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This article frames the central role played by mission-oriented public procurement in the Brazilian aerospace industry. The difficulties in mastering and promoting the evolution of several disciplines at the firm level, with a relative scarcity of funds for an R&D-intensive industry and an incomplete national innovation system represent merely a fraction of the threat faced by those dealing with Complex Products and Systems. The culture of financing flagship projects using public procurement narrows the potential solutions for complex problems, imposes time constraints to mature critical technologies and exposes these endeavours to high levels of risk. By taking the Dynamic Capabilities as a theoretical framework and Technological Readiness Level as a yardstick to the decision-making process, we have developed a construct to explore two in-depth cases. A cultural shift is required, aiming at providing the means to the progressive maturation of critical technologies using public procurement for innovation. [ABSTRACT FROM AUTHOR]

The electrolysis of water is a crucial technology for extraterrestrial in situ resource utilization in the aerospace sector. Scientific research with unique university characteristics plays a vital role in fostering talent development. Adhering to the principle of integrating science and education, this study combines aerospace-focused scientific research with undergraduate teaching to design a research-oriented experimental course. The approach involves using a two-step method of hydrothermal oxidation and high-temperature phosphidation to fabricate nickel foam self-supported bimetallic phosphide electrodes with ultra-hydrophilic and super-hydrophobic surfaces suitable for the microgravity environment of aerospace space. The performance of hydrogen production from electrolyzed water is investigated. Additionally, relevant thermodynamic concepts from undergraduate physical chemistry courses are incorporated to engage students actively, encourage independent exploration, facilitate the construction of knowledge on extraterrestrial water electrolysis, and uphold the spirit of aerospace patriotism. [ABSTRACT FROM AUTHOR]

Direct digital manufacturing (DDM) is the technology that provides the possibility of producing the final product directly from the 3D CAD model without the aid of any additional tools. Additive manufacturing is the main element of DDM for producing end-user products. The layer-on-layer creation of the product using additive manufacturing provides a lot of design freedom. The layer-on-layer production methodology enables the possibility of producing products with complex and freeform geometries. The layer-on-layer technology allows the material deposition only on the required spots, and hence a significant weight reduction is obtained during the manufacturing of products. Complex geometrical structures with light weight are the greatest interest of the aerospace, spacecraft, and automobile industries. Therefore, these industries have completely relied on novel lightweight materials for producing lightweight structures until now. However, novel lightweight materials are highly expensive and increase the cost of the products significantly. Recent studies show that additive manufacturing helps in producing lightweight structures with high structural stability without the need for expensive lightweight materials. The complete redesign of aircraft, spacecraft, and automobiles suitable for additive manufacturing increases the possibility of producing lightweight structures with high structural stability. The generative design method created for additive manufacturing opens up enormous design possibilities, but the complete redesign of the aircraft or spacecraft would take a few decades. Until then, redesigning and replacing some aerospace components are the most efficient way to achieve the goals in a certain percentage. This study aims to explore the possibilities of implementing DDM for small and medium manufacturing firms by combining the advances of computer application software, topology optimization, and additive manufacturing. The main classifications of aerospace components are static and dynamic. [ABSTRACT FROM AUTHOR]

ABSTRACT The coefficient of friction of low carbon chromium alloy steel with military grade lubricant was high, resulting in increased heat generation and temperature rise of the lubricant in the aircraft power transmission units such as engine gearbox, accessory gearbox and so on. To address this, the current research proposes the addition of TiO2 nanoparticles to MIL grade lubricant as an additive to enhance the tribological performance. In this experimental study, TiO2 nanolubricant was prepared using various surfactants for better suspension of TiO2 nanoparticles, and properties were evaluated for both base lubricant and nanolubricant. The tribological experiments were conducted using a four ball tester, a shear stability tester and a reichert tester. In a four ball test, TiO2 nanolubricant resulted in a 27.3% reduction in wear scar diameter by the addition of TiO2 nanoparticles to the base lubricant. In a shear stability test, TiO2 nanolubricant showed 80% better shear stability than the base lubricant. In the reichert test, the coefficient of friction was reduced by 13% with the TiO2 nanolubricant. The experimental findings demonstrated that the TiO2 nanoparticles, as an additive to a military grade lubricant, have superior tribological properties for aerospace applications. [ABSTRACT FROM AUTHOR]

This study delves into the manufacturing strategies employed for fabricating tensile samples utilized in the mechanical characterization of material extrusion (MEX) components constructed with polyaryletherketone (PAEK) for aerospace applications. Two distinct methods were investigated for obtaining tensile test samples: direct cutting and extraction from a box. These methods were examined under both as-printed and annealing conditions. Quasistatic tensile tests were conducted along the building direction to evaluate the impact of processing conditions on the adhesion of overlying layers. The results unveiled significant disparities in mechanical behavior and crystallinity between directly printed samples and those derived from the box. The Young's modulus exhibited marginal influence; however, the tensile strength of directly printed samples measured at 30 MPa (prior to annealing), corresponding to 50% of the strength observed in samples cut from the box (60 MPa). Moreover, the elongation at rupture of directly printed samples was found to be less than 2%, while that of cut samples exceeded 8%. Notably, directly printed samples exhibited a significant degree of incipient crystallization (12.18%), contrasting with the lower level of crystallinity observed in samples cut from the box (3.27%). These findings underscore the importance of recognizing the limitations associated with direct sample printing, emphasizing its crucial role in accurately characterizing components destined for the aerospace industry. Furthermore, this understanding is pivotal for optimizing the performance and reliability of MEX-printed PAEK components in aerospace engineering applications. [ABSTRACT FROM AUTHOR]

Self-healing composites are smart materials that can self-detect and prevent micro crack propagation and any catastrophic failure in the composite structure. In this study, dicyclopentadiene (DCPD) monomer was encapsulated with urea formaldehyde (UF) by in situ polymerization. These microcapsules were mixed with epoxy, chopped carbon fiber (CF), and multi-walled carbon nanotubes (CNT) to make self-healing composite. Both microcapsules and the composite specimens were extensively tested for their physical, thermal, and mechanical properties. The average diameter and shell thickness of the microcapsules were 268 µm and 805 nm, respectively. DMA analysis suggested that the microcapsules have a glass transition temperature (Tg) of 85°C. FTIR analysis confirmed the presence of CF, multi-walled carbon nanotubes (MWCNT), and other constituents in the composite. The tensile strength of the self-healing composites was tested as per ASTM standards. The incorporation of MWCNT in the composites has significantly improved the tensile strength of the composite without compromising on the self-healing efficiency (90%) compared the unmodified samples (72%). The encouraging results of higher glass transition temperature (85°C) combined with an improved healing efficiency (90%), can be considered as the novelties of this work. As the test results of microcapsules and composite specimens were encouraging, they can find applications in making composite structures for aerospace, windmills, and marine applications. The experimental observations and test results are discussed in detail. [ABSTRACT FROM AUTHOR]

Polyurethane (PU) foam has a high flammability and is widely used in aircraft interiors, presenting a significant danger to occupants. This study analysed three composite intumescent flame-retardant (IFR) coatings for flexible PU foam; expandable graphite (EG), ammonium polyphosphate (APP) and alginate (AG). The coatings were prepared in concentrations of 5 wt%, 10 wt%, and 50 wt% with an acrylic binder. The coated samples were characterised using cone calorimetry, SEM, and mechanical testing. The findings showed peak heat release rate, total heat release, and carbon dioxide production from the 10 wt% triple-layer coating (EG:APP:AG) was 52%, 32%, and 58% less than the PU control. The char of the 10 wt% triple-layer sample effectively suppressed smoke release and inhibited the transfer of fuel and gas volatiles. Mechanical testing demonstrated a 3.4 times increase in tensile strength and a 15.4 times increase in compressive strength (50% compression) compared to the control PU with the 10 wt% triple-layer coating. A fire dynamics simulator model was developed that demonstrated large-scale flammability modelling for commercial aircraft. Future work can explore the integration of IFR coatings into computational analysis. These new bio-based coatings produced promising results for aircraft fire safety and flammability performance for PU polymers. [ABSTRACT FROM AUTHOR]

