyk, Rebecca; Mata, Carlos

    2011-01-01

    Programmable logic controllers (PLCs) have very limited diagnostic and no prognostic capabilities, while current smart sensor designs do not have the capability to communicate over Fieldbus networks. The aim is to interface smart sensors with PLCs so that health and status information, such as failure mode identification and measurement tolerance, can be communicated via an industrial Fieldbus such as ControlNet. The SNE Industrial Fieldbus Interface (SIFI) is an embedded device that acts as a communication module in a networked smart sensor. The purpose is to enable a smart sensor to communicate health and status information to other devices, such as PLCs, via an industrial Fieldbus networking protocol. The SNE (Smart Network Element) is attached to a commercial off-the-shelf Any bus-S interface module through the SIFI. Numerous Anybus-S modules are available, each one designed to interface with a specific Fieldbus. Development of the SIFI focused on communications using the ControlNet protocol, but any of the Anybus-S modules can be used. The SIFI communicates with the Any-bus module via a data buffer and mailbox system on the Anybus module, and supplies power to the module. The Anybus module transmits and receives data on the Fieldbus using the proper protocol. The SIFI is intended to be connected to other existing SNE modules in order to monitor the health and status of a transducer. The SIFI can also monitor aspects of its own health using an onboard watchdog timer and voltage monitors. The SIFI also has the hardware to drive a touchscreen LCD (liquid crystal display) unit for manual configuration and status monitoring.

  8. Optical Neural Interfaces

    PubMed Central

    Warden, Melissa R.; Cardin, Jessica A.; Deisseroth, Karl

    2014-01-01

    Genetically encoded optical actuators and indicators have changed the landscape of neuroscience, enabling targetable control and readout of specific components of intact neural circuits in behaving animals. Here, we review the development of optical neural interfaces, focusing on hardware designed for optical control of neural activity, integrated optical control and electrical readout, and optical readout of population and single-cell neural activity in freely moving mammals. PMID:25014785

  9. Numerical and experimental study of the nonlinear interaction between a shear wave and a frictional interface.

    PubMed

    Blanloeuil, Philippe; Croxford, Anthony J; Meziane, Anissa

    2014-04-01

    The nonlinear interaction of shear waves with a frictional interface are presented and modeled using simple Coulomb friction. Analytical and finite difference implementations are proposed with both in agreement and showing a unique trend in terms of the generated nonlinearity. A dimensionless parameter ξ is proposed to uniquely quantify the nonlinearity produced. The trends produced in the numerical study are then validated with good agreement experimentally. This is carried out loading an interface between two steel blocks and exciting this interface with different amplitude normal incidence shear waves. The experimental results are in good agreement with the numerical results, suggesting the simple friction model does a reasonable job of capturing the fundamental physics. The resulting approach offers a potential way to characterize a contacting interface; however, the difficulty in activating that interface may ultimately limit its applicability. PMID:25234971

  10. The THOSE remote interface

    NASA Astrophysics Data System (ADS)

    Klawon, Kevin; Gold, Josh; Bachman, Kristen

    2013-05-01

    The DIA, in conjunction with the Army Research Lab (ARL), wants to create an Unmanned Ground Sensor (UGS) controller that is (a) interoperable across all controller platforms, (b) capable of easily adding new sensors, radios, and processes and (c) backward compatible with existing UGS systems. To achieve this, a Terra Harvest controller was created that used Java JRE 1.6 and an Open Services Gateway initiative (OSGi) platform, named Terra Harvest Open Software Environment (THOSE). OSGi is an extensible framework that provides a modularized environment for deploying functionality in "bundles". These bundles can publish, discover, and share services available from other external bundles or bundles provided by the controller core. With the addition of a web GUI used for interacting with THOSE, a natural step was then to create a common remote interface that allows 3rd party real-time interaction with the controller. This paper provides an overview of the THOSE system and its components as well as a description of the architectural structure of the remote interface, highlighting the interactions occurring between the controller and the remote interface and its role in providing a positive user experience for managing UGSS functions.

  11. Eye-voice-controlled interface

    NASA Technical Reports Server (NTRS)

    Glenn, Floyd A., III; Iavecchia, Helene P.; Ross, Lorna V.; Stokes, James M.; Weiland, William J.

    1986-01-01

    The Ocular Attention-Sensing Interface System (OASIS) is an innovative human-computer interface which utilizes eye movement and voice commands to communicate messages between the operator and the system. This report initially describes some technical issues relevant to the development of such an interface. The results of preliminary experiments which evaluate alternative eye processing algorithms and feedback techniques are presented. Candidate interface applications are also discussed.

  12. Why Mineral Interfaces Matter

    NASA Astrophysics Data System (ADS)

    Putnis, Andrew; Putnis, Christine V.

    2015-04-01

    While it is obvious that reactions between a mineral and an aqueous solution take place at the mineral-fluid interface it is only relatively recently that high spatial resolution studies have demonstrated how the local structure of the mineral surface and the chemical composition of the fluid at the interface control both the short-range and the long-range consequences of mineral-fluid interaction. Long-range consequences of fluid-mineral interaction control element cycles in the earth, the formation of ore-deposits, the chemical composition of the oceans through weathering of rocks and hence climate changes. Although weathering is clearly related to mineral dissolution, to what extent do experimentally measured dissolution rates of minerals help to understand weathering, especially weathering mechanisms? This question is related to the short-range, local reactions that take place when a mineral, that is not stable in the fluid, begins to dissolve. In this case the fluid composition at the interface will become supersaturated with respect to a different phase or phases. This may be a different composition of the same mineral e.g. a Ca-rich feldspar dissolving in a Na-rich solution results in a fluid at the interface which may be supersaturated with respect to an Na-rich feldspar. Alternatively, the interfacial fluid could be supersaturated with respect to a different mineral e.g. an Na-rich zeolite, depending on the temperature. Numerous experiments have shown that the precipitation of a more stable phase at the mineral-fluid interface results in a coupling between the dissolution and the precipitation, and the replacement of one mineral by another. This process separates the short-range mechanisms which depend only on the composition of the interfacial solution, and the long-range consequences that depend on the composition of the residual fluid released from the reacting parent mineral. Typically such residual fluids may carry metal ions tens to hundreds of

  13. Land Cover Trends Project

    USGS Publications Warehouse

    Acevedo, William

    2006-01-01

    The Land Cover Trends Project is designed to document the types, rates, causes, and consequences of land cover change from 1973 to 2000 within each of the 84 U.S. Environmental Protection Agency (EPA) Level III ecoregions that span the conterminous United States. The project's objectives are to: * Develop a comprehensive methodology using probability sampling and change analysis techniques and Landsat Multispectral Scanner (MSS), Thematic Mapper (TM), and Enhanced Thematic Mapper (ETM) data for estimating regional land cover change. * Characterize the spatial and temporal characteristics of conterminous U.S. land cover change for five periods from 1973 to 2000 (nominally 1973, 1980, 1986, 1992, and 2000). * Document the regional driving forces and consequences of change. * Prepare a national synthesis of land cover change.

  14. Reckoning wheat yield trends

    NASA Astrophysics Data System (ADS)

    Lin, M.; Huybers, P.

    2012-06-01

    Wheat yields have increased approximately linearly since the mid-twentieth century across the globe, but stagnation of these trends has now been suggested for several nations. We present a new statistical test for whether a yield time series has leveled off and apply it to wheat yield data from 47 different regions to show that nearly half of the production within our sample has transitioned to level trajectories. With the major exception of India, the majority of leveling in wheat yields occurs within developed nations—including the United Kingdom, France and Germany—whose policies appear to have disincentivized yield increases relative to other objectives. The effects of climate change and of yields nearing their maximum potential may also be important.

  15. Temperature trend biases

    NASA Astrophysics Data System (ADS)

    Venema, Victor; Lindau, Ralf

    2016-04-01

    In an accompanying talk we show that well-homogenized national dataset warm more than temperatures from global collections averaged over the region of common coverage. In this poster we want to present auxiliary work about possible biases in the raw observations and on how well relative statistical homogenization can remove trend biases. There are several possible causes of cooling biases, which have not been studied much. Siting could be an important factor. Urban stations tend to move away from the centre to better locations. Many stations started inside of urban areas and are nowadays more outside. Even for villages the temperature difference between the centre and edge can be 0.5°C. When a city station moves to an airport, which often happened around WWII, this takes the station (largely) out of the urban heat island. During the 20th century the Stevenson screen was established as the dominant thermometer screen. This screen protected the thermometer much better against radiation than earlier designs. Deficits of earlier measurement methods have artificially warmed the temperatures in the 19th century. Newer studies suggest we may have underestimated the size of this bias. Currently we are in a transition to Automatic Weather Stations. The net global effect of this transition is not clear at this moment. Irrigation on average decreases the 2m-temperature by about 1 degree centigrade. At the same time, irrigation has increased significantly during the last century. People preferentially live in irrigated areas and weather stations serve agriculture. Thus it is possible that there is a higher likelihood that weather stations are erected in irrigated areas than elsewhere. In this case irrigation could lead to a spurious cooling trend. In the Parallel Observations Science Team of the International Surface Temperature Initiative (ISTI-POST) we are studying influence of the introduction of Stevenson screens and Automatic Weather Stations using parallel measurements

  16. Trends in Cochlear Implants

    PubMed Central

    Zeng, Fan-Gang

    2004-01-01

    More than 60,000 people worldwide use cochlear implants as a means to restore functional hearing. Although individual performance variability is still high, an average implant user can talk on the phone in a quiet environment. Cochlear-implant research has also matured as a field, as evidenced by the exponential growth in both the patient population and scientific publication. The present report examines current issues related to audiologic, clinical, engineering, anatomic, and physiologic aspects of cochlear implants, focusing on their psychophysical, speech, music, and cognitive performance. This report also forecasts clinical and research trends related to presurgical evaluation, fitting protocols, signal processing, and postsurgical rehabilitation in cochlear implants. Finally, a future landscape in amplification is presented that requires a unique, yet complementary, contribution from hearing aids, middle ear implants, and cochlear implants to achieve a total solution to the entire spectrum of hearing loss treatment and management. PMID:15247993

  17. Graphic Interfaces and Online Information.

    ERIC Educational Resources Information Center

    Percival, J. Mark

    1990-01-01

    Discusses the growing importance of the use of Graphic User Interfaces (GUIs) with microcomputers and online services. Highlights include the development of graphics interfacing with microcomputers; CD-ROM databases; an evaluation of HyperCard as a potential interface to electronic mail and online commercial databases; and future possibilities.…

  18. POLYMERIC INTERFACES FOR STACK MONITORING

    EPA Science Inventory

    Research has been performed on the use of polymeric interfaces for in situ continuous stack monitoring of gaseous pollutants. Permeabilities of candidate interface materials to SO2 were measured at temperatures from ambient to 200C, and the results were used to design interfaces ...

  19. Case study for the evaluation and selection of man-machine interface (MMI) software

    SciTech Connect

    Nekimken, H.; Pope, N.; Macdonald, J.; Bibeau, R.; Gomez, B.; Sellon, D.

    1996-06-01

    The authors evaluated three of the top man-machine interface (MMI) software systems. The main categories upon which they based their evaluation on were the following: operator interface; network and data distribution; input/output (I/O) interface; application development; alarms; real-time and historical trending; support, documentation, and training; processing tools (batch, recipe, logic); reports; custom interfacing; start-up/recovery; external database; and multimedia. They also present their MMI requirements and guidelines for the selection and evaluation of these MMI systems.

  20. Fracture behavior across interfaces

    NASA Astrophysics Data System (ADS)

    Petrie, E. S.; Evans, J. P.; Jeppson, T. N.

    2011-12-01

    Faults and fracture networks at depth are important fluid pathways, especially in fine-grained, low permeability seal lithologies. Discontinues in sealing lithologies can create seal bypass systems, leading to the failure of CO2 geosequestration sites or hydrocarbon traps. We characterize the occurrence of and changes in discontinuity patterns and the associated changes in elastic moduli across sedimentologic interfaces to document the importance of these discontinuities for fluid management in the subsurface and potential for re-activation in high-pressure injection scenarios. We evaluate well-exposed, fine-grained, low-permeability Mesozoic and Paleozoic units that are seals of potential CO2 repositories on the Colorado Plateau and show evidence for open fractures and fluid flow in the subsurface. Field observations document changes in fracture distributions across lithologic boundaries allowing us to identify mechano-stratigraphic units and focus on the effect of lithologic interfaces on fracture distribution. An interface marks the boundary between facies in a seal and in this study the fractures are shown to deflect or arrest at the interface. In outcrop fracture intensity varies in from 1 to 18 fractures per meter and fracture apertures range from mm to cm. The mineralized fractures often have associated alteration halos along their boundaries; their general orientation follows that of discontinuities within the underlying reservoir facies or adjacent faults. The recognition of these changes in fracture distribution is important for forward modeling of fluid flow and risk management. Studying the occurrence of and changes in fracture patterns from outcrops and scaling it up for use in modeling at a field scale is difficult due to the lack of direct correlation between outcrop observations and subsurface data. Due to the size and amount of data needed to model fluid flow at the field scale the meso-scale (cm to m) variability of rock properties is often

  1. NESSUS/NASTRAN Interface

    NASA Technical Reports Server (NTRS)

    Millwater, Harry; Riha, David

    1996-01-01

    The NESSUS probabilistic analysis computer program has been developed with a built-in finite element analysis program NESSUS/FEM. However, the NESSUS/FEM program is specialized for engine structures and may not contain sufficient features for other applications. In addition, users often become well acquainted with a particular finite element code and want to use that code for probabilistic structural analysis. For these reasons, this work was undertaken to develop an interface between NESSUS and NASTRAN such that NASTRAN can be used for the finite element analysis and NESSUS can be used for the probabilistic analysis. In addition, NESSUS was restructured such that other finite element codes could be more easily coupled with NESSUS. NESSUS has been enhanced such that NESSUS will modify the NASTRAN input deck for a given set of random variables, run NASTRAN and read the NASTRAN result. The coordination between the two codes is handled automatically. The work described here was implemented within NESSUS 6.2 which was delivered to NASA in September 1995. The code runs on Unix machines: Cray, HP, Sun, SGI and IBM. The new capabilities have been implemented such that a user familiar with NESSUS using NESSUS/FEM and NASTRAN can immediately use NESSUS with NASTRAN. In other words, the interface with NASTRAN has been implemented in an analogous manner to the interface with NESSUS/FEM. Only finite element specific input has been changed. This manual is written as an addendum to the existing NESSUS 6.2 manuals. We assume users have access to NESSUS manuals and are familiar with the operation of NESSUS including probabilistic finite element analysis. Update pages to the NESSUS PFEM manual are contained in Appendix E. The finite element features of the code and the probalistic analysis capabilities are summarized.

  2. User interface concerns

    NASA Technical Reports Server (NTRS)

    Redhed, D. D.

    1978-01-01

    Three possible goals for the Numerical Aerodynamic Simulation Facility (NASF) are: (1) a computational fluid dynamics (as opposed to aerodynamics) algorithm development tool; (2) a specialized research laboratory facility for nearly intractable aerodynamics problems that industry encounters; and (3) a facility for industry to use in its normal aerodynamics design work that requires high computing rates. The central system issue for industry use of such a computer is the quality of the user interface as implemented in some kind of a front end to the vector processor.

  3. NESSUS/NASTRAN Interface

    NASA Technical Reports Server (NTRS)

    Millwater, Harry; Riha, David

    1996-01-01

    The NESSUS and NASTRAN computer codes were successfully integrated. The enhanced NESSUS code will use NASTRAN for the structural Analysis and NESSUS for the probabilistic analysis. Any quantities in the NASTRAN bulk data input can be random variables. Any NASTRAN result that is written to the output2 file can be returned to NESSUS as the finite element result. The interfacing between NESSUS and NASTRAN is handled automatically by NESSUS. NESSUS and NASTRAN can be run on different machines using the remote host option.

  4. Adhesion at metal interfaces

    NASA Technical Reports Server (NTRS)

    Banerjea, Amitava; Ferrante, John; Smith, John R.

    1991-01-01

    A basic adhesion process is defined, the theory of the properties influencing metallic adhesion is outlined, and theoretical approaches to the interface problem are presented, with emphasis on first-principle calculations as well as jellium-model calculations. The computation of the energies of adhesion as a function of the interfacial separation is performed; fully three-dimensional calculations are presented, and universality in the shapes of the binding energy curves is considered. An embedded-atom method and equivalent-crystal theory are covered in the framework of issues involved in practical adhesion.

  5. Access Interface Strategies

    PubMed Central

    Fager, Susan; Beukelman, David R.; Fried-Oken, Melanie; Jakobs, Tom; Baker, John

    2013-01-01

    Individuals who rely on augmentative and alternative communication (AAC) devices to support their communication often have physical movement challenges that require alternative methods of access. Technology that supports access, particularly for those with the most severe movement deficits, have expanded substantially over the years. The purposes of this article are to review the state of the science of access technologies that interface with augmentative and alternative communication devices and to propose a future research and development agenda that will enhance access options for people with limited movement capability due to developmental and acquired conditions. PMID:22590797

  6. Changing trends in thyroidectomy.

    PubMed

    Chukudebelu, O; Dias, A; Timon, C

    2012-06-01

    The objective of this study was to establish the indications, referral trends and demographics for thyroidectomies performed in our institutions over a 13-year period by a single surgeon. We conducted a retrospective chart review of 1003 consecutive thyroidectomies at our institutions during the period 1998 until 2010. The parameters incorporated to this study were age, sex, county, referral source, symptoms, thyroid status, procedure performed, histopathology and post-operative complications. The age range of patients was 4-87 years. There were 777 females and 226 males, with a sex ratio of 3.4:1. The mean age was 51 years. The commonest indications for surgery were a potential or definite neoplastic thyroid mass (781 cases--78%), compressive symptoms (119 cases-- 12%), thyrotoxicosis and endocrine related causes (103 cases--10%). 896 (89.3%) patients were euthyroid, 4 (0.4%) hypothyroid and 103 (10.3%) hyperthyroid. There were 739 partial thyroidectomies and 264 total thyroidectomies. Histopathology results showed that 742 were benign and 261 malignant, of which papillary carcinomas accounted for 75.1%, follicular carcinomas 13.4%, Hurthle cell carcinoma 1.5%, medullary thyroid carcinomas 3 %/, undifferentiated carcinomas 3%, others (lymphoma and squamous cell carcinomas) 4%. Post-operative complications were: Temporary hypocalcaemia--6.4%, Permanent hypocalcemia in--0.8%. Haemorrhage and seroma in 1.5%, unilateral vocal cord paralysis in 1.2%/, post-operative wound infection in 0.3% and pulmonary embolism in 0.01%. There was no mortality. Dublin accounted for 519 (51.7%/) of referrals, 484 (48.3%) was from the rest of the country. General practitioners accounted for 84.8%/ of referrals. Endocrine referrals comprised 9.8%. Other specialities constituted 5.4%. Two significant findings from this study were; firstly, a trend depicting increasing referral rates from the general practitioner and endocrine services. Secondly, low post-operative complication rates that

  7. Matched Interface and Boundary Method for Elasticity Interface Problems

    PubMed Central

    Wang, Bao; Xia, Kelin; Wei, Guo-Wei

    2015-01-01

    Elasticity theory is an important component of continuum mechanics and has had widely spread applications in science and engineering. Material interfaces are ubiquity in nature and man-made devices, and often give rise to discontinuous coefficients in the governing elasticity equations. In this work, the matched interface and boundary (MIB) method is developed to address elasticity interface problems. Linear elasticity theory for both isotropic homogeneous and inhomogeneous media is employed. In our approach, Lamé’s parameters can have jumps across the interface and are allowed to be position dependent in modeling isotropic inhomogeneous material. Both strong discontinuity, i.e., discontinuous solution, and weak discontinuity, namely, discontinuous derivatives of the solution, are considered in the present study. In the proposed method, fictitious values are utilized so that the standard central finite different schemes can be employed regardless of the interface. Interface jump conditions are enforced on the interface, which in turn, accurately determines fictitious values. We design new MIB schemes to account for complex interface geometries. In particular, the cross derivatives in the elasticity equations are difficult to handle for complex interface geometries. We propose secondary fictitious values and construct geometry based interpolation schemes to overcome this difficulty. Numerous analytical examples are used to validate the accuracy, convergence and robustness of the present MIB method for elasticity interface problems with both small and large curvatures, strong and weak discontinuities, and constant and variable coefficients. Numerical tests indicate second order accuracy in both L∞ and L2 norms. PMID:25914439

  8. TMS communications hardware. Volume 2: Bus interface unit

    NASA Technical Reports Server (NTRS)

    Brown, J. S.; Hopkins, G. T.

    1979-01-01

    A prototype coaxial cable bus communication system used in the Trend Monitoring System to interconnect intelligent graphics terminals to a host minicomputer is described. The terminals and host are connected to the bus through a microprocessor-based RF modem termed a Bus Interface Unit (BIU). The BIU hardware and the Carrier Sense Multiple Access Listen-While-Talk protocol used on the network are described.

  9. Trends in reservoir simulation

    SciTech Connect

    Nolen, J.S.

    1995-06-01

    The future of reservoir simulation is driven by two different and, on the surface, paradoxical trends. On the one hand, the user base is on average becoming less experienced, and on the other, increasingly complex models are being built to honor the advances in reservoir-description technology. The job of the software development community is to create software that satisfies both the ease-of-use needs of the novice and the accuracy needs of the integrated geoscience team. One of the near-term effects of these demands will be to improve the capabilities and quality of the fully integrated geoscience work-station. This will include the need for implementation of industry-wide data standards. Reservoir simulators will need to incorporate increasing amounts of interactivity and built-in expertise. Accuracy of results will be improved by increased use of unstructured grids, including automatic gridding software with dynamic capabilities. Additional research will focus on complex wells, including both in-flow performance and wellbore hydraulics. Finally, grid size will continue to escalate in step with advances in hardware and software. The growth of grid size will be mitigated by substantial efforts in upscaling, but ultimately parallel computing must provide the mechanism for continued growth.

  10. Suicide: current trends.

    PubMed

    Bailey, Rahn K; Patel, Tejas C; Avenido, Jaymie; Patel, Milapkumar; Jaleel, Mohammad; Barker, Narviar C; Khan, Jahanzeb Ali; Ali, Shahid; Jabeen, Shagufta

    2011-07-01

    Suicide is the act of a human being intentionally causing his or her own death. More than 1 million people commit suicide every year. It is the 13th leading cause of death worldwide, with China, India, and Japan accounting for almost half of all suicides. In less than 50 years, the rate of suicide among Sri Lankans has risen from a modest level to one of the highest in the world (118 per 100,000). Suicide is a major preventable cause of premature death. It is influenced by psychosocial, cultural, and environmental risk factors. The impact of suicide can be devastating for all concerned. It is common in people who are living with chronic mental illness. Individuals with severe clinical depression and alcohol use disorders are at highest risk if untreated. On an interpersonal level, friends and families of suicide victims require social support. On a national level, governments need to recognize the causes of suicide and protect those most vulnerable. If governments commit to defining national responses to prevent suicide, significant progress can be made. On a global scale, research and health organizations can identify global trends and encourage the sharing of information in effective prevention activities. In September 2010, World Suicide Prevention Day, with a theme of "Many faces, many places: suicide prevention across the world," encouraged public awareness worldwide to unite in commitment and action to promote understanding about suicide and removal of stigmatization'. There is compelling evidence that adequate prevention and awareness can reduce suicide rates. PMID:21999037

  11. [Population trends and poverty].

    PubMed

    Olmedo, C

    1998-04-01

    Implications of population growth in Ecuador for the quality of life of the poor population are analyzed. It is argued that if the gross national product (GNP) were to grow at a sustained annual rate of 5% or more, demographic trends would not present a significant obstacle to reducing poverty. National economic projections are for growth of only 2.5-3.5% annually. The continuing rapid growth of the poor population despite general slowing of demographic growth, the young age structure, the need for increased formal education to enable the poor to overcome their poverty, and the effect of unemployment on the dependency ratio will tend to hamper improvements in average productivity and per capita GNP. The need for spending on education, health, basic services, and housing will divert funds away from productive investment, generating a direct negative impact on economic growth. Over half of Ecuadorian children suffer from some degree of malnutrition, indicating that food production is inadequate to meet demand. The export-oriented agricultural policy and poor weather have led to a chronic shortage of basic foods. Progressive increase and diversification of agricultural production, along with maintenance of low prices and substantial increases in income levels and agricultural productivity, will be required if the entire population is to be fed adequately. Intense efforts will be needed from all sectors to bring demographic growth into balance with economic and development needs. PMID:12178231

  12. Chemical structure of interfaces

    NASA Technical Reports Server (NTRS)

    Grunthaner, F. J.

    1985-01-01

    The interfacial structure of silicon/dielectric and silicon/metal systems is particularly amenable to analysis using a combination of surface spectroscopies together with a variety of chemical structures of Si/SiO2, Si/SiO2Si3N4, Si/Si2N2O, Si/SiO2/Al, and Si/Native Oxide interfaces using high resolution (0.350 eV FWHM) X ray photoelectron spectroscopy. The general structure of these dielectric interfaces entails a monolayer chemical transition layer at the Si/dielectric boundary. Amorphous Si substrates show a wide variety of hydrogenated Si and Si(OH) sub x states that are not observed in thermal oxidation of single crystal material. Extended SiO2 layers greater than 8 A in thickness are shown to be stoichiometric SiO2, but to exhibit a wide variety of local network structures. In the nitrogen containing systems, an approach to stoichiometric oxynitride compounds with interesting impurity and electron trapping properties are seen. In native oxides, substantial topographical nonuniformity in oxide thickness and composition are found. Analysis of metal/oxide interfacial layers is accomplished by analytical removal of the Si substrate by UHV XeF2 dry etching methods.

  13. Mysteries at Ice Interfaces

    NASA Astrophysics Data System (ADS)

    Fain, Samuel C., Jr.

    1996-03-01

    Michael Faraday noted that ``two pieces of thawing ice, if put together, adhere and become one...the effect will take place in air, or in water, or in vacuo." Why? He proposed that ``a particle of water, which could retain the liquid state whilst touching ice only on one side, could not retain the liquid state if it were touched by ice on both sides."footnote M. Faraday, Proc. Roy. Soc. London 10, 440 (1860) The existence of special properties at interfaces of ice is generally agreed and has important environmental consequences.(J. G. Dash, H. Fu, and J. S. Wettlaufer, Rep. Prog. Phys. 58), 115 (1995) Why do different experiments infer different properties for this layer? Impurities and electric fields at the interfaces may be responsible for some of the variations in experimental results.footnote V. F. Petrenko, U. S. Army Cold Regions Research and Engineering Laboratory Report 94-22 (1994) Some background on the physical properties of ice will be discussed, including recent force microscopy measurements done at the University of Washington.footnote C.R. Slaughterbeck, E.W. Kukes, B. Pittenger, D.J. Cook, P.C. Williams, V.L. Eden, S.C. Fain, Jr., J. Vac. Sci. Technol. (in press) Supported by NSF Grant DMR-91-19701.

  14. Laparoscopic simulation interface

    DOEpatents

    Rosenberg, Louis B.

    2006-04-04

    A method and apparatus for providing high bandwidth and low noise mechanical input and output for computer systems. A gimbal mechanism provides two revolute degrees of freedom to an object about two axes of rotation. A linear axis member is coupled to the gimbal mechanism at the intersection of the two axes of rotation. The linear axis member is capable of being translated along a third axis to provide a third degree of freedom. The user object is coupled to the linear axis member and is thus translatable along the third axis so that the object can be moved along all three degrees of freedom. Transducers associated with the provided degrees of freedom include sensors and actuators and provide an electromechanical interface between the object and a digital processing system. Capstan drive mechanisms transmit forces between the transducers and the object. The linear axis member can also be rotated about its lengthwise axis to provide a fourth degree of freedom, and, optionally, a floating gimbal mechanism is coupled to the linear axis member to provide fifth and sixth degrees of freedom to an object. Transducer sensors are associated with the fourth, fifth, and sixth degrees of freedom. The interface is well suited for simulations of medical procedures and simulations in which an object such as a stylus or a joystick is moved and manipulated by the user.

  15. Mercury Shopping Cart Interface

    NASA Technical Reports Server (NTRS)

    Pfister, Robin; McMahon, Joe

    2006-01-01

    Mercury Shopping Cart Interface (MSCI) is a reusable component of the Power User Interface 5.0 (PUI) program described in another article. MSCI is a means of encapsulating the logic and information needed to describe an orderable item consistent with Mercury Shopping Cart service protocol. Designed to be used with Web-browser software, MSCI generates Hypertext Markup Language (HTML) pages on which ordering information can be entered. MSCI comprises two types of Practical Extraction and Report Language (PERL) modules: template modules and shopping-cart logic modules. Template modules generate HTML pages for entering the required ordering details and enable submission of the order via a Hypertext Transfer Protocol (HTTP) post. Shopping cart modules encapsulate the logic and data needed to describe an individual orderable item to the Mercury Shopping Cart service. These modules evaluate information entered by the user to determine whether it is sufficient for the Shopping Cart service to process the order. Once an order has been passed from MSCI to a deployed Mercury Shopping Cart server, there is no further interaction with the user.

  16. Local Conformational Changes in the DNA Interfaces of Proteins

    PubMed Central

    Sunami, Tomoko; Kono, Hidetoshi

    2013-01-01

    When a protein binds to DNA, a conformational change is often induced so that the protein will fit into the DNA structure. Therefore, quantitative analyses were conducted to understand the conformational changes in proteins. The results showed that conformational changes in DNA interfaces are more frequent than in non-interfaces, and DNA interfaces have more conformational variations in the DNA-free form. As expected, the former indicates that interaction with DNA has some influence on protein structure. The latter suggests that the intrinsic conformational flexibility of DNA interfaces is important for adjusting their conformation for DNA. The amino acid propensities of the conformationally changed regions in DNA interfaces indicate that hydrophilic residues are preferred over the amino acids that appear in the conformationally unchanged regions. This trend is true for disordered regions, suggesting again that intrinsic flexibility is of importance not only for DNA binding but also for interactions with other molecules. These results demonstrate that fragments destined to be DNA interfaces have an intrinsic flexibility and are composed of amino acids with the capability of binding to DNA. This information suggests that the prediction of DNA binding sites may be improved by the integration of amino acid preference for DNA and one for disordered regions. PMID:23418514

  17. Multiple network interface core apparatus and method

    SciTech Connect

    Underwood, Keith D.; Hemmert, Karl Scott

    2011-04-26

    A network interface controller and network interface control method comprising providing a single integrated circuit as a network interface controller and employing a plurality of network interface cores on the single integrated circuit.

  18. Flexible DCP interface. [environmental sensor and signal conditioning interface

    NASA Technical Reports Server (NTRS)

    Kanemasu, E. T.; Schimmelpfenning, H.

    1974-01-01

    The author has identified the following significant results. A user of an ERTS data collection system (DCS) must supply the sensors and signal-conditioning interface. The electronic interface must be compatible with the NASA-furnished data collection platform. A universal signal-conditioning system for use with a wide range of environmental sensors is described. The interface is environmentally and electronically compatible with the DCP and has operated satisfactorily for a complete winter wheat growing season in Kansas.

  19. General Achievement Trends: South Dakota

    ERIC Educational Resources Information Center

    Center on Education Policy, 2009

    2009-01-01

    This general achievement trends profile includes information that the Center on Education Policy (CEP) and the Human Resources Research Organization (HumRRO) obtained from states from fall 2008 through April 2009. Included herein are: (1) Bullet points summarizing key findings about achievement trends in that state at three performance…

  20. TRENDS IN RURAL SULFUR CONCENTRATIONS

    EPA Science Inventory

    This paper presents an analysis of regional trends in atmospheric concentrations in sulfur dioxide (502) and particulate sulfate (50~- ) at rural monitoring sites in the Clean Air Act Status and Trends Monitoring Network (CAsTNet) from 1990 to 1999. A two-stage approach is used t...

  1. Trends in Digital Media 2007

    ERIC Educational Resources Information Center

    Hanson-Smith, Elizabeth

    2008-01-01

    The world of CALL is changing rapidly, but there are three major trends that can be perceived as significant to language teaching and learning and likely to remain so over the next several years. This paper will discuss these trends--convergence, searchability, and collaboration--and offer examples of interesting websites that illustrate them.…

  2. Trends in Global Gender Inequality

    ERIC Educational Resources Information Center

    Dorius, Shawn F.; Firebaugh, Glenn

    2010-01-01

    This study investigates trends in gender inequality throughout the world. Using data encompassing a large majority of the world's population, we examine trends in recent decades for key indicators of gender inequality in education, mortality, political representation and economic activity. We find that gender inequality is declining in virtually…

  3. Diablo Valley College Trends, 1992.

    ERIC Educational Resources Information Center

    Birdsall, Les; And Others

    This report provides 31 charts showing trends in enrollment; transfer students; and ethnic and gender characteristics of students, faculty, and staff at Diablo Valley College (DVC), in California, up to fall 1992. Following a brief introduction highlighting statewide trends, charts are provided for the following areas: (1) DVC fall enrollments…

  4. General Achievement Trends: New Jersey

    ERIC Educational Resources Information Center

    Center on Education Policy, 2009

    2009-01-01

    This general achievement trends profile includes information that the Center on Education Policy (CEP) and the Human Resources Research Organization (HumRRO) obtained from states from fall 2008 through April 2009. Included herein are: (1) Bullet points summarizing key findings about achievement trends in that state at three performance…

  5. General Achievement Trends: North Carolina

    ERIC Educational Resources Information Center

    Center on Education Policy, 2009

    2009-01-01

    This general achievement trends profile includes information that the Center on Education Policy (CEP) and the Human Resources Research Organization (HumRRO) obtained from states from fall 2008 through April 2009. Included herein are: (1) Bullet points summarizing key findings about achievement trends in that state at three performance…

  6. Trends in Classroom Observation Scores

    ERIC Educational Resources Information Center

    Casabianca, Jodi M.; Lockwood, J. R.; McCaffrey, Daniel F.

    2015-01-01

    Observations and ratings of classroom teaching and interactions collected over time are susceptible to trends in both the quality of instruction and rater behavior. These trends have potential implications for inferences about teaching and for study design. We use scores on the Classroom Assessment Scoring System-Secondary (CLASS-S) protocol from…

  7. TRENDS IN HUMAN RELATIONS RESEARCH.

    ERIC Educational Resources Information Center

    WINICK, CHARLES

    A REVIEW OF MAIN TRENDS IN RECENT HUMAN RELATIONS RESEARCH IN THE UNITED STATES, PARTICULARLY AS ILLUSTRATED IN THE WORK OF SIGMUND LIVINGSTON FELLOWS, IS PRESENTED. THE FOCUS IS ON STUDIES DEALING WITH ETHNIC, RACIAL, OR RELIGIOUS CATEGORIES, AND ON RESEARCH DEALING WITH INTERGROUP PREJUDICE AND DISCRIMINATION. THE THREE MAJOR TRENDS IN RESEARCH…

  8. Trends in Family Child Care

    ERIC Educational Resources Information Center

    Neugebauer, Roger

    2011-01-01

    The author presents insights from various readers of "ExchangeEveryDay" regarding trends in the world of family child care. Kathleen Reticker of Acre Family Child Care in Lowell, Massachusetts thinks an increasing trend in Family Child Care is the pressure to emulate a Center, instead of seeing family child care as a different model. Over the…

  9. Trends in Philippine Library History.

    ERIC Educational Resources Information Center

    Hernandez, Vicente S.

