High Gain Amplifier with Enhanced Cascoded Compensation

A two-stage CMOS operational amplifier with both, gain-boosting and indirect current feedback frequency compensation performed by means of regulated cascode amplifiers, is presented. By using quasi-floating-gate transistors (QFGT) the supply requirements, the number of capacitors and the size of the compensation capacitors respect to other Miller schemes are reduced. A prototype was fabricated using a 0.5 μm technology, resulting, for a load of 45 pF and supply voltage of 1.65 V, in open-loop-gain of 129 dB, 23 MHz of gain-bandwidth product, 60o phase margin, 675 μW power consumption and 1% settling time of 28 ns

Levels of Sustainability Awareness in Spanish University Students of Nautical Activities as Future Managers of Sports and Active Tourism Programmes

© 2023 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/).Abstract: University students will play an important role in making decisions that will affect the environment, as future leaders of our society. Their level of sensitivity and environmental knowledge will play an important role in adequately facing future challenges. This article aims to measure the sustainability awareness of a sample of future graduates in Physical Activity and Sport Sciences in Spain. The literature supports that the sensitivity of these students can be estimated by using the Spanish adaptation of the SCQ-S. This allows for establishing the level of knowledge, attitudes and behaviour pertaining to sustainability in three dimensions: environmental, social and economic. The sample consisted of 170 students (58.8% males; 41.2% females) with a mean age of 20.5 years (±4.039). The overall Cronbach’s alpha showed a fairly good value (α = 0.836). The same was true for the Kaiser–Meyer–Olkin test values (KMO = 0.816) and Bartlett’s sphericity test (p < 0.001). The knowledge construct (4.56 ± 0.53) was the highest descriptive, followed by attitude (4.12 ± 0.59). The lowest value was behaviour (3.79 ± 0.66). By gender, girls obtained the highest sensitivity indexes. In addition, the place of habitual residence and physical activity in the natural environment were related to the overall behaviour of the university students. It is concluded that being in active contact with the natural environment allows us to have a higher level of awareness

Effects of interdot dipole coupling in mesoscopic epitaxial Fe(100) dot arrays

The domain structure and the coercivity of epitaxial Fe(100) circular dot arrays of different diameters and separations have been studied using magnetic force microscopy (MFM) and focused magneto-optical Kerr effect (MOKE). The MFM images of the 1 µm diameter single domain dot arrays show direct evidence of strong interdot dipole coupling when the separation is reduced down to 0.1 µm. The coercivity of the dots is also found to be dependent on the separation, indicating the effect of the interdot dipole coupling on the magnetization reversal process

High spatial resolution and high contrast optical speckle imaging with FASTCAM at the ORM

In this paper, we present an original observational approach, which combines, for the first time, traditional speckle imaging with image post-processing to obtain in the optical domain diffraction-limited images with high contrast (1e-5) within 0.5 to 2 arcseconds around a bright star. The post-processing step is based on wavelet filtering an has analogy with edge enhancement and high-pass filtering. Our I-band on-sky results with the 2.5-m Nordic Telescope (NOT) and the lucky imaging instrument FASTCAM show that we are able to detect L-type brown dwarf companions around a solar-type star with a contrast DI~12 at 2" and with no use of any coronographic capability, which greatly simplifies the instrumental and hardware approach. This object has been detected from the ground in J and H bands so far only with AO-assisted 8-10 m class telescopes (Gemini, Keck), although more recently detected with small-class telescopes in the K band. Discussing the advantage and disadvantage of the optical regime for the detection of faint intrinsic fluxes close to bright stars, we develop some perspectives for other fields, including the study of dense cores in globular clusters. To the best of our knowledge this is the first time that high contrast considerations are included in optical speckle imaging approach.Comment: Proceedings of SPIE conference - Ground-based and Airborne Instrumentation for Astronomy III (Conference 7735), San Diego 201