bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hybrid Active Vibration Control of Rotorbearing Systems Using Piezoelectric Actuators
Authors: Palazzolo A. B. , Jagannathan Shankar , Kascak A. F. , Montague G. T. , Kiraly L. J. 
Published: April 2021

Abstract
The vibrations of a flexible rotor are controlled using piezoelectric actuators. The controller includes active analog components and a hybrid interface with a digital computer. The computer utilizes a grid search algorithm to select feedback gains that minimize a vibration norm at a specific operating speed. These gains are then downloaded as active stiffnesses and dampings with a linear fit throughout the operating speed range to obtain a very effective vibration control.
The Problems of Active Vibration Isolation in Nonlinear and Parametric Structures
Authors: Frolov K. V. 
Published: April 2021

Abstract
The theory of active vibration control based on the principle of broad-band compensation coupled with controllable vibration damping is presented. The applications of this principle to parametric and nonlinear mechanical structures are discussed. For the first time the possibility of the active vibration control with the aid of stochastic self-excited vibration spectrum transformation nonlinear phenomena is investigated. The theoretical and experimental results are compared for various complex mechanical objects.
An Improved Extended Transfer Matrix Method for a Damped System
Authors: Huang Yuan Mao 
Published: April 2021

Abstract
Installation of a damper is a good method to reduce the torsional vibration effect and to prolong the life of a system. However, consideration of the damping effect results in a complicated system.
This study derives a mathematical model for the analysis of a single branch damped system. The extended transfer matrix method is used with Newton-Raphson iterative technique. The procedures automatically eliminate the complicated operations of the matrix inversion and reduce the multiplication of the matrix products. The natural frequencies, both real and imaginary parts of the state vectors and mode shapes of the system can be determined.
A Technological Data Base in Aircraft Production Environment
Authors: Lega Riccardo 
Published: April 2021

Abstract
In a factory, where many cells work togheter, we obviously have a significant proliferation of data and information concerning the production flow.
We have, of course, to control this event in order to avoid dramatic consequences, as incoherence, disalignment and data inconsistency.
On the other hand, we have to notice thatt data production is generated by many different applications, and by many people having different skills and responsibilities, and using different applications and technologies.
Trying to solve this problem, we decided to define an unique and solid data base structure at factory level, called Technological Data Base (TDB), in which all users (man or application) generating information, useful to production activities, must store data under their own responsibility.
Data stored in this Data Base are defined as “Consolidated”, to indicate data that are released by an application process and are used as an input or a trigger for another application process.
These consolidated data can be:
- Structured data, i.e. data that can be organized in fields or attributes, mainly coming from Planning Applications.
- Unstructured data, i.e. data that are stored in the Data Base as a bits sequence, mainly coming from CAD/CAM applications managed as a black-box by the DBMS, while specific applications (at cell level) provide to understand them.
This Technological Data Base is an object-oriented Data Base, where functions are implemented in order to store, manage, and distribute all multi-media information requested to drive and control the different plant work-centers.
A pilot application of this TDB is already working in Alenia-Pomigliano factory — in a conventional workshop environment, and it will be extended to the other factories in an automated environment.
Numerical Design of a Floating Offshore Wind Turbine Large Scale Model for Control Purposes
Authors: Taruffi Federico , Di Carlo Simone , Muggiasca Sara , Fontanella Alessandro 
Published: April 2021

Abstract
This paper deals with the numerical design of a floating offshore wind turbine outdoor large-scale prototype based on the DTU 10MW. The objective of this work is to develop a numerical simulation environment for the design of an outdoor scaled prototype. The numerical model is realized coupling the preliminary designed Blue Growth Farm large-scale turbine model with a traditional floater, the OC3 spar buoy. The numerical model is used to evaluate the loads associated with the wind turbine when combined to a floating foundation, with the focus on the coupling between the dynamics of the control system and the one of the floating platform. In addition to this, also the consistency of loads on crucial turbine components is an interesting test bench for the evaluation of the dynamical effects and drives the final design of the physical model.
Evaluation of Deep-Water Floating Wind Turbine to Power an Isolated Water Injection System
Authors: Khan Khalid S. , dos Santos Isabelle V. M. , dos Santos Guilherme B. , Salles Maurício B. C. , Monaro Renato M. 
Published: April 2021

