Browse Topic: Hazards and emergency operations

Items (5,528)
With more 5G base stations coming into play, making an accurate assessment of RF-EMF exposure currently faces increasing demand to check if they meet regulatory requirements and ensure people’s safety. We present here PSF-Net, a novel deep learning network by uniting TabPFN’s meta-learned prior knowledge and SAINT’s dual attention structure; its use makes it particularly suitable to deal with applications like prediction of downlink power density and radiation level classification under different conditions within various kinds of 5G cell. A major component in the design of this approach is an uncertainty-aware gating block that determines the optimal weighting for each model output—TabPFN or SAINT—based on the estimated prediction variance as quantified via Monte Carlo sampling during training or the prediction variance calculated using inference-time dropout. In addition, a residual multi-layer perceptron (MLP) is also included to extract refined fused features and maintain a steady
Zhang, YanjinYu, Zefeng
In order to meet the demand for the transformation of traditional manufacturing industries into intelligent manufacturing, a virtual monitoring system for the production workshops of nuclear - key products has been built. There are problems such as poor environment, long distance and remote collaborative office in this production workshop, and managers lack information tools to master the workshop status in real time. In order to minimize the harm of nuclear radiation to the human body, in view of the problems of low transparency, poor real - time performance and low data integration in traditional two - dimensional forms, configuration software and video monitoring, a remote monitoring system for virtual workshops driven by digital models has been developed. This system realizes the remote dynamic display of real - time information in the workshop based on data collection and three - dimensional modeling technologies. Virtual monitoring technology improves the management efficiency of
Wu, YimingChen, RuiLi, Na
Off-highway vehicles (OHVs) frequently operate in extreme environments—ranging from arid deserts and frozen tundras to dense forests and abrasive mining zones—where structural wear, impact damage, and environmental stress compromise their material integrity. Frequent repairs and component replacements increase operational costs, downtime, and environmental waste, making durability and sustainability key concerns for next-generation vehicle systems. This paper explores a novel class of self-healing biodegradable composites, inspired by biological systems, to address these challenges. The proposed materials combine bio-based resins, microencapsulated healing agents, and shape-memory polymers (SMPs) to autonomously repair microcracks and surface-level damage when triggered by thermal, UV, or mechanical stimuli. The design draws inspiration from natural self-healing systems such as tree bark and reptile skin, replicating their regenerative behavior to enhance structural resilience in OHVs
Vashisht, Shruti
Direct current (DC) systems are increasingly used in small power system applications ranging from combined heat and power plants aided with photovoltaic (PV) installations to powertrains of small electric vehicles. A critical safety issue in these systems is the occurrence of series arc faults, which can lead to fires due to high temperatures. This paper presents a model-based method for detecting such faults in medium- and high-voltage DC circuits. Unlike traditional approaches that rely on high-frequency signal analysis, the proposed method uses a physical circuit model and a high-gain observer to estimate deviations from nominal operation. The detection criterion is based on the variance of a disturbance estimate, allowing fast and reliable fault identification. Experimental validation is conducted using a PV system with an arc generator to simulate faults. The results demonstrate the effectiveness of the method in distinguishing fault events from normal operating variations. The
Winkler, AlexanderMayr, StefanGrabmair, Gernot
This specification covers a fluorosilicone (FVMQ) rubber in the form of molded rings.
AMS CE Elastomers Committee
This specification covers an acrylonitrile-butadiene rubber in the form of molded rings, compression seals, O-ring cord, and molded-in-place gaskets for aeronautical and aerospace applications.
AMS CE Elastomers Committee
This document is reissued for application to helicopters. It is primarily intended to apply to the engine or engines, but it shall also apply to fire protection of lines, tanks, combustion heaters, and auxiliary powerplants (APU). Post-crash fire protection is also discussed.
S-12 Powered Lift Propulsion Committee
In order to improve the evacuation efficiency of sudden fire in urban rail transit station, taking the National Exhibition and Convention Center Station of Tianjin Rail Transit Line 1 as the research object, a three-dimensional model of the station is established. Based on the evening peak passenger flow on October 1, 2023, the parameters were calculated and reasonably set in the Pathfinder software to simulate the evacuation process of 3316 people in the fire scene of train arrival, and the evacuation process of sudden fire in the station is simulated. The simulation results show that the station can basically ensure the safe emergency evacuation within 6 minutes under the existing conditions. The stairs, escalators, automatic gate machine and passageways in the station are identified as the evacuation bottlenecks. The total time for all station personnel to evacuate outside the metro station is 514.8 s. According to the simulation results, some suggestions on evacuation strategy and
Fu, YanrongWang, LianxiaLi, YijuanLiu, YiboWang, Duolong
From a quick access port to help firefighters fight EV battery fires faster to preventing public charger vandalism, here are some safety developments that haven't made the big headlines. Most of the news surrounding EV technological development in the past year has been around batteries and charging capacity. But engineers have also been busy working on security and safety issues, from charging stations to finding ways for firefighters to better douse fires. We've rounded up a few of the most notable and novel efforts below.
