Investigation into the steering ability problems of compact hovercrafts

The present paper investigates the requirements and the turning ability problems of the hovercrafts characterized by compact dimensions (with small width, powerful engine and big propellers). These vehicles require a very accurate control system, to combine the command of turning or trim with the possibility of reversing the thrust. In this article we briefly describe compact hovercrafts and focus on the various systems projected to improve their turning ability. We give an account of the steps which led to achieve our technical solutions and show the various systems of passive control surfaces adopted: to verify the different assessed implementations, several on-field tests have been performed on two vehicles, the Hover4 and the Multipurpose Air Cushion Platform (MACP). Finally we illustrate the ultimate chosen version of the system, in particular we outline the positive effects of the adoption of an unusual axis of rotation used to solve the problems created by the vertical rudders, whose centre is higher than the barycentre of the vehicle

Analisis de las dificultades en el aprendizaje autogestionado de un tema de Química

El grupo de alumnos que no regulariza la asignatura durante el cursado, en el próximo año se transforma en recursantes. Para este grupo de alumnos puede ser una opción válida que autogestionen sus aprendizajes por sistema e-learning con el acompañamiento de docentes-tutores. Como primera aproximación de esta modalidad de aprendizaje se seleccionó el tema óxido-reducción encarado a través de la utilización de diagramas de Latimer para evaluar si se logró aprendizaje sobre balanceo de ecuaciones redox, criterios de espontaneidad, procesos de dismutación o desproporción, cálculo de potenciales, entre otros. Es objetivo de este trabajo analizar, con un mismo instrumento de evaluación, las dificultades en la comprensión del tema óxido-reducción usando como estrategia el aprendizaje autogestionado en alumnos recursantes y la forma tradicional en alumnos no recursantes

Monitoring of sea-ice-atmosphere interface in the proximity of arctic tidewater glaciers: The contribution of marine robotics

The Svalbard archipelago, with its partially closed waters influenced by both oceanic conditions and large tidal glaciers, represents a prime target for understanding the effects of ongoing climate change on glaciers, oceans, and ecosystems. An understanding of the role played by tidewater glaciers in marine primary production is still affected by a lack of data from close proximity to glacier fronts, to which, for safety reasons, manned surface vessels cannot get too close. In this context, autonomous marine vehicles can play a key role in collecting high quality data in dangerous interface areas. In particular, the contribution given by light, portable, and modular marine robots is discussed in this paper. The state-of-the-art of technology and of operating procedures is established on the basis of the experience gained in campaigns carried out by Italian National Research Council (CNR) robotic researchers in Ny-Alesund, Svalbard Islands, in 2015, 2017, and 2018 respectively. The aim was to demonstrate the capability of an Unmanned Semi-Submersible Vehicle (USSV): (i) To collect water samples in contact with the front of a tidewater glacier; (ii) to work in cooperation with Unmanned Aerial Vehicles (UAV) for sea surface and air column characterisation in the proximity of the fronts of the glaciers; and (iii) to perform, when equipped with suitable tools and instruments, repetitive sampling of water surface as well as profiling the parameters of the water and air column close to the fronts of the tidewater glaciers. The article also reports the issues encountered in navigating in the middle of bergy bits and growlers as well as the problems faced in using some sensors at high latitudes

Design and construction of a modular pump-jet thruster for autonomous surface vehicle operations in extremely shallow water

open5noThis paper describes a customized thruster for Autonomous Surface Vehicles (ASV). The thruster is a Pump-Jet Module (PJM), which has been expressly designed, modeled, constructed, and tested for small-/medium-sized ASVs that perform environmental monitoring in extremely shallow waters such as wetlands (rivers, lakes, swamps, marshes), where water depth is only a few centimeters. The PJM is a fully-electric propulsion unit with a 360-degree continuous steering capability. Its main advantage is that the unit is flush with the flat bottom of the vehicle. This makes the PJM suitable for operation in extremely shallow waters because the risk of damaging the thrusting unit in case of grounding is very limited. The PJM was produced using innovative materials, and the hydraulic components were all constructed using a 3D printer.openOdetti A.; Altosole M.; Bruzzone G.; Caccia M.; Viviani M.Odetti, Angelo; Altosole, M.; Bruzzone, G.; Caccia, M.; Viviani, M

Alterations in the Expression of Antioxidant Enzyme Genes in Response to Pesticide Exposure During Embryonic Development in the Native Reptile Species Caiman latirostris

The aim of this study was to quantify the expression levels of Catalase (cat) and copper, zinc Superoxide dismutase (Cu, Zn-sod) genes involved in the antioxidant response in Caiman latirostris (broad-snouted caiman) blood, after embryonic exposure to the formulations cypermethrin (CYP), chlorpyrifos (CPF), glyphosate (GLY), and their binary and ternary mixtures. Experimental groups were: negative control (NC-distilled water), vehicle control (VC-ethanol), GLY-2%, CYP- 0.12%, CPF- 0.8%, a ternary mixture of them (TM), and three binary mixtures. The applications were made on the nest material in contact with the eggs at the beginning of the incubation period. After hatching, RNA was isolated from blood and expression levels analyzed through qPCR. The results showed downregulation in the expression of sod and cat genes in the three binary mixtures studied, compared to the controls. In addition, we found a possible antagonistic effect between different pesticides in the TM on the expression of both genes.Fil: Odetti, Lucia Magdalena. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas. Cátedra de Toxicología y Bioquímica Legal; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; ArgentinaFil: Simoniello, M. F.. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas. Cátedra de Toxicología y Bioquímica Legal; ArgentinaFil: Poletta, Gisela Laura. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas. Cátedra de Toxicología y Bioquímica Legal; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentin

