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This study presents technologies of the triple hybrid landing gear for the OMOTENASHI(Outstanding Moon exploration Technologies demonstrated by Nano Semi-Hard Impactor) spacecraft, which consists of an airbag, a crushable material as a shock absorber, and an impact resistance structure. The inflated airbag has capability to possibly mitigate impact acceleration at the instant of landing and submergence into regolith that covers a planetary surface. The crushable material with lattice structures, manufactured by a metal 3D printer, serves a dual purpose: it dissipates kinetic energy and controls the impact acceleration at landing by compressing itself within a designed deceleration distance. Further, in the impact resistance structure, the protective object is filled with resin and hollow glass beads, and the impact resistance is improved while the weight reduction is maintained. This paper provides the technical details such as the required specification, verification test results, and assembly result of the surface probe as the smallest lander of the OMOTENASHI spacecraft. • The triple hybrid landing gear appeared for the world's smallest lunar lander. • Shock absorber, airbag, and shock-resistant structure were complementarily combined. • The shock absorber with excellent mounting capability was produced by a 3D printer. • The airbag shape was designed with the Terra-mechanics theory. • Development tests suitable for small landers were demonstrated. [ABSTRACT FROM AUTHOR]

• The ballistic performances of different UHMWPE/Airbag structures are analyzed. • A material model for TPU is established and used for simulation, considering the strain rate effect. • The effects of stress dispersion and deformation restraint on ballistic performance are discussed. • Enhancing ballistic protection through the interaction of two materials is highlighted. A series of flexible structures incorporating an airbag and ultra-high molecular weight polyethylene (UHMWPE) fiber panels were designed as temporary architectures to offer both ballistic protective functions and lightweight constructions. Three primary structural configurations, monolithic structures (airbag or UHMWPE panel alone), bi-layer structures (airbag/ UHMWPE panel and UHMWPE panel/airbag), and sandwich structures (UHMWPE panel/airbag/ UHMWPE panel) were tested. A T12A carbon tool steel sphere with the diameter of 12.7 mm was utilized as the ballistic threat within an impact velocity range of 0–500 m/s. Investigations into the effect of stacking order on ballistic performance were carried out experimentally and numerically. The failure characteristics, ballistic limits, energy dissipations, impact processes and interaction effects of these structures are discussed. To facilitate the establishment of numerical models for impact analysis using ABAQUS, a material constitutive model of thermoplastic polyurethanes (TPU) including strain rate effect was developed. The numerical models of the monolithic single-sheet UHMWPE panel and airbag for impact analysis were subsequently verified by experiments in terms of impact processes and ballistic limits. The results reveal that arranging a few layers of UHMWPE panels in front of the airbag can improve the collapse ballistic limit while maintaining the failure ballistic limit. The inclusion of an airbag reduces the energy dissipation efficiency of composite structures. The potential to enhance ballistic protection through the combination of airbags and UHMWPE panels is highlighted. Stress dispersion and deformation restraint are identified as significant factors influencing the ballistic performance of the composite structures. [ABSTRACT FROM AUTHOR]

High-speed motor vehicle accidents (MVAs) are an important cause of brachial plexus injury (BPI). Some case reports have demonstrated shoulder seat belt use resulting in traction injuries to the brachial plexus. We used a national trauma registry to determine the association between seat belt use and brachial plexus injury in MVAs. The authors queried the National Trauma Databank between 2016 and 2017 for patients with a hospital admission following an MVA. Cases with BPI were identified using International Classification of Diseases, Tenth Edition, Clinical Modification , diagnosis codes. Case–control matching by age and sex was performed to identify 2 non-BPI controls for every case of BPI. Multivariable conditional logistic regression adjusting for body mass index, alcohol use, and drug use was then performed to determine the adjusted association between safety equipment use (seat belt use and airbag deployment) and BPI. A total of 526,007 cases of MVAs were identified, of which 704 (0.13%) sustained a BPI. The incidences of BPI in patients were the following without any protective device (0.16%), with airbag deployment alone (0.08%), with seat belt use alone (0.08%), and with combined airbag deployment and seat belt use (0.07%). Following 1:2 case–control matching by age and sex and multivariable conditional logistic regression, seat belt use (odds ratio [OR] 0.55; 95% confidence interval [CI] 0.42–0.71; P < 0.001) and airbag deployment (OR 0.52; 95% CI 0.33–0.82; P = 0.004) were found to be associated with decreased odds for BPI, with the least odds observed with combined seat belt use and airbag deployment (OR 0.49; 95% CI 0.33–0.74; P = 0.001). Despite anecdotal evidence suggesting increased likelihood of BPI with shoulder seat belt use, case–control analysis from a national trauma registry demonstrated that both seat belt use and airbag deployment are associated with lower odds of sustaining BPIs in MVAs, with the greatest protective effect observed with combined use. Future studies adjusting for rider location (passenger vs. driver) and other potential confounders such as make, type and speed of vehicle may help further characterize this association. [ABSTRACT FROM AUTHOR]