Clonts, Chris
Author turns classroom quest into a tome for anyone who wants to engineer safer cars. A seasoned engineer with a multi-discipline background in electronics, manufacturing systems, and forensic analysis, Erbis Biscarri brought decades of experience to the topic of automotive safety in his latest work. Biscarri's book, Fires in Conventional and Electrified Vehicles: Theory, Prevention, and Analysis, published by SAE International, offers a comprehensive guide to one of the industry's most pressing challenges: vehicle fire safety. In addition to technical analysis, Biscarri said, the book helps clarify common misconceptions, especially those surrounding electric vehicle fires, by grounding the discussion in documented incident data and established technological principles.
Blanco, Sebastian
Plastic materials are used for a wide variety of spacecraft applications including seals, bearings, fasteners, electrical insulators, thermal isolators, and radomes. Selecting plastics for use in space is complex due to wide operating temperature ranges, vacuum conditions, and exposure to radiation and atomic oxygen. Additionally, some spacecraft applications require sealing flammable propellants such as hydrogen and oxygen. This article will present some design considerations when selecting plastics for use in spacecraft. It will provide rich data on the performance characteristics of plastics as well as examples of successful spacecraft applications.
We develop a set of communications-aware behaviors that enable formations of robotic agents to travel through communications-deprived environments while remaining in contact with a central base station. These behaviors enable the agents to operate in environments common in dismounted and search and rescue operations. By operating as a mobile ad-hoc network (MANET), robotic agents can respond to environmental changes and react to the loss of any agent. We demonstrate in simulation and on custom robotic hardware a methodology that constructs a communications network by “peeling-off” individual agents from a formation to act as communication relays. We then present a behavior that reconfigures the team’s network topology to reach different locations within an environment while maintaining communications. Finally, we introduce a recovery behavior that enables agents to reestablish communications if a link in the network is lost. Our hardware trials demonstrate the systems capability to
Noren, CharlesChaudhary, SahilShirose, BurhanuddinVundurthy, BhaskarTravers, Matthew
This document is reissued for application to helicopters.
S-12 Powered Lift Propulsion Committee
Li-ion battery performance is highly dependent on the electrode materials. The composition of the negative and positive electrodes influences crucial aspects of the Li-ion cell, including energy density, ageing behavior and thermal stability. Recent Li-ion technologies include the use of composite graphite-silicon negative electrodes to improve the energy storage capacity of the otherwise graphite-only negative electrode. This article evaluates the impact of negative electrode composition (standard graphite vs. Si-Gr) on the performance of two recent technologies of Li-ion batteries from the same manufacturer, focusing on electrical performance and safety behavior. The studied technologies are the LG M50LT and LG M58T, the latest one introducing a considerable increase of capacity, passing from 4.80 to 5.65 in nominal capacity. This article abords the comparison of both technologies in electric performance, electrode composition, cell design and thermal stability. Electrical
Cruz Rodriguez, Jesus ArmandoLecompte, MatthieuRedondo-Iglesias, EduardoPelissier, SergeAbada, Sara
The increased functionality of today’s medical devices is astounding. Optical devices, for example, analyze chemicals, toxins, and biologic specimens. Semiconductor devices sense, analyze, and communicate. Microelectromechanical system (MEMS) devices utilize inertial methods to detect motion, direct light, and move components over short distances. Radiofrequency (RF) devices communicate wirelessly to other devices directly and remotely over the Internet. Handheld acoustic devices scan the body and build a virtual 3D model that shows conditions in the body. The innovation currently happening in the medical device industry is staggering, limited only by imagination and finding technical methods to implement the vision.