Abstract
The main objective of this paper is to evaluate the use of floating wind turbines for isolated offshore systems. The energy analysis is a vital step at the initial phase of the project to define topologies that will be able to feed subsea systems, a water injection system is considered as a example. The first location that we decided to look in detail is one of the largest oil regions discovered in the last hundred years and it is located on the Brazilian coast. It is important to highlight that the development is on the technological frontier of a new type of floating wind turbine application for deep waters. The focus of the study is to validate the perks of this application, such as, the production of clean and green energy capable enough to satisfy the load requirements of a Water Injection Systems (WIS) for Oil and Gas (O&G) production, chosen among other possibilities of subsea systems as an example. Water injection is effective to improve the oil recovery in reservoirs, but conventionally involves high energy consumption, significant emissions and expensive infrastructure. This work investigates different configurations combining a wind turbine, diesel generator and batteries to supply power to the off-grid load, with the basic premise that WIS can follow the generation available from the wind turbine, since it does not require a fixed injection rate. In the energetic point of view, the main result shows that the use of wind turbine and li-ion battery can cut emissions by half and increase the energy efficiency of the system.
Investigation of Nonlinear Difference-Frequency Wave Excitation on a Semisubmersible Offshore-Wind Platform With Bichromatic-Wave CFD Simulations
Authors: Wang Lu , Robertson Amy , Jonkman Jason , Yu Yi-Hsiang , Koop Arjen , Borràs Nadal Adrià , Li Haoran , Shi Wei , Pinguet Romain , Zhou Yang , Xiao Qing , Kumar Rupesh , Sarlak Hamid 
Published: April 2021

Abstract
The natural surge and pitch frequencies of semisubmersible offshore wind platforms are typically designed to be below the wave frequencies to avoid direct excitation. However, surge or pitch resonance can be excited by the nonlinear low-frequency loads generated by irregular incident waves. Second-order potential-flow models with added Morison drag have been found to underpredict this low-frequency excitation and response. As part of the OC6 project1, the authors performed computational fluid dynamics (CFD) simulations to enable a better understanding of the low-frequency loads and the limitations of lower-fidelity models. The focus of this paper is to set up a computationally cost-effective CFD simulation of a fixed semisubmersible platform to investigate nonlinear difference-frequency loads and establish the corresponding uncertainty in the results. Because of the high computing cost, CFD simulations of irregular waves can be challenging. Instead, simulations were performed with bichromatic waves having a shorter repeat period. A preliminary comparison with quadratic transfer functions from second-order potential-flow theory shows that CFD models consistently predict higher nonlinear wave loads at the difference frequency, likely because of flow separation and viscous drag not accounted for in potential-flow theory.
Mooring Fatigue Verification of the WindCrete for a 15 MW Wind Turbine
Authors: Trubat Pau , Molins Climent , Alarcon Daniel , Arramounet Valentin , Mahfouz Mohammad Youssef 
Published: April 2021

Abstract
LCOE reduction in FOWTs is heading to larger wind turbines in order to increase power production and capacity. NREL and DTU have recently developed a 15MW reference wind turbine, which can be used to validate the platform concepts for the next generation of wind turbines. Increasing the power of wind turbines leads to larger platforms due to the need to withstand the increase of the weight of the Nacelle Rotor Assembly, as well as the increase of the wind forces and pitching moment. Moreover, the larger the turbines and platforms the larger surge/sway and yaw unbalanced forces, which will need to be hold up by the mooring system.
The mooring system has to be designed to balance the wind and wave forces and provide the stiffness needed to the FOWT for a proper behavior. Moreover, the mooring system has to achieve enough reliability to prevent line failure that could lead to a chain reaction within a floating wind farm, and thus huge loses. Then, a complete and detailed fatigue analysis should be performed in order to guarantee the performance of the FOWT during its service life.
Within the CoReWind EU-2020 project, the Windcrete platform is upscaled to withstand the new EIA 15MW reference wind turbine. As concrete is used as a main material, the mass and inertia are larger than steel counterpart which leads to stiffer and more loaded mooring system. In this paper, the fatigue analysis of the Windcrete mooring system is assessed and compared using different methods.
Verification Study of CFD Simulation of Semi-Submersible Floating Offshore Wind Turbine Under Regular Waves
Authors: Wang Yu , Chen Hamn-Ching , Vaz Guilherme , Mewes Simon 
Published: April 2021

