This book provides the reader with a unique opportunity to understand the basic and applied research and technology areas that support applications to enable Transformational capabilities for US Soldiers. The research papers are in line with the theme of the 24th Army Science Conference: “Transformational Science and Technology for the Current and Future Force,” emphasizing the critical role of Science and Technology in addressing the significant challenges posed by Global War On Terrorism while simultaneously developing Transformational capabilities for the Future Force.
Sample Chapter(s)
Chapter 1: Kernel-Based Anomaly Detection in Hyperspectral Imagery (907 KB)
https://doi.org/10.1142/9789812772572_fmatter
PREFACE.
KEYWORDS.
CONTENTS.
https://doi.org/10.1142/9789812772572_0001
In this paper we present a nonlinear version of the well-known anomaly detection method referred to as the RX-algorithm. Extending this algorithm to a feature space associated with the original input space via a certain nonlinear mapping function can provide a nonlinear version of the RX-algorithm. This nonlinear RX-algorithm, referred to as the kernel RX-algorithm, is basically intractable mainly due to the high dimensionality of the feature space produced by the non-linear mapping function. However, in this paper it is shown that the kernel RX-algorithm can easily be implemented by kernelizing it in terms of kernels which implicitly compute dot products in the feature space. Improved performance of the kernel RX-algorithm over the conventional RX-algorithm is shown by testing several hyperspectral imagery for military target and mine detection.
https://doi.org/10.1142/9789812772572_0002
Ground penetrating radar is a high-resolution electromagnetic technology that has demonstrated excellent potential for high probability of detection while keeping false alarm rate low for landmine detection in on-road tests. Off-road situations require more advanced methods for dealing with the most significant reflection in GPR data, the ground bounce. Performance enhancements achieved via ground-tracking are demonstrated in terms of receiver operating characteristic curves.
https://doi.org/10.1142/9789812772572_0003
In target tracking, fusing multi-modal sensor data under a power-performance trade-off is becoming increasingly important. Proper fusion of multiple modalities can help in achieving better tracking performance while decreasing the total power consumption. In this paper, we present a framework for tracking a target given joint acoustic and video observations from a co-located acoustic array and a video camera. We demonstrate on field data that tracking of the direction-of-arrival of a target improves significantly when the video information is incorporated at time instants when the acoustic signal-to-noise ratio is low.
https://doi.org/10.1142/9789812772572_0004
New approaches offer the promise of providing energy efficient, low cost, small, and highly sensitive magnetic sensors. However, the 1/f noise of these new types of sensors is a major obstacle. Many army applications, such as detecting moving targets, require sensitivity as low frequencies. This paper reports development of a device, the MEMS flux concentrator, invented at ARL, that minimizes the effect of 1/f noise in sensors. The device accomplishes this by shifting the operating frequency to higher frequencies wheie 1/f noise is much lower. This shift is accomplished by modulating the magnetic field before it reaches the sensor. In our device, the magnetic sensor, a GMR sensor, is placed between flux concentrators that have been deposited on MEMS flaps. The motion of the MEMS flaps modulates the field by a factor of 3 at frequencies from 8 to 15 kHz. The MEMS flux concentrator should increase the sensitivity of many magnetic sensors by two to three orders of magnitude. An equally important benefit is that, because it is a modulation technique, it eliminates the problem of dealing with the large DC bias of most magnetoresistive sensors.
https://doi.org/10.1142/9789812772572_0005
We report on a novel laser-based technique coined surface laser photofragmentation-fragment detection (SPF-FD) spectroscopy for detecting explosives residues, chemical warfare agents, and other hazardous materials on surfaces in real time at ambient conditions. Our technique utilizes one or two lasers to both photolyze the target species and to facilitate the detection of the characteristic photofragments by resonance-enhanced multiphoton ionization, laser induced fluorescence, or both. We demonstrate its analytical utility on explosives RDX, HMX, CL20, and TNT, and report the effects of laser photofragmentation wavelength and energy, delay between photofragmentation and probe lasers, and electrode orientation on signal intensity. Signal to noise analyses yield limits of detection in the range of 1 to 15 ng/cm2: (S/N=3) at 1 atm and 298K.
https://doi.org/10.1142/9789812772572_0006
The purpose of this antenna optimization study is to perform antenna placement optimization for the Blue Force Tracking (BFT), Iridium, and International Maritime Satellite (INMARSAT) antennas on the proposed Mounted Battle Command On The Move (MBCOTM) Stryker system. The MBCOTM Stryker system uses the Stryker Command Vehicle (CV) as its baseline. Engineering analysis of the Stryker CV points out a number of challenges with the antenna integration. First and foremost, the BFT, INMARSAT, and Iridium share the same operational frequency bands. This presents a large potential for co-site interference on the Stryker platform. A second challenge is the degradation of antenna performance when located in close proximity to large metallic obstructions such as the weapon, hatch covers, ammo boxes and other antennas. Without proper antenna placement, these obstructions can have a significant impact on the antenna gain (Fig 1,2).
