bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comparisons of nitrogen and phosphorus removal efficiency in A2/O process, UCT process, MUCT process, enhanced phosphorus removal process and inverted A2/ O process based on GPS-X simulation
Authors: Lei Shuhan , Zhao Jianqiang , Xie Shuting , Zhao Junkai , Min Jia , Ma Xiaoqing , Yan Chunxiao 
Published: February 2022

Abstract
By using the GPS-X software, the enhanced phosphorus removal (EPR)process was simulated in this study. The comparisons among nitrogen and phosphorus removal efficiency of traditional A2/O process, University of Cape Town (UCT) process, Modified University of Cape Town (MUC) process and inverted A2/O process were conducted, in order to determine the best process under the same conditions of construction investment and running cost. The results showed that the simply reversed A2/O process exhibited poor total phosphorus (TP) removal efficiency under low carbon level. The effluent water qualities of the other three processes under low, medium and high levels of carbon source met the first B level criteria in Discharge Standard of Pollutants for Municipal Wastewater Plan (GB18918-2002) for China. The ranges of removal efficiencies of TP, TN, NH4
+-N and COD were 63.15% ∼ 94.91%, 55.38% ∼ 77.89%, 96.91% ∼ 97.70% and 90.89% ∼ 93.66%, respectively. Denitrifying phosphorus removal occurred in anoxic tank of EPR process. The phosphorus accumulation concentration was 6.91 mg/L, and the maximum phosphorus released in anaerobic tank was 24.01 mg/L, and the higher P release gave the EPR process a high P removal effiency. Except for the TN which met the first B level criteria (GB18918-2002), TP, NH4
+-N and COD met the first A level criteria GB18918-2002), above that, the process was feasible. Inverted A2/O process exhibited the highest nitrogen removal efficiency for its sufficient carbon source in anoxic tank.
The high-efficiency methods to identify lithology with well logging plates or a program
Authors: Wu Zhaohui 
Published: February 2022

Abstract
As traditional manual method to identify lithology of cored wells is laborious and lack of efficiency, two efficient methods are used this time. One method is the identification with well logging plates while another is a program. The critical values of 5 kinds of well loggings are found to be relatively stable through many trials, and some major steps should be taken before using the logs. First is to find standard rock types and their logging values. Rock types are more reliable after the observation under microscopes. The second step is to find out the logging data ranges of each rock type. The third step is to quantitatively identify rock types with the optimal critical values. In this process, the multi-array logs (M2Rn) is found to be the most effective log to distinguish mudstone and oil reservoir. Low density (DEN) value is effective to distinguish the lightest matter or pores. The other two well logs, i.e. AC and CNL, can be used to distinguish whether there is limy content. Wave impedance (PD=DEN/AC) log can be a supplementwhen that kind of data is available, and finally all lithology is identified after that. The result that calculated from well logs with a program is similar to litholgy of drilling cores. Through many trials and errors, it is finally found and proved to be a successful approach to automatically and efficiently distinguish rock types in the software of Direct and Petrel. This method is more efficient and easier to operate with a program when there are hundreds of wells, and it is a progem made that work possible. There is more widespread use in deep carbonate buried hill with this method, simply by changing the lithology codes and critical values in the program.
Multi-fidelity weight analyses for high aspect ratio strut-braced wings preliminary design
Authors: Delavenne M , Benard E , Defoort S , David C , Fabbiane N , Schotte J S , Arnoult G , Carrier G 
Published: February 2022

