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Sample records for fundamental molecular bridge

  1. Fundamental Concepts Bridging Education and the Brain

    Science.gov (United States)

    Masson, Steve; Foisy, Lorie-Marlène Brault

    2014-01-01

    Although a number of papers have already discussed the relevance of brain research for education, the fundamental concepts and discoveries connecting education and the brain have not been systematically reviewed yet. In this paper, four of these concepts are presented and evidence concerning each one is reviewed. First, the concept of…

  2. Molecular imaging. Fundamentals and applications

    Energy Technology Data Exchange (ETDEWEB)

    Tian, Jie (ed.) [Chinese Academy of Sciences, Beijing (China). Intelligent Medical Research Center

    2013-07-01

    Covers a wide range of new theory, new techniques and new applications. Contributed by many experts in China. The editor has obtained the National Science and Technology Progress Award twice. ''Molecular Imaging: Fundamentals and Applications'' is a comprehensive monograph which describes not only the theory of the underlying algorithms and key technologies but also introduces a prototype system and its applications, bringing together theory, technology and applications. By explaining the basic concepts and principles of molecular imaging, imaging techniques, as well as research and applications in detail, the book provides both detailed theoretical background information and technical methods for researchers working in medical imaging and the life sciences. Clinical doctors and graduate students will also benefit from this book.

  3. Ergonomics: A bridge between fundamentals and applied research

    Directory of Open Access Journals (Sweden)

    Subrata Ghosh

    2011-01-01

    Full Text Available Ergonomics is becoming a subject of applying fundamentals on anthropocentric dimensions for holistic welfare. The so-called conflict between Basic science and Applied research finds one of its edges in Ergonomics. Be it cutting-edge technology or frontiers of scientific innovation-all start from understanding basic scientific aptitude and skill, and the best way to get familiar with the situation is practicing basic science again and again at a regular basis. Ergonomics is diversified in such paradigms that truly set an example of such harmony between two apparently never-ending straight lines. If the spirit of Science is true human welfare, be it in the form of environmental development, machine development, technological advancement, human resource development, or development of consecutive interfaces between these components, Participatory Ergonomics is one of the vivid examples of such conglomeration. Although fundamental science may appear to be of very little practical significance, it turns out that eventually it has far greater impact on human society than much of the so-called "applied research."

  4. Molecular Determinants Fundamental to Axon Regeneration after SCI

    Science.gov (United States)

    2014-09-01

    TITLE: Molecular Determinants Fundamental to Axon Regeneration after SCI PRINCIPAL INVESTIGATOR: Jeffrey Alan Plunkett, Ph.D. Martin...TYPE FINAL 3. DATES COVERED (From - To) 1 Sept 2011 - 1 Sept 2014 4. TITLE AND SUBTITLE Molecular Determinants Fundamental to Axon Regeneration...available that restore motor impairments resulting fromspinal cord injury (SCI). Soldiers with SCI are permanently paralyzed and in needof lifelong care

  5. Materials fundamentals of molecular beam epitaxy

    CERN Document Server

    Tsao, Jeffrey Y

    1992-01-01

    The technology of crystal growth has advanced enormously during the past two decades. Among, these advances, the development and refinement of molecular beam epitaxy (MBE) has been among the msot important. Crystals grown by MBE are more precisely controlled than those grown by any other method, and today they form the basis for the most advanced device structures in solid-state physics, electronics, and optoelectronics. As an example, Figure 0.1 shows a vertical-cavity surface emitting laser structure grown by MBE. * Provides comprehensive treatment of the basic materials and surface science principles that apply to molecular beam epitaxy * Thorough enough to benefit molecular beam epitaxy researchers * Broad enough to benefit materials, surface, and device researchers * Referenes articles at the forefront of modern research as well as those of historical interest.

  6. Effects of fundamental factors on coupled vibration of wind-rail vehicle-bridge system for long-span cable-stayed bridge

    Institute of Scientific and Technical Information of China (English)

    张明金; 李永乐; 汪斌

    2016-01-01

    In a wind-vehicle-bridge (WVB) system, there are various interactions among wind, vehicle and bridge. The mechanism for coupling vibration of wind-vehicle-bridge systems is explored to demonstrate the effects of fundamental factors, such as mean wind, fluctuating wind, buffeting, rail irregularities, light rail vehicle vibration and bridge stiffness. A long cable-stayed bridge which carries light rail traffic is regarded as a numerical example. Firstly, a finite element model is built for the long cable-stayed bridge. The deck can generally be idealized as three-dimensional spine beam while cables are modeled as truss elements. Vehicles are modeled as mass-spring-damper systems. Rail irregularities and wind fluctuation are simulated in time domain by spectrum representation method. Then, aerodynamic loads on vehicle and bridge deck are measured by section model wind tunnel tests. Eight vertical and torsional flutter derivatives of bridge deck are identified by weighting ensemble least-square method. Finally, dynamic responses of the WVB system are analyzed in a series of cases. The results show that the accelerations of the vehicle are excited by the fluctuating wind and the track irregularity to a great extent. The transverse forces of wheel axles mainly depend on the track irregularity. The displacements of the bridge are predominantly determined by the mean wind and restricted by its stiffness. And the accelerations of the bridge are enlarged after adding the fluctuating wind.

  7. TiO2-Based Photocatalytic Process for Purification of Polluted Water: Bridging Fundamentals to Applications

    Directory of Open Access Journals (Sweden)

    Chuan Wang

    2013-01-01

    Full Text Available Recent years have witnessed a rapid accumulation of investigations on TiO2-based photocatalysis, which poses as a greatly promising advanced oxidation technology for water purification. As the ability of this advanced oxidation process is well demonstrated in lab and pilot scales to decompose numerous recalcitrant organic compounds and microorganism as well in water, further overpass of the hurdles that stand before the real application has become increasingly important. This review focuses on the fundamentals that govern the actual water purification process, including the fabrication of engineered TiO2-based photocatalysts, process optimization, reactor design, and economic consideration. The state of the art of photocatalyst preparation, strategies for process optimization, and reactor design determines the enhanced separation of photo-excited electron-hole (e-h pairs on the TiO2 surface. For the process optimization, the kinetic analysis including the rate-determining steps is in need. For large-scale application of the TiO2-based photocatalysis, economics is vital to balance the fundamentals and the applied factors. The fundamentals in this review are addressed from the perspective of a bridge to the real applications. This review would bring valuably alternative paradigm to the scientists and engineers for their associated research and development activities with an attempt to push the TiO2-based photocatalysis towards industrially feasible applications.

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

    CERN Document Server

    Fernández, Ariel

    2016-01-01

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

  9. Communication through molecular bridges: different bridge orbital trends result in common property trends.

    Science.gov (United States)

    Proppe, Jonny; Herrmann, Carmen

    2015-02-05

    Common trends in communication through molecular bridges are ubiquitous in chemistry, such as the frequently observed exponential decay of conductance/electron transport and of exchange spin coupling with increasing bridge length, or the increased communication through a bridge upon closing a diarylethene photoswitch. For antiferromagnetically coupled diradicals in which two equivalent spin centers are connected by a closed-shell bridge, the molecular orbitals (MOs) whose energy splitting dominates the coupling strength are similar in shape to the MOs of the dithiolated bridges, which in turn can be used to rationalize conductance. Therefore, it appears reasonable to expect the observed common property trends to result from common orbital trends. We illustrate based on a set of model compounds that this assumption is not true, and that common property trends result from either different pairs of orbitals being involved, or from orbital energies not being the dominant contribution to property trends. For substituent effects, an effective modification of the π system can make a comparison difficult.

  10. Raman Scattering at Plasmonic Junctions Shorted by Conductive Molecular Bridges

    Energy Technology Data Exchange (ETDEWEB)

    El-Khoury, Patrick Z.; Hu, Dehong; Apkarian, V. Ara; Hess, Wayne P.

    2013-04-10

    Intensity spikes in Raman scattering, accompanied by switching between line spectra and band spectra, can be assigned to shorting the junction plasmon through molecular conductive bridges. This is demonstrated through Raman trajectories recorded at a plasmonic junction formed by a gold AFM tip in contact with a silver surface coated either with biphenyl-4,4’-dithiol or biphenyl-4-thiol. The fluctuations are absent in the monothiol. In effect, the making and breaking of chemical bonds is tracked.

  11. Hydrogen molecular ions for improved determination of fundamental constants

    CERN Document Server

    Karr, J -Ph; Koelemeij, Jeroen; Korobov, Vladimir

    2016-01-01

    The possible use of high-resolution rovibrational spectroscopy of the hydrogen molecular ions H + 2 and HD + for an independent determination of several fundamental constants is analyzed. While these molecules had been proposed for metrology of nuclear-to-electron mass ratios, we show that they are also sensitive to the radii of the proton and deuteron and to the Rydberg constant at the level of the current discrepancies colloquially known as the proton size puzzle. The required level of accuracy, in the 10 --12 range, can be reached both by experiments, using Doppler-free two-photon spectroscopy schemes, and by theoretical predictions. It is shown how the measurement of several well-chosen rovibrational transitions may shed new light on the proton-radius puzzle, provide an alternative accurate determination of the Rydberg constant, and yield new values of the proton-to-electron and deuteron-to-proton mass ratios with one order of magnitude higher precision.

  12. Electronic transmission of three-terminal pyrene molecular bridge

    Institute of Scientific and Technical Information of China (English)

    Wang Li-Guang; Zhang Xiu-Mei; Terence Kin Shun Wong; Katsunori Tagami; Masaru Tsukada

    2009-01-01

    This paper investigates theoretically the electronic transmission spectra of the three terminal pyrene molecular bridge and the quantum current distribution on each bond by the tight-binding model based on nonequilibrium Green's function and the quantum current density approach, in which one π molecular orbital is taken into account per carbon atom when the energy levels and HOMO-LUMO gap are obtained. The transmission spectra show that the electronic transmission of the three terminal pyrene molecular bridge depends obviously on the incident electronic energy and the pyrene eigenencrgy. The symmetrical and oscillation properties of the transmission spectra are illustrated. A novel plus-minus energy switching function is found. The quantum current distribution shows that the loop currents inside the pyrene are induced, and some bond currents are much larger than the input and the output currents. The reasons why the loop currents and the larger bond currents are induced are the phase difference of the atomic orbits and the degeneracy of the molecular orbits. The calculations illustrate that the quantum current distributions are in good agreement with Kirchhoff quantum current conservation law.

  13. Fundamentals and application of ordered molecular assemblies to affinity biosensing.

    Science.gov (United States)

    Matharu, Zimple; Bandodkar, Amay Jairaj; Gupta, Vinay; Malhotra, Bansi Dhar

    2012-02-07

    Organization of biomolecules in two/three dimensional assemblies has recently aroused much interest in nanobiotechnology. In this context, the development of techniques for controlling spatial arrangement and orientation of the desired molecules to generate highly-ordered nanostructures in the form of a mono/multi layer is considered highly significant. The studies of monolayer films to date have focused on three distinct methods of preparation: (i) the Langmuir-Blodgett (LB) technique, involving the transfer of a monolayer assembled at the gas-liquid interface; (ii) self-assembly at the liquid-solid interface, based on spontaneous adsorption of desired molecules from a solution directly onto a solid surface; and (iii) Layer-by-layer (LBL) self-assembly at a liquid-solid interface, based on inter-layer electrostatic attractions for fabrication of multilayers. A variety of monolayers have been utilized to fabricate biomolecular electronic devices including biosensors. The composition of a monolayer based matrix has been found to influence the activity(ies) of biomolecule(s). We present comprehensive and critical analysis of ordered molecular assemblies formed by LB and self-assembly with potential applications to affinity biosensing. This critical review on fundamentals and application of ordered molecular assemblies to affinity biosensing is likely to benefit researchers working in this as well as related fields of research (401 references).

  14. Matters of taste: bridging molecular physiology and the humanities.

    Science.gov (United States)

    Rangachari, P K; Rangachari, Usha

    2015-12-01

    Taste perception was the focus of an undergraduate course in the health sciences that bridged the sciences and humanities. A problem-based learning approach was used to study the biological issues, whereas the cultural transmutations of these molecular mechanisms were explored using a variety of resources (novels, cookbooks, and films). Multiple evaluation procedures were used: problem summaries and problem-solving exercises (tripartite problem-solving exercise) for the problem-based learning component and group tasks and individual exercises for the cultural issues. Self-selected groups chose specific tasks from a prescribed list of options (setting up a journal in molecular gastronomy, developing an electronic tongue, designing a restaurant for synesthetes, organizing a farmers' market, marketing a culinary tour, framing hedonic scales, exploring changing tastes through works of art or recipe books, and crafting beers for space travel). Individual tasks were selected from a menu of options (book reviews, film reviews, conversations, creative writing, and oral exams). A few guest lecturers (wine making, cultural anthropology, film analysis, and nutritional epidemiology) added more flavor. The course was rated highly for its learning value (8.5 ± 1.2, n = 62) and helped students relate biological mechanisms to cultural issues (9.0 ± 0.9, n = 62).

  15. Fundamental Approaches in Molecular Biology for Communication Sciences and Disorders

    Science.gov (United States)

    Bartlett, Rebecca S.; Jette, Marie E.; King, Suzanne N.; Schaser, Allison; Thibeault, Susan L.

    2012-01-01

    Purpose: This contemporary tutorial will introduce general principles of molecular biology, common deoxyribonucleic acid (DNA), ribonucleic acid (RNA), and protein assays and their relevance in the field of communication sciences and disorders. Method: Over the past 2 decades, knowledge of the molecular pathophysiology of human disease has…

  16. Fundamental Approaches in Molecular Biology for Communication Sciences and Disorders

    Science.gov (United States)

    Bartlett, Rebecca S.; Jette, Marie E.; King, Suzanne N.; Schaser, Allison; Thibeault, Susan L.

    2012-01-01

    Purpose: This contemporary tutorial will introduce general principles of molecular biology, common deoxyribonucleic acid (DNA), ribonucleic acid (RNA), and protein assays and their relevance in the field of communication sciences and disorders. Method: Over the past 2 decades, knowledge of the molecular pathophysiology of human disease has…

  17. Kinetic stabilization against the oxidation reaction induced by a silaalkane cage in a thiophene-bridged molecular gyroscope.

    Science.gov (United States)

    Setaka, Wataru; Ohmizu, Soichiro; Kira, Mitsuo

    2014-02-01

    Macrocage molecules with a bridged rotor have been synthesized as molecular gyroscopes. The kinetics of the oxidation reaction of the thiophene-bridged molecular gyroscope, whose thiophene ring was bridged inside a silaalkane cage, was investigated. A remarkable kinetic stabilization against the oxidation of the thiophene moiety induced by the molecular cage framework was observed.

  18. Relativistic quantum chemistry the fundamental theory of molecular science

    CERN Document Server

    Reiher, Markus

    2014-01-01

    Einstein proposed his theory of special relativity in 1905. For a long time it was believed that this theory has no significant impact on chemistry. This view changed in the 1970s when it was realized that (nonrelativistic) Schrödinger quantum mechanics yields results on molecular properties that depart significantly from experimental results. Especially when heavy elements are involved, these quantitative deviations can be so large that qualitative chemical reasoning and understanding is affected. For this to grasp the appropriate many-electron theory has rapidly evolved. Nowadays relativist

  19. Molecular Fundaments of Mechanical Properties of Spider Silk

    Institute of Scientific and Technical Information of China (English)

    潘志娟; 刘敏; 李春萍; 李栋高; 盛家镛

    2003-01-01

    Dragline,framework and cocoon silk fibers of Araneus Ventricosus were used for this study.To investigate the microstructure mechanisms of stress-strain behavior of spider silk,firstly,amino acid compositions were analyzed and molecular conformations and crystallinity were measured with Raman spectra and X-ray diffraction respectively.The results showed that there were more amino acids with large side groups and polar ones in spider silk than those of Bombyx silk,and the amino acid distribution varied with different spider silk.The molecular structures were mainly α-helix and β-sheet,and random coil and β-turn existed as well.The proportions and arrangement of these conformations of dragline silk were different from framework and cocoon silk fibers.Microstructure was one of important factors of excellent mechanical properties of spider silk.Crystallinity of spider silk was very low,which implied that the roles of crystal on spider silk were not as great as other protein fibers.

  20. Photoinduced electron transfer across molecular bridges: electron- and hole-transfer superexchange pathways.

    Science.gov (United States)

    Natali, Mirco; Campagna, Sebastiano; Scandola, Franco

    2014-06-21

    Photoinduced electron transfer plays key roles in many areas of chemistry. Superexchange is an effective model to rationalize photoinduced electron transfer, particularly when molecular bridges between donor and acceptor subunits are present. In this tutorial review we discuss, within a superexchange framework, the complex role played by the bridge, with an emphasis on differences between thermal and photoinduced electron transfer, oxidative and reductive photoinduced processes, charge separation and charge recombination. Modular bridges are also considered, with specific attention to the distance dependence of donor-acceptor electronic coupling and electron transfer rate constants. The possibility of transition, depending on the bridge energetics, from coherent donor-acceptor electron transfer to incoherent charge injection and hopping through the bridge is also discussed. Finally, conceptual analogies between bridge effects in photoinduced electron transfer and optical intervalence transfer are outlined. Selected experimental examples, instrumental to illustration of the principles, are discussed.

  1. Fundamental studies of molecularly imprinted polymers and atropisomers

    Science.gov (United States)

    Rushton, Gregory T.

    Three distinct research goals governed the work presented herein. First, methods for characterizing the binding properties of molecularly imprinted polymers (MIPs) were investigated and reported upon. We found that although the heterogeneous nature of these materials produced highly concentration-dependent adsorption behavior, there was a dearth of analytical methods that had been previously applied that accommodated this feature. The merits of the Freundlich Isotherm in describing MIP binding properties was evaluated and found to be useful under most conditions tested. Based on this and other previous work, we also presented a more qualitative approach to analyzing MIPs using log-log isotherms. The advantage of this method was that the most important properties to a researcher, the polymer's capacity and selectivity, were easily evaluated through a visual inspection of the log-log isotherm. This approach avoided the necessity of assuming and applying a particular binding model to the isotherm before a determination of the material's utility could be assessed. When this analysis was applied to a MIP for (+)-cinchonine in aqueous and organic media, the results indicated that diastereoselectivity was achieved under both conditions. Second, host-guest interactions between a N,N'-diaryl naphthalene diimide atropisomer and a variety of organic molecules were investigated to determine the relationship between the strength of the complex formed and the rotational barrier about a Caryl-Nimide bond. We found that the barrier was sensitive to both the identity and the concentration of guest which afforded fine control over the rotational freedom of the system. This control was exploited in the design of a reversible molecular brake. Finally, two laboratory investigations based upon the these research projects were developed for use in undergraduate chemistry courses. The first was designed for a polymer course where the students investigate the binding properties of an ethyl

  2. Collective Molecular Dynamics of a Floating Water Bridge

    CERN Document Server

    Del Giudice, Emilio; Vitiello, Giuseppe

    2010-01-01

    When a high voltage is applied to pure water filling two beakers kept close to each other, a connection forms spontaneously, giving the impression of a floating water bridge. This phenomenon is of special interest, since it comprises a number of phenomena currently tackled in modern water science. The formation and the main properties of this floating water bridge are analyzed in the conceptual framework of quantum electrodynamics. The necessary conditions for the formation are investigated as well as the time evolution of the dynamics. The predictions are found in agreement with the observations.

  3. Conductance of three-terminal molecular bridge based on tight-binding theory

    Institute of Scientific and Technical Information of China (English)

    Wang Li-Guang; Li Yong; Yu Ding-Wen; Katsunori Tagami; Masaru Tsukada

    2005-01-01

    The quantum transmission characteristic of three-benzene ring nano-molecular bridge is investigated theoretically by using Green's function approach based on tight-binding theory with only aπ orbital per carbon atom at the site.The transmission probabilities that electrons transport through the molecular bridge from one terminal to the other two terminals are obtained. The electronic current distributions inside the molecular bridge are calculated and shown in graphical analogy by the current density method based on Fisher-Lee formula at the energy points E=±0.42,±1.06 and ±1.5, respectively, where the transmission spectra appear peaks. We find that the transmission spectra are related to the incident electronic energy and the molecular levels strongly, and the current distributions agree well with Kirchhoff quantum current momentum conservation law.

  4. Relationship between activation volume and polymer matrix effects on photochromic performance: bridging molecular parameter to macroscale effect.

    Science.gov (United States)

    Shima, Kentaro; Mutoh, Katsuya; Kobayashi, Yoichi; Abe, Jiro

    2015-02-19

    Photochromic compounds have attracted attention as ophthalmic lenses because of their reversible color modulation upon irradiation with light. However, the efficiency of the photochromism is strongly affected by their surrounding because of the structural changes concomitant with the photochromism, which causes the decrease in the photochromic performance in the polymer matrix. Therefore, the clarification of the degree of the structural changes is necessary to apply to the ophthalmic lenses. Bridged imidazole dimers are one of the fast photoswitch molecules possessing high photochromic quantum yield and durability. Although the enhancement of the photochromic properties of bridged imidazole dimers has been vigorously studied, the quantitative information about the structural changes has not been revealed in detail. In this study, we investigated the pressure effects on the photochromic properties of bridged imidazole dimers. The activation volume for the thermal back-reaction of the photogenerated biradical species becomes an effective measure to predict the degree of the structural change during the photochromic reaction. We revealed that the smaller activation volume is suitable for keeping the efficient photochromic reaction in the polymer matrix because the photochromic reaction is not affected by the surroundings. These fundamental insights into the molecular dynamics provide valuable information to develop fast photochromic compounds that are suitable for the use in the polymer matrix and pressure sensitive photochromic materials.

  5. Vibration-induced inelastic effects in the electron transport through multisite molecular bridges.

    Science.gov (United States)

    Zimbovskaya, Natalya A; Kuklja, Maija M

    2009-09-21

    We theoretically analyzed inelastic effects in the electron transport through molecular junctions originating from electron-vibron interactions. The molecular bridge was simulated by a periodical chain of identical hydrogenlike atoms with the nearest neighbors interaction thus providing a set of energy states for the electron tunneling. To avoid difficulties inevitably arising when advanced computational techniques are employed to study inelastic electron transport through multilevel bridges, we propose and develop a semiphenomenological approach. The latter is based on Buttiker's dephasing model within the scattering matrix formalism. We apply the proposed approach to describe features associated with electron energy transfer to vibrational phonons that appear in the second derivative of the current in the junction with respect to the bias voltage. In the particular case of a single level bridge our results agree with those obtained by proper calculations carried out within the nonequilibrium Green's functions method indicating the usefulness of the suggested approach.

  6. Modular Approaches to Flouride-Bridged Molecular Magnetic Materials

    DEFF Research Database (Denmark)

    Pedersen, Kasper Steen

    coordination polymer [Zn(viz)4ReF6] (viz = 1-vinylimidazole), demonstrating the irrelevance of low symmetry for such magnetization dynamics in systems with easy-plane magnetic anisotropy. The ability of fluoride to mediate significant exchange interactions is exemplified by the isostructural [M(viz)4ReF6] (M......Abstract While oxygen and nitrogen are ubiquitous as bridging ligators in molecule-based magnetic systems, fluoride is much less explored and studied in this respect. In this project, new polynuclear complexes and one-dimensional polymeric systems, based on fluoride linkages between transition...... metal ions and between transition metal and lanthanide ions, have been synthetized and thoroughly characterized. Assembly of kinetically robust 3d fluoride complexes with various lanthanide precursors has proven to be a convenient route to small heterometallic complexes. However, the use of more labile...

  7. Nature of water molecular bridging of the soil organic matter

    Science.gov (United States)

    Kucerik, Jiri; Siewert, Christian; Quilesfogel-Esparza, Claudia; Schaumann, Gabriele E.

    2014-05-01

    Soil is a complex anisotropic and porous system consisting of both inorganic and organic parts, air and water, inhabited and successively transformed by soil biota. Processes of soil formation are influenced by several factors. Among the most important factors belong the inorganic and organic input materials, which are mixed and transformed during soil formation. As a result, specific interactions and interrelationships develop between soil compartments. Although, they are important for soil function and its stability, they are still not well understood. This work deals with water molecule bridges (WaMB), as one of those interactions, and their relation to organic matter functioning. Differential scanning calorimetry (DSC) belongs to the family of methods of thermal analysis, i.e. it uses heat as a probe of the sample's nature. In soil science, the application of this common method is quite rare. In our previous works, DSC revealed a physical stabilization of organic matter segments in soils by development of WaMB. Results suggested the development of those bridges at ambient temperature accompanied with condensation of water into small nanodroplets. In another work, we found out that water, evaporating at the same temperature as WaMB transition occurs, correlates with the activity of soil microorganisms measured via CO2respiration. In this work, the enthalpy and kinetic parameters of water evaporation are studied in two kinds of soil: in clay-rich chernozem soils originating from Siberia and a histosol collected in Germany. We discuss the details of application of DSC, experimental arrangement and advantages and disadvantages of this approach. It is shown that enthalpy of evaporation can be used for understanding the nature of water binding in soils with well-developed aggregates. In contrast, the evaporation of water from histosol, without a typical soil texture, is more complicated because of diffusion processes. Further, the connection between enthalpy of

  8. Fundamental Transitions and Ionization Energies of the Hydrogen Molecular Ions with Few ppt Uncertainty.

    Science.gov (United States)

    Korobov, Vladimir I; Hilico, L; Karr, J-Ph

    2017-06-09

    We calculate ionization energies and fundamental vibrational transitions for H_{2}^{+}, D_{2}^{+}, and HD^{+} molecular ions. The nonrelativistic quantum electrodynamics expansion for the energy in terms of the fine structure constant α is used. Previous calculations of orders mα^{6} and mα^{7} are improved by including second-order contributions due to the vibrational motion of nuclei. Furthermore, we evaluate the largest corrections at the order mα^{8}. That allows us to reduce the fractional uncertainty to the level of 7.6×10^{-12} for fundamental transitions and to 4.5×10^{-12} for the ionization energies.

  9. Fundamental Limits:. Developing New Tools for a Better Understanding of Second-Order Molecular Nonlinear Optics

    Science.gov (United States)

    Pérez-Moreno, Javier; Clays, Koen

    The generalized Thomas-Kuhn sum rules are used to characterize the nonlinear optical response of organic chromophores in terms of fundamental parameters that can be measured experimentally. The nonlinear optical performance of organic molecules is evaluated from the combination of hyper-Rayleigh scattering measurements and the analysis in terms of the fundamental limits. Different strategies for the enhancement of nonlinear optical behavior at the molecular and supramolecular level are evaluated and new paradigms for the design of more efficient nonlinear optical molecules are proposed and investigated.

  10. Building the bridge between molecular diagnostics and therapeutics.

    Science.gov (United States)

    Schweikhardt, R Gary; Piepenbrock, Christian; Sledziewski, Andrew Z

    2003-11-01

    Molecular diagnostics will ultimately have a broad and significant impact on patient treatment. An array of emerging diagnostic tests answer specific and important clinical questions which could offer opportunities for existing and new therapeutics. The development of new diagnostic tests will take time and will require investment in new strategies to find the optimum set of markers, as well as education programs to persuade clinicians, payers and patients to use the new tests and take advantage of the improved therapeutics. Competition among the molecular technologies will be intense; however, it is expected that the most successful companies will exploit synergies between the technologies to develop the most effective molecular diagnostics and, in turn, will improve efficacy of therapeutic practice.

  11. Wind resistance challenges and fundamental research on long-span bridges%大跨度桥梁抗风技术挑战与基础研究

    Institute of Scientific and Technical Information of China (English)

    项海帆; 葛耀君

    2011-01-01

    With the rapid development of long span bridges in China, this paper focused on some engineering projects related to wind resistance challenges on three types of long span bridges, including flutter instability and control of suspension bridges, wind induced vibration of cable-stayed bridges and control of wind-rain induced cable vibration, vortex shedding vibration and control of arch bridges, and the refinements on aerodynamic flutterand buffeting of super long span bridges. It can be concluded that the intrinsic limit of span length due to aerodynamic stability is about 1 500 m for a traditional suspension bridge, and beyond or even approaching this limit, designers should be prepared to improve aerodynamic stability. The long-span cable-stayed bridges with a 1 000 m main span have high enough critical flutter speed, but the main aerodynamic concern is rain-wind induced vibration of long stay cables. Except one example of vortex-induced vibration, long-span arch bridges have no wind resistance problems. The fundamental research on wind resistance of long-span bridges was also introduced with the full-mode flutter analysis method as 3D bridge flutter precise analysis, the bridge buffeting frequency-domain analysis under skew wind action, the bridge flutter and buffeting reliability evaluation method based on second order theory and first passage theory, and the unveiling of bridge flutter evoluation process, generation mechanism and control law.%以我国30年大跨度桥梁的快速发展为研究背景,对3种大跨度桥梁的抗风技术挑战进行了基础性研究和应用性研究,着重探讨了悬索桥的颤振性能及其控制、斜拉桥风振性能与拉索风雨振控制、拱式桥涡激共振及其控制、特大桥梁风振精细化理论等一系列抗风关键问题.研究结果表明:悬索桥的颤振稳定性跨径上限约为1 500m,超过甚至接近这一上限时,必须采取措施改善加劲梁的抗风稳定性;千米级大跨度斜

  12. Some fundamental problems for an energy conserving adaptive resolution molecular dynamics scheme

    OpenAIRE

    Site, L. Delle

    2007-01-01

    Adaptive resolution molecular dynamics (MD) schemes allow for changing the number of degrees of freedom on the fly and preserve the free exchange of particles between regions of different resolution. There are two main alternatives on how to design the algorithm to switch resolution using auxiliary ''switching'' functions; force based and potential energy based approach. In this work we show that, in the framework of classical MD, the latter presents fundamental conceptual problems which make...

  13. Electronic transport in fullerene C20 bridge assisted by molecular vibrations.

    Science.gov (United States)

    Yamamoto, Takahiro; Watanabe, Kazuyuki; Watanabe, Satoshi

    2005-08-01

    The effect of molecular vibrations on electronic transport is investigated with the smallest fullerene C20 bridge, utilizing the Keldysh nonequilibrium Green's function techniques combined with the tight-binding molecular-dynamics method. Large discontinuous steps appear in the differential conductance when the applied bias voltage matches particular vibrational energies. The magnitude of the step is found to vary considerably with the vibrational mode and to depend on the local electronic states besides the strength of electron-vibration coupling. On the basis of this finding, a novel way to control the molecular motion by adjusting the gate voltage is proposed.

  14. Building bridges between cellular and molecular structural biology.

    Science.gov (United States)

    Patwardhan, Ardan; Brandt, Robert; Butcher, Sarah J; Collinson, Lucy; Gault, David; Grünewald, Kay; Hecksel, Corey; Huiskonen, Juha T; Iudin, Andrii; Jones, Martin L; Korir, Paul K; Koster, Abraham J; Lagerstedt, Ingvar; Lawson, Catherine L; Mastronarde, David; McCormick, Matthew; Parkinson, Helen; Rosenthal, Peter B; Saalfeld, Stephan; Saibil, Helen R; Sarntivijai, Sirarat; Solanes Valero, Irene; Subramaniam, Sriram; Swedlow, Jason R; Tudose, Ilinca; Winn, Martyn; Kleywegt, Gerard J

    2017-07-06

    The integration of cellular and molecular structural data is key to understanding the function of macromolecular assemblies and complexes in their in vivo context. Here we report on the outcomes of a workshop that discussed how to integrate structural data from a range of public archives. The workshop identified two main priorities: the development of tools and file formats to support segmentation (that is, the decomposition of a three-dimensional volume into regions that can be associated with defined objects), and the development of tools to support the annotation of biological structures.

  15. Modular Approaches to Flouride-Bridged Molecular Magnetic Materials

    DEFF Research Database (Denmark)

    Pedersen, Kasper Steen

    spectroscopy. Lanthanides are interesting components for magnetic materials and have a huge underexplored potential in molecular magnetic systems. Advancements are, however, significantly hindered by their complicated electronic and magnetic nature. In this project, we have studied the properties of a class...... parameter make complexes with central ions from the 4d and 5d series particularly interesting building blocks for magnetic materials. The main obstacle is the common inherent lability of hexafluoridometallates towards hydrolysis, a tendency that is strongly diminished for several 4d and 5d [MF6]2– complexes......) and electron paramagnetic resonance (EPR) spectroscopies, the magnetic properties of the isolated [ReF6]2– unit in (PPh4)2[ReF6]·2H2O have been fully studied including the slow relaxation of the magnetization observed below ca. 4 K. This slow dynamic is preserved for the tetragonal, one...

  16. Molecular Pathways Bridging Frontotemporal Lobar Degeneration and Psychiatric Disorders

    Directory of Open Access Journals (Sweden)

    Roberta eZanardini

    2016-02-01

    Full Text Available The overlap of symptoms between neurodegenerative and psychiatric diseases has been reported. Neuropsychiatric alterations are commonly observed in dementia, especially in the behavioral variant of frontotemporal dementia (bvFTD, which is the most common clinical FTD subtype. At the same time, psychiatric disorders, like schizophrenia, can display symptoms of dementia, including features of frontal dysfunction with relative sparing of memory. In the present review we discuss common molecular features in these pathologies with a special focus on FTD. Molecules like Brain Derived Neurotrophic Factor (BDNF and progranulin are linked to the pathophysiology of both neurodegenerative and psychiatric diseases. In these brain-associated illnesses, the presence of disease-associated variants in BDNF and progranulin (GRN genes cause a reduction of circulating proteins levels, through alterations in proteins expression or secretion. For these reasons, we believe that prevention and therapy of psychiatric and neurological disorders could be achieved enhancing both BDNF and progranulin levels thanks to drug discovery efforts.

  17. Nitrogen and oxygen bridged calixaromatics: synthesis, structure, functionalization, and molecular recognition.

    Science.gov (United States)

    Wang, Mei-Xiang

    2012-02-21

    Pedersen, Lehn, and Cram established supramolecular chemistry through their pioneering work with crown ethers, cryptands, and spherands. Since then, the hallmark of supramolecular science has been an increasing sophistication in the design and construction of macrocyclic molecules, as manifested in cyclodextrin derivatives, calixarenes, resorcinarenes, cyclotriveratrylenes, cucurbiturils, calixpyrroles, cyclophanes, and many other examples. Indeed, macrocyclic compounds provide unique models for the study of noncovalent molecular interactions. They also constitute building blocks for constructing high-level molecular and supramolecular architectures and fabricating molecular devices and advanced materials. As a postgraduate in the Huang laboratory in the late 1980s, I became interested in the calix[n]arenes because of their unique conformational structures and versatile complexation properties. The notion of introducing heteroatoms, and particularly nitrogen, into the bridging position of conventional calixarenes was particularly intriguing. Nitrogen, unlike methylene, can adopt either an sp(2) or sp(3) electronic configuration, providing different conjugation systems with adjacent aromatic rings. Consequently, depending on the configuration and conjugation, a range of C-N bond lengths and C-N-C bond angles is possible. The conformation and cavity size in heteroatom-bridged calixarenes might thus be tuned through the bridging heteroatoms and the number of aromatic rings. Furthermore, because heteroatom linkages significantly affect the electron density and distribution on aromatic rings, the electronic features of macrocyclic cavities might be regulated by heteroatoms. Given the essentially limitless combinations possible, only synthetic hurdles would prevent access to numerous diverse heteracalixaromatics. We began a systematic study on nitrogen- and oxygen-bridged calixarenes in 2000, years later than originally envisioned. Before this study, very few

  18. Fundamentals of photoelectric effects in molecular electronic thin film devices: applications to bacteriorhodopsin-based devices.

    Science.gov (United States)

    Hong, F T

    1995-01-01

    This tutorial lecture focuses on the fundamental mechanistic aspects of light-induced charge movements in pigment-containing membranes. The topic is relevant to molecular electronics because many prototypes optoelectronic devices are configured as pigment-containing thin films. We use reconstituted bacteriorhodopsin membranes as an example to illustrate the underlying principle of measurements and data interpretation. Bacteriorhodopsin, a light-driven proton pump, is the only protein component in the purple membrane of Halobacterium halobium. It resembles the visual pigment rhodopsin chemically but performs the function of photosynthesis. Bacteriorhodopsin thus offers an unprecedented opportunity for us to compare the visual photoreceptor and the photosynthetic apparatus from a mechanistic point of view. Bacteriorhodopsin, well known for its exceptional chemical and mechanical stability, is also a popular advanced biomaterial for molecular device construction. The tutorial approaches the subject from two angles. First, the fundamental photoelectric properties are exploited for device construction. Second, basic design principles for photosensors and photon energy converters can be elucidated via 'reverse engineering'. The concept of molecular intelligence and the principle of biomimetic science are discussed.

  19. Estimation of Fundamental Frequency of Multi-Pylon Suspension Bridges%多塔连跨悬索桥基频估算方法

    Institute of Scientific and Technical Information of China (English)

    王本劲; 马如进; 陈艾荣

    2011-01-01

    近年来,在跨海大桥的兴建中,多塔连跨悬索桥的方案引起了越来越多的关注.但由于中间桥塔处约束较弱,其动力特性与中塔刚度紧密相关,现有规范中的基频估算公式无法适用.基于能量原理,提出了适用于多塔连跨悬索桥的基频估算方法,最后给出了中塔刚度变化下的算例结果比较.结果表明,该估算方法有较高的精度,可为实际工程提供参考.%As long-span cross-sea bridges being constructed in recent years, multi-pylon suspension bridges attract increasing attention. However, because of the weak constrains of the mid - pylon, the dynamic characteristics is highly related to the rigidity of the mid-pylon, and the existing fundamental frequency estimation formula in current code is not available. Based on the energy principle, a new formula that can be applied to multi-pylon suspension bridges was proposed. Then the estimating results with respect to the changing rigidity of mid-pylon was given, which showed that the proposed formula has enough accuracy to be utilized in practical projects.

  20. Molecular bridges

    NARCIS (Netherlands)

    Berkelaar, R.P.; Söde, H.; Mocking, T.F.; Kumar, Avijit; Poelsema, Bene; Zandvliet, Henricus J.W.

    2011-01-01

    The adsorption of Cu-phthalocyanine (CuPc) molecules on Au-modified Ge(001) surfaces has been studied with low-temperature scanning tunneling microscopy. The Au-modified Ge(001) surface consists of well-ordered arrays of perfectly straight nanowires, which are separated by 1.6 nm wide and about 0.6

  1. Application of molecular simulations: Insight into liquid bridging and jetting phenomena

    Directory of Open Access Journals (Sweden)

    I. Nezbeda

    2015-03-01

    Full Text Available Molecular dynamics simulations have been performed on pure liquid water, aqueous solutions of sodium chloride, and polymer solutions exposed to a strong external electric field with the goal to gain molecular insight into the structural response to the field. Several simulation methodologies have been used to elucidate the molecular mechanisms of the processes leading to the formation of liquid bridges and jets (in the production of nanofibers. It is shown that in the established nanoscale structures, the molecules form a chain with their dipole moments oriented parallel to the applied field throughout the entire sample volume. The presence of ions may disturb this structure leading to its ultimate disintegration into droplets; the concentration dependence of the threshold field required to stabilize a liquid column has been determined. Conformational changes of the polymer in the jetting process have also been observed.

  2. Fundamental studies of interfacial excited-state charge transfer in molecularly tethered semiconductor nanoassemblies

    Science.gov (United States)

    Youker, Diane Greer

    The research presented in this dissertation focuses on elucidating the parameters affecting dynamics and yield of electron transfer reactions in semiconducting nanoparticle assemblies through the use of time-resolved spectroscopy. In particular, the dissertation focuses on photoinduced electron injection in assemblies of CdSe, CdS, or PbS quantum dots covalently bound to either metal oxide films or each other through the use of bifunctional molecular linkers. Chapter 2 elucidates the influence of electronic coupling on excited-state electron transfer from CdS quantum dots to TiO2 nanoparticles via molecular linkers with phenylene bridges. We establish that the efficiency of electron injection from CdS quantum dots to TiO2 nanoparticle varies dramatically with electronic coupling, which can be controlled by tuning the properties of molecular linkers. Chapter 3 presents the role of excitation energy on interfacial electron transfer in tethered assemblies of CdSe quantum dots and TiO2 nanoparticles. Through this work, we determined that injection efficiency from band-edge states is independent of excitation energy. However, the efficiency of injection from trap-states decreases at lower-energy excitation. We attribute the decrease to a lower energy distribution of emissive trap-states from which injection is less efficient. Chapter 4 presents the observation of multiphasic electron injection dynamics from photoexcited PbS quantum dots to TiO2 nanoparticles. In this collaborative study with Dr. Masumoto from the University of Tsukuba we observed electron injection on multiple timescales. We determined that electron injection occurred in this system through two different mechanisms. The first involved injection from thermalized PbS excited states and the second through injection of hot electrons through Auger recombination of biexcitons that creates high lying excitonic states. Chapter 5 investigates charge transfer in covalently bound quantum dot assemblies. We utilize

  3. Biofilm-Related Infections: Bridging the Gap between Clinical Management and Fundamental Aspects of Recalcitrance toward Antibiotics

    Science.gov (United States)

    Lebeaux, David; Ghigo, Jean-Marc

    2014-01-01

    SUMMARY Surface-associated microbial communities, called biofilms, are present in all environments. Although biofilms play an important positive role in a variety of ecosystems, they also have many negative effects, including biofilm-related infections in medical settings. The ability of pathogenic biofilms to survive in the presence of high concentrations of antibiotics is called “recalcitrance” and is a characteristic property of the biofilm lifestyle, leading to treatment failure and infection recurrence. This review presents our current understanding of the molecular mechanisms of biofilm recalcitrance toward antibiotics and describes how recent progress has improved our capacity to design original and efficient strategies to prevent or eradicate biofilm-related infections. PMID:25184564

  4. Microwave and submillimeter molecular transitions and their dependence on fundamental constants

    Energy Technology Data Exchange (ETDEWEB)

    Kozlov, Mikhail G. [Petersburg Nuclear Physics Institute, Gatchina (Russian Federation); St. Petersburg Electrotechnical University ' ' LETI' ' , St. Petersburg (Russian Federation); Levshakov, Sergei A. [St. Petersburg Electrotechnical University ' ' LETI' ' , St. Petersburg (Russian Federation); Ioffe Physical-Technical Institute, St. Petersburg (Russian Federation)

    2013-07-15

    Microwave and submillimeter molecular transition frequencies between nearly degenerated rotational levels, tunneling transitions, and mixed tunneling-rotational transitions show an extremely high sensitivity to the values of the fine-structure constant, {alpha}, and the electron-to-proton mass ratio, {mu}. This review summarizes the theoretical background on quantum-mechanical calculations of the sensitivity coefficients of such transitions to tiny changes in {alpha} and {mu} for a number of molecules which are usually observed in Galactic and extragalactic sources, and discusses the possibility of testing the space- and time-invariance of fundamental constants through comparison between precise laboratory measurements of the molecular rest frequencies and their astronomical counterparts. In particular, diatomic radicals CH, OH, NH{sup +}, and a linear polyatomic radical C{sub 3}H in {Pi} electronic ground state, polyatomic molecules NH{sub 3}, ND{sub 3}, NH{sub 2}D, NHD{sub 2}, H{sub 2}O{sub 2}, H{sub 3}O{sup +}, CH{sub 3}OH, and CH{sub 3}NH{sub 2} in their tunneling and tunneling-rotational modes are considered. It is shown that sensitivity coefficients strongly depend on the quantum numbers of the corresponding transitions. This can be used for astrophysical tests of Einstein's Equivalence Principle all over the Universe at an unprecedented level of sensitivity of 10{sup -9}, which is a limit three to two orders of magnitude lower as compared to the current constraints on cosmological variations of {alpha} and {mu}: {Delta}{alpha}/{alpha} < 10{sup -6}, {Delta} {mu} / {mu} < 10{sup -7}. (copyright 2013 by WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  5. Drugs meeting the molecular basis of diabetic kidney disease: bridging from molecular mechanism to personalized medicine.

    Science.gov (United States)

    Lambers Heerspink, Hiddo J; Oberbauer, Rainer; Perco, Paul; Heinzel, Andreas; Heinze, Georg; Mayer, Gert; Mayer, Bernd

    2015-08-01

    Diabetic kidney disease (DKD) is a complex, multifactorial disease and is associated with a high risk of renal and cardiovascular morbidity and mortality. Clinical practice guidelines for diabetes recommend essentially identical treatments for all patients without taking into account how the individual responds to the instituted therapy. Yet, individuals vary widely in how they respond to medications and therefore optimal therapy differs between individuals. Understanding the underlying molecular mechanisms of variability in drug response will help tailor optimal therapy. Polymorphisms in genes related to drug pharmacokinetics have been used to explore mechanisms of response variability in DKD, but with limited success. The complex interaction between genetic make-up and environmental factors on the abundance of proteins and metabolites renders pharmacogenomics alone insufficient to fully capture response variability. A complementary approach is to attribute drug response variability to individual variability in underlying molecular mechanisms involved in the progression of disease. The interplay of different processes (e.g. inflammation, fibrosis, angiogenesis, oxidative stress) appears to drive disease progression, but the individual contribution of each process varies. Drugs at the other hand address specific targets and thereby interfere in certain disease-associated processes. At this level, biomarkers may help to gain insight into which specific pathophysiological processes are involved in an individual followed by a rational assessment whether a specific drug's mode of action indeed targets the relevant process at hand. This article describes the conceptual background and data-driven workflow developed by the SysKid consortium aimed at improving characterization of the molecular mechanisms underlying DKD at the interference of the molecular impact of individual drugs in order to tailor optimal therapy to individual patients. © The Author 2015. Published by

  6. A multiscale modeling technique for bridging molecular dynamics with finite element method

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Yongchang, E-mail: yl83@buffalo.edu; Basaran, Cemal

    2013-11-15

    In computational mechanics, molecular dynamics (MD) and finite element (FE) analysis are well developed and most popular on nanoscale and macroscale analysis, respectively. MD can very well simulate the atomistic behavior, but cannot simulate macroscale length and time due to computational limits. FE can very well simulate continuum mechanics (CM) problems, but has the limitation of the lack of atomistic level degrees of freedom. Multiscale modeling is an expedient methodology with a potential to connect different levels of modeling such as quantum mechanics, molecular dynamics, and continuum mechanics. This study proposes a new multiscale modeling technique to couple MD with FE. The proposed method relies on weighted average momentum principle. A wave propagation example has been used to illustrate the challenges in coupling MD with FE and to verify the proposed technique. Furthermore, 2-Dimensional problem has also been used to demonstrate how this method would translate into real world applications. -- Highlights: •A weighted averaging momentum method is introduced for bridging molecular dynamics (MD) with finite element (FE) method. •The proposed method shows excellent coupling results in 1-D and 2-D examples. •The proposed method successfully reduces the spurious wave reflection at the border of MD and FE regions. •Big advantages of the proposed method are simplicity and inexpensive computational cost of multiscale analysis.

  7. Chemically bonded hybrid systems from functionalized hydroxypyridine molecular bridge: characterization and photophysical properties.

    Science.gov (United States)

    Yan, Bing; Qian, Kai

    2009-01-01

    A series of novel photoactive hybrid materials with organic parts covalently linked to inorganic parts via the acylamino group have been assembled by sol-gel process. The organic parts as molecular bridge derive from alpha-hydroxypyridine (HP) functionalized by 3-(triethoxysilyl)-propyl isocyanate (TESPIC). Finally homogeneous, molecular-based hybrid materials with different microstructure (uniform spherical or clubbed) are obtained, in which no phase separation is observed. This may be ascribed as the different coordination behavior of metal ions (Eu3+ (Tb3+) or Zn2+). Red emission of Eu-HP-Si, green emission of Tb-HP-Si and violet-blue luminescence of Zn-HP-Si hybrids can be achieved within these molecular-based hybrid materials. Besides, both Eu(Tb) and Zn are introduced into the same hybrid systems (Eu(Zn)-HP-Si or Tb(Zn)-HP-Si) through the covalent Si-O bond, whose sphere particle size can be modified. Especially the photoluminescence behavior can be enhanced, suggesting that intramolecular energy transfer takes place between inert Zn2+ and Eu3+ (Tb3+) in the covalently bonded hybrid systems.

  8. Photochromic molecular gyroscope with solid state rotational states determined by an azobenzene bridge.

    Science.gov (United States)

    Commins, Patrick; Garcia-Garibay, Miguel A

    2014-02-21

    We describe the synthesis, characterization, photochemical isomerization, and rotational dynamics of a crystalline molecular gyroscope containing an azobenzene bridge (trans-2) that spans from one end of the stator to other, with the intention of exploring its function as a molecular brake. While single crystal X-ray diffraction analysis of a photochemically inactive dichloromethane solvate was used to confirm the molecular and packing structures of trans-2, a nanocrystalline pseudopolymorph was shown to be photoactive, and it was analyzed by powder X-ray diffraction (PXRD), scanning electron microscopy, and variable temperature solid state (2)H NMR before and after photoisomerization. It was shown that the nanocrystalline suspension irradiated with λ = 340 nm reaches a photostationary state with 34% of cis-isomer, as compared to that observed in solution where the corresponding value is 74%. Line shape analysis of solid state (2)H NMR spectra of a phenylene-d4 isotopologue, obtained as a function of temperature, indicated that rotation in crystals of the trans-2 isomer, with a mean activation energy of 4.6 ± 0.6 kcal/mol and a pre-exponential factor exp(29.4 ± 1.7), is ten times faster than that of samples containing the cis-2 isomer, which has a higher mean activation energy of 5.1 ± 0.6 kcal/mol and a lower pre-exponential factor of exp(27.9 ± 1.3).

  9. Taxonomy, phylogeny and molecular epidemiology of Echinococcus multilocularis: From fundamental knowledge to health ecology.

    Science.gov (United States)

    Knapp, Jenny; Gottstein, Bruno; Saarma, Urmas; Millon, Laurence

    2015-10-30

    Alveolar echinococcosis, caused by the tapeworm Echinococcus multilocularis, is one of the most severe parasitic diseases in humans and represents one of the 17 neglected diseases prioritised by the World Health Organisation (WHO) in 2012. Considering the major medical and veterinary importance of this parasite, the phylogeny of the genus Echinococcus is of considerable importance; yet, despite numerous efforts with both mitochondrial and nuclear data, it has remained unresolved. The genus is clearly complex, and this is one of the reasons for the incomplete understanding of its taxonomy. Although taxonomic studies have recognised E. multilocularis as a separate entity from the Echinococcus granulosus complex and other members of the genus, it would be premature to draw firm conclusions about the taxonomy of the genus before the phylogeny of the whole genus is fully resolved. The recent sequencing of E. multilocularis and E. granulosus genomes opens new possibilities for performing in-depth phylogenetic analyses. In addition, whole genome data provide the possibility of inferring phylogenies based on a large number of functional genes, i.e. genes that trace the evolutionary history of adaptation in E. multilocularis and other members of the genus. Moreover, genomic data open new avenues for studying the molecular epidemiology of E. multilocularis: genotyping studies with larger panels of genetic markers allow the genetic diversity and spatial dynamics of parasites to be evaluated with greater precision. There is an urgent need for international coordination of genotyping of E. multilocularis isolates from animals and human patients. This could be fundamental for a better understanding of the transmission of alveolar echinococcosis and for designing efficient healthcare strategies. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Phenoxide-Bridged Zinc(II)-Bis(dipicolylamine) Probes for Molecular Imaging of Cell Death.

    Science.gov (United States)

    Clear, Kasey J; Harmatys, Kara M; Rice, Douglas R; Wolter, William R; Suckow, Mark A; Wang, Yuzhen; Rusckowski, Mary; Smith, Bradley D

    2016-02-17

    Cell death is involved in many pathological conditions, and there is a need for clinical and preclinical imaging agents that can target and report cell death. One of the best known biomarkers of cell death is exposure of the anionic phospholipid phosphatidylserine (PS) on the surface of dead and dying cells. Synthetic zinc(II)-bis(dipicolylamine) (Zn2BDPA) coordination complexes are known to selectively recognize PS-rich membranes and act as cell death molecular imaging agents. However, there is a need to improve in vivo imaging performance by selectively increasing target affinity and decreasing off-target accumulation. This present study compared the cell death targeting ability of two new deep-red fluorescent probes containing phenoxide-bridged Zn2BDPA complexes. One probe was a bivalent version of the other and associated more strongly with PS-rich liposome membranes. However, the bivalent probe exhibited self-quenching on the membrane surface, so the monovalent version produced brighter micrographs of dead and dying cells in cell culture and also better fluorescence imaging contrast in two living animal models of cell death (rat implanted tumor with necrotic core and mouse thymus atrophy). An (111)In-labeled radiotracer version of the monovalent probe also exhibited selective cell death targeting ability in the mouse thymus atrophy model, with relatively high amounts detected in dead and dying tissue and low off-target accumulation in nonclearance organs. The in vivo biodistribution profile is the most favorable yet reported for a Zn2BDPA complex; thus, the monovalent phenoxide-bridged Zn2BDPA scaffold is a promising candidate for further development as a cell death imaging agent in living subjects.

