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1.
Sensors (Basel) ; 23(14)2023 Jul 14.
Artículo en Inglés | MEDLINE | ID: mdl-37514682

RESUMEN

CubeSats require accurate determination of their orientation relative to the Sun, Earth, and other celestial bodies to operate successfully and collect scientific data. This paper presents an orientation system based on solar and magnetic sensors that offers a cost-effective and reliable solution for CubeSat navigation. Solar sensors analyze the illumination on each face to measure the satellite's orientation relative to the Sun, while magnetic sensors determine the Earth's magnetic field vector in the satellite's reference frame. By combining the measured data with the known ephemeris of the satellite, the satellite-Sun vector and the magnetic field orientation can be reconstructed. The orientation is expressed using quaternions, representing the rotation from the internal reference system of the satellite to the selected reference system. The proposed system demonstrates the ability to accurately determine the orientation of a CubeSat using only two sensors, making it suitable for installations where more complex and expensive instruments are impractical. Additionally, the paper presents a mathematical model of a low-cost CubeSat orientation system and a hardware implementation of the sensor. The technology, using solar and magnetic sensors, provides a reliable and affordable solution for CubeSat navigation, supporting the increasing sophistication of miniature payloads and enabling accurate satellite positioning in space missions.

2.
Sensors (Basel) ; 19(12)2019 Jun 13.
Artículo en Inglés | MEDLINE | ID: mdl-31200578

RESUMEN

Soft resistive tactile sensors are versatile devices with applications in next-generation flexible electronics. We developed a novel type of soft resistive tactile sensor called a soft magnetic powdery sensor (soft-MPS) and evaluated its response characteristics. The soft-MPS comprises ferromagnetic powder that is immobilized in a liquid resin such as polydimethylsiloxane (PDMS) after orienting in a magnetic field. On applying an external force to the sensor, the relative distance between particles changes, thereby affecting its resistance. Since the ferromagnetic powders are in contact from the initial state, they have the ability to detect small contact forces compared to conventional resistive sensors in which the conductive powder is dispersed in a flexible material. The sensor unit can be made in any shape by controlling the layout of the magnetic field. Soft-MPSs with different hardnesses that could detect small forces were fabricated. The soft-MPS could be applied to detect collisions in robot hands/arms or in ultra-sensitive touchscreen devices.

3.
Environ Toxicol Pharmacol ; 102: 104235, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37481049

RESUMEN

Benzodiazepines, psychotropic drugs, are among the most frequently found pharmaceuticals in aquatic matrices. An increasing number of studies are reporting their harmful effects on adults' behaviour and physiology, while little information is available regarding developing organisms exposed since early stages. Improper activation of GABA receptors during embryonic development is likely to induce relevant consequences on the morphogenesis and, at later stages, on behaviour. This study investigated the negative effects of three increasing concentrations of delorazepam on Xenopus laevis retinal and skeletal muscle morphogenesis. Morphological and ultrastructural investigations were correlated with gene expression, while Raman spectroscopy highlighted the main biochemical components affected. Conventional phototactic response and orientation in the magnetic field were assessed as indicators of proper interaction between sensory organs and the nervous system. Results confirm the profound impact of delorazepam on development and return an alarming picture of the amphibians' survival potentialities in a benzodiazepine-contaminated environment.


Asunto(s)
Benzodiazepinas , Músculo Esquelético , Femenino , Animales , Xenopus laevis , Benzodiazepinas/toxicidad , Psicotrópicos/toxicidad , Retina
4.
ACS Appl Mater Interfaces ; 14(40): 45679-45687, 2022 Oct 12.
Artículo en Inglés | MEDLINE | ID: mdl-36166313

RESUMEN

Magnetic nanofiller is helpful for improving the piezoelectric properties of P(VDF-TrFE)-based composites, which shows promising potential as a flexible sensor or energy harvester. In this work, we use the interaction between the magnetic nanofiller and magnetic field to modify the structure of CoFe2O4 (CFO)@polydopamine (PDA)/P(VDF-TrFE) composite, in which CFO@PDA works as the nanofiller into the P(VDF-TrFE) matrix. It was found that the magnetic field orientation during polymer curing can significantly increase the content of the ß-phase and d33 of the composite. Regarding a typical composite film with 7 wt % CFO@PDA, the composite exhibits versatile sensing originated from the ball impact, hot-water droplet, bending, and pressing. In a noncontact magnetic field-driven experiment, the magnetic field oriented film produced the highest output voltages of 17.4 mV at 4 Hz and 12 mV at a drive amplitude of 19 Vpp, in contrast to the values of 7.1 mV and 7 mV for the film without magnetic field orientation, respectively. The LED without any charging capacitor can be instantaneously lighted through vertically pressing the oriented films. Thus, this work proposes a strategy of magnetic field orientation to improve the piezoelectric performance of the CFO@PDA/P(VDF-TrFE) multifunctional composite film.

5.
Biomech Model Mechanobiol ; 20(2): 787-802, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33449275

RESUMEN

Magnetic drug delivery known as smart technique in medicine is basically according to combining the drug inside capsules with the magnetic property or attaching the drug with magnetic surfaces at the micro- and nanoscale. In the present study, magnetic drug delivery in the aortic artery has been investigated. To approach the more realistic problem conditions of blood flow rheology, the effect of parameters such as non-Newtonian viscosity and oscillating input has been put into consideration. Also, the investigated geometrical parameters of arteries of the aortic arch have been chosen similar to the real size. The results indicate that an increase in the diameter of microparticles rises the efficiency of particles absorption. In addition, the influence of changing the direction of the wire carrying electricity and thus changing the direction of magnetic field on magnetic drug delivery has been examined in the geometry of the aortic arc and it is found that the highest particle absorption efficiency takes place in the case that the wire is parallel to the direction of y-axis. As an example, the results show that the rate of absorption efficiency for particles with 3 µm dia is 26.83% and 19.39% when the wire generating magnetic field is parallel to the direction of y-axis and z-axis, respectively, and this value is 10.91% for the case without a magnetic field. The number of particles released from different part of the aortic arch also is affected by the direction of magnetic field. This value illustrates that the percentage of particles released from different states, is equal when the magnetic field is absent and the wire carrying electricity is parallel to y-axis and z-axis. However, the number of particles released from the 2 outputs of the left carotid and left subclavian is less than the other 2 states (i.e., the state when there is not a magnetic field, and the state when the electric current direction is parallel to the y-axis direction) for the state when the wire carrying current is parallel to the z-axis.


Asunto(s)
Aorta Torácica/diagnóstico por imagen , Sistemas de Liberación de Medicamentos , Imagenología Tridimensional , Campos Magnéticos , Análisis Numérico Asistido por Computador , Aorta Torácica/anatomía & histología , Humanos , Movimiento (Física) , Reología
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