Applying formal methods to distributed algorithms using local-global relations

Effects of self energy of the ions on the double layer structure and properties at the dielectric interface

Chemical processes at the interfaces often differ kinetically and mechanistically from the bulk counterparts, partly due to the concentration inhomogeneity of different chemicals at the interfaces. The fractionation of chemicals at the interfaces not only determines their interfacial concentrations, but also affects the physicochemical properties of the interfaces. In this thesis, three sets of chemicals/interfaces with important environmental implications are studied: (1) anion fractionation at the gas–liquid microdroplet interfaces, (2) fractionation of perfluoroalkyl surfactants and matrix components at the bubble–water interface in ultrasonically irradiated solutions, and (3) ion fractionation across the ice–water interface during the freeze–thaw cycle of electrolyte solutions. The relative anion affinity for the air–water interface, as measured by Electrospray Mass Spectrometry (ES–MS), is exponentially correlated with ionic radius. The affinities respond differently to different additives, suggesting that specific anion effects are due to different energy levels of physical interactions. Relative anion affinities at the air–methanol interfaces are almost identical to those at the air–water interface, suggesting that surface structure is not the primary driving force for interfacial anion fractionation. Perfluoroalkyl carboxylates and sulfonates can be transferred from the ocean to marine aerosols due to their high affinity for the air–water interface, but transfer to gas phase is unlikely as they remain deprotonated in aqueous phase because of their low pKa. Organic matrix components may reduce the sonochemical kinetics of Perfluorooctanesulfonate (PFOS) and Perfluorooctanoate (PFOA) by competitive adsorption onto the bubble–water interface or by lowering the interfacial temperatures. Inorganic anions, but not cations, may significantly enhance or reduce the sonochemical kinetics of PFOS and PFOA. The specific anion effects following the Hofmeister series are likely related to anions’ partitioning to and interaction with the bubble–water interface. Time–resolved confocal fluorescence microscopy of freezing electrolyte solutions reveals that the thickness of interstitial liquid films depends non–monotonically on electrolyte concentration. It also confirms that selective incorporation of cations (anions) into the ice lattice decreases (increases) the pH of the interstitial liquid films. Since the magnitude of pH change during freezing is smaller than during the subsequent thawing process, it is likely to be limited by the seepage of proton or hydroxide slowly produced via water dissociation.

With increasing computer capabilities, numerical modeling of two-phase flows has developed significantly over the last few years. Although there are two main categories, namely 'one' fluid and 'two' fluid methods, the 'one' fluid methods are more commonly used for tracking or capturing the interface between two fluids. Level set (LS), volume-of-fluid (VOF), front tracking, marker-and-cell (MAC) and lattice Boltzmann (LB) methods are all 'one' fluid methods. It is clear that there is no perfect method; each method has advantages and disadvantages which make it more appropriate for one kind of problem than for others. For instance, a LS method will accurately compute the curvature and the normal to the interface, but tends to loss mass which is physically incorrect. On the other hand, a VOF method will conserve mass up to machine precision, but the computation of the curvature and normal to the interface is not as accurate. In order to minimize the disadvantages of these methods, several authors have used two or more methods together to model two-phase flows. This is the case for the CLSVOF (Couple Level Set Volume Of Fluid) method, where LS and VOF are coupled together in order to better capture the interface. In CLSVOF, the level set function is used to compute the interface curvature and normal to the interface, while the volume of fluid function is used to capture the interface. For two-phase flows in microchannels, surface tension forces play an important role in determining the dynamics of bubbles whereas gravitational forces are generally negligible. Also it is very important to consider the interaction between the boundaries and the fluids by prescribing or computing the correct contact angle between them. The commercial CFD code FLUENT allows the use of static constant angles, or the use of User Defined Functions (UDF) to compute the dynamic contact angles. It is inappropriate to use a static contact angle to model cases involving moving contact lines. For such cases a dynamic contact angle scheme should be implemented. In this study, FLUENT was used to model adiabatic and diabatic, time dependent two-phase flows. Since FLUENT already contains a VOF method, a LS method was implemented and coupled with VOF into FLUENT via UDFs. Furthermore, since the LS function, used to compute the surface tension force, ceases to be a signed distance to the interface even after one time step, a re-initialization equation was solved after each time step. This involved using a fifth order WENO (Weighted Essentially Non Oscillatory) scheme to discretize the space derivatives (otherwise oscillations of the interface occurred), and a first order Euler method for the time integration. In another part of the study, a 3D dynamic contact angle model based on volume fraction, interface reconstruction, and experimentally available advancing and receding static contact angles was also developed and implemented into FLUENT via UDFs. Several validations for the developed CLSVOF method and dynamic contact angle model are presented in this thesis, these includes a static bubble, a bubble rising in a stagnant liquid for Morton numbers ranging from 102 to 10-11, droplet deformation due to a vortex flow field, droplets spreading over a wall under the gravity effect and droplets sliding over a wall due to gravity. These validations demonstrated the high accuracy and the stability of our methods for modeling these phenomena. A heat and mass transfer model was also implemented into the commercial CFD code FLUENT for simulating of boiling (and condensation) heat transfer. Several simulations were presented with water and R134a as working fluids. The influence of the contact angle and the wall superheat was also studied.