To optimize these communication systems on the MBCOTM Stryker system, this study will evaluate the current (baseline) antenna placements for both co-site interference and antenna gain. This study will also develop and evaluate an alternate configuration with the objective of increased antenna gain pattern performance and decreased co-site interference. This study uses Computational Electromagnetic Modeling (CEM), specifically the Finite Difference Time Domain (FDTD) method, to model and simulate effects of antenna placement on the Stryker. The traditional design method for antenna placement was based solely on engineering experience and empirical test data. CEM provides many additional measurable statistics to evaluate antenna placements. This study integrates CEM analysis and statistics into the traditional design method to optimize antenna performance.
https://doi.org/10.1142/9789812772572_0007
As the 21st century unfolds, a number of changes have already altered the character and conduct of military operations. Consequently, the military profession is subject to drastic transformations, which ones oriented our attention around questions such as "how is professional military expertise currently built, shared and transmitted in this ever-changing and unstable world?" Drawn on data collected from a recent research on Knowledge Management (KM) practices, namely on Knowledge Creation, Learning and Collaboration, the present work performs a detailed comparison of the states of these practices between the different military environments, with an emphasis on what distinguishes the Army from the others. This paper underlines the components that can be considered either as levers or constraints for the current Canadian Forces KM efforts, such as becoming a knowledge-based army, reaching acute situational awareness or accessing knowledge in the C4ISR context.
https://doi.org/10.1142/9789812772572_0008
Visions for the information needs and operational capabilities of the Future Force are similar to those for First Responders who comprise the backbone of Homeland Security personnel. There is also an increasing role for collaboration between Future Force warriors and First Responders in response to both domestic incidents and internationally through peacekeeping and related operational roles (US Army 2001; US Army 2004). The purpose of this position paper is to summarize the information environment of First Responders from the perspective of the IT/C4ISR community, seeking to highlight areas for collaboration, extension of research, and opportunities for leveraged R&D.
https://doi.org/10.1142/9789812772572_0009
How the Army achieves its transformational goal of rapid deployment depends on its perspective on weight. That is, transformation plans differ if the objective is weight reduction as opposed to weight redistribution. Weight reduction is primarily platform-centric and relies on technological advances in materials and network technology to deliver a single lightweight platform capable of surviving heavy combat. Weight redistribution considers parameters other than platform weight and the ability to distribute information in networks to meet the Army's goals; forces are re-structured into small, modular units, pre-positioned across the globe, and deployed in a time-sequential manner.
https://doi.org/10.1142/9789812772572_0010
Future military systems, such as FCS, require a robust and flexible network that supports thousands of ad hoc nodes. Therefore, networking protocols for MANETs must be made to scale. The use of hierarchy is a powerful general solution to the scaling problem. We have previously proposed methods based on Simulated Annealing (SA) to optimize hierarchy in MANETs. The challenge, however, is to improve the slow convergence time of SA, so it can be used in dynamic environments, without penalizing optimality. In previous work the importance of parameters such as cooling schedule, state transition probabilities and convergence condition are investigated. This paper proposes a new approach to decrease SA convergence time. SA is an optimization technique based on an iterative process that takes an initial solution, or map, to start the process. In this paper we analyze the effect that this initial solution has on the SA convergence time as a function of the network size. We believe that the combined modifications to SA can speed the optimization process to the point that it can quickly generate very efficient clustering solutions in large dynamic networks.
https://doi.org/10.1142/9789812772572_0011
The Objective Force concept of the future US Army is to fight wars with adversaries, which are fast evolving and have adaptive capabilities. To have advantage over these adversaries, new weapon system designs and development should be modular to operate as "system-of-systems" and should have short development cycles. This requires validated high performance computational models within this modular framework and the need to effectively utilize the High Performance Computing (HPC) resources of many Army initiatives. In this paper we present a new and advanced HPC based rigid and flexible modeling and simulation technology capable of adaptive high/low fidelity modeling that is useful in the initial design concept stage to intermediate stages and to the final design stage in a single seamless simulation environment. Two examples are considered that illustrate the capabilities and scalability of the proposed approach.
https://doi.org/10.1142/9789812772572_0012
Large-scale molecular dynamics simulation involving several hundred million atoms has been performed on parallel computers to study hypervelocity impact damage of high-strength aluminum nitride ceramic, which is of great importance for the design of penetration-resistant and light-weight armors at the Army. Results reveal an atomistic mechanism of damage initiation, i.e., the phase transformation wave front acts as a source of dislocations and micro-cracks upon the arrival of an elastic rarefaction wave. Simulation has also been performed to study atomistic mechanisms of oxidation of an Al nanoparticle, which has applications in high-energy density materials. A multi-resolution and probabilistic visualization algorithm has been developed to interactively analyze massive datasets from these simulations.