  11. Different mechanisms for hole and electron transfer along identical molecular bridges: the importance of the initial state delocalization.

    Science.gov (United States)

    Gorczak, Natalie; Tarkuç, Simge; Renaud, Nicolas; Houtepen, Arjan J; Eelkema, Rienk; Siebbeles, Laurens D A; Grozema, Ferdinand C

    2014-06-05

    We report measurements of hole and electron transfer along identical oligo-p-phenylene molecular bridges of increasing length. Although the injection barriers for hole and electron transfer are similar, we observed striking differences in the distance dependence and absolute magnitude of the rates of these two processes. Electron transfer is characterized by an almost distance-independent, fast charge-transfer rate. Hole transfer presents a much slower rate that decreases significantly with the length of the bridge. Time-dependent density functional calculations show that the observed differences can be explained by the delocalization of the respective initial excitation. The evaluation of the initial state is therefore essential when comparing charge-transfer rates between different donor-bridge-acceptor systems.

  12. The nucleotide addition cycle of RNA polymerase is controlled by two molecular hinges in the Bridge Helix domain

    Directory of Open Access Journals (Sweden)

    Weinzierl Robert OJ

    2010-10-01

    Full Text Available Abstract Background Cellular RNA polymerases (RNAPs are complex molecular machines that combine catalysis with concerted conformational changes in the active center. Previous work showed that kinking of a hinge region near the C-terminus of the Bridge Helix (BH-HC plays a critical role in controlling the catalytic rate. Results Here, new evidence for the existence of an additional hinge region in the amino-terminal portion of the Bridge Helix domain (BH-HN is presented. The nanomechanical properties of BH-HN emerge as a direct consequence of the highly conserved primary amino acid sequence. Mutations that are predicted to influence its flexibility cause corresponding changes in the rate of the nucleotide addition cycle (NAC. BH-HN displays functional properties that are distinct from BH-HC, suggesting that conformational changes in the Bridge Helix control the NAC via two independent mechanisms. Conclusions The properties of two distinct molecular hinges in the Bridge Helix of RNAP determine the functional contribution of this domain to key stages of the NAC by coordinating conformational changes in surrounding domains.

  13. 2,6-Pyridodicarboxamide-Bridged Triptycene Molecular Transmission Devices: Converting Rotation to Rocking Vibration.

    Science.gov (United States)

    Wang, Guangxia; Ma, Lishuang; Xiang, Junfeng; Wang, Ying; Chen, Xuebo; Che, Yanke; Jiang, Hua

    2015-11-20

    A series of N(2),N(6)-bis(triptycene-9-yl)pyridine-2,6-dicarboxamides 1-4 were designed and synthesized. Due to rotational constraint of the 2,6-diamidopyridine bridge, the triptycene components in the systems are held together. X-ray structures of 1-4 show that the molecules adopt a gear-like geometry in the solid states. DFT (B3LYP/6-31G(d)) calculations predict the gear-like C2 conformation as global minimum structures for 1 and 2 and suggest that, through a slippage transition process, rotation of one triptycene component would give rise to a rocking vibration of the counter component due to the barrier for rotation of the triptycene components. VT NMR studies on 1-4 show that the pair of triptycene components undergo ceaseless slippage at room temperature but nearly freeze at temperatures as low as 183 K. Decreasing the temperature freezes the slippage between triptycene components as well, thus producing the appearance of phase isomers of 3 and 4. The dynamic features of the studied molecules indicate that this kind of molecule is able to function as a kind of molecular transmission device for transforming the mode of motion from rotation to rocking vibration.

  14. Polymer Nanofibers with Outstanding Thermal Conductivity and Thermal Stability: Fundamental Linkage between Molecular Characteristics and Macroscopic Thermal Properties

    CERN Document Server

    Zhang, Teng; Luo, Tengfei

    2014-01-01

    Polymer nanofibers with high thermal conductivities and outstanding thermal stabilities are highly desirable in heat transfer-critical applications such as thermal management, heat exchangers and energy storage. In this work, we unlock the fundamental relations between the thermal conductivity and thermal stability of polymer nanofibers and their molecular characteristics by studying the temperature-induced phase transitions and thermal transport of a series of polymer nanofibers. Ten different polymer nanofibers with systematically chosen molecular structures are studied using large scale molecular dynamics simulations. We found that high thermal conductivity and good thermal stability can be achieved in polymers with rigid backbones, exemplified by {\\pi}-conjugated polymers, due to suppressed segmental rotations and large phonon group velocities. The low probability of segmental rotation does not only prevent temperature-induced phase transition but also enables long phonon mean free paths due to reduced di...

  15. A perfect time to harness advanced molecular technologies to explore the fundamental biology of Toxocara species.

    Science.gov (United States)

    Gasser, Robin B

    2013-04-15

    Toxocarosis is of major canine health and socioeconomic importance worldwide. Although many studies have given insights into toxocarosis, to date, there has been limited exploration of the molecular biology, biochemistry, genetics, epidemiology and ecology of Toxocara species as well as parasite-host interactions using '-omic' technologies. The present article gives a background on Toxocara species and toxocarosis, describes molecular tools for specific identification and genetic analysis, and provides a prospective view of the benefits that advanced molecular technologies will have towards better understanding the parasites and disease. Tackling key biological questions employing a 'systems biology' approach should lead to new and improved strategies for the treatment, diagnosis and control of toxocarosis.

  16. Strategies and outcomes of periprocedural bridging therapy with low-molecular-weight heparin in patients with mechanical heart valves.

    Science.gov (United States)

    Schulman, Jacqueline M; Majeed, Ammar; Mattsson, Eva; Schulman, Sam; Holmström, Margareta; Ågren, Anna

    2015-11-01

    Patients with mechanical heart valves (MHV) undergoing invasive procedures often receive periprocedural bridging with low-molecular-weight heparin (LMWH). The bridging strategies used in real-life and the predictors for bleeding and thrombosis are not well studied. We retrospectively assessed patients with MHV that underwent invasive procedures requiring vitamin K antagonist interruption and LMWH bridging. Thromboembolic and bleeding events occurring up to 30 days after the procedures were recorded. Predictors of major bleeding events (MBEs) were analyzed with logistic regression. We evaluated 547 patients with MHV who underwent 275 procedures during a 6.5-year period. Bridging with LMWH was used in 185 procedures in a total of 117 patients. Combined pre- and post-operative bridging was the most frequently employed (63 %). Doses of LMWH were prophylactic in 96 (52 %) of the procedures and therapeutic in 89 (48 %). The procedure-related bleeding risk was evaluated as high in 70 (38 %) and low in 115 (62 %) of the procedures. There was a trend to more frequent use of prophylactic doses (61 %) in high-risk surgery, and more therapeutic doses (53 %) in low-risk ones. There were 36 bleeding episodes, 21 (11 % of procedures) of which were classified as MBEs, but there were no thromboembolic events. Most MBEs (n = 14; 67 %) occurred in surgeries with high bleeding risk. In the multivariate analysis, the bleeding risk of the surgery itself was the only independent predictor for MBEs. For patients with MHV receiving perioperative bridging with LMWH, the major predictor for MBE is the bleeding risk of the surgery.

  17. Environmental Research Division: fundamental molecular physics and chemistry. Annual report, January-December 1983. Part I

    Energy Technology Data Exchange (ETDEWEB)

    1985-03-01

    Research progress is reported in the following areas: (1) photoionization of radicals or excited states; (2) molecular spectroscopy by resonant multiphoton ionization; (3) studies conducted with the synchrotron radiation facility at the National Bureau of Standards; (4) theoretical studies on molecular photoabsorption; (5) analysis of photoabsorption spectra of open-shell atoms; (6) the electron energy-loss spectra of molecules; and (7) cross sections and stopping powers. Items have been individually abstracted for the data base. (ACR)

  18. Fluoride-bridged {GdIII3MIII2} (M=Cr, Fe, Ga) molecular magnetic refrigerants

    DEFF Research Database (Denmark)

    Pedersen, Kasper Steen; Lorusso, Giulia; Morales, Juan José

    2014-01-01

    -lying excited states for successful design of molecular refrigerants. Molecular coolers: Even labile fluoride complexes (see picture; Gd purple, Cr/Fe/Ga orange, F green, O red) are useful precursors for polynuclear, fluoride-bridged 3d-4f systems. Molecular geometry enforces weak exchange interactions, which...

  19. Fundamental Energetic Materials Initiative: Combat Safe Energetic Ingredients Based on Molecular Design and Crystal Morphology

    Science.gov (United States)

    2011-11-30

    loading conditions at the molecular and crystal levels. Replace one of the six bulk commodity chemicals currently used in all military propellant and...tetrazocine (HMX), nitroglycerin (NG), nitrocellulose (NC)) is the only way to achieve IM compliance. B. M. Rice and J. J. Hare, “A Quantum Mechanical

  20. New Poetics of the Film Body: Docility, Molecular Fundamentalism and Twenty First Century Destiny

    Directory of Open Access Journals (Sweden)

    Flynn Susan

    2015-06-01

    Full Text Available Twenty first century film evokes a new topology of the body. Science and technology are the new century’s ‘sovereign power’ which enforces biopolitics through bodies which, by virtue of being seen at their most fundamental level, have become docile surfaces. The film body is at once manipulated and coerced into an ethos of optimization; a thoroughly scientific and ‘molecular’ optimization which proffers ‘normalization’ and intimately regulated bodies. In the film bodies of this millennium, bodily intervention results in surveillance becoming internalized. Now the body is both a means and an end of social control. This essay applies the philosophies Michel Foucault and Nikolas Rose to twenty first century Hollywood film, elucidating a new tropos, a new film body/body of film.

  1. Fundamental building blocks for molecular biowire based forward error-correcting biosensors

    Energy Technology Data Exchange (ETDEWEB)

    Liu Yang [Electrical and Computer Engineering, Michigan State University, East Lansing, MI 48824 (United States); Chakrabartty, Shantanu [Electrical and Computer Engineering, Michigan State University, East Lansing, MI 48824 (United States); Alocilja, Evangelyn C [Biosystems Engineering, Michigan State University, East Lansing, MI 48824 (United States)

    2007-10-24

    This paper describes the fabrication, characterization and modeling of fundamental logic gates that can be used for designing biosensors with embedded forward error-correction (FEC). The proposed logic gates (AND and OR) are constructed by patterning antibodies at different spatial locations along the substrate of a lateral flow immunosensor assay. The logic gates operate by converting binding events between an antigen and an antibody into a measurable electrical signal using polyaniline nanowires as the transducer. In this study, B. cereus and E. coli have been chosen as model pathogens. The functionality of the AND and OR logic gates has been validated using conductance measurements with different pathogen concentrations. Experimental results show that the change in conductance across the gates can be modeled as a log-linear response with respect to varying pathogen concentration. Equivalent circuits models for AND and OR logic gates have been derived based on measured results.

  2. Enzyme molecular dynamics simulations in different solvents: Fundamental effects and a new paradigm for rational design

    Energy Technology Data Exchange (ETDEWEB)

    Ornstein, R.L. [Pacific Northwest National Lab., Richland, WA (United States)

    1997-12-31

    Developing enzymes that are functional in nonaqueous solutions may prove useful in the development of new strategies for environmental remediation and monitoring, as well as in developing `green` processes. To gain a fundamental understanding of the structural and dynamic consequences to an enzyme induced by such solvents, we compared simulation results for the well characterized protease enzyme subtilisin Carlsberg in different solvents, including water, carbon tetrachloride, and dimethyl sulfoxide. Serendipitously, we observed a small number of solvent-dependent `tight-binding` site between the enzyme and each solvent. Such solvent-dependent `tight-binding` site information may offer a new simulation paradigm for protein engineering and drug design. Examples will be offered for the cases of subtilisin and a glutathione S-transferase.

  3. Molecular typing of Mycobacterium tuberculosis strains: a fundamental tool for tuberculosis control and elimination

    Directory of Open Access Journals (Sweden)

    Angela Cannas

    2016-06-01

    Full Text Available Tuberculosis (TB is still an important cause of morbidity and mortality worldwide. An improvement of the strategies for disease control is necessary in both low- and high-incidence TB countries. Clinicians, epidemiologists, laboratory specialists, and public health players should work together in order to achieve a significant reduction in TB transmission and spread of drug-resistant strains. Effective TB surveillance relies on early diagnosis of new cases, appropriate therapy, and accurate detection of outbreaks in the community, in order to implement proper TB control strategies. To achieve this goal, information from classical and molecular epidemiology, together with patient clinical data need to be combined. In this review, we summarize the methodologies currently used in molecular epidemiology, namely molecular typing. We will discuss their efficiency to phylogenetically characterize Mycobacterium tuberculosis isolates, and their ability to provide information that can be useful for disease control. We will also introduce next generation sequencing as the methodology that potentially could provide in a short time both, detection of new outbreaks and identification of resistance patterns. This could envision a potential of next generation sequencing as an important tool for accurate patient management and disease control.

  4. Molecular Typing of Mycobacterium Tuberculosis Strains: A Fundamental Tool for Tuberculosis Control and Elimination

    Science.gov (United States)

    Cannas, Angela; Mazzarelli, Antonio; Di Caro, Antonino; Delogu, Giovanni; Girardi, Enrico

    2016-01-01

    Tuberculosis (TB) is still an important cause of morbidity and mortality worldwide. An improvement of the strategies for disease control is necessary in both low- and high-incidence TB countries. Clinicians, epidemiologists, laboratory specialists, and public health players should work together in order to achieve a significant reduction in TB transmission and spread of drug-resistant strains. Effective TB surveillance relies on early diagnosis of new cases, appropriate therapy, and accurate detection of outbreaks in the community, in order to implement proper TB control strategies. To achieve this goal, information from classical and molecular epidemiology, together with patient clinical data need to be combined. In this review, we summarize the methodologies currently used in molecular epidemiology, namely molecular typing. We will discuss their efficiency to phylogenetically characterize Mycobacterium tuberculosis isolates, and their ability to provide information that can be useful for disease control. We will also introduce next generation sequencing as the methodology that potentially could provide in a short time both, detection of new outbreaks and identification of resistance patterns. This could envision a potential of next generation sequencing as an important tool for accurate patient management and disease control. PMID:27403266

  5. Fundamental molecular physics and chemistry. Radiological and Environmental Research Division annual report, October 1981-December 1982. Pt. 1

    Energy Technology Data Exchange (ETDEWEB)

    1983-12-01

    This document is the twelfth Annual Report of our Fundamental Molecular Physics and Chemistry Program. Scientifically, the work of the program deals with aspects of the physics and chemistry of molecules related to their interactions with photons, electrons, and other external agents. We chose these areas of study in view of our matic goals; that is to say, we chose them so that the eventual outcome of our work meets some of the needs of the US Department of Energy (DOE) and of other government agencies that support our research. First, we endeavor to determine theoretically and experimentally cross sections for electron and photon interactions with molecules, because those cross sections are indispensable for detailed microscopic analyses of the earliest processes of radiation action on any molecular substance, including biological materials. Those analyses in turn provide a sound basis for radiology and radiation dosimetry. Second, we study the spectroscopy of certain molecules and of small clusters of molecules because this topic is fundamental to the full understanding of atmospheric-pollutant chemistry.

  6. Molecular Electrical Doping of Organic Semiconductors: Fundamental Mechanisms and Emerging Dopant Design Rules.

    Science.gov (United States)

    Salzmann, Ingo; Heimel, Georg; Oehzelt, Martin; Winkler, Stefanie; Koch, Norbert

    2016-03-15

    Today's information society depends on our ability to controllably dope inorganic semiconductors, such as silicon, thereby tuning their electrical properties to application-specific demands. For optoelectronic devices, organic semiconductors, that is, conjugated polymers and molecules, have emerged as superior alternative owing to the ease of tuning their optical gap through chemical variability and their potential for low-cost, large-area processing on flexible substrates. There, the potential of molecular electrical doping for improving the performance of, for example, organic light-emitting devices or organic solar cells has only recently been established. The doping efficiency, however, remains conspicuously low, highlighting the fact that the underlying mechanisms of molecular doping in organic semiconductors are only little understood compared with their inorganic counterparts. Here, we review the broad range of phenomena observed upon molecularly doping organic semiconductors and identify two distinctly different scenarios: the pairwise formation of both organic semiconductor and dopant ions on one hand and the emergence of ground state charge transfer complexes between organic semiconductor and dopant through supramolecular hybridization of their respective frontier molecular orbitals on the other hand. Evidence for the occurrence of these two scenarios is subsequently discussed on the basis of the characteristic and strikingly different signatures of the individual species involved in the respective doping processes in a variety of spectroscopic techniques. The critical importance of a statistical view of doping, rather than a bimolecular picture, is then highlighted by employing numerical simulations, which reveal one of the main differences between inorganic and organic semiconductors to be their respective density of electronic states and the doping induced changes thereof. Engineering the density of states of doped organic semiconductors, the Fermi

  7. Molecular basis of physiological heart growth: fundamental concepts and new players

    Science.gov (United States)

    Maillet, Marjorie; van Berlo, Jop H.; Molkentin, Jeffery D.

    2015-01-01

    The heart hypertrophies in response to developmental signals as well as increased workload. Although adult-onset hypertrophy can ultimately lead to disease, cardiac hypertrophy is not necessarily maladaptive and can even be beneficial. Progress has been made in our understanding of the structural and molecular characteristics of physiological cardiac hypertrophy, as well as of the endocrine effectors and associated signalling pathways that regulate it. Physiological hypertrophy is initiated by finite signals, which include growth hormones (such as thyroid hormone, insulin, insulin-like growth factor 1 and vascular endothelial growth factor) and mechanical forces that converge on a limited number of intracellular signalling pathways (such as PI3K, AKT, AMP-activated protein kinase and mTOR) to affect gene transcription, protein translation and metabolism. Harnessing adaptive signalling mediators to reinvigorate the diseased heart could have important medical ramifications. PMID:23258295

  8. Computational Study of Ferrocene-Based Molecular Frameworks with 2,5-Diethynylpyridine as a Chemical Bridge

    Directory of Open Access Journals (Sweden)

    Feizhi Ding

    2010-04-01

    Full Text Available A computational study was carried out to examine the electronic and optical properties of the experimentally proposed ferrocene-based molecular diode that used 2,5-diethynylpyridine as a bridging unit. Density functional theory, time-dependent density functional theory, and constrained density functional theory were applied to investigate various aspects of the underlying electron transfer mechanism. The results not only advance our understanding of the experimental observations, but also demonstrate the usefulness of computational approaches for the design of new electronic materials.

  9. Synthesis, crystal structure and magnetic characterization of a cyanide-bridged Mo-Ni nanosized molecular wheel

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Daopeng; Zhang, Hongyan; Wang, Ping [Shandong Univ. of Technology, College of Chemical Engineering, Zibo (China); Kong, Lingqian [Liaocheng Univ. (China). Dongchang College

    2015-11-01

    By using K{sub 4}[Mo(CN){sub 8}] and [Ni(L)(H{sub 2}O){sub 2}][ClO{sub 4}]{sub 2} as reagents (L = 2,12-dimethyl-3,7,11,17-tetraazabicyclo [11.3.1]heptadeca-1(17),13,15-triene), a new cyanide-bridged Mo-Ni complex containing the building blocks [Ni(H{sub 2}O)(L)]{sup 2+} and [Ni(L)]{sup 2+} bridged by [Mo(CN){sub 8}]{sup 4-} units has been obtained. The complex with the formula {[Ni(H_2O)(L)][Ni(L)][Mo(CN)_8]}{sub 6} . 36H{sub 2}O . 2CH{sub 3}OH (1) was characterized by elemental analysis, IR spectroscopy and single-crystal X-ray diffraction. The structure determination reveals an octadecanuclear cluster in the form of a 36-membered macrocycle, in which the largest intramolecular W..W and Ni..Ni distances are 16.5 and 14.4 Aa, respectively, indicating that complex 1 is a nanosized molecular wheel. Investigation of its magnetic properties has shown weak antiferromagnetic coupling between the adjacent Ni(II) ions bridged by the diamagnetic [Mo(CN){sub 8}]{sup 4-} ions.

  10. The Fundamentally Different Dynamics of Dust and Gas in Molecular Clouds

    CERN Document Server

    Hopkins, Philip F

    2015-01-01

    We study the behavior of large dust grains in turbulent molecular clouds (MCs). In primarily neutral regions, dust grains move as aerodynamic particles, not necessarily with the gas. We therefore directly simulate, for the first time, the behavior of aerodynamic grains in highly supersonic, magnetohydrodynamic turbulence typical of MCs. We show that, under these conditions, grains with sizes a>0.01 micron exhibit dramatic (exceeding factor ~1000) fluctuations in the local dust-to-gas ratio (implying large small-scale variations in abundances, dust cooling rates, and dynamics). The dust can form highly filamentary structures (which would be observed in both dust emission and extinction), which can be much thinner than the characteristic width of gas filaments. Sometimes, the dust and gas filaments are not even in the same location. The 'clumping factor' of the dust (critical for dust evolution) can reach ~100, for grains in the ideal size range. The dust clustering is maximized around scales ~0.2pc*(a/micron)*...

  11. Molecular fundamentals of drug interactions in the therapy of colorectal cancer

    Directory of Open Access Journals (Sweden)

    Katarzyna Regulska

    2014-03-01

    Full Text Available Rapid advances in the field of chemotherapy have resulted in the introduction of numerous antineoplastic drugs into clinical practice, which increased the efficiency of patient management. Also the prevalent use of combination treatment based on drug action synergy contributed to the improved clinical effect associated with cytotoxic drug administration. It seems, however, obvious that the multidirectional pharmacotherapy in oncology requires a thorough knowledge of drugs’ pharmaceutical behavior in order to maximize their collective action and prevent the occurrence of unintended drug interactions that could potentially impair treatment effectiveness. In fact, drug interactions constitute a serious problem for current oncology primarily resulting from a narrow therapeutic index specific for the majority of anticancer drugs. This, in turn, indicates that even slight deviations of their pharmacokinetics could cause significant clinical consequences, manifested by alteration of the toxicological profile or reduction of therapeutic efficiency. Hence, the investigation of molecular aspects underlying the mechanisms of various drug interactions seems to be essential for proper and safe patient management. The present article is devoted to the extensive subject of drug interactions occurring in the therapy of colorectal cancer. It presents the available literature data on both positive and negative effects of interactions and it discusses their mechanisms complying with their classification into pharmacokinetic and pharmacodynamic ones.

  12. Fundamental properties of molecules on surfaces. Molecular switching and interaction of magnetic molecules with superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Hatter, Nino

    2016-12-14

    In this thesis, we investigate individual molecular switches and metal-organic complexes on surfaces with scanning tunneling microscopy (STM) and spectroscopy (STS) at low temperatures. One focus addresses the switching ability and mechanism of diarylethene on Ag(111). The other focus lies on resolving and tuning magnetic interactions of individual molecules with superconductors. 4,4'-(4,4'-(perfluorocyclopent-1-ene-1,2-diyl)bis (5-methylthiophene-4,2-diyl)dip yridine (PDTE) is a prototypical photochromic switch. We can induce a structural change of individual PDTE molecules on Ag(111) with the STM tip. This change is accompanied by a reduction of the energy gap between the occupied and unoccupied molecular orbitals. Density functional theory (DFT) calculations reveal that the induced switching corresponds to a ring-closing reaction from an open isomer in a flat adsorption configuration to a ring-closed isomer with its methyl groups in a cis configuration. The final product is thermodynamically stabilized by strong dispersion interactions with the surface. A linear dependence of the switching threshold with the tip-sample distance with a minimal threshold of 1.4 V is found, which we assign to a combination of an electric-field induced process and a tunneling-electron contribution. DFT calculations suggest a large activation barrier for a ring-closing reaction from the open flat configuration into the closed cis configuration. The interaction of magnetic molecules with superconductors is studied on manganese phthalocyanine (MnPc) adsorbed on Pb(111). We find triplets of Shiba states inside the superconducting gap. Different adsorption sites of MnPc provide a large variety of exchange coupling strengths, which lead to a collective energy shift of the Shiba triplets. We can assign the splitting of the Shiba states to be an effect of magnetic anisotropy in the system. A quantum phase transition from a ''Kondo screened'' to a &apos

  13. Gone with the heat: a fundamental constraint on the imaging of dust and molecular gas in the early Universe.

    Science.gov (United States)

    Zhang, Zhi-Yu; Papadopoulos, Padelis P; Ivison, R J; Galametz, Maud; Smith, M W L; Xilouris, Emmanuel M

    2016-06-01

    Images of dust continuum and carbon monoxide (CO) line emission are powerful tools for deducing structural characteristics of galaxies, such as disc sizes, H2 gas velocity fields and enclosed H2 and dynamical masses. We report on a fundamental constraint set by the cosmic microwave background (CMB) on the observed structural and dynamical characteristics of galaxies, as deduced from dust continuum and CO-line imaging at high redshifts. As the CMB temperature rises in the distant Universe, the ensuing thermal equilibrium between the CMB and the cold dust and H2 gas progressively erases all spatial and spectral contrasts between their brightness distributions and the CMB. For high-redshift galaxies, this strongly biases the recoverable H2 gas and dust mass distributions, scale lengths, gas velocity fields and dynamical mass estimates. This limitation is unique to millimetre/submillimetre wavelengths and unlike its known effect on the global dust continuum and molecular line emission of galaxies, it cannot be addressed simply. We nevertheless identify a unique signature of CMB-affected continuum brightness distributions, namely an increasing rather than diminishing contrast between such brightness distributions and the CMB when the cold dust in distant galaxies is imaged at frequencies beyond the Raleigh-Jeans limit. For the molecular gas tracers, the same effect makes the atomic carbon lines maintain a larger contrast than the CO lines against the CMB.

  14. Fundamental ecology is fundamental.

    Science.gov (United States)

    Courchamp, Franck; Dunne, Jennifer A; Le Maho, Yvon; May, Robert M; Thébaud, Christophe; Hochberg, Michael E

    2015-01-01

    The primary reasons for conducting fundamental research are satisfying curiosity, acquiring knowledge, and achieving understanding. Here we develop why we believe it is essential to promote basic ecological research, despite increased impetus for ecologists to conduct and present their research in the light of potential applications. This includes the understanding of our environment, for intellectual, economical, social, and political reasons, and as a major source of innovation. We contend that we should focus less on short-term, objective-driven research and more on creativity and exploratory analyses, quantitatively estimate the benefits of fundamental research for society, and better explain the nature and importance of fundamental ecology to students, politicians, decision makers, and the general public. Our perspective and underlying arguments should also apply to evolutionary biology and to many of the other biological and physical sciences. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

  15. Principles of Bridge Reliability

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle; Nowak, Andrzej S.

    The paper gives a brief introduction to the basic principles of structural reliability theory and its application to bridge engineering. Fundamental concepts like failure probability and reliability index are introduced. Ultimate as well as serviceability limit states for bridges are formulated...

  16. Accelerating FRET between Near-Infrared Emitting Quantum Dots Using a Molecular J-Aggregate as an Exciton Bridge.

    Science.gov (United States)

    Wang, Chen; Weiss, Emily A

    2017-09-13

    Fast energy transfer (EnT) among quantum dots (QDs) with near-infrared (NIR) emission is essential for fully exploiting their light harvesting and photon downconversion (multiexciton generation) abilities. This paper demonstrates a relayed EnT mechanism that accelerates the migration of NIR excitons between PbS QDs by a factor of 20 from that of one-step EnT through a polyelectrolyte and even a factor of ∼2 from that of one-step EnT between QDs in direct contact, by employing a J-aggregate (J-agg) of a cyanine dye as an exciton bridge. The donor QDs, acceptor QDs, and J-agg are electrostatically assembled into a sandwich structure with layer-by-layer deposition. Estimates of EnT rate and yield from transient and steady-state absorption and photoluminescence spectroscopies show that the rate-limiting step in the relay is EnT from the donor QD to the J-agg, while EnT from the J-agg to the acceptor QD occurs in J-agg with more intermolecular order. This work demonstrates the viability of relayed EnT through a molecular bridge as a strategy for accelerating long-distance exciton migration in assemblies of QDs, in particular in the near-infrared.

  17. INFLUENCE OF ENVIRONMENTAL FACTORS UPON FUNDAMENTAL VIBRATION FREQUENCY OF CABLES FOR CABLE-STAYED BRIDGE%环境因素对斜拉桥拉索振动基频的影响

    Institute of Scientific and Technical Information of China (English)

    吉伯海; 程苗; 傅中秋; 赵端端; 孙媛媛

    2013-01-01

    基于斜拉桥拉索有限元模型,分析了考虑拉索工程参数时阻尼器、梁体振动和温度三种环境因素对拉索振动基频的影响。结果表明:当阻尼器安装位置一定时,阻尼器对长索的基频影响大于短索的基频;当索长和阻尼器位置一定时,阻尼器对截面直径大的拉索基频的影响小于截面直径小的拉索基频;由于车辆荷载导致斜拉桥梁体振动,使得拉索的基频存在动态波动,因此在索力测量时,应选择车辆较少的时段以获得更加准确的基频;高温和低温均影响拉索基频,即拉索温度越高,基频越小;拉索温度越低,基频越大。%Based on the finite element model of cable for cable-stayed bridge , it was analyzed the influence of three environmental factors including damper , beam vibration and temperature upon the cable ’ s vibration fundamental frequency when considering engineering parameters of cable .The results show that when the damper ’ s installation position is fixed , the influence of the damper upon the long cable ’ s fundamental frequency is greater than the influence upon the short cable’s.When the cable’s length and the damper’s position are fixed, the influence of the damper upon the fundamental frequency of the cable which has large section diameter is less than the one has small section diameter .The fundamental frequency of the cable has dynamic fluctuations because of the cable -stayed bridge’s beam vibration caused by the vehicle load .To make the fundamental frequency more accurate , the time with a few vehicles may be selected when measuring the cable force .Temperature variation also has influence upon the fundamental frequency of the cable.Namely, the higher of the cable’s temperature, the smaller of the fundamental frequency;the lower of the cable ’ s temperature , the bigger of the fundamental frequency .

  18. From amino acids to nature-inspired molecular scaffolds: incorporation of medium-sized bridged heterocycles into a peptide backbone.

    Science.gov (United States)

    La-Venia, Agustina; Ventosa-Andrés, Pilar; Hradilová, Ludmila; Krchňák, Viktor

    2014-11-07

    Novel molecular scaffolds comprising two to four bridged and fused heterocycles were synthesized from amino acids using seven-membered endocyclic N-acyliminium ions as key intermediates in acid-mediated tandem reactions with internal nucleophiles. This complexity-generating synthesis proceeds with high efficiency and with full stereocontrol of the newly generated stereogenic center. These results have extended the scope of medium-sized cyclic iminium ion chemistry, making it applicable as a regio- and stereoselective synthetic strategy for the generation of complex polycyclic structures. Furthermore, its compatibility with the traditional Merrifield synthesis of peptides on solid supports allowed the incorporation of the previously unexplored conformationally restricted cyclic systems into peptides without a need to independently synthesize the scaffold.

  19. Review of the fundamental theories behind small angle X-ray scattering, molecular dynamics simulations, and relevant integrated application

    Directory of Open Access Journals (Sweden)

    Lauren Boldon

    2015-02-01

    Full Text Available In this paper, the fundamental concepts and equations necessary for performing small angle X-ray scattering (SAXS experiments, molecular dynamics (MD simulations, and MD-SAXS analyses were reviewed. Furthermore, several key biological and non-biological applications for SAXS, MD, and MD-SAXS are presented in this review; however, this article does not cover all possible applications. SAXS is an experimental technique used for the analysis of a wide variety of biological and non-biological structures. SAXS utilizes spherical averaging to produce one- or two-dimensional intensity profiles, from which structural data may be extracted. MD simulation is a computer simulation technique that is used to model complex biological and non-biological systems at the atomic level. MD simulations apply classical Newtonian mechanics’ equations of motion to perform force calculations and to predict the theoretical physical properties of the system. This review presents several applications that highlight the ability of both SAXS and MD to study protein folding and function in addition to non-biological applications, such as the study of mechanical, electrical, and structural properties of non-biological nanoparticles. Lastly, the potential benefits of combining SAXS and MD simulations for the study of both biological and non-biological systems are demonstrated through the presentation of several examples that combine the two techniques.

  20. Gone with the heat: A fundamental constraint on the imaging of dust and molecular gas in the early Universe

    CERN Document Server

    Zhang, Zhi-Yu; Ivison, R J; Galametz, Maud; Smith, M W L; Xilouris, Emmanuel M

    2016-01-01

    Images of dust continuum and CO line emission are powerful tools for deducing structural characteristics of galaxies, such as disk sizes, H$_2$ gas velocity fields and enclosed H$_2$ and dynamical masses. We report on a fundamental constraint set by the cosmic microwave background (CMB) on the observed structural and dynamical characteristics of galaxies, as deduced from dust continuum and CO-line imaging at high redshifts. As the CMB temperature rises in the distant Universe, the ensuing thermal equilibrium between the CMB and the cold dust and H$_2$ gas progressively erases all spatial and spectral contrasts between their brightness distributions and the CMB. For high-redshift galaxies, this strongly biases the recoverable H$_2$ gas and dust mass distributions, scale lengths, gas velocity fields and dynamical mass estimates. This limitation is unique to mm/submm wavelengths and unlike its known effect on the global dust continuum and molecular line emission of galaxies, it cannot be addressed simply. We nev...

  1. Charge transport through biomolecular wires in a solvent: bridging molecular dynamics and model Hamiltonian approaches.

    Science.gov (United States)

    Gutiérrez, R; Caetano, R A; Woiczikowski, B P; Kubar, T; Elstner, M; Cuniberti, G

    2009-05-22

    We present a hybrid method based on a combination of classical molecular dynamics simulations, quantum-chemical calculations, and a model Hamiltonian approach to describe charge transport through biomolecular wires with variable lengths in presence of a solvent. The core of our approach consists in a mapping of the biomolecular electronic structure, as obtained from density-functional based tight-binding calculations of molecular structures along molecular dynamics trajectories, onto a low-dimensional model Hamiltonian including the coupling to a dissipative bosonic environment. The latter encodes fluctuation effects arising from the solvent and from the molecular conformational dynamics. We apply this approach to the case of pG-pC and pA-pT DNA oligomers as paradigmatic cases and show that the DNA conformational fluctuations are essential in determining and supporting charge transport.

  2. Molecular and electronic structure of osmium complexes confined to Au(111) surfaces using a self-assembled molecular bridge

    Energy Technology Data Exchange (ETDEWEB)

    Llave, Ezequiel de la; Herrera, Santiago E.; Adam, Catherine; Méndez De Leo, Lucila P.; Calvo, Ernesto J.; Williams, Federico J., E-mail: fwilliams@qi.fcen.uba.ar [INQUIMAE-CONICET, Departamento de Química Inorgánica, Analítica y Química-Física, Facultad Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pabellón 2, Buenos Aires C1428EHA (Argentina)

    2015-11-14

    The molecular and electronic structure of Os(II) complexes covalently bonded to self-assembled monolayers (SAMs) on Au(111) surfaces was studied by means of polarization modulation infrared reflection absorption spectroscopy, photoelectron spectroscopies, scanning tunneling microscopy, scanning tunneling spectroscopy, and density functional theory calculations. Attachment of the Os complex to the SAM proceeds via an amide covalent bond with the SAM alkyl chain 40° tilted with respect to the surface normal and a total thickness of 26 Å. The highest occupied molecular orbital of the Os complex is mainly based on the Os(II) center located 2.2 eV below the Fermi edge and the LUMO molecular orbital is mainly based on the bipyridine ligands located 1.5 eV above the Fermi edge.

  3. Functional genomics bridges the gap between quantitative genetics and molecular biology.

    Science.gov (United States)

    Lappalainen, Tuuli

    2015-10-01

    Deep characterization of molecular function of genetic variants in the human genome is becoming increasingly important for understanding genetic associations to disease and for learning to read the regulatory code of the genome. In this paper, I discuss how recent advances in both quantitative genetics and molecular biology have contributed to understanding functional effects of genetic variants, lessons learned from eQTL studies, and future challenges in this field.

  4. Fundamentally updating fundamentals.

    Science.gov (United States)

    Armstrong, Gail; Barton, Amy

    2013-01-01

    Recent educational research indicates that the six competencies of the Quality and Safety Education for Nurses initiative are best introduced in early prelicensure clinical courses. Content specific to quality and safety has traditionally been covered in senior level courses. This article illustrates an effective approach to using quality and safety as an organizing framework for any prelicensure fundamentals of nursing course. Providing prelicensure students a strong foundation in quality and safety in an introductory clinical course facilitates early adoption of quality and safety competencies as core practice values.

  5. [Fe(II)LSCo(III)LS]2 ⇔ [Fe(III)LSCo(II)HS]2 photoinduced conversion in a cyanide-bridged heterobimetallic molecular square.

    Science.gov (United States)

    Mercurol, Julie; Li, Yanling; Pardo, Emilio; Risset, Olivia; Seuleiman, Mannan; Rousselière, Hélène; Lescouëzec, Rodrigue; Julve, Miguel

    2010-12-21

    The self-assembly of [Fe(III){B(pz)(4)}(CN)(3)](-) and [Co(II)(bik)(2)(S)(2)](2+) affords the diamagnetic cyanide-bridged [Fe(II)(LS)Co(III)(LS)](2) molecular square which is converted into the corresponding magnetic [Fe(III)(LS)Co(II)(HS)](2) species under light irradiation at relatively low temperatures.

  6. Molecular Mechanistic Reasoning: Toward Bridging the Gap between the Molecular and Cellular Levels in Life Science Education

    Science.gov (United States)

    van Mil, Marc H. W.; Postma, Paulien A.; Boerwinkel, Dirk Jan; Klaassen, Kees; Waarlo, Arend Jan

    2016-01-01

    Although learning about DNA, RNA, and proteins is part of the upper secondary biology curriculum in most countries, many studies report that students fail to connect molecular knowledge to phenomena at the higher level of cells, organs, and organisms. As a result, many students use memorization and rote learning as a coping strategy when presented…

  7. Radiological and Environmental Research Division annual report. Fundamental molecular physics and chemistry, June 1975--September 1976. [Summaries of research activities at Argonne National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    None

    1976-01-01

    A summary of research activities in the fundamental molecular physics and chemistry section at Argonne National Laboratory from July 1975 to September 1976 is presented. Of the 40 articles and abstracts given, 24 have been presented at conferences or have been published and will be separately abstracted. Abstracts of the remaining 16 items appear in this issue of ERA. (JFP)

  8. Bridging the Gap from Galactic to Extragalactic: Star Formation and Giant Molecular Clouds within the Nearby Spiral Galaxy NGC 300

    Science.gov (United States)

    Faesi, Christopher

    2017-01-01

    The questions surrounding the origins of stars are of key importance in astrophysics across a huge range in physical scales. However, until recently, investigations have been restricted to either detailed studies targeting a few nearby regions in the Milky Way, or kpc- or larger-scale studies of entire galaxies. Between these two scales lies a crucial gap in understanding. In this thesis work, I have taken steps in bridging this gap between Galactic and extragalactic star formation. I will present the results of a campaign of observations and modeling targeting the nearby spiral galaxy NGC 300. Using an extensive suite of multi-wavelength data I have characterized the star formation activity and molecular gas in a large sample of star-forming regions within this galaxy. Additionally, I have assembled an extensive (300 clouds) and high resolution (10 pc) catalog of Giant Molecular Clouds (GMCs) based on ALMA CO observations. This unprecedented look at the population of GMCs in a nearby spiral galaxy reveals an astonishing range of morphologies and properties in the Molecular Gas as well as providing a key testbed for comparison with GMCs in the Milky Way and other nearby galaxies. The GMCs in NGC 300 appear to have similar global properties and show scaling relations consistent with those seen in the Milky Way. Furthermore, the star formation rate appears to correlate with the mass of molecular gas with approximately 250 Gyr depletion time, extending the relation discovered in the Milky Way linearly to larger scales. These results suggest a level of universality in the star formation process within spiral galaxy disks like our own Milky Way.

  9. Bacterial molecular networks: bridging the gap between functional genomics and dynamical modelling.

    Science.gov (United States)

    van Helden, Jacques; Toussaint, Ariane; Thieffry, Denis

    2012-01-01

    This introductory review synthesizes the contents of the volume Bacterial Molecular Networks of the series Methods in Molecular Biology. This volume gathers 9 reviews and 16 method chapters describing computational protocols for the analysis of metabolic pathways, protein interaction networks, and regulatory networks. Each protocol is documented by concrete case studies dedicated to model bacteria or interacting populations. Altogether, the chapters provide a representative overview of state-of-the-art methods for data integration and retrieval, network visualization, graph analysis, and dynamical modelling.

  10. Protein attachment onto silica surfaces--a survey of molecular fundamentals, resulting effects and novel preventive strategies in CE.

    Science.gov (United States)

    Stutz, Hanno

    2009-06-01

    This review addresses the fundamentals governing the adsorption of individual protein molecules onto the surface of fused-silica capillaries, the protein aggregation to adsorbate clusters and their final accretion to monolayers with subsequent stratification to protein multilayers. The attention in CE protein separation has primarily been focused on (i) tuning the BGE including the buffer type, ionic strength, pH and additives, (ii) tailored post-rinse procedures to detach adhered protein residues and (iii) the optimization of capillary wall shielding in order to reduce protein attachment. Improvements in protein separation as well as related adverse effects are mainly discussed on the basis of parameters known to become deteriorated in case of protein adhesion, e.g. repeatability of the EOF and of migration times, peak width, theoretical plate numbers, resolution and asymmetry factor. However, knowledge of the molecular principles controlling protein adsorption onto silica surfaces is indispensable for separation optimization. Furthermore, it facilitates troubleshooting and the interpretation of undesired concomitant phenomena. This review comprehensively discusses protein adsorption models derived from surface chemistry primarily in terms of their relevance for CE, clearly showing that the adsorption process in its complexity is only partially revealed by models, which address single or binary protein solutions. In a further section theoretical concepts and surface models are related to surface phenomena encountered in CE. The final part of the review surveys recent concepts for prevention of protein adhesion, thereby addressing capillary treatment, favorable buffer types, dynamic and adhesive semi-permanent coating strategies covering the literature from 2000-2008.

  11. The quest for rationalizing the magnetism in purely organic semiquinone-bridged bisdithiazolyl molecular magnets.

    Science.gov (United States)

    Fumanal, Maria; Deumal, Mercè

    2016-07-27

    Semiquinone-bridged bisdithiazolyl-based radicals (XBBO) are appealing purely organic magnetic building blocks for the synthesis of new functional materials. Remarkably, for the phenyl-derivative PhBBO, the rationalization of its magnetism becomes a proof of concept that DFT can dramatically fail to evaluate JAB magnetic interactions between purely organic radical pairs. Instead, wavefunction-based methods are required. Once JAB's are fully characterized, the magnetic topology of PhBBO is disclosed to consist of ferromagnetic FM π-stacks that are very weakly coupled (by FM and AFM JAB interactions). The magnetic susceptibility χT(T) and magnetization M(H) of PhBBO are then calculated using a first-principles bottom-up approach. The study of the unit cell contraction upon cooling from room temperature to zero-Kelvin is relevant to propose a suitable model for the phase transition that occurs at 4.5 K. A simplistic picture tells us that the antiparallel-aligned 1D-FM-chains convert into domains of weakly either FM- or AFM-coupled 1D-FM-chains. Accordingly, the presence of these domains may introduce geometrical spin frustration below 4.5 K.

  12. Variable contact gap single-molecule conductance determination for a series of conjugated molecular bridges

    DEFF Research Database (Denmark)

    Haiss, W.; Wang, Christian; Jitchati, R.

    2008-01-01

    -distance curves and knowledge of the terminal to terminal length of the molecular wire. The contact gap separation dependence is interpreted as arising from tilting of these molecules in the junction and this model is underpinned by ab initio transport computations. In this respect we make the general observation...

  13. Photoinduced Reorganization of Motor-Doped Chiral Liquid Crystals : Bridging Molecular Isomerization and Texture Rotation

    NARCIS (Netherlands)

    Bosco, Alessandro; Jongejan, Mahthild G. M.; Eelkema, Rienk; Katsonis, Nathalie; Lacaze, Ernmanuelle; Ferrarini, Alberta; Feringa, Ben L.; Lacaze, Emmanuelle

    2008-01-01

    We recently reported that the photoisomerization of molecular motors used as chiral dopants in a cholesteric liquid crystal film induces a rotational reorganization which can be observed by optical microscopy and produces the motion of microscopic objects placed on top of the film (Feringa, B. L.;

  14. Phenoxide-bridged Zinc(II)-Bis(dipicolylamine) Probes for Molecular Imaging of Cell Death

    OpenAIRE

    Clear, Kasey J.; Harmatys, Kara M.; Rice, Douglas R.; Wolter, William R.; Suckow, Mark A.; Wang, Yuzhen; Rusckowski, Mary; Smith, Bradley D.

    2015-01-01

    Cell death is involved in many pathological conditions, and there is a need for clinical and preclinical imaging agents that can target and report cell death. One of the best known biomarkers of cell death is exposure of the anionic phospholipid phosphatidylserine (PS) on the surface of dead and dying cells. Synthetic zinc(II)-bis(dipicolylamine) (Zn2BDPA) coordination complexes are known to selectively recognize PS-rich membranes and act as cell death molecular imaging agents. However, there...

  15. Molecular targets of naturopathy in cancer research: bridge to modern medicine.

    Science.gov (United States)

    Ahmad, Aamir; Ginnebaugh, Kevin R; Li, Yiwei; Padhye, Subhash B; Sarkar, Fazlul H

    2015-01-06

    The relevance of naturopathy (defined as the practice of medicine for the treatment of human diseases with natural agents) in human cancer is beginning to be appreciated, as documented by renewed interest in nutraceutical research, the natural anticancer agents of dietary origin. Because of their pleiotropic effects and the ability to modulate multiple signaling pathways, which is a good attribute of natural agents, nutraceuticals have frequently been demonstrated to re-sensitize drug-resistant cancers. The effectiveness of nutraceuticals can be further enhanced if the tools for the relative assessment of their molecular targets are readily available. Such information can be critical for determining their most effective uses. Here, we discuss the anticancer potential of nutraceuticals and the associated challenges that have interfered with their translational potential as a naturopathic approach for the management of cancers. In the years to come, an efficient screening and assessment of molecular targets will be the key to make rapid progress in the area of drug design and discovery, especially focusing on evidence-based development of naturopathy for the treatment of human malignancies.

  16. Molecular Targets of Naturopathy in Cancer Research: Bridge to Modern Medicine

    Directory of Open Access Journals (Sweden)

    Aamir Ahmad

    2015-01-01

    Full Text Available The relevance of naturopathy (defined as the practice of medicine for the treatment of human diseases with natural agents in human cancer is beginning to be appreciated, as documented by renewed interest in nutraceutical research, the natural anticancer agents of dietary origin. Because of their pleiotropic effects and the ability to modulate multiple signaling pathways, which is a good attribute of natural agents, nutraceuticals have frequently been demonstrated to re-sensitize drug-resistant cancers. The effectiveness of nutraceuticals can be further enhanced if the tools for the relative assessment of their molecular targets are readily available. Such information can be critical for determining their most effective uses. Here, we discuss the anticancer potential of nutraceuticals and the associated challenges that have interfered with their translational potential as a naturopathic approach for the management of cancers. In the years to come, an efficient screening and assessment of molecular targets will be the key to make rapid progress in the area of drug design and discovery, especially focusing on evidence-based development of naturopathy for the treatment of human malignancies.

  17. A molecular-modeling toolbox aimed at bridging the gap between medicinal chemistry and computational sciences.

    Science.gov (United States)

    Eid, Sameh; Zalewski, Adam; Smieško, Martin; Ernst, Beat; Vedani, Angelo

    2013-01-04

    In the current era of high-throughput drug discovery and development, molecular modeling has become an indispensable tool for identifying, optimizing and prioritizing small-molecule drug candidates. The required background in computational chemistry and the knowledge of how to handle the complex underlying protocols, however, might keep medicinal chemists from routinely using in silico technologies. Our objective is to encourage those researchers to exploit existing modeling technologies more frequently through easy-to-use graphical user interfaces. In this account, we present two innovative tools (which we are prepared to share with academic institutions) facilitating computational tasks commonly utilized in drug discovery and development: (1) the VirtualDesignLab estimates the binding affinity of small molecules by simulating and quantifying their binding to the three-dimensional structure of a target protein; and (2) the MD Client launches molecular dynamics simulations aimed at exploring the time-dependent stability of ligand-protein complexes and provides residue-based interaction energies. This allows medicinal chemists to identify sites of potential improvement in their candidate molecule. As a case study, we present the application of our tools towards the design of novel antagonists for the FimH adhesin.

  18. Exciton analysis of many-body wave functions: Bridging the gap between the quasiparticle and molecular orbital pictures

    Science.gov (United States)

    Bäppler, Stefanie A.; Plasser, Felix; Wormit, Michael; Dreuw, Andreas

    2014-11-01

    Exciton sizes and electron-hole binding energies, which are central properties of excited states in extended systems and crucial to the design of modern electronic devices, are readily defined within a quasiparticle framework but are quite challenging to understand in the molecular-orbital picture. The intent of this work is to bridge this gap by providing a general way of extracting the exciton wave function out of a many-body wave function obtained by a quantum chemical excited-state computation. This methodology, which is based on the one-particle transition density matrix, is implemented within the ab initio algebraic diagrammatic construction scheme for the polarization propagator and specifically the evaluation of exciton sizes, i.e., dynamic charge separation distances, is considered. A number of examples are presented. For stacked dimers it is shown that the exciton size for charge separated states corresponds to the intermolecular separation, while it only depends on the monomer size for locally excited states or Frenkel excitons. In the case of conjugated organic polymers, the tool is applied to analyze exciton structure and dynamic charge separation. Furthermore, it is discussed how the methodology may be used for the construction of a charge-transfer diagnostic for time-dependent density-functional theory.

  19. Bridging molecular and continuous descriptions: the case of dynamics in clays

    Directory of Open Access Journals (Sweden)

    Jean-François Dufrêche

    2010-03-01

    Full Text Available The theory of transport in porous media such as clays depends on the level of description. On the macroscopic scale,hydrodynamics equations are used. These continuous descriptions are convenient to model the fluid motion in a confined system. Nevertheless, they are valid only if the pores of the material are much larger than the molecular size of the components of the system. Another approach consists in using molecular descriptions. These two methods which correspond to different levels of description are complementary. The link between them can be clarified by using a coarse-graining procedure where the microscopic laws are averaged over fast variables to get the long time macroscopic laws. We present such an approach in the case of clays. Firstly, we detail the various levels of description and the relations among them, by emphasizing the validity domain of the hydrodynamic equations. Secondly, we focus on the case of dehydrated clays where hydrodynamics is not relevant. We show that it is possible to derive a simple model for the motion of the cesium ion based on the difference on time scale between the solvent and the solute particles.A teoria de transporte em meios porosos tais como argilasdepende do nível de descrição. Na escala macroscópica, equações da hidrodinâmica são utilizadas. Tais descrições a níveldo contínuo são convenientes para tratar o movimento do fluido em sistemas confinados. No entanto, tais equações são válidas se os poros do material são muito maiores do que as moléculas das componentes do sistema. Uma outra abordagem consiste em usar descrições moleculares. Esses dois métodos que correspondem a diferentes níveis de descriçãosão complementares. A ligação entre eles pode ser elucidada usando um procedimento de mudança de escala onde são tomadas médias das leis microscópicas sobre as variáveis rápidas para se obter as leis macroscópicas para tempos longos. Apresentamos esta abordagem no

  20. Bridging Molecular Genetics and Biomarkers in Lewy Body and Related Disorders

    Directory of Open Access Journals (Sweden)

    Gilbert J. Ho

    2011-01-01

    Full Text Available Recent advances have been made in defining the genetic and molecular basis of dementia with Lewy bodies (DLBs and related neurodegenerative disorders such as Parkinson's disease (PD and Parkinson's disease dementia (PDD which comprise the spectrum of “Lewy body disorders” (LBDs. The genetic alterations and underlying disease mechanisms in the LBD overlap substantially, suggesting common disease mechanisms. As with the other neurodegenerative dementias, early diagnosis in LBD or even identification prior to symptom onset is key to developing effective therapeutic strategies, but this is dependent upon the development of robust, specific, and sensitive biomarkers as diagnostic tools and therapeutic endpoints. Recently identified mutations in the synucleins and other relevant genes in PD and DLB as well as related biomolecular pathways suggest candidate markers from biological fluids and imaging modalities that reflect the underlying disease mechanisms. In this context, several promising biomarkers for the LBD have already been identified and examined, while other intriguing possible candidates have recently emerged. Challenges remain in defining their correlation with pathological processes and their ability to detect DLB and related disorders, and perhaps a combined array of biomarkers may be needed to distinguish various LBDs.

