117,627 research outputs found
A 20 W High Gain, High Efficiency L/S-Band Power Amplifier for 5G Connected Cars
No full textThis paper presents an optimized design of
a high-power GaN based power amplifier (PA) tailored for
operation in the L/S-band, targeting advanced applications such
as 5G-connected vehicles and the Internet of Things (IoT). The
PA is implemented as the power stage within a multi stage
architecture. The design utilizes the GaN HEMT CGH40025F
from MACOM company, biased with a drain voltage of 28 V, a
gate voltage of -2.8 V, and a quiescent current of 300 mA. The
simulation results show that the PA achieves an output power
greater than 20 W and a power-added efficiency (PAE) that
exceeds 65% over the 1.9 to 2.3 GHz frequency range
Design and Simulation of Butterfly Antenna in different Lattice Configurations
No full textIn this paper, comparative analysis of the performance of a K-band wideband phased array with sequential rotation and circular polarization was carried out. Three distinct array lattices, triangular, square, and hexagonal, were examined to evaluate radiation characteristics. The goal is to understand whether reducing the number of elements in the array it observes an improvement in performances, given a constant level of mutual coupling. The simulations were carried out by CST Studio suite 2024
Investigating the mechanical behaviour of the lining system for Raphael's Cartoon “The School of Athens”
No full textLining of canvases and paper artworks is a diffused conservation methodology developed to ensure the safe and long-term preservation of weakened supports. Lining systems are generally constituted by a new supporting material or a package of new materials glued to the original artefact. This paper reports on the study of the mechanical behaviour of four multi-layered paper and canvas composites, proposed as lining systems for a large drawing on paper: the “School of Athens” by Raffaello Sanzio, dated 1508. This masterpiece is the 1:1 preparatory cartoon for the wall-painting in the Vatican rooms. Uniaxial tensile testing has been employed in this study to characterize both the single layer materials and the overall mechanical behaviour of the composites. The mechanical tests have been performed before and after artificial ageing with high humidity regime. The complex testing protocol allowed selecting the best performing composite for the final lining, and to assess a safety threshold in terms of stress value for the framing and display of the restored artwork in the new showcase. The results constitute a quantitative evaluation of the different systems, and therefore they can effectively support the conservators’ activity and methodological choices
Tas-102 in metastatic colorectal cancer (MCRC): Efficacy, tolerability, and quality of life in heavily pretreated elderly patients: A real-life study
No full textBackground: TAS-102 is an oral monotherapy, combining trifluridine and tipiracil hydrochloride, indicated for the treatment of pretreated metastatic colorectal cancer (mCRC). The aim of this real-life study is to evaluate the efficacy and safety of TAS-102 in heavily pretreated elderly patients with mCRC whose disease has progressed with standard therapies. Methods: In this retrospective observational study, we enrolled 50 elderly patients >70 years of age (median age 78 years) with a diagnosis of mCRC who were previously treated or were not considered candidates for treatment with other available therapies. Patients aged >70 years with advanced colorectal cancer and with an ECOG performance status of grade 0 (n=18) or grade 1 (n=32) were included. Overall survival and progression-free survival were the primary endpoints, whereas objective response rate, tolerability, and quality of life were the secondary endpoints. Results: Treatment with TAS-102 appeared to be well tolerated and side effects were generally mild, achieving disease control and a benefit on quality of life. The median overall survival was 6.7 (95% CI 5.7-11.3) and the median progression-free survival was 2.1 months (95% CI 1.2-3.2), estimated using the Kaplan-Meier method. Conclusion: TAS-102 represents a manageable and effective therapeutic opportunity and appeared to be well tolerated with generally mild side effects in elderly patients with mCRC who were heavily pretreated with standard therapies
IMPACT OF GREEN MOBILITY ON THE ELECTRIC POWER SYSTEM: A NUMERICAL ANALYSIS IN A 2030 SCENARIO
No full textIn this paper, a methodology is proposed to evaluate the impact on the Italian electric power system deriving from the increasing adoption of Battery Electric Vehicles (BEVs). To this purpose, a case study that involves the Lombardy region in a 2030 scenario is analyzed. To accurately estimate travel habits within the region, datasets publicly available were used, complementing them with suitable energetic models of BEVs. Detailed data about the journeys traveled by commuters in the region, distinguished by reason to move and modes of transport, were provided in input to an online routing machine to extract significant information about the vehicle’s instantaneous speed, length, and duration of each trip. This allowed for an accurate assessment of the energy and power requirements of private electric mobility in a 2030 scenario. The quantities in output to the analysis can be effectively used by transmission and distribution network operators to identify the issues that could arise on the grid due to increased demand related to electric vehicles. In addition, these analyses can support the proper design and planning of all the reinforcement actions needed on the electrical grid to improve its capability to supply the energy and power required during the charging processes
