A new nonpenetrating ballistic injury.

PubMed

Carroll, A W; Soderstrom, C A

1978-12-01

A new, nonpenetrating ballistic injury mechanism involving individuals protected by soft body armor is described. Experimental studies using laboratory animals have demonstrated that despite stopping missile penetration, the heart, liver, spleen, and spinal cord are vulnerable to injury. The rapid jolting force of an impacting bullet is contrasted with the usually encountered mechanisms producing blunt trauma injury. The experimental methodology used to assess a 20% increase in survival probability and an 80% decrease in the need for surgical intervention with a new soft body armor is reviewed. Five cases of ballistic assaults on law enforcement personnel protected by soft body armor are presented. Four emphasize the potentially lifesaving qualities of the armor, while the fifth indicates the need for torso encircling design. Hospitalization should follow all assaults, regardless of the innocuous appearance of the skin lesion and the apparent well being on the assaulted individual. Therapeutic guidelines for patient management are suggested.

A new nonpenetrating ballistic injury.

PubMed Central

Carroll, A W; Soderstrom, C A

1978-01-01

A new, nonpenetrating ballistic injury mechanism involving individuals protected by soft body armor is described. Experimental studies using laboratory animals have demonstrated that despite stopping missile penetration, the heart, liver, spleen, and spinal cord are vulnerable to injury. The rapid jolting force of an impacting bullet is contrasted with the usually encountered mechanisms producing blunt trauma injury. The experimental methodology used to assess a 20% increase in survival probability and an 80% decrease in the need for surgical intervention with a new soft body armor is reviewed. Five cases of ballistic assaults on law enforcement personnel protected by soft body armor are presented. Four emphasize the potentially lifesaving qualities of the armor, while the fifth indicates the need for torso encircling design. Hospitalization should follow all assaults, regardless of the innocuous appearance of the skin lesion and the apparent well being on the assaulted individual. Therapeutic guidelines for patient management are suggested. Images Fig. 1. Fig. 2. Fig. 3. PMID:736653

Ballistic Testing of Australian Bisalloy Steel for Armor Applications

DTIC Science & Technology

2007-06-01

CLASSIFICATION OF: 19a. NAME OF RESPONSIBLE PERSON Dwight D. Showalter a . REPORT UNCLASSIFIED b. ABSTRACT UNCLASSIFIED c . THIS PAGE UNCLASSIFIED 17...WASHINGTON PA 15301 A ND 2 SOUTHWEST RSCH INST C ANDERSON J WALKER 6220 CULEB SAN ANTONIO TX 7 DEPT OF APPL MECH & SVC R011 S NEMAT...Ballistic Testing of Australian Bisalloy Steel for Armor Applications by Dwight D. Showalter, William A . Gooch, Matt S. Burkins, Victoria

Ballistic Analysis of New Military Grade Magnesium Alloys for Armor Applications

NASA Astrophysics Data System (ADS)

Jones, Tyrone L.; Kondoh, Katsuyoshi

Since 2006, the U.S. Army has been evaluating magnesium (Mg) alloys for ballistic structural applications. While Mg-alloys have been used in military structural applications since WWII, very little research has been done to improve its mediocre ballistic performance. The Army's need for ultra-lightweight armor systems has led to research and development of high strength, high ductility Mg-alloys. The U.S. Army Research Laboratory contracted through International Technology Center-Pacific Contract Number FA-5209-09-P-0158 with the Joining and Welding Research Instituteof Osaka University to develop the next generation of high strength, high ductility Mg-alloys using a novel Spinning Water Atomization Process for rapid solidification. New alloys AMX602 and ZAXE1711 in extruded bar form were characterized for microstructure, mechanical, and ballistic response. Significant increases in ballistic performance were evident when compared to the baseline alloy AZ31B.

Medical Provider Ballistic Protection at Active Shooter Events.

PubMed

Stopyra, Jason P; Bozeman, William P; Callaway, David W; Winslow, James; McGinnis, Henderson D; Sempsrott, Justin; Evans-Taylor, Lisa; Alson, Roy L

2016-01-01

There is some controversy about whether ballistic protective equipment (body armor) is required for medical responders who may be called to respond to active shooter mass casualty incidents. In this article, we describe the ongoing evolution of recommendations to optimize medical care to injured victims at such an incident. We propose that body armor is not mandatory for medical responders participating in a rapid-response capacity, in keeping with the Hartford Consensus and Arlington Rescue Task Force models. However, we acknowledge that the development and implementation of these programs may benefit from the availability of such equipment as one component of risk mitigation. Many police agencies regularly retire body armor on a defined time schedule before the end of its effective service life. Coordination with law enforcement may allow such retired body armor to be available to other public safety agencies, such as fire and emergency medical services, providing some degree of ballistic protection to medical responders at little or no cost during the rare mass casualty incident. To provide visual demonstration of this concept, we tested three "retired" ballistic vests with ages ranging from 6 to 27 years. The vests were shot at close range using police-issue 9mm, .40 caliber, .45 caliber, and 12-gauge shotgun rounds. Photographs demonstrate that the vests maintained their ballistic protection and defeated all of these rounds. 2016.

Comparative Ballistic Performance of 20mm AP M95 and 20mm AP M75 Projectiles against Rolled Homogeneous Steel Armor

DTIC Science & Technology

1960-05-01

Dominic A. Piccione, " Comparative Ballistic Performanceof 20mm AP M95 and 20mm AP M75 Projectiles againstRolled Homogeneous Steel Armor (U)’\\ WAL-TR-160.1/1... COMPARATIVE BALLISTIC PERFORMANCE OF 20MM AP M95 AND 20MM AP M75 PROJECTILES AGAINST ROLLED HOMOGENEOUS STEEL ARMOR (U) TECHNICAL REPORT NO. WAL TR I60.l/I(c...o > -< Abt9sortf bl O *_, o o -o WATERTOWN ARSENAL LABORATORIES co COMPARATIVE BALLISTIC PERFORMANCE OF 20MM AP M95 AND 20MM AP M75

Conformable Self-Healing Ballistic Armor

DTIC Science & Technology

2011-06-28

providing additional ballistic resistance . A closable filler opening 16 comprising a threaded wide mouth aperture with 50 a threaded stopper would be...quality of abrasive , high resistance to projectiles at a relatively light weight; thus, they represent a preferred particle composition for a filler...in resisting a plurality of projectiles 60 impacting on the same general area. SUMMARY OF THE INVENTION The present invention comprises a

Wound Ballistics Modeling for Blast Loading Blunt Force Impact and Projectile Penetration.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Taylor, Paul A.

Light body armor development for the warfighter is based on trial-and-error testing of prototype designs against ballistic projectiles. Torso armor testing against blast is nonexistent but necessary to protect the heart and lungs. In tests against ballistic projectiles, protective apparel is placed over ballistic clay and the projectiles are fired into the armor/clay target. The clay represents the human torso and its behind-armor, permanent deflection is the principal metric used to assess armor protection. Although this approach provides relative merit assessment of protection, it does not examine the behind-armor blunt trauma to crucial torso organs. We propose a modeling andmore » simulation (M&S) capability for wound injury scenarios to the head, neck, and torso of the warfighter. We will use this toolset to investigate the consequences of, and mitigation against, blast exposure, blunt force impact, and ballistic projectile penetration leading to damage of critical organs comprising the central nervous, cardiovascular, and respiratory systems. We will leverage Sandia codes and our M&S expertise on traumatic brain injury to develop virtual anatomical models of the head, neck, and torso and the simulation methodology to capture the physics of wound mechanics. Specifically, we will investigate virtual wound injuries to the head, neck, and torso without and with protective armor to demonstrate the advantages of performing injury simulations for the development of body armor. The proposed toolset constitutes a significant advance over current methods by providing a virtual simulation capability to investigate wound injury and optimize armor design without the need for extensive field testing.« less

Ballistic-Failure Mechanisms in Gas Metal Arc Welds of Mil A46100 Armor-Grade Steel: A Computational Investigation

NASA Astrophysics Data System (ADS)

Grujicic, M.; Snipes, J. S.; Galgalikar, R.; Ramaswami, S.; Yavari, R.; Yen, C.-F.; Cheeseman, B. A.

2014-09-01

In our recent work, a multi-physics computational model for the conventional gas metal arc welding (GMAW) joining process was introduced. The model is of a modular type and comprises five modules, each designed to handle a specific aspect of the GMAW process, i.e.: (i) electro-dynamics of the welding-gun; (ii) radiation-/convection-controlled heat transfer from the electric-arc to the workpiece and mass transfer from the filler-metal consumable electrode to the weld; (iii) prediction of the temporal evolution and the spatial distribution of thermal and mechanical fields within the weld region during the GMAW joining process; (iv) the resulting temporal evolution and spatial distribution of the material microstructure throughout the weld region; and (v) spatial distribution of the as-welded material mechanical properties. In the present work, the GMAW process model has been upgraded with respect to its predictive capabilities regarding the spatial distribution of the mechanical properties controlling the ballistic-limit (i.e., penetration-resistance) of the weld. The model is upgraded through the introduction of the sixth module in the present work in recognition of the fact that in thick steel GMAW weldments, the overall ballistic performance of the armor may become controlled by the (often inferior) ballistic limits of its weld (fusion and heat-affected) zones. To demonstrate the utility of the upgraded GMAW process model, it is next applied to the case of butt-welding of a prototypical high-hardness armor-grade martensitic steel, MIL A46100. The model predictions concerning the spatial distribution of the material microstructure and ballistic-limit-controlling mechanical properties within the MIL A46100 butt-weld are found to be consistent with prior observations and general expectations.

Natural Mallow Fiber-Reinforced Epoxy Composite for Ballistic Armor Against Class III-A Ammunition

NASA Astrophysics Data System (ADS)

Nascimento, Lucio Fabio Cassiano; Holanda, Luane Isquerdo Ferreira; Louro, Luis Henrique Leme; Monteiro, Sergio Neves; Gomes, Alaelson Vieira; Lima, Édio Pereira

2017-10-01

Epoxy matrix composites reinforced with up to 30 vol pct of continuous and aligned natural mallow fibers were for the first time ballistic tested as personal armor against class III-A 9 mm FMJ ammunition. The ballistic efficiency of these composites was assessed by measuring the dissipated energy and residual velocity after the bullet perforation. The results were compared to those in similar tests of aramid fabric (Kevlar™) commonly used in vests for personal protections. Visual inspection and scanning electron microscopy analysis of impact-fractured samples revealed failure mechanisms associated with fiber pullout and rupture as well as epoxy cracking. As compared to Kevlar™, the mallow fiber composite displayed practically the same ballistic efficiency. However, there is a reduction in both weight and cost, which makes the mallow fiber composites a promising material for personal ballistic protection.

Mallow Fiber-Reinforced Epoxy Composites in Multilayered Armor for Personal Ballistic Protection

NASA Astrophysics Data System (ADS)

Nascimento, Lucio Fábio Cassiano; Louro, Luis Henrique Leme; Monteiro, Sergio Neves; Lima, Édio Pereira; da Luz, Fernanda Santos

2017-10-01

Lighter and less expensive polymer composites reinforced with natural fibers have been investigated as possible components of a multilayered armor system (MAS) for personal protection against high-velocity ammunition. Their ballistic performance was consistently found comparable with that of conventional Kevlar® synthetic aramid fiber. Among the numerous existing natural fibers with the potential for reinforcing polymer composites to replace Kevlar® in MAS, mallow fiber has not been fully investigated. Thus, the objective of this work is to evaluate the ballistic performance of epoxy composites reinforced with 30 vol.% of aligned mallow fibers as a second MAS layer backing a front ceramic plate. The results using high-velocity 7.62 ammunition show a similar indentation to a Kevlar® layer with the same thickness. An impedance matching calculation supports the similar ballistic performance of mallow fiber composite and Kevlar®. Reduced MAS costs associated with the mallow fiber composite are practical advantages over Kevlar®.

Ballistic Performance of Alimina/S-2 Glass-Reinforced Polymer-Matrix Composite Hybrid Lightweight Armor Against Armor Piercing (AP) and Non-AP Projectiles

DTIC Science & Technology

2007-01-01

and a phenolic -resin based polymeric matrix. Such armor panels offer superior protection against fragmented ballistic threats when compared to...database does not contain a material model for the HJ1 composite but provides a model for a Kevlar Fiber Reinforced Polymer (KFRP) containing 53 vol... phenolic resin and epoxy yield stresses and then with a ratio of the S-2 glass and aramid fibers volume fractions. To test the validity of the

Analyzing nature's protective design: The glyptodont body armor.

PubMed

du Plessis, Anton; Broeckhoven, Chris; Yadroitsev, Igor; Yadroitsava, Ina; le Roux, Stephan Gerhard

2018-06-01

Many animal species evolved some form of body armor, such as scales of fish and bony plates or osteoderms of reptiles. Although a protective function is often taken for granted, recent studies show that body armor might comprise multiple functionalities and is shaped by trade-offs among these functionalities. Hence, despite the fact that natural body armor might serve as bio-inspiration for the development of artificial protective materials, focussing on model systems in which body armor serves a solely protective function might be pivotal. In this study, we investigate the osteoderms of Glyptotherium arizonae, an extinct armadillo-like mammal in which body armor evolved as protection against predators and/or tail club blows of conspecifics. By using a combination of micro-computed tomography, reverse-engineering, stress simulations and mechanical testing of 3D printed models, we show that the combination of dense compact layers and porous lattice core might provide an optimized combination of strength and high energy absorption. Copyright © 2018 Elsevier Ltd. All rights reserved.

Development of a Meso-Scale Material Model for Ballistic Fabric and Its Use in Flexible-Armor Protection Systems

NASA Astrophysics Data System (ADS)

Grujicic, M.; Bell, W. C.; Arakere, G.; He, T.; Xie, X.; Cheeseman, B. A.

2010-02-01

A meso-scale ballistic material model for a prototypical plain-woven single-ply flexible armor is developed and implemented in a material user subroutine for the use in commercial explicit finite element programs. The main intent of the model is to attain computational efficiency when calculating the mechanical response of the multi-ply fabric-based flexible-armor material during its impact with various projectiles without significantly sacrificing the key physical aspects of the fabric microstructure, architecture, and behavior. To validate the new model, a comparative finite element method analysis is carried out in which: (a) the plain-woven single-ply fabric is modeled using conventional shell elements and weaving is done in an explicit manner by snaking the yarns through the fabric and (b) the fabric is treated as a planar continuum surface composed of conventional shell elements to which the new meso-scale unit-cell based material model is assigned. The results obtained show that the material model provides a reasonably good description for the fabric deformation and fracture behavior under different combinations of fixed and free boundary conditions. Finally, the model is used in an investigation of the ability of a multi-ply soft-body armor vest to protect the wearer from impact by a 9-mm round nose projectile. The effects of inter-ply friction, projectile/yarn friction, and the far-field boundary conditions are revealed and the results explained using simple wave mechanics principles, high-deformation rate material behavior, and the role of various energy-absorbing mechanisms in the fabric-based armor systems.

7 CFR 1755.406 - Shield or armor ground resistance measurements.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 11 2010-01-01 2010-01-01 false Shield or armor ground resistance measurements. 1755... MATERIALS, AND STANDARD CONTRACT FORMS § 1755.406 Shield or armor ground resistance measurements. (a) Shield or armor ground resistance measurements shall be made on completed lengths of copper cable and wire...

7 CFR 1755.406 - Shield or armor ground resistance measurements.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 11 2011-01-01 2011-01-01 false Shield or armor ground resistance measurements. 1755... MATERIALS, AND STANDARD CONTRACT FORMS § 1755.406 Shield or armor ground resistance measurements. (a) Shield or armor ground resistance measurements shall be made on completed lengths of copper cable and wire...

Composite structural armor for combat vehicle applications

NASA Technical Reports Server (NTRS)

Haskell, William E., III; Alesi, A. L.; Parsons, G. R.

1990-01-01

Several projects that have demonstrated the advantages of using thick composite armor technology for structural applications in armored combat vehicles are discussed. The first involved composite cargo doors for the Marine Corps LVTP-7 amphibious landing vehicle. Another was a demonstration composite turret that offered a weight reduction of 15.5 percent. The advantages of this composite armor compared to metallic armors used for combat vehicle hull and turret applications are reduced weight at equal ballistic protection; reduced back armor spall; excellent corrosion resistance; reduced production costs by parts consolidation; and inherent thermal and acoustic insulative properties. Based on the encouraging results of these past programs, the Demonstration Composite Hull Program was started in September 1986. To demonstrate this composite armor technology, the Army's newest infantry fighting vehicle, the Bradley Fighting Vehicle (BFV), was selected as a model. A composite infantry fighting vehicle, designated the CIFV for this program, has been designed and fabricated and is currently undergoing a 6000 mile field endurance test. The CIFV demonstration vehicle uses the BFV engine, transmission, suspension, track and other equipment.

Optimization, Alternative Materials and Improvements in Body Armor Shields

DTIC Science & Technology

2007-05-10

performance structures such as protective clothing , bullet-proof vests and helmets due to their high-specific strength and stiffness. The ballistic...regard each layer of the woven composite as made of weft and warp yarns, and divide each yam into 3D solid elements. It is found that the frame...0.25 mm thick layers is modeled as an orthotropic material. Even though the woven composite armor is made of yams and each yarn is made of fibers

Assessing behind armor blunt trauma (BABT) under NIJ standard-0101.04 conditions using human torso models.

PubMed

Merkle, Andrew C; Ward, Emily E; O'Connor, James V; Roberts, Jack C

2008-06-01

Although soft armor vests serve to prevent penetrating wounds and dissipate impact energy, the potential of nonpenetrating injury to the thorax, termed behind armor blunt trauma, does exist. Currently, the ballistic resistance of personal body armor is determined by impacting a soft armor vest over a clay backing and measuring the resulting clay deformation as specified in National Institute of Justice (NIJ) Standard-0101.04. This research effort evaluated the efficacy of a physical Human Surrogate Torso Model (HSTM) as a device for determining thoracic response when exposed to impact conditions specified in the NIJ Standard. The HSTM was subjected to a series of ballistic impacts over the sternum and stomach. The pressure waves propagating through the torso were measured with sensors installed in the organs. A previously developed Human Torso Finite Element Model (HTFEM) was used to analyze the amount of tissue displacement during impact and compared with the amount of clay deformation predicted by a validated finite element model. All experiments and simulations were conducted at NIJ Standard test conditions. When normalized by the response at the lowest threat level (Level I), the clay deformations for the higher levels are relatively constant and range from 2.3 to 2.7 times that of the base threat level. However, the pressures in the HSTM increase with each test level and range from three to seven times greater than Level I depending on the organ. The results demonstrate the abilities of the HSTM to discriminate between threat levels, impact conditions, and impact locations. The HTFEM and HSTM are capable of realizing pressure and displacement differences because of the level of protection, surrounding tissue, and proximity to the impact point. The results of this research provide insight into the transfer of energy and pressure wave propagation during ballistic impacts using a physical surrogate and computational model of the human torso.

Advanced Ceramic Armor Materials

DTIC Science & Technology

1990-05-11

materials, toughened alumina, fiber -reinforced glass matrix composites, and multilayer-gradient materials for ballistic testing. Fabrication and...material systems: Multilayer advanced armor materials consisting of a hard ceramic faceplate bonded to a graphite fiber -reinforced glass matrix...toughened alumina, and fiber - applied studies of advanced reinforced ceramic matrix glass and glass -ceramic composites for ballistic testing. technologies

One Dimension Analytical Model of Normal Ballistic Impact on Ceramic/Metal Gradient Armor

NASA Astrophysics Data System (ADS)

Liu, Lisheng; Zhang, Qingjie; Zhai, Pengcheng; Cao, Dongfeng

2008-02-01

An analytical model of normal ballistic impact on the ceramic/metal gradient armor, which is based on modified Alekseevskii-Tate equations, has been developed. The process of gradient armour impacted by the long rod can be divided into four stages in this model. First stage is projectile's mass erosion or flowing phase, mushrooming phase and rigid phase; second one is the formation of comminuted ceramic conoid; third one is the penetration of gradient layer and last one is the penetration of metal back-up plate. The equations of third stage have been advanced by assuming the behavior of gradient layer as rigid-plastic and considering the effect of strain rate on the dynamic yield strength.

Assessing behind armor blunt trauma in accordance with the National Institute of Justice Standard for Personal Body Armor Protection using finite element modeling.

PubMed

Roberts, Jack C; Ward, Emily E; Merkle, Andrew C; O'Connor, James V

2007-05-01

To assess the possibility of injury as a result of behind armor blunt trauma (BABT), a study was undertaken to determine the conditions necessary to produce the 44-mm clay deformation as set forth in the National Institute of Justice (NIJ) Standard 0101.04. These energy levels were then applied to a three-dimensional Human Torso Finite Element Model (HTFEM) with soft armor vest. An examination will be made of tissue stresses to determine the effects of the increased kinetic energy levels on the probability of injury. A clay finite element model (CFEM) was created with a material model that required nonlinear properties for clay. To determine these properties empirically, the results from the CFEM were matched with experimental drop tests. A soft armor vest was modeled over the clay to create a vest over clay block finite element model (VCFEM) and empirical methods were again used to obtain material properties for the vest from experimental ballistic testing. Once the properties for the vest and clay had been obtained, the kinetic energy required to produce a 44-mm deformation in the VCFEM was determined through ballistic testing. The resulting kinetic energy was then used in the HTFEM to evaluate the probability of BABT. The VCFEM, with determined clay and vest material properties, was exercised with the equivalent of a 9-mm (8-gm) projectile at various impact velocities. The 44-mm clay deformation was produced with a velocity of 785 m/s. This impact condition (9-mm projectile at 785 m/s) was used in ballistic exercises of the HTFEM, which was modeled with high-strain rate human tissue properties for the organs. The impact zones were over the sternum anterior to T6 and over the liver. The principal stresses in both soft and hard tissue at both locations exceeded the tissue tensile strength. This study indicates that although NIJ standard 0101.04 may be a good guide to soft armor failure, it may not be as good a guide in BABT, especially at large projectile kinetic

One Dimension Analytical Model of Normal Ballistic Impact on Ceramic/Metal Gradient Armor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu Lisheng; Zhang Qingjie; Zhai Pengcheng

2008-02-15

An analytical model of normal ballistic impact on the ceramic/metal gradient armor, which is based on modified Alekseevskii-Tate equations, has been developed. The process of gradient armour impacted by the long rod can be divided into four stages in this model. First stage is projectile's mass erosion or flowing phase, mushrooming phase and rigid phase; second one is the formation of comminuted ceramic conoid; third one is the penetration of gradient layer and last one is the penetration of metal back-up plate. The equations of third stage have been advanced by assuming the behavior of gradient layer as rigid-plastic andmore » considering the effect of strain rate on the dynamic yield strength.« less

Biophysical Assessment and Predicted Thermophysiologic Effects of Body Armor.

PubMed

Potter, Adam W; Gonzalez, Julio A; Karis, Anthony J; Xu, Xiaojiang

2015-01-01

Military personnel are often required to wear ballistic protection in order to defend against enemies. However, this added protection increases mass carried and imposes additional thermal burden on the individual. Body armor (BA) is known to reduce combat casualties, but the effects of BA mass and insulation on the physical performance of soldiers are less well documented. Until recently, the emphasis has been increasing personal protection, with little consideration of the adverse impacts on human performance. The purpose of this work was to use sweating thermal manikin and mathematical modeling techniques to quantify the tradeoff between increased BA protection, the accompanying mass, and thermal effects on human performance. Using a sweating thermal manikin, total insulation (IT, clo) and vapor permeability indexes (im) were measured for a baseline clothing ensemble with and without one of seven increasingly protective U.S. Army BA configurations. Using mathematical modeling, predictions were made of thermal impact on humans wearing each configuration while working in hot/dry (desert), hot/humid (jungle), and temperate environmental conditions. In nearly still air (0.4 m/s), IT ranged from 1.57 to 1.63 clo and im from 0.35 to 0.42 for the seven BA conditions, compared to IT and im values of 1.37 clo and 0.45 respectively, for the baseline condition (no BA). Biophysical assessments and predictive modeling show a quantifiable relationship exists among increased protection and increased thermal burden and decreased work capacity. This approach enables quantitative analysis of the tradeoffs between ballistic protection, thermal-work strain, and physical work performance.

Negligible heat strain in armored vehicle officers wearing personal body armor

PubMed Central

2011-01-01

Objectives This study evaluated the heat strain experienced by armored vehicle officers (AVOs) wearing personal body armor (PBA) in a sub-tropical climate. Methods Twelve male AVOs, aged 35-58 years, undertook an eight hour shift while wearing PBA. Heart rate and core temperature were monitored continuously. Urine specific gravity (USG) was measured before and after, and with any urination during the shift. Results Heart rate indicated an intermittent and low-intensity nature of the work. USG revealed six AVOs were dehydrated from pre through post shift, and two others became dehydrated. Core temperature averaged 37.4 ± 0.3°C, with maximum's of 37.7 ± 0.2°C. Conclusions Despite increased age, body mass, and poor hydration practices, and Wet-Bulb Globe Temperatures in excess of 30°C; the intermittent nature and low intensity of the work prevented excessive heat strain from developing. PMID:21801453

77 FR 22345 - Agency Information Collection Activities: Proposed Collection; Comments Requested; Body Armor in...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-04-13

... correctional officers, such as the proportion who have body armor, the rate of use, the decision-making factors... Collection; Comments Requested; Body Armor in Correctional Institutions Survey ACTION: 60-day notice of... Collection: Establishment survey and initial approval of collection. (2) Title of Form/Collection: Body Armor...

Armor Plate Ballistic Testing

DTIC Science & Technology

1944-08-02

sistanoe to penotration characteristics. However, it is one of the most important factors involved, and when the type of steel , its soundness and its...this test and not to use it in comparing radically differdnt types of plates, such as steel and Dural. Such a comparison can be made only by examining...in many oases, For this reason it became necessary to develop an additional test for the oharaoteristio in rolled armor ( steel "soundness) and cast

Experimental study of thermal comfort on stab resistant body armor.

PubMed

Ji, Tingchao; Qian, Xinming; Yuan, Mengqi; Jiang, Jinhui

2016-01-01

This research aims to investigate the impacts of exercise intensity and sequence on human physiology parameters and subjective thermal sensation when wearing stab resistant body armor under daily working conditions in China [26 and 31 °C, 45-50 % relative humidity (RH)], and to investigate on the relationship between subjective judgments and objective parameters. Eight male volunteers were recruited to complete 3 terms of exercises with different velocity set on treadmill for 90 min at 26 °C and 31 °C, 45-50 % RH. In Exercise 1 volunteers were seated during the test. In Exercise 2, volunteers walked with the velocity of 3 km/h in the first 45 min and 6 km/h in the left 45 min. In Exercise 3, volunteers walked with the velocity of 6 km/h in the first 45 min and 3 km/h in the left 45 min. The body core temperature, skin temperature and subjective judgments were recorded during the whole process. Analysis of variance was performed among all the tests. Individual discrepancy of Exercise 1 is larger than that of Exercise 2 and 3. On the premise of the same walking distance and environmental conditions, core temperature in Exercise 3 is about 0.2 °C lower than that in Exercise 2 in the end; and with the velocity decrease from 6 km/h to 3 km/h in the end, thermal tolerance of Exercise 3 is about 1 degree lower than that in Exercise 2. Skin temperatures of human trunk were at least 1 °C higher than that of limbs. Activity narrows the individual discrepancy on core temperature. Within experimental conditions, decreasing of intensity at last stage makes the core temperature lower and the whole process much tolerable. The core temperature is more sensitive to the external disturbance on the balance of the whole body, and it can reflect the subjective thermal sensation and physical exertion.

Biophysical Assessment and Predicted Thermophysiologic Effects of Body Armor

PubMed Central

Potter, Adam W.; Gonzalez, Julio A.; Karis, Anthony J.; Xu, Xiaojiang

2015-01-01

Introduction Military personnel are often required to wear ballistic protection in order to defend against enemies. However, this added protection increases mass carried and imposes additional thermal burden on the individual. Body armor (BA) is known to reduce combat casualties, but the effects of BA mass and insulation on the physical performance of soldiers are less well documented. Until recently, the emphasis has been increasing personal protection, with little consideration of the adverse impacts on human performance. Objective The purpose of this work was to use sweating thermal manikin and mathematical modeling techniques to quantify the tradeoff between increased BA protection, the accompanying mass, and thermal effects on human performance. Methods Using a sweating thermal manikin, total insulation (IT, clo) and vapor permeability indexes (im) were measured for a baseline clothing ensemble with and without one of seven increasingly protective U.S. Army BA configurations. Using mathematical modeling, predictions were made of thermal impact on humans wearing each configuration while working in hot/dry (desert), hot/humid (jungle), and temperate environmental conditions. Results In nearly still air (0.4 m/s), IT ranged from 1.57 to 1.63 clo and im from 0.35 to 0.42 for the seven BA conditions, compared to IT and im values of 1.37 clo and 0.45 respectively, for the baseline condition (no BA). Conclusion Biophysical assessments and predictive modeling show a quantifiable relationship exists among increased protection and increased thermal burden and decreased work capacity. This approach enables quantitative analysis of the tradeoffs between ballistic protection, thermal-work strain, and physical work performance. PMID:26200906

Expanding the Availability of Lightweight Aluminum Alloy Armor Plate Procured from Detailed Military Specifications

NASA Astrophysics Data System (ADS)

Doherty, Kevin; Squillacioti, Richard; Cheeseman, Bryan; Placzankis, Brian; Gallardy, Denver

For many years, the range of aluminum alloys for armor plate applications obtainable in accordance with detailed military specifications was very limited. However, the development of improved aluminum alloys for aerospace and other applications has provided an opportunity to modernize the Army portfolio for ground vehicle armor applications. While the benefits of offering additional alloy choices to vehicle designers is obvious, the process of creating detailed military specifications for armor plate applications is not trivial. A significant amount of material and testing is required to develop the details required by an armor plate specification. Due to the vast number of material programs that require standardization and with a limited amount of manpower and funds as a result of Standardization Reform in 1995, one typically requires a need statement from a vehicle program office to justify and sponsor the work. This presentation will focus on recent aluminum alloy armor plate specifications that have added capability to vehicle designers' selection of armor materials that offer possible benefits such as lower cost, higher strength, better ballistic and corrosion resistance, improved weldability, etc.

Electroencephalogram, circulation, and lung function after high-velocity behind armor blunt trauma.

PubMed

Drobin, Dan; Gryth, Dan; Persson, Jonas K E; Rocksén, David; Arborelius, Ulf P; Olsson, Lars-Gunnar; Bursell, Jenny; Kjellström, B Thomas

2007-08-01

Behind armor blunt trauma (BABT) is defined as the nonpenetrating injury resulting from a ballistic impact on personal body armor. The protective vest may impede the projectile, but some of the kinetic energy is transferred to the body, causing internal injuries and occasionally death. The aim in this study was to investigate changes in electroencephalogram (EEG) and physiologic parameters after high-velocity BABT. Eight anesthetized pigs, wearing body armor (including a ceramic plate) on the right side of their thorax, were shot with a 7.62-mm assault rifle (velocity approximately 800 m/s). The shots did not penetrate the armor and these animals were compared with control animals (n = 4), shot with blank ammunition. EEG and several physiologic parameters were thereafter monitored during a 2-hour period after the shot. All animals survived during the experimental period. Five of the exposed animals showed a temporary effect on EEG. Furthermore, exposed animals displayed decreased cardiac capacity and an impaired oxygenation of the blood. Postmortem examination revealed subcutaneous hematomas and crush injuries to the right lung. The results in our animal model indicate that high-velocity BABT induce circulatory and respiratory dysfunction, and in some cases even transient cerebral functional disturbances.

Armored garment for protecting

DOEpatents

Purvis, James W [Albuquerque, NM; Jones, II, Jack F.; Whinery, Larry D [Albuquerque, NM; Brazfield, Richard [Albuquerque, NM; Lawrie, Catherine [Tijeras, NM; Lawrie, David [Tijeras, NM; Preece, Dale S [Watkins, CO

2009-08-11

A lightweight, armored protective garment for protecting an arm or leg from blast superheated gases, blast overpressure shock, shrapnel, and spall from a explosive device, such as a Rocket Propelled Grenade (RPG) or a roadside Improvised Explosive Device (IED). The garment has a ballistic sleeve made of a ballistic fabric, such as an aramid fiber (e.g., KEVLAR.RTM.) cloth, that prevents thermal burns from the blast superheated gases, while providing some protection from fragments. Additionally, the garment has two or more rigid armor inserts that cover the upper and lower arm and protect against high-velocity projectiles, shrapnel and spall. The rigid inserts can be made of multiple plies of a carbon/epoxy composite laminate. The combination of 6 layers of KEVLAR.RTM. fabric and 28 plies of carbon/epoxy laminate inserts (with the inserts being sandwiched in-between the KEVLAR.RTM. layers), can meet the level IIIA fragmentation minimum V.sub.50 requirements for the US Interceptor Outer Tactical Vest.

The addition of body armor diminishes dynamic postural stability in military soldiers.

PubMed

Sell, Timothy C; Pederson, Jonathan J; Abt, John P; Nagai, Takashi; Deluzio, Jennifer; Wirt, Michael D; McCord, Larry J; Lephart, Scott M

2013-01-01

Poor postural stability has been identified as a risk factor for lower extremity musculoskeletal injury. The additional weight of body armor carried by Soldiers alters static postural stability and may predispose Soldiers to lower extremity musculoskeletal injuries. However, static postural stability tasks poorly replicate the dynamic military environment, which places considerable stress on the postural control system during tactical training and combat. Therefore, the purpose of this study was to examine the effects of body armor on dynamic postural stability during single-leg jump landings. Thirty-six 101st Airborne Division (Air Assault) Soldiers performed single-leg jump landings in the anterior direction with and without wearing body armor. The dynamic postural stability index and the individual stability indices (medial-lateral stability index, anterior-posterior stability index, and vertical stability index) were calculated for each condition. Paired sample t-tests were performed to determine differences between conditions. Significant differences existed for the medial-lateral stability index, anterior-posterior stability index, vertical stability index, and dynamic postural stability index (p < 0.05). The addition of body armor resulted in diminished dynamic postural stability, which may result in increased lower extremity injuries. Training programs should address the altered dynamic postural stability while wearing body armor in attempts to promote adaptations that will result in safer performance during dynamic tasks.

Spaced Armor

DTIC Science & Technology

1950-11-20

the skirting plate of the minimum thickness capable of producing the desired effect upon the projectae . There is a sound reason for this approach...obliquity. As part of a program aimed at improving the performance of carbide cored projectiles, the Watertown Arsenal arranged, some years ago, trials of...the inter- action of kinetic energy projectiles and spaced armor combinations. The . details of the ballistic testing program were laid out jointly by

Fiber-Level Modeling of Dynamic Strength of Kevlar (registered trademark) KM2 Ballistic Fabric

DTIC Science & Technology

2012-07-01

Ballistic-Performance Optimization of a Hybrid Carbon - Nanotube /E-glass Reinforced Poly-Vinyl-Ester-Epoxy-Matrix Com- posite Armor, J. Mater. Sci...2007, 42, p 5347–5359 4. M. Grujicic, W.C. Bell, L.L. Thompson, K.L. Koudela, and B.A. Cheeseman, Ballistic-Protection Performance of Carbon - Nanotube ...Armor via the Use of a Carbon - Nanotube Forest-Mat Strike Face, Mater. Des. Appl., 2008, 222, p 15–28 6. Y. Wang and X. Sun, Determining the Geometry

Ballistic impact resistance of selected organic ophthalmic lenses.

PubMed

Chou, B Ralph; Yuen, Gloria S-C; Dain, Stephen J

2011-11-01

The aim was to assess the impact resistance of coated and uncoated mid-index spectacle lens materials using the ballistic impact test. Nominally plano lenses of each material in three thicknesses were obtained. The lenses were flat edged to a 50 mm diameter. Each lens was impacted by a 6.35 mm steel ball. Impact velocities were selected using the Zippy Estimation by Sequential Testing protocol to determine the threshold fracture impact velocity. Threshold fracture impact velocity generally increased with thickness; however, there was a wide variation in performance among the various lens materials at each thickness. In all but two instances, the differences in impact velocity at each thickness of lens material were significant. Comparison of the data for CR39 and Hoya Phoenix with the results of earlier studies showed that the lens mounting is a significant factor. The fracture velocities found in the present study were significantly lower than the fracture velocities found when the lens edge is restrained in the mounting. A scratch resistant coating reduced the impact resistance of CR39. The effect of the antireflection coating on the fracture velocity depended on the nature of the base scratch-resistant coating. Mid-index lens materials of the same thickness show widely varying levels of impact resistance under the ballistic test. Impact resistance increases non-linearly with centre thickness. The lens mounting might affect the results of the ballistic impact test. The presence of 'cushion coatings' might enhance impact resistance. © 2011 The Authors. Clinical and Experimental Optometry © 2011 Optometrists Association Australia.

Influence of ballistic bench press on upper body power output in professional rugby players.

PubMed

West, Daniel J; Cunningham, Daniel J; Crewther, Blair T; Cook, Christian J; Kilduff, Liam P

2013-08-01

The use of heavy resistance exercise provides an effective preload stimulus for inducing postactivation potentiation (PAP) and increasing peak power output (PPO). However, this approach has limited application in many sporting situations (e.g., incorporation in a precompetition warm-up); and therefore, more practical strategies for inducing PAP need to be investigated. The aim of the present study was to compare the PPO changes after performing a preload stimulus of either a ballistic exercise or a traditional heavy resistance exercise. Twenty professional rugby union players completed 3 testing sessions, each separated by 48 hours. On the first occasion, subjects underwent a 3 repetition maximum (3RM)-bench press testing session. On the next 2 occasions, subjects performed a ballistic bench throw at baseline (30% of 1RM), followed by a preload stimulus of either heavy resistance training (HRT) (heavy bench press: 3 sets of 3 repetitions at 87% 1RM) or BBP (3 sets of 3 repetitions at 30% on 1RM) followed by ballistic bench throw after 8 minutes recovery. The trials were randomized and counterbalanced. Both preload stimuli protocols increased PPO compared with baseline (BBP baseline 892 ± 108 vs. 8 minutes 924 ± 119 W, p < 0.001; HRT baseline 893 ± 104 vs. 8 minutes 931 ± 116 W; p < 0.001). There were no conditional differences between PPO at 8 minutes (p = 0.141); moreover, the change in PPO from baseline was also similar between conditions (BBP Δ + 33 ± 18; HRT Δ + 38 ± 21 W; p = 0.112). In conclusion, a ballistic exercise provided an effective method of inducing PAP and increasing upper-body PPO; moreover, this elicited similar increases in PPO as a traditional heavy resistance exercise preloading stimulus.

Computational and experimental models of the human torso for non-penetrating ballistic impact.

PubMed

Roberts, J C; Merkle, A C; Biermann, P J; Ward, E E; Carkhuff, B G; Cain, R P; O'Connor, J V

2007-01-01

Both computational finite element and experimental models of the human torso have been developed for ballistic impact testing. The human torso finite element model (HTFEM), including the thoracic skeletal structure and organs, was created in the finite element code LS-DYNA. The skeletal structure was assumed to be linear-elastic while all internal organs were modeled as viscoelastic. A physical human surrogate torso model (HSTM) was developed using biosimulant materials and the same anthropometry as the HTFEM. The HSTM response to impact was recorded with piezoresistive pressure sensors molded into the heart, liver and stomach and an accelerometer attached to the sternum. For experimentation, the HSTM was outfitted with National Institute of Justice (NIJ) Level I, IIa, II and IIIa soft armor vests. Twenty-six ballistic tests targeting the HSTM heart and liver were conducted with 22 caliber ammunition at a velocity of 329 m/s and 9 mm ammunition at velocities of 332, 358 and 430 m/s. The HSTM pressure response repeatability was found to vary by less than 10% for similar impact conditions. A comparison of the HSTM and HTFEM response showed similar pressure profiles and less than 35% peak pressure difference for organs near the ballistic impact point. Furthermore, the peak sternum accelerations of the HSTM and HTFEM varied by less than 10% for impacts over the sternum. These models provide comparative tools for determining the thoracic response to ballistic impact and could be used to evaluate soft body armor design and efficacy, determine thoracic injury mechanisms and assist with injury prevention.

Wound ballistics and blast injuries.

PubMed

Prat, N J; Daban, J-L; Voiglio, E J; Rongieras, F

2017-12-01

Wounds due to gunshot and explosions, while usually observed during battlefield combat, are no longer an exceptional occurrence in civilian practice in France. The principles of wound ballistics are based on the interaction between the projectile and the human body as well as the transfer of energy from the projectile to tissues. The treatment of ballistic wounds relies on several principles: extremity wound debridement and absence of initial closure, complementary medical treatment, routine immobilization, revision surgery and secondary closure. Victims of explosions usually present with a complex clinical picture since injuries are directly or indirectly related to the shock wave (blast) originating from the explosion. These injuries depend on the type of explosive device, the environment and the situation of the victim at the time of the explosion, and are classed as primary, secondary, tertiary or quaternary. Secondary injuries due to flying debris and bomb fragments are generally the predominant presenting symptoms while isolated primary injuries (blast) are rare. The resulting complexity of the clinical picture explains why triage of these victims is particularly difficult. Certain myths, such as inevitable necrosis of the soft tissues that are displaced by the formation of the temporary cavitation by the projectile, or sterilization of the wounds by heat generated by the projectile should be forgotten. Ballistic-protective body armor and helmets are not infallible, even when they are not perforated, and can even be at the origin of injuries, either due to missile impact, or to the blast. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

75 FR 25208 - Announcement of Body Armor Research Needs Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-07

... DEPARTMENT OF COMMERCE National Institute of Standards and Technology Announcement of Body Armor Research Needs Meeting AGENCY: National Institute of Standards and Technology, Department of Commerce. ACTION: Notice of meeting. SUMMARY: The National Institute of Standards and Technology (NIST) invites...

Comparison of Biophysical Characteristics and Predicted Thermophysiological Responses of Three Prototype Body Armor Systems Versus Baseline U.S. Army Body Armor Systems

DTIC Science & Technology

2015-06-19

effective and scientifically valid method of making comparisons of clothing and equipment changes prior to conducting human research. predictive modeling...valid method of making comparisons of clothing and equipment changes prior to conducting human research. 2 INTRODUCTION Modern day...clothing and equipment changes prior to conducting human research. METHODS Ensembles Three different body armor (BA) plus clothing ensembles were

76 FR 70165 - Ballistic-Resistant Body Armor Standard Workshop

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-10

...-on-one discussion with personnel leading development of the revised standard. Time slots for individual breakout sessions may be requested from the registration page indicated below. Additional time... the general session. Individual time slots will be available on the registration page. We request that...

WARFIGHTER SUPPORT: Independent Expert Assessment of Army Body Armor Test Results and Procedures Needed Before Fielding

DTIC Science & Technology

2009-10-01

protective vest and ceramic plate inserts. GAO observed Preliminary Design Model testing of new plate designs, which resulted in the Army’s...Table 1: Organizations Contacted for Information about Body Armor Testing 46 Figures Figure 1: ESAPI Plates as Worn inside Outer Tactical Vest 11...Central Command has required that DOD personnel in its area of operations be issued the Interceptor Body Armor system, comprising ceramic plates that

Modeling the effect of non-penetrating ballistic impact as a means of detecting behind armor blunt trauma.

PubMed

Roberts, Jack C; O'Connor, James V; Ward, Emily E

2005-06-01

According to the National Institute of Justice (NIJ) Standard 0101.04, the maximum deformation a soft armor vest can undergo without penetration is 44 mm. However, this does not take into account the effect of the pressure wave or energy transferred to the organs within the torso due to behind armor blunt trauma (BABT). Therefore, a study was undertaken to develop a finite element model (FEM) to study these effects. A finite element model (FEM) of the human thorax; complete with musculoskeletal structure and internal organs (heart, liver, lungs and stomach), intercostal muscle and skin, has been developed in LS-DYNA. A Kevlar vest was modeled on the chest to simulate non-penetrating ballistic impact. Using a projectile modeled with a size and mass equivalent to a 9 mm (124 grain) bullet at 360 and 425 m/s, four impacts were simulated against NIJ Level II and Level IIIa Kevlar vests at the midsternum and right thorax. At the same velocity, the pressures decreased by a factor of 3 and the energy absorbed by the organs decreased by a factor of 6 for the NIJ Level II and Level IIIa vests, respectively. As the projectile velocity increased, the peak pressures increased by a factor of 3 while the energy absorbed by the organs increased by a factor of 4. The resulting pressure profiles and kinetic energy exhibited by the respective organs indicate this model may be useful in identifying mechanisms of injury as well as organs at an elevated injury risk as a result of BABT.

Image-guided percutaneous removal of ballistic foreign bodies secondary to air gun injuries.

PubMed

Rothermund, Jacob L; Rabe, Andrew J; Zumberge, Nicholas A; Murakami, James W; Warren, Patrick S; Hogan, Mark J

2018-01-01

Ballistic injuries with retained foreign bodies from air guns is a relatively common problem, particularly in children and adolescents. If not removed in a timely fashion, the foreign bodies can result in complications, including pain and infection. Diagnostic methods to identify the presence of the foreign body run the entire gamut of radiology, particularly radiography, ultrasound (US) and computed tomography (CT). Removal of the foreign bodies can be performed by primary care, emergency, surgical, and radiologic clinicians, with or without imaging guidance. To evaluate the modalities of radiologic detection and the experience of image-guided ballistic foreign body removal related to air gun injuries within the interventional radiology department of a large pediatric hospital. A database of more than 1,000 foreign bodies that were removed with imaging guidance by the interventional radiologists at our institution was searched for ballistic foreign bodies from air guns. The location, dimensions, diagnostic modality, duration, complications and imaging modality used for removal were recorded. In addition, the use of sedation and anesthesia required for the procedures was also recorded. Sixty-one patients with ballistic foreign bodies were identified. All foreign bodies were metallic BBs or pellets. The age of the patients ranged from 5 to 20 years. The initial diagnostic modality to detect the foreign bodies was primarily radiography. The primary modality to assist in removal was US, closely followed by fluoroscopy. For the procedure, 32.7% of the patients required some level of sedation. Only two patients had an active infection at the time of the removal. The foreign bodies were primarily in the soft tissues; however, successful removal was also performed from intraosseous, intraglandular and intratendinous locations. All cases resulted in successful removal without complications. Image-guided removal of ballistic foreign bodies secondary to air guns is a very

Ballistic Resistance of Honeycomb Sandwich Panels under In-Plane High-Velocity Impact

PubMed Central

Yang, Shu; Wang, Dong; Yang, Li-Jun

2013-01-01

The dynamic responses of honeycomb sandwich panels (HSPs) subjected to in-plane projectile impact were studied by means of explicit nonlinear finite element simulations using LS-DYNA. The HSPs consisted of two identical aluminum alloy face-sheets and an aluminum honeycomb core featuring three types of unit cell configurations (regular, rectangular-shaped, and reentrant hexagons). The ballistic resistances of HSPs with the three core configurations were first analyzed. It was found that the HSP with the reentrant auxetic honeycomb core has the best ballistic resistance, due to the negative Poisson's ratio effect of the core. Parametric studies were then carried out to clarify the influences of both macroscopic (face-sheet and core thicknesses, core relative density) and mesoscopic (unit cell angle and size) parameters on the ballistic responses of the auxetic HSPs. Numerical results show that the perforation resistant capabilities of the auxetic HSPs increase as the values of the macroscopic parameters increase. However, the mesoscopic parameters show nonmonotonic effects on the panels' ballistic capacities. The empirical equations for projectile residual velocities were formulated in terms of impact velocity and the structural parameters. It was also found that the blunter projectiles result in higher ballistic limits of the auxetic HSPs. PMID:24187526

Ballistic resistance of honeycomb sandwich panels under in-plane high-velocity impact.

PubMed

Qi, Chang; Yang, Shu; Wang, Dong; Yang, Li-Jun

2013-01-01

The dynamic responses of honeycomb sandwich panels (HSPs) subjected to in-plane projectile impact were studied by means of explicit nonlinear finite element simulations using LS-DYNA. The HSPs consisted of two identical aluminum alloy face-sheets and an aluminum honeycomb core featuring three types of unit cell configurations (regular, rectangular-shaped, and reentrant hexagons). The ballistic resistances of HSPs with the three core configurations were first analyzed. It was found that the HSP with the reentrant auxetic honeycomb core has the best ballistic resistance, due to the negative Poisson's ratio effect of the core. Parametric studies were then carried out to clarify the influences of both macroscopic (face-sheet and core thicknesses, core relative density) and mesoscopic (unit cell angle and size) parameters on the ballistic responses of the auxetic HSPs. Numerical results show that the perforation resistant capabilities of the auxetic HSPs increase as the values of the macroscopic parameters increase. However, the mesoscopic parameters show nonmonotonic effects on the panels' ballistic capacities. The empirical equations for projectile residual velocities were formulated in terms of impact velocity and the structural parameters. It was also found that the blunter projectiles result in higher ballistic limits of the auxetic HSPs.

Optimization of Gas Metal Arc Welding (GMAW) Process for Maximum Ballistic Limit in MIL A46100 Steel Welded All-Metal Armor

NASA Astrophysics Data System (ADS)

Grujicic, M.; Ramaswami, S.; Snipes, J. S.; Yavari, R.; Yen, C.-F.; Cheeseman, B. A.

2015-01-01

Our recently developed multi-physics computational model for the conventional gas metal arc welding (GMAW) joining process has been upgraded with respect to its predictive capabilities regarding the process optimization for the attainment of maximum ballistic limit within the weld. The original model consists of six modules, each dedicated to handling a specific aspect of the GMAW process, i.e., (a) electro-dynamics of the welding gun; (b) radiation-/convection-controlled heat transfer from the electric arc to the workpiece and mass transfer from the filler metal consumable electrode to the weld; (c) prediction of the temporal evolution and the spatial distribution of thermal and mechanical fields within the weld region during the GMAW joining process; (d) the resulting temporal evolution and spatial distribution of the material microstructure throughout the weld region; (e) spatial distribution of the as-welded material mechanical properties; and (f) spatial distribution of the material ballistic limit. In the present work, the model is upgraded through the introduction of the seventh module in recognition of the fact that identification of the optimum GMAW process parameters relative to the attainment of the maximum ballistic limit within the weld region entails the use of advanced optimization and statistical sensitivity analysis methods and tools. The upgraded GMAW process model is next applied to the case of butt welding of MIL A46100 (a prototypical high-hardness armor-grade martensitic steel) workpieces using filler metal electrodes made of the same material. The predictions of the upgraded GMAW process model pertaining to the spatial distribution of the material microstructure and ballistic limit-controlling mechanical properties within the MIL A46100 butt weld are found to be consistent with general expectations and prior observations.

A Simple Ballistic Material Model for Soda-Lime Glass

DTIC Science & Technology

2009-01-01

Author’s personal copy A simple ballistic material model for soda-lime glass M. Grujicic a,*, B. Pandurangan a, N. Coutris a, B.A. Cheeseman b, C...Transparent armor Material modeling Ballistic performance Soda-lime glass a b s t r a c t Various open-literature experimental findings pertaining...notwithstanding any other provision of law, no person shall be subject to a penalty for failing to comply with a collection of information if it does not

7 CFR 1755.406 - Shield or armor ground resistance measurements.

Code of Federal Regulations, 2012 CFR

2012-01-01

... or armor ground resistance measurements shall be made on completed lengths of copper cable and wire... measurement shall be made between the copper cable and wire shield and ground and between the fiber optic... instructions. (d) Applicable results. (1) For all new copper cable and wire facilities and all new fiber optic...

7 CFR 1755.406 - Shield or armor ground resistance measurements.

Code of Federal Regulations, 2013 CFR

2013-01-01

... or armor ground resistance measurements shall be made on completed lengths of copper cable and wire... measurement shall be made between the copper cable and wire shield and ground and between the fiber optic... instructions. (d) Applicable results. (1) For all new copper cable and wire facilities and all new fiber optic...

7 CFR 1755.406 - Shield or armor ground resistance measurements.

Code of Federal Regulations, 2014 CFR

2014-01-01

... or armor ground resistance measurements shall be made on completed lengths of copper cable and wire... measurement shall be made between the copper cable and wire shield and ground and between the fiber optic... instructions. (d) Applicable results. (1) For all new copper cable and wire facilities and all new fiber optic...

Mosaic Transparent Armor System Final Report CRADA No. TC02162.0

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kuntz, J. D.; Breslin, M.

This was a collaborative effort between Lawrence Livermore National Security, LLC as manager and operator of Lawrence Livermore National Laboratory (LLNL) and The Protective Group, Inc. (TPG) to improve the performance of the mosaic transparent armor system (MTAS) for transparent armor applications, military and civilian. LLNL was to provide the unique MTAS technology and designs to TPG for innovative construction and ballistic testing of improvements needed for current and near future application of the armor windows on vehicles and aircraft. The goal of the project was to advance the technology of MTAS to the point that these mosaic transparent windowsmore » would be introduced and commercially manufactured for military vehicles and aircraft.« less

Bio-inspired Armor Protective Material Systems for Ballistic Shock Mitigation

DTIC Science & Technology

2011-01-01

Coupon testing a b s t r a c t Severe transient ballistic shocks from projectile impacts, mine blasts , or overhead artillery attacks can incapacitate an...past two decades [1]. A ballistic shock results from a significant amount of concentrated energy deposited from caliber projectile impacts, mine blasts ...LS- Dyna , has been predominately utilized to calculate the target shock responses including acceleration histo- ries, shock response spectra

Finite Element Based Optimization of Material Parameters for Enhanced Ballistic Protection

NASA Astrophysics Data System (ADS)

Ramezani, Arash; Huber, Daniel; Rothe, Hendrik

2013-06-01

The threat imposed by terrorist attacks is a major hazard for military installations, vehicles and other items. The large amounts of firearms and projectiles that are available, pose serious threats to military forces and even civilian facilities. An important task for international research and development is to avert danger to life and limb. This work will evaluate the effect of modern armor with numerical simulations. It will also provide a brief overview of ballistic tests in order to offer some basic knowledge of the subject, serving as a basis for the comparison of simulation results. The objective of this work is to develop and improve the modern armor used in the security sector. Numerical simulations should replace the expensive ballistic tests and find vulnerabilities of items and structures. By progressively changing the material parameters, the armor is to be optimized. Using a sensitivity analysis, information regarding decisive variables is yielded and vulnerabilities are easily found and eliminated afterwards. To facilitate the simulation, advanced numerical techniques have been employed in the analyses.

Effect of twist on transverse impact response of ballistic fiber yarns

DOE PAGES

Song, Bo; Lu, Wei -Yang

2015-06-15

A Hopkinson bar was employed to conduct transverse impact testing of twisted Kevlar KM2 fiber yarns at the same impact speed. The speed of Euler transverse wave generated by the impact was measured utilizing a high speed digital camera. The study included fiber yarns twisted by different amounts. The Euler transverse wave speed was observed to increase with increasing amount of twist of the fiber yarn, within the range of this investigation. As a result, the higher transverse wave speeds in the more twisted fiber yarns indicate better ballistic performance in soft body armors for personal protection.

Injuries of the head from backface deformation of ballistic protective helmets under ballistic impact.

PubMed

Rafaels, Karin A; Cutcliffe, Hattie C; Salzar, Robert S; Davis, Martin; Boggess, Brian; Bush, Bryan; Harris, Robert; Rountree, Mark Steve; Sanderson, Ellory; Campman, Steven; Koch, Spencer; Dale Bass, Cameron R

2015-01-01

Modern ballistic helmets defeat penetrating bullets by energy transfer from the projectile to the helmet, producing helmet deformation. This deformation may cause severe injuries without completely perforating the helmet, termed "behind armor blunt trauma" (BABT). As helmets become lighter, the likelihood of larger helmet backface deformation under ballistic impact increases. To characterize the potential for BABT, seven postmortem human head/neck specimens wearing a ballistic protective helmet were exposed to nonperforating impact, using a 9 mm, full metal jacket, 124 grain bullet with velocities of 400-460 m/s. An increasing trend of injury severity was observed, ranging from simple linear fractures to combinations of linear and depressed fractures. Overall, the ability to identify skull fractures resulting from BABT can be used in forensic investigations. Our results demonstrate a high risk of skull fracture due to BABT and necessitate the prevention of BABT as a design factor in future generations of protective gear. © 2014 American Academy of Forensic Sciences.

Comparing the Effects of Different Body Armor Systems on the Occupational Performance of Police Officers.