Abstract
In the wake of ”flygskam” movement that emerged in Sweden a couple of years ago many voices recently raised denounce the environmental footprint of aviation. Even if the real impact of the sector could appear rather limited the critics reveal the necessity to propose cleaner aircraft to both meet public expectations and environmental goals. Because the classical wing-tube configuration seems to have reached its limits, disruptive designs must be considered. Among the perspectives to reduce emissions, high-aspect ratio wings represent a promising path to be explored within the European CleanSky2 project U-HARWARD. Indeed, substantial diminution of induced drag are expected from those new configurations resulting in fewer fuel consumption. To achieve high-aspect ratio without compromising the structural weight strut can be introduced. They allow for an alleviation of the bending moment at the wing root and therefore lighter structures. However, the consideration of those new wing configuration at early design stages is not straightforward and new methods have to be introduced. In this paper, we present three different fidelity approaches to tackle with (ultra) high-aspect ratio strut-braced wings sizing and weight estimation in preliminary design context. Already existing analytical formulations for the wings are extended, intermediate fidelity aero-structural coupling has been developed and high-fidelity structural representation are considered. Depending on the maturity of the concept these methods could be used to explore the design space, to refine the optimum or to analyse the final concept. Validation with respect to reference configurations is provided. Then the methods are applied to the analysis of strut-braced wings.
Ground effect aerodynamics of twin fuselage aircraft
Authors: Chernousov V I , Krutov A A , Savin P V , Pigusov E A 
Published: February 2022

Abstract
The paper presents experimental study results of ground effect influence on the aerodynamic characteristics of the twin fuselage transport airplane in a low-speed wind tunnel. The aerodynamic configuration has the two fuselages distributed under high-wing, and a “TT”–shaped tail. The twin fuselage transport airplane model consists of two fuselages, wing, empennage and external tank. The analysis includes studying the ground effect on the longitudinal and lateral aerodynamic characteristics and horizontal tail effectiveness. The effect of installing an external cryogenic fuel tank under the wing between the fuselages of the model was considered too. The obtained data shows the typical behaviour of the aerodynamic characteristics near the ground plate for aircraft model with high-wing and high placed horizontal tail. Ground proximity significantly increases the maximum lift-to-drag ratio and slightly changes the longitudinal moment characteristics. Horizontal tail effectiveness is maintained for all tailplane angles near the ground plate. The longitudinal and lateral stability of the twin fuselage transport airplane model is maintained in all considered modes near the ground plate.
Managing Airport Capacity and Demand: An Economic Approach
Authors: Rodríguez-Sanz Álvaro , Andrada Luis Rubio 
Published: February 2022

Abstract
This paper reviews major research trends and opportunities in airport demand and capacity management from an economic perspective. Airport capacity constraints lead to operational congestion and delays, which have become major threats to the aviation industry. They impose large costs on airlines and their passengers. Uncertainty in demand or unexpected events can cause a mismatch between capacity and demand, resulting in either capacity over-supply, with a decrease in efficiency, or airport congestion over an extended period. Moreover, airport capacity is rather difficult to define due to its multi-faceted and dynamic nature, and it depends both on the available infrastructure and on operating procedures. The non-linear relationship between airport capacity and on-time performance offers guidelines for congestion mitigation through demand and capacity management. This paper explores and produces an in-depth understanding of the capacity and demand balance problem and provides a roadmap for including economic concepts when evaluating airport capacity expansions.
Highly iterative concept development for requirement-compliant air taxis
Authors: Schuh G. , Spangenberg M. , Meyer-Hollatz T. 
Published: February 2022

Abstract
The increasing demand for individual mobility worldwide is leading to the development of new forms of mobility. Individual air mobility (e.g., air taxis) could be one innovative approach to meet this increasing demand. To successfully realise such innovative approaches, interested companies must know the technical, economic, and ecological requirements of all relevant stakeholders and integrate them in their air taxi developments. Based on these diverse requirements, a resilient air taxi concept must first be created that describes the essential characteristics of future air taxis and enables a well-founded assessment. However, in practice, it is often difficult for companies to outline such a concept and then develop it consistently and highly iteratively. To face this challenge, a process has been set up which creates a deep link between the requirements and concept development phase to assure the development of requirement-compliant air taxis in an agile manner. The process is divided into two parts. The first part connects the market analysis, requirements definition and concept creation, thus linking the requirements and concept development phase. It is based on a double diamond model consisting of two phases. In contrast, the second part is focusing on the pre-development until the end of the concept development phase by adapting the SCRUM methodology to derive a sound air taxi concept. Both parts are executed in a highly iterative manner to reflect the significant amount of uncertainty at this early process stages.
Innovative liner concept using friction powder for increasing of broadband noise absorption. Applications for broadband noise absorption in fan duct
Authors: Sandu Constantin , Humbert Thomas , Auregan Yves , Deaconu Marius , Totu Andrei , Radu Andrei , Serbescu Horatiu , Tipa Traian 
Published: February 2022

