bluuebunny/crossref_metadata_2025_split huggingface dataset:
CFD aided investigation of a three-blade propeller in multirotor UAV applications
Authors: Vlachos S , Pliakos C , Bliamis C , Yakinthos K 
Published: March 2024

Abstract
In the recent years a rapid increase of multirotor UAVs in the commercial market is observed resulting in a large number of motor/propeller concepts and thrust architectures. The limited availability of data for the aerodynamic performance of the motor/propeller system often leads to a non-optimal operation on multirotor UAVs design points. Since experimental investigations are both cost- and time-demanding, the accurate CFD modeling of UAV propellers is crucial and highly supportive in the early design phases of multirotor UAVs. In the current study, a CFD framework is employed for the performance investigation of a small-scale three-blade propeller on a lightweight micro quadrotor UAV, designed for indoor search and rescue operations. More specifically, two widely implemented methods for propeller modeling are examined, namely the Multiple Reference Frame (MRF) and the Sliding Mesh (SM). Several operating points are investigated, corresponding to different propeller rotating speeds (RPM) and Reynolds numbers. The accuracy of each method is evaluated by comparing the CFD results with those obtained from literature experimental data. Finally, the uncertainty of the computational methods is quantified through Richardson’s extrapolation method.
Preliminary design of a multirotor UAV for indoor search and rescue applications
Authors: Pliakos C , Vlachos S. , Bliamis C , Yakinthos K 
Published: March 2024

Abstract
Multirotor UAVs have become an essential tool in a wider range of applications, including among others disaster management, and search and rescue (SAR) operations. Typically, these systems operate outdoors, with their guidance and positioning being based primarily on GPS. This work is focused on the design and optimization of a multirotor UAV specifically tailored for indoor SAR applications, where GPS signal is unavailable, and obstacles are prevalent. The design incorporates a lightweight frame structure, in order to increase the UAV’s payload capability. This is necessary, since the UAV requires multiple obstacle recognition and avoidance sensors, as well as thermal and optical cameras, to successfully accomplish its mission objectives in a GPS-denied environment. Towards this goal, various trade studies were conducted including different motor/propeller configurations and airframe FEM analyses. The aerodynamic performance of the UAV is evaluated also, using dedicated CFD analyses that incorporate the effect of propellers. Lastly, a prototype of the designed configuration is produced using additive manufacturing methods and initial flight tests of the UAV are performed.
Implementing and testing a U-space system: lessons learnt
Authors: Fas-Millán M-Á , Pick A , González del Río D , Paniagua Tineo A , García García R 
Published: March 2024

Abstract
Within the framework of the European Union’s Horizon 2020 research and innovation program, one of the main goals of the Labyrinth project, which ended on May 2023, was to develop and test the Conflict Management services of a U-space-based Unmanned Traffic Management (UTM) system. The U-space ConOps provides a high-level description of the architecture, requirements and functionalities of these systems, but the implementer has a certain degree of freedom in aspects like the techniques used or some policies and procedures. The current document describes some of those implementation decisions. The prototype included, at least in a basic version, part of the services defined by the ConOps, namely e-identification, Tracking, Geo-awareness, Drone Aeronautical Information Management, Geo-fence Provision, Operation Plan Preparation/Optimization, Operation Plan Processing, Strategic and Tactical Conflict Resolution, Emergency Management, Monitoring, Traffic Information and Legal Recording. Besides, a web app interface was developed for the operator/pilot. The system was tested in simulations and real visual line of sight (VLOS) and beyond VLOS (BVLOS) flights, with both vertical take-off and landing (VTOL) and fixed-wing platforms, while assisting final users interested in incorporating drones to support their daily tasks. The three-year experience developing and testing the environment provided many lessons at different levels: functionalities, compatibility, procedures, information, usability, ground control station (GCS) integration and aircrew roles during the mission.
An agent-based model for technology adoption in Air Traffic Management
Authors: Baena M , García-Cantú O , Mocholí D , Gil P , García A 
Published: March 2024

