Additional Load Research Articles

Numerical Study on Glaze Ice Accretion Characteristics over Time for a NACA 0012 Airfoil

Ice accretion on wind turbine blades can significantly impact their aerodynamic performance, increasing additional load and reducing power generation. This paper utilizes numerical simulation to predict the cross-section at the blade tip of a small wind turbine and study the ice accretion process and aerodynamic characteristics of the airfoil. The research investigates the dynamic characteristics of ice accretion on NACA 0012 airfoil, as well as the influence of dynamic icing at different angles of attack and airflow velocities on the lift coefficient of the airfoil. The findings show that ice accretion leads to a more significant decrease in the lift coefficient of the airfoil at angles of attack of 8° and 12°. From 0 min to 30 min, the decrease rate of the lift coefficient is up to 48% and 46.2%, respectively. The aerodynamic performance of airfoil at 70 m/s deteriorates the most severely and the reduction degree of the lift coefficient can exceed 23.2%. These results may supply guidance for wind turbine anti-icing solutions.

Improving electrotactile communication with a multi-pad electrode under cognitive load.

Electrotactile systems are compact interfaces that can be used to convey information through the skin by producing a range of haptic sensations. In many applications, however, the user needs to perceive and interpret haptic stimulation while being engaged in parallel activities. Developing methods that ensure reliable recognition of electrotactile messages despite additional cognitive load is, therefore, an important step for the practical application of electrotactile displays. This study investigated if a simple strategy of repeating electrotactile messages can improve message identification during multitasking. Ten participants identified 36 spatiotemporal electrotactile messages delivered through a 3 × 2 pad-matrix electrode placed on the torso while performing a concomitant cognitive task in three conditions: the messages were presented once (No-REP), and each message was repeated three (REP3) and five (REP5) times. The main outcome measure was the success rate (SR) of message identification. During multitasking, in the No-REP condition, the SR (median (IQR)) dropped to 56.25% (22.62%), demonstrating that the cognitive task decreased performance. However, the SR significantly improved with message repetitions, reaching 72.92% (21.87%) and 81.25% (18.66%) in REP3 and REP5 conditions respectively, without a statistically significant difference between REP3 and REP5. Multitasking affected the efficacy of haptic communication, but message repetition was shown to be an effective strategy for improving performance. Additionally, only three repetitions were enough, as an additional increase in the duration of message transmission (5 repetitions) did not lead to further improvement. This study is an important step toward delivering electrotactile communication that can cope with the demands of real-world applications.

Modeling the Effect of RC Column Failure over the Frames

The locally or entirely collapse of a structure triggered by failure of one or a couple elements can be considered as progressive collapse. New load distribution and additional loads may be created for the remaining elements of the frame. To accurately understand the progressive collapse mechanism, it is needed to accurate estimation of load distribution after failure of an element. The removal of a column and pushdown analysis is a widely used approach to evaluate the progressive collapse mechanism. However, in this study, effect of removal of three different columns on the frame are studied under two conditions; a) removal of column and pushdown analysis, b) loss on the axial capacity of column under cyclic loading. To axial capacity loss of reinforced concrete column, author’s previously developed axial capacity model is employed. A 2D three-story five-bay benchmark frame is analyzed under pushdown and quasi-static cyclic loading. Distribution of loads after failure of a column is investigated under six different scenarios.

THE USE OF METAL-TIMBER STRUCTURES IN THE RECONSTRUCTION OF INDUSTRIAL BUILDINGS FOR THE RENEWAL OF RESIDENTIAL REAL ESTATE