The rate of rocket launches is accelerating, driven by the rapid global development of the space industry. Rocket launches emit gases and particulates into the stratosphere, where they impact the ozone layer via radiative and chemical processes. We create a three‐dimensional per‐vehicle inventory of stratospheric emissions, accounting for flight profiles and all major fuel types in active use (solid, kerosene, cryogenic and hypergolic). In 2019, stratospheric (15–50 km) rocket launch emissions were 5.82 Gg CO2 ${\mathrm{C}\mathrm{O}}_{2}$, 6.38 Gg H2 ${\mathrm{H}}_{2}$O, 0.28 Gg black carbon, 0.22 Gg nitrogen oxides, 0.50 Gg reactive chlorine and 0.91 Gg particulate alumina. The geographic locations of launch sites are preserved in the inventory, which covers all active launch sites in 2019. We also report the emissions data from contemporary vehicles that were not launched in 2019, so that users have freedom to construct their own launch activity scenarios. A subset of the inventory—stratospheric emissions for successful launches in 2019—is freely available and formatted for direct use in global chemistry‐climate or Earth system models. Plain Language Summary: Many governments and companies have expressed bold ambitions to grow their presence in space. However, rocket launches throw out a stream of air pollutants from their burnt fuel as they pass through the stratosphere, which is where the protective ozone layer resides. Currently, launch operators do not have to measure the impacts of their activities on the ozone layer. We gather together all the publicly available information on rocket launches in 2019, from 18 active spaceports worldwide, and make some careful assumptions to convert each rocket's fuel to its burnt fuel products left in the atmosphere. We encourage modeling groups to use our inventory for studies on how rocket launches may impact the ozone layer. Key Points: We compile a comprehensive emissions inventory of all rocket launches in 2019 at 18 active spaceportsIt itemizes chemically and radiatively active species that are produced by the main rocket fuels (kerosene, cryogenic, solid and hypergolic)We discuss the inventory's uncertainties and its usage in global models to study the impacts of rocket launches on the ozone layer [ABSTRACT FROM AUTHOR]

The aerospace industry and technology are always considered one of the country’s most important and valuable industries. The research area of "Aerospace" is among the priorities of the grand science and technology development strategies, and addressing it is strategically vital. The present research aims to estimate and predict the appropriate algorithm for identifying high-quality aerospace researchers based on Advanced Ensemble Classifier Techniques (AECT) in data mining on the outputs of scientometric analyses and predicting the most essential scientometric-related metrics to identify high-quality researchers. The present study was performed using the protocols of applied research and multiple methods. The studied population includes all aerospace researchers (1945 and 2021) indexed in "The Web of Science Core Collection (WOSCC)". DataLab software and multiple programming languages have been applied in this research. All three algorithms have an accuracy of 0.96 and an F1-score of 0.97, which indicates that the models have high accuracy, validity, sensitivity, and predictive power. The "Blending" algorithm is considered a suitable and predictive model. The output of the LightGBM algorithm is that the most important and robust metric in the evaluation of prominent researchers is a metric from the researchers' effectiveness dimension, the Q parameter. According to the knowledge obtained from the ability to predict AECT in the prediction of highquality researchers, it is possible to use the metrics mentioned in the evaluation of researchers in the field of scientometrics for more accurate and comprehensive prediction. An algorithm that can lead to the optimal and efficient classification of researchers provides the possibility of in-depth analysis of the available data about researchers and smooths the predictive power of the most high-quality researcher. The use of the proposed algorithms in this research, while suggesting the appropriate algorithm, led to reliable and valuable knowledge in classifying high-quality aerospace researchers. [ABSTRACT FROM AUTHOR]

The truss static structure system has excellent large load and lightweight characteristics. It is easy to embed actuators by substituting specific members in the structure and has the potential for multidimensional space deformation. Inspired by uniform tessellation structures, this article proposes a novel shape morphing mechanism (SMM) based on the combined design of tetrahedral-octahedral heterogeneous units (TOHUs). The relationship between the motion properties and driving configuration of the tetrahedral-octahedral units is analyzed to determine their conceptual configuration based on graph theory. Then, the weighted graph, adjacency matrix, and connection rules are evaluated to synthesize the conceptual structure for the truss mechanism. The results show that this configuration can allow multidimensional continuous deformations, including span, bend, sweep, and twist. A prototype is built to verify its deformability. Finally, the stiffness performance is analyzed based on the matrix displacement method. This research provides a comprehensive design method for constructing SMM, expands the range of combinable units and connection methods, and offers theoretical guidance for the innovative design of multidimensional deformation SMM in aerospace. [ABSTRACT FROM AUTHOR]

Aircraft in both the commercial and defense sectors undergo significant disassembly in order to access and inspect critical structures and components. To limit the extent of disassembly needed and thus increase system availability, the concept of mobile robotic inspection has been notionally discussed for over 20 years. Notably this interest in mobile robotic inspection extends beyond aircraft to include civil infrastructure, pipelines, and nuclear plants where some robotic platforms are currently in use. However, the unique challenges associated with complex aircraft systems and structures remain to be addressed. With advancements in the fields of durable polymers, autonomous materials, flexible electronics, tailorable actuation, and others, soft robotics are an increasingly viable solution to the challenge of inspection in access-limited spaces. This perspective article will overview key advancements in pertinent technical areas and highlight scientific barriers to wide-spread use and acceptance of soft robotics for aircraft inspection. [ABSTRACT FROM AUTHOR]

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Nanoclays, a specific type of nanomaterial, have emerged as versatile and dynamic materials, with tremendous potential for advanced functional applications. Despite publishing a large number of research articles, there are relatively few review articles on this topic. This comprehensive review delves into the most widely used nanoclays and explores the diverse range of applications in different fields, such as aerospace, automobile, construction, biomedical, food packaging, and polymer composites. With their ability to enhance the performance of materials and products, nanoclays have become a highly desired material in various industries. The challenges associated with nanoclays like complex properties, difficulty in developing new synthesis methods, and challenges in investigating long‐term durability and stability have been summarized. The future research directions with the exciting possibilities to develop future innovative materials have been highlighted at the end of the article. Highlights: This review provides an extensive examination of the most widely used nanoclays, detailing their properties, types, and limitations.A summary of publication trends over the last 15 years, based on Scopus data up to 2024, indicates growing interest and research output in nanoclays.Applications of nanoclays span across aerospace, automobile, construction, biomedical, food packaging, and polymer composites, showcasing their versatility.Key challenges discussed include complex properties, difficulties in new synthesis methods, and issues in long‐term durability and stability.Future research directions highlight the potential for developing innovative materials using nanoclays. [ABSTRACT FROM AUTHOR]

The Pakistani aerospace industry is embracing digitalisation (within a year), utilising budgets of less than 5% of the company’s annual revenue; however, no industry claims that these technologies have been adopted to a large extent across their R&D, production/manufacturing, MRO, and services/distributor functions. According to 67% of respondents, there are no regulations, laws, or other government policies pertaining to Industry 4.0. Technological preparedness in the form of suitable software and hardware was highlighted as the main critical success factor, while Cybersecurity and cloud computing were identified as essential implementation tools. The originality and value of this study lie in it being the first study of its type on Industry 4.0 within the Pakistani aerospace sector. This research will serve as a strategic tool for policymakers, industry leaders, and stakeholders to guide informed decision-making and propel the aerospace sector towards sustainable growth and competitiveness.