Abstract
Technology adoption depends not only on the development of new technologies, but also on the existence of regulations able to foster the implementation of such technologies. To facilitate the exploration of different policy options aimed at accelerating the adoption of new Air Traffic Management (ATM) technologies, an agent-based model that represents the behaviour of the European ATM system has been developed. This model includes representations of the main stakeholders in the ATM ecosystem: regulatory bodies, technology providers, labour unions and technology adopters, including Air Navigation Service Providers (ANSPs), airlines and airports. New ATM technologies, policies imposed, behavioural biases (e.g., loss aversion) and exogenous variables (e.g., fuel price) drive the actions of the agents, leading to the emergent global behaviour of the system. A calibration and validation process involving historical data, gaming experiments and participatory simulations was performed. The model was used to evaluate various policies that included economic incentives and penalties in two scenarios: one based on past events and another focused on the future. The results allow us to analyse which individual stakeholders benefit the most from each policy and to identify the mechanisms that emerge and drive the path of technology adoption, finding that a combination of economic incentives and penalties provides promising economical and operational results.
Radiation protection methods for suborbital aircrafts
Authors: Berti Q , Coutinho J , De Zotti L , Fanni A , Murrone M A 
Published: March 2024

Abstract
This paper presents the outcomes of a study conducted by SALTO team in the framework of the Student Aerospace Challenge, focusing on designing structures to optimize passenger protection against radiation in a suborbital vehicle. The study delves into space radiation characteristics and their potential impact on human health during suborbital flights. Through comprehensive research and the utilization of CARI-7A software, the team evaluated radiation exposure and explored both passive and active shielding solutions. The passive shielding solution involved the design of a multifunctional sandwich panel and a shielding layout for windows, minimizing weight penalties on the vehicle’s structure. Additionally, an active shielding concept utilizing high-temperature superconductor material and solenoid layouts was investigated. The study underscores the benefits and challenges associated with both passive and active shielding methods, emphasizing the importance of further exploration to enhance suborbital flight safety and pave the way for future human space exploration endeavors.
Experimental characterisation of a launcher’s fairing separation shock and its influence on RF antennas’ supporting structures
Authors: Fonseca Carmen , Alonso Daniel , Souza Alain 
Published: March 2024

Abstract
Fairing separation is a critical event during a rocket’s launch as it generates mechanical shocks that can cause partial or total onboard equipment failure. This study details the experimental results of the fairing separation shock of the launcher RFA ONE and its influence on the supporting structures of RF antennas. Accelerometers were used at multiple points of neighbouring structures to characterise the separation devices’ shock during fairing separation tests. Moreover, the shock propagation on different material structures, such as aluminium, carbon fibre, and Viton® elastomer sealant, was investigated. The results showed that the presence of Viton® sealant increased shock transmissibility. Further investigation was conducted to study the influence of applied torque on the separation locks on the shock levels. The study revealed that higher torques lead to increased magnitudes of shock acceleration. Finally, the paper provides recommendations for reducing the shock levels. The experimental results and recommendations presented in this paper provide valuable insights for launcher designers and manufacturers to ensure the safety and reliability of shock-sensitive components during flight.
Hybrid energy storage systems for high power spacecraft missions
Authors: Marín-Coca S , Roibás-Millán E , Pindado S , de Miguel M A , Valente H 
Published: March 2024

Abstract
This work aims to analyze the feasibility of utilizing hybrid storage systems to enable the operation of high-power payloads during eclipse periods. The main objective of the study is to reach possible configurations with the same performance as traditional designs, but with reduced mass and/or volume, or to maintain the mass and volume while increasing the peak power capabilities. The proposed solution involves the use of supercapacitors and high-energy lithium-ion cells, with the former serving to meet peak loads and the latter supplying the mean power needs. Additionally, a simple architecture for the electrical power system is proposed, and the sizing equations for the supercapacitors and lithium-ion cells are derived from the governing power and energy balance equations. The results allow well-founded decision-making process on the suitability of the hybrid configuration based on the peak power demand and its duration, as well as the mean power demand during eclipse operations.
High-temperature stability, water stability, and ice melting properties of salt-storage bituminous mixture AC-13
Authors: Liu Huani , Chen Zhaoming , Wu Lidong , Wang Qingliang , Wang Yanmin 
Published: March 2024

