Multi-step approach for automated scaling of photogrammetric micro-measurements

[EN] Photogrammetry can be used for the measurement of small objects with micro-features, with good results, low costs, and the possible addition of texture information to the 3D models. The performance of this technique is strongly affected by the scaling method, since it retrieves a model that must be scaled after its elaboration. In this paper, a fully automated multi-step scaling system is presented, which is based on machine vision algorithms for retrieving blurred areas. This method allows researchers to find the correct scale factor for a photogrammetric micro model and is experimentally compared to the existing manual method basing on the German guideline VDI/VDE 2634, Part 3. The experimental tests are performed on millimeter-sized certified workpieces, finding micrometric errors, when referred to reference measurements. As a consequence, the method is candidate to be used for measurements of micro-features. The proposed tool improves the performance of the manual method by eliminating operator-dependent procedures. The software tool is available online as supplementary material and represents a powerful tool to face scaling issues of micro-photogrammetric activities.Frangione, A.; Sánchez Salmerón, AJ.; Modica, F.; Percoco, G. (2019). Multi-step approach for automated scaling of photogrammetric micro-measurements. The International Journal of Advanced Manufacturing Technology. 102(1-4):747-757. https://doi.org/10.1007/s00170-018-03258-w7477571021-

Screen-Printed Chipless Wireless Temperature Sensor

A chipless wireless sensor for temperature monitoring is described in this work. The sensor is fabricated by screen printing of an RLC circuit on a flexible substrate. The sensing element is a resistive carbon paste with positive temperature coefficient placed in a small area in the interconnection between the inductor and the capacitor. This sensing layer modifies the resonance frequency of the circuit when the temperature varies. We also show the influence of the sensor sensitivity with respect to the reading distance

UHF Printed Sensor for Force Detection

In this contribution, we show the advances in the direction of designing Radiofrequency Identification (RFID) antennas with sensing capabilities. In this particular case, we have integrated a force/pressure sensor made of a silicon-based organic polymer in one of the arms of a dipole antenna made of silver paste. The sensor response to external forces modifies the resonance frequency of the dipole antenna that can be detected by an external RFID reader, building up a wireless force sensor system.Pervasive Electronics Advanced Research Laboratory(PEARL), Department of Electronics and Computer Technology, University of Granada Institute for Nanoelectronics, Technical University of Munic

Over-Stretching Tolerant Conductors on Rubber Films by Inkjet-Printing Silver Nanoparticles for Wearables

The necessity to place sensors far away from the processing unit in smart clothes or artificial skins for robots may require conductive wirings on stretchable materials at very low-cost. In this work, we present an easy method to produce wires using only commercially available materials. A consumer grade inkjet printer was used to print a wire of silver nanoparticles with a sheet resistance below 1 W/sq. on a non-pre-strained sheet of elastic silicone. This wire was stretched more than 10,000 times and was still conductive afterwards. The viscoelastic behavior of the substrate results in a temporarily increased resistance that decreases to almost the original value. After over-stretching, the wire is conductive within less than a second. We analyze the swelling of the silicone due to the ink’s solvent and the nanoparticle film on top by microscope and SEM images. Finally, a 60 mm long stretchable conductor was integrated onto wearables, and showed that it can bear strains of up to 300% and recover to a conductivity that allows the operation of an assembled LED assembled at only 1.8 V. These self-healing wires can serve as wiring and binary strain or pressure sensors in sportswear, compression underwear, and in robotic applications.This work has been partially supported the TUM Graduate School (TUM GS), and the European Union through the fellowship H2020-MSCA-IF-2017 794885-SELFSENS. Additionally, this work was supported by the German Research Foundation (DFG) and the Technical University of Munich within the Open Access Publishing Funding Programme

Multiview motion tracking based on a cartesian robot to monitor Caenorhabditis elegans in standard Petri dishes

