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Viewing 1 to 30 of 3411
2011-04-12
Technical Paper
2011-01-0271
Rami Mansour, Douglas Romilly
Rear end collisions account for approximately $9 billion annually in the United States alone. These types of collisions account for nearly 30% of all vehicle impacts making them the most common type. Soft tissue injury to the neck (i.e. “whiplash”) is typically associated with this type of collision due to the occupant dynamics of the passengers in the struck vehicle. At low relative impact velocities, whiplash-type injuries are known to occur but are typically attributed to: 1) improper seat adjustment, 2) an “out-of-position” event, or 3) a low injury threshold due to age, gender, etc. In high impact collisions, both whiplash and occupant ejection can take place, the latter placing far greater risk of injury not only to the front seat occupant, but also to any rear seat passengers as well. The automobile seating system is the predominant safety device employed to protect the occupant during these types of collisions.
2011-04-12
Technical Paper
2011-01-0276
Si-Woo Kim, So-Jung shim, Myung-Won Suh
A large study of rear-end collisions was conducted for the neck injury indicators and test procedures. Neck injury in low-speed rear-end collisions is a big issue because there are a lot of patients despite low-speed rear-end collisions. Europe, Korea and Japan introduced the specific part in the New Car Assessment Program to reduce whiplash injury in low-speed rear-end collisions. From the legal point of view, to reduce the frequency and severity of injuries caused by rearward displacement of the head in rear-end collision, USA, EC, Korea, Japan and others internationally cooperated to make the global technical regulation (GTR) in UNECE/WP29. In 2008, after much meandering, GTR No. 7 head restraints were established. However the GTR No.7 is not a unique regulation because many countries had their own opinions and domestic regulations, and many questions related to injury criteria and biomechanical issues of dummy remain unresolved.
2011-04-12
Journal Article
2011-01-0273
Jeffrey Braganza, Massoud S. Tavakoli, Janet Brelin-Fornari
The rear seat occupant has been the subject of an increasing number of research efforts in recent years. However, the majority of the research has focused on frontal impact, while there are also a number of studies concerned with low to moderate delta-V rear impact. Very limited work exists regarding the fate of the rear seat occupant involved in high-severity rear impact, especially when utilizing the BioRID anthropomorphic test device (ATD). Furthermore, it is evident that the out of position rear occupant, as defined by leaning forward prior to rear impact, is also of relevance to this line of research. The objective of this study is to explore and compare the response of BioRID and 50 th percentile Hybrid III in conjunction with the effects of head restraint geometry and the occupant seating configuration (normal seating versus forward leaning) in high-severity rear impact tests.
2011-04-12
Technical Paper
2011-01-0274
David C. Viano
Purpose: This study presents cases of fracture-dislocation of the thoracic spine in extension during severe rear impacts. The mechanism of injury was investigated. Methods: Four crashes were investigated where a lap-shoulder-belted, front-seat occupant experienced fracture-dislocation of the thoracic spine and paraplegia in a severe rear impact. Police, investigator and medical records were reviewed, the vehicle was inspected and the seat detrimmed. Vehicle dynamics, occupant kinematics and injury mechanisms were determined in this case study. Results: Each case involved a lap-shoulder-belted occupant in a high retention seat with ≻1,700 Nm moment or ≻5.5 kN strength for rearward loading. The crashes were offset rear impacts with 40-56 km/h delta V involving under-ride or override by the impacting vehicle and yaw of the struck vehicle. In each case, the occupant's pelvis was restrained on the seat by the open perimeter frame of the seatback and lap belt.
2010-04-12
Journal Article
2010-01-0516
Michelle F. Heller, William N. Newberry, Janine E. Smedley, Senthil K. Eswaran, Jeffrey J. Croteau, Michael R. Carhart
Rollover events involving multiple revolutions are dynamic, high-energy, chaotic events that may result in occupant injury. As such, there is ongoing discussion regarding methods that may reduce injury potential during rollovers. It has been suggested that increasing a vehicle's roof strength will mitigate injury potential. However, numerous experimental studies and published field accident data analyses have failed to show a causal relationship between roof deformation and occupant injury. The current study examines occupant kinematics and injury mechanisms during dolly rollover testing of a vehicle with a high roof strength-to-weight ratio (SWR = 4.8). String potentiometers and high-speed video cameras were used to capture and quantify the dynamic roof motion throughout the rollover. Instrumented Anthropomorphic Test Devices (ATDs) in the front occupant positions allowed for the assessment of occupant kinematics, loading, and injury mechanics during the rollover event.