The use of modern renovation and reconstruction methods to transform industrialbuildings into residential ones, especially in the context of post-war reconstruction efforts in Ukraine, is becoming particularly relevant. To reduce the financial burden of new construction and facilitate the resettlement of refugees from Russian aggression, it is expedient to reconstruct existing decommissioned industrial buildings in ruined cities and migration zones into residential premises. Considering the specific volumetric and spatial solutions of industrial buildings, a significant amount of work is required to reorganize the internal space of such premises for adaptation as residential ones. At the same time, the frames of production premises, due to significant distances between load-bearing structures,allow for more open and spacious premises with modern loft-style interiors. One of the ways to effectively achieve this goal is to install additional floors using metal-timber beams in industrial buildings. The low weight and high load-bearing capacity of such structures make it possible to create additional premises within the existing building volume, with minimal additional loads on the loadbearing frame and building foundations. This approach is not only economically efficient but alsooffers a unique modern way of organizing the interior for comfortable living.The aim of the research is to determine the efficiency and feasibility of using metal-timber I-beam profiles in the process of transforming industrial buildings into residential spaces. The study analyzes both domestic and foreign experience in the renewal and reconstruction of industrial buildings. The conclusions indicate that various functional adaptations of industrial buildings or complexes are possible depending on the project goals, as well as their further integration into the existing city infrastructure.However, the implementation of this concept faces the challenge of the limit of the structural load that can be applied to existing load-bearing frame structures.The reconstruction project must ensure the sustainability (or minimization) of additional loads, which allows reducing the required scope of work,project implementation time, and minimizing investment. Taking into account the industrial nature of the original interior of production premises, the loft style is best suited to the concept of renovating industrial buildings into residential ones. The аpplication of the loft style for the reconstruction of industrial zones is recommended as an economically advantageous option, supported by global experience. Special attention should be paid to the format of transforming production premises into residential ones using lightweight metal-timber roofs,which can become an organic part of the interior space.Scientific novelty. The reconstruction of industrial buildings for residential purposes is a complex and multifaceted process that requires thoughtful decisions and a competent approach. In this article, we will explore the advantages of using structures made of combined metal-timber systems to create technical solutions that meet the requirements of economic viability, environmental friendliness, andenergy efficiency in the reconstruction process.Practical significance. The application of metaltimber constructions allows for the rapid and efficient restoration of industrial buildings, transforming them into residential housing to address the shortage of living space due to the displacement of refugees from Russian aggression. These constructions have significantly lower weight and cost compared to traditional materials such as concrete or steel, while ensuring high strength and reliability.Additionally, they are made from environmentally friendly renewable materials and have an attractive appearance, making them an ideal choice for the reconstruction of industrial buildings into residential housing.

CONSTRUCTIVE SOLUTIONS FOR EXPLOSION-RESISTANT BUILDINGS WITH CIVIL PROTECTION FACILITIES

In the conditions of the large-scale war led by russia in Ukraine, the issue of designingblast-resistant buildings with civil defense facilities that can withstand additional special loads and impacts has become crucial. These impacts include artillery and missile attacks, bomb explosions, blast waves, and the spread of fires, among others. An analysis of the consequences of building and structure destruction resulting from military operationsindicates that reinforced concrete structures of buildings have superior load-bearing capacity compared to traditional brick and steel frames of pavilion-type buildings.Reinforced concrete is a non-combustible material with significant mass, improving its inertialresistance. It possesses high strength and plasticity characteristics, allowing it to deform and redistribute forces between adjacent structures, thereby preventing progressive collapse – the cascading destruction of buildings.The main principles of designing blast-resistant reinforced concrete frames for high-rise buildings involve rational constructive systems and schemes with simple and compact configurations and symmetrical plans. The structural solution of the reinforced concrete frame must ensure the redistribution of gravity loads between adjacent structures. Therefore, the joints of vertical and horizontal structures must be plastic, capable of dissipating a significant amount of explosion energy. The load-bearing elements of buildingstructures must withstand cycles of large deformations in different directions, such aspressures from the lifting of floor slabs opposing ordinary gravity loads. For buildings classified with medium (CC2) and significant (CC3) consequences, where more than 50 individuals are constantly present or periodically more than 100 people, it is necessary to design civil protection premises. These premises should be strategically located below the planned ground level.The construction of civil protection premises located in the underground floors of an explosionproof building must withstand all types of main and episodic loads and impacts and resist the spread of fire. Building frames with monolithic reinforced concrete ribbed ceilings and systems of main and secondary beams or transversely located beams rigidly fixed to vertical supporting structures – columns, pylons, walls – can withstand such loadsbest. The article investigates the reasons for the destruction of reinforced concrete slabs in high-rise frame monolithic buildings when subjected to bending or pressure from explosive loads below. It also explores the potential twisting of the building as a result of reverse explosive effects.The article presents measures to strengthen sections of floor structures in high-rise framemonolithic buildings that may be destroyed due to reverse explosive loads and upward pressure from explosive forces. The expediency of reinforcing critical areas of monolithic reinforced concrete floor slabs with external reinforcement – adhering reinforcing mats in the form of fabrics, lamellas, or carbon fiber nets to the upper zones of slabs near vertical supports – is justified.