  1. Peroxisome proliferator-activated receptors: bridging metabolic syndrome with molecular nutrition.

    Science.gov (United States)

    Guri, Amir J; Hontecillas, Raquel; Bassaganya-Riera, Josep

    2006-12-01

    Over recent years, obesity rates and the onset of obesity-induced chronic diseases have risen dramatically. The more we learn about the physiological and morphological changes that occur during obesity, the more it is becoming clear that obesity-related disorders can be traced back to adipocyte hypertrophy and inflammation at white adipose tissue (WAT). To combat this problem, the body has developed a regulatory system specifically designed at mediating the systemic response to obesity, utilizing free fatty acids (FFAs) and their metabolites as nutrient messengers to signal adaptations from peripheral tissues. These messages are predominantly interceded through the peroxisome proliferator-activated receptors (PPARs), a family of ligand-induced transcription factors that serve as a net of lipid sensors throughout the body. Understanding how and why nutrients, nutrient derivatives and metabolites exert their physiological effects are the key goals in the study of molecular nutrition. By learning about the mechanisms and tissue-specific effects of endogenous PPAR ligands and expanding our knowledge of the body's integrated homeostatic system, we will significantly increase our odds of designing safe and effective preventive and therapeutic interventions that keep us one step ahead of obesity-related diseases.

  2. Rational molecular engineering of cyclopentadithiophene-bridged D-A-π-A sensitizers combining high photovoltaic efficiency with rapid dye adsorption

    OpenAIRE

    Qipeng Chai; Wenqin Li; Jingchuan Liu; Zhiyuan Geng; He Tian; Wei-hong Zhu

    2015-01-01

    Dye-sensitized solar cell (DSSC) is considered as a feasible route to the clean and renewable energy conversion technique. The commercial application requires further enhancements on photovoltaic efficiency and simplification on the device fabrication. For avoiding the unpreferable trade-off between photocurrent (J SC) and photovoltage (V OC), here we report the molecular engineering and comprehensive photovoltaic characterization of three cyclopentadithiophene-bridged D-A-π-A motif sensitize...

  3. Fundamental frequency estimation and comfort evaluation in consideration of vehicle induced vibration effect for suspended pedestrian bridges%悬挂式人行桥基频估算及考虑车致振动效应的行人舒适性评价

    Institute of Scientific and Technical Information of China (English)

    马如进; 田雨; 陈艾荣

    2014-01-01

    将人行桥作为车行主桥的悬挂结构,形成一个组合式桥梁,共同解决人车通行问题,然而这种结构形式在主桥车辆荷载激励下人行桥的振动舒适性还有待研究。首先推导了悬挂式人行桥的基频估算公式并通过有限元计算进行了验证,研究表明悬挂式人行桥的基频很大程度上取决于车行主桥的自振特性。采用分离迭代法对某悬挂式人行桥的车致振动响应进行了分析,结果表明车行桥路面粗糙度、车速、车流密度等都会显著影响车辆通过时桥梁的振动响应,车致振动引起的人行桥跨中竖向峰值加速度可达到仅人行激励引起的相应值的一半以上,悬挂式人行桥行人舒适性评价中应考虑会降低其舒适度的车致振动效应的影响。%A pedestrian bridge suspended to a vehicular bridge to form a combined bridge,can provide passages not only for vehicles but pedestrians.However,the vibration comfort of the suspended pedestrian bridge under vehicle excitation from the vehicular bridge still needs to be discovered.Fundamental frequency estimation formulas for the suspended pedestrian bridge were proposed and verified through finite element method.The results show that fundamental frequencies of the suspended pedestrian bridge depend largely on dynamic characteristics of the vehicular bridge.The vehicle induced vibration of a long-span suspended pedestrian bridge was analyzed by using separated iteration methods. The results show that the vibration responses become larger with worse road condition or higher density traffic flow.The vibration responses have no evident relationship with vehicle speed.The vertical acceleration peak of the pedestrian bridge in mid-span under vehicle excitation exceeds half of that excited by pedestrians.Therefore,the vehicle induced vibration effect should be considered in the comfort evaluation of pedestrian bridges suspended to vehicular bridges.

  4. Railroad Bridges

    Data.gov (United States)

    Department of Homeland Security — Bridges-Rail in the United States According to The National Bridge Inspection Standards published in the Code of Federal Regulations (23 CFR 650.3), a bridge isA...

  5. Simulation of multivariate diffusion bridges

    DEFF Research Database (Denmark)

    Bladt, Mogens; Finch, Samuel; Sørensen, Michael

    We propose simple methods for multivariate diffusion bridge simulation, which plays a fundamental role in simulation-based likelihood and Bayesian inference for stochastic differential equations. By a novel application of classical coupling methods, the new approach generalizes a previously...... proposed simulation method for one-dimensional bridges to the mulit-variate setting. First a method of simulating approzimate, but often very accurate, diffusion bridges is proposed. These approximate bridges are used as proposal for easily implementable MCMC algorithms that produce exact diffusion bridges...

  6. Towards system-level understanding of baculovirus host cell interactions: from molecular fundamental studies to large-scale proteomics approaches

    Directory of Open Access Journals (Sweden)

    Francisca eMonteiro

    2012-11-01

    Full Text Available Baculoviruses are insect viruses extensively exploited as eukaryotic protein expression vectors. Molecular biology studies have provided exciting discoveries on virus-host interactions, but the application of omic high throughput techniques on the baculovirus-insect cell system has been hampered by the lack of host genome sequencing. While a broader, systems level analysis of biological responses to infection is urgently needed, recent advances on proteomic studies have yielded new insights on the impact of infection on the host cell. These works are reviewed and critically assessed in the light of current biological knowledge of the molecular biology of baculoviruses and insect cells.

  7. Stepwise preparation and characterization of molecular wires made of zinc octaethylporphyrin complexes bridged by 4, 4'-bipyridine on HOPG

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Quirina; Alcacer, LuIs; Morgado, Jorge, E-mail: quirinatf@gmail.com, E-mail: alcacer@lx.it.pt, E-mail: jmorgado@lx.it.pt [Instituto de Telecomunicacoes, Instituto Superior Tecnico, Avenida Rovisco Pais, P-1049-001 Lisboa (Portugal)

    2011-10-28

    Molecular-scale devices can be made using a step-by-step procedure, in a controllable and highly versatile way. In this report, we describe the growth of molecular wires (MW) from zinc (II) octaethylporphyrin (ZnOEP) assembled on highly oriented pyrolytic graphite (HOPG) by a step-by-step approach using 4, 4'-bipyridine (BP) to bridge the porphyrin units, via coordination of the nitrogen atom to zinc. In order to gain an insight into the molecular self-organization of these wires, we carried out a detailed scanning tunnelling microscopy (STM) analysis of each monolayer, using a solid/liquid interface technique, up to a complete ZnOEP/BP/ZnOEP/BP/ZnOEP-assembled structure. The electrical properties of the MWs were assessed by scanning tunnelling spectroscopy (STS) and by current-sensing atomic force microscopy (CS-AFM), showing an increase of electrical resistance with the length of the MW.

  8. Preparation of Core-Shell Coordination Molecular Assemblies via the Enrichment of Structure-Directing "Codes" of Bridging Ligands and Metathesis of Metal Units

    Energy Technology Data Exchange (ETDEWEB)

    Park, J; Chen, YP; Perry, Z; Li, JR; Zhou, HC

    2014-12-03

    A series of molybdenum- and copper-based MOPs were synthesized through coordination-driven process of a bridging ligand (3,3'-PDBAD, L-1) and dimetal paddlewheel clusters. Three conformers of the ligand exist with an ideal bridging angle between the two carboxylate groups of 0 degrees (H-2 zeta-L(1)), 120 degrees (H-2 beta-L-1), and of 90 degrees (H-2 beta-L-1), respectively. At ambient or lower temperature, (HL1)-L-2 and Mo-2(OAc)(4) or Cu-2(OAc)(4) were crystallized into a molecular square with ?-L-1 and Mo-2/Cu-2 units. With proper temperature elevation, not only the molecular square with ?-L-1 but also a lantern-shaped cage with a-L-1 formed simultaneously. Similar to how Watson-Crick pairs stabilize the helical structure of duplex DNA, the core-shell molecular assembly possesses favorable H-bonding interaction sites. This is dictated by the ligand conformation in the shell, coding for the formation and providing stabilization of the central lantern shaped core, which was not observed without this complementary interaction. On the basis of the crystallographic implications, a heterobimetallic cage was obtained through a postsynthetic metal ion metathesis, showing different reactivity of coordination bonds in the core and shell. As an innovative synthetic strategy, the site-selective metathesis broadens the structural diversity and properties of coordination assemblies.

  9. Thiolate-bridged dinuclear ruthenium and iron complexes as robust and efficient catalysts toward oxidation of molecular dihydrogen in protic solvents.

    Science.gov (United States)

    Yuki, Masahiro; Sakata, Ken; Hirao, Yoshifumi; Nonoyama, Nobuaki; Nakajima, Kazunari; Nishibayashi, Yoshiaki

    2015-04-01

    Thiolate-bridged dinuclear ruthenium and iron complexes are found to work as efficient catalysts toward oxidation of molecular dihydrogen in protic solvents such as water and methanol under ambient reaction conditions. Heterolytic cleavage of the coordinated molecular dihydrogen at the dinuclear complexes and the sequential oxidation of the produced hydride complexes are involved as key steps to promote the present catalytic reaction. The catalytic activity of the dinuclear complexes toward the chemical oxidation of molecular dihydrogen achieves up to 10000 TON (turnover number), and electrooxidation of molecular dihydrogen proceeds quite rapidly. The result of the density functional theory (DFT) calculation on the reaction pathway indicates that a synergistic effect between the two ruthenium atoms plays an important role to realize the catalytic oxidation of molecular dihydrogen efficiently. The present dinuclear ruthenium complex is found to work as an efficient organometallic anode catalyst for the fuel cell. It is noteworthy that the present dinuclear complex worked not only as an effective catalyst toward chemical and electrochemical oxidation of molecular dihydrogen but also as a good anode catalyst for the fuel cell. We consider that the result described in this paper provides useful and valuable information to develop highly efficient and low-cost transition metal complexes as anode catalysts in the fuel cell.

  10. Molecular modeling of directed self-assembly of block copolymers: Fundamental studies of processing conditions and evolutionary pattern design

    Science.gov (United States)

    Khaira, Gurdaman Singh

    Rapid progress in the semi-conductor industry has pushed for smaller feature sizes on integrated electronic circuits. Current photo-lithographic techniques for nanofabrication have reached their technical limit and are problematic when printing features small enough to meet future industrial requirements. "Bottom-up'' techniques, such as the directed self-assembly (DSA) of block copolymers (BCP), are the primary contenders to compliment current "top-down'' photo-lithography ones. For industrial requirements, the defect density from DSA needs to be less than 1 defect per 10 cm by 10 cm. Knowledge of both material synthesis and the thermodynamics of the self-assembly process are required before optimal operating conditions can be found to produce results adequate for industry. The work present in this thesis is divided into three chapters, each discussing various aspects of DSA as studied via a molecular model that contains the essential physics of BCP self-assembly. Though there are various types of guiding fields that can be used to direct BCPs over large wafer areas with minimum defects, this study focuses only on chemically patterned substrates. The first chapter addresses optimal pattern design by describing a framework where molecular simulations of various complexities are coupled with an advanced optimization technique to find a pattern that directs a target morphology. It demonstrates the first ever study where BCP self-assembly on a patterned substrate is optimized using a three-dimensional description of the block-copolymers. For problems pertaining to DSA, the methodology is shown to converge much faster than the traditional random search approach. The second chapter discusses the metrology of BCP thin films using TEM tomography and X-ray scattering techniques, such as CDSAXS and GISAXS. X-ray scattering has the advantage of being able to quickly probe the average structure of BCP morphologies over large wafer areas; however, deducing the BCP morphology

  11. Physical fundaments of supersonic molecular beams; Fondamenti fisici dei fasci molecolari supersonici. Parte 7: Il getto libero supersonico

    Energy Technology Data Exchange (ETDEWEB)

    Tomassetti, G. [L' Aquila Univ., L' Aquila (Italy). Dipt. di Fisica; Sanna, G.

    1999-07-01

    The structure of the free jet emitted by a converging nozzle as obtained by the method of characteristics by Ashkenas and Sherman is described in details. In particular the dependence of the field variable by the distance from the nozzle is given. The transition from continuum to molecular free regime is then considered and the sudden freeze approximation is introduced. The processing of monoatomic and polyatomic gasses is also considered. [Italian] Le caratteristiche del campo di flusso in regime continuo di un getto libero supersonico ottenute col metodo delle caratteristiche da Askenas e Sherman sono messe in evidenza. In particolare le relazioni analitiche per i parametri di flusso in funzione della distanza dal nozzle sono riportate. Viene poi considerata la transazione al regime molecolare ed e' introdotta la sudden freeze approximation. Vengono anche considerate le situazioni di non equilibrio tra gradi di liberta' interni ed esterni.

  12. Radiology fundamentals

    CERN Document Server

    Singh, Harjit

    2011-01-01

    ""Radiology Fundamentals"" is a concise introduction to the dynamic field of radiology for medical students, non-radiology house staff, physician assistants, nurse practitioners, radiology assistants, and other allied health professionals. The goal of the book is to provide readers with general examples and brief discussions of basic radiographic principles and to serve as a curriculum guide, supplementing a radiology education and providing a solid foundation for further learning. Introductory chapters provide readers with the fundamental scientific concepts underlying the medical use of imag

  13. Spectral shapes of Ar-broadened HCl lines in the fundamental band by classical molecular dynamics simulations and comparison with experiments

    Energy Technology Data Exchange (ETDEWEB)

    Tran, H., E-mail: ha.tran@lisa.u-pec.fr [Laboratoire Interuniversitaire des Systèmes Atmosphériques, UMR CNRS 7583, Université Paris Est Créteil, Université Paris Diderot, Institut Pierre-Simon Laplace, 94010 Créteil Cedex (France); Domenech, J.-L. [Instituto de Estructura de la Materia, Consejo Superior de Investigaciones Cientificas, (IEM-CSIC), Serrano 123, 28006 Madrid (Spain)

    2014-08-14

    Spectral shapes of isolated lines of HCl perturbed by Ar are investigated for the first time using classical molecular dynamics simulations (CMDS). Using reliable intermolecular potentials taken from the literature, these CMDS provide the time evolution of the auto-correlation function of the dipole moment, whose Fourier-Laplace transform leads to the absorption spectrum. In order to test these calculations, room temperature spectra of various lines in the fundamental band of HCl diluted in Ar are measured, in a large pressure range, with a difference-frequency laser spectrometer. Comparisons between measured and calculated spectra show that the CMDS are able to predict the large Dicke narrowing effect on the shape of HCl lines and to satisfactorily reproduce the shapes of HCl spectra at different pressures and for various rotational quantum numbers.

  14. Fundamental Astronomy

    CERN Document Server

    Karttunen, Hannu; Oja, Heikki; Poutanen, Markku; Donner, Karl Johan

    2007-01-01

    Fundamental Astronomy gives a well-balanced and comprehensive introduction to the topics of classical and modern astronomy. While emphasizing both the astronomical concepts and the underlying physical principles, the text provides a sound basis for more profound studies in the astronomical sciences. The fifth edition of this successful undergraduate textbook has been extensively modernized and extended in the parts dealing with the Milky Way, extragalactic astronomy and cosmology as well as with extrasolar planets and the solar system (as a consequence of recent results from satellite missions and the new definition by the International Astronomical Union of planets, dwarf planets and small solar-system bodies). Furthermore a new chapter on astrobiology has been added. Long considered a standard text for physical science majors, Fundamental Astronomy is also an excellent reference and entrée for dedicated amateur astronomers.

  15. Influence of gravity on the collective molecular dynamics of liquid water: the case of the floating water bridge

    CERN Document Server

    Del Giudice, Emilio

    2010-01-01

    Quantum electrodynamics (QED) produces a picture of liquid water as a mixture of a low density coherent phase and an high density non-coherent phase. Consequently, the Archimedes principle prescribes that, within a gravitational field, liquid water should be made up, at surface, mainly of the coherent fraction, which becomes a cage where the gas-like non-coherent fraction is trapped, acquiring a non-vanishing pressure (vapor tension). Therefore, it is possible to probe the QED picture by observing the behavior of liquid water under reduced gravity conditions. The floating water bridge could be a useful test model.

  16. Natural and magnetic optical activity of 2-D chiral cyanido-bridged Mn(II)-Nb(IV) molecular ferrimagnets.

    Science.gov (United States)

    Chorazy, Szymon; Podgajny, Robert; Nitek, Wojciech; Fic, Tomasz; Görlich, Edward; Rams, Michał; Sieklucka, Barbara

    2013-08-04

    Unique two dimensional enantiopure cyanido-bridged {[Mn(II)(R-mpm)2]2[Nb(IV)(CN)8]}·4H2O and {[Mn(II)(S-mpm)2]2[Nb(IV)(CN)8]}·4H2O (-S) (mpm = α-methyl-2-pyridine-methanol) ferrimagnets with TC = 23.5 K were synthesized and characterized. They reveal natural optical activity (NOA) due to the chiral crystal structure, and magnetic optical activity (MOA) in the presence of an external magnetic field, with the strong enhancement in the magnetically ordered phase below TC.

  17. Two new hexacoordinated coordination polymers of cadmium(II) containing bridging units only: Syntheses, structures and molecular properties

    Indian Academy of Sciences (India)

    DIPU SUTRADHAR; HABIBAR CHOWDHURY; SUSHOVAN KONER; SUBHASIS ROY; BARINDRA KUMAR GHOSH

    2016-09-01

    The syntheses, characterizations and structures of a neutral 2D coordination polymer [Cd(bnzd)(NCS)₂]n (1) and a polycationic 3D coordination polymer isolated as perchlorate salt [Cd(bnzd)₃]n(ClO₄)₂n (2) (bnzd = benzidine) are described. X-ray structural analyses reveal that each hexacoordinated cadmium(II) center in 1 adopts a distorted octahedral geometry with a CdN₄S₂ chromophore bound by two N atoms of two different bnzd units and two N and two S atoms of symmetric doubly bridged end-toend NCS− units extended in a 2D sheet. Six N atoms of six different bridged bnzd units are bonded to each cadmium(II) in 2 in a non-ended fashion affording a 3D network structure. In the crystalline state, each 2D sheet structure in 1 is further stabilized by π· · ·π interaction which in turn affords a 3D network structure through multiple intermolecular N-H· · · S hydrogen bonds. On the other hand, the 3D network structure in 2 is stabilized by weak intermolecular N-H· · ·O hydrogen bonds and C-H· · ·π interactions. Bnzd, 1 and 2 display intraligand 1(π-π*) fluorescence in DMF solution at room temperature.

  18. Rational molecular engineering of cyclopentadithiophene-bridged D-A-π-A sensitizers combining high photovoltaic efficiency with rapid dye adsorption

    Science.gov (United States)

    Chai, Qipeng; Li, Wenqin; Liu, Jingchuan; Geng, Zhiyuan; Tian, He; Zhu, Wei-Hong

    2015-06-01

    Dye-sensitized solar cell (DSSC) is considered as a feasible route to the clean and renewable energy conversion technique. The commercial application requires further enhancements on photovoltaic efficiency and simplification on the device fabrication. For avoiding the unpreferable trade-off between photocurrent (JSC) and photovoltage (VOC), here we report the molecular engineering and comprehensive photovoltaic characterization of three cyclopentadithiophene-bridged D-A-π-A motif sensitizers with a change in donor group. We make a careful choice on the donor and conjugation bridge for synergistically increasing JSC and VOC. Comparing with the reference dye WS-2, the photovoltaic efficiency with the single component dye of WS-51 increases by 18%, among one of the rare examples in pure metal-free organic dyes exceeding 10% in combination with traditional iodine redox couples. Moreover, WS-51 exhibits several prominent merits on potentially scale-up industrial application: i) facile synthetic route to target molecule, ii) simple dipping procedure without requirement of co-sensitization, and iii) rapid dye adsorption capability.

  19. Variation of Fundamental Constants

    Science.gov (United States)

    Flambaum, V. V.

    2006-11-01

    Theories unifying gravity with other interactions suggest temporal and spatial variation of the fundamental ``constants'' in expanding Universe. The spatial variation can explain a fine tuning of the fundamental constants which allows humans (and any life) to appear. We appeared in the area of the Universe where the values of the fundamental constants are consistent with our existence. We present a review of recent works devoted to the variation of the fine structure constant α, strong interaction and fundamental masses. There are some hints for the variation in quasar absorption spectra. Big Bang nucleosynthesis, and Oklo natural nuclear reactor data. A very promising method to search for the variation of the fundamental constants consists in comparison of different atomic clocks. Huge enhancement of the variation effects happens in transition between accidentally degenerate atomic and molecular energy levels. A new idea is to build a ``nuclear'' clock based on the ultraviolet transition between very low excited state and ground state in Thorium nucleus. This may allow to improve sensitivity to the variation up to 10 orders of magnitude! Huge enhancement of the variation effects is also possible in cold atomic and molecular collisions near Feshbach resonance.

  20. Myocardial Bridging

    Directory of Open Access Journals (Sweden)

    Shi-Min Yuan

    2016-02-01

    Full Text Available Abstract Myocardial bridging is rare. Myocardial bridges are most commonly localized in the middle segment of the left anterior descending coronary artery. The anatomic features of the bridges vary significantly. Alterations of the endothelial morphology and the vasoactive agents impact on the progression of atherosclerosis of myocardial bridging. Patients may present with chest pain, myocardial infarction, arrhythmia and even sudden death. Patients who respond poorly to the medical treatment with β-blockers warrant a surgical intervention. Myotomy is a preferred surgical procedure for the symptomatic patients. Coronary stent deployment has been in limited use due to the unsatisfactory long-term results.

  1. Synthesis, molecular structure, computational study and in vitro anticancer activity of dinuclear thiolato-bridged pentamethylcyclopentadienyl Rh(III) and Ir(III) complexes.

    Science.gov (United States)

    Gupta, Gajendra; Garci, Amine; Murray, Benjamin S; Dyson, Paul J; Fabre, Gabin; Trouillas, Patrick; Giannini, Federico; Furrer, Julien; Süss-Fink, Georg; Therrien, Bruno

    2013-11-21

    Neutral dinuclear dithiolato-bridged pentamethylcyclopentadienyl Rh(III) complexes of the type (C5Me5)2Rh2(μ-SR)2Cl2 (R = CH2Ph, 1; R = CH2CH2Ph, 2) and cationic dinuclear trithiolato-bridged pentamethylcyclopentadienyl Rh(III) and Ir(III) complexes of the type [(C5Me5)2M2(μ-SR)3](+) (M = Rh, R = CH2Ph, 3; M = Rh, R = CH2CH2Ph, 5; M = Rh, R = CH2C6H4-p-(t)Bu, 7: M = Ir, R = CH2Ph, 4; M = Ir, R = CH2CH2Ph, 6; M = Ir, R = CH2C6H4-p-(t)Bu, 8) have been synthesized from the chloro-bridged pentamethylcyclopentadienyl Rh(III) and Ir(III) dimers (C5Me5)2M2(μ-Cl)2Cl2 by reaction with the corresponding thiol derivative (RSH). Complexes 3-8 were isolated as chloride salts. All complexes were obtained in good yield and were fully characterized by spectroscopic methods. The molecular structures of the neutral complexes (1 and 2) show interesting features: the two rhodium atoms are bridged by two thiolato ligands with no metal-metal bonds and the pentamethylcyclopentadienyl and chlorido ligands are oriented syn to each other, an uncommon conformation for such dinuclear complexes. These structural features were rationalized using DFT calculations. Additionally, the antiproliferative activity of the complexes was evaluated against the cancerous A2780 (cisplatin sensitive) and A2780cisR (cisplatin resistant) human ovarian cell lines and on the noncancerous HEK293 human embryonic kidney cells. All complexes were found to be active and the cationic iridium complexes , and are particularly cytotoxic, with IC50 values in the nanomolar range (IC50 < 0.1 μM). The catalytic activity of the complexes for the oxidation of glutathione (GSH) to GSSG was evaluated by NMR spectroscopy.

  2. Marketing fundamentals.

    Science.gov (United States)

    Redmond, W H

    2001-01-01

    This chapter outlines current marketing practice from a managerial perspective. The role of marketing within an organization is discussed in relation to efficiency and adaptation to changing environments. Fundamental terms and concepts are presented in an applied context. The implementation of marketing plans is organized around the four P's of marketing: product (or service), promotion (including advertising), place of delivery, and pricing. These are the tools with which marketers seek to better serve their clients and form the basis for competing with other organizations. Basic concepts of strategic relationship management are outlined. Lastly, alternate viewpoints on the role of advertising in healthcare markets are examined.

  3. Automotive electronics design fundamentals

    CERN Document Server

    Zaman, Najamuz

    2015-01-01

    This book explains the topology behind automotive electronics architectures and examines how they can be profoundly augmented with embedded controllers. These controllers serve as the core building blocks of today’s vehicle electronics. Rather than simply teaching electrical basics, this unique resource focuses on the fundamental concepts of vehicle electronics architecture, and details the wide variety of Electronic Control Modules (ECMs) that enable the increasingly sophisticated "bells & whistles" of modern designs.  A must-have for automotive design engineers, technicians working in automotive electronics repair centers and students taking automotive electronics courses, this guide bridges the gap between academic instruction and industry practice with clear, concise advice on how to design and optimize automotive electronics with embedded controllers.

  4. Quantum mechanics I the fundamentals

    CERN Document Server

    Rajasekar, S

    2015-01-01

    Quantum Mechanics I: The Fundamentals provides a graduate-level account of the behavior of matter and energy at the molecular, atomic, nuclear, and sub-nuclear levels. It covers basic concepts, mathematical formalism, and applications to physically important systems.

  5. Variation of fundamental constants

    CERN Document Server

    Flambaum, V V

    2006-01-01

    We present a review of recent works devoted to the variation of the fine structure constant alpha, strong interaction and fundamental masses. There are some hints for the variation in quasar absorption spectra, Big Bang nucleosynthesis, and Oklo natural nuclear reactor data. A very promising method to search for the variation of the fundamental constants consists in comparison of different atomic clocks. Huge enhancement of the variation effects happens in transition between accidentally degenerate atomic and molecular energy levels. A new idea is to build a ``nuclear'' clock based on the ultraviolet transition between very low excited state and ground state in Thorium nucleus. This may allow to improve sensitivity to the variation up to 10 orders of magnitude! Huge enhancement of the variation effects is also possible in cold atomic and molecular collisions near Feschbach resonance.

  6. Pressure effects on the radical-radical recombination reaction of photochromic bridged imidazole dimers.

    Science.gov (United States)

    Mutoh, Katsuya; Abe, Jiro

    2014-09-07

    The bridged imidazole dimers are some of the attractive fast photochromic compounds which have potential applications to the ophthalmic lenses, real-time hologram and molecular machines. The strategy for expanding their photochromic properties such as the colour variation and tuning the decolouration rates has been vigorously investigated, but the insight into the structural changes along the photochromic reactions has not been demonstrated in detail. Here, we demonstrated the pressure dependence of the radical-radical recombination reaction of the bridged imidazole dimers. The radical-radical interaction can be controlled by applying high pressure. Our results give fundamental information about the molecular dynamics of the bridged imidazole dimers, leading to the development of new functional photochromic machines and pressure-sensitive photochromic materials.

  7. Theoretical Studies on the First Hyperpolarizabilities of One-dimensional Donor-bridge-acceptor Chromophores and New Applications of BLA in Determining Molecular First Hyperpolarizabilities

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    We present a quantum-chemical analysis of the relationship between the bond length alteration (BLA) and the static first hyperpolarizability of a series of one-dimensional (ID)chromophores with donor-bridge-acceptor (D-B-A) structures.The calculated results show that the parameter BLA can be considered as an indicator to evaluate the molecular first hyper-polarizability.Along the direction of molecular ground-state dipole moments, the evolutions of BLA can be classified into three categories: the first is a non-monotonic line, which represents most chromophores; the second is monotonic increasing; and the third, contrarily, is monotonic decreasing.On the whole, the first hyperpolarizabilities of these studied chromophores are the mortotonic functions of BLA along the direction of dipole moments.Therefore, the first hyper-polarizability of these 1D chromophores can be preliminarily evaluated in terms of the deve-lopment of BLA without a rigorous computation.In other words, one can roughly estimate the relative magnitude of the first hyperpolarizability according to the optimized geometry.

  8. Bridge Management Systems

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle

    In this paper bridge management systems are discussed with special emphasis on management systems for reinforced concrete bridges. Management systems for prestressed concrete bridges, steel bridges, or composite bridges can be developed in a similar way....

  9. Bridge engineering handbook construction and maintenance

    CERN Document Server

    Chen, Wai-Fah

    2014-01-01

    Over 140 experts, 14 countries, and 89 chapters are represented in the second edition of the Bridge Engineering Handbook. This extensive collection highlights bridge engineering specimens from around the world, contains detailed information on bridge engineering, and thoroughly explains the concepts and practical applications surrounding the subject.Published in five books: Fundamentals, Superstructure Design, Substructure Design, Seismic Design, and Construction and Maintenance, this new edition provides numerous worked-out examples that give readers step-by-step design procedures, includes c

  10. Synthesis and molecular recognition of novel oligo(ethylenediamino) bridged bis(beta-cyclodextrin)s and their copper(II) complexes: enhanced molecular binding ability and selectivity by multiple recognition.

    Science.gov (United States)

    Liu, Y; You, C C; Li, B

    2001-03-16

    Four bridged bis(beta-cyclodextrin)s tethered by different lengths of oligo(ethylenediamine)s have been synthesized and their inclusion complexation behavior with selected substrates elucidated by circular dichroism spectroscopy and fluorescence decay. In order to study their binding ability quantitatively, inclusion complexation stability constants with four dye guests, that is, brilliant green (BG), methyl orange (MO), ammonium 8-anilino-1-naphthalenesulfonic acid (ANS), and sodium 6-(p-toluidino)-2-naphthalenesulfonate (TNS), have been determined in aqueous solution at 25 degrees C with spectrophotometric, spectropolarimetric, or spectrofluorometric titrations. The results obtained indicate that the two tethered cyclodextrin units might cooperatively bind to a guest, and the molecular binding ability toward model substrates, especially linear guests such as TNS and MO, could be extended. The tether length plays a crucial role in the molecular recognition, the binding constants for ANS and TNS decrease linearly with an increase in the tether length of dimeric cyclodextrin. The Gibbs free energy changes (-deltaGo) for the unit increment per ethylene are 0.99 kJ mol(-1) for ANS and 0.44 kJmol(-1) for TNS, respectively. On the other hand, the presence of a copper(II) ion in metallobis(beta-cyclodextrin)s oligo(ethylenediamino) tethers enhances not only the original binding ability, but also the molecular selectivity through triple or multiple recognition, as compared with the parent bis(beta-cyclodextrin)s.

  11. National Bridge Inventory (NBI) Bridges

    Data.gov (United States)

    Department of Homeland Security — The NBI is a collection of information (database) describing the more than 600,000 of the Nation's bridges located on public roads, including Interstate Highways,...

  12. Correlating the Integral Sensing Properties of Zeolites with Molecular Processes by Combining Broadband Impedance and DRIFT Spectroscopy—A New Approach for Bridging the Scales

    Directory of Open Access Journals (Sweden)

    Peirong Chen

    2015-11-01

    Full Text Available Zeolites have been found to be promising sensor materials for a variety of gas molecules such as NH3, NOx, hydrocarbons, etc. The sensing effect results from the interaction of the adsorbed gas molecules with mobile cations, which are non-covalently bound to the zeolite lattice. The mobility of the cations can be accessed by electrical low-frequency (LF; mHz to MHz and high-frequency (HF; GHz impedance measurements. Recent developments allow in situ monitoring of catalytic reactions on proton-conducting zeolites used as catalysts. The combination of such in situ impedance measurements with diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS, which was applied to monitor the selective catalytic reduction of nitrogen oxides (DeNOx-SCR, not only improves our understanding of the sensing properties of zeolite catalysts from integral electric signal to molecular processes, but also bridges the length scales being studied, from centimeters to nanometers. In this work, recent developments of zeolite-based, impedimetric sensors for automotive exhaust gases, in particular NH3, are summarized. The electrical response to NH3 obtained from LF impedance measurements will be compared with that from HF impedance measurements, and correlated with the infrared spectroscopic characteristics obtained from the DRIFTS studies of molecules involved in the catalytic conversion. The future perspectives, which arise from the combination of these methods, will be discussed.

  13. Correlating the Integral Sensing Properties of Zeolites with Molecular Processes by Combining Broadband Impedance and DRIFT Spectroscopy—A New Approach for Bridging the Scales

    Science.gov (United States)

    Chen, Peirong; Schönebaum, Simon; Simons, Thomas; Rauch, Dieter; Dietrich, Markus; Moos, Ralf; Simon, Ulrich

    2015-01-01

    Zeolites have been found to be promising sensor materials for a variety of gas molecules such as NH3, NOx, hydrocarbons, etc. The sensing effect results from the interaction of the adsorbed gas molecules with mobile cations, which are non-covalently bound to the zeolite lattice. The mobility of the cations can be accessed by electrical low-frequency (LF; mHz to MHz) and high-frequency (HF; GHz) impedance measurements. Recent developments allow in situ monitoring of catalytic reactions on proton-conducting zeolites used as catalysts. The combination of such in situ impedance measurements with diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), which was applied to monitor the selective catalytic reduction of nitrogen oxides (DeNOx-SCR), not only improves our understanding of the sensing properties of zeolite catalysts from integral electric signal to molecular processes, but also bridges the length scales being studied, from centimeters to nanometers. In this work, recent developments of zeolite-based, impedimetric sensors for automotive exhaust gases, in particular NH3, are summarized. The electrical response to NH3 obtained from LF impedance measurements will be compared with that from HF impedance measurements, and correlated with the infrared spectroscopic characteristics obtained from the DRIFTS studies of molecules involved in the catalytic conversion. The future perspectives, which arise from the combination of these methods, will be discussed. PMID:26580627

  14. Bridged bis(beta-cyclodextrin)s possessing coordinated metal center(s) and their inclusion complexation behavior with model substrates: enhanced molecular binding ability by multiple recognition.

    Science.gov (United States)

    Liu, Y; Chen, Y; Li, L; Zhang, H Y; Liu, S X; Guan, X D

    2001-12-14

    To investigate quantitatively the cooperative binding ability of several beta-cyclodextrin oligomers bearing single or multiligated metal center(s), the inclusion complexation behavior of four bis(beta-cyclodextrin)s (2-5) linked by 2,2'-bipyridine-4,4'-dicarboxy tethers and their copper(II) complexes (6-9) with representative dye guests, i.e., methyl orange (MO), acridine red (AR), rhodamine B (RhB), ammonium 8-anilino-1-naphthalenesulfonic acid (ANS), and sodium 6-(p-toludino)-2-naphthalenesulfonate (TNS), have been examined in aqueous solution at 25 degrees C by means of UV-vis, circular dichroism, fluorescence, and 2D NMR spectroscopy. The results obtained indicate that bis(beta-cyclodextrin)s 2-5 can associate with one or three copper(II) ion(s) producing 2:1 or 2:3 bis(beta-cyclodextrin)-copper(II) complexes. These metal-ligated oligo(beta-cyclodextrin)s can bind two model substrates to form intramolecular 2:2 host-guest inclusion complexes and thus significantly enhance the original binding abilities of parent beta-cyclodextrin and bis(beta-cyclodextrin) toward model substrates through the cooperative binding of two guest molecules by four tethered cyclodextrin moieties, as well as the additional binding effect supplied by ligated metal center(s). Host 6 showed the highest enhancement of the stability constant, up to 38.3 times for ANS as compared with parent beta-cyclodextrin. The molecular binding mode and stability constant of substrates by bridged bis- and oligo(beta-cyclodextrin)s 2-9 are discussed from the viewpoint of the size/shape-fit interaction and molecular multiple recognition between host and guest.

  15. Density-Functional Theory with Dispersion-Correcting Potentials for Methane: Bridging the Efficiency and Accuracy Gap between High-Level Wave Function and Classical Molecular Mechanics Methods.

    Science.gov (United States)

    Torres, Edmanuel; DiLabio, Gino A

    2013-08-13

    Large clusters of noncovalently bonded molecules can only be efficiently modeled by classical mechanics simulations. One prominent challenge associated with this approach is obtaining force-field parameters that accurately describe noncovalent interactions. High-level correlated wave function methods, such as CCSD(T), are capable of correctly predicting noncovalent interactions, and are widely used to produce reference data. However, high-level correlated methods are generally too computationally costly to generate the critical reference data required for good force-field parameter development. In this work we present an approach to generate Lennard-Jones force-field parameters to accurately account for noncovalent interactions. We propose the use of a computational step that is intermediate to CCSD(T) and classical molecular mechanics, that can bridge the accuracy and computational efficiency gap between them, and demonstrate the efficacy of our approach with methane clusters. On the basis of CCSD(T)-level binding energy data for a small set of methane clusters, we develop methane-specific, atom-centered, dispersion-correcting potentials (DCPs) for use with the PBE0 density-functional and 6-31+G(d,p) basis sets. We then use the PBE0-DCP approach to compute a detailed map of the interaction forces associated with the removal of a single methane molecule from a cluster of eight methane molecules and use this map to optimize the Lennard-Jones parameters for methane. The quality of the binding energies obtained by the Lennard-Jones parameters we obtained is assessed on a set of methane clusters containing from 2 to 40 molecules. Our Lennard-Jones parameters, used in combination with the intramolecular parameters of the CHARMM force field, are found to closely reproduce the results of our dispersion-corrected density-functional calculations. The approach outlined can be used to develop Lennard-Jones parameters for any kind of molecular system.

  16. Sec62 bridges the gap from 3q amplification to molecular cell biology in non-small cell lung cancer.

    Science.gov (United States)

    Linxweiler, Maximilian; Linxweiler, Johannes; Barth, Monika; Benedix, Julia; Jung, Volker; Kim, Yoo-Jin; Bohle, Rainer M; Zimmermann, Richard; Greiner, Markus

    2012-02-01

    The molecular carcinogenesis of lung cancer has yet to be clearly elucidated. We investigated the possible oncogenic function of SEC62 in lung cancer, which was predicted based on our previous findings that lung and thyroid cancer tissue samples exhibited increased Sec62 protein levels. The SEC62 gene locus is at 3q26.2, and 3q amplification is reportedly the most common genomic alteration in non-small cell lung cancer. We analyzed SEC62 mRNA and protein levels in tissue samples from lung cancer patients by real-time quantitative PCR, Western blot, and IHC and found significantly increased SEC62 mRNA and protein levels in tumors compared with tumor-free tissue samples from the same patients. Correlation analyses revealed significantly higher Sec62 levels in tumors with lymph node metastases compared with nonmetastatic tumors, as well as in poorly compared with moderately differentiated tumors. On the basis of these promising results, we examined the role of Sec62 in cancer cell biology in vitro. Cell migration assays with lung and thyroid cancer cells showed distinct stimulation of migration in SEC62-overexpressing cells and inhibition of migration in Sec62-depleted cells. Moreover, we found that SEC62 silencing sensitized the cells to thapsigargin-induced endoplasmic reticulum stress. Thus, our results indicate that SEC62 represents a potential candidate oncogene in the amplified 3q region in cases of non-small cell lung cancer and harbors various functions in cancer cell biology.

  17. Nanomachines fundamentals and applications

    CERN Document Server

    Wang, Joseph

    2013-01-01

    This first-hand account by one of the pioneers of nanobiotechnology brings together a wealth of valuable material in a single source. It allows fascinating insights into motion at the nanoscale, showing how the proven principles of biological nanomotors are being transferred to artificial nanodevices.As such, the author provides engineers and scientists with the fundamental knowledge surrounding the design and operation of biological and synthetic nanomotors and the latest advances in nanomachines. He addresses such topics as nanoscale propulsions, natural biomotors, molecular-scale machin

  18. Bridged graphite oxide materials

    Science.gov (United States)

    Herrera-Alonso, Margarita (Inventor); McAllister, Michael J. (Inventor); Aksay, Ilhan A. (Inventor); Prud'homme, Robert K. (Inventor)

    2010-01-01

    Bridged graphite oxide material comprising graphite sheets bridged by at least one diamine bridging group. The bridged graphite oxide material may be incorporated in polymer composites or used in adsorption media.

  19. Electrothermally Tunable Bridge Resonator

    KAUST Repository

    Hajjaj, Amal Z.

    2016-12-05

    This paper demonstrates experimentally, theoretically, and numerically a wide-range tunability of an in-plane clamped-clamped microbeam, bridge, and resonator compressed by a force due to electrothermal actuation. We demonstrate that a single resonator can be operated at a wide range of frequencies. The microbeam is actuated electrothermally, by passing a DC current through it. We show that when increasing the electrothermal voltage, the compressive stress inside the microbeam increases, which leads eventually to its buckling. Before buckling, the fundamental frequency decreases until it drops to very low values, almost to zero. After buckling, the fundamental frequency increases, which is shown to be as high as twice the original resonance frequency. Analytical results based on the Galerkin discretization of the Euler Bernoulli beam theory are generated and compared to the experimental data and to simulation results of a multi-physics finite-element model. A good agreement is found among all the results.

  20. Building Bridges

    DEFF Research Database (Denmark)

    The report Building Bridges adresses the questions why, how and for whom academic audience research has public value, from the different points of view of the four working groups in the COST Action IS0906 Transforming Audiences, Transforming Societies – “New Media Genres, Media Literacy and Trust...... in the Media”, “Audience Interactivity and Participation”, “The Role of Media and ICT Use for Evolving Social Relationships” and “Audience Transformations and Social Integration”. Building Bridges is the result of an ongoing dialogue between the Action and non-academic stakeholders in the field of audience...... Belgrade), Leo Pekkala (Finnish Centre for Media Education and Audiovisual Media/MEKU), Julie Uldam (Network on Civic Engagement and Social Innovation) and Gabriella Velics (Community Media Forum Europe)....

  1. Mathematical bridges

    CERN Document Server

    Andreescu, Titu; Tetiva, Marian

    2017-01-01

    Building bridges between classical results and contemporary nonstandard problems, Mathematical Bridges embraces important topics in analysis and algebra from a problem-solving perspective. Blending old and new techniques, tactics and strategies used in solving challenging mathematical problems, readers will discover numerous genuine mathematical gems throughout that will heighten their appreciation of the inherent beauty of mathematics. Most of the problems are original to the authors and are intertwined in a well-motivated exposition driven by representative examples. The book is structured to assist the reader in formulating and proving conjectures, as well as devising solutions to important mathematical problems by making connections between various concepts and ideas from different areas of mathematics. Instructors and educators teaching problem-solving courses or organizing mathematics clubs, as well as motivated mathematics students from high school juniors to college seniors, will find Mathematical Bri...

  2. Radiological and Environmental Research Division annual report: Fundamental Molecular Physics and Chemistry, October 1977-September 1978. [Summary of research activities at Argonne National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Rowland, R. E.; Inokuti, Mitio [eds.

    1978-01-01

    Research presented includes 32 papers, six of which have appeared previously in ERA, and 26 appear in this issue of ERA. Molecular physics and chemistry including photoionization, molecular properties, oscillator strengths, scattering, shape resonances, and photoelectrons are covered. A list of publications is included. (JFP)

  3. Thermal and Mechanical Non-Equilibrium Effects on Turbulent Flows: Fundamental Studies of Energy Exchanges Through Direct Numerical Simulations, Molecular Simulations and Experiments

    Science.gov (United States)

    2016-02-26

    massive direct numerical simulations ( DNS ), detailed molecular dynamics simulations and novel laser based experimental approaches were developed to explore...TERMS Aerothermodynamics and Nonequillibrium, Hypersonic and Gas-surface Interaction 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT UU 18...multidisciplinary nature of the scientific problem, a combination of state-of-the-art massive direct numerical simulations ( DNS ), detailed molecular dynamics

  4. Plastic Bridge

    Institute of Scientific and Technical Information of China (English)

    履之

    1994-01-01

    Already ubiquitous in homes and cars, plastic is now appearing inbridges. An academic-industrial consortium based at the University ofCalifornia in San Diego is launching a three-year research program aimed atdeveloping the world’s first plastic highway bridge, a 450-foot span madeentirely from glass-,carbon,and polymer-fiber-reinforced composite mate-rials, the stuff of military aircraft. It will cross Interstate 5 to connect thetwo sides of the school’s campus.

  5. Salt bridges: geometrically specific, designable interactions.

    Science.gov (United States)

    Donald, Jason E; Kulp, Daniel W; DeGrado, William F

    2011-03-01

    Salt bridges occur frequently in proteins, providing conformational specificity and contributing to molecular recognition and catalysis. We present a comprehensive analysis of these interactions in protein structures by surveying a large database of protein structures. Salt bridges between Asp or Glu and His, Arg, or Lys display extremely well-defined geometric preferences. Several previously observed preferences are confirmed, and others that were previously unrecognized are discovered. Salt bridges are explored for their preferences for different separations in sequence and in space, geometric preferences within proteins and at protein-protein interfaces, co-operativity in networked salt bridges, inclusion within metal-binding sites, preference for acidic electrons, apparent conformational side chain entropy reduction on formation, and degree of burial. Salt bridges occur far more frequently between residues at close than distant sequence separations, but, at close distances, there remain strong preferences for salt bridges at specific separations. Specific types of complex salt bridges, involving three or more members, are also discovered. As we observe a strong relationship between the propensity to form a salt bridge and the placement of salt-bridging residues in protein sequences, we discuss the role that salt bridges might play in kinetically influencing protein folding and thermodynamically stabilizing the native conformation. We also develop a quantitative method to select appropriate crystal structure resolution and B-factor cutoffs. Detailed knowledge of these geometric and sequence dependences should aid de novo design and prediction algorithms.

  6. The [Lys(-2)-Arg(-1)-des(17-21)]-endothelin-1 peptide retains the specific Arg(-1)-Asp8 salt bridge but reveals discrepancies between NMR data and molecular dynamics simulations.

    Science.gov (United States)

    Kaas, Quentin; Aumelas, André; Kubo, Shigeru; Chino, Naoyoshi; Kobayashi, Yuji; Chiche, Laurent

    2002-09-17

    The [des(17-21)]-endothelin-1 (CSH-ET) and [Lys(-)(2)-Arg(-)(1)-des(17-21)]-endothelin-1 (KR-CSH-ET) peptides, designed by removing the five-residue hydrophobic tail from the endothelin-1 (ET-1) and [Lys(-)(2)-Arg(-)(1)]-endothelin-1 (KR-ET-1) peptides, respectively, were synthesized. Previous studies on KR-ET-1 showed that, in contrast to ET-1, this engineered compound displays a pH-dependent conformational change related to the formation of a stabilizing salt bridge between the Arg(-)(1) and Asp(8) side chains. CD and NMR spectra indicate that CSH-ET and KR-CSH-ET display conformational behavior similar to those of ET-1 and KR-ET-1, respectively. The short salt bridge-stabilized KR-CSH-ET peptide therefore appears to be an attractive elementary scaffold for drug design. The solution structure of the salt-bridged form of KR-CSH-ET was determined by NMR at pH 4.5 and is very similar to the corresponding form of the parent KR-ET-1 peptide. Molecular dynamics simulations of the salt-bridged form of KR-CSH-ET were performed using both the GB/SA implicit solvation scheme or an explicit solvation and the particle-mesh Ewald method for long-range electrostatic calculation. Unexpectedly, the Arg(-)(1)-Asp(8) salt bridge does not display in the simulation the stability that could be expected from the experimental data. The cooperative involvement of a cation-pi interaction in formation of the salt bridge has been hypothesized. Difficulties in accurately simulating cation-pi interactions might be responsible for the lack of stability in the simulation. At this time, however, no definitive explanation for the observed discrepancy between experiments and simulations is available, and further experimental studies appear to be necessary to fully understand in atomic detail the pH-dependent conformational change observed in the KR-ET-1 series.

  7. Cable Supported Bridges

    DEFF Research Database (Denmark)

    Gimsing, Niels Jørgen

    Cable supported bridges in the form of suspension bridges and cable-stayed bridges are distinguished by their ability to overcome large spans.The book concentrates on the synthesis of cable supported bridges, covering both design and construction aspects. The analytical part covers simple methods...

  8. Exchange Rates and Fundamentals.

    Science.gov (United States)

    Engel, Charles; West, Kenneth D.

    2005-01-01

    We show analytically that in a rational expectations present-value model, an asset price manifests near-random walk behavior if fundamentals are I (1) and the factor for discounting future fundamentals is near one. We argue that this result helps explain the well-known puzzle that fundamental variables such as relative money supplies, outputs,…

  9. Fundamental reaction pathway for peptide metabolism by proteasome: insights from first-principles quantum mechanical/molecular mechanical free energy calculations.

    Science.gov (United States)

    Wei, Donghui; Fang, Lei; Tang, Mingsheng; Zhan, Chang-Guo

    2013-10-31

    Proteasome is the major component of the crucial non-lysosomal protein degradation pathway in the cells, but the detailed reaction pathway is unclear. In this study, first-principles quantum mechanical/molecular mechanical free energy calculations have been performed to explore, for the first time, possible reaction pathways for proteasomal proteolysis/hydrolysis of a representative peptide, succinyl-leucyl-leucyl-valyl-tyrosyl-7-amino-4-methylcoumarin (Suc-LLVY-AMC). The computational results reveal that the most favorable reaction pathway consists of six steps. The first is a water-assisted proton transfer within proteasome, activating Thr1-O(γ). The second is a nucleophilic attack on the carbonyl carbon of a Tyr residue of substrate by the negatively charged Thr1-O(γ), followed by the dissociation of the amine AMC (third step). The fourth step is a nucleophilic attack on the carbonyl carbon of the Tyr residue of substrate by a water molecule, accompanied by a proton transfer from the water molecule to Thr1-N(z). Then, Suc-LLVY is dissociated (fifth step), and Thr1 is regenerated via a direct proton transfer from Thr1-N(z) to Thr1-O(γ). According to the calculated energetic results, the overall reaction energy barrier of the proteasomal hydrolysis is associated with the transition state (TS3(b)) for the third step involving a water-assisted proton transfer. The determined most favorable reaction pathway and the rate-determining step have provided a reasonable interpretation of the reported experimental observations concerning the substituent and isotopic effects on the kinetics. The calculated overall free energy barrier of 18.2 kcal/mol is close to the experimentally derived activation free energy of ∼18.3-19.4 kcal/mol, suggesting that the computational results are reasonable.

  10. A fundamental investigation of the surfactant-stabilized single-walled carbon nanotube/epoxy resin suspensions by molecular dynamics simulation

    Science.gov (United States)

    Rahmani, Farzin; Nouranian, Sasan; Mahdavi, Mina; O’Haver, John H.

    2017-01-01

    The surfactant-assisted stabilization of single-walled carbon nanotubes (SWCNTs) in SWCNT/epoxy resin suspensions were investigated for different surfactant types, concentrations, and temperatures using molecular dynamics simulation. One cationic surfactant, i.e. cetyltrimethylammonium bromide (CTAB), and three anionic surfactants, i.e. sodium dodecyl sulfate (SDS), sodium dodecylbenzenesulfonate (NaDDBS), and sodium cholate (SC), as well as a 1:1 mixture of CTAB and SDS were used. Potentials of mean force (PMFs) were generated between two fixed-size (6,6) SWCNTs for all neat (no surfactant) and surfactant-loaded SWCNT/epoxy resin systems at three different surfactant concentrations (0.25, 0.50, and 1.00 wt%) at room (298 K) and elevated temperature (398 K, only for low-surfactant-concentration systems). Overall, two distinct mechanisms of SWCNT stabilization by the surfactants were identified: (1) an increase in the SWCNT aggregation energy barrier due to the wrapping of the SWCNTs by the surfactant molecules, and (2) a constantly positive free energy (repulsion) for all SWCNT separation distances due to the encapsulation of the two approaching SWCNTs. With the second mechanism, there is a delay for the epoxy molecules to be pushed out from the space between the two SWCNTs. With an increase in the surfactant concentration, the first mechanism becomes more prevalent. With an increase in temperature to 398 K, all surfactants migrate to the suspending medium, thereby the second mechanism of SWCNT stabilization dominates. A drop in the SWCNT-surfactant binding energy is observed around 360–370 K, signifying the surfactant migration to the suspending medium. More or less, all surfactants stabilize the SWCNTs in an epoxy resin at one or more surfactant concentrations. However, NaDDBS exhibits a higher SWCNT aggregation barrier at high concentrations and both temperatures (298 K and 398 K), thereby providing a better SWCNT stabilization in the epoxy resin

  11. Disulfide-Bridged (Mo3S11) Cluster Polymer: Molecular Dynamics and Application as Electrode Material for a Rechargeable Magnesium Battery.

