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Background: Gestures can provide an excellent natural alternative to verbal communication in people with aphasia (PWA). However, despite numerous studies focusing on gesture production in aphasia, it is still a matter of debate whether the gesture system remains intact after language impairment and how PWA use gestures to improve communication. A likely source for the contradicting results is that many studies were conducted on individual cases or in heterogeneous groups of individuals with additional cognitive deficits such as conceptual impairment and comorbid conditions such as limb apraxia. Aims: The goal of the current study was to evaluate the integrity and function of gestures in PWA in light of cognitive theories of language-gesture relationship. Since all such theories presuppose the integrity of the conceptual system, and the absence of comorbid conditions that selectively impair gesturing (i.e., limb apraxia), our sample was selected to fulfill these assumptions. Methods & Procedures: We examined gesture production in eight PWA with preserved auditory comprehension, no comorbidities, and various degrees of expressive deficit, as well as 11 age- and education-matched controls, while they described events in 20 normed video clips. Both speech and gesture data were coded for quantitative measures of informativeness, and gestures were grouped into several functional categories (matching, complementary, compensatory, social cueing, and facilitating lexical retrieval) based on correspondence to the accompanying speech. Using rigorous group analyses, individual-case analyses, and analyses of individual differences, we provide converging evidence for the integrity and type of function(s) served by gesturing in PWA. Outcomes & Results: Our results indicate that the gesture system can remain functional even when language production is severely impaired. Our PWA heavily relied on iconic gestures to compensate for their language impairment, and the degree of such compensation was correlated with the extent of language impairment. In addition, we found evidence that producing iconic gestures was related to higher success rates in resolving lexical retrieval difficulties. Conclusions: When comprehension and comorbidities are controlled for, impairment of language and gesture systems is dissociable. In PWA with good comprehension, gesturing can provide an excellent means to both compensate for the impaired language and act as a retrieval cue. Implications for cognitive theories of language-gesture relationship and therapy are discussed. [ABSTRACT FROM AUTHOR]

Recent experimental studies involving Fabric Reinforced Cementitious Matrix (FRCM) strengthening systems externally applied to structural supports have underlined important aspects characterizing their response. In particular, failure mechanisms quite different from the ones emerged in case of traditional Fiber Reinforced Polymers (FRP) have been observed. These mechanisms particularly underline the role of additional phenomena to necessarily consider for the study and the development of theoretical models/design formulas specific for FRCMs. Aim of the present paper is to analyze the role of different aspects characterizing the behavior of FRCM strengthening systems externally applied on structural supports. Among these, it is mainly considered the role of the upper mortar layer, and, in particular, the influence of its possible damage state during the interaction mechanism between the reinforcement and the matrix. With this aim, a simple theoretical model is here presented. It accounts for the interaction between the reinforcement and the mortar matrix at the level of interface, by considering both the de-bonding and the tensile failure of mortar phenomena, which generally affect the resistant mechanism of FRCMs. The results presented in the paper underline the role of the different components of the strengthening system and their influence both in terms of local and global response. [ABSTRACT FROM AUTHOR]

Electromagnetic transient (EMT) and transient stability hybrid simulations are predominantly used to analyze the interactions between HVDC systems and the ac grids. However, the dynamics of the converters will be greatly affected by the waveforms of adjacent ac systems. Waveform distortion as well as time delay caused by interfacing can significantly increase interface errors, resulting in the decrease of the overall accuracy of the simulations. To solve such problems, a dynamic phasor based interface model (DPIM) is proposed in this paper to improve the accuracy of interfaces, especially when the fault occurs near the converters. In doing so, the whole system is partitioned into three parts: the transient stability (TS) subsystem, the EMT subsystem, and the DPIM. During each iteration, the interfaces between the TS subsystem and DPIM are represented by their Norton equivalents at the fundamental frequency and Thevenin equivalents in the dynamic phasor form. Similarly, the interfaces between DPIM and EMT subsystems are represented by their three-phase Norton equivalents and Thevenin equivalents in dynamic phasors, respectively. The effectiveness concerning the accuracy and the efficiency of the proposed method is validated by simulating a practical HVDC Project. [ABSTRACT FROM AUTHOR]