Surface Subsidence over a Coastal City Using SBAS-InSAR with Sentinel-1A Data: A Case of Nansha District, China

The loss of life and property in economically developed areas due to geological hazards caused by intense ground subsidence is incalculable. As one of the fastest growing areas in the Guangdong-Hong Kong-Macao Greater Bay Area, the study of ground subsidence in Nansha will help to provide a scientific basis for urban planning and improve the capacity of monitoring and prevention of ground subsidence. The combination of coastal soft soil foundation and urbanization conditions creates a certain risk of land subsidence. We chose Nansha District, the geographical center of the Greater Bay Area, as the study area to analyze its surface subsidence characteristics in recent years. The 20-view Sentinel-1A data and SBAS-InSAR technique were used to monitor the ground subsidence in Nansha from 2017 to 2023. The main rate of ground subsidence in Nansha ranges from −19.4 to 7.7 mm/yr and is distributed in the urban area, along the rivers, in the construction area, and in the reclamation area. As of 4 May 2023, the average ground settlement in Nansha is 10.05 mm and the maximum settlement can be up to 142.45 mm. The 6-year total settlement at all four settlement intensities is greater than 60 mm, with the highest value exceeding 110 mm. The cumulative settlement increases with time, but inverse settlement and no settlement also occur at points where settlement is severe. For settlement caused by soft soil consolidation, it is recommended that drainage pipes be installed to accelerate drainage as a means of stabilizing settlement. For settlement caused by groundwater extraction and additional loads on the road surface, it is recommended to rationally extract groundwater and reinforce the foundation of the road surface with severe settlement.

Impact of Low Catalyst Loading and Incorporation of Additives on Structure and Performance of PEM Electrolyzer Catalyst Layers

Polymer electrolyte membrane water electrolyzers (PEMWEs) are an important technology that can produce renewable hydrogen on demand, although with challenges posed by the slow kinetics of the anodic oxygen evolution reaction (OER) and degradation issues. The degradation of membrane electrode assemblies (MEAs) prepared with Ir-based catalysts is not well understood, especially with lower-loading catalyst layers and intermittent load inputs. This work investigates low-loading IrO2 catalyst layers made with different carbon-based additives, including high-surface-area carbon (HSC), graphitized HSC (gHSC), Vulcan, graphitic carbon nanofibers (gCNFs), graphitic nanoplatelets (gNPs), nitrogen-doped carbon spheres (NCs), Ti carbide (TiC) and Ti carbonitride (TiCN). While carbon-based supports have issues with corrosion at high oxidizing potentials, these materials provide a range of variations in morphology, shape, size, surface area, graphitization, and composition, allowing exploration of the impact of these parameters on catalyst layer structure to identify promising routes to improve catalyst layer structures. Catalyst layers were characterized with electron microscopy and x-ray spectroscopy to assess the distribution of catalyst, carbon additive, and ionomer. This information was correlated with electrochemical performance measurements to elucidate the impact on kinetic site access and mass transport. Selected samples were also subjected to more extended operation to investigate how the initial structures and their performance evolved.

Performance monitoring of assembled beam bridges using displacement spectrum similarity measure

The assembled beam bridge is a widespread construction, with transverse connections uniting precast beams to jointly support loads. These connections, while crucial, are the most vulnerable elements in such structures. Therefore, the development of an effective index for continuous condition assessment remains the cornerstone of structural health monitoring. The Displacement Spectrum Similarity Measure index, as per ideal conditions in numerical simulations, has shown insensitivity to short-term vehicle loads and sensitivity to transverse connection stiffness. This study extends its scope to address potential real-world interference factors, including measurement errors and deck pavement damage. Specifically, we introduce Gaussian white noise to simulate measurement errors and incorporate additional vehicle loads to emulate the impact of pavement damage. Numerical simulations confirm the robustness of the index against these challenges. Additionally, a real-time index extraction scheme is proposed and implemented on an operational bridge. The results reveal a close alignment between the transverse connection condition assessed by the index and the findings obtained through on-site surveys, thereby substantiating the viability and effectiveness of the index for real-world engineering contexts.

