Experimental analysis and simulation of the dynamix response of a propeller pitch change actuator

This paper focuses specifically on the control of the propeller pitch change mechanisms and their associated dynamics. The subject of this article is restricted to the mechanisms using a hydraulic single acting actuator. They function asymmetrically and are subject to important varying external loads under the full flight envelope. This phenomenon has an impact on their dynamic response. The question of the dynamics of these systems is rarely dealt with because, usually for aircraft applications, there is no real requirement for propeller pitch dynamic control. But, in the case of some applications, such as the Eurocopter X3, this dynamic control aspect and the safety aspect of the propeller pitch change mechanism are particularly important, because this mechanism is fully involved in aircraft safety, control and handling qualities. Firstly, this paper gives an explanation of the phenomena applied to the propeller pitch change mechanism and their contributions to its dynamic response. Then, a model of the dynamic response is proposed. Finally, an experimental identification of the pitch change mechanism dynamics concludes this article.ACKNOWLEDGMENTS This work has been supported by Eurocopter’s Innovation department, Marignane, FRANC

Experimental analysis and simulation of the dynamic response of a propeller pitch change actuator

This paper focuses specifically on the control of the propeller pitch change mechanisms and their associated dynamics. The subject of this article is restricted to the mechanisms using a hydraulic single acting actuator. They function asymmetrically and are subject to important varying external loads under the full flight envelope. This phenomenon has an impact on their dynamic response. The question of the dynamics of these systems is rarely dealt with because, usually for aircraft applications, there is no real requirement for propeller pitch dynamic control. But, in the case of some applications, such as the Eurocopter X3, this dynamic control aspect and the safety aspect of the propeller pitch change mechanism are particularly important, because this mechanism is fully involved in aircraft safety, control and handling qualities. Firstly, this paper gives an explanation of the phenomena applied to the propeller pitch change mechanism and their contributions to its dynamic response. Then, a model of the dynamic response is proposed. Finally, an experimental identification of the pitch change mechanism dynamics concludes this article

Experimental analysis and simulation of the dynamix response of a propeller pitch change actuator

This paper focuses specifically on the control of the propeller pitch change mechanisms and their associated dynamics. The subject of this article is restricted to the mechanisms using a hydraulic single acting actuator. They function asymmetrically and are subject to important varying external loads under the full flight envelope. This phenomenon has an impact on their dynamic response. The question of the dynamics of these systems is rarely dealt with because, usually for aircraft applications, there is no real requirement for propeller pitch dynamic control. But, in the case of some applications, such as the Eurocopter X3, this dynamic control aspect and the safety aspect of the propeller pitch change mechanism are particularly important, because this mechanism is fully involved in aircraft safety, control and handling qualities. Firstly, this paper gives an explanation of the phenomena applied to the propeller pitch change mechanism and their contributions to its dynamic response. Then, a model of the dynamic response is proposed. Finally, an experimental identification of the pitch change mechanism dynamics concludes this article.ACKNOWLEDGMENTS This work has been supported by Eurocopter’s Innovation department, Marignane, FRANC

CONTRIBUTIONS OF AUGMENTED REALITY IN ARCHITECTURAL PROJECT REVIEW

peer reviewedAlready present in the fields of medicine and video games, augmented reality is now being employed in architectural design. We explore here the role that this new digital tool can play, as a means of interaction, in the review of projects. To do so, we work through experiments that immerse designers in three different environments: (1) a 2D environment, composed of plans and sections, (2) an augmented reality environment on a tablet and, finally, (3) an environment combining the two approaches. We can thus dissect how augmented reality can be a relevant tool and which functionality(ies) can enrich its current potentialities in architectural design

Electrocardiographic correlates of mechanical dyssynchrony in recipients of cardiac resynchronization therapy devices

SummaryBackgroundThe relationship between electrical and mechanical indices of cardiac dyssynchronization in systolic heart failure (HF) remains poorly understood.ObjectivesWe examined retrospectively this relationship by using the daily practice tools in cardiology in recipients of cardiac resynchronization therapy (CRT) systems.MethodsWe studied 119 consecutive patients in sinus rhythm and QRS≥120ms (mean: 160±17ms) undergoing CRT device implantation. P wave duration, PR, ePR (end of P wave to QRS onset), QT, RR–QT, JT and QRS axis and morphology were putative predictors of atrioventricular (diastolic filling time [DFT]/RR), interventricular mechanical dyssynchrony (IVMD) and left intraventricular mechanical dyssynchrony (left ventricular pre-ejection interval [PEI] and other measures) assessed by transthoracic echocardiography (TTE). Correlations between TTE and electrocardiographic measurements were examined by linear regression.ResultsStatistically significant but relatively weak correlations were found between heart rate (r=−0.5), JT (r=0.3), QT (r=0.3), RR–QT intervals (r=0.5) and DFT/RR, though not with PR and QRS intervals. Weak correlations were found between: (a) QRS (r=0.3) and QT interval (r=0.3) and (b) IVMD>40ms; and between (a) ePR (r=−0.2), QRS (r=0.4), QT interval (r=0.3) and (b) LVPEI, though not with other indices of intraventricular dyssynchrony.ConclusionsThe correlations between electrical and the evaluated mechanical indices of cardiac dyssynchrony were generally weak in heart failure candidates for CRT. These data may help to explain the discordance between electrocardiographic and echocardiographic criteria of ventricular dyssynchrony in predicting the effect of CRT