    This paper divides Philippine library history into three periods, establishing a relationship between historical events and library trends. During the Spanish period, modern library trends were introduced through the establishment of the Sociedad Economica in 1780, but did not influence Philippine library culture until the later part of the 19th…

  10. 10 Core External Environmental Trends.

    ERIC Educational Resources Information Center

    El Camino Coll., Torrance, CA.

    This is an institutional report summarizing 10 core external environmental trends and their implications for El Camino College and the surrounding community. The report offers a brief description for the following trends: (1) there is more emphasis on colleges becoming learning institutions rather than teaching institutions; (2) the current and…

  11. Projecting Trends in Public Policy.

    ERIC Educational Resources Information Center

    Nagel, Stuart S.

    Looking back over the past 40 years, one can observe at least seven trends in public policy substance and in the study of public policy: (1) There is a trend toward higher goals for society in economic, social, political, and science policy. (2) Major changes in almost all fields of public policy have resulted in increased benefits for the less…

  12. Trends Shaping Education--2008 Edition

    ERIC Educational Resources Information Center

    OECD Publishing (NJ3), 2008

    2008-01-01

    This new biennial publication presents the latest available information on 26 major current trends in education, grouped in 9 broad themes (ageing, global challenges, the new economic landscape, work and jobs, the learning society, ICT, citizenship and the state, social connections and values, and sustainable affluence). For each trend, there is a…

  13. Ion distributions in electrolyte confined by multiple dielectric interfaces

    NASA Astrophysics Data System (ADS)

    Jing, Yufei; Zwanikken, Jos W.; Jadhao, Vikram; de La Cruz, Monica

    2014-03-01

    The distribution of ions at dielectric interfaces between liquids characterized by different dielectric permittivities is crucial to nanoscale assembly processes in many biological and synthetic materials such as cell membranes, colloids and oil-water emulsions. The knowledge of ionic structure of these systems is also exploited in energy storage devices such as double-layer super-capacitors. The presence of multiple dielectric interfaces often complicates computing the desired ionic distributions via simulations or theory. Here, we use coarse-grained models to compute the ionic distributions in a system of electrolyte confined by two planar dielectric interfaces using Car-Parrinello molecular dynamics simulations and liquid state theory. We compute the density profiles for various electrolyte concentrations, stoichiometric ratios and dielectric contrasts. The explanations for the trends in these profiles and discuss their effects on the behavior of the confined charged fluid are also presented.

  14. Brain computer interface for operating a robot

    NASA Astrophysics Data System (ADS)

    Nisar, Humaira; Balasubramaniam, Hari Chand; Malik, Aamir Saeed

    2013-10-01

    A Brain-Computer Interface (BCI) is a hardware/software based system that translates the Electroencephalogram (EEG) signals produced by the brain activity to control computers and other external devices. In this paper, we will present a non-invasive BCI system that reads the EEG signals from a trained brain activity using a neuro-signal acquisition headset and translates it into computer readable form; to control the motion of a robot. The robot performs the actions that are instructed to it in real time. We have used the cognitive states like Push, Pull to control the motion of the robot. The sensitivity and specificity of the system is above 90 percent. Subjective results show a mixed trend of the difficulty level of the training activities. The quantitative EEG data analysis complements the subjective results. This technology may become very useful for the rehabilitation of disabled and elderly people.

  15. NASA standard: Trend analysis techniques

    NASA Technical Reports Server (NTRS)

    1990-01-01

    Descriptive and analytical techniques for NASA trend analysis applications are presented in this standard. Trend analysis is applicable in all organizational elements of NASA connected with, or supporting, developmental/operational programs. This document should be consulted for any data analysis activity requiring the identification or interpretation of trends. Trend analysis is neither a precise term nor a circumscribed methodology: it generally connotes quantitative analysis of time-series data. For NASA activities, the appropriate and applicable techniques include descriptive and graphical statistics, and the fitting or modeling of data by linear, quadratic, and exponential models. Usually, but not always, the data is time-series in nature. Concepts such as autocorrelation and techniques such as Box-Jenkins time-series analysis would only rarely apply and are not included in this document. The basic ideas needed for qualitative and quantitative assessment of trends along with relevant examples are presented.

  16. Nuclear data interface retrospective

    SciTech Connect

    Gray, Mark G

    2008-01-01

    The Nuclear Data Interface (NDI) code library and data formats are the standards for multigroup nuclear data at Los Alamos National Laboratory. NDI's analysis, design, implementation, testing, integration, and maintenance required a ten person-year and ongoing effort by the Nuclear Data Team. Their efforts provide a unique, contemporary experience in producing a standard component library. In reflection upon that experience at NDI's decennial, we have identified several factors critical to NDI's success: it addressed real problems with appropriate simplicity, it fully supported all users, it added extra value through the code to the raw nuclear data, and its team went the distance from analysis through maintenance. In this report we review these critical success factors and discuss their implications for future standardization projects.

  17. Electron hydration: interface shells

    NASA Astrophysics Data System (ADS)

    Novakovskaya, Yulia V.; Stepanov, Nikolai F.

    2001-08-01

    Interface water cluster anions (H 2O) n- ( n ⩽ 12 ) composed of two to four fragments are simulated in the unrestricted Hartree-Fock approximation with the second order Moeller-Plesset perturbation theory corrections taken into account with the 6-31++G ** basis set either augmented or not with the floating center of eight s functions. A linear dependence of the circumsphere radius involving central molecules of the anions on 1/ n provides an estimate of the excess electron radius in condensed water (about 2.5 Å). Vertical detachment energies, approximated with linear dependences on n-1/3, are extrapolated to the values around 3.4 eV for bulk water.

  18. Porphyrins at interfaces

    NASA Astrophysics Data System (ADS)

    Auwärter, Willi; Écija, David; Klappenberger, Florian; Barth, Johannes V.

    2015-02-01

    Porphyrins and other tetrapyrrole macrocycles possess an impressive variety of functional properties that have been exploited in natural and artificial systems. Different metal centres incorporated within the tetradentate ligand are key for achieving and regulating vital processes, including reversible axial ligation of adducts, electron transfer, light-harvesting and catalytic transformations. Tailored substituents optimize their performance, dictating their arrangement in specific environments and mediating the assembly of molecular nanoarchitectures. Here we review the current understanding of these species at well-defined interfaces, disclosing exquisite insights into their structural and chemical properties, and also discussing methods by which to manipulate their intramolecular and organizational features. The distinct characteristics arising from the interfacial confinement offer intriguing prospects for molecular science and advanced materials. We assess the role of surface interactions with respect to electronic and physicochemical characteristics, and describe in situ metallation pathways, molecular magnetism, rotation and switching. The engineering of nanostructures, organized layers, interfacial hybrid and bio-inspired systems is also addressed.

  19. Human-computer interface

    DOEpatents

    Anderson, Thomas G.

    2004-12-21

    The present invention provides a method of human-computer interfacing. Force feedback allows intuitive navigation and control near a boundary between regions in a computer-represented space. For example, the method allows a user to interact with a virtual craft, then push through the windshield of the craft to interact with the virtual world surrounding the craft. As another example, the method allows a user to feel transitions between different control domains of a computer representation of a space. The method can provide for force feedback that increases as a user's locus of interaction moves near a boundary, then perceptibly changes (e.g., abruptly drops or changes direction) when the boundary is traversed.

  20. Intelligent interface design and evaluation

    NASA Technical Reports Server (NTRS)

    Greitzer, Frank L.

    1988-01-01

    Intelligent interface concepts and systematic approaches to assessing their functionality are discussed. Four general features of intelligent interfaces are described: interaction efficiency, subtask automation, context sensitivity, and use of an appropriate design metaphor. Three evaluation methods are discussed: Functional Analysis, Part-Task Evaluation, and Operational Testing. Design and evaluation concepts are illustrated with examples from a prototype expert system interface for environmental control and life support systems for manned space platforms.

  1. Interface-assisted molecular spintronics

    SciTech Connect

    Raman, Karthik V.

    2014-09-15

    Molecular spintronics, a field that utilizes the spin state of organic molecules to develop magneto-electronic devices, has shown an enormous scientific activity for more than a decade. But, in the last couple of years, new insights in understanding the fundamental phenomena of molecular interaction on magnetic surfaces, forming a hybrid interface, are presenting a new pathway for developing the subfield of interface-assisted molecular spintronics. The recent exploration of such hybrid interfaces involving carbon based aromatic molecules shows a significant excitement and promise over the previously studied single molecular magnets. In the above new scenario, hybridization of the molecular orbitals with the spin-polarized bands of the surface creates new interface states with unique electronic and magnetic character. This study opens up a molecular-genome initiative in designing new handles to functionalize the spin dependent electronic properties of the hybrid interface to construct spin-functional tailor-made devices. Through this article, we review this subject by presenting a fundamental understanding of the interface spin-chemistry and spin-physics by taking support of advanced computational and spectroscopy tools to investigate molecular spin responses with demonstration of new interface phenomena. Spin-polarized scanning tunneling spectroscopy is favorably considered to be an important tool to investigate these hybrid interfaces with intra-molecular spatial resolution. Finally, by addressing some of the recent findings, we propose novel device schemes towards building interface tailored molecular spintronic devices for applications in sensor, memory, and quantum computing.

  2. The Common Communication Interface (CCI)

    SciTech Connect

    Shipman, Galen M; Atchley, Scott; Dillow, David A; Geoffray, Patrick; Bosilca, George; Squyres, Jeffrey M; Minnich, Ronald

    2011-01-01

    There are many APIs for connecting and exchanging data between network peers. Each interface varies wildly based on metrics including performance, portability, and complexity. Specifically, many interfaces make design or implementation choices emphasizing some of the more desirable metrics (e.g., performance) while sacrificing others (e.g., portability). As a direct result, software developers building large, network-based applications are forced to choose a specific network API based on a complex, multi-dimensional set of criteria. Such trade-offs inevitably result in an interface that fails to deliver some desirable features. In this paper, we introduce a novel interface that both supports many features that have become standard (or otherwise generally expected) in other communication interfaces, and strives to export a small, yet powerful, interface. This new interface draws upon years of experience from network-oriented software development best practices to systems-level implementations. The goal is to create a relatively simple, high-level communication interface with low barriers to adoption while still providing important features such as scalability, resiliency, and performance. The result is the Common Communications Interface (CCI): an intuitive API that is portable, efficient, scalable, and robust to meet the needs of network-intensive applications common in HPC and cloud computing.

  3. mREST Interface Specification

    NASA Technical Reports Server (NTRS)

    McCartney, Patrick; MacLean, John

    2012-01-01

    mREST is an implementation of the REST architecture specific to the management and sharing of data in a system of logical elements. The purpose of this document is to clearly define the mREST interface protocol. The interface protocol covers all of the interaction between mREST clients and mREST servers. System-level requirements are not specifically addressed. In an mREST system, there are typically some backend interfaces between a Logical System Element (LSE) and the associated hardware/software system. For example, a network camera LSE would have a backend interface to the camera itself. These interfaces are specific to each type of LSE and are not covered in this document. There are also frontend interfaces that may exist in certain mREST manager applications. For example, an electronic procedure execution application may have a specialized interface for configuring the procedures. This interface would be application specific and outside of this document scope. mREST is intended to be a generic protocol which can be used in a wide variety of applications. A few scenarios are discussed to provide additional clarity but, in general, application-specific implementations of mREST are not specifically addressed. In short, this document is intended to provide all of the information necessary for an application developer to create mREST interface agents. This includes both mREST clients (mREST manager applications) and mREST servers (logical system elements, or LSEs).

  4. Interface-assisted molecular spintronics

    NASA Astrophysics Data System (ADS)

    Raman, Karthik V.

    2014-09-01

    Molecular spintronics, a field that utilizes the spin state of organic molecules to develop magneto-electronic devices, has shown an enormous scientific activity for more than a decade. But, in the last couple of years, new insights in understanding the fundamental phenomena of molecular interaction on magnetic surfaces, forming a hybrid interface, are presenting a new pathway for developing the subfield of interface-assisted molecular spintronics. The recent exploration of such hybrid interfaces involving carbon based aromatic molecules shows a significant excitement and promise over the previously studied single molecular magnets. In the above new scenario, hybridization of the molecular orbitals with the spin-polarized bands of the surface creates new interface states with unique electronic and magnetic character. This study opens up a molecular-genome initiative in designing new handles to functionalize the spin dependent electronic properties of the hybrid interface to construct spin-functional tailor-made devices. Through this article, we review this subject by presenting a fundamental understanding of the interface spin-chemistry and spin-physics by taking support of advanced computational and spectroscopy tools to investigate molecular spin responses with demonstration of new interface phenomena. Spin-polarized scanning tunneling spectroscopy is favorably considered to be an important tool to investigate these hybrid interfaces with intra-molecular spatial resolution. Finally, by addressing some of the recent findings, we propose novel device schemes towards building interface tailored molecular spintronic devices for applications in sensor, memory, and quantum computing.

  5. Aging trends -- the Philippines.

    PubMed

    Biddlecom, A E; Domingo, L J

    1996-03-01

    This report presents a description of the trends in growth of the elderly population in the Philippines and their health, disability, education, work status, income, and family support. The proportion of elderly in the Philippines is much smaller than in other Southeast Asian countries, such as Singapore and Malaysia. The elderly population aged over 65 years increased from 2.7% of total population in 1990 to 3.6% in 1990. The elderly are expected to comprise 7.7% of total population in 2025. The proportion of elderly is small due to the high fertility rate. Life expectancy averages 63.5 years. The aged dependency ratio will double from 5.5 elderly per 100 persons aged 15-64 years in 1990 to 10.5/100 in 2025. A 1984 ASEAN survey found that only 11% of elderly rated their health as bad. The 1990 Census reveals that 3.9% were disabled elderly. Most were deaf, blind, or orthopedically impaired. 16% of elderly in the ASEAN survey reported not seeing a doctor even when they needed to. 54% reported that a doctor was not visited due to the great expense. In 1980, 67% of men and 76% of women aged over 60 years had less than a primary education. The proportion with a secondary education in 2020 is expected to be about 33% for men and 33% for women. 66.5% of men and 28.5% of women aged over 60 years were in the formal labor force in 1990. Women were less likely to receive cash income from current jobs or pensions. 65% of earnings from older rural people was income from agricultural production. 60% of income among urban elderly was from children, and 23% was from pensions. Family support is provided to the elderly in the form of coresidence. In 1988, 68% of elderly aged over 60 years lived with at least one child. Retirement or nursing homes are uncommon. The Philippines Constitution states that families have a duty to care for elderly members. PMID:12292274

  6. Developing a Critical View on E-Learning Trend Reports: Trend Watching or Trend Setting?

    ERIC Educational Resources Information Center

    Boon, Jo; Rusman, Ellen; van der Klink, Marcel; Tattersall, Colin

    2005-01-01

    Trend watching reports are an indispensable resource in the e-learning domain. Many HRD departments consider these reports as essential cornerstones for the development of their e-learning strategy. But what is the quality of the forecasts made in these reports? In this article, several methods of forecasting trends are discussed, resulting in a…

  7. Monitoring grizzly bear population trends

    USGS Publications Warehouse

    Eberhardt, L.L.; Knight, R.R.; Blanchard, B.M.

    1986-01-01

    A simple different equation model was developed to provide additional perspective on observed mortality and trend data on Yellowstone grizzly bears (Ursus arctos horribilis). Records of mortalities of adult females from 1959 to 1985 were utilized, in conjunction with data on females with cubs. The overall downward trend of observed numbers of females with cubs generally agrees with the model calculations but does not adequately reflect mortality from 1970 to 1974. The model may be useful in developing a composite index of population trend.

  8. Entrainment across density interfaces

    NASA Astrophysics Data System (ADS)

    Sanchez, M. A.; Carrillo, A.; Mahjoub, O. B.

    2010-05-01

    The structure of non-homogeneous turbulence affected by stratification and rotation is investigated both by means of laboratory and numerical experiments. The experiments investigate zero mean flow across a stably stratified density interface and are used to quantify the entrainment, the mixing efficiency and different types of dominant instability and the topological aspects of the turbulent cascades detected both horizontally and vertically [1,2]. Grid turbulence in a rotating stratified two layer system is measured with PIV as well as with sonic velocimetry. Observations of the horizontal and vertical velocity energy spectra as well as the structure functions are used to estimate local mixedness, entrainment and intermittency [3,4]. The method of estimation of the average eddy diffusivity from the time series images of a sharp density interface marked by fluoresceine also take anisotropy into account. but on the long run, horizontal ( and 2D type flow such as [5]) flow directions will average out so using a single integral length scale defined in Sanchez and Redondo(1998) varying in height will be enough together with the internal frequency. The method of calculating vertical fluxes in time allows to estimate different intermittency parameters as a function of local instability e.g. Kelvin/Helmholtz, Rayleigh-Taylor or Holbmoe[6-8]. Different concentration interfaces show different fractal dimensions, that are also a power function of the local Richardson number, this may be due to different levels of intermittency and thus different spectra, which are not necessarily inertial nor in equilibrium [8,9]. [1] Sanchez M.A. and Redondo J.M.Observations from Grid Stirred Turbulence. Applied Scientific Research 59, 191-204. 1998. [2] Redondo, J.M. and Cantalapiedra I.R. Mixing in Horizontally Heterogeneous Flows . Jour. Flow Turbulence and Combustion. 51, 217-222. 1993. [3] Castilla R, Redondo J.M., Gamez P.J., Babiano A. Coherent vortices and Lagrangian Dynamics in 2D

  9. Interface effects on nanoelectronics

    NASA Astrophysics Data System (ADS)

    Conrad, Brad Richard

    2009-12-01

    Nanoelectronics consist of devices with active electronic components on the nanometer length scale. At such dimensions most, if not all, atoms or molecules composing the active device region must be on or near a surface. Also, materials effectively confined to two dimensions, or when subject to abrupt boundary conditions, generally do not behave the same as materials inside three dimensional, continuous structures. This dissertation is a quantitative determination of how surfaces and interfaces in organic nanoelectronic devices affect properties such as charge transport, electronic structure, and material fluctuations. Si/SiO2 is a model gate/gate dielectric for organic thin film transistors, therefore proper characterization and measurement of the effects of the SiO2/organic interface on device structures is extremely important. I fabricated pentacene thin film transistors on Si/SiO2 and varied the conduction channel thickness from effectively bulk (˜40nm) to 2 continuous conducting layers to examine the effect of substrate on noise generation. The electronic spectral noise was measured and the generator of the noise was determined to be due to the random spatial dependence of grain boundaries, independent of proximity to the gate oxide. This result led me to investigate the mechanisms of pentacene grain formation, including the role of small quantities of impurities, on silicon dioxide substrates. Through a series of nucleation, growth and morphology studies, I determined that impurities assist in nucleation on SiO2, decreasing the stable nucleus size by a third and increasing the overall number of grains. The pentacene growth and morphology studies prompted further exploration of pentacene crystal growth on SiO2. I developed a method of making atomically clean ultra-thin oxide films, with surface chemistry and growth properties similar to the standard thick oxides. These ultra-thin oxides were measured to be as smooth as cleaned silicon and then used as

  10. Self-Checking Memory Interface

    NASA Technical Reports Server (NTRS)

    Sievers, M. W.; Rennels, D. A.

    1984-01-01

    Memory-interface integrated circuit not only detects errors in data from other circuits but also detects errors within itself. Memory-interface chip encodes 16-bit words with Hamming code for single-error correction or double-error detection. Chip used in fault-tolerant computers under development by NASA.

  11. Polysilicon thin films and interfaces

    SciTech Connect

    Kamins, T. ); Raicu, B. ); Thompson, C.V. )

    1990-01-01

    This volume contains the proceedings of a symposium on polysilicon thin films and interfaces, held as part of the 1990 Materials Research Society Spring Meeting. Topics covered include: crystal grown fo silicon and germanium wafers for photovoltaic devices, microanalysis of tungsten silicide interface, thermal processing of polysilicon thin films, and electrical and optical properties of polysilicon sheets for photovoltaic devices.

  12. Rare-event recorder interface

    SciTech Connect

    Kuts, V.N.

    1984-03-01

    The author describes an interface for a BPA2-95 analog-digital computer with PL-80 and a Perfomom 30 perferator for rare event recording. This interface allows the height of each pulse that passes through the analog-digital converter to be recorded on punch tape. A series of three block diagrams illustrates in thorough detail the system described.

  13. Interface To The SURE Program

    NASA Technical Reports Server (NTRS)

    Johnson, Sally C.; Boerschlein, David P.

    1993-01-01

    Abstract Semi-Markov Specification Interface to SURE Tool (ASSIST) computer program is interface program enabling reliability engineers to design large semi-Markov mathematical models accurately. Language enables efficient description of large, complicated systems. Also offers, as part of bundled package with SURE and PAWS/STEM, two other reliable analysis programs developed by Systems Validation Methods group at Langley Research Center.

  14. Integrating and Interfacing Library Systems.

    ERIC Educational Resources Information Center

    Boss, Richard W.

    1985-01-01

    This overview of local library online systems that integrate several functions covers functional integration, benefits of integrated systems, turnkey systems, minicomputer and microcomputer-based systems, interfacing automated systems, types of interfaces, linking homogenous and heterogeneous systems, role of vendors, library applications, linking…

  15. XTOD - XES Interface Control Document

    SciTech Connect

    Trent, J

    2005-09-07

    This document describes the interface between the LCLS XTOD System (WBS No.1.5) and the LCLS XES (WBS No.1.6). The interface locations ranging from the beam dump to the far experimental hall are identified. Subsystems that connect at or cross the boundary are identified.

  16. Online Remote Sensing Interface

    NASA Technical Reports Server (NTRS)

    Lawhead, Joel

    2007-01-01

    BasinTools Module 1 processes remotely sensed raster data, including multi- and hyper-spectral data products, via a Web site with no downloads and no plug-ins required. The interface provides standardized algorithms designed so that a user with little or no remote-sensing experience can use the site. This Web-based approach reduces the amount of software, hardware, and computing power necessary to perform the specified analyses. Access to imagery and derived products is enterprise-level and controlled. Because the user never takes possession of the imagery, the licensing of the data is greatly simplified. BasinTools takes the "just-in-time" inventory control model from commercial manufacturing and applies it to remotely-sensed data. Products are created and delivered on-the-fly with no human intervention, even for casual users. Well-defined procedures can be combined in different ways to extend verified and validated methods in order to derive new remote-sensing products, which improves efficiency in any well-defined geospatial domain. Remote-sensing products produced in BasinTools are self-documenting, allowing procedures to be independently verified or peer-reviewed. The software can be used enterprise-wide to conduct low-level remote sensing, viewing, sharing, and manipulating of image data without the need for desktop applications.

  17. Next Generation Search Interfaces

    NASA Astrophysics Data System (ADS)

    Roby, W.; Wu, X.; Ly, L.; Goldina, T.

    2015-09-01

    Astronomers are constantly looking for easier ways to access multiple data sets. While much effort is spent on VO, little thought is given to the types of User Interfaces we need to effectively search this sort of data. For instance, an astronomer might need to search Spitzer, WISE, and 2MASS catalogs and images then see the results presented together in one UI. Moving seamlessly between data sets is key to presenting integrated results. Results need to be viewed using first class, web based, integrated FITS viewers, XY Plots, and advanced table display tools. These components should be able to handle very large datasets. To make a powerful Web based UI that can manage and present multiple searches to the user requires taking advantage of many HTML5 features. AJAX is used to start searches and present results. Push notifications (Server Sent Events) monitor background jobs. Canvas is required for advanced result displays. Lesser known CSS3 technologies makes it all flow seamlessly together. At IPAC, we have been developing our Firefly toolkit for several years. We are now using it to solve this multiple data set, multiple queries, and integrated presentation problem to create a powerful research experience. Firefly was created in IRSA, the NASA/IPAC Infrared Science Archive (http://irsa.ipac.caltech.edu). Firefly is the core for applications serving many project archives, including Spitzer, Planck, WISE, PTF, LSST and others. It is also used in IRSA's new Finder Chart and catalog and image displays.

  18. Aquatic Acoustic Metrics Interface

    Energy Science and Technology Software Center (ESTSC)

    2012-12-18

    Fishes and marine mammals may suffer a range of potential effects from exposure to intense underwater sound generated by anthropogenic activities such as pile driving, shipping, sonars, and underwater blasting. Several underwater sound recording (USR) devices have been built to acquire samples of the underwater sound generated by anthropogenic activities. Software becomes indispensable for processing and analyzing the audio files recorded by these USRs. The new Aquatic Acoustic Metrics Interface Utility Software (AAMI) is specificallymore » designed for analysis of underwater sound recordings to provide data in metrics that facilitate evaluation of the potential impacts of the sound on aquatic animals. In addition to the basic functions, such as loading and editing audio files recorded by USRs and batch processing of sound files, the software utilizes recording system calibration data to compute important parameters in physical units. The software also facilitates comparison of the noise sound sample metrics with biological measures such as audiograms of the sensitivity of aquatic animals to the sound, integrating various components into a single analytical frame.« less

  19. User interface enhancement report

    NASA Technical Reports Server (NTRS)

    Badler, N. I.; Gangel, J.; Shields, G.; Fala, G.

    1985-01-01

    The existing user interfaces to TEMPUS, Plaid, and other systems in the OSDS are fundamentally based on only two modes of communication: alphanumeric commands or data input and grapical interaction. The latter are especially suited to the types of interaction necessary for creating workstation objects with BUILD and with performing body positioning in TEMPUS. Looking toward the future application of TEMPUS, however, the long-term goals of OSDS will include the analysis of extensive tasks in space involving one or more individuals working in concert over a period of time. In this context, the TEMPUS body positioning capability, though extremely useful in creating and validating a small number of particular body positions, will become somewhat tedious to use. The macro facility helps somewhat, since frequently used positions may be easily applied by executing a stored macro. The difference between body positioning and task execution, though subtle, is important. In the case of task execution, the important information at the user's level is what actions are to be performed rather than how the actions are performed. Viewed slightly differently, the what is constant over a set of individuals though the how may vary.

  20. Aquatic Acoustic Metrics Interface

    SciTech Connect

    2012-12-18

    Fishes and marine mammals may suffer a range of potential effects from exposure to intense underwater sound generated by anthropogenic activities such as pile driving, shipping, sonars, and underwater blasting. Several underwater sound recording (USR) devices have been built to acquire samples of the underwater sound generated by anthropogenic activities. Software becomes indispensable for processing and analyzing the audio files recorded by these USRs. The new Aquatic Acoustic Metrics Interface Utility Software (AAMI) is specifically designed for analysis of underwater sound recordings to provide data in metrics that facilitate evaluation of the potential impacts of the sound on aquatic animals. In addition to the basic functions, such as loading and editing audio files recorded by USRs and batch processing of sound files, the software utilizes recording system calibration data to compute important parameters in physical units. The software also facilitates comparison of the noise sound sample metrics with biological measures such as audiograms of the sensitivity of aquatic animals to the sound, integrating various components into a single analytical frame.

  1. Power User Interface

    NASA Technical Reports Server (NTRS)

    Pfister, Robin; McMahon, Joe

    2006-01-01

    Power User Interface 5.0 (PUI) is a system of middleware, written for expert users in the Earth-science community, PUI enables expedited ordering of data granules on the basis of specific granule-identifying information that the users already know or can assemble. PUI also enables expert users to perform quick searches for orderablegranule information for use in preparing orders. PUI 5.0 is available in two versions (note: PUI 6.0 has command-line mode only): a Web-based application program and a UNIX command-line- mode client program. Both versions include modules that perform data-granule-ordering functions in conjunction with external systems. The Web-based version works with Earth Observing System Clearing House (ECHO) metadata catalog and order-entry services and with an open-source order-service broker server component, called the Mercury Shopping Cart, that is provided separately by Oak Ridge National Laboratory through the Department of Energy. The command-line version works with the ECHO metadata and order-entry process service. Both versions of PUI ultimately use ECHO to process an order to be sent to a data provider. Ordered data are provided through means outside the PUI software system.

  2. Petroleum 1996: Issues and Trends

    EIA Publications

    1997-01-01

    Examines historical trends and focuses on major petroleum issues and the events they represent. It analyzes different dimensions of the petroleum industry and related markets in terms of how they relate to the volatility in petroleum markets.

  3. Temperature Trends in Montane Lakes

    NASA Astrophysics Data System (ADS)

    Melack, J. M.; Sadro, S.; Jellison, R.

    2014-12-01

    Long-term temperature trends in lakes integrate hydrological and meteorological factors. We examine temperature trends in a small montane lake with prolonged ice-cover and large seasonal snowfall and in a large saline lake. Emerald Lake, located in the Sierra Nevada (California), is representative of high-elevation lakes throughout the region. No significant trend in outflow temperature was apparent from 1991to 2012. Snowfall in the watershed accounted for 93% of the variability in average summer lake temperatures. Mono Lake (California) lies in a closed, montane basin and is hypersaline and monomictic or meromictic. Temperature profiles have been collected from 1982 to 2010. In the upper water column, the July-August-September water temperatures increased 0.8-1.0°C over the 29 years. This rate of warming is less than published estimates based on satellite-derived skin temperatures and will discussed in the context of general limnological interpretation of temperature trends.

  4. Trends in Higher Education Computing.

    ERIC Educational Resources Information Center

    Thomas, Charles R.

    1984-01-01

    Discusses the effects which changes in computer technology are having on the organization, staffing, and budgets at institutions of higher education. Trends in computer hardware, computer software, and in office automation are also discussed. (JN)

  5. Trends in Prescription Drug Abuse

    MedlinePlus

    ... Trends and Alerts Alcohol Club Drugs Cocaine Hallucinogens Heroin Inhalants Marijuana MDMA (Ecstasy/Molly) Methamphetamine Opioids Prescription ... View all ​Research Reports Opioids: The Prescription Drug & Heroin Overdose Epidemic (HHS website) NIDA Home Site Map ...

  6. Ultrasonic characterization of metallic interfaces

    SciTech Connect

    Palmer, D.D. Jr.

    1987-11-01

    A set of diffusion bonded copper samples was prepared at different temperatures and times, allowing the bonding to proceed across the planar interfaces. To obtain a second set, interfaces were roughened to various degrees followed by diffusion bonding at a designated time/temperature condition. On all samples, ultrasonic reflection coefficient (R) maps of the bonded interfaces were obtained over a broad frequency range. In addition, the bond strengths, ..sigma.., of the interfaces were determined, thus providing an empirical ..sigma..-R correlation. Nearly all of the specimens tested failed along the interfaces, exposing fracture planes with distinctive features indicating originally bonded and unbonded areas. These features, examined metallographically, allowed for the successful testing of the ''distributed spring model'' by Baik and Thompson (J. NDE 4, 177, 1984). This model was used as an intermediate step in the development of a bond strength model to explain the observed ..sigma..-R correlation, the beginnings of which are discussed. 32 refs., 22 figs.

  7. Microsegregation in Peltier interface demarcation

    NASA Astrophysics Data System (ADS)

    Dabo, Y.; Nguyen Thi, H.; Coriell, S. R.; McFadden, G. B.; Li, Q.; Billia, B.

    2000-06-01

    Experimental results on solute microsegregation induced by Peltier interface demarcation (PID) technique during directional solidification of Bi-1 wt% Sb alloys are presented. These data are compared with the results of numerical simulation and the theory of PID is revisited. It is shown that the Peltier coefficient previously determined using Peltier pulsing has been underestimated. The quantity of interface cooling absorbed by limited Bi-growth kinetics is comparable to that covered by solute depletion, and can even be dominant for very short pulses, so that the commonly made assumption of local equilibrium at the solid-liquid interface (i.e. usual hypothesis of constant interface temperature during pulse marking for pure systems) should be abandoned and the right dependence of interface temperature on solidification velocity be included in the model. Finally, two conditions to select systems capable of efficient marking by PID microsegregation are deduced and the effects of applied current in the first instants of electric pulse clarified.

  8. Working within local funding trends.

    PubMed

    Pomales-Connors, Irma

    2004-06-01

    Like politics, environmentalism, and fashion, there are trends in health care research and funding. According to a series of reports by the Foundation Center-which collects, organizes, and communicates information on U.S. philanthropy-it is important to understand the significant financial and programmatic changes in the way foundations give. For pharmacists considering soliciting grant support, it is critical that they become aware of these trends and be responsive to the local or regional environments that affect funding. PMID:16553471

  9. Interface Structure of MoO3 on Organic Semiconductors.

    PubMed

    White, Robin T; Thibau, Emmanuel S; Lu, Zheng-Hong

    2016-01-01

    We have systematically studied interface structure formed by vapor-phase deposition of typical transition metal oxide MoO3 on organic semiconductors. Eight organic hole transport materials have been used in this study. Ultraviolet photoelectron spectroscopy and X-ray photoelectron spectroscopy are used to measure the evolution of the physical, chemical and electronic structure of the interfaces at various stages of MoO3 deposition on these organic semiconductor surfaces. For the interface physical structure, it is found that MoO3 diffuses into the underlying organic layer, exhibiting a trend of increasing diffusion with decreasing molecular molar mass. For the interface chemical structure, new carbon and molybdenum core-level states are observed, as a result of interfacial electron transfer from organic semiconductor to MoO3. For the interface electronic structure, energy level alignment is observed in agreement with the universal energy level alignment rule of molecules on metal oxides, despite deposition order inversion. PMID:26880185

  10. Interface Structure of MoO3 on Organic Semiconductors

    PubMed Central

    White, Robin T.; Thibau, Emmanuel S.; Lu, Zheng-Hong

    2016-01-01

    We have systematically studied interface structure formed by vapor-phase deposition of typical transition metal oxide MoO3 on organic semiconductors. Eight organic hole transport materials have been used in this study. Ultraviolet photoelectron spectroscopy and X-ray photoelectron spectroscopy are used to measure the evolution of the physical, chemical and electronic structure of the interfaces at various stages of MoO3 deposition on these organic semiconductor surfaces. For the interface physical structure, it is found that MoO3 diffuses into the underlying organic layer, exhibiting a trend of increasing diffusion with decreasing molecular molar mass. For the interface chemical structure, new carbon and molybdenum core-level states are observed, as a result of interfacial electron transfer from organic semiconductor to MoO3. For the interface electronic structure, energy level alignment is observed in agreement with the universal energy level alignment rule of molecules on metal oxides, despite deposition order inversion. PMID:26880185

  11. Future Trends for ``i-Learning'' Experiences

    NASA Astrophysics Data System (ADS)

    Elia, Gianluca; Poce, Antonella

    This chapter aims at shaping possible directions along with imagining the development and the evolution of the “i-Learning” paradigm. Specifically, three interdependent classes of future trends are depicted: technology-related trends and organization-related trends.