To reduce the size inconvenience of airbag systems employed in human-body protection devices while maintaining comparable gas generation performance, a new family of gas-generating energetic composites are proposed mixing Al/CuO nanothermite with copper complex (Cu(NH 3) 4 (NO 3) 2) known for its propensity to generate gases (0.03 mol/g) such as N 2 , O 2 , N 2 O through exothermic chemical decomposition (300 J/g). The aluminum (Al)/Copper oxide (CuO) couple, known as the most widely studied nanomaterial for thermite reactions, releasing a high energy, mostly heat, through chemical reaction, is employed as a source of heat to trigger and sustain the decomposition of Cu(NH 3) 4 (NO 3) 2 complex. This work permits developing a new family of gas-generating energetic composites that takes advantage of specific chemical and thermal properties of both materials. We demonstrate its capability to tune the pressurization rate, burn rate and pressure peak by varying the Al/CuO over Cu(NH 3)(NO 2) 2 mass ratio. The peak pressure of Cu(NH 3) 4 (NO 3) 2 /Al/CuO energetic composites reaches 12 MPa/g.cm3 in a close volume, which is 3.3 higher than that of traditional Al/CuO nanothermite. They achieve much longer high-pressure duration (∼30 ms). They also exhibit very intense burning with velocity reaching hundreds of m/s in opening burning experiments. These new materials appear very promising for green gas generation. [ABSTRACT FROM AUTHOR]

Aim: The primary purpose of an avalanche airbag is to prevent burial during an avalanche. Approximately twenty percent of avalanche victims deploying airbags become critically buried, however. One avalanche airbag actively deflates three minutes after deployment, potentially creating an air pocket. Our objective was to evaluate this air pocket and its potential to prevent asphyxiation.Methods: Twelve participants were fitted with an airbag and placed prone on the snow. Participants deployed the airbag and were buried in 1.5 m of snow for 60 min with vital signs including oxygen saturation (SpO2) and end-tidal CO2 (ETCO2) measured every minute. Participants completed a post-burial survey to determine head movement within the air pocket.Results: Eleven of the 12 participants (92%) completed 60 min of burial. Preburial baseline SpO2 measurements did not change significantly over burial time (P > 0.05). Preburial baseline ETCO2 measurements increased over the burial time (P < 0.02); only one ETCO2 value was outside of the normal ETCO2 range (35-45 mmHg). Participants reported they could move their head forward 11.2 cm (SD 4.8 cm) and backward 6.6 cm (SD 5.1 cm) with the majority of participants stated that they had enough head movement to separate the oral cavity from opposing snow if necessary. Visual examination during extrication revealed a well-defined air pocket in all burials.Conclusion: The avalanche airbag under study creates an air pocket that appears to delay asphyxia, which could allow extra time for rescue and improve overall survival of avalanche victims. [ABSTRACT FROM AUTHOR]

Background: Many studies have investigated the issue of facial injuries caused by car accidents, but only a few have addressed the technical and clinical aspects of such accidents and injuries in depth. The aim of this study was to identify risk factors and protective elements for facial injuries in car accidents.Methods: We analysed the technical and clinical data of patients with facial injuries caused by car accidents over a 16-year period (2000-2016) and investigated the following factors: sitting position, sex, age, accident time, use of a seatbelt, deployment of the front airbag, direction of impact, speed at the time of collision, and occurrence and location of facial injuries.Results: Of the 1291 patients involved in car accidents who were included in our study, 291 (22.5%) had suffered facial injuries. We found a significant association between occurrence of facial injuries and sex, speed at the time of collision, impact from the back, seatbelt usage, and deployment of the front airbag. In accidents occurring at speeds over 40 km/h, automobile security measures had no significant influence on the occurrence of facial injuries in drivers and front-seat passengers. In accidents occurring at speeds between 0 and 20 km/h, seatbelt usage (without airbag deployment) solely showed a significant protective influence against the occurrence of facial injuries (odd ratio [OR], 0.130; confidence interval [CI], 0.038-0.451). In contrast, patients who were in accidents at speeds between 21 and 40 km/h suffered significantly fewer facial injuries when wearing a seatbelt with the front airbag being deployed (OR, 0.245; CI, 0.091-0.665) or undeployed (OR, 0.216; CI, 0.084-0.561).Conclusion: Male sex and a high speed at the time of collision are significant risk factors for the occurrence of facial injuries. The security measurements evaluated in this study only exerted a protective influence at low speeds (below 40 km/h). This indicates a possible weakness of these security systems with regard to preventing facial injuries. Engineers could benefit from these findings and improve the efficiency of existing security measures and eventually help decrease the incidence of facial injuries. [ABSTRACT FROM AUTHOR]

