bluuebunny/crossref_metadata_2025_split huggingface dataset:
Graphene Technology for Design Efficiency of the Solar Hybrid Electrical Cryoplane and Airships
Authors: Ponyaev L , Kuprikov M , Kuprikov N , Domjan R 
Published: February 2022

Abstract
The problems of introducing graphene technologies into the design studies of complex aviation solutions of minimal weight are relevant for the development of high-strength and lightweight composite structures with surface solar nano film energy storage for hybrid electric cryogenic aircraft (hydrogen cryoplanes LH2) and airships (disk-shaped Thermoplane MAI). The optimal design is directly related to the higher specific characteristics of liquid hydrogen fuel systems together with cryocooling systems, taking into account the use of new graphene-based materials and thin flexible solar cells, which is considered for SOLARSTRATOS and MAI projects or for any projects of hybrid electric aircraft/airships and their engines. A design analysis has been carried out to improve the design capabilities when introducing graphene technologies with their unique strength, electrical superconductivity, gas tightness and low mass in the component modification of a hybrid electric propulsion (HEP) and aero elastic energy-recoverable aircraft structures. The choice of rational design solutions using combined graphene composites, quartz dampers-vibration accumulators of structures and film solar energy cells allows you to reduce the weight of larger fuel tanks with liquefied hydrogen at high and low internal pressures and at the same time include electric motors in the cryocooling system – generators, power cables and batteries with additional solar energy charging, which increases the efficiency of on-board electrical systems and reduces the initial energy level and allows to increase energy efficiency and reduce weight costs during design studies.
Aeroelastic assessment of distributed electric propulsion wings
Authors: Memmolo V. , Marano A. D. , Maio L. , Nicolosi F. , Marulo F. 
Published: February 2022

Abstract
During recent years, aircraft manufacturers focused on environmentally friendly and aerodynamically efficient aircraft concepts that could allow a radical reduction of emissions. The use of a hybrid-electric powertrain is one of the most effective ways to design near-zero-emission aircraft. These aircraft are highly performing and sophisticated so the design process must be extremely accurate. Among the various innovative aspects, the use of distributed engines to improve aerodynamic performance poses new challenges from a structural perspective due to the tip-mounted propeller demanding a complicated design due to reduced flutter performance. This results in higher stiffness requirements and consequently increased mass. Both the weight penalty needed to prevent dynamic instability, and the wing aeroelastic tailoring, crucial to minimize such an additional weight, is of utmost importance. Because of setting up a preliminary approach to estimate the static and dynamic effects of such a non-conventional wing architecture, the present paper shows a comprehensive structural analysis of a wing opportunely designed according to certification specification and equipped with a variable position powertrain. Several different engines are then moved along the wingspan to estimate how it affects the dynamic response using a simplified beam-stick finite element model. The results show that the engine position strongly affects the flutter velocity with a particular band bell curve over the wingspan with the maximum in between 60-70% wingspan. In addition, it is worth noting how the tip propeller may cause a reduction of flutter velocity with respect to the conventional configuration with the turbine mounted in between 30-40% wing-span.
Ground infrastructure investments for operation of hybrid-electric aircraft
Authors: Prapotnik Brdnik A , Kamnik R , Bozicnik S , Marksel M 
Published: February 2022

Abstract
Battery driven aircraft, hydrogen aircraft and hybrid aircraft may begin to appear at airports between 2030 and 2050. The success of their commercialization will also depend on development of accompanying ground infrastructure. We will give an overview of required ground infrastructure for handling battery and hydrogen aircraft including infrastructure for refuelling battery aircraft as well as production, transportation, safety issues and handling requirements.
CFD Wind Tunnel Assessment on the case study of the MOTHIF Blown Flap
Authors: D’Alesio Paolo , Travostino Giorgio , Planquart Philippe , Glabeke Gertjan 
Published: February 2022