The popularity of social media platforms results in a huge volume of online conversations produced every day. To help users better engage in online conversations, this article presents a novel framework to automatically recommend conversations to users based on what they said and how they behaved in their chatting histories. While prior work mostly focuses on post-level recommendation, we aim to explore conversation context and model the interaction patterns therein. Furthermore, to characterize personal interests from interleaving user interactions, we learn (1) global interactions , represented by topic and discourse word clusters to reflect users’ content and pragmatic preferences, and (2) local interactions , encoding replying relations and chronological order of conversation turns to characterize users’ prior behavior. Built on collaborative filtering, our model captures global interactions via discovering word distributions to represent users’ topical interests and discourse behaviors, while local interactions are explored with graph-structured networks exploiting both reply structure and temporal features. Extensive experiments on three datasets from Twitter and Reddit show that our model coupling global and local interactions significantly outperforms the state-of-the-art model. Further analyses show that our model is able to capture meaningful features from global and local interactions, which results in its superior performance in conversation recommendation.

A Java applet is a small application which is written in Java, and the user launches it from a web page. It has the function of realistic interface design, powerful graphics and computing functions and a serial of events interaction and response mechanism. This article analyzes the present situation of physics experiment network teaching, and then points out that the virtual simulation experiment in network teaching will involve some obvious drawbacks such as the Internet bandwidth and system security, etc. Relative to this, the Java applet shows its own unique advantages, including powerful capacity, multithreading, free installation, strong compatibility, high security, and so on. So if we apply the advantages of Java applet to physics experiment network teaching, such as restoring physical process, simulating physical phenomena, processing experimental data, etc., we can do better to promote physics teaching reform, enhance quality of physics experiment teaching, improve physics experiment teaching resources construction, and so on.

Interfacial delamination in polymer coated metal sheet : a numerical-experimental study

Over recent years there has been a growing interest in molecular semiconductors of the oligoacene family. The interest has been spurred by the unique properties of these materials for applications for electronic devices, namely being °exible, cheap and exhibit- ing relatively high charge-carrier mobilities. Despite this interest, the nature of charge transport in the materials has remained the subject of intense debate. When these oligoacenes are used for device applications, they will often be evaporated as a ¯lm onto a substrate, since the fabrication process and the handling of these thin ¯lms is easier and cheaper than using single crystals. Besides the fundamental bulk properties, for the usage in devices it is also of high importance to know how the properties of these materials di®er at the interface with metals, since the substrates and contacts are often metallic. Therefore in this work both the vibrational and electronic properties of thin ¯lms of pentacene have been investigated as well as the intrinsic charge transport mechanism for the single-crystalline bulk material of pentacene and rubrene. The ¯rst main focus in this study was on the electronic and vibrational properties of thin layers of pentacene (ranging from 1 monolayer to 6 layers of pentacene molecules) evaporated on metal surfaces. These pentacene layers have been investigated using High Resolution Electron Energy Loss Spectroscopy (HREELS), which is a surface sensitive technique that probes both the vibrational and electronic states of the top layers of the sample by detecting the loss in energy of a beam of monochromatic electrons. The main advantages of this technique in comparison to techniques like IR and Raman spectroscopy are the surface sensitivity, the high spectral resolution (FWHM of 13 cm¡1), the broad energy range (from lattice phonons to surface plasmons and interband transitions) and the ability to measure as a function of wave vector transfer. Pentacene was grown upon Ag(111) and Au(100) surfaces, forming thin layers of var- ious thicknesses. The obtained vibrational spectra were compared to the vibrational modes for an isolated molecule calculated using DFT methods. The spectra of ¯lms of over 4 molecular layers showed contributions from all the optical active modes predicted by the calculation as is expected for a non-frustrated Van Der Waals bonded crystalline material. Furthermore the spectra showed low energetic features related to the lattice phonons. Both inter- and intramolecular modes showed little to no dispersion. The spec- tra for a monolayer deviated strongly from the vibrational structure of the multi-layers. Not only were the intermolecular modes absent, all intramolecular optical active modes with a dipole moment parallel to the interface were screened by the metal surface. In the case of a monolayer of pentacene on Ag(111) the interaction with the surface is so strong that the symmetric Ag modes became optically active as a result of charge transfer from the metallic substrate. For the intermediate regime (layers of 2 to 4 molecules) the spectra showed several contributions that cannot be explained using the calculated data on the symmetry and energy of the intramolecular modes. With HREELS not only the vibrational aspects of the thin ¯lms were studied but also the electronic transitions. The spectra for layers of more than four molecular layers could be modeled by combining calculations on the position of both excitonic and band levels and calculations of the vibronic ¯ne structure. For a monolayer of pentacene, states within the electronic gap were observed, the so-called Charge Neutrality Levels, which are substrate dependent. With increasing thickness the observed presence and position of the exciton states di®ered, thereby giving more insight in the structure of pentacene near the interface. Terahertz Time Domain Spectroscopy (THz TDS) is a technique that allows determin- ing the complex frequency dependent conductivity and is a powerful tool to investigate the charge transport mechanism in materials. THz TDS was used to study the charge trans- port as a function of temperature for single crystals of both pentacene and rubrene. For pentacene the conductivity spectra at various temperatures showed a strong absorption for the low energetic vibrational modes and thereby gave evidence for the model proposed by A. Troisi and G. Orlandi. This model describes the charge transport behaviour by one single mechanism: the large °uctuations in the intermolecular coupling of electronic states caused by thermal molecular motions. Furthermore it is shown that the charge density, and as a result the interaction between charges, plays an important role in the conductivity of these materials. In conclusion, this work shows that vibrational aspects are a key factor in under- standing the charge transport in oligoacene materials, and that good knowledge of the properties of these materials at the interface is essential, since di®erences in both struc- ture and electronic interaction with the substrate give rise to di®erent vibrational and electronic states in oligoacene materials.

