The effect of disinfecting agents on the contact corrosion of medical instruments

The contacts of a tin-lead solder (IIOC 61) with copper, brass and nickel in various types of disinfectants are investigated as galvanic couples where the solder always functions as the anode. The maximum relative increase in the corrosion rate is observed in a weakly alkaline hembar solution (guanidine-based biocidic polymer compound). The active oxidizers contained in delaxon and chlorantoin solutions can decompose due to their reduction at the cathodes of the couples. Original Russian Text ? E.K. Sevidova, I.D. Roi, I.I. Stepanova, 2006, published in Zashchita Metallov, 2006, Vol. 42, No. 3, pp. 326–328.     

Capturing an area-covering robot

Area coverage is a fundamental task in robotics, where one or more robots are required to visit all points in a target area at least once. In many real-world scenarios, the need arises for protecting one’s territory from being covered by a robot, e.g., when we need to defend a building from being surveyed by an adversarial force. Therefore, this paper discusses the problem of defending a given area from being covered by a robot. In this problem, the defender needs to choose the locations of k stationary guards in the target area, each one having some probability of capturing the robot, in a way that maximizes the probability of stopping the covering robot. We consider two types of covering robots: one that has an a-priori map of the environment, including the locations of the guards; and the other has no prior knowledge of the environment, and thus has to use real-time sensor measurements in order to detect the guards and plan its path according to their discovered locations. We show that in both cases the defender can exploit the target area’s topology, and specifically the vulnerability points in the area (i.e., places that must be visited by the robot more than once), in order to increase its chances of capturing the covering robot. We also show that although in general finding an optimal strategy for a defender with zero-knowledge on the robot’s coverage strategy is \({\mathcal {NP}}\)-Hard, for certain values of k an optimal strategy can be found in polynomial time. For other cases we suggest heuristics that can significantly outperform the random baseline strategy. We provide both theoretical and empirical evaluation of our suggested algorithms.     

New distributed virtual TV set architecture for a synergistic operation of sensors and improved interaction between real and virtual worlds

A virtual TV set is a studio that is able to combine recorded actors and objects with computer generated virtual environments in real time. In order to achieve this combination seamlessly, in an ideal configuration, several elements such as cameras, objects and people should be tracked so that all their actions on the stage have a corresponding effect in the virtual world. However, in the actual professional virtual TV sets, the tracking possibilities are quite limited because of the hardware and software architecture used, which has not had a major evolution since the first prototypes presented in the nineties. This traditional architecture uses to be rigid, including just one monolithic tracking system and low levels of interactivity. In this paper, a new distributed, flexible and scalable hardware and software architecture that allows the inclusion of multiple kinds of devices in parallel is introduced. It breaks with the traditional structure of the virtual TV sets, opening the technology to an easier inclusion of new devices without the need of updating the proprietary software of the set, thus facilitating its future evolution. The design, implementation and test of this architecture, through the adaptation of a traditional virtual TV set, is presented. The tests are developed through the inclusion of modern devices (in our case Optitrack infrared cameras, Microsoft Kinect V2 and Leap Motion) that, through a synergistic operation, allow the system to solve some traditional drawbacks of this technology such as free and multiple object and camera tracking, presenter natural interaction and automatic distance keying.     

Lipid damage during frozen storage of Gadiform species captured in different seasons

Quality loss of two gadiform fish species (blue whiting, Micromesistius poutassou; hake, Merluccius merluccius) during frozen storage (–30 and –10 °C; up to 12 months) was studied. For this, hydrolytic (formation of free fatty acids, FFA) and oxidative (conjugated dienes, peroxide and interaction compound formation) lipid damage were analysed. For both species, individual fishes captured in two different trials (May and November) were considered. Increasing (p <0.05) lipid hydrolysis and oxidation (peroxide and interaction compound formation) were observed for all kinds of samples throughout the frozen storage. Interaction compound detection by fluorescence analysis showed the best correlation values with storage time. Some higher (p <0.05) hydrolysis development could be observed in hake captured in May than in its counterpart from the November trial, while frozen blue whiting did not provide definite differences for FFA formation between both trials. Concerning peroxide formation, higher (p <0.05) values were obtained for individual blue whiting and hake captured in November when compared to their corresponding May fish for both frozen storage conditions. Interaction compound formation was also found to be higher (p <0.05) for November hake fish than for its counterpart captured in May, while blue whiting did not provide definite differences between trials.     

Investigation of Contact Galvanic Couples in the Processes of Disinfection of Medical Instruments

It is shown that the contact of POS-61 solder with structural materials used for medical purposes exerts practically no influence on its corrosion rate in oxidizing disinfectant solutions. The negative effect of galvanic couples formed in these solutions is connected with rapid decomposition of disinfectants, i.e., with the process of reduction of oxidants on the cathode.