Due to the growing number of requirements and the introduction of new technologies, current trends indicate that more disciplines have been involved into the system design. The design of such multidisciplinary systems, especially during the detailed design phase, requires designers and expertise from different disciplines. Therefore, the research question about how to achieve an integrated design for multidisciplinary systems has attracted the attention from both academia and industry. In order to achieve such integrated design for multidisciplinary systems, more and more researchers focus on the interface of multidisciplinary systems because the interface plays a quite significant role to guarantee the components defined by the designers of different disciplines integrate correctly and to eventually help them to achieve the integrated design. This article presents an interface knowledge base to manage the design data and rules related to the interfaces. A knowledge-based engineering approach is then proposed. By applying the knowledge-based engineering approach, a synergistic integration of the discipline-specific components can be realised; however, the unnecessary iterations can be avoided so that a concurrent design process during the detailed design phase can be achieved. This knowledge-based engineering approach is demonstrated by the case studies based on a partial discharge detection system and a belt conveyor system. [ABSTRACT FROM AUTHOR]

Adhesively bonded joints are used in several industrial sectors. Cohezive Zone Modes can be used to predict the adhesive mechanical behaviour. This work presents an approach to calibrate Cohesive Zone Models (CZM) by means of Statistical Inverse Analysis. The Bayesian framework for Inverse Problems is used to infer about the CZM model parameters. The solution corresponds to the exploration of the posterior probability density function of the model parameters. The exploration of the posterior density is performed by means of Markov Chain Monte Carlo (MCMC) methods mixing Population-Based MCMC with Adaptive Metropolis (AD) strategies. The assessment of the approach is performed using measured data from a singlelap shear experimental set-up. Measured data from 5 testspecimens is used for calibration and measured data from five other test-specimens is used for model validation. It is proposed a stochastic effective model for the CZM parameters. The predictions of maximum force and maximum displacement that are provided by the effective model are in accordance with measured data that is used for validation. [ABSTRACT FROM AUTHOR]

This paper proposes a novel multirate co-simulation method to improve simulation efficiency of large-scale AC plus multiterminal DC (MTDC) grids. In this method, the whole system is partitioned into different AC and MTDC subsystems. They each are simulated with different time steps according to their requirements of accuracy. Unlike the existing methods where simplified models are adopted, the proposed approach fully reserves both the detailed behavior of converters and the nonlinear dynamics of large-scale AC systems. To realize the coordination between different subsystems, updating and discretization of the interface models are significant to guarantee the overall numerical accuracy and stability of the co-simulation method. Accordingly, the interface models of the partitioned AC and DC networks are represented by time-varying Thevenin and Norton equivalents. To eliminate the aliasing or time-delay errors, their parameters are derived using moving-window prediction, stepwise correction, and averaging techniques. A numerical oscillation suppression algorithm is developed for the discretization of the interface model. Thus, numerical stability is well guaranteed. The variables inside each subsystem as well as the interfaces, which are derived by augmented network equations (ANEs), are calculated simultaneously. The rate ratio of large AC and MTDC systems is determined based on our proposed criterion of electromagnetic transient simulation accuracy. The effectiveness of the cosimulation method is validated on a practical system integrating large AC and modular-multilevel-converter-based MTDC grids. [ABSTRACT FROM AUTHOR]

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Discrete fracture networks is a key ingredient in the simulation of physical processes which involve fluid ow in the underground, when the surrounding rock matrix is considered imper- vious. In this paper we present two different models to compute the pressure field and Darcy velocity in the system. The first allows a normal ow out of a fracture at the intersections, while the second grants also a tangential ow along the intersections. For the numerical discretization, we use the mixed virtual element method as it is known to handle grid elements of, almost, any arbitrary shape. The exibility of the discretization allows us to loosen the requirements on grid construction, and thus significantly simplify the ow discretization compared to traditional discrete fracture network models. A coarsening algorithm, from the algebraic multigrid literature, is also considered to further speed up the computation. The performance of the method is validated by numerical experiments. [ABSTRACT FROM AUTHOR]

