Browse Topic: Hazards and emergency operations

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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.
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.
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
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.
Safety concerns surrounding new energy vehicles have gained increasing national and social attention. Bottom impacts to power batteries are a leading cause of fires and explosions in new energy vehicles. Focusing on the safety of power battery bottom impacts, this article first proposes applying honeycomb panels to the battery’s bottom guard plate. Through the ball impact test, the effect of honeycomb panel surface material thickness on bottom protection is studied, and the mechanism of the honeycomb panel’s ball impact protection is explored. Second, the honeycomb panel and the aluminum alloy plate are structurally compounded to improve the ball impact protection ability. Finally, the optimized composite bottom guard plate is assembled on the lower box of the power battery, and the whole package ball impact experiment is successfully verified. This study serves as a reference for future research on power battery bottom impact protection and the industrial application of bottom guard
Hongguang, HuangYong, ZengWeiquan, Zeng
Radiation has garnered the most attention in the research that has been conducted on polyethylene sheets. According to the calculations, there were 145892.35 kGy in total radiation doses administered. An ultraviolet visible spectrophotometer was used to examine the impact that electron beam irradiation had on the optical constants. Two of the most crucial variables taken into account when calculating the optical constants and the absorption coefficient are the reflectance and transmittance of polyurethane sheets. Reduced light transmission through the sheet achieves these characteristics, which are related to the transmittance and reflectance of the Fresnel interface. Cross linking makes it more challenging for the polyurethane molecular chains to become fixed. Both the refractive index and the dispersion properties have been altered as a direct result of this. Despite the fact that the doses of electron irradiation were getting lower, it eventually rose to 105 kGy. Contrary to the
Kaushik, NitishSandeep, ChSrinivasan, V. P.Prakash, B. VijayaKalaiarasan, S.Arunkumar, S.
Re-refining of used lubricating oil is an economically attractive and effective recycling method that contributes significantly to resource conservation and environmental protection. The effective re-refining process of used lubricating oil undergoes thorough purification to remove contaminants and to produce high yield and good quality base oil suitable for reuse in lubricant formulation. Used lubricating oils have various hazardous materials, these can be processed with safe and efficient methods required to recover high-quality base oil products. Typically, used lubricating oil is a mixture of various types of additives, base oils, and viscometric grades as per the different types automotive and industrial applications. Re-refined base oils can be re-used to produce lubricants such as industrial and automotive lubricants like passenger car motor oils, transmission fluids, hydraulic oils, and gear oils. API classified base oils into two categories namely mineral base oils API Group I
Maloth, SwamyJoshi, Ratnadeep S.Mishra, Gopal SwaroopSamant, Nagesh N.Bhadhavath, SankerSeth, SaritaBhardwaj, AnilPaul, SubinoyArora, Ajay KumarMaheshwari, Mukul
This ARP provides design and performance recommendations for emergency exits in the passenger cabin. This ARP does not apply to Crew Emergency Exits.
S-9B Cabin Interiors and Furnishings Committee
The global use of lithium-ion batteries has doubled in just the past four years, generating alarming amounts of battery waste containing many hazardous substances. The need for effective recycling methods for spent lithium-ion batteries is becoming increasingly critical. In the journal ChemElectroChem, scientists from various Polish research institutions, including Bydgoszcz University of Science and Technology (PBS), the Institute of Fundamental Technological Research of the Polish Academy of Sciences, the Institute of Physical Chemistry of the PAS in Warsaw, and Wroclaw University of Science and Technology, presented a promising solution to this issue.
This specification covers a shampoo type carpet cleaner in the form of a liquid.
AMS J Aircraft Maintenance Chemicals and Materials Committee
This SAE Aerospace Standard (AS) provides the minimum design and performance requirements for individual, inflatable life preservers, divided into six categories: “Adult,” “Adult-Child,” “Child,” “Infant-Small Child,” “Adult-Child-Infant-Small Child,” and “Demonstration.”
