bluuebunny/crossref_metadata_2025 huggingface dataset:
Gust and landing impacts as critical load cases for wings with distributed propulsion
Authors: Schubert Martin , Dafnis Athanasios , Schröder Kai-Uwe
Published: June 2023

The integration of distributed electric propulsion and energy storage systems into the wing structure significantly affects the mass distribution of the wing. Compared with conventional aircraft which are designed with engines mounted on the inner wing and integral fuel tanks, this substantially changes the overall loads on the wing structure. Assuming a retrofit scenario, this paper studies the influence of transient gust and landing impact loads on the dynamic behavior and the structural integrity of the wing of a representative conventional 19-seater commuter aircraft of CS-23 category retrofitted with distributed electric propulsion. Modal and dynamic response analyses are conducted based on a beam model idealizing the wing box of three wing designs: the reference wing with one main turboprop engine per half-wing, and two wings with integrated distributed electric propulsion. The results show for both load cases that the wing section loads obtained by dynamic response analysis exceed those predicted by equivalent quasi-static calculations. Compared with the reference wing, a significant increase of the amplitudes of the plunge and twist deformation and consequently higher section loads and stresses are observed for the retrofitted wing designs. It is concluded that both load cases are critical with regard to the structural integrity of the wing. However, the gust load case is more critical than the landing load case. These conclusions suggest that for the structural sizing of the wing, in particular for wings with distributed propulsion, and with regard to gust and landing impacts, the commonly applied quasi-static analyses should be accompanied by dynamic response analyses.
Preliminary tests on additive-manufactured Al-Sc specimens for the setup of a numerical model for Laser Shock Peening
Authors: Zavatta Nicola , Troiani Enrico
Published: June 2023

Aluminum-Scandium alloys offer a great potential in aerospace applications due their high corrosion resistance and improved strength properties. Furthermore, these alloys have been qualified for laser additive manufacturing (AM), producing parts with static strengths rivalling their conventionally manufactured counterparts. However, laser processing also results in large residual stresses that can severely affect fatigue properties and result in geometric distortion. A proven method for reducing the fatigue-related problems in metallic structures is to drive compressive residual stresses into the affected area by means of Laser Shock Peening (LSP). This surface treatment is very effective in bulk structures, improving life performances of fatigue-sensitive aeronautical components, such as jet engines turbine blades or helicopter gearboxes. On the other hand, quite a limited number of studies has been presented on the effect of LSP on fatigue crack growth in thin components and laser AM structures. This work presents first the results of preliminary tensile tests on additive manufactured Al-Sc specimens. The tensile strengths of as-built and heat-treated samples are compared. Then, a reliable and computationally time-effective numerical model of laser peening is reviewed, referring to case studies investigated earlier. In view of applying LSP to additive manufactured Al-Sc components, the effects of different laser parameters and geometries are discussed. Finally, the possible drawbacks of the LSP treatment are addressed, in order to exploit its full potential in increasing the fatigue life of AM components.
Performances of composites made from different recycled carbon fibre semi-products
Authors: Faure Alexandre , Mantaux Olivier , Gillet Arnaud
Published: June 2023

Recycled carbon fibres (rCF) were generally chosen for their low price and environmental features. However, performances of composites made of recycled carbon fibres are often too low to compete with lightweight alloys and glass fibre composites materials. As performances of rCF composites depend strongly on the fibres architecture, new semi-products with long and aligned recycled carbon fibres were developed by MANIFICA (Cleansky European Project). The use of long (up to 250mm) and highly aligned recycled fibres now provides rCF composites with excellent mechanical properties.

The purpose of this work is to assess the performances of composites manufactured with these new rCF semi-products. Semi-products with distinct architectures developed by MANIFICA are first presented. Then mechanical performances of composite plates manufactured from the different semi-products are evaluated. Results are finally compared in order to identify the effect of the manufacturing parameters of the semi-products on the final composite properties. This crucial information will allow end-users to select the right semi-product to design recycled carbon fibre composite innovative parts.
Chemical Recycling of Carbon Fibre Reinforced Polyurethane for Aviation Applications
Authors: Höhne Carl-Christoph , Brantsch Peter , Reichert Thomas , Hanich-Spahn Ronny
Published: June 2023

Carbon fibres are widely used in carbon fibre reinforced plastics (CFRP) for aviation, automotive, windmills, sport and many more application due to their outstanding material properties. Annually, this generates about 62,000 tonnes of end-of-life (EoL) CFRP and CFRP production waste. Current EoL scenarios for CFRPs show some disadvantages: Landfilling and incineration are not sustainable and environmentally friendly. Carbon fibre recovery by pyrolysis damages the carbon fibres and incinerates the plastic material. Mechanical recycling shortens the carbon fibres and is of limited value for thermosets. However, chemical recycling routes like solvolysis offers the great potential to recover damage-free carbon fibres as well as useful monomers for a new generation of plastics. Here we provide an overview about the solvolysis of carbon fibre reinforced polyurethane material for aviation applications. Additionally, first life cycle assessment results are presented.
Circularity studies on high performance thermoplastic demonstrators for the aircraft industry – End-of-Life concepts for PEKK/carbon fiber
Authors: Coskun S. , Prado L. A. S. A. , Das T. S. G. , Kötter A. , Sterk S. , Halm J.
Published: June 2023