Highlights • A representative analysis of PTW crash configurations based on clinical data. • Definition of human body impact conditions using multibody simulations. • The most vulnerable regions of the trunk are the frontal and lateral areas. • The fastest impacts were recorded in oblique-on-side collisions. • High velocity thoracic and abdominal impacts ranged from 5 to 13 m/s. Abstract Motorcycle accidents lead to a high rate of traffic mortality and morbidity. While helmet development and mandatory wearing have reduced head injuries, little progress has been made regarding trunk protection. Wearable airbag devices represent a promising solution to prevent trunk injuries. Nevertheless, research investigations need to be performed to assess and optimise the efficiency of such devices. This work consisted in the analysis of motorcyclist trunk impact conditions involved in various crash configurations to provide critical information in order to evaluate and improve the performances of airbag devices. First, an epidemiological and an accidentological analysis of data collection related to 252 real accidents, focusing on victims admitted into the shock rooms of two French trauma centres were performed. The data obtained was combined with numerical multibody parametric investigations, allowing the reproduction of 240 accident situations. An original and representative analysis of motorcyclists' impact conditions was provided, weighting the numerical study output data according to the real accident database. The impacted regions of the human body, the impact velocity and the accident chronology obtained in this work made it possible to define critical information for airbag efficiency assessment: the zones and levels of protection, the impacted surfaces as well as the airbag intervention time and the duration of maintained inflation of the airbag. [ABSTRACT FROM AUTHOR]

• This study designed a frontal occupant protection system for an integrated second-row wheelchair seating station. • The SCaRAB has greater benefit when seatbelt geometry is suboptimal. • Results includerecommendations for belt geometry and airbag parameters suitable for occupants seated in wheelchairs. • Restraint systems initially optimized with the surrogate wheelchair also performed well with two commercial wheelchairs. The advent of automated vehicles (AVs) provides an opportunity to design integrated wheelchair seating stations that provide an equivalent level of safety for occupants using wheelchairs as those using vehicle seating. This study designed a frontal occupant protection system for an integrated second-row wheelchair seating station that includes optimized airbags and seatbelt systems. MADYMO models were used to optimize belt geometry for a midsized male ATD seated in a surrogate wheelchair fixture, with and without inclusion of a Self Conforming Rearseat Air Bag (SCaRAB). Sled tests were performed to confirm the benefits of airbag use and optimized belt geometry. Additional modeling was performed with commercial manual and power wheelchairs, to identify the effects of wheelchair design and forward clear space on occupant kinematics and injury measures. Additional sled tests were performed with manual and power wheelchairs to demonstrate effectiveness of the restraint system with commercial products. Simulations and tests both showed improved kinematics using an optimized seatbelt system geometry compared to a commonly used suboptimal D-ring location that places the shoulder belt at a more outboard location. Use of the SCaRAB helped compensate for suboptimal geometry. Results include specific recommendations for belt geometry relative to the wheelchair seating station and airbag parameters suitable for protecting occupants seated in wheelchairs. Restraint systems initially optimized using the surrogate wheelchair also performed well with the two commercial wheelchairs. The clear space required for maneuvering a wheelchair will likely prevent injurious head contact in frontal crashes. This study is the first to design a frontal optimal occupant protection system for an integrated second-row wheelchair seating station, demonstrating that it should be feasible once integrated wheelchair seating stations are included in AVs. [ABSTRACT FROM AUTHOR]