A Study on the Influence of Dewatering in the Excavation of Adjacent Tunnels under Lateral Soil Effects

The dewatering of foundation pits leads to changes in the water level and effective stress within the surrounding strata. When existing tunnels are present within the dewatering influence zone, the impact of dewatering on these tunnels cannot be ignored. The Vlasov foundation beam model was used to simulate the interaction between the tunnel and the soil, and the key parameters of the model were precisely investigated. In addition, the constraining effect of the lateral soil on the tunnel was also considered. By integrating the principles of effective stress and Dupuit’s assumption, in this work we calculated the additional load on the tunnel caused by foundation pit dewatering, which was then applied to determine the tunnel stress and deformation induced by dewatering. The accuracy of this approach is validated through comparative analysis with finite element results. Furthermore, the relationships between the permeability coefficient (kt), the spacing (d) between the tunnel and the dewatering well, the water level drop (sw), and tunnel stress and deformation were further studied. The key findings are summarized as follows. Firstly, accounting for lateral soil effects enhances computational accuracy. Secondly, an increase in soil kt leads to a greater tunnel settlement with relatively minor changes in bending moments. Thirdly, as d increases, both tunnel settlements and bending moments decrease. Additionally, as the water level dropped from 10 m to 30 m, the maximum additional stress on the tunnel increased by 94.50%, and the settlement increased by 127.43%. Consequently, it is essential to pay close attention to the tunnel segment nearest to the water level.

Effect of infill walls on progressive collapse behavior of self-centering precast concrete frame

To study the effect of infill walls on the progressive collapse resisting-performance of self-centering precast concrete (PC) frame structures, three 1/2 scaled, two-span and two-story self-centering PC frame specimens with and without infill walls were tested under quasi-static pushdown loading regime. The test results showed that the failure modes of self-centering PC frames were governed by concrete cracking and local spalling at the beam ends under progressive collapse scenario. Compared with self-centering bare frame, the presence of infill walls provided additional load path, thereby reducing the concrete damage at the beam ends to some extent. The full infill walls with lower strength could still increase the initial stiffness and peak resistance of self-centering bare frame to 2.47 times and 1.33 times, while the infill walls with 20% opening ratio could increase to 2.21 times and 1.19 times, respectively. Nevertheless, the infill walls also reduced the self-centering capacity of the structures. Numerical analyses further indicated that the magnitude of prestress force of steel strands between beams and columns, the strength of bed joints as well as the width of infill walls had a great effect on the progressive collapse of self-centering infilled frames. Finally, based on numerical results, a reduction factor formula was proposed to quickly estimate the structural resistance of self-centering infilled frames with different opening ratios.

Peer to peer solar energy sharing system for rural communities

Off-grid stand-alone solar PV systems have been given much attention for many years as they can provide clean and cheap electrical energy to communities in rural areas, particularly developing countries. However, due to their limited capacities, such PV systems are mainly used for primary and essential loads such as fans, lighting, cell phone charging, etc. In contrast, a considerable amount of excess energy is wasted every day due to insufficient battery storage. Therefore, peer-to-peer (P2P) interconnection between existing solar PV systems brings the opportunity to supply additional loads and make rural communities self-sufficient. Moreover, this innovative approach overcomes some obstacles that current mini/microgrids exhibit and plays a vital role in providing a reliable energy supply in rural areas. This paper investigates the feasibility of P2P solar energy sharing for such systems. In this regard, an IoT-enabled, cost-effective automated solar energy sharing system comprising three functional blocks has been proposed. The feasibility analysis in this paper indicates that the P2P application has increased the self-sufficiency and self-consumption of the community by 13.66% and 11.16%, respectively. As a result, a significant life cycle improvement enables the community by utilizing the proposed energy-sharing system benefits.