In this study, the circularity of the different end-of-life concepts for PEKK reinforced with high performance carbon fiber composite parts were investigated. For this, two different thermoplastic demonstrators from Clean Sky 2’s ecoTECH Project were used. Recycling and circularity of the thermoplastic components were demonstrated by scraping the continues fiber reinforced thermoplastic fuselage panel parts into small flakes, which then were to be re-used as short fiber reinforced composite particles to produce compression molded Window Frames. For scraping, two different technologies were compared by means of quality, efficiency and environmental impacts. Based on different recycling and re-use options for both thermoplastic fuselage and Window Frame demonstrators, Linear Flow Index (LFI) and Material Circularity Indicator (MCI) parameters were calculated and used to showcase the alternative circularity levels of each scenario
Environmental Improvement Potential of Flexible Polyurethane Foam for Aviation Applications - A Case Example Analysis
Authors: Höhne Carl-Christoph , Salles Ana , Brantsch Peter , Reichert Thomas , Hanich-Spahn Ronny
Published: June 2023

The assessment of the environmental impacts of an aircraft and its components parts should go beyond the use phase when assessing its sustainability and circularity. Environmental impacts from the manufacturing phases e.g. related to consumption of resources, pollutions, and the use of hazardous materials as well as those from the end-of-life phase of an aircraft must not be neglected. Hence, a life cycle assessment (LCA) screening of the environmental impacts has been conducted based on a case example of polyurethane flexible foams (PUR-FF) for application on aircraft seating cushions. This analysis covers the production of PUR-FF with a particular focus on three perspectives: (i) production of bio-materials instead of fossil-based material; (ii) reduction and replacement of hazardous chemicals like heavy metal catalysts and flame retardants; and (iii) recovery of polyol by chemical solvolysis of PUR-FFs. The main results of the environmental improvement potentials of the PUR-FF are presented here.
Synthesis and characterization of bulk mechanical properties of a bio-based resin filled by graphene nanoplatelets and cellulose nanocrystals
Authors: Tserpes K , Lagkousi S , Tourountzi E , Floros G
Published: June 2023

In the present paper, a novel bio-based resin derived from epichlorohydrin was reinforced by Graphene NanoPlatelets (GNPs) and Cellulose NanoCrystals (CNCs) in different weight ratios and characterized experimentally through tension tests and fracture toughness tests on bulk specimens. The nanofillers were applied separately. The experimental results showed that the neat resin has a Young’s modulus of 3.29 GPa, a tensile strength of 45.15 MPa, a stress intensity factor of 0.61 MPa m1/2 and a critical strain energy release rate of 0.091 kJ/m2. The level of the properties reveal that the bio-based adhesive can be used for cosmetic and for some structural applications. The addition of cellulose nanocrystals in the epoxy resin didn’t improve the mechanical properties of the neat resin mainly due to the development of intense aggregation of cellulose nanocrystals. On the other hand, the addition of graphene has led to the increase of the Young’s modulus and the fracture toughness and to the decrease of the tension strength of the resin. Development of agglomerations of graphene were also present in this case. The contradictory findings on the mechanical properties of the reinforced resin gives a clear message about the need for optimizing the manufacturing process. Both nanocomposites have undergone a complete life-cycle analysis which has shown that they are far more environmentally friendly than a conventional epoxy resin.
Heat and species map prediction for the generic MEA using an air node model derived from high level requirements
Authors: Matheis C , Norrefeldt V
Published: June 2023

Current developments to implement the More Electric Aircraft (MEA) result in a fundamental change of the aircraft systems architecture. Components may be resized or new components may be introduced. This results in new challenges for the thermal management and safety assessment of systems and therefore parametric and fast simulations tools will become crucial to explore the entire design space. The effects of component heat dissipation on airflow in the aircraft fuselage can be qualified using a zonal simulation model. Zonal airflow models subdivide the indoor space into typically 102 zones exchanging air. This allows to predict the impact of systems locations, ventilation and cooling strategies on the thermal management and safety considerations in an early design stage. This paper presents the setup of such an aircraft zonal model based on high-level requirements for a MEA of regional airplane size. These requirements cover the number of passengers, the flight profile and system components to be integrated, like e.g. the battery. Additional requirements are derived from standards for example providing information on required airflow rates and temperatures in the cabin. These requirements are translated into a geometry, ventilation pattern and systems layout. The model application is demonstrated on the example of the safety consideration in case of a battery failure leading to exhaust of harmful gas. This is done by comparing the gas dispersion for two different battery positions in the aircraft.
Changes in electric resistance of cracked copper-coated, pitch-based carbon fibres for structural health monitoring in a glider wing
Authors: Steinbild P J , Wieja N , Condé-Wolter J , Winkler A , Ehrig T , Kostka P , Modler N
Published: June 2023