  12. Multimodal Neuroelectric Interface Development

    NASA Technical Reports Server (NTRS)

    Trejo, Leonard J.; Wheeler, Kevin R.; Jorgensen, Charles C.; Totah, Joseph (Technical Monitor)

    2001-01-01

    This project aims to improve performance of NASA missions by developing multimodal neuroelectric technologies for augmented human-system interaction. Neuroelectric technologies will add completely new modes of interaction that operate in parallel with keyboards, speech, or other manual controls, thereby increasing the bandwidth of human-system interaction. We recently demonstrated the feasibility of real-time electromyographic (EMG) pattern recognition for a direct neuroelectric human-computer interface. We recorded EMG signals from an elastic sleeve with dry electrodes, while a human subject performed a range of discrete gestures. A machine-teaming algorithm was trained to recognize the EMG patterns associated with the gestures and map them to control signals. Successful applications now include piloting two Class 4 aircraft simulations (F-15 and 757) and entering data with a "virtual" numeric keyboard. Current research focuses on on-line adaptation of EMG sensing and processing and recognition of continuous gestures. We are also extending this on-line pattern recognition methodology to electroencephalographic (EEG) signals. This will allow us to bypass muscle activity and draw control signals directly from the human brain. Our system can reliably detect P-rhythm (a periodic EEG signal from motor cortex in the 10 Hz range) with a lightweight headset containing saline-soaked sponge electrodes. The data show that EEG p-rhythm can be modulated by real and imaginary motions. Current research focuses on using biofeedback to train of human subjects to modulate EEG rhythms on demand, and to examine interactions of EEG-based control with EMG-based and manual control. Viewgraphs on these neuroelectric technologies are also included.

  13. Nanoparticle Assemblies at Fluid Interfaces

    SciTech Connect

    Russell, Thomas P.

    2015-03-10

    A systematic study of the structure and dynamics of nanoparticles (NP) and NP-surfactants was performed. The ligands attached to both the NPs and NP-surfactants dictate the manner in which the nanoscopic materials assemble at fluid interfaces. Studies have shown that a single layer of the nanoscpic materials form at the interface to reduce the interactions between the two immiscible fluids. The shape of the NP is, also, important, where for spherical particles, a disordered, liquid-like monolayer forms, and, for nanorods, ordered domains at the interface is found and, if the monolayers are compressed, the orientation of the nanorods with respect to the interface can change. By associating end-functionalized polymers to the NPs assembled at the interface, NP-surfactants are formed that increase the energetic gain in segregating each NP at the interface which allows the NP-surfactants to jam at the interface when compressed. This has opened the possibility of structuring the two liquids by freezing in shape changes of the liquids.

  14. Intelligent virtual interfaces for telerobotics

    NASA Astrophysics Data System (ADS)

    Grinstein, Georges G.; Maybury, Mark T.; Mitchell, Richard B.

    1992-11-01

    One promise of telerobotics is the ability to interact in environments that are distant (e.g., deep sea or deep space), dangerous (e.g., nuclear, chemical, or biological environments), or inaccessible by humans for political or legal reasons. A key component to such interactions are sophisticated human-computer interfaces that can replicate sufficient information about a local environment to permit remote navigation and manipulation. This environment replication can, in part, be provided by technologies such as virtual reality. In addition, however, telerobotic interfaces may need to enhance human-machine interaction to assist users in task performance, for example, governing motion or manipulation controls to avoid obstacles or to restrict interaction with certain objects (e.g., avoiding contact with a live mine or a deep sea treasure). Thus, effective interactions within remote environments require intelligent virtual interfaces to telerobotic devices. In part to address this problem, MITRE is investigating virtual reality architectures that will enable enhanced interaction within virtual environments. Key components to intelligent virtual interfaces include spoken language processing, gesture recognition algorithms, and more generally, task recognition. In addition, these interfaces will eventually have to take into account properties of the user, the task, and discourse context to be more adaptive to the current situation at hand. While our work has not yet investigated the connection of virtual interfaces to external robotic devices, we have begun developing the key components for intelligent virtual interfaces for information and training systems.

  15. Interface cracks in piezoelectric materials

    NASA Astrophysics Data System (ADS)

    Govorukha, V.; Kamlah, M.; Loboda, V.; Lapusta, Y.

    2016-02-01

    Due to their intrinsic electromechanical coupling behavior, piezoelectric materials are widely used in sensors, actuators and other modern technologies. It is well known that piezoelectric ceramics are very brittle and susceptible to fracture. In many cases, fracture occurs at interfaces as debonding and cracks. This leads to an undesired degradation of electrical and mechanical performance. Because of the practical and fundamental importance of the problem, interface cracks in piezoelectric materials have been actively studied in the last few decades. This review provides a comprehensive survey of recent works on cracks situated at the interface of two materials, at least one of which has piezoelectric or piezoelectromagnetic properties. Different electric boundary conditions along the crack faces are discussed. The oscillating and contact zone models for in-plane straight interface cracks between two dissimilar piezoelectric materials or between piezoelectric and non-piezoelectric ones are reviewed. Different peculiarities related to the investigation of interface cracks in piezoelectric materials for the anti-plane case, for functionally graded and thermopiezoelectric materials are presented. Papers related to magnetoelectroelastic bimaterials, to steady state motion of interface cracks in piezoelectric bimaterials and to circular arc-cracks at the interface of piezoelectric materials are reviewed, and various methods used to address these problems are discussed. The review concludes with an outlook on future research directions.

  16. Polymers at Surfaces and Interfaces

    NASA Astrophysics Data System (ADS)

    Tsige, Mesfin

    2015-03-01

    Interfaces between solids, liquids, and gases play an important role in a wide range of practical applications and have been a subject of scientific interest since Poisson showed in 1831 that the order parameter of liquids near interfaces must deviate considerably from its bulk value. In particular, polymers at surfaces and interfaces have been a subject of extensive theoretical, experimental and computational studies for a long time due to their use in many diverse applications ranging from antifouling coatings to flexible electronic devices. Understanding the structure and thermodynamic properties of polymers at surfaces and interfaces is thus an area of fundamental and current technological interest. Although encouraging experimental progress has been made over the years in understanding the molecular structure of polymers in contact with various environments, selectively probing their structure and dynamics at surfaces and interfaces has been extremely difficult. Computer simulations, especially molecular dynamics (MD) simulations, have proven over the years to be an invaluable tool in providing molecular details at interfaces that are usually lacking in the experimental data. In this talk, I'll give an overview of some previous simulation efforts to understand the structure and dynamics of polymers at surfaces and buried interfaces. I will conclude by presenting our current and ongoing work on combining ab initio calculations and MD simulations with Sum Frequency Generation (SFG) Spectroscopy to study polymer surfaces. This approach demonstrates the future role of MD in surface science. Work supported by NSF (DMR0847580 and DMR1410290) and Petroleum Research Fund of the American Chemical Society.

  17. ARINC 653 Interface in RTEMS

    NASA Astrophysics Data System (ADS)

    Rufino, J.; Filipe, S.; Coutinho, M.; Santos, S.; Windsor, J.

    2007-08-01

    The ARINC 653 specification is assuming a key role in the provision of a standard operating system interface for safety-critical applications in the aeronautic market and it is foreseen to acquire a similar status on the space market. The ARINC 653 application interface is inde- pendent from the underlying hardware and from a given operating system implementation. This paper describes how RTEMS, the Real-Time Executive for Multiproces- sor Systems, can be adapted to offer the application interface and the functionality required by the ARINC 653 standard. The use of RTEMS is highly relevant given its qualification for on-board software of unmanned space programs.

  18. Virtual optical interfaces for transportation

    NASA Astrophysics Data System (ADS)

    Kiefer, Renaud; Kress, Bernard; Fontaine, Joseph-Joel

    2009-05-01

    Today, the ever increasing number of controls in automobile and aviation cockpits leads to the cluttering of various interfaces (keyboards, switches, panels, etc...). LCD touch screens have proved to be a good alternative to reduce cluttering by reconfiguring in real time different interfaces, appearing on demand as they are needed by the user. However, the underlying screen still remains cumbersome and fragile glass device. We present a novel way to produce virtual consoles and interfaces by projecting diffractive images and sensing the position of the fingers by the use of IR diffractive optics.

  19. Aqueous Solutions and their Interfaces

    SciTech Connect

    Xantheas, Sotiris S.; Voth, Gregory A.

    2009-04-02

    Preface of the special issue of the Journal of Physical Chemistry in conjunction with the international workshop "Aqueous Solutions and their Interfaces". The topics include the structure of liquid water, the analysis of X-ray and neutron scattering experimental data, the vibrational spectroscopy of liquid water, the structure and spectroscopy of aqueous interfaces and the development of theoretical approaches to model the structure and spectra of liquid water and interfaces. This work was supported by the US Department of Energy's Office of Basic Energy Sciences, Chemical Sciences program. Pacific Northwest National Laboratory is operated by Battelle for DOE.

  20. Automated Fluid Interface System (AFIS)

    NASA Technical Reports Server (NTRS)

    1990-01-01

    Automated remote fluid servicing will be necessary for future space missions, as future satellites will be designed for on-orbit consumable replenishment. In order to develop an on-orbit remote servicing capability, a standard interface between a tanker and the receiving satellite is needed. The objective of the Automated Fluid Interface System (AFIS) program is to design, fabricate, and functionally demonstrate compliance with all design requirements for an automated fluid interface system. A description and documentation of the Fairchild AFIS design is provided.

  1. Dispersive transport across interfaces

    NASA Astrophysics Data System (ADS)

    Berkowitz, Brian; Adler, Pierre

    2015-04-01

    Experiments demonstrating asymmetrical dispersive transport of a conservative tracer across interfaces between different porous materials have recently been performed. Here, this phenomenon is studied numerically on the pore scale. The flow field is derived by solving the Stokes equation. The dispersive transport is simulated by a large number of particles undergoing random walks under the simultaneous action of convection and diffusion. Two main two-dimensional configurations are studied; each consists of two segments (called coarse and fine) with the same structure, porosity, and length along the main flow, but different characteristic solid/pore sizes. One structure consists of two channels containing cavities of different sizes, and the second of square "grains" of different sizes. At time t=0, a large number of particles is injected (as a pulse) around a given cross-section. The corresponding breakthrough curves (BTCs) are registered as functions of time at six different cross sections. Calculations are made twice; in the first case (CtoF), particles are injected in the coarse side and are transported towards the fine one; in the second one (FtoC), the opposite case is studied. These calculations are performed for various Péclet numbers (Pe). Comparison of the resulting BTCs shows features that are similar to experimental observations, but with qualitative and quantitative differences. The influences of the medium, of the injection and observation planes, and of Pe are detailed and discussed. A BTC for pulse injection can be characterized by its maximum M(t_M) and the time tM at which it occurs. The observed differences for channels bounded by cavities are very small. However for the granular structures, M(t_M) is always larger for FtoC than for CtoF ; tM depends on all the parameters, namely Pe, the size ratio between the large and small grains, the injection and the observation planes. The numerical results are systematically compared with solutions of one

  2. Temperature trends in the mesosphere

    NASA Astrophysics Data System (ADS)

    Lübken, Franz-Josef; Berger, Uwe

    2013-04-01

    We have performed trend studies in the mesosphere in the period 1961-2009 with LIMA (Leibniz-Institute Middle Atmosphere model) which is based on ECMWF below approximately 40 km and adapts temporal variations of CO2 and O3 according to observations. There is general agreement between LIMA and observations. Temperatures in the mesosphere/lower thermosphere vary non-uniformly with time, mainly due to the influence of ozone. We have therefore separated the influence of CO2(t) and O3(t) when determining trends. It is important to distinguish between trends on pressure altitudes, zp, and geometric altitudes, zgeo, where the latter includes the effect of shrinking due to cooling at lower heights. Maximum total temperature trends reach approximately -1,3 K/dec at zp ~60 km and -1.8 K/dec at zgeo ~70 km, respectively. Carbon dioxide is the main driver of these trends in the mesosphere, whereas ozone contributes approximately one third, both on geometric and pressure heights. Depending on the time period chosen, the ozone effect on trends can be significantly smaller or larger. Temperature trends on geometric and pressure altitudes can differ by as much as -0.9 K/dec in the mesosphere. The altitudes of pressure levels in the mesosphere decrease up to several hundred meters. The shift maximizes at mesopause levels where it accumulates to more than 1 km. Most of the shrinking occurs in the mesosphere and a smaller fraction (~20%) in the stratosphere. For the first time, we have performed long term runs with LIMA applying the 20th Century Reanalysis from NCEP/NCAR dating back to 1871. Again, trends are non-uniform with time. Since the late 19th century temperatures in the mesosphere have dropped by approximately 5-7 K on pressure altitudes, and up to 10-12 K on geometric altitudes. This is much more then typical trends in the troposphere and stratosphere. It is therefore justified to summarize that the mesosphere (at least in summer and at middle latitudes) reacts

  3. Contrails, Cirrus Trends, and Climate.

    NASA Astrophysics Data System (ADS)

    Minnis, Patrick; Ayers, J. Kirk; Palikonda, Rabindra; Phan, Dung

    2004-04-01

    Rising global air traffic and its associated contrails have the potential for affecting climate via radiative forcing. Current estimates of contrail climate effects are based on coverage by linear contrails that do not account for spreading and, therefore, represent the minimum impact. The maximum radiative impact is estimated by assuming that long-term trends in cirrus coverage are due entirely to air traffic in areas where humidity is relatively constant. Surface observations from 1971 to 1995 show that cirrus increased significantly over the northern oceans and the United States while decreasing over other land areas except over western Europe where cirrus coverage was relatively constant. The surface observations are consistent with satellite-derived trends over most areas. Land cirrus trends are positively correlated with upper-tropospheric (300 hPa) humidity (UTH), derived from the National Centers for Environmental Prediction (NCEP) analyses, except over the United States and western Europe where air traffic is heaviest. Over oceans, the cirrus trends are negatively correlated with the NCEP relative humidity suggesting some large uncertainties in the maritime UTH. The NCEP UTH decreased dramatically over Europe while remaining relatively steady over the United States, thereby permitting an assessment of the cirrus contrail relationship over the United States. Seasonal cirrus changes over the United States are generally consistent with the annual cycle of contrail coverage and frequency lending additional evidence to the role of contrails in the observed trend. It is concluded that the U.S. cirrus trends are most likely due to air traffic. The cirrus increase is a factor of 1.8 greater than that expected from current estimates of linear contrail coverage suggesting that a spreading factor of the same magnitude can be used to estimate the maximum effect of the contrails. From the U.S. results and using mean contrail optical depths of 0.15 and 0.25, the maximum

  4. NASA standard: Trend analysis techniques

    NASA Technical Reports Server (NTRS)

    1988-01-01

    This Standard presents descriptive and analytical techniques for NASA trend analysis applications. Trend analysis is applicable in all organizational elements of NASA connected with, or supporting, developmental/operational programs. Use of this Standard is not mandatory; however, it should be consulted for any data analysis activity requiring the identification or interpretation of trends. Trend Analysis is neither a precise term nor a circumscribed methodology, but rather connotes, generally, quantitative analysis of time-series data. For NASA activities, the appropriate and applicable techniques include descriptive and graphical statistics, and the fitting or modeling of data by linear, quadratic, and exponential models. Usually, but not always, the data is time-series in nature. Concepts such as autocorrelation and techniques such as Box-Jenkins time-series analysis would only rarely apply and are not included in this Standard. The document presents the basic ideas needed for qualitative and quantitative assessment of trends, together with relevant examples. A list of references provides additional sources of information.

  5. Lattice dynamics investigations of phonon thermal conductivity of Si /Ge superlattices with rough interfaces

    NASA Astrophysics Data System (ADS)

    Ren, Shang-Fen; Cheng, Wei; Chen, Gang

    2006-11-01

    Phonon thermal conductivities in both growth and in-plane directions of Si /Ge superlattices (SLs) with perfect and rough interfaces are calculated by using a lattice dynamics model. In addition to the general trend, the results show that there exist fluctuations of thermal conductivity in both directions for SLs with even or odd number of layers when the layer thickness is small. Thermal conductivities in both directions of Si /Ge SLs with rough interfaces are shown to be much lower than those of SLs with perfect interfaces. To understand the influences of rough interfaces, thermal conductivities of homogeneous alloy are further calculated and compared. The results show that along the in-plane direction, the thermal conductivity of SLs with rough interfaces is about the same as that of random alloy, while in the growth direction it is lower than that of the random alloy.

  6. Antisite defects at oxide interfaces

    NASA Astrophysics Data System (ADS)

    Chen, Hanghui; Millis, Andrew

    We use ab initio calculations to estimate formation energies of cation (transition metal) antisite defects at oxide interfaces and to understand the basic physical effects that drive or suppress the formation of these defects. We find that antisite defects are favored in systems with substantial charge transfer across the interface, while Jahn-Teller distortions and itinerant ferromagnetism can prevent antisite defects and help stabilize atomically sharp interfaces. Our results enable identification of classes of systems that are more and less susceptible to the formation of antisite defects and motivate a range of experimental studies and further theoretical calculations to further explicate the oxide interface systems. This research was supported by National Science Foundation under Grant No. DMR-1120296 (H. Chen) and DOE-ER-046169 (A. J. Millis).

  7. SKITTER/implement mechanical interface

    NASA Technical Reports Server (NTRS)

    Cash, John Wilson, III; Cone, Alan E.; Garolera, Frank J.; German, David; Lindabury, David Peter; Luckado, Marshall Cleveland; Murphey, Craig; Rowell, John Bryan; Wilkinson, Brad

    1988-01-01

    SKITTER (Spacial Kinematic Inertial Translatory Tripod Extremity Robot) is a three-legged transport vehicle designed to perform under the unique environment of the moon. The objective of this project was to design a mechanical interface for SKITTER. This mechanical latching interface will allow SKITTER to use a series of implements such as drills, cranes, etc., and perform different tasks on the moon. The design emphasized versatility and detachability; that is, the interface design is the same for all implements, and connection and detachment is simple. After consideration of many alternatives, a system of three identical latches at each of the three interface points was chosen. The latching mechanism satisfies the design constraints because it facilitates connection and detachment. Also, the moving parts are protected from the dusty environment by housing plates.

  8. Superfluid Interfaces in Quantum Solids

    NASA Astrophysics Data System (ADS)

    Burovski, Evgeni; Kozik, Evgeni; Kuklov, Anatoly; Prokof'ev, Nikolay; Svistunov, Boris

    2005-04-01

    One scenario for the nonclassical moment of inertia of solid 4He discovered by Kim and Chan [Nature (London), NATUAS, 0028-0836 427, 225 (2004), 10.1038/nature02220] is the superfluidity of microcrystallite interfaces. On the basis of the most simple model of a quantum crystal—the checkerboard lattice solid—we show that the superfluidity of interfaces between solid domains can exist in a wide range of parameters. At strong enough interparticle interaction, a superfluid interface becomes an insulator via a quantum phase transition. Under the conditions of particle-hole symmetry, the transition is of the standard U(1) universality class in 3D, while in 2D the onset of superfluidity is accompanied by the interface roughening, driven by fractionally charged topological excitations.

  9. Brain-Computer Interface Workshop

    NASA Video Gallery

    At a g.tec-sponsored Brain-Computer Interface (BCI) workshop at the National Institute of Aerospace in Hampton, Va., volunteers were able to spell out words on a computer screen using using a g.tec...

  10. Colloids at NAPL-Interfaces

    NASA Astrophysics Data System (ADS)

    Baumann, Thomas; Metz, Christian

    2014-05-01

    Non-aqueous phase liquids in subsurface are relevant in the scope of contaminated sites as well as for enhanced oil recovery. In both cases colloids and engineered nanoparticles are applied to increase the efficiency of NAPL removal. Particle tracking experiments using fluoresecent latex beads and opaque particles have been run in micromodels mimicking the pore structure of subsurface media. The results show that the interface between NAPL and water is highly dynamic, especially in its early stage. There is a distinct circular flow pattern at the interface, effectively increasing the interfacial area. Concentration gradients measured with Raman Microspectrometry at low Peclet numbers suggest that the mass transfer of dissolved contaminants from the NAPL into the water is highly affected by the interface dynamics. On the other hand the interfaces themselves are less accessible, which has implications for the remediation of contaminated sites.

  11. The HEASARC graphical user interface

    NASA Technical Reports Server (NTRS)

    White, N.; Barrett, P.; Jacobs, P.; Oneel, B.

    1992-01-01

    An OSF/Motif-based graphical user interface has been developed to facilitate the use of the database and data analysis software packages available from the High Energy Astrophysics Science Archive Research Center (HEASARC). It can also be used as an interface to other, similar, routines. A small number of tables are constructed to specify the possible commands and command parameters for a given set of analysis routines. These tables can be modified by a designer to affect the appearance of the interface screens. They can also be dynamically changed in response to parameter adjustments made while the underlying program is running. Additionally, a communication protocol has been designed so that the interface can operate locally or across a network. It is intended that this software be able to run on a variety of workstations and X terminals.

  12. Blasting, graphical interfaces and Unix

    SciTech Connect

    Knudsen, S.

    1993-11-01

    A discrete element computer program, DMC (Distinct Motion Code) was developed to simulate blast-induced rock motion. To simplify the complex task of entering material and explosive design parameters as well as bench configuration, a full-featured graphical interface has been developed. DMC is currently executed on both Sun SPARCstation 2 and Sun SPARCstation 10 platforms and routinely used to model bench and crater blasting problems. This paper will document the design and development of the full-featured interface to DMC. The development of the interface will be tracked through the various stages, highlighting the adjustments made to allow the necessary parameters to be entered in terms and units that field blasters understand. The paper also discusses a novel way of entering non-integer numbers and the techniques necessary to display blasting parameters in an understandable visual manner. A video presentation will demonstrate the graphics interface and explains its use.

  13. Blasting, graphical interfaces and Unix

    SciTech Connect

    Knudsen, S.

    1994-12-31

    A discrete element computer program, DMC (Distinct Motion Code) was developed to simulate blast-induced rock motion. To simplify the complex task of entering material and explosive design parameters as well as bench configuration, a full-featured graphical interface has been developed. DMC is currently executed on both Sun SPARCstation 2 and Sun SPARCstation 10 platforms and routinely used to model bench and crater blasting problems. This paper will document the design and development of the full-featured interface to DMC. The development of the interface will be tracked through the various stages, highlighting the adjustments made to allow the necessary parameters to be entered in terms and units that field blasters understand. The paper also discusses a novel way of entering non-integer numbers and the techniques necessary to display blasting parameters in an understandable visual manner. A video presentation will demonstrate the graphics interface and explains its use.

  14. Interfacing Microcomputers with Laboratory Instruments.

    ERIC Educational Resources Information Center

    Long, Joseph W.

    1983-01-01

    Describes development of microcomputer-controlled gamma scintillation spectrometer and chromatographic data analyzer, including design and construction of interface electronics and production of software. Includes diagrams of electric circuits and project evaluation indicating that both instruments functioned as intended. (JN)

  15. Sandia ATM SONET Interface Logic

    Energy Science and Technology Software Center (ESTSC)

    1994-07-21

    SASIL is used to program the EPLD's (Erasable Programmable Logic Devices) and PAL's (Programmable Array Logic) that make up a large percentage of the Sandia ATM SONET Interface (OC3 version) for the INTEL Paragon.

  16. Interfacing with an EVA Suit

    NASA Technical Reports Server (NTRS)

    Ross, Amy

    2011-01-01

    A NASA spacesuit under the EVA Technology Domain consists of a suit system; a PLSS; and a Power, Avionics, and Software (PAS) system. Ross described the basic functions, components, and interfaces of the PLSS, which consists of oxygen, ventilation, and thermal control subsystems; electronics; and interfaces. Design challenges were reviewed from a packaging perspective. Ross also discussed the development of the PLSS over the last two decades.

  17. Coal-shale interface detector

    NASA Technical Reports Server (NTRS)

    Reid, H., Jr. (Inventor)

    1980-01-01

    A coal-shale interface detector for use with coal cutting equipment is described. The detector consists of a reciprocating hammer with an accelerometer to measure the impact of the hammer as it penetrates the ceiling or floor surface of a mine. Additionally, a pair of reflectometers simultaneously view the same surface, and the outputs from the accelerometer and reflectometers are detected and jointly registered to determine when an interface between coal and shale is being cut through.

  18. Coal-shale interface detection

    NASA Technical Reports Server (NTRS)

    Broussard, P. H.; Burch, J. L.; Drost, E. J.; Stein, R. J. (Inventor)

    1979-01-01

    A penetrometer for coal-shale interface detection is presented. It is used with coal cutting equipment consisting of a reciprocating hammer, having an accelerometer mounted thereon to measure the impact of the hammer as it penetrates the ceiling or floor surface of a mine. Additionally, a pair of reflectometers simultaneously view the same surface, and the outputs from the accelerometer and reflectometers are detected and jointly registered to determine when an interface between coal and shale is being cut through.

  19. Laser velocimeter (autocovariance) buffer interface

    NASA Technical Reports Server (NTRS)

    Clemmons, J. I., Jr.

    1981-01-01

    A laser velocimeter (autocovariance) buffer interface (LVABI) was developed to serve as the interface between three laser velocimeter high speed burst counters and a minicomputer. A functional description is presented of the instrument and its unique features which allow the studies of flow velocity vector analysis, turbulence power spectra, and conditional sampling of other phenomena. Typical applications of the laser velocimeter using the LVABI are presented to illustrate its various capabilities.

  20. Satellite services handbook. Interface guidelines

    NASA Technical Reports Server (NTRS)

    1983-01-01

    Satellite interfaces for on orbit servicing, both manned and unmanned are identified, and is intended to be used by designers of space vehicles, both foreign and domestic. A primary concern is for design of interfaces with the astronaut in the loop, especially extravehicular activity, but also intravehicular activity and operations that are remote but have man-in-the-loop. The main emphasis is on servicing in low earth orbits from the Space Shuttle and also from the Space Station or other platforms.

  1. Retained gas sampler interface volume

    SciTech Connect

    Cannon, N.S.

    1997-10-01

    The maximum Retained Gas Sampler (RGS) interface volume was determined; this volume can trap contamination gases during the sampling process. A new technique (helium backfill) for eliminating contamination gases from the RGS sampler interface volume is described, and verification testing reported. Also demonstrated was that RGS data obtained prior to the introduction of the new helium backfill technique can be compensated for air contamination using the measured oxygen concentration and normal air composition.

  2. Satellite services handbook. Interface guidelines

    NASA Astrophysics Data System (ADS)

    1983-12-01

    Satellite interfaces for on orbit servicing, both manned and unmanned are identified, and is intended to be used by designers of space vehicles, both foreign and domestic. A primary concern is for design of interfaces with the astronaut in the loop, especially extravehicular activity, but also intravehicular activity and operations that are remote but have man-in-the-loop. The main emphasis is on servicing in low earth orbits from the Space Shuttle and also from the Space Station or other platforms.

  3. The theory of interface slicing

    NASA Technical Reports Server (NTRS)

    Beck, Jon

    1993-01-01

    Interface slicing is a new tool which was developed to facilitate reuse-based software engineering, by addressing the following problems, needs, and issues: (1) size of systems incorporating reused modules; (2) knowledge requirements for program modification; (3) program understanding for reverse engineering; (4) module granularity and domain management; and (5) time and space complexity of conventional slicing. The definition of a form of static program analysis called interface slicing is addressed.

  4. Mediterranean Ocean Colour Chlorophyll Trends.

    PubMed

    Colella, Simone; Falcini, Federico; Rinaldi, Eleonora; Sammartino, Michela; Santoleri, Rosalia

    2016-01-01

    In being at the base of the marine food web, phytoplankton is particularly important for marine ecosystem functioning (e.g., biodiversity). Strong anthropization, over-exploitation of natural resources, and climate change affect the natural amount of phytoplankton and, therefore, represent a continuous threat to the biodiversity in marine waters. In particular, a concerning risks for coastal waters is the increase in nutrient inputs of terrestrial/anthropogenic origin that can lead to undesirable modifications of phytoplankton concentration (i.e., eutrophication). Monitoring chlorophyll (Chl) concentration, which is a proxy of phytoplankton biomass, is an efficient tool for recording and understanding the response of the marine ecosystem to human pressures and thus for detecting eutrophication. Here, we compute Chl trends over the Mediterranean Sea by using satellite data, also highlighting the fact that remote sensing may represent an efficient and reliable solution to synoptically control the "good environmental status" (i.e., the Marine Directive to achieve Good Environmental Status of EU marine waters by 2020) and to assess the application of international regulations and environmental directives. Our methodology includes the use of an ad hoc regional (i.e., Mediterranean) algorithm for Chl concentration retrieval, also accounting for the difference between offshore (i.e., Case I) and coastal (i.e., Case II) waters. We apply the Mann-Kendall test and the Sens's method for trend estimation to the Chl concentration de-seasonalized monthly time series, as obtained from the X-11 technique. We also provide a preliminary analysis of some particular trends by evaluating their associated inter-annual variability. The high spatial resolution of our approach allows a clear identification of intense trends in those coastal waters that are affected by river outflows. We do not attempt to attribute the observed trends to specific anthropogenic events. However, the trends

  5. Mediterranean Ocean Colour Chlorophyll Trends

    PubMed Central

    Colella, Simone; Falcini, Federico; Rinaldi, Eleonora; Sammartino, Michela; Santoleri, Rosalia

    2016-01-01

    In being at the base of the marine food web, phytoplankton is particularly important for marine ecosystem functioning (e.g., biodiversity). Strong anthropization, over-exploitation of natural resources, and climate change affect the natural amount of phytoplankton and, therefore, represent a continuous threat to the biodiversity in marine waters. In particular, a concerning risks for coastal waters is the increase in nutrient inputs of terrestrial/anthropogenic origin that can lead to undesirable modifications of phytoplankton concentration (i.e., eutrophication). Monitoring chlorophyll (Chl) concentration, which is a proxy of phytoplankton biomass, is an efficient tool for recording and understanding the response of the marine ecosystem to human pressures and thus for detecting eutrophication. Here, we compute Chl trends over the Mediterranean Sea by using satellite data, also highlighting the fact that remote sensing may represent an efficient and reliable solution to synoptically control the “good environmental status” (i.e., the Marine Directive to achieve Good Environmental Status of EU marine waters by 2020) and to assess the application of international regulations and environmental directives. Our methodology includes the use of an ad hoc regional (i.e., Mediterranean) algorithm for Chl concentration retrieval, also accounting for the difference between offshore (i.e., Case I) and coastal (i.e., Case II) waters. We apply the Mann-Kendall test and the Sens’s method for trend estimation to the Chl concentration de-seasonalized monthly time series, as obtained from the X-11 technique. We also provide a preliminary analysis of some particular trends by evaluating their associated inter-annual variability. The high spatial resolution of our approach allows a clear identification of intense trends in those coastal waters that are affected by river outflows. We do not attempt to attribute the observed trends to specific anthropogenic events. However, the

  6. Trends in Student Aid, 2013. Trends in Higher Education Series

    ERIC Educational Resources Information Center

    Baum, Sandy; Payea, Kathleen

    2013-01-01

    Trends in Student Aid, an annual College Board publication since 1983, is a compendium of detailed, up-to-date information on the funding that is available to help students pay for college. This report documents grant aid from federal and state governments, colleges and universities, employers, and other private sources, as well as loans, tax…

  7. NAEP Trends: Main NAEP vs. Long-Term Trend

    ERIC Educational Resources Information Center

    Beaton, Albert E.; Chromy, James R.

    2010-01-01

    The objectives of this research are to (a) compare the trend lines after some adjustments for level and scale only and determine if and how they differ; (b) describe the methodology of each assessment and identify similarities and differences; and (c) attempt to explain any observed differences based on comparable subsets or on special analysis.…

  8. Trends in College Pricing, 2013. Trends in Higher Education Series

    ERIC Educational Resources Information Center

    Baum, Sandy; Ma, Jennifer

    2013-01-01

    Concerns about rising tuition and how students can afford to finance their major investments in postsecondary education are widespread. Solid insights into these questions require accurate and up-to-date information about prices. "Trends in College Pricing, 2013" reports on the prices charged by colleges and universities in 2013-14, how…

  9. Trends in College Pricing, 2011. Trends in Higher Education Series

    ERIC Educational Resources Information Center

    Baum, Sandy; Ma, Jennifer

    2011-01-01

    The published prices on which the analysis in "Trends in College Pricing" is based come from data reported by institutions on the College Board's Annual Survey of Colleges. This survey, which is distributed to nearly 4,000 postsecondary institutions across the country, collects a wealth of data on enrollment, admission, degrees and majors,…

  10. Systems Vaccinology: Applications, Trends, and Perspectives.

    PubMed

    Sollner, Johannes

    2016-01-01

    The strategies employed in vaccinology have improved since the seminal work of Edward Jenner in the eighteenth century. Stimulated by failure to develop vaccines for cancers and chronic infectious diseases as well as an emergence of a multitude of new technologies not available earlier, vaccinology has moved from a largely experimental art to a new phase of innovation. Currently, immune reactions can be predicted and modeled before they occur and formulations can be optimized in advance for genetic background, age, sex, lifestyle, environmental factors, and microbiome. A multitude of scientific insights and technological advancements have led us to this current status, yet possibly none of the recent developments is individually more promising to achieve these goals than the interdisciplinary science of systems vaccinology. This review summarizes current trends and applications of systems vaccinology, including technically tangible areas of vaccine and immunology research which allow the transformative process into a truly broad understanding of vaccines, thereby effectively modeling interaction of vaccines with health and disease. It is becoming clear that a multitude of factors have to be considered to understand inter-patient variability of vaccine responses including those characterized from the interfaces between the immune system, microbiome, metabolome, and the nervous system. PMID:27076127

  11. Hydrophobic effect at aqueous interfaces

    NASA Technical Reports Server (NTRS)

    Pohorille, Andrew

    2005-01-01

    Conceptual basis for hydrophobic effects in bulk water and at aqueous interfaces have similar conceptual basis but often manifests itself differently. Using a wide range of computer simulations as the basis, I will review different forms of hydrophobic effects at a variety of interfaces starting from simple liquid-vapor and water-oil interfaces and progressing to water-membrane interfaces. I will start with discussing how water is organized at different interfaces, stressing both similarities and differences. The main thread is that, as in the bulk liquid, hydrophobic effects have profound influence on conformational equilibria and organization of both small molecules and macromolecules, but the result of this influence is quite different. Specifically, it will be shown that many small, but not necessarily amphiphilic molecules tend to accumulate at the interface and, and this tendency will be explained. Furthermore, I will show that many short peptides that are disordered in water spontaneously fold into well-defined structures in the interfacial environment. Biological implications of this self-organizing effect will be discussed.

  12. Active matter clusters at interfaces.

    NASA Astrophysics Data System (ADS)

    Copenhagen, Katherine; Gopinathan, Ajay

    2016-03-01

    Collective and directed motility or swarming is an emergent phenomenon displayed by many self-organized assemblies of active biological matter such as clusters of embryonic cells during tissue development, cancerous cells during tumor formation and metastasis, colonies of bacteria in a biofilm, or even flocks of birds and schools of fish at the macro-scale. Such clusters typically encounter very heterogeneous environments. What happens when a cluster encounters an interface between two different environments has implications for its function and fate. Here we study this problem by using a mathematical model of a cluster that treats it as a single cohesive unit that moves in two dimensions by exerting a force/torque per unit area whose magnitude depends on the nature of the local environment. We find that low speed (overdamped) clusters encountering an interface with a moderate difference in properties can lead to refraction or even total internal reflection of the cluster. For large speeds (underdamped), where inertia dominates, the clusters show more complex behaviors crossing the interface multiple times and deviating from the predictable refraction and reflection for the low velocity clusters. We then present an extreme limit of the model in the absence of rotational damping where clusters can become stuck spiraling along the interface or move in large circular trajectories after leaving the interface. Our results show a wide range of behaviors that occur when collectively moving active biological matter moves across interfaces and these insights can be used to control motion by patterning environments.