Abstract
This paper presents research related influence of friction powders on enlarging the absorption band of acoustic liners used for reduction of tonal noise in fan duct of aero-engine. Kundt tube measurements done at COMOTI using fine powders (granules) made of various light-weight materials placed in the honeycomb cells of SDOF liners have shown a considerable broadening of the absorbed band of frequencies without a significant decreasing of absorption at the resonance frequency. Although the phenomenon is generally present for any type of powder, it was observed that for some powders the absorption is higher than for others. On the other hand, it was observed that the effect of the filling percentage of the cavity is important. Then, experiments done at the grazing flow facility of CNRS-Le Mans University have shown that the phenomenon is also present for high acoustic incident levels (up to 140dB) and M=0.13 while it still depends by the nature of powder material. The best results were obtained for the cork powder when the honeycomb is filled with powder at 66% of its height. For this material, the broadening of the transmission loss well was maximum. This phenomenon could be explained by the apparition of friction between powder granules which are taking place at very low scale consuming the noise power on a broader range of frequencies. It is supposed that the friction between the particles of powder have major influence because the best noise absorption was obtained for powders with a large distribution of particles’ dimensions while for particles with a small dimensional distribution (expanded polyester balls, for example) the transmission well broadening was smaller. The friction powders technology is simple and can be easily adapted to existing acoustic liner technologies with small manufacturing costs. This feature is conferred by the fact that powders can be easily poured in the honeycombs at the required height. The friction powder technology can be applied not only for the fan duct. In future, it could also be applied for reduction of jet noise reflected by pressure side of wing and for cabin noise reduction.
Prediction of Fan Tone Radiation Scattered By A Cylindrical Fuselage
Authors: Rouvas D-M. , McAlpine A. 
Published: February 2022

Abstract
A theoretical prediction method of the scattering of fan tone radiation from a turbofan inlet duct by the airframe fuselage is presented. The fan tone noise is modelled by an acoustic disc source that represents the sound field at the inlet duct termination. Adjacent to the source is a cylindrical fuselage that scatters the fan tone radiation. The prediction method is valid for upstream sound radiation. The acoustic pressure on the cylindrical fuselage is affected by refraction of the sound as it propagates through the fuselage boundary layer. This effect known as boundary layer shielding is more prominent forward of the turbofan, since the fan tone noise radiated from the inlet duct is propagating upstream. An asymptotic approach is used to model sound propagation through a boundary layer which is modelled by a thin linear shear velocity profile. Consequently the scattered pressure field can be computed very quickly, thus providing a fast and efficient prediction method. Although a realistic fuselage turbulent boundary layer does not resemble a linear shear layer, it is shown that the effect of acoustic shielding by a turbulent boundary layer can be modelled by taking a liner shear profile with a shape factor that matches the shape factor for a realistic turbulent profile.
The impact of propulsive architecture on the design of a 19-passenger hybrid-electric aircraft
Authors: Nasoulis Christos P. , Protopapadakis Georgios , Gkoutzamanis Vasilis G. , Kalfas Anestis I. 
Published: February 2022