Error handling in multimodal voice-enabled interfaces of tour-guide robots using graphical models

This paper describes two approaches to the automatic generation of behavioral VHDL models from descriptions written in natural language. Both approaches are based on a modeling style in which behavior is represented by a system of interconnected processes. The first approach employs a semantic grammar to directly generate a single VHDL process from a paragraph written in a restricted English called ModelSpeak. The second approach accepts more general English and generates models consisting of multiple processes. series of sentences describing the behavior of a single process and generated correct VHDL code for it. This interface requires the behavior be expressed in a highly restricted English called ModelSpeak (10). Conditional expressions (if statements) may be nested to two levels, and interaction is invoked by the interface to resolve scope ambiguity of loops. This interface is implemented with a semantic grammar (3) in Prolog. The second interface (Approach II) to the Modeler's Assistant for natural language is substantially more complex, but accepts more general English expressions and generates multiple-process models. In this approach, each sentence is parsed by a bottom-up, parallel chart parser to generate a set of valid parse trees. The trees are examined by a Semantic Analyzer (7) to determine one which is semantically correct, and a conceptual graph (14) (semantic network) of its meaning is generated. Once the conceptual graph of individual sentences are joined together (12), a program called the Linker (8) analyzes the graph to produce a Process Model Graph and VHDL process code for the Modeler's Assistant. Nodes in the conceptual graph representing verbs typically generate processes or the conditions which govern them. Nodes representing objects generate signals. The modeling style underlying the Linker produces a sizable collection of processes, each consisting of a single if_then statement. To avoid unnecessary bus resolutions, multiple processes assigning to the same signal are merged. Since signal types are generally not expressed in the English description, they may be added interactively later. Before describing the approaches in more detail, related research on natural language interfaces is reviewed briefly.

What's the relationship between the new communicative technology and the society? Instead of a macro perspective, this article tries to use a micro perspective to analyze human-computer interaction. By the micro analysis, I answer the question of how to design human-computer interface. This article focuses on a new technology, the Skype's webcam, and uses affordance theory to examine biological and cultural constraints and creativities. The examination focuses on the nonverbal communicative element-gaze. How do people change their visual perception and the rules of interaction? How do people create embodied interaction and new rules? The data transcribes the conversation and gaze in the use of Skype. The research finds that special media space influences people's visual perception and changes the ways of communication. The human- computer interaction designers should be concerned about these issues. Finally, this article tries to answer the basic question of communication, i.e., where the meaning is from. Language is no longer the privileged communicative element in new technology. Verbal and nonverbal elements intertwine with each other in the symphony of meanings. No element is more important than another. This article emphasizes the importance of nonverbal communicative element in human-computer interaction interface design.