Ensuring the accuracy of indirect nonlinear dynamic reduced-order models

Numerous powerful methods exist for developing reduced-order models (ROMs) from finite element (FE) models. Ensuring the accuracy of these ROMs is essential; however, the validation using dynamic responses is expensive. In this work, we propose a method to ensure the accuracy of ROMs without extra dynamic FE simulations. It has been shown that the well-established implicit condensation and expansion (ICE) method can produce an accurate ROM when the FE model’s static behaviour are captured accurately. However, this is achieved via a fitting procedure, which may be sensitive to the selection of load cases and ROM’s order, especially in the multi-mode case. To alleviate this difficulty, we define an error metric that can evaluate the ROM’s fitting error efficiently within the displacement range, specified by a given energy level. Based on the fitting result, the proposed method provides a strategy to enrich the static dataset, i.e. additional load cases are found until the ROM’s accuracy reaches the required level. Extending this to the higher-order and multi-mode cases, some extra constraints are incorporated into the standard fitting procedure to make the proposed method more robust. A curved beam is utilised to validate the proposed method, and the results show that the method can robustly ensure the accuracy of the static fitting of ROMs.

Dynamic measurements to assess stress levels on buried hydraulic structures

ABSTRACT Old masonry structures have a very special nature that require periodical inspection and evaluation programs. The problem becomes more sophisticated when dealing with vital buried hydraulic structures under continuous functional operation while bearing additional loads from running public services such as railways. This could add extra challenges for determining their structural performance and engineering characteristics if conventional methods are used. Moreover, traditional methods are sometimes costly, time consuming, and can lead to some damage to the structure. The importance of the current research is therefore providing a rapid methodology for evaluating these structures to confirm their current ability to resist operating loads safely, especially when subjected to aging. In this study, the evaluation depends mainly on analyzing the vibration acceleration response of a structure under dynamic loads. Insight into system identification using formal modal analysis was also conducted. Simultaneously, calibrated numerical model was then adopted to predict the expected level of internal stresses. An old masonry irrigation intake buried culvert underneath the main railway lines was selected for examination. The structure was firstly plugged from both sides and emptied, site inspection as well as core sampling of construction materials were conducted. Vibration time history was recorded due to train passage with different speeds. The filed measurements along with mathematical model were used to estimate the level of stresses among the structure. The results showed the ability of the proposed method to evaluate structures in an easy and rapid fashion compared to traditional methods without stopping serviceability of the structure.

Complementary regional energy features for spoofed speech detection

Automatic speaker verification systems are found to be vulnerable to spoof attacks such as voice conversion, text-to-speech, and replayed speech. As the security of biometric systems is vital, many countermeasures have been developed for spoofed speech detection. To satisfy the recent developments on speech synthesis, publicly available datasets became more and more challenging (e.g., ASVspoof 2019 and 2021 datasets). A variety of replay attack configurations were also considered in those datasets, as they do not require expertise, hence easily performed. This work utilizes regional energy features, which are experimentally proven to be more effective than the traditional frame-based energy features. The proposed energy features are independent from the utterance length and are extracted over nonoverlapping time-frequency regions of the magnitude spectrum. Different configurations are considered in the experiments to verify the regional energy features’ contribution to the performance. First, light convolutional neural network – long short-term memory (LCNN – LSTM) model with linear frequency cepstral coefficients is used to determine the optimal number of regional energy features. Then, SE-Res2Net model with log power spectrogram features is used, which achieved comparable results to the state-of-the-art for ASVspoof 2019 logical access condition. Physical access condition from ASVspoof 2019 dataset, logical access and deep fake conditions from ASVspoof 2021 dataset are also used in the experiments. The regional energy features achieved improvements for all conditions with almost no additional computational or memory loads (less than 1% increase in the model size for SE-Res2Net). The main advantages of the regional energy features can be summarized as i) capturing nonspeech segments, ii) extracting band-limited information. Both aspects are found to be discriminative for spoofed speech detection.

Moderate mass loss enhances flight performance via alteration of flight kinematics and postures in a passerine bird.