Abstract
The increasing interest in Small Air Transportation (SAT), to enhance global connectivity, is highlighting the need for reducing take-off distance: lift coefficient has to be increased without penalizing the configuration drag, weight and complexity.
Within the EU Clean Sky 2 projects, a blown flap configuration has been developed to allow STOL capabilities of a future affordable and green commuter belonging to EASA CS 23.
The blowing system design choice is aimed at keeping the inevitable associated increase in pitching moment very low, and not penalizing performance when blowing fails.
In collaboration between Piaggio Aerospace and the MOTHIF consortium, a wing model was designed, built and tested in the VKI’s large subsonic L1-A wind tunnel, reproducing bi-dimensional preliminary results obtained during the design phase.
In order to reduce and predict three dimensional and blockage effects, CFD has been used extensively to obtain a proper test chamber configuration and to reproduce some wind tunnel test results, so that both the accuracy of wind tunnel and design methodology can be assessed.
This work presents the comparison between experimental data and CFD simulations to demonstrate the usefulness of simulations to reduce both the risk for erroneous results in experimental activities and their related cost.
Latest developments in AWAS: the Advanced Weather Awareness System in the COAST Project
Authors: Montesarchio M , Zollo A L , Ferrucci M , Bucchignani E 
Published: February 2022

Abstract
In the framework of the COAST (Cost Optimized Avionics SysTem) project funded by Clean Sky 2 Joint Undertaking in the European Union’s Horizon 2020 Research and Innovation Programme, several key technologies are under development, aimed to enable single pilot operations of Small Air Transport (SAT) vehicles. One of these technologies is AWAS (Advanced Weather Awareness System), which aims to provide and visualize on board of the aircraft updated weather information regarding areas affected by weather hazards, in order to increase the weather awareness of the pilot. The system is composed by three main components: AWAS on-ground, devoted to generate and provide on board data regarding weather hazards observed and forecast along the flight route; AWAS on-board, aimed to send on-ground information concerning aircraft position and current time and to elaborate data provided by AWAS on-ground; AWAS Human Machine Interface (HMI), that visualize data on-board over a Portable Electronic Device (PED). AWAS on-ground and AWAS on-board segments are connected each other via a low-cost satellite communication system. The meteorological information is extracted from MATISSE (Meteorological AviaTIon Supporting System), a prototype software developed by the Meteorology Laboratory of CIRA. This paper describes the main functionalities and components of the system under development, highlighting the advancements achieved with respect to the one presented in 2020, and the work performed to allow the on-board integration of AWAS system. Furthermore, the paper reports the main results obtained during the dedicated flight test campaign successfully completed in summer 2021, validating the technology when integrated into the aircraft.
Performance comparison of LaB6 and C12A7:e-emitters for space electric propulsion cathodes
Authors: Toledo J. , Plaza J F , Post A , Zschätzsch D , Reitemeyer M , Chen L , Gurciullo A , Siegl A , Klar P J , Lascombes P. , Seifert B. 
Published: February 2022

Abstract
This work, based on an EU-funded project, NEMESIS, is aiming at developing electride-based cathode technology which is compatible with all kinds of electric propulsion systems requiring neutralization. Its target is to demonstrate and validate the performance of a novel C12A7:e-electride material as electron emitter instead of traditional thermionic emitters such as lanthanum hexaboride, LaBe, or barium oxide, BaO. In this study, a fair comparison between LaBe and C12A7:e-samples was performed both addressing pure material characterization parameters as well as comparing performance as cathodes under different architectures and operational conditions. In this case, a current/cathode power ratio around 3 mA/W was obtained when using the C12A7:e-sample in a plasma environment with Ar, which is approximately one order of magnitude higher compared to the LaB6 sample.
Synthesis of design solutions for preliminary aerodynamic design of an advanced supersonic transport under parametric epistemic uncertainty
Authors: Bashkirov I G , Veresnikov G S 
Published: February 2022