Structural health monitoring based on detecting strain enables further exploitation of the lightweight potential of aircraft structures. Since carbon fibres (CF) can be easily integrated into aircraft structures made of fibre-reinforced plastics (FRP), their use in sensor applications has become subject of research. One of many novel approaches is the use of cracked CF for strain detection. During loading and unloading, the fibre cracks are opening and closing respectively, resulting in substantial changes in the electric resistance of the CF. The high dependence of the electric resistance on the mechanical strain enables spatially resolved strain sensing along the CF based on the electric time domain reflectometry (ETDR) principle. However, due to high inhomogeneity of the used pitch-based CF and the resulting electric properties, the ETDR-signal is degraded largely by impedance mismatch along the transmission line, which limits the measuring length of a spatially resolved sensor. In this contribution, a concept for a spatially resolved CF-based strain sensor is described, outlining the challenges that need to be addressed. One approach for the extension of the measuring length is lowering the base resistivity of the used CF, which is discussed in detail. In order to achieve a low base resistivity while maintaining the characteristic of opening and closing fibre cracks, copper-coated CF are investigated. The copper-coated pitch-based CF are integrated into test specimens consisting of a composite material and are subjected to tensile loading. Simultaneously to the deflection, the electrical resistance is measured. Consequently, the sensitivity to strain of the CF is determined and discussed.
Single-Pilot Incapacitation in commercial aviation - Evaluation of an Operational Concept
Authors: Vizioli Aurora De Bortoli , Bonelli Stefano , Mallozzi Gianmaria , Lieb Teemu Joonas , Martins Ana P. G. , Friedrich Max , Capasso Pasquale Junior , Senatore Costantino , Godano Francesco , Contissa Giuseppe , Sartor Galileo , dos Reis Ricardo J.N.
Published: June 2023

To implement Single Pilot Operations (SPO) in commercial aviation, safety levels must be maintained compared to current operations. In this paper we present a concept of operations aiming at supporting flight and landing of a single-piloted aircraft in case the onboard single pilot becomes incapacitated. The concept relies on Ground Station positions being manned by ground station operators who monitor the aircraft, support the single pilot as needed, and take over control in case of incapacitation. The concept was evaluated through a number of evaluation activities, including two simulation campaigns. The results suggest that the concept could be a robust proposal to address single pilot incapacitation, and no major showstoppers have been identified from an operational, legal, and regulatory point of view. In this paper, the key technological, infrastructural, and procedural enablers that shall contribute to maintain SPO safety levels as in current dual-pilot operations are also discussed.
Design, manufacturing and flight-testing of a fixed-wing, small-scale UAV for the transportation of blood bags to remote locations
Authors: Karageorgiou A , Kantouris P , Metallidou N , Charizani A , Panagiotou P
Published: June 2023

The current work presents the design, manufacturing, and flight-testing of a fixed-wing, small-scale Unmanned Aerial Vehicle (UAV). The research activities presented in this paper have all been conducted by the Aristotle Space & Aeronautics Team (ASAT), a Greek aerospace student team, for their participation in the international student competition Air Cargo Challenge 2022. Its mission is to carry bags of blood to a remote location. The design requirements refer to a short take-off distance of 60m of rough terrain, climb time of 60s and a cruise/loiter time of 120s. Size restrictions also apply, as the aircraft must fit inside a 1.5m x 1.5m x 0.5m volume, in its deployed form. A step-by-step presentation of the design procedure is conducted, emphasizing on the critical design decisions, such as the airfoil, cargo bay location and wing planform design. The corresponding trade studies are shown, along with the main advantages of the resulting configuration. The in-house manufacturing process is consequently described, focusing on the molds tooling, as well as on the carbon fiber and fiberglass manufacturing techniques. Finally, the results of the flight testing are shown, including the initial challenges that lead to the fine-tuning of the UAV. The test results are validated against the design data and the overall performance of the aerial vehicle is discussed.
Visual aid for unmanned aircraft navigation in unknown environments
Authors: Uzun S S , Soken H E
Published: June 2023

This study presents a visual-aided inertial navigation technique that can be used for unmanned aircraft in unknown environments. An angular and linear velocity estimation algorithm, which is based on the solution of the Wahba’s problem, is developed using sequential images for visual odometry. It is possible that the visual sensors do not receive continuous measurements throughout the mission, for example, when a sufficient number of features cannot be detected by the camera. Considering that a closed loop Extended Kalman Filter algorithm is designed for integration of visual odometry measurements with the inertial measurements to have accurate pose estimation throughout the flight.
Enabling UAS BVLOS flights in CTR
Authors: Kleczatský A , Hulínská Š , Kraus J
Published: June 2023