Augmented tabletops have recently attracted considerable attention in the literature. However, little has been known about the effects that these interfaces have on learning tasks. In this paper, we report on the results of an empirical study that explores the usage of tabletop systems in an expressive collaborative learning task. In particular, we focus on measuring the difference in learning outcomes at individual and group levels between students using two interfaces: traditional computer and augmented tabletop with tangible input.No significant effects of the interface on individual learning gain were found. However, groups using traditional computer learned significantly more from their partners than those using tabletop interface. Further analysis showed an interaction effect of the condition and the group heterogeneity on learning outcomes. We also present our qualitative findings in terms of how group interactions and strategy differ in the two conditions.

This workshop will provide a forum for researchers, practitioners and developers interested in user engagement and emotion in the context of human information interaction. Specifically, the workshop aims to address the following questions: “How do we ensure that the measurement of subjective information experience is robust and scalable?”, “How do we design interfaces for engaging and emotionally compelling experiences?”, and “How do we prevent disengagement?” The ability to answer these questions relies upon: a solid conceptual understanding of subjective experiences; robust, scalable approaches to measuring engagement; and the ability to utilize this knowledge in information systems and interface design. This three-part half-day workshop will include: talks by the organizers to ground the workshop’s themes; position paper presentations and design exemplars from attendees, and an interactive session focused on design scenarios and prototyping. The intersection of emotion and engagement with measurement and design in information interaction contexts is a timely issue for the iSchool community.

Contents: Jake Harwood: Lifespan Communication Theory - Margaret J. Pitts/Mary Lee Hummert: Lifespan Communication Methodology - Carol A. Miller/Laura S. DeThorne: Communication Development: Distributed Across People, Resources, and Time - Beth Bonniwell Haslett/Wendy Samter: Parent-Infant Communication - Helen G. M. Vossen/Jessica Taylor Piotrowski/Patti M. Valkenburg: Media Use and Effects in Childhood - Robert L. Duran/Diane T. Prusank: Children's Peer Relationships Outside the Family - Jennifer H. Waldeck: Communication and Learning - Piotr S. Bobkowski/Autumn Shafer: The Digital Bridge into Adulthood:Media Uses and Effects in Adolescence - Michael L. Hecht: Adolescent Identity and Substance Use Prevention - Kevin B. Wright/Shawn King: Adolescent Online Friendship and Peer Relationships - Emerging Adulthood Communication - Alyssa Ann Lucas: Emerging Adults in College: Communication, Friendships, and Risky Sexual Behaviors - Tara G. McManus: Commitment and Marriage - Michael W. Kramer/Karen K. Myers: Communication and Workplace Socialization: A Lifespan Examination of the Work-Life Interface - Andrew C. High: Friend Me, Poke Me, Then Comfort Me: An Exploration of Supportive Communication in Online Social Networking Sites - Jordan Soliz/Craig Fowler: Sandwich Relationships: Intergenerational Communication - Dennis S. Gouran: Communicating in Professional Life The Nature and Evolution of Superior-Subordinate Interactions - Diane T. Prusank: Spouse and Parent: Television Images of Major Roles of Adulthood - Older Adulthood Communication - James D. Robinson/Kathleen B. Watters: Media Use and Effects in Older Adulthood - Fran C. Dickson/Patrick Hughes: The Socially and Sexually Active Later-Life Family Member - Carla L. Fisher/Mollie Rose Canzona: Health Care Interactions in Older Adulthood - Howard Giles/Chan L. Thai/Abby Prestin: End-of-Life Interactions.

Examples, Ion Properties and Concepts: The Past and What Can Be Learnt from It (W Kunz et al.) Specific Ion Properties (G Hefter) Ion-Surfactant Interactions: Experiments and Models (E Leonitis) Promising Experimental Techniques: Probing Specific Ion Effects with Grazing Incidence X-Ray Diffraction (J Daillant) Neutron Scattering, Simulation, Denaturants (P E Mason & G Neilson) Specific Ion Effects at The Air-Water Interface - New Experimental Studies (V Craig) Newest Results From Theory and Simulation: Simulations of Ions at the Air-Water Interface and Near Biomolecules (M Lund & P Jungwirth) Simulations of Ion Near Water-Solid Interfaces and in Bulk Water (R Netz & D Horinek) HNC Calculations of Specific Ion Effects (L Belloni) and other papers.

As smart homes become more widespread, the need for more natural forms of interaction in the home also increases. On the one hand, forcing a user to go to a central home controller at every required change does not make sense. On the other hand, having a different controller for each device is also quite overwhelming. Object-Specific Interfaces (OSIs) allow an interface customized to an object of interest to show up on a mobile device when in close proximity to it. The interface can be passive, thus showing a manual or information, or interactive and so would allow for device monitoring and controlling.