Abstract Nanoclays, a specific type of nanomaterial, have emerged as versatile and dynamic materials, with tremendous potential for advanced functional applications. Despite publishing a large number of research articles, there are relatively few review articles on this topic. This comprehensive review delves into the most widely used nanoclays and explores the diverse range of applications in different fields, such as aerospace, automobile, construction, biomedical, food packaging, and polymer composites. With their ability to enhance the performance of materials and products, nanoclays have become a highly desired material in various industries. The challenges associated with nanoclays like complex properties, difficulty in developing new synthesis methods, and challenges in investigating long‐term durability and stability have been summarized. The future research directions with the exciting possibilities to develop future innovative materials have been highlighted at the end of the article. Highlights This review provides an extensive examination of the most widely used nanoclays, detailing their properties, types, and limitations. A summary of publication trends over the last 15 years, based on Scopus data up to 2024, indicates growing interest and research output in nanoclays. Applications of nanoclays span across aerospace, automobile, construction, biomedical, food packaging, and polymer composites, showcasing their versatility. Key challenges discussed include complex properties, difficulties in new synthesis methods, and issues in long‐term durability and stability. Future research directions highlight the potential for developing innovative materials using nanoclays.

The aerospace industry and technology are always considered one of the country’s most important and valuable industries. The research area of "Aerospace" is among the priorities of the grand science and technology development strategies, and addressing it is strategically vital. The present research aims to estimate and predict the appropriate algorithm for identifying high-quality aerospace researchers based on Advanced Ensemble Classifier Techniques (AECT) in data mining on the outputs of scientometric analyses and predicting the most essential scientometric-related metrics to identify high-quality researchers. The present study was performed using the protocols of applied research and multiple methods. The studied population includes all aerospace researchers (1945 and 2021) indexed in "The Web of Science Core Collection (WOSCC)". DataLab software and multiple programming languages have been applied in this research. All three algorithms have an accuracy of 0.96 and an F1-score of 0.97, which indicates that the models have high accuracy, validity, sensitivity, and predictive power. The "Blending" algorithm is considered a suitable and predictive model. The output of the LightGBM algorithm is that the most important and robust metric in the evaluation of prominent researchers is a metric from the researchers' effectiveness dimension, the Q parameter. According to the knowledge obtained from the ability to predict AECT in the prediction of high-quality researchers, it is possible to use the metrics mentioned in the evaluation of researchers in the field of scientometrics for more accurate and comprehensive prediction. An algorithm that can lead to the optimal and efficient classification of researchers provides the possibility of in-depth analysis of the available data about researchers and smooths the predictive power of the most high-quality researcher. The use of the proposed algorithms in this research, while suggesting the appropriate algorithm, led to reliable and valuable knowledge in classifying high-quality aerospace researchers.

Purpose: Today, researchers encounter challenges in scientific collaboration and the alignment of results with their peers. This study aims to evaluate the accuracy of identification and the extent of researchers' genuine participation in the convergence of multi-authored articles written by aerospace researchers, utilizing the three-dimensional Collaborative Author Writing Hierarchy (CAWH). Author associativity is a concept closely linked to scientific collaboration and multi-authored publications. The complexity of knowledge and the increasing demand for specialization and interdisciplinary skills have shaped scientific participation. Aerospace researchers and specialists are pivotal in conducting scientific and industrial research within the aerospace sector, focusing on technology development and providing support and guidance to fellow researchers. The aerospace industry is multi-faceted, strategic, and dynamic, possessing significant potential for wealth generation, economic development, enhancing national competitiveness on the global stage, job creation, and export opportunities. In various fields of study, numerous indicators have been established for observing, monitoring, and quantitatively and qualitatively evaluating researchers' publications, leading to the introduction of diverse metrics accordingly.Methodology: The research is applied in nature and employs an analytical approach. To assess the improvement in accurately identifying the author's true contributions in published articles, a composite measure that examines multiple dimensions has been utilized. The research outputs of aerospace researchers were analyzed, drawing on data categorized under "Engineering, Aerospace" in the Web of Science Core Collection (WOSCC). English-language articles published from 1945 to 2021 were extracted for this study. Data extraction was conducted on February 4, 2022, a Friday. The current research community encompasses all aerospace researchers from 1945 to 2021, comprising 153,994 records indexed in the Web of Science Core Collection (WOSCC). The total number of authors is 161,156, of whom 154,450 researchers with identifiable names (without sampling) were examined. The total number of citations is 2,617,712. Data extracted from the scientific website during the research period were analyzed. In this research, two tools, namely the "MiMFa Scraper, were employed to gather detailed information about each author. Additionally, another tool was utilized to match the gauge information with PHP (Hypertext Preprocessor). This tool is considered part of the DataLab software suite. Ravar PreMap software was also used to standardize the data. To normalize the data, the codes developed in the DataLab software were implemented. Excel 2016 was also utilized to extract data from various websites using PHP. The CAWH measure is defined as the average number of weighted citations based on co-author credit for a researcher.Findings: The results of the H-weighted co-authorship index indicate "Florian Menter" (from ANSYS Germany GmbH), "Chae M. Rhie" (from Raytheon Technologies USA), "Philippe R. Spalart" (from Boeing), "Edward F. Crawley" (from Massachusetts (from the Institute of Technology (MIT)), "Irving Reed" (from university (from Southern California) are in rank fifth ranks of among based on the CAWH index. This measure was used to calculate the utilizing assessment of each author in writing a multi-author article.Conclusion: The emphasis on recognizing researchers' contributions in article writing will be beneficial and effective for both researchers and the scientific community. Acknowledging researchers' involvement in writing allows them to showcase their contributions and achievements fairly and transparently. This approach enables researchers to properly receive their scientific credit and build their reputation, thereby gaining a competitive advantage within scientific communities. Within research teams, the implementation of this measure will enhance collaboration, facilitate the division of labor, and more equitably determine the rights and benefits of each team member. This approach fosters active collaboration and enhances the productivity of research teams. It enables research organizations and universities to conduct more accurate scientific evaluations of individuals and allocate resources based on equitable distribution and participation. Additionally, this method can improve transparency and build trust within research organizations. Consequently, it can help cultivate a culture of participation and cooperation within scientific communities. This approach can foster healthy, justice-oriented competition in science and enhance the quality of research. The evaluation offers readers and the scientific community detailed information about the authors and their collaborators involved in the research. This transparency enables readers to better assess the contributions and expertise of the article’s authors, thereby increasing their trust in the results and citations presented. Overall, acknowledging the participation of researchers in writing articles supports the scientific process and advances the field of science. This approach offers guidance for justice, transparency, cooperation, and the enhancement of research quality within scientific communities. It fosters an environment conducive to scientific development and progress, which can be assessed and refined using the index introduced in this study.

The paper presents a wireless system integrated with a machine learning (ML) model for structural health monitoring (SHM) of carbon fiber reinforced polymer (CFRP) structures, primarily targeting aerospace applications. The system collects data via carbon nanotube (CNT) piezoresistive sensors embedded within CFRP coupons, wirelessly transmitting these data to a central server for processing. A deep neural network (DNN) model predicts mechanical properties and can be extended to forecast structural failures, facilitating proactive maintenance and enhancing safety. The modular design supports scalability and can be embedded within digital twin frameworks, offering significant benefits to aircraft operators and manufacturers. The system utilizes an ML model with a mean absolute error (MAE) of 0.14 on test data for forecasting mechanical properties. Data transmission latency throughout the entire system is less than one second in a LAN setup, highlighting its potential for real-time monitoring applications in aerospace and other industries. However, while the system shows promise, challenges such as sensor reliability under extreme environmental conditions and the need for advanced ML models to handle diverse data streams have been identified as areas for future research.