Abstract
The paper considers the problem of parametric synthesis of design solutions at the stage of preliminary aerodynamic design of an advanced supersonic transport (SST) under epistemic uncertainty. To solve such a problem, optimization models were developed with objective functions and constraints depending on the input and optimizable uncertain parameters, information on which is formed on the basis of expert estimates. The non-deterministic representation of such parameters is formed on the basis of the uncertainty theory by Dr Baoding Liu (Tsinghua University, China), which provides low computational complexity for a wide range of objective functions and constraints at the stage of preliminary aerodynamic design. With the use of the developed non-deterministic optimization models, typical problems of the synthesis of SST design parameters under epistemic uncertainty are formulated and solved.
Unmanned helicopter flight control actuator specification through mission profile analysis
Authors: Jérémy’’ Roussel , Marc Budinger , Laurent Ruet 
Published: February 2022

AbstractHelicopter dronization is expanding, as for example with the VSR700 project, and leads to the design and the integration of electromechanical actuators (EMA) into the primary flight control system (PFCS). The PFCS is in charge of controlling the helicopter flight over its 4 axis (roll, pitch, yaw, vertical). It controls the blade pitch through dedicated mechanical kinematics and actuators. The hydraulic technology has been conventionally used in actuators for more than 60 years. On the other hand, the introduction of the EMA technology requires the reconsideration of design practices right at development start. Indeed, the establishment and synthesis of the specification need to deal with – new design drivers (high performance points, wear, fatigue) and - new inherent technological imperfections (friction, inertia and reduction ratio). To address these topics, this paper draws a list of the main EMA design drivers to focus on along with a brief description of the main EMA components. Then, it proposes indicators evaluated over a complete mission profile in time coming from measurement on a given applicative helicopter flight. These indicators are chosen and elaborated to provide an image of the design drivers responsible for rapid and gradual degradations of the actuator components. Also, they give an idea of the importance taken by the actuator imperfections into the global performance. Furthermore, we explain how mission profiles are processed depending of data sources. Finally, through a comparison with a standard aircraft mission profile, we emphasize the specificity of the helicopter application use case.
The DressMAN 3.2-System for evaluation of thermal comfort in the Passenger Cabin Ground Demonstrator
Authors: Visser Michael , Park Sumee , Stratbücker Sebastian , Norrefeldt Victor , Lindner Andreas 
Published: February 2022

Abstract
This paper describes an improved measurement method and sensor development for the assessment of the indoor thermal environment. The disadvantage of the state of the art concept of the equivalent temperature to describe inhomogeneous environments is pointed out and how the DressMAN 3.2 sensor system provides improvements to this measurement principle. The measurement system has been prepared in order to accompany thermal tests in the Passenger Cabin Ground Demonstrator developed within the CleanSky2 Regional project. This shall allow the objective assessment of the passenger comfort in the mock-up without the need for extensive subject test campaigns.
The effects of manual XCT focusing on extracted surface texture data
Authors: Slocombe Jonathan , Blunt Liam 
Published: February 2022

Abstract
X-Ray computed tomography, (XCT) has begun to prove itself as a valid method to quantify internal and external surface metrology of parts. However, the understanding of how a small change in the capture settings of the XCT can affect the surface data extracted from parts needs to be developed so that like all metrology instruments the operating window in which the technology provides repeatable results with minimum uncertainty is understood. For XCT there exists a clear point of uncertainty in the measurement process, this being at the generation point of the x-rays, at this point the electron beam impacts a target material causing the generation of x-rays. As the intensity and size of the electron beam focal spot have direct control of the produced x-rays, it is important to align the filament in such a way that the best quality radiographs are generated. The more optimally focused each individually radiograph is in an XCT scan the better quality the 3D model acquired will be, thus leading to more representative surface data extraction. The present paper details an investigation into the effects of this focusing procedure on the extracted surface data. Further to this, the results of the study were compared to work showing the variation in extracted surface data resulting from a full filament change. The present study found that variance in extracted surface texture parameters resulting from beam refocussing exceeded that when comparing filaments, leading to the conclusion that the installation process is likely to be the main contributing factor to the variance noted in both studies.
Observational evaluation of global climate model simulations of arctic sea ice and adjacent land pertaining to the radiative effects of frozen hydrometeors
Authors: Li J L F , Lee Wei-Liang , Xu Kuan-Man , Jiang J H , Wang Yi-Hui , Fetzer Eric , Stephens Graeme , Yu Jia-Yuh , Liu Yinghui 
Published: February 2022