    Science.gov (United States)

    Truong, Quang Duc; Kempaiah Devaraju, Murukanahally; Nguyen, Duc N; Gambe, Yoshiyuki; Nayuki, Keiichiro; Sasaki, Yoshikazu; Tran, Phong D; Honma, Itaru

    2016-09-14

    Exploring novel electrode materials is critical for the development of a next-generation rechargeable magnesium battery with high volumetric capacity. Here, we showed that a distinct amorphous molybdenum sulfide, being a coordination polymer of disulfide-bridged (Mo3S11) clusters, has great potential as a rechargeable magnesium battery cathode. This material provided good reversible capacity, attributed to its unique structure with high flexibility and capability of deformation upon Mg insertion. Free-terminal disulfide moiety may act as the active site for reversible insertion and extraction of magnesium.

  12. Bridges in Complex Networks

    CERN Document Server

    Wu, Ang-Kun; Liu, Yang-Yu

    2016-01-01

    A bridge in a graph is an edge whose removal disconnects the graph and increases the number of connected components. We calculate the fraction of bridges in a wide range of real-world networks and their randomized counterparts. We find that real networks typically have more bridges than their completely randomized counterparts, but very similar fraction of bridges as their degree-preserving randomizations. We define a new edge centrality measure, called bridgeness, to differentiate the importance of a bridge in damaging a network. We find that certain real networks have very large average and variance of bridgeness compared to their degree-preserving randomizations and other real networks. Finally, we offer an analytical framework to calculate the bridge fraction and average bridgeness for uncorrelated random networks with arbitrary degree distributions.

  13. Bridging Innate and Adaptive Antitumor Immunity Targeting Glycans

    Science.gov (United States)

    Pashov, Anastas; Monzavi-Karbassi, Bejatolah; Raghava, Gajendra P. S.; Kieber-Emmons, Thomas

    2010-01-01

    Effective immunotherapy for cancer depends on cellular responses to tumor antigens. The role of major histocompatibility complex (MHC) in T-cell recognition and T-cell receptor repertoire selection has become a central tenet in immunology. Structurally, this does not contradict earlier findings that T-cells can differentiate between small hapten structures like simple glycans. Understanding T-cell recognition of antigens as defined genetically by MHC and combinatorially by T cell receptors led to the “altered self” hypothesis. This notion reflects a more fundamental principle underlying immune surveillance and integrating evolutionarily and mechanistically diverse elements of the immune system. Danger associated molecular patterns, including those generated by glycan remodeling, represent an instance of altered self. A prominent example is the modification of the tumor-associated antigen MUC1. Similar examples emphasize glycan reactivity patterns of antigen receptors as a phenomenon bridging innate and adaptive but also humoral and cellular immunity and providing templates for immunotherapies. PMID:20617150

  14. Different Effect of the Additional Electron-Withdrawing Cyano Group in Different Conjugation Bridge: The Adjusted Molecular Energy Levels and Largely Improved Photovoltaic Performance.

    Science.gov (United States)

    Li, Huiyang; Fang, Manman; Hou, Yingqin; Tang, Runli; Yang, Yizhou; Zhong, Cheng; Li, Qianqian; Li, Zhen

    2016-05-18

    Four organic sensitizers (LI-68-LI-71) bearing various conjugated bridges were designed and synthesized, in which the only difference between LI-68 and LI-69 (or LI-70 and LI-71) was the absence/presence of the CN group as the auxiliary electron acceptor. Interestingly, compared to the reference dye of LI-68, LI-69 bearing the additional CN group exhibited the bad performance with the decreased Jsc and Voc values. However, once one thiophene moiety near the anchor group was replaced by pyrrole with the electron-rich property, the resultant LI-71 exhibited a photoelectric conversion efficiency increase by about 3 folds from 2.75% (LI-69) to 7.95% (LI-71), displaying the synergistic effect of the two moieties (CN and pyrrole). Computational analysis disclosed that pyrrole as the auxiliary electron donor (D') in the conjugated bridge can compensate for the lower negative charge in the electron acceptor, which was caused by the CN group as the electron trap, leading to the more efficient electron injection and better photovoltaic performance.

  15. What determines water-bridge lifetimes at the surface of DNA? Insight from systematic molecular dynamics analysis of water kinetics for various DNA sequences.

    Science.gov (United States)

    Yonetani, Yoshiteru; Kono, Hidetoshi

    2012-01-01

    The lifetime during which a water molecule resides at the surface of a biomolecule varies according to the hydration site. What determines this variety of lifetimes? Despite many previous studies, there is still no uniform picture quantitatively explaining this phenomenon. Here we calculate the lifetime for a particular hydration pattern in the DNA minor groove, the water bridge, for various DNA sequences to show that the water-bridge lifetime varies from 1 to ~300ps in a sequence-dependent manner. We find that it follows 1/k(V(step))P(m), where P(m) and V(step) are two crucial factors, namely the probability of forming a specific hydrogen bond in which more than one donor atom participates, and the structural fluctuation of DNA, respectively. This relationship provides a picture of the water kinetics with atomistic detail and shows that water dissociation occurs when a particular hydrogen-bonding pattern appears. The rate constant of water dissociation k can be described as a function of the structural fluctuations of DNA. This picture is consistent with the model of Laage and Hynes proposing that hydrogen-bond switching occurs when an unusual number of hydrogen bonds are formed. The two new factors suggested here are discussed in the context of the surface's geometry and electrostatic nature, which were previously proposed as the determinants of water lifetimes.

  16. Fundamentals of gas dynamics

    CERN Document Server

    Babu, V

    2014-01-01

    Fundamentals of Gas Dynamics, Second Edition isa comprehensively updated new edition and now includes a chapter on the gas dynamics of steam. It covers the fundamental concepts and governing equations of different flows, and includes end of chapter exercises based on the practical applications. A number of useful tables on the thermodynamic properties of steam are also included.Fundamentals of Gas Dynamics, Second Edition begins with an introduction to compressible and incompressible flows before covering the fundamentals of one dimensional flows and normal shock wav

  17. Crystal science fundamentals

    OpenAIRE

    Ramachandran, V.; Halfpenny, PJ; Roberts, KJ

    2017-01-01

    The fundamentals of crystal science notably crystallography, crystal chemistry, crystal defects, crystal morphology and the surface chemistry of crystals are introduced with particular emphasis on organic crystals.

  18. Fundamental investigations of catalyst nanoparticles

    DEFF Research Database (Denmark)

    Elkjær, Christian Fink

    fundamental understanding of catalytic processes and our ability to make use of that understanding. This thesis presents fundamental studies of catalyst nanoparticles with particular focus on dynamic processes. Such studies often require atomic-scale characterization, because the catalytic conversion takes...... place on the molecular and atomic level. Transmission electron microscopy (TEM) has the ability to image nanostructures with atomic resolution and reveal the atomic configuration of the important nanoparticle surfaces. In the present work, TEM has been used to study nanoparticles in situ at elevated...... different topics, each related to different aspects of nanoparticle dynamics and catalysis. The first topic is the reduction of a homogeneous solid state precursor to form the catalytically active phase which is metal nanoparticles on an inert support. Here, we have reduced Cu phyllosilicate to Cu on silica...

  19. Fundamentals of Physics

    Science.gov (United States)

    Halliday, David; Resnick, Robert; Walker, Jearl

    2003-01-01

    No other book on the market today can match the success of Halliday, Resnick and Walker's Fundamentals of Physics! In a breezy, easy-to-understand style the book offers a solid understanding of fundamental physics concepts, and helps readers apply this conceptual understanding to quantitative problem solving.

  20. Dependence and Fundamentality

    Directory of Open Access Journals (Sweden)

    Justin Zylstra

    2014-12-01

    Full Text Available I argue that dependence is neither necessary nor sufficient for relative fundamentality. I then introduce the notion of 'likeness in nature' and provide an account of relative fundamentality in terms of it and the notion of dependence. Finally, I discuss some puzzles that arise in Aristotle's Categories, to which the theory developed is applied.

  1. Molecular Design of Crown Ethers. 191. Synthesis of Novel Disulfide- and Diselenide-Bridged Bis (benzo-12-crown-4)s and their Ag+ Selective Electrode Properties

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Two novel heteroatom-bridged bis (benzo-12-crown-4 ether)s, i.e. bis [2-nitro-4,5-(1,4,7,10-tetraoxadecamethylene)phenyl] disulfide 1 and diselenide 2, have been synthesized. X-ray crystallographic structure was obtained for 1. Ion selective electrodes (ISE) for Ag+, containing 1 and 2 in PVC membrane as neutral carriers, were prepared, and their selectivity coefficients for Ag+ (KpolAg,M) were determined against other heavy metal ions, alkali and alkaline-earth metal ions, and ammonium ion. These ISEs showed excellent Ag+ selectivities, log (KpolAg,M) -3.8, against most of the interfering cations examined, except for Hg+.

  2. Molecular and Cellular Fundamentals of Aerobic Cometabolism

    Science.gov (United States)

    1998-10-01

    heterocycles, and several heteroatom ring compounds), ethers, thioethers and primary amines (Arp, et al . , 1 996). AMO has not yet been purified to...Alexander, 1 967) and petroleum hydrocarbons (Foster, 1 962). Collectively, these studies established that many compounds can be transformed by...oxidation as "the oxidation of non-growth hydrocarbons when present in a medium where one or more different hydrocarbons are furnishedfor growth

  3. Taizhou Yangtze River Bridge

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    Taizhou Bridge lies between Taizhou, Zhenjiang and Changzhou City in Jiangsu Province. The total length of Taizhou Bridge is 62.088 kin. The whole line is designed by freeway codes with six lanes in two directions. The wholeinvestment is 9.37 billion RMB and the planned construction duration is 5.5 years. The main bridge crossing the Yangtze River is a continuous three-pylon two-span suspension bridge with the main span of 1 080 m. The bridge system is realized for the first time and ranks first in the world until now.

  4. Fundamentals of electronics

    CERN Document Server

    Schubert, Thomas F

    2015-01-01

    This book, Electronic Devices and Circuit Application, is the first of four books of a larger work, Fundamentals of Electronics. It is comprised of four chapters describing the basic operation of each of the four fundamental building blocks of modern electronics: operational amplifiers, semiconductor diodes, bipolar junction transistors, and field effect transistors. Attention is focused on the reader obtaining a clear understanding of each of the devices when it is operated in equilibrium. Ideas fundamental to the study of electronic circuits are also developed in the book at a basic level to

  5. Composite timber-concrete road bridge structure

    Directory of Open Access Journals (Sweden)

    Stojić Dragoslav

    2007-01-01

    Full Text Available This work presents preliminary design of the road bridge made of laminated timber. The supporting system of the main bearing elements is made of the laminated timber in the system of arch with three joints; the bridge slab is designed as continuous slab, made of nine equal fields; each pair is made as composite timber-concrete beam, where the road slab is made of concrete and the needle pieces are made of timber. Fundament is based on HW piles. All the elements are designed to Eurocode.

  6. Fundamentals of electrochemical science

    CERN Document Server

    Oldham, Keith

    1993-01-01

    Key Features* Deals comprehensively with the basic science of electrochemistry* Treats electrochemistry as a discipline in its own right and not as a branch of physical or analytical chemistry* Provides a thorough and quantitative description of electrochemical fundamentals

  7. Fundamentals of crystallography

    CERN Document Server

    2011-01-01

    Crystallography is a basic tool for scientists in many diverse disciplines. This text offers a clear description of fundamentals and of modern applications. It supports curricula in crystallography at undergraduate level.

  8. Fundamentals of structural dynamics

    CERN Document Server

    Craig, Roy R

    2006-01-01

    From theory and fundamentals to the latest advances in computational and experimental modal analysis, this is the definitive, updated reference on structural dynamics.This edition updates Professor Craig's classic introduction to structural dynamics, which has been an invaluable resource for practicing engineers and a textbook for undergraduate and graduate courses in vibrations and/or structural dynamics. Along with comprehensive coverage of structural dynamics fundamentals, finite-element-based computational methods, and dynamic testing methods, this Second Edition includes new and e

  9. Masses of Fundamental Particles

    CERN Document Server

    Terazawa, Hidezumi

    2011-01-01

    Not only the masses of fundamental particles including the weak bosons, Higgs scalar, quarks, and leptons, but also the mixing angles of quarks and those of neutrinos are all explained and/or predicted in the unified composite model of quarks and leptons successfully. In addition, both of the two anomalies recently found by the CDF Collaboration are suggested to be taken as evidences for the substructure of the fundamental particles.

  10. Information security fundamentals

    CERN Document Server

    Peltier, Thomas R

    2013-01-01

    Developing an information security program that adheres to the principle of security as a business enabler must be the first step in an enterprise's effort to build an effective security program. Following in the footsteps of its bestselling predecessor, Information Security Fundamentals, Second Edition provides information security professionals with a clear understanding of the fundamentals of security required to address the range of issues they will experience in the field.The book examines the elements of computer security, employee roles and r

  11. Syntheses, molecular and crystalline architectures, and luminescence behaviour of terephthalate bridged heptacoordinated dinuclear lead(II) complexes containing a pentadentate N-donor Schiff base

    Indian Academy of Sciences (India)

    Subhasis Roy; Somnath Choubey; Sumitava Khan; Kishalay Bhar; Partha Mitra; Barindra Kumar Ghosh

    2013-07-01

    One-pot synthesis using a 2:2:1:2 molar ratio of Pb(OAc)2·3H2O, L, piperidinum terephthalate (ptp) and NaClO4/NH4PF6 at room temperature affords two dinuclear compounds of the type [Pb2(L)2(- tp)](ClO4/PF6)2 (1/2) [L=N,N'-(bis-(pyridin-2-yl)benzylidene)diethylenetriamine and tp = terephthalate dianion]. The compounds are characterized by microanalytical, spectroscopic, thermal and other physicochemical results. X-ray structural analyses of 1 and 2 reveal that each heptacoordinated lead(II) centre with a PbN5O2 chromophore are bound by five N atoms of L and connected through O atoms of a bis(bidentate) tp bridge. The arrangements of L and tp suggest a gap around the metal centre due to occupation of a stereo-active lone pair of electrons reflecting a hemidirected coordination around the metal centre. The complexes exhibit reasonable thermal stabilities with the tolerate temperatures ca. 255°C for 1 and 263°C for 2. The complexes display intraligand (-*) fluorescence in the solid state and in DMF solutions at room temperature.

  12. Development of a real-time scour monitoring system for bridge safety evaluation

    Science.gov (United States)

    Lin, Tzu-Kang; Chang, Yu-Shian

    2017-01-01

    The fact that hydraulic problems are major factors in bridge collapse has made bridge scour monitoring an important research topic. In view of the complex nonlinear behavior of bridge structure/soil/water interactions, the fundamental frequency of the bridge may gradually change as the height of the bed drops during scour. With an insufficient embedded depth, the bridge may collapse or sink unexpectedly without warning. As experimental investigation in past research has shown that bridge failure may be governed by rigid body motion, a real-time bridge scour monitoring system to distinguish the influence of rigid body motion from the vibration frequency of the bridge is proposed. The signal measured from the superstructure of the bridge is decomposed into a structural vibration set controlling the fundamental frequency change and a rigid body motion set controlling the rigid body motion, and an instability index to examine the safety condition of the bridge is further proposed. Following a successful preliminary single-pile scour experiment, the method is applied to a series of full-bridge testing. According to analysis result, the instability index deviated considerably from its original range before the bridge piles began tilting significantly, allowing an early warning alert for bridge safety evaluation.

  13. Electron transfer through rigid organic molecular wires enhanced by electronic and electron-vibration coupling.

    Science.gov (United States)

    Sukegawa, Junpei; Schubert, Christina; Zhu, Xiaozhang; Tsuji, Hayato; Guldi, Dirk M; Nakamura, Eiichi

    2014-10-01

    Electron transfer (ET) is a fundamental process in a wide range of biological systems, photovoltaics and molecular electronics. Therefore to understand the relationship between molecular structure and ET properties is of prime importance. For this purpose, photoinduced ET has been studied extensively using donor-bridge-acceptor molecules, in which π-conjugated molecular wires are employed as bridges. Here, we demonstrate that carbon-bridged oligo-p-phenylenevinylene (COPV), which is both rigid and flat, shows an 840-fold increase in the ET rate compared with the equivalent flexible molecular bridges. A 120-fold rate enhancement is explained in terms of enhanced electronic coupling between the electron donor and the electron acceptor because of effective conjugation through the COPVs. The remainder of the rate enhancement is explained by inelastic electron tunnelling through COPV caused by electron-vibration coupling, unprecedented for organic molecular wires in solution at room temperature. This type of nonlinear effect demonstrates the versatility and potential practical utility of COPVs in molecular device applications.

  14. Fundamentals of algebraic topology

    CERN Document Server

    Weintraub, Steven H

    2014-01-01

    This rapid and concise presentation of the essential ideas and results of algebraic topology follows the axiomatic foundations pioneered by Eilenberg and Steenrod. The approach of the book is pragmatic: while most proofs are given, those that are particularly long or technical are omitted, and results are stated in a form that emphasizes practical use over maximal generality. Moreover, to better reveal the logical structure of the subject, the separate roles of algebra and topology are illuminated. Assuming a background in point-set topology, Fundamentals of Algebraic Topology covers the canon of a first-year graduate course in algebraic topology: the fundamental group and covering spaces, homology and cohomology, CW complexes and manifolds, and a short introduction to homotopy theory. Readers wishing to deepen their knowledge of algebraic topology beyond the fundamentals are guided by a short but carefully annotated bibliography.

  15. Fundamentals of turbomachines

    CERN Document Server

    Dick, Erik

    2015-01-01

    This book explores the working principles of all kinds of turbomachines. The same theoretical framework is used to analyse the different machine types. Fundamentals are first presented and theoretical concepts are then elaborated for particular machine types, starting with the simplest ones.For each machine type, the author strikes a balance between building basic understanding and exploring knowledge of practical aspects. Readers are invited through challenging exercises to consider how the theory applies to particular cases and how it can be generalised.   The book is primarily meant as a course book. It teaches fundamentals and explores applications. It will appeal to senior undergraduate and graduate students in mechanical engineering and to professional engineers seeking to understand the operation of turbomachines. Readers will gain a fundamental understanding of turbomachines. They will also be able to make a reasoned choice of turbomachine for a particular application and to understand its operation...

  16. Monte Carlo fundamentals

    Energy Technology Data Exchange (ETDEWEB)

    Brown, F.B.; Sutton, T.M.

    1996-02-01

    This report is composed of the lecture notes from the first half of a 32-hour graduate-level course on Monte Carlo methods offered at KAPL. These notes, prepared by two of the principle developers of KAPL`s RACER Monte Carlo code, cover the fundamental theory, concepts, and practices for Monte Carlo analysis. In particular, a thorough grounding in the basic fundamentals of Monte Carlo methods is presented, including random number generation, random sampling, the Monte Carlo approach to solving transport problems, computational geometry, collision physics, tallies, and eigenvalue calculations. Furthermore, modern computational algorithms for vector and parallel approaches to Monte Carlo calculations are covered in detail, including fundamental parallel and vector concepts, the event-based algorithm, master/slave schemes, parallel scaling laws, and portability issues.

  17. Bridge Crossing Simulator

    Science.gov (United States)

    2014-10-07

    Requirement BCS Computer-controlled hydraulic actuation system to impart simulated crossing loads on an entire bridge structure undergoing fatigue test ...structure. Bridge test site with prepared embankments corresponding to the span and bank condition requirements of the bridge under test Conduct real...Center (AEC). (5) Sample size and number of crossings required. The number of required simulated crossings to conduct fatigue testing per the

  18. Fundamentals of fluid lubrication

    Science.gov (United States)

    Hamrock, Bernard J.

    1991-01-01

    The aim is to coordinate the topics of design, engineering dynamics, and fluid dynamics in order to aid researchers in the area of fluid film lubrication. The lubrication principles that are covered can serve as a basis for the engineering design of machine elements. The fundamentals of fluid film lubrication are presented clearly so that students that use the book will have confidence in their ability to apply these principles to a wide range of lubrication situations. Some guidance on applying these fundamentals to the solution of engineering problems is also provided.

  19. Infosec management fundamentals

    CERN Document Server

    Dalziel, Henry

    2015-01-01

    Infosec Management Fundamentals is a concise overview of the Information Security management concepts and techniques, providing a foundational template for both experienced professionals and those new to the industry. This brief volume will also appeal to business executives and managers outside of infosec who want to understand the fundamental concepts of Information Security and how it impacts their business decisions and daily activities. Teaches ISO/IEC 27000 best practices on information security management Discusses risks and controls within the context of an overall information securi

  20. Fundamentals of piping design

    CERN Document Server

    Smith, Peter

    2013-01-01

    Written for the piping engineer and designer in the field, this two-part series helps to fill a void in piping literature,since the Rip Weaver books of the '90s were taken out of print at the advent of the Computer Aid Design(CAD) era. Technology may have changed, however the fundamentals of piping rules still apply in the digitalrepresentation of process piping systems. The Fundamentals of Piping Design is an introduction to the designof piping systems, various processes and the layout of pipe work connecting the major items of equipment forthe new hire, the engineering student and the vetera

  1. Homeschooling and religious fundamentalism

    Directory of Open Access Journals (Sweden)

    Robert KUNZMAN

    2010-10-01

    Full Text Available This article considers the relationship between homeschooling and religious fundamentalism by focusing on their intersection in the philosophies and practices of conservative Christian homeschoolers in the United States. Homeschooling provides an ideal educational setting to support several core fundamentalist principles: resistance to contemporary culture; suspicion of institutional authority and professional expertise; parental control and centrality of the family; and interweaving of faith and academics. It is important to recognize, however, that fundamentalism exists on a continuum; conservative religious homeschoolers resist liberal democratic values to varying degrees, and efforts to foster dialogue and accommodation with religious homeschoolers can ultimately helpstrengthen the broader civic fabric.

  2. Pragmatic electrical engineering fundamentals

    CERN Document Server

    Eccles, William

    2011-01-01

    Pragmatic Electrical Engineering: Fundamentals introduces the fundamentals of the energy-delivery part of electrical systems. It begins with a study of basic electrical circuits and then focuses on electrical power. Three-phase power systems, transformers, induction motors, and magnetics are the major topics.All of the material in the text is illustrated with completely-worked examples to guide the student to a better understanding of the topics. This short lecture book will be of use at any level of engineering, not just electrical. Its goal is to provide the practicing engineer with a practi

  3. Fundamentals of nonlinear optics

    CERN Document Server

    Powers, Peter E

    2011-01-01

    Peter Powers's rigorous but simple description of a difficult field keeps the reader's attention throughout. … All chapters contain a list of references and large numbers of practice examples to be worked through. … By carefully working through the proposed problems, students will develop a sound understanding of the fundamental principles and applications. … the book serves perfectly for an introductory-level course for second- and third-order nonlinear optical phenomena. The author's writing style is refreshing and original. I expect that Fundamentals of Nonlinear Optics will fast become pop

  4. Fundamentals of continuum mechanics

    CERN Document Server

    Rudnicki, John W

    2014-01-01

    A concise introductory course text on continuum mechanics Fundamentals of Continuum Mechanics focuses on the fundamentals of the subject and provides the background for formulation of numerical methods for large deformations and a wide range of material behaviours. It aims to provide the foundations for further study, not just of these subjects, but also the formulations for much more complex material behaviour and their implementation computationally.  This book is divided into 5 parts, covering mathematical preliminaries, stress, motion and deformation, balance of mass, momentum and energ

  5. Antennas fundamentals, design, measurement

    CERN Document Server

    Long, Maurice

    2009-01-01

    This comprehensive revision (3rd Edition) is a senior undergraduate or first-year graduate level textbook on antenna fundamentals, design, performance analysis, and measurements. In addition to its use as a formal course textbook, the book's pragmatic style and emphasis on the fundamentals make it especially useful to engineering professionals who need to grasp the essence of the subject quickly but without being mired in unnecessary detail. This new edition was prepared for a first year graduate course at Southern Polytechnic State University in Georgia. It provides broad coverage of antenna

  6. Fundamentals of magnetism

    CERN Document Server

    Reis, Mario

    2013-01-01

    The Fundamentals of Magnetism is a truly unique reference text, that explores the study of magnetism and magnetic behavior with a depth that no other book can provide. It covers the most detailed descriptions of the fundamentals of magnetism providing an emphasis on statistical mechanics which is absolutely critical for understanding magnetic behavior. The books covers the classical areas of basic magnetism, including Landau Theory and magnetic interactions, but features a more concise and easy-to-read style. Perfect for upper-level graduate students and industry researchers, The Fu

  7. Semiconductor bridge (SCB) detonator

    Science.gov (United States)

    Bickes, Jr., Robert W.; Grubelich, Mark C.

    1999-01-01

    The present invention is a low-energy detonator for high-density secondary-explosive materials initiated by a semiconductor bridge igniter that comprises a pair of electrically conductive lands connected by a semiconductor bridge. The semiconductor bridge is in operational or direct contact with the explosive material, whereby current flowing through the semiconductor bridge causes initiation of the explosive material. Header wires connected to the electrically-conductive lands and electrical feed-throughs of the header posts of explosive devices, are substantially coaxial to the direction of current flow through the SCB, i.e., substantially coaxial to the SCB length.

  8. Bridging the Gap

    OpenAIRE

    Kramer Overgaard, Majken; Broeng, Jes; Jensen, Monika Luniewska; Murdock, Karen; Schmidt, Iben Julie

    2015-01-01

    Bridging the Gap (BtG) is a 2-year project funded by The Danish Industry Foundation. The goal of Bridging the Gap has been to create a new innovation model which will increase the rate at which Danish universities can spinout new technology ventures. Bridging the Gap (BtG) is a 2-year project funded by The Danish Industry Foundation. The goal of Bridging the Gap has been to create a new innovation model which will increase the rate at which Danish universities can spinout new technology ve...

  9. Bridging the Gap

    DEFF Research Database (Denmark)

    Kramer Overgaard, Majken; Broeng, Jes; Jensen, Monika Luniewska;

    Bridging the Gap (BtG) is a 2-year project funded by The Danish Industry Foundation. The goal of Bridging the Gap has been to create a new innovation model which will increase the rate at which Danish universities can spinout new technology ventures.......Bridging the Gap (BtG) is a 2-year project funded by The Danish Industry Foundation. The goal of Bridging the Gap has been to create a new innovation model which will increase the rate at which Danish universities can spinout new technology ventures....

  10. Homeschooling and Religious Fundamentalism

    Science.gov (United States)

    Kunzman, Robert

    2010-01-01

    This article considers the relationship between homeschooling and religious fundamentalism by focusing on their intersection in the philosophies and practices of conservative Christian homeschoolers in the United States. Homeschooling provides an ideal educational setting to support several core fundamentalist principles: resistance to…

  11. Fundamental partial compositeness

    DEFF Research Database (Denmark)

    Sannino, Francesco; Strumia, Alessandro; Tesi, Andrea

    2016-01-01

    We construct renormalizable Standard Model extensions, valid up to the Planck scale, that give a composite Higgs from a new fundamental strong force acting on fermions and scalars. Yukawa interactions of these particles with Standard Model fermions realize the partial compositeness scenario. Unde...

  12. Fundamentals of Business Economics

    OpenAIRE

    2013-01-01

    Powerpoint presentations of the 9 theoretical units of the subject: Fundamentals of Business Economics. Business Administration Degree. Faculty of Economics. University of Alicante En el marco de ayudas a preparación de materiales docentes en lengua inglesa, por parte del Servei de Política Llingüística de la Universidad de Alicante

  13. Fundamental Physics Microgravity Sensitivity

    Science.gov (United States)

    Israelsson, Ulf

    1998-01-01

    An introduction followed by a brief discussion about the sensitivity to microgravity environment disturbances for some recent and planned experiments in microgravity fundamental physics will be presented. In particular, correlation between gravity disturbances and the quality of science data sets measured by the Confined Helium Experiment (CHEX) during ground testing and during the November 1997 USMP-4 flight will be described.

  14. Fundamental Metallurgy of Solidification

    DEFF Research Database (Denmark)

    Tiedje, Niels

    2004-01-01

    The text takes the reader through some fundamental aspects of solidification, with focus on understanding the basic physics that govern solidification in casting and welding. It is described how the first solid is formed and which factors affect nucleation. It is described how crystals grow from ...

  15. Fundamentals of convolutional coding

    CERN Document Server

    Johannesson, Rolf

    2015-01-01

    Fundamentals of Convolutional Coding, Second Edition, regarded as a bible of convolutional coding brings you a clear and comprehensive discussion of the basic principles of this field * Two new chapters on low-density parity-check (LDPC) convolutional codes and iterative coding * Viterbi, BCJR, BEAST, list, and sequential decoding of convolutional codes * Distance properties of convolutional codes * Includes a downloadable solutions manual

  16. Fundamentals of soil science

    Science.gov (United States)

    This study guide provides comments and references for professional soil scientists who are studying for the soil science fundamentals exam needed as the first step for certification. The performance objectives were determined by the Soil Science Society of America's Council of Soil Science Examiners...

  17. Fundamentals and Optimal Institutions

    DEFF Research Database (Denmark)

    Gonzalez-Eiras, Martin; Harmon, Nikolaj Arpe; Rossi, Martín

    2016-01-01

    of regulatory institutions such as revenue sharing, salary caps or luxury taxes. We show, theoretically and empirically, that these large differences in adopted institutions can be rationalized as optimal responses to differences in the fundamental characteristics of the sports being played. This provides...

  18. Fundamentals of astrodynamics

    NARCIS (Netherlands)

    Wakker, K.F.

    2015-01-01

    This book deals with the motion of the center of mass of a spacecraft; this discipline is generally called astrodynamics. The book focuses on an analytical treatment of the motion of spacecraft and provides insight into the fundamentals of spacecraft orbit dynamics. A large number of topics are trea

  19. Fundamentals of plasma physics

    CERN Document Server

    Bittencourt, J A

    1986-01-01

    A general introduction designed to present a comprehensive, logical and unified treatment of the fundamentals of plasma physics based on statistical kinetic theory. Its clarity and completeness make it suitable for self-learning and self-paced courses. Problems are included.

  20. O USO DO CORPO COMO FERRAMENTA PEDAGÓGICA: UM MODELO ALTERNATIVO QUE DESCONSIDERA A AUSÊNCIA DE RECURSOS ESPECÍFICOS PARA O ENSINO DE BIOQUÍMICA E BIOLOGIA MOLECULAR NO ENSINO FUNDAMENTAL

    Directory of Open Access Journals (Sweden)

    Leandro Marcio Moreira

    2007-05-01

    Full Text Available Com muita freqüência, conceitos científicos sofrem alterações por intermédio de novasdescobertas, mas pouco deste novo conhecimento é repassado aos alunos, principalmenteàqueles que compõem o Ensino Fundamental II (EF-II e o Ensino Médio (EM, pois acomplexidade das informações geradas dificulta esta abordagem. Entretanto, dia após dia sefala cada vez mais em assuntos que mexem com a curiosidade das pessoas, como é o caso doDNA e do metabolismo, geralmente relacionando tais assuntos com doenças emergentes comocâncer, diabetes, Alzheimer, entre outras. Se o assunto é tão comentado assim nos meios decomunicação, por que não dar uma ênfase mais técnica a respeito destes tópicos em sala deaula, demonstrando ao aluno uma forma diferenciada de compreender conceitos,essencialmente por intermédio de atividades lúdicas. Neste trabalho são descritas duasatividades lúdico-pedagógicas que demonstram, de maneira prática, uma alternativa sobrecomo ensinar os processos de divisão celular mitótica e fisiologia do sistema respiratório paraalunos do EF-II, envolvendo a descoberta de conceitos importantes para a compreensão dosfenômenos moleculares envolvidos com estes assuntos. Estas atividades ainda apresentam apeculiaridade de terem baixo custo de produção e fácil implementação.

  1. Natural vibration dynamics of Rainbow Bridge, Utah

    Science.gov (United States)

    Moore, J. R.; Thorne, M. S.; Wood, J. R.; Doyle, S.; Stanfield, E.; White, B.

    2015-12-01

    We measured resonant frequencies of Rainbow Bridge, Utah, one of the world's longest rock spans, during a field experiment recording ambient vibration data. Measurements were generated over 20 hours on March 23-24, 2015 using two broadband three-component seismometers placed on the bridge, and compared to concurrent data from nearby reference stations 20 and 220 m distant. We identified seven distinct modes of vibration for Rainbow Bridge between 1 and 6 Hz. Data for each resonant frequency was then analyzed to determine the frequency-dependent polarization vector in an attempt to clarify mode shapes; e.g. the fundamental mode represents out-of-plane horizontal flexure. We compared experimental data to results of 3D numerical modal analysis, using a new photogrammetric model of Rainbow Bridge generated in this study imported into COMSOL Multiphysics. Results compare well with measured data for seven of the first eight modeled modes, matching vibrational frequencies and polarization orientations generally within 10%. Only predicted mode 6 was not explicitly apparent in our experimental data. Large site-to-reference spectral ratios resolved from experimental data indicate high amplification on the bridge as compared to nearby bedrock.

  2. Sustainable Bridge Infrastructure Procurement

    DEFF Research Database (Denmark)

    Safi, Mohammed; Du, Guangli; Simonsson, Peter

    2016-01-01

    The lack of a flexible but systematic approach for integrating lifecycle aspects into bridge investment decisions is a major obstacle hindering the procurement of sustainable bridge infrastructures. This paper addresses this obstacle by introducing a holistic approach that agencies could use...

  3. Bridge the Gap

    DEFF Research Database (Denmark)

    Marselis, Randi Lorenz

    2017-01-01

    This article focuses on photo projects organised for teenage refugees by the Society for Humanistic Photography (Berlin, Germany). These projects, named Bridge the Gap I (2015), and Bridge the Gap II (2016), were carried out in Berlin and brought together teenagers with refugee and German...

  4. Anthropogenic sources stimulate resonance of a natural rock bridge

    Science.gov (United States)

    Moore, Jeffrey R.; Thorne, Michael S.; Koper, Keith D.; Wood, John R.; Goddard, Kyler; Burlacu, Relu; Doyle, Sarah; Stanfield, Erik; White, Benjamin

    2016-09-01

    The natural modes of vibration of bedrock landforms, as well as the sources and effects of stimulated resonance remain poorly understood. Here we show that seismic energy created by an induced earthquake and an artificial reservoir has spectral content coincident with the natural modes of vibration of a prominent rock bridge. We measured the resonant frequencies of Rainbow Bridge, Utah using data from two broadband seismometers placed on the span, and identified eight distinct vibrational modes between 1 and 6 Hz. A distant, induced earthquake produced local ground motion rich in 1 Hz energy, stimulating a 20 dB increase in measured power at the bridge's fundamental mode. Moreover, we establish that wave action on Lake Powell, an artificial reservoir, generates microseismic energy with peak power ~1 Hz, also exciting resonance of Rainbow Bridge. These anthropogenic sources represent relatively new energy input for the bridge with unknown consequences for structural fatigue.

  5. Fundamentals of semiconductor lasers

    CERN Document Server

    Numai, Takahiro

    2015-01-01

    This book explains physics under the operating principles of semiconductor lasers in detail based on the experience of the author, dealing with the first manufacturing of phase-shifted DFB-LDs and recent research on transverse modes.   The book also bridges a wide gap between journal papers and textbooks, requiring only an undergraduate-level knowledge of electromagnetism and quantum mechanics, and helps readers to understand journal papers where definitions of some technical terms vary, depending on the paper. Two definitions of the photon density in the rate equations and two definitions of the phase-shift in the phase-shifted DFB-LD are explained, and differences in the calculated results are indicated, depending on the definitions.    Readers can understand the physics of semiconductor lasers and analytical tools for Fabry-Perot LDs, DFB-LDs, and VCSELs and will be stimulated to develop semiconductor lasers themselves.

  6. Fundamental stellar parameters

    CERN Document Server

    Wittkowski, M

    2004-01-01

    I present a discussion of fundamental stellar parameters and their observational determination in the context of interferometric measurements with current and future optical/infrared interferometric facilities. Stellar parameters and the importance of their determination for stellar physics are discussed. One of the primary uses of interferometry in the field of stellar physics is the measurement of the intensity profile across the stellar disk, both as a function of position angle and of wavelength. High-precision fundamental stellar parameters are also derived by characterizations of binary and multiple system using interferometric observations. This topic is discussed in detail elsewhere in these proceedings. Comparison of observed spectrally dispersed center-to-limb intensity variations with models of stellar atmospheres and stellar evolution may result in an improved understanding of key phenomena in stellar astrophysics such as the precise evolutionary effects on the main sequence, the evolution of meta...

  7. Fundamentals of nuclear physics

    CERN Document Server

    Takigawa, Noboru

    2017-01-01

    This book introduces the current understanding of the fundamentals of nuclear physics by referring to key experimental data and by providing a theoretical understanding of principal nuclear properties. It primarily covers the structure of nuclei at low excitation in detail. It also examines nuclear forces and decay properties. In addition to fundamentals, the book treats several new research areas such as non-relativistic as well as relativistic Hartree–Fock calculations, the synthesis of super-heavy elements, the quantum chromodynamics phase diagram, and nucleosynthesis in stars, to convey to readers the flavor of current research frontiers in nuclear physics. The authors explain semi-classical arguments and derivation of its formulae. In these ways an intuitive understanding of complex nuclear phenomena is provided. The book is aimed at graduate school students as well as junior and senior undergraduate students and postdoctoral fellows. It is also useful for researchers to update their knowledge of diver...

  8. Fundamentals of differential beamforming

    CERN Document Server

    Benesty, Jacob; Pan, Chao

    2016-01-01

    This book provides a systematic study of the fundamental theory and methods of beamforming with differential microphone arrays (DMAs), or differential beamforming in short. It begins with a brief overview of differential beamforming and some popularly used DMA beampatterns such as the dipole, cardioid, hypercardioid, and supercardioid, before providing essential background knowledge on orthogonal functions and orthogonal polynomials, which form the basis of differential beamforming. From a physical perspective, a DMA of a given order is defined as an array that measures the differential acoustic pressure field of that order; such an array has a beampattern in the form of a polynomial whose degree is equal to the DMA order. Therefore, the fundamental and core problem of differential beamforming boils down to the design of beampatterns with orthogonal polynomials. But certain constraints also have to be considered so that the resulting beamformer does not seriously amplify the sensors’ self noise and the mism...

  9. Fundamentals of Polarized Light

    Science.gov (United States)

    Mishchenko, Michael

    2003-01-01

    The analytical and numerical basis for describing scattering properties of media composed of small discrete particles is formed by the classical electromagnetic theory. Although there are several excellent textbooks outlining the fundamentals of this theory, it is convenient for our purposes to begin with a summary of those concepts and equations that are central to the subject of this book and will be used extensively in the following chapters. We start by formulating Maxwell's equations and constitutive relations for time- harmonic macroscopic electromagnetic fields and derive the simplest plane-wave solution that underlies the basic optical idea of a monochromatic parallel beam of light. This solution naturally leads to the introduction of such fundamental quantities as the refractive index and the Stokes parameters. Finally, we define the concept of a quasi-monochromatic beam of light and discuss its implications.

  10. What is Fundamental?

    CERN Multimedia

    2004-01-01

    Discussing what is fundamental in a variety of fields, biologist Richard Dawkins, physicist Gerardus 't Hooft, and mathematician Alain Connes spoke to a packed Main Auditorium at CERN 15 October. Dawkins, Professor of the Public Understanding of Science at Oxford University, explained simply the logic behind Darwinian natural selection, and how it would seem to apply anywhere in the universe that had the right conditions. 't Hooft, winner of the 1999 Physics Nobel Prize, outlined some of the main problems in physics today, and said he thinks physics is so fundamental that even alien scientists from another planet would likely come up with the same basic principles, such as relativity and quantum mechanics. Connes, winner of the 1982 Fields Medal (often called the Nobel Prize of Mathematics), explained how physics is different from mathematics, which he described as a "factory for concepts," unfettered by connection to the physical world. On 16 October, anthropologist Sharon Traweek shared anecdotes from her ...

  11. Fundamental composite electroweak dynamics

    DEFF Research Database (Denmark)

    Arbey, Alexandre; Cacciapaglia, Giacomo; Cai, Haiying

    2017-01-01

    Using the recent joint results from the ATLAS and CMS collaborations on the Higgs boson, we determine the current status of composite electroweak dynamics models based on the expected scalar sector. Our analysis can be used as a minimal template for a wider class of models between the two limiting...... cases of composite Goldstone Higgs and Technicolor-like ones. This is possible due to the existence of a unified description, both at the effective and fundamental Lagrangian levels, of models of composite Higgs dynamics where the Higgs boson itself can emerge, depending on the way the electroweak...... space at the effective Lagrangian level. We show that a wide class of models of fundamental composite electroweak dynamics are still compatible with the present constraints. The results are relevant for the ongoing and future searches at the Large Hadron Collider....

  12. Disulfide Bridges: Bringing Together Frustrated Structure in a Bioactive Peptide.

    Science.gov (United States)

    Zhang, Yi; Schulten, Klaus; Gruebele, Martin; Bansal, Paramjit S; Wilson, David; Daly, Norelle L

    2016-04-26

    Disulfide bridges are commonly found covalent bonds that are usually believed to maintain structural stability of proteins. Here, we investigate the influence of disulfide bridges on protein dynamics through molecular dynamics simulations on the cysteine-rich trypsin inhibitor MCoTI-II with three disulfide bridges. Correlation analysis of the reduced cyclic peptide shows that two of the three disulfide distances (Cys(11)-Cys(23) and Cys(17)-Cys(29)) are anticorrelated within ∼1 μs of bridge formation or dissolution: when the peptide is in nativelike structures and one of the distances shortens to allow bond formation, the other tends to lengthen. Simulations over longer timescales, when the denatured state is less structured, do not show the anticorrelation. We propose that the native state contains structural elements that frustrate one another's folding, and that the two bridges are critical for snapping the frustrated native structure into place. In contrast, the Cys(4)-Cys(21) bridge is predicted to form together with either of the other two bridges. Indeed, experimental chromatography and nuclear magnetic resonance data show that an engineered peptide with the Cys(4)-Cys(21) bridge deleted can still fold into its near-native structure even in its noncyclic form, confirming the lesser role of the Cys(4)-Cys(21) bridge. The results highlight the importance of disulfide bridges in a small bioactive peptide to bring together frustrated structure in addition to maintaining protein structural stability.

  13. Fundamentals of Stochastic Networks

    CERN Document Server

    Ibe, Oliver C

    2011-01-01

    An interdisciplinary approach to understanding queueing and graphical networks In today's era of interdisciplinary studies and research activities, network models are becoming increasingly important in various areas where they have not regularly been used. Combining techniques from stochastic processes and graph theory to analyze the behavior of networks, Fundamentals of Stochastic Networks provides an interdisciplinary approach by including practical applications of these stochastic networks in various fields of study, from engineering and operations management to communications and the physi

  14. Fundamentals of queueing theory

    CERN Document Server

    Gross, Donald; Thompson, James M; Harris, Carl M

    2013-01-01

    Praise for the Third Edition ""This is one of the best books available. Its excellent organizational structure allows quick reference to specific models and its clear presentation . . . solidifies the understanding of the concepts being presented.""-IIE Transactions on Operations Engineering Thoroughly revised and expanded to reflect the latest developments in the field, Fundamentals of Queueing Theory, Fourth Edition continues to present the basic statistical principles that are necessary to analyze the probabilistic nature of queues. Rather than pre

  15. Fundamentals of Monte Carlo

    Energy Technology Data Exchange (ETDEWEB)

    Wollaber, Allan Benton [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-06-16

    This is a powerpoint presentation which serves as lecture material for the Parallel Computing summer school. It goes over the fundamentals of the Monte Carlo calculation method. The material is presented according to the following outline: Introduction (background, a simple example: estimating π), Why does this even work? (The Law of Large Numbers, The Central Limit Theorem), How to sample (inverse transform sampling, rejection), and An example from particle transport.

  16. High voltage engineering fundamentals

    CERN Document Server

    Kuffel, E; Hammond, P

    1984-01-01

    Provides a comprehensive treatment of high voltage engineering fundamentals at the introductory and intermediate levels. It covers: techniques used for generation and measurement of high direct, alternating and surge voltages for general application in industrial testing and selected special examples found in basic research; analytical and numerical calculation of electrostatic fields in simple practical insulation system; basic ionisation and decay processes in gases and breakdown mechanisms of gaseous, liquid and solid dielectrics; partial discharges and modern discharge detectors; and over

  17. Biomedical engineering fundamentals

    CERN Document Server

    Bronzino, Joseph D

    2014-01-01

    Known as the bible of biomedical engineering, The Biomedical Engineering Handbook, Fourth Edition, sets the standard against which all other references of this nature are measured. As such, it has served as a major resource for both skilled professionals and novices to biomedical engineering.Biomedical Engineering Fundamentals, the first volume of the handbook, presents material from respected scientists with diverse backgrounds in physiological systems, biomechanics, biomaterials, bioelectric phenomena, and neuroengineering. More than three dozen specific topics are examined, including cardia

  18. Fundamentals of neurobiology.

    Science.gov (United States)

    Greg Hall, D

    2011-01-01

    Session 1 of the 2010 STP/IFSTP Joint Symposium on Toxicologic Neuropathology, titled "Fundamentals of Neurobiology," was organized to provide a foundation for subsequent sessions by presenting essential elements of neuroanatomy and nervous system function. A brief introduction to the session titled "Introduction to Correlative Neurobiology" was provided by Dr. Greg Hall (Eli Lilly and Company, Indianapolis, IN). Correlative neurobiology refers to considerations of the relationships between the highly organized and compartmentalized structure of nervous tissues and the functioning within this system.

  19. Fundamentals of Biomechanics

    OpenAIRE

    Duane Knudson

    2007-01-01

    DESCRIPTION This book provides a broad and in-depth theoretical and practical description of the fundamental concepts in understanding biomechanics in the qualitative analysis of human movement. PURPOSE The aim is to bring together up-to-date biomechanical knowledge with expert application knowledge. Extensive referencing for students is also provided. FEATURES This textbook is divided into 12 chapters within four parts, including a lab activities section at the end. The division is as follow...

  20. Fundamentals of linear algebra

    CERN Document Server

    Dash, Rajani Ballav

    2008-01-01

    FUNDAMENTALS OF LINEAR ALGEBRA is a comprehensive Text Book, which can be used by students and teachers of All Indian Universities. The Text has easy, understandable form and covers all topics of UGC Curriculum. There are lots of worked out examples which helps the students in solving the problems without anybody's help. The Problem sets have been designed keeping in view of the questions asked in different examinations.

  1. Neutrons and Fundamental Symmetries

    Energy Technology Data Exchange (ETDEWEB)

    Plaster, Bradley [Univ. of Kentucky, Lexington, KY (United States). Dept. of Physics and Astronomy

    2016-01-11

    The research supported by this project addressed fundamental open physics questions via experiments with subatomic particles. In particular, neutrons constitute an especially ideal “laboratory” for fundamental physics tests, as their sensitivities to the four known forces of nature permit a broad range of tests of the so-called “Standard Model”, our current best physics model for the interactions of subatomic particles. Although the Standard Model has been a triumphant success for physics, it does not provide satisfactory answers to some of the most fundamental open questions in physics, such as: are there additional forces of nature beyond the gravitational, electromagnetic, weak nuclear, and strong nuclear forces?, or why does our universe consist of more matter than anti-matter? This project also contributed significantly to the training of the next generation of scientists, of considerable value to the public. Young scientists, ranging from undergraduate students to graduate students to post-doctoral researchers, made significant contributions to the work carried out under this project.

  2. Value of Fundamental Science

    Science.gov (United States)

    Burov, Alexey

    Fundamental science is a hard, long-term human adventure that has required high devotion and social support, especially significant in our epoch of Mega-science. The measure of this devotion and this support expresses the real value of the fundamental science in public opinion. Why does fundamental science have value? What determines its strength and what endangers it? The dominant answer is that the value of science arises out of curiosity and is supported by the technological progress. Is this really a good, astute answer? When trying to attract public support, we talk about the ``mystery of the universe''. Why do these words sound so attractive? What is implied by and what is incompatible with them? More than two centuries ago, Immanuel Kant asserted an inseparable entanglement between ethics and metaphysics. Thus, we may ask: which metaphysics supports the value of scientific cognition, and which does not? Should we continue to neglect the dependence of value of pure science on metaphysics? If not, how can this issue be addressed in the public outreach? Is the public alienated by one or another message coming from the face of science? What does it mean to be politically correct in this sort of discussion?

  3. Bridge technology report

    CERN Document Server

    2013-01-01

    Please note this is a Short Discount publication. As LANs have proliferated, new technologies and system concepts have come to the fore. One of the key issues is how to interconnect networks. One means of interconnection is to use a 'bridge'. Other competing technologies are repeaters, routers, and gateways. Bridges permit traffic isolation, connect network segments together and operate at the MAC layer. Further, because they operate at the MAC layer, they can handle a variety of protocols such as TCP/IP, SNA, and X.25. This report focuses on the specific technology of bridging two netw

  4. FUNDAMENTALS OF BIOMECHANICS

    Directory of Open Access Journals (Sweden)

    Duane Knudson

    2007-09-01

    Full Text Available DESCRIPTION This book provides a broad and in-depth theoretical and practical description of the fundamental concepts in understanding biomechanics in the qualitative analysis of human movement. PURPOSE The aim is to bring together up-to-date biomechanical knowledge with expert application knowledge. Extensive referencing for students is also provided. FEATURES This textbook is divided into 12 chapters within four parts, including a lab activities section at the end. The division is as follows: Part 1 Introduction: 1.Introduction to biomechanics of human movement; 2.Fundamentals of biomechanics and qualitative analysis; Part 2 Biological/Structural Bases: 3.Anatomical description and its limitations; 4.Mechanics of the musculoskeletal system; Part 3 Mechanical Bases: 5.Linear and angular kinematics; 6.Linear kinetics; 7.Angular kinetics; 8.Fluid mechanics; Part 4 Application of Biomechanics in Qualitative Analysis :9.Applying biomechanics in physical education; 10.Applying biomechanics in coaching; 11.Applying biomechanics in strength and conditioning; 12.Applying biomechanics in sports medicine and rehabilitation. AUDIENCE This is an important reading for both student and educators in the medicine, sport and exercise-related fields. For the researcher and lecturer it would be a helpful guide to plan and prepare more detailed experimental designs or lecture and/or laboratory classes in exercise and sport biomechanics. ASSESSMENT The text provides a constructive fundamental resource for biomechanics, exercise and sport-related students, teachers and researchers as well as anyone interested in understanding motion. It is also very useful since being clearly written and presenting several ways of examples of the application of biomechanics to help teach and apply biomechanical variables and concepts, including sport-related ones

  5. Information security fundamentals

    CERN Document Server

    Blackley, John A; Peltier, Justin

    2004-01-01

    Effective security rules and procedures do not exist for their own sake-they are put in place to protect critical assets, thereby supporting overall business objectives. Recognizing security as a business enabler is the first step in building a successful program.Information Security Fundamentals allows future security professionals to gain a solid understanding of the foundations of the field and the entire range of issues that practitioners must address. This book enables students to understand the key elements that comprise a successful information security program and eventually apply thes

  6. El grupo fundamental

    Directory of Open Access Journals (Sweden)

    Carlos A. Robles Corbalá

    2015-12-01

    Full Text Available En este artículo se aborda un problema clásico para poder detectar si dos espacios topológicos son homeomorfos o no. Para lo cual a cada espacio topológico se le asocia un grupo algebraico, de tal suerte que si los espacios son homeomorfos, entonces los grupos asociados serán isomorfos. Se presenta una construcción del grupo fundamental de un espacio topológico y se enfoca en demostrar que efectivamente es un grupo.

  7. Fundamentals of calculus

    CERN Document Server

    Morris, Carla C

    2015-01-01

    Fundamentals of Calculus encourages students to use power, quotient, and product rules for solutions as well as stresses the importance of modeling skills.  In addition to core integral and differential calculus coverage, the book features finite calculus, which lends itself to modeling and spreadsheets.  Specifically, finite calculus is applied to marginal economic analysis, finance, growth, and decay.  Includes: Linear Equations and FunctionsThe DerivativeUsing the Derivative Exponential and Logarithmic Functions Techniques of DifferentiationIntegral CalculusIntegration TechniquesFunctions

  8. Fundamentals of engineering electromagnetism

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Nam; Yoon, Youngro; Jun, Sukhee; Jun, Hoin

    2004-08-15

    It indicates fundamentals of engineering electromagnetism. It mentions electromagnetic field model of introduction and International system of units and universal constant, Vector analysis with summary and orthogonal coordinate systems, electrostatic field on Coulomb's law and Gauss's law, electrostatic energy and strength, steady state current with Ohm's law and Joule's law and calculation of resistance, crystallite field with Vector's electrostatic potential, Biot-Savart law and application and Magnetic Dipole, time-Savart and Maxwell equation with potential function and Faraday law of electromagnetic induction, plane electromagnetic wave, transmission line, a wave guide and cavity resonator and antenna arrangement.