2011-04-12
Technical Paper
2011-01-0014
Yuji Fujiyama, Daisuke Sonoyama, Kazuhiro Obayashi, Qiang Yu PhD
Evaluations of dummy injury readings obtained in regulatory crash tests and new car assessment program tests provide indices for the development of crash safety performance in the process of developing new vehicles. Based on these indices, vehicle body structures and occupant restraint systems are designed to meet the required occupant injury criteria. There are many types of regulatory tests and new car assessment program tests that are conducted to evaluate vehicle safety performance in side impacts. Factoring all of the multiple test configurations into the development of new vehicles requires advanced design capabilities based on a good understanding of the mechanisms producing dummy injury readings. In recent years, advances in computer-aided engineering (CAE) tools and computer processing power have made it possible to run simulations of occupant restraint systems such as side airbags and seatbelts.
2011-04-12
Technical Paper
2011-01-0013
June-Young Song, Kangwook Lee, Byung-Jae Ahn
The main role of CAB(side curtain airbag) is to protect the occupant's head in the event of side crash. The updated US NCAP for model year 2010 requires more extended coverage of CAB. It is not only required to cover the 50th%ile driver but also the 5th%ile driver and rear passenger. Although the general safety analysis model using only concerned sub-structure of the vehicle and prescribed structural motion is sufficient to handle frequent jobs, the analysis model with increased efficiency is needed when optimization is to be studied as it requires more runs and the model gets enlarged to consider extended sub-structure. In this study, three types of simplified analysis models are introduced. The first has an impactor which is composed of the head and neck with prescribed translational motions. It only uses the upper parts of the original sub-structure hence the run time is saved by 60∼70%.
2011-04-12
Technical Paper
2011-01-0203
Steve Thorne, Bruce W. Leppla
ACC radar systems gather valuable data about the speed of forward vehicles, and then utilize that information to best regulate the spacing between those forward vehicles and the ACC host. However, such radar-gathered data can also be useful to help prevent rear-end collisions involving the host vehicle. Embedded in that data is information revealing decelerations of forward vehicles that holds particular value to any driver that might be trailing the host vehicle - especially if their vision is screened by the bulk of the host vehicle. In this paper, a hybrid stop lamp system is proposed whereby ACC radar data gathered by a host vehicle is automatically conveyed to the trailing driver utilizing a new light element integrated with the host vehicle's stop lamp system.
2011-04-12
Journal Article
2011-01-0104
Yoshinori Tanaka, Hideki Yonezawa, Naruyuki Hosokawa, Yasuhiro Matsui
Accident data show that the head and the chest are the most frequently injured body regions in side impact fatal accidents. Curtain side air bag (CSA) and thorax side air bag (SAB) have been installed by manufacturers for the protection devices for these injuries. In this research, first we studied the recent side impact accident data in Japan and verified that the head and chest continued to be the most frequently injured body regions in fatal accidents. Second, we studied the occupant seating postures in vehicles on the roads, and found from the vehicle's side view that the head location of 56% of the drivers was in line or overlapped with the vehicle's B-pillar. This observation suggests that in side collisions head injuries may occur frequently due to contacts with the B-pillar. Third, we conducted a side impact test series for struck vehicles with and without CSA and SAB.
2011-04-12
Technical Paper
2011-01-0107
Yan Fu, Guosong Li, Ren-Jye Yang, Baohua xiao, Krishnakanth Aekbote
With the increasing demands of developing vehicles for global markets, different regulations and public domain tests need to be considered simultaneously for side impact. Various side impact countermeasures, such as side airbags, door trim, energy absorbing foams etc., are employed to meet multiple side impact performance requirements. However, it is quite a challenging task to design a balanced side impact restraint system that can meet all side impact requirements for multiple crash modes. This paper presents an integrated multi-objective optimal design and robustness assessment framework for vehicle side impact restraint system design.