Abstract
Utilization of Computational Fluid Dynamics (CFD) codes to perform hydrodynamic analysis of Floating Offshore Wind Turbines (FOWTs) is increasing recently. However, verification studies of the simulations that quantifying numerical uncertainties and permitting a detailed validation in a next phase is often disregarded. In this work, a verification study of CFD simulations of a semi-submersible FOWT design under regular waves is performed. To accomplish this goal, Response Amplitude Operators (RAOs) are derived from the computational results of the heave, surge and pitch motions. Four grids with different grid sizes with a constant refinement ratio are generated for verification of spatial convergence. Three different time increments are paired with each grid for verification of temporal convergence. The verification study is performed by estimation of the numerical errors and uncertainties using procedures proposed by Eca and Hoekstra [1].
Active surveillance for carbapenemase-producing Klebsiella pneumoniae and correlation with infection in subjects attending an Italian tertiary-care hospital: a 7-year retrospective study
Authors: Calderaro Adriana , Buttrini Mirko , Martinelli Monica , Montecchini Sara , Covan Silvia , Ruggeri Alberto , Rodighiero Isabella , Di Maio Alan , Galullo Mariapia , Larini Sandra , Arcangeletti Maria Cristina , Chezzi Carlo , De Conto Flora 
Published: April 2021

ObjectivesThe distribution of carbapenemase-producing Klebsiella pneumoniae (CPKP) phenotypes and genotypes in samples collected during 2011–2018 was evaluated. The association between patients with CPKP-positive rectal swab and those with CPKP infection, as well as the overall analysis of CPKP-infected patients, was performed.SettingThe study was performed in a tertiary-care hospital located in Northern Italy.ParticipantsTwo groups were considered: 22 939 ‘at-risk’ patients submitted to active surveillance for CPKP detection in rectal swabs/stools and 1094 CPKP-infected patients in which CPKP was detected in samples other than rectal swabs.ResultsCPKP-positive rectal swabs were detected in 5% (1150/22 939). A CPKP infection was revealed in 3.1% (719/22 939) of patients: 582 with CPKP-positive rectal swab (50.6% of the 1150 CPKP-positive rectal swabs) and 137 with CPKP-negative rectal swab. The 49.4% (568/1150) of the patients with CPKP-positive rectal swab were carriers. The overall frequency of CPKP-positive patients (carriers and infected) was almost constant from 2012 to 2016 (excluding the 2015 peak) and then increased in 2017–2018. blaKPC was predominant followed by blaVIM. No difference was observed in the frequency of CPKP-positive rectal swab patients among the different material groups. Among the targeted carbapenemase genes, blaVIM was more significantly detected from urine than from other samples.ConclusionsThe high prevalence of carriers without evidence of infection, representing a potential reservoir of CPKP, suggests to maintain the guard about this problem, emphasising the importance of active surveillance for timely detection and separation of carriers, activation of contact precautions and antibiotic treatment guidance on suspicion of infection.
Maturation reaction norm evolution under varying conditions of eco-evolutionary change
Authors: Gobin Jenilee , Fox Michael G. , Dunlop Erin S. 
Published: April 2021