  13. Global trends in hybrid imaging.

    PubMed

    Hricak, Hedvig; Choi, Byung Ihn; Scott, Andrew M; Sugimura, Kazuro; Muellner, Ada; von Schulthess, Gustav K; Reiser, Maximilian F; Graham, Michael M; Dunnick, N Reed; Larson, Steven M

    2010-11-01

    At the 2009 Scientific Assembly and Annual Meeting of the Radiological Society of North America, a special session was devoted to global trends in hybrid imaging. This article expands on the key points of the session, focusing primarily on positron emission tomography/computed tomography. Global trends in hybrid imaging equipment acquisition, usage, and image interpretation practices are reviewed, and emerging requirements for training and clinical privileging are discussed. Also considered are the current benefits of hybrid imaging for patient care and workflow and the potential of hybrid imaging for advancing drug development and personalized medicine. PMID:20829539

  14. Work-Family Interface for Same-Sex, Dual-Earner Couples: Implications for Counselors

    ERIC Educational Resources Information Center

    Perrone, Kristin M.

    2005-01-01

    The author highlights information for career counselors to consider when addressing work-family interface with individuals who are members of same-sex, dual-earner couples or families. D. E. Super's (1990) life-span, life-space theory is the framework used to organize the literature review and discussion of current trends. Issues related to the…

  15. User Interfaces for Patient-Centered Communication of Health Status and Care Progress

    ERIC Educational Resources Information Center

    Wilcox-Patterson, Lauren

    2013-01-01

    The recent trend toward patients participating in their own healthcare has opened up numerous opportunities for computing research. This dissertation focuses on how technology can foster this participation, through user interfaces to effectively communicate personal health status and care progress to hospital patients. I first characterize the…

  16. Special Education Issues, Trends, and Future Predictions.

    ERIC Educational Resources Information Center

    Siegel, Janna

    This paper identifies and discusses major issues and trends in special education in the United States, including implications of these trends for future developments. Trends are discussed for the following areas: (1) philosophy and law (a communitarian philosophy is emerging); (2) labels and terminology (a trend toward declassification); (3)…

  17. Case study on the evolution of hetero-oligomer interfaces based on the differences in paralogous proteins

    PubMed Central

    Aoto, Saki; Yura, Kei

    2015-01-01

    We addressed the evolutionary trace of hetero-oligomer interfaces by comparing the structures of paralogous proteins; one of them is a monomer or homo-oligomer and the other is a hetero-oligomer. We found different trends in amino acid conservation pattern and hydrophobicity between homo-oligomer and hetero-oligomer. The degree of amino acid conservation in the interface of homo-oligomer has no obvious difference from that in the surface, whereas the degree of conservation is much higher in the interface of hetero-oligomer. The interface of homo-oligomer has a few very conserved residue positions, whereas the residue conservation in the interface of hetero-oligomer tends to be higher. In addition, the interface of hetero-oligomer has a tendency of being more hydrophobic compared with the one in homo-oligomer. We conjecture that these differences are related to the inherent symmetry in homo-oligomers that cannot exist in hetero-oligomers. Paucity of the structural data precludes statistical tests of these tendencies, yet the trend can be applied to the prediction of the interface of hetero-oligomer. We obtained putative interfaces of the subunits in CPSF (cleavage and polyadenylation specificity factor), one of the human pre-mRNA 3′-processing complexes. The locations of predicted interface residues were consistent with the known experimental data. PMID:27493859

  18. Energy conversion and fuel production from electrochemical interfaces

    NASA Astrophysics Data System (ADS)

    Markovic, Nenad

    2012-02-01

    Design and synthesis of energy efficient and stable electrochemical interfaces (materials and double layer components) with tailor properties for accelerating and directing chemical transformations is the key to developing new alternative energy systems -- fuel cells, electrolizers and batteries. In aqueous electrolytes, depending on the nature of the reacting species, the supporting electrolyte, and the metal electrodes, two types of interactions have traditionally been considered: (i) direct -- covalent - bond formation between adsorbates and electrodes, involving chemisorption, electron transfer, and release of the ion hydration shell; and (ii) relatively weak non-covalent metal-ion forces that may affect the concentration of ions in the vicinity of the electrode but do not involve direct metal-adsorbate bonding. The range of physical phenomena associated with these two classes of bonds is unusually broad, and are of paramount importance to understand activity of both metal-electrolyte two phase interfaces and metal-Nafion-electrolyte three phase interfaces. Furthermore, in the past, researcher working in the field of fuel cells (converting hydrogen and oxygen into water) and electrolyzers (splitting water back to H2 and O2) ) seldom focused on understanding the electrochemical compliments of these reactions in battery systems, e.g., the lithium-air system. In this lecture, we address the importance of both covalent and non-covalent interactions in controlling catalytic activity at the two-phase and three-phase interfaces. Although the field is still in its infancy, a great deal has already been learned and trends are beginning to emerge that give new insight into the relationship between the nature of bonding interactions and catalytic activity/stability of electrochemical interfaces. In addition, to bridge the gap between the ``water battery'' (fuel cell <-> electrolyzer) and the Li-air battery systems we demonstrate that this would require fundamentally new

  19. TRENDS IN RURAL SULFUR CONCENTRATIONS

    EPA Science Inventory

    As the focus of environmental management has shifted toward regional- scale strategies, there is a growing need to develop statistical methodology for the estimation of regional trends in air pollution. This information is critical to assessing the effects of legislated emission ...

  20. International Trends in Curriculum Frameworks.

    ERIC Educational Resources Information Center

    Le Metais, Joanna

    2003-01-01

    The International Review of Curriculum and Assessment Frameworks in 18 countries identified trends related to participation and engagement: responsiveness, inclusion, and curricular differentiation; key skills; and creativity development and citizenship education. Common economic and social pressures are leading to some convergence among nations.…

  1. Trends in Environmental Health Engineering

    ERIC Educational Resources Information Center

    Rowe, D. R.

    1972-01-01

    Reviews the trends in environmental health engineering and describes programs in environmental engineering technology and the associated environmental engineering courses at Western Kentucky University (four-year program), Wytheville Community College (two-year program), and Rensselaer Polytechnic Institute (four-year program). (PR)

  2. Adoption Research: Trends, Topics, Outcomes

    ERIC Educational Resources Information Center

    Palacios, Jesus; Brodzinsky, David

    2010-01-01

    The current article provides a review of adoption research since its inception as a field of study. Three historical trends in adoption research are identified: the first focusing on risk in adoption and identifying adoptee-nonadoptee differences in adjustment; the second examining the capacity of adopted children to recover from early adversity;…

  3. Overview of Selected Drug Trends.

    ERIC Educational Resources Information Center

    Adams, Edgar H.; And Others

    This document begins with a brief overview of findings from national surveys conducted by the National Institute on Drug Abuse which show increasing drug use throughout the 1970s and a decreasing trend in drug use during the 1980s. In spite of this decline, drug use in the U.S. is described as still constituting a major public health problem that…

  4. New Trends in Student Housing.

    ERIC Educational Resources Information Center

    Koch, David; Wesse, David; Stickney, Robert

    1999-01-01

    Discusses the influence of residence halls in supporting a college's admissions and recruiting process for attracting highly qualified students. It explores the trends in student housing needs and how a school can meet those needs, and examines possible funding solutions for dormitory renovations. Recommendations for developing housing strategies…

  5. Recruiting Trends, 2009-2010

    ERIC Educational Resources Information Center

    Collegiate Employment Research Institute (NJ3), 2010

    2010-01-01

    This paper presents the recruiting trends for 2009-2010. This year's report is based on over 2,500 respondents, of which approximately 2,259 provided useable information with 1,846 including complete hiring figures used for the projections. The researchers continued their focus on fast-growth companies and expanded their efforts to ensure a…

  6. Bucking Trends: Expanding the Arts

    ERIC Educational Resources Information Center

    Levin, Kathi R.

    2008-01-01

    The arts and music have been unintended victims of the No Child Left Behind Act. Several reports point to sharp reductions in student access to K-12 arts education, yet some school districts nationwide have managed to buck the trend. These districts, in communities rural through urban, are systemically embedding the arts at the core of teaching…

  7. SETDA's National Trends Report 2008

    ERIC Educational Resources Information Center

    State Educational Technology Directors Association, 2008

    2008-01-01

    The State Educational Technology Directors Association (SETDA) is pleased to release its fifth annual National Trends Report on the use of federal funds to support educational technology. This report documents findings from Round 5 (FY 06) of the No Child Left Behind, Title II, Part D, Enhancing Education Through Technology (NCLB IID) program. The…

  8. Manpower Trends in Canada: Chartbook.

    ERIC Educational Resources Information Center

    Department of Labour, Ottawa (Ontario). Economics and Research Branch.

    The major changes taking place in the occupational and industrial structure of the labor force are highlighted by graphic illustrations of changing manpower needs. Some apparent trends are: (1) the very rapid rate of growth of the total labor force, (2) the relatively slow growth rate of the manufacturing labor force, (3) the rapid growth of the…

  9. Demographic Trends: Impact on Schools

    ERIC Educational Resources Information Center

    Chong, Sylvia N. Y.; Cheah, Horn Mun

    2010-01-01

    Background: Singapore is experiencing great demographic change. These demographic trends show fewer young people and declining birth rates, greater longevity for ageing generations and an increase in the number of non-Singaporean residents. Statistics also show that more than half of the total population increase in the last decades was…

  10. Shifting Trends in Special Education

    ERIC Educational Resources Information Center

    Scull, Janie; Winkler, Amber M.

    2011-01-01

    This report examines trends in the number of special-education students and personnel at both the national and state levels from 2000-01 to 2009-10. It finds that the overall population of special-education students, after decades of increases, peaked in the 2004-05 school year and has declined since. But within this population, individual…

  11. Trends in Turkish Education Studies

    ERIC Educational Resources Information Center

    Varisoglu, Behice; Sahin, Abdullah; Goktas, Yuksel

    2013-01-01

    The purpose of this study was to determine trends in the subject areas, methods, data collection tools, data analysis methods, and sample types used in recent studies on Turkish education, published in journals from 2000-2011. A total of 558 articles from 44 journals were selected from databases by the purposive sampling method and examined using…

  12. Higher Education Profiles & Trends 2013

    ERIC Educational Resources Information Center

    Tennessee Higher Education Commission, 2013

    2013-01-01

    The statute [T.C.A. Section 49-7-202(c)(7)] requires the Tennessee Higher Education Commission to prepare a biennial report for the governor and the general assembly, "commenting upon major developments, trends, new policies, budgets and financial considerations which in the judgment of the commission will be useful to the governor and to the…

  13. Information Technology: Perspectives and Trends.

    ERIC Educational Resources Information Center

    Robinson, Doug

    The full impact of the current information technology and networking revolution remains unknown, but the experiences of organizations and individuals who are using the tools and resources offered by information technology suggest that it may change our social fabric. Some of the current and emerging trends in information technology include: the…

  14. Recruiting Trends, 2005-2006

    ERIC Educational Resources Information Center

    Collegiate Employment Research Institute (NJ3), 2006

    2006-01-01

    Almost 900 employers responded to this year's "Recruiting Trends" survey, the largest response in the history of this project. Hiring of college graduates is expected to increase by single digits minimally, or double digits if certain geographic sectors are excluded (between 6% and 14%). This growth follows a robust 20% increase in hiring reported…

  15. Recruiting Trends, 2008-2009

    ERIC Educational Resources Information Center

    Collegiate Employment Research Institute (NJ3), 2009

    2009-01-01

    This paper presents the recruiting trends for 2008-2009. This year's report is based on 945 respondents, including 57 K-12 schools. The researchers continued their focus on fast-growth small companies and expended most of their energy in retaining their sample distribution, knowing that the prevailing economic situation would reduce responses.…

  16. Recruiting Trends, 2007-2008

    ERIC Educational Resources Information Center

    Collegiate Employment Research Institute (NJ3), 2008

    2008-01-01

    This paper presents the recruiting trends for 2007-2008. This year's report is based on 994 respondents, including 84 K-12 school districts. The researchers focused attention on growing companies, based on lists from Forbes and Inc. magazines, and as a result, they have more small and medium-size employers represented this year. The sample…

  17. The Trend toward Retirement Jobs

    ERIC Educational Resources Information Center

    Buddy, Juanita Warren

    2008-01-01

    Many library media specialists are deciding to return to the workplace after retiring from full-time employment. This article focuses on general information about the trend of retirees acquiring retirement jobs, how and why retired library media specialists return to work, their perceptions of challenges facing library media programs, and advice…

  18. Recruiting Trends, 2006-2007

    ERIC Educational Resources Information Center

    Collegiate Employment Research Institute (NJ3), 2007

    2007-01-01

    College students who plan on entering the labor market can expect to see more job opportunities in the spring of 2007, according to information supplied by 864 companies and organizations to this year's Recruiting Trends Report. After two years of double digit growth, the expansion will slow to a modest 4% to 6%. Two opposing factors appear to be…

  19. Productivity Trends in Intercity Trucking

    ERIC Educational Resources Information Center

    Carnes, Richard B.

    1974-01-01

    Productivity trends indicate intercity trucking productivity increased an average 2.7 percent a year, a fairly uniform increased productivity rate but substantially lower as compared to air carrier, railroad, and pipeline transportation. Factors affecting productivity are gradual introduction of technological innovation, larger capacity trucks,…

  20. Trends in Personal Injury Suits.

    ERIC Educational Resources Information Center

    van der Smissen, Betty

    1985-01-01

    Professional competence becomes more important as personal injury suits against recreation enterprises and parks focus increasingly on the professional responsible for facility safety. All professionals should be aware of and educated in risk management. Trends in liability awards and providers' legal responsibilities in various situations are…

  1. Six Trends in Library Design.

    ERIC Educational Resources Information Center

    Harrington, Drew

    2001-01-01

    Describes six trends in current library facilities design, whether for new buildings or renovations: self-service and operational efficiency; flexibility and technology integration; green/sustainable buildings that use the natural environment; collaboration between public and school/college libraries; aesthetics; and customizing to the local…

  2. Economic Trends and Higher Education.

    ERIC Educational Resources Information Center

    Ottinger, Cecilia A.

    1992-01-01

    This research brief highlights current and projected economic trends that affect higher education and discusses some of their implications. The brief is organized into three sections: (1) national economic conditions affecting higher education, which presents data on gross national product, inflation, the Higher Education Price Index, the federal…

  3. ANTIMICROBIAL RESISTANCE TRENDS IN SALMONELLA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background: Since the early 1990’s there has been increasing awareness and concern regarding the development of antimicrobial resistance among bacteria of public health significance. Reports targeting zoonotic bacteria, and in particular Salmonella species, suggest that resistance is trending upwar...

  4. Emerging Trends in Secondary Education.

    ERIC Educational Resources Information Center

    Picus, Larry; Cohen, Carolyn

    In 4 stages, this paper, prepared by the Northwest Regional Educational Laboratory (NWREL), examines trends in secondary education: a review of 11 major studies from the 1970's; responses from 320 Northwest high school principals to survey questionnaires; a telephone survey of 21 local, state, regional, and national observers of youth employment…

  5. The Internet: Trends and Directions.

    ERIC Educational Resources Information Center

    Anderson, Byron

    1996-01-01

    Examines current trends and directions in information technology and telecommunications. Discusses legislation; mergers and acquisitions; Internet service providers; fiscal control in libraries and the pooling of electronic information access through consortiums; demand for more bandwidth; technology selection; Internet usage patterns; the…

  6. Current Trends in Language Teaching

    ERIC Educational Resources Information Center

    Revue des Langues Vivantes, 1975

    1975-01-01

    Examines the effects of Chomsky's theories of linguistics and language acquisition on language teaching methodology, specifically on the use of the audio-lingual method. Current trends in methodology move in two basic directions: 1) towards relaxation of the tighter restrictions of the audio-lingual method, and 2) towards development of techniques…

  7. Main Trends in Information Technology.

    ERIC Educational Resources Information Center

    Griffiths, Jose-Marie

    1982-01-01

    Describes applications of new technology to information handling on the basis of two trends--the miniaturization of electronic circuits and the shift from analog to digital modes of communication. Information technologies discussed are microcomputers, word processors, telecommunications, storage technologies, databases, videotex, and teletext.…

  8. Global Trends in Workplace Learning

    ERIC Educational Resources Information Center

    Lee, Lung-Sheng; Lai, Chun-Chin

    2012-01-01

    The paradigm of human resource development has shifted to workplace learning and performance. Workplace can be an organization, an office, a kitchen, a shop, a farm, a website, even a home. Workplace learning is a dynamic process to solve workplace problems through learning. An identification of global trends of workplace learning can help us to…

  9. Economic and Labor Market Trends

    ERIC Educational Resources Information Center

    Nightingale, Demetra Smith; Fix, Michael

    2004-01-01

    A number of economic and labor market trends in the United States over the past 30 years affect the well-being of workers and their families. This article describes key changes taking place and the implications for social and economic policies designed to help low-income working families and their children, particularly those families that include…

  10. America's Changing Population: Demographic Trends.

    ERIC Educational Resources Information Center

    Morrison, Peter A.

    1981-01-01

    Surveys the importance of migration trends in the United States away from the Northeastern urban areas into the sunbelt states of the West and Southwest. Emphasis is placed on ways in which this demographic transformation disturbs social, economic, and political arrangements. (DB)

  11. Recent Trends in Karst Geomorphology.

    ERIC Educational Resources Information Center

    Palmer, Arthur N.

    1984-01-01

    Recent trends related to the karst processes and the evolution of karst landscapes are discussed. The hydrochemical processes responsible for the origin of karst are expanded on to illustrate the present scope of karst studies. These geomorphological studies are combined with concepts and techniques from hydraulics, chemistry, and mathematics. (JN)

  12. Utah: Going against the Trends.

    ERIC Educational Resources Information Center

    Jarvik, Elaine

    1982-01-01

    While enrollment and demographic trends worry the higher education community in other states, Utah's higher education future is bright. Financial support from the Mormon Church, high birth rate, strong institutions (both public and private), a cohesive, conservative community, and large potential natural resources give optimism to the state. (MSE)

  13. Employment Trends in Energy Extraction.

    ERIC Educational Resources Information Center

    Greene, Richard

    1981-01-01

    Between 1973 and 1980, employment in the basic energy extraction industries--coal, oil, and natural gas--has risen by more than 91 percent. The Arab oil embargo and subsequent emphasis on development of domestic energy sources are responsible for this trend. (Author/SK)

  14. Physics through the 1990s: Scientific interfaces and technological applications

    NASA Technical Reports Server (NTRS)

    1986-01-01

    The volume examines the scientific interfaces and technological applications of physics. Twelve areas are dealt with: biological physics-biophysics, the brain, and theoretical biology; the physics-chemistry interface-instrumentation, surfaces, neutron and synchrotron radiation, polymers, organic electronic materials; materials science; geophysics-tectonics, the atmosphere and oceans, planets, drilling and seismic exploration, and remote sensing; computational physics-complex systems and applications in basic research; mathematics-field theory and chaos; microelectronics-integrated circuits, miniaturization, future trends; optical information technologies-fiber optics and photonics; instrumentation; physics applications to energy needs and the environment; national security-devices, weapons, and arms control; medical physics-radiology, ultrasonics, MNR, and photonics. An executive summary and many chapters contain recommendations regarding funding, education, industry participation, small-group university research and large facility programs, government agency programs, and computer database needs.

  15. Physics through the 1990s: Scientific interfaces and technological applications

    NASA Astrophysics Data System (ADS)

    The volume examines the scientific interfaces and technological applications of physics. Twelve areas are dealt with: biological physics-biophysics, the brain, and theoretical biology; the physics-chemistry interface-instrumentation, surfaces, neutron and synchrotron radiation, polymers, organic electronic materials; materials science; geophysics-tectonics, the atmosphere and oceans, planets, drilling and seismic exploration, and remote sensing; computational physics-complex systems and applications in basic research; mathematics-field theory and chaos; microelectronics-integrated circuits, miniaturization, future trends; optical information technologies-fiber optics and photonics; instrumentation; physics applications to energy needs and the environment; national security-devices, weapons, and arms control; medical physics-radiology, ultrasonics, MNR, and photonics. An executive summary and many chapters contain recommendations regarding funding, education, industry participation, small-group university research and large facility programs, government agency programs, and computer database needs.

  16. Airborne Precision Spacing for Dependent Parallel Operations Interface Study

    NASA Technical Reports Server (NTRS)

    Volk, Paul M.; Takallu, M. A.; Hoffler, Keith D.; Weiser, Jarold; Turner, Dexter

    2012-01-01

    This paper describes a usability study of proposed cockpit interfaces to support Airborne Precision Spacing (APS) operations for aircraft performing dependent parallel approaches (DPA). NASA has proposed an airborne system called Pair Dependent Speed (PDS) which uses their Airborne Spacing for Terminal Arrival Routes (ASTAR) algorithm to manage spacing intervals. Interface elements were designed to facilitate the input of APS-DPA spacing parameters to ASTAR, and to convey PDS system information to the crew deemed necessary and/or helpful to conduct the operation, including: target speed, guidance mode, target aircraft depiction, and spacing trend indication. In the study, subject pilots observed recorded simulations using the proposed interface elements in which the ownship managed assigned spacing intervals from two other arriving aircraft. Simulations were recorded using the Aircraft Simulation for Traffic Operations Research (ASTOR) platform, a medium-fidelity simulator based on a modern Boeing commercial glass cockpit. Various combinations of the interface elements were presented to subject pilots, and feedback was collected via structured questionnaires. The results of subject pilot evaluations show that the proposed design elements were acceptable, and that preferable combinations exist within this set of elements. The results also point to potential improvements to be considered for implementation in future experiments.

  17. Theory of Interface States at Silicon / Transition - - Silicide Interfaces.

    NASA Astrophysics Data System (ADS)

    Lim, Hunhwa

    The Si/NiSi(,2)(111) interface is of both fundamental and techno- logical interest: From the fundamental point of view, it is the best characterized of all semiconductor/metal interfaces, with two well-determined geometries (A and B) involving nearly perfect bonding. (This is because Si and NiSi(,2) have nearly the same lattice spacing.) Consequently, a theoretical treatment of this system makes sense--as it would not for messier systems--and one can have some confidence that the theoretical predictions are relevant to experimental observa- tions. From the technological point of view, Si/NiSi(,2) is representative of the class of semiconductor/metal interfaces that are currently of greatest interest in regard to electronic devices--Si/transition -metal-silicide interfaces. The calculations of this dissertation are for the intrinsic interface states of Si/NiSi(,2)-A geometry. These calculations also provide a foundation for later studies of defects at this interface, and for studies of other related systems, such as CoSi(,2). The calculations employ empirical tight-binding Hamiltonians for both Si and NiSi(,2) (with the parameters fitted to prior calculations of the bulk band structures, which appear to be in agreement with the available experimental data on bulk Si and NiSi(,2)). They also employ Green's function techniques--in particular, the subspace Hamiltonian technique. Our principal results are the following: (1) Interface state disper- sion curves are predicted along the symmetry lines (')(GAMMA)(')M, (')M(')K and (')K(')(GAMMA) of the surface Brillouin zone. (2) A prominent band of interface states is found which disperses downward from an energy within the Si band gap to an energy below the Si valence band edge E(,(upsilon)) as the planar wavevector (')k increases from (')(GAMMA) ((')k = 0) to (')M or (')K (symmetry points at boundary of the surface Brillouin zone). This band of inter- face states should be observable. It produces a peak in the surface

  18. Inelastic decay of electrons in Shockley-type metal-organic interface states

    NASA Astrophysics Data System (ADS)

    Tsirkin, S. S.; Zaitsev, N. L.; Nechaev, I. A.; Tonner, R.; Höfer, U.; Chulkov, E. V.

    2015-12-01

    We present a theoretical study of lifetimes of interface states (IS) on metal-organic interfaces PTCDA/Ag(111), NTCDA/Ag(111), PFP/Ag(111), and PTCDA/Ag(100), describing and explaining the recent experimental data. By means of unfolding the band structure of one of the interfaces under study onto the Ag(111) Brillouin zone we demonstrate that the Brillouin zone folding upon organic monolayer deposition plays a minor role in the phase space for electron decay, and hence weakly affects the resulting lifetimes. The presence of the unoccupied molecular states below the IS gives a small contribution to the IS decay rate, which is mostly determined by the change of the phase space of bulk states upon the energy shift of the IS. The calculated lifetimes follow the experimentally observed trends. In particular, we explain the trend of the unusual increase of the IS lifetimes with rising temperature.

  19. Trends...

    ERIC Educational Resources Information Center

    Creighton, B. W.; And Others

    1972-01-01

    Includes 11 sub-articles dealing with innovative recreational programs in Alaska, Michigan, Tennessee, Illinois, and California. Activities and facilities described include bus rides, artificial ice skating and skiing, rooftop playgrounds, wood structures, dam sites, and enclosed buildings. (NQ)

  20. Fluxes across a thermohaline interface

    NASA Astrophysics Data System (ADS)

    Fleury, M.; Lueck, R. G.

    1991-07-01

    Measurements of velocity and temperature microstructure and hydrography were made with a towed vehicle moving in and around a single interface in a double-diffusive staircase. The interface was traversed 222 times in a saw-tooth pattern over a track 35 km long. The salinity and potential temperature and density in the mixed layers adjacent to the interface were spatially uniform except for one 8 km long anomaly. The rate of dissipation of kinetic energy was uniformly low in the interface and in the mixed layers, except for one section 600 m long where a Kelvin-Helmholtz instability generated turbulence. For the non-turbulent section of the interface, the mean rate of dissipation was 30.2 × 10 -10 W kg -1 in the mixed layers and 9.5 × 10 -10 W kg -1 in the interface. The non-dimensional dissipation rate, ɛ/vN 2, was almost always less than 16 in the interface and therfore, there was no turblent buoyancy flux according to ROHRet al. (1988, Journal of Fluid Mechanics, 195, 77-111). The average double-diffusive flux of buoyancy by heat was 3.6 × 10 -10 W kg -1. Under certain assumptions the ratio of the flux of buoyancy by heat and salt can be estimated to be 0.53 ± 0.10, in good agreement with laboratory and theoretical estimates for salt fingers. The average Cox number was about 8 in the interface, consistent with the theories of STERN (1975, Ocean circulation physics, Academic Press) and KUNZE (1987, Journal of Marine Research, 45 533-556), but displayed an inverse dependence on the vertical temperature gradient which was not predicted. As a result, the flux of buoyancy, as well as the individual contributions by heat and salt, were independent of the local mean vertical temperature gradient and the buoyancy frequency. The length of the turbulent section of the interface was only 1.7% of the total length observed. However, the turbulence was intense—the mean rate of dissipation was 2.5 × 10 -8 W kg -1—and may have sufficiently enhanced the flux of heat to

  1. Active matter clusters at interfaces

    NASA Astrophysics Data System (ADS)

    Copenhagen, Katherine; Gopinathan, Ajay

    Collective and directed motility or swarming is an emergent phenomenon displayed by many self-organized assemblies of active biological matter such as clusters of embryonic cells during tissue development and flocks of birds. Such clusters typically encounter very heterogeneous environments. What happens when a cluster encounters an interface between two different environments has implications for its function and fate. Here we study this problem by using a mathematical model of a cluster that treats it as a single cohesive unit whose movement depends on the nature of the local environment. We find that low speed clusters which exert forces but no active torques, encountering an interface with a moderate difference in properties can lead to refraction or even total internal reflection of the cluster. For large speeds and clusters with active torques, they show more complex behaviors crossing the interface multiple times, becoming trapped at the interface and deviating from the predictable refraction and reflection of the low velocity clusters. Our results show a wide range of behaviors that occur when collectively moving active biological matter moves across interfaces and these insights can be used to control motion by patterning environments.

  2. XML Translator for Interface Descriptions

    NASA Technical Reports Server (NTRS)

    Boroson, Elizabeth R.

    2009-01-01

    A computer program defines an XML schema for specifying the interface to a generic FPGA from the perspective of software that will interact with the device. This XML interface description is then translated into header files for C, Verilog, and VHDL. User interface definition input is checked via both the provided XML schema and the translator module to ensure consistency and accuracy. Currently, programming used on both sides of an interface is inconsistent. This makes it hard to find and fix errors. By using a common schema, both sides are forced to use the same structure by using the same framework and toolset. This makes for easy identification of problems, which leads to the ability to formulate a solution. The toolset contains constants that allow a programmer to use each register, and to access each field in the register. Once programming is complete, the translator is run as part of the make process, which ensures that whenever an interface is changed, all of the code that uses the header files describing it is recompiled.

  3. A UNIX interface to supercomputers

    SciTech Connect

    McBryan, O.A.

    1985-01-01

    We describe a convenient interface between UNIX-based work-stations or minicomputers, and supercomputers such as the CRAY series machines. Using this interface, the user can issue commands entirely on the UNIX system, with remote compilation, loading and execution performed on the supercomputer. The interface is not a remote login interface. Rather the domain of various UNIX utilities such as compilers, archivers and loaders are extended to include the CRAY. The user need know essentially nothing about the CRAY operating system, commands or filename restrictions. Standard UNIX utilities will perform CRAY operations transparently. UNIX command names and arguments are mapped to corresponding CRAY equivalents, suitable options are selected as needed, UNIX directory tree filenames are coerced to allowable CRAY names and all source and output files are automatically transferred between the machines. The primary purpose of the software is to allow the programmer to benefit from the interactive features of UNIX systems including screen editors, software maintenance utilities such as make and SCCS and in general to avail of the large set of UNIX text manipulation features. The interface was designed particularly to support development of very large multi-file programs, possibly consisting of hundreds of files and hundreds of thousands of lines of code. All CRAY source is kept on the work-station. We have found that using the software, the complete program development phase for a large CRAY application may be performed entirely on a work-station.

  4. DIRAC: Secure web user interface

    NASA Astrophysics Data System (ADS)

    Casajus Ramo, A.; Sapunov, M.

    2010-04-01

    Traditionally the interaction between users and the Grid is done with command line tools. However, these tools are difficult to use by non-expert users providing minimal help and generating outputs not always easy to understand especially in case of errors. Graphical User Interfaces are typically limited to providing access to the monitoring or accounting information and concentrate on some particular aspects failing to cover the full spectrum of grid control tasks. To make the Grid more user friendly more complete graphical interfaces are needed. Within the DIRAC project we have attempted to construct a Web based User Interface that provides means not only for monitoring the system behavior but also allows to steer the main user activities on the grid. Using DIRAC's web interface a user can easily track jobs and data. It provides access to job information and allows performing actions on jobs such as killing or deleting. Data managers can define and monitor file transfer activity as well as check requests set by jobs. Production managers can define and follow large data productions and react if necessary by stopping or starting them. The Web Portal is build following all the grid security standards and using modern Web 2.0 technologies which allow to achieve the user experience similar to the desktop applications. Details of the DIRAC Web Portal architecture and User Interface will be presented and discussed.

  5. Interface dynamics of competing tissues

    NASA Astrophysics Data System (ADS)

    Podewitz, Nils; Jülicher, Frank; Gompper, Gerhard; Elgeti, Jens

    2016-08-01

    Tissues can be characterized by their homeostatic stress, i.e. the value of stress for which cell division and cell death balance. When two different tissues grow in competition, a difference of their homeostatic stresses determines which tissue grows at the expense of the second. This then leads to the propagation of the interface separating the tissues. Here, we study structural and dynamical properties of this interface by combining continuum theory with mesoscopic simulations of a cell-based model. Using a simulation box that moves with the interface, we find that a stationary state exists in which the interface has a finite width and propagates with a constant velocity. The propagation velocity in the simulations depends linearly on the homeostatic stress difference, in excellent agreement with the analytical predictions. This agreement is also seen for the stress and velocity profiles. Finally, we analyzed the interface growth and roughness as a function of time and system size. We estimated growth and roughness exponents, which differ from those previously obtained for simple tissue growth.

  6. EDITORIAL: The interface between geophysics and engineering

    NASA Astrophysics Data System (ADS)

    2004-03-01

    Journal of Geophysics and Engineering (JGE) aims to publicize and promote research and developments in geophysics and in related areas of engineering. As stated in the journal scope, JGE is positioned to bridge the gap between earth physics and geo-engineering, where it reflects a growing trend in both industry and academia. JGE covers those aspects of engineering that bear closely on geophysics or on the targets and problems that geophysics addresses. Typically this will be engineering focused on the subsurface, particularly petroleum engineering, rock mechanics, geophysical software engineering, drilling technology, remote sensing, instrumentation and sensor design. There is a trend, visible throughout academia, for rapid expansion in cross-disciplinary, multi-disciplinary and inter-disciplinary working. Many of the most important and exciting problems and advances are being made at the boundaries between traditional subject areas and, increasingly, techniques from one discipline are finding applications in others. There is a corresponding increasing requirement for researchers to be aware of developments in adjacent areas and for papers published in one area to be readily accessible, both in terms of location and language, to those in others. One such area that is expanding rapidly is that at the interface between geophysics and engineering. There are three principal developments. Geophysics, and especially applied geophysics, is increasingly constrained by the limits of technology, particularly computing technology. Consequently, major advances in geophysics are often predicated upon major developments in engineering and many research geophysicists are working in multi-disciplinary teams with engineers. Engineering problems relevant to the sub-surface are increasingly looking to advances in geophysics to provide part of the solution. Engineering systems, for example, for tunnel boring or petroleum reservoir management, are using high-resolution geophysical

  7. EVA-glass interface bond stability

    NASA Technical Reports Server (NTRS)

    Koenig, J. L.

    1984-01-01

    The ethylene vinyl acetate/glass interface bond stability was investigated. Special methods to determine the structure of polymer/glass interface were developed. Structural changes related to hydrothermal degradation of polymer/glass interface are examined. Methods to inhibit the degradation reaction which occur at polymer/glass interface are developed.

  8. PinBus Interface Design

    SciTech Connect

    Hammerstrom, Donald J.; Adgerson, Jewel D.; Sastry, Chellury; Pratt, Richard M.; Pratt, Robert G.

    2009-12-30

    On behalf of the U.S. Department of Energy, PNNL has explored and expanded upon a simple control interface that might have merit for the inexpensive communication of smart grid operational objectives (demand response, for example) to small electric end-use devices and appliances. The approach relies on bi-directional communication via the electrical voltage states of from one to eight shared interconnection pins. The name PinBus has been suggested and adopted for the proposed interface protocol. The protocol is defined through the presentation of state diagrams and the pins’ functional definitions. Both simulations and laboratory demonstrations are being conducted to demonstrate the elegance and power of the suggested approach. PinBus supports a very high degree of interoperability across its interfaces, allowing innumerable pairings of devices and communication protocols and supporting the practice of practically any smart grid use case.

  9. Flow in presence of interfaces

    NASA Astrophysics Data System (ADS)

    Lunati, I.