The addition of graphene in Al-based composites results in the creation of a high-content interface, which serves as the primary contributor to the reinforcement performance of the composites. Nevertheless, the reinforcing agent at the nanoscale level exhibits extremely high reactivity, making it prone to reacting with the Al matrix at the interface and producing the brittle phase Al 4 C 3. In this paper, the electronic structure and interface stability of the graphene/aluminum with alloy atoms were systematically studied using first-principles calculation based on density functional theory. The interactions of four different alloying atoms (Mg, Cu, Ti, and Ni) were analyzed, the results show that the four metal atoms exhibit varying levels of micro-alloying, and the coating of alloying atoms enhances the interfacial bonding stability. The band structure calculations of interfacial configurations with alloy atoms (Mg, Cu, Ti, Ni) indicate that Cu and Mg have little impact on the integrity of graphene layers at the interface, while Ni and Ti are detrimental to the integrity of graphene at the interface. The composites were fabricated through a process of vacuum hot-press sintering, and a series of characterization experiments were conducted to confirm the accuracy of our calculations. This study offers theoretical guidance for future development of aluminum alloy composites by exploring the impact of alloying atoms on the stability and electronic structure of the graphene/aluminum alloy interface. • The effect of alloying atom cladding on graphene/aluminum alloy interface was investigated using first principles. • The results of bond populations show that the bonding strength of several Graphene/Al alloy interfaces is: Ti > Ni > Cu > Mg. • The composites were fabricated through a process of vacuum hot-press sintering, which conducted to confirm the accuracy of our calculations. [ABSTRACT FROM AUTHOR]

A cohesive interface model based on a master curve is proposed for the analysis of delamination in paperboard under various loading, unloading, and reloading conditions. The model is thermodynamically consistent and considers the effects of elasticity, plasticity, and damage. The proposed model is verified by comparing its predictions with experimental data obtained from multiple loading–unloading–reloading cycle experiments using a split double cantilever beam specimen. The results show that the model can predict the cyclic behavior of shear loading and provide insight into the damage evolution associated with different loading paths by analyzing the shear stress distribution in the fracture process zone. The model's calibration process requires monotonic normal and shear loading data but only cyclic normal loading data. Additionally, the model accounts for the paperboard's fiber–fiber friction and normal dilatation due to shear loading. In total, nine parameters are needed to calibrate the model. • A cohesive interface model for delamination in paperboard is proposed. • The model considers the effects of elasticity, plasticity, and damage. • The model is validated by comparing it to split double cantilever beam specimen data. • The model predicts cyclic shear load behavior and damage evolution via load paths. • The calibration needs normal and shear data but only cyclic normal loading data. [ABSTRACT FROM AUTHOR]

The research on the control strategy and dynamic characteristics of the Molten Carbonate Fuel Cell-Micro Gas Turbine (MCFC-MGT) hybrid power system has received much attention. The use of the Hardware-In-the-Loop Simulation (HILS) method to study the MCFC-MGT hybrid power system, where the MCFC is the model subsystem and the MGT is the physical subsystem, is an effective means to save development cost and time. The difficulty with developing the MCFC-MGT HILS system is the transfer of the mass, energy, and momentum between the physical subsystem and the model subsystem. Hence, a new Simulation−Stimulation (Sim−Stim) interface model of the MCFC-MGT HILS hybrid power system to achieve a consistent mass, energy, and momentum with the prototype system of the MCFC-MGT hybrid power system is proposed. In order to validate the Sim−Stim interface model before application in an actual system, both a real-time model of the MCFC-MGT hybrid power system and the MCFC-MGT HILS hybrid power system based on the Sim−Stim interface model were developed in the Advanced PROcess Simulation (APROS) platform. The step-up and step-down of the current density, which were strict for the Sim−Stim interface model, were studied in these two models. The results demonstrated that the Sim−Stim interface model developed for the MCFC-MGT HILS hybrid power system is rapid and reasonable.

