Temporal dynamics of a ring dye laser with a stimulated Brillouin scattering mirror

We present a numerical study of the temporal dynamics of a stimulated Brillouin scattering ring resonator. A coaxial flash-lamp-pumped Rh6G dye laser is assumed. The influence of the most important parameters on the temporal evolution of the resonator is analyzed, namely, the acoustic decay time of the nonlinear material, the features of the external injection pulse - its pulse width, energy, and spatial quality - and the coupling mirror reflectivity. We found the conditions to initiate and maintain laser oscillation in the ring resonator as long as the duration of the pumping system pulse persisted.     

Multimodal augmented reality tangible gaming

This paper presents tangible augmented reality gaming environment that can be used to enhance entertainment using a multimodal tracking interface. Players can interact using different combinations between a pinch glove, a Wiimote, a six-degrees-of-freedom tracker, through tangible ways as well as through I/O controls. Two tabletop augmented reality games have been designed and implemented including a racing game and a pile game. The goal of the augmented reality racing game is to start the car and move around the track without colliding with either the wall or the objects that exist in the gaming arena. Initial evaluation results showed that multimodal-based interaction games can be beneficial in gaming. Based on these results, an augmented reality pile game was implemented with goal of completing a circuit of pipes (from a starting point to an end point on a grid). Initial evaluation showed that tangible interaction is preferred to keyboard interaction and that tangible games are much more enjoyable.     

Robotized spraying of prefabricated panels

A robotic manufacturing cell of pre-fabricated glass reinforced cement panels for construction industry has been developed by DISAM for the Spanish construction company Dragados, SA. The main contribution of the developed system is the automatic programming and control of the whole plan. The architect's 3D-drawing of the building facade done on a CAD system serves as input. From the CAD design, the optimum facade to panels partition is obtained. In order to manufacture each panel, automatic task and path planning are performed for the equipment present in the manufacturing cell: spraying robot, PLCs, control computer, etc     

Physicochemical properties of ready‐to‐eat extruded nixtamalized maize‐based snacks enriched with grasshopper

The aim of this research was to prepare an extruded snack based on nixtamalized maize flour (Zea mays L.) (NMF) enriched with grasshopper meal (Sphenarium purpurascens Ch.) (GM) using a single screw extruder with a compression screw ratio of 3:1. A central experimental design comprising three independent variables, namely, extrusion temperature (T = 120–180 °C), feed moisture content (FMC = 18–22 g/100 g) and the grasshopper meal proportion (GMP = 0–40 g/100 g), was used. Increasing T decreased (P < 0.05) the expansion index (EI), bulk density (BD) and hardness (H). Increasing the FMC increased (P < 0.05) the EI. Increasing the GMP decreased (P < 0.05) the EI, H and water absorption index (WAI) and increased (P < 0.05) the BD and total colour difference (ΔE). The treatments that resulted in better general acceptability were those that contained a lower GMP. An extruded snack acceptable to the consumer can be obtained from a blend of NMF and GM, and up to 8.11 g/100 g of GM can be incorporated without affecting the physicochemical properties and acceptance of the snack.     

Settlement of embankment fills constructed of granite fines

This paper presents a study on the application of granite fines (GF) originating from the granite industry in the Northwest of Spain for the construction of embankment fills. A numerical solver was developed to simulate the unsaturated consolidation of a compacted earthfill (water content close to saturation), introducing the effect of secondary compression, and reproducing the construction process to be followed. The results obtained are quite encouraging, since settlements were found to be within an acceptable range. Nevertheless, the results also showed the need to improve the experimental characterization of the “in-situ” preconsolidation of the GF before using them in real applications.     

Quasi-spherical focal spot in two-photon scanning microscopy by three-ring apodization

We present a beam-shaping technique for two-photon excitation (TPE) fluorescence microscopy. We show that by inserting a properly designed three-ring pupil filter in the illumination beam of the microscope, the effective optical sectioning capacity of such a system improves so that the point spread function gets a quasi-spherical shape. Such an improvement, which allows the acquisition of 3D images with isotropic quality, is obtained at the expense of only a small increase of the overall energy in the axial sidelobes. The performance of this technique is illustrated with a scanning TPE microscopy experiment in which the image of small beads is obtained. We demonstrate an effective narrowing of 12.5% in the axial extent of the point spread function, while keeping the 82% of the spot-fluorescence efficiency.