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In this paper, a single-chip front-end (SCFE) operating in Ku-band (12–17 GHz) is presented. It is designed exploiting a GaN on SiC technology featured by 150 nm gate length provided by UMS foundry. This MMIC integrates high power and low noise amplification functions enabled by a single-pole double-throw (SPDT) switch, occupying a total area of 20 mm2. The transmitting chain (Tx) presents a 39 dBm output power, a power added efficiency (PAE) higher than 30% and a 22 dB power gain. The receive path (Rx) offers a low noise figure (NF) lower than 2.8 dB with 25 dB of linear gain. The Rx port output power leakage is limited on chip to be below 15 dBm even at high compression levels. Finally, a complete characterization of the SCFE in the Rx and Tx modes is presented, also showing the measurement of the recovery time in the presence of large-signal interferences.

It is well-acknowledged that cognitive and physical decline associated with aging can be prevented or reduced with the engagement in regular physical activity (PA). Dance activities combine cardiovascular, cognitive, and coordinative demands, providing a popular leisure PA among elderly. This study examined the correlations between quality of life (QoL), cognitive and physical performance, and PA level in older adults who participated in at least 10 years of amateur ballroom dancing. Methods: The study was designed as an observational study. A sample of 20 (10 men; age range: 65 to 80 years; BMI: 26.3 ± 3.0 kg/m2) amateur senior dancers were compared with a sample of 18 (8 men; age range: 65 to 75 years; BMI: 25.5 ± 2.4 kg/m2) non-sedentary individuals (control group) following an adapted PA program. Quality of life and cognitive functioning assessment tools were administered: 36 Health Status Survey (SF-36v2), Montreal Cognitive Assessment (MoCA), and Cognitive Reserve Index questionnaire (CRIq). Physical performance was measured with their preferred walking speed (PWS), and level of moderate to vigorous physical activity (MVPA) was evaluated using a multi-sensor activity monitor. Results: Participants presented a good SF-36v2 physical component and a very good mental com- ponent summary, a total MoCA score within the limits, and an average total CRIq score. Their PWS and daily MVPA were high. Differences neither in the three questionnaires nor in PWS and PA level were observed between groups. A significant, moderate, and positive correlation was found between PWS and SF-36v2 physical component summary score. Conclusion: Ballroom dancing seems to allow elderly individuals to maintain good cognitive and physical abilities, QoL, an acceptable normal cognitive reserve, notable physical performance, and PA level to the same extent as an adapted PA program. Both types of PA seem to be able to contrast the mental and physical decline associated with aging.

Objectives: Extracorporeal respiratory support, including low blood flow systems providing mainly extracorporeal CO2 removal, are increasingly applied in clinical practice. Gas exchange physiology during extracorporeal respiratory support is complex and differs between full extracorporeal membrane oxygenation and extracorporeal CO2 removal. Aim of the present article is to review pathophysiological aspects which are relevant for the understanding of hypoxemia development during extracorporeal CO2 removal. We will describe the mathematical and physiologic background underlying changes in respiratory quotient and alveolar oxygen tension during venovenous extracorporeal gas exchange and highlight the clinical implications. Design: Theoretical analysis of venovenous extracorporeal gas exchange. Setting: Italian university research hospital. Patients: None. Interventions: None. Measurements and main results: While the effect of extracorporeal CO2 removal on the respiratory quotient of the native lung has long been known, the role of extracorporeal oxygenation in dictating changes in the respiratory quotient has been less addressed. Indeed, both extracorporeal CO2 removal and extracorporeal oxygen delivery affect the respiratory quotient of the native lung and thus influence the alveolar PO2. Indeed, for the same amount of extracorporeal CO2 extraction, it is possible to reduce the FIO2, reduce the risk of absorption atelectasis, and maintain the same alveolar PO2, by increasing the extracorporeal oxygen delivery. Conclusions: Worsening of hypoxemia is frequent during low-flow extracorporeal CO2 removal combined with ultraprotective mechanical ventilation. In this context, increasing extracorporeal oxygen delivery, increases the respiratory quotient of the native lung and could reduce both the occurrence of alveolar hypoxia and absorption atelectasis, thus optimizing the residual lung function.

Starting from the mathematical bases of waveform engineering, this contribution demonstrates the effectiveness of class-F power amplifier design in different bias conditions, provided the correct harmonic content is presented at the input. To validate the theoretical assumptions, low-frequency multi-harmonic load-pull measurements are carried out on a 1-mm gate periphery GaN HEMT, giving an experimental proof of the validity of the extended harmonic manipulation approach.

Early Greek bronze vessels exported out of Greece among indigenous societies attest, together with the more diffused figured pottery, the spread of Greek cultural model and social practices. Found generally in funerary contexts from Southern Italy to the Black Sea, they represented wealth, power and identification with the Greek aristocratic culture and society and it is interesting trying to recognize the function, these objects could have in the indigenous contexts where they were found.

The purpose of this invited paper is to give readers a comprehensive and critical overview on how to extract equivalent-circuit models for GaN HEMTs, which are the preferred devices for high-power high-frequency applications. This overview is meant to provide a practical modeling know-how for this advanced type of transistor, in order to support its development for improving device technology and circuit design. With the aim to broaden knowledge to empower models, experimental results are presented as illustrative examples of the most crucial challenges faced by the microwave engineers in modeling high-power GaN HEMTs. All the relevant aspects are covered, going from linear (also noise) to nonlinear models. The analysis is mainly focused on the modeling of distinctive peculiarities of GaN HEMTs. Particular attention is paid to study the importance of accurately modeling the kink effect in the output reflection coefficient, because of the relatively high transconductance, the peak in the magnitude of the short circuit current-gain, because of the relatively large intrinsic capacitances, and the low-frequency dispersion, because of trapping and thermal effects. Furthermore, to emphasize the key role of accurate device models for a successful circuit design, a practical example of power amplifier is discussed.

In this paper, the use of advanced traffic data is discussed to contribute to the ongoing debate about their applications in dynamic origin-destination (OD) estimation. This is done by discussing the advantages and disadvantages of traffic data with support of the findings of a benchmark study. The benchmark framework is designed to assess the performance of the dynamic OD estimation methods using different traffic data. Results show that despite the use of traffic condition data to identify traffic regime, the use of unreliable prior OD demand has a strong influence on estimation ability. The greatest estimation occurs when the prior OD demand information is aligned with the real traffic state or omitted and using information from automatic vehicle identification (AVI) measurements to establish accurate and meaningful values of OD demand. A common feature observed by methods in this paper indicates that advanced traffic data require more research attention and new techniques to turn them into usable information., Transport & Planning, Civil Engineering and Geosciences

In this work, the design of a C-band class-AB power amplifier based on the waveform engineering approach is presented. The design leverages the low-frequency characterization of the transistor to obtain the prediction of its optimum operating condition. An exhaustive validation of the realized amplifier fully validates the proposed design technique.