In recent years, the widespread use of drones for the transport of people and cargo in and between cities has become increasingly considered. From the point of view of airspace organization, world capitals with high potential for this operation mostly have one common parameter - airspaces defined as controlled zones are established above them, as an integral part of airspace around large international airports. Given the current state of knowledge and the global degree of implementation of unmanned traffic management, it is necessary to solve how to integrate the operation of drones alongside aircraft with crew on board, for which the current rules are defined. On the other hand, the rules for the joint operation of manned and unmanned aircraft, have not yet been sufficiently defined. The aim of this paper is to present the needs for individual solutions for this dedicated part of integration at the European Union member states level and to define the sub-areas that need to be defined and put into operation by regulators and interested institutions. This is achieved through analysis and a specific case study that identifies individual needs and helps to classify them. The combination of identified needs allow the creation of a flowchart showing the logical procedure for the gradual adaptation of Beyond Visual Line of Sight traffic in controlled zones.
Evaluation of Extended Projected Profiles impact on vertical trajectory prediction
Authors: Xia Chen , Gallego Christian Eduardo Verdonk , Valdés Rosa Arnaldo , Comendado Víctor Fernando Gómez
Published: June 2023

The future Air Traffic Management System (ATM) is based on the concept of Trajectory Based Operations (TBO), in which all stakeholders have access to a consistent and synchronised view of flight trajectories. In the TBO framework, the trajectory prediction plays a key role. Inaccuracy of current trajectory predictors caused by the lack of a common understanding of stakeholders’ intents can be reduced by the sharing of information by airspace users. A step towards a shared information network is the Extended Projected Profile (EPP), downlinked from airborne to ground via automatic dependent surveillance contract (ADS-C). In summary, it contains the flight intent from the Flight Management System (FMS) and other information. This paper explores the EPP messages and the possible performance enhancement they introduce in the predictions of the top of descent (TOD) and the descent vertical profile. 1
Preliminary Validation Results of a Novel Concept of Operations for RPAS Integration in TMA and at Airports
Authors: Schwoch Gunnar , Duca Gabriella , Ferraiuolo Vera , Filippone Edoardo , Lanzi Paola , Petersen Co , Rocchio Riccardo , Sangermano Vittorio , Teutsch Jürgen
Published: June 2023

The paper describes the results of recent research activities carried out to investigate the safe integration of Remotely Piloted Aircraft System (RPAS) into ATC controlled airspace with a focus on Terminal Manoeuvring Areas (TMAs) and airports. The research activities presented in this paper started with the definition of RPAS-specific use cases and the development of a preliminary novel Concept of Operations. This was followed by the definition and the execution of a simulation test plan for the validation of this new operational concept. The validation campaign has been carried out involving aerospace research centres in the Netherlands (Royal NLR), Germany (DLR), and Italy (CIRA), respectively. Different aspects of RPAS integration in the TMA were considered, such as latency of command & control (C2) link and voice communication link, Automatic Take-off and Landing (ATOL) operations, contingency procedures, and handover of control between two different remote pilot stations. The validation exercises were conducted using real-time human-in-the-loop simulation facilities to assess the human performance of both air traffic controllers and remote pilots. The results showed that the proposed novel concept of operations is suitable for the integration of RPAS at TMAs and airports, with 80% of the objectives fully and 20% partially achieved, and acceptable to excellent results regarding acceptance/situational awareness (8.2/9.0 out of 10 points; higher is better) and workload (2.6 out of 10 points; lower is better).
Sesar PJ13 Erica “Enable RPAS Insertion in Controlled Airspace”- Validation experiment for the long-term integration of RPAS in an Italian TMA air traffic scenario
Authors: Manzo Alessandro , Riccardi Giovanni , D’Angelo Giuseppe , Pompei Gino , Taurino Damiano , Ghita Alexandra , Ciniglio Umberto , Cusimano Salvatore
Published: June 2023

Remotely Piloted Aircraft Systems (RPAS), are increasingly becoming a part of our day-to-day lives. The vast range of possible uses is creating a new industry with a large economic potential. The technological developments are being developed at a much faster pace than that for manned aviation. From an operational perspective, the challenge lies in integrating the worlds of manned and unmanned aircraft in a safe and efficient way allowing both types of aircraft to use the same airspace. This paper is aimed at describing the results of a validation exercise executed in the frame of the SESAR Programme, with the objective to validate the operational and technical means for the integration of certified RPAS in an Italian Terminal Manouvering Area (TMA).
Learning for Air Traffic Management: guidelines for future AI systems
Authors: Cocchioni M. , Bonelli S. , Westin C. , Borst C. , Bang M. , Hilburn B.
Published: June 2023