PubMed

Schram, Ben; Orr, Robin; Pope, Rodney; Hinton, Ben; Norris, Geoff

2018-05-01

Policing duties may inherently be dangerous due to stab, blunt trauma and ballistic threats. The addition of individual light armor vests (ILAVs) has been suggested as a means to protect officers. However, the addition of the extra load of the ILAV may affect officer ability to conduct occupational tasks. The purpose of this study was to determine if wearing any of three different ILAVs made by different companies with their preferred materials and designs (ILAV A, 4.68 percent body weight, ILAV B, 4.05 percent body weight, & ILAV C, 3.71 percent body weight) affected occupational task performance when compared to that in normal station wear. A prospective, within-subjects repeated measures design was employed, using a counterbalanced randomization in which each ILAV was worn for an entire day while officers completed a variety of occupationally relevant tasks. These tasks included a victim drag, car exit and 5-meter sprint, step down and marksmanship task. To compare the effects of the ILAVs on these tasks, a multivariate repeated measures analysis of variance (ANOVA) was conducted, with post hoc pairwise comparisons using a Bonferroni adjustment. Results showed that performance in each task did not vary between any of the ILAV or normal station wear conditions. There was less variability in the marksmanship task with ILAV B, however. The results suggest that none of the ILAVs used in this study were heavy enough to significantly affect task performance in the assessed tasks when compared to wearing normal station wear.

Comparing the Effects of Different Body Armor Systems on the Occupational Performance of Police Officers

PubMed Central

Orr, Robin; Hinton, Ben; Norris, Geoff

2018-01-01

Policing duties may inherently be dangerous due to stab, blunt trauma and ballistic threats. The addition of individual light armor vests (ILAVs) has been suggested as a means to protect officers. However, the addition of the extra load of the ILAV may affect officer ability to conduct occupational tasks. The purpose of this study was to determine if wearing any of three different ILAVs made by different companies with their preferred materials and designs (ILAV A, 4.68 percent body weight, ILAV B, 4.05 percent body weight, & ILAV C, 3.71 percent body weight) affected occupational task performance when compared to that in normal station wear. A prospective, within-subjects repeated measures design was employed, using a counterbalanced randomization in which each ILAV was worn for an entire day while officers completed a variety of occupationally relevant tasks. These tasks included a victim drag, car exit and 5-meter sprint, step down and marksmanship task. To compare the effects of the ILAVs on these tasks, a multivariate repeated measures analysis of variance (ANOVA) was conducted, with post hoc pairwise comparisons using a Bonferroni adjustment. Results showed that performance in each task did not vary between any of the ILAV or normal station wear conditions. There was less variability in the marksmanship task with ILAV B, however. The results suggest that none of the ILAVs used in this study were heavy enough to significantly affect task performance in the assessed tasks when compared to wearing normal station wear. PMID:29723995

Armored RNA Technology for Production of Ribonuclease-Resistant Viral RNA Controls and Standards

PubMed Central

Pasloske, Brittan L.; Walkerpeach, Cindy R.; Obermoeller, R. Dawn; Winkler, Matthew; DuBois, Dwight B.

1998-01-01

The widespread use of sensitive assays for the detection of viral and cellular RNA sequences has created a need for stable, well-characterized controls and standards. We describe the development of a versatile, novel system for creating RNase-resistant RNA. “Armored RNA” is a complex of MS2 bacteriophage coat protein and RNA produced in Escherichia coli by the induction of an expression plasmid that encodes the coat protein and an RNA standard sequence. The RNA sequences are completely protected from RNase digestion within the bacteriophage-like complexes. As a prototype, a 172-base consensus sequence from a portion of the human immunodeficiency virus type 1 (HIV-1) gag gene was synthesized and cloned into the packaging vector used to produce the bacteriophage-like particles. After production and purification, the resulting HIV-1 Armored RNA particles were shown to be resistant to degradation in human plasma and produced reproducible results in the Amplicor HIV-1 Monitor assay for 180 days when stored at −20°C or for 60 days at 4°C. Additionally, Armored RNA preparations are homogeneous and noninfectious. PMID:9817878

Mechanical properties of silicone based composites as a temperature insensitive ballistic backing material for quantifying back face deformation.

PubMed

Edwards, Tara D; Bain, Erich D; Cole, Shawn T; Freeney, Reygan M; Halls, Virginia A; Ivancik, Juliana; Lenhart, Joseph L; Napadensky, Eugene; Yu, Jian H; Zheng, James Q; Mrozek, Randy A

2018-04-01

This paper describes a new witness material for quantifying the back face deformation (BFD) resulting from high rate impact of ballistic protective equipment. Accurate BFD quantification is critical for the assessment and certification of personal protective equipment, such as body armor and helmets, and ballistic evaluation. A common witness material is ballistic clay, specifically, Roma Plastilina No. 1 (RP1). RP1 must be heated to nearly 38°C to pass calibration, and used within a limited time frame to remain in calibration. RP1 also exhibits lot-to-lot variability and is sensitive to time, temperature, and handling procedures, which limits the BFD accuracy and reproducibility. A new silicone composite backing material (SCBM) was developed and tested side-by-side with heated RP1 using quasi-static indentation and compression, low velocity impact, spherical projectile penetration, and both soft and hard armor ballistic BFD measurements to compare their response over a broad range of strain rates and temperatures. The results demonstrate that SCBM mimics the heated RP1 response at room temperature and exhibits minimal temperature sensitivity. With additional optimization of the composition and processing, SCBM could be a drop-in replacement for RP1 that is used at room temperature during BFD quantification with minimal changes to the current RP1 handling protocols and infrastructure. It is anticipated that removing the heating requirement, and temperature-dependence, associated with RP1 will reduce test variability, simplify testing logistics, and enhance test range productivity. Published by Elsevier B.V.

Computer Aided Ballistic Orbit Classification Around Small Bodies

NASA Astrophysics Data System (ADS)

Villac, Benjamin F.; Anderson, Rodney L.; Pini, Alex J.

2016-09-01

Orbital dynamics around small bodies are as varied as the shapes and dynamical states of these bodies. While various classes of orbits have been analyzed in detail, the global overview of relevant ballistic orbits at particular bodies is not easily computed or organized. Yet, correctly categorizing these orbits will ease their future use in the overall trajectory design process. This paper overviews methods that have been used to organize orbits, focusing on periodic orbits in particular, and introduces new methods based on clustering approaches.

77 FR 39259 - Agency Information Collection Activities; Proposed Collection; Comments Requested: Body Armor in...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-02

... technological collection techniques or other forms of information technology, e.g., permitting electronic... associated with prison environments. There is little data on body armor use by correctional officers, such as...

Measuring the Blast and Ballistic Performance of Armor

DTIC Science & Technology

2015-10-15

Typical ballistic test instrumentation is depicted in Fig. 1. The gun system employs a Mann barrel , available in a range of calibers1 (e.g., .22 cal...setup. (A) Mann barrel gun system; (B) computer and data acquisition interface; (C) remote, manual trigger; (D) velocity screens; (E) high speed video...1 Caliber corresponds to the diameter of the gun barrel , usually expressed in inches; e.g., .30 cal

Wall slipping behavior of foam with nanoparticle-armored bubbles and its flow resistance factor in cracks.

PubMed

Lv, Qichao; Li, Zhaomin; Li, Binfei; Husein, Maen; Shi, Dashan; Zhang, Chao; Zhou, Tongke

2017-07-11

In this work, wall slipping behavior of foam with nanoparticle-armored bubbles was first studied in a capillary tube and the novel multiphase foam was characterized by a slipping law. A crack model with a cuboid geometry was then used to compare with the foam slipping results from the capillary tube and also to evaluate the flow resistance factor of the foam. The results showed that the slipping friction force F FR in the capillary tube significantly increased by addition of modified SiO 2 nanoparticles, and an appropriate power law exponents by fitting F FR vs. Capillary number, Ca, was 1/2. The modified nanoparticles at the surface were bridged together and formed a dense particle "armor" surrounding the bubble, and the interconnected structures of the "armor" with strong steric integrity made the surface solid-like, which was in agreement with the slip regime associated with rigid surface. Moreover, as confirmed by 3D microscopy, the roughness of the bubble surface increased with nanoparticle concentration, which in turn increased the slipping friction force. Compared with pure SDBS foam, SDBS/SiO 2 foam shows excellent stability and high flow resistance in visual crack. The resistance factor of SiO 2 /SDBS foam increased as the wall surface roughness increased in core cracks.

The method of neutron imaging as a tool for the study of the dynamics of water movement in wet aramid-based ballistic body armour panels

NASA Astrophysics Data System (ADS)

Reifler, Felix A.; Lehmann, Eberhard H.; Frei, Gabriel; May, Hans; Rossi, René

2006-07-01

A new non-destructive method based on neutron imaging (neutron radiography) to determine the exact water content in aramid-based soft body armour panels is presented. While investigating the ballistic resistance of aramid-based body armour panels under a wet condition, it is important to precisely determine their water content and its chronological development. Using the presented method, the influence of water amount and location on impact testing as well as its time dependence was shown. In the ballistic panels used, spreading of water strongly depended on the kind of quilting. Very fast water migration could be observed when the panels were held vertically. Some first results regarding the water distribution in wet panels immediately after the impact are presented. On the basis of the presented results, requirements for a standard for testing the performance of ballistic panels in the wet state are deduced.

Composite armor, armor system and vehicle including armor system

DOEpatents

Chu, Henry S.; Jones, Warren F.; Lacy, Jeffrey M.; Thinnes, Gary L.

2013-01-01

Composite armor panels are disclosed. Each panel comprises a plurality of functional layers comprising at least an outermost layer, an intermediate layer and a base layer. An armor system incorporating armor panels is also disclosed. Armor panels are mounted on carriages movably secured to adjacent rails of a rail system. Each panel may be moved on its associated rail and into partially overlapping relationship with another panel on an adjacent rail for protection against incoming ordnance from various directions. The rail system may be configured as at least a part of a ring, and be disposed about a hatch on a vehicle. Vehicles including an armor system are also disclosed.

Enhanced stab resistance of armor composites with functionalized silica nanoparticles

NASA Astrophysics Data System (ADS)

Mahfuz, Hassan; Clements, Floria; Rangari, Vijaya; Dhanak, Vinod; Beamson, Graham

2009-03-01

Traditionally shear thickening fluid (STF) reinforced with Kevlar has been used to develop flexible armor. At the core of the STF-Kevlar composites is a mixture of polyethylene glycol (PEG) and silica particles. This mixture is often known as STF and is consisted of approximately 45 wt % PEG and 55 wt % silica. During rheological tests, STF shows instantaneous spike in viscosity above a critical shear rate. Fabrication of STF-Kevlar composites requires preparation of STF, dilution with ethanol, and then impregnation with Kevlar. In the current approach, nanoscale silica particles were dispersed directly into a mixture of PEG and ethanol through a sonic cavitation process. Two types of silica nanoparticles were used in the investigation: 30 nm crystalline silica and 7 nm amorphous silica. The admixture was then reinforced with Kevlar fabric to produce flexible armor composites. In the next step, silica particles are functionalized with a silane coupling agent to enhance bonding between silica and PEG. The performance of the resulting armor composites improved significantly. As evidenced by National Institute of Justice spike tests, the energy required for zero-layer penetration (i.e., no penetration) jumped twofold: from 12 to 25 J cm2/g. The source of this improvement has been traced to the formation of siloxane (Si-O-Si) bonds between silica and PEG and superior coating of Kevlar filaments with particles. Fourier transform infrared, x-ray photoemission spectroscopy, and scanning electron microscopy studies were performed to examine chemical bonds, elemental composition, and particle dispersion responsible for such improvement. In summary, our experiments have demonstrated that functionalization of silica particles followed by direct dispersion into PEG resulted in superior Kevlar composites having much higher spike resistance.

Ballistic near-field heat transport in dense many-body systems

NASA Astrophysics Data System (ADS)

Latella, Ivan; Biehs, Svend-Age; Messina, Riccardo; Rodriguez, Alejandro W.; Ben-Abdallah, Philippe

2018-01-01

Radiative heat transport mediated by near-field interactions is known to be superdiffusive in dilute, many-body systems. Here we use a generalized Landauer theory of radiative heat transfer in many-body planar systems to demonstrate a nonmonotonic transition from superdiffusive to ballistic transport in dense systems. We show that such a transition is associated to a change of the polarization of dominant modes. Our findings are complemented by a quantitative study of the relaxation dynamics of the system in the different regimes of heat transport. This result could have important consequences on thermal management at nanoscale of many-body systems.

Acute Effects of Static vs. Ballistic Stretching on Strength and Muscular Fatigue Between Ballet Dancers and Resistance-Trained Women.

PubMed

Lima, Camila D; Brown, Lee E; Wong, Megan A; Leyva, Whitney D; Pinto, Ronei S; Cadore, Eduardo L; Ruas, Cassio V

2016-11-01

Lima, CD, Brown, LE, Wong, MA, Leyva, WD, Pinto, RS, Cadore, EL, and Ruas, CV. Acute effects of static vs. ballistic stretching on strength and muscular fatigue between ballet dancers and resistance-trained women. J Strength Cond Res 30(11): 3220-3227, 2016-Stretching is used to increase joint range of motion, but the acute effects can decrease muscle strength. However, this may depend on the population or mode of stretching. The purpose of this study was to compare the acute effects of static vs. ballistic stretching on strength and muscular fatigue between ballet dancers and resistance-trained women. Fifteen resistance-trained women (age 23.8 ± 1.80 years, mass 67.47 ± 7.77 kg, height 168.30 ± 5.53 cm) and 12 ballet dancers (age 22.8 ± 3.04 years, mass 58.67 ± 5.65 kg, height 168.00 ± 7.69 cm) performed 5 days of testing. The first day was control (no stretching), whereas the other 4 days were static or ballistic stretching in a counterbalanced order. Range of motion, strength, and fatigue tests were also performed. Both groups demonstrated a significant decrease in hamstrings strength after static (102.71 ± 2.67 N·m) and ballistic stretching (99.49 ± 2.61 N·m) compared with control (113.059 ± 3.25 N·m), with no changes in quadriceps strength. For fatigue, only ballet dancers demonstrated a decrease from control (71.79 ± 4.88%) to ballistic (65.65 ± 8.19%), but no difference with static (65.01 ± 12.29%). These findings suggest that stretching decreases hamstrings strength similarly in ballet dancers and resistance-trained women, with no differences between modes of stretching. However, ballistic stretching only decreased muscular fatigue in ballet dancers, but not in resistance-trained women. Therefore, no stretching should be performed before strength performance. However, ballistic stretching may decrease acute muscular fatigue in ballet dancers.

Muscle activity during leg strengthening exercise using free weights and elastic resistance: effects of ballistic vs controlled contractions.

PubMed

Jakobsen, Markus Due; Sundstrup, Emil; Andersen, Christoffer H; Aagaard, Per; Andersen, Lars L

2013-02-01

The present study's aim was to evaluate muscle activity during leg exercises using elastic vs. isoinertial resistance at different exertion and loading levels, respectively. Twenty-four women and eighteen men aged 26-67 years volunteered to participate in the experiment. Electromyographic (EMG) activity was recorded in nine muscles during a standardized forward lunge movement performed with dumbbells and elastic bands during (1) ballistic vs. controlled exertion, and (2) at low, medium and high loads (33%, 66% and 100% of 10 RM, respectively). The recorded EMG signals were normalized to MVC EMG. Knee joint angle was measured using electronic inclinometers. The following results were obtained. Loading intensity affected EMG amplitude in the order: lowBallistic contractions always produced greater EMG activity than slow controlled contractions, and for most muscles ballistic contractions with medium load showed similar EMG amplitude as controlled contractions with high load. At flexed knee joint positions with elastic resistance, quadriceps and gluteus EMG amplitude during medium-load ballistic contractions exceeded that recorded during high-load controlled contractions. Quadriceps and gluteus EMG amplitude increased at flexed knee positions. In contrast, hamstrings EMG amplitude remained constant throughout ROM during dumbbell lunge, but increased at more extended knee joint positions during lunges using elastic resistance. Based on these results, it can be concluded that lunges performed using medium-load ballistic muscle contractions may induce similar or even higher leg muscle activity than lunges using high-load slow-speed contractions. Consequently, lunges using elastic resistance appear to be equally effective in inducing high leg muscle activity as traditional lunges using isoinertial resistance. Copyright © 2012 Elsevier B.V. All rights reserved.

An integrated approach towards future ballistic neck protection materials selection.

PubMed

Breeze, John; Helliker, Mark; Carr, Debra J

2013-05-01

Ballistic protection for the neck has historically taken the form of collars attached to the ballistic vest (removable or fixed), but other approaches, including the development of prototypes incorporating ballistic material into the collar of an under body armour shirt, are now being investigated. Current neck collars incorporate the same ballistic protective fabrics as the soft armour of the remaining vest, reflecting how ballistic protective performance alone has historically been perceived as the most important property for neck protection. However, the neck has fundamental differences from the thorax in terms of anatomical vulnerability, flexibility and equipment integration, necessitating a separate solution from the thorax in terms of optimal materials selection. An integrated approach towards the selection of the most appropriate combination of materials to be used for each of the two potential designs of future neck protection has been developed. This approach requires evaluation of the properties of each potential material in addition to ballistic performance alone, including flexibility, mass, wear resistance and thermal burden. The aim of this article is to provide readers with an overview of this integrated approach towards ballistic materials selection and an update of its current progress in the development of future ballistic neck protection.

A first-principles analysis of ballistic conductance, grain boundary scattering and vertical resistance in aluminum interconnects

NASA Astrophysics Data System (ADS)

Zhou, Tianji; Lanzillo, Nicholas A.; Bhosale, Prasad; Gall, Daniel; Quon, Roger

2018-05-01

We present an ab initio evaluation of electron scattering mechanisms in Al interconnects from a back-end-of-line (BEOL) perspective. We consider the ballistic conductance as a function of nanowire size, as well as the impact of surface oxidation on electron transport. We also consider several representative twin grain boundaries and calculate the specific resistivity and reflection coefficients for each case. Lastly, we calculate the vertical resistance across the Al/Ta(N)/Al and Cu/Ta(N)/Cu interfaces, which are representative of typical vertical interconnect structures with diffusion barriers. Despite a high ballistic conductance, the calculated specific resistivities at grain boundaries are 70-100% higher in Al than in Cu, and the vertical resistance across Ta(N) diffusion barriers are 60-100% larger for Al than for Cu. These results suggest that in addition to the well-known electromigration limitations in Al interconnects, electron scattering represents a major problem in achieving low interconnect line resistance at fine dimensions.

Inroads in the Non-Invasive Diagnostics of Ballistic Impact Damage

DTIC Science & Technology

2006-11-01

2004; Wells, et al., 2002), Ti - 6Al - 4V metallic armor materials (Wells, et al., 2004) and, most recently, on a ballistic gelatin target (Wells, 2006...spiral cracking outside of the penetration cavity in a Ti - 6Al - 4V sample disk. This type of volumetric damage characterization information, otherwise...visualization of the penetration cavity and spiral cracking in a Ti - 6Al - 4V sample. 4 Figure 8. Quantitative 3-D unit damage fraction

Perforation of Thin Aluminum Alloy Plates by Blunt Projectiles - Experimental and Numerical Investigation

NASA Astrophysics Data System (ADS)

Wei, Gang; Zhang, Wei

2013-06-01

Reducing the armor weight has become a research focus in terms of armored material with the increasing requirement of the mobility and flexibility of tanks and armored vehicles in modern local wars. Due to high strength-to-density ratio, aluminum alloy has become a potential light armored material. In this study, both lab-scale ballistic test and finite element simulation were adopted to examine the ballistic resistance of aluminum alloy targets. Blunt high strength steel projectiles with 12.7 mm diameter were launched by light gas gun against 3.3 mm thick aluminum alloy plates at velocity of 90 ~ 170 m/s. The ballistic limit velocity was obtained. Plugging failure and obvious structure deformation of targets were observed, and with the impact velocity increasing, the target structure deformation decrease gradually. Corresponding 2D finite element simulations were conducted by ABAQUS/EXPLICIT combined with material performance testing. Good agreement between the numerical simulations and the experimental results was found. National Natural Science Foundation of China (No.: 11072072).

Investigation of New Materials and Methods of Construction of Personnel Armor

DTIC Science & Technology

2008-12-01

NEW MATERIALS AND METHODS OF CONSTRUCTION OF PERSONNEL ARMOR by Poh, Choon Wei December 2008 Thesis Advisor: Robert S. Hixson Second...REPORT TYPE AND DATES COVERED Master’s Thesis 4. TITLE AND SUBTITLE Investigation of New Materials and Methods of Construction of Personnel Armor 6...personnel and vehicle armor. However, much of this work has focused on finding materials that were very ‘strong’ to resist penetration of objects moving

Perforation of Thin Aluminum Alloy Plates by Blunt Projectiles - Experimental and Numerical Investigation

NASA Astrophysics Data System (ADS)

Wei, Gang; Zhang, Wei; Xiao, Xinke; Guo, Zitao

2011-06-01

Reducing the armor weight has become a research focus in terms of armored material with the increasing requirement of the mobility and flexibility of tanks and armored vehicles in modern local wars. Due to high strength-to-density ratio, aluminum alloy has become a potential light armored material. In this study, both lab-scale ballistic test and finite element simulation were adopted to examine the ballistic resistance of aluminum alloy targets. Blunt high strength steel projectiles with 12.7 mm diameter were launched by light gas gun against 3.3 mm thick aluminum alloy plates at velocity of 90 ~170 m/s. The ballistic limit velocity was obtained. Plugging failure and obvious structure deformation of targets were observed, and with the impact velocity increasing, the target structure deformation decrease gradually. Corresponding 2D finite element simulations were conducted by ABAQUS/EXPLICIT combined with material performance testing. Good agreement between the numerical simulations and the experimental results was found. Detailed computational results were provided to understand the deformation and failure mechanisms of the aluminum alloy plates.

The effect of high-pressure devitrification and densification on ballistic-penetration resistance of fused silica

NASA Astrophysics Data System (ADS)

Avuthu, Vasudeva Reddy

Despite the clear benefits offered by more advanced transparent materials, (e.g. transparent ceramics offer a very attractive combination of high stiffness and high hardness levels, highly-ductile transparent polymers provide superior fragment-containing capabilities, etc.), ballistic ceramic-glass like fused-silica remains an important constituent material in a majority of transparent impact-resistant structures (e.g. windshields and windows of military vehicles, portholes in ships, ground vehicles and spacecraft) used today. Among the main reasons for the wide-scale use of glass, the following three are most frequently cited: (i) glass-structure fabrication technologies enable the production of curved, large surface-area, transparent structures with thickness approaching several inches; (ii) relatively low material and manufacturing costs; and (iii) compositional modifications, chemical strengthening, and controlled crystallization have been demonstrated to be capable of significantly improving the ballistic properties of glass. In the present work, the potential of high-pressure devitrification and densification of fused-silica as a ballistic-resistance-enhancement mechanism is investigated computationally. In the first part of the present work, all-atom molecular-level computations are carried out to infer the dynamic response and material microstructure/topology changes of fused silica subjected to ballistic impact by a nanometer-sized hard projectile. The analysis was focused on the investigation of specific aspects of the dynamic response and of the microstructural changes such as the deformation of highly sheared and densified regions, and the conversion of amorphous fused silica to SiO2 crystalline allotropic modifications (in particular, alpha-quartz and stishovite). The microstructural changes in question were determined by carrying out a post-processing atom-coordination procedure. This procedure suggested the formation of high-density stishovite (and

Simple go/no-go test for subcritical damage in body armor panels

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fisher, Jason; Chimenti, D. E.

2011-06-23

The development of a simple test for subcritical damage in body armor panels using pressure-sensitive dye-indicator film has been performed and demonstrated effective. Measurements have shown that static indicator levels are accurately reproduced in dynamic loading events. Impacts from hard blunt impactors instrumented with an accelerometer and embedded force transducer were studied. Reliable correlations between the indicator film and instrumented impact force are shown for a range of impact energies. Force and acceleration waveforms with corresponding indicator film results are presented for impact events onto damaged and undamaged panels. We find that panel damage can occur at impact levels farmore » below the National Institute of Justice acceptance test standard.« less

Potentiation: Effect of Ballistic and Heavy Exercise on Vertical Jump Performance.

PubMed

Hester, Garrett M; Pope, Zachary K; Sellers, John H; Thiele, Ryan M; DeFreitas, Jason M

2017-03-01

Hester, GM, Pope, ZK, Sellers, JH, Thiele, RM, and DeFreitas, JM. Potentiation: Effect of ballistic and heavy exercise on vertical jump performance. J Strength Cond Res 31(3): 660-666, 2017-The purpose of this study was to compare the acute effects of heavy and ballistic conditioning protocols on vertical jump performance in resistance-trained men. Fourteen resistance-trained men (mean ± SD: age = 22 ± 2.1 years, body mass = 86.29 ± 9.95 kg, and height = 175.39 ± 9.34 cm) with an average relative full squat of 2.02 ± 0.28 times their body mass participated in this study. In randomized, counterbalanced order, subjects performed two countermovement vertical jumps before and 1, 3, 5, and 10 minutes after either performing 10 rapid jump squats or 5 heavy back squats. The back squat protocol consisted of 5 repetitions at 80% one repetition maximum (1RM), whereas the jump squat protocol consisted of 10 repetitions at 20% 1RM. Peak jump height (in centimeters) using a jump mat, along with power output (in Watts) and velocity (in meters per second) through a linear transducer, was recorded for each time interval. There was no significant condition × time interaction for any of the dependent variables (p = 0.066-0.127). In addition, there was no main effect for condition for any of the dependent variables (p = 0.457-0.899). Neither the ballistic nor heavy protocol used in this study enhanced vertical jump performance at any recovery interval. The use of these protocols in resistance-trained men to produce postactivation potentiation is not recommended.

Force-Velocity Relationship of Upper Body Muscles: Traditional Versus Ballistic Bench Press.

PubMed

García-Ramos, Amador; Jaric, Slobodan; Padial, Paulino; Feriche, Belén

2016-04-01

This study aimed to (1) evaluate the linearity of the force-velocity relationship, as well as the reliability of maximum force (F0), maximum velocity (V0), slope (a), and maximum power (P0); (2) compare these parameters between the traditional and ballistic bench press (BP); and (3) determine the correlation of F0 with the directly measured BP 1-repetition maximum (1RM). Thirty-two men randomly performed 2 sessions of traditional BP and 2 sessions of ballistic BP during 2 consecutive weeks. Both the maximum and mean values of force and velocity were recorded when loaded by 20-70% of 1RM. All force-velocity relationships were strongly linear (r > .99). While F0 and P0 were highly reliable (ICC: 0.91-0.96, CV: 3.8-5.1%), lower reliability was observed for V0 and a (ICC: 0.49-0.81, CV: 6.6-11.8%). Trivial differences between exercises were found for F0 (ES: < 0.2), however the a was higher for the traditional BP (ES: 0.68-0.94), and V0 (ES: 1.04-1.48) and P0 (ES: 0.65-0.72) for the ballistic BP. The F0 strongly correlated with BP 1RM (r: 0.915-0.938). The force-velocity relationship is useful to assess the upper body maximal capabilities to generate force, velocity, and power.

Preparing soft-bodied arthropods for arthropods for microscope examination: Armored Scales (Insects: Hemiptera: Diaspididae)

USDA-ARS?s Scientific Manuscript database

Proper identification of armored scales (Hemiptera: Diaspididae) requires preparation of the specimen on a microscope slide. This training video provides visual instruction on how to prepare armored scales specimens on microscope slides for examination and identification. Steps ranging from collect...

Perforation of thin aluminum alloy plates by blunt projectiles: An experimental and numerical investigation

NASA Astrophysics Data System (ADS)

Wei, G.; Zhang, W.

2014-04-01

Reducing the armor weight has become a research focus in terms of armored material. Due to high strength-to-density ratio, aluminum alloy has become a potential light armored material. In this study, both lab-scale ballistic test and finite element simulation were adopted to examine the ballistic resistance of aluminum alloy targets. Blunt high strength steel projectiles with 12.7 mm diameter were launched by light gas gun against 3.3 mm thickness 7A04 aluminum alloy plates at a velocity of 90~170 m/s. The ballistic limit velocity was obtained. Plugging failure and obvious structure deformation of targets were observed. Corresponding 2D finite element simulations were conducted by ABAQUS/EXPLICIT combined with material performance testing. The validity of numerical simulations was verified by comparing with the experimental results. Detailed analysis of the failure modes and characters of the targets were carried out to reveal the target damage mechanism combined with the numerical simulation.

Factors Modulating Post-Activation Potentiation of Jump, Sprint, Throw, and Upper-Body Ballistic Performances: A Systematic Review with Meta-Analysis.

PubMed

Seitz, Laurent B; Haff, G Gregory

2016-02-01

Although post-activation potentiation (PAP) has been extensively examined following the completion of a conditioning activity (CA), the precise effects on subsequent jump, sprint, throw, and upper-body ballistic performances and the factors modulating these effects have yet to be determined. Moreover, weaker and stronger individuals seem to exhibit different PAP responses; however, how they respond to the different components of a strength-power-potentiation complex remains to be elucidated. This meta-analysis determined (1) the effect of performing a CA on subsequent jump, sprint, throw, and upper-body ballistic performances; (2) the influence of different types of CA, squat depths during the CA, rest intervals, volumes of CA, and loads during the CA on PAP; and (3) how individuals of different strength levels respond to these various strength-power-potentiation complex components. A computerized search was conducted in ADONIS, ERIC, SPORTDiscus, EBSCOhost, Google Scholar, MEDLINE, and PubMed databases up to March 2015. The analysis comprised 47 studies and 135 groups of participants for a total of 1954 participants. The PAP effect is small for jump (effect size [ES] = 0.29), throw (ES = 0.26), and upper-body ballistic (ES = 0.23) performance activities, and moderate for sprint (ES = 0.51) performance activity. A larger PAP effect is observed among stronger individuals and those with more experience in resistance training. Plyometric (ES = 0.47) CAs induce a slightly larger PAP effect than traditional high-intensity (ES = 0.41), traditional moderate-intensity (ES = 0.19), and maximal isometric (ES = -0.09) CAs, and a greater effect after shallower (ES = 0.58) versus deeper (ES = 0.25) squat CAs, longer (ES = 0.44 and 0.49) versus shorter (ES = 0.17) recovery intervals, multiple- (ES = 0.69) versus single- (ES = 0.24) set CAs, and repetition maximum (RM) (ES = 0.51) versus sub-maximal (ES = 0.34) loads during the CA. It is noteworthy

Armor and anesthesia: exposure, feeling, and the soldier's body.

PubMed

MacLeish, Kenneth T

2012-03-01

For many civilians, the high-tech weapons, armor, and military medicine with which U.S. soldiers are equipped present an image of lethal capacity and physical invulnerability. But, as this article explores, soldiers themselves just as often associate the life-sustaining technology of modern warfare with feelings that range from a pragmatic ambivalence about exposure to harm all the way to profoundly unsettling vulnerability. This article, based on fieldwork among soldiers and military families at the U.S. Army's Ft. Hood, examines sensory and affective dimensions of soldiers' intimate bodily relationships with the technologies that alternately or even simultaneously keep them alive and expose them to harm. I argue that modern military discipline and technology conspire to cultivate soldiers as highly durable, capable, unfeeling, interchangeable bodies, or what might be called, after Susan Buck-Morss (1992), anesthetic subjects. But for soldiers themselves, their training, combat environment, protective gear, and weapons are a rich font of both emotional and bodily feeling that exists in complex tension with the also deeply felt military imperative to carry on in the face of extreme discomfort and danger.

Effect of armor and carrying load on body balance and leg muscle function.

PubMed

Park, Huiju; Branson, Donna; Kim, Seonyoung; Warren, Aric; Jacobson, Bert; Petrova, Adriana; Peksoz, Semra; Kamenidis, Panagiotis

2014-01-01

This study investigated the impact of weight and weight distribution of body armor and load carriage on static body balance and leg muscle function. A series of human performance tests were conducted with seven male, healthy, right-handed military students in seven garment conditions with varying weight and weight distributions. Static body balance was assessed by analyzing the trajectory of center of plantar pressure and symmetry of weight bearing in the feet. Leg muscle functions were assessed by analyzing the peak electromyography amplitude of four selected leg muscles during walking. Results of this study showed that uneven weight distribution of garment and load beyond an additional 9 kg impaired static body balance as evidenced by increased sway of center of plantar pressure and asymmetry of weight bearing in the feet. Added weight on non-dominant side of the body created greater impediment to static balance. Increased garment weight also elevated peak EMG amplitude in the rectus femoris to maintain body balance and in the medial gastrocnemius to increase propulsive force. Negative impacts on balance and leg muscle function with increased carrying loads, particularly with an uneven weight distribution, should be stressed to soldiers, designers, and sports enthusiasts. Copyright © 2013 Elsevier B.V. All rights reserved.

A Comparison between Bench Press Throw and Ballistic Push-Up tests to assess upper-body power in trained individuals.

PubMed

Bartolomei, Sandro; Nigro, Federico; Ruggeri, Sandro; Lanzoni, Ivan Malagoli; Ciacci, Simone; Merni, Franco; Sadres, Eliahu; Hoffman, Jay R; Semprini, Gabriele

2018-03-06

The purpose of the present study was to validate the ballistic push-up test performed with hands on a force plate (BPU) as a method to measure upper-body power. Twenty-eight experienced resistance trained men (age = 25.4 ± 5.2 y; body mass = 78.5 ± 9.0 kg; body height = 179.6 ± 7.8 cm) performed, two days apart, a bench press 1RM test and upper-body power tests. Mean power and peak power were assessed using the bench press throw test (BT) and the BPU test performed in randomized order. The area under the force/power curve (AUC) obtained at BT was also calculated. Power expressed at BPU was estimated using a time-based prediction equation. Mean force and the participant's body weight were used to predict the bench press 1RM. Pearson product moment correlations were used to examine relationships between the power assessment methods and between the predicted 1RM bench and the actual value. Large correlations (0.79; p < 0.001) were found between AUC and mean power expressed at BPU. Large correlations were also detected between mean power and peak power expressed at BT and BPU (0.75; p < 0.001 and 0.74; p < 0.001, respectively). Very large correlations (0.87; p < 0.001) were found between the 1RM bench and the 1RM predicted by the BPU. Results of the present study indicate that BPU represents a valid and reliable method to estimate the upper-body power in resistance-trained individuals.

An Investigation of Three Extremity Armor Systems: Determination of Physiological, Biomechanical, and Physical Performance Effects and Quantification of Body Area Coverage

DTIC Science & Technology

2012-03-19

THREE EXTREMITY ARMOR SYSTEMS: DETERMINATION OF PHYSIOLOGICAL, BIOMECHANICAL, AND PHYSICAL PERFORMANCE EFFECTS AND QUANTIFICATION OF BODY AREA...PHYSICAL PERFORMANCE EFFECTS AND QUANTIFICATION OF BODY AREA COVERAGE 5a. CONTRACT NUMBER MIPR #M9545006MPR6CC7 5b. GRANT NUMBER 5c. PROGRAM ELEMENT...WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) 8. PERFORMING ORGANIZATION REPORT NUMBER NATICK/TR-12/014 9

DOE Office of Scientific and Technical Information (OSTI.GOV)

Taylor, Paul A.; Cooper, Candice Frances; Burnett, Damon J.

Light body armor development for the warfighter is based on trial-and-error testing of prototype designs against ballistic projectiles. Torso armor testing against blast is virtually nonexistent but necessary to ensure adequate protection against injury to the heart and lungs. In this report, we discuss the development of a high-fidelity human torso model, it's merging with the existing Sandia Human Head-Neck Model, and development of the modeling & simulation (M&S) capabilities necessary to simulate wound injury scenarios. Using the new Sandia Human Torso Model, we demonstrate the advantage of virtual simulation in the investigation of wound injury as it relates tomore » the warfighter experience. We present the results of virtual simulations of blast loading and ballistic projectile impact to the tors o with and without notional protective armor. In this manner, we demonstrate the ad vantages of applying a modeling and simulation approach to the investigation of wound injury and relative merit assessments of protective body armor without the need for trial-and-error testing.« less

Resonance and streaming of armored microbubbles

NASA Astrophysics Data System (ADS)

Spelman, Tamsin; Bertin, Nicolas; Stephen, Olivier; Marmottant, Philippe; Lauga, Eric

2015-11-01

A new experimental technique involves building a hollow capsule which partially encompasses a microbubble, creating an ``armored microbubble'' with long lifespan. Under acoustic actuation, such bubble produces net streaming flows. In order to theoretically model the induced flow, we first extend classical models of free bubbles to describe the streaming flow around a spherical body for any known axisymmetric shape oscillation. A potential flow model is then employed to determine the resonance modes of the armored microbubble. We finally use a more detailed viscous model to calculate the surface shape oscillations at the experimental driving frequency, and from this we predict the generated streaming flows.

A ballistic evaluation of the impact resistance of spectacle lens materials.

PubMed

Oliver, A L; Chou, B R

1993-10-01

The impact resistance of chemically and thermally hardened glass lenses of 2.2- and 3.0-mm thicknesses was evaluated using a ballistic test. Each lens was edged and mounted into a spectacle frame, which was placed on a standard headform. A 6.5-mm steel ball was fired from an air gun at the center of the lens at increasing speeds until the lens broke. The multiple impact data were used to plot cumulative breakage curves. We found that heat-treated photochromic glass and heat-treated crown glass fail at similar missile speeds and that chemical treating considerably improves the impact resistance of crown glass but not of photochromic glass. The poorer performance of photochromic lenses indicates that they should not be prescribed when optimal impact protection is required. Plastic lenses show superior performance.

Shock destruction armor system

DOEpatents

Froeschner, Kenneth E.

1993-01-01

A shock destruction armor system is constructed and arranged to destroy the force of impact of a projectile by shock hydrodynamics. The armor system is designed to comprise a plurality of superimposed armor plates each preferably having a thickness less than five times the projectile's diameter and are preferably separated one-from-another by a distance at least equal to one-half of the projectile's diameter. The armor plates are effective to hydrodynamically and sequentially destroy the projectile. The armor system is particularly adapted for use on various military vehicles, such as tanks, aircraft and ships.

Ballistics and anatomical modelling - A review.

PubMed

Humphrey, Caitlin; Kumaratilake, Jaliya

2016-11-01

Ballistics is the study of a projectiles motion and can be broken down into four stages: internal, intermediate, external and terminal ballistics. The study of the effects a projectile has on a living tissue is referred to as wound ballistics and falls within terminal ballistics. To understand the effects a projectile has on living tissues the mechanisms of wounding need to be understood. These include the permanent and temporary cavities, energy, yawing, tumbling and fragmenting. Much ballistics research has been conducted including using cadavers, animal models and simulants such as ballistics ordnance gelatine. Further research is being conducted into developing anatomical, 3D, experimental and computational models. However, these models need to accurately represent the human body and its heterogeneous nature which involves understanding the biomechanical properties of the different tissues and organs. Further research is needed to accurately represent the human tissues with simulants and is slowly being conducted. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

The Effects of Ballistic and Non-Ballistic Bench Press on Mechanical Variables.

PubMed

Moir, Gavin L; Munford, Shawn N; Moroski, Lindsey L; Davis, Shala E

2017-02-21

To investigate the effects of ballistic and non-ballistic bench press performed with loads equivalent to 30 and 90% 1-repetition maximum (1-RM) on mechanical variables. Eleven resistance-trained men (age: 23.0 ± 1.4 years; mass: 98.4 ± 14.4 kg) attended four testing sessions where they performed one of the following sessions: 1) three sets of five non-ballistic repetitions performed with a load equivalent to 30% 1-RM (30N-B), 2) three sets of five ballistic repetitions performed with a load equivalent to 30% 1-RM (30B), 3) three sets of four non-ballistic repetitions with a load equivalent to 90% 1-RM (90N-B), 4) three sets of four ballistic repetitions with a load equivalent to 90% 1-RM (90B). Force plates and a 3-D motion analysis system were used to determine the velocity, force, power output (PO) and work during each repetition. The heavier loads resulted in significantly greater forces applied to the barbell (mean differences: 472-783 N, p<0.001), but lower barbell velocities (mean differences: 0.85-1.20 m/s, p<0.001) and PO (mean differences: 118-492 W, p≤0.022). The ballistic conditions enhanced the mechanical variables only at the lower load with 30B producing significantly greater force (mean difference: 263 N, p<0.001), velocity (mean difference: 0.33 m/s, p<0.001), and PO (mean difference: 335 W, p<0.001) compared to 30N-B. Furthermore, the increase in PO across the 3 sets in 30B was significantly different from all other conditions (p=0.013). The total mechanical work performed was significantly greater for the conditions with the heavier loads compared to those with the lighter loads (mean differences: 3,62-5,600 J, p<0.001) and that performed during the ballistic conditions was significantly greater than that performed during the non-ballistic conditions with the same load (mean differences: 945-1,030 J, p<0.001). Ballistic bench press may be an effective exercise for developing power output and multiple sets may elicit post

Metallurgical Examination of 2 Inch, 2-1/2 Inch, and 3 Inch Rolled Homogeneous Armor Employed in the Ballistic Evaluation of Armor against 57 mm and 90 mm ARmor-Piercing Projectiles

DTIC Science & Technology

1949-08-24

t I- Results of Hardoed Survey* at Aberden Proving Ground an at Watertown Axue Average Average Surface Hardness...of surface hardness determination, made at Aberdeen ProvIng Ground and crocea-sectional hardness surveys made at Watertcwn Arsenal are limted in Table...Against 57 ma and, 90 w Armor-Piercing Ammunvtion,," At the request of this Arsenall,, Aerdeen Proving Ground provided 80 x 120" sections cut from a

Study on Protection Mechanism of 30CrMnMo-UHMWPE Composite Armor

PubMed Central

Zhou, Yu; Li, Guoju; Fan, Qunbo; Wang, Yangwei; Zheng, Haiyang; Tan, Lin; Xu, Xuan

2017-01-01

The penetration of a 30CrMnMo ultra-high molecular weight polyethylene armor by a high-speed fragment was investigated via experiments and simulations. Analysis of the projectile revealed that the nose (of the projectile) is in the non-equilibrium state at the initial stage of penetration, and the low-speed regions undergo plastic deformation. Subsequently, the nose-tail velocities of the projectile were virtually identical and fluctuated together. In addition, the effective combination of the steel plate and polyethylene (PE) laminate resulted in energy absorption by the PE just before the projectile nose impacts the laminate. This early absorption plays a positive role in the ballistic performance of the composite armor. Further analysis of the internal energy and mass loss revealed that the PE laminate absorbs energy via the continuous and stable failure of PE fibers during the initial stages of penetration, and absorbs energy via deformation until complete penetration occurs. The energy absorbed by the laminate accounts for 68% of the total energy absorption, indicating that the laminate plays a major role in energy absorption during the penetration process. PMID:28772764

Supercurrent and multiple Andreev reflections in micrometer-long ballistic graphene Josephson junctions.

PubMed

Zhu, Mengjian; Ben Shalom, Moshe; Mishchsenko, Artem; Fal'ko, Vladimir; Novoselov, Kostya; Geim, Andre

2018-02-08

Ballistic Josephson junctions are predicted to support a number of exotic physics processess, providing an ideal system to inject the supercurrent in the quantum Hall regime. Herein, we demonstrate electrical transport measurements on ballistic superconductor-graphene-superconductor junctions by contacting graphene to niobium with a junction length up to 1.5 μm. Hexagonal boron nitride encapsulation and one-dimensional edge contacts guarantee high-quality graphene Josephson junctions with a mean free path of several micrometers and record-low contact resistance. Transports in normal states including the observation of Fabry-Pérot oscillations and Sharvin resistance conclusively witness the ballistic propagation in the junctions. The critical current density J C is over one order of magnitude larger than that of the previously reported junctions. Away from the charge neutrality point, the I C R N product (I C is the critical current and R N the normal state resistance of junction) is nearly a constant, independent of carrier density n, which agrees well with the theory for ballistic Josephson junctions. Multiple Andreev reflections up to the third order are observed for the first time by measuring the differential resistance in the micrometer-long ballistic graphene Josephson junctions.

Finite element analysis for the evaluation of protective functions of helmets against ballistic impact.

PubMed

Lee, H P; Gong, S W

2010-10-01

The ballistic impact of a human head model protected by a Personnel Armor System Ground Troops Kevlar® helmet is analysed using the finite element method. The emphasis is to examine the effect of the interior cushioning system as a shock absorber in mitigating ballistic impact to the head. The simulations of the frontal and side impacts of the full metal jacket (FMJ) and fragment-simulating projectile (FSP) were carried out using LS-DYNA. It was found that the Kevlar® helmet with its interior nylon and leather strap was able to defeat both the FMJ and FSP without the projectiles penetrating the helmet. However, the head injuries caused by the FMJ impact can be fatal due to the high stiffness of the interior strap. The bulge section at the side of the Kevlar® helmet had more room for deformation that resulted in less serious head injuries.

Evaluating Upper-Body Strength and Power From a Single Test: The Ballistic Push-up.

PubMed

Wang, Ran; Hoffman, Jay R; Sadres, Eliahu; Bartolomei, Sandro; Muddle, Tyler W D; Fukuda, David H; Stout, Jeffrey R

2017-05-01

Wang, R, Hoffman, JR, Sadres, E, Bartolomei, S, Muddle, TWD, Fukuda, DH, and Stout, JR. Evaluating upper-body strength and power from a single test: the ballistic push-up. J Strength Cond Res 31(5): 1338-1345, 2017-The purpose of this study was to examine the reliability of the ballistic push-up (BPU) exercise and to develop a prediction model for both maximal strength (1 repetition maximum [1RM]) in the bench press exercise and upper-body power. Sixty recreationally active men completed a 1RM bench press and 2 BPU assessments in 3 separate testing sessions. Peak and mean force, peak and mean rate of force development, net impulse, peak velocity, flight time, and peak and mean power were determined. Intraclass correlation coefficients were used to examine the reliability of the BPU. Stepwise linear regression was used to develop 1RM bench press and power prediction equations. Intraclass correlation coefficient's ranged from 0.849 to 0.971 for the BPU measurements. Multiple regression analysis provided the following 1RM bench press prediction equation: 1RM = 0.31 × Mean Force - 1.64 × Body Mass + 0.70 (R = 0.837, standard error of the estimate [SEE] = 11 kg); time-based power prediction equation: Peak Power = 11.0 × Body Mass + 2012.3 × Flight Time - 338.0 (R = 0.658, SEE = 150 W), Mean Power = 6.7 × Body Mass + 1004.4 × Flight Time - 224.6 (R = 0.664, SEE = 82 W); and velocity-based power prediction equation: Peak Power = 8.1 × Body Mass + 818.6 × Peak Velocity - 762.0 (R = 0.797, SEE = 115 W); Mean Power = 5.2 × Body Mass + 435.9 × Peak Velocity - 467.7 (R = 0.838, SEE = 57 W). The BPU is a reliable test for both upper-body strength and power. Results indicate that the mean force generated from the BPU can be used to predict 1RM bench press, whereas peak velocity and flight time measured during the BPU can be used to predict upper-body power. These findings support the potential use of the BPU as a valid method to evaluate upper-body strength and power.

Buildings vs. ballistics: Quantifying the vulnerability of buildings to volcanic ballistic impacts using field studies and pneumatic cannon experiments

NASA Astrophysics Data System (ADS)

Williams, G. T.; Kennedy, B. M.; Wilson, T. M.; Fitzgerald, R. H.; Tsunematsu, K.; Teissier, A.

2017-09-01

Recent casualties in volcanic eruptions due to trauma from blocks and bombs necessitate more rigorous, ballistic specific risk assessment. Quantitative assessments are limited by a lack of experimental and field data on the vulnerability of buildings to ballistic hazards. An improved, quantitative understanding of building vulnerability to ballistic impacts is required for informing appropriate life safety actions and other risk reduction strategies. We assessed ballistic impacts to buildings from eruptions at Usu Volcano and Mt. Ontake in Japan and compiled available impact data from eruptions elsewhere to identify common damage patterns from ballistic impacts to buildings. We additionally completed a series of cannon experiments which simulate ballistic block impacts to building claddings to investigate their performance over a range of ballistic projectile velocities, masses and energies. Our experiments provide new insights by quantifying (1) the hazard associated with post-impact shrapnel from building and rock fragments; (2) the effect of impact obliquity on damage; and (3) the additional impact resistance buildings possess when claddings are struck in areas directly supported by framing components. This was not well identified in previous work which may have underestimated building vulnerability to ballistic hazards. To improve assessment of building vulnerability to ballistics, we use our experimental and field data to develop quantitative vulnerability models known as fragility functions. Our fragility functions and field studies show that although unreinforced buildings are highly vulnerable to large ballistics (> 20 cm diameter), they can still provide shelter, preventing death during eruptions.

Protective ability of the standard U.S. Military Personal Armor System, Ground Troops (PASGT) fragmentation vest against common small arms projectiles.

PubMed

Roberts, G K; Bullian, M E

1993-08-01

This study analyzes the ballistic protection provided by the standard U.S. Military Personal Armor System, Ground Troops fragmentation vest against threats from handgun and shotgun projectiles. Damage assessment was conducted using 10% ordnance gelatin, a tissue simulant which has been proven to have a close correlation with living tissue. The standard fragmentation vest was shown to provide protection from commonly encountered handgun bullets and shotgun pellets, but not from shotgun slugs or center-fire rifle bullets.

Statistical description of flume experiments on mixed-size bed-load transport and bed armoring processes

NASA Astrophysics Data System (ADS)

Chen, D.; Zhang, Y.

2008-12-01

The objective of this paper is to describe the statistical properties of experiments on non-uniform bed-load transport as well as the mechanism of bed armoring processes. Despite substantial effort made over the last two decades, the ability to compute the bed-load flux in a turbulent system remains poor. The major obstacles include the poor understanding of the formation of armor lays on bed surfaces. Such a layer is much flow-resistible than the underlying material and therefore significantly inhibits sediment transport from the reach. To study the problem, we conducted a flume study for mixed sand/gravel sediments. We observed that aggregated sediment blocks were the most common characters in armor layers - the largest sizes resist hydraulic forces, while the smaller sizes add interlocking support and prevent loss of fine material through gaps between the larger particles. Fractional transport rates with the existing of armor layers were measured with time by sediment trapping method at the end of flume. To address the intermittent and time-varying behavior of bed-load transport during bed armoring processes, we investigated the probability distribution of the fractional bed-load transport rates, and the underlying dynamic model derived from the continuous time random walk framework. Results indicate that it is critical to consider the impact of armor layers when a flow is sufficient to move some of the finer particles and yet insufficient to move all the larger particles on a channel bed.

Transparent Armor Cost Benefit Study

DTIC Science & Technology

2007-03-06

Armored HMMWVs (M1114s) 2003 2005 2006 UNCLASSIFIED UNCLASSIFIED 3/6/2007 4/17 2006 “Iraqi Pope Glass” 2004-2005 - GPK Recent HistoryEarly OIF Curb Wt...10,300lbs GVW: 12,100lbs UNCLASSIFIED UNCLASSIFIED 3/6/2007 5/17 Future Transparent Gun Shields Requirement: Upgrade GPKS with transparent armor for...enhanced situational awareness while maintaining soldier cover within armor envelope. AHI GS & GPK Upgraded Gunner Shield – Transparent Armored Gun

Assessment and monitoring of ballistic and maximal upper-body strength qualities in athletes.

PubMed

Young, Kieran P; Haff, G Gregory; Newton, Robert U; Gabbett, Tim J; Sheppard, Jeremy M

2015-03-01

To evaluate whether the dynamic strength index (DSI: ballistic peak force/isometric peak force) could be effectively used to guide specific training interventions and detect training-induced changes in maximal and ballistic strength. Twenty-four elite male athletes were assessed in the isometric bench press and a 45% 1-repetition-maximum (1RM) ballistic bench throw using a force plate and linear position transducer. The DSI was calculated using the peak force values obtained during the ballistic bench throw and isometric bench press. Athletes were then allocated into 2 groups as matched pairs based on their DSI and strength in the 1RM bench press. Over the 5 wk of training, athletes performed either high-load (80-100% 1RM) bench press or moderate-load (40-55% 1RM) ballistic bench throws. The DSI was sensitive to disparate training methods, with the bench-press group increasing isometric bench-press peak force (P=.035, 91% likely), and the ballistic-bench-throw group increasing bench-throw peak force to a greater extent (P≤.001, 83% likely). A significant increase (P≤.001, 93% likely) in the DSI was observed for both groups. The DSI can be used to guide specific training interventions and can detect training-induced changes in isometric bench-press and ballistic bench-throw peak force over periods as short as 5 wk.

Armored DNA in recombinant Baculoviruses as controls in molecular genetic assays.

PubMed

Freystetter, Andrea; Paar, Christian; Stekel, Herbert; Berg, Jörg

2017-10-01

The widespread use of molecular PCR-based assays in analytical and clinical laboratories brings about the need for test-specific, stable, and reliable external controls (EC) as well as standards and internal amplification controls (IC), in order to arrive at consistent test results. In addition, there is also a growing need to produce and provide stable, well-characterized molecular controls for quality assurance programs. In this study, we describe a novel approach to generate armored double-stranded DNA controls, which are encapsulated in baculovirus (BV) particles of the species Autographa californica multiple nucleopolyhedrovirus. We used the well-known BacPAK™ Baculovirus Expression System (Takara-Clontech), removed the polyhedrin promoter used for protein expression, and generated recombinant BV-armored DNAs. The obtained BV-armored DNAs were readily extracted by standard clinical DNA extraction methods, showed favorable linearity and performance in our clinical PCR assays, were resistant to DNase I digestion, and exhibited marked stability in human plasma and serum. BV-armored DNA ought to be used as ECs, quantification standards, and ICs in molecular assays, with the latter application allowing for the entire monitoring of clinical molecular assays for sample adequacy. BV-armored DNA may also be used to produce double-stranded DNA reference materials for, e.g., quality assurance programs. The ease to produce BV-armored DNA should make this approach feasible for a broad spectrum of molecular applications. Finally, as BV-armored DNAs are non-infectious to mammals, they may be even more conveniently shipped than clinical specimen.

Effect of concentric and eccentric velocity during heavy-load non-ballistic elbow flexion resistance exercise.

PubMed

Sampson, John A; Donohoe, Alison; Groeller, Herbert

2014-05-01

Mechanical and neuromuscular benefits arise during ballistic stretch-shortening cycle muscle activation, yet resistance training regimens are typically non-ballistic, and in contrast to ballistic movement, require a concentric deceleration phase. Twelve healthy males performed a unilateral, six repetition maximum non-ballistic elbow flexion-extension task during; (i) rapid shortening (RS), (ii) stretch-shortening cycle (SSC) and (iii) a 2-s eccentric and 2-s concentric control (C). A load cell and shaft encoder recorded respectively force and velocity. Surface electromyographic root mean square amplitude (EMGRMS) was recorded in the biceps and triceps brachii, and is reported as the relative (%) difference, normalised to control (C). The average lengthening and shortening velocity of SSC (0.57 ± 0.03 ms(-1); 0.43 ± 0.02 ms(-1)) was significantly greater than RS (0.22 ± 0.01 ms(-1); 0.35 ± 0.01 ms(-1)), and C (0.17 ± 0.00 ms(-1), 0.20 ± 0.00 ms(-1)). Peak eccentric force was increased (P<0.0001) and in the first 5% of concentric movement during SSC, in the first and last repetitions respectively (194.7 ± 8.4N, 164.1 ± 7.5 N) when compared to RS (163.3 ± 8.9 N, 152.4 ± 7.5 N) and C (155.9 ± 8.5 N, 152.2 ± 8.7 N). Eccentric EMGRMS in the biceps brachii was significantly increased during the first three and final repetitions of SSC (31.9 ± 10.9%, 46.7 ± 12.4, 69.3 ± 13.6%, 92.0 ± 16.4%), and the third and last repetitions of RS (35.9 ± 7.4%, 50.3 ± 10.9%), compared to C (0.00%, 15.8 ± 4.0%, 23.7 ± 4.1%, 39.2 ± 8.6%). In the current study, eccentric limb velocity potentiated eccentric and concentric force, concentric velocity, and eccentric EMG amplitude during non-ballistic exercise. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

Field Expedient Armor Modifications to US Armored Vehicles

DTIC Science & Technology

2006-06-01

Technology” (Fort Knox, KY: US Army Armor Center, 1983). 12 2Ian V. Hogg. Armour in Conflict, The Design and Tactics of Armoured Fighting...making their own whitewash. Lacking whitewash, they often resorted to commandeering white bed linen to drape over their vehicles. Both techniques proved...other Armoured Fighting Vehicles of World War II (New York: Exeter Books, 1983), 256. 19White, I. D., “Report on US vs. German Armor,” Exhibit 2, p. 6

The application of computed tomography in wound ballistics research

NASA Astrophysics Data System (ADS)

Tsiatis, Nick; Moraitis, Konstantinos; Papadodima, Stavroula; Spiliopoulou, Chara; Kelekis, Alexis; Kelesis, Christos; Efstathopoulos, Efstathios; Kordolaimi, Sofia; Ploussi, Agapi

2015-09-01

In wound ballistics research there is a relationship between the data that characterize a bullet and the injury resulted after shooting when it perforates the human body. The bullet path in the human body following skin perforation as well as the damaging effect cannot always be predictable as they depend on various factors such as the bullet's characteristics (velocity, distance, type of firearm and so on) and the tissue types that the bullet passes through. The purpose of this presentation is to highlight the contribution of Computed Tomography (CT) in wound ballistics research. Using CT technology and studying virtual “slices” of specific areas on scanned human bodies, allows the evaluation of density and thickness of the skin, the subcutaneous tissue, the muscles, the vital organs and the bones. Density data taken from Hounsfield units can be converted in g/ml by using the appropriate software. By evaluating the results of this study, the anatomy of the human body utilizing ballistic gel will be reproduced in order to simulate the path that a bullet follows. The biophysical analysis in wound ballistics provides another application of CT technology, which is commonly used for diagnostic and therapeutic purposes in various medical disciplines.

