The paper addresses the dynamic modeling and numerical simulation of a novel single-rotor wind system with a planetary speed increaser and counter-rotating direct current (dC) generator, patented by authors, during th...
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The paper addresses the dynamic modeling and numerical simulation of a novel single-rotor wind system with a planetary speed increaser and counter-rotating direct current (dC) generator, patented by authors, during the transient stage from rest. The proposed analytical dynamic algorithm involves the decomposition of the wind system into its component rigid bodies, followed by the description of theirdynamic equations using the Newton-Euler method. The linear mechanical characteristics of the dC generator and windrotor are added to these dynamic equations. These equations allow for the establishment of the close-form equation of motion of the wind system and, implicitly, the time variation of the mechanical power parameters. Numerical simulations of the obtained analytical dynamic model were performed in MATLAB-Simulink in start-up mode from rest for the case study of a 100 kW wind turbine. These results allowed highlighting the time variation of angular velocities and accelerations, torques, and powers for all system shafts, both in the transient regime and steady-state. The implementation, in this case, of the counter-rotating generator indicates a 6.4% contribution of the mobile stator to the generator's total power. The paper's results are useful in the design, virtual prototyping, and optimization processes of modern wind energy conversion systems.
Monoclonal antibodies (mAbs) have become a cornerstone in therapeutic development, increasingly administered via subcutaneous (SC) injection due to its convenience and patient adherence benefits. However, accurately p...
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Monoclonal antibodies (mAbs) have become a cornerstone in therapeutic development, increasingly administered via subcutaneous (SC) injection due to its convenience and patient adherence benefits. However, accurately predicting SC bioavailability in humans remains a challenge, largely due to the limitations of traditional animal models that fail to provide reliable predictions for clinical outcomes, creating a significant gap in preclinical evaluations. To address this, we have developed an integrated in-vitro/in-silico approach that employs functional principal component analysis (FPCA) to summarize the release and transmission profiles information generated by the Subcutaneous Injection Site Simulator (SCISSOr) platform. The FPCA method extracted main shape functions from SCISSOr profiles, representing the most significant variations, and the resulting FPC scores were used as predictors in the modelling process. We employed self-validated ensemble modelling (SVEM) to predict the SC human bioavailability of mAbs based on the transmission andrelease features. SVEM is an ensemble modelling technique allowing the use of all observations for both training and validation making it a suitable method for small sample sizes. The model was further tested on new four commercial mAbs, demonstrating a good agreement between the predicted and actual bioavailability, and outperforming monkey data. We then elucidated how SCISSOrrelease and transmission profile are correlated with different mAbs and formulation parameters. This approach represents valuable addition to the toolkit for predicting the SC human bioavailability of mAbs. By combining in-vitro and in-silico methods, we offer a reliable approach that can outperform preclinical animal models.
This paper presents the conception, design andrealization of a fully-differential two-stage CMOS amplifier that is unconditionally stable for any value of the capacitive load. This is simply achieved by sending a sca...
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ISBN:
(纸本)9798350330991;9798350331004
This paper presents the conception, design andrealization of a fully-differential two-stage CMOS amplifier that is unconditionally stable for any value of the capacitive load. This is simply achieved by sending a scaledreplica of the output stage current to the amplifier virtual ground such as to create a Left Half-Plane (LHP) zero in the loop-gain that either cancels or tracks the output pole in all process, voltage, and temperature (PVT) conditions. Consequently, from a stability point of view the amplifier behaviorresembles that of a single-pole OTA. Starting from an existing two-stage gain-programmable amplifier, designed in a 0.18 mu m Bipolar-CMOS-dMOS (BCd) process, that was able to drive only 10pF without incurring into stability issues, a simple circuit has been added to extend the stability to any capacitive load value. Measurements, given with loads ranging from 0pF to 100nF, show high degree of stability in any load conditions. In the used 0.18 mu m BCd technology, silicon area and current consumption of the extra circuit are only 0.0004mm2 and 2 mu A, respectively, with a 5V power supply.
Classifying multi-attributes is gaining interest in the research and business community, especially for person re-identification (reId) and fashion trend analysis. However, manual annotation of multi-attributes is qui...
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A single-stage transonic axial-flow fan is simulated using graphic processing unit (GPU)-Accelerated wall-modeled large-eddy simulations. The computational meshes are generated using Voronoi diagram-based approach. Tw...
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Synoptic extreme winds are traditionally mapped at the lower bound of the countrywide macroscale resolution (hundreds of km) on the basis of time series measured at land anemometric stations, while the assessment of t...
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Synoptic extreme winds are traditionally mapped at the lower bound of the countrywide macroscale resolution (hundreds of km) on the basis of time series measured at land anemometric stations, while the assessment of the design wind speed at the construction site is entrusted to the designer within the so-calledreturn criterion. Coarse, uneven distribution of the stations, uncertainties in their setup, measurement errors, challenging subjective evaluation of the exposure roughness, inconsistencies among national wind provisions are some of the critical issues affecting the in force map-and-return approach. This study is intended to test an alternative approach to directly assess the wind hazard at the lower bound of the meso-y scale resolution (about 2 km) around a construction site. The approach is grounded on data issued from a weather forecast computational model, its reanalysis by means of assimilatedremote sensing observations, and possibly its downscaling. Three different reanalysis/downscaling models are adopted. The resulting wind maps over the Italian Country are critically compared with measurements at 21 stations. The errors made by each model are assessed for current and extreme wind speed with different return periods. Finally, a reanalysis-based engineering approach to design wind speed is presented by proposing model correction factors.