Probabilistic maturation reaction norms (PMRNs) are commonly used to infer evolution of maturation age and size in wild fish stocks, but how well estimates from phenotypic data actually reflect underlying genotypes is debated. We used an eco-genetic model of a commercially harvested freshwater fish to simulate populations undergoing various levels of fisheries-induced evolution and density-dependent feedback and evaluated effects on the estimation of PMRNs. We estimated PMRNs from phenotypic data sampled from simulated populations (age, length, and maturation status of individuals), as is done for wild stocks, and compared estimates with the known maturation genotypes of individuals in the simulated population. PMRN estimates were robust to changes in the strength of density-dependent growth and high levels of fisheries-induced evolution. However, our ability to detect slower rates of evolution was limited, especially when individuals matured within a narrow range of ages. Furthermore, low numbers of immature or mature individuals within a given age class limited our ability to robustly estimate midpoints for more than one or two ages, despite our large sample sizes (n = 200 randomly sampled individuals of each age per year), highlighting a challenge with this approach. Nonetheless, this study suggests that the widely applied method of estimating PMRNs from readily available phenotypic data to detect underlying evolution of maturation schedule is robust to some key factors that vary in wild populations.
Characterization of heavy mineral concentrates and detrital gold particles from the Bigorne granite-hosted gold deposit in the Iberian Variscan Belt
Authors: Leal Sara , Lima Alexandre , Noronha Fernando 
Published: April 2021

Abstract
The Bigorne gold deposit, located in the Iberian Variscan belt, is a gold-bearing vein system, which cross-cuts Variscan granites. The hypogene mineralization corresponds to sheet-veins parallel to the late-Variscan Penacova–Régua–Verín fault. A combined study was undertaken of gold particles from hypogene mineralization and locally derived eluvial material, as well as gold from alluvial deposits in local drainages, to assess possible sources of the alluvial gold. The geochemistry and mineralogy of heavy mineral concentrates revealed a similar signature to the hosted granites and hypogene mineralization, which indicates a local source for the surficial materials, with limited contribution from surrounding rocks. Hypogene and detrital gold particles at Bigorne area are entirely primary in origin and correspond essentially to a Au–Ag alloy (<22 wt% Ag), locally with minor amounts of Cu. The compositional range of Ag and Cu is a consequence of variation in parameters formation of the deposit, such as temperature. Our study highlights the first results on gold detrital particles chemistry for granite-hosted gold deposits in the Iberian Variscan belt, and has provided a platform for further work to characterize gold from this environment, such that it may be used as a generic indicator mineral together with other resistant ore minerals.
The Automatic Detection of Pedestrians under the High-Density Conditions by Deep Learning Techniques
Authors: Jin Cheng-Jie , Shi Xiaomeng , Hui Ting , Li Dawei , Ma Ke 
Published: April 2021

The automatic detection and tracking of pedestrians under high-density conditions is a challenging task for both computer vision fields and pedestrian flow studies. Collecting pedestrian data is a fundamental task for the modeling and practical implementations of crowd management. Although there are many methods for detecting pedestrians, they may not be easily adopted in the high-density situations. Therefore, we utilized one emerging method based on the deep learning algorithm. Based on the top-view video data of some pedestrian flow experiments recorded by an unmanned aerial vehicle (UAV), we produce our own training datasets. We train the detection model by using Yolo v3, a very popular deep learning model among many available detection models in recent years. We find the detection results are good; e.g., the precisions, recalls, and F1 scores could be larger than 0.95 even when the pedestrian density is as high as

9.0

ped

/

m

2

. We think this approach could be used for the other pedestrian flow experiments or field data which have similar configurations and can also be useful for automatic crowd density estimation.
Targeting Triple-Negative Breast Cancer with Combination Therapy of EGFR CAR T Cells and CDK7 Inhibition
Authors: Xia Lin , Zheng Zaozao , Liu Jun-yi , Chen Yu-jie , Ding Jiancheng , Hu Guo-sheng , Hu Ya-hong , Liu Suling , Luo Wen-xin , Xia Ning-shao , Liu Wen 
Published: April 2021