The SESAR-funded Modern ATM via Human / Automation Learning Optimisation (MAHALO) project recently completed two years of technical work exploring the human performance impacts of AI and Machine Learning (ML), as applied to enroute ATC conflict detection and resolution (CD&R). It first developed a hybrid ML CD&R capability, along with a realtime simulation platform and experimental User Interface. After a series of development trials, the project culminated in a pair of field studies (i.e., human-in-the-loop trials) across two EU countries, with a total of 35 operational air traffic controllers. In each of these two field studies, controller behaviour was first captured in a pre-test phase, and used to train the ML system. Subsequent main experiment trials then experimentally manipulated within controllers both Conformance (as either a personalised-, group average-, or optimized model) and Transparency (as ether a baseline vector depiction, an enhanced graphical diagram, or a diagram-plus-text presentation). The proposed paper presents guidelines on the design and implementation of ML systems in Air Traffic Control, derived from the results and lesson learned from the Simulations, as well as the qualitative feedback received from the controllers themselves.
Machine Learning Supporting Enhanced Optimized Spacing Delivery between Consecutive Departing Aircraft
Authors: De Petris L , De Visscher I , Stempfel G , Jacques A , Saidi M , Chalon Morgan C
Published: June 2023

The Optimised Spacing Delivery (further referred to as OSD) tool has the objective of calculating the necessary time spacing between two consecutive departing aircraft in order to fulfil all required spacing and separation constraints. OSD, developed in SESAR 2020 Wave 1 [1] is based on analytical models [2] to predict aircraft trajectory and speed profiles. The use of this tool by Air Traffic Controller supports the safe, consistent and efficient delivery of the required separation or spacing between consecutive departure pairs by providing the time required between departure aircraft pairs via an automated count-down timer to the tower runway controller. In order to improve OSD, this paper introduces the enhanced Optimised Spacing Delivery (further referred to as eOSD) tool which builds on the OSD tool using Machine Learning techniques to make more accurate predictions of aircraft behaviour (e.g. trajectory/climb profile, speed profile) and wind on the initial departure path, so further optimising spacing delivery between consecutive departures. Zurich airport data were used to develop and asses the performance of the eOSD tool compared to the OSD tool.
Effects of Sweep on the Flutter of Wraparound Fins
Authors: Demir E , Şahin H L , Doğan V Z , Yaman Y
Published: June 2023

In the field of missile and rocket design, efficiency is a crucial aspect considering factors such as weight, storage, stealth, and cost. Wraparound fins (WAFs) have been used for many years to control the trajectory of missiles and rockets because of their compactness and effectiveness. However, WAFs are structurally more flexible than other types of fins, which may negatively impact their dynamic behavior and aeroelastic response. This can cause catastrophic instabilities, such as flutter. To mitigate these challenges, it is essential to consider both aerodynamic and structural models of WAFs during the design process. In this study, the flutter velocity and frequency of WAFs were investigated in relation to different structural design configurations and sweep angles, in order to understand and improve the aeroelastic performance of swept WAFs.
An active filtering strategy of LCL filter for inverter power supply of electromagnetic pump
Authors: Zhao Jiawei , Liu Shichao , Yang Shuaifei , Wang Changhuan , Li Yang , Wu Chunyu , Liu Yang
Published: June 2023

The inverter power supply for an electromagnetic pump is a motor controller based on a three-phase inverter. This inverter needs to be followed by an LCL filter as a filter for connecting the electromagnetic pump. But the LCL filter has a large resonance spike at the resonance point. This can cause relatively large interference to the control system and also increase the harmonics of the inverter power supply output current. Therefore, it is necessary to suppress the resonant spikes of the LCL filter. In this paper, an active filtering strategy based on a trap is proposed by comparing the existing passive filtering strategies. The trap can be used to generate an anti-resonant peak at the resonance point of the LCL, which is used to cancel the resonant spike of the LCL filter. This method ensures the resonant peak suppression effect without affecting the filtering effect of the LCL filter.
A method of aeronautical electrical interface circuit design and simulation analysis based on Saber
Authors: Wang Kunyu , Wu Jianwen , Chen Ruang , Zhao Wei , Liu Liang , Wang Peng , Zhou Wei
Published: June 2023

In this paper, the idea of model-based system engineering is adopted. For the aircraft’s electrical interface circuit, Saber software is used to carry out “device-circuit” modeling and simulation, and the corresponding hardware circuits are verified and compared. Simulation and hardware verification results show that the modeling method designed in this paper can better integrate the rapidity of modeling and the accuracy of the simulation. In order to deal with the “neck jam” problem, domestic components are widely used today. This study provides a solution for optimizing process design and improving the degree of digitalization and provides model support for Model Based Systems Engineering (MBSE) in China’s aviation field.
Collaborative optimal scheduling of integrated energy system considering carbon trading
Authors: Du Chong , Qin Bin , Zhang Simin , Li Cao , Guo Chuangxin
Published: June 2023

In order to further realize the zero carbon transition of the energy system, this paper proposes a robust optimal scheduling model for transmission and distribution collaboration considering carbon trading. In this model, the multi energy equipment in the integrated energy system is modeled for transmission and distribution coordination. The long-distance power transmission network is an electricity gas coupling network, and the energy hub is the park distribution network. The nonconvex dynamic power flow network is relaxed by using the method of second-order cone programming, and the ADMM method is used to ensure that the optimal energy coordination is obtained between regions under the limited information exchange, so as to ensure user privacy. The validity of the scheduling model is proved by the case study.
Hardware Circuit Design of Intelligent Induction Control Classified Garbage Can
Authors: Tang Lili , Sheng Ge
Published: June 2023