We present a case of a fatal motor vehicle collision of a 22-year-old car driver, who died at the scene after losing control of his car, and subsequently collided with a tree by the roadside. The subsequent autopsy revealed penetrating injuries on the neck, severing the larynx, carotid artery, jugular vein and fracturing the cervical vertebrae. Internal examination showed the offending material to be a semi-cylindrical metal fragment, which had lodged within the paravertebral muscle. Examination of the car with the authorities found that the metal fragment originated from a defective airbag booster cannister, which shattered upon deployment. [ABSTRACT FROM AUTHOR]

Fatal and serious injuries of vulnerable road users (VRU) occur frequently in the events of vehicle impact. Front-end crashworthiness of vehicle can considerably affect VRU injuries in impact accidents, and vehicular design signifies a key issue in automobile engineering. This paper provides a comprehensive review on the state-of-the-art on the assessments and design of frontal structures for VRU protection through experiment, simulation and optimization methods. First, the impact-induced injury mechanisms of different human parts are evaluated. Second, different safety regulations and assessment procedures for VRU protection in the world are compared in detail, which include impact conditions, impact areas, injury indices, etc. Experimental testing platforms are outlined thoroughly for different types of VRU impacts. Third, virtual test systems for VRU protection are introduced by including multi-body system model, finite element analysis (FEA) model, and hybrid/coupling model. Fourth, a range of front-end structure designs are discussed comprehensively for reducing VRU injuries as reported in the literature. The contributions of front-end geometry and energy-absorption space on the impact responses of the head and lower extremity/pelvis of VRU are assessed. The passive and active protection designs of frontal structures, such as engine hood and bumper, are appraised in detail. A range of design optimization techniques are reviewed to highlight their effectiveness for reducing the injury of VRU. In addition, other protective measures for VRU are briefly introduced, such as helmet, wearable airbag, automatic emergency braking (AEB) system, automatic emergency steering (AES) system and Vehicle-to-Everything (V2X). Finally, concluding remarks and outlooks are provided for the future research and development on VRU protection. [Display omitted] • Injury mechanism and criteria of head, thorax and lower extremity. • Different safety regulations and assessment procedures involving VRU protection. • Experimental and virtual test platforms for different types of VRU impacts. • Design criteria and procedures for reducing VRU injuries. • Wearable devices and intelligent connecting technology for VRU protection. [ABSTRACT FROM AUTHOR]

This study evaluated the biofidelity of the WorldSID and the ES-2re under whole-body side impact conditions with and without a side airbag using the biomechanical cadaveric response data generated from 4.3 m/s whole-body side impact tests. Impact forces, spinal kinematics, and chest deflections were considered in the biofidelity evaluation. Average responses and response corridors of PMHS were created using a time-alignment technique to reduce variability of the PMHS responses while maintaining the sum of the time shifts to be zero for each response. Biofidelity of the two dummies was compared using a correlation and analysis (CORA) method. The WorldSID demonstrated better biofidelity than the ES-2re in terms of CORA ratings in the conditions with airbag (0.53 vs. 0.46) and without an airbag (0.57 vs. 0.49). Lastly, the kinematic analysis of the two dummies indicated an overly compliant shoulder response of the WorldSID and excessive forward rotation of the ES-2re relative to the PMHS. [ABSTRACT FROM AUTHOR]

Abstract: While belt usage among rear-seat passengers is disproportionately lower than their front-seat counterpart, this may have serious consequences in the event of a crash not only for the unbelted rear-seat passenger but also for the front-seat passengers as well. To quantify that effect, the objective of the study is to evaluate the increased likelihood of driver fatality in the presence of unrestrained rear-seat passengers in a severe frontal collision. U.S.-based census data from 2001 to 2009 fatal motor vehicle crashes was used to enroll frontal crashes which involved 1998 or later year vehicle models with belted drivers and at least one adult passenger in the rear left seat behind the driver. Results using multivariate logistic regression analysis indicated that the odds of a belt restrained driver sustaining a fatal injury was 137% (95% CI=95%, 189%) higher when the passenger behind the driver was unbelted in comparison to a belted case while the effects of driver age, sex, speed limit, vehicle body type, airbag deployment and driver ejection were controlled in the model. The likelihood of driver fatality due to an unrestrained rear left passenger increased further (119–197%) in the presence of additional unrestrained rear seat passengers in the rear middle or right seats. The results from the study highlight the fact that future advances to front row passive safety systems (e.g. multi-stage airbag deployment) must be adapted to take into account the effect of unrestrained rear-seat passengers. [Copyright &y& Elsevier]