Kevlar® as a Potential Accident Radiation Dosimeter for First Responders, Law Enforcement and Military Personnel.

PubMed

Romanyukha, Alexander; Trompier, François; Benevides, Luis A

2016-08-01

Today the armed forces and law enforcement personnel wear body armor, helmets, and flak jackets composed substantially of Kevlar® fiber to prevent bodily injury or death resulting from physical, ballistic, stab, and slash attacks. Therefore, there is a high probability that during a radiation accident or its aftermath, the Kevlar®-composed body armor will be irradiated. Preliminary study with samples of Kevlar® foundation fabric obtained from body armor used by the U.S. Marine Corps has shown that all samples evaluated demonstrated an EPR signal, and this signal increased with radiation dose. Based on these results, the authors predict that, with individual calibration, exposure at dose above 1 Gy can be reliably detected in Kevlar® samples obtained from body armor. As a result of these measurements, a post-event reconstruction of exposure dose can be obtained by taking various samples throughout the armor body and helmet worn by the same irradiated individual. The doses can be used to create a whole-body dose map that would be of vital importance in a case of a partial body or heterogeneous exposure.

Laminate armor and related methods

DOEpatents

Chu, Henry S; Lillo, Thomas M; Zagula, Thomas M

2013-02-26

Laminate armor and methods of manufacturing laminate armor. Specifically, laminate armor plates comprising a commercially pure titanium layer and a titanium alloy layer bonded to the commercially pure titanium outer layer are disclosed, wherein an average thickness of the titanium alloy inner layer is about four times an average thickness of the commercially pure titanium outer layer. In use, the titanium alloy layer is positioned facing an area to be protected. Additionally, roll-bonding methods for manufacturing laminate armor plates are disclosed.

Principles of ballistics applicable to the treatment of gunshot wounds.

PubMed

Swan, K G; Swan, R C

1991-04-01

Ballistics is the science of the motion of a projectile through the barrel of a firearm (internal ballistics), during its subsequent flight (external ballistics), and during its final complicated motion after it strikes a target (terminal ballistics). Wound ballistics is a special case of terminal ballistics. Although wound ballistics is at best sets of approximations, its principles enter usefully into an evaluation of a gunshot wound and its treatment. A special consideration in these cases is their medicolegal aspects. At a minimum, the medical team receiving the patient should exert care not to destroy the clothing and in particular to cut around and not through bullet holes, to turn over to law enforcement officials any metallic foreign body recovered from the patient, and to describe precisely, or even to photograph, any entrance or exit wounds.

Stretch-and-release fabrication, testing and optimization of a flexible ceramic armor inspired from fish scales.

PubMed

Martini, Roberto; Barthelat, Francois

2016-10-13

Protective systems that are simultaneously hard to puncture and compliant in flexion are desirable, but difficult to achieve because hard materials are usually stiff. However, we can overcome this conflicting design requirement by combining plates of a hard material with a softer substrate, and a strategy which is widely found in natural armors such as fish scales or osteoderms. Man-made segmented armors have a long history, but their systematic implementation in a modern and a protective system is still hampered by a limited understanding of the mechanics and the design of optimization guidelines, and by challenges in cost-efficient manufacturing. This study addresses these limitations with a flexible bioinspired armor based on overlapping ceramic scales. The fabrication combines laser engraving and a stretch-and-release method which allows for fine tuning of the size and overlap of the scales, and which is suitable for large scale fabrication. Compared to a continuous layer of uniform ceramic, our fish-scale like armor is not only more flexible, but it is also more resistant to puncture and more damage tolerant. The proposed armor is also about ten times more puncture resistant than soft elastomers, making it a very attractive alternative to traditional protective equipment.

Shock imprint and rolling direction influence upon the breaking tenacity for 2P armor steel

NASA Astrophysics Data System (ADS)

Zichil, V.; Coseru, A.; Schnakovszky, C.; Herghelegiu, E.; Radu, C.

2016-08-01

The state of art in present literature shows that the breaking tenacity of a material is influenced by the integrity of the structure. Since armors used in aviation and to protect military vehicles are frequently impact loaded, through the contact between armor sheet and projectiles, or other foreign bodies, the authors have proposed to study the dependence between the breaking tenacity of 2P armor steel depending on the direction of the rolling of the armor plate, of the geometry (spherical imprint, pyramidal and linear imprint) and the depth of the deformation that results after impact. Tests were conducted upon CT (ASTM E- 399) specimen type, using the critical factor of stress intensity during the state of planar strain.

Fabrication, testing and modeling of a new flexible armor inspired from natural fish scales and osteoderms.

PubMed

Chintapalli, Ravi Kiran; Mirkhalaf, Mohammad; Dastjerdi, Ahmad Khayer; Barthelat, Francois

2014-09-01

Crocodiles, armadillo, turtles, fish and many other animal species have evolved flexible armored skins in the form of hard scales or osteoderms, which can be described as hard plates of finite size embedded in softer tissues. The individual hard segments provide protection from predators, while the relative motion of these segments provides the flexibility required for efficient locomotion. In this work, we duplicated these broad concepts in a bio-inspired segmented armor. Hexagonal segments of well-defined size and shape were carved within a thin glass plate using laser engraving. The engraved plate was then placed on a soft substrate which simulated soft tissues, and then punctured with a sharp needle mounted on a miniature loading stage. The resistance of our segmented armor was significantly higher when smaller hexagons were used, and our bio-inspired segmented glass displayed an increase in puncture resistance of up to 70% compared to a continuous plate of glass of the same thickness. Detailed structural analyses aided by finite elements revealed that this extraordinary improvement is due to the reduced span of individual segments, which decreases flexural stresses and delays fracture. This effect can however only be achieved if the plates are at least 1000 stiffer than the underlying substrate, which is the case for natural armor systems. Our bio-inspired system also displayed many of the attributes of natural armors: flexible, robust with 'multi-hit' capabilities. This new segmented glass therefore suggests interesting bio-inspired strategies and mechanisms which could be systematically exploited in high-performance flexible armors. This study also provides new insights and a better understanding of the mechanics of natural armors such as scales and osteoderms.

Development of a Meso-Scale Material Model for Ballistic Fabric and Its Use in Flexible-Armor Protection Systems

DTIC Science & Technology

2010-02-01

s mobility. Early materials used included leather , silk, metal chain mail, and metal plates. Replacement of metal with a nylon (poly-amide) fabric...tests of flexible-fabric armor, and as shown by Tan et al. (Ref 24) in a series of postimpact fabric-inspection studies, play an important role in

Innovative 3D Textile Structures for Soft Body Armor Protection: The EPIDARM Project

NASA Astrophysics Data System (ADS)

Maillet, Jérôme; Lefebvre, Marie; Boussu, François; Pirlot, Marc

There is a real need for battlefield soldiers to be protected from ­ballistic and CBRNE threats and also to be in permanent contact and localization with the logistic support of the commander. Ballistic, CBRNE and tactical jackets are currently three different components, developed separately and worn on top of each other. One of the EPIDARM project's targets is to propose a personal protection demonstration for the optimal system configuration in order to reduce the cost and weight while improving protection. The systems approach used for the EPIDARM program considers the protective system inside its environment (threat, the wearer - generic soldier, task and climates). The latest emergent technologies in ballistic and CBRN protection, ergonomic effectiveness and financial cost are considered and help to select final solutions.

The use of gelatine in wound ballistics research.

PubMed

Carr, D J; Stevenson, T; Mahoney, P F

2018-04-25

Blocks of gelatine are used in both lethality and survivability studies for broadly the same reason, i.e. comparison of ammunition effects using a material that it is assumed represents (some part of) the human body. The gelatine is used to visualise the temporary and permanent wound profiles; elements of which are recognised as providing a reasonable approximation to wounding in humans. One set of researchers aim to improve the lethality of the projectile, and the other to understand the effects of the projectile on the body to improve survivability. Research areas that use gelatine blocks are diverse and include ammunition designers, the medical and forensics communities and designers of ballistic protective equipment (including body armour). This paper aims to provide an overarching review of the use of gelatine for wound ballistics studies; it is not intended to provide an extensive review of wound ballistics as that already exists, e.g. Legal Med 23:21-29, 2016. Key messages are that test variables, projectile type (bullet, fragmentation), impact site on the body and intermediate layers (e.g. clothing, personal protective equipment (PPE)) can affect the resulting wound profiles.

Penetration Resistance of Armor Ceramics: Dimensional Analysis and Property Correlations

DTIC Science & Technology

2015-08-01

been reported in experimental studies. Particular ceramics analyzed here are low- and high-purity alumina, aluminum nitride, boron carbide, silicon...analyzed here are low- and high-purity alumina, aluminum nitride, boron carbide, silicon carbide, and titanium diboride. Data for penetration depth...include high hardness, high elastic stiffness, high strengths (static/dynamic compressive, shear, and bending), and low density relative to armor steels

Baseline UT Measurements for Armor Inspection

NASA Astrophysics Data System (ADS)

Margetan, Frank J.; Richter, Nate; Barnard, Dan; Hsu, David; Gray, Tim; Brasche, Lisa; Bruce Thompson, R.

2010-02-01

Some prototype armor panels are fabricated from several layers of dissimilar material bonded together. These may include ceramics, graphite composites, fiberglass composites and rubber. The ultrasonic properties of these layers influence inspections for armor defects. In this paper we describe measurements of ultrasonic velocity, attenuation, sound beam distortion and signal fluctuations for the individual layers comprising one armor prototype. We then discuss how knowledge of these properties can be used when choosing an optimum frequency for an ultrasonic pitch/catch immersion inspection. In our case an effective inspection frequency near 1.5 MHz affords: (1) adequate strength of through-transmitted signals in unflawed armor; (2) adequate lateral resolution for detecting small disbonds at interfaces; and (3) low levels of UT signal fluctuations due to the natural inhomogeneity of certain armor layers. The utility of this approach is demonstrated using armor panels containing artificial disbonds at selected interfaces.

Some Mechanical and Ballistic Properties of Titanium and Titanium Alloys

DTIC Science & Technology

1950-03-07

treated alloy steel armor, Justifies high expectations that titanium alloys may make excellent armor meterials . The corrosion resistant properties of...Fur* Metal Beat Treated -7-4 - -I-re Tensile Strength in pot 13,000 5 0,oo 230,000 203400 speifict Gravity 2.71 7.87 4.54 2.9 7.9 4.6 Stroe4cth-Vleight...solution of HCI: 50 parts by volume ECl-specific gravity 1.19 (37.6%) 50 parts by volume H2 0 2. Concentrated RIP: Hl-specific gravity 1.15 (14%) 3. 5

Transparent Armor Cost Benefit Study

DTIC Science & Technology

2008-04-01

2005 2006 UNCLASSIFIED UNCLASSIFIED 4/30/2008 4/17 2006 “Iraqi Pope Glass” 2004-2005 - GPK Recent HistoryEarly OIF Curb Wt: 10,300lbs GVW: 12,100lbs...UNCLASSIFIED UNCLASSIFIED 4/30/2008 5/17 Future Transparent Gun Shields Requirement: Upgrade GPKS with transparent armor for enhanced situational...awareness while maintaining soldier cover within armor envelope. AHI GS & GPK Upgraded Gunner Shield – Transparent Armored Gun Shield (TAGS

Transparent Armor Cost Benefit Study

DTIC Science & Technology

2006-10-30

added this cocoon to approximately 100 HMMWVs in Ramadi. 2006 “Iraqi Pope Glass” 2004-2005 - GPK Recent HistoryEarly OIF Curb Wt: 10,300lbs GVW...12,100lbs UNCLASSIFIED UNCLASSIFIED 10/30/2006 5/14 Future Transparent Gun Shields Requirement: Upgrade GPKS with transparent armor for enhanced...situational awareness while maintaining soldier cover within armor envelope. AHI GS & GPK Upgraded Gunner Shield – Transparent Armored Gun Shield (TAGS

Transient sheath overvoltages in armored power cables

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gustavsen, B.; Sletbak, J.

1996-07-01

This paper is concerned with methods of limiting the build-up of transient voltages between sheath and armor in long armored power cables. Calculations by a frequency dependent cable model demonstrate that this voltage can be efficiently limited to an acceptable level by introducing sheath-armor bondings at regular intervals, or by using a semiconductive sheath-armor interlayer. The paper investigates the required minimum length between bondings, as well as the required conductivity of the sheath-armor interlayer if the use of bondings is to be avoided.

The Need to Mobilize Armor in Afghanistan

DTIC Science & Technology

2009-02-20

success. 1 Kenneth W. Estes, Marines Under Armor (Naval Institute Press,2000)34 2 Increasing Combat...4 Kenneth W. Estes, Marines Under Armor (Naval Institute Press,2000) 202 5 Kenneth W. Estes, Marines Under ... Armor (Naval Institute Press,2000) 198- 202 6 Kenneth W. Estes, Marines Under Armor (Naval Institute Press,2000) 203 8 mechanized unit was needed to

Ballistic Transport Exceeding 28 μm in CVD Grown Graphene.

PubMed

Banszerus, Luca; Schmitz, Michael; Engels, Stephan; Goldsche, Matthias; Watanabe, Kenji; Taniguchi, Takashi; Beschoten, Bernd; Stampfer, Christoph

2016-02-10

We report on ballistic transport over more than 28 μm in graphene grown by chemical vapor deposition (CVD) that is fully encapsulated in hexagonal boron nitride. The structures are fabricated by an advanced dry van-der-Waals transfer method and exhibit carrier mobilities of up to three million cm(2)/(Vs). The ballistic nature of charge transport is probed by measuring the bend resistance in cross- and square-shaped devices. Temperature-dependent measurements furthermore prove that ballistic transport is maintained exceeding 1 μm up to 200 K.

Optimal ballistically captured Earth-Moon transfers

NASA Astrophysics Data System (ADS)

Ricord Griesemer, Paul; Ocampo, Cesar; Cooley, D. S.

2012-07-01

The optimality of a low-energy Earth-Moon transfer terminating in ballistic capture is examined for the first time using primer vector theory. An optimal control problem is formed with the following free variables: the location, time, and magnitude of the transfer insertion burn, and the transfer time. A constraint is placed on the initial state of the spacecraft to bind it to a given initial orbit around a first body, and on the final state of the spacecraft to limit its Keplerian energy with respect to a second body. Optimal transfers in the system are shown to meet certain conditions placed on the primer vector and its time derivative. A two point boundary value problem containing these necessary conditions is created for use in targeting optimal transfers. The two point boundary value problem is then applied to the ballistic lunar capture problem, and an optimal trajectory is shown. Additionally, the problem is then modified to fix the time of transfer, allowing for optimal multi-impulse transfers. The tradeoff between transfer time and fuel cost is shown for Earth-Moon ballistic lunar capture transfers.

Heavy Wrought Armor Metallurgical Evaluation of Commercially Produced Heavy Wrought Armor to Improve the Specification Requirements

DTIC Science & Technology

1948-02-02

Armor, Steel , Wrought, Over 4" WAL Project No.: 8.11-G TITLE HEAVY WROUGHT ARMOR Metallurgical Evaluation of Commercially Produced * . Heavy Wrought...Tentative Specification AXS-1803 Armor Plate: Steel , Wrought, Homogeneous (4" to 1211 inclusive). The results of the investi- gation indicated the...Plate: Steel , Wrought, Homogeneous (4" to 12" inclusive)". .’o* -... . . . . .’"-’ ."-. - -- -" - -"-. ."-. 2

Magneto-ballistic transport in GaN nanowires

DOE Office of Scientific and Technical Information (OSTI.GOV)

Santoruvo, Giovanni, E-mail: giovanni.santoruvo@epfl.ch; Allain, Adrien; Ovchinnikov, Dmitry

2016-09-05

The ballistic filtering property of nanoscale crosses was used to investigate the effect of perpendicular magnetic fields on the ballistic transport of electrons on wide band-gap GaN heterostructures. The straight scattering-less trajectory of electrons was modified by a perpendicular magnetic field which produced a strong non-linear behavior in the measured output voltage of the ballistic filters and allowed the observation of semi-classical and quantum effects, such as quenching of the Hall resistance and manifestation of the last plateau, in excellent agreement with the theoretical predictions. A large measured phase coherence length of 190 nm allowed the observation of universal quantum fluctuationsmore » and weak localization of electrons due to quantum interference up to ∼25 K. This work also reveals the prospect of wide band-gap GaN semiconductors as a platform for basic transport and quantum studies, whose properties allow the investigation of ballistic transport and quantum phenomena at much larger voltages and temperatures than in other semiconductors.« less

Armored spring-core superconducting cable and method of construction

DOEpatents

McIntyre, Peter M.; Soika, Rainer H.

2002-01-01

An armored spring-core superconducting cable (12) is provided. The armored spring-core superconducting cable (12) may include a spring-core (20), at least one superconducting strand (24) wound onto the spring-core (20), and an armored shell (22) that encases the superconducting strands (24). The spring-core (20) is generally a perforated tube that allows purge gases and cryogenic liquids to be circulated through the armored superconducting cable (12), as well as managing the internal stresses within the armored spring-core superconducting cable (12). The armored shell (22) manages the external stresses of the armored spring-core superconducting cable (12) to protect the fragile superconducting strands (24). The armored spring-core superconducting cable (12) may also include a conductive jacket (34) formed outwardly of the armored shell (22).

Light Armored Vehicles in Operations Other Than War

DTIC Science & Technology

2002-05-01

8Kenneth W. Estes, Marines Under Armor (Annapolis, MD: Naval Institute Press, 2000), 212. 6 attach and detach elements in task organizing for a...operations. Kenneth W. Estes writes in his book Marines Under Armor : “The light armored vehicles of the LAR battalions, by contrast [to tanks], continue...Martin’s Press, 1991. Estes, Kenneth W., Marines under Armor : The Marine Corps and the Armored Fighting Vehicle. 1916-2000. Annapolis, Maryland: Naval

Ballistic Anisotropic Magnetoresistance of Single-Atom Contacts.

PubMed

Schöneberg, J; Otte, F; Néel, N; Weismann, A; Mokrousov, Y; Kröger, J; Berndt, R; Heinze, S

2016-02-10

Anisotropic magnetoresistance, that is, the sensitivity of the electrical resistance of magnetic materials on the magnetization direction, is expected to be strongly enhanced in ballistic transport through nanoscale junctions. However, unambiguous experimental evidence of this effect is difficult to achieve. We utilize single-atom junctions to measure this ballistic anisotropic magnetoresistance (AMR). Single Co and Ir atoms are deposited on domains and domain walls of ferromagnetic Fe layers on W(110) to control their magnetization directions. They are contacted with nonmagnetic tips in a low-temperature scanning tunneling microscope to measure the junction conductances. Large changes of the magnetoresistance occur from the tunneling to the ballistic regime due to the competition of localized and delocalized d-orbitals, which are differently affected by spin-orbit coupling. This work shows that engineering the AMR at the single atom level is feasible.

Armor in Battle

DTIC Science & Technology

1986-03-01

Singling 2-59 808th TD Battalion: After-Action Report 2-88 Friendly Fire 2-92 Troyes - An Armored Attack 2-96 A Tank Platoon in Tunisia 2-106 L Calculated...damage as they did. 2-95 AF TROYE - ANAARIORED ATTACK BY BRIGADIEZR GENERAL ARTHUR L. WEST, JR. COLONEL MOSBY P. MILLER ... GNPERAL WOOD came in to...23 August. CCA, 4th Armored Division, coimnanded by Colonel Bruce C. Clarke, received orders on 24 August to seize Troyes , France, and secure

An Exploration of Integrated Ground Weapons Concepts for Armor/Anti- Armor Missions

DTIC Science & Technology

1991-01-01

de - vii signs. We examined the potential of these light armor designs closely, but did not compare them with the MBT designs. The main problem in...man MBT .............................. 93 35. Three-man remote turret des :6n: side view ............................ 95 36. Three-man remote turret...configurations, including two- and three-man ver- sions with remote and manned turrets. Section V describes some light armored vehicle de - signs, including two

Highly deformable bones: unusual deformation mechanisms of seahorse armor.

PubMed

Porter, Michael M; Novitskaya, Ekaterina; Castro-Ceseña, Ana Bertha; Meyers, Marc A; McKittrick, Joanna

2013-06-01

Multifunctional materials and devices found in nature serve as inspiration for advanced synthetic materials, structures and robotics. Here, we elucidate the architecture and unusual deformation mechanisms of seahorse tails that provide prehension as well as protection against predators. The seahorse tail is composed of subdermal bony plates arranged in articulating ring-like segments that overlap for controlled ventral bending and twisting. The bony plates are highly deformable materials designed to slide past one another and buckle when compressed. This complex plate and segment motion, along with the unique hardness distribution and structural hierarchy of each plate, provide seahorses with joint flexibility while shielding them against impact and crushing. Mimicking seahorse armor may lead to novel bio-inspired technologies, such as flexible armor, fracture-resistant structures or prehensile robotics. Copyright © 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Multiple pole electromagnetic propulsion system with separated ballistic guidance and electrical current contact surfaces

DOEpatents

Sims, Jr., James R.

2008-07-15

An electromagnetic propulsion system is disclosed having separate rails for ballistic guidance and for carrying current. In this system, one or more pairs of ballistic guidance rails are provided, with each ballistic guidance rail having a pair of current carrying rails joined to it to form a combined rail. Each combined rail is separated electrically from adjacent combined rails by electrically insulating blocks. Each of the current carrying rails in a given combined rail pair have the same electrical polarity, and the polarities alternate between adjacent combined rails. Armatures contact current carrying rails to complete the circuit to generate the accelerating Lorentz force on the armatures. Bore riders on the sabot and/or projectile are in contact with the ballistic guide rails. Separation of the current carrying and ballistic guidance functions increases resistance of the system to rail movement and bending, as well as reduced wear/damage to the rails. In further embodiments, a circumferential over wrap providing compressive force on the rails further increases resistance of the system to rail movement and bending.

Lightening Body Armor: Arroyo Support to the Army Response to Section 125 of the National Defense Authorization Act for Fiscal Year 2011

DTIC Science & Technology

2012-01-01

nel from fragmenting munitions, and the addition of SAPI will successfully defend against AK-47 ball ammunition. The ESAPI and XSAPI plates were...d ) Frequency of incidents of firefights 7.62 x 39mm ball Fragmenting munitions Threat X Threat Y Threat E Threat F Threat A Threat C Threat D...the threat in Afghani- stan today is primarily fragmenting munitions, 7.62mm x 39 ball bullets, and 7.62mm x 54R ball bullets. Current body armor

Ergonomics assessment of composite ballistic inserts for bullet- and fragment-proof vests.

PubMed

Majchrzycka, Katarzyna; Brochocka, Agnieszka; Luczak, Anna; Lężak, Krzysztof

2013-01-01

Personal protective equipment worn by uniformed services (e.g., the police and the military) must ensure protection against bodily injuries. However, a high degree of protection is always associated with significant discomfort. This article presents the results of an assessment of the ergonomics parameters of new special purpose products, ballistic inserts with improved ballistic resistance, and an assessment of the impact of the burden related to their use on the psychomotor performance of the subjects. An obstacle course and subjective ergonomics assessment questionnaires were used in tests. Thermal discomfort was also assessed. Psychological testing included tests enabling an assessment of the subjects' cognitive and psychomotor performance, and a subjective assessment of mental load. The tests did not show any decrease in the comfort of use of the new inserts with improved ballistic resistance compared to the inserts currently used.

Ballistic Transport for Limit-Periodic Jacobi Matrices with Applications to Quantum Many-Body Problems

NASA Astrophysics Data System (ADS)

Fillman, Jake

2017-03-01

We study Jacobi matrices that are uniformly approximated by periodic operators. We show that if the rate of approximation is sufficiently rapid, then the associated quantum dynamics are ballistic in a rather strong sense; namely, the (normalized) Heisenberg evolution of the position operator converges strongly to a self-adjoint operator that is injective on the space of absolutely summable sequences. In particular, this means that all transport exponents corresponding to well-localized initial states are equal to one. Our result may be applied to a class of quantum many-body problems. Specifically, we establish a lower bound on the Lieb-Robinson velocity for an isotropic XY spin chain on the integers with limit-periodic couplings.

Ballistic Protection

DTIC Science & Technology

2011-06-14

ground vehicle Program Management (PM) needs. Base Armor • Small Arms/Frag Opaque B-kits • Medium Cal/Frag Opaque B-kits • Transparent Armor Appliqué...packaged/mounted on a vehicle -representative structure and after introducing relevant environments and relevant threat engagements. Yes 4 MIL-STD 810...Contamination by Fluids • Solar Radiation • Rain • Humidity • Salt Fog • Sand & Dust • Acidic Atmosphere • Vibration • Shock • Fire, Smoke & Toxicity ATPD

Hierarchically Enhanced Impact Resistance of Bioinspired Composites.

PubMed

Gu, Grace X; Takaffoli, Mahdi; Buehler, Markus J

2017-07-01

An order of magnitude tougher than nacre, conch shells are known for being one of the toughest body armors in nature. However, the complexity of the conch shell architecture creates a barrier to emulating its cross-lamellar structure in synthetic materials. Here, a 3D biomimetic conch shell prototype is presented, which can replicate the crack arresting mechanisms embedded in the natural architecture. Through an integrated approach combining simulation, additive manufacturing, and drop tower testing, the function of hierarchy in conch shell's multiscale microarchitectures is explicated. The results show that adding the second level of cross-lamellar hierarchy can boost impact performance by 70% and 85% compared to a single-level hierarchy and the stiff constituent, respectively. The overarching mechanism responsible for the impact resistance of conch shell is the generation of pathways for crack deviation, which can be generalized to the design of future protective apparatus such as helmets and body armor. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Protection mechanisms of the iron-plated armor of a deep-sea hydrothermal vent gastropod

PubMed Central

Yao, Haimin; Dao, Ming; Imholt, Timothy; Huang, Jamie; Wheeler, Kevin; Bonilla, Alejandro; Suresh, Subra; Ortiz, Christine

2010-01-01

Biological exoskeletons, in particular those with unusually robust and multifunctional properties, hold enormous potential for the development of improved load-bearing and protective engineering materials. Here, we report new materials and mechanical design principles of the iron-plated multilayered structure of the natural armor of Crysomallon squamiferum, a recently discovered gastropod mollusc from the Kairei Indian hydrothermal vent field, which is unlike any other known natural or synthetic engineered armor. We have determined through nanoscale experiments and computational simulations of a predatory attack that the specific combination of different materials, microstructures, interfacial geometries, gradation, and layering are advantageous for penetration resistance, energy dissipation, mitigation of fracture and crack arrest, reduction of back deflections, and resistance to bending and tensile loads. The structure-property-performance relationships described are expected to be of technological interest for a variety of civilian and defense applications. PMID:20133823

Novel formulations of ballistic gelatin. 1. Rheological properties.

PubMed

Zecheru, Teodora; Său, Ciprian; Lăzăroaie, Claudiu; Zaharia, Cătălin; Rotariu, Traian; Stănescu, Paul-Octavian

2016-06-01

Ballistic gelatin is the simulant of the human body during field tests in forensics and other related fields, due to its physical and mechanical similarities to human trunk and organs. Since the ballistic gelatin used in present has important issues to overcome, an alternative approach is the use of gelatin-polymer composites, where a key factor is the insertion of biocompatible materials, which replicate accurately the human tissues. In order to be able to obtain an improved material in terms of mechanical performances by an easy industrial-scale technology, before the verification of the ballistic parameters by shooting in agreement with military standards, one of the best and cheapest solutions is to perform a thorough check of their rheological properties, in standard conditions. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

[Wound Ballistics – a Brief Overview].

PubMed

Bolliger, Stephan A; Eggert, Sebastian; Thali, Michael J

2016-02-03

Wound ballistics examines the specific effect, namely the wound profile, of bullets on the body by firing at synthetic models made of ordnance gelatine, glycerin soap and synthetic bones, validated with real cases from (battlefield) surgery and forensic pathology. Wound profile refers to the penetration depth, the bullet deformation/ fragmentation, the diameter of the permanent and the temporary wound cavity. Knowing these features and the used ammunition a surgeon can rapidly assess the amount damage within a patient. The forensic pathologist can draw conclusions as to the used ammunition based on the wound profile. By measuring of the destructive capability of different ammunition types, wound ballistics lays the foundation for guidelines concerning the maximum effect of military ammunition.

Ballistic movements of jumping legs implemented as variable components of cricket behaviour.

PubMed

Hustert, R; Baldus, M

2010-12-01

Ballistic accelerations of a limb or the whole body require special joint mechanisms in many animals. Specialized joints can be moved by stereotypic or variable motor control during motor patterns with and without ballistic components. As a model of variable motor control, the specialized femur-tibia (knee) joints of cricket (Acheta domesticus) hindlegs were studied during ballistic kicking, jumping and swimming and in non-ballistic walking. In this joint the tendons of the antagonistic flexor and the extensor muscles attach at different distances from the pivot and the opposed lever arms form an angle of 120 deg. A 10:1 ratio of their effective lever arms at full knee flexion helps to prepare for most ballistic extensions: the tension of the extensor can reach its peak while it is restrained by flexor co-contraction. In kicks, preparatory flexion is rapid and the co-contraction terminates just before knee extensions. Therefore, mainly the stored tension of the extensor muscle accelerates the small mass of the tibia. Jumps are prepared with slower extensor-flexor co-contractions that flex both knees simultaneously and then halt to rotate both legs outward to a near horizontal level. From there, catapult extension of both knees accelerates the body, supported by continued high frequency motor activity to their tibia extensor muscles during the ongoing push-off from the substrate. Premature extension of one knee instantly takes load from the lagging leg that extends and catches up, which finally results in a straight jump. In swimming, synchronous ballistic power strokes of both hindlegs drive the tibiae on a ventral-to-posterior trajectory through the water, well coordinated with the swimming patterns of all legs. In walking, running and climbing the steps of the hindlegs range between 45 deg flexion and 125 deg extension and use non-ballistic, alternating activity of knee flexor and extensor muscles. Steep climbing requires longer bursts from the extensor tibiae

Armored long RNA controls or standards for branched DNA assay for detection of human immunodeficiency virus type 1.

PubMed

Zhan, Sien; Li, Jinming; Xu, Ruihuan; Wang, Lunan; Zhang, Kuo; Zhang, Rui

2009-08-01

The branched DNA (bDNA) assay is a reliable method for quantifying the RNA of human immunodeficiency virus type 1 (HIV-1). The positive controls and standards for this assay for the detection of HIV-1 consist of naked RNA, which is susceptible to degradation by RNase. Armored RNA is a good candidate for an RNase-resistant positive control or standard. However, its use has been limited by the maximal length of the exogenous RNA packaged into virus-like particles by routine armored RNA technology. In the present study, we produced armored long RNA (armored L-RNA) controls or standards (AR-HIV-pol-3034b) for a bDNA assay of HIV-1 by increasing the amount and affinity of the pac sites (the pac site is a specific 19-nucleotide stem-loop region located at the 5' terminus of the MS2 bacteriophage replicase gene) by a one-plasmid double-expression system. AR-HIV-pol-3034b was completely resistant to DNase and RNase, was stable in normal human EDTA-preserved plasma at 4 degrees C for at least 6 months, and produced reproducible, linear results in the Versant HIV-1 RNA 3.0 assay. In conclusion, AR-HIV-pol-3034b could act as a positive control or standard in a bDNA assay for the detection of HIV-1. In addition, the one-plasmid double-expression system can be used as a better platform than the one-plasmid expression system and the two-plasmid coexpression system for expressing armored L-RNA.

3D-printing a 'family' of biomimetic models to explain armored grasping in syngnathid fishes.

PubMed

Porter, Michael M; Ravikumar, Nakul

2017-11-06

Seahorses and pipehorses evolved at least two independent strategies for tail grasping, despite being armored with a heavy body plating. To help explain mechanical trade-offs associated with the different designs, we created a 'family' of 3D-printed models that mimic variations in the presence and size of their armored plates. We measured the performance of the biomimetic proxies across several mechanical metrics, representative of their protective and prehensile capacities. Our results show that the models mimicking the tails of seahorses are the best all-around performers, while those of the distal-most, prehensile region of pipehorses are more flexible, but less protected. The comparison also reveals that different adaptive strategies provide different task-specific performance advantages, which could be leveraged for the design of armored manipulators or other bio-inspired technologies.

Characteristics of ballistic and blast injuries.

PubMed

Powers, David B; Delo, Robert I

2013-03-01

Ballistic injury wounds are formed by variable interrelated factors, such as the nature of the tissue, the compositional makeup of the bullet, distance to the target, and the velocity, shape, and mass of the of the projectile. This complex arrangement, with the ultimate outcome dependent on each other, makes the prediction of wounding potential difficult to assess. As the facial features are the component of the body most involved in a patient's personality and interaction with society, preservation of form, cosmesis, and functional outcome should remain the primary goals in the management of ballistic injury. A logical, sequential analysis of the injury patterns to the facial complex is an absolutely necessary component for the treatment of craniomaxillofacial ballistic injuries. Fortunately, these skill sets should be well honed in all craniomaxillofacial surgeons through their exposure to generalized trauma, orthognathic, oncologic, and cosmetic surgery patients. Identification of injured tissues, understanding the functional limitations of these injuries, and preservation of both hard and soft tissues minimizing the need for tissue replacement are paramount.

Ballistics for the neurosurgeon.

PubMed

Jandial, Rahul; Reichwage, Brett; Levy, Michael; Duenas, Vincent; Sturdivan, Larry

2008-02-01

Craniocerebral injuries from ballistic projectiles are qualitatively different from injuries in unconfined soft tissue with similar impact. Penetrating and nonpenetrating ballistic injuries are influenced not only by the physical properties of the projectile, but also by its ballistics. Ballistics provides information on the motion of projectiles while in the gun barrel, the trajectory of the projectile in air, and the behavior of the projectile on reaching its target. This basic knowledge can be applied to better understand the ultimate craniocerebral consequences of ballistic head injuries.

Fracture of Rolled Homogeneous Steel Armor (Nucleation Threshold Stress).

DTIC Science & Technology

1980-01-01

AD-AO81 618 ARMY ARMAMENT RESEARCH AND DEVELOPMENT COMMAND ABERD--ETC F/B 19/4 FRACTURE OF ROLLED HOMOGENEOUS STEEL ARMOR (NUCLEATION THRESHOL--ETC(U...ARBRL-MR-02984A QQ FRACTURE OF ROLLED HOMOGENEOUS STEEL ARMOR (NUCLEATION THRESHOLD STRESS) Gerald L Moss Lynn SeamanLy~ S, ,.DTIC S ELECTED January...nucleation stress, Crack threshold stress, Fracture, Fracture stress, Spallation, Armor, Rolled homogeneous steel armor M~ AS$TRACr (Vita ssf -- ebb

Local and distant trauma after hypervelocity ballistic impact to the pig hind limb.

PubMed

Chen, Jin; Zhang, Bo; Chen, Wei; Kang, Jian-Yi; Chen, Kui-Jun; Wang, Ai-Min; Wang, Jian-Min

2016-01-01

The development of high-energy weapons could increase the velocity of projectiles to well over 1000 m/s. The nature of the injuries caused by the ballistic impact of projectiles at velocities much faster than 1000 m/s is unclear. This study characterizes the mechanical and biochemical alterations caused by high-speed ballistic impact generated by spherical steel ball to the hind limbs of the pig. That the local and distal injuries caused by hypervelocity ballistic impact to the living body are also identified. It is showed that the severity of the injury was positively correlated with the velocity of the projectile. And 4000 m/s seems to be the critical velocity for the 5.6 mm spherical steel ball, which would cause severe damage to either local or distal organs, as below that speed the projectile penetrated the body while above that speed it caused severe damage to the body. In addition, vaporization prevented the projectile from penetrating the body and the consequent pressure wave seems to be the causal factor for the distant damage.

Dynamic Behavior and Optimization of Advanced Armor Ceramics: January-December 2012 Annual Report

DTIC Science & Technology

2015-03-01

tasks are reviewed: Nanostructured Armor Ceramics: Focus on Boron Carbide; The Role of Microstructure in the Impact Resistance for Silicon Carbide...Task 2: The Role of Microstructure in the Impact Resistance for Silicon Carbide (SiC), Core Program 22 3.1 Long-Range Goals 22 3.2 Background 22 3.3...from a 2-gr drop test using corn starch as a C source; D(0.9) = 1.27 μm ....................................................................12 Fig

Ballistic representation for kinematic access

NASA Astrophysics Data System (ADS)

Alfano, Salvatore

2011-01-01

This work uses simple two-body orbital dynamics to initially determine the kinematic access for a ballistic vehicle. Primarily this analysis was developed to assess when a rocket body might conjunct with an orbiting satellite platform. A family of access opportunities can be represented as a volume for a specific rocket relative to its launch platform. Alternately, the opportunities can be represented as a geographical footprint relative to aircraft or satellite position that encompasses all possible launcher locations for a specific rocket. A thrusting rocket is treated as a ballistic vehicle that receives all its energy at launch and follows a coasting trajectory. To do so, the rocket's burnout energy is used to find its equivalent initial velocity for a given launcher's altitude. Three kinematic access solutions are then found that account for spherical Earth rotation. One solution finds the maximum range for an ascent-only trajectory while another solution accommodates a descending trajectory. In addition, the ascent engagement for the descending trajectory is used to depict a rapid access scenario. These preliminary solutions are formulated to address ground-, sea-, or air-launched vehicles.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smith, Barton; Rajic, Slobodan; Hunter, Scott Robert

The objective of this work was to demonstrate that a superhydrophobic coating technology developed at Oak Ridge National Laboratory (ORNL) increases the water repellency of ballistic fabric beyond that provided by existing water repellency treatments. This increased water repellency has the potential to provide durable ballistic fabric for body armor without adding significant weight to the armor or significant manufacturing cost. Specimens of greige and scoured ballistic fabric were treated with a superhydrophobic coating and their weights and degree of water repellency were compared to specimens of untreated fabric. Treatment of both greige and scoured ballistic fabrics yielded highly watermore » repellent fabrics. Our measurements of the water droplet contact angles gave values of approximately 150 , near the lower limit of 160 for superhydrophobic surfaces. The coatings increased the fabric weights by approximately 6%, an amount that is many times less than the estimated weight increase in a conventional treatment of ballistic fabric. The treated fabrics retained a significant amount of water repellency following a basic abrasion test, with water droplet contact angles decreasing by 14 to 23 . Microscopic analysis of the coating applied to woven fabrics indicated that the coating adhered equally well to fibers of greige and scoured yarns. Future evaluation of the superhydrophobic water repellent treatment will involve the manufacture of shoot packs of treated fabric for ballistic testing and provide an analysis of manufacturing scale-up and cost-to-benefit considerations.« less

Armored Long RNA Controls or Standards for Branched DNA Assay for Detection of Human Immunodeficiency Virus Type 1▿

PubMed Central

Zhan, Sien; Li, Jinming; Xu, Ruihuan; Wang, Lunan; Zhang, Kuo; Zhang, Rui

2009-01-01

The branched DNA (bDNA) assay is a reliable method for quantifying the RNA of human immunodeficiency virus type 1 (HIV-1). The positive controls and standards for this assay for the detection of HIV-1 consist of naked RNA, which is susceptible to degradation by RNase. Armored RNA is a good candidate for an RNase-resistant positive control or standard. However, its use has been limited by the maximal length of the exogenous RNA packaged into virus-like particles by routine armored RNA technology. In the present study, we produced armored long RNA (armored L-RNA) controls or standards (AR-HIV-pol-3034b) for a bDNA assay of HIV-1 by increasing the amount and affinity of the pac sites (the pac site is a specific 19-nucleotide stem-loop region located at the 5′ terminus of the MS2 bacteriophage replicase gene) by a one-plasmid double-expression system. AR-HIV-pol-3034b was completely resistant to DNase and RNase, was stable in normal human EDTA-preserved plasma at 4°C for at least 6 months, and produced reproducible, linear results in the Versant HIV-1 RNA 3.0 assay. In conclusion, AR-HIV-pol-3034b could act as a positive control or standard in a bDNA assay for the detection of HIV-1. In addition, the one-plasmid double-expression system can be used as a better platform than the one-plasmid expression system and the two-plasmid coexpression system for expressing armored L-RNA. PMID:19494069

Hybrid composite laminates reinforced with Kevlar/carbon/glass woven fabrics for ballistic impact testing.

PubMed

Randjbaran, Elias; Zahari, Rizal; Jalil, Nawal Aswan Abdul; Majid, Dayang Laila Abang Abdul

2014-01-01

Current study reported a facile method to investigate the effects of stacking sequence layers of hybrid composite materials on ballistic energy absorption by running the ballistic test at the high velocity ballistic impact conditions. The velocity and absorbed energy were accordingly calculated as well. The specimens were fabricated from Kevlar, carbon, and glass woven fabrics and resin and were experimentally investigated under impact conditions. All the specimens possessed equal mass, shape, and density; nevertheless, the layers were ordered in different stacking sequence. After running the ballistic test at the same conditions, the final velocities of the cylindrical AISI 4340 Steel pellet showed how much energy was absorbed by the samples. The energy absorption of each sample through the ballistic impact was calculated; accordingly, the proper ballistic impact resistance materials could be found by conducting the test. This paper can be further studied in order to characterise the material properties for the different layers.

Hybrid Composite Laminates Reinforced with Kevlar/Carbon/Glass Woven Fabrics for Ballistic Impact Testing

PubMed Central

Randjbaran, Elias; Zahari, Rizal; Abdul Jalil, Nawal Aswan; Abang Abdul Majid, Dayang Laila

2014-01-01

Current study reported a facile method to investigate the effects of stacking sequence layers of hybrid composite materials on ballistic energy absorption by running the ballistic test at the high velocity ballistic impact conditions. The velocity and absorbed energy were accordingly calculated as well. The specimens were fabricated from Kevlar, carbon, and glass woven fabrics and resin and were experimentally investigated under impact conditions. All the specimens possessed equal mass, shape, and density; nevertheless, the layers were ordered in different stacking sequence. After running the ballistic test at the same conditions, the final velocities of the cylindrical AISI 4340 Steel pellet showed how much energy was absorbed by the samples. The energy absorption of each sample through the ballistic impact was calculated; accordingly, the proper ballistic impact resistance materials could be found by conducting the test. This paper can be further studied in order to characterise the material properties for the different layers. PMID:24955400

NDE of hybrid armor structures using acoustography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sandhu, Jaswinder S.; Pergantis, Charles G.

2011-06-23

The US Army is investigating the use of composite materials to deliver lightweight and more effective armor protection systems to soldiers and other army assets. However, widespread use of such hybrid armor will require a reliable but fast NDE methodology to ensure integrity of these components during manufacturing and while in service. Traditional ultrasonic inspection of such hybrid armor structures may prove to be very effective, but point-by-point ultrasonic scanning is inherently time-consuming and manufacturing slowdowns could develop in high-volume production of such armor systems. In this paper, we report on the application of acoustography for the NDE of hybridmore » armor structures. Acoustography differs from conventional ultrasonic testing in that test objects are inspected in full field, analogously to real time x-ray imaging. The approach uses a novel, super high resolution large area acousto-optic (AO) sensor, which allows image formation through simple ultrasound shadow casting, analogous to x-ray image formation. This NDE approach offers significant inspection speed advantage over conventional point-by-point ultrasonic scanning procedures and is well-suited for high volume production. We will report initial results on a number of hybrid armor plate specimens employing composite materials that are being investigated by the US Army. Acoustography NDE results will also be verified using other complimentary NDE methods.« less

75 FR 78268 - Draft NIJ Selection and Application Guide to Ballistic-Resistant Body Armor for Law Enforcement...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-12-15

... INFORMATION CONTACT: Casandra Robinson, by telephone at 202-305-2596 [Note: this is not a toll-free telephone number], or by e- mail at casandra.robinson@usdoj.gov . Dr. John H. Laub, Director, National Institute of...

Ballistic Missile Intercept from UCAV

DTIC Science & Technology

2011-12-01

aerodynamic forces acting on the ballistic missile , generates a ballistic flight path of the ballistic missile target based on the model developed by...for use against ballistic missile targets) [14] Hutchins, R., ME4703 “ Missile Flight Analysis ” Course Notes, Spring 2005. [15] Stevens, B., and...NAVAL POSTGRADUATE SCHOOL MONTEREY, CALIFORNIA THESIS Approved for public release; distribution is unlimited BALLISTIC MISSILE

Development and Verification of Body Armor Target Geometry Created Using Computed Tomography Scans

DTIC Science & Technology

2017-07-13

designated by other authorized documents. Citation of manufacturer’s or trade names does not constitute an official endorsement or approval of...modeling consisted of manual measurement of armor systems and translating those measurements to computer-aided design geometry, which can be tedious and...computer-aided design (CAD) human geometry model (referred to throughout as ORCA man) that is used in the Operational Requirement-based Casualty Assessment

Nondestructive ultrasonic characterization of armor grade silicon carbide

NASA Astrophysics Data System (ADS)

Portune, Andrew Richard

Ceramic materials have traditionally been chosen for armor applications for their superior mechanical properties and low densities. At high strain rates seen during ballistic events, the behavior of these materials relies upon the total volumetric flaw concentration more so than any single anomalous flaw. In this context flaws can be defined as any microstructural feature which detriments the performance of the material, potentially including secondary phases, pores, or unreacted sintering additives. Predicting the performance of armor grade ceramic materials depends on knowledge of the absolute and relative concentration and size distribution of bulk heterogeneities. Ultrasound was chosen as a nondestructive technique for characterizing the microstructure of dense silicon carbide ceramics. Acoustic waves interact elastically with grains and inclusions in large sample volumes, and were well suited to determine concentration and size distribution variations for solid inclusions. Methodology was developed for rapid acquisition and analysis of attenuation coefficient spectra. Measurements were conducted at individual points and over large sample areas using a novel technique entitled scanning acoustic spectroscopy. Loss spectra were split into absorption and scattering dominant frequency regimes to simplify analysis. The primary absorption mechanism in polycrystalline silicon carbide was identified as thermoelastic in nature. Correlations between microstructural conditions and parameters within the absorption equation were established through study of commercial and custom engineered SiC materials. Nonlinear least squares regression analysis was used to estimate the size distributions of boron carbide and carbon inclusions within commercial SiC materials. This technique was shown to additionally be capable of approximating grain size distributions in engineered SiC materials which did not contain solid inclusions. Comparisons to results from electron microscopy

Ceramic composite protection for turbine disc bursts. [for the A-300 aircraft

NASA Technical Reports Server (NTRS)

Gardner, P. B.

1977-01-01

Ceramic composite turbine disc protection panels for the A300B were developed using armor technology. Analytical predictions for modifying the ballistic projectile armor system were verified by a test program conducted to qualify the rotor containment system. With only a slight change in the areal density of the armor system a more than two-fold increase in kinetic energy protection level was achieved. Thickness of the fiberglass reinforced plastic backing material was increased to achieve an optimum ratio of ceramic thickness to backing thickness for the different ballistic defeat condition.

User s Manual for Armor Stone Evaluation Model (ARMOR): Great Lakes Armor Stone Study

DTIC Science & Technology

2015-08-01

Broderick and Ahrens (1982) defined damage to an armor layer by the normalized eroded cross-section area as S = Ae/(Dn50)2, where Ae is the measured...84. Broderick , L., and J. P. Ahrens. 1982. Rip-rap stability scale effects. Technical Paper 82- 3. Vicksburg, MS: U.S. Army Engineer Waterways

Targeting Ballistic Lunar Capture Trajectories Using Periodic Orbits in the Sun-Earth CRTBP

NASA Technical Reports Server (NTRS)

Cooley, D.S.; Griesemer, Paul Ricord; Ocampo, Cesar

2009-01-01

A particular periodic orbit in the Earth-Sun circular restricted three body problem is shown to have the characteristics needed for a ballistic lunar capture transfer. An injection from a circular parking orbit into the periodic orbit serves as an initial guess for a targeting algorithm. By targeting appropriate parameters incrementally in increasingly complicated force models and using precise derivatives calculated from the state transition matrix, a reliable algorithm is produced. Ballistic lunar capture trajectories in restricted four body systems are shown to be able to be produced in a systematic way.

A simple Boltzmann transport equation for ballistic to diffusive transient heat transport

DOE Office of Scientific and Technical Information (OSTI.GOV)

Maassen, Jesse, E-mail: jmaassen@purdue.edu; Lundstrom, Mark

2015-04-07

Developing simplified, but accurate, theoretical approaches to treat heat transport on all length and time scales is needed to further enable scientific insight and technology innovation. Using a simplified form of the Boltzmann transport equation (BTE), originally developed for electron transport, we demonstrate how ballistic phonon effects and finite-velocity propagation are easily and naturally captured. We show how this approach compares well to the phonon BTE, and readily handles a full phonon dispersion and energy-dependent mean-free-path. This study of transient heat transport shows (i) how fundamental temperature jumps at the contacts depend simply on the ballistic thermal resistance, (ii) thatmore » phonon transport at early times approach the ballistic limit in samples of any length, and (iii) perceived reductions in heat conduction, when ballistic effects are present, originate from reductions in temperature gradient. Importantly, this framework can be recast exactly as the Cattaneo and hyperbolic heat equations, and we discuss how the key to capturing ballistic heat effects is to use the correct physical boundary conditions.« less

Influence of particle size on the low and high strain rate behavior of dense colloidal dispersions of nanosilica

NASA Astrophysics Data System (ADS)

Asija, Neelanchali; Chouhan, Hemant; Gebremeskel, Shishay Amare; Bhatnagar, Naresh

2017-01-01

Shear thickening is a non-Newtonian flow behavior characterized by the increase in apparent viscosity with the increase in applied shear rate, particularly when the shear rate exceeds a critical value termed as the critical shear rate (CSR). Due to this remarkable property of shear-thickening fluids (STFs), they are extensively used in hip protection pads, protective gear for athletes, and more recently in body armor. The use of STFs in body armor has led to the development of the concept of liquid body armor. In this study, the effect of particle size is explored on the low and high strain rate behavior of nanosilica dispersions, so as to predict the efficacy of STF-aided personal protection systems (PPS), specifically for ballistic applications. The low strain rate study was conducted on cone and plate rheometer, whereas the high strain rate characterization of STF was conducted on in-house fabricated split Hopkinson pressure bar (SHPB) system. Spherical nanosilica particles of three different sizes (100, 300, and 500 nm) as well as fumed silica particles of four different specific surface areas (Aerosil A-90, A-130, A-150, and A-200), respectively, were used in this study. The test samples were prepared by dispersing nanosilica particles in polypropylene glycol (PPG) using ultrasonic homogenization method. The low strain rate studies aided in determining the CSR of the synthesized STF dispersions, whereas the high strain rate studies explored the impact-resisting ability of STFs in terms of the impact toughness and the peak stress attained during the impact loading of STF in SHPB testing.

An investigation into the relationship between thermal shock resistance and ballistic performance of ceramic materials

NASA Astrophysics Data System (ADS)

Beaumont, Robert

Currently, there are no reliable methods for screening potential armour materials and hence full-scale ballistic trials are needed. These are both costly and time-consuming in terms of the actual test and also in the materials development that needs to take place to produce sufficient material to give a meaningful result. Whilst it will not be possible to dispense with ballistic trials before material deployment in armour applications, the ability to shorten the development cycle would be advantageous. The thermal shock performance of ceramic armour materials has been highlighted as potential marker for ballistic performance. Hence the purpose of this study was to investigate this further. A new thermal shock technique that reproduced features relevant to ballistic testing was sought. As it would be beneficial to have a simple test that did not use much material, a water-drop method was adopted. This was combined with a variety of characterisation techniques, administered pre- and post-shock. The methods included measurement of the amplitude of ultrasonic wave transmission through the sample alongside residual strength testing using a biaxial ball-on-ball configuration and reflected light and confocal microscopy. Once the protocols had been refined the testing regime was applied to a group of ceramic materials. The materials selected were from two broad groups: alumina and carbide materials. Carbide ceramics show superior performance to alumina ceramics in ballistic applications so it was essential that any screening test would be easily able to differentiate the two groups. Within the alumina family, two commercially available materials, AD995 and Sintox FA, were selected. These were tested alongside three developmental silicon carbide-boron carbide composites, which had identical chemical compositions but different microstructures and thus presented more of a challenge in terms of differentiation. The results from the various tests were used to make predictions

10. Storage and shipping container, ballistic missile, mounted on ballistic ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

10. Storage and shipping container, ballistic missile, mounted on ballistic missile trailer, view from left front - Ellsworth Air Force Base, Delta Flight, 10 mile radius around Exit 127 off Interstate 90, Interior, Jackson County, SD

11. Storage and shipping container, ballistic missile, mounted on ballistic ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

11. Storage and shipping container, ballistic missile, mounted on ballistic missile trailer, view from left side - Ellsworth Air Force Base, Delta Flight, 10 mile radius around Exit 127 off Interstate 90, Interior, Jackson County, SD

Body models in forensic ballistics: reconstruction of a gunshot injury to the chest by bullet fragmentation after shooting through a finger.

PubMed

Thali, M J; Kneubuehl, B P; Dirnhofer, R; Zollinger, U

2001-11-15

Forensic science uses substitutes to reconstruct injury patterns in order to answer questions regarding the dynamic formation of unusual injuries. Using a case study, an experimental simulation of a finger was designed, for the first time with a combination of hard wood and glycerin soap. With this model as an intermediate target simulation, it was possible not only to demonstrate the "bullet-body (finger) interaction", but also to recreate the wound pattern found in the victim. This case demonstrates that by using ballistic models and body-part substitutes, gunshot cases can be reproduced simply and economically, without coming into conflict with ethical guidelines.

"Ballistic Six" Upper-Extremity Plyometric Training for the Pediatric Volleyball Players.

PubMed

Turgut, Elif; Cinar-Medeni, Ozge; Colakoglu, Filiz F; Baltaci, Gul

2017-09-19

The Ballistic Six exercise program includes commonly used upper-body exercises, and the program is recommended for overhead throwing athletes. The purpose of the current study was to investigate the effects of a 12-week the Ballistic Six upper-extremity plyometric training program on upper-body explosive power, endurance, and reaction time in pediatric overhead athletes. Twenty-eight female pediatric volleyball players participated in the study. The participants were randomly divided into 2 study groups: an intervention group (upper-extremity plyometric training in addition to the volleyball training; n = 14) and a control group (the volleyball training only; n = 14). All the participants were assessed before and after a 12-week training program for upper-body power, strength and endurance, and reaction time. Statistical comparison was performed using an analysis of variance test. Comparisons showed that after a 12-week training program, the Ballistic Six upper-body plyometric training program resulted in more improvements in an overhead medicine ball throwing distance and a push-up performance, as well as greater improvements in the reaction time in the nonthrowing arm when compared with control training. In addition, a 12-week training program was found to be effective in achieving improvements in the reaction time in the throwing arm for both groups similarly. Compared with regular training, upper-body plyometric training resulted in additional improvements in upper-body power and strength and endurance among pediatric volleyball players. The findings of the study provide a basis for developing training protocols for pediatric volleyball players.