Many birds experience fluctuations in body mass throughout the annual life cycle. The flight efficiency hypothesis posits that adaptive mass loss can enhance avian flight ability. However, whether birds can increase additional wing loading following mass loss and how birds adjust flight kinematics and postures remain largely unexplored. We investigated physiological changes in body condition in breeding female Eurasian tree sparrows (Passer montanus) through a dietary restriction experiment and determined the changes in flight kinematics and postures. Body mass decreased significantly, but the external maximum load and mass-corrected total load increased significantly after 3days of dietary restriction. After 6days of dietary restriction (DR6), hematocrit, pectoralis and hepatic fat content, take-off speed, theoretical maximum range speed and maximum power speed declined significantly. Notably, the load capacity and power margin remained unchanged relative to the control group. The wing stroke amplitude and relative downstroke duration were not affected by the interaction between diet restriction and extra load. Wing stroke amplitude significantly increased after DR6 treatment, while the relative downstroke duration significantly decreased. The stroke plane angle significantly increased after DR6 treatment only in the load-free condition. In addition, the sparrows adjusted their body angle and stroke plane angle in response to the extra load, but stroke amplitude and wingbeat frequency remained unchanged. Therefore, birds can maintain and even enhance their flight performance by adjusting flight kinematics and postures after a short-term mass loss.

Architectural Design of Representational State Transfer Application Programming Interface with Application-Level Base64-Encoding and Zlib Data Compression

Representational State Transfer (REST) is an architectural style that underlies the protocol of HyperText Transfer Protocol (HTTP)and is used by web applications. The implementation of REST principles in web services is often known as RESTful API. The standard communication used in RESTful APIs uses HTTP without involving data compression. There are quite a lot of RESTful API clients in the form of mobile applications that use metered networks. Thus, reducing the required bandwidth during transmission is suggested to be beneficial. The data compression technique is widely known to reduce data size, but this additional step may yield side effects such as increased memory usage and processing time. This study aims to investigate how the data compression process, which specifically uses Zlib and Base64 encoding, may put additional load on the whole process of delivering content to a RESTful API. The performance and characteristics in terms of bandwidth saved when distributing JSON data from a RESTful API in compressed format are also be investigated. According to the experiment result, it is suggested that the compression process can reduce network bandwidth by up to 66% with negligible additional memory usage for the compression and decompression processes.

The Impact of the Off-Design Conditions on the Entropy Wave Interaction With a High-Pressure Turbine Stage

Abstract The study of component interactions in aeronautical engines is a key aspect to improve the aerodynamic, aeromechanical, and thermal performance and to reduce greenhouse gas and noise emissions. In this context, combustor systems (working with lean and premixed flames) generate pressure, velocity, and temperature fluctuations that interact with the turbine module producing combustor instability, performance degradation, and noise generation. A correct understanding of this interaction is thus required by the designers, especially with a view to introducing sustainable aviation fuel to achieve zero-emission aviation. This paper tackles this topic from a numerical and experimental point of view, focusing on off-design turbine conditions possibly encountered during an aero-engine mission. In detail, the effect of different stage loadings (obtained by keeping the stage pressure ratio and modifying the rotational speed) on engine-representative entropy waves evolving through the turbine stage is investigated. The combination of numerical and experimental results, that show a good agreement in terms of disturbance evolution within the stage, allows a deeper understanding of the flow field features that impact the stage aerodynamics and modify the secondary flow structures and the entropy wave transport, diffusion, and decay through the rotor. Moreover, the most loaded operating condition reveals the appearance of a rotating instability at the rotor tip that also interacts with the injected disturbance. Finally, the numerical results (coming from full annulus URANS computation with incoming disturbances) are further post-processed to extract indirect noise emissions at the different load conditions and to assess the additional loading on the rotor blade caused by the presence of the disturbance.