    2011-12-01

    Although most physical properties and empirical laws are well defined and experimentally tested only for homogeneous systems, being able to solve environmental problems requires dealing with systems that are inherently heterogeneous. This is particularly true for applications in hydrogeology, where properties (such as permeability) can vary over orders of magnitude. The most challenging cases are those of flow in presence of interfaces, i.e., region characterized by sharp and abrupt contrasts in properties or state. Interfaces require a special treatment, both conceptually and numerically (e.g., quantity such as pressure can become discontinuous), and must be accurately described because of the important phenomena that can take place (e.g., reaction or instability) and influence the behavior of the system at large scales. We discuss the problems related with an accurate description of the propagation of a fluid-fluid interface in a pore geometry, and with the evolution of an unstable front between two fluids of different densities.

  10. Holographic interface-particle potential

    NASA Astrophysics Data System (ADS)

    Nagasaki, Koichi; Tanida, Hiroaki; Yamaguchi, Satoshi

    2012-01-01

    We consider two mathcal{N} = {4} supersymmetric gauge theories connected by an interface and the gravity dual of this system. This interface is expressed by a fuzzy funnel solution of Nahm's equation in the gauge theory side. The gravity dual is a probe D5-brane in AdS5 × S 5. The potential energy between this interface and a test particle is calculated in both the gauge theory side and the gravity side by the expectation value of a Wilson loop. In the gauge theory it is evaluated by just substituting the classical solution to the Wilson loop. On the other hand it is done by the on-shell action of the fundamental string stretched between the AdS boundary and the D5-brane in the gravity. We show the gauge theory result and the gravity one agree with each other.

  11. Nanofluidic interfaces in microfluidic networks

    DOE PAGESBeta

    Millet, Larry J.; Doktycz, Mitchel John; Retterer, Scott T.

    2015-09-24

    The integration of nano- and microfluidic technologies enables the construction of tunable interfaces to physical and biological systems across relevant length scales. The ability to perform chemical manipulations of miniscule sample volumes is greatly enhanced through these technologies and extends the ability to manipulate and sample the local fluidic environments at subcellular, cellular and community or tissue scales. Here we describe the development of a flexible surface micromachining process for the creation of nanofluidic channel arrays integrated within SU-8 microfluidic networks. The use of a semi-porous, silicon rich, silicon nitride structural layer allows rapid release of the sacrificial silicon dioxidemore » during the nanochannel fabrication. Nanochannel openings that form the interface to biological samples are customized using focused ion beam milling. The compatibility of these interfaces with on-chip microbial culture is demonstrated.« less

  12. Nanofluidic interfaces in microfluidic networks

    SciTech Connect

    Millet, Larry J.; Doktycz, Mitchel John; Retterer, Scott T.

    2015-09-24

    The integration of nano- and microfluidic technologies enables the construction of tunable interfaces to physical and biological systems across relevant length scales. The ability to perform chemical manipulations of miniscule sample volumes is greatly enhanced through these technologies and extends the ability to manipulate and sample the local fluidic environments at subcellular, cellular and community or tissue scales. Here we describe the development of a flexible surface micromachining process for the creation of nanofluidic channel arrays integrated within SU-8 microfluidic networks. The use of a semi-porous, silicon rich, silicon nitride structural layer allows rapid release of the sacrificial silicon dioxide during the nanochannel fabrication. Nanochannel openings that form the interface to biological samples are customized using focused ion beam milling. The compatibility of these interfaces with on-chip microbial culture is demonstrated.

  13. Interfacing with the Computational Brain

    PubMed Central

    Jackson, Andrew; Fetz, Eberhard E.

    2012-01-01

    Neuroscience is just beginning to understand the neural computations that underlie our remarkable capacity to learn new motor tasks. Studies of natural movements have emphasized the importance of concepts such as dimensionality reduction within hierarchical levels of redundancy, optimization of behavior in the presence of sensorimotor noise and internal models for predictive control. These concepts also provide a framework for understanding the improvements in performance seen in myoelectric-controlled interface (MCI) and brain-machine interface (BMI) paradigms. Recent experiments reveal how volitional activity in the motor system combines with sensory feedback to shape neural representations and drives adaptation of behavior. By elucidating these mechanisms, a new generation of intelligent interfaces can be designed to exploit neural plasticity and restore function after neurological injury. PMID:21659037

  14. Conjugated Polymer Surfaces and Interfaces

    NASA Astrophysics Data System (ADS)

    Salaneck, W. R.; Stafstrom, S.; Brédas, J. L.

    2003-10-01

    The authors illustrate the basic physics and materials science of conjugated polymers and their interfaces, particularly, but not exclusively, as they are applied to polymer-based light emitting diodes. The approach is to describe the basic physical and associated chemical principles that apply to these materials, which in many instances are different from those that apply to their inorganic counterparts. The main aim of the authors is to highlight specific issues and properties of polymer surfaces and interfaces that are relevant in the context of the emerging field of polymer-based electronics in general, and polymer-based light emitting diodes in particular. Both theoretical and experimental methods used in the study of these systems are discussed. This book will be of interest to graduate students and research workers in departments of physics, chemistry, electrical engineering and materials sciences studying polymer surfaces and interfaces and their application in polymer-based electronics.

  15. Swimming bacteria at complex interfaces

    NASA Astrophysics Data System (ADS)

    Lopez, Diego; Lauga, Eric

    2013-11-01

    Swimming microorganisms such as bacteria often move in confined geometries. Such confinement can be caused by the presence of solid boundaries, free surfaces, or liquid interfaces. It is well established that confinement affects significantly locomotion, generating additional forces and torques on the bacteria. In the presence of a solid boundary (imposing a no-slip condition), microorganisms using helical propulsion undergo circular motion (clockwise in the case of E. coli). Conversely, close to a free (no-shear) surface the circular motion is reversed. However, realistic interfaces are complex, and experimental results do not always agree with theoretical predictions. In this work, we show, using analytical modeling, how different complex interfaces affect a nearby bacterium and modify its swimming kinematics. IUSTI UMR 7343, Polytech Marseille, France.

  16. Usable Interface Design for Everyone

    NASA Astrophysics Data System (ADS)

    de Castro Lozano, Carlos; Salcines, Enrique García; Sainz de Abajo, Beatriz; Burón Fernández, F. Javier; Ramírez, José Miguel; Recellado, José Gabriel Zato; Montoya, Rafael Sanchez; Bell, John; Marin, Francisco Alcantud

    When designing "interfaces for everyone" for interactive systems, it is important to consider factors such as cost, the intended market, the state of the environment, etc. User interfaces are fundamental for the developmental process in any application, and its design must be contemplated from the start. Of the distinct parts of a system (hardware and software), it is the interface that permits the user access to computer resources. The seven principles of "Universal Design" or "Design for Everyone" focus on a universal usable design, but at the same time acknowledge the influences of internal and external factors. Structural changes in social and health services could provide an increase in the well-being of a country's citizens through the use of self-care programming and proactive management/prevention of disease. Automated home platforms can act as an accessibility instrument which permits users to avoid, compensate, mitigate, or neutralize the deficiencies and dependencies caused by living alone.

  17. Multi-robot control interface

    DOEpatents

    Bruemmer, David J.; Walton, Miles C.

    2011-12-06

    Methods and systems for controlling a plurality of robots through a single user interface include at least one robot display window for each of the plurality of robots with the at least one robot display window illustrating one or more conditions of a respective one of the plurality of robots. The user interface further includes at least one robot control window for each of the plurality of robots with the at least one robot control window configured to receive one or more commands for sending to the respective one of the plurality of robots. The user interface further includes a multi-robot common window comprised of information received from each of the plurality of robots.

  18. Trends in accelerator control systems

    SciTech Connect

    Crowley-Milling, M.C.

    1984-04-01

    Over the years, we have seen a revolution in control systems that has followed the ever decreasing cost of computer power and memory. It started with the data gathering, when people distrusted the computer to perform control actions correctly, through the stage of using a computer to perform control actions correctly, through the stage of using a computer system to provide a convenient remote look and adjust facility, to the present day, when more and more emphasis is being placed on using a computer system to simulate or model all or parts of the accelerator, feed in the required performance and calling for the computers to set the various parameters and then measure the actual performance, with iteration if necessary. The progress that has been made in the fields of architecture, communications, computers, interface, software design and operator interface is reviewed.

  19. Using SPC and Trending to Reduce FOD

    NASA Technical Reports Server (NTRS)

    Wallentine, Mark

    2005-01-01

    This paper presents viewgraphs showing the trends and Statistical Process Control (SPC) used by ATK-Thiokol to reduce Foreign Object Debris (FOD). Some of the topics include: 1) Amazing Little Known and Less Used Facts; 2) Critical Nature of Rocket Manufacturing; 3) ATK-Thiokol Foreign Object Debris (FOD) Philosophy; 4) FOD Trending and SPC at ATK-Thiokol Philosophy; 5) Trending and Statistical Process Control (SPC) Basic Philosophy; 6) Trending and Statistical Process Control (SPC); 7) FOD Trending and SPC at ATK-Thiokol Trending; 8) FOD Trending and SPC at ATK-Thiokol Specific Instances; 9) FOD Trending and SPC at ATK-Thiokol Contamination in Air; and 10) FOD Trending and SPC at ATK-Thiokol Nitrogen Dewpoint.

  20. Correlation Between Thermal Interface Conductance and Mechanical Adhesion Strength in Cu-Coated Glassy Carbon

    NASA Astrophysics Data System (ADS)

    Pelzl, J.; Kijamnajsuk, P.; Chirtoc, M.; Horny, N.; Eisenmenger-Sittner, C.

    2015-09-01

    The influence of defective areas in the interface on the correlation between the thermal interface conductance and the mechanical adhesion strength was investigated on as-prepared and heat-treated samples of copper-coated carbon flat specimens with different bonding layers between the copper film and the substrate. The thermal interface conductance was determined by frequency-domain photothermal radiometry. The mechanical adhesion strength of the film coating was deduced from pull-off experiments. The imperfect interfaces were modeled by two different values for the thermal interface conductance, G1 and G2, which co-exist at different areas on the interface and are weighted according to their areas, A1 and A2. The model parameters were determined by adjusting the frequency dependence of the normalized phases and phase differences of the PTR signals from as-prepared and heat-treated samples. The total thermal conductance of the interface was found to exhibit a correlation with the adhesion strength for most of the heat-treated samples whereas, among the as-prepared samples, considerable deviations from such a trend exist. The observations are explained by the impact of supplementary stress on the adhesion strength measurements which are due to the strain developed during the preparation process at the interface. The interfacial stress and strain are mostly released during thermal annealing. A semi-empirical formula was developed that describes the impact of the defective areas on the adhesion strength using the experimentally determined thermal model parameters.

  1. Interface design for health care environments: the role of cognitive science.

    PubMed Central

    Patel, V. L.; Kushniruk, A. W.

    1998-01-01

    An important challenge in the development of computer-based health care environments is the design of effective user interfaces. In this paper we consider a number of aspects of interface design related to the study of human-computer interaction from a cognitive perspective. It is argued that user interfaces must be designed with consideration of the information requirements, cognitive capabilities and limitations of the end users. Greater concern for fundamental research in design of user interfaces is also needed to complement short-term goals and approaches to improving user interfaces. Towards these objectives, several emerging trends are beginning to have an important impact in the design of health care interfaces. This includes the recognition of the need for iterative design and evaluation of user interfaces, applying theoretical frameworks and methods from cognitive science. An understanding of distributed as well as individual cognition will also become critical in the development of effective user interfaces as access to health care systems becomes increasingly widespread. PMID:9929179

  2. Anthropomorphizing the User Interface: A Case for Interface Guides.

    ERIC Educational Resources Information Center

    Jones, Marshall G.

    Anthropomorphism can be defined as the attribution of human characteristics or behavior to inanimate objects. People give names to their automobiles and computers as a way to relate to complicated pieces of technology that they use regularly, but do not fully understand. Software designers may claim that their interfaces are intuitive, but in…

  3. Immersed interface methods. Final report

    SciTech Connect

    LeVeque, R.J.; Adams, L.M.; Bube, K.P.

    1996-11-01

    Cartesian grid methods encompass a wide variety of techniques used to solve partial differential equations in more than one space dimension on uniform Cartesian grids even when the underlying geometry is complex and not aligned with the grid. The authors` groups work on Immersed Interface Methods (IIM) was originally motivated by the desire to understand and improve the ``Immersed Boundary Method``, developed by Charles Peskin to solve incompressible Navier-Stokes equations in complicated geometries with moving elastic boundaries. This report briefly discusses the development of the Immersed Interface Methods and gives examples of application of the method in solving several partial differential equations.

  4. The dynamic interface: A review

    PubMed Central

    Jain, Rachna; Kapoor, Daljit

    2015-01-01

    The implant-to-tissue interface is an extremely dynamic region of interaction. Generally, a surgical procedure is performed on a patient to insert a foreign material into the bone, and the body is called on to “heal” the wound. The time schedule crucial for a healing process that is expected to result in restitution ad integrum must be determined with respect to the condition of the individual patient and tissue to be treated. There are various factors responsible for the formation of an adequate bone–implant interface. A comprehensive review of the response of bone to implant is described. PMID:26539385

  5. User interfaces to expert systems

    SciTech Connect

    Agarwal, A.; Emrich, M.L.

    1988-10-01

    Expert Systems are becoming increasingly popular in environments where the user is not well versed in computers or the subject domain. They offer expert advice and can also explain their lines of reasoning. As these systems are applied to highly technical areas, they become complex and large. Therefore, User Systems Interfaces (USIs) become critical. This paper discusses recent technologies that can be applied to improved user communication. In particular, bar menus/graphics, mouse interfaces, touch screens, and voice links will be highlighted. Their applications in the context of SOFTMAN (The Software Manager Apprentice) a knowledge-based system are discussed. 18 refs., 2 figs.

  6. Chemical reactions at aqueous interfaces

    NASA Astrophysics Data System (ADS)

    Vecitis, Chad David

    2009-12-01

    Interfaces or phase boundaries are a unique chemical environment relative to individual gas, liquid, or solid phases. Interfacial reaction mechanisms and kinetics are often at variance with homogeneous chemistry due to mass transfer, molecular orientation, and catalytic effects. Aqueous interfaces are a common subject of environmental science and engineering research, and three environmentally relevant aqueous interfaces are investigated in this thesis: 1) fluorochemical sonochemistry (bubble-water), 2) aqueous aerosol ozonation (gas-water droplet), and 3) electrolytic hydrogen production and simultaneous organic oxidation (water-metal/semiconductor). Direct interfacial analysis under environmentally relevant conditions is difficult, since most surface-specific techniques require relatively `extreme' conditions. Thus, the experimental investigations here focus on the development of chemical reactors and analytical techniques for the completion of time/concentration-dependent measurements of reactants and their products. Kinetic modeling, estimations, and/or correlations were used to extract information on interfacially relevant processes. We found that interfacial chemistry was determined to be the rate-limiting step to a subsequent series of relatively fast homogeneous reactions, for example: 1) Pyrolytic cleavage of the ionic headgroup of perfluorooctanesulfonate (PFOS) and perfluorooctanoate (PFOA) adsorbed to cavitating bubble-water interfaces during sonolysis was the rate-determining step in transformation to their inorganic constituents carbon monoxide, carbon dioxide, and fluoride; 2) ozone oxidation of aqueous iodide to hypoiodous acid at the aerosol-gas interface is the rate-determining step in the oxidation of bromide and chloride to dihalogens; 3) Electrolytic oxidation of anodic titanol surface groups is rate-limiting for the overall oxidation of organics by the dichloride radical. We also found chemistry unique to the interface, for example: 1

  7. Fluorescent fluid interface position sensor

    DOEpatents

    Weiss, Jonathan D.

    2004-02-17

    A new fluid interface position sensor has been developed, which is capable of optically determining the location of an interface between an upper fluid and a lower fluid, the upper fluid having a larger refractive index than a lower fluid. The sensor functions by measurement, of fluorescence excited by an optical pump beam which is confined within a fluorescent waveguide where that waveguide is in optical contact with the lower fluid, but escapes from the fluorescent waveguide where that waveguide is in optical contact with the upper fluid.

  8. Interface standards for computer equipment

    NASA Technical Reports Server (NTRS)

    1976-01-01

    The ability to configure data systems using modules provided by independent manufacturers is complicated by the wide range of electrical, mechanical, and functional characteristics exhibited within the equipment provided by different manufacturers of computers, peripherals, and terminal devices. A number of international organizations were and still are involved in the creation of standards that enable devices to be interconnected with minimal difficulty, usually involving only a cable or data bus connection that is defined by the standard. The elements covered by an interface standard are covered and the most prominent interface standards presently in use are identified and described.

  9. Osteoclasts in the interface with electrospun hydroxyapatite.

    PubMed

    Pasuri, Jenni; Holopainen, Jani; Kokkonen, Hanna; Persson, Maria; Kauppinen, Kyösti; Lehenkari, Petri; Santala, Eero; Ritala, Mikko; Tuukkanen, Juha

    2015-11-01

    Electrospinning is a method to produce lightweight, resorbable and bioinspired scaffolds for tissue engineering. Here we investigated the influence of electrospun hydroxyapatite fibers (HA) on macrophages and osteoclasts. A mouse macrophage cell line (RAW 264.7) and human bone marrow derived primary osteoclasts (hOC) were cultured with electrospun HA fibers embedded in Matrigel. Cell morphology and the secretion of pro-inflammatory cytokines (IL-6 and TNF-α) were analyzed using macrophages. Both fluorescent microscopy and scanning electron microscopy indicated that the cell morphology differed on the various materials (HA fibers on Matrigel, pure Matrigel and a glass control). Control macrophages were activated with bacterial lipopolysaccharide (LPS) but electrospun HA did not provoke an inflammatory response. Cytokine secretion detected with enzyme-linked immunosorbent assay (ELISA) also supported this observation. LPS, but not HA fibers, stimulated TNF-α and IL-6 secretion by macrophages at the 2 day time point. After 4 days in culture there was an increasing trend in cytokine secretion in the HA fiber samples. Human bone marrow myeloid precursor cells were able to fuse and differentiate on the fibrous mineral scaffold to form functional multinuclear osteoclasts that were able to resorb the HA nanofibers. This indicates that osteoclasts do not necessarily need a continuous bone surface but osteoclast ruffled border membranes can form a resorption interface with a fibrous mineral scaffold. PMID:26342323

  10. Trends in Mobile Application Development

    NASA Astrophysics Data System (ADS)

    Holzer, Adrian; Ondrus, Jan

    Major software companies, such as Apple and Google, are disturbing the relatively safe and established actors of the mobile application business. These newcomers have caused significant structural changes by imposing and enforcing their own rules for the future of mobile application development. The implications of these changes do not only concern the mobile network operators and mobile phone manufacturers. This changed environment also brings additional opportunities and constraints for current mobile application developers. Therefore, developers need to assess what their options are and how they can take advantages of these current trends. In this paper, we take a developer’s perspective in order to explore how the structural changes will influence the mobile application development markets. Moreover, we discuss what aspects developers need to take into account in order to position themselves within the current trends.

  11. TRENDS IN SENESCENT LIFE EXPECTANCY

    PubMed Central

    Bongaarts, John

    2009-01-01

    The distinction between senescent and non-senescent mortality proves to be very valuable for describing and analyzing age patterns of death rates. Unfortunately, standard methods for estimating these mortality components are lacking. The first part of this study discusses alternative methods for estimating background and senescent mortality among adults and proposes a simple approach based on death rates by causes of death. The second part examines trends in senescent life expectancy (i.e. the life expectancy implied by senescent mortality) and compares them with trends in conventional longevity indicators between 1960 and 2000 in a group of 17 developed countries with low mortality. Senescent life expectancy for females rises at an average rate of 1.54 years per decade between 1960 and 2000 in these countries. The shape of the distribution of senescent deaths by age remains relatively invariant while the entire distribution shifts over time to higher ages as longevity rose. PMID:19851933

  12. Developmental trends in adaptive memory.

    PubMed

    Otgaar, Henry; Howe, Mark L; Smeets, Tom; Garner, Sarah R

    2014-01-01

    Recent studies have revealed that memory is enhanced when information is processed for fitness-related purposes. The main objective of the current experiments was to test developmental trends in the evolutionary foundation of memory using different types of stimuli and paradigms. In Experiment 1, 11-year-olds and adults were presented with neutral, negative, and survival-related DRM word lists. We found a memory benefit for the survival-related words and showed that false memories were more likely to be elicited for the survival-related word lists than for the other lists. Experiment 2 examined developmental trends in the survival processing paradigm using neutral, negative, and survival-related pictures. A survival processing advantage was found for survival-related pictures in adults, for negative pictures in 11/12-year-olds, and for neutral pictures in 7/8-year-olds. In Experiment 3, 11/12-year-olds and adults had to imagine the standard survival scenario or an adapted survival condition (or pleasantness condition) that was designed to reduce the possibilities for elaborative processing. We found superior memory retention for both survival scenarios in children and adults. Collectively, our results evidently show that the survival processing advantage is developmentally invariant and that certain proximate mechanisms (elaboration and distinctiveness) underlie these developmental trends. PMID:23521432

  13. Modern population trends in Bangladesh.

    PubMed

    Abul-basher, M M

    1985-01-01

    Population growth trends in Bangladesh in the 1871-1981 period were analyzed, with emphasis on fertility and mortality differentials, to provide a basis for population planning. Following proclamation of British Imperial Rule in 1857, mortality rates in Bangladesh began to decline as a result of preventive measures against natural disasters such as draught and famine, but the fertility rate remained unaltered. The demographic pattern was unstable over time, reflecting the impact of the influenza epidemic of 1918-19, war, migration, and economic development. Population growth accelerated greatly during the 1961-74 period, when industrialization emerged and job opportunities were created in the urban centers. Economic hardship, food shortages, and the introduction of family planning curbed urban growth drastically and total growth to some extent in 1974-81. On the average, growth has been higher in the Dhaka and Chittagong Divisions of Bangladesh than in the Khulna and Rajshahi Divisions. Differences in population growth among the regions are attributable largely to internal and external migration. The regression polynomial model best fits past population trends in Bangladesh and can reproduce the observed population by 99.60%. This polynomial is most suitable for graduation and prediction of population trends. PMID:12280834

  14. Trends in international electricity markets

    SciTech Connect

    Toner, P.; Vera, I.

    1995-12-31

    The electric power industry is expected to continue experiencing significant changes throughout the beginning of the next century as the world becomes increasingly dependent on electricity. Three major trends characterize the industry worldwide: growth in demand, changes in its structure, and shifts in generation fuel mix. Electricity will remain the fastest growing form of end-use energy worldwide throughout 2010. Non-OECD countries will experience the largest growth in electricity demand as governments attempt to satisfy electricity requirements indispensable to ensure economic development. Increasing world dependence on electricity is accompanied by dramatic changes in the electric power industry in key areas such as regulation structure, and ownership. These changes imply more competitive environments and greater efficiency. Another important trend expected to continue is the shifts in the fuel mix of world electricity generation. The next 15 years will be characterized by increasing shares of natural gas and renewable fuel consumption while nuclear, oil and coal shares will decrease. This paper summarizes major trends in international electricity markets and describes important developments in world regions such as North America, Europe, Asia and Central and South America.

  15. [Somatic trends in Moscow children].

    PubMed

    Fedotova, T K

    2008-01-01

    Somatic trends was considered in Moscow children in a wide age range of 3 to 17 years, by attracting several series of data since the 1990s. To have the greater informative value in data analyses, investigators use the normalized rather than absolute values of various anthropometric signs in the considered data series versus the 2005 data in the age range of 3 to 7 years and versus the 1980s data in the range of 8 to 17 years. The overall somatic tendency in Moscow children aged 3 to 17 years in past decades is towards a transverse body development and some dolichomorphism with a continuous increase in longitudinal skeletal sizes. These processes are most pronounced in girls than in boys and preschool children than in school ones. The stronger somatic trend in preschool children can be associated with that they are, as compared with schoolchildren, neophytes in the compact anthropogenic space and have been, in the past decades, involved in the neurogenic growth stimulators world (a computer and computer games, unlimited TV seeing, inevitable intensive preparation for new-generation schools--increased intellectual-load lyceums and colleges). The decreased transverse body development and overall constitution asthenization seem to result from somatic muscular component abatement with no clear trends in adipopexis in schoolchildren and with an increase in subcutaneous fat deposition in preschool children. PMID:18507175

  16. Trends in Culturally Relevant Interface Design Features for Latino Web Site Users

    ERIC Educational Resources Information Center

    Sachau, Lori L.; Hutchinson, Susan R.

    2012-01-01

    There is a lack of published research on designing Web-based instruction for the adult U.S. Latino population. Instructional designers need guidance on how to design culturally relevant learning environments for this audience, particularly for Latino people from Mexican heritage. The authors used content analysis to investigate the extent to which…

  17. Trends and Opportunities at the Interface of Experiment and Simulation in Micromechanics of Polycrystalline Solids

    SciTech Connect

    Dawson, Paul

    2008-08-06

    Polycrystalline solids have been used as structural materials for centuries. In spite of this longevity, the quantitative connection between a material's microstructure and its derivative mechanical properties remains remarkably poor, even for such familiar materials as the alloys of aluminum steel and titanium. However, recent advances in methods for making spatially-resolved diffraction measurements and simulating finely discretized virtual material specimens present collective opportunities to substantially change this. The simulations predict spatially-resolved fields of the mechanical behaviors. These, in turn, coincide with emerging diffraction data at points throughout the material that characterize the evolution of its microstructural state, and data that quantify its mechanical properties through the application of in situ loading. Such data are only loosely integrated and challenge researchers to use them comprehensively and effectively in concert with modeling. The computer infrastructure needed to support a high level of coordination between experiments and simulations will be discussed.

  18. WSR-88D Cell Trends

    NASA Technical Reports Server (NTRS)

    Wheeler, Mark M.

    1998-01-01

    This report documents the Applied Meteorology Unit's evaluation of the Cell Trends display as a tool for radar operators to use in their evaluation of storm cell strength. The objective of the evaluation is to assess the utility of the WSR-88D graphical Cell Trends display for local radar cell interpretation in support of the 45th Weather Squadron (45 WS), Spaceflight Meteorology Group (SMG), and National Weather Service (NWS) Melbourne (MLB) operational requirements. The analysis procedure was to identify each cell and track the maximum reflectivity, height of maximum reflectivity, storm top, storm base, hail and severe hail probability, cell-based Vertically Integrated Liquid (VIL) and core aspect ratio using WATADS Build 9.0 cell trends information. One problem noted in the analysis phase was that the Storm Cell Identification and Tracking (SCIT) algorithm had a difficult time tracking the small cells associated with the Florida weather regimes. The analysis indicated numerous occasions when a cell track would end or an existing cell would be give a new ID in the middle of its life cycle. This investigation has found that most cells, which produce hail or microburst events, have discernable Cell Trends signatures. Forecasters should monitor the PUP's Cell Trends display for cells that show rapid (1 scan) changes in both the heights of maximum reflectivity and cell-based VIEL. It is important to note that this a very limited data set (four case days). Fifty-two storm cells were analyzed during those four days. The above mentioned t=ds, increase in the two cell attributes for hail events and decrease in the two cell attributes for wind events were noted in most of the cells. The probability of detection was 88% for both events. The False Alarm Rate (FAR) was a 36% for hail events and a respectable 25% for microburst events. In addition the Heidke Skill Score (HSS) is 0.65 for hail events and 0.67 for microburst events. For random forecast the HSS is 0 and that a

  19. Intelligent interfaces for expert systems

    NASA Technical Reports Server (NTRS)

    Villarreal, James A.; Wang, Lui

    1988-01-01

    Vital to the success of an expert system is an interface to the user which performs intelligently. A generic intelligent interface is being developed for expert systems. This intelligent interface was developed around the in-house developed Expert System for the Flight Analysis System (ESFAS). The Flight Analysis System (FAS) is comprised of 84 configuration controlled FORTRAN subroutines that are used in the preflight analysis of the space shuttle. In order to use FAS proficiently, a person must be knowledgeable in the areas of flight mechanics, the procedures involved in deploying a certain payload, and an overall understanding of the FAS. ESFAS, still in its developmental stage, is taking into account much of this knowledge. The generic intelligent interface involves the integration of a speech recognizer and synthesizer, a preparser, and a natural language parser to ESFAS. The speech recognizer being used is capable of recognizing 1000 words of connected speech. The natural language parser is a commercial software package which uses caseframe instantiation in processing the streams of words from the speech recognizer or the keyboard. The systems configuration is described along with capabilities and drawbacks.

  20. Coal-rock interface detector

    NASA Technical Reports Server (NTRS)

    Rose, S. D.; Crouch, C. E.; Jones, E. W. (Inventor)

    1979-01-01

    A coal-rock interface detector is presented which employs a radioactive source and radiation sensor. The source and sensor are separately and independently suspended and positioned against a mine surface of hydraulic pistons, which are biased from an air cushioned source of pressurized hydraulic fluid.

  1. Microcomputer to Multichannel Analyzer Interface.

    ERIC Educational Resources Information Center

    Metz, Roger N.

    1982-01-01

    Describes a microcomputer-based multichannel analyzer (MCA) in which the front end is connected to a microcomputer through a custom interface. Thus an MCA System of 1024 channel resolution, programmable in Basic rather than in machine language and having moderate cost, is achieved. (Author/SK)

  2. Graphical fiber shaping control interface

    NASA Astrophysics Data System (ADS)

    Basso, Eric T.; Ninomiya, Yasuyuki

    2016-03-01

    In this paper, we present an improved graphical user interface for defining single-pass novel shaping techniques on glass processing machines that allows for streamlined process development. This approach offers unique modularity and debugging capability to researchers during the process development phase not usually afforded with similar scripting languages.

  3. Strength Development At Thermoset Interfaces

    NASA Astrophysics Data System (ADS)

    Wool, R. P.; Raghavan, J.

    1997-03-01

    A basic set of 10 polymer-polymer matrix interfaces has been identified to play a vital role in the technical apects of composite manufacturing, repair, recycling, welding and joining of thermoset matrix composites. A model vinyl ester resin was used in compact tension experiments with side-A and side-B, to determine the fracture energy G. Surprisingly, G was very small compared to the virgin strength (co-cured side-A with side-B) when liquid resin in side A was cured against previously cured side-B. Apparently, the chain extension reactions were not sufficient to achieve sufficient molecular connectivity at the interface. Several methods of repair were explored for fractured specimens, the most successful being the use of polystyrene connector chains at the interface with a molecular weight near M = 200,000. However, the complete virgin strength was never recovered, despite several chemical treatments, including crack healing. Strength results for all 10 interfaces, subjected to a variety of chemical treatments and surface preparation techniques are presented.

  4. Gluing Soft Interfaces by Nanoparticles

    NASA Astrophysics Data System (ADS)

    Cao, Zhen; Dobrynin, Andrey

    Using a combination of the molecular dynamics simulations and scaling analysis we studied reinforcement of interface between two soft gel-like materials by spherical nanoparticles. Analysis of the simulations shows that the depth of penetration of a nanoparticle into a gel is determined by a balance of the elastic energy of the gel and nanoparticle deformations and the surface energy of nanoparticle/gel interface. In order to evaluate work of adhesion of the reinforced interface, the potential of mean force for separation of two gels was calculated. These simulations showed that the gel separation proceeds through formation of necks connecting nanoparticle with two gels. The shapes of the necks are controlled by a fine interplay between nanoparticle/gel surface energies and elastic energy of the neck deformation. Our simulations showed that by introducing nanoparticles at soft interfaces, the work required for separation of two gels could be 10-100 times larger than the work of adhesion between two gels without nanoparticle reinforcement. These results provide insight in understanding the mechanism of gluing soft gels and biological tissues by nano- and micro-sized particles. NSF DMR-1409710.

  5. Willow: a uniform search interface.

    PubMed Central

    Ketchell, D S; Freedman, M M; Jordan, W E; Lightfoot, E M; Heyano, S; Libbey, P A

    1996-01-01

    The objective of the Willow Project is to develop a uniform search interface that allows a diverse community of users to retrieve information from heterogeneous network-based information resources. Willow separates the user interface from the database management or information retrieval system. It provides a graphic user interface to a variety of information resources residing on diverse hosts, and using different search engines and idiomatic query languages through networked-based client-server and Transmission Control Protocol/Internet Protocol (TCP/IP) protocols. It is based on a "database driver'' model, which allows new database hosts to be added without altering Willow itself. Willow employs a multimedia extension mechanism to launch external viewers to handle data in almost any form. Drivers are currently available for a local BRS/SEARCH system and the Z39.50 protocol. Students, faculty, clinicians, and researchers at the University of Washington are currently offered 30 local and remote databases via Willow. They conduct more than 250,000 sessions a month in libraries, medical centers and clinics, laboratories, and offices, and from home. The Massachusetts Institute of Technology is implementing Willow as its uniform search interface to Z39.50 hosts. PMID:8750388

  6. Interface Reconstruction with Directional Walking

    SciTech Connect

    Yao, J

    2009-05-22

    Young's interface reconstruction with three-dimensional arbitrary mesh, in general, is rather tedious to implement compared to the case of a regular mesh. The main difficulty comes from the construction of a planar facet that bounds a certain volume inside a cell. Unlike the five basic configurations with a Cartesian mesh, there can be a great number of different configurations in the case of a general mesh. We represent a simple method that can derive the topology/geometry of the intersection of arbitrary planar objects in a uniform way. The method is based on a directional walking on the surface of objects, and links the intersection points with the paths of the walking naturally defining the intersection of objects. The method works in both two and three dimensions. The method does not take advantage of convexity, thus decomposition of an object is not necessary. Therefore, the solution with this method will have a reduced number of edges and less data storage, compared with methods that use shape decomposition. The treatment is general for arbitrary polyhedrons, and no look-up tables are needed. The same operation can easily be extended for curved geometry. The implementation of this new algorithm shall allow the interface reconstruction on an arbitrary mesh to be as simple as it is on a regular mesh. Furthermore, we exactly compute the integral of partial cell volume bounded by quadratic interface. Therefore, interface reconstruction with higher than second order accuracy can be achieved on an arbitrary mesh.

  7. Miniaturized neural interfaces and implants

    NASA Astrophysics Data System (ADS)

    Stieglitz, Thomas; Boretius, Tim; Ordonez, Juan; Hassler, Christina; Henle, Christian; Meier, Wolfgang; Plachta, Dennis T. T.; Schuettler, Martin

    2012-03-01

    Neural prostheses are technical systems that interface nerves to treat the symptoms of neurological diseases and to restore sensory of motor functions of the body. Success stories have been written with the cochlear implant to restore hearing, with spinal cord stimulators to treat chronic pain as well as urge incontinence, and with deep brain stimulators in patients suffering from Parkinson's disease. Highly complex neural implants for novel medical applications can be miniaturized either by means of precision mechanics technologies using known and established materials for electrodes, cables, and hermetic packages or by applying microsystems technologies. Examples for both approaches will be introduced and discussed. Electrode arrays for recording of electrocorticograms during presurgical epilepsy diagnosis have been manufactured using approved materials and a marking laser to achieve an integration density that is adequate in the context of brain machine interfaces, e.g. on the motor cortex. Microtechnologies have to be used for further miniaturization to develop polymer-based flexible and light weighted electrode arrays to interface the peripheral and central nervous system. Polyimide as substrate and insulation material will be discussed as well as several application examples for nerve interfaces like cuffs, filament like electrodes and large arrays for subdural implantation.