Abstract
This study explores the linkage of frozen hydrometeors (cloud ice and falling ice/snow) with sea ice and adjacent lands through surface energy budget using model-observation comparisons to quantify the roles of the falling ice radiative effects (FIREs) in determining the extent and thickness of Arctic sea ice and adjacent land surface radiation budget and land surface skin (Ts) and surface (SAT) temperatures. The Coupled Model Intercomparison Project Phase 5 (CMIP5) models without FIREs tend to produce underestimated downward longwave radiation, and overestimated shortwave downward radiation and surface albedo, resulting in too-cold skin temperature (TS) and surface air temperature (SAT) and overestimated sea ice concentration (SIC) and thickness (SIT). By comparing two simulations of late 20th Century climate from CESM1-CAM5 model with inclusion and exclusion of FIREs, it is found that TS, SAT, radiation, SIC, and SIT and their seasonal cycles are improved with the inclusion of FIREs. Exclusion of FIREs results in underestimated net downward longwave radiative flux, which is highly correlated with overestimated surface albedo, colder TS, and SAT with a confidence level at 99% (p < 1%). These biases in CESM1-CAM5 resemble those in CMIP5 models without FIREs. With the inclusion of FIREs, the SIC bias is reduced by 2%–15% in summer, while the SIT is improved up to 90% in winter despite little improvement in SIC. These findings suggest a potential link among the increased downward longwave flux, decreased downward shortwave flux, and decreased surface air and land surface temperatures locally, which then drives SIC melting and SIT thinning when FIREs are included relative to when FIREs are excluded. It is suggested that the roles played by FIREs over the Arctic regions are of the same order of importance as those over the Southern Oceans despite the differences in geography and impact of human activity.
scGAC: a graph attentional architecture for clustering single-cell RNA-seq data
Authors: Cheng Yi , Ma Xiuli 
Published: February 2022

Abstract

Motivation
Emerging single-cell RNA sequencing (scRNA-seq) technology empowers biological research at cellular level. One of the most crucial scRNA-seq data analyses is clustering single cells into subpopulations. However, the high variability, high sparsity and high dimensionality of scRNA-seq data pose lots of challenges for clustering analysis. Although many single-cell clustering methods have been recently developed, few of them fully exploit latent relationship among cells, thus leading to suboptimal clustering results.

Results
Here, we propose a novel unsupervised clustering method, scGAC (single-cell Graph Attentional Clustering), for scRNA-seq data. scGAC firstly constructs a cell graph and refines it by network denoising. Then, it learns clustering-friendly representation of cells through a graph attentional autoencoder, which propagates information across cells with different weights and captures latent relationship among cells. Finally, scGAC adopts a self-optimizing method to obtain the cell clusters. Experiments on 16 real scRNA-seq datasets show that scGAC achieves excellent performance and outperforms existing state-of-art single-cell clustering methods.

Availability and implementation
Python implementation of scGAC is available at Github (https://github.com/Joye9285/scGAC) and Figshare (https://figshare.com/articles/software/scGAC/19091348).

Supplementary information
Supplementary data are available at Bioinformatics online.
PreRBP-TL: prediction of species-specific RNA-binding proteins based on transfer learning
Authors: Zhang Jun , Yan Ke , Chen Qingcai , Liu Bin 
Published: February 2022

