Download or read book Modeling of the Non Auditory Response to Blast Overpressure Calculation of the Internal Mechanical Response of Sheep to Blast Loading written by and published by . This book was released on 1990 with total page 64 pages. Available in PDF, EPUB and Kindle. Book excerpt: Calculations are made of the intrathoracic pressure expected from blast loading of sheep. A mathematical model of the chest wall and lung parenchyma have been formulated as a system of differential equations which include the effects of chest wall mass and resistance, density of the parenchyma and an adiabatic equation of state for air within the parenchyma. The differential equations are discretized as a system of nonlinear finite difference equations with the blast loading appearing as a boundary condition. This finite system is then solved on a computer using an implicit solution algorithm. Blast loadings used in the calculations are from field tests and correspond to animal response ranging from no injury to severe injury. Intrathoracic pressure in the esophagus and at four locations within the lung parenchyma, all in the approximate plat of the seventh thoracic vertebra, are compared with field test measurements for four occupational levels and four injury levels of blast overpressure. Keywords: RA 3, Numerical analysis, Differential equations, Weapons effects(Biological), Blast injuries, Non- auditory responses to blast overpressure, Thoracic injury.

Download or read book Military Quantitative Physiology Problems and Concepts in Military Operational Medicine written by The Borden Institute, U.S. Army Medical Department and published by Government Printing Office. This book was released on 2017-07-26 with total page 430 pages. Available in PDF, EPUB and Kindle. Book excerpt: Few human activities demand or deserve as much attention of the citizens of a nation as the array of man-made and natural “environmental” threats faced by the soldiers and other warriors defending the nation – those that pose the risk of disease, injury, combat wounds, and even death. This book is the Army’s first detailing research in computational physiology models and highlighting pivotal research. It outlines the extent to which basic and applied biomedical scientists, clinicians, modelers, and others strive to understand the extent of these threats, and provide intellectual and materiel options to mitigate these risks. This book summarizes major Army research efforts to quantify and model military relevant physiology. These chapters highlight the translation of this research into useful predictive tools. The tools are of importance to medical planners, materiel developers, commanders, and in many cases, every soldier. These chapters detail the experimental basis for many of the predictive tools that are currently in use. This book is written for military clinicians, and medical researchers who may be reasonably expected to explain some of the background, as well as those who will extend the research. Many people will find this book interesting because it details research on topics that affect everyone in everyday life, including how we sleep, eat, and exercise, as well as more specific topics such as the effects of caffeine on performance, risks associated with laser pointers, and even Army blast models that have influenced safety thresholds for car airbag deployments.

Download or read book Military Quantitative Physiology written by Karl Friedl and published by Department of the Army. This book was released on 2012 with total page 438 pages. Available in PDF, EPUB and Kindle. Book excerpt: NOTE: NO FURTHER DISCOUNT FOR THIS PRINT PRODUCT- OVERSTOCK SALE -- Significantly reduced list price Few human activities demand or deserve as much attention of the citizens of a nation as the array of man-made and natural "environmental" threats faced by the soldiers and other warriors defending the nation - those that pose the risk of disease, injury, combat wounds, and even death. This book is the Army's first detailing research in computational physiology models and highlighting pivotal research. It outlines the extent to which basic and applied biomedical scientists, clinicians, modelers, and others stribe to understand the extent of these threats, and provide intellectual and materiel options to mitigate these risks. This book summarizes major Army research efforts to quantify and model military relevant physiology. These chapters highlight the translation of this research into useful predictive tools. The tools are of importance to medical planners, materiel developers, commanders, and in many cases, every soldier. These chapters detail the experimental basis for many of the predictive tools that are currently in use. This book is written for military clinicians, and medical researchers who may be reasonably expected to explain some of the background, as well as those who will extend the research. Many people will find this book interesting because it details research on topics that affect everyone in everyday life, including how we sleep, eat, and exercise, as well as more specific topics such as the effects of caffeine on performance, risks associated with laser pointers, and even Army blast models that have influenced safety thresholds for car airbag deployments.

Download or read book Modeling of the Non Auditory Response to Blast Overpressure Summary of Blast Overpressure Field Data written by and published by . This book was released on 1990 with total page 149 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report is a compilation of blast overpressure field data taken at the Blast Overpressure Test Site in Albuquerque, New Mexico. The work was conducted under the direction of Dr. D.R. Richmond and a complete list of source documents is contained in the Reference section. Most of the field tests involved sheep placed in the blast environment. The purpose was to empirically correlate injury to blast wave parameters. This report summarizes the test data compiled to date, but is by no means all inclusive. Corresponding to each test are plots of the associated incident pressure field. The purpose of this report is to provide a convenient summary of these tests for use by all researchers. This report is organized into seven sections, each devoted to a different blast study. They are: Armored Personnel Carrier (APC); Bunker Summer Studies of 85, 86, 87; Double Peak; and Iso-Impulse. Within each section, a separate page describes each combination of charge type, charge weight, height of burst, and range. Keywords: RA 3, Weapons effects (Biological), Non-auditory responses, Blast overpressure, Explosions, Blast injuries, Field data, Tables(Data).