  8. Brush/Fin Thermal Interfaces

    NASA Technical Reports Server (NTRS)

    Knowles, Timothy R.; Seaman, Christopher L.; Ellman, Brett M.

    2004-01-01

    Brush/fin thermal interfaces are being developed to increase heat-transfer efficiency and thereby enhance the thermal management of orbital replaceable units (ORUs) of electronic and other equipment aboard the International Space Station. Brush/fin thermal interfaces could also be used to increase heat-transfer efficiency in terrestrial electronic and power systems. In a typical application according to conventional practice, a replaceable heat-generating unit includes a mounting surface with black-anodized metal fins that mesh with the matching fins of a heat sink or radiator on which the unit is mounted. The fins do not contact each other, but transfer heat via radiation exchange. A brush/fin interface also includes intermeshing fins, the difference being that the gaps between the fins are filled with brushes made of carbon or other fibers. The fibers span the gap between intermeshed fins, allowing heat transfer by conduction through the fibers. The fibers are attached to the metal surfaces as velvet-like coats in the manner of the carbon fiber brush heat exchangers described in the preceding article. The fiber brushes provide both mechanical compliance and thermal contact, thereby ensuring low contact thermal resistance. A certain amount of force is required to intermesh the fins due to sliding friction of the brush s fiber tips against the fins. This force increases linearly with penetration distance, reaching 1 psi (6.9 kPa) for full 2-in. (5.1 cm) penetration for the conventional radiant fin interface. Removal forces can be greater due to fiber buckling upon reversing the sliding direction. This buckling force can be greatly reduced by biasing the fibers at an angle perpendicularly to the sliding direction. Means of containing potentially harmful carbon fiber debris, which is electrically conductive, have been developed. Small prototype brush/fin thermal interfaces have been tested and found to exhibit temperature drops about onesixth of that of conventional

  9. Thermal Performance and Reliability Characterization of Bonded Interface Materials (BIMs): Preprint

    SciTech Connect

    DeVoto, D.; Paret, P.; Mihalic, M.; Narumanchi, S.; Bar-Cohen, A.; Matin, K.

    2014-08-01

    Thermal interface materials are an important enabler for low thermal resistance and reliable electronics packaging for a wide array of applications. There is a trend towards bonded interface materials (BIMs) because of their potential for low thermal resistivity (< 1 mm2K/W). However, BIMs induce thermomechanical stresses in the package and can be prone to failures and integrity risks. Deteriorated interfaces can result in high thermal resistance in the package and degradation and/or failure of the electronics. DARPA's Thermal Management Technologies program has addressed this challenge, supporting the development of mechanically-compliant, low resistivity nano-thermal interface (NTI) materials. In this work, we describe the testing procedure and report the results of NREL's thermal performance and reliability characterization of an initial sample of four different NTI-BIMs.

  10. A sharp interface method for SPH

    NASA Astrophysics Data System (ADS)

    Zhang, Mingyu; Deng, Xiao-Long

    2015-12-01

    A sharp interface method (SIM) for smoothed particle hydrodynamics (SPH) has been developed to simulate two-phase flows with clear interfaces. The level set function is introduced to capture the interface implicitly. The interface velocity is used to evolve the level set function. The smoothness of the level set function helps to improve the accuracy of the interface curvature. Material discontinuity across the interface is dealt with by the ghost fluid method. The interface states are calculated by applying the jump conditions and are extended to the corresponding ghost fluid particles. The ghost fluid method helps to get smooth and stable calculation near the interface. The performance of the developed method is validated by benchmark tests. The developed SIM for SPH can be applied to simulate low speed two-phase flows of high density ratios with clear interface accurately and stably.

  11. MIB Galerkin method for elliptic interface problems.

    PubMed

    Xia, Kelin; Zhan, Meng; Wei, Guo-Wei

    2014-12-15

    Material interfaces are omnipresent in the real-world structures and devices. Mathematical modeling of material interfaces often leads to elliptic partial differential equations (PDEs) with discontinuous coefficients and singular sources, which are commonly called elliptic interface problems. The development of high-order numerical schemes for elliptic interface problems has become a well defined field in applied and computational mathematics and attracted much attention in the past decades. Despite of significant advances, challenges remain in the construction of high-order schemes for nonsmooth interfaces, i.e., interfaces with geometric singularities, such as tips, cusps and sharp edges. The challenge of geometric singularities is amplified when they are associated with low solution regularities, e.g., tip-geometry effects in many fields. The present work introduces a matched interface and boundary (MIB) Galerkin method for solving two-dimensional (2D) elliptic PDEs with complex interfaces, geometric singularities and low solution regularities. The Cartesian grid based triangular elements are employed to avoid the time consuming mesh generation procedure. Consequently, the interface cuts through elements. To ensure the continuity of classic basis functions across the interface, two sets of overlapping elements, called MIB elements, are defined near the interface. As a result, differentiation can be computed near the interface as if there is no interface. Interpolation functions are constructed on MIB element spaces to smoothly extend function values across the interface. A set of lowest order interface jump conditions is enforced on the interface, which in turn, determines the interpolation functions. The performance of the proposed MIB Galerkin finite element method is validated by numerical experiments with a wide range of interface geometries, geometric singularities, low regularity solutions and grid resolutions. Extensive numerical studies confirm the

  12. Technique for converting non-conforming hexahedral-to-hexahedral interfaces into conforming interfaces

    DOEpatents

    Staten, Matthew L.; Shepherd, Jason F.; Ledoux, Frank; Shimada, Kenji; Merkley, Karl G.; Carbonera, Carlos

    2013-03-05

    A technique for conforming an interface between a first mesh and a second mesh is disclosed. A first interface surface in the first mesh and a second interface surface in the second mesh residing along the interface are identified. The first and second interface surfaces are initially non-conforming along the interface. Chords within the first and second interface surfaces that fall within a threshold separation distance of each other are paired. Sheets having chords that reside within the first or second interface surfaces are recursively inserted into or extracted from one or both of the first and second meshes until all remaining chords within the first interface surface are paired with corresponding chords in the second interface surface and all remaining chords within the second interface surface are paired with corresponding chords in the first interface surface.

  13. Lessons learned from trend analysis of Shuttle Payload Processing problem reports

    NASA Technical Reports Server (NTRS)

    Heuser, Robert E.; Pepper, Richard E., Jr.; Smith, Anthony M.

    1989-01-01

    In the wake of the Challenger accident, NASA has placed an increasing emphasis on trend analysis techniques. These analyses provide meaningful insights into system and hardware status, and also develop additional lessons learned from historical data to aid in the design and operation of future space systems. This paper presents selected results from such a trend analysis study that was conducted on the problem report data files for the Shuttle Payload Processing activities. Specifically, the results shown are for the payload canister system which interfaces with and transfers payloads from their processing facilities to the orbiter.

  14. Rural Conditions and Trends, 1990-1994.

    ERIC Educational Resources Information Center

    Rural Conditions and Trends, 1994

    1994-01-01

    The five volumes of Rural Conditions and Trends for 1990-1994 contain information and statistical data on economic and social conditions and trends of interest to rural educators and researchers. Articles cover the following areas: macroeconomic trends; employment; unemployment; industry; earnings; income; poverty; population; national economic…

  15. Subgroup Achievement and Gap Trends: Vermont, 2010

    ERIC Educational Resources Information Center

    Center on Education Policy, 2010

    2010-01-01

    This paper profiles the student subgroup achievement and gap trends in Vermont for 2010. Vermont's demographic profile is such that achievement trends could only be determined for white, male and female, and low-income student subgroups. In grade 8 (the only grade in which subgroup trends were analyzed by achievement level), the white, low-income,…

  16. Subgroup Achievement and Gap Trends: Wyoming, 2010

    ERIC Educational Resources Information Center

    Center on Education Policy, 2010

    2010-01-01

    This paper profiles the student subgroup achievement and gap trends in Wyoming for 2010. Wyoming's demographic profile is such that achievement trends could only be determined for white, Latino, male and female, and low-income student subgroups. In grade 8 (the only grade in which subgroup trends were analyzed by achievement level), the white,…

  17. ACPYPE - AnteChamber PYthon Parser interfacE

    PubMed Central

    2012-01-01

    Background ACPYPE (or AnteChamber PYthon Parser interfacE) is a wrapper script around the ANTECHAMBER software that simplifies the generation of small molecule topologies and parameters for a variety of molecular dynamics programmes like GROMACS, CHARMM and CNS. It is written in the Python programming language and was developed as a tool for interfacing with other Python based applications such as the CCPN software suite (for NMR data analysis) and ARIA (for structure calculations from NMR data). ACPYPE is open source code, under GNU GPL v3, and is available as a stand-alone application at http://www.ccpn.ac.uk/acpype and as a web portal application at http://webapps.ccpn.ac.uk/acpype. Findings We verified the topologies generated by ACPYPE in three ways: by comparing with default AMBER topologies for standard amino acids; by generating and verifying topologies for a large set of ligands from the PDB; and by recalculating the structures for 5 protein–ligand complexes from the PDB. Conclusions ACPYPE is a tool that simplifies the automatic generation of topology and parameters in different formats for different molecular mechanics programmes, including calculation of partial charges, while being object oriented for integration with other applications. PMID:22824207

  18. PREFACE: TNT 2004: Trends in Nanotechnology

    NASA Astrophysics Data System (ADS)

    Correia, Antonio; Serena, Pedro A.; Saenz, Juan Jose; Welland, Mark; Reifenberger, Ron

    2005-05-01

    were awarded. We would like to thank all the participants for their assistance, as well as the authors for their written contributions. TNT2004 is the successful consequence of a coordinated effort from several institutions: PHANTOMS Foundation, Universidad Autónoma de Madrid, Consejo Superior de Investigaciones Científicas, Universidad Carlos III de Madrid, Universidad Complutense de Madrid, Universidad SEK, Universidad de Salamanca, CMP Científica, University of Cambridge/IRC, NIMS, Nanotechnology Research Institute (NRI), University of Purdue, Georgia Institute of Technology and IEEE. In addition, we are indebted to the following institutions, companies and government agencies for their help and financial support: PHANTOMS Network/European Commission (IST/FET Program), NASA, Air Force Office of Scientific Research, Motorola, IoP, iNANO, NSERC/CRSNG (Nano Innovation Platform), Junta de Castilla y León, Donostia International Physics Center, Sociedad de Microscopía Española (SME), Nanonet, Wiley-VCH, Raith GmbH, The European Office of Aerospace Research and Development (EOARD), The Office of Naval Research International Field Office (ONRIFO), World Scientific and Imperial College Press, Ministerio de Educación y Ciencia, Parque Científico de Barcelona and Parque Científico de Madrid. We would also like to thank the following companies for their participation: NanoTec, Raith GmbH, Scientec, BFI Optilas, Schaefer, Interface Ltd, World Scientific and Imperial College Press and Institute of Physics Publishing. We invite readers of this special issue to join us at the next `Trends in Nanotechnology' conference, which will take place at Oviedo (Spain) in 2005, (http://www.tnt2005.org).

  19. Generic trending and analysis system

    NASA Technical Reports Server (NTRS)

    Keehan, Lori; Reese, Jay

    1994-01-01

    The Generic Trending and Analysis System (GTAS) is a generic spacecraft performance monitoring tool developed by NASA Code 511 and Loral Aerosys. It is designed to facilitate quick anomaly resolution and trend analysis. Traditionally, the job of off-line analysis has been performed using hardware and software systems developed for real-time spacecraft contacts; then, the systems were supplemented with a collection of tools developed by Flight Operations Team (FOT) members. Since the number of upcoming missions is increasing, NASA can no longer afford to operate in this manner. GTAS improves control center productivity and effectiveness because it provides a generic solution across multiple missions. Thus, GTAS eliminates the need for each individual mission to develop duplicate capabilities. It also allows for more sophisticated tools to be developed because it draws resources from several projects. In addition, the GTAS software system incorporates commercial off-the-shelf tools software (COTS) packages and reuses components of other NASA-developed systems wherever possible. GTAS has incorporated lessons learned from previous missions by involving the users early in the development process. GTAS users took a proactive role in requirements analysis, design, development, and testing. Because of user involvement, several special tools were designed and are now being developed. GTAS users expressed considerable interest in facilitating data collection for long term trending and analysis. As a result, GTAS provides easy access to large volumes of processed telemetry data directly in the control center. The GTAS archival and retrieval capabilities are supported by the integration of optical disk technology and a COTS relational database management system.

  20. International programs - A growing trend

    NASA Technical Reports Server (NTRS)

    Bunner, A. N.

    1990-01-01

    The National Aeronautics and Space Administration has collaborated successfully in space science missions with a multiplicity of partners, including the European Space Agency, Federal Republic of Germany, the Netherlands, United Kingdom, Japan, and the Soviet Union, among others. These collaborations generally arise out of common scientific goals and in the interest of economizing to take advantage of skills and capabilities among the partners. A trend towards increased cooperation in space is expected to continue as the global scientific community works together to plan future space science missions and the missions become more sophisticated.

  1. New trends in aminoglycosides use

    PubMed Central

    Fosso, Marina Y.; Li, Yijia; Garneau-Tsodikova, Sylvie

    2014-01-01

    Despite their inherent toxicity and the acquired bacterial resistance that continuously threaten their long-term clinical use, aminoglycosides (AGs) still remain valuable components of the antibiotic armamentarium. Recent literature shows that the AGs’ role has been further expanded as multi-tasking players in different areas of study. This review aims at presenting some of the new trends observed in the use of AGs in the past decade, along with the current understanding of their mechanisms of action in various bacterial and eukaryotic cellular processes. PMID:25071928

  2. Trends in magnetic recording media

    NASA Astrophysics Data System (ADS)

    Köster, E.

    1993-03-01

    The fifth M.R.M. Conference in Perugia presents an opportunity to analyse the market situation of magnetic recording media, the trend in future recording systems and the potential of present contenders for flexible media to meet future requirements. The main products in quantity and value are either in their zenith of product cycle or near to it. Highly innovative systems are needed in order to stimulate new applications or markets. The most challenging application is digital recording of HDTV for which particle in polymer binder technology is not yet fully ruled out by thin film ME technology. Improvements are expected from magnetic particles and binder, dispersion as well as coating technology.

  3. The Integrated Mode Management Interface

    NASA Technical Reports Server (NTRS)

    Hutchins, Edwin

    1996-01-01

    Mode management is the processes of understanding the character and consequences of autoflight modes, planning and selecting the engagement, disengagement and transitions between modes, and anticipating automatic mode transitions made by the autoflight system itself. The state of the art is represented by the latest designs produced by each of the major airframe manufacturers, the Boeing 747-400, the Boeing 777, the McDonnell Douglas MD-11, and the Airbus A320/A340 family of airplanes. In these airplanes autoflight modes are selected by manipulating switches on the control panel. The state of the autoflight system is displayed on the flight mode annunciators. The integrated mode management interface (IMMI) is a graphical interface to autoflight mode management systems for aircraft equipped with flight management computer systems (FMCS). The interface consists of a vertical mode manager and a lateral mode manager. Autoflight modes are depicted by icons on a graphical display. Mode selection is accomplished by touching (or mousing) the appropriate icon. The IMMI provides flight crews with an integrated interface to autoflight systems for aircraft equipped with flight management computer systems (FMCS). The current version is modeled on the Boeing glass-cockpit airplanes (747-400, 757/767). It runs on the SGI Indigo workstation. A working prototype of this graphics-based crew interface to the autoflight mode management tasks of glass cockpit airplanes has been installed in the Advanced Concepts Flight Simulator of the CSSRF of NASA Ames Research Center. This IMMI replaces the devices in FMCS equipped airplanes currently known as mode control panel (Boeing), flight guidance control panel (McDonnell Douglas), and flight control unit (Airbus). It also augments the functions of the flight mode annunciators. All glass cockpit airplanes are sufficiently similar that the IMMI could be tailored to the mode management system of any modern cockpit. The IMMI does not replace the

  4. Universal sensor interface module (USIM)

    NASA Astrophysics Data System (ADS)

    King, Don; Torres, A.; Wynn, John

    1999-01-01

    A universal sensor interface model (USIM) is being developed by the Raytheon-TI Systems Company for use with fields of unattended distributed sensors. In its production configuration, the USIM will be a multichip module consisting of a set of common modules. The common module USIM set consists of (1) a sensor adapter interface (SAI) module, (2) digital signal processor (DSP) and associated memory module, and (3) a RF transceiver model. The multispectral sensor interface is designed around a low-power A/D converted, whose input/output interface consists of: -8 buffered, sampled inputs from various devices including environmental, acoustic seismic and magnetic sensors. The eight sensor inputs are each high-impedance, low- capacitance, differential amplifiers. The inputs are ideally suited for interface with discrete or MEMS sensors, since the differential input will allow direct connection with high-impedance bridge sensors and capacitance voltage sources. Each amplifier is connected to a 22-bit (Delta) (Sigma) A/D converter to enable simultaneous samples. The low power (Delta) (Sigma) converter provides 22-bit resolution at sample frequencies up to 142 hertz (used for magnetic sensors) and 16-bit resolution at frequencies up to 1168 hertz (used for acoustic and seismic sensors). The video interface module is based around the TMS320C5410 DSP. It can provide sensor array addressing, video data input, data calibration and correction. The processor module is based upon a MPC555. It will be used for mode control, synchronization of complex sensors, sensor signal processing, array processing, target classification and tracking. Many functions of the A/D, DSP and transceiver can be powered down by using variable clock speeds under software command or chip power switches. They can be returned to intermediate or full operation by DSP command. Power management may be based on the USIM's internal timer, command from the USIM transceiver, or by sleep mode processing management

  5. Command Interface ASIC - Analog Interface ASIC Chip Set

    NASA Technical Reports Server (NTRS)

    Ruiz, Baldes; Jaffe, Burton; Burke, Gary; Lung, Gerald; Pixler, Gregory; Plummer, Joe; Katanyoutanant,, Sunant; Whitaker, William

    2003-01-01

    A command interface application-specific integrated circuit (ASIC) and an analog interface ASIC have been developed as a chip set for remote actuation and monitoring of a collection of switches, which can be used to control generic loads, pyrotechnic devices, and valves in a high-radiation environment. The command interface ASIC (CIA) can be used alone or in combination with the analog interface ASIC (AIA). Designed primarily for incorporation into spacecraft control systems, they are also suitable for use in high-radiation terrestrial environments (e.g., in nuclear power plants and facilities that process radioactive materials). The primary role of the CIA within a spacecraft or other power system is to provide a reconfigurable means of regulating the power bus, actuating all valves, firing all pyrotechnic devices, and controlling the switching of power to all switchable loads. The CIA is a mixed-signal (analog and digital) ASIC that includes an embedded microcontroller with supporting fault-tolerant switch control and monitoring circuitry that is capable of connecting to a redundant set of interintegrated circuit (I(sup 2)C) buses. Commands and telemetry requests are communicated to the CIA. Adherence to the I(sup 2)C bus standard helps to reduce development costs by facilitating the use of previously developed, commercially available components. The AIA is a mixed-signal ASIC that includes the analog circuitry needed to connect the CIA to a custom higher powered version of the I(sup 2)C bus. The higher-powered version is designed to enable operation with bus cables longer than those contemplated in the I(sup 2)C standard. If there are multiple higher-power I(sup 2)C-like buses, then there must an AIA between the CIA and each such bus. The AIA includes two identical interface blocks: one for the side-A I(sup 2)C clock and data buses and the other for the side B buses. All the AIAs on each side are powered from a common power converter module (PCM). Sides A and B

  6. Numerical modeling of materials processes with fluid-fluid interfaces

    NASA Astrophysics Data System (ADS)

    Yanke, Jeffrey Michael

    A numerical model has been developed to study material processes that depend on the interaction between fluids with a large discontinuity in thermophysical properties. A base model capable of solving equations of mass, momentum, energy conservation, and solidification has been altered to enable tracking of the interface between two immiscible fluids and correctly predict the interface deformation using a volume of fluid (VOF) method. Two materials processes investigated using this technique are Electroslag Remelting (ESR) and plasma spray deposition. ESR is a secondary melting technique that passes an AC current through an electrically resistive slag to provide the heat necessary to melt the alloy. The simulation tracks the interface between the slag and metal. The model was validated against industrial scale ESR ingots and was able to predict trends in melt rate, sump depth, macrosegregation, and liquid sump depth. In order to better understand the underlying physics of the process, several constant current ESR runs simulated the effects of freezing slag in the model. Including the solidifying slag in the imulations was found to have an effect on the melt rate and sump shape but there is too much uncertainty in ESR slag property data at this time for quantitative predictions. The second process investigated in this work is the deposition of ceramic coatings via plasma spray deposition. In plasma spray deposition, powderized coating material is injected into a plasma that melts and carries the powder towards the substrate were it impacts, flattening out and freezing. The impacting droplets pile up to form a porous coating. The model is used to simulate this rain of liquid ceramic particles impacting the substrate and forming a coating. Trends in local solidification time and porosity are calculated for various particle sizes and velocities. The predictions of decreasing porosity with increasing particle velocity matches previous experimental results. Also, a

  7. Determination of fiber-matrix interface failure parameters from off-axis tests

    NASA Technical Reports Server (NTRS)

    Naik, Rajiv A.; Crews, John H., Jr.

    1993-01-01

    Critical fiber-matrix (FM) interface strength parameters were determined using a micromechanics-based approach together with failure data from off-axis tension (OAT) tests. The ply stresses at failure for a range of off-axis angles were used as input to a micromechanics analysis that was performed using the personal computer-based MICSTRAN code. FM interface stresses at the failure loads were calculated for both the square and the diamond array models. A simple procedure was developed to determine which array had the more severe FM interface stresses and the location of these critical stresses on the interface. For the cases analyzed, critical FM interface stresses were found to occur with the square array model and were located at a point where adjacent fibers were closest together. The critical FM interface stresses were used together with the Tsai-Wu failure theory to determine a failure criterion for the FM interface. This criterion was then used to predict the onset of ply cracking in angle-ply laminates for a range of laminate angles. Predictions for the onset of ply cracking in angle-ply laminates agreed with the test data trends.

  8. Nonequilibrium thermodynamics of an interface

    NASA Astrophysics Data System (ADS)

    Savin, Thierry; Schweizer, Marco; Öttinger, Hans Christian

    Interfacial thermodynamics has deep ramifications in understanding the boundary conditions of transport theories. We present a formulation of local equilibrium for interfaces that extends the thermodynamics of the ``dividing surface,'' as introduced by Gibbs, to nonequilibrium settings such as evaporation or condensation. By identifying the precise position of the dividing surface in the interfacial region with a gauge degree of freedom, we exploit gauge-invariance requirements to consistently define the intensive variables for the interface. The model is verified under stringent conditions by employing high-precision nonequilibrium molecular dynamics simulations of a coexisting vapor-liquid Lennard-Jones fluid. We conclude that the interfacial temperature is determined using the surface tension as a ``thermometer,'' and can be significantly different from the temperatures of the adjacent phases.

  9. Is structural interface standardization beneficial?

    NASA Astrophysics Data System (ADS)

    Dombert, W. E.

    1983-11-01

    Factors applicable to fixed angle, large field and fixed angle, large building flat plate photovoltaic (PV) generator arrays are discussed in the context of standardization. It is concluded that structural interface standardization may be highly desirable in any one major project, but not at this time in the overall PV industry. Attempts to mandate such standardization will act as a deterrent to long-range improvements. In specific projects, structural standardization should be defined at the largest practical interface, leaving the maximum possible freedom to the module and array manufacturer. There is a corollary area, however, where detailed standards would benefit the industry; the matter of Standard Practices. Work being done towards definition of acceptable/desirable practices in materials, finishes, fastening and locking methods, grounding techniques, lightning protection, etc., and in handling the environmental ranges, should be continued.

  10. Nonequilibrium thermodynamics of an interface

    NASA Astrophysics Data System (ADS)

    Schweizer, Marco; Öttinger, Hans Christian; Savin, Thierry

    2016-05-01

    Interfacial thermodynamics has deep ramifications in understanding the boundary conditions of transport theories. We present a formulation of local equilibrium for interfaces that extends the thermodynamics of the "dividing surface," as introduced by Gibbs, to nonequilibrium settings such as evaporation or condensation. By identifying the precise position of the dividing surface in the interfacial region with a gauge degree of freedom, we exploit gauge-invariance requirements to consistently define the intensive variables for the interface. The model is verified under stringent conditions by employing high-precision nonequilibrium molecular-dynamics simulations of a coexisting vapor-liquid Lennard-Jones fluid. We conclude that the interfacial temperature is determined using the surface tension as a "thermometer," and it can be significantly different from the temperatures of the adjacent phases. Our findings lay foundations for nonequilibrium interfacial thermodynamics.

  11. Nonequilibrium thermodynamics of an interface.

    PubMed

    Schweizer, Marco; Öttinger, Hans Christian; Savin, Thierry

    2016-05-01

    Interfacial thermodynamics has deep ramifications in understanding the boundary conditions of transport theories. We present a formulation of local equilibrium for interfaces that extends the thermodynamics of the "dividing surface," as introduced by Gibbs, to nonequilibrium settings such as evaporation or condensation. By identifying the precise position of the dividing surface in the interfacial region with a gauge degree of freedom, we exploit gauge-invariance requirements to consistently define the intensive variables for the interface. The model is verified under stringent conditions by employing high-precision nonequilibrium molecular-dynamics simulations of a coexisting vapor-liquid Lennard-Jones fluid. We conclude that the interfacial temperature is determined using the surface tension as a "thermometer," and it can be significantly different from the temperatures of the adjacent phases. Our findings lay foundations for nonequilibrium interfacial thermodynamics. PMID:27300960

  12. Trends in mobile satellite communication

    NASA Technical Reports Server (NTRS)

    Johannsen, Klaus G.; Bowles, Mike W.; Milliken, Samuel; Cherrette, Alan R.; Busche, Gregory C.

    1993-01-01

    Ever since the U.S. Federal Communication Commission opened the discussion on spectrum usage for personal handheld communication, the community of satellite manufacturers has been searching for an economically viable and technically feasible satellite mobile communication system. Hughes Aircraft Company and others have joined in providing proposals for such systems, ranging from low to medium to geosynchronous orbits. These proposals make it clear that the trend in mobile satellite communication is toward more sophisticated satellites with a large number of spot beams and onboard processing, providing worldwide interconnectivity. Recent Hughes studies indicate that from a cost standpoint the geosynchronous satellite (GEOS) is most economical, followed by the medium earth orbit satellite (MEOS) and then by the low earth orbit satellite (LEOS). From a system performance standpoint, this evaluation may be in reverse order, depending on how the public will react to speech delay and collision. This paper discusses the trends and various mobile satellite constellations in satellite communication under investigation. It considers the effect of orbital altitude and modulation/multiple access on the link and spacecraft design.

  13. Chandra monitoring, trends, and response

    NASA Astrophysics Data System (ADS)

    Spitzbart, Brad D.; Wolk, Scott J.; Isobe, Takashi

    2002-12-01

    The Chandra X-ray Observatory was launched in July, 1999 and has yielded extraordinary scientific results. Behind the scenes, our Monitoring and Trends Analysis (MTA) system has proven to be a valuable resource. With three years worth of on-orbit data, we have available a vast array of both telescope diagnostic information and analysis of scientific data to access Observatory performance. As part of Chandra's Science Operations Team (SOT), the primary goal of MTA is to provide tools for effective decision making leading to the most efficient production of quality science output from the Observatory. We occupy a middle ground between flight operations, chiefly concerned with the health and safety of the spacecraft, and validation and verification, concerned with the scientific validity of the data taken and whether or not they fulfill the observer's requirements. In that role we provide and receive support from systems engineers, instrument experts, operations managers, and scientific users. MTA tools, products, and services include real-time monitoring and alert generation for the most mission critical components, long term trending of all spacecraft systems, detailed analysis of various subsystems for life expectancy or anomaly resolution, and creating and maintaining a large SQL database of relevant information. This is accomplished through the use of a wide variety of input data sources and flexible, accessible programming and analysis techniques. This paper will discuss the overall design of the system, its evolution and the resources available.

  14. Food consumption trends and drivers

    PubMed Central

    Kearney, John

    2010-01-01

    A picture of food consumption (availability) trends and projections to 2050, both globally and for different regions of the world, along with the drivers largely responsible for these observed consumption trends are the subject of this review. Throughout the world, major shifts in dietary patterns are occurring, even in the consumption of basic staples towards more diversified diets. Accompanying these changes in food consumption at a global and regional level have been considerable health consequences. Populations in those countries undergoing rapid transition are experiencing nutritional transition. The diverse nature of this transition may be the result of differences in socio-demographic factors and other consumer characteristics. Among other factors including urbanization and food industry marketing, the policies of trade liberalization over the past two decades have implications for health by virtue of being a factor in facilitating the ‘nutrition transition’ that is associated with rising rates of obesity and chronic diseases such as cardiovascular disease and cancer. Future food policies must consider both agricultural and health sectors, thereby enabling the development of coherent and sustainable policies that will ultimately benefit agriculture, human health and the environment. PMID:20713385

  15. TRENDS: Compendium of Benchmark Objects

    NASA Astrophysics Data System (ADS)

    Gonzales, Erica J.; Crepp, Justin R.; Bechter, Eric; Johnson, John A.; Montet, Benjamin T.; Howard, Andrew; Marcy, Geoffrey W.; Isaacson, Howard T.

    2016-01-01

    The physical properties of faint stellar and substellar objects are highly uncertain. For example, the masses of brown dwarfs are usually inferred using theoretical models, which are age dependent and have yet to be properly tested. With the goal of identifying new benchmark objects through observations with NIRC2 at Keck, we have carried out a comprehensive adaptive-optics survey as part of the TRENDS (TaRgetting bENchmark-objects with Doppler Spectroscopy) high-contrast imaging program. TRENDS targets nearby (d < 100 pc), Sun-like stars showing long-term radial velocity accelerations. We present the discovery of 28 confirmed, co-moving companions as well as 19 strong candidate companions to F-, G-, and K-stars with well-determined parallaxes and metallicities. Benchmark objects of this nature lend themselves to a three dimensional orbit determination that will ultimately yield a precise dynamical mass. Unambiguous mass measurements of very low mass companions, which straddle the hydrogen-burning boundary, will allow our compendium of objects to serve as excellent testbeds to substantiate theoretical evolutionary and atmospheric models in regimes where they currently breakdown (low temperature, low mass, and old age).

  16. Mask industry assessment trend analysis

    NASA Astrophysics Data System (ADS)

    Shelden, Gilbert; Marmillion, Patricia; Hughes, Greg

    2008-04-01

    Microelectronics industry leaders routinely name the cost and cycle time of mask technology and mask supply as top critical issues. A survey was created with support from SEMATECH and administered by SEMI North America to gather information about the mask industry as an objective assessment of its overall condition. This year's survey data were presented in detail at BACUS and the detailed trend analysis presented at EMLC. The survey is designed with the input of semiconductor company mask technologists, merchant mask suppliers, and industry equipment makers. This year's assessment is the sixth in the current series of annual reports. With continued industry support, the report can be used as a baseline to gain perspective on the technical and business status of the mask and microelectronics industries. The report will continue to serve as a valuable reference to identify the strengths and opportunities of the mask industry. The results will be used to guide future investments on critical path issues. This year's survey is basically the same as the 2005 and 2006 surveys. Questions are grouped into eight categories: General Business Profile Information, Data Processing, Yields and Yield Loss, Mechanisms, Delivery Times, Returns and Services, Operating Cost Factors, and Equipment Utilization. Within each category is a multitude of questions that creates a detailed profile of both the business and technical status of the critical mask industry. Note: the questions covering operating cost factors and equipment utilization were added to the survey only in 2005; therefore, meaningful trend analysis is not available.

  17. Interface Schottky barrier engineering via strain in metal-semiconductor composites.

    PubMed

    Ma, Xiangchao; Dai, Ying; Yu, Lin; Huang, Baibiao

    2016-01-21

    The interfacial carrier transfer property, which is dominated by the interface Schottky barrier height (SBH), plays a crucial role in determining the performance of metal-semiconductor heterostructures in a variety of applications. Therefore, artificially controlling the interface SBH is of great importance for their industrial applications. As a model system, the Au/TiO2 (001) heterostructure is studied using first-principles calculations and the tight-binding method in the present study. Our investigation demonstrates that strain can be an effective way to decrease the interface SBH and that the n-type SBH can be more effectively decreased than the p-type SBH. Astonishingly, strain affects the interface SBH mainly by changing the intrinsic properties of Au and TiO2, whereas the interfacial potential alignment is almost independent of strain due to two opposite effects, which are induced by strain at the interfacial region. These observed trends can be understood on the basis of the general free-electron gas model of typical metals, the tight-binding theory and the crystal-field theory, which suggest that similar trends may be generalized for many other metal-semiconductor heterostructures. Given the commonness and tunability of strain in typical heterostructures, we anticipate that the tunability of the interface SBH with strain described here can provide an alternative effective way for realizing more efficient applications of relevant heterostructures. PMID:26511292

  18. Virtual Frame Buffer Interface Program

    NASA Technical Reports Server (NTRS)

    Wolfe, Thomas L.

    1990-01-01

    Virtual Frame Buffer Interface program makes all frame buffers appear as generic frame buffer with specified set of characteristics, allowing programmers to write codes that run unmodified on all supported hardware. Converts generic commands to actual device commands. Consists of definition of capabilities and FORTRAN subroutines called by application programs. Developed in FORTRAN 77 for DEC VAX 11/780 or DEC VAX 11/750 computer under VMS 4.X.

  19. Auditory interfaces: The human perceiver

    NASA Technical Reports Server (NTRS)

    Colburn, H. Steven

    1991-01-01

    A brief introduction to the basic auditory abilities of the human perceiver with particular attention toward issues that may be important for the design of auditory interfaces is presented. The importance of appropriate auditory inputs to observers with normal hearing is probably related to the role of hearing as an omnidirectional, early warning system and to its role as the primary vehicle for communication of strong personal feelings.

  20. Vibrational spectroscopy of water interfaces

    SciTech Connect

    Du, Q.

    1994-12-01

    The second order nonlinear optical processes of second harmonic generation and sum frequency generation are powerful and versatile tools for studying all kinds of surfaces. They possess unusual surface sensitivity due to the symmetry properties of the second order nonlinear susceptibility. The technique of infrared-visible sum frequency generation (SFG) is particularly attractive because it offers a viable way to do vibrational spectroscopy on any surfaces accessible to light with submonolayer sensitivity. In this thesis, the author applies SFG to study a number of important water interfaces. At the air/water interface, hydrophobic solid/water and liquid/water interfaces, it was found that approximately 25% of surface water molecules have one of their hydrogen pointing away from the liquid water. The large number of unsatisfied hydrogen bonds contributes significantly to the large interfacial energy of the hydrophobic surfaces. At the hydrophilic fused quartz/water interface and a fatty acid monolayer covered water surface, the structure and orientation of surface water molecules are controlled by the hydrogen bonding of water molecules with the surface OH groups and the electrostatic interaction with the surface field from the ionization of surface groups. A change of pH value in the bulk water can significantly change the relative importance of the two interactions and cause a drastic change in orientation of the surface water molecules. SFG has also been applied to study the tribological response of some model lubricant films. Monolayers of Langmuir-Blodgett films were found to disorder orientationaly under mildly high pressure and recover promptly upon removal of the applied pressure.