Abstract
This study investigated the road performance and ice melting performance of the AC-13 bituminous mixture prepared with the equal volume replacement of mineral powder from a self-made salt-storage bitumen pavement additive. The results show that adding salt storage bitumen additive improves the bituminous mixture’s high-temperature stability and reduces the bituminous mixture’s water stability. When the replacement rates of the salt storage additive are 50%, 75%, and 100%, the Tensile Strength Ratio (TSR) decreases by 3.35%, 5.95%, and 8.11%, respectively. The dynamic stability (DS) also increases by 4.21%, 7.30%, and 5.62%, respectively. The melting ice rate and salt precipitation tests demonstrate that the salt storage bituminous mixture with a replacement rate of 100% achieves a 36% ice melting rate and 0.3% salt precipitation at -5°C, meeting the standard requirements.
Design of superhydrophobic coatings fabricated by spraying for anti-icing
Authors: Fan Lei , He Jinhang , Li Bo , Bai Jie , Zhu Tao , Song Linbo , Hua Xujiang , Yuan Yuan 
Published: March 2024

Abstract
The icing of transmission lines has a serious impact on people’s lives and disrupts the secure and steady functioning of the power grid, causing huge economic losses. To retard the icing of transmission line glass insulators, we prepared coatings on a glass slide by spraying using epoxy resin, fluorosilicone resin, and hydrophobic silicon dioxide (SiO2). The study examined the microscopical morphology, wetting behaviour, and anti-icing and self-cleaning characteristics of coatings containing various SiO2 mass fractions. The findings indicated that the SiO2 mass fraction notably impacted the micro-nanostructure, anti-wettability, and anti-icing performance of coatings. In addition, the largest contact angle (168.2°), the smallest sliding angle (2.6°), and the longest freezing time (181.7 s) were measured for the superhydrophobic coating with SiO2 mass fraction of 34%, which was attributed to the most uniform microstructure. The superhydrophobic coatings fabricated through spraying exhibited good anti-icing and self-cleaning properties. This facilitates the anti-icing and anti-fouling of transmission line glass insulators.
Research and application of key technology of energy saving and capacity increasing for overhead conductors with carbon fiber composite core reinforced
Authors: Zeng Wei , Dang Peng 
Published: March 2024

Abstract
Aluminum conductor composite core (ACCC) has many excellent comprehensive properties and is gradually popularized and applied in overhead transmission lines. As an energy-saving and environmentally friendly capacitance-increasing conductor, ACCC gives full play to the advantages of carbon fiber materials. This article analyzes the test results of ACCC and compares them with traditional aluminum conductor steel reinforced (ACSR) in terms of mechanical and electrical properties and proposes the development trend of ACCC.
Additive manufacturing and performance research of aluminum-based ceramic cores
Authors: Song Haifeng , Tang Jinqiu , Zhang Hongchang 
Published: March 2024

Abstract
As a ceramic core for forming the cooling structure of the intrinsic cavern of turbine blades, the quality of tubular turbine blades is directly affected by their accuracy and performance. In this paper, based on the DLP photocuring technology, the 50% by volume alumina porcelain suspensions with low viscosity were successfully prepared. Secondly, the effects of printing parameters on the curing characteristics were explored to obtain the best printing parameters. The alumina porcelain properties were analyzed for the heating treatment process effect. As the temperature increases, its mechanical properties increase. In addition, the porosity of the patulous orifice reached 48%. The flexural strength of the alumina porcelain component was 26 MPa, which met the requirements of a high-temperature compound metal blade for the porcelain core.
Study on the effect of microstructure change of 20CrNiV5 high strength and toughness steel on hardenability
Authors: Li Dongyuan , Song Shupeng , Xia Wenbin , Zhou Yong , Lu Ze , Wu Run 
Published: March 2024