Nucleophilicity and electrophilicity are important properties for evaluating the reactivity and selectivity of chemical reactions. It allows the ranking of nucleophiles and electrophiles on reactivity scales, enabling...
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Nucleophilicity and electrophilicity are important properties for evaluating the reactivity and selectivity of chemical reactions. It allows the ranking of nucleophiles and electrophiles on reactivity scales, enabling a better understanding and prediction of reaction outcomes. Building upon ourrecent work (N. ree, A. H. G & ouml;ller and J. H. Jensen, Automated quantum chemistry for estimating nucleophilicity and electrophilicity with applications to retrosynthesis and covalent inhibitors, digit. discov., 2024, 3, 347-354), we introduce an atom-based machine learning (ML) approach for predicting methyl cation affinities (MCAs) and methyl anion affinities (MAAs) to estimate nucleophilicity and electrophilicity, respectively. The ML models are trained and validated on QM-deriveddata from around 50 000 neutral drug-like molecules, achieving Pearson correlation coefficients of 0.97 for MCA and 0.95 for MAA on the held-out test sets. In addition, we demonstrate the ML approach on two different applications: first, as a general tool for filtering retrosynthetic routes based on chemical selectivity predictions, and second, as a tool for assessing the chemical stability of esters and carbamates towards hydrolysis reactions. The code is freely available on GitHub under the MIT open source license and as a web application at https://***.
In this paper, a method for evaluating the buckling length of atrium columns in the slide-sway buckling mode using the lateral stiffness of the frame and the story height is proposed. The proposed method, by treating ...
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Self-healing materials have gained significant attention due to their ability to autonomously repairdamage, extending material lifespan. In this study, bio-based self-healing polyurethanes were synthesized using modi...
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Self-healing materials have gained significant attention due to their ability to autonomously repairdamage, extending material lifespan. In this study, bio-based self-healing polyurethanes were synthesized using modified castor oil (MCO) as the soft segment and 5-(2-hydroxyethyl)- 6-methyl- 2-aminouracil (UPY) and 2,2'-diaminodiphenyldisulfide (dTdA) as dynamic components. The synergistic effect of quadruple hydrogen bonding anddisulfide bonds was investigated by varying the n(UPY)/n(dTdA) ratio. Structural and mechanical properties were characterized using Ir, dSC, TGA, Xrd, and tensile testing. The results revealed that the castor oil-based polyurethanes exhibited transparency and amorphous structures, making them promising bio-based self-healing materials. When the dTdA content was 9.54% and the UPY content was 1.62%, the material achieved a self-healing efficiency of 96.38% under 80 degrees C for 12 h. Additionally, at a dTdA content of 6.65% and a UPY content of 2.43%, the tensile strength reached 17.76 MPa. Mechanistic analysis revealed that disulfide bonds played a dominant role in self-healing, while hydrogen bonds provided additional reinforcement. This work presents a novel bio-based polyurethane system with tunable mechanical and self-healing properties, contributing to the development of sustainable smart materials.
during the transmission process of high-speed signals in the FCBGA package substrate, any impedance discontinuity will cause reflection anddistortion of the voltage signal, causing signal quality problems. Therefore,...
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ISBN:
(纸本)9798350353808
during the transmission process of high-speed signals in the FCBGA package substrate, any impedance discontinuity will cause reflection anddistortion of the voltage signal, causing signal quality problems. Therefore, it is very critical to match the impedance on the transmission line andreduce impedance discontinuity to ensure the quality of signal transmission. High-speed signals are very sensitive to impedance discontinuity, so impedance matching in high-speed signals is particularly important for signal quality. This article analyzes the main reasons for impedance discontinuity when high-speed signals are conducted on transmission lines. Based on the simulation results, an optimal design method is proposed to improve the problem of impedance discontinuity of highspeed signals in engineering. Firstly, based on the transmission line theory, the causes and consequences of signal impedance discontinuity are analyzed. Secondly, the simulation software HFSS is used to analyze the influence of parameter changes of each optimization quantity on the differential signal impedance from three aspects: vias, transmission lines, andreference planes. Finally, if the process capability allows, based on the simulation results, the system optimization scheme for high-speed signal transmission is determined with the optimal differential signal impedance as the goal. The simulation results show that: when the stacking parameters and line width parameters remain unchanged, the continuity of the reference plane must be ensured. The larger the differential line spacing, the closer the differential impedance is to 2 times the single-ended impedance. When the spacing is larger than 3 times the line width, the differential impedance tends to stabilize. The via is an important impedance discontinuity point. The main optimization method is to increase the anti-pad size. The via impedance can also be optimized by reducing the via hole size, reducing the via pad size anddecreasing the via
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