Abstract
The electrification of aircraft is an on-going endeavor, currently examined intensively in the general aviation class. However, for the commuter class, the proper selection of the hybrid-electric propulsive architecture is instrumental, to fully exploit the electrification benefit. Within this work, a comparison of two 19-seater aircraft with different hybrid-electric propulsive components is made, using an in-house aircraft conceptual design tool. The first aircraft is based on a twin-turboprop parallel-hybrid configuration that cruises at low Mach number speeds and altitude. On the other hand, the second aircraft variant is based on a tri-fan series/parallel-hybrid configuration with an aft Boundary Layer Ingestion system that operates at both higher altitude and Mach numbers. A design space exploration is performed where different degrees of hybridization and batteries specific energy are considered, to define the technological requirements for each architecture. The evaluation of the propulsive architectures is based on block fuel reduction, overall mission duration, direct operating costs and total environmental impact. The results aim to quantify the benefits of each configuration and determine the one with the closest entry into service. Finally, it is observed that the overall environmental impact reduces by 26 % and 17 % for the turboprop and turbofan variants respectively.
Design of Hybrid-Electric Small Air Transports
Authors: Orefice F. , Marciello V. , Nicolosi F. , Zhang Q. , Wortmann G. , Menu J. , Cusati V. 
Published: February 2022

Abstract
The potential benefits of hybrid-electric or full-electric propulsion have led to the proliferation of many concepts over the past decade. The lack of conceptual design methods capable of grasping the effects of the new propulsive technologies is often due to the absence of industrial data supporting the research. In the present work, two objectives are pursued. On the one hand, the introduction of semi-empirical methods for weight estimation based on the data provided by the industrial partners of the ELICA CS2 project. On the other hand, the establishment of generative engineering as a conceptual design tool for propulsive system architecting and fault tolerance analysis. The applications of the proposed conceptual design methods deal with two different years of entrance in service.
Towards simulation of disassembly of bonded composite parts using the laser shock technique
Authors: Kormpos P , Tserpes K , Floros G 
Published: February 2022

Abstract
In this work, a model for simulating the laser shock-based disassembly of composite components is developed using the LS-DYNA explicit code. The laser shock technique has been used in the past for the non-destructive testing of adhesive bonds, but with appropriate adjustments it is possible to create a localized tensile stress that is high enough for adhesive failure to occur, making it suitable for use in the disassembly of bonded parts. In this first attempt, we focus on the development of a multiple loading instances simulation process, aiming to completely debond two carbon fiber reinforced plastic (CFRP) plates. The process of laser shock for disassembly requires an increased number of loading instances in order to cover the full bonded area. That, in addition to the short time duration in which the phenomena are evolved, poses a serious challenge for the numerical simulations, and thus a reliable procedure must be defined in terms of functionality and computational cost. Indeed, an iterative method, where the deformed model is used as input in subsequent simulations is evaluated, optimized and compared with a more traditional single model simulation.
InnEO’Space PhD: Preparing Young Researchers for a successful career on Earth Observation applications
Authors: Mothe Josiane , Bayer Aurelie , Castello Valentina , Ciaccio Valentina , Frate Fabio Del , Santis Davide De , Ivanovici Mihai , Kerisel Anne Lehuerou , Necşoi Daniela , Ndong Aude Nzeh , Neptune Nathalie , Perier-Camby Maude , Recchioni Marco , Ullah Zia , Voinea Mihaela 
Published: February 2022

Abstract
InnEO’Space PhD project is preparing young researchers for a successful career by developing modernised and transferable PhD courses and learning resources based on innovation skills and employers’ needs as well as in-depth knowledge of high stakes and approaches of Earth Observation in many application domains. The mains objectives of Inn’EO Space PhD are to enhance and develop researchers’ innovation-oriented mind-sets and skills through Earth Observation, raise awareness about employment opportunities in academia and industry among researchers and scientists, tackle future skills mismatches and create new synergies between PhD students and researchers and potential employers. The first action has been to develop the InnEOStartech where the program was set for European PhD students with the aim of developing their taste for entrepreneurship spirit through idea of founding a company or designing an application. The second action has been to develop a summer school that delivered both technical skills and soft skills, thus providing all the ingredients for an innovation-oriented mindset. From these activities we shall develop a series of SPOCs (Small Private Online Courses) that will be made available to the community for further dissemination and exploitation.
New Intelligent Semi-Products based on Recycled Carbon Fibres
Authors: Faure Alexandre , Mantaux Olivier , Gillet Arnaud , Cazaurang Gilles 
Published: February 2022