  9. Fundamentals of attosecond optics

    CERN Document Server

    Chang, Zenghu

    2011-01-01

    Attosecond optical pulse generation, along with the related process of high-order harmonic generation, is redefining ultrafast physics and chemistry. A practical understanding of attosecond optics requires significant background information and foundational theory to make full use of these cutting-edge lasers and advance the technology toward the next generation of ultrafast lasers. Fundamentals of Attosecond Optics provides the first focused introduction to the field. The author presents the underlying concepts and techniques required to enter the field, as well as recent research advances th

  10. Fundamentals of microwave photonics

    CERN Document Server

    Urick, V J; McKinney , Jason D

    2015-01-01

    A comprehensive resource to designing andconstructing analog photonic links capable of high RFperformanceFundamentals of Microwave Photonics provides acomprehensive description of analog optical links from basicprinciples to applications.  The book is organized into fourparts. The first begins with a historical perspective of microwavephotonics, listing the advantages of fiber optic links anddelineating analog vs. digital links. The second section coversbasic principles associated with microwave photonics in both the RFand optical domains.  The third focuses on analog modulationformats-starti

  11. Mathematical analysis fundamentals

    CERN Document Server

    Bashirov, Agamirza

    2014-01-01

    The author's goal is a rigorous presentation of the fundamentals of analysis, starting from elementary level and moving to the advanced coursework. The curriculum of all mathematics (pure or applied) and physics programs include a compulsory course in mathematical analysis. This book will serve as can serve a main textbook of such (one semester) courses. The book can also serve as additional reading for such courses as real analysis, functional analysis, harmonic analysis etc. For non-math major students requiring math beyond calculus, this is a more friendly approach than many math-centric o

  12. Fundamentals of Project Management

    CERN Document Server

    Heagney, Joseph

    2011-01-01

    With sales of more than 160,000 copies, Fundamentals of Project Management has helped generations of project managers navigate the ins and outs of every aspect of this complex discipline. Using a simple step-by-step approach, the book is the perfect introduction to project management tools, techniques, and concepts. Readers will learn how to: ò Develop a mission statement, vision, goals, and objectives ò Plan the project ò Create the work breakdown structure ò Produce a workable schedule ò Understand earned value analysis ò Manage a project team ò Control and evaluate progress at every stage.

  13. Fundamental concepts of mathematics

    CERN Document Server

    Goodstein, R L

    Fundamental Concepts of Mathematics, 2nd Edition provides an account of some basic concepts in modern mathematics. The book is primarily intended for mathematics teachers and lay people who wants to improve their skills in mathematics. Among the concepts and problems presented in the book include the determination of which integral polynomials have integral solutions; sentence logic and informal set theory; and why four colors is enough to color a map. Unlike in the first edition, the second edition provides detailed solutions to exercises contained in the text. Mathematics teachers and people

  14. Fundamentals of semiconductor devices

    CERN Document Server

    Lindmayer, Joseph

    1965-01-01

    Semiconductor properties ; semiconductor junctions or diodes ; transistor fundamentals ; inhomogeneous impurity distributions, drift or graded-base transistors ; high-frequency properties of transistors ; band structure of semiconductors ; high current densities and mechanisms of carrier transport ; transistor transient response and recombination processes ; surfaces, field-effect transistors, and composite junctions ; additional semiconductor characteristics ; additional semiconductor devices and microcircuits ; more metal, insulator, and semiconductor combinations for devices ; four-pole parameters and configuration rotation ; four-poles of combined networks and devices ; equivalent circuits ; the error function and its properties ; Fermi-Dirac statistics ; useful physical constants.

  15. Fundamental of biomedical engineering

    CERN Document Server

    Sawhney, GS

    2007-01-01

    About the Book: A well set out textbook explains the fundamentals of biomedical engineering in the areas of biomechanics, biofluid flow, biomaterials, bioinstrumentation and use of computing in biomedical engineering. All these subjects form a basic part of an engineer''s education. The text is admirably suited to meet the needs of the students of mechanical engineering, opting for the elective of Biomedical Engineering. Coverage of bioinstrumentation, biomaterials and computing for biomedical engineers can meet the needs of the students of Electronic & Communication, Electronic & Instrumenta

  16. Fundamentals of Cavitation

    CERN Document Server

    Franc, Jean-Pierre

    2005-01-01

    The present book is aimed at providing a comprehensive presentation of cavitation phenomena in liquid flows. It is further backed up by the experience, both experimental and theoretical, of the authors whose expertise has been internationally recognized. A special effort is made to place the various methods of investigation in strong relation with the fundamental physics of cavitation, enabling the reader to treat specific problems independently. Furthermore, it is hoped that a better knowledge of the cavitation phenomenon will allow engineers to create systems using it positively. Examples in the literature show the feasibility of this approach.

  17. Fundamentals of photonics

    CERN Document Server

    Saleh, Bahaa E A

    2007-01-01

    Now in a new full-color edition, Fundamentals of Photonics, Second Edition is a self-contained and up-to-date introductory-level textbook that thoroughly surveys this rapidly expanding area of engineering and applied physics. Featuring a logical blend of theory and applications, coverage includes detailed accounts of the primary theories of light, including ray optics, wave optics, electromagnetic optics, and photon optics, as well as the interaction of photons and atoms, and semiconductor optics. Presented at increasing levels of complexity, preliminary sections build toward more advan

  18. Electronic circuits fundamentals & applications

    CERN Document Server

    Tooley, Mike

    2015-01-01

    Electronics explained in one volume, using both theoretical and practical applications.New chapter on Raspberry PiCompanion website contains free electronic tools to aid learning for students and a question bank for lecturersPractical investigations and questions within each chapter help reinforce learning Mike Tooley provides all the information required to get to grips with the fundamentals of electronics, detailing the underpinning knowledge necessary to appreciate the operation of a wide range of electronic circuits, including amplifiers, logic circuits, power supplies and oscillators. The

  19. Shaking Table Tests of Curved Bridge considering Bearing Friction Sliding Isolation

    Directory of Open Access Journals (Sweden)

    Lei Yan

    2016-01-01

    Full Text Available Specific to severe damage to curved bridges in earthquakes caused by the excessive force of the fixed bearings and piers, a new seismic design method on curved bridges considering bearing friction sliding isolation is proposed in this paper. Seismic model bridge and isolation model bridge with similarity ratio of 1/20 were made and the shaking table comparison test was conducted. The experimental results show that the isolation model curved bridge suffered less seismic damage than the seismic model curved bridge. The fundamental frequencies of the seismic model bridge and isolation model bridge decreased and the damping ratio increased with the increase of seismic intensity. Compared with seismic curved bridge, the maximum reduction rates of peak acceleration along the radial and tangential directions on the top of pier of the isolation model curved bridge were 47.3% and 55.5%, respectively, and the maximum reduction rate of the peak strain on the bottom of pier of the isolation model curved bridge was 43.4%. For the isolation model curved bridge, the maximum reduction rate of peak acceleration on the top of pier was 24.6% compared with that on the bottom of pier. The study results can provide experimental basis for the seismic design of curved bridges.

  20. Building bridges within the bacterial chromosome.

    Science.gov (United States)

    Song, Dan; Loparo, Joseph J

    2015-03-01

    All organisms must dramatically compact their genomes to accommodate DNA within the cell. Bacteria use a set of DNA-binding proteins with low sequence specificity called nucleoid-associated proteins (NAPs) to assist in chromosome condensation and organization. By bending or bridging DNA, NAPs also facilitate chromosome segregation and regulate gene expression. Over the past decade, emerging single-molecule and chromosome conformation capture techniques have investigated the molecular mechanisms by which NAPs remodel and organize the bacterial chromosome. In this review we describe how such approaches reveal the biochemical mechanisms of three NAPs that are believed to facilitate DNA bridging: histone-like nucleoid structuring protein (H-NS), ParB, and structural maintenance of chromosomes (SMC). These three proteins form qualitatively different DNA bridges, leading to varied effects on transcription and chromosome segregation.

  1. The MOND Fundamental Plane

    CERN Document Server

    Cardone, V F; Diaferio, A; Tortora, C; Molinaro, R

    2010-01-01

    Modified Newtonian Dynamics (MOND) has been shown to be able to fit spiral galaxy rotation curves as well as giving a theoretical foundation for empirically determined scaling relations, such as the Tully - Fisher law, without the need for a dark matter halo. As a complementary analysis, one should investigate whether MOND can also reproduce the dynamics of early - type galaxies (ETGs) without dark matter. As a first step, we here show that MOND can indeed fit the observed central velocity dispersion $\\sigma_0$ of a large sample of ETGs assuming a simple MOND interpolating functions and constant anisotropy. We also show that, under some assumptions on the luminosity dependence of the Sersic n parameter and the stellar M/L ratio, MOND predicts a fundamental plane for ETGs : a log - linear relation among the effective radius $R_{eff}$, $\\sigma_0$ and the mean effective intensity $\\langle I_e \\rangle$. However, we predict a tilt between the observed and the MOND fundamental planes.

  2. Testing Our Fundamental Assumptions

    Science.gov (United States)

    Kohler, Susanna

    2016-06-01

    Science is all about testing the things we take for granted including some of the most fundamental aspects of how we understand our universe. Is the speed of light in a vacuum the same for all photons regardless of their energy? Is the rest mass of a photon actually zero? A series of recent studies explore the possibility of using transient astrophysical sources for tests!Explaining Different Arrival TimesArtists illustration of a gamma-ray burst, another extragalactic transient, in a star-forming region. [NASA/Swift/Mary Pat Hrybyk-Keith and John Jones]Suppose you observe a distant transient astrophysical source like a gamma-ray burst, or a flare from an active nucleus and two photons of different energies arrive at your telescope at different times. This difference in arrival times could be due to several different factors, depending on how deeply you want to question some of our fundamental assumptions about physics:Intrinsic delayThe photons may simply have been emitted at two different times by the astrophysical source.Delay due to Lorentz invariance violationPerhaps the assumption that all massless particles (even two photons with different energies) move at the exact same velocity in a vacuum is incorrect.Special-relativistic delayMaybe there is a universal speed for massless particles, but the assumption that photons have zero rest mass is wrong. This, too, would cause photon velocities to be energy-dependent.Delay due to gravitational potentialPerhaps our understanding of the gravitational potential that the photons experience as they travel is incorrect, also causing different flight times for photons of different energies. This would mean that Einsteins equivalence principle, a fundamental tenet of general relativity (GR), is incorrect.If we now turn this problem around, then by measuring the arrival time delay between photons of different energies from various astrophysical sources the further away, the better we can provide constraints on these

  3. Fundamentals of Space Systems

    Science.gov (United States)

    Pisacane, Vincent L.

    2005-06-01

    Fundamentals of Space Systems was developed to satisfy two objectives: the first is to provide a text suitable for use in an advanced undergraduate or beginning graduate course in both space systems engineering and space system design. The second is to be a primer and reference book for space professionals wishing to broaden their capabilities to develop, manage the development, or operate space systems. The authors of the individual chapters are practicing engineers that have had extensive experience in developing sophisticated experimental and operational spacecraft systems in addition to having experience teaching the subject material. The text presents the fundamentals of all the subsystems of a spacecraft missions and includes illustrative examples drawn from actual experience to enhance the learning experience. It included a chapter on each of the relevant major disciplines and subsystems including space systems engineering, space environment, astrodynamics, propulsion and flight mechanics, attitude determination and control, power systems, thermal control, configuration management and structures, communications, command and telemetry, data processing, embedded flight software, survuvability and reliability, integration and test, mission operations, and the initial conceptual design of a typical small spacecraft mission.

  4. Bridging Humanism and Behaviorism.

    Science.gov (United States)

    Chu, Lily

    1980-01-01

    Humanistic behaviorism may provide the necessary bridge between behaviorism and humanism. Perhaps the most humanistic approach to teaching is to learn how certain changes will help students and how these changes can be accomplished. (Author/MLF)

  5. State's First Bridge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Article with details on the state's first bridge that crossed the Noxubee River adjacent to the Noxubee National Wildlife Refuge Boundary. Details also included...

  6. Bridged Race Population Estimates

    Data.gov (United States)

    U.S. Department of Health & Human Services — Population estimates from "bridging" the 31 race categories used in Census 2000, as specified in the 1997 Office of Management and Budget (OMB) race and ethnicity...

  7. Germ Cell Intercellular Bridges

    Science.gov (United States)

    Greenbaum, Michael P.; Iwamori, Tokuko; Buchold, Gregory M.; Matzuk, Martin M.

    2011-01-01

    Stable intercellular bridges are a conserved feature of gametogenesis in multicellular animals observed more than 100 years ago, but their function was unknown. Many of the components necessary for this structure have been identified through the study of cytokinesis in Drosophila; however, mammalian intercellular bridges have distinct properties from those of insects. Mammalian germ cell intercellular bridges are composed of general cytokinesis components with additional germ cell–specific factors including TEX14. TEX14 is an inactive kinase essential for the maintenance of stable intercellular bridges in gametes of both sexes but whose loss specifically impairs male meiosis. TEX14 acts to impede the terminal steps of abscission by competing for essential component CEP55, blocking its interaction in nongerm cells with ALIX and TSG101. Additionally, TEX14-interacting protein RBM44, whose localization in stabile intercellular bridges is limited to pachytene and secondary spermatocytes, may participate in processes such as RNA transport but is nonessential to the maintenance of intercellular bridge stability. PMID:21669984

  8. Long Span Bridges in Scandinavia

    DEFF Research Database (Denmark)

    Gimsing, Niels Jørgen

    1998-01-01

    The first Scandinavian bridge with a span of more than 500 m was the Lillebælt Suspension Bridge opened to traffic in 1970.Art the end of the 20th century the longest span of any European bridge is found in the Storebælt East Bridge with a main span of 1624 m. Also the third longest span in Europe...... is found in Scandinavia - the 1210 m span of the Höga Kusten Bridge in Sweden.The Kvarnsund Bridge in Norway was at the completion in 1991 the longest cable-stayed bridge in the world, and the span of 530 m is still thge longest for cable-stayed bridges in concrete. The Øresund Bridge with its sapn of 490...... m is the longest among cable-stayed bridges for both road and railway traffic....

  9. Simple simulation of diffusion bridges with application to likelihood inference for diffusions

    DEFF Research Database (Denmark)

    Bladt, Mogens; Sørensen, Michael

    2014-01-01

    With a view to statistical inference for discretely observed diffusion models, we propose simple methods of simulating diffusion bridges, approximately and exactly. Diffusion bridge simulation plays a fundamental role in likelihood and Bayesian inference for diffusion processes. First a simple me...

  10. Simple simulation of diffusion bridges with application to likelihood inference for diffusions

    DEFF Research Database (Denmark)

    Bladt, Mogens; Sørensen, Michael

    2014-01-01

    With a view to statistical inference for discretely observed diffusion models, we propose simple methods of simulating diffusion bridges, approximately and exactly. Diffusion bridge simulation plays a fundamental role in likelihood and Bayesian inference for diffusion processes. First a simple me...

  11. Digital Fourier analysis fundamentals

    CERN Document Server

    Kido, Ken'iti

    2015-01-01

    This textbook is a thorough, accessible introduction to digital Fourier analysis for undergraduate students in the sciences. Beginning with the principles of sine/cosine decomposition, the reader walks through the principles of discrete Fourier analysis before reaching the cornerstone of signal processing: the Fast Fourier Transform. Saturated with clear, coherent illustrations, "Digital Fourier Analysis - Fundamentals" includes practice problems and thorough Appendices for the advanced reader. As a special feature, the book includes interactive applets (available online) that mirror the illustrations.  These user-friendly applets animate concepts interactively, allowing the user to experiment with the underlying mathematics. For example, a real sine signal can be treated as a sum of clockwise and counter-clockwise rotating vectors. The applet illustration included with the book animates the rotating vectors and the resulting sine signal. By changing parameters such as amplitude and frequency, the reader ca...

  12. Fundamentals of quantum mechanics

    CERN Document Server

    House, J E

    2017-01-01

    Fundamentals of Quantum Mechanics, Third Edition is a clear and detailed introduction to quantum mechanics and its applications in chemistry and physics. All required math is clearly explained, including intermediate steps in derivations, and concise review of the math is included in the text at appropriate points. Most of the elementary quantum mechanical models-including particles in boxes, rigid rotor, harmonic oscillator, barrier penetration, hydrogen atom-are clearly and completely presented. Applications of these models to selected “real world” topics are also included. This new edition includes many new topics such as band theory and heat capacity of solids, spectroscopy of molecules and complexes (including applications to ligand field theory), and small molecules of astrophysical interest.

  13. Fundamental partial compositeness

    CERN Document Server

    Sannino, Francesco

    2016-01-01

    We construct renormalizable Standard Model extensions, valid up to the Planck scale, that give a composite Higgs from a new fundamental strong force acting on fermions and scalars. Yukawa interactions of these particles with Standard Model fermions realize the partial compositeness scenario. Successful models exist because gauge quantum numbers of Standard Model fermions admit a minimal enough 'square root'. Furthermore, right-handed SM fermions have an SU(2)$_R$-like structure, yielding a custodially-protected composite Higgs. Baryon and lepton numbers arise accidentally. Standard Model fermions acquire mass at tree level, while the Higgs potential and flavor violations are generated by quantum corrections. We further discuss accidental symmetries and other dynamical features stemming from the new strongly interacting scalars. If the same phenomenology can be obtained from models without our elementary scalars, they would reappear as composite states.

  14. Lasers Fundamentals and Applications

    CERN Document Server

    Thyagarajan, K

    2010-01-01

    Lasers: Fundamentals and Applications, serves as a vital textbook to accompany undergraduate and graduate courses on lasers and their applications. Ever since their invention in 1960, lasers have assumed tremendous importance in the fields of science, engineering and technology because of their diverse uses in basic research and countless technological applications. This book provides a coherent presentation of the basic physics behind the way lasers work, and presents some of their most important applications in vivid detail. After reading this book, students will understand how to apply the concepts found within to practical, tangible situations. This textbook includes worked-out examples and exercises to enhance understanding, and the preface shows lecturers how to most beneficially match the textbook with their course curricula. The book includes several recent Nobel Lectures, which will further expose students to the emerging applications and excitement of working with lasers. Students who study lasers, ...

  15. Fundamentals of Structural Engineering

    CERN Document Server

    Connor, Jerome J

    2013-01-01

    Fundamentals of Structural Engineering provides a balanced, seamless treatment of both classic, analytic methods and contemporary, computer-based techniques for conceptualizing and designing a structure. The book’s principle goal is to foster an intuitive understanding of structural behavior based on problem solving experience for students of civil engineering and architecture who have been exposed to the basic concepts of engineering mechanics and mechanics of materials. Making it distinct from many other undergraduate textbooks, the authors of this text recognize the notion that engineers reason about behavior using simple models and intuition they acquire through problem solving. The approach adopted in this text develops this type of intuition  by presenting extensive, realistic problems and case studies together with computer simulation, which allows rapid exploration of  how a structure responds to changes in geometry and physical parameters. This book also: Emphasizes problem-based understanding of...

  16. Fundamentals of sustainable neighbourhoods

    CERN Document Server

    Friedman, Avi

    2015-01-01

    This book introduces architects, engineers, builders, and urban planners to a range of design principles of sustainable communities and illustrates them with outstanding case studies. Drawing on the author’s experience as well as local and international case studies, Fundamentals of Sustainable Neighbourhoods presents planning concepts that minimize developments' carbon footprint through compact communities, adaptable and expandable dwellings, adaptable landscapes, and smaller-sized yet quality-designed housing. This book also: Examines in-depth global strategies for minimizing the residential carbon footprint, including district heating, passive solar gain, net-zero residences, as well as preserving the communities' natural assets Reconsiders conceptual approaches in building design and urban planning to promote a better connection between communities and nature Demonstrates practical applications of green architecture Focuses on innovative living spaces in urban environments

  17. Fundamentals of phosphors

    CERN Document Server

    Yen, William M; Yamamoto, Hajime

    2006-01-01

    Drawing from the second edition of the best-selling Handbook of Phosphors, Fundamentals of Phosphors covers the principles and mechanisms of luminescence in detail and surveys the primary phosphor materials as well as their optical properties. The book addresses cutting-edge developments in phosphor science and technology including oxynitride phosphors and the impact of lanthanide level location on phosphor performance.Beginning with an explanation of the physics underlying luminescence mechanisms in solids, the book goes on to interpret various luminescence phenomena in inorganic and organic materials. This includes the interpretation of the luminescence of recently developed low-dimensional systems, such as quantum wells and dots. The book also discusses the excitation mechanisms by cathode-ray and ionizing radiation and by electric fields to produce electroluminescence. The book classifies phosphor materials according to the type of luminescence centers employed or the class of host materials used and inte...

  18. Superconductivity fundamentals and applications

    CERN Document Server

    Buckel, Werner

    2004-01-01

    This is the second English edition of what has become one of the definitive works on superconductivity in German -- currently in its sixth edition. Comprehensive and easy to understand, this introductory text is written especially with the non-specialist in mind. The authors, both long-term experts in this field, present the fundamental considerations without the need for extensive mathematics, describing the various phenomena connected with the superconducting state, with liberal insertion of experimental facts and examples for modern applications. While all fields of superconducting phenomena are dealt with in detail, this new edition pays particular attention to the groundbreaking discovery of magnesium diboride and the current developments in this field. In addition, a new chapter provides an overview of the elements, alloys and compounds where superconductivity has been observed in experiments, together with their major characteristics. The chapter on technical applications has been considerably expanded...

  19. Fundamentals of Fire Phenomena

    DEFF Research Database (Denmark)

    Quintiere, James

    discipline. It covers thermo chemistry including mixtures and chemical reactions; Introduces combustion to the fire protection student; Discusses premixed flames and spontaneous ignition; Presents conservation laws for control volumes, including the effects of fire; Describes the theoretical bases...... analyses. Fire phenomena encompass everything about the scientific principles behind fire behaviour. Combining the principles of chemistry, physics, heat and mass transfer, and fluid dynamics necessary to understand the fundamentals of fire phenomena, this book integrates the subject into a clear...... for empirical aspects of the subject of fire; Analyses ignition of liquids and the importance of evaporation including heat and mass transfer; Features the stages of fire in compartments, and the role of scale modelling in fire. The book is written by Prof. James G. Quintiere from University of Maryland...

  20. Fundamentals of Fire Phenomena

    DEFF Research Database (Denmark)

    Quintiere, James

    Understanding fire dynamics and combustion is essential in fire safety engineering and in fire science curricula. Engineers and students involved in fire protection, safety and investigation need to know and predict how fire behaves to be able to implement adequate safety measures and hazard...... analyses. Fire phenomena encompass everything about the scientific principles behind fire behaviour. Combining the principles of chemistry, physics, heat and mass transfer, and fluid dynamics necessary to understand the fundamentals of fire phenomena, this book integrates the subject into a clear...... discipline. It covers thermo chemistry including mixtures and chemical reactions; Introduces combustion to the fire protection student; Discusses premixed flames and spontaneous ignition; Presents conservation laws for control volumes, including the effects of fire; Describes the theoretical bases...

  1. Fundamentals of quantum chemistry

    CERN Document Server

    House, J E

    2004-01-01

    An introduction to the principles of quantum mechanics needed in physical chemistry. Mathematical tools are presented and developed as needed and only basic calculus, chemistry, and physics is assumed. Applications include atomic and molecular structure, spectroscopy, alpha decay, tunneling, and superconductivity. New edition includes sections on perturbation theory, orbital symmetry of diatomic molecules, the Huckel MO method and Woodward/Hoffman rules as well as a new chapter on SCF and Hartree-Fock methods. * This revised text clearly presents basic q

  2. The effects of the dimethylether bridging moiety in the H-cluster of the Clostridium pasteurianum hydrogenase on the mechanism of H{sub 2} production: A quantum mechanics/molecular mechanics study

    Energy Technology Data Exchange (ETDEWEB)

    Trohalaki, Steven [Air Force Research Laboratory, Materials and Manufacturing Directorate, Wright-Patterson Air Force Base, OH 45433 (United States); General Dynamics Information Technology, Inc. (United States); Pachter, Ruth [Air Force Research Laboratory, Materials and Manufacturing Directorate, Wright-Patterson Air Force Base, OH 45433 (United States)

    2010-12-15

    [Fe-Fe]-hydrogenases are naturally occurring metalloenzymes that catalyze the reversible production of H{sub 2} from two protons and two electrons. [Fe-Fe]-hydrogenases found in two species -Clostridium pasteurianum (CpI) and Desulfovibrio desulfuricans (DdH) - were shown with x-ray crystallography to have active sites that are very similar, although several atoms that bridge the dithiolate ligand were unresolved. In earlier work, we employed density functional theory (DFT) within a QM/MM method to investigate two previously proposed mechanisms of hydrogen production by DdH and CpI hydrogenases. In one mechanism (I), a CO ligand bridging two Fe atoms in the active site rotates to a terminal position while in the other (II) the CO bridge remains intact throughout the catalytic cycle. We previously assumed that the active sites for the two hydrogenases were identical; each had a dimethylamine bridging moiety, whose basicity is important for Mechanism II. Our overall conclusion, taking into consideration an energy comparison for the two mechanisms and activation energies for the CO-unbridging step in Mechanism I, was that Mechanism II was favored for both hydrogenases. In this paper, we extend our previous work to show that Mechanism II is favored over Mechanism I even if the bridging moiety in CpI hydrogenase is dimethylether, a significantly weaker base than dimethylamine, providing further support for Mechanism II even though experimental verification of the bridging moiety for the CpI H-cluster is lacking. (author)

  3. Fundamentals of ergonomic exoskeleton robots

    NARCIS (Netherlands)

    Schiele, A.

    2008-01-01

    This thesis is the first to provide the fundamentals of ergonomic exoskeleton design. The fundamental theory as well as technology necessary to analyze and develop ergonomic wearable robots interacting with humans is established and validated by experiments and prototypes. The fundamentals are (1) a

  4. Fundamentals of ergonomic exoskeleton robots

    NARCIS (Netherlands)

    Schiele, A.

    2008-01-01

    This thesis is the first to provide the fundamentals of ergonomic exoskeleton design. The fundamental theory as well as technology necessary to analyze and develop ergonomic wearable robots interacting with humans is established and validated by experiments and prototypes. The fundamentals are (1) a

  5. Fundamentals of klystron testing

    Energy Technology Data Exchange (ETDEWEB)

    Caldwell, J.W. Jr.

    1978-08-01

    Fundamentals of klystron testing is a text primarily intended for the indoctrination of new klystron group test stand operators. It should significantly reduce the familiarization time of a new operator, making him an asset to the group sooner than has been experienced in the past. The new employee must appreciate the mission of SLAC before he can rightfully be expected to make a meaningful contribution to the group's effort. Thus, the introductory section acquaints the reader with basic concepts of accelerators in general, then briefly describes major physical aspects of the Stanford Linear Accelerator. Only then is his attention directed to the klystron, with its auxiliary systems, and the rudiments of klystron tube performance checks. It is presumed that the reader is acquainted with basic principles of electronics and scientific notation. However, to preserve the integrity of an indoctrination guide, tedious technical discussions and mathematical analysis have been studiously avoided. It is hoped that the new operator will continue to use the text for reference long after his indoctrination period is completed. Even the more experienced operator should find that particular sections will refresh his understanding of basic principles of klystron testing.

  6. GRBs and Fundamental Physics

    Science.gov (United States)

    Petitjean, Patrick; Wang, F. Y.; Wu, X. F.; Wei, J. J.

    2016-12-01

    Gamma-ray bursts (GRBs) are short and intense flashes at the cosmological distances, which are the most luminous explosions in the Universe. The high luminosities of GRBs make them detectable out to the edge of the visible universe. So, they are unique tools to probe the properties of high-redshift universe: including the cosmic expansion and dark energy, star formation rate, the reionization epoch and the metal evolution of the Universe. First, they can be used to constrain the history of cosmic acceleration and the evolution of dark energy in a redshift range hardly achievable by other cosmological probes. Second, long GRBs are believed to be formed by collapse of massive stars. So they can be used to derive the high-redshift star formation rate, which can not be probed by current observations. Moreover, the use of GRBs as cosmological tools could unveil the reionization history and metal evolution of the Universe, the intergalactic medium (IGM) properties and the nature of first stars in the early universe. But beyond that, the GRB high-energy photons can be applied to constrain Lorentz invariance violation (LIV) and to test Einstein's Equivalence Principle (EEP). In this paper, we review the progress on the GRB cosmology and fundamental physics probed by GRBs.

  7. Fundamental Limits of Cooperation

    CERN Document Server

    Lozano, Angel; Andrews, Jeffrey G

    2012-01-01

    Cooperation is viewed as a key ingredient for interference management in wireless systems. This paper shows that cooperation has fundamental limitations. The main result is that even full cooperation between transmitters cannot in general change an interference-limited network to a noise-limited network. The key idea is that there exists a spectral efficiency upper bound that is independent of the transmit power. First, a spectral efficiency upper bound is established for systems that rely on pilot-assisted channel estimation; in this framework, cooperation is shown to be possible only within clusters of limited size, which are subject to out-of-cluster interference whose power scales with that of the in-cluster signals. Second, an upper bound is also shown to exist when cooperation is through noncoherent communication; thus, the spectral efficiency limitation is not a by-product of the reliance on pilot-assisted channel estimation. Consequently, existing literature that routinely assumes the high-power spect...

  8. Revisiting energy efficiency fundamentals

    Energy Technology Data Exchange (ETDEWEB)

    Perez-Lombard, L.; Velazquez, D. [Grupo de Termotecnia, Escuela Superior de Ingenieros, Universidad de Sevilla, Camino de los Descubrimientos s/n, 41092 Seville (Spain); Ortiz, J. [Building Research Establishment (BRE), Garston, Watford, WD25 9XX (United Kingdom)

    2013-05-15

    Energy efficiency is a central target for energy policy and a keystone to mitigate climate change and to achieve a sustainable development. Although great efforts have been carried out during the last four decades to investigate the issue, focusing into measuring energy efficiency, understanding its trends and impacts on energy consumption and to design effective energy efficiency policies, many energy efficiency-related concepts, some methodological problems for the construction of energy efficiency indicators (EEI) and even some of the energy efficiency potential gains are often ignored or misunderstood, causing no little confusion and controversy not only for laymen but even for specialists. This paper aims to revisit, analyse and discuss some efficiency fundamental topics that could improve understanding and critical judgement of efficiency stakeholders and that could help in avoiding unfounded judgements and misleading statements. Firstly, we address the problem of measuring energy efficiency both in qualitative and quantitative terms. Secondly, main methodological problems standing in the way of the construction of EEI are discussed, and a sequence of actions is proposed to tackle them in an ordered fashion. Finally, two key topics are discussed in detail: the links between energy efficiency and energy savings, and the border between energy efficiency improvement and renewable sources promotion.

  9. Fluorescence lifetimes: fundamentals and interpretations.

    Science.gov (United States)

    Noomnarm, Ulai; Clegg, Robert M

    2009-01-01

    Fluorescence measurements have been an established mainstay of photosynthesis experiments for many decades. Because in the photosynthesis literature the basics of excited states and their fates are not usually described, we have presented here an easily understandable text for biology students in the style of a chapter in a text book. In this review we give an educational overview of fundamental physical principles of fluorescence, with emphasis on the temporal response of emission. Escape from the excited state of a molecule is a dynamic event, and the fluorescence emission is in direct kinetic competition with several other pathways of de-excitation. It is essentially through a kinetic competition between all the pathways of de-excitation that we gain information about the fluorescent sample on the molecular scale. A simple probability allegory is presented that illustrates the basic ideas that are important for understanding and interpreting most fluorescence experiments. We also briefly point out challenges that confront the experimenter when interpreting time-resolved fluorescence responses.

  10. The aesthetic composite bridge.

    Science.gov (United States)

    Feinman, R A

    1997-01-01

    New developments are constantly introduced in the search for the optimal treatment modality to restore a single anterior tooth. The patient attention has shifted to aesthetics of the restoration, biocompatibility of the dental materials utilized, conservative preparation of the teeth to be restored, and the retention of intact adjacent dentition. The learning objective of this article is to review the methods currently utilized and to present a recently introduced treatment modality--the two-component bridge, which combines the strength and resiliency of composite resin with the aesthetic advantages of porcelain. The technology of the material is reviewed, the predominantly lingual tooth preparation procedures are outlined, and the bridge try-in is described. The advantages of the two-component bridge are presented along with the contraindications and suggestions of careful case selection. Three cases with congenitally missing maxillary lateral incisors in youthful patients are presented to supplement the theoretical outline and to describe and illustrate the clinical procedure.

  11. Istanbul Bridge Conference 2014

    CERN Document Server

    Gülkan, Polat; Mahmoud, Khaled

    2016-01-01

      The book includes peer-reviewed contributions selected from presentations given at the Istanbul Bridge Conference 2014, held from August 11 – 13 in Istanbul, Turkey. It reports on the current challenges in bridge engineering faced by professionals around the globe, giving a special emphasis to recently developed techniques, innovations and opportunities. The book covers key topics in the field, including modeling and analysis methods; construction and erection techniques; design for extreme events and condition assessment and structural health monitoring. There is a balanced presentation of theory, research and practice. This book, which provides the readers with a comprehensive and timely reference guide on current practices in bridge engineering, is intended for professionals, academic researchers and students alike.

  12. Active Control of Suspension Bridges

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle

    In this paper some recent research on active control of very long suspension bridges, is presented. The presentation is based on research work at Aalborg University, Denmark. The active control system is based on movable flaps attached to the bridge girder. Wind load on bridges with or without...... flaps attached to the girder is briefly presented. A simple active control system is discussed. Results from wind tunnel experiments with a bridge section show that flaps can be used effectively to control bridge girder vibrations. Flutter conditions for suspension bridges with and without flaps...

  13. Maximum Entropy Fundamentals

    Directory of Open Access Journals (Sweden)

    F. Topsøe

    2001-09-01

    Full Text Available Abstract: In its modern formulation, the Maximum Entropy Principle was promoted by E.T. Jaynes, starting in the mid-fifties. The principle dictates that one should look for a distribution, consistent with available information, which maximizes the entropy. However, this principle focuses only on distributions and it appears advantageous to bring information theoretical thinking more prominently into play by also focusing on the "observer" and on coding. This view was brought forward by the second named author in the late seventies and is the view we will follow-up on here. It leads to the consideration of a certain game, the Code Length Game and, via standard game theoretical thinking, to a principle of Game Theoretical Equilibrium. This principle is more basic than the Maximum Entropy Principle in the sense that the search for one type of optimal strategies in the Code Length Game translates directly into the search for distributions with maximum entropy. In the present paper we offer a self-contained and comprehensive treatment of fundamentals of both principles mentioned, based on a study of the Code Length Game. Though new concepts and results are presented, the reading should be instructional and accessible to a rather wide audience, at least if certain mathematical details are left aside at a rst reading. The most frequently studied instance of entropy maximization pertains to the Mean Energy Model which involves a moment constraint related to a given function, here taken to represent "energy". This type of application is very well known from the literature with hundreds of applications pertaining to several different elds and will also here serve as important illustration of the theory. But our approach reaches further, especially regarding the study of continuity properties of the entropy function, and this leads to new results which allow a discussion of models with so-called entropy loss. These results have tempted us to speculate over

  14. Fundamentals of Space Medicine

    Science.gov (United States)

    Clément, Gilles

    2005-03-01

    A total of more than 240 human space flights have been completed to date, involving about 450 astronauts from various countries, for a combined total presence in space of more than 70 years. The seventh long-duration expedition crew is currently in residence aboard the International Space Station, continuing a permanent presence in space that began in October 2000. During that time, investigations have been conducted on both humans and animal models to study the bone demineralization and muscle deconditioning, space motion sickness, the causes and possible treatment of postflight orthostatic intolerance, the changes in immune function, crew and crew-ground interactions, and the medical issues of living in a space environment, such as the effects of radiation or the risk of developing kidney stones. Some results of these investigations have led to fundamental discoveries about the adaptation of the human body to the space environment. Gilles Clément has been active in this research. This readable text presents the findings from the life science experiments conducted during and after space missions. Topics discussed in this book include: adaptation of sensory-motor, cardio-vascular, bone, and muscle systems to the microgravity of spaceflight; psychological and sociological issues of living in a confined, isolated, and stressful environment; operational space medicine, such as crew selection, training and in-flight health monitoring, countermeasures and support; results of space biology experiments on individual cells, plants, and animal models; and the impact of long-duration missions such as the human mission to Mars. The author also provides a detailed description of how to fly a space experiment, based on his own experience with research projects conducted onboard Salyut-7, Mir, Spacelab, and the Space Shuttle. Now is the time to look at the future of human spaceflight and what comes next. The future human exploration of Mars captures the imagination of both the

  15. Bridging Innate and Adaptive Antitumor Immunity Targeting Glycans

    Directory of Open Access Journals (Sweden)

    Anastas Pashov

    2010-01-01

    Full Text Available Effective immunotherapy for cancer depends on cellular responses to tumor antigens. The role of major histocompatibility complex (MHC in T-cell recognition and T-cell receptor repertoire selection has become a central tenet in immunology. Structurally, this does not contradict earlier findings that T-cells can differentiate between small hapten structures like simple glycans. Understanding T-cell recognition of antigens as defined genetically by MHC and combinatorially by T cell receptors led to the “altered self” hypothesis. This notion reflects a more fundamental principle underlying immune surveillance and integrating evolutionarily and mechanistically diverse elements of the immune system. Danger associated molecular patterns, including those generated by glycan remodeling, represent an instance of altered self. A prominent example is the modification of the tumor-associated antigen MUC1. Similar examples emphasize glycan reactivity patterns of antigen receptors as a phenomenon bridging innate and adaptive but also humoral and cellular immunity and providing templates for immunotherapies.

  16. Existing Steel Railway Bridges Evaluation

    Science.gov (United States)

    Vičan, Josef; Gocál, Jozef; Odrobiňák, Jaroslav; Koteš, Peter

    2016-12-01

    The article describes general principles and basis of evaluation of existing railway bridges based on the concept of load-carrying capacity determination. Compared to the design of a new bridge, the modified reliability level for existing bridges evaluation should be considered due to implementation of the additional data related to bridge condition and behaviour obtained from regular inspections. Based on those data respecting the bridge remaining lifetime, a modification of partial safety factors for actions and materials could be respected in the bridge evaluation process. A great attention is also paid to the specific problems of determination of load-caring capacity of steel railway bridges in service. Recommendation for global analysis and methodology for existing steel bridge superstructure load-carrying capacity determination are described too.

  17. BUILDING "BRIDGES" WITH QUALITY ASSURANCE

    Science.gov (United States)

    The papr describes how, rather than building "bridges" across centuries, quality assurance (QA) personnel have the opportunity to build bridges across technical disciplines, between public and private organizations, and between different QA groups. As reviewers and auditors of a...

  18. The Bridges Program.

    Science.gov (United States)

    Bohnen, Elizabeth; Klie, Judy

    This report describes BRIDGES, an employment equity special measures training program developed by the City of Toronto (Ontario, Canada). It was designed to help women employees move from their traditional jobs into trades, technical or operation (TTO) jobs within their own organization. The program is a combination of classroom sessions, shop…

  19. Bridging a Cultural Gap

    Science.gov (United States)

    Leviatan, Talma

    2008-01-01

    There has been a broad wave of change in tertiary calculus courses in the past decade. However, the much-needed change in tertiary pre-calculus programmes--aimed at bridging the gap between high-school mathematics and tertiary mathematics--is happening at a far slower pace. Following a discussion on the nature of the gap and the objectives of a…

  20. Building a Straw Bridge

    Science.gov (United States)

    Teaching Science, 2015

    2015-01-01

    This project is for a team of students (groups of two or three are ideal) to design and construct a model of a single-span bridge, using plastic drinking straws as the building material. All steps of the design, construction, testing and critiquing stages should be recorded by students in a journal. Students may like to include labelled diagrams,…

  1. DOE Information Bridge

    CERN Document Server

    United States. Department of Energy. Office of Scientific and Technical Information

    DOE Information Bridge, a component of EnergyFiles, provides free, convenient, and quick access to full-text DOE research and development reports in physics, chemistry, materials, biology, environmental sciences, energy technologies, engineering, computer and information science, renewable energy, and other topics. This vast collection includes over 43,000 reports that have been received and processed by OSTI since January 1995.

  2. Bridge over troubled water?

    DEFF Research Database (Denmark)

    Svendsen, Gunnar Lind Haase; Nannestad, Peter; Svendsen, Gert Tinggaard

    2008-01-01

    The problem of integrating non-Western immigrants into Western welfare states is the focus of this paper. To address this issue, we suggest a social capital approach in which we apply the conceptual pair of bridging social capital (BR), which connects an individual to the broader social structure...

  3. Looking Beyond the Bridge

    DEFF Research Database (Denmark)

    Jahn, Elke; Rosholm, Michael

    We perform a comprehensive analysis of the stepping-stone effect of temporary agency employment on unemployed workers. Using the timing-of-events approach, we not only investigate whether agency employment is a bridge into regular employment but also analyze its effect on post-unemployment wages...

  4. Bridging the Technological Gap.

    Science.gov (United States)

    Lazow, Robert; And Others

    The aim of "Bridging the Technological Gap" (BTG), a federally funded demonstration project, is to use microcomputer technology in the rehabilitation of the psychiatrically disabled. Through the use of a custom designed microcomputer software package, clients receive remediation in areas of specific cognitive and behavioral deficits. The project…

  5. Building Bridges to China.

    Science.gov (United States)

    Wasta, Stephanie; Scott, Margaret

    1998-01-01

    Describes a theme cycle called "Building Bridges to China" developed for third grade students that focuses on the similarities between the lives of children and families in China and the United States. Explains that the theme cycle addresses the National Geography Standards and three of the National Council for the Social Studies standards. (CMK)

  6. Communication technology update and fundamentals

    CERN Document Server

    Grant, August E

    2010-01-01

    New communication technologies are being introduced at an astonishing rate. Making sense of these technologies is increasingly difficult. Communication Technology Update and Fundamentals is the single best source for the latest developments, trends, and issues in communication technology. Featuring the fundamental framework along with the history and background of communication technologies, Communication Technology Update and Fundamentals, 12th edition helps you stay ahead of these ever-changing and emerging technologies.As always, every chapter ha

  7. Revised Rules for Concrete Bridges

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle; Jensen, F. M.; Middleton, C.;

    This paper is based on research performed for the Highway Agency, London, UK under the project DPU/9/44 "Revision of Bridge Assessment Rules Based on Whole Life Performance: Concrete Bridges" It contains details of a methodology which can be used to generate Whole Life (WL) reliability profiles....... These WL reliability profiles may be used to establish revised rules for Concrete Bridges....

  8. The Bridges of Taishun County

    Institute of Scientific and Technical Information of China (English)

    MaJianhe

    2003-01-01

    The American film The Bridges of Madison County captured the imagination of many Chinese moviegoers with its bittersweet love story and scenes of rustic covered bridges. But the U.S. can't lay sole claim to such spectacular rural sights:China has its own county worldrenowned for unforgettable bridges.

  9. Dynamic Bridge Response for a Bridge-friendly Truck

    Directory of Open Access Journals (Sweden)

    V. Šmilauer

    2004-01-01

    Full Text Available A truck with controlled semi-active suspensions traversing a bridge is examined for benefits to the bridge structure. The original concept of a road-friendly truck was extended to a bridge-friendly vehicle, using the same optimization tools. A half-car model with two independently driven axles is coupled with simply supported bridges (beam, slab model with the span range from 5 m to 50 m. Surface profile of the bridge deck is either stochastic or in the shape of a bump or a pot in the mid-span. Numerical integration in the MATLAB/SIMULINK environment solves coupled dynamic equations of motion with optimized truck suspensions. The rear axle generates the prevailing load and to a great extent determines the bridge response. A significant decrease in contact road-tire forces is observed and the mid-span bridge deflections are on average smaller, when compared to commercial passive suspensions. 

  10. Laser-fundamentals and applications

    Energy Technology Data Exchange (ETDEWEB)

    Schinagl, W.

    1982-09-01

    The survey article gives an introduction to laser technology. Fundamentals and physical aspects are discussed at large. After a brief historical review and a discussion of the physical fundamentals, important types of laser, characteristics of laser radiation and its applications in medicine are discussed.

  11. The Fundamental Scale of Descriptions

    CERN Document Server

    Febres, Gerardo

    2014-01-01

    The complexity of a system description is a function of the entropy of its symbolic description. Prior to computing the entropy of the system description, an observation scale has to be assumed. In natural language texts, typical scales are binary, characters, and words. However, considering languages as structures built around certain preconceived set of symbols, like words or characters, is only a presumption. This study depicts the notion of the Description Fundamental Scale as a set of symbols which serves to analyze the essence a language structure. The concept of Fundamental Scale is tested using English and MIDI music texts by means of an algorithm developed to search for a set of symbols, which minimizes the system observed entropy, and therefore best expresses the fundamental scale of the language employed. Test results show that it is possible to find the Fundamental Scale of some languages. The concept of Fundamental Scale, and the method for its determination, emerges as an interesting tool to fac...

  12. Bridging as Coercive Accommodation

    CERN Document Server

    Bos, J W; Mineur, A M; Bos, Johan; Buitelaar, Paul; Mineur, Anne-Marie

    1995-01-01

    In this paper we discuss the notion of "bridging" in Discourse Representation Theory as a tool to account for discourse referents that have only been established implicitly, through the lexical semantics of other referents. In doing so, we use ideas from Generative Lexicon theory, to introduce antecedents for anaphoric expressions that cannot be "linked" to a proper antecedent, but that do not need to be "accommodated" because they have some connection to the network of discourse referents that is already established.

  13. Bridging Classroom Language Ethnography

    OpenAIRE

    GRENFELL, MICHAEL JAMES

    2012-01-01

    PUBLISHED Paper #5: Bridging Classroom Language Ethnography, New Literacy Studies and Bourdieu?s Social Philosophy: Principles and Practice The purpose of this paper is to analyze and synthesize the various ways that classroom language ethnography, NLS, and Bourdieu?s social philosophy, were integrated. The goal of the analysis and synthesis is to provide a fresh perspective and fruitful insights on literacy in all its manifestations that provides the foundations for a more robust...

  14. Environmental life cycle assessment comparison between two bridge types: reinforced concrete bridge and steel composite bridge

    DEFF Research Database (Denmark)

    Du, Guangli; Karoumi, Raid

    2013-01-01

    not been integrated into the decision-making process. This paper presents a systematic LCA method for quantifying the environmental impacts for bridges. The comparison study is performed between a reinforced concrete bridge and a steel bridge as an alternative design, with several key maintenance and EOL......The concept of sustainable construction has attracted an increased attention. Bridge infrastructures and their belonged construction activities consume considerable material and energy, which is responsible for large environmental burdens. However, the environmental assessment of bridges has...

  15. Re(I) bridged porphyrin dyads, triads and tetrads

    Indian Academy of Sciences (India)

    M Yedukondalu; M Ravikanth

    2011-03-01

    Porphyrin rings containing two meso-pyridyl groups either in cis or trans fashion can be used to construct Re(I) bridged multiporphyrin assemblies. The cis-dipyridyl porphyrins with various porphyrin cores such as N4, N3O, N3S, N2S2 have been used to react with Re(CO)5Cl in THF at refluxing temperature and constructed planar Re(I) bridged porphyrin dyads containing either one type of porphyrin subunit or two types of porphyrin subunits. The trans-dipyridyl porphyrins have been used to construct Re(I) bridged porphyrin squares. The porphyrin dyads have been explored for singlet-singlet energy transfer studies and porphyrin squares have been used for catalysis, chemical sensing, molecular sieving and photocurrent production studies. An overview of synthesis of Re(I) bridged porphyrin dyads, triads and tetrads and their interesting photophysical properties are highlighted in this paper.

  16. Fundamental mechanisms of micromachine reliability

    Energy Technology Data Exchange (ETDEWEB)

    DE BOER,MAARTEN P.; SNIEGOWSKI,JEFFRY J.; KNAPP,JAMES A.; REDMOND,JAMES M.; MICHALSKE,TERRY A.; MAYER,THOMAS K.

    2000-01-01

    Due to extreme surface to volume ratios, adhesion and friction are critical properties for reliability of Microelectromechanical Systems (MEMS), but are not well understood. In this LDRD the authors established test structures, metrology and numerical modeling to conduct studies on adhesion and friction in MEMS. They then concentrated on measuring the effect of environment on MEMS adhesion. Polycrystalline silicon (polysilicon) is the primary material of interest in MEMS because of its integrated circuit process compatibility, low stress, high strength and conformal deposition nature. A plethora of useful micromachined device concepts have been demonstrated using Sandia National Laboratories' sophisticated in-house capabilities. One drawback to polysilicon is that in air the surface oxidizes, is high energy and is hydrophilic (i.e., it wets easily). This can lead to catastrophic failure because surface forces can cause MEMS parts that are brought into contact to adhere rather than perform their intended function. A fundamental concern is how environmental constituents such as water will affect adhesion energies in MEMS. The authors first demonstrated an accurate method to measure adhesion as reported in Chapter 1. In Chapter 2 through 5, they then studied the effect of water on adhesion depending on the surface condition (hydrophilic or hydrophobic). As described in Chapter 2, they find that adhesion energy of hydrophilic MEMS surfaces is high and increases exponentially with relative humidity (RH). Surface roughness is the controlling mechanism for this relationship. Adhesion can be reduced by several orders of magnitude by silane coupling agents applied via solution processing. They decrease the surface energy and render the surface hydrophobic (i.e. does not wet easily). However, only a molecular monolayer coats the surface. In Chapters 3-5 the authors map out the extent to which the monolayer reduces adhesion versus RH. They find that adhesion is

  17. The Development of Maritime English Learning Model Using Authentic Assessment Based Bridge Simulator in Merchant Marine Polytechnic, Makassar

    Science.gov (United States)

    Fauzi, Ahmad; Bundu, Patta; Tahmir, Suradi

    2016-01-01

    Bridge simulator constitutes a very fundamental and vital tool to trigger and ensure that seamen or seafarers possess the standardized competence required. By using the bridge simulator technique, a reality based study can be presented easily and delivered to the students in ongoing basis to their classroom or study place. Afterwards, the validity…

  18. Fundamental principles of heat transfer

    CERN Document Server

    Whitaker, Stephen

    1977-01-01

    Fundamental Principles of Heat Transfer introduces the fundamental concepts of heat transfer: conduction, convection, and radiation. It presents theoretical developments and example and design problems and illustrates the practical applications of fundamental principles. The chapters in this book cover various topics such as one-dimensional and transient heat conduction, energy and turbulent transport, forced convection, thermal radiation, and radiant energy exchange. There are example problems and solutions at the end of every chapter dealing with design problems. This book is a valuable int

  19. Fundamentals of technology project management

    CERN Document Server

    Garton, Colleen

    2012-01-01

    Designed to provide software engineers, students, and IT professionals with an understanding of the fundamentals of project management in the technology/IT field, this book serves as a practical introduction to the subject. Updated with information on how Fundamentals of Project Management integrates with and complements Project Management Institute''s Project Management Body of Knowledge, this collection explains fundamental methodologies and techniques while also discussing new technology, tools, and virtual work environments. Examples and case studies are based on technology projects, and t

  20. Fundamentals of fluorescence and fluorescence microscopy.

    Science.gov (United States)

    Wolf, David E

    2013-01-01

    This chapter discusses the fundamental physics of fluorescence. The application of fluorescence to microscopy represents an important transition in the development of microscopy, particularly as it applies to biology. It enables quantitating the amounts of specific molecules within a cell, determining whether molecules are complexing on a molecular level, measuring changes in ionic concentrations within cells and organelles, and measuring molecular dynamics. This chapter also discusses the issues important to quantitative measurement of fluorescence and focuses on four of quantitative measurements of fluorescence--boxcar-gated detection, streak cameras, photon correlation, and phase modulation. Although quantitative measurement presents many pitfalls to the beginner, it also presents significant opportunities to one skilled in the art. This chapter also examines how fluorescence is measured in the steady state and time domain and how fluorescence is applied in the modern epifluorescence microscope.

  1. Fundamental approach to discrete mathematics

    CERN Document Server

    Acharjya, DP

    2005-01-01

    Salient Features Mathematical logic, fundamental concepts, proofs and mathematical induction (Chapter 1) Set theory, fundamental concepts, theorems, proofs, Venn diagrams, product of sets, application of set theory and fundamental products (Chapter 2) An introduction to binary relations and concepts, graphs, arrow diagrams, relation matrix, composition of relations, types of relation, partial order relations, total order relation, closure of relations, poset, equivalence classes and partitions. (Chapter 3) An introduction to functions and basic concepts, graphs, composition of functions, floor and ceiling function, characteristic function, remainder function, signum function and introduction to hash function. (Chapter 4) The algebraic structure includes group theory and ring theory. Group theory includes group, subgroups, cyclic group, cosets, homomorphism, introduction to codes and group codes and error correction for block code. The ring theory includes general definition, fundamental concepts, integra...

  2. Clinical fundamentals for radiation oncologists.

    Science.gov (United States)

    Yang, Jack

    2011-11-01

    Clinical fundamentals for radiation oncologists. Hasan Murshed. Medical Physics Publishing, Madison, WI, 2011. 680 pp. (soft cover), Price: $90.00. 978-1-930524-43-9. © 2011 American Association of Physicists in Medicine.