Ballistic projectile trajectory determining system

DOEpatents

Karr, T.J.

1997-05-20

A computer controlled system determines the three-dimensional trajectory of a ballistic projectile. To initialize the system, predictions of state parameters for a ballistic projectile are received at an estimator. The estimator uses the predictions of the state parameters to estimate first trajectory characteristics of the ballistic projectile. A single stationary monocular sensor then observes the actual first trajectory characteristics of the ballistic projectile. A comparator generates an error value related to the predicted state parameters by comparing the estimated first trajectory characteristics of the ballistic projectile with the observed first trajectory characteristics of the ballistic projectile. If the error value is equal to or greater than a selected limit, the predictions of the state parameters are adjusted. New estimates for the trajectory characteristics of the ballistic projectile are made and are then compared with actual observed trajectory characteristics. This process is repeated until the error value is less than the selected limit. Once the error value is less than the selected limit, a calculator calculates trajectory characteristics such a the origin and destination of the ballistic projectile. 8 figs.

Ballistic projectile trajectory determining system

DOEpatents

Karr, Thomas J.

1997-01-01

A computer controlled system determines the three-dimensional trajectory of a ballistic projectile. To initialize the system, predictions of state parameters for a ballistic projectile are received at an estimator. The estimator uses the predictions of the state parameters to estimate first trajectory characteristics of the ballistic projectile. A single stationary monocular sensor then observes the actual first trajectory characteristics of the ballistic projectile. A comparator generates an error value related to the predicted state parameters by comparing the estimated first trajectory characteristics of the ballistic projectile with the observed first trajectory characteristics of the ballistic projectile. If the error value is equal to or greater than a selected limit, the predictions of the state parameters are adjusted. New estimates for the trajectory characteristics of the ballistic projectile are made and are then compared with actual observed trajectory characteristics. This process is repeated until the error value is less than the selected limit. Once the error value is less than the selected limit, a calculator calculates trajectory characteristics such a the origin and destination of the ballistic projectile.

Thermal modeling of W rod armor.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nygren, Richard Einar

2004-09-01

Sandia has developed and tested mockups armored with W rods over the last decade and pioneered the initial development of W rod armor for International Thermonuclear Experimental Reactor (ITER) in the 1990's. We have also developed 2D and 3D thermal and stress models of W rod-armored plasma facing components (PFCs) and test mockups and are applying the models to both short pulses, i.e. edge localized modes (ELMs), and thermal performance in steady state for applications in C-MOD, DiMES testing and ITER. This paper briefly describes the 2D and 3D models and their applications with emphasis on modeling for an ongoingmore » test program that simulates repeated heat loads from ITER ELMs.« less

Ballistic missile defense technologies

NASA Astrophysics Data System (ADS)

1985-09-01

A report on Ballistic Missile Technologies includes the following: Executive summary; Introduction; Ballistic missiles then and now; Deterrence, U.S. nuclear strategy, and BMD; BMD capabilities and the strategic balance; Crisis stability, arms race stability, and arms control issues; Ballistic missile defense technologies; Feasibility; Alternative future scenarios; Alternative R&D programs.

On the influence of particle morphology on the post-impact ballistic response of ceramic armour materials

NASA Astrophysics Data System (ADS)

Hameed, Amer; Appleby-Thomas, Gareth; Wood, David; Jaansalu, Kevin

2015-06-01

Recent studies have shown evidence that the ballistic-resistance of fragmented (comminuted) ceramics is independent of the original strength of the material. In particular, experimental investigations into the ballistic behaviour of such fragmented ceramics have indicated that this response is correlated to shattered ceramic morphology. This suggests that careful control of ceramic microstructure - and therefore failure paths - might provide a route to optimise post-impact ballistic performance, thereby enhancing multi-hit capability. In this study, building on previous in-house work, ballistic tests were conducted using pre-formed `fragmented-ceramic' analogues based around three morphologically differing (but chemically identical) alumina feedstock materials compacted into target `pucks. In an evolution of previous work, variation of target thickness provided additional insight into an apparent morphology-based contribution to ballistic response.

46 CFR 111.05-7 - Armored and metallic sheathed cable.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 4 2011-10-01 2011-10-01 false Armored and metallic sheathed cable. 111.05-7 Section 111.05-7 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING... Armored and metallic sheathed cable. When installed, the metallic armor or sheath must meet the...

46 CFR 111.05-7 - Armored and metallic sheathed cable.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 4 2010-10-01 2010-10-01 false Armored and metallic sheathed cable. 111.05-7 Section 111.05-7 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING... Armored and metallic sheathed cable. When installed, the metallic armor or sheath must meet the...

46 CFR 111.05-7 - Armored and metallic sheathed cable.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 4 2014-10-01 2014-10-01 false Armored and metallic sheathed cable. 111.05-7 Section 111.05-7 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING... Armored and metallic sheathed cable. When installed, the metallic armor or sheath must meet the...

46 CFR 111.05-7 - Armored and metallic sheathed cable.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 4 2013-10-01 2013-10-01 false Armored and metallic sheathed cable. 111.05-7 Section 111.05-7 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING... Armored and metallic sheathed cable. When installed, the metallic armor or sheath must meet the...

46 CFR 111.05-7 - Armored and metallic sheathed cable.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 4 2012-10-01 2012-10-01 false Armored and metallic sheathed cable. 111.05-7 Section 111.05-7 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING... Armored and metallic sheathed cable. When installed, the metallic armor or sheath must meet the...

76 FR 35024 - National Institute of Justice Stab-Resistant Body Armor Standard Workshop

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-15

.... Space is limited at this workshop, and as a result, only 50 participants will be allowed to register. We.../2011_NIJ_Stab-resistant_BA_Workshop.aspx . Registration will close on July 8, 2011. DATES: The workshop...

Ballistic tongue projection in a miniaturized salamander.

PubMed

Deban, Stephen M; Bloom, Segall V

2018-05-20

Miniaturization of body size is often accompanied by peculiarities in morphology that can have functional consequences. We examined the feeding behavior and morphology of the miniaturized plethodontid salamander Thorius, one of the smallest vertebrates, to determine if its performance and biomechanics differ from those of its larger relatives. High-speed imaging and dynamics analysis of feeding at a range of temperatures show that tongue projection in Thorius macdougalli is ballistic and achieves accelerations of up to 600 G with low thermal sensitivity, indicating that tongue projection is powered by an elastic-recoil mechanism. Preceding ballistic projection is an unusual preparatory phase of tongue protrusion, which, like tongue retraction, shows lower performance and higher thermal sensitivity that are indicative of movement being powered directly by muscle shortening. The variability of tongue-projection kinematics and dynamics is comparable to larger ballistic-tongued plethodontids and reveals that Thorius is capable of modulating its tongue movements in response to prey distance. Morphological examination revealed that T. macdougalli possesses a reduced number of myofibers in the tongue muscles, a large projector muscle mass relative to tongue mass, and an unusual folding of the tongue skeleton, compared with larger relatives. Nonetheless, T. macdougalli retains the elaborated collagen aponeuroses in the projector muscle that store elastic energy and a tongue skeleton that is free of direct myofiber insertion, two features that appear to be essential for ballistic tongue projection in salamanders. © 2018 Wiley Periodicals, Inc.

Computational Study of a Functionally Graded Ceramic-Metallic Armor

DTIC Science & Technology

2006-12-15

UNCLAS –Dist. A - Approved for public release Computational Study of a Functionally Graded Ceramic-Metallic Armor Douglas W. Templeton1, Tara J...efficiency of a postulated FGM ceramic-metallic armor system composed of aluminum nitride (AlN) and aluminum. The study had two primary...2006 2. REPORT TYPE N/ A 3. DATES COVERED - 4. TITLE AND SUBTITLE Computational Study of a Functionally Graded Ceramic-Metallic Armor 5a

Armored CAR T cells enhance antitumor efficacy and overcome the tumor microenvironment.

PubMed

Yeku, Oladapo O; Purdon, Terence J; Koneru, Mythili; Spriggs, David; Brentjens, Renier J

2017-09-05

Chimeric antigen receptor (CAR) T cell therapy has shown limited efficacy for the management of solid tumor malignancies. In ovarian cancer, this is in part due to an immunosuppressive cytokine and cellular tumor microenvironment which suppresses adoptively transferred T cells. We engineered an armored CAR T cell capable of constitutive secretion of IL-12, and delineate the mechanisms via which these CAR T cells overcome a hostile tumor microenvironment. In this report, we demonstrate enhanced proliferation, decreased apoptosis and increased cytotoxicity in the presence of immunosuppressive ascites. In vivo, we show enhanced expansion and CAR T cell antitumor efficacy, culminating in improvement in survival in a syngeneic model of ovarian peritoneal carcinomatosis. Armored CAR T cells mediated depletion of tumor associated macrophages and resisted endogenous PD-L1-induced inhibition. These findings highlight the role of the inhibitory microenvironment and how CAR T cells can be further engineered to maintain efficacy.

Potentiation Following Ballistic and Nonballistic Complexes: The Effect of Strength Level.

PubMed

Suchomel, Timothy J; Sato, Kimitake; DeWeese, Brad H; Ebben, William P; Stone, Michael H

2016-07-01

Suchomel, TJ, Sato, K, DeWeese, BH, Ebben, WP, and Stone, MH. Potentiation following ballistic and nonballistic complexes: the effect of strength level. J Strength Cond Res 30(7): 1825-1833, 2016-The purpose of this study was to compare the temporal profile of strong and weak subjects during ballistic and nonballistic potentiation complexes. Eight strong (relative back squat = 2.1 ± 0.1 times body mass) and 8 weak (relative back squat = 1.6 ± 0.2 times body mass) males performed squat jumps immediately and every minute up to 10 minutes following potentiation complexes that included ballistic or nonballistic concentric-only half-squat (COHS) performed at 90% of their 1 repetition maximum COHS. Jump height (JH) and allometrically scaled peak power (PPa) were compared using a series of 2 × 12 repeated measures analyses of variance. No statistically significant strength level main effects for JH (p = 0.442) or PPa (p = 0.078) existed during the ballistic condition. In contrast, statistically significant main effects for time existed for both JH (p = 0.014) and PPa (p < 0.001); however, no statistically significant pairwise comparisons were present (p > 0.05). Statistically significant strength level main effects existed for PPa (p = 0.039) but not for JH (p = 0.137) during the nonballistic condition. Post hoc analysis revealed that the strong subjects produced statistically greater PPa than the weaker subjects (p = 0.039). Statistically significant time main effects existed for time existed for PPa (p = 0.015), but not for JH (p = 0.178). No statistically significant strength level × time interaction effects for JH (p = 0.319) or PPa (p = 0.203) were present for the ballistic or nonballistic conditions. Practical significance indicated by effect sizes and the relationships between maximum potentiation and relative strength suggest that stronger subjects potentiate earlier and to a greater extent than weaker subjects during ballistic and nonballistic potentiation

Armored Force: The Rapid Development of a Uniquely American Force

DTIC Science & Technology

2010-03-19

tank dominated the Armored Force in 1940. The latest model, the M2A4 , weighed 12 tons and carried a 37mm main gun mounted in a single turret. It also...exploitation phase. Second, armor was concentrated in sufficient mass at the point of the breakthrough. This enabled the armored units to blast their

Linking crime guns: the impact of ballistics imaging technology on the productivity of the Boston Police Department's Ballistics Unit.

PubMed

Braga, Anthony A; Pierce, Glenn L

2004-07-01

Ballistics imaging technology has received national attention as a potent tool for moving the law enforcement response to violent gun criminals forward by linking multiple crime scenes to one firearm. This study examines the impact of ballistics imaging technology on the productivity of the Boston Police Department's Ballistics Unit. Using negative binomial regression models to analyze times series data on ballistics matches, we find that ballistics imaging technology was associated with a more than sixfold increase in the monthly number of ballistics matches made by the Boston Police Department's Ballistics Unit. Cost-effectiveness estimates and qualitative evidence also suggest that ballistics imaging technology allows law enforcement agencies to make hits that would not have been possible using traditional ballistics methods.

Embedded-monolith armor

DOE Office of Scientific and Technical Information (OSTI.GOV)

McElfresh, Michael W.; Groves, Scott E; Moffet, Mitchell L.

2016-07-19

A lightweight armor system utilizing a face section having a multiplicity of monoliths embedded in a matrix supported on low density foam. The face section is supported with a strong stiff backing plate. The backing plate is mounted on a spall plate.

Effects of Re-heating Tissue Samples to Core Body Temperature on High-Velocity Ballistic Projectile-tissue Interactions.

PubMed

Humphrey, Caitlin; Henneberg, Maciej; Wachsberger, Christian; Maiden, Nicholas; Kumaratilake, Jaliya

2017-11-01

Damage produced by high-speed projectiles on organic tissue will depend on the physical properties of the tissues. Conditioning organic tissue samples to human core body temperature (37°C) prior to conducting ballistic experiments enables their behavior to closely mimic that of living tissues. To minimize autolytic changes after death, the tissues are refrigerated soon after their removal from the body and re-heated to 37°C prior to testing. This research investigates whether heating 50-mm-cube samples of porcine liver, kidney, and heart to 37°C for varying durations (maximum 7 h) can affect the penetration response of a high-speed, steel sphere projectile. Longer conditioning times for heart and liver resulted in a slight loss of velocity/energy of the projectile, but the reverse effect occurred for the kidney. Possible reasons for these trends include autolytic changes causing softening (heart and liver) and dehydration causing an increase in density (kidney). © 2017 American Academy of Forensic Sciences.

Quasi-ballistic Electronic Thermal Conduction in Metal Inverse Opals.

PubMed

Barako, Michael T; Sood, Aditya; Zhang, Chi; Wang, Junjie; Kodama, Takashi; Asheghi, Mehdi; Zheng, Xiaolin; Braun, Paul V; Goodson, Kenneth E

2016-04-13

Porous metals are used in interfacial transport applications that leverage the combination of electrical and/or thermal conductivity and the large available surface area. As nanomaterials push toward smaller pore sizes to increase the total surface area and reduce diffusion length scales, electron conduction within the metal scaffold becomes suppressed due to increased surface scattering. Here we observe the transition from diffusive to quasi-ballistic thermal conduction using metal inverse opals (IOs), which are metal films that contain a periodic arrangement of interconnected spherical pores. As the material dimensions are reduced from ∼230 nm to ∼23 nm, the thermal conductivity of copper IOs is reduced by more than 57% due to the increase in surface scattering. In contrast, nickel IOs exhibit diffusive-like conduction and have a constant thermal conductivity over this size regime. The quasi-ballistic nature of electron transport at these length scales is modeled considering the inverse opal geometry, surface scattering, and grain boundaries. Understanding the characteristics of electron conduction at the nanoscale is essential to minimizing the total resistance of porous metals for interfacial transport applications, such as the total electrical resistance of battery electrodes and the total thermal resistance of microscale heat exchangers.

Wound ballistics: theory and practice.

PubMed

Ordog, G J; Wasserberger, J; Balasubramanium, S

1984-12-01

Ballistics is the study of the natural laws governing projectile missiles and their predictable performances, and wound ballistics is the study of a missile's effect on living tissue. A knowledge of these topics is essential to determine the extent and type of injury from a missile. The type of missile can often be determined by radiography. The caliber can be measured directly if the bullet is close to the x-ray plate and the x-ray tube is at least six feet from the film. Changing these distances can result in a maximum magnification of the bullet image of 20%, and the exact amount can be calculated using a formula provided. Definitions of ballistic and wound ballistic terms are provided, as are examples of wound ballistics in application.

Toroidal midplane neutral beam armor and plasma limiter

DOEpatents

Kugel, Henry W.; Hand Jr, Samuel W.; Ksayian, Haig

1986-02-04

For use in a tokamak fusion reactor having a midplane magnetic coil on the inner wall of an evacuated toriodal chamber within which a neutral beam heated, fusing plasma is magnetically confined, a neutral beam armor shield and plasma limiter is provided on the inner wall of the toroidal chamber to shield the midplane coil from neutral beam shine-thru and plasma deposition. The armor shield/plasma limiter forms a semicircular enclosure around the midplane coil with the outer surface of the armor shield/plasma limiter shaped to match, as closely as practical, the inner limiting magnetic flux surface of the toroidally confined, indented, bean-shaped plasma. The armor shield/plasma limiter includes a plurality of semicircular graphite plates each having a pair of coupled upper and lower sections with each plate positioned in intimate contact with an adjacent plate on each side thereof so as to form a closed, planar structure around the entire outer periphery of the circular midplane coil. The upper and lower plate sections are adapted for coupling to heat sensing thermocouples and to a circulating water conduit system for cooling the armor shield/plasma limiter.The inner center portion of each graphite plate is adapted to receive and enclose a section of a circular diagnostic magnetic flux loop so as to minimize the power from the plasma confinement chamber incident upon the flux loop.

Toroidal midplane neutral beam armor and plasma limiter

DOEpatents

Kugel, Henry W.; Hand, Jr, Samuel W.; Ksayian, Haig

1986-01-01

For use in a tokamak fusion reactor having a midplane magnetic coil on the inner wall of an evacuated toriodal chamber within which a neutral beam heated, fusing plasma is magnetically confined, a neutral beam armor shield and plasma limiter is provided on the inner wall of the toroidal chamber to shield the midplane coil from neutral beam shine-thru and plasma deposition. The armor shield/plasma limiter forms a semicircular enclosure around the midplane coil with the outer surface of the armor shield/plasma limiter shaped to match, as closely as practical, the inner limiting magnetic flux surface of the toroidally confined, indented, bean-shaped plasma. The armor shield/plasma limiter includes a plurality of semicircular graphite plates each having a pair of coupled upper and lower sections with each plate positioned in intimate contact with an adjacent plate on each side thereof so as to form a closed, planar structure around the entire outer periphery of the circular midplane coil. The upper and lower plate sections are adapted for coupling to heat sensing thermocouples and to a circulating water conduit system for cooling the armor shield/plasma limiter.The inner center portion of each graphite plate is adapted to receive and enclose a section of a circular diagnostic magnetic flux loop so as to minimize the power from the plasma confinement chamber incident upon the flux loop.

Armours for soft bodies: how far can bioinspiration take us?

PubMed

White, Zachary W; Vernerey, Franck J

2018-05-15

The development of armour is as old as the dawn of civilization. Early man looked to natural structures to harvest or replicate for protection, leaning on millennia of evolutionary developments in natural protection. Since the advent of more modern weaponry, Armor development has seemingly been driven more by materials research than bio-inspiration. However, parallels can still be drawn between modern bullet-protective armours and natural defensive structures. Soft armour for handgun and fragmentation threats can be likened to mammalian skin, and similarly, hard armour can be compared with exoskeletons and turtle shells. Via bio-inspiration, it may be possible to develop structures previously un-researched for ballistic protection. This review will cover current modern ballistic protective structures focusing on energy dissipation and absorption methods, and their natural analogues. As all armour is a compromise between weight, flexibility and protection, the imbricated structure of scaled skin will be presented as a better balance between these factors.

On the collapse pressure of armored bubbles and drops.

PubMed

Pitois, O; Buisson, M; Chateau, X

2015-05-01

Drops and bubbles wrapped in dense monolayers of hydrophobic particles are known to sustain a significant decrease of their internal pressure. Through dedicated experiments we investigate the collapse behavior of such armored water drops as a function of the particle-to-drop size ratio in the range 0.02-0.2. We show that this parameter controls the behavior of the armor during the deflation: at small size ratios the drop shrinkage proceeds through the soft crumpling of the monolayer, at intermediate ratios the drop becomes faceted, and for the largest studied ratios the armor behaves like a granular arch. The results show that each of the three morphological regimes is characterized by an increasing magnitude of the collapse pressure. This increase is qualitatively modeled thanks to a mechanism involving out-of-plane deformations and particle disentanglement in the armor.

Investigation of Advanced Personnel Armor Using Layered Construction

DTIC Science & Technology

2009-12-01

foam were constructed to test against baseline armor AISI 4140 steel plate. A hypothetical orthotropic material model closely resembling that of...against baseline armor AISI 4140 steel plate. A hypothetical orthotropic material model closely resembling that of Dyneema HB25 was derived based on...54 2. Steel AISI 4140 ...................................................................................56 3. Composite Plates

Wound ballistic evaluation of the Taser® XREP ammunition.

PubMed

Kunz, Sebastian N; Adamec, Jiri; Zinka, Bettina; Münzel, Daniela; Noël, Peter B; Eichner, Simon; Manthei, Axel; Grove, Nico; Graw, M; Peschel, Oliver

2013-01-01

The Taser® eXtended Range Electronic Projectile (XREP®) is a wireless conducted electrical weapon (CEW) designed to incapacitate a person from a larger distance. The aim of this study was to analyze the ballistic injury potential of the XREP. Twenty rounds were fired from the Taser®X12 TM shotgun into ballistic soap covered with artificial skin and clothing at different shooting distances (1-25 m). One shot was fired at pig skin at a shooting distance of 10 m. The average projectile velocity was 67.0 m/s. The kinetic energy levels on impact varied from 28-52 J. Depending on the intermediate target, the projectiles penetrated up to 4.2 cm into the ballistic soap. On impact the nose assembly did not separate from the chassis, and no electrical activation was registered. Upon impact, a skin penetration of the XREP cannot be excluded. However, it is very unlikely at shooting distances of 10 m or more. Clothing and a high elasticity limit of the target body area can significantly reduce the penetration risk on impact.

Characterization and Cytotoxic Assessment of Ballistic Aerosol Particulates for Tungsten Alloy Penetrators into Steel Target Plates

PubMed Central

Machado, Brenda I.; Murr, Lawrence E.; Suro, Raquel M.; Gaytan, Sara M.; Ramirez, Diana A.; Garza, Kristine M.; Schuster, Brian E.

2010-01-01

The nature and constituents of ballistic aerosol created by kinetic energy penetrator rods of tungsten heavy alloys (W-Fe-Ni and W-Fe-Co) perforating steel target plates was characterized by scanning and transmission electron microscopy. These aerosol regimes, which can occur in closed, armored military vehicle penetration, are of concern for potential health effects, especially as a consequence of being inhaled. In a controlled volume containing 10 equispaced steel target plates, particulates were systematically collected onto special filters. Filter collections were examined by scanning and transmission electron microscopy (SEM and TEM) which included energy-dispersive (X-ray) spectrometry (EDS). Dark-field TEM identified a significant nanoparticle concentration while EDS in the SEM identified the propensity of mass fraction particulates to consist of Fe and FeO, representing target erosion and formation of an accumulating debris field. Direct exposure of human epithelial cells (A549), a model for lung tissue, to particulates (especially nanoparticulates) collected on individual filters demonstrated induction of rapid and global cell death to the extent that production of inflammatory cytokines was entirely inhibited. These observations along with comparisons of a wide range of other nanoparticulate species exhibiting cell death in A549 culture may suggest severe human toxicity potential for inhaled ballistic aerosol, but the complexity of the aerosol (particulate) mix has not yet allowed any particular chemical composition to be identified. PMID:20948926

Characterization and cytotoxic assessment of ballistic aerosol particulates for tungsten alloy penetrators into steel target plates.

PubMed

Machado, Brenda I; Murr, Lawrence E; Suro, Raquel M; Gaytan, Sara M; Ramirez, Diana A; Garza, Kristine M; Schuster, Brian E

2010-09-01

The nature and constituents of ballistic aerosol created by kinetic energy penetrator rods of tungsten heavy alloys (W-Fe-Ni and W-Fe-Co) perforating steel target plates was characterized by scanning and transmission electron microscopy. These aerosol regimes, which can occur in closed, armored military vehicle penetration, are of concern for potential health effects, especially as a consequence of being inhaled. In a controlled volume containing 10 equispaced steel target plates, particulates were systematically collected onto special filters. Filter collections were examined by scanning and transmission electron microscopy (SEM and TEM) which included energy-dispersive (X-ray) spectrometry (EDS). Dark-field TEM identified a significant nanoparticle concentration while EDS in the SEM identified the propensity of mass fraction particulates to consist of Fe and FeO, representing target erosion and formation of an accumulating debris field. Direct exposure of human epithelial cells (A549), a model for lung tissue, to particulates (especially nanoparticulates) collected on individual filters demonstrated induction of rapid and global cell death to the extent that production of inflammatory cytokines was entirely inhibited. These observations along with comparisons of a wide range of other nanoparticulate species exhibiting cell death in A549 culture may suggest severe human toxicity potential for inhaled ballistic aerosol, but the complexity of the aerosol (particulate) mix has not yet allowed any particular chemical composition to be identified.

The Armored Infantry in the US Force Structure.

DTIC Science & Technology

1985-12-02

armored infantry and tank integration occurred during the capture of the town of Troyes , France, in 1944, by Task Force West of the 4th Armored...Singling and Troyes . The same can not be said of the foot infantryman because normally he was not associated with tanks. Such was the case in the previously

Combat body armor and injuries to the head, face, and neck region: a systematic review.

PubMed

Tong, Darryl; Beirne, Ross

2013-04-01

There has been a reported increase in combat-related head, face, and neck (HFN) injuries among service personnel wearing combat body armor (CBA) that have deployed to Iraq and Afghanistan. Modern ceramic plate CBA has decreased the incidence of fatal-penetrating injuries to the torso but offers no protection to the limbs and face which remain exposed to gunshot wounds and fragments from explosive devices. The aim of this review was to systematically summarize the literature reporting on HFN injuries sustained by combat personnel wearing CBA and to highlight recommendations for increased protection to the facial region. Three major contributing factors were identified with this proportional increase in HFN injuries, namely the increased survivability of soldiers because of CBA, fragments injuries from explosive devices, and the lack of protection to the face and limbs. There appears to be no evidence to suggest that by virtue of wearing CBA the likelihood of sustaining an HFN injury increases as such, but a higher incidence of fragment injuries to the HFN region may be due to the more common use of improvised explosive devicess and other explosive devices. Further development of lightweight protection for the face is needed. Reprint & Copyright © 2013 Association of Military Surgeons of the U.S.

Attenuation of blast pressure behind ballistic protective vests.

PubMed

Wood, Garrett W; Panzer, Matthew B; Shridharani, Jay K; Matthews, Kyle A; Capehart, Bruce P; Myers, Barry S; Bass, Cameron R

2013-02-01

Clinical studies increasingly report brain injury and not pulmonary injury following blast exposures, despite the increased frequency of exposure to explosive devices. The goal of this study was to determine the effect of personal body armour use on the potential for primary blast injury and to determine the risk of brain and pulmonary injury following a blast and its impact on the clinical care of patients with a history of blast exposure. A shock tube was used to generate blast overpressures on soft ballistic protective vests (NIJ Level-2) and hard protective vests (NIJ Level-4) while overpressure was recorded behind the vest. Both types of vest were found to significantly decrease pulmonary injury risk following a blast for a wide range of conditions. At the highest tested blast overpressure, the soft vest decreased the behind armour overpressure by a factor of 14.2, and the hard vest decreased behind armour overpressure by a factor of 56.8. Addition of body armour increased the 50th percentile pulmonary death tolerance of both vests to higher levels than the 50th percentile for brain injury. These results suggest that ballistic protective body armour vests, especially hard body armour plates, provide substantial chest protection in primary blasts and explain the increased frequency of head injuries, without the presence of pulmonary injuries, in protected subjects reporting a history of blast exposure. These results suggest increased clinical suspicion for mild to severe brain injury is warranted in persons wearing body armour exposed to a blast with or without pulmonary injury.

Scientific evaluation of the ArmorGuard mobile barrier system.

DOT National Transportation Integrated Search

2011-06-17

"Accidents and injuries occur during maintenance activities that could be protected by the ArmorGuard or BalsiBeam mobile barrier systems. The main purpose of this study is to perform a scientific evaluation of the utility of the ArmorGuard system in...

An Exceptionally Preserved Three-Dimensional Armored Dinosaur Reveals Insights into Coloration and Cretaceous Predator-Prey Dynamics.

PubMed

Brown, Caleb M; Henderson, Donald M; Vinther, Jakob; Fletcher, Ian; Sistiaga, Ainara; Herrera, Jorsua; Summons, Roger E

2017-08-21

Predator-prey dynamics are an important evolutionary driver of escalating predation mode and efficiency, and commensurate responses of prey [1-3]. Among these strategies, camouflage is important for visual concealment, with countershading the most universally observed [4-6]. Extant terrestrial herbivores free of significant predation pressure, due to large size or isolation, do not exhibit countershading. Modern predator-prey dynamics may not be directly applicable to those of the Mesozoic due to the dominance of very large, visually oriented theropod dinosaurs [7]. Despite thyreophoran dinosaurs' possessing extensive dermal armor, some of the most extreme examples of anti-predator structures [8, 9], little direct evidence of predation on these and other dinosaur megaherbivores has been documented. Here we describe a new, exquisitely three-dimensionally preserved nodosaurid ankylosaur, Borealopelta markmitchelli gen. et sp. nov., from the Early Cretaceous of Alberta, which preserves integumentary structures as organic layers, including continuous fields of epidermal scales and intact horn sheaths capping the body armor. We identify melanin in the organic residues through mass spectroscopic analyses and observe lighter pigmentation of the large parascapular spines, consistent with display, and a pattern of countershading across the body. With an estimated body mass exceeding 1,300 kg, B. markmitchelli was much larger than modern terrestrial mammals that either are countershaded or experience significant predation pressure as adults. Presence of countershading suggests predation pressure strong enough to select for concealment in this megaherbivore despite possession of massive dorsal and lateral armor, illustrating a significant dichotomy between Mesozoic predator-prey dynamics and those of modern terrestrial systems. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

[Characteristics and Treatment Strategies for Penetrating Injuries on the Example of Gunshot and Blast Victims without Ballistic Body Armour in Afghanistan (2009 - 2013)].

PubMed

Güsgen, Christoph; Willms, Arnulf; Richardsen, Ines; Bieler, Dan; Kollig, Erwin; Schwab, Robert

2017-08-01

Much like other countries, Germany has recently seen terrorist attacks being planned, executed or prevented at the last minute. This highlights the need for expertise in the treatment of penetrating torso traumas by bullets or explosions. Data on the treatment of firearm injuries and, even more so, blast injuries often stems from crises or war regions. However, it is difficult to compare injuries from such regions with injuries from civilian terrorist attacks due to the ballistic body protection (protective vests, body armour) worn by soldiers. Methods An analysis was performed based on data from patients who were treated in the German Military Hospital Mazar-e Sharif for gunshots or injuries from explosions in the years 2009 to 2013. The data selection was based on patients with penetrating injuries to the thorax and/or abdomen. For better comparability with civilian attack scenarios, this study only included civilian patients without ballistic body protection (body armour, protective vests). Results Out of 117 analysed patients, 58 were affected by firearms and 59 by explosive injuries of the thorax or abdomen. 60% of patients had a thoracic injury, 69% had an abdominal injury, and 25.6% had combined thoracic-abdominal injuries. Blast injury patients were significantly more affected by thoracic trauma. As regards abdominal injuries, liver, intestinal, and colonic lesions were leading in number. Patients with blast injuries had significantly more injured organs and a significantly higher ISS averaging 29. 26% of the shot patients and 41% of the blast wounded patients received Damage Control Surgery (DCS). Despite a lower ISS, gunshot victims did not have a lower total number of operations per patient. Overall mortality was 13.7% (10.3% gunshot wounds, 16.7% blast injury). The highest mortality rate (25.7%) was recorded for patients with combined thoracoabdominal injuries (vs. 8.3% for thoracic and 8.7% for abdominal injuries). The ISS of deceased patients was

Potentiation Effects of Half-Squats Performed in a Ballistic or Nonballistic Manner.

PubMed

Suchomel, Timothy J; Sato, Kimitake; DeWeese, Brad H; Ebben, William P; Stone, Michael H

2016-06-01

This study examined and compared the acute effects of ballistic and nonballistic concentric-only half-squats (COHSs) on squat jump performance. Fifteen resistance-trained men performed a squat jump 2 minutes after a control protocol or 2 COHSs at 90% of their 1 repetition maximum (1RM) COHS performed in a ballistic or nonballistic manner. Jump height (JH), peak power (PP), and allometrically scaled peak power (PPa) were compared using three 3 × 2 repeated-measures analyses of variance. Statistically significant condition × time interaction effects existed for JH (p = 0.037), PP (p = 0.041), and PPa (p = 0.031). Post hoc analysis revealed that the ballistic condition produced statistically greater JH (p = 0.017 and p = 0.036), PP (p = 0.031 and p = 0.026), and PPa (p = 0.024 and p = 0.023) than the control and nonballistic conditions, respectively. Small effect sizes for JH, PP, and PPa existed during the ballistic condition (d = 0.28-0.44), whereas trivial effect sizes existed during the control (d = 0.0-0.18) and nonballistic (d = 0.0-0.17) conditions. Large statistically significant relationships existed between the JH potentiation response and the subject's relative back squat 1RM (r = 0.520; p = 0.047) and relative COHS 1RM (r = 0.569; p = 0.027) during the ballistic condition. In addition, large statistically significant relationship existed between JH potentiation response and the subject's relative back squat strength (r = 0.633; p = 0.011), whereas the moderate relationship with the subject's relative COHS strength trended toward significance (r = 0.483; p = 0.068). Ballistic COHS produced superior potentiation effects compared with COHS performed in a nonballistic manner. Relative strength may contribute to the elicited potentiation response after ballistic and nonballistic COHS.

Structural Health Monitoring of M1114 High Mobility Multipurpose Wheeled Vehicle Armor System

DTIC Science & Technology

2012-03-01

compressional waves or compression waves (Russell, 1999). Pulse Echo Pulse echo method uses the transducer to perform both the sending and the...monolithic system of pure steel will not be sufficient because it would become too heavy and compromise its maneuverability and nimbleness. In order to...produce a limited number of M1114’s with hardened steel armor with bullet-resistant glass for the passenger cabinet against small arms fire. Even with its

CORROSION RESISTANT JACKETED METAL BODY

DOEpatents

Brugmann, E.W.

1958-08-26

S>Metal jacketed metallic bodies of the type used as feel elements fer nuclear reactors are presented. The fuel element is comprised of a plurality of jacketed cylindrical bodies joined in end to end abutting relationship. The abutting ends of the internal fissionable bodies are provided with a mating screw and thread means for joining the two together. The jacket material is of a corrosion resistant metal and overlaps the abutting ends of the internal bodies, thereby effectively sealing these bodies from contact with exteral reactive gases and liquids.

On the Trajectories of Projectiles Depicted in Early Ballistic Woodcuts

ERIC Educational Resources Information Center

Stewart, Sean M.

2012-01-01

Motivated by quaint woodcut depictions often found in many late 16th and 17th century ballistic manuals of cannonballs fired in air, a comparison of their shapes with those calculated for the classic case of a projectile moving in a linear resisting medium is made. In considering the asymmetrical nature of such trajectories, the initial launch…

Armor and Anesthesia

PubMed Central

MacLeish, Kenneth T.

2013-01-01

For many civilians, the high-tech weapons, armor, and military medicine with which U.S. soldiers are equipped present an image of lethal capacity and physical invulnerability. But, as this article explores, soldiers themselves just as often associate the life-sustaining technology of modern warfare with feelings that range from a pragmatic ambivalence about exposure to harm all the way to profoundly unsettling vulnerability. This article, based on fieldwork among soldiers and military families at the U.S. Army’s Ft. Hood, examines sensory and affective dimensions of soldiers’ intimate bodily relationships with the technologies that alternately or even simultaneously keep them alive and expose them to harm. I argue that modern military discipline and technology conspire to cultivate soldiers as highly durable, capable, unfeeling, interchangeable bodies, or what might be called, after Susan Buck-Morss (1992), anesthetic subjects. But for soldiers themselves, their training, combat environment, protective gear, and weapons are a rich font of both emotional and bodily feeling that exists in complex tension with the also deeply felt military imperative to carry on in the face of extreme discomfort and danger. PMID:22574391

Deformations on Hole and Projectile Surfaces Caused By High Velocity Friction During Ballistic Impact

NASA Astrophysics Data System (ADS)

Karamış, M. B.

2018-01-01

In this study, the deformations caused by the ballistic impact on the MM composites and on projectile surfaces are examined. The hole section and grain deformation of unreinforced targets are also examined after impact. The relatively high complexity of impact problems is caused by the large number of intervening parameters like relative velocity of projectile and target, shape of colliding objects, relative stiffness and masses, time-dependent surface of contact, geometry and boundary conditions and material characteristics. The material used in this investigation are 2024 and 7075 aluminum alloys as matrix reinforced with SiC and Al2O3 particles. The matrix materials are extensively used in defense applications due to its favorable ballistic properties, moderate strength, high corrosion resistance and super plastic potential. Two different composites were produced; one by casting and the other by lamination. The ballistic tests of the composite targets were carried out according to NIJ Standard-0101.04, Temperature 21 °C, RH=65% with 7.62 mm projectiles. The bullet weight was 9.6 g and their muzzle velocities were in the range of 770-800 m/s. The projectiles consisted of a steel core, copper jacket and lead material. The composite targets were positioned 15 m from the rifle. The interaction between projectiles and the target hole created after impact were examined by light microscopy and photography. Different damage and failure mechanisms such as petalling, cracking, spalling, dishing, etc., were observed on the target body. On the other hand, dramatic wear and damages on the projectile surface were also observed. The targets were supported with Al-5083 backing blocks having 40 mm thickness.

Preliminary study into the skeletal injuries sustained to the spine from posterior non-perforating ballistic impacts into body armour.

PubMed

Jennings, Rosalind M; Malbon, C; Brock, F; Harrisson, S E; Carr, D J

2018-05-21

The aim of this paper was to examine any injuries from posterior behind armour blunt trauma ballistic impacts directly over the spine onto typical hard body armours. Due to the spine being close to the surface of the skin and a lack of any previous specific research into this topic, this study was designed to gain preliminary insight into the mechanisms involved and injuries caused. Pigs were chosen as the closest representative of human spine, tissue and skin, although their spines are deeper under the surface than humans. Baseline spine and ribs shots were conducted to ensure that the study was effective. This study used a 65 kg cadaveric pig eviscerated torso and 7.62 NATO ammunition (7.62×51; L2A2; mean velocity=838 m/s, SD=4 m/s) impacting hard body armour plates over the spine. Injuries were inspected, and sections were removed for X-ray and micro-CT assessment. There was no visible soft tissue damage under the impact point on the armour over the spine, and no bony injuries were reported. Baseline rib shots resulted in multiple rib fractures; some showed minimal displacement of the bone. Baseline spine shot resulted in damage across the spine involving spinal cord and bone. No injuries were noted from the spinal impacts, and the rib shots resulted in injuries consistent with those previously reported. The anatomical differences between pigs and humans does not preclude that bony injuries could occur in a human from these types of spinal ballistic impacts. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Tunnel and field effect carrier ballistics

NASA Technical Reports Server (NTRS)

Kaiser, William J. (Inventor); Bell, L. Douglas (Inventor)

1989-01-01

Methods and apparatus for interacting carriers with a structure of matter employ an electrode for emitting said carriers at a distance from a surface of that structure, and cause such carriers to travel along ballistic trajectories inside that structure by providing along the mentioned distance a gap for performance of a process selected from the group of carrier tunneling and field emission and injecting carriers emitted by the mentioned electrode and that process ballistically into the structure through the gap and the mentioned surface. The carriers are collected or analyzed after their travel along ballistic trajectories in the structure of matter. Pertinent information on the inside of the structure is obtained by conducting inside that structure what conventionally would have been considered external ballistics, while performing the carrier-propelling internal ballistics conversely outside that structure.

Armored instrumentation cable for geothermal well logging

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dennis, B.R.; Johnson, J.; Todd, B.

1981-01-01

Multiconductor armored well-logging cable is used extensively by the oil and natural gas industry to lower various instruments used to measure the geological and geophysical parameters into deep wellbores. Advanced technology in oil-well drilling makes it possible to achieve borehole depths of 9 km (30,000 ft). The higher temperatures in these deeper boreholes demand advancements in the design and manufacturing of wireline cable and in the electrical insulating and armoring materials used as integral components. If geothermal energy is proved an abundant economic resource, drilling temperatures approaching and exceeding 300/sup 0/C will become commonplace. The adaptation of teflons as electricalmore » insulating material permitted use of armored cable in geothermal wellbores where temperatures are slightly in excess of 200/sup 0/C, and where the concentrations of corrosive minerals and gases are high. Teflon materials presently used in wireline cables, however, are not capable of continuous operation at the anticipated higher temperatures.« less

Identification of fundamental deformation and failure mechanisms in armor ceramics

NASA Astrophysics Data System (ADS)

Muller, Andrea Marie

Indentation of a surface with a hard sphere can be used to examine micromechanical response of a wide range of materials and has been shown to generate loading conditions resembling early stages of ballistic impact events. Cracking morphologies also show similarities, particularly with formation of cone cracks at the contact site. The approach in this thesis is to use this indentation technique to characterize contact damage and deformation processes in armor ceramics, as well as identify the role of cone cracking and inelastic behavior. To accomplish these objectives, an instrumented indentation system was designed and fabricated, extending depth-sensing capabilities originally developed for nano-indentation to higher forces. This system is also equipped with an acoustic emission system to detect onset of cone cracking and subsequent failure. Once calibrated and verified the system was used to evaluate elastic modulus and cone crack initiation forces of two commercial float glasses. As-received air and tin surfaces of soda-lime-silica and borosilicate float glass were tested to determine differences in elastic and fracture behavior. Information obtained from load--displacement curves and visual inspection of indentation sites were used to determine elastic modulus, and conditions for onset of cone cracking as a function of surface roughness. No difference in reduced modulus or cone cracking loads on as-received air and tin surfaces were observed. Abraded surfaces showed the tin surface to be slightly more resistant to cone cracking. A study focusing on the transition from elastic to inelastic deformation in two transparent fine-grained polycrystalline spinels with different grain sizes was then conducted. Congruent experiments included observations on evolution of damage, examinations of sub-surface damage and inspection of remnant surface profiles. Indentation stress--strain behavior obtained from load--displacement curves revealed a small difference in yielding

Quantifying the effectiveness of shoreline armoring removal on coastal biota of Puget Sound.

PubMed

Lee, Timothy S; Toft, Jason D; Cordell, Jeffery R; Dethier, Megan N; Adams, Jeffrey W; Kelly, Ryan P

2018-01-01

Shoreline armoring is prevalent around the world with unprecedented human population growth and urbanization along coastal habitats. Armoring structures, such as riprap and bulkheads, that are built to prevent beach erosion and protect coastal infrastructure from storms and flooding can cause deterioration of habitats for migratory fish species, disrupt aquatic-terrestrial connectivity, and reduce overall coastal ecosystem health. Relative to armored shorelines, natural shorelines retain valuable habitats for macroinvertebrates and other coastal biota. One question is whether the impacts of armoring are reversible, allowing restoration via armoring removal and related actions of sediment nourishment and replanting of native riparian vegetation. Armoring removal is targeted as a viable option for restoring some habitat functions, but few assessments of coastal biota response exist. Here, we use opportunistic sampling of pre- and post-restoration data for five biotic measures (wrack % cover, saltmarsh % cover, number of logs, and macroinvertebrate abundance and richness) from a set of six restored sites in Puget Sound, WA, USA. This broad suite of ecosystem metrics responded strongly and positively to armor removal, and these results were evident after less than one year. Restoration responses remained positive and statistically significant across different shoreline elevations and temporal trajectories. This analysis shows that removing shoreline armoring is effective for restoration projects aimed at improving the health and productivity of coastal ecosystems, and these results may be widely applicable.

Quantifying the effectiveness of shoreline armoring removal on coastal biota of Puget Sound

PubMed Central

Toft, Jason D.; Adams, Jeffrey W.

2018-01-01

Shoreline armoring is prevalent around the world with unprecedented human population growth and urbanization along coastal habitats. Armoring structures, such as riprap and bulkheads, that are built to prevent beach erosion and protect coastal infrastructure from storms and flooding can cause deterioration of habitats for migratory fish species, disrupt aquatic–terrestrial connectivity, and reduce overall coastal ecosystem health. Relative to armored shorelines, natural shorelines retain valuable habitats for macroinvertebrates and other coastal biota. One question is whether the impacts of armoring are reversible, allowing restoration via armoring removal and related actions of sediment nourishment and replanting of native riparian vegetation. Armoring removal is targeted as a viable option for restoring some habitat functions, but few assessments of coastal biota response exist. Here, we use opportunistic sampling of pre- and post-restoration data for five biotic measures (wrack % cover, saltmarsh % cover, number of logs, and macroinvertebrate abundance and richness) from a set of six restored sites in Puget Sound, WA, USA. This broad suite of ecosystem metrics responded strongly and positively to armor removal, and these results were evident after less than one year. Restoration responses remained positive and statistically significant across different shoreline elevations and temporal trajectories. This analysis shows that removing shoreline armoring is effective for restoration projects aimed at improving the health and productivity of coastal ecosystems, and these results may be widely applicable. PMID:29492331

Anesthetic management of a case of armored brain.

PubMed

Gupta, Surender Kumar; Pandia, Mihir Prakash

2015-01-01

Armored brain is condition, which occurs due to calcification in a chronic subdural hematoma (SDH). Here, we are reporting a case of armored brain due to chronic SDH as a complication of vetriculoperitoneal shunt (VP shunt). Patient had undergone major surgery for removal of calcified hematoma. VP shunt is a simple surgery, but can lead to catastrophic complications like this. In this report, we had described this condition and its aspects.

27 CFR 478.148 - Armor piercing ammunition intended for sporting or industrial purposes.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 27 Alcohol, Tobacco Products and Firearms 3 2014-04-01 2014-04-01 false Armor piercing ammunition... AMMUNITION COMMERCE IN FIREARMS AND AMMUNITION Exemptions, Seizures, and Forfeitures § 478.148 Armor piercing ammunition intended for sporting or industrial purposes. The Director may exempt certain armor piercing...

27 CFR 478.148 - Armor piercing ammunition intended for sporting or industrial purposes.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 27 Alcohol, Tobacco Products and Firearms 3 2013-04-01 2013-04-01 false Armor piercing ammunition... AMMUNITION COMMERCE IN FIREARMS AND AMMUNITION Exemptions, Seizures, and Forfeitures § 478.148 Armor piercing ammunition intended for sporting or industrial purposes. The Director may exempt certain armor piercing...

27 CFR 478.148 - Armor piercing ammunition intended for sporting or industrial purposes.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 27 Alcohol, Tobacco Products and Firearms 3 2011-04-01 2010-04-01 true Armor piercing ammunition... AMMUNITION COMMERCE IN FIREARMS AND AMMUNITION Exemptions, Seizures, and Forfeitures § 478.148 Armor piercing ammunition intended for sporting or industrial purposes. The Director may exempt certain armor piercing...

27 CFR 478.148 - Armor piercing ammunition intended for sporting or industrial purposes.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 27 Alcohol, Tobacco Products and Firearms 3 2012-04-01 2010-04-01 true Armor piercing ammunition... AMMUNITION COMMERCE IN FIREARMS AND AMMUNITION Exemptions, Seizures, and Forfeitures § 478.148 Armor piercing ammunition intended for sporting or industrial purposes. The Director may exempt certain armor piercing...

Analysis of Multiple-Impact Ballistic Performance of a Tempered Glass Laminate with a Strike Face Film

DTIC Science & Technology

2014-02-01

a 0.18 in thick polymer interlayer between two layers of 0.5 in tempered silica based “ soda lime ” glass . A 0.08 in shatter resistant film was...AFCEC-CX-TY-TR-2014-0005 ANALYSIS OF MULTIPLE-IMPACT BALLISTIC PERFORMANCE OF A TEMPERED GLASS LAMINATE WITH A STRIKE FACE FILM Michael A. Magrini...Interim Technical Report 3 JAN 2012 to 2 JAN 2013 Analysis of Multiple-Impact Ballistic Performance of A Tempered Glass Laminate with a Strike Face Film

48 CFR 252.225-7030 - Restriction on Acquisition of Carbon, Alloy, and Armor Steel Plate.

Code of Federal Regulations, 2012 CFR

2012-10-01

... of Carbon, Alloy, and Armor Steel Plate. 252.225-7030 Section 252.225-7030 Federal Acquisition... Acquisition of Carbon, Alloy, and Armor Steel Plate. As prescribed in 225.7011-3, use the following clause: Restriction on Acquisition of Carbon, Alloy, and Armor Steel Plate (DEC 2006) (a) Carbon, alloy, and armor...

48 CFR 252.225-7030 - Restriction on Acquisition of Carbon, Alloy, and Armor Steel Plate.

Code of Federal Regulations, 2010 CFR

2010-10-01

... of Carbon, Alloy, and Armor Steel Plate. 252.225-7030 Section 252.225-7030 Federal Acquisition... Acquisition of Carbon, Alloy, and Armor Steel Plate. As prescribed in 225.7011-3, use the following clause: Restriction on Acquisition of Carbon, Alloy, and Armor Steel Plate (DEC 2006) (a) Carbon, alloy, and armor...

48 CFR 252.225-7030 - Restriction on Acquisition of Carbon, Alloy, and Armor Steel Plate.

Code of Federal Regulations, 2014 CFR

2014-10-01

... of Carbon, Alloy, and Armor Steel Plate. 252.225-7030 Section 252.225-7030 Federal Acquisition... Acquisition of Carbon, Alloy, and Armor Steel Plate. As prescribed in 225.7011-3, use the following clause: Restriction on Acquisition of Carbon, Alloy, and Armor Steel Plate (DEC 2006) (a) Carbon, alloy, and armor...

48 CFR 252.225-7030 - Restriction on Acquisition of Carbon, Alloy, and Armor Steel Plate.

Code of Federal Regulations, 2013 CFR

2013-10-01

... of Carbon, Alloy, and Armor Steel Plate. 252.225-7030 Section 252.225-7030 Federal Acquisition... Acquisition of Carbon, Alloy, and Armor Steel Plate. As prescribed in 225.7011-3, use the following clause: Restriction on Acquisition of Carbon, Alloy, and Armor Steel Plate (DEC 2006) (a) Carbon, alloy, and armor...

48 CFR 252.225-7030 - Restriction on Acquisition of Carbon, Alloy, and Armor Steel Plate.

Code of Federal Regulations, 2011 CFR

2011-10-01

... of Carbon, Alloy, and Armor Steel Plate. 252.225-7030 Section 252.225-7030 Federal Acquisition... Acquisition of Carbon, Alloy, and Armor Steel Plate. As prescribed in 225.7011-3, use the following clause: Restriction on Acquisition of Carbon, Alloy, and Armor Steel Plate (DEC 2006) (a) Carbon, alloy, and armor...

Ballistic vs. diffusive heat transfer across nanoscopic films of layered crystals

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shen, Meng; Keblinski, Pawel, E-mail: keblip@rpi.edu

2014-04-14

We use non-equilibrium molecular dynamics to study the heat transfer mechanism across sandwich interfacial structures of Si/n-atomic-layers/Si, with 1 ≤ n ≤ 20 and atomic layers composed of WSe{sub 2} and/or graphene. In the case of WSe{sub 2} sheets, we observe that the thermal resistance of the sandwich structure is increasing almost linearly with the number of WSe{sub 2} sheets, n, indicating a diffusive phonon transport mechanism. By contrast in the case of n graphene layers, the interfacial thermal resistance is more or less independent on the number of layers for 1 ≤ n ≤ 10, and is associated with ballistic phonon transport mechanism. We attribute the diffusivemore » heat transfer mechanism across WSe{sub 2} sheets to abundant low frequency and low group velocity optical modes that carry most of the heat across the interface. By contrast, in graphene, acoustic modes dominate the thermal transport across the interface and render a ballistic heat flow mechanism.« less

Low-energy ballistic lunar transfers

NASA Astrophysics Data System (ADS)

Parker, Jeffrey S.

A systematic method is developed that uses dynamical systems theory to model, analyze, and construct low-energy ballistic lunar transfers (BLTs). It has been found that low-energy BLTs may be produced by intersecting the stable manifold of an unstable Earth-Moon three-body orbit with the Earth. A spacecraft following such a trajectory is only required to perform a single maneuver, namely, the Trans-Lunar Injection maneuver, in order to complete the transfer. After the Trans-Lunar Injection maneuver, the spacecraft follows an entirely ballistic trajectory that asymptotically approaches and arrives at the target lunar three-body orbit. Because these orbit transfers require no orbit insertion maneuver at the three-body orbit, the transfers may be used to send spacecraft 25--40% more massive than spacecraft sent to the same orbits via conventional, direct transfers. From the targeted three-body orbits, the spacecraft may transfer to nearly any region within the Earth-Moon system, including any location on the surface of the Moon. The systematic methods developed in this research allow low-energy BLTs to be characterized by six parameters. It has been found that BLTs exist in families, where a family of BLTs consists of transfers whose parameters vary in a continuous fashion from one end of the family to the other. The families are easily identified and studied using a BLT State Space Map (BLT Map). The present research studies BLT Maps and has surveyed a wide variety of BLTs that exist in the observed families. It has been found that many types of BLTs may be constructed between 185-km low Earth parking orbits and lunar three-body orbits that require less than 3.27 km/s and fewer than 120 days of transfer time. Under certain conditions, BLTs may be constructed that require less than 3.2 km/s and fewer than 100 days of transfer time. It has been found that BLTs may implement LEO parking orbits with nearly any combination of altitude and inclination; they may depart from

Overlapping Ballistic Ejecta Fields: Separating Distinct Blasts at Kings Bowl, Idaho

NASA Astrophysics Data System (ADS)

Borg, C.; Kobs-Nawotniak, S. E.; Hughes, S. S.; Sears, D. W. G.; Heldmann, J. L.; Lim, D. S. S.; Haberle, C. W.; Sears, H.; Elphic, R. C.; Kobayashi, L.; Garry, W. B.; Neish, C.; Karunatillake, S.; Button, N.; Purcell, S.; Mallonee, H.; Ostler, B.

2015-12-01

Kings Bowl is a ~2200ka pit crater created by a phreatic blast along a volcanic fissure in the eastern Snake River Plain (ESRP), Idaho. The main crater measures approximately 80m in length, 30m in width, and 30m in depth, with smaller pits located nearby on the Great Rift fissure, and has been targeted by the FINESSE team as a possible analogue for Cyane Fossae, Mars. The phreatic eruption is believed to have occurred due to the interaction of groundwater with lava draining back into the fissure following a lava lake high stand, erupting already solidified basalt from this and previous ERSP lava flows. The contemporaneous draw back of the lava with the explosions may conceal some smaller possible blast pits as more lava drained into the newly formed pits. Ballistic ejecta from the blasts occur on both sides of the fissure. To the east, the ballistic blocks are mantled by fine tephra mixed with eolian dust, the result of a westerly wind during the explosions. We use differential GPS to map the distribution of ballistic blocks on the west side of the fissure, recording position, percent vesiculation, and the length of 3 mutually perpendicular axes for each block >20cm along multiple transects parallel to the fissure. From the several hundred blocks recorded, we have been able to separate the ballistic field into several distinct blast deposits on the basis of size distributions and block concentration. The smaller pits identified from the ballistic fields correspond broadly to the northern and southern limits of the tephra/dust field east of the fissure. Soil formation and bioturbation of the tephra by sagebrush have obliterated any tephrostratigraphy that could have been linked to individual blasts. The ballistic block patterns at Kings Bowl may be used to identify distinct ejecta groups in high-resolution imagery of Mars or other planetary bodies.

Glass matrix armor

DOEpatents

Calkins, Noel C.

1991-01-01

An armor system which utilizes glass. A plurality of constraint cells are mounted on a surface of a substrate, which is metal armor plate or a similar tough material, such that the cells almost completely cover the surface of the substrate. Each constraint cell has a projectile-receiving wall parallel to the substrate surface and has sides which are perpendicular to and surround the perimeter of the receiving wall. The cells are mounted such that, in one embodiment, the substrate surface serves as a sixth side or closure for each cell. Each cell has inside of it a plate, termed the front plate, which is parallel to and in contact with substantially all of the inside surface of the receiving wall. The balance of each cell is completely filled with a projectile-abrading material consisting of glass and a ceramic material and, in certain embodiments, a polymeric material. The glass may be in monolithic form or particles of ceramic may be dispersed in a glass matrix. The ceramic material may be in monolithic form or may be in the form of particles dispersed in glass or dispersed in said polymer.

