Mechanical characteristics of optical coatings prepared by various techniques: a comparative study

Good performance of optical coatings depends on the appropriate combination of optical and mechanical properties. Therefore, successful applications require good understanding of the relationship between optical microstructural and mechanical characteristics and film stability. In addition, there is a lack of standard mechanical tests that allow one to compare film properties measured in different laboratories. We give an overview of the methodology of mechanical measurements suitable for optical coatings; this includes depth-sensing indentation, scratch resistance, friction, abrasion and wear testing, and stress and adhesion evaluation. We used the techniques mentioned above in the same laboratory to systematically compare the mechanical behavior of frequently used high- and low-index materials, namely, TiO2, Ta2O5, and SiO2, prepared by different complementary techniques. They include ion-beam-assisted deposition by electron-beam evaporation, magnetron sputtering, dual-ion-beam sputtering, plasma-enhanced chemical-vapor deposition, and filtered cathodic arc deposition. The mechanical properties are correlated with the film microstructure that is inherently related to energetic conditions during film growth.     

Understanding the Role of Body Movement in Player Engagement

The introduction of full-body controllers has made computer games more accessible and promises to provide a more natural and engaging experience to players. However, the relationship between body movement and game engagement is not yet well understood. In this article, I consider how body movement affects the player's experience during game play. I start by presenting a taxonomy of body movements observed during game play. These are framed in the context of a body of previously published research that is then embedded into a novel model of engagement. This model describes the relationship between the taxonomy of movement and the type of engagement that each class of movement facilitates. I discuss the factors that may inhibit or enhance such relationship. Finally, I conclude by considering how the proposed model could lead to a more systematic and effective use of body movement for enhancing game experience.     

Congestion-aware ant colony based routing algorithms for efficient application execution on Network-on-Chip platform

Networks-on-Chip (NoC) is an interesting option in design of communication infrastructures for embedded systems. It provides a scalable structure and balanced communication between the cores. Parallel applications that take advantage of the NoC architectures, are usually are communication-intensive. Thus, a big deal of data packets is transmitted simultaneously through the network. In order to avoid congestion delays that deteriorate the execution time of the implemented applications, an efficient routing strategy must be thought of carefully. In this paper, the ant colony optimization paradigm is explored to find and optimize routes in a mesh-based NoC. The proposed routing algorithms are simple yet efficient. The routing optimization is driven by the minimization of total latency during packets transmission between the tasks that compose the application. The presented performance evaluation is threefold: first, the impact of well-known synthetic traffic patterns is assessed; second, randomly generated applications are mapped into the NoC infrastructure and some synthetic communication traffics, that follow known patterns, are used to simulate real situations; third, sixteen real-world applications of the E3S and one specific application for digital image processing are mapped and their execution time evaluated. In both cases, the obtained results are compared to those obtained with known general purpose algorithms for deadlock free routing. The comparison avers the effectiveness and superiority of the ant colony inspired routing.     

Tributyl citrate oligomers as plasticizers for poly (lactic acid): thermo-mechanical film properties and aging

Poly (lactic acid), PLA, is a biodegradable thermoplastic that can be produced from renewable resources. The polymer is of interest for production of films for packaging applications. However, plasticization of PLA is required in order to obtain films with sufficient flexibility. PLA was blended with tributyl citrate (TbC) and two oligomers of TbC that were synthesized by transesterification of tributyl citrate (TbC) and diethylene glycol (DEG). Dynamic mechanical analysis (DMA) and differential scanning calorimetry (DSC) were used to investigate the dynamic mechanical and thermal properties of the blends. All the plasticizers investigated decreased the glass transition temperature of PLA, and the reduction was the largest with the plasticizer having the lowest molecular weight. The PLA matrix became saturated with plasticizer at a certain concentration and phase separation occurred; the higher the molecular weight of the plasticizer, the lower the saturation concentration. Aging of the blends at room temperature for several months induced partial phase separation in the material. It was observed that the morphological stability of the blends was enhanced when the plasticizer concentration was reasonably low, i.e. 10-15 wt%.     