2011-04-12
Journal Article
2011-01-0579
Eric Raphael, Raymond Kiefer, Pini Reisman, Gaby Hayon
Forward Collision Alert (or Forward Collision Warning) systems provide alerts intended to assist drivers in avoiding or mitigating the harm caused by rear-end crashes. These systems currently use front-grille mounted, forward-looking radar devices as the primary sensor. In contrast, Lane Departure Warning (LDW) systems employ forward-looking cameras mounted behind the windshield to monitor lane markings ahead and warn drivers of unintended lane violations. The increasing imaging sensor resolution and processing capability of forward-looking cameras, as well recent important advances in machine vision algorithms, have pushed the state-of-the-art for camera-based features. Consequently, camera-based systems are emerging as a key crash avoidance system component in both a primary and supporting sensing role. There are currently no production vehicles with cameras used as the sole FCA sensing device.
2011-04-12
Technical Paper
2011-01-0587
Scott Geisler, Michelle Michelini
This paper describes how information available through the OnStar system represents a unique and powerful mechanism to assess field crash rates. Included within is a description of how vehicle and OnStar information may be gathered, organized and analyzed. The resulting data provides the capability to conducts various studies of field activity and/or events. In this case, a study was conducted to try to determine if certain vehicle equipment might have an impact on field crash rates. The process is exemplified via a description of a study conducted by GM OnStar in 2009. Two analyses were conducted comparing crash rates of selected vehicle models, with and without certain advanced safety sensing and warning features. Specifically, beginning in the 2008 Model Year, General Motors introduced Lane Departure Warning and Side Blind Zone Alert into US/Canada production. Utilizing data on crashes, drawn from OnStar Automatic Crash Response events, analyses of crash rates were conducted.
2011-04-12
Technical Paper
2011-01-0544
Dinesh Mana, Dhanendra Nagwanshi, Matthew Marks, Arunachala P
High repair cost and the subsequent increase in insurance cost in a highly competitive automobile market have forced every automobile original equipment manufacturer (OEM) to comply with the FMVSS and ECE-42 regulatory requirements of low-speed vehicle damageability. Although, the terminologies used are different, similar regulatory requirements also exist in Asia-pacific region. At the rear side, reducing the damage to expensive vehicle components in a low-speed pendulum impact or a low-speed barrier impact can attain a good rating for low-speed vehicle damageability. This paper focuses on a detailed study of various lightweight plastic rear beam designs and their effectiveness in reducing the damage to the vehicle during low-speed vehicle-to-vehicle collision or vehicle to barrier collision.
2011-04-12
Journal Article
2011-01-0545
Joerg Bakker, Christian Sachs, Dietmar Otte, Rainer Justen, Lars Hannawald, Flavio Friesen
The potential impact of real world accident scenarios on fuel cell vehicles equipped with a compressed hydrogen storage system is analyzed from a component point of view. Even though hydrogen compressed gas tanks can sustain very high loads, in this study a simplification is made. It is investigated to what extent different real world accident scenarios with conventional vehicles have caused deformation of the vehicle in the area where a hydrogen tank would have been integrated in a fuel cell vehicle. The study is based on accident data from the GIDAS (German In-Depth Accident Study) database. Deformation matrices for each passenger car in the database are defined over a deformation grid largely independent of vehicle type and shape. The matrices are combined to statistically analyze the occurrence of deformations in selected regions of a vehicle.
2013-04-08
Technical Paper
2013-01-0805
John J. Christopher, Mark R. Sochor, Joseph Pellettiere, Robert Scott Salzar
Monitoring head accelerations as an indicator of possible brain injury may lead to faster identification of injury and treatments. This study investigates the skull-coupling of a tri-axial accelerometer mounted to a back molar and compares it with a tri-axial accelerometer inserted in the boney ear canal. These tri-axial accelerometers were mounted to three post mortem human surrogate (PMHS) skulls, and compared with a rigid, skull-mounted laboratory sensor reference cube. Each specimen was subjected to both a high-g loading from a vertical drop tower and a low frequency cyclic loading from a shaker device. The specimens were subjected to an approximate 150g input acceleration on the drop tower, and up to 10g at a frequency of 9Hz on the shaker device. Each specimen was tested on all three of the anatomical axes on both the drop tower and the cyclic shaker.