’Stinger under Armor:’ An Analysis of Alternatives

DTIC Science & Technology

1990-01-01

This paper examines a concept for employment of the Stinger Air Defense Artillery weapon system known as ’Stinger under Armor .’ It traces the...areas air defense in the pre-FAADS era. This broader deficiency ultimately drove the need for ’Stinger under Armor ’ as a short-term solution to a current battlefield vulnerability.

Whole-Body and Hepatic Insulin Resistance in Obese Children

PubMed Central

Ibarra-Reynoso, Lorena del Rocío; Pisarchyk, Liudmila; Pérez-Luque, Elva Leticia; Garay-Sevilla, Ma. Eugenia; Malacara, Juan Manuel

2014-01-01

Background Insulin resistance may be assessed as whole body or hepatic. Objective To study factors associated with both types of insulin resistance. Methods Cross-sectional study of 182 obese children. Somatometric measurements were registered, and the following three adiposity indexes were compared: BMI, waist-to-height ratio and visceral adiposity. Whole-body insulin resistance was evaluated using HOMA-IR, with 2.5 as the cut-off point. Hepatic insulin resistance was considered for IGFBP-1 level quartiles 1 to 3 (<6.67 ng/ml). We determined metabolite and hormone levels and performed a liver ultrasound. Results The majority, 73.1%, of obese children had whole-body insulin resistance and hepatic insulin resistance, while 7% did not have either type. HOMA-IR was negatively associated with IGFBP-1 and positively associated with BMI, triglycerides, leptin and mother's BMI. Girls had increased HOMA-IR. IGFBP-1 was negatively associated with waist-to-height ratio, age, leptin, HOMA-IR and IGF-I. We did not find HOMA-IR or IGFBP-1 associated with fatty liver. Conclusion In school-aged children, BMI is the best metric to predict whole-body insulin resistance, and waist-to-height ratio is the best predictor of hepatic insulin resistance, indicating that central obesity is important for hepatic insulin resistance. The reciprocal negative association of IGFBP-1 and HOMA-IR may represent a strong interaction of the physiological processes of both whole-body and hepatic insulin resistance. PMID:25411786

Whither Ballistic Missile Defense?

DTIC Science & Technology

1992-11-30

Conference on Technical Marketing 2000: Opportunities and Strategies for a Changing World) I intend to discuss the prospects for SDI in a changing...Technical Marketing 2000: Opportunities and Strategies for a Changing World) Descriptors, Keywords: Cooper Speech Ballistic Missile Defense...WHITHER BALLISTIC MISSILE DEFENSE? BY AMBASSADOR HENRY F. COOPER NOVEMBER 30,1992 TECHNICAL MARKETING SOCIETY OF AMERICA WASHINGTON, DC

Simulated Tank Anti-Armor Gunnery System (STAGS-TOW).

DTIC Science & Technology

1983-05-01

to train TOW gunners. It is derived from a model previously developed for DRAGON. The system employs a terrain board with model enemy armored vehicles ...gunnery training. TOW is a crew-portable, heavy anti-tank weapon designed to attack and defeat armored vehicles and field fortifications. The missile is...a target area, converts the infrared energy to electrical signals and then to visible light and displays the visible light as a real-time scene for

Anesthetic management of a case of armored brain

PubMed Central

Gupta, Surender Kumar; Pandia, Mihir Prakash

2015-01-01

Armored brain is condition, which occurs due to calcification in a chronic subdural hematoma (SDH). Here, we are reporting a case of armored brain due to chronic SDH as a complication of vetriculoperitoneal shunt (VP shunt). Patient had undergone major surgery for removal of calcified hematoma. VP shunt is a simple surgery, but can lead to catastrophic complications like this. In this report, we had described this condition and its aspects. PMID:25558206

Management of civilian ballistic fractures.

PubMed

Seng, V S; Masquelet, A C

2013-12-01

The management of ballistic fractures, which are open fractures, has often been studied in wartime and has benefited from the principles of military surgery with debridement and lavage, and the use of external fixation for bone stabilization. In civilian practice, bone stabilization of these fractures is different and is not performed by external fixation. Fifteen civilian ballistic fractures, Gustilo II or IIIa, two associated with nerve damage and none with vascular damage, were reviewed. After debridement and lavage, ten internal fixations and five conservative treatments were used. No superficial or deep surgical site infection was noted. Fourteen of the 15 fractures (93%) healed without reoperation. Eleven of the 15 patients (73%) regained normal function. Ballistic fractures have a bad reputation due to their many complications, including infections. In civilian practice, the use of internal fixation is not responsible for excessive morbidity, provided debridement and lavage are performed. Civilian ballistic fractures, when they are caused by low-velocity firearms, differ from military ballistic fractures. Although the principle of surgical debridement and lavage remains the same, bone stabilization is different and is similar to conventional open fractures. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

Armored Family of Vehicles (AFV). Phase 1 Report. Book 7. Volume 11

DTIC Science & Technology

1987-08-31

Armored Family of Vehicles. Specific requirements and products are described which initiate the training development process and a training management ...approach for the TRADOC and proponent schools to plan, develop, manage and integrate the training subsystem(s) for the Armored Family of Vehicles...Procedures. q. Charter, Armored Family of Vehicles. r. Operational and Organizational (O&W) Plan for AFV. s. System MANPRINT Management Plan for AFV

A Feasibility Study of the Flare-Cylinder Configuration as a Reentry Body Shape for an Intermediate Range Ballistic Missile

NASA Technical Reports Server (NTRS)

Garland, B. J.; Hall, J. R.

1958-01-01

A study has been made of a flare-cylinder configuration to investigate its feasibility as a reentry body of an intermediate range ballistic missile. Factors considered were heating, weight, stability, and impact velocity. A series of trajectories covering the possible range of weight-drag ratios were computed for simple truncated nose shapes of varying pointedness, and hence varying weight-drag ratios. Four trajectories were chosen for detailed temperature computation from among those trajectories estimated to be possible. Temperature calculations were made for both "conventional" (for example, copper, Inconel, and stainless steel) and "unconventional" (for example, beryllium and graphite) materials. Results of the computations showed that an impact Mach number of 0.5 was readily obtainable for a body constructed from conventional materials. A substantial increase in subsonic impact velocity above a Mach number of 0.5 was possible without exceeding material temperature limits. A weight saving of up to 134 pounds out of 822 was possible with unconventional materials. This saving represents 78 percent of the structural weight. Supersonic impact would require construction of the body from unconventional materials but appeared to be well within the range of attainability.

CORROSION RESISTANT JACKETED METAL BODY

DOEpatents

Brugmann, E.W.

1958-08-26

Jacketed metal bodies of the type used as fuel elements for nuclear reactors, which contain an internal elongated body of fissionable material jacketed in a corrosion resistant metal are described. The ends of the internal bodies are provided with screw threads having a tapered outer end. The jacket material overlaps the ends and extends into the tapered section of the screw threaded opening. Screw caps with a mating tapered section are screwed into the ends of the body to compress the jacket material in the tapered sections to provtde an effective seal against corrosive gases and liquids.

Pangolin armor: Overlapping, structure, and mechanical properties of the keratinous scales.

PubMed

Wang, Bin; Yang, Wen; Sherman, Vincent R; Meyers, Marc A

2016-09-01

The pangolin has a flexible dermal armor consisting of overlapping keratinous scales. Although they show potential for bioinspired flexible armor, the design principles of pangolin armor are barely known. Here we report on the overlapping organization, hierarchical structure (from the nano to the mesolevel), and mechanical response of scales from ground (Chinese) and arboreal (African tree) pangolins. Both scales exhibit the same overlapping organization, with each scale at the center of neighboring scales arranged in a hexagonal pattern. The scales have a cuticle of several layers of loosely attached flattened keratinized cells, while the interior structure exhibits three regions distinguished by the geometry and orientations of the keratinized cells, which form densely packed lamellae; each one corresponds to one layer of cells. Unlike most other keratinous materials, the scales show a crossed-lamellar structure (∼5μm) and crossed fibers (∼50μm). A nano-scale suture structure, observed for the first time, outlines cell membranes and leads to an interlocking interface between lamellae, thus enhancing the bonding and shear resistance. The tensile response of the scales shows an elastic limit followed by a short plateau prior to failure, with Young's modulus ∼1 GPa and tensile strength 60-100MPa. The mechanical response is transversely isotropic, a result of the cross lamellar structure. The strain rate sensitivity in the range of 10(-5)-10(-1)s(-1) region is found to be equal to 0.07-0.08, typical of other keratins and polymers. The mechanical response is highly dependent on the degree of hydration, a characteristic of keratins. Although many fish and reptiles have protective scales and carapaces, mammals are characteristically fast and light. The pangolin is one of the few mammal possessing a flexible dermal armor for protection from predators, such as lions. Here we study the arrangement of the scales as well as their hierarchical structure from the nano

Advanced Metals and Ceramics for Armor and Anti-Armor Applications. High-Fidelity Design and Processing of Advanced Armor Ceramics

DTIC Science & Technology

2007-06-01

microstructures through advanced powder processing , (7) nondestructive evaluation of ceramic armor, (8) investigation of the relation between quasi-static...of a green microstructure of a compact prepared by this process using Superior Graphite 490 powder that had been twice beneficiated by settling and...create a dense, uniform microstructure of highly oriented grains • Determined the relationship between processing parameters, such as shear and solids

On motion in a resisting medium: A historical perspective

NASA Astrophysics Data System (ADS)

Hackborn, William W.

2016-02-01

This paper examines, compares, and contrasts ideas about motion, especially the motion of a body in a resisting medium, proposed by Galileo, Newton, and Tartaglia, the author of the first text on exterior ballistics, within the context of the Aristotelian philosophy prevalent when these scholars developed their ideas. This historical perspective offers insights on the emergence of a scientific paradigm for motion, particularly with respect to the challenge of incorporating into this paradigm the role played by the medium.

Development of a Character Simulator for Battlefield Virtual Environments

DTIC Science & Technology

2010-04-01

existent. Second, human muscle strength is highly idealized. It is usually measured under static (“ isometric ”) conditions (i.e., body does not move and...28, No. 1 Suppl, pp. S116-S124, January 1988. 8 R.D. Eisler, et al, Improved Fibers and Material Systems for Personnel Ballistic Armor, Final...043, January 1988. 11 Undocumented conversation on 17 December 1996 with Callis Goodrich at NRaD in San Diego and Chris Field a contract employee

Wounding patterns and human performance in knife attacks: optimising the protection provided by knife-resistant body armour.

PubMed

Bleetman, A; Watson, C H; Horsfall, I; Champion, S M

2003-12-01

-type of Police uniform that is inherently stab and slash resistant will eventually replace the current obvious and often bulky extra protective vest. Attempts at making a combined garment will need to be guided by ergonomic considerations and field testing. A similar anatomical regional risk model might also be appropriate in the design of anti-ballistic armour and combined anti-ballistic and knife-resistant armour.

Ballistic phonon transport in holey silicon.

PubMed

Lee, Jaeho; Lim, Jongwoo; Yang, Peidong

2015-05-13

When the size of semiconductors is smaller than the phonon mean free path, phonons can carry heat with no internal scattering. Ballistic phonon transport has received attention for both theoretical and practical aspects because Fourier's law of heat conduction breaks down and the heat dissipation in nanoscale transistors becomes unpredictable in the ballistic regime. While recent experiments demonstrate room-temperature evidence of ballistic phonon transport in various nanomaterials, the thermal conductivity data for silicon in the length scale of 10-100 nm is still not available due to experimental challenges. Here we show ballistic phonon transport prevails in the cross-plane direction of holey silicon from 35 to 200 nm. The thermal conductivity scales linearly with the length (thickness) even though the lateral dimension (neck) is as narrow as 20 nm. We assess the impact of long-wavelength phonons and predict a transition from ballistic to diffusive regime using scaling models. Our results support strong persistence of long-wavelength phonons in nanostructures and are useful for controlling phonon transport for thermoelectrics and potential phononic applications.

Cross-Validation of Predictor Equations for Armor Crewman Performance

DTIC Science & Technology

1980-01-01

Technical Report 447 CROSS-VALIDATION OF PREDICTOR EQUATIONS FOR ARMOR CREWMAN PERFORMANCE Anthony J. Maitland , Newell K. Eaton, and Janet F. Neft...ORG. REPORT NUMBER Anthony J/ Maitland . Newell K/EatorV. and B OTATO RN UBR. 9- PERFORMING ORGANIZATION NAME AND ADDRESS I0. PROGRAM ELEMENT, PROJECT...Technical Report 447 CROSS-VALIDATION OF PREDICTOR EQUATIONS FOR ARMOR CREWMAN PERFORMANCE Anthony J. Maitland , Newell K. Eaton, Accession For and

Army National Guard Air Defense Artillery Modernization: A Vision for the Future

DTIC Science & Technology

1994-05-15

plan to replace Stinger Under Armor (SUA) for the ARNG, and no guarantee that the BSFV will be in the future ARNG force, divisional assets will remain...Ballistic Missile SUA Stinger Under Armor TAA Total Army Analysis TAAD Theater Area Air Defense TASM Tactical Air-to-Surface Missiles TBM Tactical

Constrained ceramic-filled polymer armor

DOEpatents

Sandstrom, D.J.; Calkins, N.C.; Gac, F.D.

1990-11-13

An armor system is disclosed in which a plurality of constraint cells are mounted on a surface of a substrate, which is metal armor plate or a similar tough material, such that the cells almost completely cover the surface of the substrate. Each constraint cell has a projectile-receiving wall parallel to the substrate surface and has sides which are perpendicular to and surround the perimeter of the receiving wall. The cells are mounted such that, in one embodiment, the substrate surface serves as a sixth side or closure for each cell. Each cell has inside of it a plate, termed the front plate, which is parallel to and in contact with substantially all of the inside surface of the receiving wall. The balance of each cell is completely filled with a projectile-abrading material, which is a ceramic material in particulate form dispersed in a polymeric matrix. 5 figs.

Constrained ceramic-filled polymer armor

DOEpatents

Sandstrom, Donald J.; Calkins, Noel C.; Gac, Frank D.

1990-01-01

An armor system in which a plurality of constraint cells are mounted on a surface of a substrate, which is metal armor plate or a similar tough material, such that the cells almost completely cover the surface of the substrate. Each constraint cell has a projectile-receiving wall parallel to the substrate surface and has sides which are perpendicular to and surround the perimeter of the receiving wall. The cells are mounted such that, in one embodiment, the substrate surface serves as a sixth side or closure for each cell. Each cell has inside of it a plate, termed the front plate, which is parallel to and in contact with substantially all of the inside surface of the receiving wall. The balance of each cell is completely filled with a projectile-abrading material, which is a ceramic material in particulate form dispersed in a polymeric matrix.

8. BUILDING NO. 611. INTERIOR OF ARMOR PLATELINED TESTING CHAMBER. ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

8. BUILDING NO. 611. INTERIOR OF ARMOR PLATE-LINED TESTING CHAMBER. 1/2' THICK ARMOR PLATING BOLTED TO WALLS, FLOOR AND CEILING. WALLS CONSTRUCTED OF 24' THICK REINFORCED CONCRETE. VENTS IN CEILING EXHAUST SMOKE FROM EXPLOSIONS. SMALLEST WHEELED VEHICLES HOLD DUDS. - Picatinny Arsenal, 600 Area, Test Areas District, State Route 15 near I-80, Dover, Morris County, NJ

Single-Enzyme Nanoparticles Armored by a Nanometer-Scale Organic/Inorganic Network

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Jungbae; Grate, Jay W.

2003-09-01

We have developed armored single-enzyme nanoparticles (SENs), which dramatically stabilize a protease (a-chymotrypsin, CT) by surrounding each enzyme molecule with a porous composite organic/inorganic shell of less than a few nanometers thick. The armored enzymes show no decrease in CT activity at 30C for four days while free CT activity is rapidly reduced by orders of magnitude. The armored shell around CT is sufficiently thin and porous that it does not place any serious mass-transfer limitation on substrates. This unique approach will have a great impact in using enzymes in various fields.

Shell-armored wood cobbles as a potential criterion for detrital coal deposits

DOE Office of Scientific and Technical Information (OSTI.GOV)

DiMarco, M.J.; Nummedal, D.

1986-01-01

Shell-armored wood cobbles occur on detrital-peat beaches along the seaward edge of the Mississippi Delta. Shell material consists exclusively of Mulinia lateralis, a dwarf surf clam. Soft, heavy, waterlogged wood fragments are abraded and become armored by hard shells in response to wave activity on the beach. Although their preservation potential is suspect, fossilized shell-armored wood clasts would probably be recognized as a type of coal ball and might indicate an allochthonous origin for the host coal.

An Approach to Analyze Personnel Injury of Reflective Spall from Small-Arms Protective Body Armor

DTIC Science & Technology

2011-07-01

2  Figure 2. Protective plate system on the ORCA human anatomy . .................................................2  Figure 3...stature and is fitted with a medium size protective plate. Representation of the ORCA human anatomy wearing the protective plate system is shown in...Figure 1. Gelatin block placement for experimental testing. Figure 2. Protective plate system on the ORCA human anatomy . Ballistic Gelatin Test

Clothing adjustments for concealed soft body armor during moderate physical exertion.

PubMed

Ryan, Greg A; Bishop, Stacy H; Herron, Robert L; Katica, Charles P; Elbon, Bre'anna L; Bosak, Andrew M; Bishop, Phillip

2015-01-01

Previous research has studied the impact of Level II concealed soft body armor (SBA) on the augmentation of heat storage in a hot environment simulating a typical summer day in the southeastern United States (wet bulb globe temperature [WBGT] = 30°C) and noted a significant difference between macro- and micro-WBGTs. The purpose of this study was to characterize the microclimate (micro-WBGT) under a concealed Level II SBA during 60 min of moderately intense work at two separate macro-WBGTs (26°C and 30°C), and to establish WBGT corrections to allow prediction of heat strain in an individual wearing a concealed Level II SBA. A single trial was performed with nine volunteers (27 ± 4 years) outfitted with a simulated standard law enforcement uniform and a traditional concealed Level II SBA, in a moderately warm environment (WBGT = 26°C). Each participant performed cycles of 12 min of walking (1.25 L · min(-1)) and 3 min of arm curls (14.3 kg, 0.6 L · min(-1)) with a 5 min rest after every other cycle, for a total of 60 minutes. This trial was compared to an identical previously completed 60-min work bout at 30°C. A two-way repeated measures ANOVA with Post hoc Bonferroni and paired samples t-test analysis was conducted. A greater difference between macro- micro-WBGTs existed at 26°C compared to the 30°C macro-WBGT. Under these conditions, a moderate work in Level II SBA requires a WBGT correction of 8.9°C and 6.2°C at macro-WBGTs of 26°C and 30°C, respectively. A modified simple linear regression prediction model was established for mean Micro-WBGT for each macro-WBGTs after the plateau point at the 30 min mark. The derivation regressions at 26°C (R(2) = 0.99), and 30°C (R(2) = 0.99) indicate that micro-WBGT could be predicted for each 15 minutes time at both macro-WBGTs tested for individuals doing moderate intensity (300 Kcals · hr(-1)) work wearing concealed Level II SBA.

External Ballistics. Part 1

DTIC Science & Technology

1978-07-11

trajectories and aEe gAven the concepts cf tke oEtiaua sclticas of the problems of e.termal ballistics. Is estimated the effect c different perturkation... development receimed the d*signed kallistic calculaticns ct scattering trajectoies bith the firiqg icckets and artillery shells. The application/use of...problems, solved in the course of external ballistics, they at* bscught informaticn fzca the histccl of the development of the thecrj of flight and

A Histological Analysis of Visceral Organs to Evaluate the Effect of Duration of Heating From Refrigeration to Core Body Temperature for Ballistics Investigations.

PubMed

Humphrey, Caitlin; Kumaratilake, Jaliya

2017-12-01

Animal organs have been used in ballistics research to investigate the effects on human organs. Such organs are refrigerated until the investigation to minimize autolytic degradation and at times have been reheated to the human core body temperature to simulate the in situ environment. The aim of this investigation was to study the microstructural changes that may occur in fresh chilled visceral organs of the thorax and abdomen (ie, heart, lung, liver, and kidney) during the period of reheating to 37°C. Fifty-millimeter cubes of porcine heart, lung, liver, and kidney were taken rapidly after slaughter, chilled overnight, and the next morning were reheated to core body temperature (37°C). Histological changes occurring in the tissues during the reheating phase were investigated. The findings indicated that no cytoplasmic or nuclear changes occurred in any of the tissues during the period of reheating. Therefore, reheating of animal organs to the human core body temperature is not necessary, if the organs are refrigerated.

The Advantages of Normalizing Electromyography to Ballistic Rather than Isometric or Isokinetic Tasks.

PubMed

Suydam, Stephen M; Manal, Kurt; Buchanan, Thomas S

2017-07-01

Isometric tasks have been a standard for electromyography (EMG) normalization stemming from anatomic and physiologic stability observed during contraction. Ballistic dynamic tasks have the benefit of eliciting maximum EMG signals for normalization, despite having the potential for greater signal variability. It is the purpose of this study to compare maximum voluntary isometric contraction (MVIC) to nonisometric tasks with increasing degrees of extrinsic variability, ie, joint range of motion, velocity, rate of contraction, etc., to determine if the ballistic tasks, which elicit larger peak EMG signals, are more reliable than the constrained MVIC. Fifteen subjects performed MVIC, isokinetic, maximum countermovement jump, and sprint tasks while EMG was collected from 9 muscles in the quadriceps, hamstrings, and lower leg. The results revealed the unconstrained ballistic tasks were more reliable compared to the constrained MVIC and isokinetic tasks for all triceps surae muscles. The EMG from sprinting was more reliable than the constrained cases for both the hamstrings and vasti. The most reliable EMG signals occurred when the body was permitted its natural, unconstrained motion. These results suggest that EMG is best normalized using ballistic tasks to provide the greatest within-subject reliability, which beneficially yield maximum EMG values.

Effects of acute static, ballistic, and PNF stretching exercise on the muscle and tendon tissue properties.

PubMed

Konrad, A; Stafilidis, S; Tilp, M

2017-10-01

The purpose of this study was to investigate the influence of a single static, ballistic, or proprioceptive neuromuscular facilitation (PNF) stretching exercise on the various muscle-tendon parameters of the lower leg and to detect possible differences in the effects between the methods. Volunteers (n = 122) were randomly divided into static, ballistic, and PNF stretching groups and a control group. Before and after the 4 × 30 s stretching intervention, we determined the maximum dorsiflexion range of motion (RoM) with the corresponding fascicle length and pennation angle of the gastrocnemius medialis. Passive resistive torque (PRT) and maximum voluntary contraction (MVC) were measured with a dynamometer. Observation of muscle-tendon junction (MTJ) displacement with ultrasound allowed us to determine the length changes in the tendon and muscle, respectively, and hence to calculate stiffness. Although RoM increased (static: +4.3%, ballistic: +4.5%, PNF: +3.5%), PRT (static: -11.4%, ballistic: -11.5%, PNF: -13,7%), muscle stiffness (static: -13.1%, ballistic: -20.3%, PNF: -20.2%), and muscle-tendon stiffness (static: -11.3%, ballistic: -10.5%, PNF: -13.7%) decreased significantly in all the stretching groups. Only in the PNF stretching group, the pennation angle in the stretched position (-4.2%) and plantar flexor MVC (-4.6%) decreased significantly. Multivariate analysis showed no clinically relevant difference between the stretching groups. The increase in RoM and the decrease in PRT and muscle-tendon stiffness could be explained by more compliant muscle tissue following a single static, ballistic, or PNF stretching exercise. © 2017 The Authors Scandinavian Journal of Medicine & Science In Sports Published by John Wiley & Sons Ltd.

48 CFR 225.7011 - Restriction on carbon, alloy, and armor steel plate.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Restriction on carbon, alloy, and armor steel plate. 225.7011 Section 225.7011 Federal Acquisition Regulations System DEFENSE... on carbon, alloy, and armor steel plate. ...

48 CFR 225.7011 - Restriction on carbon, alloy, and armor steel plate.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 48 Federal Acquisition Regulations System 3 2011-10-01 2011-10-01 false Restriction on carbon, alloy, and armor steel plate. 225.7011 Section 225.7011 Federal Acquisition Regulations System DEFENSE... on carbon, alloy, and armor steel plate. ...

48 CFR 225.7011 - Restriction on carbon, alloy, and armor steel plate.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 48 Federal Acquisition Regulations System 3 2013-10-01 2013-10-01 false Restriction on carbon, alloy, and armor steel plate. 225.7011 Section 225.7011 Federal Acquisition Regulations System DEFENSE... on carbon, alloy, and armor steel plate. ...

48 CFR 225.7011 - Restriction on carbon, alloy, and armor steel plate.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 48 Federal Acquisition Regulations System 3 2012-10-01 2012-10-01 false Restriction on carbon, alloy, and armor steel plate. 225.7011 Section 225.7011 Federal Acquisition Regulations System DEFENSE... on carbon, alloy, and armor steel plate. ...

48 CFR 225.7011 - Restriction on carbon, alloy, and armor steel plate.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 48 Federal Acquisition Regulations System 3 2014-10-01 2014-10-01 false Restriction on carbon, alloy, and armor steel plate. 225.7011 Section 225.7011 Federal Acquisition Regulations System DEFENSE... on carbon, alloy, and armor steel plate. ...

Computational Modeling of Dynamic Failure Mechanisms in Armor/Anti-Armor Materials

DTIC Science & Technology

1991-02-01

June 1983. Xavier, Celio; Da Costa, Carlos R.C. Estudo do Comportamento Mecanico de Placas de Alumina Sob Impacto Balistico. (A Study of the Mechanical...0 40 10 0.0 La 2.0 SUMMARY OF RESULTS The emphasis of the project in the first two years was to evaluate the literature and survey private industry...of Materials of Interest for Lightweight Armor," Report LA -3858-MS, Los Alamos Scientific Laboratory, Los Alamos, New Mexico, January 22, 1968

Short Ballistic Josephson Coupling in Planar Graphene Junctions with Inhomogeneous Carrier Doping

NASA Astrophysics Data System (ADS)

Park, Jinho; Lee, Jae Hyeong; Lee, Gil-Ho; Takane, Yositake; Imura, Ken-Ichiro; Taniguchi, Takashi; Watanabe, Kenji; Lee, Hu-Jong

2018-02-01

We report on short ballistic (SB) Josephson coupling in junctions embedded in a planar heterostructure of graphene. Ballistic Josephson coupling is confirmed by the Fabry-Perot-type interference of the junction critical current Ic . The product of Ic and the normal-state junction resistance RN , normalized by the zero-temperature gap energy Δ0 of the superconducting electrodes, turns out to be exceptionally large close to 2, an indication of strong Josephson coupling in the SB junction limit. However, Ic shows a temperature dependence that is inconsistent with the conventional short-junction-like behavior based on the standard Kulik-Omel'yanchuk prediction. We argue that this feature stems from the effects of inhomogeneous carrier doping in graphene near the superconducting contacts, although the junction is in fact in the short-junction limit.

Tolerance of the skull to blunt ballistic temporo-parietal impact.

PubMed

Raymond, David; Van Ee, Chris; Crawford, Gregory; Bir, Cynthia

2009-11-13

Less-lethal ballistic projectiles are used by police personnel to temporarily incapacitate suspects. While the frequency of these impacts to the head is low, they account for more serious injuries than impacts to any other body region. As a result, there is an urgent need to assess the tolerance of the head to such impacts. The focus of this study was to investigate the tolerance of the temporo-parietal skull to blunt ballistic impact and establish injury criteria for risk assessment. Seven unembalmed isolated cadaver heads were subjected to fourteen impacts. Specimens were instrumented with a nine-accelerometer array as well as strain gages surrounding the impact site. Impacts were performed with a 38 mm instrumented projectile at velocities ranging from 18 to 37 m/s. CT images and autopsies were performed to document resulting fractures. Peak fracture force for the seven resulting fractures was 5633+/-2095 N. Peak deformation for fracture-producing impacts was 7.8+/-3.2 mm. The blunt criterion (BC), peak force and principal strain were determined to be the best predictors of depressed comminuted fractures. Temporo-parietal tolerance levels were consistent with previous studies. An initial force tolerance level of 2346 N is established for the temporo-parietal region for blunt ballistic impact with a 38 mm diameter impactor.

Computational Investigation of Effects of Grain Size on Ballistic Performance of Copper

NASA Astrophysics Data System (ADS)

He, Ge; Dou, Yangqing; Guo, Xiang; Liu, Yucheng

2018-01-01

Numerical simulations were conducted to compare ballistic performance and penetration mechanism of copper (Cu) with four representative grain sizes. Ballistic limit velocities for coarse-grained (CG) copper (grain size ≈ 90 µm), regular copper (grain size ≈ 30 µm), fine-grained (FG) copper (grain size ≈ 890 nm), and ultrafine-grained (UG) copper (grain size ≈ 200 nm) were determined for the first time through the simulations. It was found that the copper with reduced grain size would offer higher strength and better ductility, and therefore renders improved ballistic performance than the CG and regular copper. High speed impact and penetration behavior of the FG and UG copper was also compared with the CG coppers strengthened by nanotwinned (NT) regions. The comparison results showed the impact and penetration resistance of UG copper is comparable to the CG copper strengthened by NT regions with the minimum twin spacing. Therefore, besides the NT-strengthened copper, the single phase copper with nanoscale grain size could also be a strong candidate material for better ballistic protection. A computational modeling and simulation framework was proposed for this study, in which Johnson-Cook (JC) constitutive model is used to predict the plastic deformation of Cu; the JC damage model is to capture the penetration and fragmentation behavior of Cu; Bao-Wierzbicki (B-W) failure criterion defines the material's failure mechanisms; and temperature increase during this adiabatic penetration process is given by the Taylor-Quinney method.

Buckling in armored droplets.

PubMed

Sicard, François; Striolo, Alberto

2017-06-29

The buckling mechanism in droplets stabilized by solid particles (armored droplets) is tackled at a mesoscopic level using dissipative particle dynamics simulations. We consider one spherical water droplet in a decane solvent coated with nanoparticle monolayers of two different types: Janus (particles whose surface shows two regions with different wetting properties) and homogeneous. The chosen particles yield comparable initial three-phase contact angles, selected to maximize the adsorption energy at the interface. We study the interplay between the evolution of droplet shape, layering of the particles, and their distribution at the interface when the volume of the droplets is reduced. We show that Janus particles affect strongly the shape of the droplet with the formation of a crater-like depression. This evolution is actively controlled by a close-packed particle monolayer at the curved interface. In contrast, homogeneous particles follow passively the volume reduction of the droplet, whose shape does not deviate too much from spherical, even when a nanoparticle monolayer/bilayer transition is detected at the interface. We discuss how these buckled armored droplets might be of relevance in various applications including potential drug delivery systems and biomimetic design of functional surfaces.

Airborne ballistic camera tracking systems

NASA Technical Reports Server (NTRS)

Redish, W. L.

1976-01-01

An operational airborne ballistic camera tracking system was tested for operational and data reduction feasibility. The acquisition and data processing requirements of the system are discussed. Suggestions for future improvements are also noted. A description of the data reduction mathematics is outlined. Results from a successful reentry test mission are tabulated. The test mission indicated that airborne ballistic camera tracking systems are feasible.

Examples of the nonlinear dynamics of ballistic capture and escape in the earth-moon system

NASA Technical Reports Server (NTRS)

Belbruno, Edward A.

1990-01-01

An example of a trajectory is given which is initially captured in an elliptic resonant orbit about the earth and then ballistically escapes the earth-moon system. This is demonstrated by a numerical example in three-dimensions using a planetary ephemeris. Another example shows a mechanism of how an elliptic orbit about the earth can increase its energy by performing a complex nonlinear transition to an elliptic orbit of a larger semi-major axis. Capture is also considered. An application of ballistic capture at the moon via an unstable periodic orbit using the four-body sun-earth-moon-S/C interaction is described.

Cloth Ballistic Vest Alters Response to Blast

DTIC Science & Technology

1988-01-01

Detrick, Frederick, MD 21701-501 ELEMENT NO. NO. NO. jACCESSION NO. 11. TITLE (include Security Classification) CLOTH BALLSISTIC VEST ALTERS RESPONSE...Suppl. ’rintd in USA Cloth Ballistic Vest Alters Response to Blast YANCY Y. PHILLIPS, M.D., THOMAS G. MUNDIE, PH.D., JOHN T. YELVERTON, M.S., AND DONALD R...RICHMOND, PH.D. Ballistic wounds have been and will remain the principal cause of casualties in combat. Cloth ballistic vests (CBV) play an

Cloth ballistic vest alters response to blast.

PubMed

Phillips, Y Y; Mundie, T G; Yelverton, J T; Richmond, D R

1988-01-01

Ballistic wounds have been and will remain the principal cause of casualties in combat. Cloth ballistic vests (CBV) play an important role in limiting critical wounds from fragments and small-arms fire. There is an increased risk of primary blast injury on the modern battlefield. In a previous study, volunteers were exposed to short-duration blast waves of low peak pressure (18.6 +/- 0.8 kPa). Pressure measurements made in the distal esophagus as an estimate of intrathoracic pressure (ITP) were significantly higher (p less than 0.05) when the standard U.S. Army ballistic jacket was worn (8.7 +/- 1.2 kPa) than when fatigues alone were worn (7.4 +/- 0.7 kPa). In this study 58 sheep were exposed to nominal blast levels of 115, 230, 295, and 420 kPa peak pressure in groups of 12, 18, 16, and 12, respectively. Half of each group was fitted with a CBV. Lung weight index (LWI), lung weight expressed as a percentage of body weight, was used as a measure of blast injury. Use of the CBV was associated with a significant increase in LWI (p less than 0.05) which averaged 21% for the two middle exposure groups. At the 420 kPa level, two of six non-CBV animals died as opposed to five of six animals wearing the CBV. Intrathoracic pressure was generally higher in the CBV group. Likely mechanisms of injury enhancement include an increase in target surface area and an alteration of the effective loading function on the thorax. This information may be useful in the triage and treatment of casualties exposed to intense blast environments.

Construction of armored RNA containing long-size chimeric RNA by increasing the number and affinity of the pac site in exogenous rna and sequence coding coat protein of the MS2 bacteriophage.

PubMed

Wei, Baojun; Wei, Yuxiang; Zhang, Kuo; Yang, Changmei; Wang, Jing; Xu, Ruihuan; Zhan, Sien; Lin, Guigao; Wang, Wei; Liu, Min; Wang, Lunan; Zhang, Rui; Li, Jinming

2008-01-01

To construct a one-plasmid expression system of the armored RNA containing long chimeric RNA by increasing the number and affinity of the pac site. The plasmid pET-MS2-pac was constructed with one C-variant pac site, and then the plasmid pM-CR-2C containing 1,891-bp chimeric sequences and two C-variant pac sites was produced. Meanwhile, three plasmids (pM-CR-C, pM-CR-2W and pM-CR-W) were obtained as parallel controls with a different number and affinity of the pac site. Finally, the armored RNA was expressed and purified. The armored RNA with 1,891 bases target RNA was expressed successfully by the one-plasmid expression system with two C-variant pac sites, while for one pac site, no matter whether the affinity was changed or not, only the 1,200 bases target RNA was packaged. It was also found that the C-variant pac site could increase the expression efficiency of the armored RNA. The armored RNA with 1,891-bp exogenous RNA in our study showed the characterization of ribonuclease resistance and stability at different time points and temperature conditions. The armored RNA with 1,891 bases exogenous RNA was constructed and the expression system can be used as a platform for preparation of the armored RNA containing long RNA sequences. Copyright 2008 S. Karger AG, Basel.

Preparation and Evaluation of Ribonuclease-Resistant Viral HIV RNA Standards Based on Armored RNA Technology

PubMed

Gholami, Mohammad; Ravanshad, Mehrdad; Baesi, Kazem; Samiee, Siamak M.; Hosseini Rozbahani, Negin; Mohraz, Minoo

2018-05-19

The human immunodeficiency virus type 1 (HIV-1) is an infectious viral agent that gradually extinguishes the immune system, resulting in acquired immune deficiency syndrome (AIDS). The aim of this study was to construct an RNA-positive control based on armored (AR) RNA technology, using HIV-1 RNA as a model. The MS2 maturase, a coat protein gene (at positions 1765 to 1787) and HIV-1 pol gene were cloned into pET-32a plasmid. The prepared plasmid was transformed into Escherichia coli strain BL2 (DE3), and the expression of the construct was induced by 1 mM of isopropyl-L-thio-D-galactopyranoside (IPTG) at 37 °C for 16 h to obtain the fabricated AR RNA. The AR RNA was precipitated and purified using polyethylene glycol and Sephacryl S-200 chromatography. The stability of AR RNA was evaluated by treatment with DNase I and RNase A and confirmed by transmission electron microscopy and gel agarose electrophoresis. Tenfold serial dilution of AR RNA from 101 to 105 was prepared; real-time PCR assays had a range of detection between 101 and 105, R2 value was 0.998, and the slope of the standard curve was -3.33. Prepared AR RNA, as a positive control, could be used as a basis for launching an in-house HIV-1 virus assay and other infectious agents. It can be readily available to laboratories and HIV research centers. The AR RNA is non-infectious and highly resistant to ribonuclease enzyme and can reduce the risk of infection in the clinical laboratory.

Sagnac effect and Ritz ballistic hypothesis (Review)

NASA Astrophysics Data System (ADS)

Malykin, G. B.

2010-12-01

It is shown that the Ritz ballistic hypothesis, which is based on the vector summation of the speed of light with the velocity of the radiation source, contradicts the fact of existence of the Sagnac effect. Based on a particular example of a three-mirror ring interferometer, it is shown that the application of the Ritz ballistic hypothesis leads to an obvious calculation error, namely, to the appearance of a difference in the propagation times of counterpropagating waves in the absence of rotation. A review is given of experiments and of results of processing of astronomical observations and discussions devoted to testing the Ritz ballistic hypothesis. A number of other physical phenomena that refute the Ritz ballistic hypothesis are considered.

Armor in Vietnam

DTIC Science & Technology

1976-05-01

battles a-Riuot the insurgent enemy, especially with armor. French contingents were present in Tndo Chinh P-w early as 1852, but it was not until 1884...committed to Vietnam were straight infantry. These troons er•A tran -norted in hn4±{ copters and usually airlifted to the battle zone; however, once...0STAINf0 FROM VKTNAM NATIONAL MAP SERVICE (NOS) PHU-YEN OCTOBER 19665 OARLAC ......... KKAN1+ HOA QLWA- DUC TUYEN- DUC PHUOC- NINH_ C;ry OF -10 T CAM RANK TAY

Applications of computational modeling in ballistics

NASA Technical Reports Server (NTRS)

Sturek, Walter B.

1987-01-01

The development of the technology of ballistics as applied to gun launched Army weapon systems is the main objective of research at the U.S. Army Ballistic Research Laboratory (BRL). The primary research programs at the BRL consist of three major ballistic disciplines: exterior, interior, and terminal. The work done at the BRL in these areas was traditionally highly dependent on experimental testing. A considerable emphasis was placed on the development of computational modeling to augment the experimental testing in the development cycle; however, the impact of the computational modeling to this date is modest. With the availability of supercomputer computational resources recently installed at the BRL, a new emphasis on the application of computational modeling to ballistics technology is taking place. The major application areas are outlined which are receiving considerable attention at the BRL at present and to indicate the modeling approaches involved. An attempt was made to give some information as to the degree of success achieved and indicate the areas of greatest need.

Armored Enzyme-Nanohybrids and Their Catalytic Function Under Challenging Conditions.

PubMed

Zore, Omkar V; Kasi, Rajeswari M; Kumar, Challa V

2017-01-01

Synthesis and characterization of highly stable and functional bienzyme-polymer triads assembled on layered graphene oxide (GO) are described here. Glucose oxidase (GOx) and horseradish peroxidase (HRP) were used as model enzymes and polyacrylic acid (PAA) as model polymer to armor the enzymes. PAA-armored GOx and HRP covalent conjugates were further protected from denaturation by adsorption onto GO nanosheets. Structure and morphology of this enzyme-polymer-nanosheet hybrid biocatalyst (GOx-HRP-PAA/GO) were confirmed by agarose gel electrophoresis, zeta potential, circular dichroism, and transmission electron microscopy. The armored biocatalysts retained full enzymatic activities under challenging conditions of pH (2.5-7.4), warm temperatures (65°C), and presence of chemical denaturants, 4mM sodium dodecyl sulfate, while GOx/HRP physical mixtures without the armor had very little activity under the same conditions. Therefore, this novel combination of two orthogonal approaches, enzyme conjugation with PAA and subsequent physical adsorption onto GO nanosheets, resulted in super stable hybrid biocatalysts that function under harsh conditions. Therefore, this general and powerful approach may be used to design environmentally friendly, green, biocompatible, and biodegradable biocatalysts for energy production in biofuel cell or biobattery applications. © 2017 Elsevier Inc. All rights reserved.

Ballistic thermophoresis of adsorbates on free-standing graphene.

PubMed

Panizon, Emanuele; Guerra, Roberto; Tosatti, Erio

2017-08-22

The textbook thermophoretic force which acts on a body in a fluid is proportional to the local temperature gradient. The same is expected to hold for the macroscopic drift behavior of a diffusive cluster or molecule physisorbed on a solid surface. The question we explore here is whether that is still valid on a 2D membrane such as graphene at short sheet length. By means of a nonequilibrium molecular dynamics study of a test system-a gold nanocluster adsorbed on free-standing graphene clamped between two temperatures [Formula: see text] apart-we find a phoretic force which for submicron sheet lengths is parallel to, but basically independent of, the local gradient magnitude. This identifies a thermophoretic regime that is ballistic rather than diffusive, persisting up to and beyond a 100-nanometer sheet length. Analysis shows that the phoretic force is due to the flexural phonons, whose flow is known to be ballistic and distance-independent up to relatively long mean-free paths. However, ordinary harmonic phonons should only carry crystal momentum and, while impinging on the cluster, should not be able to impress real momentum. We show that graphene and other membrane-like monolayers support a specific anharmonic connection between the flexural corrugation and longitudinal phonons whose fast escape leaves behind a 2D-projected mass density increase endowing the flexural phonons, as they move with their group velocity, with real momentum, part of which is transmitted to the adsorbate through scattering. The resulting distance-independent ballistic thermophoretic force is not unlikely to possess practical applications.

Ballistic thermophoresis of adsorbates on free-standing graphene

PubMed Central

Panizon, Emanuele; Guerra, Roberto; Tosatti, Erio

2017-01-01

The textbook thermophoretic force which acts on a body in a fluid is proportional to the local temperature gradient. The same is expected to hold for the macroscopic drift behavior of a diffusive cluster or molecule physisorbed on a solid surface. The question we explore here is whether that is still valid on a 2D membrane such as graphene at short sheet length. By means of a nonequilibrium molecular dynamics study of a test system—a gold nanocluster adsorbed on free-standing graphene clamped between two temperatures ΔT apart—we find a phoretic force which for submicron sheet lengths is parallel to, but basically independent of, the local gradient magnitude. This identifies a thermophoretic regime that is ballistic rather than diffusive, persisting up to and beyond a 100-nanometer sheet length. Analysis shows that the phoretic force is due to the flexural phonons, whose flow is known to be ballistic and distance-independent up to relatively long mean-free paths. However, ordinary harmonic phonons should only carry crystal momentum and, while impinging on the cluster, should not be able to impress real momentum. We show that graphene and other membrane-like monolayers support a specific anharmonic connection between the flexural corrugation and longitudinal phonons whose fast escape leaves behind a 2D-projected mass density increase endowing the flexural phonons, as they move with their group velocity, with real momentum, part of which is transmitted to the adsorbate through scattering. The resulting distance-independent ballistic thermophoretic force is not unlikely to possess practical applications. PMID:28774954

Preliminary design of Viking Armored Gun System

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gogolewski, R.P.; Cunningham, B.J.

We have completed the preliminary design of our third lightweight armored fighting vehicle -- the Viking Armored Gun System (AGS). The AGS vehicle features a two-man crew, the Ares 75mm Universal Turret System, and the John Deere 4026R Rotary Engine. In the spirit of our earlier AFV designs, our primary concern is to provide the AGS with sufficient firepower and survivability while utilizing off-the-shelf'' sub-systems and components in order to reduce developmental time and acquisition cost. We still envision that prototypic vehicles could be built within a thirty (30) month developmental/demonstration program. We still believe that vehicles of this classmore » should be built and tested soon to assess their full tactical, operational, and strategic utilities.« less

Ballistic missile defense effectiveness

NASA Astrophysics Data System (ADS)

Lewis, George N.

2017-11-01

The potential effectiveness of ballistic missile defenses today remains a subject of debate. After a brief discussion of terminal and boost phase defenses, this chapter will focus on long-range midcourse defenses. The problems posed by potential countermeasures to such midcourse defenses are discussed as are the sensor capabilities a defense might have available to attempt to discriminate the actual missile warhead in a countermeasures environment. The role of flight testing in assessing ballistic missile defense effectiveness is discussed. Arguments made about effectiveness by missile defense supporters and critics are summarized.

Toroidal midplane neutral beam armor and plasma limiter

DOEpatents

Kugel, H.W.; Hand, S.W. Jr.; Ksayian, H.

1985-05-31

This invention contemplates an armor shield/plasma limiter positioned upon the inner wall of a toroidal vacuum chamber within which is magnetically confined an energetic plasma in a tokamak nuclear fusion reactor. The armor shield/plasma limiter is thus of a general semi-toroidal shape and is comprised of a plurality of adjacent graphite plates positioned immediately adjacent to each other so as to form a continuous ring upon and around the toroidal chamber's inner wall and the reactor's midplane coil. Each plate has a generally semi-circular outer circumference and a recessed inner portion and is comprised of upper and lower half sections positioned immediately adjacent to one another along the midplane of the plate. With the upper and lower half sections thus joined, a channel or duct is provided within the midplane of the plate in which a magnetic flux loop is positioned. The magnetic flux loop is thus positioned immediately adjacent to the fusing toroidal plasma and serves as a diagnostic sensor with the armor shield/plasma limiter minimizing the amount of power from the energetic plasma as well as from the neutral particle beams heating the plasma incident upon the flux loop.

MRI issues for ballistic objects: information obtained at 1.5-, 3- and 7-Tesla.

PubMed

Dedini, Russell D; Karacozoff, Alexandra M; Shellock, Frank G; Xu, Duan; McClellan, R Trigg; Pekmezci, Murat

2013-07-01

Few studies exist for magnetic resonance imaging (MRI) issues and ballistics, and there are no studies addressing movement, heating, and artifacts associated with ballistics at 3-tesla (T). Movement because of magnetic field interactions and radiofrequency (RF)-induced heating of retained bullets may injure nearby critical structures. Artifacts may also interfere with the diagnostic use of MRI. To investigate these potential hazards of MRI on a sample of bullets and shotgun pellets. Laboratory investigation, ex vivo. Thirty-two different bullets and seven different shotgun pellets, commonly encountered in criminal trauma, were assessed relative to 1.5-, 3-, and 7-T magnetic resonance systems. Magnetic field interactions, including translational attraction and torque, were measured. A representative sample of five bullets were then tested for magnetic field interactions, RF-induced heating, and the generation of artifacts at 3-T. At all static magnetic field strengths, non-steel-containing bullets and pellets exhibited no movement, whereas one steel core bullet and two steel pellets exhibited movement in excess of what might be considered safe for patients in MRI at 1.5-, 3- and 7-Tesla. At 3-T, the maximum temperature increase of five bullets tested was 1.7°C versus background heating of 1.5°C. Of five bullets tested for artifacts, those without a steel core exhibited small signal voids, whereas a single steel core bullet exhibited a very large signal void. Ballistics made of lead with copper or alloy jackets appear to be safe with respect to MRI-related movement at 1.5-, 3-, and 7-T static magnetic fields, whereas ballistics containing steel may pose a danger if near critical body structures because of strong magnetic field interactions. Temperature increases of selected ballistics during 3-T MRI was not clinically significant, even for the ferromagnetic projectiles. Finally, ballistics containing steel generated larger artifacts when compared with ballistics

Methods for Analysis and Simulation of Ballistic Impact

DTIC Science & Technology

2017-04-01

ARL-RP-0597 ● Apr 2017 US Army Research Laboratory Methods for Analysis and Simulation of Ballistic Impact by John D Clayton...Laboratory Methods for Analysis and Simulation of Ballistic Impact by John D Clayton Weapons and Materials Research Directorate, ARL...analytical, and numerical methods of ballistics research . Similar lengthy references dealing with pertinent aspects include [8, 9]. In contrast, the

Effect of surface texture and structure on the development of stable fluvial armors

NASA Astrophysics Data System (ADS)

Bertin, Stephane; Friedrich, Heide

2018-04-01

Stable fluvial armors are found in river systems under conditions of partial sediment transport and limited sediment supply, a common occurrence in nature. Stable armoring is also readily recreated in experimental flumes. Initially, this bed stabilizing phenomenon was examined for different flow discharges and solely related to surface coarsening and bedload transport reduction. The models developed suggest a specific armor composition (i.e., texture) dependent on the parent bed material and formative discharge. Following developments in topographic remote sensing, recent research suggests that armor structure is an important control on bed stability and roughness. In this paper, replicated flume runs during which digital elevation models (DEMs) were collected from both exposed and flooded gravel beds are used to interpret armoring manifestations and to assess their replicability. A range of methodologies was used for the analysis, providing information on (i) surface grain size and orientation, (ii) bed-elevation distributions, (iii) the spatial coherence of the elevations at the grain-scale, (iv) surface slope and aspect, (v) grain imbrication and (vi) the spatial variability in DEM properties. The bed-surface topography was found to be more responsive than bed-material size to changes in flow strength. Our experimental results also provide convincing evidence that gravel-beds' response to water-work during parallel degradation is unique (i.e., replicable) given the formative parameters. Based on this finding, relationships between the armors' properties and formative parameters are proposed, and are supported by adding extensive data from previous research.

Room-temperature ballistic transport in III-nitride heterostructures.

PubMed

Matioli, Elison; Palacios, Tomás

2015-02-11

Room-temperature (RT) ballistic transport of electrons is experimentally observed and theoretically investigated in III-nitrides. This has been largely investigated at low temperatures in low band gap III-V materials due to their high electron mobilities. However, their application to RT ballistic devices is limited by their low optical phonon energies, close to KT at 300 K. In addition, the short electron mean-free-path at RT requires nanoscale devices for which surface effects are a limitation in these materials. We explore the unique properties of wide band-gap III-nitride semiconductors to demonstrate RT ballistic devices. A theoretical model is proposed to corroborate experimentally their optical phonon energy of 92 meV, which is ∼4× larger than in other III-V semiconductors. This allows RT ballistic devices operating at larger voltages and currents. An additional model is described to determine experimentally a characteristic dimension for ballistic transport of 188 nm. Another remarkable property is their short carrier depletion at device sidewalls, down to 13 nm, which allows top-down nanofabrication of very narrow ballistic devices. These results open a wealth of new systems and basic transport studies possible at RT.

Functional trade-off between strength and thermal capacity of dermal armor: Insights from girdled lizards.

PubMed

Broeckhoven, Chris; du Plessis, Anton; Hui, Cang

2017-10-01

The presence of dermal armor is often unambiguously considered the result of an evolutionary predator-prey arms-race. Recent studies focusing predominantly on osteoderms - mineralized elements embedded in the dermis layer of various extant and extinct vertebrates - have instead proposed that dermal armor might exhibit additional functionalities besides protection. Multiple divergent functionalities could impose conflicting demands on a phenotype, yet, functional trade-offs in dermal armor have rarely been investigated. Here, we use high-resolution micro-computed tomography and voxel-based simulations to test for a trade-off between the strength and thermal capacity of osteoderms using two armored cordylid lizards as model organisms. We demonstrate that high vascularization, associated with improved thermal capacity might limit the strength of osteoderms. These results call for a holistic, cautionary future approach to studies investigating dermal armor, especially those aiming to inspire artificial protective materials. Copyright © 2017 Elsevier Ltd. All rights reserved.

Terminal ballistics of the 9mm with Action Safety bullet or Blitz-Action-Trauma (BAT) ammunition.

PubMed

Lantz, P E; Stone, R S; Broudy, D; Morgan, T M

1994-05-01

Specialty ammunition creating atypical gunshot wounds of entrance can create confusion and may be misinterpreted by pathologists unfamiliar with the terminal ballistics of these projectiles. The previously unreported wound ballistics caused by the 9mm with Action Safety bullet described in a homicide highlights the atypical entrance wound(s) and wounding capacity of this novel ammunition. Manufactured by Geco division of Dynamit Nobel, the bullet consists of a nonjacketed solid copper alloy bullet body without a conventional lead core. The large deformation well and part of the smaller central channel is filled with a hard plastic core and post that creates a round nose bullet. The internal ballistics and unique design allow the plastic nose cap and post to separate from the copper alloy base while still in the barrel. The radiolucent nose cap leaves the bullet's path but can still penetrate tissue giving the appearance of a separate but smaller entrance wound. The sharp leading edge of the deformation well and relative high velocity of the bullet body creates a punched out entrance wound with minimal marginal abrasion. When the plastic nose cap or fragments of the plastic post impact the subject, test firings may allow an inference to the muzzle-target distance even in the absence of soot deposition or stippling.

Nondestructive characterization of UHMWPE armor materials

NASA Astrophysics Data System (ADS)

Chiou, Chien-Ping; Margetan, Frank J.; Barnard, Daniel J.; Hsu, David K.; Jensen, Terrence; Eisenmann, David

2012-05-01

Ultra-high molecular weight polyethylene (UHMWPE) is a material increasingly used for fabricating helmet and body armor. In this work, plate specimens consolidated from thin fiber sheets in series 3124 and 3130 were examined with ultrasound, X-ray and terahertz radiation. Ultrasonic through-transmission scans using both air-coupled and immersion modes revealed that the 3130 series material generally had much lower attenuation than the 3124 series, and that certain 3124 plates had extremely high attenuation. Due to the relatively low inspection frequencies used, pulse-echo immersion ultrasonic testing could not detect distinct flaw echoes from the interior. To characterize the nature of the defective condition that was responsible for the high ultrasonic attenuation, terahertz radiation in the time-domain spectroscopy mode were used to image the flaws. Terahertz scan images obtained on the high attenuation samples clearly showed a distribution of a large number of defects, possibly small planar delaminations, throughout the volume of the interior. Their precise nature and morphology are to be verified by optical microscopy of the sectioned surface.

Optimization of armored spherical tanks for storage on the lunar surface

NASA Technical Reports Server (NTRS)

Bents, D. J.; Knight, D. A.

1992-01-01

A redundancy strategy for reducing micrometeroid armoring mass is investigated, with application to cryogenic reactant storage for a regenerative fuel cell (RFC) on the lunar surface. In that micrometeoroid environment, the cryogenic fuel must be protected from loss due to tank puncture. The tankage must have a sufficiently high probability of survival over the length of the mission so that the probability of system failure due to tank puncture is low compared to the other mission risk factors. Assuming that a single meteoroid penetration can cause a storage tank to lose its contents, two means are available to raise the probability of surviving micrometeoroid attack to the desired level. One can armor the tanks to a thickness sufficient to reduce probability of penetration of any tank to the desired level or add extra capacity in the form of spare tanks that results in survival of a given number out of the ensemble at the desired level. A combination of these strategies (armoring and redundancy) is investigated. The objective is to find the optimum combination which yields the lowest shielding mass per cubic meter of surviving fuel out of the original ensemble. The investigation found that, for the volumes of fuel associated with multikilowatt class cryo storage RFC's, and the armoring methodology and meteoroid models used, storage should be fragmented into small individual tanks. Larger installations (more fuel) pay less of a shielding penalty than small installations. For the same survival probability over the same time period, larger volumes will require less armoring mass per unit volume protected.

30 CFR 75.700 - Grounding metallic sheaths, armors, and conduits enclosing power conductors.

Code of Federal Regulations, 2010 CFR

2010-07-01

... conduits enclosing power conductors. 75.700 Section 75.700 Mineral Resources MINE SAFETY AND HEALTH... Grounding § 75.700 Grounding metallic sheaths, armors, and conduits enclosing power conductors. [Statutory Provisions] All metallic sheaths, armors, and conduits enclosing power conductors shall be electrically...

30 CFR 75.700 - Grounding metallic sheaths, armors, and conduits enclosing power conductors.

Code of Federal Regulations, 2011 CFR

2011-07-01

... conduits enclosing power conductors. 75.700 Section 75.700 Mineral Resources MINE SAFETY AND HEALTH... Grounding § 75.700 Grounding metallic sheaths, armors, and conduits enclosing power conductors. [Statutory Provisions] All metallic sheaths, armors, and conduits enclosing power conductors shall be electrically...