  1. Multiple man-machine interfaces

    NASA Technical Reports Server (NTRS)

    Stanton, L.; Cook, C. W.

    1981-01-01

    The multiple man machine interfaces inherent in military pilot training, their social implications, and the issue of possible negative feedback were explored. Modern technology has produced machines which can see, hear, and touch with greater accuracy and precision than human beings. Consequently, the military pilot is more a systems manager, often doing battle against a target he never sees. It is concluded that unquantifiable human activity requires motivation that is not intrinsic in a machine.

  2. Tire/runway friction interface

    NASA Technical Reports Server (NTRS)

    Yager, Thomas J.

    1990-01-01

    An overview is given of NASA Langley's tire/runway pavement interface studies. The National Tire Modeling Program, evaluation of new tire and landing gear designs, tire wear and friction tests, and tire hydroplaning studies are examined. The Aircraft Landing Dynamics Facility is described along with some ground friction measuring vehicles. The major goals and scope of several joint FAA/NASA programs are identified together with current status and plans.

  3. Software handlers for process interfaces

    NASA Technical Reports Server (NTRS)

    Bercaw, R. W.

    1976-01-01

    Process interfaces are developed in an effort to reduce the time, effort, and money required to install computer systems. Probably the chief obstacle to the achievement of these goals lies in the problem of developing software handlers having the same degree of generality and modularity as the hardware. The problem of combining the advantages of modular instrumentation with those of modern multitask operating systems has not been completely solved, but there are a number of promising developments. The essential principles involved are considered.

  4. A comparison of Internet search trends and sexually transmitted infection rates using Google trends.

    PubMed

    Johnson, Amy K; Mehta, Supriya D

    2014-01-01

    Google Trends was used to determine the relationship between sexually transmitted infection (STI)-related search engine trends and STI rates. Trends seem to be similar to the relative rates of STIs and to regional differences in rates. Search engine trends are an innovative tool to integrate into STI surveillance. PMID:24326584

  5. Chiral magnetism at oxide interfaces

    NASA Astrophysics Data System (ADS)

    Randeria, Mohit

    2014-03-01

    There are tantalizing hints of magnetism at the n-type LaAlO3/SrTiO3 interface, but the experimental evidence remains controversial in view of some of the differences between different samples and probes. I will argue that if magnetism exists at interfaces, symmetry arguments imply chiral interactions that lead to a spiral ground state in zero external field and skyrmion crystals for H ≠ 0 . I will next present a microscopic model that provides a possible mechanism for the formation of local moments. I will show that the coupling of these moments to itinerant electrons leads to ferromagnetic double exchange together with Dzyaloshinskii-Moriya (DM) interactions and an easy-plane ``compass'' anisotropy, which arise from Rashba spin-orbit coupling (SOC) due to the lack of inversion symmetry at the interface. The compass term, often ignored in the literature on chiral magnetism, is shown to play a crucial role in determining the magnetic ground state. I will compare our results with existing torque magnetometry data on LAO/STO and try to reconcile it with scanning SQUID magnetometry. Finally, I will present the phase diagram in a field and show that easy-plane anisotropy stabilizes an unexpectedly large skyrmion crystal phase and describe its properties. (Work done in collaboration with Sumilan Banerjee, Onur Erten, Daniel Kestner and James Rowland). Supported by DOE-BES DE-SC0005035, NSF-DMR-1006532 and NSF MRSEC DMR-0820414.

  6. Detonation interaction with an interface

    NASA Astrophysics Data System (ADS)

    Lieberman, D. H.; Shepherd, J. E.

    2007-09-01

    Detonation interaction with an interface was investigated, where the interface separated a combustible from an oxidizing or inert mixture. The ethylene-oxygen combustible mixture had a fuel-rich composition to promote secondary combustion with the oxidizer in the turbulent mixing zone (TMZ) that resulted from the interaction. Sharp interfaces were created by using a nitro-cellulose membrane to separate the two mixtures. The membrane was mounted on a wood frame and inserted in the experimental test section at a 45° angle to the bulk flow direction. The membrane was destroyed by the detonation wave. The interaction resulted in a transmitted and reflected wave at a node point similar to regular shock refraction. A detonation refraction analysis was carried out to compare with the measured shock angles. It was observed that the measured angle is consistently lower than the predicted value. An uncertainty analysis revealed possible explanations for this systematic variation pointing to factors such as the incident wave curvature and the role of the nitro-cellulose diaphragm. Analysis of the TMZ and Mach stem formed from the reflection of the transmitted shock wave off the solid boundary were carried out and found to justify the size and strength of these features as a function of the test gas composition. The role of secondary combustion in the TMZ was also investigated and found to have a small influence on the wave structure.

  7. Microprocessor-based interface for oceanography

    NASA Technical Reports Server (NTRS)

    Hansen, G. R.

    1979-01-01

    Ocean floor imaging system incorporates five identical microprocessor-based interface units each assigned to specific sonar instrument to simplify system. Central control module based on same microprocessor eliminates need for custom tailoring hardware interfaces for each instrument.

  8. Formal specification of human-computer interfaces

    NASA Technical Reports Server (NTRS)

    Auernheimer, Brent

    1990-01-01

    A high-level formal specification of a human computer interface is described. Previous work is reviewed and the ASLAN specification language is described. Top-level specifications written in ASLAN for a library and a multiwindow interface are discussed.

  9. Reinventing the energy modelling-policy interface

    NASA Astrophysics Data System (ADS)

    Strachan, Neil; Fais, Birgit; Daly, Hannah

    2016-03-01

    Energy modelling has a crucial underpinning role for policy making, but the modelling-policy interface faces several limitations. A reinvention of this interface would better provide timely, targeted, tested, transparent and iterated insights from such complex multidisciplinary tools.

  10. Programmable atom-photon quantum interface

    NASA Astrophysics Data System (ADS)

    Kurz, Christoph; Eich, Pascal; Schug, Michael; Müller, Philipp; Eschner, Jürgen

    2016-06-01

    We present the implementation of a programmable atom-photon quantum interface, employing a single trapped +40Ca ion and single photons. Depending on its mode of operation, the interface serves as a bidirectional atom-photon quantum-state converter, as a source of entangled atom-photon states, or as a quantum frequency converter of single photons. The interface lends itself particularly to interfacing ions with spontaneous parametric down-conversion-based single-photon or entangled-photon-pair sources.

  11. Atomistic modeling of dislocation-interface interactions

    SciTech Connect

    Wang, Jian; Valone, Steven M; Beyerlein, Irene J; Misra, Amit; Germann, T. C.

    2011-01-31

    Using atomic scale models and interface defect theory, we first classify interface structures into a few types with respect to geometrical factors, then study the interfacial shear response and further simulate the dislocation-interface interactions using molecular dynamics. The results show that the atomic scale structural characteristics of both heterophases and homophases interfaces play a crucial role in (i) their mechanical responses and (ii) the ability of incoming lattice dislocations to transmit across them.

  12. Relaxation, Structure, and Properties of Semicoherent Interfaces

    NASA Astrophysics Data System (ADS)

    Shao, S.; Wang, J.

    2016-01-01

    Materials containing a high density of interfaces are promising candidates for future energy technologies because interfaces acting as sources, sinks, and barriers for defects can improve mechanical and irradiation properties of materials. A semicoherent interface widely occurring in various materials is composed of a network of misfit dislocations and coherent regions separated by misfit dislocations. In this article, we review the relaxation mechanisms, structure, and properties of (111) semicoherent interfaces in face-centered cubic structures.

  13. INL Multi-Robot Control Interface

    Energy Science and Technology Software Center (ESTSC)

    2005-03-30

    The INL Multi-Robot Control Interface controls many robots through a single user interface. The interface includes a robot display window for each robot showing the robot’s condition. More than one window can be used depending on the number of robots. The user interface also includes a robot control window configured to receive commands for sending to the respective robot and a multi-robot common window showing information received from each robot.

  14. Interfaces in novel electronic materials

    NASA Astrophysics Data System (ADS)

    Liu, Fude

    Materials are now an important constraint of Si-based devices. One of the most serious problems is now the field effect transistor (FET) gate dielectric. It is desirable to find high-K dielectrics to replace Si02 so that a physically thicker gate dielectric can be used and then the tunneling effect can be reduced or avoided. Very recently, more interest has been shown in the La-based materials. In this study, a main part of effort was put on amorphous LaScO3 and La2O3/SiO2 alloys grown on Si (001) substrate. We have demonstrated that amorphous high-K oxide layers can be deposited directly on Si substrate as gate dielectrics for CMOS devices. However, oxygen diffusion through the high-K layers and reaction with Si substrate increased the EOT and the interface roughness at 1000°C. So possible oxygen sources at 1000°C need to be eliminated. All these results give us a deep understanding about the promising La-based oxides as the next generation gate dielectric. Compared to the mature Si industry, III-nitrides had not earned a most respected place in modern devices until recently. Unlike silicon and other traditional materials, III-nitrides are particularly suitable for high-frequency, high-power and high-temperature applications. Unfortunately, the choice of appropriate substrate materials for III-nitrides is still one of the biggest issues to be solved. Sapphire offers a compromise as the most widely used substrate material to date. And much remains to be known about the interface structures and GaN inversion domain boundaries (IDBs). In this study, we tried to determine these interface structures and GaN-IDBs. To the GaN films on c-sapphire with a low temperature AIN (LT-AIN) nucleation layer, the interface atomic structure of LT-AIN on c-sapphire and the exact 3-D geometry of AIN pits were determined for the first time. The GaN IDBs were also studied in detail. A transition region with mixed polarities was found with the convergent beam electron diffraction (CBED

  15. Properties of interfaces of diamond

    NASA Astrophysics Data System (ADS)

    Nemanich, R. J.; Bergman, L.; Turner, K. F.; van der Weide, J.; Humphreys, T. P.

    1993-04-01

    Results related to two different interface aspects involving diamond are described: (1) the initial states of CVD diamond film growth, and (2) the negative electron affinity and formation of metal-diamond interfaces. The surface and interface properties are probed with STM, Raman scattering/photoluminescence and angle-resolved UV photoemission spectroscopy (ARUPS). STM measurements of diamond nuclei on Si after various plasma growth processes show both flat and hillocked structures characteristics of 2-dimensional and 3-dimensional growth modes, respectively. STS measurements show distinct I- V characteristics of the nuclei and the substrate. The presence of optical defects and the diamond quality are studied with micro-Raman/photoluminescence measurements. The results indicate an increased density of impurity-related defects during the initial stages of growth. The interface properties of Ti on natural crystal (1 1 1) and (1 0 0) surfaces are studied with ARUPS using 21.2 eV HeI emission. Prior to deposition the diamond (1 1 1) is chemically cleaned, and a sharp (0.5 eV FWHM) peak is observed at the position of the conduction band minimum, indicating a negative electron affinity surface. After a subsequent argon plasma clean this peak disappears, while the spectrum shows a shift of 0.5 eV towards higher energies. Upon sub-monolayer titanium deposition on (1 1 1) diamond, the negative electron affinity peak reappears. Further titanium depositions causes this titanium-induced negative electron affinity peak to be attenuated, indicating that the emission originates from the interface. A similar experiment, done on the diamond (1 0 0) surface, however, does not result in a negative electron affinity. By determining the relative positions of the diamond valence band edge and the titanium Fermi level, the Schottky barrier height of titanium on diamond is measured. A model, based on the Schottky barrier height of titanium on diamond, and the work function of titanium, is

  16. Towards automation of user interface design

    NASA Technical Reports Server (NTRS)

    Gastner, Rainer; Kraetzschmar, Gerhard K.; Lutz, Ernst

    1992-01-01

    This paper suggests an approach to automatic software design in the domain of graphical user interfaces. There are still some drawbacks in existing user interface management systems (UIMS's) which basically offer only quantitative layout specifications via direct manipulation. Our approach suggests a convenient way to get a default graphical user interface which may be customized and redesigned easily in further prototyping cycles.

  17. Properties of interfaces and transport across them.

    PubMed

    Cabezas, H

    2000-01-01

    Much of the biological activity in cell cytoplasm occurs in compartments some of which may be formed, as suggested in this book, by phase separation, and many of the functions of such compartments depend on the transport or exchange of molecules across interfaces. Thus a fundamentally based discussion of the properties of phases, interfaces, and diffusive transport across interfaces has been given to further elucidate these phenomena. An operational criterion for the width of interfaces is given in terms of molecular and physical arguments, and the properties of molecules inside phases and interfaces are discussed in terms of molecular arguments. In general, the properties of the interface become important when the molecules diffusing across are smaller than the width of the interface. Equilibrium partitioning, Donnan phenomena, and electrochemical potentials at interfaces are also discussed in detail. The mathematical expressions for modeling transport across interfaces are discussed in detail. These describe a practical and detailed model for transport across interfaces. For molecules smaller than the width of the interface, this includes a detailed model for diffusion inside the interface. Last, the question of the time scale for phase formation and equilibration in biological systems is discussed. PMID:10610364

  18. Film bonded fuel cell interface configuration

    DOEpatents

    Kaufman, Arthur; Terry, Peter L.

    1985-01-01

    An improved interface configuration for use between adjacent elements of a fuel cell stack. The interface is impervious to gas and liquid and provides resistance to corrosion by the electrolyte of the fuel cell. A multi-layer arrangement for the interface provides bridging electrical contact with a hot-pressed resin filling the void space.

  19. Atomic and electronic structure of interfaces in materials systems for future semiconductor devices

    NASA Astrophysics Data System (ADS)

    Lopatin, Sergei

    Because of the intrinsic limits of the Si/SiO2 based industry, there is a great trend towards the monolithic integration of new materials into already well developed silicon technology. Having lasted for several decades now, downscaling reaches the limit, in which a critical device dimension approaches the size of one atom. At this level of the miniaturization, it is not the bulk material, but the interface between the two materials that what controls the properties of the resulting optoelectronic device. Thus, the characterization of precise atomic arrangements at different interfaces and the influence of these arrangements on the optoelectronic properties of interfaces is required. Therefore, in this study, a combination of scanning transmission electron microscopy (STEM) techniques and density functional theory calculations was used as a research tool for the characterization of interfaces. The STEM instruments used for the study were equipped with prototypes of spherical aberration correctors, enabling to achieve the highest resolution currently available both in space and energy. The combination of experimental and theoretical methods was applied to study interfaces between Si/GaAs, Si/Ge, Ge/SiO2, Si/HfO2 and Si/Al2O3. As the result of the present research, a new dislocation configuration at the Si/GaAs interface was reported for the first time. The influence of this dislocation structure on the electrical properties of the Si/GaAs interface was analyzed. Also, the transition from Si to GaAs and from Si to Ge at corresponding interfaces was described with atomic precision. For the first time, the interface between Ge and SiO2 was shown to have "ideal" characteristics (chemical abruptness and sharpness). This indicates the potential, both for a more successful use of Ge in high-speed devices and for advances in interface engineering to enhance performance in electronic devices. The features of Si/HfO2 and Si/Al2O3 interfaces, namely the distribution and

  20. Terahertz applications: trends and challenges

    NASA Astrophysics Data System (ADS)

    Robin, Thierry; Bouye, Clementine; Cochard, Jacques

    2014-03-01

    The objective of our work [1] was to determine the opportunities and challenges for Terahertz application development for the next years with a focus on systems: for homeland security and for Non Destructive Testing (NDT). Terahertz radiation has unique abilities and has been the subject of extensive research for many years. Proven concepts have emerged for numerous applications including Industrial NDT, Security, Health, Telecommunications, etc. Nevertheless, there has been no widely deployed application and Businesses based on THz technologies are still in their infancy. Some technological, market and industrial barriers are still to be broken. We summarize the final analysis and data: study of the technology trends and major bottlenecks per application segment, main challenges to be addressed in the next years, key opportunities for THz technologies based on market needs and requirements.

  1. [Radioprotectors: History, Trends and Prospects].

    PubMed

    Gudkov, S V; Popova, N R; Bruskov, V I

    2015-01-01

    The search for ideal protective agents for use in a variety of radiation scenarios has continued for more than six decades. This review describes the history of the major discoveries, shows the chronology of the changes in attitudes, trends and paradigms. The readers are invited to meet with various classes of chemical compounds that have the potential to protect against acute and late effects of ionizing radiation when administered either before or after radiation exposure. The work represents characteristics of radioprotective agents such as a dose reduction factor, time of administration, tissue specificity, toxicity; the mechanisms of their action and practical applications are also described. A separate chapter considers the further development prospects and directions in this field of research. PMID:26394481

  2. Current trends in cardiac rehabilitation

    PubMed Central

    Dafoe, W; Huston, P

    1997-01-01

    Cardiac rehabilitation can reduce mortality and morbidity for patients with many types of cardiac disease cost-effectively, yet is generally underutilized. Rehabilitation is helpful not only for patients who have had a myocardial infarction but also for those with stable angina or congestive heart failure or those who have undergone myocardial revascularization procedures, a heart transplant or heart valve surgery. The beneficial effects of rehabilitation include a reduction in the rate of death from cardiovascular disease, improved exercise tolerance, fewer cardiac symptoms, improved lipid levels, decreased cigarette smoking, improvement in psychosocial well-being and increased likelihood of return to work. Rehabilitation involves a multidisciplinary team that focuses on education, individually tailored exercise, risk-factor modification and the optimization of functional status and mental health. Current research trends in this area include the evaluation of new secondary-prevention modalities and alternative program options, such as home-based rehabilitation. PMID:9054823

  3. Current trends in dental implants

    PubMed Central

    Gaviria, Laura; Salcido, John Paul; Guda, Teja

    2014-01-01

    Tooth loss is very a very common problem; therefore, the use of dental implants is also a common practice. Although research on dental implant designs, materials and techniques has increased in the past few years and is expected to expand in the future, there is still a lot of work involved in the use of better biomaterials, implant design, surface modification and functionalization of surfaces to improve the long-term outcomes of the treatment. This paper provides a brief history and evolution of dental implants. It also describes the types of implants that have been developed, and the parameters that are presently used in the design of dental implants. Finally, it describes the trends that are employed to improve dental implant surfaces, and current technologies used for the analysis and design of the implants. PMID:24868501

  4. Petroleum 1996 - issues and trends

    SciTech Connect

    1997-09-01

    Increasingly, users of the Energy Information Administration`s petroleum data and analytical reports have expressed an interest in a recurring report that takes a broad view of the petroleum sector. What is sought is some perspective on the complex interrelationships that comprise an industry and markets accounting for 40 percent of the energy consumed in the United States and ranging from the drilling rig in the oil field to the pump at the local gasoline station. This report comprehensively examines historical trends, and selectively focuses on major issues and the events they represent. It analyzes different dimensions of the industry and related markets in terms of how they relate to a common theme, in this case, the volatility in petroleum markets.

  5. Recent Inland Water Temperature Trends

    NASA Astrophysics Data System (ADS)

    Hook, Simon; Healey, Nathan; Lenters, John; O'Reilly, Catherine

    2016-04-01

    We are using thermal infrared satellite data in conjunction with in situ measurements to produce water temperatures for all the large inland water bodies in North America and the rest of the world for potential use as climate indicator. Recent studies have revealed significant warming of inland waters throughout the world. The observed rate of warming is - in many cases - greater than that of the ambient air temperature. These rapid, unprecedented changes in inland water temperatures have profound implications for lake hydrodynamics, productivity, and biotic communities. Scientists are just beginning to understand the global extent, regional patterns, physical mechanisms, and ecological consequences of lake warming. As part of our work we have collected thermal infrared satellite data from those satellite sensors that provide long-term and frequent spaceborne thermal infrared measurements of inland waters including ATSR, AVHRR, and MODIS and used these to examine trends in water surface temperature for approximately 169 of the largest inland water bodies in the world. We are now extending this work to generate temperature time-series of all North American inland water bodies that are sufficiently large to be studied using 1km resolution satellite data for the last 3 decades, approximately 268 lakes. These data are then being related to changes in the surface air temperature and compared with regional trends in water surface temperature derived from CMIP5/IPCC model simulations/projections to better predict future temperature changes. We will discuss the available datasets and processing methodologies together with the patterns they reveal based on recent changes in the global warming, with a particular focus on the inland waters of the southwestern USA.

  6. Future trends in image coding

    NASA Astrophysics Data System (ADS)

    Habibi, Ali

    1993-01-01

    The objective of this article is to present a discussion on the future of image data compression in the next two decades. It is virtually impossible to predict with any degree of certainty the breakthroughs in theory and developments, the milestones in advancement of technology and the success of the upcoming commercial products in the market place which will be the main factors in establishing the future stage to image coding. What we propose to do, instead, is look back at the progress in image coding during the last two decades and assess the state of the art in image coding today. Then, by observing the trends in developments of theory, software, and hardware coupled with the future needs for use and dissemination of imagery data and the constraints on the bandwidth and capacity of various networks, predict the future state of image coding. What seems to be certain today is the growing need for bandwidth compression. The television is using a technology which is half a century old and is ready to be replaced by high definition television with an extremely high digital bandwidth. Smart telephones coupled with personal computers and TV monitors accommodating both printed and video data will be common in homes and businesses within the next decade. Efficient and compact digital processing modules using developing technologies will make bandwidth compressed imagery the cheap and preferred alternative in satellite and on-board applications. In view of the above needs, we expect increased activities in development of theory, software, special purpose chips and hardware for image bandwidth compression in the next two decades. The following sections summarize the future trends in these areas.

  7. Transient interfacial tension and dilatational rheology of diffuse polymer-polymer interfaces

    NASA Astrophysics Data System (ADS)

    Peters, Gerrit W. M.; Zdravkov, Alexander N.; Meijer, Han E. H.

    2005-03-01

    We demonstrate the influence of molecular weight and molecular weight asymmetry across an interface on the transient behavior of the interfacial tension. The interfacial tension was measured as a function of time for a range of polymer combinations with a broad range of interfacial properties using a pendant/sessile drop apparatus. The results show that neglecting mutual solubility, assumed to be a reasonable approximation in many cases, very often does not sustain. Instead, a diffuse interface layer develops in time with a corresponding transient interfacial tension. Depending on the specific combination of polymers, the transient interfacial tension is found to increase or decrease with time. The results are interpreted in terms of a recently proposed model [Shi et al., Macromolecules 37, 1591 (2004)], giving relative characteristic diffusion time scales in terms of molecular weight, molecular weight distribution, and viscosities. However, the time scales obtained from this theoretical approach do not give a conclusive trend. Using oscillatory dilatational interfacial experiments the viscoelastic behavior of these diffusive interfaces is demonstrated. The time evolution of the interfacial tension and the dilatational elasticity show the same trend as predicted by the theory of diffuse interfaces, supporting the idea that the polymer combinations under consideration indeed form diffuse interfaces. The dilatational elasticity and the dilatational viscosity show a frequency dependency that is described qualitatively by a simple Fickian diffusion model and quantitatively by a Maxwell model. The characteristic diffusion times provided by the latter show that the systems with thick interfaces (tens of microseconds and more) can be considered as slower diffusive systems compared to the systems with thinner interfaces (a few micrometers in thickness and less) can be considered as fast diffusive systems.

  8. Trends in communicative access solutions for children with cerebral palsy.

    PubMed

    Myrden, Andrew; Schudlo, Larissa; Weyand, Sabine; Zeyl, Timothy; Chau, Tom

    2014-08-01

    Access solutions may facilitate communication in children with limited functional speech and motor control. This study reviews current trends in access solution development for children with cerebral palsy, with particular emphasis on the access technology that harnesses a control signal from the user (eg, movement or physiological change) and the output device (eg, augmentative and alternative communication system) whose behavior is modulated by the user's control signal. Access technologies have advanced from simple mechanical switches to machine vision (eg, eye-gaze trackers), inertial sensing, and emerging physiological interfaces that require minimal physical effort. Similarly, output devices have evolved from bulky, dedicated hardware with limited configurability, to platform-agnostic, highly personalized mobile applications. Emerging case studies encourage the consideration of access technology for all nonverbal children with cerebral palsy with at least nascent contingency awareness. However, establishing robust evidence of the effectiveness of the aforementioned advances will require more expansive studies. PMID:24820337

  9. Trends of DC Power Technologies and their Applications

    NASA Astrophysics Data System (ADS)

    Hirose, Keiichi

    Renewable energy resources such as photovoltaic panels and wind turbines have been increasing rapidly to prevent global warming. The number of energy storage systems and many types of batteries is also growing to keep supply and demand balance in local areas. Interfaces of these facilities are direct current (DC). Most of modern electrical appliances also use DC power inside them. Therefore, DC power technologies with some features are expected to meet requirements for new electrical power systems, for example smartgrids, microgrids, and other electrical applications. In recent years, DC power applications in data centers, commercial buildings, and dwellings have been developed in Japan, the U.S. European countries, and so on. At the same time, international standardization activities had started. This paper describes trends of DC power technologies and their applications.

  10. Buffering agents modify the hydration landscape at charged interfaces.

    PubMed

    Trewby, William; Livesey, Duncan; Voïtchovsky, Kislon

    2016-02-23

    Buffering agents are widely used to stabilise the pH of solutions in soft matter and biological sciences. They are typically composed of weak acids and bases mixed in an aqueous solution, and can interact electrostatically with charged surfaces such as biomembranes. Buffers can induce protein aggregation and structural modification of soft interfaces, but a molecular-level picture is still lacking. Here we use high-resolution atomic force microscopy to investigate the effect of five commonly used buffers, namely 4-(2-hydroxyethyl)piperazine-1-ethanesulfonic acid (HEPES), 2-(N-morpholino)ethanesulfonic acid (MES), monosodium phosphate, saline sodium citrate (SSC) and tris(hydroxymethyl)aminomethane (Tris) on the hydration landscape of Muscovite mica in solution. Mica is an ideal model substrate due to its negative surface charge and identical lattice parameter when compared with gel-phase lipid bilayers. We show that buffer molecules can produce cohesive aggregates spanning over tens of nanometres of the interface. SSC, Tris and monosodium phosphate tend to create an amorphous mesh layer several molecules thick and with no preferential ordering. In contrast, MES and HEPES adopt epitaxial arrangements commensurate with the underlying mica lattice, suggesting that they offer the most suitable solution for high-resolution studies. To confirm that this effect persisted in biologically-relevant interfaces, the experiments were repeated on a silica-supported lipid bilayer. Similar trends were observed for this system using atomic force microscopy as well as ellipsometry. The effect of the buffering agents can be mitigated by the inclusion of salt which helps displace them from the interface. PMID:26837938

  11. Interface solitons in thermal nonlinear media

    SciTech Connect

    Ma Xuekai; Yang Zhenjun; Lu Daquan; Hu Wei

    2011-05-15

    We demonstrate the existence of fundamental and dipole interface solitons in one-dimensional thermal nonlinear media with a step in linear refractive index. Fundamental interface solitons are found to be always stable and the stability of dipole interface solitons depends on the difference in linear refractive index. The mass center of interface solitons always locates in the side with higher refractive index. The two intensity peaks of dipole interface solitons are unequal except under some specific conditions, which is different from their counterparts in uniform thermal nonlinear media.

  12. Intelligent subsystem interface for modular hardware system

    NASA Technical Reports Server (NTRS)

    Krening, Douglas N. (Inventor); Lannan, Gregory B. (Inventor); Schneiderwind, Michael J. (Inventor); Schneiderwind, Robert A. (Inventor); Caffrey, Robert T. (Inventor)

    2000-01-01

    A single chip application specific integrated circuit (ASIC) which provides a flexible, modular interface between a subsystem and a standard system bus. The ASIC includes a microcontroller/microprocessor, a serial interface for connection to the bus, and a variety of communications interface devices available for coupling to the subsystem. A three-bus architecture, utilizing arbitration, provides connectivity within the ASIC and between the ASIC and the subsystem. The communication interface devices include UART (serial), parallel, analog, and external device interface utilizing bus connections paired with device select signals. A low power (sleep) mode is provided as is a processor disable option.

  13. TAXI Interface Demultiplexes Proprietarily Formatted Data

    NASA Technical Reports Server (NTRS)

    Newnan, Bruce G.; Ahiport, Steven F.

    2001-01-01

    The 'TAXI Direct-to-Disk' interface is a special purpose interface unit for demultiplexing of data from a Racal Storeplex (or equivalent) multichannel recorder onto one or more hard disks that reside in, and/or are controlled by, a personal computer (PC). The acronym 'TAXI' signifies transparent asynchronous transceiver interface. The TAXI interface was developed for original use in capturing data from instrumentation on a test stand in a NASA rocket testing facility. The installation of the TAXI interface, in conjunction with other modifications, causes the transfer of data to take place in real time, so that the data are immediately available for review during or after the test.

  14. Transient aspects of stream interface signatures

    SciTech Connect

    Crooker, N.U.; Shodhan, S.; Forsyth, R.J.; Burton, M.E.; Gosling, J.T.; Fitzenreiter, R.J.; Lepping, R.P.

    1999-06-01

    Although stream interfaces are steady-state, corotating boundaries between slow and fast solar wind, their signatures are sometimes associated with transient features. Here the authors illustrate two modes of association: interfaces trailing interplanetary coronal mass ejections (ICMEs) at 1 AU and interfaces within ICMEs in the range 4--5 AU. The former are readily understood as boundaries between transient slow wind and steady-state fast wind, where the ICMEs add variability to the interface signatures. The latter are puzzling and may be related to evolution of interfaces.

  15. Dislocation punching from ceramic/metal interfaces

    SciTech Connect

    Taya, M. ); Mori, T. . Dept. of Materials Science and Engineering)

    1994-07-01

    Relaxation of misfit strains at interfaces between two different materials by dislocation punching is studied analytically by focusing on two types of interfaces: planar and nonplanar. As an example of planar type interface, the case of metal coating/ceramic substrate system is studied while ceramic filler/metal matrix composite system is examined as an example of a nonplanar interface. Based on the present analytical model, the condition for dislocation punching for each interface is established. Validity of the dislocation punching model is verified by comparing the analytical results with limited experimental results, resulting in a good agreement.

  16. Tailoring thermal interfaces with nanomaterials

    NASA Astrophysics Data System (ADS)

    Seshadri, Indira

    Thermal interfaces are key to ensure the reliable performance of many semiconductor, energy and electronic systems. High thermal conductivity (k), low elastic modulus (E) interface materials are required to dissipate heat and relieve thermo-mechanical stresses. The aim of this thesis is to develop compliant, high k nanocomposite materials for thermal interface applications utilizing nanostructured networks. Realizing high k nanocomposites is a challenge because of difficulties in incorporating high fractions of uniformly dispersed nanofillers and countering low filler-matrix interfacial conductance, while retaining a low elastic modulus. In this thesis, it is demonstrated that these issues are obviated by using < 5 volume % sub-10-nm cold welded gold nanowire fillers to obtain an unprecedented 30-fold increase in polydimethylsiloxane thermal conductivity that is 6-fold higher than previously reported nanocomposites at low nanofiller loadings and exceeds theoretical predictions. The nanowire diameter and aspect ratio are key to obtain cold-welded networks that enhance k at low filler fractions, while fostering low E. Along with high k, tailoring high thermal contact conductance G c is crucial for many applications. This thesis reveals a critical correlation between the rheological behavior of a high k gold-nanowire-filled polydimethylsiloxane nanocomposite and its thermal contact conductance with copper. At a critical filler fraction, an abrupt increase in the nanocomposite k is accompanied by a liquid-solid transition and a multifold decrease in Gc. These concurrent changes are attributed to nanowire percolation network formation and pre-cure polymer gelation that inhibits the formation of conformal void-free interfaces. These findings will be important for designing processing sequences to realize heterointerfaces with nanowire filled high k nanocomposite materials. Another important finding of this thesis is that nanowire networks can result in mechanical

  17. Surface rheology and interface stability.

    SciTech Connect

    Yaklin, Melissa A.; Cote, Raymond O.; Moffat, Harry K.; Grillet, Anne Mary; Walker, Lynn; Koehler, Timothy P.; Reichert, Matthew D.; Castaneda, Jaime N.; Mondy, Lisa Ann; Brooks, Carlton, F.

    2010-11-01

    We have developed a mature laboratory at Sandia to measure interfacial rheology, using a combination of home-built, commercially available, and customized commercial tools. An Interfacial Shear Rheometer (KSV ISR-400) was modified and the software improved to increase sensitivity and reliability. Another shear rheometer, a TA Instruments AR-G2, was equipped with a du Nouey ring, bicone geometry, and a double wall ring. These interfacial attachments were compared to each other and to the ISR. The best results with the AR-G2 were obtained with the du Nouey ring. A Micro-Interfacial Rheometer (MIR) was developed in house to obtain the much higher sensitivity given by a smaller probe. However, it was found to be difficult to apply this technique for highly elastic surfaces. Interfaces also exhibit dilatational rheology when the interface changes area, such as occurs when bubbles grow or shrink. To measure this rheological response we developed a Surface Dilatational Rheometer (SDR), in which changes in surface tension with surface area are measured during the oscillation of the volume of a pendant drop or bubble. All instruments were tested with various surfactant solutions to determine the limitations of each. In addition, foaming capability and foam stability were tested and compared with the rheology data. It was found that there was no clear correlation of surface rheology with foaming/defoaming with different types of surfactants, but, within a family of surfactants, rheology could predict the foam stability. Diffusion of surfactants to the interface and the behavior of polyelectrolytes were two subjects studied with the new equipment. Finally, surface rheological terms were added to a finite element Navier-Stokes solver and preliminary testing of the code completed. Recommendations for improved implementation were given. When completed we plan to use the computations to better interpret the experimental data and account for the effects of the underlying bulk

  18. Metawidgets in the multimodal interface

    SciTech Connect

    Blattner, M.M. Anderson Cancer Center, Houston, TX ); Glinert, E.P.; Jorge, J.A.; Ormsby, G.R. . Dept. of Computer Science)

    1991-01-01

    We analyze two intertwined and fundamental issues concerning computer-to-human communication in the multimodal interfaces: the interplay between sound and graphics, and the role of object persistence. Our observations lead us to introduce metawidgets as abstract entities capable of manifesting themselves to users as image, as sound, or as various combinations and/or sequences of the two media. We show examples of metawidgets in action, and discuss mechanisms for choosing among alternative media for metawidget instantiation. Finally, we describe a couple of experimental microworlds we have implemented to test out some of our ideas. 17 refs., 7 figs.