  3. Fundamentals of modern unsteady aerodynamics

    CERN Document Server

    Gülçat, Ülgen

    2010-01-01

    This introduction to the principles of unsteady aerodynamics covers all the core concepts, provides readers with a review of the fundamental physics, terminology and basic equations, and covers hot new topics such as the use of flapping wings for propulsion.

  4. Fundamental measure theory for hard-sphere mixtures: a review.

    Science.gov (United States)

    Roth, Roland

    2010-02-17

    Hard-sphere systems are one of the fundamental model systems of statistical physics and represent an important reference system for molecular or colloidal systems with soft repulsive or attractive interactions in addition to hard-core repulsion at short distances. Density functional theory for classical systems, as one of the core theoretical approaches of statistical physics of fluids and solids, has to be able to treat such an important system successfully and accurately. Fundamental measure theory is up to date the most successful and most accurate density functional theory for hard-sphere mixtures. Since its introduction fundamental measure theory has been applied to many problems, tested against computer simulations, and further developed in many respects. The literature on fundamental measure theory is already large and is growing fast. This review aims to provide a starting point for readers new to fundamental measure theory and an overview of important developments.

  5. Conjugated polyelectrolytes fundamentals and applications

    CERN Document Server

    Liu, Bin

    2013-01-01

    This is the first monograph to specifically focus on fundamentals and applications of polyelectrolytes, a class of molecules that gained substantial interest due to their unique combination of properties. Combining both features of organic semiconductors and polyelectrolytes, they offer a broad field for fundamental research as well as applications to analytical chemistry, optical imaging, and opto-electronic devices. The initial chapters introduce readers to the synthesis, optical and electrical properties of various conjugated polyelectrolytes. This is followed by chapters on the applica

  6. Fundamentals of electronic image processing

    CERN Document Server

    Weeks, Arthur R

    1996-01-01

    This book is directed to practicing engineers and scientists who need to understand the fundamentals of image processing theory and algorithms to perform their technical tasks. It is intended to fill the gap between existing high-level texts dedicated to specialists in the field and the need for a more practical, fundamental text on image processing. A variety of example images are used to enhance reader understanding of how particular image processing algorithms work.

  7. Open Source Fundamental Industry Classification

    OpenAIRE

    Kakushadze, Zura; Yu, Willie

    2017-01-01

    We provide complete source code for building a fundamental industry classification based on publically available and freely downloadable data. We compare various fundamental industry classifications by running a horserace of short-horizon trading signals (alphas) utilizing open source heterotic risk models (https://ssrn.com/abstract=2600798) built using such industry classifications. Our source code includes various stand-alone and portable modules, e.g., for downloading/parsing web data, etc.

  8. Expected Devaluation and Economic Fundamentals

    OpenAIRE

    Alun H. Thomas

    1993-01-01

    Recent incidents of exchange rate collapse have provoked interest in the extent to which such events are determined by economic fundamentals. This paper considers whether interest rate differentials are appropriate measures of the risk of devaluation and whether this measure of devaluation risk reflects the movements of variables which capture internal and external balance. The paper finds that interest rate differentials reflect devaluation risk but that movements in fundamental variables ha...

  9. The active-bridge oscillator

    Energy Technology Data Exchange (ETDEWEB)

    Wessendorf, K.O.

    1998-07-01

    This paper describes the Active-Bridge Oscillator (ABO), a new concept in high-stability oscillator design. The ABO is ab ridge-type oscillator design that is easly to design and overcomes many of the operational and design difficulties associated with standard bridge oscillator designs. The ABO will oscillate with a very stable output amplitude over a wide range of operating conditions without the use of an automatic-level-control (ALC). A standard bridge oscillator design requires an ALC to maintain the desired amplitude of oscillation. for this and other reasons, bridge oscilaltors are not used in mainstream designs. Bridge oscillators are generally relegated to relatively low-volume, high-performance applications. The Colpitts and Pierce designs are the most popular oscillators but are typically less stable than a bridge-type oscillator.

  10. Vulnerability of bridges to fire

    DEFF Research Database (Denmark)

    Giuliani, Luisa; Crosti, C.; Gentili, F.

    2012-01-01

    Even if recent effort in developing methodology and measures for design structures against fire and explosions has been mostly focused on buildings, bridges can also be very sensitive to those actions, as witnesses by some recent bridge accidents, which caused major economic losses and also...... endangered people safety in few cases. Purpose of this paper is making a focus on the state of the art of the research and current regulations concerning the response of bridges to fire. Several cases of bridge fires are reported and a focus is made on the occurrence and consequence of bridge fires......, considering both the costs deriving by structural damages and by limited serviceability and other indirect societal aspects. Few cases of recent bridge fire are reviewed in detail and structural consequences are highlighted, distinguishing between damages directly induced by fire and damages induced by local...

  11. Three-dimensional structure of a sunspot light bridge

    CERN Document Server

    Felipe, T; Khomenko, E; Kuckein, C; Ramos, A Asensio; Balthasar, H; Berkefeld, T; Denker, C; Feller, A; Franz, M; Hofmann, A; Kiess, C; Lagg, A; Nicklas, H; Suárez, D Orozco; Yabar, A Pastor; Rezaei, R; Schlichenmaier, R; Schmidt, D; Schmidt, W; Sigwarth, M; Sobotka, M; Solanki, S K; Soltau, D; Staude, J; Strassmeier, K G; Volkmer, R; von der Lühe, O; Waldmann, T

    2016-01-01

    Active regions are the most prominent manifestations of solar magnetic fields; their generation and dissipation are fundamental problems in solar physics. Light bridges are commonly present during sunspot decay, but a comprehensive picture of their role in the removal of photospheric magnetic field is still missing. We study the three dimensional configuration of a sunspot and in particular its light bridge during one of the last stages of its decay. We present the magnetic and thermodynamical stratification inferred from full Stokes inversions of the photospheric Si I 10827 \\AA\\ and Ca I 10839 \\AA\\ lines obtained with the GREGOR Infrared Spectrograph of the GREGOR telescope at Observatorio del Teide, Tenerife, Spain. The analysis is complemented by a study of continuum images covering the disk passage of the active region, which are provided by the Helioseismic and Magnetic Imager on board the Solar Dynamics Observatory. The sunspot shows a light bridge with penumbral continuum intensity that separates the c...

  12. Uniaxially stressed germanium with fundamental direct band gap

    OpenAIRE

    Geiger, R.; Zabel, T.; Marin, E; Gassenq, A.; Hartmann, J.-M.; Widiez, J.; Escalante, J.; Guilloy, K.; Pauc, N.; Rouchon, D.; Diaz, G. Osvaldo; Tardif, S; Rieutord, F.; Duchemin, I.; Niquet, Y. -M.

    2015-01-01

    We demonstrate the crossover from indirect- to direct band gap in tensile-strained germanium by temperature-dependent photoluminescence. The samples are strained microbridges that enhance a biaxial strain of 0.16% up to 3.6% uniaxial tensile strain. Cooling the bridges to 20 K increases the uniaxial strain up to a maximum of 5.4%. Temperature-dependent photoluminescence reveals the crossover to a fundamental direct band gap to occur between 4.0% and 4.5%. Our data are in good agreement with n...

  13. Bridge Aesthetics and Structural Honesty

    DEFF Research Database (Denmark)

    Gimsing, Niels Jørgen

    1999-01-01

    In bridges the overall form must be chosen with due respect to the transmission of forces if efficient structures shall be created, The design must therefore be governed by experienced structural engineers - in some cases assisted by aesthetic advisers on specific issues. Some basic requirements...... decisive for choosing the form of trusses, arches and cable-stayed bridges are outlined, and several examples show bridges designed without giving priority to the structural aspects....

  14. Morphological aspects of myocardial bridges.

    Science.gov (United States)

    Lujinović, Almira; Kulenović, Amela; Kapur, Eldan; Gojak, Refet

    2013-11-01

    Although some myocardial bridges can be asymptomatic, their presence often causes coronary disease either through direct compression of the "tunnel" segment or through stimulation and accelerated development of atherosclerosis in the segment proximally to the myocardial bridge. The studied material contained 30 human hearts received from the Department of Anatomy. The hearts were preserved 3 to 5 days in 10% formalin solution. Thereafter, the fatty tissue was removed and arterial blood vessels prepared by careful dissection with special reference to the presence of the myocardial bridges. Length and thickness of the bridges were measured by the precise electronic caliper. The angle between the myocardial bridge fibre axis and other axis of the crossed blood vessel was measured by a goniometer. The presence of the bridges was confirmed in 53.33% of the researched material, most frequently (43.33%) above the anterior interventricular branch. The mean length of the bridges was 14.64 ± 9.03 mm and the mean thickness was 1.23 ± 1.32 mm. Myocardial bridge fibres pass over the descending blood vessel at the angle of 10-90 degrees. The results obtained on a limited sample suggest that the muscular index of myocardial bridge is the highest for bridges located on RIA, but that the difference is not significant in relation to bridges located on other branches. The results obtained suggest that bridges located on other branches, not only those on RIA, could have a great contractive power and, consequently, a great compressive force, which would be exerted on the wall of a crossed blood vessel.

  15. Modular FRP Composite Bridge Deck

    OpenAIRE

    ECT Team, Purdue

    2007-01-01

    The bridge infrastructure of the United States is in constant need of repair and rehabilitation. It is reported that 43% of the bridges in the USA have been identified as being structurally deficient or functionally obsolete due to corrosion. SuperdeckTM, a non-corrosive fiber reinforced polymer (FRP) composite bridge deck. The Deck is designed and engineered into a lightweight, strong and rigid structure that will not corrode. The deck sections, composed of hexagon and double-trapezoid profi...

  16. Bridging Literature and Linguistics

    Directory of Open Access Journals (Sweden)

    Abdul Wahab

    2002-01-01

    Full Text Available Abstract: Two majors linguistics and literature in the schools of letters both in the state and private universities throughout Indonesia are commonly separated sharply. Courses of literature in the Department of Linguistics are offered minimally, such that the students of linguistics are not given a conducive atmosphere to express their literary appreciation. Likewise, courses of linguistics in the Department of Literature are very restricted, so that the students of literature are unable to analyze literary works from the points of linguistic view. This paper tries to bridge linguistics and literature. The attempt to bridge linguistics and literature is based on three postulates: (I literature consists of linguistic objects designed with an artistic end, (2 linguistic objects are formal objects, and (3 a formal account of linguistic object designed with an artistic end approximates a formal account of that artistic design. Two major directions in the approaches and emphases will be presented in the paper exogenous and endogenous. Exogenous approach tries to search for adequate description of (1 poetic language as contrasted with ordinary language, (2 language of a particular author contrasted with that of other authors, and (3 a particular literary work contrasted with other works of the same author. This part touches upon three areas of exogenous approach isolation, description, and characterization. Endogenous, on the hand, is based upon an assumption that a writer exhibits, probably without realizing it, certain systematic preferences for particular aspects of linguistic patterns. Planning a bridge between linguistics and literature is by no means without problems. Therefore, this paper also presents some possible solutions.

  17. Bridging Literature and Linguistics

    Directory of Open Access Journals (Sweden)

    Abdul Wahab

    2003-01-01

    Full Text Available Two majors linguistics and literature in the schools of letters both in the state and private universities throughout Indonesia are commonly separated sharply. Courses of literature in the Department of Linguistics are offered minimally, such that the students of linguistics are not given a conducive atmosphere to express their literary appreciation. Likewise, courses of linguistics in the Department of Literature are very restricted, so that the students of literature are unable to analyze literary works from the points of linguistic view. This paper tries to bridge linguistics and literature. The attempt to bridge linguistics and literature is based on three postulates: (1 literature consists of linguistic objects designed with an artistic end, (2 linguistic objects are formal objects, and (3 a formal account of linguistic object designed with an artistic end approximates a formal account of that artistic design. Two major directions in the approaches and emphases will be presented in the paper exogenous and endogenous. Exogenous approach tries to search for adequate description of (1 poetic language as contrasted with ordinary language, (2 language of a particular author contrasted with that of other authors, and (3 a particular literary work contrasted with other works of the same author. This part touches upon three areas of exogenous approach isolation, description, and characterization. Endogenous, on the hand, is based upon an assumption that a writer exhibits, probably without realizing it, certain systematic preferences for particular aspects of linguistic patterns. Planning a bridge between linguistics and literature is by no means without problems. Therefore, this paper also presents some possible solutions.

  18. Fundamental relation between molecular geometry and real-space topology. Combined AIM, ELI-D, and ASF analysis of hapticities and intramolecular hydrogen-hydrogen bonds in zincocene-related compounds.

    Science.gov (United States)

    Mebs, Stefan; Chilleck, Maren Annika; Meindl, Kathrin; Hübschle, Christian Bertram

    2014-06-19

    Despite numerous advanced and widely distributed bonding theories such as MO, VB, NBO, AIM, and ELF/ELI-D, complex modes of bonding such as M-Cp*((R)) interactions (hapticities) in asymmetrical metallocenes or weak intramolecular interactions (e.g., hydrogen-hydrogen (H···H) bonds) still remain a challenge for these theories in terms of defining whether or not an atom-atom interaction line (a "chemical bond") should be drawn. In this work the intramolecular Zn-C(Cp*(R)) (R = Me, -(CH2)2NMe2, and -(CH2)3NMe2) and H···H connectivity of a systematic set of 12 zincocene-related compounds is analyzed in terms of AIM and ELI-D topology combined with the recently introduced aspherical stockholder fragment (ASF) surfaces. This computational analysis unravels a distinct dependency of the AIM and ELI-D topology against the molecular geometry for both types of interactions, which confirms and extends earlier findings on smaller sets of compounds. According to these results the complete real-space topology including strong, medium, and weak interactions of very large compounds such as proteins may be reliably predicted by sole inspection of accurately determined molecular geometries, which would on the one hand afford new applications (e.g., accurate estimation of numbers, types, and strengths of intra- and intermolecular interactions) and on the other hand have deep implications on the significance of the method.

  19. Linguistic Barriers and Bridges

    DEFF Research Database (Denmark)

    Thuesen, Frederik

    2016-01-01

    The influence of language on social capital in low-skill and ethnically diverse workplaces has thus far received very limited attention within the sociology of work. As the ethnically diverse workplace is an important social space for the construction of social relations bridging different social...... and intercultural communication, this article analyses interviews with 31 employees from two highly ethnically diverse Danish workplaces. The article shows how linguistic barriers such as different levels of majority language competence and their consequent misunderstandings breed mistrust and hostility, whilst...

  20. Bridging The Inferential Gap

    Science.gov (United States)

    Stewart, Walter F.; Shah, Nirav R.; Selna, Mark J.; Paulus, Ronald A.; Walker, James M.

    2009-01-01

    Most clinical decisions involve bridging the inferential gap: Clinicians are required to “fill in” where they lack knowledge or where no knowledge yet exists. In this context we consider how the inferential gap is a product, in part, of how knowledge is created, the limits to gaining access to such knowledge, and the variable ways in which knowledge is translated into decisions. We consider how electronic health records (EHRs) will help narrow this gap by accelerating the creation of evidence relevant to everyday practice needs and facilitating real-time use of knowledge in practice. PMID:17259202

  1. Thermal bridges of modern windows

    DEFF Research Database (Denmark)

    Hansen, Ernst Jan de Place; Møller, Eva B.; Nielsen, Anker

    2013-01-01

    With its focus on reduced energy consumption, contemporary housing construction requires a highly insulated and airtight building envelope with as few thermal bridges as possible.Windows must be carefully designed, as thermal bridges can lead to surface condensation or mold growth, even if the wi......With its focus on reduced energy consumption, contemporary housing construction requires a highly insulated and airtight building envelope with as few thermal bridges as possible.Windows must be carefully designed, as thermal bridges can lead to surface condensation or mold growth, even...

  2. Modelling railway bridge asset management

    OpenAIRE

    Le, Bryant Linh Hai

    2014-01-01

    The UK has a long history in the railway industry with a large number of railway assets. Railway bridges form one of the major asset groups with more than 35,000 bridges. The majority of the bridge population are old being constructed over 100 years ago. Many of the bridges were not designed to meet the current network demand. With an expected increasing rate of deterioration due to the increasing traffic loads and intensities, the management authorities are faced with the difficult task of k...

  3. Fundamental units: physics and metrology

    CERN Document Server

    Okun, Lev Borisovich

    2003-01-01

    The problem of fundamental units is discussed in the context of achievements of both theoretical physics and modern metrology. On one hand, due to fascinating accuracy of atomic clocks, the traditional macroscopic standards of metrology (second, metre, kilogram) are giving way to standards based on fundamental units of nature: velocity of light $c$ and quantum of action $h$. On the other hand, the poor precision of gravitational constant $G$, which is widely believed to define the ``cube of theories'' and the units of the future ``theory of everything'', does not allow to use $G$ as a fundamental dimensional constant in metrology. The electromagnetic units in SI are actually based on concepts of prerelativistic classical electrodynamics such as ether, electric permitivity and magnetic permeability of vacuum. Concluding remarks are devoted to terminological confusion which accompanies the progress in basic physics and metrology.

  4. Fundamental physics in particle traps

    CERN Document Server

    Vogel, Manuel

    2014-01-01

    This volume provides detailed insight into the field of precision spectroscopy and fundamental physics with particles confined in traps. It comprises experiments with electrons and positrons, protons and antiprotons, antimatter and highly charged ions, together with corresponding theoretical background. Such investigations represent stringent tests of quantum electrodynamics and the Standard model, antiparticle and antimatter research, test of fundamental symmetries, constants, and their possible variations with time and space. They are key to various aspects within metrology such as mass measurements and time standards, as well as promising to further developments in quantum information processing. The reader obtains a valuable source of information suited for beginners and experts with an interest in fundamental studies using particle traps.

  5. Fatigue tests on aluminium bridges

    NARCIS (Netherlands)

    Maljaars, J.; Soetens, F.; Straalen, IJ.J. van

    2004-01-01

    Traffic bridges are subjected to variable loads and should therefore be checked on fatigue. Especially low weight materials, like aluminium, are sensitive to fatigue, because the variable load is a substantial part of the total load. This paper shows the structural design of an aluminium bridge load

  6. Fatigue tests on aluminium bridges

    NARCIS (Netherlands)

    Maljaars, J.; Soetens, F.; Straalen, IJ.J. van

    2005-01-01

    Traffic bridges are subjected to variable loads and should therefore be checked on fatigue. Especially low weight materials, like aluminium, are sensitive to fatigue, because the variable load is a substantial part of the total load. This paper shows the structural design of an aluminium bridge load

  7. London Bridge Is Shaking Funny

    Institute of Scientific and Technical Information of China (English)

    1995-01-01

    Bridges generally don’t fall down without warning;they crack first. Searching for cracks is a tedious business,though, and bridge inspectors bave been known to miss them. Charles Farrar,a civil engineer at Los Alamos Na-

  8. Astrophysical probes of fundamental physics

    Energy Technology Data Exchange (ETDEWEB)

    Martins, C.J.A.P. [Centro de Astrofisica, Universidade do Porto, Rua das Estrelas, 4150-762 Porto (Portugal); DAMTP, University of Cambridge, Wilberforce Road, Cambridge CB3 0WA (United Kingdom)

    2009-10-15

    I review the motivation for varying fundamental couplings and discuss how these measurements can be used to constrain fundamental physics scenarios that would otherwise be inaccessible to experiment. I highlight the current controversial evidence for varying couplings and present some new results. Finally I focus on the relation between varying couplings and dark energy, and explain how varying coupling measurements might be used to probe the nature of dark energy, with some advantages over standard methods. In particular I discuss what can be achieved with future spectrographs such as ESPRESSO and CODEX.

  9. The fundamentals of mathematical analysis

    CERN Document Server

    Fikhtengol'ts, G M

    1965-01-01

    The Fundamentals of Mathematical Analysis, Volume 1 is a textbook that provides a systematic and rigorous treatment of the fundamentals of mathematical analysis. Emphasis is placed on the concept of limit which plays a principal role in mathematical analysis. Examples of the application of mathematical analysis to geometry, mechanics, physics, and engineering are given. This volume is comprised of 14 chapters and begins with a discussion on real numbers, their properties and applications, and arithmetical operations over real numbers. The reader is then introduced to the concept of function, i

  10. RFID design fundamentals and applications

    CERN Document Server

    Lozano-Nieto, Albert

    2010-01-01

    RFID is an increasingly pervasive tool that is now used in a wide range of fields. It is employed to substantiate adherence to food preservation and safety standards, combat the circulation of counterfeit pharmaceuticals, and verify authenticity and history of critical parts used in aircraft and other machinery-and these are just a few of its uses. Goes beyond deployment, focusing on exactly how RFID actually worksRFID Design Fundamentals and Applications systematically explores the fundamental principles involved in the design and characterization of RFID technologies. The RFID market is expl

  11. Fundamentals of multicore software development

    CERN Document Server

    Pankratius, Victor; Tichy, Walter F

    2011-01-01

    With multicore processors now in every computer, server, and embedded device, the need for cost-effective, reliable parallel software has never been greater. By explaining key aspects of multicore programming, Fundamentals of Multicore Software Development helps software engineers understand parallel programming and master the multicore challenge. Accessible to newcomers to the field, the book captures the state of the art of multicore programming in computer science. It covers the fundamentals of multicore hardware, parallel design patterns, and parallel programming in C++, .NET, and Java. It

  12. Fundamental Research and Developing Countries

    CERN Document Server

    Narison, Stéphan

    2002-01-01

    In the first part of this report, I discuss the sociological role of fundamental research in Developing Countries (DC) and how to realize this program. In the second part, I give a brief and elementary introduction to the field of high-energy physics (HEP), accessible to a large audience not necessary physicists. The aim of this report is to make politicians and financial backers aware on the long-term usefulness of fundamental research in DC and on the possible globalisation of HEP and, in general, of science.

  13. Fundamental approach to discrete mathematics

    CERN Document Server

    Acharjya, DP

    2009-01-01

    About the Book: The book `Fundamental Approach to Discrete Mathematics` is a required part of pursuing a computer science degree at most universities. It provides in-depth knowledge to the subject for beginners and stimulates further interest in the topic. The salient features of this book include: Strong coverage of key topics involving recurrence relation, combinatorics, Boolean algebra, graph theory and fuzzy set theory. Algorithms and examples integrated throughout the book to bring clarity to the fundamental concepts. Each concept and definition is followed by thoughtful examples.

  14. Development of cooperative system bridges

    Institute of Scientific and Technical Information of China (English)

    ZHANG Zhe; WAN Qi-bai; SHI Lei

    2008-01-01

    Cooperative system bridges comprise several basic structures that act jointly to improve structural characteristics. We delved into the historical development of cooperative system bridges. Cooperative systems are classified as different-load cooperative systems and same-load cooperative systems by distinguishing the modes of load distribution. For different-load cooperation, individual basic structures are at different positions in the direction along bridge axis and carry the loads separately. While for same-load cooperation, all basic structures overlap in geometrical locations and support the entire loads conjointly. The choosing of span ratios between basic structures, the design of connections of different-load cooperative systems were discussed as well as optimizations of relative rigidity for same-load cooperative systems which greatly influence structural characteristics. The general situation and several structural measurements of several cooperative bridges were demonstrated. This information can assist engineers in developing their concepts in cooperative systems and can lead to more efficient and economical cooperative bridges.

  15. Advances in tomography: probing the molecular architecture of cells.

    Science.gov (United States)

    Fridman, Karen; Mader, Asaf; Zwerger, Monika; Elia, Natalie; Medalia, Ohad

    2012-11-01

    Visualizing the dynamic molecular architecture of cells is instrumental for answering fundamental questions in cellular and structural biology. Although modern microscopy techniques, including fluorescence and conventional electron microscopy, have allowed us to gain insights into the molecular organization of cells, they are limited in their ability to visualize multicomponent complexes in their native environment. Cryo-electron tomography (cryo-ET) allows cells, and the macromolecular assemblies contained within, to be reconstructed in situ, at a resolution of 2-6 nm. By combining cryo-ET with super-resolution fluorescence microscopy approaches, it should be possible to localize proteins with high precision inside cells and so elucidate a more realistic view of cellular processes. Thus, cryo-ET may bridge the resolution gap between cellular and structural biology.

  16. The cross-bridge spring: can cool muscles store elastic energy?

    Science.gov (United States)

    George, N T; Irving, T C; Williams, C D; Daniel, T L

    2013-06-07

    Muscles not only generate force. They may act as springs, providing energy storage to drive locomotion. Although extensible myofilaments are implicated as sites of energy storage, we show that intramuscular temperature gradients may enable molecular motors (cross-bridges) to store elastic strain energy. By using time-resolved small-angle x-ray diffraction paired with in situ measurements of mechanical energy exchange in flight muscles of Manduca sexta, we produced high-speed movies of x-ray equatorial reflections, indicating cross-bridge association with myofilaments. A temperature gradient within the flight muscle leads to lower cross-bridge cycling in the cooler regions. Those cross-bridges could elastically return energy at the extrema of muscle lengthening and shortening, helping drive cyclic wing motions. These results suggest that cross-bridges can perform functions other than contraction, acting as molecular links for elastic energy storage.

  17. Linguistic Barriers and Bridges

    DEFF Research Database (Denmark)

    Thuesen, Frederik

    2016-01-01

    and intercultural communication, this article analyses interviews with 31 employees from two highly ethnically diverse Danish workplaces. The article shows how linguistic barriers such as different levels of majority language competence and their consequent misunderstandings breed mistrust and hostility, whilst......The influence of language on social capital in low-skill and ethnically diverse workplaces has thus far received very limited attention within the sociology of work. As the ethnically diverse workplace is an important social space for the construction of social relations bridging different social...... groups, the sociology of work needs to develop a better understanding of the way in which linguistic diversity influences the formation of social capital, i.e. resources such as the trust and reciprocity inherent in social relations in such workplaces. Drawing on theories about intergroup contact...

  18. Cascaded resonant bridge converters

    Science.gov (United States)

    Stuart, Thomas A. (Inventor)

    1989-01-01

    A converter for converting a low voltage direct current power source to a higher voltage, high frequency alternating current output for use in an electrical system where it is desired to use low weight cables and other circuit elements. The converter has a first stage series resonant (Schwarz) converter which converts the direct current power source to an alternating current by means of switching elements that are operated by a variable frequency voltage regulator, a transformer to step up the voltage of the alternating current, and a rectifier bridge to convert the alternating current to a direct current first stage output. The converter further has a second stage series resonant (Schwarz) converter which is connected in series to the first stage converter to receive its direct current output and convert it to a second stage high frequency alternating current output by means of switching elements that are operated by a fixed frequency oscillator. The voltage of the second stage output is controlled at a relatively constant value by controlling the first stage output voltage, which is accomplished by controlling the frequency of the first stage variable frequency voltage controller in response to second stage voltage. Fault tolerance in the event of a load short circuit is provided by making the operation of the first stage variable frequency voltage controller responsive to first and second stage current limiting devices. The second stage output is connected to a rectifier bridge whose output is connected to the input of the second stage to provide good regulation of output voltage wave form at low system loads.

  19. Fundamentals: IVC and Computer Science

    NARCIS (Netherlands)

    Gozalvez, Javier; Haerri, Jerome; Hartenstein, Hannes; Heijenk, Gerhard J.; Kargl, Frank; Petit, Jonathan; Scheuermann, Björn; Tieler, Tessa; Altintas, O.; Dressler, F.; Hartenstein, H.; Tonguz, O.K.

    The working group on “Fundamentals: IVC and Computer Science‿ discussed the lasting value of achieved research results as well as potential future directions in the field of inter- vehicular communication. Two major themes ‘with variations’ were the dependence on a specific technology (particularly

  20. Fundamentals: IVC and Computer Science

    NARCIS (Netherlands)

    Gozalvez, Javier; Haerri, Jerome; Hartenstein, Hannes; Heijenk, Gerhard J.; Kargl, Frank; Petit, Jonathan; Scheuermann, Björn; Tieler, Tessa; Altintas, O.; Dressler, F.; Hartenstein, H.; Tonguz, O.K.

    2013-01-01

    The working group on “Fundamentals: IVC and Computer Science‿ discussed the lasting value of achieved research results as well as potential future directions in the field of inter- vehicular communication. Two major themes ‘with variations’ were the dependence on a specific technology (particularly

  1. Brake Fundamentals. Automotive Articulation Project.

    Science.gov (United States)

    Cunningham, Larry; And Others

    Designed for secondary and postsecondary auto mechanics programs, this curriculum guide contains learning exercises in seven areas: (1) brake fundamentals; (2) brake lines, fluid, and hoses; (3) drum brakes; (4) disc brake system and service; (5) master cylinder, power boost, and control valves; (6) parking brakes; and (7) trouble shooting. Each…

  2. Calorimetry fundamentals, instrumentation and applications

    CERN Document Server

    Sarge, Stefan M; Hemminger, Wolfgang

    2014-01-01

    Clearly divided into three parts, this practical book begins by dealing with all fundamental aspects of calorimetry. The second part looks at the equipment used and new developments. The third and final section provides measurement guidelines in order to obtain the best results. The result is optimized knowledge for users of this technique, supplemented with practical tips and tricks.

  3. Fundamentals of EU VAT law

    NARCIS (Netherlands)

    van Doesum, A.; van Kesteren, H.W.M.; van Norden, G.J.

    2016-01-01

    Fundamentals of EU VAT Law aims at providing a deep insight into the systematics, the functioning and the principles of the European Value Added Tax (VAT) system. VAT is responsible for generating approximately EUR 903 billion per year in tax revenues across the European Union – revenues that play a

  4. Fundamentals of Microelectronics Processing (VLSI).

    Science.gov (United States)

    Takoudis, Christos G.

    1987-01-01

    Describes a 15-week course in the fundamentals of microelectronics processing in chemical engineering, which emphasizes the use of very large scale integration (VLSI). Provides a listing of the topics covered in the course outline, along with a sample of some of the final projects done by students. (TW)

  5. Fundamentals of Welding. Teacher Edition.

    Science.gov (United States)

    Fortney, Clarence; And Others

    These instructional materials assist teachers in improving instruction on the fundamentals of welding. The following introductory information is included: use of this publication; competency profile; instructional/task analysis; related academic and workplace skills list; tools, materials, and equipment list; and 27 references. Seven units of…

  6. Status of Fundamental Physics Program

    Science.gov (United States)

    Lee, Mark C.

    2003-01-01

    Update of the Fundamental Physics Program. JEM/EF Slip. 2 years delay. Reduced budget. Community support and advocacy led by Professor Nick Bigelow. Reprogramming led by Fred O Callaghan/JPL team. LTMPF M1 mission (DYNAMX and SUMO). PARCS. Carrier re baselined on JEM/EF.

  7. Different Variants of Fundamental Portfolio

    Directory of Open Access Journals (Sweden)

    Tarczyński Waldemar

    2014-06-01

    Full Text Available The paper proposes the fundamental portfolio of securities. This portfolio is an alternative for the classic Markowitz model, which combines fundamental analysis with portfolio analysis. The method’s main idea is based on the use of the TMAI1 synthetic measure and, in limiting conditions, the use of risk and the portfolio’s rate of return in the objective function. Different variants of fundamental portfolio have been considered under an empirical study. The effectiveness of the proposed solutions has been related to the classic portfolio constructed with the help of the Markowitz model and the WIG20 market index’s rate of return. All portfolios were constructed with data on rates of return for 2005. Their effectiveness in 2006- 2013 was then evaluated. The studied period comprises the end of the bull market, the 2007-2009 crisis, the 2010 bull market and the 2011 crisis. This allows for the evaluation of the solutions’ flexibility in various extreme situations. For the construction of the fundamental portfolio’s objective function and the TMAI, the study made use of financial and economic data on selected indicators retrieved from Notoria Serwis for 2005.

  8. Fundamental stellar properties from asteroseismology

    DEFF Research Database (Denmark)

    Silva Aguirre, V.; Casagrande, L.; Miglio, A.

    2013-01-01

    Accurate characterization of stellar populations is of prime importance to correctly understand the formation and evolution process of our Galaxy. The field of asteroseismology has been particularly successful in such an endeavor providing fundamental parameters for large samples of stars in diff...

  9. Fundamentals of Biomass pellet production

    DEFF Research Database (Denmark)

    Holm, Jens Kai; Henriksen, Ulrik Birk; Hustad, Johan Einar

    2005-01-01

    Pelletizing experiments along with modelling of the pelletizing process have been carried out with the aim of understanding the fundamental physico-chemical mechanisms that control the quality and durability of biomass pellets. A small-scale California pellet mill (25 kg/h) located with the Biomass...

  10. Energy informatics: Fundamentals and standardization

    Directory of Open Access Journals (Sweden)

    Biyao Huang

    2017-06-01

    Full Text Available Based on international standardization and power utility practices, this paper presents a preliminary and systematic study on the field of energy informatics and analyzes boundary expansion of information and energy system, and the convergence of energy system and ICT. A comprehensive introduction of the fundamentals and standardization of energy informatics is provided, and several key open issues are identified.

  11. Biological Computing Fundamentals and Futures

    OpenAIRE

    Akula, Balaji; Cusick, James

    2009-01-01

    The fields of computing and biology have begun to cross paths in new ways. In this paper a review of the current research in biological computing is presented. Fundamental concepts are introduced and these foundational elements are explored to discuss the possibilities of a new computing paradigm. We assume the reader to possess a basic knowledge of Biology and Computer Science

  12. Fundamentals: IVC and computer science

    NARCIS (Netherlands)

    Gozalvez, Javier; Haerri, Jerome; Hartenstein, Hannes; Heijenk, Geert; Kargl, Frank; Petit, Jonathan; Scheuermann, Björn; Tieler, Tessa; Altintas, O.; Dressler, F.; Hartenstein, H.; Tonguz, O.K.

    2013-01-01

    The working group on “Fundamentals: IVC and Computer Science” discussed the lasting value of achieved research results as well as potential future directions in the field of inter- vehicular communication. Two major themes ‘with variations’ were the dependence on a specific technology (particularly

  13. Bridging Physics and Biology Teaching through Modeling

    CERN Document Server

    Hoskinson, Anne-Marie; Zwickl, Benjamin M; Hinko, Kathleen; Caballero, Marcos D

    2013-01-01

    As the frontiers of biology become increasingly interdisciplinary, the physics education community has engaged in ongoing efforts to make physics classes more relevant to life sciences majors. These efforts are complicated by the many apparent differences between these fields, including the types of systems that each studies, the behavior of those systems, the kinds of measurements that each makes, and the role of mathematics in each field. Nonetheless, physics and biology are both fundamental sciences that rely on observations and measurements to construct models of the natural world. In the present theoretical article, we propose that efforts to bridge the teaching of these two disciplines must emphasize shared scientific practices, particularly scientific modeling. We define modeling using language common to both disciplines and highlight how an understanding of the modeling process can help reconcile apparent differences between physics and biology. We elaborate how models can be used for explanatory, pre...

  14. Torsional instability in suspension bridges: The Tacoma Narrows Bridge case

    Science.gov (United States)

    Arioli, Gianni; Gazzola, Filippo

    2017-01-01

    All attempts of aeroelastic explanations for the torsional instability of suspension bridges have been somehow criticised and none of them is unanimously accepted by the scientific community. We suggest a new nonlinear model for a suspension bridge and we perform numerical experiments with the parameters corresponding to the collapsed Tacoma Narrows Bridge. We show that the thresholds of instability are in line with those observed the day of the collapse. Our analysis enables us to give a new explanation for the torsional instability, only based on the nonlinear behavior of the structure.

  15. Ultrafast vibrational energy relaxation of the water bridge.

    Science.gov (United States)

    Piatkowski, Lukasz; Wexler, Adam D; Fuchs, Elmar C; Schoenmaker, Hinco; Bakker, Huib J

    2012-05-14

    We report the energy relaxation of the OH stretch vibration of HDO molecules contained in an HDO:D(2)O water bridge using femtosecond mid-infrared pump-probe spectroscopy. We found that the vibrational lifetime is shorter (~630 ± 50 fs) than for HDO molecules in bulk HDO:D(2)O (~740 ± 40 fs). In contrast, the thermalization dynamics following the vibrational relaxation are much slower (~1.5 ± 0.4 ps) than in bulk HDO:D(2)O (~250 ± 90 fs). These differences in energy relaxation dynamics strongly indicate that the water bridge and bulk water differ on a molecular scale.

  16. Vectorial optical fields fundamentals and applications

    CERN Document Server

    2014-01-01

    Polarization is a vector nature of light that plays an important role in optical science and engineering. While existing textbook treatments of light assume beams with spatially homogeneous polarization, there is an increasing interest in vectorial optical fields with spatially engineered states of polarization. New effects and phenomena have been predicted and observed for light beams with these unconventional polarization states. This edited review volume aims to provide a comprehensive overview and summarize the latest developments in this important emerging field of optics. This book will cover the fundamentals including mathematical and physical descriptions, experimental generation, manipulation, focusing, propagation, and the applications of the engineered vectorial optical fields in focal field engineering, plasmonic focusing and optical antenna, single molecular imaging, optical tweezers/trapping, as well as optical measurements and instrumentations. Readership: Students, professionals, post-graduat...

  17. Fundamental limits of optical force and torque

    Science.gov (United States)

    Rahimzadegan, A.; Alaee, R.; Fernandez-Corbaton, I.; Rockstuhl, C.

    2017-01-01

    Optical force and torque provide unprecedented control on the spatial motion of small particles. A valid scientific question, that has many practical implications, concerns the existence of fundamental upper bounds for the achievable force and torque exerted by a plane wave illumination with a given intensity. Here, while studying isotropic particles, we show that different light-matter interaction channels contribute to the exerted force and torque, and analytically derive upper bounds for each of the contributions. Specific examples for particles that achieve those upper bounds are provided. We study how and to which extent different contributions can add up to result in the maximum optical force and torque. Our insights are important for applications ranging from molecular sorting, particle manipulation, and nanorobotics up to ambitious projects such as laser-propelled spaceships.

  18. Fundamental Limits of Optical Force and Torque

    CERN Document Server

    Rahimzadegan, Aso; Fernandez-Corbaton, Ivan; Rockstuhl, Carsten

    2016-01-01

    Optical force and torque provide unprecedented control on the spatial motion of small particles. A valid scientific question, that has many practical implications, concerns the existence of fundamental upper bounds for the achievable force and torque exerted by a plane wave illumination with a given intensity. Here, while studying isotropic particles, we show that different light-matter interaction channels contribute to the exerted force and torque and analytically derive upper bounds for each of the contributions. Specific examples for particles that achieve those upper bounds are provided. We study how and to which extent different contributions can be made to add up. Our insights are important for applications ranging from molecular sorting, particle manipulation, nanorobotics up to ambitious projects such as laser-propelled spaceships.

  19. National Bridge Inventory - National Geospatial Data Asset (NGDA) Bridges

    Data.gov (United States)

    Department of Transportation — The NBI (NTAD 2015) is a collection of information (database) describing the more than 610,000 of the Nation's bridges located on public roads, including Interstate...

  20. Bridge Creek IMW database - Bridge Creek Restoration and Monitoring Project

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The incised and degraded habitat of Bridge Creek is thought to be limiting a population of ESA-listed steelhead (Oncorhynchus mykiss). A logical restoration approach...

  1. Reliability Assessment of Concrete Bridges

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle; Middleton, C. R.

    This paper is partly based on research performed for the Highways Agency, London, UK under the project DPU/9/44 "Revision of Bridge Assessment Rules Based on Whole Life Performance: concrete bridges". It contains the details of a methodology which can be used to generate Whole Life (WL) reliability...... profiles. These WL reliability profiles may be used to establish revised rules for concrete bridges. This paper is to some extend based on Thoft-Christensen et. al. [1996], Thoft-Christensen [1996] et. al. and Thoft-Christensen [1996]....

  2. General design of Sutong Bridge

    Institute of Scientific and Technical Information of China (English)

    Zhang Xigang; Yuan Hong; Pei Minshan; Dai Jie; Xu Lin

    2009-01-01

    The main span of Sutong Bridge is a double-pylon, double-plane cable-stayed bridge with steel box girder, which has the world's longest central span of 1 088 m within cable-stayed bridges. To overcome problems caused by severe meteorological conditions, perplexing hydrological conditions, deep buried bedrock and higher navigation level, many new technics and methods were created. Keys including structural system, steel box girder, stayed cable, tower, pier, tower foundation, collision avoidance system, wind-resistance, seismic-resistance, structural nonlinear response and structural static stability were presented individually in this paper.

  3. Dimeric [Mo2 S12 ](2-) Cluster: A Molecular Analogue of MoS2 Edges for Superior Hydrogen-Evolution Electrocatalysis.

    Science.gov (United States)

    Huang, Zhongjie; Luo, Wenjia; Ma, Lu; Yu, Mingzhe; Ren, Xiaodi; He, Mingfu; Polen, Shane; Click, Kevin; Garrett, Benjamin; Lu, Jun; Amine, Khalil; Hadad, Christopher; Chen, Weilin; Asthagiri, Aravind; Wu, Yiying

    2015-12-07

    Proton reduction is one of the most fundamental and important reactions in nature. MoS2 edges have been identified as the active sites for hydrogen evolution reaction (HER) electrocatalysis. Designing molecular mimics of MoS2 edge sites is an attractive strategy to understand the underlying catalytic mechanism of different edge sites and improve their activities. Herein we report a dimeric molecular analogue [Mo2 S12 ](2-) , as the smallest unit possessing both the terminal and bridging disulfide ligands. Our electrochemical tests show that [Mo2 S12 ](2-) is a superior heterogeneous HER catalyst under acidic conditions. Computations suggest that the bridging disulfide ligand of [Mo2 S12 ](2-) exhibits a hydrogen adsorption free energy near zero (-0.05 eV). This work helps shed light on the rational design of HER catalysts and biomimetics of hydrogen-evolving enzymes.

  4. Dimeric [Mo₂S₁₂]²⁻ Cluster: A Molecular Analogue of MoS₂ Edges for Superior Hydrogen-Evolution Electrocatalysis

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Zhongjie; Luo, Wenjia; Ma, Lu; Yu, Mingzhe; Ren, Xiaodi; He, Mingfu; Polen, Shan; Click, Kevin; Garrett, Benjamin R.; Lu, Jun; Amine, Khalil

    2015-12-07

    Proton reduction is one of the most fundamental and important reactions in nature. MoS2 edges have been identified as the active sites for hydrogen evolution reaction (HER) electrocatalysis. Designing molecular mimics of MoS2 edge sites is an attractive strategy to understand the underlying catalytic mechanism of different edge sites and improve their activities. Herein we report a dimeric molecular analogue [Mo₂S₁₂]²⁻, as the smallest unit possessing both the terminal and bridging disulfide ligands. Our electrochemical tests show that [Mo₂S₁₂]²⁻ is a superior heterogeneous HER catalyst under acidic conditions. Computations suggest that the bridging disulfide ligand of [Mo₂S₁₂]²⁻ exhibits a hydrogen adsorption free energy near zero (-0.05eV). This work helps shed light on the rational design of HER catalysts and biomimetics of hydrogen-evolving enzymes.

  5. Fundamental neutron physics at LANSCE

    Energy Technology Data Exchange (ETDEWEB)

    Greene, G.

    1995-10-01

    Modern neutron sources and science share a common origin in mid-20th-century scientific investigations concerned with the study of the fundamental interactions between elementary particles. Since the time of that common origin, neutron science and the study of elementary particles have evolved into quite disparate disciplines. The neutron became recognized as a powerful tool for studying condensed matter with modern neutron sources being primarily used (and justified) as tools for neutron scattering and materials science research. The study of elementary particles has, of course, led to the development of rather different tools and is now dominated by activities performed at extremely high energies. Notwithstanding this trend, the study of fundamental interactions using neutrons has continued and remains a vigorous activity at many contemporary neutron sources. This research, like neutron scattering research, has benefited enormously by the development of modern high-flux neutron facilities. Future sources, particularly high-power spallation sources, offer exciting possibilities for continuing this research.

  6. THE FUNDAMENTS OF EXPLANATORY CAUSES

    Directory of Open Access Journals (Sweden)

    Lavinia Mihaela VLĂDILĂ

    2015-07-01

    Full Text Available The new Criminal Code in the specter of the legal life the division of causes removing the criminal feature of the offence in explanatory causes and non-attributable causes. This dichotomy is not without legal and factual fundaments and has been subjected to doctrinaire debates even since the period when the Criminal Code of 1969 was still in force. From our perspective, one of the possible legal fundaments of the explanatory causes results from that the offence committed is based on the protection of a right at least equal with the one prejudiced by the action of aggression, salvation, by the legal obligation imposed or by the victim’s consent.

  7. Fundamentals of condensed matter physics

    CERN Document Server

    Cohen, Marvin L

    2016-01-01

    Based on an established course and covering the fundamentals, central areas, and contemporary topics of this diverse field, Fundamentals of Condensed Matter Physics is a much-needed textbook for graduate students. The book begins with an introduction to the modern conceptual models of a solid from the points of view of interacting atoms and elementary excitations. It then provides students with a thorough grounding in electronic structure as a starting point to understand many properties of condensed matter systems - electronic, structural, vibrational, thermal, optical, transport, magnetic and superconductivity - and methods to calculate them. Taking readers through the concepts and techniques, the text gives both theoretically and experimentally inclined students the knowledge needed for research and teaching careers in this field. It features 200 illustrations, 40 worked examples and 150 homework problems for students to test their understanding. Solutions to the problems for instructors are available at w...

  8. Astrophysical Probes of Fundamental Physics

    CERN Document Server

    Martins, C J A P

    2006-01-01

    I review the theoretical motivation for varying fundamental couplings and discuss how these measurements can be used to constrain a number of fundamental physics scenarios that would otherwise be inacessible to experiment. As a case study I will focus on the relation between varying couplings and dark energy, and explain how varying coupling measurements can be used to probe the nature of dark energy, with important advantages over the standard methods. Assuming that the current observational evidence for varying $\\alpha$ and $\\mu$ is correct, a several-sigma detection of dynamical dark energy is feasible within a few years, using currently operational ground-based facilities. With forthcoming instruments like CODEX, a high-accuracy reconstruction of the equation of state may be possible all the way up to redshift $z\\sim4$.

  9. Fundamentals of estuarine physical oceanography

    CERN Document Server

    Bruner de Miranda, Luiz; Kjerfve, Björn; Castro Filho, Belmiro Mendes de

    2017-01-01

    This book provides an introduction to the complex system functions, variability and human interference in ecosystem between the continent and the ocean. It focuses on circulation, transport and mixing of estuarine and coastal water masses, which is ultimately related to an understanding of the hydrographic and hydrodynamic characteristics (salinity, temperature, density and circulation), mixing processes (advection and diffusion), transport timescales such as the residence time and the exposure time. In the area of physical oceanography, experiments using these water bodies as a natural laboratory and interpreting their circulation and mixing processes using theoretical and semi-theoretical knowledge are of fundamental importance. Small-scale physical models may also be used together with analytical and numerical models. The book highlights the fact that research and theory are interactive, and the results provide the fundamentals for the development of the estuarine research.

  10. Fundamentals of electronic systems design

    CERN Document Server

    Lienig, Jens

    2017-01-01

    This textbook covers the design of electronic systems from the ground up, from drawing and CAD essentials to recycling requirements. Chapter by chapter, it deals with the challenges any modern system designer faces: the design process and its fundamentals, such as technical drawings and CAD, electronic system levels, assembly and packaging issues and appliance protection classes, reliability analysis, thermal management and cooling, electromagnetic compatibility (EMC), all the way to recycling requirements and environmental-friendly design principles. Enables readers to face various challenges of designing electronic systems, including coverage from various engineering disciplines; Written to be accessible to readers of varying backgrounds; Uses illustrations extensively to reinforce fundamental concepts; Organized to follow essential design process, although chapters are self-contained and can be read in any order.

  11. Unified Theory of Fundamental Interactions

    Institute of Scientific and Technical Information of China (English)

    WU Ning

    2003-01-01

    Based on local gauge invariance, four different kinds of fundamental interactions in nature are unified in a theory which has SU(3)C( )SU SU(2)L( )U(1)( )s Gravitational Gauge Group gauge symmetry. In this approach,gravitational field, like electromagnetic field, intermediate gauge field, and gluon field, is represented by gauge potential.Four kinds of fundamental interactions are formulated in the similar manner, and therefore can be unified in a direct or semi-direct product group. The model discussed in this paper is a renormalizable quantum model and can be regarded as an extension of the standard model to gravitational interactions, so it can be used to study quantum effects of gravitational interactions.

  12. Composing Europe's Fundamental Rights Area

    DEFF Research Database (Denmark)

    Storgaard, Louise Halleskov

    2015-01-01

    The article offers a perspective on how the objective of a strong and coherent European protection standard pursued by the fundamental rights amendments of the Lisbon Treaty can be achieved, as it proposes a discursive pluralistic framework to understand and guide the relationship between the EU...... Court of Justice and the European Court of Human Rights. It is argued that this framework – which is suggested as an alternative to the EU law approach to the Strasbourg system applied by the CJEU in Opinion 2/13 and its Charter-based case law – has a firm doctrinal, case law and normative basis....... The article ends by addressing three of the most pertinent challenges to European fundamental rights protection through the prism of the proposed framework....

  13. Modern measurements fundamentals and applications

    CERN Document Server

    Petri, D; Carbone, P; Catelani, M

    2015-01-01

    This book explores the modern role of measurement science for both the technically most advanced applications and in everyday and will help readers gain the necessary skills to specialize their knowledge for a specific field in measurement. Modern Measurements is divided into two parts. Part I (Fundamentals) presents a model of the modern measurement activity and the already recalled fundamental bricks. It starts with a general description that introduces these bricks and the uncertainty concept. The next chapters provide an overview of these bricks and finishes (Chapter 7) with a more general and complex model that encompasses both traditional (hard) measurements and (soft) measurements, aimed at quantifying non-physical concepts, such as quality, satisfaction, comfort, etc. Part II (Applications) is aimed at showing how the concepts presented in Part I can be usefully applied to design and implement measurements in some very impor ant and broad fields. The editors cover System Identification (Chapter 8...

  14. Fundamentals of plastic optical fibers

    CERN Document Server

    Koike, Yasuhiro

    2014-01-01

    Polymer photonics is an interdisciplinary field which demands excellence both in optics (photonics) and materials science (polymer). However, theses disciplines have developed independently, and therefore the demand for a comprehensive work featuring the fundamentals of photonic polymers is greater than ever.This volume focuses on Polymer Optical Fiber and their applications. The first part of the book introduces typical optical fibers according to their classifications of material, propagating mode, and structure. Optical properties, the high bandwidth POF and transmission loss are discussed,

  15. Fundamental Scaling Laws in Nanophotonics

    OpenAIRE

    Ke Liu; Shuai Sun; Arka Majumdar; Volker J. Sorger

    2016-01-01

    The success of information technology has clearly demonstrated that miniaturization often leads to unprecedented performance, and unanticipated applications. This hypothesis of “smaller-is-better” has motivated optical engineers to build various nanophotonic devices, although an understanding leading to fundamental scaling behavior for this new class of devices is missing. Here we analyze scaling laws for optoelectronic devices operating at micro and nanometer length-scale. We show that optoe...

  16. Variation of fundamental constants: theory

    Science.gov (United States)

    Flambaum, Victor

    2008-05-01

    Theories unifying gravity with other interactions suggest temporal and spatial variation of the fundamental ``constants'' in expanding Universe. There are some hints for the variation of different fundamental constants in quasar absorption spectra and Big Bang nucleosynthesis data. A large number of publications (including atomic clocks) report limits on the variations. We want to study the variation of the main dimensionless parameters of the Standard Model: 1. Fine structure constant alpha (combination of speed of light, electron charge and Plank constant). 2. Ratio of the strong interaction scale (LambdaQCD) to a fundamental mass like electron mass or quark mass which are proportional to Higgs vacuum expectation value. The proton mass is propotional to LambdaQCD, therefore, the proton-to-electron mass ratio comes into this second category. We performed necessary atomic, nuclear and QCD calculations needed to study variation of the fundamental constants using the Big Bang Nucleosynthsis, quasar spectra, Oklo natural nuclear reactor and atomic clock data. The relative effects of the variation may be enhanced in transitions between narrow close levels in atoms, molecules and nuclei. If one will study an enhanced effect, the relative value of systematic effects (which are not enhanced) may be much smaller. Note also that the absolute magnitude of the variation effects in nuclei (e.g. in very narrow 7 eV transition in 229Th) may be 5 orders of magnitude larger than in atoms. A different possibility of enhancement comes from the inversion transitions in molecules where splitting between the levels is due to the quantum tunneling amplitude which has strong, exponential dependence on the electron to proton mass ratio. Our study of NH3 quasar spectra has already given the best limit on the variation of electron to proton mass ratio.