Preservation and storage of prepared ballistic gelatine.

PubMed

Mattijssen, E J A T; Alberink, I; Jacobs, B; van den Boogaard, Y

2016-02-01

The use of ballistic gelatine, generally accepted as a human muscle tissue simulant in wound ballistic studies, might be improved by adding a preservative (Methyl 4-hydroxybenzoate) which inhibits microbial growth. This study shows that replacing a part of the gelatine powder by the preservative does not significantly alter the penetration depth of projectiles. Storing prepared blocks of ballistic gelatine over time decreased the penetration depth of projectiles. Storage of prepared gelatine for 4 week already showed a significant effect on the penetration depth of projectiles. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Feasibility of ballistic strengthening exercises in neurologic rehabilitation.

PubMed

Williams, Gavin; Clark, Ross A; Hansson, Jessica; Paterson, Kade

2014-09-01

Conventional methods for strength training in neurologic rehabilitation are not task specific for walking. Ballistic strength training was developed to improve the functional transfer of strength training; however, no research has investigated this in neurologic populations. The aim of this pilot study was to evaluate the feasibility of applying ballistic principles to conventional leg strengthening exercises in individuals with mobility limitations as a result of neurologic injuries. Eleven individuals with neurologic injuries completed seated and reclined leg press using conventional and ballistic techniques. A 2 × 2 repeated-measures analysis of variance was used to compare power measures (peak movement height and peak velocity) between exercises and conditions. Peak jump velocity and peak jump height were greater when using the ballistic jump technique rather than the conventional concentric technique (P < 0.01). These findings suggest that when compared with conventional strengthening exercises, the incorporation of ballistic principles was associated with increased peak height and peak velocities.

Armored brain: A case report and review of the literature

PubMed Central

Petraglia, Anthony L.; Moravan, Michael J.; Jahromi, Babak S.

2011-01-01

Background: Calcified chronic subdural hematomas occur infrequently. When the calcifications are extensive and bilateral, the condition is termed “armored brain”. We describe a case of “armored brain” incidentally discovered in an adult presenting with abdominal pain and mild headaches, long after initial placement of a ventriculo-peritoneal (VP) shunt. Case Description: A 38-year-old woman, treated at infancy with a VP shunt, presented with a 2-month history of abdominal pain associated with nausea and chills. She was neurologically intact on exam. An abdominal computed tomography (CT) scan demonstrated a rim-enhancing loculated fluid collection surrounding the patient's distal VP shunt catheter tip. As a part of her initial work-up, she received a head CT to evaluate the proximal VP shunt, which demonstrated large bilateral chronic subdural hematomas with heavily calcified walls. She was eventually taken to the operating room (OR) for replacement of the distal catheter. It was felt that her acute clinical presentation was unrelated to the bilateral, calcified subdural hematomas and thus the decision was made to manage them conservatively. Conclusions: This rare complication of chronic shunting for hydrocephalus is sometimes referred to as armored brain. Surgery for armored brain is infrequently indicated and beneficial in only small subgroup of patients, with management guided by clinical presentation. Our patient fully recovered after shunt revision alone. PMID:21918735

Armored brain: A case report and review of the literature.

PubMed

Petraglia, Anthony L; Moravan, Michael J; Jahromi, Babak S

2011-01-01

Calcified chronic subdural hematomas occur infrequently. When the calcifications are extensive and bilateral, the condition is termed "armored brain". We describe a case of "armored brain" incidentally discovered in an adult presenting with abdominal pain and mild headaches, long after initial placement of a ventriculo-peritoneal (VP) shunt. A 38-year-old woman, treated at infancy with a VP shunt, presented with a 2-month history of abdominal pain associated with nausea and chills. She was neurologically intact on exam. An abdominal computed tomography (CT) scan demonstrated a rim-enhancing loculated fluid collection surrounding the patient's distal VP shunt catheter tip. As a part of her initial work-up, she received a head CT to evaluate the proximal VP shunt, which demonstrated large bilateral chronic subdural hematomas with heavily calcified walls. She was eventually taken to the operating room (OR) for replacement of the distal catheter. It was felt that her acute clinical presentation was unrelated to the bilateral, calcified subdural hematomas and thus the decision was made to manage them conservatively. This rare complication of chronic shunting for hydrocephalus is sometimes referred to as armored brain. Surgery for armored brain is infrequently indicated and beneficial in only small subgroup of patients, with management guided by clinical presentation. Our patient fully recovered after shunt revision alone.

Investigation of Ballistic Penetration through Tibia Soft Tissue Simulant

NASA Astrophysics Data System (ADS)

Nguyen, Thuy-Tien N.; Masouros, Spyros D.; Tear, Gareth R.; Proud, William G.; Institute of Shock Physics; CentreBlast Injury Studies, Imperial College London, UK Team

2017-06-01

High energy trauma events such as from explosions and ballistic weapons can cause severe damage to the human body. The resulting injuries are very complex and their mechanism is not fully understood. Secondary blast injuries, effectively ballistic traumas, to the extremities are commonly reported, especially to the tibia. The aim of this study is to quantify the effect of parameters such as projectile mass and velocity, and impact location on injury thresholds in the leg. The bones of the leg were set in biofidelic gelatin tissue simulant. A 32-mm-bore gas gun was used to launch a sabot carrying a carbon steel projectile 0.5 to 1.1 g in mass at the sample with speeds of 50 to 300 m/s. Penetration depth and impact velocity were recorded. The effect of different postures - such as standing and non-weight bearing -- on injury were considered. The resulting injuries were scored clinically and their correlation with the various impact parameters was calculated. The project is funded by the Royal British Legion, United Kingdom.

Further testing and development of simulation models for UT inspections of armor

NASA Astrophysics Data System (ADS)

Margetan, Frank J.; Richter, Nathaniel; Thompson, R. Bruce

2012-05-01

In previous work we introduced an approach for simulating ultrasonic pulse/echo immersion inspections of multi-layer armor panels. Model inputs include the thickness, density, velocity and attenuation of each armor layer, the focal properties of the transducer, and a measured calibration signal. The basic model output is a response-versus-time waveform (ultrasonic A-scan) which includes echoes from all interfaces including those arising from reverberations within layers. Such A-scans can be predicted both for unflawed panels and panels containing a large disbond at any given interface. In this paper we continue our testing of the simulation software, applying it now to an armor panel consisting of SiC ceramic tiles fully embedded in a titanium-alloy matrix. An interesting specimen of such armor became available in which some tile/metal interfaces appear to be well bonded, while others have disbonded areas of various sizes. We compare measured and predicted A-scans for UT inspections, and also demonstrate an extension of the model to predict ultrasonic C-scans over regions containing a small, isolated disbond.

Effects of Different Relative Loads on Power Performance During the Ballistic Push-up.

PubMed

Wang, Ran; Hoffman, Jay R; Sadres, Eliahu; Bartolomei, Sandro; Muddle, Tyler W D; Fukuda, David H; Stout, Jeffrey R

2017-12-01

Wang, R, Hoffman, JR, Sadres, E, Bartolomei, S, Muddle, TWD, Fukuda, DH, and Stout, JR. Effects of different relative loads on power performance during the ballistic push-up. J Strength Cond Res 31(12): 3411-3416, 2017-The purpose of this investigation was to examine the effect of load on force and power performance during a ballistic push-up. Sixty (24.5 ± 4.3 years, 1.75 ± 0.07 m, and 80.8 ± 13.5 kg) recreationally active men who participated in this investigation completed all testing and were included in the data analysis. All participants were required to perform a 1 repetition maximum bench press, and ballistic push-ups without external load (T1), with 10% (T2) and 20% (T3) of their body mass. Ballistic push-ups during T2 and T3 were performed using a weight loaded vest. Peak and mean force, power, as well as net impulse and flight time were determined for each ballistic push-up. Peak and mean force were both significantly greater (p < 0.01) during T3 (1,062 ± 202 and 901 ± 154 N, respectively), than both T2 (1,017 ± 202 and 842 ± 151 N, respectively) and T1 (960 ± 188 and 792 ± 140 N, respectively). Peak and mean power were significantly greater (p < 0.01) during T1 (950 ± 257 and 521 ± 148 W, respectively), than both T2 (872 ± 246 and 485 ± 143 W, respectively) and T3 (814 ± 275 and 485 ± 162 W, respectively). Peak and mean power were greatest during T1, regardless of participants' strength levels. Significant (p < 0.01) greater net impulse and smaller peak velocity and flight time were also noted from T1 to T3. Results of this investigation indicated that maximal power outputs were achieved without the use of an external load when performing the ballistic push-up, regardless of the participants' level of strength.

[Ballistic approach in head injuries caused by missiles].

PubMed

Jourdan, P; Billant, J B; Desgeorges, M

1989-01-01

If the missile head injury treatment is relatively well codified, wound ballistic, on the other hand, is not well known of neurosurgeons. Different means of study and tissue simulants are being listed. In face of numerous contradictory results, we shall only retain the M.L. Fackler method with 10% gelatin. Experimental results will depend on: 1. Missile parameters. For instance, in soft homogeneous tissue, one can discern shells with an uncertain path, full jacketed bullets which tumble after a variable "neck", and non jacketed missiles which cause wound through "mushrooming" and/or fragmentation effect. Buckshot wounds obey the rule "all or none". 2. Body reactions, particularly the clash with a hard material like bone, which can overturn everything described in soft tissues. These wound ballistic notions have lead us to formulate two pathogenic hypothesizes, allowing us to understand sometime case reports which had first seemed paradoxical: the brain structure, enclosed in the skull will not able to survive any major temporary cavity, the more or less deep missile pathway through the skull will be very different according to the type and energy of the missile, and to the hardness of pierced bone.

Analysis of Tile-Reinforced Composite Armor. Part 1; Advanced Modeling and Strength Analyses

NASA Technical Reports Server (NTRS)

Davila, C. G.; Chen, Tzi-Kang; Baker, D. J.

1998-01-01

The results of an analytical and experimental study of the structural response and strength of tile-reinforced components of the Composite Armored Vehicle are presented. The analyses are based on specialized finite element techniques that properly account for the effects of the interaction between the armor tiles, the surrounding elastomers, and the glass-epoxy sublaminates. To validate the analytical predictions, tests were conducted with panels subjected to three-point bending loads. The sequence of progressive failure events for the laminates is described. This paper describes the results of Part 1 of a study of the response and strength of tile-reinforced composite armor.

Trajectories of ballistic impact ejecta on a rotating Earth

NASA Technical Reports Server (NTRS)

Alvarez, W.

1994-01-01

On an airless, slowly rotating planetary body like the Moon, ejecta particles from an impact follow simple ballistic trajectories. If gaseous interactions in the fireball are ignored, ejecta particles follow elliptical orbits with the center of the planetary body at one focus until they encounter the surface at the point of reimpact. The partial elliptical orbit of the ejecta particle lies in a plane in inertial (galactic) coordinates. Because of the slow rotation rate (for example, 360 degrees/28 days for the Moon), the intersection of the orbital plane and the surface remains nearly a great circle during the flight time of the ejecta. For this reason, lunar rays, representing concentrations of ejecta with the same azimuth but different velocities and/or ejecta angles, lie essentially along great circles. Ejecta from airless but more rapidly rotating bodies will follow more complicated, curving trajectories when plotted in the coordinate frame of the rotating planet or viewed as rays on the planetary surface. The curvature of trajectories of ejecta particles can be treated as a manifestation of the Coriolis effect, with the particles being accelerated by Coriolis pseudoforces. However, it is more straightforward to calculate the elliptical orbit in inertial space and then determine how far the planet rotates beneath the orbiting ejecta particle before reimpact. The Earth's eastward rotation affects ballistic ejecta in two ways: (1) the eastward velocity component increases the velocity of eastbound ejecta and reduces the velocity of westbound ejecta; and (2) the Earth turns underneath inflight ejecta, so that although the latitude of reimpact is not changed, the longitude is displaced westward, with the displacement increasing as a function of the time the ejecta remains aloft.

Body temperature and resistance to evaporative water loss in tropical Australian frogs.

PubMed

Tracy, Christopher R; Christian, Keith A; Betts, Gregory; Tracy, C Richard

2008-06-01

Although the skin of most amphibians measured to date offers no resistance to evaporative water loss (EWL), some species, primarily arboreal frogs, produce skin secretions that increase resistance to EWL. At high air temperatures, it may be advantageous for amphibians to increase EWL as a means to decrease body temperature. In Australian hylid frogs, most species do not decrease their resistance at high air temperature, but some species with moderate resistance (at moderate air temperatures) gradually decrease resistance with increasing air temperature, and some species with high resistance (at moderate air temperatures) abruptly decrease resistance at high air temperatures. Lower skin resistance at high air temperatures decreases the time to desiccation, but the lower body temperatures allow the species to avoid their critical thermal maximum (CT(Max)) body temperatures. The body temperatures of species with low to moderate resistances to EWL that do not adjust resistance at high air temperatures do not warm to their CT(Max), although for some species, this is because they have high CT(Max) values. As has been reported previously for resistance to EWL generally, the response pattern of change of EWL at high air temperatures has apparently evolved independently among Australian hylids. The mechanisms involved in causing resistance and changes in resistance are unknown.

The Natural Armor of Fish: An Exploration of a Biological Composite

NASA Astrophysics Data System (ADS)

Murcia, Sandra C.

In the search for advanced structural materials, scientists are finding inspiration from materials in nature and biological composites. The need for lighter protective materials has directed attention to armored skins, which possess a combination of flexibility, puncture resistance and capacity for energy dissipation. This rare combination of properties is found in the armored skin of modern fish, and achieved by overlapping scales with exceptional specific strength and toughness. The main objectives of this research were to develop new understanding on the constituent layers and lamination patterns of elasmoid scales from teleost fish, and understand their importance to the mechanical properties relevant to armor performance. The investigation consists of five aims that address properties of the scales as a structural material, the spatial variations over the body of fish, the microstructure and properties of the individual layers, and the design and performance of the interface between these layers. An exploration of scales from Cyprinus carpio showed that the fracture resistance of elasmoid fish scales is largely dependent on the anatomical position and the corresponding microstructure. Elasmoid scales were found to consist of three principle layers, including the external highly mineralized limiting layer (LL), as well as the external (EE) and internal (IE) elasmodine, which consist of a number of lamina (or plies) of unidirectional type I collagen fibrils. While the fracture resistance increased with scale thickness, it was highly correlated with the number of plies in the elasmodine and ratio of mineralized plies in the EE. Furthermore, the hierarchical structure of the scales and the molecular level bonds were found to be of importance. Removal of the intra molecular water enabled inter-peptide bonding of the collagen fibrils, which increased the strength and elastic modulus. Furthermore, mineral crystals at the intra-fibrilar spaces impeded the formation of

26th International Symposium on Ballistics

DTIC Science & Technology

2011-09-16

judicious use of analytical predictions correlated with ballistic testing and post - test failure morphology investigations. •Our approach...ballistic predictions. The numerical predictions correlate well with the damage pattern. Post - Test Morphology Simulation Imbedded Steel Plate Removed Post ... Test •Numerical simulation of damage to embedded steel plate compares well with the post - test plate morphology •Multi-strike modeling in work

Correlation of nosetip boundary-layer transition data measured in ballistics-range experiments

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reda, D.C.

1980-01-01

Preablated nosetips of various carbonaceous materials were tested in a ballistics range. Surface-temperature contours, measured with image-converter cameras, were used to define boundary-layer transition-front contours. Measurements of surface roughness, surface temperature, average transition-front location, and freestream environment were combined with calculations of nosetip flowfields, and with calculations of laminar boundary-layer development in these flowfields, to transform all data into various dimensionless parameters. These parameters were defined by previous attempts to correlate existing wind-tunnel data for transition on rough/blunt bodies. Of the available correlating techniques, only one, based on the concept of a constant (critical) roughness Reynolds number for transition, wasmore » found to successfully describe both the wind-tunnel and ballistics-range data, thereby validating the extrapolation of this concept to actual reentry-vehicle materials and environments.« less

Ballistic damage in hybrid composite laminates

NASA Astrophysics Data System (ADS)

Phadnis, Vaibhav A.; Pandya, Kedar S.; Naik, Niranjan K.; Roy, Anish; Silberschmidt, Vadim V.

2015-07-01

Ballistic damage of hybrid woven-fabric composites made of plain-weave E-glass- fabric/epoxy and 8H satin-weave T300 carbon-fabric/epoxy is studied using a combination of experimental tests, microstructural studies and finite-element (FE) analysis. Ballistic tests were conducted with a single-stage gas gun. Fibre damage and delamination were observed to be dominating failure modes. A ply-level FE model was developed, with a fabric-reinforced ply modelled as a homogeneous orthotropic material with capacity to sustain progressive stiffness degradation due to fibre/matrix cracking, fibre breaking and plastic deformation under shear loading. Simulated damage patterns on the front and back faces of fabric-reinforced composite plates provided an insight into their damage mechanisms under ballistic loading.

Acousto-ultrasonic system for the inspection of composite armored vehicles

NASA Astrophysics Data System (ADS)

Godinez, Valery F.; Carlos, Mark F.; Delamere, Michael; Hoch, William; Fotopoulos, Christos; Dai, Weiming; Raju, Basavaraju B.

2001-04-01

In this paper the design and implementation of a unique acousto-ultrasonics system for the inspection of composite armored vehicles is discussed. The system includes a multi-sensor probe with a position-tracking device mounted on a computer controlled scanning bridge. The system also includes an arbitrary waveform generator with a multiplexer and a multi-channel acoustic emission board capable of simultaneously collecting and processing up to four acoustic signals in real time. C-scans of an armored vehicle panel with defects are presented.

Modeling terminal ballistics using blending-type spline surfaces

NASA Astrophysics Data System (ADS)

Pedersen, Aleksander; Bratlie, Jostein; Dalmo, Rune

2014-12-01

We explore using GERBS, a blending-type spline construction, to represent deform able thin-plates and model terminal ballistics. Strategies to construct geometry for different scenarios of terminal ballistics are proposed.

Multifunctionality of chiton biomineralized armor with an integrated visual system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Ling; Connors, Matthew; Kolle, Mathias

2015-11-20

Nature provides a multitude of examples of multifunctional structural materials. There are often trade-offs in these materials because few of them are equally well suited for multiple tasks. One such example is the biomineralized armor of the chiton Acanthopleura granulata, which incorporates an integrated sensory system that includes hundreds of eyes with aragonite-based lens. Here, we used optical experiments to demonstrate directly, for the first time, that these microscopic, mineralized lenses are able to form images. Furthermore, our experiments revealed that the optical performance of these polycrystalline lenses is enhanced by the reduction of spherical aberration through the shape ofmore » the lens and that birefringence scattering is minimized by the use of relatively large, co-aligned grains (~10 μm as compared to ~1 μm in the non-eye regions). Additionally, we used multi-scale mechanical testing techniques to show that A. granulata’s lenses are an integral component of its biomineralized armor, but that both the intrinsic and overall mechanical properties of the lenses are compromised as compared to the primary solid regions of the armor plates. Our results demonstrate that as the size, complexity, and functionality of the integrated sensory elements increases, the local mechanical performance of the armor decreases. But, A. granulata has evolved several strategies to compensate for its local mechanical vulnerabilities to form a multifunctional system with co-optimized overall optical and structural functions.« less

Definition of an anti-missile ballistic defense architecture for Europe

NASA Astrophysics Data System (ADS)

Deas, M.; Tanter, A.

1995-01-01

The end of the Seventies and beginning of the Eighties showed significant technological developments in ballistic missiles, in particular,impact precision. These improvements caused Western strategists to be concerned with use of ballistic missiles equipped with conventional loads against military objectives (the Pact of Varsovie). The concept of ballistic missile tactical had been born. The ballistic vector, which until this time was marked with a 'strategic' label, was then 'standardized' and has interested a number of countries in the process of its development. The world has just entered the era of the ballistic proliferation. From the very start of the Eighties, the United States and, to a lesser degree, NATO lead studies and reflections concerned with defense against tactical ballistic missiles within a East West framework. From these studies the ATBM (Anti Tactical Ballistic Missile) made its appearance. In spite of the attempts at control, missile proliferation has accelerated and led, towards the end of the Eighties and the beginning of the Nineties, to the awakening of a new risk known as proliferating. The 1991 Gulf War was accelerated in this manner. This conflict also clarified the fact that the ballistic weapon constituted a formidable means of pressure for countries which had it, in spite of the PATRIOT, which demonstrated the feasibility of an active defense against ballistic missiles, in spite of their limited performances. This present presentation proposes an overall analysis of the ballistic risk and the possible threat which could result from it and examines the means available for protection against this risk by looking further into all the defensive means. This will constitute the main part of the speech. Lastly, we will endeavor to evaluate the difficulties faced by the architects of the DAMB.

Initial Validation of Ballistic Shock Transducers

DTIC Science & Technology

2017-06-05

objective of this TOP is to describe various methods and instrumentation used in the initial validation of accelerometers to be used in both Ballistic...MILITARY STANDARD 810G CHANGE NOTICE 1, METHOD 522.2, SECTION 4.4.2 ....................................... A-1 B. GLOSSARY...Procedure (TOP) is to describe various methods and instrumentation used in the initial validation of accelerometers to be used in both Ballistic

A nanomagnetic study of phase transition in manganite thin films and ballistic magnetoresistance in magnetic nanocontacts

NASA Astrophysics Data System (ADS)

Chung, Seok-Hwan

This work focuses on two largely unexplored phenomena in micromagnetics: the temperature-driven paramagnetic insulator to ferromagnetic (FM) metallic phase transition in perovskite manganite and ballistic magnetoresistance in spin-polarized nanocontacts. To investigate the phase transition, an off-the-shelf commercial scanning force microscope was redesigned for operation at temperatures from 350 K to 100 K. This adaptation is elaborated in this thesis. Using this system, both ferromagnetic and charge-ordered domain structures of (La 1-xPrx)0.67Ca0.33MnO3 thin film were observed by magnetic force microscopy (MFM) and electric force microscopy (EFM) operated in the vicinity of the peak resistance temperature (Tp). Predominantly in-plane oriented FM domains of sub-micrometer size emerge below Tp and their local magnetic moment increased as the temperature is reduced. Charge-ordered insulating regions show a strong electrostatic interaction with an EFM tip at a few degrees above Tp and the interaction correlates well with the temperature dependence of resistivity of the film. Cross-correlation analysis between topography and magnetic structure on several substrates indicates FM domains form on the flat regions of the surface, while charge ordering occurs at surface protrusions. In the investigation of ballistic magnetoresistance, new results on half-metallic ferromagnets formed by atomic or nanometer contacts of CrO2-CrO 2 and CrO2-Ni are presented showing magnetoconductance as high as 400%. Analysis of the magnetoconductance versus conductance data for all materials known to exhibit so-called ballistic magnetoresistance strongly suggests that magnetoconductance of nanocontacts follows a universal mechanism. If the maximum magnetoconductance is normalized to unity and the conductance is scaled with the resistivity of the material, then all data points fall onto a universal curve independent of the contact material and the transport mechanism. The analysis has been

Collaborative Point Paper on Active Protection Systems

DTIC Science & Technology

2006-10-01

for the Hunter VHP CIED Program. Also, General Dynamics Armament and Technical Products (GDATP), Burlington, VT is contracted by the Marine Corps...the incoming threat at a relatively long distance. Specific details about the composition and mechanism of this explosive interceptor device are...relatively thin shell of ballistic steel and composite armor, also known as hybrid armor, designed to provide optimal protection from specific threats

Wound ballistics 101: the mechanisms of soft tissue wounding by bullets.

PubMed

Stefanopoulos, P K; Pinialidis, D E; Hadjigeorgiou, G F; Filippakis, K N

2017-10-01

The mechanisms of soft tissue injury by bullets are reviewed, in the belief that the current incidence of firearm injuries in many urban areas necessitates an understanding of wound ballistics on the part of trauma surgeons who may not be familiar with the wounding factors involved. Review of the literature, with technical information obtained from appropriate non-medical texts. Despite numerous publications concerning the treatment of gunshot wounds, relatively few papers contain details on the mechanisms of ballistic trauma, with the main body of evidence derived from previous laboratory and animal studies which have only recently been systematically appraised. These studies have shown that in rifle injuries the main wound tract is surrounded by an area of damaged tissue as a result of the temporary cavitation induced once the bullet becomes destabilized or deformed. On the other hand, the more commonly encountered non-deforming handgun bullets cause damage limited to the bullet's path, mainly as a result of localized crush injury. The bullet's construction and ballistic behavior within tissue determine to what extent the previously overestimated velocity factor may influence wound severity. The damage produced from temporary cavitation depends on the tensile properties of the tissues involved, and in high-energy injuries may lead to progressive muscle tissue necrosis. Therefore, the term "high-energy" should be reserved for those injuries with substantial tissue damage extending beyond the visible wound tract.

Composite materials and bodies including silicon carbide and titanium diboride and methods of forming same

DOEpatents

Lillo, Thomas M.; Chu, Henry S.; Harrison, William M.; Bailey, Derek

2013-01-22

Methods of forming composite materials include coating particles of titanium dioxide with a substance including boron (e.g., boron carbide) and a substance including carbon, and reacting the titanium dioxide with the substance including boron and the substance including carbon to form titanium diboride. The methods may be used to form ceramic composite bodies and materials, such as, for example, a ceramic composite body or material including silicon carbide and titanium diboride. Such bodies and materials may be used as armor bodies and armor materials. Such methods may include forming a green body and sintering the green body to a desirable final density. Green bodies formed in accordance with such methods may include particles comprising titanium dioxide and a coating at least partially covering exterior surfaces thereof, the coating comprising a substance including boron (e.g., boron carbide) and a substance including carbon.

Ballistic Fracturing of Carbon Nanotubes.

PubMed

Ozden, Sehmus; Machado, Leonardo D; Tiwary, ChandraSekhar; Autreto, Pedro A S; Vajtai, Robert; Barrera, Enrique V; Galvao, Douglas S; Ajayan, Pulickel M

2016-09-21

Advanced materials with multifunctional capabilities and high resistance to hypervelocity impact are of great interest to the designers of aerospace structures. Carbon nanotubes (CNTs) with their lightweight and high strength properties are alternative to metals and/or metallic alloys conventionally used in aerospace applications. Here we report a detailed study on the ballistic fracturing of CNTs for different velocity ranges. Our results show that the highly energetic impacts cause bond breakage and carbon atom rehybridizations, and sometimes extensive structural reconstructions were also observed. Experimental observations show the formation of nanoribbons, nanodiamonds, and covalently interconnected nanostructures, depending on impact conditions. Fully atomistic reactive molecular dynamics simulations were also carried out in order to gain further insights into the mechanism behind the transformation of CNTs. The simulations show that the velocity and relative orientation of the multiple colliding nanotubes are critical to determine the impact outcome.

Process of infection of armored scale insects (Diaspididae) by an entomopathogenic Cosmospora sp.

PubMed

Mauchline, Nicola; Hallett, Ian; Hill, Garry; Casonato, Seona

2011-09-01

Several species in the fungal genus Cosmospora (synonym Nectria) (anamorph Fusarium) are specialist entomopathogens of armored scale insects (Diaspididae), known to cause periodic epizootics in host populations. Inconsistent mortality rates recorded under laboratory conditions prompted a study into the process of infection of armored scale insects by this fungus. Scale insect mortality following exposure to a Cosmospora sp. (Culture Collection Number: CC89) from New Zealand was related to insect age, with reproductively mature insects having a significantly higher infection rate than immature insects. Examination using scanning electron microscopy found no evidence that the fungus penetrated directly through the wax test (cap) of the scale insect or through the un-lifted interface between the test and the substrate on which the insect resided. However, fungal hyphae were observed growing beneath the test when the test of the reproductively mature insect lifted away from the substrate for the purpose of releasing crawlers, the mobile pre-settled juveniles. Once the hyphae of CC89 advanced under the test, germ-tubes readily penetrated the insect body through a number of natural openings (e.g. spiracles, vulva, stylet), with mycosis observed within seven days after inoculation. Direct penetration through the cuticle of the scale insect was not observed. Copyright © 2011 Elsevier Inc. All rights reserved.

Passive Cooling of Body Armor

NASA Astrophysics Data System (ADS)

Holtz, Ronald; Matic, Peter; Mott, David

2013-03-01

Warfighter performance can be adversely affected by heat load and weight of equipment. Current tactical vest designs are good insulators and lack ventilation, thus do not provide effective management of metabolic heat generated. NRL has undertaken a systematic study of tactical vest thermal management, leading to physics-based strategies that provide improved cooling without undesirable consequences such as added weight, added electrical power requirements, or compromised protection. The approach is based on evaporative cooling of sweat produced by the wearer of the vest, in an air flow provided by ambient wind or ambulatory motion of the wearer. Using an approach including thermodynamic analysis, computational fluid dynamics modeling, air flow measurements of model ventilated vest architectures, and studies of the influence of fabric aerodynamic drag characteristics, materials and geometry were identified that optimize passive cooling of tactical vests. Specific architectural features of the vest design allow for optimal ventilation patterns, and selection of fabrics for vest construction optimize evaporation rates while reducing air flow resistance. Cooling rates consistent with the theoretical and modeling predictions were verified experimentally for 3D mockups.

Relationships Between Potentiation Effects After Ballistic Half-Squats and Bilateral Symmetry.

PubMed

Suchomel, Timothy J; Sato, Kimitake; DeWeese, Brad H; Ebben, William P; Stone, Michael H

2016-05-01

The purposes of this study were to examine the effect of ballistic concentric-only half-squats (COHS) on subsequent squat-jump (SJ) performances at various rest intervals and to examine the relationships between changes in SJ performance and bilateral symmetry at peak performance. Thirteen resistance-trained men performed an SJ immediately and every minute up to 10 min on dual force plates after 2 ballistic COHS repetitions at 90% of their 1-repetition-maximum COHS. SJ peak force, peak power, net impulse, and rate of force development (RFD) were compared using a series of 1-way repeated-measures ANOVAs. The percent change in performance at which peak performance occurred for each variable was correlated with the symmetry index scores at the corresponding time point using Pearson correlation coefficients. Statistical differences in peak power (P = .031) existed between rest intervals; however, no statistically significant pairwise comparisons were present (P > .05). No statistical differences in peak force (P = .201), net impulse (P = .064), and RFD (P = .477) were present between rest intervals. The relationships between changes in SJ performance and bilateral symmetry after the rest interval that produced the greatest performance for peak force (r = .300, P = .319), peak power (r = -.041, P = .894), net impulse (r = -.028, P = .927), and RFD (r = -.434, P = .138) were not statistically significant. Ballistic COHS may enhance SJ performance; however, the changes in performance were not related to bilateral symmetry.

Light Armor Plate Development

DTIC Science & Technology

1923-07-28

to thie time ot shipment will be ini- eluded, 06otioIjAs -- HistoT. On Dec ember 2S# lt~. uVeity -four plates -*ere raaivad fro* Watertown Are nal, Th...only AT .Jwi-ace Vvrl/ac e 914yramof specl .mens elsed for h7eat- treatment 12aiomArmor- P/ate Anyepstyatio,, Vi -oorner o! ogoii uipe’Aven va...tempering temperatures applied. Only oarburized specimens were suboted to the double- quenching treatment (see table IV). The purpose of this Waq to

Wound ballistics of the pig mandibular angle: a preliminary finite element analysis and experimental study.

PubMed

Chen, Yubin; Miao, Yingyun; Xu, Chuan; Zhang, Gang; Lei, Tao; Tan, Yinghui

2010-04-19

To study wound ballistics of the mandibular angle, a combined hexahedral-tetrahedral finite element (FE) model of the pig mandible was developed to simulate ballistic impact. An experimental study was carried out by measuring impact load parameters from 14 fresh pig mandibles that were shot at the mandibular angle by a standard 7.62 mm M43 bullet. FE analysis was executed through the LS-DYNA code under impact loads similar to those obtained from the experimental study. The resulting residual velocity, the transferred energy from the bullet to the mandible, and the surface area of the entrance wound had no statistical differences between the FE simulation and the experimental study. However, the mean surface area of the exit wounds in the experimental study was significantly larger than that in the simulation. According to the FE analysis, the stress concentrated zones were mainly located at the region of impact, condylar neck, coronoid process and mandibular body. The simulation results also indicated that trabecular bone had less stress concentration and a lower speed of stress propagation compared with cortical bone. The FE model is appropriate and conforms to the basic principles of wound ballistics. This modeling system will be helpful for further investigations of the biomechanical mechanisms of wound ballistics. Copyright 2009 Elsevier Ltd. All rights reserved.

Balancing ballistic protection against physiological strain: evidence from laboratory and field trials.

PubMed

Taylor, Nigel A S; Burdon, Catriona A; van den Heuvel, Anne M J; Fogarty, Alison L; Notley, Sean R; Hunt, Andrew P; Billing, Daniel C; Drain, Jace R; Silk, Aaron J; Patterson, Mark J; Peoples, Gregory E

2016-02-01

This project was based on the premise that decisions concerning the ballistic protection provided to defence personnel should derive from an evaluation of the balance between protection level and its impact on physiological function, mobility, and operational capability. Civilians and soldiers participated in laboratory- and field-based studies in which ensembles providing five levels of ballistic protection were evaluated, each with progressive increases in protection, mass (3.4-11.0 kg), and surface-area coverage (0.25-0.52 m(2)). Physiological trials were conducted on volunteers (N = 8) in a laboratory, under hot-dry conditions simulating an urban patrol: walking at 4 km·h(-1) (90 min) and 6 km·h(-1) (30 min or to fatigue). Field-based trials were used to evaluate tactical battlefield movements (mobility) of soldiers (N = 31) under tropical conditions, and across functional tests of power, speed, agility, endurance, and balance. Finally, trials were conducted at a jungle training centre, with soldiers (N = 32) patrolling under tropical conditions (averaging 5 h). In the laboratory, work tolerance was reduced as protection increased, with deep-body temperature climbing relentlessly. However, the protective ensembles could be grouped into two equally stressful categories, each providing a different level of ballistic protection. This outcome was supported during the mobility trials, with the greatest performance decrement evident during fire and movement simulations, as the ensemble mass was increased (-2.12%·kg(-1)). The jungle patrol trials similarly supported this outcome. Therefore, although ballistic protection does increase physiological strain, this research has provided a basis on which to determine how that strain can be balanced against the mission-specific level of required personal protection.

The Armys Armored Multi Purpose Vehicle (AMPV): Background and Issues for Congress

DTIC Science & Technology

2017-01-11

M-113 personnel carriers, which are still in service in a variety of support capacities in Armored Brigade Combat Teams (ABCTs). While M-113s no...reliability, and interoperability by mission role variant within the Heavy Brigade Combat Team (HBCT) [now known as the Armored Brigade Combat Team – ABCT... teams within complex operational environments. For example, “commanders will not allow them to leave Forward Operating Bases (FOBs) or enter

Quantum Mechanical Modeling of Ballistic MOSFETs

NASA Technical Reports Server (NTRS)

Svizhenko, Alexei; Anantram, M. P.; Govindan, T. R.; Biegel, Bryan (Technical Monitor)

2001-01-01

The objective of this project was to develop theory, approximations, and computer code to model quasi 1D structures such as nanotubes, DNA, and MOSFETs: (1) Nanotubes: Influence of defects on ballistic transport, electro-mechanical properties, and metal-nanotube coupling; (2) DNA: Model electron transfer (biochemistry) and transport experiments, and sequence dependence of conductance; and (3) MOSFETs: 2D doping profiles, polysilicon depletion, source to drain and gate tunneling, understand ballistic limit.

2005 22nd International Symposium on Ballistics. Volume 1 - Tuesday

DTIC Science & Technology

2005-11-18

Electric Power in Active Armour Applications, Martin van de Voorde, R. Boeschoten, TNO Defence, Security and Safety Prevention of Sympathetic Detonation...and Kevlar®/Steel Armor - Experimental Data and Hydrocode Modeling with Eulerian and Lagrangian Methods, Dale S. Preece, Vanessa S. Berg, and Loyd R...Applications, Martin van de Voorde, R. Boeschoten, TNO Defence, Security and Safety Prevention of Sympathetic Detonation Between Reactive Armor Sandwiches

Optimization of armored spherical tanks for storage on the lunar surface

NASA Technical Reports Server (NTRS)

Bents, D. J.; Knight, D. A.

1992-01-01

A redundancy strategy for reducing micrometeroid armoring mass is investigated, with application to cryogenic reactant storage for a regenerative fuel cell (RFC) on the lunar surface. In that micrometeoroid environment, the cryogenic fuel must be protected from loss due to tank puncture. The tankage must have a sufficiently high probability of survival over the length of the mission so that the probability of system failure due to tank puncture is low compared to the other mission risk factors. Assuming that a single meteoroid penetration can cause a storage tank to lose its contents, two means are available to raise the probability of surviving micrometeoroid attack to the desired level. One can armor the tanks to a thickness sufficient to reduce probability of penetration of any tank to the desired level or add extra capacity in the form of space tanks that results in survival of a given number out of the ensemble at the desired level. A combination of these strategies (armor and redundancy) is investigated.

Segment-specific resistivity improves body fluid volume estimates from bioimpedance spectroscopy in hemodialysis patients.

PubMed

Zhu, F; Kuhlmann, M K; Kaysen, G A; Sarkar, S; Kaitwatcharachai, C; Khilnani, R; Stevens, L; Leonard, E F; Wang, J; Heymsfield, S; Levin, N W

2006-02-01

Discrepancies in body fluid estimates between segmental bioimpedance spectroscopy (SBIS) and gold-standard methods may be due to the use of a uniform value of tissue resistivity to compute extracellular fluid volume (ECV) and intracellular fluid volume (ICV). Discrepancies may also arise from the exclusion of fluid volumes of hands, feet, neck, and head from measurements due to electrode positions. The aim of this study was to define the specific resistivity of various body segments and to use those values for computation of ECV and ICV along with a correction for unmeasured fluid volumes. Twenty-nine maintenance hemodialysis patients (16 men) underwent body composition analysis including whole body MRI, whole body potassium (40K) content, deuterium, and sodium bromide dilution, and segmental and wrist-to-ankle bioimpedance spectroscopy, all performed on the same day before a hemodialysis. Segment-specific resistivity was determined from segmental fat-free mass (FFM; by MRI), hydration status of FFM (by deuterium and sodium bromide), tissue resistance (by SBIS), and segment length. Segmental FFM was higher and extracellular hydration of FFM was lower in men compared with women. Segment-specific resistivity values for arm, trunk, and leg all differed from the uniform resistivity used in traditional SBIS algorithms. Estimates for whole body ECV, ICV, and total body water from SBIS using segmental instead of uniform resistivity values and after adjustment for unmeasured fluid volumes of the body did not differ significantly from gold-standard measures. The uniform tissue resistivity values used in traditional SBIS algorithms result in underestimation of ECV, ICV, and total body water. Use of segmental resistivity values combined with adjustment for body volumes that are neglected by traditional SBIS technique significantly improves estimations of body fluid volume in hemodialysis patients.

Manufacturing process scale-up of optical grade transparent spinel ceramic at ArmorLine Corporation

NASA Astrophysics Data System (ADS)

Spilman, Joseph; Voyles, John; Nick, Joseph; Shaffer, Lawrence

2013-06-01

While transparent Spinel ceramic's mechanical and optical characteristics are ideal for many Ultraviolet (UV), visible, Short-Wave Infrared (SWIR), Mid-Wave Infrared (MWIR), and multispectral sensor window applications, commercial adoption of the material has been hampered because the material has historically been available in relatively small sizes (one square foot per window or less), low volumes, unreliable supply, and with unreliable quality. Recent efforts, most notably by Technology Assessment and Transfer (TA and T), have scaled-up manufacturing processes and demonstrated the capability to produce larger windows on the order of two square feet, but with limited output not suitable for production type programs. ArmorLine Corporation licensed the hot-pressed Spinel manufacturing know-how of TA and T in 2009 with the goal of building the world's first dedicated full-scale Spinel production facility, enabling the supply of a reliable and sufficient volume of large Transparent Armor and Optical Grade Spinel plates. With over $20 million of private investment by J.F. Lehman and Company, ArmorLine has installed and commissioned the largest vacuum hot press in the world, the largest high-temperature/high-pressure hot isostatic press in the world, and supporting manufacturing processes within 75,000 square feet of manufacturing space. ArmorLine's equipment is capable of producing window blanks as large as 50" x 30" and the facility is capable of producing substantial volumes of material with its Lean configuration and 24/7 operation. Initial production capability was achieved in 2012. ArmorLine will discuss the challenges that were encountered during scale-up of the manufacturing processes, ArmorLine Optical Grade Spinel optical performance, and provide an overview of the facility and its capabilities.

Comparison of V50 Shot Placement on Final Outcome

DTIC Science & Technology

2014-11-01

molecular- weight polyethylene (UHMWPE). In V50 testing of those types of materials, large delaminations may occur that influence the results. This...placement, a proper evaluation of materials may not be possible. 15. SUBJECT TERMS ballistics, V50 test, logistic regression , statistical inference...from an impact. While this may work with ceramics or metal armor, it is inappropriate for use on composite armors like ultra-high-molecular- weight

Localised boundary air layer and clothing evaporative resistances for individual body segments.

PubMed

Wang, Faming; del Ferraro, Simona; Lin, Li-Yen; Sotto Mayor, Tiago; Molinaro, Vincenzo; Ribeiro, Miguel; Gao, Chuansi; Kuklane, Kalev; Holmér, Ingvar

2012-01-01

Evaporative resistance is an important parameter to characterise clothing thermal comfort. However, previous work has focused mainly on either total static or dynamic evaporative resistance. There is a lack of investigation of localised clothing evaporative resistance. The objective of this study was to study localised evaporative resistance using sweating thermal manikins. The individual and interaction effects of air and body movements on localised resultant evaporative resistance were examined in a strict protocol. The boundary air layer's localised evaporative resistance was investigated on nude sweating manikins at three different air velocity levels (0.18, 0.48 and 0.78 m/s) and three different walking speeds (0, 0.96 and 1.17 m/s). Similarly, localised clothing evaporative resistance was measured on sweating manikins at three different air velocities (0.13, 0.48 and 0.70 m/s) and three walking speeds (0, 0.96 and 1.17 m/s). Results showed that the wind speed has distinct effects on local body segments. In contrast, walking speed brought much more effect on the limbs, such as thigh and forearm, than on body torso, such as back and waist. In addition, the combined effect of body and air movement on localised evaporative resistance demonstrated that the walking effect has more influence on the extremities than on the torso. Therefore, localised evaporative resistance values should be provided when reporting test results in order to clearly describe clothing local moisture transfer characteristics. Localised boundary air layer and clothing evaporative resistances are essential data for clothing design and assessment of thermal comfort. A comprehensive understanding of the effects of air and body movement on localised evaporative resistance is also necessary by both textile and apparel researchers and industry.

CD28z CARs and Armored CARs

PubMed Central

Pegram, Hollie J.; Park, Jae H.; Brentjens, Renier J.

2015-01-01

CD19-targeted chimeric antigen receptor (CAR) T cells are currently being tested in the clinic with very promising outcomes. However, limitations to CAR T cell therapy exist. These include lack of efficacy against some tumors, specific targeting of tumor cells without affecting normal tissue and retaining activity within the suppressive tumor microenvironment. Whilst promising clinical trials are in progress, preclinical development is focused on optimizing CAR design, to generate “armored CAR T cells” which are protected from the inhibitory tumor microenvironment. Studies investigating the expression of cytokine transgenes, combination therapy with small molecule inhibitors or monoclonal antibodies are aimed at improving the anti-tumor efficacy of CAR T cell therapy. Other strategies aimed at improving CAR T cell therapy include utilizing dual CARs and chemokine receptors to more specifically target tumor cells. This review will describe the current clinical data and some novel “armored CAR T cell” approaches for improving anti-tumor efficacy therapy. PMID:24667958

CD28z CARs and armored CARs.

PubMed

Pegram, Hollie J; Park, Jae H; Brentjens, Renier J

2014-01-01

CD19-targeted chimeric antigen receptor (CAR) T cells are currently being tested in the clinic with very promising outcomes. However, limitations to CAR T cell therapy exist. These include lack of efficacy against some tumors, specific targeting of tumor cells without affecting normal tissue and retaining activity within the suppressive tumor microenvironment. Whereas promising clinical trials are in progress, preclinical development is focused on optimizing CAR design, to generate "armored CAR T cells," which are protected from the inhibitory tumor microenvironment. Studies investigating the expression of cytokine transgenes, combination therapy with small molecule inhibitors, or monoclonal antibodies, are aimed at improving the antitumor efficacy of CAR T cell therapy. Other strategies aimed at improving CAR T cell therapy include using dual CARs and chemokine receptors to more specifically target tumor cells. This review will describe the current clinical data and some novel armored CAR T cell approaches for improving antitumor efficacy therapy.

Cost of space-based laser ballistic missile defense.

PubMed

Field, G; Spergel, D

1986-03-21

Orbiting platforms carrying infrared lasers have been proposed as weapons forming the first tier of a ballistic missile defense system under the President's Strategic Defense Initiative. As each laser platform can destroy a limited number of missiles, one of several methods of countering such a system is to increase the number of offensive missiles. Hence it is important to know whether the cost-exchange ratio, defined as the ratio of the cost to the defense of destroying a missile to the cost to the offense of deploying an additional missile, is greater or less than 1. Although the technology to be used in a ballistic missile defense system is still extremely uncertain, it is useful to examine methods for calculating the cost-exchange ratio. As an example, the cost of an orbiting infrared laser ballistic missile defense system employed against intercontinental ballistic missiles launched simultaneously from a small area is compared to the cost of additional offensive missiles. If one adopts lower limits to the costs for the defense and upper limits to the costs for the offense, the cost-exchange ratio comes out substantially greater than 1. If these estimates are confirmed, such a ballistic missile defense system would be unable to maintain its effectiveness at less cost than it would take to proliferate the ballistic missiles necessary to overcome it and would therefore not satisfy the President's requirements for an effective strategic defense. Although the method is illustrated by applying it to a space-based infrared laser system, it should be straightforward to apply it to other proposed systems.

106-17 Telemetry Standards. Annex A.4. Asynchronous Recorder Multiplexer Output Re-Constructor (ARMOR)

DTIC Science & Technology

2017-07-01

Output Re-Constructor 1. General This standard defines the recommended multiplexer format for single-channel data recording on small-format (1/2 in...which is 1-based, is determined by the position of the channel’s module in the ARMOR system . The first input channel found in the ARMOR system is

A Novel Binarization Algorithm for Ballistics Firearm Identification

NASA Astrophysics Data System (ADS)

Li, Dongguang

The identification of ballistics specimens from imaging systems is of paramount importance in criminal investigation. Binarization plays a key role in preprocess of recognizing cartridges in the ballistic imaging systems. Unfortunately, it is very difficult to get the satisfactory binary image using existing binary algorithms. In this paper, we utilize the global and local thresholds to enhance the image binarization. Importantly, we present a novel criterion for effectively detecting edges in the images. Comprehensive experiments have been conducted over sample ballistic images. The empirical results demonstrate the proposed method can provide a better solution than existing binary algorithms.

Nonlinear Ballistic Transport in an Atomically Thin Material.

PubMed

Boland, Mathias J; Sundararajan, Abhishek; Farrokhi, M Javad; Strachan, Douglas R

2016-01-26

Ultrashort devices that incorporate atomically thin components have the potential to be the smallest electronics. Such extremely scaled atomically thin devices are expected to show ballistic nonlinear behavior that could make them tremendously useful for ultrafast applications. While nonlinear diffusive electron transport has been widely reported, clear evidence for intrinsic nonlinear ballistic transport in the growing array of atomically thin conductors has so far been elusive. Here we report nonlinear electron transport of an ultrashort single-layer graphene channel that shows quantitative agreement with intrinsic ballistic transport. This behavior is shown to be distinctly different than that observed in similarly prepared ultrashort devices consisting, instead, of bilayer graphene channels. These results suggest that the addition of only one extra layer of an atomically thin material can make a significant impact on the nonlinear ballistic behavior of ultrashort devices, which is possibly due to the very different chiral tunneling of their charge carriers. The fact that we observe the nonlinear ballistic response at room temperature, with zero applied magnetic field, in non-ultrahigh vacuum conditions and directly on a readily accessible oxide substrate makes the nanogap technology we utilize of great potential for achieving extremely scaled high-speed atomically thin devices.

Effect of measurement on the ballistic-diffusive transition in turbid media.

PubMed

Glasser, Ziv; Yaroshevsky, Andre; Barak, Bavat; Granot, Er'el; Sternklar, Shmuel

2013-10-01

The dependence of the transition between the ballistic and the diffusive regimes of turbid media on the experimental solid angle of the detection system is analyzed theoretically and experimentally. A simple model is developed which shows the significance of experimental conditions on the location of the ballistic-diffusive transition. It is demonstrated that decreasing the solid angle expands the ballistic regime; however, this benefit is bounded by the initial Gaussian beam diffraction. In addition, choosing the appropriate wavelength according to the model's principles provides another means of expanding the ballistic regime. Consequently, by optimizing the experimental conditions, it should be possible to extract the ballistic image of a tissue with a thickness of 1 cm.

Ballistic impact response of lipid membranes.

PubMed

Zhang, Yao; Meng, Zhaoxu; Qin, Xin; Keten, Sinan

2018-03-08

Therapeutic agent loaded micro and nanoscale particles as high-velocity projectiles can penetrate cells and tissues, thereby serving as gene and drug delivery vehicles for direct and rapid internalization. Despite recent progress in developing micro/nanoscale ballistic tools, the underlying biophysics of how fast projectiles deform and penetrate cell membranes is still poorly understood. To understand the rate and size-dependent penetration processes, we present coarse-grained molecular dynamics simulations of the ballistic impact of spherical projectiles on lipid membranes. Our simulations reveal that upon impact, the projectile can pursue one of three distinct pathways. At low velocities below the critical penetration velocity, projectiles rebound off the surface. At intermediate velocities, penetration occurs after the projectile deforms the membrane into a tubular thread. At very high velocities, rapid penetration occurs through localized membrane deformation without tubulation. Membrane tension, projectile velocity and size govern which phenomenon occurs, owing to their positive correlation with the reaction force generated between the projectile and the membrane during impact. Two critical membrane tension values dictate the boundaries among the three pathways for a given system, due to the rate dependence of the stress generated in the membrane. Our findings provide broad physical insights into the ballistic impact response of soft viscous membranes and guide design strategies for drug delivery through lipid membranes using micro/nanoscale ballistic tools.

Graphene-Armored Aluminum Foil with Enhanced Anticorrosion Performance as Current Collectors for Lithium-Ion Battery.

PubMed

Wang, Mingzhan; Tang, Miao; Chen, Shulin; Ci, Haina; Wang, Kexin; Shi, Liurong; Lin, Li; Ren, Huaying; Shan, Jingyuan; Gao, Peng; Liu, Zhongfan; Peng, Hailin

2017-12-01

Aluminum (Al) foil, as the most accepted cathode current collector for lithium-ion batteries (LIBs), is susceptible to local anodic corrosions during long-term operations. Such corrosions could lead to the deterioration or even premature failure of the batteries and are generally believed to be a bottleneck for next-generation 5 V LIBs. Here, it is demonstrated that Al foil armored by conformal graphene coating exhibits significantly reinforced anodic corrosion resistance in both LiPF 6 and lithium bis(trifluoromethanesulphonyl) imide (LiTFSI) based electrolytes. Moreover, LiMn 2 O 4 cells using graphene-armored Al foil as current collectors (LMO/GA) demonstrate enhanced electrochemical performance in comparison with those using pristine Al foil (LMO/PA). The long-term discharge capacity retention of LMO/GA cell after ≈950 h straight operations at low rate (0.5 C) reaches up to 91%, remarkably superior to LMO/PA cell (75%). The self-discharge propensity of LMO/GA is clearly relieved and the rate/power performance is also improved with graphene mediations. This work not only contributes to the long-term stable operations of LIBs but also might catalyze the deployment of 5 V LIBs in the future. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The National Ballistics Imaging Comparison (NBIC) project.

PubMed

Song, J; Vorburger, T V; Ballou, S; Thompson, R M; Yen, J; Renegar, T B; Zheng, A; Silver, R M; Ols, M

2012-03-10

In response to the guidelines issued by the American Society of Crime Laboratory Directors/Laboratory Accreditation Board (ASCLD/LAB-International) to establish traceability and quality assurance in U.S. crime laboratories, a NIST/ATF joint project entitled National Ballistics Imaging Comparison (NBIC) was initialized in 2008. The NBIC project aims to establish a National Traceability and Quality System for ballistics identifications in crime laboratories within the National Integrated Ballistics Information Network (NIBIN) of the U.S. NIST Standard Reference Material (SRM) 2460 bullets and 2461 cartridge cases are used as reference standards. 19 ballistics examiners from 13 U.S. crime laboratories participated in this project. They each performed 24 periodic image acquisitions and correlations of the SRM bullets and cartridge cases over the course of a year, but one examiner only participated in Phase 1 tests of SRM cartridge case. The correlation scores were collected by NIST for statistical analyses, from which control charts and control limits were developed for the proposed Quality System and for promoting future assessments and accreditations for firearm evidence in U.S. forensic laboratories in accordance with the ISO 17025 Standard. Published by Elsevier Ireland Ltd.

[A survey of mental health status in armored vehicle crew].

PubMed

Yang, Q L; Kao, X B; Wu, G B; Guo, S W; Chai, W L; Chen, Y N; Ji, L J; Wang, Y Q

2016-06-20

To investigate the mental health status in armored vehicle crew (commanders, gunners, and drivers) , to know the level of mental health in them, and to provide educational intervention. In April 2009, 120 male armored vehicle crew with >2 driving years were enrolled as battle group, and 70 male persons within the same age group who were not engaged in armored vehicle operation were enrolled as control group. The Symptom Checklist-90 (SCL-90) was used to evaluate the mental status of the 180 subjects. Compared with the control group, the battle group showed significantly higher scores on the subscales of obsessive-compulsive symptom, interpersonal sensitivity, depression, anxiety, phobic anxiety, and paranoid ideation (t=2.323, 3.250, 3.158, 2.712, 2.391, and 2.137, all P<0.05) , as well as significantly higher total score, number of positive items, and average score of positive symptoms (t=4.128, 4.357, and 4.632, all P<0.05). In the battle group, the scores on the subscales of somatization, obsessive-compulsive symptom, interpersonal sensitivity, depression, anxiety, hostility, phobic anxiety, paranoid ideation, psychoticism, and additional items, total score, number of positive items, and average score of positive symptoms were significantly lower than the military reference values (t=4.364, 5.127, 5.280, 3.783, 7.012, 5.361, 4.369, 6.167, 6.476, 3.558, 6.357, 4.379, and 6.763, all P<0.05). A survey should be performed on the mental health status of armored vehicle crew, including obsessive-compulsive symptom, interpersonal sensitivity, depression, and anxiety. Mental health service for the crew should be enhanced to improve their psychological quality.

Mechanisms of stability of armored bubbles: FY 1996 Final Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rossen, W.R.; Kam, S.I.