A novel damage mechanics-based continuous micro-model for the analysis of masonry-walls is presented and compared with other two well-known discrete micro-models. The discrete micro-models discretize masonry micro-structure with nonlinear interfaces for mortar-joints, and continuum elements for units. The proposed continuous micro-model discretizes both units and mortar-joints with continuum elements, making use of a tension/compression damage model, here refined to properly reproduce the nonlinear response under shear and to control the dilatancy. The three investigated models are validated against experimental results. They all prove to be similarly effective, with the proposed model being less time-consuming, due to the efficient format of the damage model. Critical issues for these types of micro-models are analysed carefully, such as the accuracy in predicting the failure load and collapse mechanism, the computational efficiency and the level of approximation given by a 2D plane-stress assumption. [ABSTRACT FROM AUTHOR]

A discontinuous approach aimed at modeling the brittle fracture behavior of mesoscopic 100Cr6 (SAE 52100) steel specimens is presented in this work. The proposal accounts for explicitly considering carbide particles and martensitic matrix in a metallographic image based mesoscale model. Two-dimensional numerical tests are carried out for the mesoscale specimens including a temperature dependent elastoplastic matrix dealing with the martensitic/austenitic phases and the embedded elastic carbide particles. A fracture damage-based interface constitutive rule is then employed for modeling the brittle behavior occurring at the joint between both the carbides-to-matrix and the matrix-to-matrix interfaces. The soundness and capability of the proposed formulation dealing with the quench cracking phenomenon is demonstrated. Experimental tensile test results on a 100Cr6 steel in its martensitic phase, at room and high temperature, are employed and the evaluation of microcracks formation during a High-Speed-Quenching test is also discussed. [ABSTRACT FROM AUTHOR]

We analyze the motion of a sharp interface between fresh and salt groundwater in horizontal, confined aquifers of infinite extend. The analysis is based on earlier results of De Josselin de Jong (Proc Euromech 143:75-82, 1981). Parameterizing the height of the interface along the horizontal base of the aquifer and assuming the validity of the Dupuit-Forchheimer approximation in both the fresh and saltwater, he derived an approximate interface motion equation. This equation is a nonlinear doubly degenerate diffusion equation in terms of the height of the interface. In that paper, he also developed a stream function-based formulation for the dynamics of a two-fluid interface. By replacing the two fluids by one hypothetical fluid, with a distribution of vortices along the interface, the exact discharge field throughout the flow domain can be determined. Starting point for our analysis is the stream function formulation. We derive an exact integro-differential equation for the movement of the interface. We show that the pointwise differential terms are identical to the approximate Dupuit-Forchheimer interface motion equation as derived by De Josselin de Jong. We analyze (mathematical) properties of the additional integral term in the exact interface motion formulation to validate the approximate Dupuit-Forchheimer interface motion equation. We also consider the case of flat interfaces, and we study the behavior of the toe of the interface. In particular, we give a criterion for finite or infinite speed of propagation. [ABSTRACT FROM AUTHOR]

Activated carbon (AC) is a broad-spectrum adsorbent but is flammable and has low adsorption capacities for polar and/or high-boiling volatile organic compounds (VOCs), while zeolites exhibit high thermal stability but poor adsorption of macromolecular and nonpolar VOCs. In this study, zeolite/AC composites were synthesized with the aim of obtaining broad-spectrum, efficient, and safe adsorbents for VOCs. Dimethyldiallylammonium chloride (DDA)-modified AC was used as a carrier for an in situ hydrothermal reaction enabling assembly with zeolites due to electrostatic attraction. Interface models were constructed for their phases, which revealed the binding force and simulated the binding process. The adsorption and flame resistance of the composites were evaluated. The results showed that DDA effectively modified AC to give it a long-lasting positive charge in solutions. High-silicon and pure-silicon zeolites exhibited low negative charges or were even neutral; it was difficult to combine with the modified AC via electrostatic attractions. Instead, LTA zeolites with high aluminum contents and negative charges were used, and the seed-induction method was used. Ethanol and ultrasonic dispersion were used to prevent agglomeration of the seeds and modified AC powder, so they were self-assembled electrostatically. Moreover, the crystallization time was extended and composites with high zeolite loadings were successfully prepared. According to the model calculation, the binding energy between the zeolite and AC before and after the DDA modification were 324.97 and 1076.46 kcal mol -1 , respectively, and the distance between them was shortened by 2.7 Å after DDA treatment. As a result, AC and zeolite combined more closely and exhibited a stronger binding energy. The adsorption capacity for highly polar dichloromethane was improved by zeolite loading on the AC, and the bed penetration time was doubled. However, impregnation with inorganic sodium enhanced the reactivities of the organic components in the composite, and the ignition point was slightly reduced. Furthermore, the electrostatic self-assembly method can expand to prepare the LTA zeolite/columnar AC composite from shaped AC, greatly improving its application prospects.