This design is based on the STC89C52RC single chip microcomputer and the integration of various multi-function modules to complete the overall system control. It is composed of the core modules of humidity detection, relay drive, metal detection, intelligent alarm, MQ-2 smoke sensor, infrared sensing, ultrasonic detection, etc. We collect specific information through ultrasonic testing, and LCD1602 displays the current status; an infrared sensor and a smoke sensor are used for relevant monitoring; a humidity sensor and metal sensor automatically remind us to classify and put garbage; a relay analog control trash can automatically open and close. The system has the characteristics of ideal performance, low cost, convenient design, simple structure, and intelligence. It has found a feasible solution for the current environmental pollution problem to do garbage classification and treatment. It can play an important role in smart homes, smart campuses, intelligent transportation, telemedicine, and other fields, and will have a broader market prospect and application fields.
Distributed coordinated control of hybrid energy storage in offshore oil field microgrid in short time scale
Authors: Tong Li
Published: June 2023

The offshore oilfield microgrid can effectively integrate distributed power and hybrid energy storage, and its coordinated control can effectively ensure the safe and stable operation of the microgrid. In order to ensure the effect of coordinated control and improve the efficiency of coordinated control, a distributed coordinated control method for hybrid energy storage of offshore oil field microgrids in a short time scale is proposed. By setting two objective functions, namely, short time scale and optimal allocation of hybrid energy storage power of offshore oilfield microgrid, configuration capacity, and operation power constraints, a two-stage distributed coordinated control model for hybrid energy storage of offshore oilfield microgrid is constructed. The experimental results show that the proposed hybrid energy storage distributed coordination control method for offshore oilfield microgrids has a good effect and high efficiency, and can effectively ensure the stable operation of offshore oilfield microgrids. The experimental results show that the proposed distributed coordinated control method for hybrid energy storage of offshore oilfield microgrids has a good effect and high efficiency. When the number of iterations reaches 100, the coordinated control time of this method can reach a lower time. It effectively ensures the stable operation of the offshore oil field microgrid.
Numerical Analysis of the Deposition Characteristics in the Initial Deposition Stage in RSC
Authors: Zhang Yan , Yue Kai , Zhang Xin Ru , Zhang Xin Xin
Published: June 2023

The coal gasification syngas cooler is important for recovering the sensible heat generated during coal gasification. The ash layer formed on the heat transfer surface can seriously decrease the heat exchange efficiency. Establishing the initial layer is a prerequisite for massive ash deposition and will accelerate the accumulation of the ash and slag particles. In this study, numerical simulations are conducted to analyze the behavior of ash particles in large-scale industrial equipment. The deposition characteristics during the initial fouling and slagging stage in RSC are explored. The results show that in this stage, ash or slag particles mainly stick on the side wall, and only small particles deposit on the upper cone. The surface energy is the dominant factor influencing the composition of the initial layer. The adhesion ratio of FeS2 and ZnS particles is over ten times higher than that of SiO2 particles. With the decrease of the inlet flow rate and the increase of the inlet swirl velocity, the location corresponding to the maximum deposition proportion moves upward, and the local maximum deposition proportion increases.
Research on Optimization Operation of Wind Power Station
Authors: Feng Qiming , Qian Suping
Published: June 2023

Wind energy is the most widely utilized renewable energy source. Because wind energy is environmentally friendly, clean, abundant, and easy to develop, wind power generation technology has been vigorously promoted. Through the assessment of wind resources and the mining of data from wind power generators, it turns out that wind power resource is abundant in the wind plant area, but their utilization is very low. According to the wind speed and the actual measured power of the wind generator, the law of wind power variation with wind speed is derived by curve fitting, and then combined with the performance parameters of the wind generator, the theoretical power curve of the wind generator is obtained. On this basis, the power of wind generators in different locations is calculated according to different wind speeds, so as to select the most suitable wind generator model, which provides a theoretical solution for the optimal use of wind resources.
Saskatchewan’s oil and gas methane: how have underestimated emissions in Canada impacted progress toward 2025 climate goals?
Authors: Seymour Scott P , Li Hugh Z , MacKay Katlyn , Kang Mary , Xie Donglai
Published: June 2023