1996-11-01

Theoretical and experimental studies examine how a coating, or {open_quotes}armor,{close_quotes} of partially wetted solid particles can stabilize tiny bubbles against diffusion of gas into the surrounding liquid, in spite of the high capillary pressures normally associated with such bubbles. Experiments with polymethylmethacrylate (PNMA) beads and carbonated water demonstrate that armored bubbles can persist for weeks in liquid unsaturated with respect to the gas in the bubbles. This question is of concern regarding gas discharges from waste tanks at the Hanford reservation. The stresses on the solid-solid contacts between particles in such cases is large and could drive sintering of themore » particles into a rigid framework. Stability analysis suggests that a slightly shrunken bubble would not expel a solid particle from its armor to relieve stress and allow the bubble to shrink further. Expulsion of particles from more stressed bubbles at zero capillary pressure is energetically favored in some cases. It is not clear, however, whether this expulsion would proceed spontaneously from a small perturbation or require a large initial disturbance of the bubble. In some cases, it appears that a bubble would expel some particles and shrink, but the bubble would approach a final, stable size rather than disappear completely. This simplified analysis leaves out several factors. For instance, only one perturbation toward expelling a solid from the armor is considered; perhaps other perturbations would be more energetically favored than that tested. Other considerations (particle deformation, surface roughness, contact-angle hysteresis, and adhesion or physical bonding between adjacent particles) would make expelling solids more difficult than indicated by this theoretical study.« less

Micro-engineered first wall tungsten armor for high average power laser fusion energy systems

NASA Astrophysics Data System (ADS)

Sharafat, Shahram; Ghoniem, Nasr M.; Anderson, Michael; Williams, Brian; Blanchard, Jake; Snead, Lance; HAPL Team

2005-12-01

The high average power laser program is developing an inertial fusion energy demonstration power reactor with a solid first wall chamber. The first wall (FW) will be subject to high energy density radiation and high doses of high energy helium implantation. Tungsten has been identified as the candidate material for a FW armor. The fundamental concern is long term thermo-mechanical survivability of the armor against the effects of high temperature pulsed operation and exfoliation due to the retention of implanted helium. Even if a solid tungsten armor coating would survive the high temperature cyclic operation with minimal failure, the high helium implantation and retention would result in unacceptable material loss rates. Micro-engineered materials, such as castellated structures, plasma sprayed nano-porous coatings and refractory foams are suggested as a first wall armor material to address these fundamental concerns. A micro-engineered FW armor would have to be designed with specific geometric features that tolerate high cyclic heating loads and recycle most of the implanted helium without any significant failure. Micro-engineered materials are briefly reviewed. In particular, plasma-sprayed nano-porous tungsten and tungsten foams are assessed for their potential to accommodate inertial fusion specific loads. Tests show that nano-porous plasma spray coatings can be manufactured with high permeability to helium gas, while retaining relatively high thermal conductivities. Tungsten foams where shown to be able to overcome thermo-mechanical loads by cell rotation and deformation. Helium implantation tests have shown, that pulsed implantation and heating releases significant levels of implanted helium. Helium implantation and release from tungsten was modeled using an expanded kinetic rate theory, to include the effects of pulsed implantations and thermal cycles. Although, significant challenges remain micro-engineered materials are shown to constitute potential

A ballistic mission to fly by Comet Halley

NASA Technical Reports Server (NTRS)

Boain, R. J.; Hastrup, R. C.

1980-01-01

The paper describes the available options, ballistic trajectory opportunities, and a preliminary reference trajectory that were selected as a basis for spacecraft design studies and programmatic planning for a Halley ballistic intercept mission in 1986. The paper also presents trajectory, performance, and navigation data which support the preliminary selection.

Cost of space-based laser ballistic missile defense

DOE Office of Scientific and Technical Information (OSTI.GOV)

Field, G.; Spergel, D.

1986-03-21

Orbiting platforms carrying infrared lasers have been proposed as weapons forming the first tier of a ballistic missile defense system under the President's Strategic Defense Initiative. As each laser platform can destroy a limited number of missiles, one of several methods of countering such a system is to increase the number of offensive missiles. Hence it is important to know whether the cost-exchange ratio, defined as the ratio of the cost to the defense of destroying a missile to the cost to the offense of deploying an additional missile, is greater or less than 1. Although the technology to bemore » used in a ballistic missile defense system is still extremely uncertain, it is useful to examine methods for calculating the cost-exchange ration. As an example, the cost of an orbiting infrared laser ballistic missile defense system employed against intercontinental ballistic missiles launched simultaneously from a small area is compared to the cost of additional offensive missiles. If one adopts lower limits to the costs for the defense and upper limits to the costs for the offense, the cost-exchange ratio comes out substantially greater than 1. If these estimates are confirmed, such a ballistic missile defense system would be unable to maintain its effectiveness at less cost than it would take to proliferate the ballistic missiles necessary to overcome it and would therefore not satisfy the President's requirements for an effective strategic defense. Although the method is illustrated by applying it to a space-based infrared laser system, it should be straightforward to apply it to other proposed systems. 28 references, 2 tables.« less

Ballistic food transport in toucans.

PubMed

Baussart, Sabine; Korsoun, Leonid; Libourel, Paul-Antoine; Bels, Vincent

2009-08-01

The basic mechanism of food transport in tetrapods is lingual-based. Neognathous birds use this mechanism for exploiting a large diversity of food resources, whereas paleognathous birds use cranioinertial mechanism with or without tongue involvement. Food transport in two neognathous species of toucans (Ramphastos toco and R. vitellinus) is defined as ballistic transport mechanism. Only one transport cycle is used for moving the food from the tip of the beak to the pharynx. The food is projected between jaws with similar initial velocity in both species. At the time of release, the angle between trajectory of food position and horizontal is higher in R. vitellinus with a shorter beak than in R. toco. The tongue never makes contact with the food nor is it used to expand the buccal cavity. Tongue movement is associated with throat expansion, permitting the food to reach the entrance of the esophagus at the end of the ballistic trajectory. Selection of large food items in the diet may explain the evolutionary trend of using ballistic transport in the feeding behavior of toucans, which plays a key role in ecology of tropical forest. 2009 Wiley-Liss, Inc.

Ballistic trauma: lessons learned from iraq and afghanistan.

PubMed

Shin, Emily H; Sabino, Jennifer M; Nanos, George P; Valerio, Ian L

2015-02-01

Management of upper extremity injuries secondary to ballistic and blast trauma can lead to challenging problems for the reconstructive surgeon. Given the recent conflicts in Iraq and Afghanistan, advancements in combat-casualty care, combined with a high-volume experience in the treatment of ballistic injuries, has led to continued advancements in the treatment of the severely injured upper extremity. There are several lessons learned that are translatable to civilian trauma centers and future conflicts. In this article, the authors provide an overview of the physics of ballistic injuries and principles in the management of such injuries through experience gained from military involvement in Iraq and Afghanistan.

Ballistic Trauma: Lessons Learned from Iraq and Afghanistan

PubMed Central

Shin, Emily H.; Sabino, Jennifer M.; Nanos, George P.; Valerio, Ian L.

2015-01-01

Management of upper extremity injuries secondary to ballistic and blast trauma can lead to challenging problems for the reconstructive surgeon. Given the recent conflicts in Iraq and Afghanistan, advancements in combat-casualty care, combined with a high-volume experience in the treatment of ballistic injuries, has led to continued advancements in the treatment of the severely injured upper extremity. There are several lessons learned that are translatable to civilian trauma centers and future conflicts. In this article, the authors provide an overview of the physics of ballistic injuries and principles in the management of such injuries through experience gained from military involvement in Iraq and Afghanistan. PMID:25685099

Ballistic Missile Early Warning System Clear Air Force Station, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Ballistic Missile Early Warning System - Clear Air Force Station, Ballistic Missile Early Warning System Site II, One mile west of mile marker 293.5 on Parks Highway, 5 miles southwest of Anderson, Anderson, Denali Borough, AK

Ballistic transport in graphene grown by chemical vapor deposition

DOE Office of Scientific and Technical Information (OSTI.GOV)

Calado, V. E.; Goswami, S.; Xu, Q.

2014-01-13

In this letter, we report the observation of ballistic transport on micron length scales in graphene synthesised by chemical vapour deposition (CVD). Transport measurements were done on Hall bar geometries in a liquid He cryostat. Using non-local measurements, we show that electrons can be ballistically directed by a magnetic field (transverse magnetic focussing) over length scales of ∼1 μm. Comparison with atomic force microscope measurements suggests a correlation between the absence of wrinkles and the presence of ballistic transport in CVD graphene.

The Effect of Whole-Body Vibration on Lower-Body Resistance Detraining in College-Age Women

ERIC Educational Resources Information Center

Lindsay, Keston G.; Nichols, David L.; Davis, Ronald W.; Marshall, David D.

2018-01-01

Purpose: This study explored the effect of whole-body vibration (WBV) using accelerations of 2.56 "g" to 7.68 "g" on lower-body detraining. Methods: All participants (N = 20) were trained using a lower-body resistance-training program for 30 min twice per week from Week 0 to Week 6. At the end of the program, they were randomly…

Ballistics: a primer for the surgeon.

PubMed

Volgas, David A; Stannard, James P; Alonso, Jorge E

2005-03-01

The purpose of this paper is to review the literature on ballistics and to sort through the plethora of myth and popular opinion. The trauma surgeon is increasingly faced with gunshot wounds. Knowledge of ballistics is important to help in assessing the patterns of wounds that are seen. There are many factors that affect the flight of a bullet to its target. Many of these factors also affect the behaviour of the bullet after it strikes the target. It is primarily these factors that interest the surgeon.

Correlation of nosetip boundary-layer transition data measured in ballistics-range experiments

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reda, D.C.

1979-11-01

Preablated nosetips of various carbonaceous materials were tested in a ballistics range. Surface-temperature contours, measured with image-converter cameras, were used to define boundary-layer transition-fron contours. Measurements of surface roughness, surface temperature, average transition-calculations of nosetip flowfields, and with calculations of laminar boundary-layer development in these flowfields, to transform all data into various dimensionless parameters. These parameters were defined by previous attempts to correlate existing wind-tunnel data for transition on rough/blunt bodies.

Understanding the ballistic event : Methodology and observations relevant to ceramic armour

NASA Astrophysics Data System (ADS)

Healey, Adam

The only widely-accepted method of gauging the ballistic performance of a material is to carry out ballistic testing; due to the large volume of material required for a statistically robust test, this process is very expensive. Therefore a new test, or suite of tests, that employ widely-available and economically viable characterisation methods to screen candidate armour materials is highly desirable; in order to design such a test, more information on the armour/projectile interaction is required. This work presents the design process and results of using an adapted specimen configuration to increase the amount of information obtained from a ballistic test. By using a block of ballistic gel attached to the ceramic, the fragmentation generated during the ballistic event was captured and analysed. In parallel, quasi-static tests were carried out using ring-on-ring biaxial disc testing to investigate relationships between quasi-static and ballistic fragment fracture surfaces. Three contemporary ceramic armour materials were used to design the test and to act as a baseline; Sintox FA alumina, Hexoloy SA silicon carbide and 3M boron carbide. Attempts to analyse the post-test ballistic sample non-destructively using X-ray computed tomography (XCT) were unsuccessful due to the difference in the density of the materials and the compaction of fragments. However, the results of qualitative and quantitative fracture surface analysis using scanning electron microscopy showed similarities between the fracture surfaces of ballistic fragments at the edges of the tile and biaxial fragments; this suggests a relationship between quasi-static and ballistic fragments created away from the centre of impact, although additional research will be required to determine the reason for this. Ballistic event-induced porosity was observed and quantified on the fracture surfaces of silicon carbide samples, which decreased as distance from centre of impact increased; upon further analysis this

Room-temperature ballistic energy transport in molecules with repeating units

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rubtsova, Natalia I.; Nyby, Clara M.; Zhang, Hong

2015-06-07

In materials, energy can propagate by means of two limiting regimes: diffusive and ballistic. Ballistic energy transport can be fast and efficient and often occurs with a constant speed. Using two-dimensional infrared spectroscopy methods, we discovered ballistic energy transport via individual polyethylene chains with a remarkably high speed of 1440 m/s and the mean free path length of 14.6 Å in solution at room temperature. Whereas the transport via the chains occurs ballistically, the mechanism switches to diffusive with the effective transport speed of 130 m/s at the end-groups attached to the chains. A unifying model of the transport inmore » molecules is presented with clear time separation and additivity among the transport along oligomeric fragments, which occurs ballistically, and the transport within the disordered fragments, occurring diffusively. The results open new avenues for making novel elements for molecular electronics, including ultrafast energy transporters, controlled chemical reactors, and sub-wavelength quantum nanoseparators.« less

Anthropometric Cockpit Compatibility Assessment of US Army Aircraft for Large and Small Personnel Wearing A Cold Weather, Armored Vest, Chemical Defense Protective Clothing Configuration

DTIC Science & Technology

1984-07-01

12 5. Survival Vest-Armor Plate Insert Configurations Employed ...................... 14 6. Summary of Critical Anthropometric Measure- ments...to assure an adequate aviator-to-cockpit fit for personnel wearing cold weather, survival vest with armor plate , and chemical defense protective...trousers (NSN 8415-00-407-1060). Survival vest, armor plated (NSN 8470-00-935-3192) The armor- plated survival vest could have the armor inserted in

76 FR 69764 - Stab-Resistant Body Armor Standard Workshop

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-09

... standard. Time slots for individual breakout sessions may be requested from the registration page indicated below. Additional time slots will be made available if needed to accommodate attendee requests. Workshop... will be allowed to register for the general session. Individual time slots will be available on the...

Ballistic Deficits for Ionization Chamber Pulses in Pulse Shaping Amplifiers

NASA Astrophysics Data System (ADS)

Kumar, G. Anil; Sharma, S. L.; Choudhury, R. K.

2007-04-01

In order to understand the dependence of the ballistic deficit on the shape of rising portion of the voltage pulse at the input of a pulse shaping amplifier, we have estimated the ballistic deficits for the pulses from a two-electrode parallel plate ionization chamber as well as for the pulses from a gridded parallel plate ionization chamber. These estimations have been made using numerical integration method when the pulses are processed through the CR-RCn (n=1-6) shaping network as well as when the pulses are processed through the complex shaping network of the ORTEC Model 472 spectroscopic amplifier. Further, we have made simulations to see the effect of ballistic deficit on the pulse-height spectra under different conditions. We have also carried out measurements of the ballistic deficits for the pulses from a two-electrode parallel plate ionization chamber as well as for the pulses from a gridded parallel plate ionization chamber when these pulses are processed through the ORTEC 572 linear amplifier having a simple CR-RC shaping network. The reasonable matching of the simulated ballistic deficits with the experimental ballistic deficits for the CR-RC shaping network clearly establishes the validity of the simulation technique

On the physics of momentum in ballistics: can the human body be displaced or knocked down by a small arms projectile?

PubMed

Karger, B; Kneubuehl, B P

1996-01-01

Shooting incidents are often portrayed as resulting in a sometimes violent backwards displacement of the victim. This opinion is also not infrequently held by expert witnesses. The physical force responsible for this would be momentum (mass x velocity). The physics of momentum in ballistic injury is explained in detail. The maximum momentum transferred from different small arms projectiles including large calibre rifles and a 12-gauge shotgun only results in a backwards motion of a 80 kg target body of 0.01-0.18 m/s, which is negligible compared to the velocity of a pedestrian (1-2 m/s). Furthermore, counterbalance is constantly maintained by neurophysiological reflexes. So the effect of the momentum transferred from the missile is virtually zero and there is no backwards motion of the person shot. Empirical evidence verifying these calculations can be obtained from hunting big game, from human gunshot victims and from a video documentary demonstrating the lack of any backwards motion of a person wearing body armour after hits from a centre fire rifle. So the alleged backwards hurling of a person shot is nothing but a myth which should be refuted not only because it is incorrect but also because it can result in miscarriages of justice.

Shock Tunnel Studies of the Hypersonic Flowfield around the Hypervelocity Ballistic Models with Aerospikes

NASA Astrophysics Data System (ADS)

Balakalyani, G.; Saravanan, S.; Jagadeesh, G.

Reduced drag and aerodynamic heating are the two basic design requirements for any hypersonic vehicle [1]. The flowfield around an axisymmetric blunt body is characterized by a bow shockwave standing ahead of its nose. The pressure and temperature behind this shock wave are very high. This increased pressure and temperature are responsible for the high levels of drag and aerodynamic heating over the body. In the past, there have been many investigations on the use of aerospikes as a drag reduction tool. These studies on spiked bodies aim at reducing both the drag and aerodynamic heating by modifying the hypersonic flowfield ahead of the nose of the body [2]. However, most of them used very simple configurations to experimentally study the drag reduction using spikes at hypersonic speeds [3] and therefore very little experimental data is available for a realistic geometric configuration. In the present study, the standard AGARD Hypervelocity Ballistic model 1 is used as the test model. The addition of the spike to the blunt body significantly alters the flowfield ahead of the nose, leading to the formation of a low pressure conical recirculation region, thus causing a reduction in drag and wall heat flux [4]. In the present investigation, aerodynamic drag force is measured over the Hypervelocity Ballistic model-1, with and without spike, at a flow enthalpy of 1.7 MJ/kg. The experiments are carried out at a Mach number of 8 and at zero angle of attack. An internally mountable accelerometer based 3-component force balance system is used to measure the aerodynamic forces on the model. Also computational studies are carried out to complement the experiments.

Ballistic intercept missions to Comet Encke

NASA Technical Reports Server (NTRS)

Mumma, M. (Compiler)

1975-01-01

The optimum ballistic intercept of a spacecraft with the comet Encke is determined. The following factors are considered in the analysis: energy requirements, encounter conditions, targeting error, comet activity, spacecraft engineering requirements and restraints, communications, and scientific return of the mission. A baseline model is formulated which includes the basic elements necessary to estimate the scientific return for the different missions considered. Tradeoffs which have major impact on the cost and/or scientific return of a ballistic mission to comet Encke are identified and discussed. Recommendations are included.

Intracranial Pressure Response to Non-Penetrating Ballistic Impact: An Experimental Study Using a Pig Physical Head Model and Live Pigs

PubMed Central

Liu, Hai; Kang, Jianyi; Chen, Jing; Li, Guanhua; Li, Xiaoxia; Wang, Jianmin

2012-01-01

This study was conducted to characterize the intracranial pressure response to non-penetrating ballistic impact using a "scalp-skull-brain" pig physical head model and live pigs. Forty-eight ballistic tests targeting the physical head model and anesthetized pigs protected by aramid plates were conducted with standard 9 mm bullets at low (279-297 m/s), moderate (350-372 m/s), and high (409-436 m/s) velocities. Intracranial pressure responses were recorded with pressure sensors embedded in similar brain locations in the physical head model and the anesthetized pigs. Three parameters of intracranial pressure were determined from the measured data: intracranial maximum pressure (Pmax), intracranial maximum pressure impulse (PImax), and the duration of the first positive phase (PPD). The intracranial pressure waves exhibited blast-like characteristics for both the physical model and l live pigs. Of all three parameters, Pmax is most sensitive to impact velocity, with means of 126 kPa (219 kPa), 178 kPa (474 kPa), and 241 kPa (751 kPa) for the physical model (live pigs) for low, moderate, and high impact velocities, respectively. The mean PPD becomes increasingly short as the impact velocity increases, whereas PImax shows the opposite trend. Although the pressure parameters of the physical model were much lower than those of the live pigs, good correlations between the physical model and the live pigs for the three pressure parameters, especially Pmax, were found using linear regression. This investigation suggests that Pmax is a preferred parameter for predicting the severity of the brain injury resulting from behind armor blunt trauma (BABT). PMID:23055817

Ballistic Blocks Surrounding Kilauea's Caldera

NASA Astrophysics Data System (ADS)

Swanson, D.; Zolkos, S.; Haravitch, B.

2010-12-01

Thousands of lithic blocks dot the surface around Kilauea’s caldera, erupted ballistically at the end of the 1790 eruption or soon thereafter. Most of the blocks occur in the western and southern sectors, probably reflecting the proximity of vents on the caldera floor. We mapped the ejecta field, measuring most of the blocks with nominal diameters ((a+b+c)/3) more than 75 cm and many of the smaller ones, noting distinctive lithologies. The distributions, sizes, and lithologies suggest 7-8 different ballistic bursts from 3-4 generalized vent areas. We measured 15 blocks with nominal diameters (ND) of 150-201 cm, 169 blocks with ND 100-149 cm, 308 blocks with ND 75-99 cm, 684 blocks with ND 50-74 cm, and 545 blocks with ND 25-49 cm. The smaller blocks were measured only in outlying areas, where they were the largest in the neighborhood, but they occur throughout the field. Twelve blocks with ND >150 cm lie within 1.7 km west and south of the center of Halema`uma`u; a vent near this location likely erupted the blocks. Three of the largest blocks, however, are 2.2-2.7 km north of Halema`uma`u and probably came from a more northerly vent. This interpretation is supported by the distributions of all blocks with ND >100 cm, which define at least 4, and possibly 5, different dispersal lobes; three cluster near Halema`uma`u, one is slightly north, and the one with the three large blocks is still farther north. The blocks have typical lithologies for Kilauea’s summit, including coarse basalt or fine gabbro derived from the centers of thick flows, solidified lakes, or small intrusions. Three lithologies are distinctive and help define 3, possibly 4, discrete bursts. Blocks of fine-grained basalt riddled with segregation veins occur only in a lobe 1.3 km wide reaching as far as 1.8 km southwest of Halema`uma`u; this lobe overlaps slightly with one defined by block size but is mostly distinct and probably indicates a separate burst. A cluster of blocks with puffy, somewhat

Acquisition of Armored Vehicles Purchased Through Contract W914NS-05-M-1189

DTIC Science & Technology

2005-10-21

vehicles. Results. The Multi-National Security Transition Command – Iraq (MNSTC-I) purchased seven armored Mercedes - Benz vehicles that did not have...contractor to provide seven armored Mercedes - Benz vehicles. The vehicles were to be used by the Multi-National Security Transition Command (MNSTC-I) to...ability to provide the vehicles immediately. The contract called for the delivery of seven Mercedes - Benz sedans at a price of $135,000 per vehicle that

Relevance of Armor in Counterinsurgency Operations

DTIC Science & Technology

2012-06-08

to evacuate its wounded and break contact, a limitation was identified and reported higher. The report identified that U.S. units suffered a deficit ...frighten the secessionist forces into capitulating. This operation occurred in the wake of sporadic small arms contact during the movement of the...engine noise and the sounds of the battle. Relationships between dismounted infantry and armor who had trained together would have solved this issue

Composite treatment of ceramic tile armor

DOEpatents

Hansen, James G. R. [Oak Ridge, TN; Frame, Barbara J [Oak Ridge, TN

2010-12-14

An improved ceramic tile armor has a core of boron nitride and a polymer matrix composite (PMC) facing of carbon fibers fused directly to the impact face of the tile. A polyethylene fiber composite backing and spall cover are preferred. The carbon fiber layers are cured directly onto the tile, not adhered using a separate adhesive so that they are integral with the tile, not a separate layer.

Composite treatment of ceramic tile armor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hansen, James G. R.; Frame, Barbara J

An improved ceramic tile armor has a core of boron nitride and a polymer matrix composite (PMC) facing of carbon fibers fused directly to the impact face of the tile. A polyethylene fiber composite backing and spall cover are preferred. The carbon fiber layers are cured directly onto the tile, not adhered using a separate adhesive so that they are integral with the tile, not a separate layer.

Non-Ballistic Vapor-Driven Ejecta

NASA Technical Reports Server (NTRS)

Wrobel, K. E.; Schultz, P. H.; Heineck, J. T.

2004-01-01

Impact-induced vaporization is a key component of early-time cratering mechanics. Previous experimental [1,2] and computational [e.g., 3] studies focused on the generation and expansion of vapor clouds in an attempt to better understand vaporization in hypervelocity impacts. Presented here is a new experimental approach to the study of impact-induced vaporization. The three-dimensional particle image velocimetry (3D PIV) system captures interactions between expanding vapor phases and fine particulates. Particles ejected early in the cratering process may be entrained in expanding gas phases generated at impact, altering their otherwise ballistic path of flight. 3D PIV allows identifying the presence of such non-ballistic ejecta from very early times in the cratering process.

Ballistic Jumping Drops on Superhydrophobic Surfaces via Electrostatic Manipulation.

PubMed

Li, Ning; Wu, Lei; Yu, Cunlong; Dai, Haoyu; Wang, Ting; Dong, Zhichao; Jiang, Lei

2018-02-01

The ballistic ejection of liquid drops by electrostatic manipulating has both fundamental and practical implications, from raindrops in thunderclouds to self-cleaning, anti-icing, condensation, and heat transfer enhancements. In this paper, the ballistic jumping behavior of liquid drops from a superhydrophobic surface is investigated. Powered by the repulsion of the same kind of charges, water drops can jump from the surface. The electrostatic acting time for the jumping of a microliter supercooled drop only takes several milliseconds, even shorter than the time for icing. In addition, one can control the ballistic jumping direction precisely by the relative position above the electrostatic field. The approach offers a facile method that can be used to manipulate the ballistic drop jumping via an electrostatic field, opening the possibility of energy efficient drop detaching techniques in various applications. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Developmental timing differences underlie armor loss across threespine stickleback populations.

PubMed

Currey, Mark C; Bassham, Susan; Perry, Stephen; Cresko, William A

2017-11-01

Comparing ontogenetic patterns within a well-described evolutionary context aids in inferring mechanisms of change, including heterochronies or deletion of developmental pathways. Because selection acts on phenotypes throughout ontogeny, any within-taxon developmental variation has implications for evolvability. We compare ontogenetic order and timing of locomotion and defensive traits in three populations of threespine stickleback that have evolutionarily divergent adult forms. This analysis adds to the growing understanding of developmental genetic mechanisms of adaptive change in this evolutionary model species by delineating when chondrogenesis and osteogenesis in two derived populations begin to deviate from the developmental pattern in their immediate ancestors. We found that differences in adult defensive morphologies arise through abolished or delayed initiation of these traits rather than via an overall heterochronic shift, that intra-population ontogenetic variation is increased for some derived traits, and that altered armor developmental timing differentiates the derived populations from each other despite parallels in adult lateral plate armor phenotypes. We found that changes in ossified elements of the pelvic armor are linked to delayed and incomplete development of an early-forming pelvic cartilage, and that this disruption likely presages the variable pelvic vestiges documented in many derived populations. © 2017 Wiley Periodicals, Inc.

Higher-Than-Ballistic Conduction in Viscous Electron Fluids

NASA Astrophysics Data System (ADS)

Levitov, Leonid

Strongly interacting electrons can move in a neatly coordinated way, reminiscent of the movement of viscous fluids. This talk will argue that in viscous flows interactions facilitate transport, allowing conductance to exceed the fundamental Sharvin-Landauer quantum-ballistic limit. The effect is particularly striking for the flow through a viscous point contact, a constriction exhibiting the quantum-mechanical ballistic transport at T = 0 but governed by electron hydrodynamics at elevated temperatures. Conductance grows as a square of the constriction width, i.e. faster than the linear width dependence for noninteracting fermions. The crossover between the ballistic and viscous regimes occurs when the mean free path for e-e collisions becomes comparable to the constriction width. Further, we will discuss the negative nonlocal response, a signature effect of viscous transport. This response exhibits an interesting nonmonotonic behavior vs. T at the viscous-to-balistic transition. The response is negative but small in the highly viscous regime at elevated temperatures. The value grows as the temperature is lowered and the system becomes less viscous, reaching the most negative values in the crossover region where the mean free path is comparable to the distance between contacts. Subsequently, it reverses sign at even lower temperatures, becoming positive as the system enters the ballistic regime. This peculiar behavior provides a clear signature of the ballistic-to-viscous transition and enables a direct measurement of the electron-electron collision mean free path.

Transverse isotropic modeling of the ballistic response of glass reinforced plastic composites

DOE Office of Scientific and Technical Information (OSTI.GOV)

Taylor, P.A.

1997-12-31

The use of glass reinforced plastic (GRP) composites is gaining significant attention in the DoD community for use in armor applications. These materials typically possess a laminate structure consisting of up to 100 plies, each of which is constructed of a glass woven roving fabric that reinforces a plastic matrix material. Current DoD attention is focused on a high strength, S-2 glass cross-weave (0/90) fabric reinforcing a polyester matrix material that forms each ply of laminate structure consisting anywhere from 20 to 70 plies. The resulting structure displays a material anisotropy that is, to a reasonable approximation, transversely isotropic. Whenmore » subjected to impact and penetration from a metal fragment projectile, the GRP displays damage and failure in an anisotropic manner due to various mechanisms such as matrix cracking, fiber fracture and pull-out, and fiber-matrix debonding. In this presentation, the author will describe the modeling effort to simulate the ballistic response of the GRP material described above using the transversely isotropic (TI) constitutive model which has been implemented in the shock physics code, CTH. The results of this effort suggest that the model is able to describe the delamination behavior of the material but has some difficulty capturing the in-plane (i.e., transverse) response of the laminate due to its cross-weave fabric reinforcement pattern which causes a departure from transverse isotropy.« less

Ballistic Reconstruction of a Migrating Bullet in the Parapharyngeal Space

PubMed Central

Bächinger, David; Bolliger, Stephan; Huber, Gerhard F.; Laske, Roman D.

2015-01-01

A 21-year-old male suffering from severe throat pain after being hit by a bullet in Syria claimed that he was shot through his eye and that the bullet subsequently descended behind his throat. Even though the first medical report stated that this course is implausible, meticulous workup provided evidence that the bullet might have entered the parapharyngeal space in a more cranial position than the one it was found eight months later. Our case highlights that bullets are able to move within the body, rendering ballistic reconstruction difficult. However, after removal of the bullet the patient's symptoms completely resolved. PMID:26770857

Armor structures

DOEpatents

Chu, Henry Shiu-Hung [Idaho Falls, ID; Lacy, Jeffrey M [Idaho Falls, ID

2008-04-01

An armor structure includes first and second layers individually containing a plurality of i-beams. Individual i-beams have a pair of longitudinal flanges interconnected by a longitudinal crosspiece and defining opposing longitudinal channels between the pair of flanges. The i-beams within individual of the first and second layers run parallel. The laterally outermost faces of the flanges of adjacent i-beams face one another. One of the longitudinal channels in each of the first and second layers faces one of the longitudinal channels in the other of the first and second layers. The channels of the first layer run parallel with the channels of the second layer. The flanges of the first and second layers overlap with the crosspieces of the other of the first and second layers, and portions of said flanges are received within the facing channels of the i-beams of the other of the first and second layers.

Use of armored RNA as a standard to construct a calibration curve for real-time RT-PCR.

PubMed

Donia, D; Divizia, M; Pana', A

2005-06-01

Armored Enterovirus RNA was used to standardize a real-time reverse transcription (RT)-PCR for environmental testing. Armored technology is a system to produce a robust and stable RNA standard, trapped into phage proteins, to be used as internal control. The Armored Enterovirus RNA protected sequence includes 263 bp of highly conserved sequences in 5' UTR region. During these tests, Armored RNA has been used to produce a calibration curve, comparing three different fluorogenic chemistry: TaqMan system, Syber Green I and Lux-primers. The effective evaluation of three amplifying commercial reagent kits, in use to carry out real-time RT-PCR, and several extraction procedures of protected viral RNA have been carried out. The highest Armored RNA recovery was obtained by heat treatment while chemical extraction may decrease the quantity of RNA. The best sensitivity and specificity was obtained using the Syber Green I technique since it is a reproducible test, easy to use and the cheapest one. TaqMan and Lux-primer assays provide good RT-PCR efficiency in relationship to the several extraction methods used, since labelled probe or primer request in these chemistry strategies, increases the cost of testing.

Bilateral vagotomy inhibits apnea and attenuates other physiological responses after blunt chest trauma.

PubMed

Gryth, Dan; Rocksén, David; Arborelius, Ulf P; Drobin, Dan; Persson, Jonas K E; Sondén, Anders; Bursell, Jenny; Olsson, Lars-Gunnar; Kjellström, B Thomas

2008-06-01

Behind armor blunt trauma (BABT) is defined as the nonpenetrating injury resulting from a ballistic impact on body armor. Some of the kinetic energy is transferred to the body, causing internal injuries and, occasionally, death. The aim of this study was to investigate if apnea and other pathophysiological effects after BABT is a vagally mediated reflex. Sixteen anesthetized pigs wearing body armor, of which five were vagotomized, were shot with a standard 7.62 mm assault rifle. These animals were compared with control animals (n = 8), shot with blank ammunition. We performed bilateral vagotomy before the shot and assessed the outcome on the apnea period, respiration, circulation, and brain function. Animals were monitored during a 2-hour period after the shot. Nonvagotomized animals had a mean apnea period of 22 (6-44) seconds. This group also showed a significant decrease in oxygen saturation compared with control animals. Furthermore, electroencephalogram-changes were more pronounced in nonvagotomized animals. In contrast, vagotomized animals were protected from apnea and showed only a minor decrease in oxygen saturation. All exposed animals showed impaired circulation, and postmortem examination revealed a pulmonary contusion. This study shows that apnea after BABT is a vagally mediated reflex that can be inhibited by bilateral vagotomy. Our results indicate that the initial apnea period is an important factor for hypoxia after BABT. Supported ventilation should begin immediately if the affected person is unconscious and suffers from apnea. It should continue until the neurologic paralysis disappears and sufficient spontaneous breathing begins.

Trismus in Face Transplantation Following Ballistic Trauma.

PubMed

Krezdorn, Nicco; Alhefzi, Muayyad; Perry, Bridget; Aycart, Mario A; Tasigiorgos, Sotirios; Bueno, Ericka M; Green, Jordan R; Pribaz, Julian J; Pomahac, Bohdan; Caterson, Edward J

2018-06-01

Trismus can be a challenging consequence of ballistic trauma to the face, and has rarely been described in the setting of face transplantation. Almost half of all current face transplant recipients in the world received transplantation to restore form and function after a ballistic injury. Here we report our experience and challenges with long standing trismus after face transplantation. We reviewed the medical records of our face transplant recipients whose indication was ballistic injury. We focused our review on trismus and assessed the pre-, peri- and postoperative planning, surgery and functional outcomes. Two patients received partial face transplantation, including the midface for ballistic trauma. Both patients suffered from impaired mouth opening, speech intelligibility, and oral competence. Severe scarring of the temporomandibular joint (TMJ) required intraoperative release in both patients, and additional total condylectomy on the left side 6 months posttransplant for 1 patient. Posttransplant, both patients achieved an improvement in mouth opening; however, there was persistent trismus. One year after transplantation, range of motion of the jaw had improved for both patients. Independent oral food intake was possible 1 year after surgery, although spillage of liquids and mixed consistency solids persisted. Speech intelligibility testing showed impairments in the immediate postoperative period, with improvement to over 85% for both patients at 1 year posttransplant. Ballistic trauma to the face and subsequent reconstructive measures can cause significant scarring and covert injuries to structures such as the TMJ, resulting in long standing trismus. Meticulous individual planning prior to interventions such as face transplantation must take these into account. We encourage intraoperative evaluation of these structures as well as peri- and postoperative treatment when necessary. Due to the nature of the primary injury, functional outcomes after face

Higher-than-ballistic conduction of viscous electron flows

PubMed Central

Guo, Haoyu; Ilseven, Ekin; Falkovich, Gregory; Levitov, Leonid S.

2017-01-01

Strongly interacting electrons can move in a neatly coordinated way, reminiscent of the movement of viscous fluids. Here, we show that in viscous flows, interactions facilitate transport, allowing conductance to exceed the fundamental Landauer’s ballistic limit Gball. The effect is particularly striking for the flow through a viscous point contact, a constriction exhibiting the quantum mechanical ballistic transport at T=0 but governed by electron hydrodynamics at elevated temperatures. We develop a theory of the ballistic-to-viscous crossover using an approach based on quasi-hydrodynamic variables. Conductance is found to obey an additive relation G=Gball+Gvis, where the viscous contribution Gvis dominates over Gball in the hydrodynamic limit. The superballistic, low-dissipation transport is a generic feature of viscous electronics. PMID:28265079

Ballistic One-Dimensional InAs Nanowire Cross-Junction Interconnects.

PubMed

Gooth, Johannes; Borg, Mattias; Schmid, Heinz; Schaller, Vanessa; Wirths, Stephan; Moselund, Kirsten; Luisier, Mathieu; Karg, Siegfried; Riel, Heike

2017-04-12

Coherent interconnection of quantum bits remains an ongoing challenge in quantum information technology. Envisioned hardware to achieve this goal is based on semiconductor nanowire (NW) circuits, comprising individual NW devices that are linked through ballistic interconnects. However, maintaining the sensitive ballistic conduction and confinement conditions across NW intersections is a nontrivial problem. Here, we go beyond the characterization of a single NW device and demonstrate ballistic one-dimensional (1D) quantum transport in InAs NW cross-junctions, monolithically integrated on Si. Characteristic 1D conductance plateaus are resolved in field-effect measurements across up to four NW-junctions in series. The 1D ballistic transport and sub-band splitting is preserved for both crossing-directions. We show that the 1D modes of a single injection terminal can be distributed into multiple NW branches. We believe that NW cross-junctions are well-suited as cross-directional communication links for the reliable transfer of quantum information as required for quantum computational systems.

A Ballistics Examination of Firearm Injuries Involving Breast Implants.

PubMed

Pannucci, Christopher J; Cyr, Adam J; Moores, Neal G; Young, Jason B; Szegedi, Martin

2018-03-01

This ballistics study examines whether saline breast implants can decrease tissue penetration in firearm injuries. We hypothesize that the fluid column within a saline breast implant can alter bullet velocity and/or bullet pattern of mushrooming. The two experimental groups included saline implants with 7.4 cm projection and a no implant group. The experimental design allowed the bullet to pass-through an implant and into ballistics gel (n = 10) or into ballistics gel without passage through an implant (n = 11). Shots that passed through an implant had 20.6% decreased penetration distance when compared to shots that did not pass-through an implant; this difference was statistically significant (31.9 cm vs. 40.2 cm, p < 0.001). Implant group bullets mushroomed prior to gel entry, but the no implant group mushroomed within the gel. Bullet passage through a saline breast implant results in direct bullet velocity reduction and earlier bullet mushrooming; this causes significantly decreased ballistics gel penetration. © 2017 American Academy of Forensic Sciences.

Structure and mechanical behaviors of protective armored pangolin scales and effects of hydration and orientation.

PubMed

Liu, Z Q; Jiao, D; Weng, Z Y; Zhang, Z F

2016-03-01

As natural flexible dermal armor, pangolin scales provide effective protection against predatory threats and possess other notable properties such as anti-adhesion and wear-resistance. In this study, the structure, mechanical properties, deformation and damage behaviors of pangolin scales were systematically investigated with the effects of hydration and orientation evaluated. The scales are divided into three macro-layers constituted by overlapping keratin tiles with distinct lamellar arrangements which are further composed of lower-ordered lamellae. Both hardness and strength are significantly decreased by hydration; while the plasticity is markedly improved concomitantly, and as such, the mechanical damages are mitigated. The tensile strength invariably approximates to one third of hardness in value. The tensile deformation is dominated by lamellae stretching and pulling out under wet condition, which is distinct from the trans-lamellar fracture in dry samples. The compressive behaviors are featured by pronounced plasticity in both dry and wet scales; and notable strain-hardening capacity is introduced by hydration, especially along the thickness direction wherein kinking occurs. Inter-lamellar cracking is effectively alleviated in wet samples compared with the dry ones and both of them deform by macroscopic buckling. This study may help stimulate possible inspiration for the design of high-performance synthetic armor materials by mimicking pangolin scales. Copyright © 2015 Elsevier Ltd. All rights reserved.

The Army’s Armored Multi-Purpose Vehicle (AMPV): Background and Issues for Congress

DTIC Science & Technology

2016-09-14

for Congress Congressional Research Service Summary The Armored Multi-Purpose Vehicle (AMPV) is the Army’s proposed replacement for the Vietnam ...for armor and mechanized infantry units. 1 Known as the M-113, it entered production in 1960 and saw extensive wartime service in Vietnam . Considered...needed to operate as part of combined arms teams within complex operational environments . For example, “commanders will not allow them to leave Forward

Ballistic parameters and trauma potential of pistol crossbows.

PubMed

Frank, Matthias; Schikorr, Wolfgang; Tesch, Ralf; Werner, Ronald; Hanisch, Steffen; Peters, Dieter; Ekkernkamp, Axel; Bockholdt, Britta; Seifert, Julia

2013-07-01

Hand-held pistol crossbows, which are smaller versions of conventional crossbows, have recently increased in popularity. Similar to conventional crossbows, life threatening injuries due to bolts discharged from pistol crossbows are reported in forensic and traumatological literature. While the ballistic background of conventional crossbows is comprehensively investigated, there are no investigations on the characteristic ballistic parameters (draw force, potential energy, recurve factor, kinetic energy, and efficiency) of pistol crossbows. Two hand-held pistol crossbows (Barnett Commando and Mini Cross Bow, rated draw force 362.9 N or 80 lbs) were tested. The maximum draw force was investigated using a dynamic tensile testing machine (TIRAtest 2705, TIRA GmbH). The potential energy was determined graphically by polynomial regression as area under the force-draw curve. External ballistic parameters of the bolts discharged from pistol crossbows were measured using a redundant ballistic speed measurement system (Dual-BMC 21a and Dual-LS 1000, Werner Mehl Kurzzeitmesstechnik). The average maximum draw force was 190.3 and 175.6 N for the Barnett and Mini Cross Bow, respectively. The corresponding total energy expended was 10.7 and 11 J, respectively. The recurve factor was calculated to be 0.705 and 1.044, respectively. Average bolt velocity was measured 43 up to 52 m/s. The efficiency was calculated up to 0.94. To conclude, this work provides the pending ballistic data on this special subgroup of crossbows which operate on a remarkable low kinetic energy level. Furthermore, it demonstrates that the nominal draw force pretended in the sales brochure is grossly exaggerated.

Development of impact resistant boron/aluminum composites for turbojet engine fan blades

NASA Technical Reports Server (NTRS)

Melnyk, P.; Toth, I. J.

1975-01-01

Composite fabrication was performed by vacuum press diffusion bonding by both the foil-filament array and preconsolidated monotape methods. The effect of matrix material, fiber diameter, matrix enhancement, fiber volume reinforcement, test temperature, angle-plying, notch, impact orientation, processing variables and fabrication methods on tensile strength and Charpy impact resistance are evaluated. Root attachment concepts, were evaluated by room and elevated temperature tensile testing, as well as by pendulum-Izod and ballistic impact testing. Composite resistance to foreign object damage was also evaluated by ballistic impacting of panels using projectiles of gelatin, RTV rubber and steel at various velocities, and impingement angles. A significant improvement in the pendulum impact resistance of B-Al composites was achieved.

Finite Element Modeling of the Behavior of Armor Materials Under High Strain Rates and Large Strains

NASA Astrophysics Data System (ADS)

Polyzois, Ioannis

For years high strength steels and alloys have been widely used by the military for making armor plates. Advances in technology have led to the development of materials with improved resistance to penetration and deformation. Until recently, the behavior of these materials under high strain rates and large strains has been primarily based on laboratory testing using the Split Hopkinson Pressure Bar apparatus. With the advent of sophisticated computer programs, computer modeling and finite element simulations are being developed to predict the deformation behavior of these metals for a variety of conditions similar to those experienced during combat. In the present investigation, a modified direct impact Split Hopkinson Pressure Bar apparatus was modeled using the finite element software ABAQUS 6.8 for the purpose of simulating high strain rate compression of specimens of three armor materials: maraging steel 300, high hardness armor (HHA), and aluminum alloy 5083. These armor materials, provided by the Canadian Department of National Defence, were tested at the University of Manitoba by others. In this study, the empirical Johnson-Cook visco-plastic and damage models were used to simulate the deformation behavior obtained experimentally. A series of stress-time plots at various projectile impact momenta were produced and verified by comparison with experimental data. The impact momentum parameter was chosen rather than projectile velocity to normalize the initial conditions for each simulation. Phenomena such as the formation of adiabatic shear bands caused by deformation at high strains and strain rates were investigated through simulations. It was found that the Johnson-Cook model can accurately simulate the behavior of body-centered cubic (BCC) metals such as steels. The maximum shear stress was calculated for each simulation at various impact momenta. The finite element model showed that shear failure first occurred in the center of the cylindrical specimen and

Ballistic heat conduction and mass disorder in one dimension.

PubMed

Ong, Zhun-Yong; Zhang, Gang

2014-08-20

It is well-known that in the disordered harmonic chain, heat conduction is subballistic and the thermal conductivity (κ) scales asymptotically as lim(L--> ∞) κ ∝ L(0.5) where L is the chain length. However, using the nonequilibrium Green's function (NEGF) method and analytical modelling, we show that there exists a critical crossover length scale (LC) below which ballistic heat conduction (κ ∝ L) can coexist with mass disorder. This ballistic-to-subballistic heat conduction crossover is connected to the exponential attenuation of the phonon transmittance function Ξ i.e. Ξ(ω, L) = exp[-L/λ(ω)], where λ is the frequency-dependent attenuation length. The crossover length can be determined from the minimum attenuation length, which depends on the maximum transmitted frequency. We numerically determine the dependence of the transmittance on frequency and mass composition as well as derive a closed form estimate, which agrees closely with the numerical results. For the length-dependent thermal conductance, we also derive a closed form expression which agrees closely with numerical results and reproduces the ballistic to subballistic thermal conduction crossover. This allows us to characterize the crossover in terms of changes in the length, mass composition and temperature dependence, and also to determine the conditions under which heat conduction enters the ballistic regime. We describe how the mass composition can be modified to increase ballistic heat conduction.

Time-gated ballistic imaging using a large aperture switching beam.

PubMed

Mathieu, Florian; Reddemann, Manuel A; Palmer, Johannes; Kneer, Reinhold

2014-03-24

Ballistic imaging commonly denotes the formation of line-of-sight shadowgraphs through turbid media by suppression of multiply scattered photons. The technique relies on a femtosecond laser acting as light source for the images and as switch for an optical Kerr gate that separates ballistic photons from multiply scattered ones. The achievable image resolution is one major limitation for the investigation of small objects. In this study, practical influences on the optical Kerr gate and image quality are discussed theoretically and experimentally applying a switching beam with large aperture (D = 19 mm). It is shown how switching pulse energy and synchronization of switching and imaging pulse in the Kerr cell influence the gate's transmission. Image quality of ballistic imaging and standard shadowgraphy is evaluated and compared, showing that the present ballistic imaging setup is advantageous for optical densities in the range of 8 < OD < 13. Owing to the spatial transmission characteristics of the optical Kerr gate, a rectangular aperture stop is formed, which leads to different resolution limits for vertical and horizontal structures in the object. Furthermore, it is reported how to convert the ballistic imaging setup into a schlieren-type system with an optical schlieren edge.

Higher-than-ballistic conduction of viscous electron flows.

PubMed

Guo, Haoyu; Ilseven, Ekin; Falkovich, Gregory; Levitov, Leonid S

2017-03-21

Strongly interacting electrons can move in a neatly coordinated way, reminiscent of the movement of viscous fluids. Here, we show that in viscous flows, interactions facilitate transport, allowing conductance to exceed the fundamental Landauer's ballistic limit [Formula: see text] The effect is particularly striking for the flow through a viscous point contact, a constriction exhibiting the quantum mechanical ballistic transport at [Formula: see text] but governed by electron hydrodynamics at elevated temperatures. We develop a theory of the ballistic-to-viscous crossover using an approach based on quasi-hydrodynamic variables. Conductance is found to obey an additive relation [Formula: see text], where the viscous contribution [Formula: see text] dominates over [Formula: see text] in the hydrodynamic limit. The superballistic, low-dissipation transport is a generic feature of viscous electronics.

Variability of Plyometric and Ballistic Exercise Technique Maintains Jump Performance.

PubMed

Chandler, Phillip T; Greig, Matthew; Comfort, Paul; McMahon, John J

2018-06-01

Chandler, PT, Greig, M, Comfort, P, and McMahon, JJ. Variability of plyometric and ballistic exercise technique maintains jump performance. J Strength Cond Res 32(6): 1571-1582, 2018-The aim of this study was to investigate changes in vertical jump technique over the course of a training session. Twelve plyometric and ballistic exercise-trained male athletes (age = 23.4 ± 4.6 years, body mass = 78.7 ± 18.8 kg, height = 177.1 ± 9.0 cm) performed 3 sets of 10 repetitions of drop jump (DJ), rebound jump (RJ) and squat jump (SJ). Each exercise was analyzed from touchdown to peak joint flexion and peak joint flexion to take-off. Squat jump was analyzed from peak joint flexion to take-off only. Jump height, flexion and extension time and range of motion, and instantaneous angles of the ankle, knee, and hip joints were measured. Separate 1-way repeated analyses of variance compared vertical jump technique across exercise sets and repetitions. Exercise set analysis found that SJ had lower results than DJ and RJ for the angle at peak joint flexion for the hip, knee, and ankle joints and take-off angle of the hip joint. Exercise repetition analysis found that the ankle joint had variable differences for the angle at take-off, flexion, and extension time for RJ. The knee joint had variable differences for flexion time for DJ and angle at take-off and touchdown for RJ. There was no difference in jump height. Variation in measured parameters across repetitions highlights variable technique across plyometric and ballistic exercises. This did not affect jump performance, but likely maintained jump performance by overcoming constraints (e.g., level of rate coding).

Trajectory characteristics and heating of hypervelocity projectiles having large ballistic coefficients

NASA Technical Reports Server (NTRS)

Tauber, Michael E.

1986-01-01

A simple, approximate equation describing the velocity-density relationship (or velocity-altitude) has been derived from the flight of large ballistic coefficient projectiles launched at high speeds. The calculations obtained by using the approximate equation compared well with results for numerical integrations of the exact equations of motion. The flightpath equation was used to parametrically calculate maximum body decelerations and stagnation pressures for initial velocities from 2 to 6 km/s. Expressions were derived for the stagnation-point convective heating rates and total heat loads. The stagnation-point heating was parametrically calculated for a nonablating wall and an ablating carbon surface. Although the heating rates were very high, the pulse decayed quickly. The total nose-region heat shield weight was conservatively estimated to be only about 1 percent of the body mass.

Targeting Low-Energy Ballistic Lunar Transfers

NASA Technical Reports Server (NTRS)

Parker, Jeffrey S.

2010-01-01

Numerous low-energy ballistic transfers exist between the Earth and Moon that require less fuel than conventional transfers, but require three or more months of transfer time. An entirely ballistic lunar transfer departs the Earth from a particular declination at some time in order to arrive at the Moon at a given time along a desirable approach. Maneuvers may be added to the trajectory in order to adjust the Earth departure to meet mission requirements. In this paper, we characterize the (Delta)V cost required to adjust a low-energy ballistic lunar transfer such that a spacecraft may depart the Earth at a desirable declination, e.g., 28.5(white bullet), on a designated date. This study identifies the optimal locations to place one or two maneuvers along a transfer to minimize the (Delta)V cost of the transfer. One practical application of this study is to characterize the launch period for a mission that aims to launch from a particular launch site, such as Cape Canaveral, Florida, and arrive at a particular orbit at the Moon on a given date using a three-month low-energy transfer.

Historical overview of wound ballistics research.

PubMed

Maiden, Nick

2009-01-01

Ballistics involves the study of the scientific properties of projectiles, their behavior and their terminal effects on biological tissues and other materials. Wound ballistics deals with the analysis of injuries caused by projectiles and the behavior of projectiles within human or other biological tissues. The nineteenth century witnessed the development of both of these areas with Kocher's hydrodynamic theory and the understanding of the significance of bullet deformation in causing tissue injury. The degree of traumatic disruption of tissues and organs was also related to direct energy transfer from projectiles. While subsequent research has concentrated on elucidating further mechanisms of injury, the exact cause of remote tissue damage from high energy projectiles is still the subject of ongoing research. Much of the contemporary literature regarding wound ballistics concentrates on the forensic aspects and their application for legal purposes, in particular the investigation of shooting scenes. There have been many advances in this area, particularly in relation to the identification of various types of gunshot wounds and how their appearance can be used to establish if a shooting was accidental, deliberate (homicidal) or self inflicted (suicidal).

Thermo-Electron Ballistic Coolers or Heaters

NASA Technical Reports Server (NTRS)

Choi, Sang H.

2003-01-01

Electronic heat-transfer devices of a proposed type would exploit some of the quantum-wire-like, pseudo-superconducting properties of single-wall carbon nanotubes or, optionally, room-temperature-superconducting polymers (RTSPs). The devices are denoted thermo-electron ballistic (TEB) coolers or heaters because one of the properties that they exploit is the totally or nearly ballistic (dissipation or scattering free) transport of electrons. This property is observed in RTSPs and carbon nanotubes that are free of material and geometric defects, except under conditions in which oscillatory electron motions become coupled with vibrations of the nanotubes. Another relevant property is the high number density of electrons passing through carbon nanotubes -- sufficient to sustain electron current densities as large as 100 MA/square cm. The combination of ballistic motion and large current density should make it possible for TEB devices to operate at low applied potentials while pumping heat at rates several orders of magnitude greater than those of thermoelectric devices. It may also enable them to operate with efficiency close to the Carnot limit. In addition, the proposed TEB devices are expected to operate over a wider temperature range

The Need For and Benefits of the Creation of the Light Armored Reconnaissance Regiment

DTIC Science & Technology

2010-04-14

instead of the 8 battalions reporting straight to a commanding general provides significant advantages . When asked about the benefits of the recent...The Need For and Benefits of the Creation of the Light Armored N/A Reconnaissance Regiment 5b. GRANT NUMBER N/A 5c. PROGRAM ELEMENT NUMBER N/A 6...MASTER OF MILITARY STUDIES THE NEED FOR AND BENEFITS OF THECREATION OF THE LIGHT ARMORED RECONNAISSANCE REGIMENT SUBMITTED IN PARTIAL FULFILLMENT OF

From hopping to ballistic transport in graphene-based electronic devices

NASA Astrophysics Data System (ADS)

Taychatanapat, Thiti

This thesis describes electronic transport experiments in graphene from the hopping to the ballistic regime. The first experiment studies dual-gated bilayer graphene devices. By applying an electric field with these dual gates, we can open a band gap in bilayer graphene and observe an increase in resistance of over six orders of magnitude as well as a strongly non-linear behavior in the transport characteristics. A temperature-dependence study of resistance at large electric field at the charge neutrality point shows the change in the transport mechanism from a hopping dominated regime at low temperature to a diffusive regime at high temperature. The second experiment examines electronic properties of Bernal-stacked trilayer graphene. Due to the low mobility of trilayer graphene on SiO 2substrates, we employ hexagonal boron nitride as a local substrate to improve its mobility. This led us to observe a quantum Hall effect with multiple Landau level crossings, proving the coexistence of massless and massive Dirac fermions in Bernal-stacked trilayer graphene. From the position of these crossing points in magnetic field and electron density, we can deduce the band parameters used to model its band structure. At high magnetic field, we observe broken symmetry states via Landau level splittings as well as crossings among these broken-symmetry states. In the third experiment, we investigate transverse magnetic focusing (TMF) in mono-, bi-, and tri-layer graphene. The ability to tune density allows us to electronically modify focal points and investigate TMF continuously from hole to electron regimes. This also allows us to observe the change in band structure of trilayer graphene as a function of applied electric field. Finally, we also observe TMF at room temperature in monolayer graphene which unambiguously proves the existence of ballistic transport at room temperature.

Steering and collimating ballistic electrons with amphoteric refraction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Radu, A.; Dragoman, D.; Iftimie, S.

2012-07-15

We show that amphoteric refraction of ballistic electrons, i.e., positive or negative refraction depending on the incidence angle, occurs at an interface between an isotropic and an anisotropic medium and can be employed to steer and collimate electron beams. The steering angle is determined by the materials' parameters, but the degree of collimation can be tuned in a significant range by changing the energy of ballistic electrons.

Thermodynamic properties of UF sub 6 measured with a ballistic piston compressor

NASA Technical Reports Server (NTRS)

Sterritt, D. E.; Lalos, G. T.; Schneider, R. T.

1973-01-01

From experiments performed with a ballistic piston compressor, certain thermodynamic properties of uranium hexafluoride were investigated. Difficulties presented by the nonideal processes encountered in ballistic compressors are discussed and a computer code BCCC (Ballistic Compressor Computer Code) is developed to analyze the experimental data. The BCCC unfolds the thermodynamic properties of uranium hexafluoride from the helium-uranium hexafluoride mixture used as the test gas in the ballistic compressor. The thermodynamic properties deduced include the specific heat at constant volume, the ratio of specific heats for UF6, and the viscous coupling constant of helium-uranium hexafluoride mixtures.