A Novel Ultra Wide Bandwidth Antenna for Millimetre Waves
No full textIn this paper, a novel bowtie-shaped antenna is introduced. The design at millimeter waves is presented. Simulation results carried out by CST Studio Suite 2024 show a Return Loss value is higher than 10 dB over the 14 GHz to 30 GHz frequency band and a Gain of 2.08 dBi at the operating frequency which is 25 GHz
Anoxic treatment for the disinfestation of wood cultural heritage: assessment of the effects and harmfulness on different species
No full textWooden artefacts, wood painted panels and historic furniture represent a significant part of our cultural heritage. Their preservation over time is a challenging task, and insect infestation still represents a primary cause of loss of cultural heritage artefacts. Anoxic conditions have proved to be effective in pest control and have been extensively applied to the management of museum collections. The present work reports on the evaluation of the effects and harmfulness of nitrogen-based anoxic treatment on different wood species with or without superficial finishings. Specimens were prepared in order to be representative of various surfaces of cultural heritage objects. A complete monitoring of the treatment effects was performed by means of a multianalytical approach. FTIR spectroscopy in the MID-IR and NIR regions was conducted to assess the absence of chemical alterations, and the results were subjected to chemometric treatment by multivariate analysis. Colorimetric characterization of the surfaces was performed to monitor any undesired colour change induced by the conservation treatment. The absence of superficial mechanical damages was evaluated by means of optical and scanning electron microscopy. The results confirmed that the anoxic procedure is not harmful to the treated surfaces with respect to aesthetic, chemical and microstructural considerations, even when the most stressful conditions are applied. As wood permeability is an important parameter in order to plan an effective intervention, in this study, a simplified method to estimate the permeability of wood to oxygen in different conditions was tested
Participation of Aggregated DERs to the Ancillary Services Market: A Monte Carlo Simulation-Based Heuristic Greedy-Indexing Model
No full textIn an effort to improve the stability and secure operation of the grid, regulatory bodies are opening Ancillary Services Markets participation to Distributed Energy Resources (DERs), energy storage systems, and demand response. Within this framework, this study proposes a model that simulates the coordinated operation of an aggregate of power plants, including non-dispatchable DERs and, as regulating units, Combined Heat and Power (CHP) generation and electrochemical energy storage systems. A Monte Carlo procedure is adopted to realistically create a population of aggregation scenarios. The real-time operation of the DER portfolio is managed through a Heuristic Greedy-Indexing logic, which allows the Aggregator to select the optimal control action to implement according to the technical and economic quantities characterizing the market and the grid. The techno-economic performance of the proposed algorithm is evaluated by simulating its interaction with the electricity markets. Finally, a sensitivity analysis is performed to analyze the profitability in different scenarios. The novel mathematical model proposed showed to be effective in managing a complex problem like the one at hand with an acceptable computational effort. The numerical results obtained confirmed that the aggregated participation in the market could provide interesting economic returns, especially if a CHP unit is involved as regulating unit, while the feasibility of the batteries adoption is still limited by the actual cost of the technology
Fibrin sealant agents: clinical application of TachoSil® in abdominal surgery. Six years experience in an emergency surgery department and review of the literature
No full textThe success of every surgical procedure depends on an appropriate hemostatis. Topical haemostatic agents, like fibrin sealants, are an option for providing haemostasis and may be particularly useful for complex injuries
Design of a 8 way Ka-band Power Combiner using Stripline Transitions
No full textThis paper introduces and analyzes two different Ka-Band spatial power-combiner architectures. Both power combiners analyzed in this paper present stripline outputs. This type of spatial combiner shows optimal efficiency and optimal Return Loss values over the entire bandwidth of interest. Simulations related to four output stripline combiner and eight outputs stripline combiner were carried out by CST Studio Suite 2024
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