Abstract: Introduction: In the U.S. alone, an estimated 30,000 knee–thigh–hip (KTH) injuries occur annually in frontal motor vehicle collisions. These fractures typically occur through occupant contact with the vehicle''s knee bolster. Research has suggested that knee airbags (KABs) can mitigate the forces sustained during this contact, resulting in decreased injury risk; however, previous research has been limited by small sample sizes or by occurring in a controlled setting. The objective of the current study is to determine the effectiveness of KABs on KTH fracture risk using nationally representative, real-world data. Methods: Using combined data from the Crash Injury Research and Engineering Network and the National Automotive Sampling Survey, a matched cohort study was conducted among front-seat occupants of vehicles involved in a frontal collision occurring from 2000 to 2009. Occupants exposed to a KAB deployment were matched to occupants with no KAB deployment based on age ±5 years, sex, seatbelt use, vehicle seating position (i.e., driver or front passenger), car vehicle body type, collision impact, and sampling weight. A Cox proportional hazards model was used to calculate risk ratios (RRs) and associated 95% confidence intervals (95% CI) to estimate the association between KAB deployment and lower extremity fracture risk. Results: There was no association between KAB deployment and risk of lower extremity fracture (RR 0.83, 95% CI 0.52–1.31). A notable pattern in fracture risk, though not statistically significant, was observed, with a decreased risk of hip (RR 0.72, 95% CI 0.26–1.97) and thigh fracture (RR 0.81, 95% CI 0.32–2.05), and an increased risk of tibia/fibula (RR 1.23, 95% CI 0.52–2.90) and foot fracture (RR 1.96, 95% CI 0.72–5.32). Conclusions: The results of the current study suggest that KABs are not associated with the risk of lower extremity fractures. However, given the small sample size of the current study, it is difficult to definitively say whether the observed injury pattern is representative of the true pattern. [Copyright &y& Elsevier]

Abstract: Against problems in terms of stability, airtightness and so on of current fast sealing airbag, stability and airtightness of fast sealing airbag in simulating tunnel was studied through combining theoretical analysis and experiment. The ideal viton material is finally found after comparing and analyzing heat resistance, flame resistance, wear resistance, hardness and air permeability of different kinds of rubber. Sealing and wind blocking effects of airbags made from selected material are tested in simulating tunnel. Rate of air leakage and changing rate of wind pressure of each kind of rubber are also determined and further verified, with result that both indexes of viton material are the least, respectively only 4.25% and 4.66%. [Copyright &y& Elsevier]

Abstract: Airbag-based methods for crew impact attenuation have been highlighted as a potential simple, lightweight means of enabling safe land-landings for the Orion Crew Exploration Vehicle, and the next generation of ballistic shaped spacecraft. To investigate the feasibility of this concept during a nominal 7.62m/s Orion landing, a full-scale personal airbag system 24% lighter than the Orion baseline has been developed, and subjected to 38 drop tests on land. Through this effort, the system has demonstrated the ability to maintain the risk of injury to an occupant during a 7.85m/s, 0° impact angle land-landing to within the NASA specified limit of 0.5%. In accomplishing this, the personal airbag system concept has been proven to be feasible. Moreover, the obtained test results suggest that by implementing anti-bottoming airbags to prevent direct contact between the system and the landing surface, the system performance during landings with 0° impact angles can be further improved, by at least a factor of two. Additionally, a series of drop tests from the nominal Orion impact angle of 30° indicated that severe injury risk levels would be sustained beyond impact velocities of 5m/s. This is a result of the differential stroking of the airbags within the system causing a shearing effect between the occupant seat structure and the spacecraft floor, removing significant stroke from the airbags. [Copyright &y& Elsevier]

Abstract: To overcome the disadvantage of existing fast airtight devices, a latest-model airbag type fast airtight device was devised. Operating principle, structure and installation procedure of the device are presented in detail. Based on related technical parameters of return airway section on working face 15108 of Shi Gang Coal Mine, ANSYS analysis model was created. With a certain pressure and temperature condition, stress and strain in x, y and z directions of the airbag were calculated and the results proved the feasibility of the design proposal. Through field test and analysis of experiment results, the advantage and disadvantage of the latest-model fast airtight device were summarized, in hope to offer some inspiration to the development of airbag type mine airtight device. [Copyright &y& Elsevier]