  17. Fundamental Composite (Goldstone) Higgs Dynamics

    DEFF Research Database (Denmark)

    Cacciapaglia, G.; Sannino, Francesco

    2014-01-01

    We provide a unified description, both at the effective and fundamental Lagrangian level, of models of composite Higgs dynamics where the Higgs itself can emerge, depending on the way the electroweak symmetry is embedded, either as a pseudo-Goldstone boson or as a massive excitation of the conden......We provide a unified description, both at the effective and fundamental Lagrangian level, of models of composite Higgs dynamics where the Higgs itself can emerge, depending on the way the electroweak symmetry is embedded, either as a pseudo-Goldstone boson or as a massive excitation...... of the condensate. We show that, in general, these states mix with repercussions on the electroweak physics and phenomenology. Our results will help clarify the main differences, similarities, benefits and shortcomings of the different ways one can naturally realize a composite nature of the electroweak sector...... transforming according to the fundamental representation of the gauge group. This minimal choice enables us to use recent first principle lattice results to make the first predictions for the massive spectrum for models of composite (Goldstone) Higgs dynamics. These results are of the upmost relevance to guide...

  18. Novel Silver Cobaltacarborane Complexes with a Linearly Bridging Halide

    Energy Technology Data Exchange (ETDEWEB)

    Park, Hyun Seo; Bae, Hye Jin; Do, Youngkyu [KAIST, Daejeon (Korea, Republic of); Park, Youngwhan [LG Chem/Research Park, Daejeon (Korea, Republic of); Go, Min Jeong; Lee, Junseong [Chonnam National Univ., Gwangju (Korea, Republic of)

    2013-10-15

    The structural versatility of halides mainly originates from their coordinating abilities of adopting a bridging bond between two or more metal atoms, as well as a terminal bond. Moreover, a halide bridging bond angle is so flexible that thermodynamic stability can be endowed with proper geometry, which conceptually varies from acute to right, obtuse, and linear. In spite of innumerable reports on molecular metal halides, examples of the linearly bridging fashion are very scarce. The reason for the rarity of the linear M. X. M arrangement can be easily explained by the VSEPR (Valence Shell Electron Pair Repulsion) concept. The linear M. X. M formation has only been achieved by adopting a macrocyclic chelate ligand, which is structurally demanding, so that the VSEPR repulsions among lone-pair electrons on the halide atom could be overcome.

  19. The Higgs Bridge

    CERN Document Server

    Allen, Roland E

    2013-01-01

    The particle recently discovered at the Large Hadron Collider near Geneva is almost certainly a Higgs boson, the long-sought completion of the Standard Model of particle physics. But this discovery, an achievement by more than six thousand scientists (including students), is actually much more than a mere capstone of the Standard Model. It instead represents a bridge from the Standard Model to exciting discoveries of the future, at higher energies or in other experiments, and to the properties of matter at very low temperatures. The mere existence of a particle with zero spin implies a need for new physics, with the most likely candidate being supersymmetry, which requires that every known particle has a superpartner yet to be discovered. And phenomena similar to the Higgs are seen in superconducting metals and superfluid gases at low temperatures, which extend down to a millionth or even a billionth of a degree Kelvin. So the discovery of a Higgs boson has a central place in our attempts both to achieve a tr...

  20. Mineral bridges in nacre revisited

    CERN Document Server

    Checa, Antonio G; Willinger, Marc-Georg

    2012-01-01

    We confirm with high-resolution techniques the existence of mineral bridges between superposed nacre tablets. In the towered nacre of both gastropods and the cephalopod Nautilus there are large bridges aligned along the tower axes, corresponding to gaps (150-200 nm) in the interlamellar membranes. Gaps are produced by the interaction of the nascent tablets with a surface membrane that covers the nacre compartment. In the terraced nacre of bivalves bridges associated with elongated gaps in the interlamellar membrane (> 100 nm) have mainly been found at or close to the edges of superposed parental tablets. To explain this placement, we hypothesize that the interlamellar membrane breaks due to differences in osmotic pressure across it when the interlamellar space below becomes reduced at an advanced stage of calcification. In no cases are the minor connections between superimposed tablets (< 60 nm), earlier reported to be mineral bridges, found to be such.

  1. The stories of two bridges in Ghana

    DEFF Research Database (Denmark)

    Andreasen, Jørgen

    2004-01-01

    Public participation in bridge building was promoted by un habitat in the village of Mankrong. The neighbouring village did not participate in the construction of their bridge. The first flooding washed the second bridge down while the "participative bridge" stood up....

  2. SURGERY OF SYMPTOMATIC MYOCARDIAL BRIDGING

    Directory of Open Access Journals (Sweden)

    N. Maghamipour N. Safaei

    2007-06-01

    Full Text Available Myocardial bridging with systolic compression of the left anterior descending coronary artery (LAD may be associated with myocardial ischemia. In symptomatic myocardial bridging unresponsive to medical treatment, surgical unroofing of the left LAD can be performed. Little information is available about the long-term prognosis of patients with this coronary anomaly after the surgical unroofing, so we decided to evaluate the result of this operation. A total of 26 patients underwent surgical unroofing of myocardial bridging. Patients had a myocardial bridge of at least 3 cm in length in the middle of LAD and with more than 70% compression during systole. Unroofing was performed with cardiopulmonary bypass in 16 and with off pump technique in 10 patients. In 6 patients repeat angiographies for control of myotomy were done. In one of them a nonsignificant 20% narrowing was seen. Postoperative scintigraphic and angiographic studies demonstrated restoration of coronary flow and myocardial perfusion without residual myocardial bridges under beta-stimulation in 24 patients. Two patients had residual narrowing. With off pump technique, 1 patient had perforation of the right ventricle and 1 patient underwent reoperation because of incomplete unroofing during the first operation. None of the patients with cardiopulmonary bypass technique had residual chest pain or other complications. Surgical unroofing of myocardial bridging with the aid of cardiopulmonary bypass is a safe and easy procedure with low operative risk and with excellent functional results.

  3. Food-Bridging: A New Network Construction to Unveil the Principles of Cooking

    Directory of Open Access Journals (Sweden)

    Tiago Simas

    2017-06-01

    Full Text Available In this manuscript, we propose, analyze, and discuss a possible new principle behind traditional cuisine: the Food-bridging hypothesis and its comparison with the food-pairing hypothesis using the same dataset and graphical models employed in the food-pairing study by Ahn et al. (2011. The Food-bridging hypothesis assumes that if two ingredients do not share a strong molecular or empirical affinity, they may become affine through a chain of pairwise affinities. That is, in a graphical model as employed by Ahn et al., a chain represents a path that joints the two ingredients, the shortest path represents the strongest pairwise chain of affinities between the two ingredients. Food-pairing and Food-bridging are different hypotheses that may describe possible mechanisms behind the recipes of traditional cuisines. Food-pairing intensifies flavor by mixing ingredients in a recipe with similar chemical compounds, and food-bridging smoothes contrast between ingredients. Both food-pairing and food-bridging are observed in traditional cuisines, as shown in this work. We observed four classes of cuisines according to food-pairing and food-bridging: (1 East Asian cuisines, at one extreme, tend to avoid food-pairing as well as food-bridging; and (4 Latin American cuisines, at the other extreme, follow both principles. For the two middle classes: (2 Southeastern Asian cuisines, avoid food-pairing and follow food-bridging; and (3 Western cuisines, follow food-pairing and avoid food-bridging.

  4. Variation of fundamental constants: theory and observations

    CERN Document Server

    Flambaum, V V

    2007-01-01

    Review of recent works devoted to the variation of the fundamental constants is presented including atomic clocks, quasar absorption spectra, and Oklo natural nuclear reactor data. Assuming linear variation with time we can compare different results. From the quasar absorption spectra: $\\dot{\\mu}/\\mu=(1 \\pm 3) \\times 10^{-16}$ yr$^{-1}$. A combination of this result and the atomic clock results gives the best limt on variation of $\\alpha$: $\\dot{\\alpha}/\\alpha=(-0.8 \\pm 0.8) \\times 10^{-16}$ yr$^{-1}$. The Oklo natural reactor gives the best limit on the variation of $m_s/\\Lambda_{QCD}$ where $m_s$ is the strange quark mass. Huge enhancement of the relative variation effects happens in transitions between close atomic, molecular and nuclear energy levels. We suggest several new cases where the levels are very narrow. Large enhancement of the variation effects is also possible in cold atomic and molecular collisions near Feshbach resonance. Massive bodies (stars or galaxies) can also affect physical constants....

  5. Fundamental Limits to Cellular Sensing

    Science.gov (United States)

    ten Wolde, Pieter Rein; Becker, Nils B.; Ouldridge, Thomas E.; Mugler, Andrew

    2016-03-01

    In recent years experiments have demonstrated that living cells can measure low chemical concentrations with high precision, and much progress has been made in understanding what sets the fundamental limit to the precision of chemical sensing. Chemical concentration measurements start with the binding of ligand molecules to receptor proteins, which is an inherently noisy process, especially at low concentrations. The signaling networks that transmit the information on the ligand concentration from the receptors into the cell have to filter this receptor input noise as much as possible. These networks, however, are also intrinsically stochastic in nature, which means that they will also add noise to the transmitted signal. In this review, we will first discuss how the diffusive transport and binding of ligand to the receptor sets the receptor correlation time, which is the timescale over which fluctuations in the state of the receptor, arising from the stochastic receptor-ligand binding, decay. We then describe how downstream signaling pathways integrate these receptor-state fluctuations, and how the number of receptors, the receptor correlation time, and the effective integration time set by the downstream network, together impose a fundamental limit on the precision of sensing. We then discuss how cells can remove the receptor input noise while simultaneously suppressing the intrinsic noise in the signaling network. We describe why this mechanism of time integration requires three classes (groups) of resources—receptors and their integration time, readout molecules, energy—and how each resource class sets a fundamental sensing limit. We also briefly discuss the scheme of maximum-likelihood estimation, the role of receptor cooperativity, and how cellular copy protocols differ from canonical copy protocols typically considered in the computational literature, explaining why cellular sensing systems can never reach the Landauer limit on the optimal trade

  6. Fundamental cycles and graph embeddings

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    In this paper, we investigate fundamental cycles in a graph G and their relations with graph embeddings. We show that a graph G may be embedded in an orientable surface with genus at least g if and only if for any spanning tree T , there exists a sequence of fundamental cycles C1, C2, . . . , C2g with C2i-1 ∩ C2i≠ф for 1≤ i ≤g. In particular, among β(G) fundamental cycles of any spanning tree T of a graph G, there are exactly 2γM (G) cycles C1, C2, . . . , C2γM (G) such that C2i-1 ∩ C2i≠ф for 1 ≤i≤γM (G), where β(G) and γM (G) are the Betti number and the maximum genus of G, respectively. This implies that it is possible to construct an orientable embedding with large genus of a graph G from an arbitrary spanning tree T (which may have very large number of odd components in G\\E(T )). This is different from the earlier work of Xuong and Liu, where spanning trees with small odd components are needed. In fact, this makes a common generalization of Xuong, Liu and Fu et al. Furthermore, we show that (1) this result is useful for locating the maximum genus of a graph having a specific edge-cut. Some known results for embedded graphs are also concluded; (2) the maximum genus problem may be reduced to the maximum matching problem. Based on this result and the algorithm of Micali-Vazirani, we present a new efficient algorithm to determine the maximum genus of a graph in O((β(G)) 25 ) steps. Our method is straight and quite different from the algorithm of Furst, Gross and McGeoch which depends on a result of Giles where matroid parity method is needed.

  7. Redundancy Evaluation of Fracture Critical Bridges

    OpenAIRE

    Bapat, Amey Vivek

    2014-01-01

    Cases of brittle fractures in major bridges prompted AASHTO to publish its first fracture control plan in 1978. It focused on material and fabrication standards, and required periodic 24-month hands-on inspection of bridges with fracture critical members. The practical result of this plan was to significantly increase the life cycle cost of these bridges, rendering them uneconomical. Apart from the Point Pleasant Bridge that failed in 1967, no other bridge has collapsed in the USA following a...

  8. Nanophenomena at surfaces fundamentals of exotic condensed matter phenomena

    CERN Document Server

    Michailov, Michail

    2011-01-01

    This book presents the state of the art in nanoscale surface physics. It outlines contemporary trends in the field covering a wide range of topical areas: atomic structure of surfaces and interfaces, molecular films and polymer adsorption, biologically inspired nanophysics, surface design and pattern formation, and computer modeling of interfacial phenomena. Bridging 'classical' and 'nano' concepts, the present volume brings attention to the physical background of exotic condensed-matter properties. The book is devoted to Iwan Stranski and Rostislaw Kaischew, remarkable scientists, who played

  9. Computing fundamentals introduction to computers

    CERN Document Server

    Wempen, Faithe

    2014-01-01

    The absolute beginner's guide to learning basic computer skills Computing Fundamentals, Introduction to Computers gets you up to speed on basic computing skills, showing you everything you need to know to conquer entry-level computing courses. Written by a Microsoft Office Master Instructor, this useful guide walks you step-by-step through the most important concepts and skills you need to be proficient on the computer, using nontechnical, easy-to-understand language. You'll start at the very beginning, getting acquainted with the actual, physical machine, then progress through the most common

  10. Computing fundamentals digital literacy edition

    CERN Document Server

    Wempen, Faithe

    2014-01-01

    Computing Fundamentals has been tailor made to help you get up to speed on your Computing Basics and help you get proficient in entry level computing skills. Covering all the key topics, it starts at the beginning and takes you through basic set-up so that you'll be competent on a computer in no time.You'll cover: Computer Basics & HardwareSoftwareIntroduction to Windows 7Microsoft OfficeWord processing with Microsoft Word 2010Creating Spreadsheets with Microsoft ExcelCreating Presentation Graphics with PowerPointConnectivity and CommunicationWeb BasicsNetwork and Internet Privacy and Securit

  11. Photovoltaics fundamentals, technology and practice

    CERN Document Server

    Mertens, Konrad

    2013-01-01

    Concise introduction to the basic principles of solar energy, photovoltaic systems, photovoltaic cells, photovoltaic measurement techniques, and grid connected systems, overviewing the potential of photovoltaic electricity for students and engineers new to the topic After a brief introduction to the topic of photovoltaics' history and the most important facts, Chapter 1 presents the subject of radiation, covering properties of solar radiation, radiation offer, and world energy consumption. Chapter 2 looks at the fundamentals of semiconductor physics. It discusses the build-up of semiconducto

  12. Solid Lubrication Fundamentals and Applications

    Science.gov (United States)

    Miyoshi, Kazuhisa

    2001-01-01

    Solid Lubrication Fundamentals and Applications description of the adhesion, friction, abrasion, and wear behavior of solid film lubricants and related tribological materials, including diamond and diamond-like solid films. The book details the properties of solid surfaces, clean surfaces, and contaminated surfaces as well as discussing the structures and mechanical properties of natural and synthetic diamonds; chemical-vapor-deposited diamond film; surface design and engineering toward wear-resistant, self-lubricating diamond films and coatings. The author provides selection and design criteria as well as applications for synthetic and natural coatings in the commercial, industrial and aerospace industries..

  13. Fundamentals of liquid crystal devices

    CERN Document Server

    Yang, Deng-Ke

    2014-01-01

    Revised throughout to cover the latest developments in the fast moving area of display technology, this 2nd edition of Fundamentals of Liquid Crystal Devices, will continue to be a valuable resource for those wishing to understand the operation of liquid crystal displays. Significant updates include new material on display components, 3D LCDs and blue-phase displays which is one of the most promising new technologies within the field of displays and it is expected that this new LC-technology will reduce the response time and the number of optical components of LC-modules. Prof. Yang is a pion

  14. Fundamentals of ultrasonic phased arrays

    CERN Document Server

    Schmerr, Lester W

    2014-01-01

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

  15. Fundamental Limits of Ultrathin Metasurfaces

    CERN Document Server

    Arbabi, Amir

    2014-01-01

    We present universal theoretical limits on the operation and performance of non-magnetic passive ultrathin metasurfaces. In particular, we prove that their local transmission, reflection, and polarization conversion coefficients are confined to limited regions of the complex plane. As a result, full control over the phase of the light transmitted through such metasurfaces cannot be achieved if the polarization of the light is not to be affected at the same time. We also establish fundamental limits on the maximum polarization conversion efficiency of these metasurfaces, and show that they cannot achieve more than 25% polarization conversion efficiency in transmission.

  16. Fundamentals of soft matter science

    CERN Document Server

    Hirst, Linda S

    2012-01-01

    ""The publication is written at a very fundamental level, which will make it easily readable for undergraduate students. It will certainly also be a valuable text for students and postgraduates in interdisciplinary programmes, as not only physical aspects, but also the chemistry and applications are presented and discussed. … The book is well illustrated, and I really do like the examples and pictures provided for simple demonstration experiments, which can be done during the lectures. Also, the experimental techniques chapter at the end of the book may be helpful. The question sections are he

  17. Fundamentals of spread spectrum modulation

    CERN Document Server

    Ziemer, Rodger E

    2007-01-01

    This lecture covers the fundamentals of spread spectrum modulation, which can be defined as any modulation technique that requires a transmission bandwidth much greater than the modulating signal bandwidth, independently of the bandwidth of the modulating signal. After reviewing basic digital modulation techniques, the principal forms of spread spectrum modulation are described. One of the most important components of a spread spectrum system is the spreading code, and several types and their characteristics are described. The most essential operation required at the receiver in a spread spect

  18. Communication technology update and fundamentals

    CERN Document Server

    Grant, August E

    2014-01-01

    A classic now in its 14th edition, Communication Technology Update and Fundamentals is the single best resource for students and professionals looking to brush up on how these technologies have developed, grown, and converged, as well as what's in store for the future. It begins by developing the communication technology framework-the history, ecosystem, and structure-then delves into each type of technology, including everything from mass media, to computers and consumer electronics, to networking technologies. Each chapter is written by faculty and industry experts who p

  19. Fundamental Laser Welding Process Investigations

    DEFF Research Database (Denmark)

    Bagger, Claus; Olsen, Flemming Ove

    1998-01-01

    In a number of systematic laboratory investigations the fundamental behavior of the laser welding process was analyzed by the use of normal video (30 Hz), high speed video (100 and 400 Hz) and photo diodes. Sensors were positioned to monitor the welding process from both the top side and the rear...... side of the specimen.Special attention has been given to the dynamic nature of the laser welding process, especially during unstable welding conditions. In one series of experiments, the stability of the process has been varied by changing the gap distance in lap welding. In another series...

  20. Electronic imaging fundamentals: basic theory.

    Science.gov (United States)

    Vizy, K N

    1983-01-01

    Introduction of the computer into the field of medical imaging, as typified by the extensive use of digital subtraction angiography (DSA), created an important need for a basic understanding of the principles of digital imaging. This paper reviews these fundamental principles, starting with the definition of images and the interaction of these images with television display systems, then continuing with a detailed description of the way in which imaging systems are specified. This work defines the basic terms and concepts that will be used throughout the contents of this issue.

  1. Foam engineering fundamentals and applications

    CERN Document Server

    2012-01-01

    Containing contributions from leading academic and industrial researchers, this book provides a much needed update of foam science research. The first section of the book presents an accessible summary of the theory and fundamentals of foams. This includes chapters on morphology, drainage, Ostwald ripening, coalescence, rheology, and pneumatic foams. The second section demonstrates how this theory is used in a wide range of industrial applications, including foam fractionation, froth flotation and foam mitigation. It includes chapters on suprafroths, flotation of oil sands, foams in enhancing petroleum recovery, Gas-liquid Mass Transfer in foam, foams in glass manufacturing, fire-fighting foam technology and consumer product foams.

  2. Reconstruction of fundamental SUSY parameters

    Energy Technology Data Exchange (ETDEWEB)

    P. M. Zerwas et al.

    2003-09-25

    We summarize methods and expected accuracies in determining the basic low-energy SUSY parameters from experiments at future e{sup +}e{sup -} linear colliders in the TeV energy range, combined with results from LHC. In a second step we demonstrate how, based on this set of parameters, the fundamental supersymmetric theory can be reconstructed at high scales near the grand unification or Planck scale. These analyses have been carried out for minimal supergravity [confronted with GMSB for comparison], and for a string effective theory.

  3. Fundamentals of magnetism and electricity

    CERN Document Server

    Arya, SN

    2009-01-01

    Fundamentals of Magnetism and Electricity is a textbook on the physics of electricity, magnetism, and electromagnetic fields and waves. It is written mainly with the physics student in mind, although it will also be of use to students of electrical and electronic engineering. The approach is concise but clear, and the author has assumed that the reader will be familiar with the basic phenomena. The theory, however, is set out in a completely self-contained and coherent way and developed to the point where the reader can appreciate the beauty and coherence of the Maxwell equations.

  4. Quantum Uncertainty and Fundamental Interactions

    Directory of Open Access Journals (Sweden)

    Tosto S.

    2013-04-01

    Full Text Available The paper proposes a simplified theoretical approach to infer some essential concepts on the fundamental interactions between charged particles and their relative strengths at comparable energies by exploiting the quantum uncertainty only. The worth of the present approach relies on the way of obtaining the results, rather than on the results themselves: concepts today acknowledged as fingerprints of the electroweak and strong interactions appear indeed rooted in the same theoretical frame including also the basic principles of special and general relativity along with the gravity force.

  5. Autodesk Combustion 4 fundamentals courseware

    CERN Document Server

    Autodesk,

    2005-01-01

    Whether this is your first experience with Combustion software or you're upgrading to take advantage of the many new features and tools, this guide will serve as your ultimate resource to this all-in-one professional compositing application. Much more than a point-and-click manual, this guide explains the principles behind the software, serving as an overview of the package and associated techniques. Written by certified Autodesk training specialists for motion graphic designers, animators, and visual effects artists, Combustion 4 Fundamentals Courseware provides expert advice for all skill le

  6. Fundamentals of gas particle flow

    CERN Document Server

    Rudinger, G

    1980-01-01

    Fundamentals of Gas-Particle Flow is an edited, updated, and expanded version of a number of lectures presented on the "Gas-Solid Suspensions” course organized by the von Karman Institute for Fluid Dynamics. Materials presented in this book are mostly analytical in nature, but some experimental techniques are included. The book focuses on relaxation processes, including the viscous drag of single particles, drag in gas-particles flow, gas-particle heat transfer, equilibrium, and frozen flow. It also discusses the dynamics of single particles, such as particles in an arbitrary flow, in a r

  7. Synthesis and Crystal Structure of a Cyano-bridged Bimetallic Complex[La(DMSO)3(H2O)3Cr(CN)6]·H2O (DMSO = Dimethylsulfoxide) with One-dimensional Chain Molecular Structure

    Institute of Scientific and Technical Information of China (English)

    梁淑惠; 车云霞; 郑吉民

    2004-01-01

    The title complex [La(DMSO)3(H2O)3Cr(CN)6](H2O was obtained by the reaction of LaCl3(7H2O, DMSO and K3[Cr(CN)6] in aqueous solution on a hot water bath. The crystal crystallizes in orthorhombic, space group P212121 with a = 9.827(3), b = 15.037(4), c = 17.633(5)A, C12H26CrLaN6O7S3, Mr = 653.48, Z = 4, V = 2605.7(13) A3, Dc = 1.666 g/m3, μ (MoKα) = 2.314 mm-1, F(000) = 1300, R = 0.0205 and wR = 0.0481 for 5038 observed reflections (I > 2σ(I)). La3+ ion is eight-coordinated by three DMSO molecules, three H2O molecules and two [Cr(CN)6]3- units. The structure of the title complex possesses a cyano-bridged onedimensional zigzag chain structure with alternating La(DMSO)3(H2O)3 and Cr(CN)6 moieties, which are linked by some hydrogen bonds to form a 3D network structure.

  8. Probabilistic model for bridge structural evaluation using nondestructive inspection data

    Science.gov (United States)

    Carrion, Francisco; Lopez, Jose Alfredo; Balankin, Alexander

    2005-05-01

    A bridge management system developed for the Mexican toll highway network applies a probabilistic-reliability model to estimate load capacity and structural residual life. Basic inputs for the system are the global inspection data (visual inspections and vibration testing), and the information from the environment conditions (weather, traffic, loads, earthquakes); although, the model takes account for additional non-destructive testing or permanent monitoring data. Main outputs are the periodic maintenance, rehabilitation and replacement program, and the updated inspection program. Both programs are custom-made to available funds and scheduled according to a priority assignation criterion. The probabilistic model, tailored to typical bridges, accounts for the size, age, material and structure type. Special bridges in size or type may be included, while in these cases finite element deterministic models are also possible. Key feature is that structural qualification is given in terms of the probability of failure, calculated considering fundamental degradation mechanisms and from actual direct observations and measurements, such as crack distribution and size, materials properties, bridge dimensions, load deflections, and parameters for corrosion evaluation. Vibration measurements are basically used to infer structural resistance and to monitor long term degradation.

  9. Fundamentals of equations of state

    CERN Document Server

    Eliezer, Shalom; Hora, Heinrich

    2002-01-01

    The equation of state was originally developed for ideal gases, and proved central to the development of early molecular and atomic physics. Increasingly sophisticated equations of state have been developed to take into account molecular interactions, quantization, relativistic effects, etc. Extreme conditions of matter are encountered both in nature and in the laboratory, for example in the centres of stars, in relativistic collisions of heavy nuclei, in inertial confinement fusion (where a temperature of 10 9 K and a pressure exceeding a billion atmospheres can be achieved). A sound knowledg

  10. Violation of fundamental symmetries and variation of fundamental constants in atomic phenomena

    Science.gov (United States)

    Flambaum, V. V.

    2007-06-01

    We present a review of recent works on variation of fundamental constants and violation of parity in atoms and nuclei. Theories unifying gravity with other interactions suggest temporal and spatial variation of the fundamental ``constants'' in expanding Universe. The spatial variation can explain fine tuning of the fundamental constants which allows humans (and any life) to appear. We appeared in the area of the Universe where the values of the fundamental constants are consistent with our existence. We describe recent works devoted to the variation of the fine structure constant α, strong interaction and fundamental masses (Higgs vacuum). There are some hints for the variation in quasar absorption spectra, Big Bang nucleosynthesis, and Oklo natural nuclear reactor data. A very promising method to search for the variation consists in comparison of different atomic clocks. Huge enhancement of the variation effects happens in transitions between very close atomic and molecular energy levels. A new idea is to build a ``nuclear'' clock based on UV transition in Thorium nucleus. This may allow to improve sensitivity to the variation up to 10 orders of magnitude! Measurements of violation of fundamental symmetries, parity (P) and time reversal (T), in atoms allows one to test unification theories in atomic experiments. We have developed an accurate method of many-body calculations - all-orders summation of dominating diagrams in residual e-e interaction. To calculate QED radiative corrections to energy levels and electromagnetic amplitudes in many-electron atoms and molecules we derived the ``radiative potential'' and the low-energy theorem. This method is simple and can be easily incorporated into any many-body theory approach. Using the radiative correction and many-body calculations we obtained the PNC amplitude EPNC = -0.898(1 +/- 0.5%) × 10-11ieaB(-QW/N). From the measurements of the PNC amplitude we extracted the Cs weak charge QW = -72.66(29)exp(36)theor. The

  11. Molecular Determinants Fundamental to Axon Regeneration After SCI

    Science.gov (United States)

    2010-07-01

    cord, thereby contributing to fai led functiona l resw rat ion. Previous work has demonstra ted that some brainstern neurons J in the adult zebra fish ...completeness of the transection and amount of additional tissue loss. Once we have chosen our approach we can start injuring fish and backfill...device. We can freely use this device and have started practicing. In parallel to the above, we have optimized histological steps such as fish

  12. Molecular Determinants Fundamental to Axon Regeneration after SCI

    Science.gov (United States)

    2012-06-01

    sequence for zebrafish neurocan b was released. This data indicates neurocan b exhibits more homology to mammalian neurocan than neurocan a, the...zebrafish paralog we originally planned to clone. Our new cloning strategy is to prepare an open reading frame (ORF) clone of zebrafish neurocan b...expression of the growth- promoting L1 cell adhesion molecule homolog , neuronal adhesion molecule L1.1 (nadl1.1). Our goal is to understand how nadl1.1

  13. Fundamental Research of Molecular Beam Epitaxy for Device Applications.

    Science.gov (United States)

    1980-11-01

    deep traps in the film. 32 REFERENCES 1. A. Y. Cho, J. Vac. Sci. Technol. 16, 275 (1979). 2. P. E. Luscher , W. S. Knodle and Y. G. Chai, Electronics 53...Divi- both spectra. The donor-to-acceptor transition at 1.477 eV is sion, especially P. E. Luscher , for providing the Varian also observed. However...Wood and B. A. Joyce, J. Appi. Phys. 49, 4854 (1978). ’P. E. Luscher , Solid State Technol. 20. 43 (1977). 4D. M. Collins, Appl. Phys. Lett. 3S, 67 (1979

  14. Fundamental Study of Antimonide Nanostructures by Molecular Beam Epitaxy

    Science.gov (United States)

    2016-02-04

    suggestions for reducing the burden, to Department of Defense, Executive Services , Directorate (0704-0188).   Respondents should be aware that...12. DISTRIBUTION/AVAILABILITY STATEMENT A DISTRIBUTION UNLIMITED: PB Public Release 13. SUPPLEMENTARY NOTES 14. ABSTRACT The research objective was...Engineering (ICSE 2014), Inya Lake Hotel , Yangon, Myanmar, 30 December, 2014. DISTRIBUTION A: Distribution approved for public release.

  15. Generalization and extensions of capillary thinning driven self-assembly of nanostructured air-bridges

    Science.gov (United States)

    Pabba, Santosh

    In Harfenist's brush-on method (Nano Lett., 2004, 4, 1931), polymer dissolved in a volatile solvent is manually brushed over an array of micro-machined pillars, which causes the self assembly of arrays of air-bridges, often of nanometer diameter. This study considers ways to extend the brush-on method by incorporating new materials and new reactions that self-assemble into air-bridges. The study also considers ways to broaden the complexity of device fabrication built up on self assembled air-bridges. These developments include (1) A number of different functional polymeric materials (biocompatible, biodegradable, nanocomposite and amphiphilic copolymers) at different mass fractions and molecular weights are used for demonstrating the applicability of drawing fiber air-bridges by brush-on. Fiber air-bridges with a diameter as small as 20 nm spanning an air gap of 1 mum are fabricated. (2) Considering molecular weight and concentration, it is demonstrated that brush-on can be successful of low concentrations of 1 wt % (10x lower than previously reported) if 5x higher molecular weight polymers are used than previously reported. This is significant both in working with polymers that have low solubility or for solutions of lower viscosities. The viscosity only needs to be large at the later stages of capillary thinning. This is achieved by strain hardening that occurs for highly entangled polymers and polymers of sufficient molecular weight that can entangle at low concentrations. (3) Enzymatic biopolymerization is used for the first time to self assemble highly ordered arrays of air-bridges by brush-on. When fibrinogen solutions are brushed over a thrombin primed surface, or monomeric actin over a KCI primed array, fiber air-bridges are formed, sometimes reaching diameters as small as 16 nm. The uniformity in diameter of one hand-brushed array of 358 parallel fibrin air-bridges was 36.4 nm (6.8 nm standard deviation). (4) Rather than brushing liquid polymers onto an

  16. O que é Psicopatologia Fundamental

    Directory of Open Access Journals (Sweden)

    Manoel Tosta Berlinck

    Full Text Available Se para os romanos, posição significava lugar onde uma pessoa ou coisa estaria colocada, para os gregos, a noção de posição é de natureza muito mais relacional. Da posição determinada pela postura do corpo, diferenciavam pelo menos duas outras: a do historiador, que não inventa, apenas ouviu falar por aí, e a do teatro, que mostrava o corpo humano em um estado natural de pathos (sofrimento. Ao se pensar o psiquismo e o aparelho psíquico como prolongamentos do sistema imunológico e já que, segundo o autor, pathos é sempre somático, a psique é, seguindo a tradição socrática, estritamente corporal. É próprio, pois, à Psicopatologia Fundamental, reconhecer a existência de múltiplas posições corporais-discursivas e reconhecer que aqueles que ocupam outras posições reconheçam a especificidade de sua posição. A partir do conceito de posição, e seus desdobramentos em pathos e logos, o autor desenvolve sua concepção de Psicopatologia Fundamental.

  17. The Fundamental Manifold of Spheroids

    CERN Document Server

    Zaritsky, D; Zabludoff, A I; Zaritsky, Dennis; Gonzalez, Anthony H.; Zabludoff, Ann I.

    2006-01-01

    We present a unifying empirical description of the structural and kinematic properties of all spheroids embedded in dark matter halos. We find that the stellar spheroidal components of galaxy clusters, which we call cluster spheroids (CSphs) and which are typically one hundred times the size of normal elliptical galaxies, lie on a "fundamental plane" as tight as that defined by ellipticals (rms in effective radius of ~0.07), but that has a different slope. The slope, as measured by the coefficient of the log(sigma) term, declines significantly and systematically between the fundamental planes of ellipticals, brightest cluster galaxies (BCGs), and CSphs.We attribute this decline primarily to a continuous change in M_e/L_e, the mass-to-light ratio within the effective radius r_e, with spheroid scale. The magnitude of the slope change requires that it arises principally from differences in the relative distributions of luminous and dark matter, rather than from stellar population differences such as in age and m...

  18. Field Theory of Fundamental Interactions

    Science.gov (United States)

    Wang, Shouhong; Ma, Tian

    2017-01-01

    First, we present two basic principles, the principle of interaction dynamics (PID) and the principle of representation invariance (PRI). Intuitively, PID takes the variation of the action under energy-momentum conservation constraint. We show that the PID is the requirement of the presence of dark matter and dark energy, the Higgs field and the quark confinement. PRI requires that the SU(N) gauge theory be independent of representations of SU(N). It is clear that PRI is the logic requirement of any gauge theory. With PRI, we demonstrate that the coupling constants for the strong and the weak interactions are the main sources of these two interactions, reminiscent of the electric charge. Second, we emphasize that symmetry principles-the principle of general relativity and the principle of Lorentz invariance and gauge invariance-together with the simplicity of laws of nature, dictate the actions for the four fundamental interactions. Finally, we show that the PID and the PRI, together with the symmetry principles give rise to a unified field model for the fundamental interactions, which is consistent with current experimental observations and offers some new physical predictions. The research is supported in part by the National Science Foundation (NSF) grant DMS-1515024, and by the Office of Naval Research (ONR) grant N00014-15-1-2662.

  19. Fundamental Studies on Aluminum Fuels

    Science.gov (United States)

    1944-12-01

    higher molecular weight com- pounds of suitable shape. Innumerable synthetic detergents illustrate this. The typical picture with polymeric...tendency to assoc- iate appears to ba the rule with higher molocular weight com- C t pounds of suitable shape. Innumerable synthetic ... detergents illustrate this. The typical picture with polymeric colloids such as polystyrene (Bartovics and Mark, J. am. Chj.n. toe. 65, 2319

  20. Mechanism and Dynamics of Charge Transfer in Donor-Bridge-Acceptor Systems

    NARCIS (Netherlands)

    Gorczak-Vos, N.

    2016-01-01

    Photoinduced charge transfer in organic materials is a fundamental process in various biological and technological areas. Donor-bridge-acceptor (DBA) molecules are used as model systems in numerous theoretical and experimental work to systematically study and unravel the underlying mechanisms of cha

  1. Neuroscience and education: prime time to build the bridge.

    Science.gov (United States)

    Sigman, Mariano; Peña, Marcela; Goldin, Andrea P; Ribeiro, Sidarta

    2014-04-01

    As neuroscience gains social traction and entices media attention, the notion that education has much to benefit from brain research becomes increasingly popular. However, it has been argued that the fundamental bridge toward education is cognitive psychology, not neuroscience. We discuss four specific cases in which neuroscience synergizes with other disciplines to serve education, ranging from very general physiological aspects of human learning such as nutrition, exercise and sleep, to brain architectures that shape the way we acquire language and reading, and neuroscience tools that increasingly allow the early detection of cognitive deficits, especially in preverbal infants. Neuroscience methods, tools and theoretical frameworks have broadened our understanding of the mind in a way that is highly relevant to educational practice. Although the bridge's cement is still fresh, we argue why it is prime time to march over it.

  2. The Akashi Kaikyo Bridge and the Storebælt Bridge

    DEFF Research Database (Denmark)

    Gimsing, Niels Jørgen

    1999-01-01

    With the completion of the Akashi Kaikyo Bridge and the Storebælt East Bridge the development of the suspension bridge technology in the 20th century has manifested itself in two impressive structures. With the present echnology may bridges of similar (and also more modest) dimensions...... will undoubtedly be built far into the next century. For bridges going beyond the spans of existing bridges it is, however, likely that new concepts will be developed....

  3. Weigh-in-motion and smart bridges

    Science.gov (United States)

    Lai, Leon L.

    1997-05-01

    The bridge Weigh-In-Motion (WIM) system uses bridge structures as weigh scales to measure axle and gross vehicle weights and vehicle configurations without stopping or detouring the vehicles. Because the system is mobile and is almost invisible to the truck drivers, it can be used to collect unbiased traffic data for transportation and loadometer study. The WIM + RESPONSE system, which is an expansion of the original WIM system, was developed to collect additional bridge response data and perform bridge structural evaluation. These additional bridge response data provide bridge engineers with information necessary for improving bridge design and evaluation procedures. Bridge health monitoring and damage detection may also be conducted with long term installation of the WIM + RESPONSE system. This paper discusses what has been achieved by the WIM + RESPONSE system and how the system can be further improved to enhance its functions in a smart bridge.

  4. A strange bridge by Leonardo

    CERN Document Server

    Huylebrouck, Dirk

    2013-01-01

    On folio 855 recto of the Codex Atlanticus, Leonardo da Vinci drew three 'easily movable' bridges, but one of them is enigmatic: all 'replicas' in Leonardo museums and exhibitions come as a surprise, to say the least, to any engineer or architect whose attention is drawn to it. This is the case for models in Amboise (France), Chicago and Portland (USA), Florence (Italy) and for the one of the traveling exhibition by the Australian company 'Grande Exhibitions' that already visited 40 major cities in the world. All 'replicas' of the bridge model attributed to Leonardo have pillars standing on the deck of the bridge, while the deck is suspended by cables attached on these pillars. At first sight this problem does not catch the attention of the observer, as the bridge seems to be a mixed form of a beam and a suspension bridge, but it was not overlooked by my colleague architect-engineer Dr. Laurens Luyten (Gent, Belgium). Yet, after a TV-interview in Brussels so much pressure was exerted by some of the museum col...

  5. River ice jams at bridges

    Energy Technology Data Exchange (ETDEWEB)

    Sullivan, D. [New Brunswick Dept. of Transportation, Fredericton, NB (Canada); Beltaos, S. [National Water Research Institute, Burlington, ON (Canada)

    2000-12-01

    Ice jamming, known to cause high water levels at even moderate river flows, is described as both the main and least understood source of ice-related bridge damages. This paper describes a joint study by the New Brunswick Department of Transportation, the Department of the Environment, local governments, and the National Water Research Institute, designed to address problems associated with the interaction of ice jams and bridges. The study consists of collecting information at each of four sites in New Brunswick including: historical data on ice jam locations, causes, and water levels; channel bathymetry, width and slope within each study centred at the respective bridge; and documentation of ice conditions throughout the ice season, including measurement of ice cover thickness, observation of breakup mechanisms, times, causes, characteristics and possible impacts of ice jam release. Data analysis will include determination of high stages due to ice jams or surges caused by upstream ice jam releases, scour potential of surges, and quantification of the structure's capacity to restrain ice movement and to cause jams. The principal objective of the study is to advance beyond empiricism and to develop rational design criteria for bridges by anticipating the effects of climate changes and by incorporating local meteorological and hydrometric records into bridge design for added safety.

  6. Floating liquid bridge charge dynamics

    Science.gov (United States)

    Teschke, Omar; Soares, David Mendez; Gomes, Whyllerson Evaristo; Valente Filho, Juracyr Ferraz

    2016-01-01

    The interaction of liquid with electric fields is investigated in a configuration where up to 13 kV are applied between electrodes resulting in a 106 V/m electric field in the capillaries and where there is the formation of a free-standing fluid bridge in the interelectrode gap. The Mott-Gurney equation was fitted to the measured ionization current vs applied voltage curve which indicates that the ionization rate at the high-voltage anode electrode dimethylsulfoxide (DMSO) interface and space charging in the interelectrode gap determine the floating liquid bridge current for a given cathode-to-anode voltage. Space charge effects were measured in the cathode becker and also at the liquid bridge since the ionized charges at the anode migrate to the bridge outer surface and decrease the interfacial tension from 43 mJ/m2 to 29 mJ/m2. Two distinct structural regions then form the bridge, a charged plastic (bulk modulus ˜100 MPa) conducting outer layer with a surface conductivity of ˜10-9 Ω-1, which shapes and supports the floating fluid structure, and an inner liquid cylinder, where DMSO molecules flow.

  7. Fundamental triangulation networks in Denmark

    Directory of Open Access Journals (Sweden)

    Borre Kai

    2014-04-01

    Full Text Available The first triangulation activity on Danish ground was carried out by the astronomer Tycho Brahe who resided on the island Hven. He wanted to determine the longitude difference of his observatory Uraniborg to Copenhagen. A by-product was a map of his island made in 1579. In 1761 the Royal Danish Academy of Sciences and Letters initiated a mapping project which should be based on the principle of triangulation. Eventually 24 maps were printed in varying scales, predominantly in 1:120 000. The last map was engraved in 1842. The Danish GradeMeasurement initiated remeasurements and redesign of the fundamental triangulation network. This network served scientific as well as cartographic purposes in more than a century. Only in the 1960s all triangulation sides were measured electronically. A combined least-squares adjustment followed in the 1970s

  8. Silicon photonics fundamentals and devices

    CERN Document Server

    Deen, M Jamal

    2012-01-01

    The creation of affordable high speed optical communications using standard semiconductor manufacturing technology is a principal aim of silicon photonics research. This would involve replacing copper connections with optical fibres or waveguides, and electrons with photons. With applications such as telecommunications and information processing, light detection, spectroscopy, holography and robotics, silicon photonics has the potential to revolutionise electronic-only systems. Providing an overview of the physics, technology and device operation of photonic devices using exclusively silicon and related alloys, the book includes: * Basic Properties of Silicon * Quantum Wells, Wires, Dots and Superlattices * Absorption Processes in Semiconductors * Light Emitters in Silicon * Photodetectors , Photodiodes and Phototransistors * Raman Lasers including Raman Scattering * Guided Lightwaves * Planar Waveguide Devices * Fabrication Techniques and Material Systems Silicon Photonics: Fundamentals and Devices outlines ...

  9. Fundamentals of reversible flowchart languages

    DEFF Research Database (Denmark)

    Yokoyama, Tetsuo; Axelsen, Holger Bock; Glück, Robert

    2016-01-01

    . Although reversible flowcharts are superficially similar to classical flowcharts, there are crucial differences: atomic steps are limited to locally invertible operations, and join points require an explicit orthogonalizing conditional expression. Despite these constraints, we show that reversible......Abstract This paper presents the fundamentals of reversible flowcharts. They are intended to naturally represent the structure and control flow of reversible (imperative) programming languages in a simple computation model, in the same way classical flowcharts do for conventional languages......, structured reversible flowcharts are as expressive as unstructured ones, as shown by a reversible version of the classic Structured Program Theorem. We illustrate how reversible flowcharts can be concretized with two example programming languages, complete with syntax and semantics: a low-level unstructured...

  10. Phononic crystals fundamentals and applications

    CERN Document Server

    Adibi, Ali

    2016-01-01

    This book provides an in-depth analysis as well as an overview of phononic crystals. This book discusses numerous techniques for the analysis of phononic crystals and covers, among other material, sonic and ultrasonic structures, hypersonic planar structures and their characterization, and novel applications of phononic crystals. This is an ideal book for those working with micro and nanotechnology, MEMS (microelectromechanical systems), and acoustic devices. This book also: Presents an introduction to the fundamentals and properties of phononic crystals Covers simulation techniques for the analysis of phononic crystals Discusses sonic and ultrasonic, hypersonic and planar, and three-dimensional phononic crystal structures Illustrates how phononic crystal structures are being deployed in communication systems and sensing systems.

  11. Fluid mechanics fundamentals and applications

    CERN Document Server

    Cengel, Yunus

    2013-01-01

    Cengel and Cimbala's Fluid Mechanics Fundamentals and Applications, communicates directly with tomorrow's engineers in a simple yet precise manner. The text covers the basic principles and equations of fluid mechanics in the context of numerous and diverse real-world engineering examples. The text helps students develop an intuitive understanding of fluid mechanics by emphasizing the physics, using figures, numerous photographs and visual aids to reinforce the physics. The highly visual approach enhances the learning of Fluid mechanics by students. This text distinguishes itself from others by the way the material is presented - in a progressive order from simple to more difficult, building each chapter upon foundations laid down in previous chapters. In this way, even the traditionally challenging aspects of fluid mechanics can be learned effectively. McGraw-Hill is also proud to offer ConnectPlus powered by Maple with the third edition of Cengel/Cimbabla, Fluid Mechanics. This innovative and powerful new sy...

  12. Astronomical reach of fundamental physics

    Science.gov (United States)

    Burrows, Adam S.; Ostriker, Jeremiah P.

    2014-02-01

    Using basic physical arguments, we derive by dimensional and physical analysis the characteristic masses and sizes of important objects in the universe in terms of just a few fundamental constants. This exercise illustrates the unifying power of physics and the profound connections between the small and the large in the cosmos we inhabit. We focus on the minimum and maximum masses of normal stars, the corresponding quantities for neutron stars, the maximum mass of a rocky planet, the maximum mass of a white dwarf, and the mass of a typical galaxy. To zeroth order, we show that all these masses can be expressed in terms of either the Planck mass or the Chandrasekar mass, in combination with various dimensionless quantities. With these examples, we expose the deep interrelationships imposed by nature between disparate realms of the universe and the amazing consequences of the unifying character of physical law.

  13. Queueing networks a fundamental approach

    CERN Document Server

    Dijk, Nico

    2011-01-01

    This handbook aims to highlight fundamental, methodological and computational aspects of networks of queues to provide insights and to unify results that can be applied in a more general manner.  The handbook is organized into five parts: Part 1 considers exact analytical results such as of product form type. Topics include characterization of product forms by physical balance concepts and simple traffic flow equations, classes of service and queue disciplines that allow a product form, a unified description of product forms for discrete time queueing networks, insights for insensitivity, and aggregation and decomposition results that allow subnetworks to be aggregated into single nodes to reduce computational burden. Part 2 looks at monotonicity and comparison results such as for computational simplification by either of two approaches: stochastic monotonicity and ordering results based on the ordering of the proces generators, and comparison results and explicit error bounds based on an underlying Markov r...

  14. Optical Metamaterials Fundamentals and Applications

    CERN Document Server

    Cai, Wenshan

    2010-01-01

    Metamaterials—artificially structured materials with engineered electromagnetic properties—have enabled unprecedented flexibility in manipulating electromagnetic waves and producing new functionalities. In just a few years, the field of optical metamaterials has emerged as one of the most exciting topics in the science of light, with stunning and unexpected outcomes that have fascinated scientists and the general public alike. This volume details recent advances in the study of optical metamaterials, ranging from fundamental aspects to up-to-date implementations, in one unified treatment. Important recent developments and applications such as superlenses and cloaking devices are also treated in detail and made understandable. Optical Metamaterials will serve as a very timely book for both newcomers and advanced researchers in this rapidly evolving field. Early praise for Optical Metamaterials: "...this book is timely bringing to students and other new entrants to the field the most up to date concepts. Th...

  15. Cognition is … Fundamentally Cultural

    Directory of Open Access Journals (Sweden)

    Andrea Bender

    2013-01-01

    Full Text Available A prevailing concept of cognition in psychology is inspired by the computer metaphor. Its focus on mental states that are generated and altered by information input, processing, storage and transmission invites a disregard for the cultural dimension of cognition, based on three (implicit assumptions: cognition is internal, processing can be distinguished from content, and processing is independent of cultural background. Arguing against each of these assumptions, we point out how culture may affect cognitive processes in various ways, drawing on instances from numerical cognition, ethnobiological reasoning, and theory of mind. Given the pervasive cultural modulation of cognition—on all of Marr’s levels of description—we conclude that cognition is indeed fundamentally cultural, and that consideration of its cultural dimension is essential for a comprehensive understanding.

  16. Cognition is … Fundamentally Cultural.

    Science.gov (United States)

    Bender, Andrea; Beller, Sieghard

    2013-03-01

    A prevailing concept of cognition in psychology is inspired by the computer metaphor. Its focus on mental states that are generated and altered by information input, processing, storage and transmission invites a disregard for the cultural dimension of cognition, based on three (implicit) assumptions: cognition is internal, processing can be distinguished from content, and processing is independent of cultural background. Arguing against each of these assumptions, we point out how culture may affect cognitive processes in various ways, drawing on instances from numerical cognition, ethnobiological reasoning, and theory of mind. Given the pervasive cultural modulation of cognition-on all of Marr's levels of description-we conclude that cognition is indeed fundamentally cultural, and that consideration of its cultural dimension is essential for a comprehensive understanding.

  17. Multiphase flow dynamics 1 fundamentals

    CERN Document Server

    Kolev, Nikolay Ivanov

    2004-01-01

    Multi-phase flows are part of our natural environment such as tornadoes, typhoons, air and water pollution and volcanic activities as well as part of industrial technology such as power plants, combustion engines, propulsion systems, or chemical and biological industry. The industrial use of multi-phase systems requires analytical and numerical strategies for predicting their behavior. In its third extended edition this monograph contains theory, methods and practical experience for describing complex transient multi-phase processes in arbitrary geometrical configurations, providing a systematic presentation of the theory and practice of numerical multi-phase fluid dynamics. In the present first volume the fundamentals of multiphase dynamics are provided. This third edition includes various updates, extensions and improvements in all book chapters.

  18. Multiphase flow dynamics 1 fundamentals

    CERN Document Server

    Kolev, Nikolay Ivanov

    2007-01-01

    Multi-phase flows are part of our natural environment such as tornadoes, typhoons, air and water pollution and volcanic activities as well as part of industrial technology such as power plants, combustion engines, propulsion systems, or chemical and biological industry. The industrial use of multi-phase systems requires analytical and numerical strategies for predicting their behavior. In its third extended edition this monograph contains theory, methods and practical experience for describing complex transient multi-phase processes in arbitrary geometrical configurations, providing a systematic presentation of the theory and practice of numerical multi-phase fluid dynamics. In the present first volume the fundamentals of multiphase dynamics are provided. This third edition includes various updates, extensions and improvements in all book chapters.

  19. Fundamentals of Condensed Matter Physics

    Science.gov (United States)

    Cohen, Marvin L.; Louie, Steven G.

    2016-05-01

    Part I. Basic Concepts: Electrons and Phonons: 1. Concept of a solid: qualitative introduction and overview; 2. Electrons in crystals; 3. Electronic energy bands; 4. Lattice vibrations and phonons; Part II. Electron Intercations, Dynamics and Responses: 5. Electron dynamics in crystals; 6. Many-electron interactions: the interacting electron gas and beyond; 7. Density functional theory; 8. The dielectric function for solids; Part III. Optical and Transport Phenomena: 9. Electronic transitions and optical properties of solids; 10. Electron-phonon interactions; 11. Dynamics of crystal electrons in a magnetic field; 12. Fundamentals of transport phenomena in solids; Part IV. Superconductivity, Magnetism, and Lower Dimensional Systems: 13. Using many-body techniques; 14. Superconductivity; 15. Magnetism; 16. Reduced-dimensional systems and nanostructures; Index.

  20. Microwave engineering concepts and fundamentals

    CERN Document Server

    Khan, Ahmad Shahid

    2014-01-01

    Detailing the active and passive aspects of microwaves, Microwave Engineering: Concepts and Fundamentals covers everything from wave propagation to reflection and refraction, guided waves, and transmission lines, providing a comprehensive understanding of the underlying principles at the core of microwave engineering. This encyclopedic text not only encompasses nearly all facets of microwave engineering, but also gives all topics—including microwave generation, measurement, and processing—equal emphasis. Packed with illustrations to aid in comprehension, the book: •Describes the mathematical theory of waveguides and ferrite devices, devoting an entire chapter to the Smith chart and its applications •Discusses different types of microwave components, antennas, tubes, transistors, diodes, and parametric devices •Examines various attributes of cavity resonators, semiconductor and RF/microwave devices, and microwave integrated circuits •Addresses scattering parameters and their properties, as well a...

  1. Polyhedral Scattering of Fundamental Monopoles

    CERN Document Server

    Battye, R; Rychenkova, P; Sutcliffe, P; Battye, Richard; Gibbons, Gary; Rychenkova, Paulina; Sutcliffe, Paul

    2003-01-01

    The dynamics of n slowly moving fundamental monopoles in the SU(n+1) BPS Yang-Mills-Higgs theory can be approximated by geodesic motion on the 4n-dimensional hyperkahler Lee-Weinberg-Yi manifold. In this paper we apply a variational method to construct some scaling geodesics on this manifold. These geodesics describe the scattering of n monopoles which lie on the vertices of a bouncing polyhedron; the polyhedron contracts from infinity to a point, representing the spherically symmetric n-monopole, and then expands back out to infinity. For different monopole masses the solutions generalize to form bouncing nested polyhedra. The relevance of these results to the dynamics of well separated SU(2) monopoles is also discussed.