Experimental testing in automotive development sometimes relies on ad hoc approaches like ‘One Factor at a Time’, particularly in time- and resource-limited situations. While widely used, these approaches are limited in their ability to systematically capture parameter interactions and system complexities, which poses significant challenges in safety-critical applications like high-voltage battery systems. This study systematically investigates the factors influencing thermal runaway in lithium-ion battery cells using a statistical full-factorial experimental design. Key parameters, including state of charge, cell capacity and heating trigger power, have been analyzed under controlled conditions with an autoclave setup, enabling precise measurement of thermal and mechanical responses. The use of automotive-grade lithium-ion cells ensures relevance for next-generation applications. By employing factorial regression and statistical analysis, the study identifies critical temperatures
Ceylan, DenizKulzer, André CasalWinterholler, NinaWeinmann, JohannesSchiek, Werner
This specification establishes the engineering requirements for producing an anodic coating on titanium and titanium alloys and the properties of the coating.
AMS B Finishes Processes and Fluids Committee
This specification covers an alkaline rust remover compound in the form of a liquid concentrate or a water-soluble powder for dilution with water.
AMS J Aircraft Maintenance Chemicals and Materials Committee
This specification covers a solvent-based compound in the form of a liquid.
AMS J Aircraft Maintenance Chemicals and Materials Committee
This SAE Aerospace Standard (AS) provides design criteria for onboard stairways intended for use by passengers aboard multi-deck transport category airplanes. It is not intended for stairways designed for use only by crewmembers, supernumeries, or maintenance personnel. Additionally, this AS does not apply to fuselage mounted or external stairways used for boarding passengers, which are covered by ARP836.
S-9B Cabin Interiors and Furnishings Committee
This SAE Aerospace Recommended Practice (ARP) establishes general criteria for the installation (e.g., type, location, accessibility, stowage) and crew member training needed for portable fire extinguishers.
S-9A Safety Equipment and Survival Systems Committee
Researchers have developed a new type of sensor platform using a gold nanoparticle array. The sensor is made up of a series of gold disk-shaped nanoparticles on a glass slide. When an infrared laser is pointed at a precise arrangement of the particles, they start to emit unusual amounts of ultraviolet (UV) light.
Noise reduction at the source level is key to achieve the overall vehicle level interior targets. This paper presents a novel approach that integrates directivity analysis with simulation techniques to optimize acoustic encapsulation design for automotive sound sources to achieve the targeted radiation levels. The foundation for this methodology is to measure the angular distribution of sound pressure levels around the noise source so called Directivity, at every frequency of interest and determine the most effective acoustic encapsulation to achieve the targeted sound radiation. Accurate measurement of directivity in physical testing with fine angular resolutions can be complex and expensive, this study utilizes numerical simulation techniques using FEA to mitigate the challenges in mid frequency range. The scope of the study is focused on mid frequency sound pressure levels between 500-2500 Hz, which are determined to be significant contributors to overall DU noise. The first step is
Kaluvakota, SrikanthGhaisas, NikhilPilz, Fernando
This study presents a novel methodology for optimizing the acoustic performance of rotating machinery by combining scattered 3D sound intensity data with numerical simulations. The method is demonstrated on the rear axle of a truck. Using Scan&Paint 3D, sound intensity data is rapidly acquired over a large spatial area with the assistance of a 3D sound intensity probe and infrared stereo camera. The experimental data is then integrated into far-field radiation simulations, enabling detailed analysis of the acoustic behavior and accurate predictions of far-field sound radiation. This hybrid approach offers a significant advantage for assessing complex acoustic sources, allowing for quick and reliable evaluation of noise mitigation solutions.
Fernandez Comesana, DanielVael, GeorgesRobin, XavierOrselli, JosephSchmal, Jared
Heavy Duty (HD) linehaul vehicles are majorly used in transportation of goods and heavy loads between different cities or long distances. Considering the current trend, payload capacity of these heavy-duty trucks are increasing due to constant increase in the load demand. Due to which engine torques of these HD vehicles are increasing which in turn increases the transmission input torque. At higher torque levels, gear excitation also increases and transmission becomes more susceptible towards higher noise radiation. The transmission is an integral part of the driveline in a heavy duty commercial vehicle. Along with speed and torque conversion, the transmission design is crucial to achieve better fuel economy. Important factors to consider in the transmission design are duty cycle, torque capacity, fuel economy and overall weight. Global vehicle pass-by noise regulations for HD commercial vehicles are becoming more stringent and transmissions are expected to be very quiet. Historically
Rastogi, SarthakMilind, T. R.
With the exponential rise in drone activity, safely managing low-flying airspace has become challenging — especially in highly populated areas. Just last month an unauthorized drone collided with a ‘Super Scooper’ aircraft above the Los Angeles wildfires, grounding the aircraft for several days and hampering the firefighting efforts.