AbstractMotivationRNA-binding proteins (RBPs) play crucial roles in post-transcriptional regulation. Accurate identification of RBPs helps to understand gene expression, regulation, etc. In recent years, some computational methods were proposed to identify RBPs. However, these methods fail to accurately identify RBPs from some specific species with limited data, such as bacteria.ResultsIn this study, we introduce a computational method called PreRBP-TL for identifying species-specific RBPs based on transfer learning. The weights of the prediction model were initialized by pretraining with the large general RBP dataset and then fine-tuned with the small species-specific RPB dataset by using transfer learning. The experimental results show that the PreRBP-TL achieves better performance for identifying the species-specific RBPs from Human, Arabidopsis, Escherichia coli and Salmonella, outperforming eight state-of-the-art computational methods. It is anticipated PreRBP-TL will become a useful method for identifying RBPs.Availability and implementationFor the convenience of researchers to identify RBPs, the web server of PreRBP-TL was established, freely available at http://bliulab.net/PreRBP-TL.Supplementary informationSupplementary data are available at Bioinformatics online.
Effect of modifying high-risk factors and prehabilitation on the outcomes of colorectal cancer surgery: controlled before and after study
Authors: Bojesen Rasmus D. , Grube Camilla , Buzquurz Fatima , Miedzianogora Rebecca E. G. , Eriksen Jens R. , Gögenur Ismail 
Published: February 2022

Abstract

Background
Low functional capacity, malnutrition, and anaemia are associated with an increased risk of complications after surgery. These high-risk indicators can be improved through preoperative interventions. The aim of the study was to examine the effect of screening for modifiable high-risk factors combined with targeted interventions on postoperative complications in patients undergoing colorectal cancer surgery.

Methods
A controlled before-and-after study was conducted including patients with colorectal cancer undergoing elective curative surgery between August 2015 and October 2018, in two institutions (intervention and control hospital). The intervention consisted of a screening for anaemia, low functional capacity, and nutritional status and their implementation (iron supplementation, prehabilitation, nutritional supplements, and consultation with a dietician), for a minimum of 4 weeks before surgery. The primary outcome was a composite measure consisting of unplanned admission to the intensive care unit, complications with Clavien–Dindo score of 3a or above, length of hospital stay less than 10 days, readmission, or death within 30 days during the postoperative course.

Results
A total of 1591 patients were included for analysis with 839 at the intervention hospital and 752 at the control hospital. In a difference-in-difference analysis, adjusted for age, sex, smoking, stage of disease, ASA score, surgical approach, and surgical procedure, the intervention was associated with a 10.9 per cent (95 per cent c.i. 2.1 to 19.7 per cent) absolute risk reduction of a complicated postoperative course, primarily due to a reduction in severe complications.

Conclusion
The combined intervention of screening and prehabilitation was associated with a decreased risk of a complicated course, primarily in a reduction of severe complications.
Emergency general surgery: impact of distance and rurality on mortality
Authors: Wohlgemut Jared M. , Ramsay George , Bekheit Mohamed , Scott Neil W. , Watson Angus J. M. , Jansen Jan O. 
Published: February 2022

Abstract

Background
There is debate about whether the distance from hospital, or rurality, impacts outcomes in patients admitted under emergency general surgery (EGS). The aim of this study was to determine whether distance from hospital, or rurality, affects the mortality of emergency surgical patients admitted in Scotland.

Methods
This was a retrospective population-level cohort study, including all EGS patients in Scotland aged 16 years or older admitted between 1998 and 2018. A multiple logistic regression model was created with inpatient mortality as the dependent variable, and distance from hospital (in quartiles) as the independent variable of interest, adjusting for age, sex, co-morbidity, deprivation, admission origin, diagnosis category, operative category, and year of admission. A second multiple logistic regression model was created with a six-fold Scottish Urban Rural Classification (SURC) as the independent variable of interest. Subgroup analyses evaluated patients who required operations, emergency laparotomy, and inter-hospital transfer.

Results
Data included 1 572 196 EGS admissions. Those living in the farthest distance quartile from hospital had lower odds of mortality than those in the closest quartile (OR 0.829, 95 per cent c.i. 0.798 to 0.861). Patients from the most rural areas (SURC 6) had higher odds of survival than those from the most urban (SURC 1) areas (OR 0.800, 95 per cent c.i. 0.755 to 0.848). Subgroup analysis showed that these effects were not observed for patients who required emergency laparotomy or transfer.

Conclusion
EGS patients who live some distance from a hospital, or in rural areas, have lower odds of mortality, after adjusting for multiple covariates. Rural and distant patients undergoing emergency laparotomy have no survival advantage, and transferred patients have higher mortality.