Geopolymers are cementitious materials with exceptional mechanical and physical properties, making them suitable for aerospace applications. Considering their excellent performance, the present investigation aims to develop geopolymers with designed physical properties to address some issues in the aerospace industry. In this sense, the influence of the alkaline activator on the final properties was evaluated. For the development of the geopolymers, sodium hydroxide and sodium metasilicate solutions were preparedto obtain the alkaline activator. The synthesis process also consisted of a mixing stage using a mixer to obtain a homogenous paste. After mixing, the curing process consisted of a first thermal treatment at 60 °C for 4 h to evaporate the excess water, avoid excessive contraction, and promote strength at early ages. Subsequently, the geopolymers were left at rest for 28 days until the final properties were achieved. The influence of the solid-to-liquidratio (S/L) on the microstructure of the geopolymers was evaluated. For this purpose, X-ray fluorescence spectrometry, X-ray diffraction, and infrared spectrometry analyses were performed. The results show that the content of the alkaline activator promotes variations inthe presence of different crystalline phases, which is more noticeable as the S/L ratio increases. Likewise, the infrared spectra display peaks at different wavelengths regarding the variations in elemental composition, which are more evident with the changes in the S/L ratio. In addition, physical studies, such as thermal conductivity and resistance to gamma radiation were conducted for different geopolymer compositions. The results indicate that changes in properties are not too sensitive to compositional variations, although slight modifications exist. Finally, these studies are significant as aerospace-focused materials are directly exposed to this kind of phenomena. The designed geopolymers have to be able to resist and maintain their properties through exposure to any energy.

Exposure to high levels of radiation can cause acute, long-term health effects, such as acute radiation syndrome, cancer, and cardiovascular disease. This is an important occupational hazard in different fields, such as the aerospace and healthcare industry, as well as a crucial burden to overcome to boost space applications and exploration. Protective bulky equipment made of heavy metals is not suitable for many advanced purporses, such as mobile devices, wearable shields, and manned spacecrafts. In the latter case, the in-space manufacturing of protective shields is highly desirable and remains an unmet need. Composites made of polymers and high atomic number fillers are potential means for radiation protection due to their low weight, good flexibility, and good processability. In the present work, we developed electrospun composites based on polycaprolactone (polymer matrix) and tungsten powder for application as shielding materials. Electrospinning is a versatile technology that is easily scalable at an industrial level and allows obtaining very lightweight, flexible sheet materials for wearables. By controlling tungsten powder size, we engineered homogeneous, stable and processable suspensions to fabricate radiation composite shielding sheets. The shielding capability was assessed by an in vivo model on prototype composite sheets containing 80 w% of W filler in a polycaprolactone (PCL) fibrous matrix by means of irradiation tests (X-rays) on mice. The obtained results are promising; as expected, the shielding effectivity of the developed composite material increases with the thickness/number of stacked layers. It is worth noting that a thin barrier consisting of 24 layers of the innovative shielding material reduces the extent of apoptosis by 1.5 times compared to the non-shielded mice. [ABSTRACT FROM AUTHOR]

The decentralization of production processes organized in global supply chains has made it possible to connect the different levels through industrial digitalization, an evolution derived from the Fourth Industrial Revolution which incorporates enabling technologies. This context raises the need to analyze sectors that, due to the complexity of their projects, require more efficient supply chain management. Two clear examples of these sectors are aerospace and shipbuilding, which demand greater efficiency and sustainability in their operations. The main objective of this study is to compare these two sectors to evaluate the degree of sustainability of their supply chains and how Industry 4.0 technologies have contributed to achieving these goals. To perform this, the Delphi method will be used, a tool that collects information through expert opinions, which will provide key indicators for the comparison. The use of this method will facilitate the identification of convergences and divergences in the management of sustainability in both sectors. Through this analysis, the expected results will reflect the specific needs of each industry in terms of productivity and sustainability. Thus, the study will offer a comprehensive view of how the aerospace and shipbuilding sectors can move toward more sustainable and efficient production models, integrating Industry 4.0 concepts and improving the management of their global supply chains. [ABSTRACT FROM AUTHOR]

This paper provides the necessary and sufficient conditions for a multi-degrees-of-freedom linear potential system with an arbitrary damping matrix to be uncoupled into independent subsystems of at most two degrees-of-freedom using a real orthogonal transformation. The incorporation of additional information about the matrices, which many structural and mechanical systems commonly possess, shows a reduction in the number of these conditions to three. Several new results are obtained and are illustrated through examples. A useful general form for the damping matrix is developed that guarantees the uncoupling of such systems when they satisfy just two conditions. The results provided herein lead to new physical insights into the dynamical behavior of potential systems with general damping matrices and robust computational procedures. It is shown that the dynamics of a damped potential system in which the damping matrix may be arbitrary is identical to that of a damped gyroscopic potential system with a symmetric damping matrix. This brings, for the first time, these two systems, which are seen today as belonging to different categories of dynamical systems, under a unified framework. [ABSTRACT FROM AUTHOR]

Although scholars often portray Mexico as caught in the "middle-income trap," this description obscures important subnational variation in patterns of economic development. We leverage this variation by examining the case of Querétaro, a state with high levels of structural transformation and economic growth since the 1980s. We reconstruct the historical trajectory of its two leading industries, automotive and aerospace. We observe that while both have cumulatively delivered real developmental gains, each also exhibits a complex mix of strengths and weaknesses. We further find that these industries' advancements and hindrances over time appear closely related to the kinds of "partial" coalitions — groups of actors from the state, private firms, and civil society organizations such as labor unions — which participate in industry-level decision-making. Both industries saw periods of "upgrading" when the partial coalitions supporting them were expanding their cognitive diversity while avoiding gross imbalances in the distribution of power among their members. They likewise experienced periods of stagnation when either of those coalition conditions underwent major change. These findings suggest that debates on escaping the middle-income trap should consider how changes in partial political coalitions affect policy models and options. [ABSTRACT FROM AUTHOR]