Improving critical buildings energy resilience via shared autonomous electric vehicles — A sequential optimization framework

The interdependence between electric power systems and transportation systems is rapidly increasing due to the high adoption of Electric Vehicles (EVs) and their charging infrastructures. Electric vehicles can represent additional load for the power system, but can also bring new opportunities for contributing to the efficient and resilient operations of the power grid. This is mainly because of their ability to provide back power to the system when it is not used for transportation, essentially serving as a moving battery source for the power grid. This so-called Vehicle-to-Grid (V2G), Vehicle-to-Building (V2B), or, generally, Vehicle-to-X (V2X) capability of EVs has been extensively studied in the literature. However, the upcoming development of autonomous driving systems and their integration within sharing mobility services can significantly add to the possibilities of interaction between the transportation system and the power grid. This paradigm is studied to a much lesser extent in the existing literature. Shared Autonomous Electric Vehicles (SAEVs) could allow for more control of the actions of the fleet allowing for large-scale coordinated responses both to mobility and energy demands. This coordinated response can be particularly useful for providing emergency power services in case of power loss while maintaining a high level of transportation service. Thus, improving the overall resilience of the system. In this work, we develop a dynamic optimization framework to evaluate the potential contribution of the SAEV fleet for improving critical buildings’ energy resilience via V2B services. The model considers passengers’ pick-up and transportation, relocation of vehicles, and battery charging and discharging. Power outage scenarios for critical buildings are considered and the potential of the SAEV fleet to fully or partially respond to the emergency power outage is studied. In addition, sensitivity analysis for key parameters such as the outage parameters is introduced. The results of the case study for the Ile-de-France region in France shows that the SAEV fleet has the potential to provide V2B service for critical building at an acceptable loss of passenger total waiting time on the transportation side. Furthermore, it is shown that it is capable of satisfying the emergency power load at a lower cost compared to investing in extra backup generators unless the outage occurs at significantly high frequencies.

Design of experiments framework for performance and environmental assessment in automotive context

Environmental sustainability is a crucial topic in the mobility industry, where manufacturers face severe legislative requirements to reduce cars’ environmental impacts. To address this, the paper presents a novel assessment approach for life-cycle emissions that aids designers in developing environmentally sustainable automotive products without compromising performance. The method compares different alternatives regarding materials, processes, and geometric parameters from both the performance and environmental perspectives. A Design of Experiments study is conducted to calculate specific objective indicators that indicate improvements or worsening in the design alternative. The Finite Element Method is used to simulate mechanical performance, the Life Cycle Assessment methodology is applied to evaluate the environmental impact of alternatives. An exterior roof component is used as exemplary study, and the most promising alternatives are classified using an aggregated score combining performance and environmental objectives. Additional load cases are used to ensure the suitability of these solutions.

Synthesis of persistent luminescence nanocage as both drug nanocarrier and autofluorescence-free bioimaging agent for the theranostics of bacterial infection

Persistent luminescent nanoparticles (PLNPs) have promising applications in long-term autofluorescence-free bioimaging due to the long and multiple activatable afterglow nature. Coating a mesoporous shell on the surface of PLNPs is a usual way to give PLNPs additional drug loading capability, but often leads to the reduction of afterglow luminescence. Herein, we report the fabrication of hyaluronic acid (HA) grafted near-infrared (NIR) PLNP with hollow nanocage structure (PLNC) without the need for an additional mesoporous coating for enhanced targeted autofluorescence-free afterglow imaging and nanocarrier mediated drug delivery to treat bacterial infection. The PLNC was prepared by calcinating solid Cr-doped MgSn(OH)6 in a reducing atmosphere. The as-synthesized PLNC not only gave better persistence luminescence than solid Cr-doped zinc gallogermanate PLNPs for autofluorescence-free bioimaging, but also possessed mesoporous structure as a nanocarrier for drug delivery. As a proof of concept, antimicrobial drug rifampicin (RIF) loaded amino modified PLNC (PLNC-NH2) was prepared for antimicrobial application. RIF loaded PLNC-NH2 was further modified with hyaluronic acid (HA) to make RIF loaded PLNC-HA selectively target to the site of bacterial infection. The developed RIF loaded PLNC-HA not only exhibited efficient antimicrobial therapeutic effects, but also provided autofluorescence-free targeted afterglow imaging of the infection site for guided therapy. This work provides a new simple way for the synthesis of mesoporous PLNCs with additional drug delivery function for nanotheranostic application.