Programmed Recognition between Complementary Dinucleolipids To Control the Self-Assembly of Lipidic Amphiphiles

This is the peer reviewed version of the following article: Morales‐Reina, S., Giri, C., Leclercq, M., Vela‐Gallego, S., de la Torre, I., Caston, J. R., ... & de la Escosura, A. (2020). Programmed Recognition between Complementary Dinucleolipids To Control the Self‐Assembly of Lipidic Amphiphiles. Chemistry–A European Journal, 26(5), 1082-1090, which has been published in final form at https://doi.org/10.1002/chem.201904217. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions.One of the major goals in systems chemistry is to create molecular assemblies with emergent properties that are characteristic of life. An interesting approach toward this goal is based on merging different biological building blocks into synthetic systems with properties arising from the combination of their molecular components. The covalent linkage of nucleic acids (or their constituents: nucleotides, nucleosides and nucleobases) with lipids in the same hybrid molecule leads, for example, to the so-called nucleolipids. Herein, we describe nucleolipids with a very short sequence of two nucleobases per lipid, which, in combination with hydrophobic effects promoted by the lipophilic chain, allow control of the self-assembly of lipidic amphiphiles to be achieved. The present work describes a spectroscopic and microscopy study of the structural features and dynamic self-assembly of dinucleolipids that contain adenine or thymine moieties, either pure or in mixtures. This approach leads to different self-assembled nanostructures, which include spherical, rectangular and fibrillar assemblies, as a function of the sequence of nucleobases and chiral effects of the nucleolipids involved. We also show evidence that the resulting architectures can encapsulate hydrophobic molecules, revealing their potential as drug delivery vehicles or as compartments to host interesting chemistries in their interior.Research in Madrid received support from the Spanish Ministry of Economy and Competitivity (MINECO: CTQ‐2014‐53673‐P, CTQ‐2017‐89539‐P, and EUIN2017‐87022). This work was also supported in part by grants to JRC from MINECO (BFU2017‐88736‐R), and Comunidad Autónoma de Madrid (P2018/NMT‐4389). A.d.l.E. and M.S. thank the interdisciplinary framework provided by the European COST Action CM1304 (“Emergence and evolution of complex chemical systems”). A.d.l.E. and C.G. acknowledge the “Programme for Post‐Doctoral Talent Attraction to CEI UAM+CSIC—Intertalentum” (GA 713366). Research in Mons was supported by the Wallonia Region and the Fund for Scientific Research (FNRS, Belgium) under the grants MIS No. F.4532.16 (SHERPA) and EOS No. 30650939 (PRECISION). Confocal fluorescence microscopy was performed with the help of Sylvia Gutierrez Erlandsson, from the Advanced Light Microscopy Service of Centro Nacional de Biotecnologia (CNB). The professional editing service NB Revisions was used for technical preparation of the text prior to submission

Reionization with star-forming galaxies: insights from the Low-z Lyman Continuum Survey

The fraction of ionizing photons escaping from galaxies, $f_{esc}$, is at the same time a crucial parameter in modelling reionization and a very poorly known quantity, especially at high redshift. Recent observations are starting to constrain the values of $f_{esc}$ in low-z star-forming galaxies, but the validity of this comparison remains to be verified. Applying at high-z the empirical relation between $f_{esc}$ and the UV slope trends derived from the Low-z Lyman Continuum Survey, we use the DELPHI semi-analytical galaxy formation model to estimate the global ionizing emissivity of high-z galaxies, which we use to compute the resulting reionization history. We find that both the global ionizing emissivity and reionization history match the observational constraints. Assuming that the low-z correlations hold during the epoch of reionization, we find that galaxies with $-16 \lesssim M_{UV} \lesssim -13.5$ are the main drivers of reionization. We derive a population-averaged $\langle f_{esc} \rangle \simeq 8\%, 10\%, 20\%$ at z=4.5, 6, 8.Comment: 5+1 page, 3 figures, submitted to A&

Measurements of particle emissions and contrail ice particle properties behind a large passenger aircraft burning 100% sustainable aviation fuel in cruise

