Design issues and experimental characterization of a continuously-tuned adaptive CMOS LNA

This paper presents the design implementation and experimental characterization of an adaptive Low Noise Amplifier (LNA) intended for multi-standard Radio Frequency (RF) wireless transceivers. The circuit —fabricated in a 90-nm CMOS technology— is a two-stage inductively degenerated common-source topology that combines PMOS varactors with programmable load to make the operation of the circuit continuously tunable. Practical design issues are analyzed, considering the effect of circuit parasitics associated to the chip package and integrated inductors, capacitors and varactors. Experimental measurements show a continuous tuning of NF and Sparameters within the 1.75-2.23GHz band, featuring NF19.6dB and IIP3> −9.8dBm, with a power dissipation < 23mW from a 1-V supply voltage.Ministerio de Ciencia e Innovación (FEDER) TEC2007-67247-C02-01/MICJunta de Andalucía, Consejo Regional de Innovación, ciencia y empresa TIC-253

Relationship between antioxidant capacity and total phenolic content of red, rosé and white wines

Phenolic compounds are one of the most important quality parameters of wines, since they contribute to wine organoleptic characteristics such as colour, astringency, and bitterness. Furthermore, several studies have pointed out that many show biological properties of interest, related to their antioxidant capacity. This antioxidant activity has been thoroughly studied and a wide variety of methods have been developed to evaluate it. In this study, the antioxidant activity of commercial Terras Madeirenses Portuguese wines (Madeira Island) was measured by three different analytical methods: [1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay, 2,2′-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid (ABTSradical dot+)) radical cation decolourisation, and ferric reducing/antioxidant power (FRAP) for the evaluation of reducing power (PR) and correlate them with the total phenolic content determined with the Folin–Ciocalteu’s reagent using gallic acid as a standard. The total polyphenol concentration was found to vary from 252 to 1936 mg/l gallic acid equivalents (GAE). The antiradical activity varied from 0.042 to 0.715 mM Trolox equivalents and the antioxidant capacity varied from 344 to 1105 mg/l gallic acid equivalents (GAE). For the reduction power we obtained 3.45–3.86 mM quercetin equivalents

Geologia Sul Portuguesa, com ênfase na estratigrafia, vulcanologia física, geoquímica e mineralizações da faixa piritosa

O presente trabalho resulta da adaptação e actualização do artigo «O Complexo Vulcano--Sedimentar da Faixa Piritosa: Estratigrafia, Vulcanismo e Mineralizações Associadas no Contexto da Zona Sul Portuguesa» de autoria de Oliveira et al., inserido no Livro Geologia de Portugal no Contexto da Ibéria, editado por Rui Dias, Alexandre Araújo, Pedro Terrinha e Carlos Kulberg e publicado pela Universidade de Évora, em 2006, durante o VII Congresso Nacional de Geologia

Design of an adaptive LNA for hand-held devices in a 1-V 90-nm standard RF CMOS technology: From circuit analysis to layout

[EN]: This paper deals the design of a reconfigurable Low-Noise Amplifier (LNA) for the next generation of wireless hand-held devices by using a lumped circuit approach based on physical laws. The purpose is not only to present simulation results showing the fulfillment of different standard specifications, but also to demonstrate that each design step has a physical meaning such that the mathematical design flow is simple as well as suitable for hand-work in both laboratory and classroom. The circuit under analysis, which is designed according to technological design rules of a 90nm CMOS technology, is a two-stage topology including inductive-source degeneration, MOS-varactor based tuning networks, and programmable bias currents. This proposal, with reduced number of inductors and minimum power dissipation, adapts its performance to different standard specifications; the LNA is designed to cope with the requirements of GSM (PCS1900), WCDMA, Bluetooth and WLAN (IEEE 802.11b-g). In order to evaluate the effect of technology parasitics on the LNA performance, simulation results demonstrate that the LNA features NF16dB, S11-3.3 dBm over the 1.85-2.48 GHz band. For all the standards under study the adaptive power consumption varies from 25.3 mW to 53.3mW at a power supply of 1-V. The layout of the reconfigurable LNA occupies an area of 1.8mm2.[ES]: Este trabajo presenta el diseño de un amplificador de bajo ruido, LNA (del inglés Low‐Noise Amplifier) reconfigurable para la siguiente generación de dispositivos portátiles de comunicación inalámbricos, usando la aproximación de circuitos concentrados sustentada en leyes físicas. El propósito de este trabajo no es sólo presentar resultados de simulación que muestran el cumplimiento de especificaciones para cada estándar, sino también demostrar que cada paso de diseño tiene un significado físico haciendo que el procedimiento matemático de diseño sea simple y adecuado para el trabajo a mano tanto para actividades en laboratorio como en el aula. El circuito bajo análisis, diseñado en una tecnología CMOS 90nm, consta de dos etapas que incluyen degeneración inductiva de fuente, redes de entonado basadas en varactores MOS, y corrientes de polarización programables. Esta propuesta, con reducido número de inductores y mínima disipación de potencia, adapta su desempeño a las diversas especificaciones de cada estándar; el LNA se diseña para cubrir los requerimientos de GSM (PCS1900), WCDMA, Bluetooth y WLAN (IEEE 802.11b‐g). Para evaluar el efecto de las no idealidades de la tecnología en el desempeño del LNA, las simulaciones demuestran que el circuito cumple parámetros como NF16dB, S11< ‐5.5dB, S22‐3.3dBm en la banda 1.85‐ 2.48GHz. Para todos los estándares bajo estudio, el consumo adaptivo de potencia varía de 25.3 mW a 53.3mW usando una fuente de alimentación de 1‐V. El patrón geométrico del LNA reconfigurable consume un área de 1.8mm2.Peer Reviewe