Purpose: Today, researchers encounter challenges in scientific collaboration and the alignment of results with their peers. This study aims to evaluate the accuracy of identification and the extent of researchers' genuine participation in the convergence of multi-authored articles written by aerospace researchers, utilizing the three-dimensional Collaborative Author Writing Hierarchy (CAWH). Author associativity is a concept closely linked to scientific collaboration and multi-authored publications. The complexity of knowledge and the increasing demand for specialization and interdisciplinary skills have shaped scientific participation. Aerospace researchers and specialists are pivotal in conducting scientific and industrial research within the aerospace sector, focusing on technology development and providing support and guidance to fellow researchers. The aerospace industry is multi-faceted, strategic, and dynamic, possessing significant potential for wealth generation, economic development, enhancing national competitiveness on the global stage, job creation, and export opportunities. In various fields of study, numerous indicators have been established for observing, monitoring, and quantitatively and qualitatively evaluating researchers' publications, leading to the introduction of diverse metrics accordingly. Methodology: The research is applied in nature and employs an analytical approach. To assess the improvement in accurately identifying the author's true contributions in published articles, a composite measure that examines multiple dimensions has been utilized. The research outputs of aerospace researchers were analyzed, drawing on data categorized under "Engineering, Aerospace" in the Web of Science Core Collection (WOSCC). English-language articles published from 1945 to 2021 were extracted for this study. Data extraction was conducted on February 4, 2022, a Friday. The current research community encompasses all aerospace researchers from 1945 to 2021, comprising 153,994 records indexed in the Web of Science Core Collection (WOSCC). The total number of authors is 161,156, of whom 154,450 researchers with identifiable names (without sampling) were examined. The total number of citations is 2,617,712. Data extracted from the scientific website during the research period were analyzed. In this research, two tools, namely the "MiMFa Scraper, were employed to gather detailed information about each author. Additionally, another tool was utilized to match the gauge information with PHP (Hypertext Preprocessor). This tool is considered part of the DataLab software suite. Ravar PreMap software was also used to standardize the data. To normalize the data, the codes developed in the DataLab software were implemented. Excel 2016 was also utilized to extract data from various websites using PHP. The CAWH measure is defined as the average number of weighted citations based on coauthor credit for a researcher. Findings: The results of the H-weighted co-authorship index indicate "Florian Menter" (from ANSYS Germany GmbH), "Chae M. Rhie" (from Raytheon Technologies USA), "Philippe R. Spalart" (from Boeing), "Edward F. Crawley" (from Massachusetts (from the Institute of Technology (MIT)), "Irving Reed" (from university (from Southern California) are in rank fifth ranks of among based on the CAWH index. This measure was used to calculate the utilizing assessment of each author in writing a multi-author article. Conclusion: The emphasis on recognizing researchers' contributions in article writing will be beneficial and effective for both researchers and the scientific community. Acknowledging researchers' involvement in writing allows them to showcase their contributions and achievements fairly and transparently. This approach enables researchers to properly receive their scientific credit and build their reputation, thereby gaining a competitive advantage within scientific communities. Within research teams, the implementation of this measure will enhance collaboration, facilitate the division of labor, and more equitably determine the rights and benefits of each team member. This approach fosters active collaboration and enhances the productivity of research teams. It enables research organizations and universities to conduct more accurate scientific evaluations of individuals and allocate resources based on equitable distribution and participation. Additionally, this method can improve transparency and build trust within research organizations. Consequently, it can help cultivate a culture of participation and cooperation within scientific communities. This approach can foster healthy, justice-oriented competition in science and enhance the quality of research. The evaluation offers readers and the scientific community detailed information about the authors and their collaborators involved in the research. This transparency enables readers to better assess the contributions and expertise of the article’s authors, thereby increasing their trust in the results and citations presented. Overall, acknowledging the participation of researchers in writing articles supports the scientific process and advances the field of science. This approach offers guidance for justice, transparency, cooperation, and the enhancement of research quality within scientific communities. It fosters an environment conducive to scientific development and progress, which can be assessed and refined usisng the index introduced in this study. [ABSTRACT FROM AUTHOR]

Geopolymers are cementitious materials with exceptional mechanical and physical properties, making them suitable for aerospace applications. Considering their excellent performance, the present investigation aims to develop geopolymers with designed physical properties to address some issues in the aerospace industry. In this sense, the influence of the alkaline activator on the final properties was evaluated. For the development of the geopolymers, sodium hydroxide and sodium metasilicate solutions were preparedto obtain the alkaline activator. The synthesis process also consisted of a mixing stage using a mixer to obtain a homogenous paste. After mixing, the curing process consisted of a first thermal treatment at 60 °C for 4 h to evaporate the excess water, avoid excessive contraction, and promote strength at early ages. Subsequently, the geopolymers were left at rest for 28 days until the final properties were achieved. The influence of the solid-to-liquidratio (S/L) on the microstructure of the geopolymers was evaluated. For this purpose, X-ray fluorescence spectrometry, X-ray diffraction, and infrared spectrometry analyses were performed. The results show that the content of the alkaline activator promotes variations inthe presence of different crystalline phases, which is more noticeable as the S/L ratio increases. Likewise, the infrared spectra display peaks at different wavelengths regarding the variations in elemental composition, which are more evident with the changes in the S/L ratio. In addition, physical studies, such as thermal conductivity and resistance to gamma radiation were conducted for different geopolymer compositions. The results indicate that changes in properties are not too sensitive to compositional variations, although slight modifications exist. Finally, these studies are significant as aerospace-focused materials are directly exposed to this kind of phenomena. The designed geopolymers have to be able to resist and maintain their properties through exposure to any energy. [ABSTRACT FROM AUTHOR]

This study investigates the drag coefficient of three models of suborbital rockets with different nosecones. A test section allowing for force measurement of a 1:50 scale rocket model was designed with the aid of numerical simulations. The velocity obtained in the wind tunnel corresponds with a Mach number of 2.45. RANS simulations were used in verifying operating parameters, as well as testing the support configurations for connecting the model with the bottom wall of the tunnel section. Pressure distribution measurements on the top and bottom walls of the wind tunnel matched simulation results well. The shock structure in the test section was visualized using the schlieren technique, revealing that the measured angle of the main shock generated at the tip of the rocket matched the simulation data. Finally, the measured forces were compared with simulations for one of the nosecone configurations. Despite very good agreement for pressure distribution on the wind tunnel walls and shock structure, a significant mismatch in the forces measured was nevertheless observed: the simulated CD (0.57) being four times larger than that obtained in measurements (0.138). Further analysis of the test section is required to pinpoint the source of discrepancies and redesign the force measurement system to achieve improved force results. [ABSTRACT FROM AUTHOR]

In our paper, we examine the simultaneous impact of the agglomeration economy (AE) and the innovation ecosystem (IE) on the competency development of SMEs in the Piemonte region in three high-tech sectors: aerospace, mechatronics, and automotive. This study focuses on the critical challenge for SMEs: survival and market position expansion amidst rapidly changing external environments. We used the capability approach, which includes identifying and assessing a company's competencies through the capability matrix, as a tool to analyse a company's competitiveness in the industry based on structural changes; we determined the key insights from managerial practices of SMEs that help to comprehend the behaviour of high-performing, sustainable-performing, and low-performing companies in the development of competencies. The key finding is that SMEs' sustainability in the context of structural changes in the external environment is primarily influenced by factors such as investment in the development of company competencies, industrial cooperation, strategic planning, cross-fertilisation, and the impact of company age and size on the availability of resources, along with the level of internationalisation. This study also identifies the main challenges these SMEs face, particularly the lack of highly skilled human resources to meet the sector's specific needs, as well as the difficulties companies face in adapting to changes in consumer behaviour and forecasting future business strategies. In addition, this study introduces the AE and IE variables as strategic tools to enable company representatives to improve their development strategies. [ABSTRACT FROM AUTHOR]

Minimizing the drilling-induced damage on the walls and sub-surfaces of the drilled holes is a challenging but demanding task, especially on hard-to-machine materials such as CFRP/Ti-6Al-4 V stacks. In general, these stacks are highly preferred in aerospace structural applications. This paper analyzes the surface integrity of the drilled CFRP holes when they are stacked above the Ti-6Al-4 V alloy, by incorporating the laser-based marking of micro-textures on the flank and rake faces of the drill, which enables the micro-pool lubrication between the cutting-edges and work material. Comparative experimentations were conducted under MQL conditions. Considering the flank face micro-grooved drill, consistently lower thrust forces were observed across the entire range of cutting speeds and feeds, achieving reductions of up to 17 to 20%. Furthermore, the tool life study was performed, which reveals a substantial 26% enhancement in tool life with the flank face grooved drill, emphasizing its significant advantages for enhanced machining performance. [ABSTRACT FROM AUTHOR]