2013-04-08
Journal Article
2013-01-0800
John Patalak, Thomas Gideon
Over the last twenty years, large improvements in occupant safety have been made in NASCAR®'s (National Association for Stock Car Auto Racing, Inc.) racing series. While proper occupant protection requires both occupant restraint and preservation of sufficient occupant survival space, this study is focused mainly on the latter of these two necessities. The NASCAR tubular vehicle chassis has evolved through the years to provide improved protection for the driver in rollover incidents. The chassis has continued to progress over time to improve its strength as unique crashes sometimes highlighted opportunities for advancement. Recent enhancements tested using computer modeling, quasi-static testing, and full scale drop tests have improved the roof structure of the stock car chassis. These improvements have been incorporated into the 2013 NASCAR Sprint Cup and Nationwide Series cars.
2013-04-08
Technical Paper
2013-01-1260
Paul Freeman, Sameer Samant, John R. Wagner, Kim Alexander, Philip Pidgeon
Despite the growing acceptance of driver education programs, there remains a class of unpredictable and dangerous vehicle situations for which very little training or education is offered. Included in this list is a condition called run-off-the-road (ROR) which occurs when the wheels of the vehicle leave the paved surface of the road and begin to travel on the lower friction surfaces of the shoulder or side of the road. Unsuccessful recovery from ROR contributes to an overwhelming percentage of motorized vehicle crash fatalities and injuries. Most present solutions involve roadway infrastructure management and driver assistance systems. While these solutions have contributed varying amounts of success to the ROR problem, they remain limited as they do not directly address the critical cause of ROR crashes which is driver performance errors.
2013-04-08
Technical Paper
2013-01-1246
Bhavesh Prabhulal Gangani, Anil Vidye
Improvised Explosive Devices (IEDs) and Anti-Tank (AT) mines are a significant threat for military vehicles and their occupants. These explosive devices are designed for the destruction and damage of armored and other vehicles, by using them in battle fields on routes of army vehicles. The blast event results in effects like shockwave, fragments, fire, gases, blast overpressure as well as the vertical impulse load. A blast event affects occupants inside the vehicle in the form of various types of injuries (lower leg, spinal, chest, head etc) and trauma. The Lower leg is the foremost injured body region in a blast event. The term lower leg is used to designate the tibia, fibula and the foot/ankle complex in this paper. Detonations occurring under a vehicle produce high velocity floorboard flutter/deformation and transmit axial loads to lower leg and create injuries.
2013-04-08
Journal Article
2013-01-1268
Craig Wilkinson, Jonathan Lawrence, Tim Nelson, James Bowler
Collision related data stored in the airbag control modules (ACM's) of Toyota vehicles can provide useful information to collision investigators, including both front and rear collision severity. Previous studies of ACM's from other manufacturers found that the devices underestimated the actual speed change in low speed frontal collisions. To quantify the accuracy and sensitivity of select 2005 to 2008 Toyota ACM's, in-vehicle crash tests and linear sled tests were performed in both front and rear impact orientations. A 2005 Toyota Corolla with five extra ACM's mounted in the right front seat position underwent a series of vehicle-to-barrier collisions with speed changes of up to 10 km/h. Next, the same six Toyota ACMs underwent a range of crash pulses using a linear sled. In all in-vehicle tests, the speed change reported by the ACM underestimated the actual speed change for frontal collisions, and overestimated the actual speed change for rear-end collisions.
2013-04-08
Technical Paper
2013-01-1162
Mauro Velardocchia, Michiel Unger, Alessandro Vigliani, Nicola Leone, Kajetan Kietlinski, Enrico Galvagno
The paper presents a simulation methodology created to support an integrated safety system development process which was tested for the side impact collision load case. The methodology is based on the coupled and complementary use of two software packages: PreScan and Madymo. PreScan was utilized for designing two traffic scenarios and the sensing and control systems for the side collision recognition, while Madymo was utilized for assessing the effects of pre-crash deployment of thorax airbag. The collision conditions from the scenarios were used as input to define a Madymo side collision model of the host vehicle and to investigate and optimize several airbag deployment parameters: pre-crash deployment time, airbag permeability, vent hole size and vent hole opening time.