Problemas cuantitativos y comprensión de conceptos

Los docentes de química a nivel universitario usamos «problemas», habitualmente de tipo cuantitativo, para enseñar y para evaluar. En este trabajo ponemos en duda de que lo hagamos en forma eficaz. Se muestra, a partir de pruebas diagnósticas de pares de problemas (uno cuantitativo y otro cualitativo similar), que muchos estudiantes pueden resolver los problemas cuantitativos sin una adecuada comprensión conceptual.Chemistry professors at university level make use of «problems», usually of a quantitative type, to teach and evaluate. In this article we question the fact of whether they do it in an efficient way. From diagnostic test of pairs of problems (a quantitative and a similar qualitative one) it is shown that many students can solve quantitative problems without an appropriate conceptual comprehension

IgG4 related disease in elderly: A case report

IgG4-related systemic disease (IgG4-RSD) is an emerging autoimmune disorder that may affect several organs, with signs of organ fibrosis, storiform masses for hystopathological plasmacellular infiltration and plasmatic elevation of IgG4. This clinical condition frequently occurs in the sixth decade and may be considered an autoimmunity of the elderly; the disease may have a smouldering course with frequent misdiagnosis for the co-occurrence of comorbidity and clinical complexity. The present case report describes the clinical case of an 81 years old woman admitted to the geriatric ward for remittent fever and functional decline. The past clinical history reported an isolated CT scan suggestive of retroperitoneal fibrosis of unknown origin with and a drug regimen that included chronic corticosteroids (prednisone 5 mg oad). The in hospital diagnostic workout demonstrated the presence of a thoracic aneurysm. Several possible diagnoses among inflammatory, autoimmune (connective tissue disease, vasculitis, sarcoidosis, amyloidosis), infectious (mycotic) or neoplastic conditions were ruled out, as well as any drug association with higher risk of retroperitoneal fibrosis. Thus, the clinical hypothesis of an IgG4 chronic periaortitis was formulated due to the co-occurrence of all the three major components: the presence of a retroperitoneal fibrosis, IgG4 related abdominal aortitis and peryaneurysmal fibrosis. Patient\u2019s comorbidity did not allow performing the histological analysis. The present clinical case is original and adds knowledge to the 76 cases of thoracic aortitis due to IgG4 systemic disease out of the 3482 cases of disease reported so far. Further clinical investigation is needed to provide a homogeneous diagnostic workout for tailored early therapeutic intervention on the single geriatric patient. Moreover, a growing awareness of the disease is needed, especially in geriatrics, to providing a better standard of care and to improving the disease clinical knowledge and managemen

New cost-effective technologies applied to the study of the glacier melting influence on physical and biological processes in Kongsfjorden area (Svalbard)

The Arctic region is greatly affected by climate change, with evident alterations in both physical and biological processes: temperatures are changing at a rate that is twice the global average and phytoplankton productivity is directly affected by ice melting. Continuous monitoring of this ecosystem is fundamental to gain greater understanding of the impact of changes on the natural environment, but the Global Ocean Observing System only provides partial coverage in these extreme areas, which are particularly difficult to reach. Technological progress in oceanographic measurement capabilities is indispensable for the implementation of marine observatories, especially in these remote regions. In recent years, autonomous systems and cost-effective technologies have proved to be valuable for increasing spatial and temporal coverage of data. This is the case with the innovative ArLoC (Arctic Low-Cost) probe, which was designed and developed for easy integration into various types of platforms, enabling continuous measurement of temperature, pressure and fluorescence of chlorophyll a. This work reports on the results of two scientific campaigns carried out in Kongsfjorden (Svalbard Islands) in 2018 in the framework of the UVASS (Unmanned Vehicles for Autonomous Sensing and Sampling) research project. The ArLoC probe was integrated onboard the PROTEUS (Portable RObotic TEchnology for Unmanned Surveys) unmanned semi-submersible vehicle and this allowed us to collect important data in the stretches of sea near tidewater glacier fronts. The acquired data showed several significant effects of glacier melting such as: high temperature and salinity gradients, which cause considerable variations in water mass stratification, and an increase in turbidity and the chlorophyll a concentration, which directly affects primary productivity and the trophic chain. During the surveys, ArLoC proved to be an easy-to-integrate, very reliable instrument, which permitted high spatial resolution investigation of ecological processes during glacier melting as never studied before

Underwater Drone Architecture for Marine Digital Twin: Lessons Learned from SUSHI DROP Project

The ability to observe the world has seen significant developments in the last few decades, alongside the techniques and methodologies to derive accurate digital replicas of observed environments. Underwater ecosystems present greater challenges and remain largely unexplored, but the need for reliable and up-to-date information motivated the birth of the Interreg Italy–Croatia SUSHI DROP Project (SUstainable fiSHeries wIth DROnes data Processing). The aim of the project is to map ecosystems for sustainable fishing and to achieve this goal a prototype of an Unmanned Underwater Vehicle (UUV), named Blucy, has been designed and developed. Blucy was deployed during project missions for surveying the benthic zone in deep waters of the Adriatic Sea with noninvasive techniques compared to the use of trawl nets. This article describes the strategies followed, the instruments applied and the challenges to be overcome to obtain an accurately georeferenced underwater survey with the goal of creating a marine digital twin