This study investigates active filling friction stir repair (AF-FSR) and passive filling friction stir repair (PF-FSR) for repairing AISI 304 stainless steel sheets, focusing on addressing the challenges posed by high melting point metals. The research involved repairing overlapping 2 mm thick sheets with pre-drilled holes of 2, 4, and 6 mm diameters, simulating broken components. Various process parameters, including rotational speed, dwell time, and the use of metal fillers, were tested to evaluate their impact on repair quality. The results demonstrated that PF-FSR provided superior mechanical strength to AF-FSR, particularly for larger pre-hole diameters. PF-FSR achieved higher shear tension strength due to better defect filling and reduced void formation, with shear tension strengths exceeding 25 kN for larger pre-holes and lower variability in strength measurements. AF-FSR was less effective for larger pre-holes, resulting in significant voids and reduced strength. Microstructural analysis revealed that PF-FSR facilitated more efficient material mixing and filling, minimizing unrepaired regions. However, excessive rotational speeds and dwell times in PF-FSR led to deformation and flash formation, highlighting the need for optimal parameter selection. Although further studies are needed, this study confirms the feasibility of FSR techniques for repairing small defects in AISI 304 steels, offering valuable insights for sustainable manufacturing practices in industries such as automotive and aerospace, where efficient and reliable repair methods are critical. [ABSTRACT FROM AUTHOR]

The article provides a comprehensive review of the latest developments in the field of laser surface hardening (LSH) and its modeling techniques. LSH is a crucial process for enhancing the surface properties of metals, particularly their hardness and wear resistance, without compromising their bulk properties. This review highlights the fundamental principles of LSH, the types of lasers used, and the key parameters influencing the hardening process. It delves into various modeling approaches, including finite element method (FEM) simulations, analytical models, and empirical models (using statistical methods), emphasizing the integration of advanced computational techniques such as machine learning and artificial intelligence to improve the accuracy and efficiency of LSH simulations. The review also explores practical applications across different industries, showcasing how LSH models have been used to solve real-world challenges in the automotive, aerospace, and tool manufacturing sectors. Finally, it addresses current limitations and outlines future research directions, suggesting potential areas for further advancements in the modeling and application of LSH processes. [ABSTRACT FROM AUTHOR]

Aotearoa New Zealand's rapidly growing aerospace sector is still in its infancy, which presents us with the unique opportunity to incorporate sustainability as a key performance parameter from the outset. Through surveys and interviews with key stakeholder groups, we show that currently, the sector largely deprioritises environmental sustainability and compliance with Te Tiriti o Waitangi in favour of economic growth. Actors are not incentivised to consider any aspects of sustainability. While environmental concerns are acknowledged, they are often viewed as technical challenges to overcome by individual companies, rather than global systemic issues that require a collaborative approach. Moreover, the Government's role as a customer, investor and regulator creates a sustainability leadership vacuum, with no clear commitment to quantify or prioritise sustainability within the sector. The results highlight the need for a new approach to balance growth with genuine sustainable development principles using innovative governance models.Abbreviations: DPMC: Department of the Prime Minister and Cabinet; LCA: life cycle assessments; LCANZ: Life Cycle Association of New Zealand; LEO: low Earth orbit; MBIE: Ministry for Business, Innovation and Employment; NASA: National Aeronautics and Space Administration; NZ: New Zealand; NZSA: New Zealand Space Agency: U.S.: United States (of America) [ABSTRACT FROM AUTHOR]

The electrically excited homopolar inductor machine has a static excitation coil as well as a robust rotor, which makes it attractive in the field of high-speed superconducting machines. This paper designed and analyzed a megawatt class superconducting homopolar inductor machine for aerospace application. To improve the power density, a mass-reduced rotor structure is proposed. Firstly, the main structure parameters of the superconducting homopolar inductor machine are derived based on the required power and speed. Secondly, the electromagnetic performance of the superconducting homopolar inductor machine is analyzed based on the finite element method. Thirdly, a mass-reduced rotor is proposed to improve its power density. The structural performance of the rotor and the electromagnetic performance of the superconducting homopolar inductor machine before and after rotor-mass reduction are evaluated. Compared with the initial rotor, the mass of the mass-reduced rotor is reduced from 66.56 kg to 50.02 kg, which increases the power density by 14.3%. The result shows that a superconducting homopolar inductor machine with a mass-reduced rotor can effectively improve its power density without affecting its output power. [ABSTRACT FROM AUTHOR]

Introduction: Robotics uptake in the aerospace industry is low, mainly due to the low-volume/high-accuracy production that aerospace manufacturers require. Furthermore, aerospace manufacturing and assembly sites are often unstructured environments not specifically suitable for robots to operate in. Methods: This paper introduces a robotic visual inspection system using off-the-shelf components able to inspect the mounting holes for wing slat actuators without the need for fixed-coordinate programming; the part just needs to be left within reach of the robot. Our system sets one of the opposed pairs of mounting holes as a reference (the "datum") and then compares the tilt of all other pairs of mounting holes with respect to it. Under the assumption that any deviation in the mounting hole tilt is not systematic but due to normal manufacturing tolerances, our system will either guarantee the correct alignment of all mounting holes or highlight the existence of misaligned holes. Results and Discussion: Computer-vision tilt measurements are performed with an error of below 0.03° using custom optimization for the sub-pixel determination of the center and radius of the mounting holes. The error introduced by the robot's motion from the datum to each of the remaining hole pairs is compensated by moving back to the datum and fixing the orientation again before moving to inspect the next hole pair. This error is estimated to be approximately 0.05°, taking the total tilt error estimation for any mounting hole pair to be 0.08° with respect to the datum. This is confirmed by manually measuring the tilt of the hole pairs using a clock gauge on a calibrated table (not used during normal operation). [ABSTRACT FROM AUTHOR]

Artificial Intelligence (AI) has transformed the way human-computer interaction (HCI) teams are able to collaborate and coordinate in various domains, including aviation. AI's transformative capabilities can enhance teamwork, efficiency, and safety, particularly in risk management. AI's ability to process vast amounts of data and provide real-time insights enables informed decision-making and automation of repetitive tasks in aviation. By combining the strengths of AI and humans, outlined in our modified version of the 'HABA-MABA' framework, a dynamic teamwork relationship emerges, provided roles are successfully allocated. AI systems are able to act as intelligent assistants, offering timely recommendations, fostering effective communication, and facilitating coordination among crew members. Its adaptability and capacity for learning improve collaboration abilities, tailoring strategies to meet the team's specific needs. This paper explores the theories, considerations, and implications of human-AI teams in aviation, highlighting potential benefits, training recommendations, and future research directions. While human-AI teams offer numerous benefits, addressing the risks, limitations, and ethical considerations is crucial to ensuring safe and efficient operations. Future research must prioritize transparency, explainability, adaptability, and real-world testing to unlock the full potential of human-AI teams and foster successful integration across diverse domains. [ABSTRACT FROM AUTHOR]

The paper presents a wireless system integrated with a machine learning (ML) model for structural health monitoring (SHM) of carbon fiber reinforced polymer (CFRP) structures, primarily targeting aerospace applications. The system collects data via carbon nanotube (CNT) piezoresistive sensors embedded within CFRP coupons, wirelessly transmitting these data to a central server for processing. A deep neural network (DNN) model predicts mechanical properties and can be extended to forecast structural failures, facilitating proactive maintenance and enhancing safety. The modular design supports scalability and can be embedded within digital twin frameworks, offering significant benefits to aircraft operators and manufacturers. The system utilizes an ML model with a mean absolute error (MAE) of 0.14 on test data for forecasting mechanical properties. Data transmission latency throughout the entire system is less than one second in a LAN setup, highlighting its potential for realtime monitoring applications in aerospace and other industries. However, while the system shows promise, challenges such as sensor reliability under extreme environmental conditions and the need for advanced ML models to handle diverse data streams have been identified as areas for future research. [ABSTRACT FROM AUTHOR]