Personalized video adaptation framework (PIAF): high-level semantic adaptation

Despite much work on Universal Multimedia Experience (UME), existing video adaptation approaches cannot yet be considered as truly user-centric, mostly due to their poor handling of semantic user preferences. Indeed, these works mainly concentrate on lower-level user preferences but do neither consider any fine-grained object-level adaptation nor evaluate different adaptation options based on predicted user expectations. Moreover, these works do not provide owners with property rights that enable them to place restrictions on the types of modifications to be made to the video content. To address these shortcomings, we propose the Personalized vIdeo Adaptation Framework (PIAF) for high-level semantic video adaptation. PIAF is a fully integrated framework providing all the requirements for a semantic video adaptation. It defines a video annotation model and a user profile model comprising semantic constraints that are delineated in a consistent way, based on the standards MPEG-7 and MPEG-21. At the heart of the framework, the Adaptation Decision Taking Engine (ADTE) computes utility values for different adaptation options, considering each shot separately. The corresponding utility function evaluates the possible choices by evaluating multiple parameters that capture different dimensions of a multimedia experience: amount of modified content, modifications to key objects and shots with respect to the semantic integrity of the original content, expected processing cost of the adaptation, and the anticipated visual and temporal quality of the adapted content. Furthermore, the ADTE can deal with intellectual property issues by selecting an adaptation plan of good quality that also satisfies constraints specified by the content owner. This paper places a significant emphasis on theoretical details of the utility function and the computation of the adaptation plan. It also presents the results and evaluation of the adaptation process both in simulation and user study.     

Influence of ageing on the dynamic behaviour and the electrochemical characteristics of a 500 We PEMFC stack

In this study, a 500 We 19 cells Proton exchange membrane fuel cell (PEMFC) stack was aged for ∼1200 h and submitted to current steps between different operating levels. Using two different multi-channel data acquisition systems (one at 100 kHz and one at 1 Hz). the evolution with ageing of individual cells and full stack's short term (∼10 s) and medium term (∼4 min) dynamic performances was followed. Undershoots and overshoots behaviours were observed for respective current step-up and step-down. It appeared that, in studied operating conditions, the first time constant was related to the charge transfer at electrode/electrolyte interfaces. After the first “plateau”, the voltage evolution was explained by a membrane water content evolution.     

Multifold behavior of the information transmission by the quantum 3-switch

Quantum Information Processing - A Correction to this paper has been published: https://doi.org/10.1007/s11128-019-2234-5     

Distribution of NGF and NT-3-like protein immunoreactivity in the teleost kidney

By means of immunochemistry and immunohistochemistry, we investigated in the kidney of freshwater and marine teleostean species for the presence and localization of three neurotrophins: nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), and neurotrophin (NT)-3. In both species studied, NGF-like and NT-3-like immunoreactivity were present in the kidney with different distribution patterns, while BDNF-like immunoreactivity was never detected. In goldfish, NGF-like and NT-3-like immunoreactivity were identified extensively in cells along part of the arterial branches adjacent to the afferent arterioles. In scorpion fish, NGF-like and NT-3-like immunoreactive cells were observed both on afferent arterioles and on adjacent secondary branches derived from renal arteries. No immunoreactivity was detected in other renal structures. A staining pattern of immunoreactivity similar to that obtained for NGF and NT-3 was detected utilizing S100 antibody as a juxtaglomerular (JG) cell marker. Double immunolabellings NGF/S100 and NT-3/S100 evidenced the coexistence of neurotrophin-like proteins and S100-like protein in the same immunoreactive cells, thus identifying them as juxtaglomerular cells. Western blot analysis revealed the presence of molecules immunoreactive to NGF and NT-3, whose molecular weights were very similar to those of the corresponding mammalian neurotrophins. These findings extend the presence and distribution of NGF-like and NT-3-like IR in the kidney to teleost species, suggesting a probable participation of these proteins in the renal functions of freshwater and marine teleosts.