Abstract

EGFR-targeted chimeric antigen receptor (CAR) T cells are potent and specific in suppressing the growth of triple-negative breast cancer (TNBC) in vitro and in vivo. However, in this study, a subset of mice soon acquired resistance, which limits the potential use of EGFR CAR T cells. We aimed to find a way to overcome the observed resistance. Transcriptomic analysis results revealed that EGFR CAR T-cell treatment induced a set of immunosuppressive genes, presumably through IFNγ signaling, in EGFR CAR T-cell–resistant TNBC tumors. The EGFR CAR T-cell–induced immunosuppressive genes were associated with EGFR CAR T-cell–activated enhancers and were especially sensitive to THZ1, a CDK7 inhibitor we screened out of a panel of small molecules targeting epigenetic modulators. Accordingly, combination therapy with THZ1 and EGFR CAR T cells suppressed immune resistance, tumor growth, and metastasis in TNBC tumor models, including human MDA-MB-231 cell–derived and TNBC patient–derived xenografts, and mouse EMT6 cell–derived allografts. Taken together, we demonstrated that transcriptional modulation using epigenetic inhibitors could overcome CAR T-cell therapy–induced immune resistance, thus providing a therapeutic avenue for treating TNBC in the clinic.
Comparison of Admission Lung Ultrasound and Left Ventricular End-Diastolic Pressure in Patients Undergoing Primary Percutaneous Coronary Intervention
Authors: Neves de Araujo Gustavo , Beltrame Rafael , Pinheiro Machado Guilherme , Luchese Custodio Julia , Zimerman Andre , Donelli da Silveira Anderson , Scolari Fernado Luís , Corsetti Bergoli Luiz Carlos , Gonçalves Sandro Cadaval , Pereira Lima Marques Felipe , Fuchs Felipe Costa , Vugman Wainstein Marco , Vugman Wainstein Rodrigo 
Published: April 2021

Background:
Left ventricular end-diastolic pressure (LVEDP) is related to ventricular dysfunction and increased retrograde pulmonary capillary pressure. Lung ultrasound (LUS) is a sensitive and easy-to-use method for assessment of pulmonary congestion. Both methods have shown prognostic value in patients with ST-segment–elevation myocardial infarction. Our aim was to evaluate the correlation between LVEDP and bedside LUS and to compare their prognostic value in patients undergoing primary percutaneous coronary intervention.

Methods:
Prospective cohort study of ST-segment–elevation myocardial infarction patients treated in a tertiary care hospital in Brazil. LUS was performed immediately before coronary angiography. LVEDP was recorded before primary percutaneous coronary intervention, blinded to LUS results. Primary outcome was any in-hospital major adverse cardiovascular event, defined as in-hospital mortality, new myocardial infarction, stroke, and new cardiogenic shock.

Results:

In total, 218 patients were included; their mean age was 60 (±12) years, and 64% were men. Cardiogenic shock was present in 16.5% of patients on admission. Overall in-hospital mortality was 15%. Median LVEDP was 19 mm Hg (interquartile range, 13–28); median LUS zones positive for pulmonary congestion were 1/patient (interquartile range, 0–5); Spearman correlation between them was 0.33 (
P
<0.001). LVEDP and LUS C statistic for in-hospital major adverse cardiovascular event was 0.63 ([95% CI, 0.55–0.70]
P
=0.002) and 0.71 ([95% CI, 0.64–0.77]
P
<0.001), respectively. In multivariable analysis, LUS remained associated with in-hospital major adverse cardiovascular event (odds ratio, 1.14 [95% CI, 1.06–1.23];
P
=0.01) for every positive LUS zone; LVEDP, however, did not (odds ratio, 1.01 [95% CI, 0.99–1.03];
P
=0.23).

Conclusions:
We found a weak correlation between LVEDP and LUS in our cohort of ST-segment–elevation myocardial infarction patients undergoing primary percutaneous coronary intervention. Pulmonary congestion in acute heart failure is a complex pathophysiological process and goes beyond fluid overload and hemodynamics. Unlike LVEDP, LUS was significantly associated with in-hospital major adverse cardiovascular event, new cardiogenic shock, and in-hospital mortality in multivariable analysis.

Graphic Abstract:

A
graphic abstract
is available for this article.