The aerospace industry is a fast‐growing high‐tech sector related to the national economic lifeline and national defence security. In the context of prosperous cooperation and fierce competition between countries, a multi‐layered global aerospace network, from production to trade, has been formed. However, the high‐tech aerospace trade structure and its spatial pattern as the mirror of the industry lack systematic research. This study constructs global high‐tech aerospace trade networks to review the trade dynamics, identify the core countries and explore the regional structure and geographical characteristics. Different high‐tech aerospace segments show varying evolutionary characteristics, with exports more concentrated than imports. The United States and Western Europe dominate the import and export market in all categories of high‐tech aerospace trade, especially in high‐end segment, holding organizational authority in the community structure. Although Asia is rising rapidly in some areas, it still has a long way to go to become a global hub. [ABSTRACT FROM AUTHOR]

In the aircraft mounted accessory gearbox and gas turbine engine gearbox, a significant rise in temperature of lubricant was consistently observed due to the high coefficient of friction (COF) between the moving parts. This phenomenon limits the speed and power transmission of the gearbox. To resolve this, the current study recommends adding specific nanoparticles (NP) as an additive to the military (MIL) grade lubricant to reduce frictional resistance between the gears. Surfactants were also added to hexagonal boron nitride (h-BN) and molybdenum disulfide (MoS2) nanolubricants (NL) to improve NP suspension. Tribological investigations were conducted with a four-ball tester, a shear stability tester, and a Reichert tester to examine the lubricants. During the four-ball test, the wear scar diameter (WSD) on the specimen decreased by 16.73% and 12.3% with h-BN and MoS2 NL, respectively, compared to the results obtained using the base lubricant (BL). In the shear stability test, h-BN NL demonstrated 93%, and MoS2 NL demonstrated 67% more shear stability than the BL, while the COF was reduced by 13% in both h-BN and MoS2 NLs during the Reichert test. These test results prove that h-BN and MoS2 NPs, when added to a MIL standard BL, can demonstrate improved tribological capabilities even at extreme operational conditions. [ABSTRACT FROM AUTHOR]

Fused deposition modelling (FDM) is a widely used 3D printing technique known for its versatility across industries. However, achieving optimal strength, crucial for applications like the automotive and aerospace industries, remains a challenge. This study demonstrates the efficacy of metal-infused filaments in enhancing FDM's strength and quality. By incorporating metal particles into polymer matrices, their mechanical properties are notably improved. PLA and metal-infill PLA (copper, silver) are tested, with silver PLA showing notably higher tensile strength and hardness. Considerations such as infill density and pattern are discussed for optimizing object strength. This work underscores the potential of metal-infused FDM printing for advancing manufacturing capabilities, especially for intricate, high-strength metal components. [ABSTRACT FROM AUTHOR]

Many tools are available for managing complexity in the development of large aerospace systems. Complexity manifests in components, software and so many possible human interactions that all the operational states of the system are not predicted ahead of time. System behaviors are seemingly unexpected, unpredictable, and often unwanted. However, finding these failure modes before they happen can be done by techniques that are qualitative, quantitative, or mixed methods, used situationally, as needed for each particular circumstance. Through studies of failure investigations from NASA and the aerospace industry, recommendations coalesce on using a systems perspective to increase communication and reduce the risk of failure. Overall, a consistent outcome of these investigations is the suggestion to listen to as many value‐added perspectives as possible. Preventing failures in operation is managed by improving collaboration within and among teams, which is an effective way to reveal those perspectives, through both formal and informal communication techniques properly contextualized. [ABSTRACT FROM AUTHOR]

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AbstractCarbon fabric-reinforced polymer (CFRP) composites have replaced most aluminum and ferrous alloys in aerospace construction owing to their attractive high strength-to-weight ratio. CFRPs used in aircraft should have electromagnetic shielding ability in addition to structural properties. Hence, the study of Electromagnetic (EM) wave shielding by hybrid CFRPs is an important topic of research. In this article, we summarize research advancements for enhancing the EM wave shielding of CFRP composites in the X-band frequency range. This study focuses on the manufacturing and performance of carbon-fabric-based composites with metals, metal oxides, and carbon-based fillers. The factors influencing the EM wave shielding ability of the CFRP composites are also discussed. The EM wave shielding of Carbon fibers (CF) was remarkably improved by coating, electroless plating, and synthesizing nanoparticles on the carbon fiber surface. It was found that the carbonious fillers and metal nanofillers such as Nickel (Ni), Iron (Fe), and Silver (Ag)-loaded multilayer CFRP composites showed better absorption modes of EM wave shielding with good structural properties. Owing to the Ag nanowire coating on the CFs, the shielding effectiveness was drastically improved. However, in addition to the type of filler, the structural properties are also influenced by the manufacturing method and type of composite. In the case of laminated composites, the absorption-laminated EM shielding is influenced by the architecture of the plys and the type and number of interplay in the composite construction. In addition, the techniques adopted for the synthesis of nanoparticles and dispersion in composites for effective EM shielding are challenging tasks.

Abstract The rate of rocket launches is accelerating, driven by the rapid global development of the space industry. Rocket launches emit gases and particulates into the stratosphere, where they impact the ozone layer via radiative and chemical processes. We create a three‐dimensional per‐vehicle inventory of stratospheric emissions, accounting for flight profiles and all major fuel types in active use (solid, kerosene, cryogenic and hypergolic). In 2019, stratospheric (15–50 km) rocket launch emissions were 5.82 Gg CO2, 6.38 Gg H2O, 0.28 Gg black carbon, 0.22 Gg nitrogen oxides, 0.50 Gg reactive chlorine and 0.91 Gg particulate alumina. The geographic locations of launch sites are preserved in the inventory, which covers all active launch sites in 2019. We also report the emissions data from contemporary vehicles that were not launched in 2019, so that users have freedom to construct their own launch activity scenarios. A subset of the inventory—stratospheric emissions for successful launches in 2019—is freely available and formatted for direct use in global chemistry‐climate or Earth system models.

The trapped-vortex combustor (TVC) is an alternative combustor design to conventional aeroengine combustors. The separate fuel and air injection of this combustor and its compact design make it a perfect candidate for conventional fuel usage. Moreover, the performance of a trapped-vortex combustor with alternative fuels such as ammonia and hydrogen in the actual operating conditions of an aeroengine is not well understood. The present paper focused on the performance evaluation of TVCs with the futuristic fuels ammonia and hydrogen including under the realistic operating conditions of a combustor. The investigated fuels were injected into a cavity with 0-,15-, 30- and 45-degree transverse-angled air injectors to evaluate the mixing enhancement of the air and fuel under idle and low-power conditions. The mixing behavior of hydrogen showed a significant difference from the conventional fuel, i.e., propane. It was also noticed that the transverse injection of the air helped to improve the mixing efficiency as compared to the normal injection configuration. Mixing efficiency was higher for the 30- and 45-degree transverse-angled air injectors compared to the 0- and 15-degree transverse-angled air injectors.

Carbon/carbon (C/C) three-dimensional textile composites are widely used in aerospace, rail transit, photovoltaic thermal field and other high temperature components due to their strong designability, excellent mechanical properties and high temperature resistance. However, the internal yarn structure of C/C three-dimensional textile composites is complex and has high porosity, showing a high degree of anisotropy and heterogeneity. These factors will bring great difficulties in revealing the mechanical properties and damage mechanism. Therefore, starting from practical applications, the research status of C/C three-dimensional textile composites is reviewed in recent years from three aspects: micro reconstruction, mechanical performance characterization, and numerical simulation. The aim is to provide important support for the integrated preparation of C/C three-dimensional textile composites structure and function, the exploration of deep learning models, and the construction of progressive damage testing platforms in high-temperature experimental environments.