Canada has set ambitious methane emission reduction targets for its oil and gas industry, and recently, the province of Saskatchewan—Canada’s second largest oil producing region—announced it has already exceeded the first of these targets. Using detailed operator-reported emissions data, published for the first time from Saskatchewan in 2022, we estimate the province’s upstream oil and gas methane inventory to independently evaluate the reported emission reductions. While the inventory suggests that Saskatchewan has surpassed its target, the inclusion of recently published site-level aerial measurement data from cold heavy oil production with sand (CHOPS) wells suggests that the methane inventory is underestimated by between 30% and 40%. This inventory update is supported by new regional aerial measurements confirming the continued underestimation of emissions at CHOPS wells. Since these emissions likely evade required reduction under current regulations, we evaluate achievable emission levels if such CHOPS emissions are accurately measured/reported. The results show Saskatchewan can achieve much deeper emission reductions under current regulations with improved emission measurement, reporting, and verification methods. We discuss the benefits and risks inherent in Saskatchewan’s regulatory approach where emission limits are primarily set at the operator-level.
Identification of a characteristic VOCs pattern in the exhaled breath of post-COVID subjects: are metabolic alterations induced by the infection still detectable?
Authors: Di Gilio Alessia , Palmisani Jolanda , Picciariello Arcangelo , Zambonin Carlo , Aresta Antonella , De Vietro Nicoletta , Franchini Silvana A , Ventrella Gianrocco , Nisi Marirosa R , Licen Sabina , Barbieri Pierluigi , Altomare Donato F , de Gennaro Gianluigi
Published: June 2023

SARS-CoV-2 is expected to cause metabolic alterations due to viral replication and the host immune response resulting in increase of cytokine secretion and cytolytic activity. The present prospective observational study is addressed at exploring the potentialities of breath analysis in discrimination between patients with a documented previous history of symptomatic SARS-CoV-2 infection and, at the moment of the enrollment, exhibiting a negative nasopharyngeal swab and acquired immunity (post-COVID) and healthy subjects with no evidence of previous SARS-CoV-2 infection (no-COVID). The main purpose is to understand if traces of metabolic alterations induced during the acute phase of the infection are still detectable after negativization, in the form of a characteristic volatile organic compound (VOC) pattern. An overall number of 60 volunteers aged between 25 and 70 years were enrolled in the study (post-COVID: n.30; no-COVID: n. 30), according to well-determined criteria. Breath and ambient air samples were collected by means of an automated sampling system (Mistral) and analyzed by thermal desorption-gas chromatography-mass spectrometry (TD-GC/MS). Statistical tests (Wilcoxon/Kruskal–Wallis test) and multivariate data analysis (principal component analysis (PCA), linear discriminant analysis) were performed on data sets. Among all compounds detected (76 VOCs in 90% of breath samples), 5 VOCs (1-propanol, isopropanol, 2-(2-butoxyethoxy)ethanol, propanal and 4-(1,1-dimethylpropyl)phenol) showed abundances in breath samples collected from post-COVID subjects significantly different with respect to those collected from no-COVID group (Wilcoxon/Kruskal–Wallis test, p-values <0.05). Although not completely satisfactory separation between the groups was obtained, variables showing significant differences between the two groups and higher loadings for PCA are recognized biomarkers of COVID-19, according to previous studies in literature. Therefore, based on the outcomes obtained, traces of metabolic alterations induced by SARS-CoV-2 infection are still detectable after negativization. This evidence raises questions about the eligibility of post-COVID subjects in observational studies addressed at the detection of COVID-19. (Ethical Committee Registration number: 120/AG/11).
On simultaneous similarity of families of commuting operators
Authors: Kouchekian Sherwin , Shekhtman Boris
Published: June 2023

Characterization of simultaneous similarity for commuting

m
m

- tuples of operators is an open problem even in finite-dimensional spaces; known as “A wild problem in linear algebra”. In this paper we offer a criterion for simultaneous similarity of

m
m

-tuples of

k
k

-cyclic commuting operators on an arbitrary Banach space. Moreover, we obtain an additional equivalence condition in the case of finite dimensional Banach spaces, which extends the result found by Shekhtman [Math. Stat. 1 (2013), pp. 157–161] for pairs of cyclic commuting matrices. We also present two applications of our results, one in the case of general multiplication operators on Banach spaces of analytic function, and one for

m
m

-tuples of commuting square matrices.
Ideal approach to convergence in functional spaces
Authors: Bardyla Serhii , Šupina Jaroslav , Zdomskyy Lyubomyr
Published: June 2023

We solve the last standing open problem from the seminal paper by J. Gerlits and Zs. Nagy [Topology Appl. 14 (1982), pp. 151–161], which was later reposed by A. Miller, T. Orenshtein, and B. Tsaban. Namely, we show that under 

p

=

c

\mathfrak {p}=\mathfrak {c}

there is a 

δ
\delta

-set that is not a 

γ
\gamma

-set. Thus we constructed a subset

A
A

of reals such that the space

C

p

(
A
)

\mathrm {C}_p(A)

of all real-valued continuous functions on

A
A

is not Fréchet–Urysohn, but possesses the Pytkeev property. Moreover, under 

C
H

\mathbf {CH}

we construct a 

π
\pi

-set that is not a 

δ
\delta

-set solving a problem by M. Sakai. In fact, we construct various examples of

δ
\delta

-sets that are not

γ
\gamma

-sets, satisfying finer properties parametrized by ideals on natural numbers. Finally, we distinguish ideal variants of the Fréchet–Urysohn property for many different Borel ideals in the realm of functional spaces.
Matrix obstructions cause multiscale disruption in collective epithelial migration by suppressing leader cell function
Authors: Lee Ye Lim , Mathur Jairaj , Walter Christopher , Zmuda Hannah , Pathak Amit
Published: June 2023