Abstract: An airbag is composed of a housing assembly, door assembly, cushion assembly, and an inflator. The inflator is an essential part that generates gas for the airbag. When an airbag is activated, it effectively absorbs the crash energy of the passenger by inflating a cushion. In the present study, tank tests were performed with newly synthesized propellants with various compositions, and the results are compared with the numerical results. In the simulation of the inflator, a zonal model has been adopted which consisted of four zones of flow regions: combustion chamber, filter, gas plenum, and discharge tank. Each zone was described by the conservation equations with specified constitutive relations for gas. The pressure and temperature of each zone of the inflator were calculated and analyzed, and the results were compared with the tank test data. The similarity of the pressure curve and closed bomb calculation show that the modeled results are well correlated with the experimental data. [Copyright &y& Elsevier]

Abstract: This paper considers pre-impact vehicle maneuvers and analyzes the resulting driver motion from their comfort seating position. Part I of this work consisted of analyzing the driver behavior during a simulated crash in a car driving simulator. The configuration of the virtual accident led to an unavoidable frontal crash with a truck. The typical response to this type of emergency event was to brace rearward into the seat and to straighten the arms against the steering wheel, or, to swerve to attempt to avoid the impacting vehicle. In a turn crossover maneuvers, the forearm is directly positioned on the airbag module at time of crash. This position represents a potential injurious situation and is investigated in this Part II. Static airbag-deployment tests were realized in collaboration with Zodiac using conventional airbag (sewn cushion, pyrotechnical system and open event) and a Hybrid III 50th Male Dummy seated with the left arm positioned in the path of the deploying airbag. These experiments were numerically reproduced with Madymo® and the ellipsoid Hybrid III dummy model. The dummy arm interaction with airbag was correlated with experiments. Then, a numerical simulation of a frontal collision at 56km/h was realized. The results of the computational runs put forward injurious situations when the driver''s arm was in front of the steering wheel. Indeed, in this case, the arm could hit the head under airbag deployment and induced serious neck bending and violent head launching. To mitigate head and neck trauma in this out-of-position situation, an airbag prototype (bonded cushion, two pure helium cold gas generators allowing mono- or multi-stage inflating, patented silicone membrane) was proposed by Zodiac. The results of static airbag-deployment tests with conventional and prototype airbags showed a significant reduction of the maximum linear head acceleration and neck bending with airbag prototype when a dual stage inflating was ignited, due to a reduced ‘flinging’ of the arm. [Copyright &y& Elsevier]

Abstract: This paper presents an application of stochastic Petri nets (SPN) to calculate the availability of safety critical on-demand systems. Traditional methods of estimating system reliability include standards—based or field return-based reliability prediction methods. These methods do not take into account the effect of fault-detection capability and penalize the addition of detection circuitry due to the higher parts count. Therefore, calculating system availability, which can be linked to the system''s probability of failure on demand (P fd), can be a better alternative to reliability prediction. The process of estimating the P fd of a safety system can be further complicated by the presence of system imperfections such as partial-fault detection by users and untimely or uncompleted repairs. Additionally, most system failures cannot be represented by Poisson process Markov chain methods, which are commonly utilized for the purposes of estimating P fd, as these methods are not well-suited for the analysis of non-Poisson failures. This paper suggests a methodology and presents a case study of SPN modeling adequately handling most of the above problems. The model will be illustrated with a case study of an automotive electronics airbag controller as an example of a safety critical on-demand system. [Copyright &y& Elsevier]

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Abstract: The aim of this work is to develop a stable and fast algorithm for simulation of an airbag deployment. The mechanical structure problem is solved with commercially available finite element software. A 3D Navier–Stokes code for compressible fluids is developed to solve the fluid mechanic problem. For reasons of stability, a fixed rectangular grid is used. The contour adjustment is achieved by blocking off the outer cells, which can be switched on or off as the airbag surface passes by. To provide a conservative system during the contour adjustment, a method for the handling of the boundary was developed. [Copyright &y& Elsevier]

Abstract: An experimental study was conducted to evaluate the ignitibility of a family of potential gas-generator solid propellants under different CO2 laser heat fluxes and chamber operating conditions. Six types of solid propellant were tested: one baseline and five variations. The ingredients of the baseline propellant were ammonium nitrate, guanidine nitrate, potassium nitrate, and polyvinyl alcohol. The other five propellant variations were obtained by adding different amounts of carbon black, ammonium perchlorate, RDX, and triamino guanidine nitrate to the baseline formulation. The propellants were tested in a high-pressure windowed strand burner, which was pressurized with either air or argon purge gases. Propellant ignition was accomplished by a 50-W CO2 laser. The ignition delay times of the propellants were measured at pressures of 1 and 69atm using high-speed video cameras. In this paper, the test results and comparison of the ignition and combustion characteristics of these propellants were presented. [Copyright &y& Elsevier]