Modern aircraft, ships, and offshore structures are increasingly constructed using fiber-reinforced composite materials. However, when subjected to lightning strikes, these materials can suffer significant structural and functional damage due to their electrical and thermal properties. This study aims to develop a novel finite element (FE) model to minimize the error in estimating the thermal damage caused during lightning strikes. This will aid in design and optimization of lightning protection systems. The developed model introduces a simplified numerical approach to model the lightning arc interaction with CFRP laminate. The existing FE model includes idealized loading conditions, leading to high error in estimation of severe damage area and in-depth damage. The proposed methodology incorporates a more realistic lightning-induced loading pattern to improve accuracy. Several cases are analyzed using available FE methods and compared to the proposed model (case 6) to evaluate the
Sontakkey, AkshayKotambkar, MangeshKaware, Kiran
This aerospace standard provides guidance for use in demonstrating compliance with powerplant fire protection requirements by fire test.
A-22 Fire Protection and Flammability Testing Committee
Hurricane evacuations generate high traffic demand with increased crash risk. To mitigate such risk, transportation agencies can adopt high-resolution vehicle data to predict real-time crash risks. Previous crash risk prediction models mainly used limited infrastructure sensor data without covering many road segments. In this article, we present methods to determine potential crash risks during hurricane evacuation from an emerging alternative data source known as connected vehicle data that contain vehicle speed and acceleration information collected at a high frequency (mean = 14.32, standard deviation = 6.82 s). The dataset was extracted from a database of connected vehicle data for the evacuation period of Hurricane Ida on Interstate-10 in Louisiana. Five machine learning models were trained considering weather features and different traffic characteristics extracted from the connected vehicle data. The results indicate that the Gaussian process boosting and extreme gradient
Syed, Zaheen E MuktadiHasan, Samiul
As stepper motors become more and more widely used in engineering systems (vehicles, 3-D printers, manufacturing tools, and similar), the effects of their induced magnetic fields present a concern during the packing and orientation of components within the system. For applications requiring security, this is also a concern as the background electromagnetic radiation (EMF) can be captured at a distance and used to reproduce the motion of the motor during operation. One proposed alternative is to use customized non-magnetic plastic shields created using additive manufacturing. Some small studies have been completed which show some effectiveness of this approach but these studies have been small-scale and difficult to reproduce. To seek a more rigorous answer to this question and collect reproducible data, the present study used full factorial design of experiments with several replications. Three materials were used: Polylactide (PLA), PLA with 25% (weight) copper powder, and PLA with 15
Hu, HenryPatterson, Albert E.Karim, Muhammad FaeyzPorter, LoganKolluru, Pavan V.
Lead-filled aprons are currently used for atomic number (Z)-grade radiation shielding in the medical industry to protect personnel from hazardous gamma radiation. These apron garments are made with lead-filled elastomeric sheets encased in polymeric fabrics and are both heavy and bulky to meet necessary shielding requirements. In addition, there are environmental safety concerns surrounding disposal of these garments due to their lead content. An innovator at NASA Langley Research Center has developed a novel method for making thin, lightweight radiation shielding that can be sprayed or melted onto common textiles used in clothing such as cotton, nylon, polyester, Nomex, and Kevlar.
Innovators at NASA Johnson Space Center have designed a pneumatic nail penetration trigger system that drives a Li-ion battery cell into thermal runaway using a tungsten nail. By creating a targeted rupture in a battery cell’s outer casing, researchers can initiate an exothermic chain reaction within the battery, much like a short circuit, causing a spike in temperature that can lead to battery failure, fire or explosion.
Conventional solid polymer electrolyte batteries perform poorly due to structural limitations that hinder an optimal electrode contact. This could not eliminate the issue of “dendrites”, where lithium grows in tree-like structures during repeated charging and discharging cycles. Dendrites are a critical issue, as an irregular lithium growth can disrupt battery connections, potentially causing fires and explosions.
U.S. Army Combat Capabilities Development Command Chemical Biological Center (DEVCOM CBC) researchers are developing a way to scan for chemical biological agent on surfaces on the fly. Literally on the fly as it consists of an AI-enabled spectrometer mounted on an unmanned aerial vehicle (UAV) or unmanned ground vehicle (UGV) sending back vital data in real time. It is called Hyperspectral Threat Anomaly Detection, or HyperThreAD for short.
Batteries in electric vehicles can fail quickly, sometimes catching fire without much warning. Sandia National Laboratories is working to detect these failures early and provide sufficient warning time to vehicle occupants.