Topological obstructions in extracellular matrix soften epithelial cells and slow their migration. Cellular obstruction sensing requires an optimal balance of protrusions and cell-cell adhesions.
Efficient production of bispecific antibodies—optimization of transfection strategy leads to high-level stable cell line generation of a Fabs-in-tandem immunoglobin
Authors: Gong Shiyong , Wu Chengbin
Published: June 2023

Bispecific antibodies (bsAbs) are often composed of more than two component chains, such as Fabs-in-tandem immunoglobin (FIT-Ig) comprising three different component chains, which bring challenges for generating a high proportion of the correctly assembled bsAbs in a stable cell line. During the CHO-K1 stable cell line construction of a FIT-Ig, we investigated the FIT-Ig component chain ratio in transfection, where two sets of expression vectors were designed. Both designs utilized two vectors for co-transfection. Multiple transfections with plasmid ratio adjustment were applied, and the resultant minipools were evaluated for expression titer and quality of produced FIT-Ig. The results suggested that abundant outer Fab short chains (twofold chain genes versus other chains) can promote complete FIT-Ig assembly and therefore reduce the fragmental impurities of FIT-Ig. This adjustment of the component chain ratios at the beginning is beneficial to FIT-Ig stable cell line generation and brings favorable clones to process development.
National Identities in Global Health: Kenya’s Vaccine Diplomacy During the Covid-19 Pandemic
Authors: Harrington John , Ngira David
Published: June 2023

How do national identities matter in global health? Our paper addresses this question through a study of Kenya’s vaccine diplomacy during the Covid-19 pandemic. It combines critical perspectives, challenging the neglect of African agency in international relations (IR), with constructivist approaches highlighting the importance of discourse in the exercise of agency. The insight that identity is an important resource in the realization of foreign policy goals is confirmed by our review of interventions by senior Kenyan leaders, as well as ministries and official bodies, concerned with vaccine procurement during the pandemic. Moreover, this material shows that identity is not pre-given, but rather performed in discourse, being adapted and renewed in speeches, briefings, policy documents, and so on. Identities are plural, not singular, drawing on historic and cultural resources proper to individual states. This allows us to link the range of identities performed during the Covid-19 pandemic to earlier moments in Kenya’s diplomatic history, noting the continued pertinence of its image, variously, as ‘an island of stability’, ‘a good global health citizen’, ‘a member of the pan-African community of states’, and ‘an active contributor to IR’.
Estimated Population Health Benefits of Intensive Systolic Blood Pressure Treatment Among SPRINT-Eligible US Adults
Authors: Derington Catherine G , Bress Adam P , Berchie Ransmond O , Herrick Jennifer S , Shen Jincheng , Ying Jian , Greene Tom , Tajeu Gabriel S , Sakhuja Swati , Ruiz-Negrón Natalia , Zhang Yiyi , Howard George , Levitan Emily B , Muntner Paul , Safford Monika M , Whelton Paul K , Weintraub William S , Moran Andrew E , Bellows Brandon K
Published: June 2023

Background

The Systolic Blood Pressure Intervention Trial (SPRINT) demonstrated an intensive (<120 mm Hg) vs. standard (<140 mm Hg) systolic blood pressure (SBP) goal lowered cardiovascular disease (CVD) risk. Estimating the effect of intensive SBP lowering among SPRINT-eligible adults most likely to benefit can guide implementation efforts.

Methods

We studied SPRINT participants and SPRINT-eligible participants in the Reasons for Geographic and Racial Differences in Stroke (REGARDS) Study and National Health and Nutrition Examination Surveys (NHANES). A published algorithm of predicted CVD benefit with intensive SBP treatment was used to categorize participants into low, medium, or high predicted benefit. CVD event rates were estimated with intensive and standard treatment.

Results

Median age was 67.0, 72.0, and 64.0 years in SPRINT, SPRINT-eligible REGARDS, and SPRINT-eligible NHANES participants, respectively. The proportion with high predicted benefit was 33.0% in SPRINT, 39.0% in SPRINT-eligible REGARDS, and 23.5% in SPRINT-eligible NHANES. The estimated difference in CVD event rate (standard minus intensive) was 7.0 (95% confidence interval [CI] 3.4–10.7), 8.4 (95% CI 8.2–8.5), and 6.1 (95% CI 5.9–6.3) per 1,000 person-years in SPRINT, SPRINT-eligible REGARDS participants, and SPRINT-eligible NHANES participants, respectively (median 3.2-year follow-up). Intensive SBP treatment could prevent 84,300 (95% CI 80,800–87,920) CVD events per year in 14.1 million SPRINT-eligible US adults; 29,400 and 28,600 would be in 7.0 million individuals with medium or high predicted benefit, respectively.

Conclusions

Most of the population health benefit from intensive SBP goals could be achieved by treating those characterized by a previously published algorithm as having medium or high predicted benefit.