Abstract
The carbon fibre recycling industry is not yet able to operate at full capacity. This lack of potential is a repercussion of a low demand for recycled carbon fibres (rCF) to manufacture new composite materials. As a matter of fact, few semi-products containing recycled carbon fibres are available on the market. Moreover, rCF semi-products available do not allow to manufacture high performances composite parts. The MANIFICA project, based on highly realigned carbon fibres after steam thermolysis, aims at producing new semi-products from recycled carbon fibres for high performance composites. In this article we introduce the I2M/Université de Bordeaux re-alignment process producing continuous tapes made of highly aligned long discontinuous fibres. These tapes are then used to manufacture new intelligent rCF semi-products. In the first part, the mechanical properties of rCF composites based on different semi-products are compared. In the second part, several semi products based on realigned fibres tapes are presented. This work demonstrates that high performance products can be targeted with recycled carbon fibres, thanks to the development of these intelligent semi-products.
ECO-CLIP: circular economy from factory waste material towards aircraft structural components
Authors: Travieso-Puente R , Martín-Pérez C , González-Castro N , Rodríguez-Senín E , Vidal-Navarro J , Vicente-Guerrero G , Veldman S L 
Published: February 2022

Abstract
This paper discusses the development of short fibre frame clips and system brackets made from recycling CF/LMPAEK factory waste composites employing two technologies (injection molding and 3D-printing). The project will develop and validate fused deposition modeling (FDM) as cost-efficient process to manufacture system brackets using the novel formulation of recycled composite as raw material. Energy directors development for ultrasonic welding is presented for successful joining of the clips to the fuselage, avoiding fasteners. The manufactured parts will be assembled into the lower half of the multifunctional fuselage demonstrator. The results were developed within ECO-CLIP project, which aims to: (1) assess technical aspects of material recyclability and (2) assess the economic and environmental validity of the technology.
Analysis and validation of mathematical models of secondary velocities along vertical and transverse directions in wide open-channel turbulent flows
Authors: Kundu Snehasis , Chattopadhyay Titas 
Published: February 2022

Abstract
Cellular secondary flows are inevitably present in turbulent flows through ducts, natural or artificial channels, and compound channels. Secondary currents significantly modify the characteristics of turbulent quantities, the pattern of primary flow velocity by causing dip-phenomenon. To understand the detailed mechanism and hidden cause, modelling of secondary flow velocities is crucial. In this study, proper mathematical models of secondary flow velocities along vertical and transverse directions are proposed for steady and uniform turbulent flow through wide open channels with equal smooth and rough bed strips. Starting from the continuity and the Reynolds averaged Navier–Stokes equations, governing equation for secondary velocity is derived first and then using appropriate boundary conditions (no-slip boundary conditions at channel bottom and free surface, and maximum vertical velocity in magnitude at the interface of two cellular secondary cells and at mid-depth of the channel. All these conditions are consistent with several experimental observations). A new model of the streamwise Reynolds shear stress is proposed for the entire cross-sectional plane and using it, the analytical solutions are obtained. Proposed models include the effects of viscosity of the fluid and the eddy viscosity model of turbulence. All suggested models are validated with existing experimental data in rectangular open-channel flows, compound open channel flows, and duct flows, and satisfactory results are obtained. Furthermore, models are also compared with existing empirical models from literature to show the effectiveness and superiority of proposed models. Apart from these, the obtained results from this study are used to investigate the effects of vertical and transverse secondary flow velocities on the settling velocity vector in a cross-sectional plane. Effective alternative models for the settling velocity vector are suggested. The model of settling velocity vector is also compared with the existing model. Finally, all results are justified from physical viewpoints.