Download or read book Modeling of the Non Auditory Response to Blast Overpressure Considerations in Developing a Mechanistically Based Model of Blast Induced Injury to Air Containing Organs written by and published by . This book was released on 1990 with total page 27 pages. Available in PDF, EPUB and Kindle. Book excerpt: In order to anticipate the potential for injury in a wide variety of blast environments, without the excessive use of animal tests, it is necessary to develop a mechanistic understanding that can be used reliably. The process by which the blast wave produces injury is conceived to have the following intermediate steps. The external blast creates a pressure load distribution on the body that sets it in mechanical motion. That motion is transmitted through the body structure to the air-containing organs, where rapid distortions cause stresses within the organ tissue. The combination of stress and motion does work on the tissue and, when certain material limits are exceeded, results in injury. Multiple, isolated exposures lead to a nonlinear accumulation of damage. This paper discusses the non-organ-specific aspects of modeling this process and demonstrates that the general characteristics of injury observed in animal field tests can be explained. Injury to the larynx is used to make a quantitative validation and a simple-wave, multiple-short Damage-Risk Criterion (DRC) is developed. Keywords: RA 3, Non-auditory response, Blast overpressure, Protective equipment, Weapons effects(Biological), DRC, Larynx, Air-containing organs, Stress(Physiology).

Download or read book Modeling of the Non Auditory Response to Blast Overpressure written by James H. Stuhmiller and published by . This book was released on 1987 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: The goal of this project is to develop mathematical models of the physical processes that cause blast injury so that the results of tests using animals in simple blast environments can be safely translated to estimating hazard to man exposed to blast both in the free field and within enclosures. The present project builds upon earlier work to develop models of the mechanics of the thorax and lung exposed to simple blast waves. The scope of activity has been expanded to include the lung, the gastro-intestinal track, the upper respiratory tract, and the tympanic organs. In addition, the work now addresses occupational and combat level exposures. This report covers the second year of the contract. A considerable amount of progress has been made in understanding the basic mechanisms of injury and in providing practical tools for the measurement and prediction of blast effects. Keywords: Blast overpressure, Injury, Modeling.

Download or read book Modeling of the Non Auditory Response to Blast Overpressure Use of Surrogate and Analytical Models to Understand the Parameters Controlling Blast Injury to the Gastro Intestinal Tract written by James H. Stuhmiller and published by . This book was released on 1990 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt: Previous experimental studies using excised, perfused rabbit intestine in a sealed water tank, have provided direct visual observation that air bubbles produce local, violent, intestinal wall motion when they collapse under blast loading and that injury directly correlates with those motions. Measurements of the pressure within the bubble was shown to correlate with the motion of the wall and with injury. It was speculated that this pressure is an indirect measure of the stress in the wall tissue and therefore could be a means of quantifying the injury process. An analytical model of the dynamics of a bubble within an elastic membrane has been developed. Surrogate models, using materials with properties similar to that of intestine wall, but arranged in simpler geometric configurations, have been used to collect data on the dynamic process. The model results are compared and discussed. Keywords: RA 3, Weapons effects(Biological), Non-auditory responses, Blast overpressure, Explosions, G.I. Tract, Blast injury. (JG).

Download or read book Modeling of the Non Auditory Response to Blast Overpressure The State of Modeling Blast Injury written by and published by . This book was released on 1990 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt: To understand the importance of the findings of the modeling project and to appreciate the need for extending those ideas, it is necessary to review the state of knowledge of blast overpressure injury at the time that the modeling project was initiated and how the needs of Army have evolved. In the early 1980's, two methods existed for assessing blast overpressure injury: one, Military Standard 1474B (Ref. 1), for use in occupational situations, and the other, the Bowen curves (Ref. 2), for use in combat conditions. Mil. Std. 1474-B is a standard developed for predicting auditory hazard based on observed values of peak pressure level and duration. It contains the so-called 'Z-line, ' above which no soldier should be exposed because of possible nonauditory injury that no amount of hearing protection could prevent. The nature of that injury is unspecified and the curve was not based on any observational data, although it might have reflected the intuition of the committee. The other curves in the standard were based primarily on small calibre weapons and, at the time of its creation, the Z-line was well removed from any operational weapon system.

Download or read book Government Reports Annual Index written by and published by . This book was released on 1990 with total page 1316 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Government Reports Announcements Index written by and published by . This book was released on 1990-11 with total page 720 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Health Hazard Assessment for Blast Overpressure Exposures Subtitle Biological Response to Blast Overpressure A Summary of Modeling written by and published by . This book was released on 1996 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: A soldier in training is exposed to a variety of blast sources that can adversely affect his auditory and nonauditory systems. While auditory standards have been formulated for many decades, knowledge about nonauditory effects of blast have not been captured in a criteria that can be applied to all circumstances. For the past 15 years, JAYCOR, working together with the Walter Reed Army Institute of Research, has been using modeling, simulation, and data analysis to determine the nature of injury in animal models, capture that understanding in physiologically correct mathematical models, and extend the findings to objective criteria that can be used to set exposure limits. This paper summarizes the accomplishments of that effort.