2013-04-08
Technical Paper
2013-01-1160
Libo Cao, Ruifeng Zhang, Huiqin Chen, Xianyang Zhao
Child Restraint Systems (CRS), when used properly, can effectively avoid or reduce injury for children in motor vehicle crashes. To deal with the problems of the high rate of misuse of the CRS and submarining in frontal crashes when child occupants using traditional vehicle seat belts, a novel integrated child safety seat (ICSS) with a four-point seat belt and a ring-shaped lap belt was developed in this study. It is easy to operate and has lower rate of misuse. To study the protection performance of the newly developed ICSS in frontal crashes, a sled test and a series of simulations were conducted. The frontal impact sled test was conducted according to the European regulation ECE R44, which includes a Q6 anthropomorphic test device (ATD) and the impact velocity is 50 km/h. The simulation model included the ICSS model and the Q6 ATD model was developed in the MADYMO software, and the simulation model was validated by the sled test.
2013-04-08
Technical Paper
2013-01-1242
Yasuhiro Dokko, Toshiyuki Yanaoka, Kazuki Ohashi
Corresponding to the increasing need for the protection of elderly people from traffic accidents, the authors have been developing age-specific human FE models capable of predicting body kinematics and skeletal injuries for younger adult (35y.o.) and the elderly (75y.o.). The models have been developed and validated part by part referring to the literature and then integrated into whole bodies. Validation had been conducted in order of single bones, components and whole body. Whole body kinematics in frontal impact had been validated against the PMHS frontal belt restrained sled tests series, resulting in good biofidelity scores. In this study, the models were validated for lateral impact. The models were validated against several impact tests of body regions from ISO-TR9790 and against recently published full scale lateral sled tests for whole body kinematics. In most cases, the results showed good biofidelity of the models.
2013-11-11
Technical Paper
2013-22-0005
Vishal Gupta, King H. Yang
Most studies of pedestrian injuries focus on reducing traumatic injuries due to the primary impact between the vehicle and the pedestrian. However, based on the Pedestrian Crash Data Study (PCDS), some researchers concluded that one of the leading causes of head injury for pedestrian crashes can be attributed to the secondary impact, defined as the impact of the pedestrian with the ground after the primary impact of the pedestrian with the vehicle. The purpose of this study is to understand if different vehicle front-end profiles can affect the risk of pedestrian secondary head impact with the ground and thus help in reducing the risk of head injury during secondary head impact with ground. Pedestrian responses were studied using several front-end profiles based off a mid-size vehicle and a SUV that have been validated previously along with several MADYMO pedestrian models.
2013-11-11
Technical Paper
2013-22-0003
David Poulard, François Bermond, Karine Bruyère
Thoracic injuries are a major cause of mortality in frontal collisions, especially for elderly female and obese people. Car occupant individual characteristics like age, gender and Body Mass Index (BMI) are known to influence human vulnerability tolerance in crashes. The objective of the this study was to perform in vivo test experiments to quantify the influence of subject characteristics in terms of age, gender and anthropometry and on thorax mechanical response variability under belt loading. Thirty-nine relaxed volunteers of different anthropometries, genders and age were submitted to non-injurious sled tests (4 g, 8 km/h) with a sled buck representing the environment of a front passenger restrained by a 3-point belt. A resulting shoulder belt force FRes was computed using the external and internal shoulder belt loads and considering shoulder belt geometry.
2013-11-11
Technical Paper
2013-22-0009
Sijia Zhang, Kristen J. Nicholson, Jenell R. Smith, Taylor M. Gilliland, Peter P. Syré, Beth A. Winkelstein
Both traumatic and slow-onset disc herniation can directly compress and/or chemically irritate cervical nerve roots, and both types of root injury elicit pain in animal models of radiculopathy. This study investigated the relative contributions of mechanical compression and chemical irritation of the nerve root to spinal regulation of neuronal activity using several outcomes. Modifications of two proteins known to regulate neurotransmission in the spinal cord, the neuropeptide calcitonin gene-related peptide (CGRP) and glutamate transporter 1 (GLT-1), were assessed in a rat model after painful cervical nerve root injuries using a mechanical compression, chemical irritation or their combination of injury. Only injuries with compression induced sustained behavioral hypersensitivity (p≤0.05) for two weeks and significant decreases (p<0.037) in CGRP and GLT-1 immunoreactivity to nearly half that of sham levels in the superficial dorsal horn.