Abstract: The installation of airbags in motor vehicles, in association with the use of seat belts, has reduced the incidence of head injuries, as well as significantly decreasing morbidity and mortality in motor vehicle accidents. Nevertheless, the literature on the subject increasingly refers to lesions related to airbag deployment. These are usually minor, but in certain circumstances, severe and fatal injuries can result. This is a case report of serious injury due to airbag deployment, involving a restrained driver who suffered occipital condylar injury when his airbag deployed in a frontal collision. The range of airbag associated injuries is reported and predisposing factors, such as the probable proximity to the airbag housing, is discussed. [Copyright &y& Elsevier]

Abstract: An experimental investigation on the determination of ballistic properties and burning behavior of a composite solid propellant for airbag application was conducted. The experimental results were obtained using a high-pressure optical strand burner. Steady-state burning rates were determined for a pressure range of 20.8–41.5MPa and initial propellant temperatures of −30 to +80°C. For the pressure and temperature ranges tested, the temperature sensitivity was on the order of 1×10−3 K−1. The pressure exponent was found to be a function of the initial propellant temperature and was 0.75 at 25°C. The activation energy and the pre-exponential factor of the Arrhenius equation are 2.735kcal/mol and 15.06cm/s, respectively. The pressure deflagration limit for this propellant was found to be in the range of 8.37–8.72MPa. During combustion, small condensed-phase spherical particles were ejected from the burning surface. The size of the particles decreased with either increasing the pressure or the initial propellant temperature. For pressures below 41.4MPa, average particle size was on the order of 900μm, and at 84.4MPa, the bead size was much smaller, on the order of 300μm. A chemical analysis on these particles using both the ESEM and the X-ray diffraction method indicated that the material of the beads was mostly sodium chloride with a small amount of silicon-containing compounds. [Copyright &y& Elsevier]

Abstract: Automotive airbags are now a widely accepted safety measure designed to reduce morbidity associated with motor vehicle accidents. Their usage is increasing with multiple airbags (driver, passenger and side curtain) being fitted to many vehicles. However the deployment of airbags has been identified as causing injuries in some instances including minor burns. There are three mechanisms for thermal burns due to an airbag; contact with the hot expelled gases from the airbag, contact with the hot airbag itself and melting of clothing from either of these contacts. A mathematical model is used here to predict the likelihood and severity of the first two types of burns. It is shown that direct contact with high temperature exhaust gases venting from the airbag can indeed lead to burns and that burns from contacting the hot airbag material are possible but far less likely to occur. [Copyright &y& Elsevier]

Providing new generations of airbags with reliable information about the vehicle inner space occupancy in order to minimize inappropriate inflation is a real challenge. Within this paper two techniques to rebuilt the 3D cockpit scene, are presented; beside the well-known stereoscopic vision principles, 3D reconstruction based on matricial sensor combined with an infrared structured light emitter is described. From the 3D points acquired by these sensors a 3D description of the seat area is built, pertinent attributes are extracted, and using a previously learnt data base, the current seat situation is identified amongst the learnt situations (empty seat, baby seat in normal or rear position, occupant, ...). First promising results are depicted. [Copyright &y& Elsevier]

The mechanisms of injury of the human neck are potentially related to the forces and bending moments acting on the spinal column. An injury criterion that combines the effects of the time history of force and moment, Nij, has been adopted by the USA federal government for vehicle crash regulations. This paper presents two analytical approaches to evaluate the Nij injury criterion using previously published biomechanical data: a direct fit optimization analysis and a statistical analysis. The results show that no values used in the Nij criterion corresponding to compressive force, extension moment and flexion moment will optimally separate the injury and non-injury cases in the biomechanical data set. Only the tensile force allows identification of the injury risk. All indications are that increasing the weight given to moment decreases the accuracy of the prediction. [Copyright &y& Elsevier]