COMT Val158Met polymorphism, cognitive stability and cognitive flexibility: an experimental examination

<p>Abstract</p> <p>Background</p> <p>Dopamine in prefrontal cortex (PFC) modulates core cognitive processes, notably working memory and executive control. Dopamine regulating genes and polymorphisms affecting PFC - including Catechol-O-Methyltransferase (COMT) Val158Met - are crucial to understanding the molecular genetics of cognitive function and dysfunction. A mechanistic account of the COMT Val158Met effect associates the Met allele with increased tonic dopamine transmission underlying maintenance of relevant information, and the Val allele with increased phasic dopamine transmission underlying the flexibility of updating new information. Thus, consistent with some earlier work, we predicted that Val carriers would display poorer performance when the maintenance component was taxed, while Met carriers would be less efficient when rapid updating was required.</p> <p>Methods</p> <p>Using a Stroop task that manipulated level of required cognitive stability and flexibility, we examined reaction time performance of patients with schizophrenia (n = 67) and healthy controls (n = 186) genotyped for the Val/Met variation.</p> <p>Results</p> <p>In both groups we found a Met advantage for tasks requiring cognitive stability, but no COMT effect when a moderate level of cognitive flexibility was required, or when a conflict cost measure was calculated.</p> <p>Conclusions</p> <p>Our results do not support a simple stability/flexibility model of dopamine COMT Val/Met effects and suggest a somewhat different conceptualization and experimental operationalization of these cognitive components.</p

Design of an adaptive LNA for hand-held devices in a 1-V 90-nm standard RF CMOS technology: From circuit analysis to layout

This paper deals the design of a reconfigurable Low-Noise Amplifier (LNA) for the next generation of wireless hand-held devices by using a lumped circuit approach based on physical laws. The purpose is not only to present simulation results showing the fulfillment of different standard specifications, but also to demonstrate that each design step has a physical meaning such that the mathematical design flow is simple as well as suitable for hand-work in both laboratory and classroom. The circuit under analysis, which is designed according to technological design rules of a 90nm CMOS technology, is a two-stage topology including inductive-source degeneration, MOS-varactor based tuning networks, and programmable bias currents. This proposal, with reduced number of inductors and minimum power dissipation, adapts its performance to different standard specifications; the LNA is designed to cope with the requirements of GSM (PCS1900), WCDMA, Bluetooth and WLAN (IEEE 802.11b-g). In order to evaluate the effect of technology parasitics on the LNA performance, simulation results demonstrate that the LNA features NF16dB, S11-3.3 dBm over the 1.85-2.48 GHz band. For all the standards under study the adaptive power consumption varies from 25.3 mW to 53.3mW at a power supply of 1-V. The layout of the reconfigurable LNA occupies an area of 1.8mm2.Este trabajo presenta el diseño de un amplificador de bajo ruido, LNA (del inglés Low‐Noise Amplifier) reconfigurable para la siguiente generación de dispositivos portátiles de comunicación inalámbricos, usando la aproximación de circuitos concentrados sustentada en leyes físicas. El propósito de este trabajo no es sólo presentar resultados de simulación que muestran el cumplimiento de especificaciones para cada estándar, sino también demostrar que cada paso de diseño tiene un significado físico haciendo que el procedimiento matemático de diseño sea simple y adecuado para el trabajo a mano tanto para actividades en laboratorio como en el aula. El circuito bajo análisis, diseñado en una tecnología CMOS 90nm, consta de dos etapas que incluyen degeneración inductiva de fuente, redes de entonado basadas en varactores MOS, y corrientes de polarización programables. Esta propuesta, con reducido número de inductores y mínima disipación de potencia, adapta su desempeño a las diversas especificaciones de cada estándar; el LNA se diseña para cubrir los requerimientos de GSM (PCS1900), WCDMA, Bluetooth y WLAN (IEEE 802.11b‐g). Para evaluar el efecto de las no idealidades de la tecnología en el desempeño del LNA, las simulaciones demuestran que el circuito cumple parámetros como NF16dB, S11‐3.3dBm en la banda 1.85‐ 2.48GHz. Para todos los estándares bajo estudio, el consumo adaptivo de potencia varía de 25.3 mW a 53.3mW usando una fuente de alimentación de 1‐V. El patrón geométrico del LNA reconfigurable consume un área de 1.8mm2