This document is intended to describe how to conduct lightning direct effects tests and indirect system upset effects tests. Indirect effects upset and damage tolerance tests for individual equipment items are addressed in RTCA DO-160/ED-14. Documents relating to other aspects of the certification process, including definition of the lightning environment, zoning, and indirect effects certification, are listed in Section 2. This document presents test techniques for simulated lightning testing of aircraft and the associated systems. This document does not include design criteria, nor does it specify which items should or should not be tested. Acceptable levels of damage and/or pass/fail criteria for the qualification tests must be approved by the appropriate airworthiness authority for each particular case. When lightning tests are a part of a certification plan, the test methods described herein are an acceptable means, but not the only means, of meeting the test requirements of the
AE-2 Lightning Committee
While DNA damage caused by space radiation exposure has long been recognized as a major threat to astronaut health, a recent study published in Redox Biology (Stolc et al., 2024) reveals an unexpected culprit in the atmosphere of the International Space Station (ISS) itself: elevated carbon dioxide (CO2) levels. In this study, mice were sent into space where they spent 5–6 week aboard the ISS.
Tunnels play a crucial role in urban transportation, yet they frequently encounter various incidents during operation. Manual video inspections and sensor-based systems are inefficient and limited in accurately detecting and addressing these issues. The emergence of artificial intelligence has led to the development of object detection models such as YOLO, which have shown promise in real-time anomaly detection. However, these single-modality models achieve suboptimal results when dealing with complex events. Multi-modal large language models (LLMs) offer a potential solution, with their ability to process and understand information from different modalities. This paper develops a novel tunnel traffic anomaly detection method that combines single-modal models and multi-modal LLMs. The proposed system first employs YOLO for an initial detection round and then utilizes a specially designed LLM with an effective prompt and a data filtering strategy tailored for traffic tunnel scenarios
Liu, HongyuZhou, RuohanBai, JiayangLi, Yuanqi
Lithium-ion batteries are prone to thermal failures under extreme conditions, leading to thermal runaway and safety risks such as fire or explosion. Therefore, effective temperature prediction and diagnosis are crucial. This paper proposes a thermal fault diagnosis method based on the Informer time series model. By extracting temperature-related features and conducting correlation analysis, a 9-dimensional input parameter matrix is constructed. Experimental results show that the model can maintain an absolute temperature prediction error within 0.5°C when predicting 10 seconds in advance, with higher accuracy than the LSTM model. Additionally, a three-level warning mechanism based on the forgetting coefficient further enhances diagnostic accuracy. Validation using test data and real vehicle data demonstrates that this method can efficiently diagnose and locate thermal faults in batteries, with low computational costs, making it suitable for online applications.
Sun, YefanZhu, XiaopengZhang, ZhengjiePeng, ZhaoxiaYang, ShichunLiu, Xinhua
Nowadays, there are many technologies emerging like firefighting robots, quadcopters, and drones which are capable of operating in hazardous disaster scenarios. In recent years, fire emergencies have become an increasingly serious problem, leading to hundreds of deaths, thousands of injuries, and the destruction of property worth millions of dollars. According to the National Crime Records Bureau (NCRB), India recorded approximately 1,218 fire incidents resulting in 1,694 deaths in 2020 alone. Globally, the World Health Organization (WHO) estimates that fires account for around 265,000 deaths each year, with the majority occurring in low- and middle-income countries. The existing fire-extinguishing systems are often inefficient and lack proper testing, causing significant delays in firefighting efforts. These delays become even more critical in situations involving high-rise buildings or bushfires, where reaching the affected areas is particularly challenging. The leading causes of
Karthikeyan, S.Nithish, U.Sanjay, S.Sibiraj, T.Vishnu, J.
X-rays are a common component of diagnostic testing and industrial monitoring, used for everything from monitoring your teeth to scanning your suitcase at the airport. But the high-energy rays also produce ionizing radiation, which can be dangerous after prolonged or excessive exposures. Now, researchers publishing in ACS Central Science have taken a step toward safer x-rays by creating a highly sensitive and foldable detector that produces good quality images with smaller dosages of the rays.
Spaceflight outside of the Earth’s protective magnetic field is dangerous from a cosmic radiation perspective. Inside Earth’s magnetic field, where the manned International Space Station (ISS) orbits, the radiation encountered is minimal and almost all is deflected by our planet’s magnetic fields. However, outside that protective shield, the Sun’s solar wind (high energy radiation, solar energetic particles or SEPs) consisting of protons, electrons, alpha particles, and plasmas continuously bombards the spacecraft for the months or years of spaceflight.
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