Abstract
High-pressure and high-load drilling environment in the deep soil requires high strength and toughness of the oil well pipe, so the oil well pipe steel must be heat-treated, and the hardenability of the steel is particularly important in manufacturing. In this paper, Gleeble-3500 thermal simulator is used to measure the CCT curves of 20CrNiV5 steel, and the influence of microstructure on hardenability is studied. Deformation inhibits the martensitic transformation of the steel and leads to the decrease of its hardenability; the inhomogeneity of the steel pipe after hot forming also has an important impact on the hardenability, and the multiphase microstructure of bainite and ferrite after hot rolling leads to austenitic heating. Austenite grains are small and uneven, which reduces the hardenability of the steel. The microstructure of the inner and outer layers of the hot-formed steel pipe is smaller than that of the middle layer. After heat treatment, its smaller austenite results in weak hardenability.
Imprinted CNTs field emission cathode for electron brushing
Authors: Wang Zhanliang , Lin Zhanpeng , Yan Lei , Xu Zhifeng , Liu Jianlong , He Zhiyuan , Jianmucuo Dongzhi , Jiang Ruirui , Gong Yubin 
Published: March 2024

Abstract
Microchannel plates (MCPs) are the key components for low-level light night vision systems. Electron brushing is a crucial processing for MCPs manufacturing. In this paper, an imprinted carbon nanotubes (CNTs) field emission cathode is fabricated and tested. And the electron brushing experiment based on this cathode is carried out. The result shows that the imprinted CNTs cathode has some advantages and can be used in electron brushing. This research lays the foundation for massive, low cost and highly efficient electron brushing applications in the future.
Supercritical CO2 recompression Brayton power cycle for hybrid concentrating solar and biomass power plant
Authors: Liu C L , Li Z Y , Hao N , Bian W J , Chen Q 
Published: March 2024

Abstract
The supercritical CO2 Brayton cycle has great potential in various renewable energy systems. The supercritical CO2 recompression Brayton power cycle for hybrid concentrating solar and biomass power plant is proposed and analyzed in this paper. The supercritical CO2 is heated by both the molten salt and flue gas from the biomass boiler. The inlet temperature of the turbine in the supercritical CO2 recompression Brayton power cycle for hybrid power plant rises to 620 °C. The waste heat from the system is recovered by the steam turbine to improve energy utilization efficiency. The efficiency of the supercritical CO2 recompression Brayton power cycle increases from 0.382 to 0.41. The efficiency of the steam cycle is 0.46, and the efficiency of the combined cycle is 0.427.
A multipurpose numerical method for imaging studies and tomographic reconstruction
Authors: Celora A. , Guiotto F. , Caruggi F. , Croci G. , Gorini G. , Grosso G. , Hu Z. , Lazzaro E. , Marcer G. , Nocente M. , Putignano O. , Scionti J. , Scioscioli F. , Tardocchi M. , Muraro A. 
Published: March 2024

Abstract
A multipurpose software, called Revolt, has been developed to fully exploit the imaging
capabilities of Triple-GEM 2D cameras for X-rays and neutrons detection. Both tomographic
inversion techniques and synthetic data production methods are based on the modeling of a
transport matrix between the 2D spatially resolved signal on a detector and the 3D signal emission
in the experimental space.

The core task of the Revolt software is to provide a transport
matrix between the two quantities via a numerical-geometrical approach. The method is based on the
analytical evaluation of detector pixels Line Of Sight generated via a Monte Carlo method to
include obstacle shading on the detector image.

The Revolt implementation and validation are
described in this work, which provides a solid base for future application of tomographic
inversion techniques in the context of fusion plasma physics.
Test measurements of an ASIC for X-ray material discrimination by using on-chip time domain integration and a CdTe sensor
Authors: Zoladz M. , Grybos P. , Choręgiewicz K. 
Published: March 2024

Abstract
Using time-domain integration (TDI) and a two-dimensional sensor is beneficial for X-ray imaging of moving objects. Applying on-chip instead off-chip TDI decreases the required data throughput between an ASIC and the backend several times [1]. This, in turn, allows us to significantly simplify the ASIC itself as well as the backend.

We present the results of test measurements of an ASIC dedicated for X-ray material discrimination by using on-chip TDI and a CdTe sensor.

The main part of the ASIC is an 192 × 64 pixel matrix. The pixel size is 100 μm × 100 μm, so the chip size is approximately 6.7 mm × 2 cm. The chip is manufactured in a 130 nm CMOS technology with 8 metal layers. A single pixel analog front-end consists of a charge-sensitive amplifier, a shaper, and three discriminators followed by counters. The test was conducted with a 0.75 mm thick CdTe sensor.