[EN] Data from manual healthspan assays of the nematode Caenorhabditis elegans (C. elegans) can be complex to quantify. The first attempts to quantify motor performance were done manually, using the so-called thrashing or body bends assay. Some laboratories have automated these approaches using methods that help substantially to quantify these characteristic movements in small well plates. Even so, it is sometimes difficult to find differences in motor behaviour between strains, and/or between treated vs untreated worms. For this reason, we present here a new automated method that increases the resolution flexibility, in order to capture more movement details in large standard Petri dishes, in such way that those movements are less restricted. This method is based on a Cartesian robot, which enables high-resolution images capture in standard Petri dishes. Several cameras mounted strategically on the robot and working with different fields of view, capture the required C. elegans visual information. We have performed a locomotion-based healthspan experiment with several mutant strains, and we have been able to detect statistically significant differences between two strains that show very similar movement patterns.This work was supported by the research agency of the Spanish Ministry of Science and Innovation under Grant RTI2018-094312-B-I00 (European FEDER funds).Puchalt-Rodríguez, JC.; González-Rojo, JF.; Gómez-Escribano, AP.; Vázquez-Manrique, RP.; Sánchez Salmerón, AJ. (2022). Multiview motion tracking based on a cartesian robot to monitor Caenorhabditis elegans in standard Petri dishes. Scientific Reports. 12(1):1-11. https://doi.org/10.1038/s41598-022-05823-611112

Screen Printed Security-Button for Radio Frequency Identification Tags

Radio frequency identi cation (RFID) security is a relevant matter. The wide spread of RFID applications in the general society and the persistent attempts to safeguard it con rm it, especially since its use involves payments and the store or transmission of sensitive information. In this contribution, we present an innovative solution for improving the security of RFID passive tags through the use of a screen printed button, that allows the reception and transmission only when a certain level of physical pressure normal to its plane is applied. The materials and fabrication technology used demonstrate an easy to implement and cost-effective system, valuable in several scenarios where the user has straight contact with the tags and where its usage is direct and intentional.This work was supported by the fellowship under Grant 2020-MSCA-IF-2017-794885-SELFSENS

Daily rhythms of acute stress responses and antioxidant systems in the European sea bass (Dicentrarchus labrax): Effects of the time of the year

Fish reared in aquaculture face various acute stressors, including air exposure during handling. Research on the stress response in fish can provide essential insights into their physiology and help define better aquaculture practices. In this study, we investigated the daily rhythms in the stress-axis response of the European sea bass (Dicentrarchus labrax) subjected to an acute stressor consisting of air exposure (1 min), and how this response is influenced by the time of the day and the season of the year. In addition, rhythms in antioxidant systems were also assessed. The experiments were performed in late Autumn (December) and late Spring (June), with natural photoperiod (10 L:14D and 15 L:9D, respectively) and water temperature (ranging from 19.47 ± 0.17 December to 22.13 ± 0.13 ◦ ◦ C in C in June). Samples were collected throughout a 24-h cycle at Zeitgeber time (ZT) 0.5, 4, 7.5, 12, 16, 20, and 24.5 h at both seasons. At each sampling point, an untreated control (CTRL) group was sampled, while a STRESS group was exposed to air for one minute, returned to the tank, and sampled one hour later. Fish were sacrificed to collect plasma samples, hypothalamus and liver. Plasma samples were analyzed for cortisol, glucose, and lactate. In the hypothalamus, the mRNA expression levels of corticotropin-releasing hormone (crh) and crh-binding protein (crh-bp) were quantified using quantitative RT-PCR (qPCR). In the liver, genes related to antioxidant systems (catalase, superoxide dismutase 1, glutathione peroxidase,and glutathione reductase) and mitochondrial markers of stress (uncoupling protein 1, cytochrome c oxidase IV and peroxiredoxin3) were also analyzed by qPCR. The results revealed that most stress indicators (cortisol, cat, sod1, gsh-px, gsr, ucp1, coxIV) displayed daily rhythms. Furthermore, the stress response was significantly influenced by the time of day and the season in which the stressor was applied. In June, cortisol and glucose responses to stress were higher during the day than at night. The increase observed after stress in genes related to the antioxidant system was more significant in June than in December. Conversely, the response of mitochondrial markers was greater in December. Taken together, these findings highlight that the stress response of the European sea bass is time- dependent, both on a daily and a seasonal basis. This emphasizes the importance of considering cyclic environmental factors and circadian rhythms in aquaculture procedures to enhance fish welfare