2013-11-11
Technical Paper
2013-22-0010
Erik G. Takhounts, Matthew J. Craig, Kevin Moorhouse, Joe McFadden, Vikas Hasija
Rotational motion of the head as a mechanism for brain injury was proposed back in the 1940s. Since then a multitude of research studies by various institutions were conducted to confirm/reject this hypothesis. Most of the studies were conducted on animals and concluded that rotational kinematics experienced by the animal's head may cause axonal deformations large enough to induce their functional deficit. Other studies utilized physical and mathematical models of human and animal heads to derive brain injury criteria based on deformation/pressure histories computed from their models.
2013-11-11
Technical Paper
2013-22-0007
Becky Mueller, Charles Farmer, Jessica Jermakian, David Zuby
Pedestrian protection evaluations have been developed to encourage vehicle front-end designs that mitigate the consequences of vehicle-to-pedestrian crashes. The European New Car Assessment Program (Euro NCAP) evaluates pedestrian head protection with impacts against vehicle hood, windshield, and A-pillars. The Global Technical Regulation No. 9 (GTR 9), being evaluated for U.S. regulation, limits head protection evaluations to impacts against vehicle hoods. The objective of this study was to compare results from pedestrian head impact testing to the real-world rates of fatal and incapacitating injuries in U.S. pedestrian crashes. Data from police reported pedestrian crashes in 14 states were used to calculate real-world fatal and incapacitating injury rates for seven 2002-07 small cars. Rates were 2.17-4.04 per 100 pedestrians struck for fatal injuries and 10.45-15.35 for incapacitating injuries.
2013-11-11
Technical Paper
2013-22-0008
Yasuhiro Matsui, Shoko Oikawa, Kenichi Ando
The first purpose of this study is to clarify the relation between the car impact velocity and pedestrian injury severity or mortality risk. We investigated the frequency of serious injuries and fatalities of pedestrians using vehicle-pedestrian accident data from the database of the Institute for Traffic Accident Research and Data Analysis (ITARDA) in Japan. The vehicle types considered are sedans, minivans, and box vans (ordinary automobiles) and light passenger cars and light cargo vans (light automobiles). The results revealed that a 10-km/h reduction in impact velocity could mitigate severe pedestrian injuries in cases involving impact velocities of 40 km/h or more for the five vehicle types analyzed. Specifically, if the impact velocity was 30 km/h or less, the frequency of serious injuries was less than 27% and the frequency of fatalities was less than 5% for the five vehicle types.
2013-11-11
Technical Paper
2013-22-0011
Chantal S. Parenteau, Peter Ehrlich, Linda Ma, Grace L. Su, Sven Holcombe, Stewart C. Wang
Liver injuries can be significant in vehicle crashes. In this study, the liver anatomy was quantified in both adult and pediatric populations as a function of gender and age. Five anatomical liver measurements were determined using CT scans of 260 normal livers. These measurements include the area and volume, and the length, width, and girth of the liver (IRB HUM00041441). To characterize geometrical shape, an inscribed sphere and circumscribed ellipsoid were fitted on the measurements. In the pediatric population the liver area and volume continuously increased with age. When normalized by patient weight, volume measurements show a decrease in volume with age, suggesting that the liver occupies a smaller proportion of the body with age. In the adult population, liver measurements varied with gender. The superior and inferior locations of the liver were also recorded with respect to the spine. The lower portion was at the L3 in small children and at L2 as children approached puberty.
2013-11-11
Technical Paper
2013-22-0012
Yuan-Chiao Lu, Andrew R. Kemper, Scott Gayzik, Costin D. Untaroiu, Philippe Beillas
The liver is one of the most frequently injured abdominal organs during motor vehicle crashes. Realistic numerical assessments of liver injury risk for the entire occupant population require incorporating inter-subject variations into numerical models. The main objective of this study was to quantify the shape variations of human liver in a seated posture and the statistical distributions of its material properties. Statistical shape analysis was applied to construct shape models of the livers of 15 adult human subjects, recorded in a typical seated (occupant) posture. The principal component analysis was then utilized to obtain the modes of variation, the mean model, and 95% statistical boundary shape models. In addition, a total of 52 tensile tests were performed on the parenchyma of three fresh human livers at four loading rates (0.01, 0.1, 1, and 10 s−1) to characterize the rate-dependent and failure properties of the human liver.
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