First, we show the results of the discriminator offset correction followed by the evaluation of the pixel analog front-end gain and noise conducted with single energy radiation. Next, the results of moving objects imaging are obtained by using an industrial X-ray machine for food inspection (continuous energy spectrum). This is carried out to present an example of the image and evaluate the image signal to noise ratio for different energy discriminator thresholds, sensor bias voltages, detector module temperatures and object speeds.
Evaluation of staining betung bamboo (Dendrocalamus asper) using natural and synthetic dyes with and without the addition of preservatives
Authors: Al’Afifah J A , Sumardi I , Darwis A , Melani L , Suhaya Y 
Published: March 2024

Abstract
Bamboo is a widely utilized product. The use of dyes in coloring is now becoming important in bamboo dyeing as color can provide consumer appeal and improve aesthetics. Unlike wood, bamboo has a relatively uniform color, which is beige on the inside and green on the outside. Another important step in bamboo processing is preservation. This research examines bamboo colored using synthetic dyes using textile dyes which are azo group, natural dyes derived from the extraction of sappan wood, and examines the addition of borax boric preservatives. There are four treatments: natural dyes with preservatives, natural dyes only, synthetic dyes with preservative, and synthetic dyes only. Several tests were carried out, namely retention, penetration, staining evaluation using the CIELab method, and color change tests. It was found that natural dyes exhibited higher retention than synthetic ones, and both dyes without preservatives surpassed those with preservatives. Penetration was higher in natural dyes and those with preservatives. In comparison to the natural dyes, the color produced from synthetic dyes has a higher red intensity and a darker brightness level. While the addition of preservatives produces a lighter color with a higher brightness value. All treatments showed discoloration due to UV light exposure.
Microwave drying vs hot-steam-air drying of seedless noni fruit: drying performance and post-drying quality
Authors: Yuniarti K , Setiadi A , Basri E , Fahriansyah  , Saefudin  
Published: March 2024

Abstract
Noni fruit contains several beneficial compounds for health, including scopoletin as its active component. The fruits contain a high moisture content, generally above 80%, rendering them to rot quickly. The drying process can potentially increase the fruit’s shelf life as it reduces the moisture content, stop the enzymatic reactions/microorganism activities and inhibit the quality degradation. This study compared the drying performance and post-process quality of noni fruit slices from the microwave and hot-steam-air drying at 50°C and 60°C. The drying performance parameters were time and rate. Several post-drying quality parameters stipulated in Indonesia pharmacopoea standard, such as scopoletin, total ash, and insoluble-acid ash contents, were observed. The results show the drying rate of noni fruit ranged from -3.51 x 10−3 % min−1 (for microwave-drying) to -2.45 x 10-5 % min−1 (for hot-steam-air drying at 50°C). Noni fruits from hot-steam-air drying at 60°C had the highest scopoletin content (22.47 mg kg−1) and the lowest total ash content (4.78%). Microwave-dried noni fruit had the lowest insoluble-acid ash content (0.02%). Drying methods significantly affected the drying rate, total ash content, and insoluble-acid ash content of noni fruit. Treatment scoring shows microwave- and hot-steam-air drying at 60°C are potential options for drying noni fruit.
Recent major advancements in perovskite solar cells
Authors: Xu Lijia , Wang Si , Pu Mingbo , Guo Yinghui , Li Xiong , Luo Xiangang 
Published: March 2024

Abstract
Perovskite solar cells (PSCs) have gained intensive attention as promising next-generation photovoltaic technologies because of their ever-increasing power conversion efficiency, inexpensive material components, and simple fabrication method of solution processing. The efficiency and long-term stability of PSCs have gradually grown in recent years, and steady progress has been made towards the large area perovskite solar modules. This review summarizes the representative works on PSCs that were globally published recently from the viewpoints of efficiency, stability, and large-scale production. Further, we emphasize the current main obstacles in high-throughput manufacturing and provide a quick overview of several prospective next-generation researches.