  2. Materials Fundamentals of Gate Dielectrics

    CERN Document Server

    Demkov, Alexander A

    2006-01-01

    This book presents materials fundamentals of novel gate dielectrics that are being introduced into semiconductor manufacturing to ensure the continuous scalling of the CMOS devices. This is a very fast evolving field of research so we choose to focus on the basic understanding of the structure, thermodunamics, and electronic properties of these materials that determine their performance in device applications. Most of these materials are transition metal oxides. Ironically, the d-orbitals responsible for the high dielectric constant cause sever integration difficulties thus intrinsically limiting high-k dielectrics. Though new in the electronics industry many of these materials are wel known in the field of ceramics, and we describe this unique connection. The complexity of the structure-property relations in TM oxides makes the use of the state of the art first-principles calculations necessary. Several chapters give a detailed description of the modern theory of polarization, and heterojunction band discont...

  3. Fundamental Travel Demand Model Example

    Science.gov (United States)

    Hanssen, Joel

    2010-01-01

    Instances of transportation models are abundant and detailed "how to" instruction is available in the form of transportation software help documentation. The purpose of this paper is to look at the fundamental inputs required to build a transportation model by developing an example passenger travel demand model. The example model reduces the scale to a manageable size for the purpose of illustrating the data collection and analysis required before the first step of the model begins. This aspect of the model development would not reasonably be discussed in software help documentation (it is assumed the model developer comes prepared). Recommendations are derived from the example passenger travel demand model to suggest future work regarding the data collection and analysis required for a freight travel demand model.

  4. Astronomical reach of fundamental physics.

    Science.gov (United States)

    Burrows, Adam S; Ostriker, Jeremiah P

    2014-02-18

    Using basic physical arguments, we derive by dimensional and physical analysis the characteristic masses and sizes of important objects in the universe in terms of just a few fundamental constants. This exercise illustrates the unifying power of physics and the profound connections between the small and the large in the cosmos we inhabit. We focus on the minimum and maximum masses of normal stars, the corresponding quantities for neutron stars, the maximum mass of a rocky planet, the maximum mass of a white dwarf, and the mass of a typical galaxy. To zeroth order, we show that all these masses can be expressed in terms of either the Planck mass or the Chandrasekar mass, in combination with various dimensionless quantities. With these examples, we expose the deep interrelationships imposed by nature between disparate realms of the universe and the amazing consequences of the unifying character of physical law.

  5. Green Manufacturing Fundamentals and Applications

    CERN Document Server

    2013-01-01

    Green Manufacturing: Fundamentals and Applications introduces the basic definitions and issues surrounding green manufacturing at the process, machine and system (including supply chain) levels. It also shows, by way of several examples from different industry sectors, the potential for substantial improvement and the paths to achieve the improvement. Additionally, this book discusses regulatory and government motivations for green manufacturing and outlines the path for making manufacturing more green as well as making production more sustainable. This book also: • Discusses new engineering approaches for manufacturing and provides a path from traditional manufacturing to green manufacturing • Addresses regulatory and economic issues surrounding green manufacturing • Details new supply chains that need to be in place before going green • Includes state-of-the-art case studies in the areas of automotive, semiconductor and medical areas as well as in the supply chain and packaging areas Green Manufactu...

  6. Fundamentals of Protein NMR Spectroscopy

    CERN Document Server

    Rule, Gordon S

    2006-01-01

    NMR spectroscopy has proven to be a powerful technique to study the structure and dynamics of biological macromolecules. Fundamentals of Protein NMR Spectroscopy is a comprehensive textbook that guides the reader from a basic understanding of the phenomenological properties of magnetic resonance to the application and interpretation of modern multi-dimensional NMR experiments on 15N/13C-labeled proteins. Beginning with elementary quantum mechanics, a set of practical rules is presented and used to describe many commonly employed multi-dimensional, multi-nuclear NMR pulse sequences. A modular analysis of NMR pulse sequence building blocks also provides a basis for understanding and developing novel pulse programs. This text not only covers topics from chemical shift assignment to protein structure refinement, as well as the analysis of protein dynamics and chemical kinetics, but also provides a practical guide to many aspects of modern spectrometer hardware, sample preparation, experimental set-up, and data pr...

  7. Fundamentals of modern unsteady aerodynamics

    CERN Document Server

    Gülçat, Ülgen

    2016-01-01

    In this book, the author introduces the concept of unsteady aerodynamics and its underlying principles. He provides the readers with a comprehensive review of the fundamental physics of free and forced unsteadiness, the terminology and basic equations of aerodynamics ranging from incompressible flow to hypersonics. The book also covers modern topics related to the developments made in recent years, especially in relation to wing flapping for propulsion. The book is written for graduate and senior year undergraduate students in aerodynamics and also serves as a reference for experienced researchers. Each chapter includes ample examples, questions, problems and relevant references.   The treatment of these modern topics has been completely revised end expanded for the new edition. It now includes new numerical examples, a section on the ground effect, and state-space representation.

  8. Behavior of composite rigid frame bridge under bi-directional seismic excitations

    Directory of Open Access Journals (Sweden)

    Xiaogang Liu

    2014-02-01

    Full Text Available Pushover analysis and time history analysis are conducted to explore the bi-directional seismic behavior of composite steel-concrete rigid frame bridge, which is composed of RC piers and steel-concrete composite girders. Both longitudinal and transverse directions excitations are investigated using OpenSees. Firstly, the applicability of pushover analysis based on the fundamental mode is discussed. Secondly, an improved pushover analysis method considering the contribution of higher modes is proposed, and the applicability on composite rigid frame bridges under bi-directional earthquake is verified. Based on this method, an approach to predict the displacement responses of composite rigid frame bridge under random bi-directional seismic excitations by revising the elasto-plastic demand curve is also proposed. It is observed that the developed method yield a good estimate on the responses of composite rigid frame bridges under bi-directional seismic excitations.

  9. The effect of circular bridge piers with different inclination angles toward downstream on scour

    Indian Academy of Sciences (India)

    Mohammad Vaghef; Masoud Ghodsian; Saeid Salimi

    2016-01-01

    A fundamental principle in the safe design of bridge piers is to estimate maximum scour depth. As such, many researchers devoted their efforts to study the phenomenon of scour around bridge piers and to present relationships to estimate maximum scour depth. In the current research, scour around circular bridge piers with two different diameters and different inclination angles toward downstream has been investigated experimentally under clear water and different discharges. The obtained results revealed that increase in the inclination angle leads to a significant decrease in the scour depth, dimensions of sediment ridge and scour hole. Moreover, by comparing the data obtained from vertical bridge pier and well-known relationships, a relationship having the most agreement with the results was selected and modified to estimate equilibrium scour depth around inclined piers.

  10. Fundamental Physics and Precision Measurements

    Science.gov (United States)

    Hänsch, T. W.

    2006-11-01

    "Very high precision physics has always appealed to me. The steady improvement in technologies that afford higher and higher precision has been a regular source of excitement and challenge during my career. In science, as in most things, whenever one looks at something more closely, new aspects almost always come into play …" With these word from the book "How the Laser happened", Charles H. Townes expresses a passion for precision that is now shared by many scientists. Masers and lasers have become indispensible tools for precision measurements. During the past few years, the advent of femtosecond laser frequency comb synthesizers has revolutionized the art of directly comparing optical and microwave frequencies. Inspired by the needs of precision laser spectroscopy of the simple hydrogen atom, such frequency combs are now enabling ultra-precise spectroscopy over wide spectral ranges. Recent laboratory experiments are already setting stringent limits for possible slow variations of fundamental constants. Laser frequency combs also provide the long missing clockwork for optical atomic clocks that may ultimately reach a precision of parts in 1018 and beyond. Such tools will open intriguing new opportunities for fundamental experiments including new tests of special and general relativity. In the future, frequency comb techniques may be extended into the extreme ultraviolet and soft xray regime, opening a vast new spectral territory to precision measurements. Frequency combs have also become a key tool for the emerging new field of attosecond science, since they can control the electric field of ultrashort laser pulses on an unprecedented time scale. The biggest surprise in these endeavours would be if we found no surprise.

  11. Fundamental enabling issues in nanotechnology :

    Energy Technology Data Exchange (ETDEWEB)

    Floro, Jerrold Anthony [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Foiles, Stephen Martin [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Hearne, Sean Joseph [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Hoyt, Jeffrey John [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Seel, Steven Craig [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Webb III, Edmund Blackburn [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Morales, Alfredo Martin [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Zimmerman, Jonathan A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2007-10-01

    To effectively integrate nanotechnology into functional devices, fundamental aspects of material behavior at the nanometer scale must be understood. Stresses generated during thin film growth strongly influence component lifetime and performance; stress has also been proposed as a mechanism for stabilizing supported nanoscale structures. Yet the intrinsic connections between the evolving morphology of supported nanostructures and stress generation are still a matter of debate. This report presents results from a combined experiment and modeling approach to study stress evolution during thin film growth. Fully atomistic simulations are presented predicting stress generation mechanisms and magnitudes during all growth stages, from island nucleation to coalescence and film thickening. Simulations are validated by electrodeposition growth experiments, which establish the dependence of microstructure and growth stresses on process conditions and deposition geometry. Sandia is one of the few facilities with the resources to combine experiments and modeling/theory in this close a fashion. Experiments predicted an ongoing coalescence process that generates signficant tensile stress. Data from deposition experiments also supports the existence of a kinetically limited compressive stress generation mechanism. Atomistic simulations explored island coalescence and deposition onto surfaces intersected by grain boundary structures to permit investigation of stress evolution during later growth stages, e.g. continual island coalescence and adatom incorporation into grain boundaries. The predictive capabilities of simulation permit direct determination of fundamental processes active in stress generation at the nanometer scale while connecting those processes, via new theory, to continuum models for much larger island and film structures. Our combined experiment and simulation results reveal the necessary materials science to tailor stress, and therefore performance, in

  12. Spitzer view of massive star formation in the tidally stripped Magellanic Bridge

    Energy Technology Data Exchange (ETDEWEB)

    Chen, C.-H. Rosie; Indebetouw, Remy [Department of Astronomy, University of Virginia, Charlottesville, VA 22904 (United States); Muller, Erik; Kawamura, Akiko [National Astronomical Observatory of Japan, Mitaka, Tokyo 181-8588 (Japan); Gordon, Karl D.; Meixner, Margaret; Seale, Jonathan P.; Shiao, Bernie [Space Telescope Science Institute, Baltimore, MD 21218 (United States); Sewiło, Marta [Department of Physics and Astronomy, Johns Hopkins University, Baltimore, MD 21218 (United States); Whitney, Barbara A.; Meade, Marilyn R. [Department of Astronomy, University of Wisconsin-Madison, Madison, WI 53706 (United States); Fukui, Yasuo [Department of Astrophysics, Nagoya University, Furocho, Chikusaku, Nagoya 464-8602 (Japan); Madden, Suzanne C. [CEA, Laboratoire AIM, Irfu/SAp, Orme des Merisiers, F-91191 Gif-sur-Yvette (France); Oliveira, Joana M.; Van Loon, Jacco Th. [Astrophysics Group, Lennard-Jones Laboratories, Keele University, Keele, Staffordshire ST5 5BG (United Kingdom); Robitaille, Thomas P., E-mail: rchen@mpifr-bonn.mpg.de [Max Planck Institute for Astronomy, D-69117 Heidelberg (Germany)

    2014-04-20

    The Magellanic Bridge is the nearest low-metallicity, tidally stripped environment, offering a unique high-resolution view of physical conditions in merging and forming galaxies. In this paper, we present an analysis of candidate massive young stellar objects (YSOs), i.e., in situ, current massive star formation (MSF) in the Bridge using Spitzer mid-IR and complementary optical and near-IR photometry. While we definitely find YSOs in the Bridge, the most massive are ∼10 M {sub ☉}, <<45 M {sub ☉} found in the LMC. The intensity of MSF in the Bridge also appears to be decreasing, as the most massive YSOs are less massive than those formed in the past. To investigate environmental effects on MSF, we have compared properties of massive YSOs in the Bridge to those in the LMC. First, YSOs in the Bridge are apparently less embedded than in the LMC: 81% of Bridge YSOs show optical counterparts, compared to only 56% of LMC sources with the same range of mass, circumstellar dust mass, and line-of-sight extinction. Circumstellar envelopes are evidently more porous or clumpy in the Bridge's low-metallicity environment. Second, we have used whole samples of YSOs in the LMC and the Bridge to estimate the probability of finding YSOs at a given H I column density, N(H I). We found that the LMC has ∼3 × higher probability than the Bridge for N(H I) >12 × 10{sup 20} cm{sup –2}, but the trend reverses at lower N(H I). Investigating whether this lower efficiency relative to H I is due to less efficient molecular cloud formation or to less efficient cloud collapse, or to both, will require sensitive molecular gas observations.

  13. Fundamental studies of retrograde reactions in direct liquefaction

    Energy Technology Data Exchange (ETDEWEB)

    Serio, M.A.; Solomon, P.R.; Kroo, E.; Charpenay, S.; Bassilakis, R.

    1991-12-17

    The overall objective of the program was to improve the understanding of retrograde reactions and their dependencies on coal rank and structure, and/or coal modifications and reaction conditions. Because retrograde reactions are competitive with bond breaking reactions, an understanding of both is required to shift the competition in favor of the latter. Related objectives were to clarify the conflicting observations reported in literature on such major topics as the role of oxygen groups in retrograde reactions and to provide a bridge from very fundamental studies on pure compounds to phenomenological studies on actual coal. This information was integrated into the FG-DVC model, which was improved and extended to the liquefaction context.

  14. Thermal bridges of modern windows

    DEFF Research Database (Denmark)

    Hansen, Ernst Jan de Place; Møller, Eva B.; Nielsen, Anker

    2013-01-01

    With its focus on reduced energy consumption, contemporary housing construction requires a highly insulated and airtight building envelope with as few thermal bridges as possible.Windows must be carefully designed, as thermal bridges can lead to surface condensation or mold growth, even...... if the window has an U-factor of 1 W/(m2·K) or lower. This paper describes the development of modern, energy efficient Danish windows with reduced thermal bridges. It focuses on materials, geometry, and sealing of window panes based on a literature review. Examples of modern windows are presented. Experience...... with the minimum acceptable surface temperature regarding surface condensation or mold growth, implemented in the Danish Building Regulations in 2010, and the calculation method for this temperature based on international standards is discussed. The introduction of the minimum acceptable surface temperature has...

  15. Contactless Bridge Weigh-in-Motion

    OpenAIRE

    Ojio, T.; Carey, Ciaran; O'Brien, Eugene J.; Doherty, C; Taylor, S E

    2016-01-01

    Bridge weigh-in-motion (WIM) uses existing bridges to find the weights of vehicles that pass overhead. Contactless bridge weigh-in-motion (cBWIM) uses bridges to weigh vehicles without the need for any sensors to be attached to the bridge. A camera is mounted on the back of a telescope, which magnifies the image to the extent that submillimeter bridge deflections can be measured accurately. A second camera is used to monitor traffic and to determine axle spacings. The two cameras are synchron...

  16. Bridging faults in BiCMOS circuits

    Science.gov (United States)

    Menon, Sankaran M.; Malaiya, Yashwant K.; Jayasumana, Anura P.

    1993-01-01

    Combining the advantages of CMOS and bipolar, BiCMOS is emerging as a major technology for many high performance digital and mixed signal applications. Recent investigations revealed that bridging faults can be a major failure mode in IC's. Effects of bridging faults in BiCMOS circuits are presented. Bridging faults between logical units without feedback and logical units with feedback are considered. Several bridging faults can be detected by monitoring the power supply current (I(sub DDQ) monitoring). Effects of bridging faults and bridging resistance on output logic levels were examined along with their effects on noise immunity.

  17. An Expert System for Concrete Bridge Management

    DEFF Research Database (Denmark)

    Brito, J. de; Branco, F. A.; Thoft-Christensen, Palle

    1997-01-01

    management systems are presently being implemented by bridge authorities in several countries. The prototype of an expert system for concrete bridge management is presented in this paper, with its functionality relying on two modules. The inspection module relies on a periodic acquisition of field......The importance of bridge repair versus new bridge construction has risen in recent decades due to high deterioration rates that have been observed in these structures. Budgets both for building new bridges and keeping the existing ones are always limited. To help rational decision-making, bridge...

  18. Future perspectives in melanoma research: meeting report from the "Melanoma Bridge", Napoli, December 5th-8th 2013.

    Science.gov (United States)

    Ascierto, Paolo A; Grimaldi, Antonio M; Anderson, Ana Carrizosa; Bifulco, Carlo; Cochran, Alistair; Garbe, Claus; Eggermont, Alexander M; Faries, Mark; Ferrone, Soldano; Gershenwald, Jeffrey E; Gajewski, Thomas F; Halaban, Ruth; Hodi, F Stephen; Kefford, Richard; Kirkwood, John M; Larkin, James; Leachman, Sancy; Maio, Michele; Marais, Richard; Masucci, Giuseppe; Melero, Ignacio; Palmieri, Giuseppe; Puzanov, Igor; Ribas, Antoni; Saenger, Yvonne; Schilling, Bastian; Seliger, Barbara; Stroncek, David; Sullivan, Ryan; Testori, Alessandro; Wang, Ena; Ciliberto, Gennaro; Mozzillo, Nicola; Marincola, Francesco M; Thurin, Magdalena

    2014-10-28

    The fourth "Melanoma Bridge Meeting" took place in Naples, December 5 to 8th, 2013. The four topics discussed at this meeting were: Diagnosis and New Procedures, Molecular Advances and Combination Therapies, News in Immunotherapy, and Tumor Microenvironment and Biomarkers.

  19. Communication: Fitting potential energy surfaces with fundamental invariant neural network

    Science.gov (United States)

    Shao, Kejie; Chen, Jun; Zhao, Zhiqiang; Zhang, Dong H.

    2016-08-01

    A more flexible neural network (NN) method using the fundamental invariants (FIs) as the input vector is proposed in the construction of potential energy surfaces for molecular systems involving identical atoms. Mathematically, FIs finitely generate the permutation invariant polynomial (PIP) ring. In combination with NN, fundamental invariant neural network (FI-NN) can approximate any function to arbitrary accuracy. Because FI-NN minimizes the size of input permutation invariant polynomials, it can efficiently reduce the evaluation time of potential energy, in particular for polyatomic systems. In this work, we provide the FIs for all possible molecular systems up to five atoms. Potential energy surfaces for OH3 and CH4 were constructed with FI-NN, with the accuracy confirmed by full-dimensional quantum dynamic scattering and bound state calculations.

  20. Photochromic organometallics with a dithienylethene (DTE) Bridge, [Y-C[triple bond]C-DTE-C[triple bond]C-Y] (Y={MCp*(dppe)}): photoswitchable molecular wire (M=Fe) versus dual photo- and electrochromism (M=Ru).

    Science.gov (United States)

    Tanaka, Yuya; Ishisaka, Takuya; Inagaki, Akiko; Koike, Takashi; Lapinte, Claude; Akita, Munetaka

    2010-04-26

    Dinuclear acetylide-type complexes bridged by a photochromic dithienylethene unit (DTE), [Y-C[triple bond]C-DTE-C[triple bond]C-Y] 1 (Y={MCp*(dppe)}; Cp*=pentamethylcyclopentadienyl, M=Fe (1(Fe)), Ru (1(Ru))), have been prepared, and their wirelike and switching behavior, as well as their oxidation chemistry has been investigated. The DTE complexes 1 exhibit photochromic behavior in a manner similar to organic DTE derivatives; UV irradiation causes ring closure of the open isomer 1O to form the closed isomer 1C and visible-light irradiation of the resultant 1C causes reverse ring opening to regenerate 1O. But the performance is dependent on the metals. With respect to the interconversion rates and the 1C content at the photostationary state under UV irradiation, the ruthenium complex 1(Ru) is superior to the iron analogue 1(Fe). The wirelike performance is associated with the photochromic processes, and the efficient switching performance has been verified for 1(Fe) as characterized by the V(ab) values [V(ab) is the electronic coupling derived from intervalence charge-transfer (IVCT) bands: V(ab)(1(Fe)C; ON)=0.047 eV versus V(ab)(1(Fe)O; OFF)=0 eV], and are also supported by the large switching factor (SF=K(C)(C; ON)/K(C)(O; OFF)=39; K(C)=comproportionation constant). SF for 1(Ru) is determined to be 4.2. The remarkable switching behavior arises from the different pi-conjugated systems in the two isomeric forms, that is, cross-conjugated (1O) and fully conjugated pi-systems (1C). It was also found that, in contrast to the reversible redox behavior of the iron complex 1(Fe), the ruthenium complex 1(Ru)O undergoes oxidative ring closure to form the dicationic species of the closed isomer 1(Ru)C(2+) and, thus, the ruthenium system 1(Ru) shows dual photo- and electrochromism. The distinct oxidation behavior of 1(Fe) and 1(Ru) can be ascribed to the spin distribution on the diradical intermediates 1(Fe)O(2+) and 1(Ru)O(2+), as supported by DFT calculations.

  1. Charge-transport-induced dissociation in donor-bridge-acceptor complexes.

    Science.gov (United States)

    Brisker, Daria; Peskin, Uri

    2008-12-28

    Possible mechanisms for charge-transport-induced dissociation in donor-bridge-acceptor complexes are studied. Two mechanisms for dissociation at the molecular bridge are captured within a simple model of an anharmonic bridge vibration coupled nonlinearly to an electronic degree of freedom. A direct mechanism is associated with vibronic excitations to the nuclear continuum and an alternative dissociation mechanism involves intermediate quasibound vibrational states (Feshbach resonances). The two different mechanisms of charge-transport-induced dissociation are analyzed and their interplay as a function of the system parameters is examined. A parameter regime is suggested where the phenomenon should be experimentally accessible.

  2. Balanced bridge feedback control system

    Science.gov (United States)

    Lurie, Boris J. (Inventor)

    1990-01-01

    In a system having a driver, a motor, and a mechanical plant, a multiloop feedback control apparatus for controlling the movement and/or positioning of a mechanical plant, the control apparatus has a first local bridge feedback loop for feeding back a signal representative of a selected ratio of voltage and current at the output driver, and a second bridge feedback loop for feeding back a signal representative of a selected ratio of force and velocity at the output of the motor. The control apparatus may further include an outer loop for feeding back a signal representing the angular velocity and/or position of the mechanical plant.

  3. Excitation Methods for Bridge Structures

    Energy Technology Data Exchange (ETDEWEB)

    Farrar, C.R.; Duffy, T.A.; Cornwell, P.J.; Doebling, S.W.

    1999-02-08

    This paper summarizes the various methods that have been used to excited bridge structures during dynamic testing. The excitation methods fall into the general categories of ambient excitation methods and measured-input excitation methods. During ambient excitation the input to the bridge is not directly measured. In contrast, as the category label implies, measured-input excitations are usually applied at a single location where the force input to the structure can be monitored. Issues associated with using these various types of measurements are discussed along with a general description of the various excitation methods.

  4. How Do Fundamental Christians Deal with Depression?

    Science.gov (United States)

    Spinney, Douglas Harvey

    1991-01-01

    Provides explanation of developmental dynamics in experience of fundamental Christians that provoke reactive depression. Describes depressant retardant defenses against depression that have been observed in Christian fundamental subculture. Suggests four counseling strategies for helping fundamentalists. (Author/ABL)

  5. Optimum selection on bridge erection with floating crane in East China Sea Bridge and Hangzhou Bay Bridge

    Institute of Scientific and Technical Information of China (English)

    Shunquan Qin; Pu Zhou; Youheng Hua

    2004-01-01

    @@ Introduction With the rapid development of China′s economy, many bridges will be built over the Chinese coastal waters of Pacific Ocean. Among them, construction of East China Sea Bridge has been commenced in June 2001, and will be completed at the end of 2005, Hangzhou Bay Bridge was also started to construct in June 2003(Fig. 1). These two ultralong bridges are designed as twin expressway bridges standing side by side each carries a 3-lane one-way carriageway. The total width is 31.5m and 33.0m respectively. East China Sea Bridge starts from Nanhui District, Shanghai and extends to the Yangshan Deep Water Port Area, which is located at one of the Qiqu Islands. The total length of the bridge is about 31.0 km, in which 25 km are on the sea, and 22 km is in the unnavigable region. Hangzhou Bay Bridge across the mouth of Qiantang River.

  6. Is myocardial bridging a bridge connecting to cardiovascular events?

    Institute of Scientific and Technical Information of China (English)

    LI Jian-jun

    2010-01-01

    @@ Coronary arteries and their major branches usually course on the surface of the heart in the subepicardial tissue. However, a muscle hber overlying the intramyocardial segment of an epicardial coronary artery was defined as myocardial bridging (MB), and subsequently the artery coursing within the myocardium is called a tunneled artery.

  7. Fundamentals and Techniques of Nonimaging

    Energy Technology Data Exchange (ETDEWEB)

    O' Gallagher, J. J.; Winston, R.

    2003-07-10

    This is the final report describing a long term basic research program in nonimaging optics that has led to major advances in important areas, including solar energy, fiber optics, illumination techniques, light detectors, and a great many other applications. The term ''nonimaging optics'' refers to the optics of extended sources in systems for which image forming is not important, but effective and efficient collection, concentration, transport, and distribution of light energy is. Although some of the most widely known developments of the early concepts have been in the field of solar energy, a broad variety of other uses have emerged. Most important, under the auspices of this program in fundamental research in nonimaging optics established at the University of Chicago with support from the Office of Basic Energy Sciences at the Department of Energy, the field has become very dynamic, with new ideas and concepts continuing to develop, while applications of the early concepts continue to be pursued. While the subject began as part of classical geometrical optics, it has been extended subsequently to the wave optics domain. Particularly relevant to potential new research directions are recent developments in the formalism of statistical and wave optics, which may be important in understanding energy transport on the nanoscale. Nonimaging optics permits the design of optical systems that achieve the maximum possible concentration allowed by physical conservation laws. The earliest designs were constructed by optimizing the collection of the extreme rays from a source to the desired target: the so-called ''edge-ray'' principle. Later, new concentrator types were generated by placing reflectors along the flow lines of the ''vector flux'' emanating from lambertian emitters in various geometries. A few years ago, a new development occurred with the discovery that making the design edge-ray a functional of some

  8. Condutância molecular e biomolecular

    Directory of Open Access Journals (Sweden)

    Gama A. Arnóbio S. da

    2000-01-01

    Full Text Available The concept of molecular conductance is discussed in terms of the propagation of an electronic interaction, between electron donor and acceptor groups, through the bonds of a molecular structure where these groups are embedded. The electronic interaction propagation is described by a Green's function matrix element, in a donor-bridge-acceptor molecular system reduced to a two-level representation.

  9. Structural Health Monitoring of Bridges with Fiber Bragg Grating Sensors

    Directory of Open Access Journals (Sweden)

    Francisco Navarro-Henríquez

    2014-11-01

    Systems with fiber optic sensors FBG (Fiber Bragg Grating are consolidated in the Structural Health Monitoring (SMH of bridges, Nondestructive Testing (NDT static and dynamic measurements of deformation, displacement, deflection, temperature and vibration. This article provides a brief introduction to the technology and the fundamentals of fiber optic sensors, also present comparative advantages over its traditional counterpart is presented. Their characteristics are described and measurement graphics are presented as an application example of the FBG sensors. Finally, some key aspects to consider for proper use in the field are mentioned.

  10. [Fundamentals of chronobiology: nyctohemeral rhythms].

    Science.gov (United States)

    Bourdon, L; Buguet, A

    2004-09-01

    Most biological activities fluctuate throughout the day and contribute to a better adaptation to the organism's daily activity. During the last 30 Years, chronobiology has aimed at studying these biological rhythms, explaining most of the biological mechanisms of i) the endogenous circadian rhythmicity, ii) the neurophysiological mechanisms of the photic system that allows its external resetting, and iii) the neuroendocrine mechanisms of internal rhythm synchronization. Moreover, the description of specific biological rhythm disorders and rhythm problems at the cellular and even the molecular level have prompted the emerging fields of chronopharmacology and chronotherapeutics. Copyright 2004 Masson

  11. Virtual and composite fundamentals in the ERM

    NARCIS (Netherlands)

    Knot, KHW; Sturm, JE

    1999-01-01

    A latent-variable approach is applied to identify the appropriate driving process for fundamental exchange rates in the ERM. From the time-series characteristics of so-called "virtual fundamentals" and "composite fundamentals", a significant degree of mean reversion can be asserted. The relative deg

  12. IDDT: Fundamentals and Test Generation

    Institute of Scientific and Technical Information of China (English)

    KUANG JiShun(邝继顺); YOU ZhiQiang(尤志强); ZHU QiJian(朱启建); MIN YingHua(闵应骅)

    2003-01-01

    It is the time to explore the fundamentals of IDDT testing when extensive workhas been done for IDDT testing since it was proposed. This paper precisely defines the concept ofaverage transient current (IDDT) of CMOS digital ICs, and experimentally analyzes the feasibilityof IDDT test generation at gate level. Based on the SPICE simulation results, the paper suggests aformula to calculateIDDT by means of counting only logical up-transitions, which enablesIDDT testgeneration at logic level. The Bayesian optimization algorithm is utilized for IDDT test generation.Experimental results show that about 25% stuck-open faults are withIDDT testability larger than2.5, and likely to beIDDT testable. It is also found that most IDDT testable faults are located nearthe primary inputs of a circuit under test. IDDT test generation does not require fault sensitizationprocedure compared with stuck-at fault test generation. Furthermore, some redundant stuck-atfaults can be detected by using IDDT testing.

  13. Fundamental studies of fusion plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Aamodt, R.E.; Catto, P.J.; D' Ippolito, D.A.; Myra, J.R.; Russell, D.A.

    1992-05-26

    The major portion of this program is devoted to critical ICH phenomena. The topics include edge physics, fast wave propagation, ICH induced high frequency instabilities, and a preliminary antenna design for Ignitor. This research was strongly coordinated with the world's experimental and design teams at JET, Culham, ORNL, and Ignitor. The results have been widely publicized at both general scientific meetings and topical workshops including the speciality workshop on ICRF design and physics sponsored by Lodestar in April 1992. The combination of theory, empirical modeling, and engineering design in this program makes this research particularly important for the design of future devices and for the understanding and performance projections of present tokamak devices. Additionally, the development of a diagnostic of runaway electrons on TEXT has proven particularly useful for the fundamental understanding of energetic electron confinement. This work has led to a better quantitative basis for quasilinear theory and the role of magnetic vs. electrostatic field fluctuations on electron transport. An APS invited talk was given on this subject and collaboration with PPPL personnel was also initiated. Ongoing research on these topics will continue for the remainder fo the contract period and the strong collaborations are expected to continue, enhancing both the relevance of the work and its immediate impact on areas needing critical understanding.

  14. Levitated Optomechanics for Fundamental Physics

    Science.gov (United States)

    Rashid, Muddassar; Bateman, James; Vovrosh, Jamie; Hempston, David; Ulbricht, Hendrik

    2015-05-01

    Optomechanics with levitated nano- and microparticles is believed to form a platform for testing fundamental principles of quantum physics, as well as find applications in sensing. We will report on a new scheme to trap nanoparticles, which is based on a parabolic mirror with a numerical aperture of 1. Combined with achromatic focussing, the setup is a cheap and readily straightforward solution to trapping nanoparticles for further study. Here, we report on the latest progress made in experimentation with levitated nanoparticles; these include the trapping of 100 nm nanodiamonds (with NV-centres) down to 1 mbar as well as the trapping of 50 nm Silica spheres down to 10?4 mbar without any form of feedback cooling. We will also report on the progress to implement feedback stabilisation of the centre of mass motion of the trapped particle using digital electronics. Finally, we argue that such a stabilised particle trap can be the particle source for a nanoparticle matterwave interferometer. We will present our Talbot interferometer scheme, which holds promise to test the quantum superposition principle in the new mass range of 106 amu. EPSRC, John Templeton Foundation.

  15. Fundamental Scaling Laws in Nanophotonics

    Science.gov (United States)

    Liu, Ke; Sun, Shuai; Majumdar, Arka; Sorger, Volker J.

    2016-11-01

    The success of information technology has clearly demonstrated that miniaturization often leads to unprecedented performance, and unanticipated applications. This hypothesis of “smaller-is-better” has motivated optical engineers to build various nanophotonic devices, although an understanding leading to fundamental scaling behavior for this new class of devices is missing. Here we analyze scaling laws for optoelectronic devices operating at micro and nanometer length-scale. We show that optoelectronic device performance scales non-monotonically with device length due to the various device tradeoffs, and analyze how both optical and electrical constrains influence device power consumption and operating speed. Specifically, we investigate the direct influence of scaling on the performance of four classes of photonic devices, namely laser sources, electro-optic modulators, photodetectors, and all-optical switches based on three types of optical resonators; microring, Fabry-Perot cavity, and plasmonic metal nanoparticle. Results show that while microrings and Fabry-Perot cavities can outperform plasmonic cavities at larger length-scales, they stop working when the device length drops below 100 nanometers, due to insufficient functionality such as feedback (laser), index-modulation (modulator), absorption (detector) or field density (optical switch). Our results provide a detailed understanding of the limits of nanophotonics, towards establishing an opto-electronics roadmap, akin to the International Technology Roadmap for Semiconductors.

  16. Fundamental Scaling Laws in Nanophotonics.

    Science.gov (United States)

    Liu, Ke; Sun, Shuai; Majumdar, Arka; Sorger, Volker J

    2016-11-21

    The success of information technology has clearly demonstrated that miniaturization often leads to unprecedented performance, and unanticipated applications. This hypothesis of "smaller-is-better" has motivated optical engineers to build various nanophotonic devices, although an understanding leading to fundamental scaling behavior for this new class of devices is missing. Here we analyze scaling laws for optoelectronic devices operating at micro and nanometer length-scale. We show that optoelectronic device performance scales non-monotonically with device length due to the various device tradeoffs, and analyze how both optical and electrical constrains influence device power consumption and operating speed. Specifically, we investigate the direct influence of scaling on the performance of four classes of photonic devices, namely laser sources, electro-optic modulators, photodetectors, and all-optical switches based on three types of optical resonators; microring, Fabry-Perot cavity, and plasmonic metal nanoparticle. Results show that while microrings and Fabry-Perot cavities can outperform plasmonic cavities at larger length-scales, they stop working when the device length drops below 100 nanometers, due to insufficient functionality such as feedback (laser), index-modulation (modulator), absorption (detector) or field density (optical switch). Our results provide a detailed understanding of the limits of nanophotonics, towards establishing an opto-electronics roadmap, akin to the International Technology Roadmap for Semiconductors.

  17. Hyperbolic metamaterials: fundamentals and applications.

    Science.gov (United States)

    Shekhar, Prashant; Atkinson, Jonathan; Jacob, Zubin

    2014-01-01

    Metamaterials are nano-engineered media with designed properties beyond those available in nature with applications in all aspects of materials science. In particular, metamaterials have shown promise for next generation optical materials with electromagnetic responses that cannot be obtained from conventional media. We review the fundamental properties of metamaterials with hyperbolic dispersion and present the various applications where such media offer potential for transformative impact. These artificial materials support unique bulk electromagnetic states which can tailor light-matter interaction at the nanoscale. We present a unified view of practical approaches to achieve hyperbolic dispersion using thin film and nanowire structures. We also review current research in the field of hyperbolic metamaterials such as sub-wavelength imaging and broadband photonic density of states engineering. The review introduces the concepts central to the theory of hyperbolic media as well as nanofabrication and characterization details essential to experimentalists. Finally, we outline the challenges in the area and offer a set of directions for future work.

  18. Information physics fundamentals of nanophotonics.

    Science.gov (United States)

    Naruse, Makoto; Tate, Naoya; Aono, Masashi; Ohtsu, Motoichi

    2013-05-01

    Nanophotonics has been extensively studied with the aim of unveiling and exploiting light-matter interactions that occur at a scale below the diffraction limit of light, and recent progress made in experimental technologies--both in nanomaterial fabrication and characterization--is driving further advancements in the field. From the viewpoint of information, on the other hand, novel architectures, design and analysis principles, and even novel computing paradigms should be considered so that we can fully benefit from the potential of nanophotonics. This paper examines the information physics aspects of nanophotonics. More specifically, we present some fundamental and emergent information properties that stem from optical excitation transfer mediated by optical near-field interactions and the hierarchical properties inherent in optical near-fields. We theoretically and experimentally investigate aspects such as unidirectional signal transfer, energy efficiency and networking effects, among others, and we present their basic theoretical formalisms and describe demonstrations of practical applications. A stochastic analysis of light-assisted material formation is also presented, where an information-based approach provides a deeper understanding of the phenomena involved, such as self-organization. Furthermore, the spatio-temporal dynamics of optical excitation transfer and its inherent stochastic attributes are utilized for solution searching, paving the way to a novel computing paradigm that exploits coherent and dissipative processes in nanophotonics.

  19. Enhancing the versatility and functionality of fast photochromic bridged imidazole dimers by flipping imidazole rings.

    Science.gov (United States)

    Shima, Kentaro; Mutoh, Katsuya; Kobayashi, Yoichi; Abe, Jiro

    2014-03-12

    The widely tunable optical properties and the visible sensitivity have been required for fast photochromic molecules whose coloration-decoloration cycle completes in μs to ms time scale not only for practical applications such as full-color holographic displays but also for fundamental researches in biochemistry. However, the so far developed [2.2]paracyclophane-bridged imidazole dimers, which are one of the best candidates for fast photochromic molecules, have their weaknesses for these requirements. Herein, we overcome the issues with sustaining fast photochromism and high durability by flipping the two imidazole rings (the head-to-tail and tail-to-tail forms). The alteration in the relative configuration of the imidazole rings suppresses the broad absorption band resulting from the radical-radical interaction. The substitution to the 2-position of the imidazole ring of the tail-to-tail form gives the drastic changes in the steady-state and the transient absorption spectra. The pyrene-substituted tail-to-tail form demonstrates that the transient absorption spectrum is featured by the inherent spectrum of the imidazolyl radical. This molecular framework is easy to functionalize fast photochromic molecules such as sensitizations to the red light, chirality, and biological tagging, and therefore it is versatile for various fast photochromic applications.

  20. The molecular architecture of lamins in somatic cells.

    Science.gov (United States)

    Turgay, Yagmur; Eibauer, Matthias; Goldman, Anne E; Shimi, Takeshi; Khayat, Maayan; Ben-Harush, Kfir; Dubrovsky-Gaupp, Anna; Sapra, K Tanuj; Goldman, Robert D; Medalia, Ohad

    2017-03-09

    The nuclear lamina is a fundamental constituent of metazoan nuclei. It is composed mainly of lamins, which are intermediate filament proteins that assemble into a filamentous meshwork, bridging the nuclear envelope and chromatin. Besides providing structural stability to the nucleus, the lamina is involved in many nuclear activities, including chromatin organization, transcription and replication. However, the structural organization of the nuclear lamina is poorly understood. Here we use cryo-electron tomography to obtain a detailed view of the organization of the lamin meshwork within the lamina. Data analysis of individual lamin filaments resolves a globular-decorated fibre appearance and shows that A- and B-type lamins assemble into tetrameric filaments of 3.5 nm thickness. Thus, lamins exhibit a structure that is remarkably different from the other canonical cytoskeletal elements. Our findings define the architecture of the nuclear lamin meshworks at molecular resolution, providing insights into their role in scaffolding the nuclear lamina.

  1. The Wien Bridge Oscillator Family

    DEFF Research Database (Denmark)

    Lindberg, Erik

    2006-01-01

    A tutorial in which the Wien bridge family of oscillators is defined and investigated. Oscillators which do not fit into the Barkhausen criterion topology may be designed. A design procedure based on initial complex pole quality factor is reported. The dynamic transfer characteristic...

  2. Noise Considerations in Resistance Bridges

    DEFF Research Database (Denmark)

    Diamond, Joseph M.

    1963-01-01

    A signal-to-noise analysis is made of the Wheatstone bridge, where the unknown and standard resistors may be at different temperatures, a situation which occurs in resistance thermometry. The limiting condition is assumed to be dissipation in the unknown resistor. It is shown that the ratio arms ...

  3. Intercellular bridges in vertebrate gastrulation.

    Directory of Open Access Journals (Sweden)

    Luca Caneparo

    Full Text Available The developing zebrafish embryo has been the subject of many studies of regional patterning, stereotypical cell movements and changes in cell shape. To better study the morphological features of cells during gastrulation, we generated mosaic embryos expressing membrane attached Dendra2 to highlight cellular boundaries. We find that intercellular bridges join a significant fraction of epiblast cells in the zebrafish embryo, reaching several cell diameters in length and spanning across different regions of the developing embryos. These intercellular bridges are distinct from the cellular protrusions previously reported as extending from hypoblast cells (1-2 cellular diameters in length or epiblast cells (which were shorter. Most of the intercellular bridges were formed at pre-gastrula stages by the daughters of a dividing cell maintaining a membrane tether as they move apart after mitosis. These intercellular bridges persist during gastrulation and can mediate the transfer of proteins between distant cells. These findings reveal a surprising feature of the cellular landscape in zebrafish embryos and open new possibilities for cell-cell communication during gastrulation, with implications for modeling, cellular mechanics, and morphogenetic signaling.

  4. A Rapidly Deployable Bridge System

    Science.gov (United States)

    2013-01-15

    A Rapidly Deployable Bridge System Gareth R. Thomas1 and Bernard J. Sia2 1ATA Engineering, 11995 El Camino Real, San Diego, CA 92130; PH (858) 480...PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) ATA Engineering,11995 El Camino Real,San Diego,CA,92130 8. PERFORMING ORGANIZATION REPORT NUMBER

  5. Architectural engineering of FRP bridges

    OpenAIRE

    Smits, J.E.P.

    2014-01-01

    This paper deals with the use of Fibre Reinforced Polymers (FRP's) in architectural and structural bridge design. The challenges and opportunities that come with this relatively new material are discussed. An inventory is made of recent engineers' solutions in FRP, followed by a discussion on architectural application of FRP's derived from the authors architectural practice.

  6. Bridge Aesthetics and Structural Honesty

    DEFF Research Database (Denmark)

    Gimsing, Niels Jørgen

    1999-01-01

    In bridges the overall form must be chosen with due respect to the transmission of forces if efficient structures shall be created, The design must therefore be governed by experienced structural engineers - in some cases assisted by aesthetic advisers on specific issues. Some basic requirements...

  7. Architectural engineering of FRP bridges

    NARCIS (Netherlands)

    Smits, J.E.P.

    2014-01-01

    This paper deals with the use of Fibre Reinforced Polymers (FRP's) in architectural and structural bridge design. The challenges and opportunities that come with this relatively new material are discussed. An inventory is made of recent engineers' solutions in FRP, followed by a discussion on archit

  8. Vulnerability of bridges to fire

    DEFF Research Database (Denmark)

    Giuliani, Luisa; Crosti, C.; Gentili, F.

    2012-01-01

    , considering both the costs deriving by structural damages and by limited serviceability and other indirect societal aspects. Few cases of recent bridge fire are reviewed in detail and structural consequences are highlighted, distinguishing between damages directly induced by fire and damages induced by local...

  9. History of cable-stayed bridges

    DEFF Research Database (Denmark)

    Gimsing, Niels Jørgen

    1999-01-01

    The principle of supporting a bridge deck by inclined tension members leading to towers on either side of the span has been known for centuries. However, the real development of cable-stayed bridges did not begin before the 1950s. Since then the free span has been increased from 183 m...... in the Strömsund Bridge (from 1955) to 890 m in the Tatara Bridge (from 1999)....

  10. Field performance of timber bridges. 5, Little Salmon Creek stress-laminated deck bridge

    Science.gov (United States)

    M. A. Ritter; J. A. Kainz; G. J. Porter

    The Little Salmon Creek bridge was constructed in November 1988 on the Allegheny National Forest in Pennsylvania. The bridge is a simple span, single-lane, stress-laminated deck superstructure that is approximately 26-ft long and 16-ft wide. The bridge is unique in that it is the first known stress-laminated timber bridge to be constructed of hardwood lumber. The...

  11. Field performance of timber bridges. 6, Hoffman Run stress-laminated deck bridge

    Science.gov (United States)

    M. A. Ritter; P. D. Hilbrich Lee; G. J. Porter

    The Hoffman Run bridge, located just outside Dahoga, Pennsylvania, was constructed in October 1990. The bridge is a simple-span, single-lane, stress-laminated deck superstructure that is approximately 26 ft long and 16 ft wide. It is the second stress-laminated timber bridge to be constructed of hardwood lumber in Pennsylvania. The performance of the bridge was...

  12. Equilibrium morphologies and effective spring constants of capillary bridges.

    Science.gov (United States)

    Kusumaatmaja, Halim; Lipowsky, Reinhard

    2010-12-21

    We theoretically study the behavior of a liquid bridge formed between a pair of rigid and parallel plates. The plates are smooth, they may either be homogeneous or decorated by circular patches of more hydrophilic domains, and they are generally not identical. We calculate the mechanical equilibrium distance of the liquid bridge as a function of liquid volume, contact angle, and radius of the chemical domain. We show that a liquid bridge can be an equilibrium configuration as long as the sum of the contact angles at the two walls is larger than 180°. When comparisons are possible, our results agree well with recent analytical and molecular dynamics simulation results. We also derive the effective spring constant of the liquid bridge as it is perturbed from its equilibrium distance. The spring constant diverges when the sum of the contact angles is 180° and is finite otherwise. The value of the spring constant decreases with increasing contact angle and volume, and the rate at which it decreases depends strongly on the properties of the two plates.

  13. Building Bridges One Line at a Time

    Science.gov (United States)

    Grigsby, Cathy Murray

    2012-01-01

    In this article, first-grade students were taught the different kinds of lines that were part of the construction of various bridges--the curved lines of the arches of stone bridges, straight lines connecting the cables of a suspension bridge, vertical lines, horizontal lines, and so on. They gained practice in drawing structures and in fine brush…

  14. Comparison between Modern Violin Bridge and Baroque Violin Bridge by Photoelastic Observation and Frequency Analysis

    Science.gov (United States)

    Matsutani, Akihiro

    2004-05-01

    A comparison between the modern bridge and the baroque bridge of the violin by photoelastic observation was carried out. The relationship between the stress part and the hole is symmetric in the modern and baroque bridges. The measured spectral envelopes of baroque bridges are similar to those of modern bridges in D- or G-strings, and have peaks at a frequency higher than those of modern bridges in E-string. The visualization method as used in this study may provide hints for the design of violin bridges.

  15. Neutral molecular cluster formation of sulfuric acid–dimethylamine observed in real time under atmospheric conditions

    CERN Document Server

    Kürten, Andreas; Simon, Mario; Sipilä, Mikko; Sarnela, Nina; Junninen, Heikki; Adamov, Alexey; Almeida, João; Amorim, Antonio; Bianchi, Federico; Breitenlechner, Martin; Dommen, Josef; Donahue, Neil M; Duplissy, Jonathan; Ehrhart, Sebastian; Flagan, Richard C; Franchin, Alessandro; Hakala, Jani; Hansel, Armin; Heinritzi, Martin; Hutterli, Manuel; Kangasluoma, Juha; Kirkby, Jasper; Laaksonen, Ari; Lehtipalo, Katrianne; Leiminger, Markus; Makhmutov, Vladimir; Mathot, Serge; Onnela, Antti; Petäjä, Tuukka; Praplan, Arnaud P; Riccobono, Francesco; Rissanen, Matti P; Rondo, Linda; Schobesberger, Siegfried; Seinfeld, John H; Steiner, Gerhard; Tomé, António; Tröstl, Jasmin; Winkler, Paul M; Williamson, Christina; Wimmer, Daniela; Ye, Penglin; Baltensperger, Urs; Carslaw, Kenneth S; Kulmala, Markku; Worsnop, Douglas R; Curtius, Joachim

    2014-01-01

    For atmospheric sulfuric acid (SA) concentrations the presence of dimethylamine (DMA) at mixing ratios of several parts per trillion by volume can explain observed boundary layer new particle formation rates. However, the concentration and molecular composition of the neutral (uncharged) clusters have not been reported so far due to the lack of suitable instrumentation. Here we report on experiments from the Cosmics Leaving Outdoor Droplets chamber at the European Organization for Nuclear Research revealing the formation of neutral particles containing up to 14 SA and 16 DMA molecules, corresponding to a mobility diameter of about 2 nm, under atmospherically relevant conditions. These measurements bridge the gap between the molecular and particle perspectives of nucleation, revealing the fundamental processes involved in particle formation and growth. The neutral clusters are found to form at or close to the kinetic limit where particle formation is limited only by the collision rate of SA molecules. Even tho...

  16. Discrete Calculus as a Bridge between Scales

    Science.gov (United States)

    Degiuli, Eric; McElwaine, Jim

    2012-02-01

    Understanding how continuum descriptions of disordered media emerge from the microscopic scale is a fundamental challenge in condensed matter physics. In many systems, it is necessary to coarse-grain balance equations at the microscopic scale to obtain macroscopic equations. We report development of an exact, discrete calculus, which allows identification of discrete microscopic equations with their continuum equivalent [1]. This allows the application of powerful techniques of calculus, such as the Helmholtz decomposition, the Divergence Theorem, and Stokes' Theorem. We illustrate our results with granular materials. In particular, we show how Newton's laws for a single grain reproduce their continuum equivalent in the calculus. This allows introduction of a discrete Airy stress function, exactly as in the continuum. As an application of the formalism, we show how these results give the natural mean-field variation of discrete quantities, in agreement with numerical simulations. The discrete calculus thus acts as a bridge between discrete microscale quantities and continuous macroscale quantities. [4pt] [1] E. DeGiuli & J. McElwaine, PRE 2011. doi: 10.1103/PhysRevE.84.041310

  17. ESTIMATION OF ECONOMIC EXPEDIENCY OF «BRIDGE-PRE-BRIDGE TERRITORY» SYSTEM

    Directory of Open Access Journals (Sweden)

    A. A. Lapko

    2008-01-01

    Full Text Available The paper considers principles that form «Bridge-Pre-Bridge Territory» system. The method is proposed for calculation of expenses on technical research for development of projects on usage of pre-bridge territories. Usage of site class number for natural conditions makes it possible to estimate investment attractiveness of «Bridge-Pre-Bridge Territory» system.

  18. Beginning Course Surveys: Bridges for Knowing and Bridges for Being

    Directory of Open Access Journals (Sweden)

    David Starr-Glass

    2011-06-01

    Full Text Available The use of a participant survey, administered at the outset of an online course, can provide information useful in the management of the learning environment and in its subsequent redesign. Such information can clarify participants’ prior experience, expectations, and demographics. But the very act of enquiring about the learner also signals the instructor’s social presence, relational interest, and desire to enter into an authentic dialogue. This study examines the use of participant surveys in online management courses. The first section discusses the informational bridges that this instrument provides. The second section considers survey responses to open-ended questions dealing with student sentiments. This analysis suggests that the survey plays a valuable part in accentuating social presence and in initiating relational bridges with participants.

  19. 33 CFR 115.70 - Advance approval of bridges.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Advance approval of bridges. 115... BRIDGES BRIDGE LOCATIONS AND CLEARANCES; ADMINISTRATIVE PROCEDURES § 115.70 Advance approval of bridges. (a) The General Bridge Act of 1946 requires the approval of the location and plans of bridges...

  20. Stargate GTM: Bridging Descriptor and Activity Spaces.

    Science.gov (United States)

    Gaspar, Héléna A; Baskin, Igor I; Marcou, Gilles; Horvath, Dragos; Varnek, Alexandre

    2015-11-23

    Predicting the activity profile of a molecule or discovering structures possessing a specific activity profile are two important goals in chemoinformatics, which could be achieved by bridging activity and molecular descriptor spaces. In this paper, we introduce the "Stargate" version of the Generative Topographic Mapping approach (S-GTM) in which two different multidimensional spaces (e.g., structural descriptor space and activity space) are linked through a common 2D latent space. In the S-GTM algorithm, the manifolds are trained simultaneously in two initial spaces using the probabilities in the 2D latent space calculated as a weighted geometric mean of probability distributions in both spaces. S-GTM has the following interesting features: (1) activities are involved during the training procedure; therefore, the method is supervised, unlike conventional GTM; (2) using molecular descriptors of a given compound as input, the model predicts a whole activity profile, and (3) using an activity profile as input, areas populated by relevant chemical structures can be detected. To assess the performance of S-GTM prediction models, a descriptor space (ISIDA descriptors) of a set of 1325 GPCR ligands was related to a B-dimensional (B = 1 or 8) activity space corresponding to pKi values for eight different targets. S-GTM outperforms conventional GTM for individual activities and performs similarly to the Lasso multitask learning algorithm, although it is still slightly less accurate than the Random Forest method.