RNase-Resistant Virus-Like Particles Containing Long Chimeric RNA Sequences Produced by Two-Plasmid Coexpression System▿

PubMed Central

Wei, Yuxiang; Yang, Changmei; Wei, Baojun; Huang, Jie; Wang, Lunan; Meng, Shuang; Zhang, Rui; Li, Jinming

2008-01-01

RNase-resistant, noninfectious virus-like particles containing exogenous RNA sequences (armored RNA) are good candidates as RNA controls and standards in RNA virus detection. However, the length of RNA packaged in the virus-like particles with high efficiency is usually less than 500 bases. In this study, we describe a method for producing armored L-RNA. Armored L-RNA is a complex of MS2 bacteriophage coat protein and RNA produced in Escherichia coli by the induction of a two-plasmid coexpression system in which the coat protein and maturase are expressed from one plasmid and the target RNA sequence with modified MS2 stem-loop (pac site) is transcribed from another plasmid. A 3V armored L-RNA of 2,248 bases containing six gene fragments—hepatitis C virus, severe acute respiratory syndrome coronavirus (SARS-CoV1, SARS-CoV2, and SARS-CoV3), avian influenza virus matrix gene (M300), and H5N1 avian influenza virus (HA300)—was successfully expressed by the two-plasmid coexpression system and was demonstrated to have all of the characteristics of armored RNA. We evaluated the 3V armored L-RNA as a calibrator for multiple virus assays. We used the WHO International Standard for HCV RNA (NIBSC 96/790) to calibrate the chimeric armored L-RNA, which was diluted by 10-fold serial dilutions to obtain samples containing 106 to 102 copies. In conclusion, the approach we used for armored L-RNA preparation is practical and could reduce the labor and cost of quality control in multiplex RNA virus assays. Furthermore, we can assign the chimeric armored RNA with an international unit for quantitative detection. PMID:18305135

Persistence of 10-year old Exxon Valdez oil on Gulf of Alaska beaches: The importance of boulder-armoring

USGS Publications Warehouse

Irvine, Gail V.; Mann, Daniel H.; Short, Jeffrey W.

2006-01-01

Oil stranded as a result of the 1989 Exxon Valdez spill has persisted for >10 years at study sites on Gulf of Alaska shores distant from the spill's origin. These sites were contaminated by "oil mousse", which persists in these settings due to armoring of underlying sediments and their included oil beneath boulders. The boulder-armored beaches that we resampled in 1999 showed continued contamination by subsurface oil, despite their exposure to moderate to high wave energies. Significant declines in surface oil cover occurred at all study sites. In contrast, mousse has persisted under boulders in amounts similar to what was present in 1994 and probably in 1989. Especially striking is the general lack of weathering of this subsurface oil over the last decade. Oil at five of the six armored-beach sites 10 years after the spill is compositionally similar to 11-day old Exxon Valdez oil. Analysis of movements in the boulder-armor that covers the study beaches reveals that only minor shifts have occurred since 1994, suggesting that over the last five, and probably over the last 10 years, boulder-armors have remained largely unmoved at the study sites. These findings emphasize the importance of particular geomorphic parameters in determining stranded oil persistence. Surface armoring, combined with stranding of oil mousse, results in the unexpectedly lengthy persistence of only lightly to moderately weathered oil within otherwise high-energy wave environments.

Methods of producing armor systems, and armor systems produced using such methods

DOEpatents

Chu, Henry S; Lillo, Thomas M; McHugh, Kevin M

2013-02-19

An armor system and method involves providing a core material and a stream of atomized coating material that comprises a liquid fraction and a solid fraction. An initial layer is deposited on the core material by positioning the core material in the stream of atomized coating material wherein the solid fraction of the stream of atomized coating material is less than the liquid fraction of the stream of atomized coating material on a weight basis. An outer layer is then deposited on the initial layer by positioning the core material in the stream of atomized coating material wherein the solid fraction of the stream of atomized coating material is greater than the liquid fraction of the stream of atomized coating material on a weight basis.

27 CFR 478.149 - Armor piercing ammunition manufactured or imported for the purpose of testing or experimentation.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 27 Alcohol, Tobacco Products and Firearms 3 2011-04-01 2010-04-01 true Armor piercing ammunition... FIREARMS AND AMMUNITION COMMERCE IN FIREARMS AND AMMUNITION Exemptions, Seizures, and Forfeitures § 478.149 Armor piercing ammunition manufactured or imported for the purpose of testing or experimentation. The...

27 CFR 478.149 - Armor piercing ammunition manufactured or imported for the purpose of testing or experimentation.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 27 Alcohol, Tobacco Products and Firearms 3 2010-04-01 2010-04-01 false Armor piercing ammunition... FIREARMS AND AMMUNITION COMMERCE IN FIREARMS AND AMMUNITION Exemptions, Seizures, and Forfeitures § 478.149 Armor piercing ammunition manufactured or imported for the purpose of testing or experimentation. The...

27 CFR 478.149 - Armor piercing ammunition manufactured or imported for the purpose of testing or experimentation.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 27 Alcohol, Tobacco Products and Firearms 3 2012-04-01 2010-04-01 true Armor piercing ammunition... FIREARMS AND AMMUNITION COMMERCE IN FIREARMS AND AMMUNITION Exemptions, Seizures, and Forfeitures § 478.149 Armor piercing ammunition manufactured or imported for the purpose of testing or experimentation. The...

27 CFR 478.149 - Armor piercing ammunition manufactured or imported for the purpose of testing or experimentation.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 27 Alcohol, Tobacco Products and Firearms 3 2014-04-01 2014-04-01 false Armor piercing ammunition... FIREARMS AND AMMUNITION COMMERCE IN FIREARMS AND AMMUNITION Exemptions, Seizures, and Forfeitures § 478.149 Armor piercing ammunition manufactured or imported for the purpose of testing or experimentation. The...

27 CFR 478.149 - Armor piercing ammunition manufactured or imported for the purpose of testing or experimentation.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 27 Alcohol, Tobacco Products and Firearms 3 2013-04-01 2013-04-01 false Armor piercing ammunition... FIREARMS AND AMMUNITION COMMERCE IN FIREARMS AND AMMUNITION Exemptions, Seizures, and Forfeitures § 478.149 Armor piercing ammunition manufactured or imported for the purpose of testing or experimentation. The...

Ballistic mode Mercury orbiter missions.

NASA Technical Reports Server (NTRS)

Hollenbeck, G. R.

1973-01-01

The MVM'73 Mercury flyby mission will initiate exploration of this unique planet. No firm plans for follow-on investigations have materialized due to the difficult performance requirements of the next logical step, an orbiter mission. Previous investigations of ballistic mode flight opportunities have indicated requirements for a Saturn V class launch vehicle. Consequently, most recent effort has been oriented to use of solar electric propulsion. More comprehensive study of the ballistic flight mode utilizing Venus gravity-assist has resulted in identification of timely high-performance mission opportunities compatible with programmed launch vehicles and conventional spacecraft propulsion technologies. A likely candidate for an initial orbiter mission is a 1980 opportunity which offers net orbiter spacecraft mass of about 435 kg with the Titan IIIE/Centaur launch vehicle and single stage solid propulsion for orbit insertion.

MIDAS - Mission design and analysis software for the optimization of ballistic interplanetary trajectories

NASA Technical Reports Server (NTRS)

Sauer, Carl G., Jr.

1989-01-01

A patched conic trajectory optimization program MIDAS is described that was developed to investigate a wide variety of complex ballistic heliocentric transfer trajectories. MIDAS includes the capability of optimizing trajectory event times such as departure date, arrival date, and intermediate planetary flyby dates and is able to both add and delete deep space maneuvers when dictated by the optimization process. Both powered and unpowered flyby or gravity assist trajectories of intermediate bodies can be handled and capability is included to optimize trajectories having a rendezvous with an intermediate body such as for a sample return mission. Capability is included in the optimization process to constrain launch energy and launch vehicle parking orbit parameters.

A Materials Approach in the Development of Multi-Threat Warfighter Head Protection

DTIC Science & Technology

2008-12-01

TUSJp TYSlp ’--- --"IO,,5083-="" H13 .’ (AI) ’AZ31B-H2’",(~",),,-- __ Figure 6. Specific Strength of Mg vs. Al Alloy Armor Plate of current interest because...perfonnance in metal alloys, and higher stiffness typically contributes to enhanced energy absorption upon ballistic impact ; therefore, one would predict...Helmets, and ballistic helmets in particular. have not been dominated by stiffness requirements but rather other properties (e.g., crash, impact

A novel method to produce armored double-stranded DNA by encapsulation of MS2 viral capsids.

PubMed

Zhang, Lei; Sun, Yu; Chang, Le; Jia, Tingting; Wang, Guojing; Zhang, Rui; Zhang, Kuo; Li, Jinming

2015-09-01

With the rapid development of molecular diagnostic techniques, there is a growing need for quality controls and standards with favorable properties to monitor the entire detection process. In this study, we describe a novel method to produce armored hepatitis B virus (HBV) and human papillomavirus (HPV) DNA for use in nucleic acid tests, which was confirmed to be stable, homogeneous, noninfectious, nuclease resistant, and safe for shipping. We demonstrated that MS2 bacteriophage could successfully package double-stranded DNA of 1.3-, 3-, 3.5-, and 6.5-kb length into viral capsids with high reassembly efficiency. This is the first application of RNA bacteriophage MS2 as a platform to encapsulate double-stranded DNA, forming virus-like particles (VLPs) which were indistinguishable from native MS2 capsids in size and morphology. Moreover, by analyzing the interaction mechanism of pac site and the MS2 coat protein (CP), we found that in addition to the recognized initiation signal TR-RNA, TR-DNA can also trigger spontaneous reassembly of CP dimers, providing a more convenient and feasible method of assembly. In conclusion, this straightforward and reliable manufacturing approach makes armored DNA an ideal control and standard for use in clinical laboratory tests and diagnostics, possessing prospects for broad application, especially providing a new platform for the production of quality controls for DNA viruses.

Heat Coulomb blockade of one ballistic channel

NASA Astrophysics Data System (ADS)

Sivre, E.; Anthore, A.; Parmentier, F. D.; Cavanna, A.; Gennser, U.; Ouerghi, A.; Jin, Y.; Pierre, F.

2018-02-01

Quantum mechanics and Coulomb interaction dictate the behaviour of small circuits. The thermal implications cover fundamental topics from quantum control of heat to quantum thermodynamics, with prospects of novel thermal machines and an ineluctably growing influence on nanocircuit engineering. Experimentally, the rare observations thus far include the universal thermal conductance quantum and heat interferometry. However, evidence for many-body thermal effects paving the way to markedly different heat and electrical behaviours in quantum circuits remains wanting. Here we report on the observation of the Coulomb blockade of electronic heat flow from a small metallic circuit node, beyond the widespread Wiedemann-Franz law paradigm. We demonstrate this thermal many-body phenomenon for perfect (ballistic) conduction channels to the node, where it amounts to the universal suppression of precisely one quantum of conductance for the transport of heat, but none for electricity. The inter-channel correlations that give rise to such selective heat current reduction emerge from local charge conservation, in the floating node over the full thermal frequency range (<~temperature × kB/h). This observation establishes the different nature of the quantum laws for thermal transport in nanocircuits.

Verification of models for ballistic movement time and endpoint variability.

PubMed

Lin, Ray F; Drury, Colin G

2013-01-01

A hand control movement is composed of several ballistic movements. The time required in performing a ballistic movement and its endpoint variability are two important properties in developing movement models. The purpose of this study was to test potential models for predicting these two properties. Twelve participants conducted ballistic movements of specific amplitudes using a drawing tablet. The measured data of movement time and endpoint variability were then used to verify the models. This study was successful with Hoffmann and Gan's movement time model (Hoffmann, 1981; Gan and Hoffmann 1988) predicting more than 90.7% data variance for 84 individual measurements. A new theoretically developed ballistic movement variability model, proved to be better than Howarth, Beggs, and Bowden's (1971) model, predicting on average 84.8% of stopping-variable error and 88.3% of aiming-variable errors. These two validated models will help build solid theoretical movement models and evaluate input devices. This article provides better models for predicting end accuracy and movement time of ballistic movements that are desirable in rapid aiming tasks, such as keying in numbers on a smart phone. The models allow better design of aiming tasks, for example button sizes on mobile phones for different user populations.

Comparative transition performance of several nosetip materials as defined by ballistics-range testing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reda, D.C.

1979-01-01

Requirements and techniques for conducting aerothermodynamic tests of reentry body nosetips/materials in hypersonic ballistics-range environments (ISA 22nd IIS), and associated data interpretation/analyses methods using interactive graphics (ISA 24th IIS) have been outlined. Such testing, which centers on the utilization of electro-optical pyrometry for the measurement of nosetip surface temperature distributions, has provided both the aerothermodynamics and materials-development communities with valuable new capabilities. From an aerothermodynamics standpoint, experimental results serve to test the validity of existing computer codes/correlations, as well as to expand the data base necessary for the generation of improved predictive techniques. From a materials-development standpoint, results serve tomore » define relationships between fabrication/processing methods and associated material thermal response as well as to provide for relative ranking of candidate materials under controlled reentry conditions. Following these multipurpose objectives, ballistic-range tests of preablated graphite and carbon/carbon composite nosetips have been conducted. Results are presented herein which illustrate the comparative transition performance of five nosetip materials from both mean and statistical (degree-of-asymmetry) viewpoints.« less

History of the Army Ground Forces. Study Number 27. History of the Armored Force, Command and Center

DTIC Science & Technology

1946-01-01

Forces be- *• came closer. With its redesignation as the Armored Command on 2 Tuly 1945, the activ- ities of the Armored Force became more closely...techniques. Num- ber of graduates not available. .,- Clerical Courses Clerical Course - Opened 4 November 1940; closed 22 Tuly 1944. Duration of each class - 8

Transparent Materials for Armor - A Cost Study

DTIC Science & Technology

2010-01-11

UNCLASSIFIED UNCLASSIFIED Example: M1114 Recent History 2006 “Iraqi Pope Glass” 2004-2005 GPK (Gunner Protection Kit) Early OIF Curb Wt: 10,300lbs GVW...12,100lbs More Vehicles More Attacks More Glass UNCLASSIFIED UNCLASSIFIED Future Transparent Gun Shields Requirement: Upgrade GPKs with transparent...Objective AHI GS & GPK Baseline Field Modified GS & APK UNCLASSIFIED UNCLASSIFIED •Average Total ($) for transparent armor increased by about 20% (each

12. Photocopy of lithograph (source unknown) The Armor Lithograph Company, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

12. Photocopy of lithograph (source unknown) The Armor Lithograph Company, Ltd., Pittsburgh, Pennsylvania, ca. 1888 COURTHOUSE AND JAIL, FROM THE WEST - Allegheny County Courthouse & Jail, 436 Grant Street (Courthouse), 420 Ross Street (Jail), Pittsburgh, Allegheny County, PA

Ballistic edge states in Bismuth nanowires revealed by SQUID interferometry.

PubMed

Murani, Anil; Kasumov, Alik; Sengupta, Shamashis; Kasumov, Yu A; Volkov, V T; Khodos, I I; Brisset, F; Delagrange, Raphaëlle; Chepelianskii, Alexei; Deblock, Richard; Bouchiat, Hélène; Guéron, Sophie

2017-07-05

The protection against backscattering provided by topology is a striking property. In two-dimensional insulators, a consequence of this topological protection is the ballistic nature of the one-dimensional helical edge states. One demonstration of ballisticity is the quantized Hall conductance. Here we provide another demonstration of ballistic transport, in the way the edge states carry a supercurrent. The system we have investigated is a micrometre-long monocrystalline bismuth nanowire with topological surfaces, that we connect to two superconducting electrodes. We have measured the relation between the Josephson current flowing through the nanowire and the superconducting phase difference at its ends, the current-phase relation. The sharp sawtooth-shaped phase-modulated current-phase relation we find demonstrates that transport occurs selectively along two ballistic edges of the nanowire. In addition, we show that a magnetic field induces 0-π transitions and ϕ 0 -junction behaviour, providing a way to manipulate the phase of the supercurrent-carrying edge states and generate spin supercurrents.

Ballistic edge states in Bismuth nanowires revealed by SQUID interferometry

PubMed Central

Murani, Anil; Kasumov, Alik; Sengupta, Shamashis; Kasumov, Yu A.; Volkov, V. T.; Khodos, I. I.; Brisset, F.; Delagrange, Raphaëlle; Chepelianskii, Alexei; Deblock, Richard; Bouchiat, Hélène; Guéron, Sophie

2017-01-01

The protection against backscattering provided by topology is a striking property. In two-dimensional insulators, a consequence of this topological protection is the ballistic nature of the one-dimensional helical edge states. One demonstration of ballisticity is the quantized Hall conductance. Here we provide another demonstration of ballistic transport, in the way the edge states carry a supercurrent. The system we have investigated is a micrometre-long monocrystalline bismuth nanowire with topological surfaces, that we connect to two superconducting electrodes. We have measured the relation between the Josephson current flowing through the nanowire and the superconducting phase difference at its ends, the current–phase relation. The sharp sawtooth-shaped phase-modulated current–phase relation we find demonstrates that transport occurs selectively along two ballistic edges of the nanowire. In addition, we show that a magnetic field induces 0–π transitions and φ0-junction behaviour, providing a way to manipulate the phase of the supercurrent-carrying edge states and generate spin supercurrents. PMID:28677681

One-Dimensional Modelling of Internal Ballistics

NASA Astrophysics Data System (ADS)

Monreal-González, G.; Otón-Martínez, R. A.; Velasco, F. J. S.; García-Cascáles, J. R.; Ramírez-Fernández, F. J.

2017-10-01

A one-dimensional model is introduced in this paper for problems of internal ballistics involving solid propellant combustion. First, the work presents the physical approach and equations adopted. Closure relationships accounting for the physical phenomena taking place during combustion (interfacial friction, interfacial heat transfer, combustion) are deeply discussed. Secondly, the numerical method proposed is presented. Finally, numerical results provided by this code (UXGun) are compared with results of experimental tests and with the outcome from a well-known zero-dimensional code. The model provides successful results in firing tests of artillery guns, predicting with good accuracy the maximum pressure in the chamber and muzzle velocity what highlights its capabilities as prediction/design tool for internal ballistics.

Use of Body Armor Protection Levels with Squad Automatic Weapon Fighting Load Impacts Soldier Performance, Mobility, and Postural Control

DTIC Science & Technology

2015-05-01

changes have been historically seen with the heavier approach march load between 21 kg and 33 kg (Schiffman et al., 2006, and Harman et al., 1999) or...the heaviest emergency approach march load greater than 32 kg (Attwells et al., 2006, and Harman et al., 1999). Increasing ballistic protection...vital to maintaining upright posture while walking ( Harman et al., 1999). Alterations made lower in the kinematic chain, such as the hip flexion

Dynamic Stability Analysis of Blunt Body Entry Vehicles Using Time-Lagged Aftbody Pitching Moments

NASA Technical Reports Server (NTRS)

Kazemba, Cole D.; Braun, Robert D.; Schoenenberger, Mark; Clark, Ian G.

2013-01-01

This analysis defines an analytic model for the pitching motion of blunt bodies during atmospheric entry. The proposed model is independent of the pitch damping sum coefficient present in the standard formulation of the equations of motion describing pitch oscillations of a decelerating blunt body, instead using the principle of a time-lagged aftbody moment as the forcing function for oscillation divergence. Four parameters, all with intuitive physical relevance, are introduced to fully define the aftbody moment and the associated time delay. It is shown that the dynamic oscillation responses typical to blunt bodies can be produced using hysteresis of the aftbody moment in place of the pitch damping coefficient. The approach used in this investigation is shown to be useful in understanding the governing physical mechanisms for blunt body dynamic stability and in guiding vehicle and mission design requirements. A validation case study using simulated ballistic range test data is conducted. From this, parameter identification is carried out through the use of a least squares optimizing routine. Results show good agreement with the limited existing literature for the parameters identified, suggesting that the model proposed could be validated by an experimental ballistic range test series. The trajectories produced by the identified parameters were found to match closely those from the MER ballistic range tests for a wide array of initial conditions and can be identified with a reasonable number of ballistic range shots and computational effort.

Missile Defense: Ballistic Missile Defense System Testing Delays Affect Delivery of Capabilities

DTIC Science & Technology

2016-04-28

Page 1 GAO- 16 -339R Ballistic Missile Defense 441 G St. N.W. Washington, DC 20548 April 28, 2016 Congressional Committees Missile Defense...Ballistic Missile Defense System Testing Delays Affect Delivery of Capabilities For over half a century , the Department of Defense (DOD) has been...81, § 232 (a) (2011). 2 GAO- 16 -339R Ballistic Missile Defense baselines, we analyzed the testing goals for selected elements, which are

Enzyme Armoring by an Organosilica Layer: Synthesis and Characterization of Hybrid Organic/Inorganic Nanobiocatalysts.

PubMed

Correro, M Rita; Sykora, Sabine; Corvini, Philippe F-X; Shahgaldian, Patrick

2017-01-01

The availability of highly stable and reusable enzymes is one of the main challenges in bio-based industrial processes. Enzyme immobilization and encapsulation represent promising strategies to reach this goal. In this chapter, the synthetic strategy to produce hybrid organic/inorganic nanobiocatalysts (NBC) is reported. This strategy is based on the sequential immobilization of an enzyme on the surface of silica nanoparticles followed by the growth, at the surface of the nanoparticles, of a shielding layer which serves as an armor to protect the enzyme against denaturation/degradation. This armor is produced through a thickness-controlled organosilane poly-condensation onto the nanoparticle surface around the enzyme to form a protective organosilica layer. The armored nanobiocatalysts present enhanced catalytic activity and improved stability against heat, pH, chaotropic agents, proteases, and ultrasound. The method is versatile in that it can be successfully adapted to a number of different enzymes. © 2017 Elsevier Inc. All rights reserved.

Automated generation and optimization of ballistic lunar capture transfer trajectories

NASA Astrophysics Data System (ADS)

Griesemer, Paul Ricord

The successful completion of the Hiten mission in 1991 provided real-world validation of a class of trajectories defined as ballistic lunar capture transfers. This class of transfers is often considered for missions to the Moon and for tours of the moons of other planets. In this study, the dynamics of the three and four body problems are examined to better explain the mechanisms of low energy transfers in the Earth-Moon system, and to determine their optimality. Families of periodic orbits in the restricted Earth-Sun-spacecraft three body problem are shown to be generating families for low energy transfers between orbits of the Earth. The low energy orbit-to-orbit transfers are shown to require less fuel than optimal direct transfers between the same orbits in the Earth-Sun-spacecraft circular restricted three body problem. The low energy transfers are categorized based on their generating family and the number of flybys in the reference three body trajectory. The practical application of these generating families to spacecraft mission design is demonstrated through a robust nonlinear targeting algorithm for finding Sun-Earth-Moon-spacecraft four body transfers based on startup transfers indentified in the Earth-Sun three body problem. The local optimality of the transfers is examined through use of Lawden's primer vector theory, and new conditions of optimality for single-impulse-to-capture lunar transfers are established.

Influence of Scattering on Ballistic Nanotransistor Design

NASA Technical Reports Server (NTRS)

Anantram, M. P.; Svizhenko, Alexei; Biegel, Bryan, A. (Technical Monitor)

2002-01-01

Importance of this work: (1) This is the first work to model electron-phonon scattering within a quantum mechanical approach to nanotransistors. The simulations use the non equilibrium Green's function method. (2) A simple equation which captures the importance of scattering as a function of the spatial location from source to drain is presented. This equation helps interpret the numerical simulations. (3) We show that the resistance per unit length in the source side is much larger than in the drain side. Thus making scattering in the source side of the device much more important than scattering in the drain side. Numerical estimates of ballisticity for 10nm channel length devices in the presence of of electron-phonon scattering are given. Based on these calculations, we propose that to achieve a larger on-current in nanotransistors, it is crucial to keep the highly doped source extension region extremely small, even if this is at the cost of making the highly doped drain extension region longer.

Ballistic Josephson junctions based on CVD graphene

NASA Astrophysics Data System (ADS)

Li, Tianyi; Gallop, John; Hao, Ling; Romans, Edward

2018-04-01

Josephson junctions with graphene as the weak link between superconductors have been intensely studied in recent years, with respect to both fundamental physics and potential applications. However, most of the previous work was based on mechanically exfoliated graphene, which is not compatible with wafer-scale production. To overcome this limitation, we have used graphene grown by chemical vapour deposition (CVD) as the weak link of Josephson junctions. We demonstrate that very short, wide CVD-graphene-based Josephson junctions with Nb electrodes can work without any undesirable hysteresis in their electrical characteristics from 1.5 K down to a base temperature of 320 mK, and their gate-tuneable critical current shows an ideal Fraunhofer-like interference pattern in a perpendicular magnetic field. Furthermore, for our shortest junctions (50 nm in length), we find that the normal state resistance oscillates with the gate voltage, consistent with the junctions being in the ballistic regime, a feature not previously observed in CVD-graphene-based Josephson junctions.

Superelement Analysis of Tile-Reinforced Composite Armor

NASA Technical Reports Server (NTRS)

Davila, Carlos G.

1998-01-01

Super-elements can greatly improve the computational efficiency of analyses of tile-reinforced structures such as the hull of the Composite Armored Vehicle. By taking advantage of the periodicity in this type of construction, super-elements can be used to simplify the task of modeling, to virtually eliminate the time required to assemble the stiffness matrices, and to reduce significantly the analysis solution time. Furthermore, super-elements are fully transferable between analyses and analysts, so that they provide a consistent method to share information and reduce duplication. This paper describes a methodology that was developed to model and analyze large upper hull components of the Composite Armored Vehicle. The analyses are based on two types of superelement models. The first type is based on element-layering, which consists of modeling a laminate by using several layers of shell elements constrained together with compatibility equations. Element layering is used to ensure the proper transverse shear deformation in the laminate rubber layer. The second type of model uses three-dimensional elements. Since no graphical pre-processor currently supports super-elements, a special technique based on master-elements was developed. Master-elements are representations of super-elements that are used in conjunction with a custom translator to write the superelement connectivities as input decks for ABAQUS.

76 FR 14589 - Defense Federal Acquisition Regulation Supplement; Repeal of Restriction on Ballistic Missile...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-17

...-AH18 Defense Federal Acquisition Regulation Supplement; Repeal of Restriction on Ballistic Missile...). Section 222 repeals the restriction on purchase of Ballistic Missile Defense research, development, test... Ballistic Missile Defense research, development, test, and evaluation that was required by section 222 of...

CFD Simulations of the Supersonic Inflatable Aerodynamic Decelerator (SIAD) Ballistic Range Tests

NASA Technical Reports Server (NTRS)

Brock, Joseph; Stern, Eric; Wilder, Michael

2017-01-01

A series of ballistic range tests were performed on a scaled model of the Supersonic Flight Demonstration Test (SFDT) intended to test the Supersonic Inflatable Aerodynamic Decelerator (SIAD) geometry. The purpose of these experiments were to provide aerodynamic coefficients of the vehicle to aid in mission and vehicle design. The experimental data spans the moderate Mach number range, $3.8-2.0$, with a total angle of attack ($alpha_T$) range, $10o-20o$. These conditions are intended to span the Mach-$alpha$ space for the majority of the SFDT experiment. In an effort to validate the predictive capabilities of Computational Fluid Dynamics (CFD) for free-flight aerodynamic behavior, numerical simulations of the ballistic range experiment are performed using the unstructured finite volume Navier-Stokes solver, US3D. Comparisons to raw vehicle attitude, and post-processed aerodynamic coefficients are made between simulated results and experimental data. The resulting comparisons for both raw model attitude and derived aerodynamic coefficients show good agreement with experimental results. Additionally, near body pressure field values for each trajectory simulated are investigated. Extracted surface and wake pressure data gives further insights into dynamic flow coupling leading to a potential mechanism for dynamic instability.

Impact Resistance of Lightweight Hybrid Structures for Gas Turbine Engine Fan Containment Applications

NASA Technical Reports Server (NTRS)

Hebsur, Mohan G.; Noebe, Ronald D.; Revilock, Duane M.

2003-01-01

The ballistic impact resistance of hybrid composite sandwich structures was evaluated with the ultimate goal of developing new materials or structures for potential gas turbine engine fan containment applications. The sandwich structures investigated consisted of GLARE-5 laminates as face sheets with lightweight cellular metallic materials such as honeycomb, foam, and lattice block as a core material. The impact resistance of these hybrid sandwich structures was compared to GLARE-5 laminates and 2024-T3 Al sheet, which were tested as a function of areal weight (material thickness). The GLARE-5 laminates exhibited comparable impact properties to that of 2024-T3 Al at low areal weights, even though there were significant differences in the static tensile properties of these materials. The GLARE-5, however, did have a greater ballistic limit than straight aluminum sheet at higher areal weights. Furthermore, there is up to a 25% advantage in ballistic limit for the GLARE-5/foam sandwich structures compared to straight 2024-T3 Al. But no advantage in ballistic limit was observed between any of the hybrid sandwich structures and thicker versions of GLARE-5. Recommendations for future work are provided, based on these preliminary data.

Estimation of ballistic block landing energy during 2014 Mount Ontake eruption

NASA Astrophysics Data System (ADS)

Tsunematsu, Kae; Ishimine, Yasuhiro; Kaneko, Takayuki; Yoshimoto, Mitsuhiro; Fujii, Toshitsugu; Yamaoka, Koshun

2016-05-01

The 2014 Mount Ontake eruption started just before noon on September 27, 2014. It killed 58 people, and five are still missing (as of January 1, 2016). The casualties were mainly caused by the impact of ballistic blocks around the summit area. It is necessary to know the magnitude of the block velocity and energy to construct a hazard map of ballistic projectiles and design effective shelters and mountain huts. The ejection velocities of the ballistic projectiles were estimated by comparing the observed distribution of the ballistic impact craters on the ground with simulated distributions of landing positions under various sets of conditions. A three-dimensional numerical multiparticle ballistic model adapted to account for topographic effect was used to estimate the ejection angles. From these simulations, we have obtained an ejection angle of γ = 20° from vertical to horizontal and α = 20° from north to east. With these ejection angle conditions, the ejection speed was estimated to be between 145 and 185 m/s for a previously obtained range of drag coefficients of 0.62-1.01. The order of magnitude of the mean landing energy obtained using our numerical simulation was 104 J.

Ballistic Evaluation of 6055 Aluminum

DTIC Science & Technology

2015-09-01

impacts from various munitions including armor-piercing (AP) and fragment-simulating projectiles (FSPs). Additionally, Table 2 provides the required...percentage of the combination of silicon and iron cannot exceed 0.40%. 2. Experimental Procedure The V50 is defined as the impact velocity at which...152 mm (6 inches) behind the target to determine the outcome of each shot. An impact is regarded as a complete penetration (CP), or loss, if the

High-speed Imaging of Global Surface Temperature Distributions on Hypersonic Ballistic-Range Projectiles

NASA Technical Reports Server (NTRS)

Wilder, Michael C.; Reda, Daniel C.

2004-01-01

The NASA-Ames ballistic range provides a unique capability for aerothermodynamic testing of configurations in hypersonic, real-gas, free-flight environments. The facility can closely simulate conditions at any point along practically any trajectory of interest experienced by a spacecraft entering an atmosphere. Sub-scale models of blunt atmospheric entry vehicles are accelerated by a two-stage light-gas gun to speeds as high as 20 times the speed of sound to fly ballistic trajectories through an 24 m long vacuum-rated test section. The test-section pressure (effective altitude), the launch velocity of the model (flight Mach number), and the test-section working gas (planetary atmosphere) are independently variable. The model travels at hypersonic speeds through a quiescent test gas, creating a strong bow-shock wave and real-gas effects that closely match conditions achieved during actual atmospheric entry. The challenge with ballistic range experiments is to obtain quantitative surface measurements from a model traveling at hypersonic speeds. The models are relatively small (less than 3.8 cm in diameter), which limits the spatial resolution possible with surface mounted sensors. Furthermore, since the model is in flight, surface-mounted sensors require some form of on-board telemetry, which must survive the massive acceleration loads experienced during launch (up to 500,000 gravities). Finally, the model and any on-board instrumentation will be destroyed at the terminal wall of the range. For these reasons, optical measurement techniques are the most practical means of acquiring data. High-speed thermal imaging has been employed in the Ames ballistic range to measure global surface temperature distributions and to visualize the onset of transition to turbulent-flow on the forward regions of hypersonic blunt bodies. Both visible wavelength and infrared high-speed cameras are in use. The visible wavelength cameras are intensified CCD imagers capable of integration

Transverse-Weld Tensile Properties of a New Al-4Cu-2Si Alloy as Filler Metal

NASA Astrophysics Data System (ADS)

Sampath, K.

2009-12-01

AA2195, an Al-Cu-Li alloy in the T8P4 age-hardened condition, is a candidate aluminum armor for future combat vehicles, as this material offers higher static strength and ballistic protection than current aluminum armor alloys. However, certification of AA2195 alloy for armor applications requires initial qualification based on the ballistic performance of welded panels in the as-welded condition. Currently, combat vehicle manufacturers primarily use gas metal arc welding (GMAW) process to meet their fabrication needs. Unfortunately, a matching GMAW consumable electrode is currently not commercially available to allow effective joining of AA2195 alloy. This initial effort focused on an innovative, low-cost, low-risk approach to identify an alloy composition suitable for effective joining of AA2195 alloy, and evaluated transverse-weld tensile properties of groove butt joints produced using the identified alloy. Selected commercial off-the-shelf (COTS) aluminum alloy filler wires were twisted to form candidate twisted filler rods. Representative test weldments were produced using AA2195 alloy, candidate twisted filler rods and gas tungsten arc welding (GTAW) process. Selected GTA weldments produced using Al-4wt.%Cu-2wt.%Si alloy as filler metal consistently provided transverse-weld tensile properties in excess of 275 MPa (40 ksi) UTS and 8% El (over 25 mm gage length), thereby showing potential for acceptable ballistic performance of as-welded panels. Further developmental work is required to evaluate in detail GMAW consumable wire electrodes based on the Al-Cu-Si system containing 4.2-5.0 wt.% Cu and 1.6-2.0 wt.% Si.

Probing the Mechanical Strength of an Armored Bubble and Its Implication to Particle-Stabilized Foams

NASA Astrophysics Data System (ADS)

Taccoen, Nicolas; Lequeux, François; Gunes, Deniz Z.; Baroud, Charles N.

2016-01-01

Bubbles are dynamic objects that grow and rise or shrink and disappear, often on the scale of seconds. This conflicts with their uses in foams where they serve to modify the properties of the material in which they are embedded. Coating the bubble surface with solid particles has been demonstrated to strongly enhance the foam stability, although the mechanisms for such stabilization remain mysterious. In this paper, we reduce the problem of foam stability to the study of the behavior of a single spherical bubble coated with a monolayer of solid particles. The behavior of this armored bubble is monitored while the ambient pressure around it is varied, in order to simulate the dissolution stress resulting from the surrounding foam. We find that above a critical stress, localized dislocations appear on the armor and lead to a global loss of the mechanical stability. Once these dislocations appear, the armor is unable to prevent the dissolution of the gas into the surrounding liquid, which translates into a continued reduction of the bubble volume, even for a fixed overpressure. The observed route to the armor failure therefore begins from localized dislocations that lead to large-scale deformations of the shell until the bubble completely dissolves. The critical value of the ambient pressure that leads to the failure depends on the bubble radius, with a scaling of Δ Pcollapse∝R-1 , but does not depend on the particle diameter. These results disagree with the generally used elastic models to describe particle-covered interfaces. Instead, the experimental measurements are accounted for by an original theoretical description that equilibrates the energy gained from the gas dissolution with the capillary energy cost of displacing the individual particles. The model recovers the short-wavelength instability, the scaling of the collapse pressure with bubble radius, and the insensitivity to particle diameter. Finally, we use this new microscopic understanding to predict

Insulin resistance, body composition, and fat distribution in obese children with nonalcoholic fatty liver disease.

PubMed

Yang, Hye Ran; Chang, Eun Jae

2016-01-01

The aim of this study was to evaluate the influence of body composition, especially distribution of body fat, and insulin resistance on nonalcoholic fatty liver disease (NAFLD) in obese children. One hundred obese children (66 boys, 34 girls) with (n=60) and without NAFLD (n=40) were assessed. Anthropometry, laboratory tests, abdominal ultrasonography, and dual energy x-ray absorption metry (DXA) were evaluated in all subjects. Subject age and measurements of liver enzymes, γ- glutamyl transpeptidase (γGT), uric acid, high-density lipoprotein cholesterol, and insulin resistance were significantly different between the non-NAFLD group and NAFLD group. Body fat and trunk fat percentage were significantly different between the two groups (p<0.001 and p=0.003), whereas extremity fat percentage was not (p=0.683). Insulin resistance correlated significantly with body fat and trunk fat percentages, age, liver enzymes, γGT, and uric acid in obese children. Multiple logistic regression analysis indicated that insulin resistance and trunk fat percentage significantly affected the development of NAFLD in obese children. Body fat, especially abdominal fat, influences the development of insulin resistance and subsequent NAFLD in obese children. Therefore, body composition measurement using DXA, in conjunction with biochemical tests, may be beneficial in evaluating obese children with NAFLD.

Does on-water resisted rowing increase or maintain lower-body strength?

PubMed

Lawton, Trent W; Cronin, John B; McGuigan, Michael R

2013-07-01

Over the past 30 years, endurance volumes have increased by >20% among the rowing elite; therefore, informed decisions about the value of weight training over other possible activities in periodized training plans for rowing need to be made. The purpose of this study was to quantify the changes in lower-body strength development after two 14-week phases of intensive resisted on-water rowing, either incorporating weight training or rowing alone. Ten elite women performed 2 resisted rowing ("towing ropes," e.g., 8 × 3 minutes) plus 6 endurance (e.g., 16-28 km at 70-80% maximum heart rate) and 2 rate-regulated races (e.g., 8,000 m at 24 strokes per minute) on-water each week. After a 4-week washout phase, the 14-week phase was repeated with the addition of 2 weight-training sessions (e.g., 3-4 sets × 6-15 reps). Percent (±SD) and standardized differences in effects (effect size [ES] ± 90% confidence limit) for 5-repetition leg pressing and isometric pulling strength were calculated from data ratio scaled for body mass, log transformed and adjusted for pretest scores. Resisted rowing alone did not increase leg pressing (-1.0 ± 5.3%, p = 0.51) or isometric pulling (5.3 ± 13.4%, p = 0.28) strength. In contrast, after weight training, a moderately greater increase in leg pressing strength was observed (ES = 0.72 ± 0.49, p = 0.03), although differences in isometric pulling strength were unclear (ES = 0.56 ± 1.69, p = 0.52). In conclusion, intensive on-water training including resisted rowing maintained but did not increase lower-body strength. Elite rowers or coaches might consider the incorporation of high-intensity nonfatiguing weight training concurrent to endurance exercise if increases in lower-body strength without changes in body mass are desired.

Stability analyses of the mass abrasive projectile high-speed penetrating into a concrete target Part III: Terminal ballistic trajectory analyses

NASA Astrophysics Data System (ADS)

Wu, H.; Chen, X. W.; Fang, Q.; Kong, X. Z.; He, L. L.

2015-08-01

During the high-speed penetration of projectiles into concrete targets (the impact velocity ranges from 1.0 to 1.5 km/s), important factors such as the incident oblique and attacking angles, as well as the asymmetric abrasions of the projectile nose induced by the target-projectile interactions, may lead to obvious deviation of the terminal ballistic trajectory and reduction of the penetration efficiency. Based on the engineering model for the mass loss and nose-blunting of ogive-nosed projectiles established, by using the Differential Area Force Law (DAFL) method and semi-empirical resistance function, a finite differential approach was programmed (PENTRA2D) for predicting the terminal ballistic trajectory of mass abrasive high-speed projectiles penetrating into concrete targets. It accounts for the free-surface effects on the drag force acting on the projectile, which are attributed to the oblique and attacking angles, as well as the asymmetric nose abrasion of the projectile. Its validation on the prediction of curvilinear trajectories of non-normal high-speed penetrators into concrete targets is verified by comparison with available test data. Relevant parametric influential analyses show that the most influential factor for the stability of terminal ballistic trajectories is the attacking angle, followed by the oblique angle, the discrepancy of asymmetric nose abrasion, and the location of mass center of projectile. The terminal ballistic trajectory deviations are aggravated as the above four parameters increase.

Hydroxyapatite-armored poly(ε-caprolactone) microspheres and hydroxyapatite microcapsules fabricated via a Pickering emulsion route.

PubMed

Fujii, Syuji; Okada, Masahiro; Nishimura, Taiki; Maeda, Hayata; Sugimoto, Tatsuya; Hamasaki, Hiroyuki; Furuzono, Tsutomu; Nakamura, Yoshinobu

2012-05-15

Hydroxyapatite (HAp) nanoparticle-armored poly(ε-caprolactone) (PCL) microspheres were fabricated via a "Pickering-type" emulsion solvent evaporation method in the absence of any molecular surfactants. It was clarified that the interaction between carbonyl/carboxylic acid groups of PCL and the HAp nanoparticles at an oil-water interface played a crucial role in the preparation of the stable Pickering-type emulsions and the HAp nanoparticle-armored microspheres. The HAp nanoparticle-armored PCL microspheres were characterized in terms of size, size distribution, morphology, and chemical compositions using scanning electron microscopy, laser diffraction, energy dispersive X-ray microanalysis, and thermogravimetric analysis. The presence of HAp nanoparticles at the surface of the microspheres was confirmed by scanning electron microscopy and energy dispersive X-ray microanalysis. Pyrolysis of the PCL cores led to the formation of the corresponding HAp hollow microcapsules. Copyright © 2012 Elsevier Inc. All rights reserved.

Geometrical optimization of a local ballistic magnetic sensor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kanda, Yuhsuke; Hara, Masahiro; Nomura, Tatsuya

2014-04-07

We have developed a highly sensitive local magnetic sensor by using a ballistic transport property in a two-dimensional conductor. A semiclassical simulation reveals that the sensitivity increases when the geometry of the sensor and the spatial distribution of the local field are optimized. We have also experimentally demonstrated a clear observation of a magnetization process in a permalloy dot whose size is much smaller than the size of an optimized ballistic magnetic sensor fabricated from a GaAs/AlGaAs two-dimensional electron gas.

Heat guiding and focusing using ballistic phonon transport in phononic nanostructures

NASA Astrophysics Data System (ADS)

Anufriev, Roman; Ramiere, Aymeric; Maire, Jeremie; Nomura, Masahiro

2017-05-01

Unlike classical heat diffusion at macroscale, nanoscale heat conduction can occur without energy dissipation because phonons can ballistically travel in straight lines for hundreds of nanometres. Nevertheless, despite recent experimental evidence of such ballistic phonon transport, control over its directionality, and thus its practical use, remains a challenge, as the directions of individual phonons are chaotic. Here, we show a method to control the directionality of ballistic phonon transport using silicon membranes with arrays of holes. First, we demonstrate that the arrays of holes form fluxes of phonons oriented in the same direction. Next, we use these nanostructures as directional sources of ballistic phonons and couple the emitted phonons into nanowires. Finally, we introduce thermal lens nanostructures, in which the emitted phonons converge at the focal point, thus focusing heat into a spot of a few hundred nanometres. These results motivate the concept of ray-like heat manipulations at the nanoscale.

Heat guiding and focusing using ballistic phonon transport in phononic nanostructures.

PubMed

Anufriev, Roman; Ramiere, Aymeric; Maire, Jeremie; Nomura, Masahiro

2017-05-18

Unlike classical heat diffusion at macroscale, nanoscale heat conduction can occur without energy dissipation because phonons can ballistically travel in straight lines for hundreds of nanometres. Nevertheless, despite recent experimental evidence of such ballistic phonon transport, control over its directionality, and thus its practical use, remains a challenge, as the directions of individual phonons are chaotic. Here, we show a method to control the directionality of ballistic phonon transport using silicon membranes with arrays of holes. First, we demonstrate that the arrays of holes form fluxes of phonons oriented in the same direction. Next, we use these nanostructures as directional sources of ballistic phonons and couple the emitted phonons into nanowires. Finally, we introduce thermal lens nanostructures, in which the emitted phonons converge at the focal point, thus focusing heat into a spot of a few hundred nanometres. These results motivate the concept of ray-like heat manipulations at the nanoscale.

Weldability and Impact Energy Properties of High-Hardness Armor Steel

NASA Astrophysics Data System (ADS)

Cabrilo, Aleksandar; Geric, Katarina; Jovanovic, Milos; Vukic, Lazic

2018-03-01

In this study, the weldability of high-hardness armor steel by the gas metal arc welding method has been investigated. The study was aimed at determining the weakness points of manual welding compared to automated welding through microhardness testing, the cooling rate, tensile characteristics and nondestructive analysis. Detailed studies were performed for automated welding on the impact energy and microhardness in the fusion line, as the most sensitive zone of the armor steel weld joint. It was demonstrated that the selection of the preheating and interpass temperature is important in terms of the cooling rate and quantity of diffusible and retained hydrogen in the weld joint. The tensile strength was higher than 800 MPa. The width of the heat-affected zone did not exceed 15.9 mm, measured from the weld centerline, while the impact energy results were 74 and 39 J at 20 and - 40 °C, respectively.

Modeling internal ballistics of gas combustion guns.

PubMed

Schorge, Volker; Grossjohann, Rico; Schönekess, Holger C; Herbst, Jörg; Bockholdt, Britta; Ekkernkamp, Axel; Frank, Matthias

2016-05-01

Potato guns are popular homemade guns which work on the principle of gas combustion. They are usually constructed for recreational rather than criminal purposes. Yet some serious injuries and fatalities due to these guns are reported. As information on the internal ballistics of homemade gas combustion-powered guns is scarce, it is the aim of this work to provide an experimental model of the internal ballistics of these devices and to investigate their basic physical parameters. A gas combustion gun was constructed with a steel tube as the main component. Gas/air mixtures of acetylene, hydrogen, and ethylene were used as propellants for discharging a 46-mm caliber test projectile. Gas pressure in the combustion chamber was captured with a piezoelectric pressure sensor. Projectile velocity was measured with a ballistic speed measurement system. The maximum gas pressure, the maximum rate of pressure rise, the time parameters of the pressure curve, and the velocity and path of the projectile through the barrel as a function of time were determined according to the pressure-time curve. The maximum gas pressure was measured to be between 1.4 bar (ethylene) and 4.5 bar (acetylene). The highest maximum rate of pressure rise was determined for hydrogen at (dp/dt)max = 607 bar/s. The muzzle energy was calculated to be between 67 J (ethylene) and 204 J (acetylene). To conclude, this work provides basic information on the internal ballistics of homemade gas combustion guns. The risk of injury to the operator or bystanders is high, because accidental explosions of the gun due to the high-pressure rise during combustion of the gas/air mixture may occur.

Armor of cermet with metal therein increasing with depth

DOEpatents

Wilkins, M.L.; Holt, A.C.; Cline, C.F.; Foreschner, K.E.

1973-07-01

The system described consists of a ceramic matrix having a gradient of fine ductile metallic particles dispersed therein in an amount of from 0.0%, commencing at the front or impact surface of the armor, to about 2 to 15% by volume along the interface to the back of the system. (auth)

Nuclease-resistant double-stranded DNA controls or standards for hepatitis B virus nucleic acid amplification assays

PubMed Central

2009-01-01

Background Identical blood samples tested using different kits can give markedly different hepatitis B virus (HBV) DNA levels, which can cause difficulty in the interpretation of viral load. A universal double-stranded DNA control or standard that can be used in all commercial HBV DNA nucleic acid amplification assay kits is urgently needed. By aligning all HBV genotypes (A-H), we found that the surface antigen gene and precore-core gene regions of HBV are the most conserved regions among the different HBV genotypes. We constructed a chimeric fragment by overlapping extension polymerase chain reaction and obtained a 1,349-bp HBVC+S fragment. We then packaged the fragment into lambda phages using a traditional lambda phage cloning procedure. Results The obtained armored DNA was resistant to DNase I digestion and was stable, noninfectious to humans, and could be easily extracted using commercial kits. More importantly, the armored DNA may be used with all HBV DNA nucleic acid amplification assay kits. Conclusions The lambda phage packaging system can be used as an excellent expression platform for armored DNA. The obtained armored DNA possessed all characteristics of an excellent positive control or standard. In addition, this armored DNA is likely to be appropriate for all commercial HBV DNA nucleic acid amplification detection kits. Thus, the constructed armored DNA can probably be used as a universal positive control or standard in HBV DNA assays. PMID:20025781

Armored Scales and Their Parasitoids on Commercial Avocados Grown in California or Imported from Mexico.

PubMed

Morse, J G; Rugman-Jones, P F; Woolley, J B; Heraty, J M; Triapitsyn, S V; Hofshi, R; Stouthamer, R

2016-10-01

Levels of armored scales (Hemiptera: Diaspididae) on Mexican Hass avocados imported into California over May 2008-June 2009 were monitored on 135 trucks entering the state via the Blythe border station, the entry point receiving the highest volume of fruit. Levels of live sessile scales were 3.9-fold higher than indicated in a previous survey (September 2007-April 2008) although levels of live eggs and crawlers were similar to previous levels. A survey of avocado fruit in California infested with armored scales detected four species known to be endemic but failed to find any of the seven exotic Diaspididae entering the state on Mexican fruit. Monitoring of Mexican armored scales on imported avocados from September 2007 to December 2010 recovered 10 species of parasitoids predominated by two species of Signiphora Ashmead (Hymenoptera: Signiphoridae). One of these species, Signiphora flavopalliata Ashmead, comprised 36% of all collected Mexican parasitoids and is a known hyperparasitoid. A survey of armored scale parasitoids present on commercial California avocados detected 17 genetic signatures, with only four of these in common with those detected on imported Mexican fruit. The implications of these findings are discussed. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Resistance training predicts 6-yr body composition change in postmenopausal women.

PubMed

Bea, Jennifer W; Cussler, Ellen C; Going, Scott B; Blew, Robert M; Metcalfe, Lauve L; Lohman, Timothy G

2010-07-01

The aim of this study was to examine the association of exercise frequency (ExFreq) and volume (total weight lifted by military press and squats (SQ)) with change in body composition among postmenopausal women participating in a progressive resistance training study. Previously, sedentary women (n = 122, age = 56.3 +/- 4.3 yr) were followed for 6 yr. At 6 yr, there were women who had been randomly assigned to resistance training at baseline (n = 65) controls that were permitted to cross over to the exercise program at 1 yr (n = 32) and 25 true controls. Exercisers and crossovers directed to perform eight core exercises for two sets of eight repetitions at 70%-80% of one-repetition maximum, three times weekly, plus progressive weight bearing, stretching, and balance. Body weight and fat were measured at baseline and annually using anthropometry and dual-energy x-ray absorptiometry. Average change in body weight and total body fat were 0.83 +/- 5.39 and 0.64 +/- 4.95 kg at 6 yr, respectively. In multiple linear regression, ExFreq, military press, and SQ were significantly inversely associated with change in body weight (standardized beta coefficient (SBC) = -0.22 to -0.28, P < 0.01), fat (SBC = -0.25 to -0.33, P < 0.01), and trunk fat (SBC = -0.20 to -0.31, P < 0.03) after adjusting for age, years on hormone therapy, change in lean soft tissue, baseline body composition, and baseline habitual exercise. The lowest tertile of SQ (equivalent to 2.5% attendance) demonstrated significant gain in weight, fat, and trunk fat over 6 yr (P < 0.004), whereas the highest tertile SQ (equivalent to 64% attendance) was able to maintain their weight, total, and regional fat. We conclude that resistance training is a viable long-term method to prevent weight gain and deleterious changes in body composition in postmenopausal women.

Ballistic Evaluation of 2060 Aluminum

DTIC Science & Technology

2016-05-24

thicknesses subjected to impacts from various munitions including armor-piercing (AP) and fragment-simulating projectiles (FSPs). Additionally, Table 2...Experimental Procedure The V50 is defined as the impact velocity at which the projectile is equally as likely to penetrate the target as it is to arrest. A...0.51-mm (0.020-inch) 2024 T3 Al witness plate was positioned 152 mm (6 inches) behind the target to determine the outcome of each shot. An impact is

Conventional Prompt Global Strike and Long-Range Ballistic Missiles: Background and Issues

DTIC Science & Technology

2012-02-13

Ballistic Missiles Congressional Research Service Forward-Based Global Strike ( FBGS ...missiles in the CPGS program. Forward-Based Global Strike ( FBGS ) Analysts have also explored the option of deploying long-range land-based ballistic

Acute Effects of Different Stretching Techniques on the Number of Repetitions in A Single Lower Body Resistance Training Session

PubMed Central

Sá, Marcos A.; Neto, Gabriel R.; Costa, Pablo B.; Gomes, Thiago M.; Bentes, Cláudio M.; Brown, Amanda F.; Novaes, Jefferson S.

2015-01-01

This study aimed to investigate the acute effects of passive static and ballistic stretching on maximal repetition performance during a resistance training session (RTS). Nine male subjects underwent three experimental conditions: ballistic stretching (BS); passive static stretching (PSS); and a specific warm-up (SW). The RTS was composed of three sets of 12RM for the following exercises: leg press 45 (LP), leg extension (LE), leg curl (LC), and plantar flexors (PF). Performance of six sessions was assessed 48 hours apart. The first visit consisted of a familiarization session including stretching methods and exercises used in the RTS. On the second and third visit, a strength test and retest were performed. During the fourth to the sixth visit, the volunteers randomly performed the following protocols: BS+RTS; PSS+RTS; or SW+RTS. For the sum of the RM number of each three-set exercise, significant differences were found between PSS vs. SW for the LP (p = 0.001); LE (p = 0.005); MF (p = 0.001); and PF (p = 0.038). For the comparison between the methods of stretching PSS vs. BS, significant differences were found only for the FP (p = 0.019). When analyzing the method of stretching BS vs. SW, significant differences were found for the LP (p = 0.014) and MF (p = 0.002). For the total sum of the RM number of three sets of the four exercises that composed the RTS, significant differences were observed (p < 0.05) in the following comparisons: PPS vs. SW (p = 0.001), PPS vs. BS (p = 0.008), and BS vs. SW (p = 0.002). Accordingly, the methods of passive static and ballistic stretching should not be recommended before a RTS. PMID:25964821

Ballistic phonon transmission in quasiperiodic acoustic nanocavities

NASA Astrophysics Data System (ADS)

Mo, Yuan; Huang, Wei-Qing; Huang, Gui-Fang; Chen, Yuan; Hu, Wangyu; Wang, Ling-Ling; Pan, Anlian

2011-04-01

Ballistic phonon transport is investigated in acoustic nanocavities modulated in a quasiperiodic manner at low temperatures. Two different types of quasiperiodic acoustic nanocavities are considered: the lengths of nanocavities (QPL) and the lengths of the bridges (QPD) connecting two successive nanocavities are modulated according to the Fibonacci rule. We demonstrate that the transmission spectra and thermal conductance in both systems are similar, which is more prominent in QPD than in QPL. The transmission and thermal conductance of QPD are larger than those of QPL due to the fact that constant nanocavity length in QPD would strengthen ballistic phonon resonant transport, while varying nanocavity length in QPL lead to strong phonon scattering.

Ballistic anisotropic magnetoresistance in core-shell nanowires and rolled-up nanotubes

NASA Astrophysics Data System (ADS)

Chang, Ching-Hao; Ortix, Carmine

2017-01-01

In ferromagnetic nanostructures, the ballistic anisotropic magnetoresistance (BAMR) is a change in the ballistic conductance with the direction of magnetization due to spin-orbit interaction. Very recently, a directional dependent ballistic conductance has been predicted to occur in a number of newly synthesized nonmagnetic semiconducting nanostructures subject to externally applied magnetic fields, without necessitating spin-orbit coupling. In this paper, we review past works on the prediction of this BAMR effect in core-shell nanowires (CSN) and rolled-up nanotubes (RUNTs). This is complemented by new results, we establish for the transport properties of tubular nanosystems subject to external magnetic fields.

P-body proteins regulate transcriptional rewiring to promote DNA replication stress resistance.

PubMed

Loll-Krippleber, Raphael; Brown, Grant W

2017-09-15

mRNA-processing (P-) bodies are cytoplasmic granules that form in eukaryotic cells in response to numerous stresses to serve as sites of degradation and storage of mRNAs. Functional P-bodies are critical for the DNA replication stress response in yeast, yet the repertoire of P-body targets and the mechanisms by which P-bodies promote replication stress resistance are unknown. In this study we identify the complete complement of mRNA targets of P-bodies during replication stress induced by hydroxyurea treatment. The key P-body protein Lsm1 controls the abundance of HHT1, ACF4, ARL3, TMA16, RRS1 and YOX1 mRNAs to prevent their toxic accumulation during replication stress. Accumulation of YOX1 mRNA causes aberrant downregulation of a network of genes critical for DNA replication stress resistance and leads to toxic acetaldehyde accumulation. Our data reveal the scope and the targets of regulation by P-body proteins during the DNA replication stress response.P-bodies form in response to stress and act as sites of mRNA storage and degradation. Here the authors identify the mRNA targets of P-bodies during DNA replication stress, and show that P-body proteins act to prevent toxic accumulation of these target transcripts.

Does small-bodied salmon spawning activity enhance streambed mobility?

NASA Astrophysics Data System (ADS)

Hassan, Marwan A.; Tonina, Daniele; Buxton, Todd H.