  19. Helmholtz solitons at nonlinear interfaces.

    PubMed

    Sánchez-Curto, J; Chamorro-Posada, P; McDonald, G S

    2007-05-01

    Reflection and refraction of spatial solitons at dielectric interfaces, accommodating arbitrarily angles of incidence, is studied. Analysis is based on Helmholtz soliton theory, which eliminates the angular restriction associated with the paraxial approximation. A novel generalization of Snell's law is discovered that is valid for collimated light beams and the entire angular domain. Our new theoretical predictions are shown to be in excellent agreement with full numerical simulations. New qualitative features of soliton refraction and limitations of previous paraxial analyses are highlighted. PMID:17410257

  20. Avalanche dynamics of elastic interfaces.

    PubMed

    Le Doussal, Pierre; Wiese, Kay Jörg

    2013-08-01

    Slowly driven elastic interfaces, such as domain walls in dirty magnets, contact lines wetting a nonhomogeneous substrate, or cracks in brittle disordered material proceed via intermittent motion, called avalanches. Here we develop a field-theoretic treatment to calculate, from first principles, the space-time statistics of instantaneous velocities within an avalanche. For elastic interfaces at (or above) their (internal) upper critical dimension d≥d(uc) (d(uc)=2,4 respectively for long-ranged and short-ranged elasticity) we show that the field theory for the center of mass reduces to the motion of a point particle in a random-force landscape, which is itself a random walk [Alessandro, Beatrice, Bertotti, and Montorsi (ABBM) model]. Furthermore, the full spatial dependence of the velocity correlations is described by the Brownian-force model (BFM) where each point of the interface sees an independent Brownian-force landscape. Both ABBM and BFM can be solved exactly in any dimension d (for monotonous driving) by summing tree graphs, equivalent to solving a (nonlinear) instanton equation. We focus on the limit of slow uniform driving. This tree approximation is the mean-field theory (MFT) for realistic interfaces in short-ranged disorder, up to the renormalization of two parameters at d=d(uc). We calculate a number of observables of direct experimental interest: Both for the center of mass, and for a given Fourier mode q, we obtain various correlations and probability distribution functions (PDF's) of the velocity inside an avalanche, as well as the avalanche shape and its fluctuations (second shape). Within MFT we find that velocity correlations at nonzero q are asymmetric under time reversal. Next we calculate, beyond MFT, i.e., including loop corrections, the one-time PDF of the center-of-mass velocity u[over ·] for dimension d

  1. EXPRESS Pallet Payload Interface Requirements

    NASA Technical Reports Server (NTRS)

    Holt, Alan C.

    2004-01-01

    A viewgraph presentation describing the EXPRESS Pallet Space Station payload interface requirements is shown. The topics include: 1) External Payload Sites; 2) EXPRESS Pallet with Six Payload Envelopes; 3) EXPRESS Pallet in Payload Bay Representative Layout; 4) EXPRESS Pallet Installation SSRMS positions pallet for PAS mating on S3 truss; 5) EXPRESS Pallet Major Components; 6) EXPRESS Pallet Adapter; 7) EXPRESS Pallet Center Location Payload Envelope; 8) Envelope Restriction for EXPRESS Pallet Corner Payload Locations; 9) EXPRESS Pallet-PAS Truss Configuration; and 10) EXPRESS Pallet Payload Services and Specifications.

  2. Praxis input/output interface

    SciTech Connect

    Shapiro, R.E.; Evans, A. Jr.

    1981-01-01

    This document is intended as an introduction to the use of RMS facilities via Praxis (this interface hereafter called Praxis-RMS). It is presumed that the reader is familiar with Praxis conventions as well as with RMS use (at the MACRO level). Since Praxis-RMS was designed to be functionally equivalent to MACRO-RMS, the explanations follow the pattern of the DEC MACRO-RMS documentation (particularly the programmer's reference manual). A complete list of the procedures that make up Praxis-RMS appears at the end of this document (with parameters), along with the constants (grouped by type) that can be used as actual parameters.

  3. Gloved Human-Machine Interface

    NASA Technical Reports Server (NTRS)

    Adams, Richard (Inventor); Olowin, Aaron (Inventor); Hannaford, Blake (Inventor)

    2015-01-01

    Certain exemplary embodiments can provide a system, machine, device, manufacture, circuit, composition of matter, and/or user interface adapted for and/or resulting from, and/or a method and/or machine-readable medium comprising machine-implementable instructions for, activities that can comprise and/or relate to: tracking movement of a gloved hand of a human; interpreting a gloved finger movement of the human; and/or in response to interpreting the gloved finger movement, providing feedback to the human.

  4. The patient-sensor interface

    PubMed Central

    Crockett, G. S.

    1970-01-01

    During the assessment of monitoring equipment on acute medical cases in a general ward, a quantitative investigation of technical faults revealed that 44% of these occurred at the patient-sensor interface. While the attachment of the equipment was accepted by the patient and was suitable for application by nursing staff, this degree of technical breakdown indicates that more progress is necessary in the design of this aspect of monitoring equipment before it is possible to have a reliable system. ImagesFig. 1 PMID:5476136

  5. Gestural interfaces for immersive environments

    NASA Astrophysics Data System (ADS)

    Margolis, Todd

    2014-02-01

    We are witnessing an explosion of new forms of Human Computer Interaction devices lately for both laboratory research and home use. With these new affordance in user interfaces (UI), how can gestures be used to improve interaction for large scale immersive display environments. Through the investigation of full body, head and hand tracking, this paper will discuss various modalities of gesture recognition and compare their usability to other forms of interactivity. We will explore a specific implementation of hand gesture tracking within a large tiled display environment for use with common collaborative media interaction activities.

  6. Physical significance of interfaces on fracture growth

    SciTech Connect

    Wang, J.J.; Guo, Q. )

    1993-08-01

    Details of the interfaces between two geologic materials are normally neglected in predicting the growth of hydraulic fractures. In addition, perfect bonding is assumed across the interface. However, due to a combination of reasons, the perfect bonding assumption is violated to various degrees. Assessment for potential slippage is important to fracture-growth modeling. As a fracture approaches an interface, both mode I (for a fracture crossing the interface) and mode II (for a fracture extending in the interface) stress-intensity factors need to be evaluated. Should the interface properties be such that the mode I stress-intensity factor reach the critical value, the fracture will cross the interface. Should the converse happen and the mode II stress-intensity factor become critical, slippage along the interface will occur. If both the critical stress intensity factors are reached simultaneously, both fractures across the interface and slippage will occur. Good description of the interface material is needed to model the fracturing process. Methodology to model the physical significance of interfaces for calculating two-dimensional fracture growth includes descriptions of applications to oil/gas recovery and the injection of contaminants in isolated formations.

  7. Experiments showing dynamics of materials interfaces

    SciTech Connect

    Benjamin, R.F.

    1997-02-01

    The discipline of materials science and engineering often involves understanding and controlling properties of interfaces. The authors address the challenge of educating students about properties of interfaces, particularly dynamic properties and effects of unstable interfaces. A series of simple, inexpensive, hands-on activities about fluid interfaces provides students with a testbed to develop intuition about interface dynamics. The experiments highlight the essential role of initial interfacial perturbations in determining the dynamic response of the interface. The experiments produce dramatic, unexpected effects when initial perturbations are controlled and inhibited. These activities help students to develop insight about unstable interfaces that can be applied to analogous problems in materials science and engineering. The lessons examine ``Rayleigh-Taylor instability,`` an interfacial instability that occurs when a higher-density fluid is above a lower-density fluid.

  8. Multi-port power electronic interface for renewable energy sources

    NASA Astrophysics Data System (ADS)

    Jiang, Wei

    Energy intensive products and services are penetrating people's daily life as well as different sectors of industry during recent decades. Further effort to improve efficiency, reduce green house gas and hazardous particle emission lead to the emergence of the "more electric" concept in several industries including transportation. This trend, however, burdens the aging power system and existing local power networks. To offer a remedy to the problem and a smooth transition to a more reliable, more diverse, and more efficient power grid of the future, the concept of Multi-port Power Electronic Interface (MPEI) for localized power processing is introduced in this dissertation, which interfaces and manages various sources, loads and storages. Different means of integrating multiple sources and storages into the existing power system are studied and evaluated; the six phase-leg structure is chosen to interface five sources/loads: fuel cell, wind turbine, solar cell, battery and utility grid. Partitioning of source-interface and load-interface on a system level as well as analysis and modeling on small signal level are performed. A novel control structure for source-interface is proposed in the design, which forms Controlled Quasi Current Source (CQCS) during the load sharing operation and offers several salient advantages: • Inherent average current-mode control. • Easy share of steady state current/power. • Share of load dynamics for better source protection. Local control loops for various input ports are designed based on linearized system model; controller performance is tuned to accommodate the characteristics of different sources. To maintain a sustainable operation, different modes of operation are defined for MPEI; detailed state-transition with associated events are also defined in each operation mode. Prototype of MPEI is built and control system is implemented digitally in a digital signal processor; steady state and transient performance of MPEI is

  9. Evaluation of trends in wheat yield models

    NASA Technical Reports Server (NTRS)

    Ferguson, M. C.

    1982-01-01

    Trend terms in models for wheat yield in the U.S. Great Plains for the years 1932 to 1976 are evaluated. The subset of meteorological variables yielding the largest adjusted R(2) is selected using the method of leaps and bounds. Latent root regression is used to eliminate multicollinearities, and generalized ridge regression is used to introduce bias to provide stability in the data matrix. The regression model used provides for two trends in each of two models: a dependent model in which the trend line is piece-wise continuous, and an independent model in which the trend line is discontinuous at the year of the slope change. It was found that the trend lines best describing the wheat yields consisted of combinations of increasing, decreasing, and constant trend: four combinations for the dependent model and seven for the independent model.

  10. American families: trends and correlates.

    PubMed

    Davanzo, J; Rahman, M O

    1993-01-01

    Discussion focused on the nature of the roles of the family, a review of the major demographic changes (marriage, cohabitation, nonfamily households, remarriage, fertility, teenage pregnancy, and female employment) affecting the American family in the past decades, and the nature of the impact on women, men, and children. There were four major trends identified: 1) increased proportions of children living in single-parent families due to high rates of divorce and increased childbearing outside of marriage; 2) increased proportions of adults in nontraditional living arrangements; 3) increased female labor force participation during all stages of the life cycle; and 4) decreased proportions of children and increased proportions of older people out of total population due to declining mortality and fertility rates. Family formation arises out of childbearing and childrearing roles, the need for companionship and emotional support, and the opportunities for specialization and trade, and the economies of scale. The costs of family living may include the potential for disagreement, conflict, loss of privacy, and time and money. There were a number of reasons identified for not maintaining traditional families consisting of a married couple with children. The trends were for later age at marriage: 24.4 years in 1992 for women, increased cohabitation (almost 50% cohabiting prior to first marriage in 1985-86), decreased number of married couple households, and increased number of adults in non-family households. The divorce rate has risen over the past 100 years with peaks in the 1970s; the reasons were identified as increased baby boomers and new marriages, increased labor participation of women, and changes in gender roles. The stabilization and slight decline in rates may be due to a natural leveling, the likelihood of greater stability within new marriages, and the aging of the baby boomers. An anticipated increase in divorce rates in the future was also justified

  11. Signal trend identification with fuzzy methods.

    SciTech Connect

    Reifman, J.; Tsoukalas, L. H.; Wang, X.; Wei, T. Y. C.

    1999-08-19

    A fuzzy-logic-based methodology for on-line signal trend identification is introduced. Although signal trend identification is complicated by the presence of noise, fuzzy logic can help capture important features of on-line signals and classify incoming power plant signals into increasing, decreasing and steady-state trend categories. In order to verify the methodology, a code named PROTREN is developed and tested using plant data. The results indicate that the code is capable of detecting transients accurately, identifying trends reliably, and not misinterpreting a steady-state signal as a transient one.

  12. Recent Trends and Advances in Sedimentology.

    ERIC Educational Resources Information Center

    Suttner, Lee J.

    1979-01-01

    Briefly surveys recent trends and developments in sedimentology. Includes Clastic sedimentary petrology, petrology of argillaceous rocks, terrigenous depositional environments, and chemical sedimentology. (MA)

  13. The interactive digital video interface

    NASA Technical Reports Server (NTRS)

    Doyle, Michael D.

    1989-01-01

    A frequent complaint in the computer oriented trade journals is that current hardware technology is progressing so quickly that software developers cannot keep up. A example of this phenomenon can be seen in the field of microcomputer graphics. To exploit the advantages of new mechanisms of information storage and retrieval, new approaches must be made towards incorporating existing programs as well as developing entirely new applications. A particular area of need is the correlation of discrete image elements to textural information. The interactive digital video (IDV) interface embodies a new concept in software design which addresses these needs. The IDV interface is a patented device and language independent process for identifying image features on a digital video display and which allows a number of different processes to be keyed to that identification. Its capabilities include the correlation of discrete image elements to relevant text information and the correlation of these image features to other images as well as to program control mechanisms. Sophisticated interrelationships can be set up between images, text, and program control mechanisms.

  14. Probing the Buried Magnetic Interfaces.

    PubMed

    Liu, Wenqing; Zhou, Qionghua; Chen, Qian; Niu, Daxin; Zhou, Yan; Xu, Yongbing; Zhang, Rong; Wang, Jinlan; van der Laan, Gerrit

    2016-03-01

    Understanding magnetism in ferromagnetic metal/semiconductor (FM/SC) heterostructures is important to the development of the new-generation spin field-effect transistor. Here, we report an element-specific X-ray magnetic circular dichroism study of the interfacial magnetic moments for two FM/SC model systems, namely, Co/GaAs and Ni/GaAs, which was enabled using a specially designed FM1/FM2/SC superstructure. We observed a robust room temperature magnetization of the interfacial Co, while that of the interfacial Ni was strongly diminished down to 5 K because of hybridization of the Ni d(eg) and GaAs sp(3) states. The validity of the selected method was confirmed by first-principles calculations, showing only small deviations (<0.02 and <0.07 μB/atom for Co/GaAs and Ni/GaAs, respectively) compared to the real FM/SC interfaces. Our work proved that the electronic structure and magnetic ground state of the interfacial FM2 is not altered when the topmost FM2 is replaced by FM1 and that this model is applicable generally for probing the buried magnetic interfaces in the advanced spintronic materials.. PMID:26887429

  15. Continuous Liquid Interface Production (CLIP)

    NASA Astrophysics Data System (ADS)

    Tumbleston, John

    Continuous liquid interface production (CLIP) can rapidly produce 3D parts using a range of polymeric materials. A DLP-based form of additive manufacturing, CLIP proceeds via projecting a sequence of UV images through an oxygen-permeable, UV-transparent window below a liquid resin bath. A thin uncured liquid layer, or dead zone, is created above the window and maintains a liquid interface below the advancing part. Above the dead zone, the curing part is drawn out of the resin bath creating suction forces that renew reactive liquid resin. The dead zone is created due to oxygen inhibition of photopolymerization, a process that is traditionally a nuisance in other photopolymerization applications. However, for CLIP oxygen inhibition and creation of the dead zone allows for a continuous mode of printing where UV exposure, resin renewal, and part elevation are conducted simultaneously. This continual process is fundamentally different from traditional bottom-up stereolithography printers where these steps must be conducted in separate and discrete steps. Furthermore, the relatively gentle nature of CLIP due to the established dead zone enables the use of unique materials with a wide range of mechanical properties. This presentation will showcase the CLIP technology and provide a detailed picture of interactions between different resin and process parameters. New applications for 3D printing that span the micro- to macro-scale enabled by CLIP's combination of unique materials and part production speed will also be presented.

  16. Brain Computer Interfaces, a Review

    PubMed Central

    Nicolas-Alonso, Luis Fernando; Gomez-Gil, Jaime

    2012-01-01

    A brain-computer interface (BCI) is a hardware and software communications system that permits cerebral activity alone to control computers or external devices. The immediate goal of BCI research is to provide communications capabilities to severely disabled people who are totally paralyzed or ‘locked in’ by neurological neuromuscular disorders, such as amyotrophic lateral sclerosis, brain stem stroke, or spinal cord injury. Here, we review the state-of-the-art of BCIs, looking at the different steps that form a standard BCI: signal acquisition, preprocessing or signal enhancement, feature extraction, classification and the control interface. We discuss their advantages, drawbacks, and latest advances, and we survey the numerous technologies reported in the scientific literature to design each step of a BCI. First, the review examines the neuroimaging modalities used in the signal acquisition step, each of which monitors a different functional brain activity such as electrical, magnetic or metabolic activity. Second, the review discusses different electrophysiological control signals that determine user intentions, which can be detected in brain activity. Third, the review includes some techniques used in the signal enhancement step to deal with the artifacts in the control signals and improve the performance. Fourth, the review studies some mathematic algorithms used in the feature extraction and classification steps which translate the information in the control signals into commands that operate a computer or other device. Finally, the review provides an overview of various BCI applications that control a range of devices. PMID:22438708

  17. Body language user interface (BLUI)

    NASA Astrophysics Data System (ADS)

    Brody, Arthur W.; Olmsted, Coert

    1998-07-01

    We analyze a 3D skeletal representation of the user in spatial and temporal domains as a tool necessary to recognizing the gestures of drawing, picking and grabbing. The mechanisms of visual perception that are called upon in the imaginative process of artistic creation use those same tactile and kinesthetic pathways and structures in the brain which are employed when we manipulate the 3D world. We see, in fact, with our sensual bodies as well as with our eyes. Our interface is built on an analysis of pointing and gesturing and how they related to the perception of form in space. We report on our progress in implementing a body language user interface for artistic computer interaction, i.e., an human/computer interaction based on an analysis of how an artist uses her body in the act of creation. Using two synchronous TV cameras, we have videotaped an environment into which an artist moves, assumes a canonical (Da Vinci) pose and subsequently makes a series of simple gestures. The video images are processed to generate an animated 3D skeleton that corresponds to the skeleton of the artist. The locus of the path taken by the drawing hand is the source of a trace of particles. Our presentation shows the two simultaneous videos, the associated animated 3D skeleton, that skeleton as an instance of motion capture for a constrained model of a human skeleton and the trace of the path taken by the drawing hand.

  18. Micromachined devices for interfacing neurons

    NASA Astrophysics Data System (ADS)

    Stieglitz, Thomas; Beutel, Hansjoerg; Blau, Cornelia; Meyer, Joerg-Uwe

    1998-07-01

    Micromachining technologies were established to fabricate microelectrode arrays and devices for interfacing parts of the central or peripheral nervous system. The devices were part of a neural prosthesis that allows simultaneous multichannel recording and multisite stimulation of neurons. Overcoming the brittle mechanics of silicon devices and challenging housing demands close to the nerve we established a process technology to fabricate light-weighted and highly flexible polyimide based devices. Platinum and iridium thin-film electrodes were embedded in the polyimide. With reactive ion etching we got the possibility to simply integrate interconnections and to form nearly arbitrary outer shapes of the devices. We designed multichannel devices with up to 24 electrodes in the shape of plates, hooks and cuffs for different applications. In vitro tests exhibited stable electrode properties and no cytotoxicity of the materials and the devices. Sieve electrodes were chronically implanted in rats to interface the regenerating sciatic nerve. After six months, recordings and stimulation of the nerve via electrodes on the micro-device proved functional reinnervation of the limb. Concentric circular structures were designed for a retina implant for the blind. In preliminary studies in rabbits, evoked potentials in the visual cortex corresponded to stimulation sites of the implant.

  19. Nuclear Proliferation Technology Trends Analysis

    SciTech Connect

    Zentner, Michael D.; Coles, Garill A.; Talbert, Robert J.

    2005-10-04

    A process is underway to develop mature, integrated methodologies to address nonproliferation issues. A variety of methodologies (both qualitative and quantitative) are being considered. All have one thing in common, a need for a consistent set of proliferation related data that can be used as a basis for application. One approach to providing a basis for predicting and evaluating future proliferation events is to understand past proliferation events, that is, the different paths that have actually been taken to acquire or attempt to acquire special nuclear material. In order to provide this information, this report describing previous material acquisition activities (obtained from open source material) has been prepared. This report describes how, based on an evaluation of historical trends in nuclear technology development, conclusions can be reached concerning: (1) The length of time it takes to acquire a technology; (2) The length of time it takes for production of special nuclear material to begin; and (3) The type of approaches taken for acquiring the technology. In addition to examining time constants, the report is intended to provide information that could be used to support the use of the different non-proliferation analysis methodologies. Accordingly, each section includes: (1) Technology description; (2) Technology origin; (3) Basic theory; (4) Important components/materials; (5) Technology development; (6) Technological difficulties involved in use; (7) Changes/improvements in technology; (8) Countries that have used/attempted to use the technology; (9) Technology Information; (10) Acquisition approaches; (11) Time constants for technology development; and (12) Required Concurrent Technologies.

  20. Trends in stratospheric minor constituents

    NASA Technical Reports Server (NTRS)

    Stolarski, R. S.; Chu, W. P.; Coffey, M. T.; Heaps, W. S.; Kaye, J. A.; Mccormick, M. P.; Zander, R.

    1989-01-01

    Photochemical models predict that increasing source gas concentrations are also expected to lead to changes in the concentrations of both catalytically active radical species (such as NO2, ClO, and OH) and inactive reservoir species (such as HNO3, HCl, and H2O). For simplicity, we will refer to all these as trace species. Those species that are expected to have increasing concentration levels are investigated. Additionally, the trace species concentration levels are monitored for unexpected changes on the basis of the measure increase in source gases. Carrying out these investigations is difficult due to the limited data base of measurements of stratospheric trace species. In situ measurements are made only infrequently, and there are few satelliteborne measurements, most over a time space insufficient for trend determination. Instead, ground-based measurements of column content must be used for many species, and interpretation is complicated by contributions from the troposphere or mesosphere or both. In this chapter, we examine existing measurements as published or tabulated.

  1. Vascular Injuries: Trends in Management

    PubMed Central

    Wani, Mohd Lateef; Ahangar, Ab Gani; Ganie, Farooq Ahmad; Wani, Shadab Nabi; Wani, Nasir-ud-din

    2012-01-01

    Abstract Vascular injury presents a great challenge to the emergency resident because these injuries require urgent intervention to prevent loss of life or limb. Sometimes serious vascular injury presents with only subtle or occult signs or symptoms. The patient may present weeks or months after initial injury with symptoms of vascular insufficiency, embolization, pseudoaneurysm, arteriovenous fistula etc. Although the majority of vascular injuries are caused by penetrating trauma from gunshot wounds, stabbing or blast injury, the possibility of vascular injury needs to be considered in patients presenting with displaced long bone fractures, crush injury, prolonged immobilization in a fixed position by tight casts or bandages and various invasive procedures. iatrogenic vascular injuries constitute about 10% of cases in most series; however the incidence is an increasing trend because more endovascular procedures such as angioplasty and cardiac catheterization are being performed routinely. Civilian trauma is more frequently seen in young males. However, it can occur at any age due to road accidents, firearms, bomb blasts and diagnostic procedures. Most of the time, civilian trauma causes less tissue damage. There is an epidemic of vascular injuries in Kashmir valley because of problems in law and order in the past two decades. This review deals with the topic in detail. PMID:24350103

  2. Total ozone trend over Cairo

    NASA Technical Reports Server (NTRS)

    Hassan, G. K. Y.

    1994-01-01

    A world wide interest in protecting ozone layer against manmade effects is now increasing. Assessment of the ozone depletion due to these activities depends on how successfully we can separate the natural variabilities from the data. The monthly mean values of total ozone over Cairo (30 05N) for the period 1968-1988, have been analyzed using the power spectral analysis technique. The technique used in this analysis does not depend on a pre-understanding of the natural fluctuations in the ozone data. The method depends on increasing the resolution of the spectral peaks in order to obtain the more accurate sinusoidal fluctuations with wavelength equal to or less than record length. Also it handles the possible sinusoidal fluctuations with wavelength equal to or less than record length. The results show that it is possible to detect some of the well known national fluctuations in the ozone record such as annual, semiannual, quasi-biennial and quasi-quadrennial oscillations. After separating the natural fluctuations from the ozone record, the trend analysis of total ozone over Cairo showed that a decrease of about -1.2% per decade has occurred since 1979.

  3. Future trends in international terrorism

    SciTech Connect

    Jenkins

    1985-12-01

    This survey offers a depressing but conservative view of future trends in terrorism. Terrorism persists. It may double in volume, but the world does not end in terrorist anarchy. Few changes are foreseen in terrorist tactics or targets. Terrorists will escalate their violence, their attacks will become more indiscriminate, we may see political demands based upon threats of food contamination, but terrorists probably will not enter the Armageddon world of mass destruction. Terrorism will become institutionalized as a mode of armed conflict for some, no less legitimate than other modes of conflict. The media will increase its ability to cover terrorist incidents; we will see even more terrorism. The extraordinary security measures taken against terrorism will have become a permanent part of the landscape, of our life style. They will no longer attract comment. That may be the most insidious and perhaps the most worrisome development in the coming years. Terrorism will become an accepted fact of contemporary life--commonplace, ordinary, banal, and therefore somehow tolerable.

  4. Mask industry assessment trend analysis

    NASA Astrophysics Data System (ADS)

    Shelden, Gilbert; Hector, Scott; Marmillion, Pat; Lercel, Michael

    2006-06-01

    Microelectronics industry leaders routinely name mask cost and cycle time as top issues of concern. In 2002, a survey was created with support from SEMATECH and administered by SEMI North America to gather information about the mask industry as an objective assessment of its overall condition. The survey is designed with the input of mask technologists from semiconductor manufacturers, merchant mask suppliers, and makers of mask equipment. The 2005 survey was the fourth in the current series of annual surveys. The survey data can be used as a baseline for the mask industry and the microelectronics industry to gain a perspective on the technical and business status of the mask industry. The results may be used to guide future investments on critical path issues. Questions are grouped into categories: general business profile information, data processing, yields and yield loss mechanisms, delivery times, returns and services, operating cost factors, and equipment utilization. Because the questions covering operating cost factors and equipment utilization were just added to the survey, no trend analysis is possible. Within each category are many questions that together create a detailed profile of both the business and technical status of the mask industry. The assessment participation has changed from year to year. The 2005 survey, for example, includes inputs from eight major global merchant and captive mask manufacturers whose revenue represents approximately 85% of the global mask market.

  5. Mask industry assessment trend analysis

    NASA Astrophysics Data System (ADS)

    Hughes, Greg; Yun, Henry

    2009-01-01

    Microelectronics industry leaders routinely name the cost and cycle time of mask technology and mask supply as top critical issues. A survey was created with support from SEMATECH to gather information about the mask industry as an objective assessment of its overall condition. This year's survey data were presented in detail at BACUS and the detailed trend analysis presented at EMLC. The survey is designed with the input of semiconductor company mask technologists and merchant mask suppliers. This year's assessment is the seventh in the current series of annual reports. With continued industry support, the report can be used as a baseline to gain perspective on the technical and business status of the mask and microelectronics industries. The report will continue to serve as a valuable reference to identify the strengths and opportunities of the mask industry. The results will be used to guide future investments on critical path issues. This year's survey is basically the same as the surveys in 2005 through 2007. Questions are grouped into seven categories: General Business Profile Information, Data Processing, Yields and Yield Loss, Mechanisms, Delivery Times, Returns, and Services. (Examples are given below). Within each category is a multitude of questions that creates a detailed profile of both the business and technical status of the critical mask industry.

  6. [Charge generation and separation at liquid interfaces

    SciTech Connect

    Eisenthal, K.B.

    1992-01-01

    The research is divided into 3 parts: (1)Sum Frequency Generation (SFG) and Monolayer Structure. Picosecond lasers are combined by difference frequency mixing in a nonlinear crystal to generate picosecond, tunable IR pulses, which are used to study orientation of C[double bond]N and CD[sub 3] chromosphores (head group and tail) on lipid monolayers CD[sub 3](CH[sub 2])[sub 21]CN at air/water interface. (2)Femtosecond Dynamics. The femtosecond colliding pulse mode locked laser is being modified to carry out pump-second harmonic (SH) probe studies at liquid interfaces. Picosecond SH knowhow of intermolecular energy transfer, excited state isomerization, and rotational motions at interfaces is now being applied to femtosecond scale. Aromatics adsorbed at air/water interface, generated changes in SH probe signal and their decay back to original value. If the laser is tightly focussed at interface, multiphoton absorption processes occur which destroy the sample; this effect will be exploited. (3)Interface Potential and Acid-Base Equilibria. The interface potential is a key to charge transport; using SHG, we plan to measure the pKa of organic acids at interfaces. In these studies at silica/aqueous interface, the water molecules extending from the interface into the bulk (about 50[Angstrom]) were strongly polarized by SiO[sup [minus

  7. Tailoring thermal interfaces with nanomaterials

    NASA Astrophysics Data System (ADS)

    Seshadri, Indira

    Thermal interfaces are key to ensure the reliable performance of many semiconductor, energy and electronic systems. High thermal conductivity (k), low elastic modulus (E) interface materials are required to dissipate heat and relieve thermo-mechanical stresses. The aim of this thesis is to develop compliant, high k nanocomposite materials for thermal interface applications utilizing nanostructured networks. Realizing high k nanocomposites is a challenge because of difficulties in incorporating high fractions of uniformly dispersed nanofillers and countering low filler-matrix interfacial conductance, while retaining a low elastic modulus. In this thesis, it is demonstrated that these issues are obviated by using < 5 volume % sub-10-nm cold welded gold nanowire fillers to obtain an unprecedented 30-fold increase in polydimethylsiloxane thermal conductivity that is 6-fold higher than previously reported nanocomposites at low nanofiller loadings and exceeds theoretical predictions. The nanowire diameter and aspect ratio are key to obtain cold-welded networks that enhance k at low filler fractions, while fostering low E. Along with high k, tailoring high thermal contact conductance G c is crucial for many applications. This thesis reveals a critical correlation between the rheological behavior of a high k gold-nanowire-filled polydimethylsiloxane nanocomposite and its thermal contact conductance with copper. At a critical filler fraction, an abrupt increase in the nanocomposite k is accompanied by a liquid-solid transition and a multifold decrease in Gc. These concurrent changes are attributed to nanowire percolation network formation and pre-cure polymer gelation that inhibits the formation of conformal void-free interfaces. These findings will be important for designing processing sequences to realize heterointerfaces with nanowire filled high k nanocomposite materials. Another important finding of this thesis is that nanowire networks can result in mechanical

  8. Measuring the impact of the approach to migration in the quality of web service interfaces

    NASA Astrophysics Data System (ADS)

    Mateos, Cristian; Crasso, Marco; Rodriguez, Juan M.; Zunino, Alejandro; Campo, Marcelo

    2015-01-01

    There is a good consensus on the strategic value of service-oriented architecture (SOA) as a way of structuring systems, and a common trend is to migrate legacy applications that use outdated technologies and architectures to SOA. We study the effects in the resulting Web Service interfaces of applying two traditional migration approaches combined with common ways of building services, namely, direct migration with code-first and indirect migration with contract-first. The migrated system was a 35-year-old COBOL system of a government agency that serves several millions of users. In addition, we provide a deep explanation of the trade-offs involved in following either combinations. Results confirm that the 'fast and cheap' approach to move into SOA, which is commonplace in the industry, may deliver poor service interfaces, and interface quality is also subject to the tools supporting the migration process.

  9. REGIONAL TRENDS IN RURAL SULFUR CONCENTRATIONS

    EPA Science Inventory

    This paper presents an analysis of trends in atmospheric concentrations of sulfur dioxide (SO,) and particulate sulfate (SO42-) at rural monitoring sites in the Clean Air Act Status and Trends Monitoring Network (CASTNet) from 1990 to 1999. A two-stage approach is used to estimat...

  10. Subgroup Achievement and Gap Trends: Oklahoma, 2010

    ERIC Educational Resources Information Center

    Center on Education Policy, 2010

    2010-01-01

    This paper profiles the student subgroup achievement and gap trends in Oklahoma for 2010. Oklahoma made progress in narrowing achievement gaps for most major subgroups on the End-of-Instruction (EOI) test in Algebra I. Trends in achievement gaps could not be determined for other grades in math, or for any grades in reading, because the state…

  11. Statistical Trends in Broadcasting. Ninth Edition.

    ERIC Educational Resources Information Center

    Blair (John) and Co., New York, NY.

    A review of trends in broadcasting and an overall economic profile of the broadcasting industry for 1972, with projections for 1973, are given by a collection of tables and graphs. The first portion presents data on total advertising expenditures and trends, along with information on the gross national product and personal consumption spending.…

  12. Top Four Trends in Student Information Systems

    ERIC Educational Resources Information Center

    Weathers, Robert

    2013-01-01

    The modern student information systems (SIS) is a powerful administrative tool with robust functionality. As such, it is essential that school and district administrators consider the top trends in modern student information systems before going forward with system upgrades or new purchases. These trends, described herein, are: (1) Support for…

  13. Early Childhood Trends around the World

    ERIC Educational Resources Information Center

    Neugebauer, Roger

    2007-01-01

    This article shares the views of the members of the World Forum community regarding early childhood education trends around the world. It summarizes trends from Eastern Europe, the Caucasus, Central Asia, Denmark, The Netherlands, Italy, Turkey, Nepal, Vietnam, Tajikistan, Hong Kong, Singapore, India, New Zealand, Jordan, Palestine, Egypt,…

  14. Trends in high temperature gas turbine materials

    NASA Technical Reports Server (NTRS)

    Grisaffe, S. J.; Dreshfield, R. L.

    1981-01-01

    High performance - high technology materials are among the technologies that are required to allow the fruition of such improvements. Materials trends in hot section components are reviewed, and materials for future use are identified. For combustors, airfoils, and disks, a common trend of using multiple material construction to permit advances in technology is identified.

  15. 2012 Application Trends Survey. Early Release Edition

    ERIC Educational Resources Information Center

    Estrada, Rebecca; Bruggeman, Paula

    2012-01-01

    The 2012 Application Trends Survey conducted by the Graduate Management Admission Council[R] (GMAC[R]) is the industry source for comprehensive statistics and timely insights into the demand for graduate management education worldwide. Since 2000, this survey of admission professionals has provided information on application volume trends,…

  16. Ecotherapy: A Counter to Society's Unhealthy Trend?

    ERIC Educational Resources Information Center

    Sackett, Corrine R.

    2010-01-01

    We are facing a societal trend of lethargy in today's youth. Technology, fear, and limited green spaces keep our children inside and inactive. This article explores this trend and proposes ecotherapy, which promotes mental health in the context of the environment and through the use of green spaces, as a method the counseling profession can…

  17. Trend Toward Multiple Authorship: Update and Extension.

    ERIC Educational Resources Information Center

    Zook, Avery, II

    1987-01-01

    Updated by five years the research of Strahan (1982) who noted trend toward multiple authorship in "Journal of Counseling Psychology" (JCP) articles, and also examined "The Counseling Psychologist" (TCP). Concluded that the trend toward multiple authorship in JCP and TCP may be leveling off. (Author/KS)

  18. Recent Trends in Fiction for Adolescents.

    ERIC Educational Resources Information Center

    Davis, James E.

    1967-01-01

    To determine present trends in junior novels, researchers compared 23 novels written after 1959 with characteristics of junior novels written before that date. The following trends were identified: (1) The action in the majority of novels occurs over a few months. (2) Simple and compound sentences often connected by "and" predominate. (3) The…

  19. Subgroup Achievement and Gap Trends: Kansas, 2010

    ERIC Educational Resources Information Center

    Center on Education Policy, 2010

    2010-01-01

    This paper profiles the student subgroup achievement and gap trends in Kansas for 2010. In grade 8 (the only grade in which subgroup trends were analyzed by achievement level), Kansas students showed across-the-board gains--both reading and math at the basic, proficient, and advanced levels for racial/ethnic subgroups, low income students, and…

  20. Comments on TEC trends. [Thermionic Energy Conversion

    NASA Technical Reports Server (NTRS)

    Morris, J. F.

    1979-01-01

    The paper comments on published and projected thermionic-energy-conversion (TEC) performance trends. This commentary includes graphs and an appendix relating TEC performance parameters, plots of predicted and actual TEC trends, a figure relating projected cost of electricity to overall efficiency for TEC topping, and a discussion of the implications of these relationships.