Secondary and High School students are usually adolescents, most of them in the urban areas and metropolitan cities are aware about the existence, various opportunities, career paths and advancements of the space industry. They are constantly updated, given they have access to quality and organized education models and a competitive environment. Although, the students in the rural areas who are equally ambitious and talented yet are not fortunate enough to have access to the state of art facilities like the counterparts. Even if they try and gain access with their self-interest, they do not have the motivation to sustain the passion, given their lack of clarity in subject, lack of awareness about engaging in various ways and fields in space other than technological related and mainly lack of driving force. The purpose of this paper is to develop and present an education model, exclusively for the high school students of the rural areas and inculcate sustainable passion for space. As opposed to the primary school students, the secondary school students have a consciousness of the space industry. This paper will talk about various plans and strategies, that will allow them to gain exposure, guide them about the existence of different career paths which are not entirely technological related, yet are still essential in the space like, administrative framework for example. This opens a new dimension in their brain helping them realize how they can be part of the industry in countless ways, and this shall assist them in being on the right track to space. In addition to, hosting creative space themed exhibitions, fun and engaging model design competitions, workshops, all of these would widen their knowledge boundaries and help them challenge their skills. A real time case study example from a school located in the rural southern of India shall be focused on this paper. Including data from a survey thereby the results, with action plans shall be presented in detail, which will aid in the analysis of the need, feasibility, and long-term sustenance of this approach and the requirement to scale it over different rural areas globally. • Need for improvised education models in rural areas elucidated, with data collection. • Data analysis and correlation of space education awareness, for high school students across two geographical locations. • Readily executable action plans age groupwise, for real-time education models in remote areas globally. [ABSTRACT FROM AUTHOR]

Hall thrusters are electric propulsion devices that are widely used in modern spaceflight. To obtain the critical corrosion data effectively and accurately during long-life tests of Hall thrusters, this paper proposes an automated corrosion measurement method based on three-dimensional point cloud technology. This method uses binocular structured light scanning method to obtain surface point cloud data. The point cloud topology relationship of these disordered data is also established by KD-tree and radius filtering. The base plane is determined according to the average of the outer circle plane in the discharge chamber, and the original point cloud data is sliced transversely and longitudinally. The point cloud of section data is extracted and the corrosion width data is obtained according to the round hole feature extraction and center of circle calculation. The corrosion angle is calculated according to the angle between the straight line and the normal of the section. The proposed method has been verified and the results show that the overall error accuracy is within 60 μm, which meets the requirements for automatic measurement of Hall thruster corrosion. It is a real and effective method to obtain the critical corrosion data during long-life tests of Hall thrusters. [ABSTRACT FROM AUTHOR]

The global space industry is growing rapidly, with an increasing number of annual rocket launches. Gases and particulates are emitted by rockets directly into the middle and upper atmosphere, where the protective ozone layer resides. These emissions have been shown to damage ozone – highlighting the need for proper management of the upper atmosphere environment. We summarise the emission byproducts from rocket launches and discuss their involvement in chemical and radiative processes in the stratosphere, along with potential implications for the ozone layer due to an anticipated increase in rocket launch emissions in the future. We then present a potential vision for sustainable launches, including tractable pathways for both the aerospace industry and the ozone research community. We canvass international and domestic environmental regulation to consider how existing frameworks might be applied to rocket launches. We further identify gaps in aerospace industry practice where cooperation with environmental management and atmospheric science fields could lead to best-practise outcomes. [ABSTRACT FROM AUTHOR]

The trapped-vortex combustor (TVC) is an alternative combustor design to conventional aeroengine combustors. The separate fuel and air injection of this combustor and its compact design make it a perfect candidate for conventional fuel usage. Moreover, the performance of a trapped-vortex combustor with alternative fuels such as ammonia and hydrogen in the actual operating conditions of an aeroengine is not well understood. The present paper focused on the performance evaluation of TVCs with the futuristic fuels ammonia and hydrogen including under the realistic operating conditions of a combustor. The investigated fuels were injected into a cavity with 0-,15-, 30- and 45-degree transverse-angled air injectors to evaluate the mixing enhancement of the air and fuel under idle and low-power conditions. The mixing behavior of hydrogen showed a significant difference from the conventional fuel, i.e., propane. It was also noticed that the transverse injection of the air helped to improve the mixing efficiency as compared to the normal injection configuration. Mixing efficiency was higher for the 30- and 45-degree transverse-angled air injectors compared to the 0- and 15-degree transverse-angled air injectors. [ABSTRACT FROM AUTHOR]

Exposures to hydrazines occur during aeronautic and space operations and pose a potential risk to personnel. Historically, extensive preparatory countermeasures have been taken due to concern for severe toxicity. This study seeks to better understand manifestations of acute occupational exposures to hydrazine to guide recommendations for management. A retrospective database review of records from four United States regional poison centers was conducted of all human exposures to hydrazine, monomethylhydrazine, or 1,1-dimethylhydrazine over two decades. Following case abstraction, descriptive statistics were performed to characterize demographics, manifestations, treatments, and outcomes. One hundred and thirty-five cases were identified, and most were adult males exposed to inhaled hydrazine propellant vapors. Fifty-seven percent of patients were asymptomatic following exposure; otherwise, common symptoms were dyspnea, throat irritation, cough, ocular irritation, and headache. All patients were evacuated or received decontamination, with a few reports of symptomatic treatments, including oxygen supplementation and salbutamol (albuterol). Patients usually recovered quickly and were released after a brief healthcare facility evaluation or observed locally. No patients developed delayed symptoms. Symptoms of severe toxicity were not observed, and there were no deaths. Acute exposures to hydrazines during operations within the aerospace industry appear to be limited primarily to mucosal and mild pulmonary irritation without significant neurologic, hepatic, or hematologic toxicity. These findings are contrary to previously established expectations and may be related to low-level exposures or possibly due to current emergency countermeasures. Care in occupational hydrazine exposure will focus on evacuation, decontamination, and symptomatic management of chemical irritant properties of hydrazines. It is reasonable to manage mild cases outside of a healthcare facility. Continued endeavors in human space exploration and habitation will increase the risk of these exposures, making it imperative that clinicians be comfortable with the care and management of these patients. [ABSTRACT FROM AUTHOR]

2219-T87 is a precipitation hardenable aluminum-copper alloy which sees wide use in structural aerospace components. Thick panels of this alloy are joined via self-reacting friction welding (SRFSW); however, this thermomechanical process can result in significant loss of the alloy's strengthening precipitates and large residual stresses which are detrimental to mechanical behavior and performance. High-resolution maps of the residual strain and stress states along the normal, transverse, and longitudinal directions of 2219-T87 SRFSW were obtained using neutron diffraction measurements. Residual stress had the highest tensile value in the heat-affected zone (HAZ) and the largest compressive stress in the base metal region of the normal and transverse directions. Line profile residual stress distributions displayed an "M"-shaped distribution in each direction with the longitudinal direction being the most pronounced while 2D residual stresses displayed an hourglass-shaped pattern. Average maximal longitudinal residual stress values ranged from 60.6 to 85.6% of yield. Microhardness testing across the transverse weld section produced a "V"-shaped curve with slight hardness recovery in the stir zone. Maximal and minimal microhardness values were observed in the base metal (154 HV) and thermomechanically affected zone (82 HV), respectively. Microstructural evolution was recorded using optical microscopy and showed decreasing grain size from the HAZ to the stir zone. [ABSTRACT FROM AUTHOR]