The use of sustainable aviation fuels (SAF) derived from biomass and waste materials can provide one approach to partially decarbonize air traffic relatively quickly and offers a pathway to mitigate the non-CO2 climate impacts from long-lived contrails on short time scales. Many SAFs naturally contain no or only low amounts of aromatic compounds which act as soot precursors during combustion. As soot particles serve as primary nucleus for contrail ice, lower soot emissions should result in lower contrail ice particle numbers. In the joint project ECLIF3 (Emissions and Climate Impact of alternative Fuels), DLR, Airbus, Rolls-Royce, Neste and other participants aimed to characterize emissions and contrail properties behind a modern passenger aircraft burning both conventional Jet A-1 fuel and HEFA-SPK (Hydroprocessed Esters and Fatty Acids Synthetic Paraffinic Kerosene) and a blend of HEFA-SPK and Jet A-1 on both engines on the ground and in flight. For the first time, flight tests in cruise using 100% HEFA-SPK on all engines were feasible in this framework. In two field campaigns in 2021 an Airbus A350-900 equipped with Rolls Royce Trent XWB-84 engines served as source aircraft. With the DLR Falcon 20E5 research aircraft we probed trace gases, volatile and non-volatile particles, and ice particle properties. The independent fuel tanks of the A350 permitted us to sample emissions from reference Jet A-1 and HEFA-SPK in similar meteorological conditions. Measurements of the exhaust closely behind the engine exit and up to several minutes behind the lead aircraft allowed us to characterize both, direct engine emissions depending on engine thrust conditions and the effects on contrail formation and properties. With respect to the Jet A-1 used here, we find a significant reduction in non-volatile particle emissions when burning HEFA-SPK; similar trends are seen in the ice particle numbers in the contrails. The results outline the importance of fuel composition (e.g. sulfur and aromatics content) on particle emissions and contrail formation. The analysis also shows the complexity of the contrail formation process and its dependence on fuel composition, engine thrust and meteorological conditions in the ambient atmosphere

Antiretroviral-naive and -treated HIV-1 patients can harbour more resistant viruses in CSF than in plasma

Objectives The neurological disorders in HIV-1-infected patients remain prevalent. The HIV-1 resistance in plasma and CSF was compared in patients with neurological disorders in a multicentre study. Methods Blood and CSF samples were collected at time of neurological disorders for 244 patients. The viral loads were >50 copies/mL in both compartments and bulk genotypic tests were realized. Results On 244 patients, 89 and 155 were antiretroviral (ARV) naive and ARV treated, respectively. In ARV-naive patients, detection of mutations in CSF and not in plasma were reported for the reverse transcriptase (RT) gene in 2/89 patients (2.2%) and for the protease gene in 1/89 patients (1.1%). In ARV-treated patients, 19/152 (12.5%) patients had HIV-1 mutations only in the CSF for the RT gene and 30/151 (19.8%) for the protease gene. Two mutations appeared statistically more prevalent in the CSF than in plasma: M41L (P = 0.0455) and T215Y (P = 0.0455). Conclusions In most cases, resistance mutations were present and similar in both studied compartments. However, in 3.4% of ARV-naive and 8.8% of ARV-treated patients, the virus was more resistant in CSF than in plasma. These results support the need for genotypic resistance testing when lumbar puncture is performe

CropPol: a dynamic, open and global database on crop pollination

Seventy five percent of the world's food crops benefit from insect pollination. Hence, there has been increased interest in how global change drivers impact this critical ecosystem service. Because standardized data on crop pollination are rarely available, we are limited in our capacity to understand the variation in pollination benefits to crop yield, as well as to anticipate changes in this service, develop predictions, and inform management actions. Here, we present CropPol, a dynamic, open and global database on crop pollination. It contains measurements recorded from 202 crop studies, covering 3,394 field observations, 2,552 yield measurements (i.e. berry weight, number of fruits and kg per hectare, among others), and 47,752 insect records from 48 commercial crops distributed around the globe. CropPol comprises 32 of the 87 leading global crops and commodities that are pollinator dependent. Malus domestica is the most represented crop (32 studies), followed by Brassica napus (22 studies), Vaccinium corymbosum (13 studies), and Citrullus lanatus (12 studies). The most abundant pollinator guilds recorded are honey bees (34.22% counts), bumblebees (19.19%), flies other than Syrphidae and Bombyliidae (13.18%), other wild bees (13.13%), beetles (10.97%), Syrphidae (4.87%), and Bombyliidae (0.05%). Locations comprise 34 countries distributed among Europe (76 studies), Northern America (60), Latin America and the Caribbean (29), Asia (20), Oceania (10), and Africa (7). Sampling spans three decades and is concentrated on 2001-05 (21 studies), 2006-10 (40), 2011-15 (88), and 2016-20 (50). This is the most comprehensive open global data set on measurements of crop flower visitors, crop pollinators and pollination to date, and we encourage researchers to add more datasets to this database in the future. This data set is released for non-commercial use only. Credits should be given to this paper (i.e., proper citation), and the products generated with this database should be shared under the same license terms (CC BY-NC-SA). This article is protected by copyright. All rights reserved