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Dynamic Response Index
The Dynamic Response Index (DRI) is a measure of the likelihood of spinal damage arising from a vertical shock load such as might be encountered in a military environment (i.e., during a mine blast, or in an ejection seat). The DRI is a dimensionless number which is proportional to the maximum spinal compression suffered during the event. The DRI is derived as the solution to an equation which models the human spine as a lumped single-degree-of-freedom spring-shock absorber system. The model uses an ordinary linear second-order differential equation with constant coefficients with spinal compression as the variable. The forcing function in the equation is the accelerative shock load delivered to the pelvis by the event. The equation is given below: + 2 \cdot \zeta \cdot \omega \cdot + \omega^2 \cdot X = In this equation, X denotes the spinal compression, and d2z/dt2 denotes the time-dependent shock acceleration (the input). The coefficients ω and ζ are the lumped spina ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spinal Damage
Spine or spinal may refer to: Science Biology * Vertebral column, also known as the backbone * Dendritic spine, a small membranous protrusion from a neuron's dendrite * Thorns, spines, and prickles, needle-like structures in plants * Spine (zoology), needle-like structures in animals * SPINE (molecular biology) (strep–protein interaction experiment), a method for the detection of protein interactions Medicine * Spinal anaesthesia or "a spinal", an injection generally through a fine needle, usually long * The Spine, a set of national services within the UK NHS Connecting for Health#The Spine (including PDS & PSIS), NHS Connecting for Health Arts, entertainment and media * ''The Spine (album)'', a 2004 ''They Might Be Giants'' album, including the songs "Spine" and "Spines" * Spine (1986 film), ''Spine'' (1986 film), American film * The Spine (film), ''The Spine'' (film), a 2009 animated short by Chris Landreth * ''The Spine'', a novel by Ladislav Bublík Fictional entities * Spi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vertical Shock Load
Vertical is a geometric term of location which may refer to: * Vertical direction, the direction aligned with the direction of the force of gravity, up or down * Vertical (angles), a pair of angles opposite each other, formed by two intersecting straight lines that form an "X" * Vertical (music), a musical interval where the two notes sound simultaneously * "Vertical", a type of wine tasting in which different vintages of the same wine type from the same winery are tasted * Vertical Aerospace, stylised as "Vertical", British aerospace manufacturer * Vertical Kilometer, a discipline of skyrunning * Vertical market, a market in which vendors offer goods and services specific to an industry Media * ''Vertical'' (1967 film), Soviet movie starring Vladimir Vysotsky * "Vertical" (''Sledge Hammer!''), 1987 television episode * ''Vertical'' (novel), 2010 novel by Rex Pickett * Vertical Entertainment, an American independent film distributor and production company * Vertical (p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Differential Equation
In mathematics, a differential equation is an equation that relates one or more unknown functions and their derivatives. In applications, the functions generally represent physical quantities, the derivatives represent their rates of change, and the differential equation defines a relationship between the two. Such relations are common; therefore, differential equations play a prominent role in many disciplines including engineering, physics, economics, and biology. Mainly the study of differential equations consists of the study of their solutions (the set of functions that satisfy each equation), and of the properties of their solutions. Only the simplest differential equations are solvable by explicit formulas; however, many properties of solutions of a given differential equation may be determined without computing them exactly. Often when a closed-form expression for the solutions is not available, solutions may be approximated numerically using computers. The theory of d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
STANAG 4569