The purpose of this study is to test the hypothesis that the upper cervical spine is weaker than the lower cervical spine in pure flexion and extension bending, which may explain the propensity for upper cervical spine injuries in airbag deployments. An additional objective is to evaluate the relative strength and flexibility of the upper and lower cervical spine in an effort to better understand injury mechanisms, and to provide quantitative data on bending responses and failure modes. Pure moment flexibility and failure testing was conducted on 52 female spinal segments in a pure-moment test frame. The average moment at failure for the O-C2 segments was 23.7±3.4 N m for flexion and 43.3±9.3 N m for extension. The ligamentous upper cervical spine was significantly stronger in extension than in flexion (p=0.001). The upper cervical spine was significantly stronger than the lower cervical spine in extension. The relatively high strength of the upper cervical spine in tension and in extension is paradoxical given the large number of upper cervical spine injuries in out-of-position airbag deployments. This discrepancy is most likely due to load sharing by the active musculature. [Copyright &y& Elsevier]

A prior investigation by the authors demonstrated that incorporating 25% of copper complex (Cu(NH 3) 4 (NO 3) 2) into Al/CuO nanothermite enables to produce highly-reactive gas-generating energetic composites for emerging micro-airbag applications. To further improve the decomposition of the copper complex into gaseous species (N 2 , O 2 , N 2 O), during the thermite reaction, we employed ball milling technique to diminish its grain size down to the nanoscale. Results show that premilling the copper complex i.e. refining its grains without much modifying their structures, increases the pressure generation and burn rate by a factor 1.5 and 2, respectively. It also maintains a high degree of performances along with a wider range of thermite to copper complex mass ratio. [ABSTRACT FROM AUTHOR]

The installation of airbags as standard equipment in modern cars, combined with the use of seat belts, has reduced the severity of crash-related injuries. However, new airbag-related maxillofacial injuries directly associated with airbag deployment raise questions about the potential dangers of these devices when they operate improperly. Here, we report a rare case of a patient who sustained a mid-facial injury, including a naso-orbital-ethmoid fracture, due to an airbag that inflated improperly when the driver placed her hand on the car's horn switch. The airbag was thought to be deployed following the crash at the same timing of sounding the horn. [ABSTRACT FROM AUTHOR]

Workers in different industrial sectors, mainly in the construction and energy areas, face the daily risky situation of falling from the height accidentally, even wearing safety harnesses. To actively protect workers, a safety jacket is proposed. The jacket is equipped with an airbag cushion and an inertial measurement unit, located on the back, to sense the body motion hl. An algorithm deploys the airbag automatically for falls from heights greater than 1 m, leaving enough time for the airbag to be fully inflated. The proposed algorithm is tested and validated against experimental data collected during real falls performed by a professional stuntman, and during months of daily routine workers' life. Particular attention is devoted to the calibration of the tuning parameters, with the aim of the best trade-off between false positives' minimization, reactiveness, and robustness. • The article presents a new innovative algorithm for the triggering, before the impact with the ground, of an airbag for workers falling from heights (> 1 m). • The airbag triggering algorithm is very simple and inexpensive, using only , using only accelerations sampled at 400 Hz and recorded by a triaxial waist IMU. • The detection algorithm is based on a new 5-step accelerations' manipulation: • Filtering • Total acceleration norm computation • Gravity debiasing • Falling speed computation • Impact speed thresholding • Calibration of filters and speed thresholding has been achieved with stuntmen falls. Airbag validation ensured with 500 activity hours of 20 real workers thresholding has been achieved. • Special care has been devoted to minimizing false positives. The algorithm cannot operate properly with intense vibrations or on vehicles. [ABSTRACT FROM AUTHOR]

Abstract: Purpose: To report a case of airbag induced corneal ectasia. Methods: Case report. Results: A patient 3 years post-LASIK developed bilateral corneal ectasia worse in the right eye following airbag deployment in a road traffic accident. At last follow up, best corrected vision was 20/40 with −4.00/−4.00×25 in the right eye and 20/25 with −1.25/−0.50×135 in the left eye. Conclusions: This is a rare presentation of trauma induced ectasia in a patient post-LASIK. It is possible that reduction in biomechanical integrity of the cornea from prior refractive surgery contributed to this presentation. [Copyright &y& Elsevier]

Abstract: Purpose: To describe a case of airbag-induced corneal flap in a previously normal cornea. Methods: Case report. Results: A 27-year-old woman presented with complete loss of vision in her left eye following a road traffic accident which involved airbag deployment. There was no previous ocular history. Examination revealed a large corneal flap of 6mm in diameter, extending to the depth of anterior stroma. This was accompanied by a traumatic optic neuropathy. One month follow-up revealed complete reattachment of the corneal flap. Conclusions: This is the first reported case of a corneal flap induced by airbag deployment in a cornea with previously normal architecture. [Copyright &y& Elsevier]