Download or read book Biologic Response to Complex Blast Waves written by and published by . This book was released on 1985 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Small, bare charges were detonated inside an M59 armored personnel carrier (APC) in an attempt to simulate the complex blast waves generated by the jets from shaped-charge warheads penetrating into armored vehicles. Anesthetized sheep were placed inside the APC at 91- and 122-cm ranges from 57- or ll3-g pentolite charges. Pressure-time was measured by pressure transducers either mounted on the animals or free standing at comparable ranges on the opposite side of the vehicle. In general, the waveforms were characterized by an initial shock wave of less than l-msec duration followed by repeated reflections of decreasing magnitude. No deaths nor lung hemorrhages were observed, but all the animals sustained severe ear injury. Animals subjected to peak overpressures of 1.2 to 2.3 bar from the 113-g explosions also received slight non-auditory blast injuries to the upper respiratory and gastrointestinal tracts; those exposed to peak overpressures of just under 1 bar from the 57-g charges did not. The non-auditory blast injuries inside the APC were more severe than those sustained by sheep at comparable distances from 1l3-g charges in the open. The results suggested that the biological consequences of a complex wave of the type encountered in this study may be equated approximately to a Friedlander wave with a peak overpressure equal to that of the complex wave and with a total impulse equal to the impulse over the first 2 to 3 msec of the complex wave.

Download or read book Blast Overpressure Studies Nonauditory Damage Risk Assessment for Simulated Muzzle Blast from a L2Omm Ml2l Mortar System written by and published by . This book was released on 1997 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This study was undertaken to establish the subthreshold, threshold, and suprathresholds for nonauditory injuries in a simulated muzzle blast environment like that produced when firing a 120mm M121 mortar system. A vertical axis explosively driven shock tube, in combination with reflector shields, was used to produce the required muzzle blast pressure-time pattern. Varying numbers of anesthetized sheep were subjected to 6 or 50 blasts of simulated muzzle blast waves in 1.5- to 3.0-dB increments. The results of the study demonstrated that sheep could be exposed to Pmax levels consisting of 6 blasts of 36 kPa each and 50 blasts of 30 kPa each and sustain no injuries to trivial upper respiratory tract injuries at most. Threshold injuries were calculated to occur at 53 and 34 kPa for 6- and 50-blast exposures, respectively. Suprathresholds for URT and GI tract lesions were predicted to be 69 and 46 kPa for 6 and 50 blasts each. A suprathreshold for lung hemorrhage was predicted at 277 kPa for 6 exposures. Comparative analyses of this study with previous complex wave studies demonstrated that the safe nonauditory subthreshold for as many as 100 complex blastwave exposures was 22 kPa.

Download or read book Blast Overpressure Studies written by Daniel L. Johnson and published by . This book was released on 1998 with total page 269 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Blast Overpressure Studies Part II Nonauditory Damage Risk Assessment for Simulated Weapons Fired 100 Times from an Enclosure written by Barbara Merickel and published by . This book was released on 1997 with total page 100 pages. Available in PDF, EPUB and Kindle. Book excerpt: Anesthetized sheep were exposed to a reverberant wave environment like that produced from firing an antitank weapon from a room. The simulation was accomplished by detonating C4 explosives outside a chamber of 18.2 m3 volume. The blast wave traveled into the chamber through a 20-cm I.D. tube and was reflected off the back wall and subsequently throughout the chamber. The resulting waveform very closely approximated that generated by a Carl-Gustav antitank weapon fired from a chamber. Part I of the studies indicated that for a series of 1 shot or 3 shots, 2.5 minutes apart, multiple shots have a strong additive effect, decreasing the subthreshold levels. The subthreshold for a single blast was estimated to be above a peak of 48 kPa. The subthreshold for 3 exposures was estimated to be at 44 kPa. This study, called Part II, used 100 shots, 1 minute apart. For this exposure, a subthreshold peak of at least 23 kPa was verified using 19 animals.

Download or read book The Response of Cylindrical Shells to External Blast Loading written by William J. Schuman (Jr.) and published by . This book was released on 1963 with total page 178 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Relationship Between Selected Blast wave Parameters and the Response of Mammals Exposed to Air Blast written by Donald R. Richmond and published by . This book was released on 1966 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt: For personnel standing or prone-side-on to the charge when it is detonated at or near the surface, the side-on incident plus dynamic pressures become the effective pressure; however, with orientations end-on in this situation, only the side-on incident pressure appears to be the maximal effective pressure.