Flexible CMOS low-noise amplifiers for beyond-3G wireless hand-held devices

This paper explores the use of reconfigurable Low-Noise Amplifiers (LNAs) for the implementation of CMOS Radio Frequency (RF) front-ends in the next generation of multi-standard wireless transceivers. Main circuit strategies reported so far for multi-standard LNAs are reviewed and a novel flexible LNA intended for Beyond-3G RF hand-held terminals is presented. The proposed LNA circuit consists of a two-stage topology that combines inductive-source degeneration with PMOS-varactor based tuning network and a programmable load to adapt its performance to different standard specifications without penalizing the circuit noise and with a reduced number of inductors as compared to previous reported reconfigurable LNAs. The circuit has been designed in a 90-nm CMOS technology to cope with the requirements of the GSM, WCDMA, Bluetooth and WLAN (IEEE 802.11b-g) standards. Simulation results, including technology and packaging parasitics, demonstrate correct operation of the circuit for all the standards under study, featuring NF13.3dB and IIP3>10.9dBm, over a 1.85GHz-2.4GHz band, with an adaptive power consumption between 17mW and 22mW from a 1-V supply voltage. Preliminary experimental measurements are included, showing a correct reconfiguration operation within the operation band

Serious video games in engineering education: A scoping review

Video games have become an important element of contemporary life. The need to use them in the field of education has given rise to the appearance of serious video games, which have been specially designed to achieve objectives at different educational levels and generate spaces for educational innovation. The purpose of this work is to investigate the use of serious video games in engineering education. A scoping review was carried out on serious video games that were used or designed for this purpose. The search was done in the Scopus and Web of Science databases between 2016 and 2021. The main results show that there is a strong inclination towards serious simulation video games, and they have a good degree of educational acceptance among ingineering students.Departamento de PedagogíaG.I. Ágora, Grupo de Estudios e Investigaciones Educativas en Tecnologías de la Comunicación, Orientación e Intervención Sociocultural (HUM 648

Traffic light optimization of an intersection: a portuguese case study

Smart cities aim to rise strategies that reduce issues caused by the urban population growth and fast urbanization. Thus, traffic light optimization emerges as an important option for urban traffic management. The main goal of this study is to improve traffic light management at a specific intersection, in the City of Guimarães (Portugal), where high-intensity traffic and an active pedestrian area were observed, generating traffic queues. To achieve the goals, a simulation-based optimization strategy using the Particle Swarm Optimization combined with the Simulation of Urban Mobility software was used to minimize the average waiting time of the vehicles by determining the optimal value of the traffic light cycle. The computational results showed it is possible to decrease by 78.2% the average value of the waiting time. In conclusion, by better managing the traffic light cycle time, traffic flow without congestion or queues can be achieved.This work has been supported by FCT—Fundação para a Ciência e Tecnologia within the R&D Units Project Scope: UIDB/00319/2020 and the project “Integrated and Innovative Solutions for the well-being of people in complex urban centers” within the Project Scope NORTE-01-0145-FEDER-000086

Future challenges in cephalopod research

We thank Anto´nio M. de Frias Martins, past President of the Unitas Malacologica and Peter Marko, President of the American Malacological Society for organizing the 2013 World Congress of Malacology, and the Cephalopod International Advisory Committee for endorsing a symposium held in honour of Malcolm R. Clarke. In particular, we would like to thank the many professional staff from the University of the Azores for their hospitality, organization, troubleshooting and warm welcome to the Azores. We also thank Malcolm Clarke’s widow, Dorothy, his daughter Zoe¨, Jose´ N. Gomes-Pereira and numerous colleagues and friends of Malcolm’s from around the world for joining us at Ponta Delgada. We are grateful to Lyndsey Claro (Princeton University Press) for granting copyright permissions.Peer reviewedPublisher PD