Fabrication of low cost and low impact RH and temperature sensors for the Internet of Environmental-Friendly Things

Given the increasing number of connected devices as a consequence of the Internet of Things (IoT) revolution, the issue of the removal and recycling of electronics is becoming more and more urgent. In this context, biodegradable electronics is expected to be one of the biggest technological revolutions to tackle this problem. Following this direction, in this work we present the fabrication and characterization of temperature and humidity sensors based on biodegradable materials with the goal of making their removal easier as well as reducing their environmental impact. In particular, these multi-sensing devices were fabricated following a screen-printing process using a carbon-based paste and a conjugated polymer, both on paper and on a water soluble substrate. The results are more than promising and show how with our biodegradable sensors it is possible to obtain a sensitivity of 1 dec/20%RH to moisture content and around 0.04%/°C sensitivity to temperature. It is demonstrated that the simplicity and flexibility of the fabrication approach followed in this work paves the way to a set of new “green” IoT nodes that could be extended to wide range of sensing applications

Life history baseline of unexploited populations: The case of Beryx splendens from the Sierra Leone Rise

This study examines for the first time the biology of alfonsino (Beryx splendens) from three small seamounts of the Sierra Leone Rise (SLR), an unexploited and fragile ecosystem in the Atlantic, using data from an experimental survey carried out in 2001 by Spanish longliners. In general, the lack of rigorous baseline data limits the implementation of efficient management and conservation plans in fisheries strategies. Therefore, the main aim of present study was to provide baseline information on basic biological parameters of the alfonsino population associated with an unexploited ecosystem. A total of 17296 individuals of alfonsino were sampled from SLR. Alfonsino is gonochoric and presented an unbalanced sex ratio, there were significantly more females than males. Taking into account the results in stage of maturity of alfonsino and the gonadosomatic index values during studied period, we can conclude that at least one reproductive period in these seamounts was in the late spring and early summer. The spawning stage was attained at a minimum fork length of 23 and 25 cm for males and females, respectively. The size at which 50% of the population attains sexual maturity was approximately 28 and 27 cm for males and females, respectively. The stock structure of alfonsino showed a segregation of the size with the depth, as they increase in size they move into the deeper water.Versión del edito

Preliminary data on the ovarian histological structures observed in black hakes (M. polli and M. senegalensis) off Mauritania

The black hakes, Merluccius polli and M. senegalensis, are target species of a trawl Spanish fleet in Mauritanian waters. M. polli is a deep-water hake while M. senegalensis shows a shallower distribution. Both species are mixed in the landings, although the deeper hake totals a greater fraction (85%) of the catch due to the fishing strategy of the trawl fleet. The female gonads of both hakes were collected during an experimental survey carried out in the Mauritanian EEZ. Mature ovaries were examined from the start of the reproductive season in this area. Ovaries were processed by a standard histological technique. Histological characteristics of ovarian tissues and oocyte stages were studied by light microscopy. The ovaries of black hakes showed various stages of oocyte development from the small sized, chromatin nuclear and perinucleolar oocytes, and the medium sized, cortical alveoli and vitellogenic oocytes. This last stage presents yolk granules occupying the cytoplasm at different levels. In the case of M. senegalensis, the presence of large sized oocytes with early migration of the nucleus to the animal pole, as well as fusion of oil droplets indicate maturation and imminent spawning, thus, indicating an earlier spawning than M. polli. Furthermore, postovulatory follicles observed in M. senegalensis indicate a recent batch spawning episode. This result is concordant with the values of GSI obtained for both species in these waters. The reproductive period extends from October to Mars with a defined peak in December - January for females of both hakes, although the shallower species, M. senegalensis, shows an earlier spawning in this study. Atretic stages were observed, but their incidence was low because the sampling corresponds to the beginning of the spawning period. The species are multiple batch spawners as suggested by their oocyte size frequency distribution in the ovary. The present study is a first approach to ovarian histology of M. polli and M. senegalensis, and intended to provide basic knowledge for further detailed studies on the reproductive biology of these species, essential for an adequate assessment of this stock.Instituto Español de Oceanografía (IEO