NATO AEP-55 STANAG 4569 is a NATO Standardization Agreement covering the standards for the "Protection Levels for Occupants of Logistic and Light Armored Vehicles". The standard covers strikes from kinetic energy, artillery and IED blasts. Level 1 Kinetic Energy 7.62×51mm NATO Ball (Ball M80) at 30 meters with velocity 833 m/s 5.56×45mm NATO Ball (SS109) at 30 meters with a velocity of 900 m/s 5.56×45mm NATO Ball (M193) at 30 meters with a velocity of 937 m/s Protection against all three threats must be provided. Grenade and Mine Blast Hand grenades, unexploded artillery fragmenting submunitions, and other small anti personnel explosive devices detonated under the vehicle. Artillery 20 mm FSP (simulating 155 mm threat) at 520 m/sec from a distance of 100 meters. (Due to very low probability of a large fragment retaining enough velocity at these distances, STANAG 4569 makes this optional.) Angle: azimuth 360°; elevation: 0–18° Level 2 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Back Injury
Back injuries result from damage, wear, or trauma to the bones, muscles, or other tissues of the back. Common back injuries include sprains and strains, herniated discs, and fractured vertebrae. The lumbar spine is often the site of back pain. The area is susceptible because of its flexibility and the amount of body weight it regularly bears. It is estimated that low-back pain may affect as much as 80 to 90 percent of the general population in the United States.Putz-Anderson, Vern, Thomas Waters, and Arun Garg. (1994)Applications Manual for the Revised NIOSH Lifting Equation National Institute for Occupational Safety and Health. NIOSH (DHHS) Publication 94–110. Classification Soft tissue graded system Muscle and soft tissue injuries can be classified using a graded system. * Grade 1 muscle strain is the least severe with damage to few muscle fibers and little if any loss of function. * Grade 2 muscle strain indicates a mild to moderate injury with appreciable tissue d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crashworthiness
Crashworthiness is the ability of a structure to protect its occupants during an impact. This is commonly tested when investigating the safety of aircraft and vehicles. Depending on the nature of the impact and the vehicle involved, different criteria are used to determine the crashworthiness of the structure. Crashworthiness may be assessed either prospectively, using computer models (e.g., LS-DYNA, PAM-CRASH, MSC Dytran, MADYMO) or experiments, or retrospectively by analyzing crash outcomes. Several criteria are used to assess crashworthiness prospectively, including the deformation patterns of the vehicle structure, the acceleration experienced by the vehicle during an impact, and the probability of injury predicted by human body models. Injury probability is defined using criteria, which are mechanical parameters (e.g., force, acceleration, or deformation) that correlate with injury risk. A common injury criterion is the head impact criterion (HIC). Crashworthiness is asse ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ejection Seat
In aircraft, an ejection seat or ejector seat is a system designed to rescue the aircraft pilot, pilot or other aircrew, crew of an aircraft (usually military) in an emergency. In most designs, the seat is propelled out of the aircraft by an explosive charge or rocket motor, carrying the pilot with it. The concept of an ejectable escape crew capsule has also been tried. Once clear of the aircraft, the ejection seat deploys a parachute. Ejection seats are common on certain types of military aircraft. History A bungee cord, bungee-assisted escape from an aircraft took place in 1910. In 1916, Everard Calthrop, an early inventor of parachutes, patented an ejector seat using compressed air. The modern layout for an ejection seat was first introduced by Romanian inventor Anastase Dragomir in the late 1920s. The design featured a ''parachuted cell'' (a dischargeable chair from an aircraft or other vehicle). It was successfully tested on 25 August 1929 at the Paris-Orly Airport ne ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spinal Injury
A spinal cord injury (SCI) is damage to the spinal cord that causes temporary or permanent changes in its function. Symptoms may include loss of muscle function, sensation, or autonomic function in the parts of the body served by the spinal cord below the level of the injury. Injury can occur at any level of the spinal cord and can be ''complete'', with a total loss of sensation and muscle function at lower sacral segments, or ''incomplete'', meaning some nervous signals are able to travel past the injured area of the cord up to the Sacral S4-5 spinal cord segments. Depending on the location and severity of damage, the symptoms vary, from numbness to paralysis, including bowel or bladder incontinence. Long term outcomes also range widely, from full recovery to permanent tetraplegia (also called quadriplegia) or paraplegia. Complications can include muscle atrophy, loss of voluntary motor control, spasticity, pressure sores, infections, and breathing problems. In the majority o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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