S-9A Safety Equipment and Survival Systems Committee
In the fall of 2023, NASA hot fire tested an aluminum-based, 3D-printed rocket engine nozzle. What made the event remarkable is that aluminum isn’t typically used for additive manufacturing because the process causes it to crack, and it isn’t used in rocket engines due to its low melting point. Yet the test was a success.
Letter from the Focus Issue Editors
Shen, RuiqingWang, Qingsheng
The environment and test waveforms defined in this SAE Aerospace Recommended Practice (ARP) account for the best lightning data and analysis currently available. The quantified environment and levels herein represent the minimum currently required by certifying authorities, which is consistent with the approach applied in related lightning documents. Lightning, like other weather phenomenon, is probabilistic in nature. Levels and waveforms vary considerably from one flash to the next. Within this document, standardized voltage and current waveforms have been derived to represent the lightning environment external to an aircraft. These standardized waveforms are used to assess the effects of lightning on aircraft. The standardized external current waveforms have, in turn, been used to derive standardized transient voltage and current test waveforms that can be expected to appear on cable bundles and at equipment interfaces within an aircraft. When deriving these latter internal induced
AE-2 Lightning Committee
Passenger vehicles like buses tend to soak up heat when they are parked under an open sky. The temperatures inside the vehicle can get very high during daytime due to heating, which reduces the thermal comfort levels. All three modes of heat transfer, i.e., conduction, convection and radiation contribute to the heating process. Cool-down tests are performed to replicate this thermal behaviour and evaluate the time required for cooling the internal bus volume to comfortable temperatures. The phenomenon can also be analysed using CFD, and accounts of numerous such studies are available however, the effects of all three modes of heat transfer for practical application are rarely studied. In view of this, an effort has been made to develop a fast and reasonably accurate transient numerical method to predict the thermal behaviour of the cool-down process for a school bus cabin. The effects of all three modes of heating (conduction, convection, and solar radiation) have been evaluated, and
Sharma, ShantanuSingh, RamanandZucker, JamesMoore, Chris
Electric Vehicles numbers are increasing at a rapid pace in the Indian market. As per the different feedbacks from the customers and reports available in media, there is an increase in Electric Vehicle (EV) battery fire accidents. The same is because of increased EV numbers, malfunctioning of battery and improper handling of EV systems. EV industry is looking for a solution for preventing these mis happenings by using advanced safety technology. This includes improvement in existing safety system through advanced warning backed by artificial intelligence, programming tools using new computing languages such as Python, Java etc. In present work temperature which happens to be major contributor in battery fire cases is being monitored with the help of programming used in battery management systems. In this process algorithm is being developed with the help of python as programming language. The same was test run on the selected parameters for validation of the developed programs for
Vashist, DevendraSharma, AryanAnand, Aditya
This document provides guidance for oxygen cylinder installation on commerical aircraft based on airworthiness requirements, and methods practiced within aerospace industry. It covers considerations for oxygen systems from beginning of project phase up to production, maintenance, and servicing. The document is related to requirements of DOT-approved oxygen cylinders, as well to those designed and manufactured to standards of ISO 11119. However, its basic rules may also be applicable to new development pertaining to use of such equipment in an oxygen environment. For information regarding oxygen cylinders itself, also refer to AIR825/12.
A-10 Aircraft Oxygen Equipment Committee
This SAE Aerospace Recommended Practice (ARP) recommends design features for facilitating relocation of portable slide/rafts for deployment at an alternate exit under ditching conditions.
S-9A Safety Equipment and Survival Systems Committee
Researchers at the National Institute of Standards and Technology (NIST) and colleagues have developed standards and calibrations for optical microscopes that allow quantum dots to be aligned with the center of a photonic component to within an error of 10 to 20 nanometers (about one-thousandth the thickness of a sheet of paper). Such alignment is critical for chip-scale devices that employ the radiation emitted by quantum dots to store and transmit quantum information.
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