https://doi.org/10.1142/9789812772572_0013
Incineration is one of the technologies being used by the US Army to destroy the highly toxic chemical agents and munitions contained within the Chemical Weapons Stockpile. In this paper we describe a suite of models for conducting detailed simulations of chemical demilitarization incinerator operation. The models contain 3D furnace and canister geometries and all of the relevant physics and chemistry. The destruction of chemical agent is predicted using non-equilibrium chemistry models. Models have been developed for a Liquid Incinerator, Metal Parts Furnace, and a Deactivation Furnace System. Using computational chemistry methods, chemical kinetics have been developed that describe the incineration of organo-phosphorus nerve agent (GB, VX) and sulfur mustard (H, HD, HT). The models have been used to study a variety of scenarios to develop a deeper understanding of furnace operation and agent destruction when processing munitions or equipment containing or contaminated by chemical agent. Model results demonstrate the incinerators to be robust systems that destroy chemical agent in a safe and efficient manner.
https://doi.org/10.1142/9789812772572_0014
A recent study showed that the complex 3-D shock/boundary layer interaction of a pin placed next to a fin produces an asymmetric lift force that can be utilized for flight control of a projectile. The current study was completed to validate this new technology. A similar projectile was modeled, using high performance fluid dynamic computations and six degree-of-freedom trajectory simulations, to determine the projectile's flight characteristics prior to being flown in the US Army Research Laboratory's Aerodynamic Experimental Facility. A flight test was designed using this asymmetric lift to produce roll torque. Analysis of the flight data determined that the projectiles with pins developed the expected rolling moments. Computations were completed after the range test on the experimental model for computational validation.
https://doi.org/10.1142/9789812772572_0015
This article addresses some issues and solutions for ballistic impact computations. A discussion of the strengths and weaknesses of existing computational techniques is presented, and this is followed by a description of a new computational technique that is well-suited for ballistic impact computations. This new approach uses both finite elements and meshless particles. The initial grid is composed entirely of finite elements. Then as the solution progresses, the highly strained finite elements are automatically converted into meshless particles. Generally, most of the grid remains as finite elements, and this allows for an accurate and efficient solution for the less distorted portion of the problem. Only the highly distorted regions of the problem are converted into meshless particles, and these meshless particles can accurately and robustly represent the high distortions that the finite elements are not able to represent. Several examples are provided to illustrate this approach. Included is the capability to compute the formation of Behind Armor Debris (BAD) and to track it through large distances.
https://doi.org/10.1142/9789812772572_0016
In this paper, the results of a series of experiments funded by DARPA to determine the feasibility of using small actuators to provide directional control for a supersonic projectile are presented. Controlling the flight of the projectile was accomplished by taking advantage of complex shock-boundary layer interactions produced by mechanical devices. One set of wind tunnel tests performed at the Georgia Tech Research Institute characterized the force levels produced by the small actuators on a scale model, while another set of experiments determined the optimum geometry and location of the actuators. The end result of the experiments was to demonstrate that the use of pin based actuators for guidance is a feasible method to control the flight of supersonic munitions.
https://doi.org/10.1142/9789812772572_0017
A new type of experiment has been developed to subject rods to dynamic transverse impact similar to that encountered in attack of modern armors. Two tungsten alloys with five different surface finishes were examined. It was found that there were two failure modes: one involved transverse fracture that initiates from surface flaws. The other was a consequence of gouge instability on the sliding surface. Polishing suppressed the first mode and enhanced the second.
https://doi.org/10.1142/9789812772572_0018
A variety of molecular dynamics simulations of energetic materials is presented, demonstrating the ability to predict structural and thermodynamic properties of these materials. The studies are also used to explore, at an atomic level, dynamic processes that might influence conversion of the material to products. These studies are are presented to illustrate how information generated through molecular dynamics simulations can be used in the design, development and testing of energetic materials.
https://doi.org/10.1142/9789812772572_0019
The Army is developing hypergolic, liquid and gelled bipropellants for a small, selectable-thrust, liquid rocket engine (LRE) that can power tactical missiles for both current and future combat systems. The use of gel propellants brings the advantages of selectable thrust and the promise of small engine size but also introduces new challenges in combustion control. One of these challenges is the efficient mixing of gelled oxidizer and fuel to obtain maximum performance from the LRE combustor without increasing the size of the engine. The Army's impinging stream vortex engine, ISVE, offers an efficient alternative to increasing the combustion chamber volume of a LRE and has already generated excellent performance test data. Since the ISVE is a new concept, analytical models that relate engine performance to engine design parameters are just beginning to emerge. In order to fully exploit the performance that have been realized for the ISVE, it is desirable to understand the underlying flow physics of the engine. This paper describes the Army's effort to use multidimensional, multiphase computational fluid dynamics, combined with high-performance computers to generate simulations of the ISVE that reveal combustion patterns as well as predict chamber pressure and thrust levels for the engine. The goal is to utilize this computational tool to optimize the ISVE performance for a host of strategic Army missions.
https://doi.org/10.1142/9789812772572_0020
We are developing a robust, compact, and affordable photonic proximity sensor for munition fuze applications. Successful implementation of this sensor will provide a new capability for direct fire applications. The photonic component development exploits pioneering work and unique expertise at ARDEC, ARL, and Sandia National Laboratories by combining key optoelectronic technologies to design and demonstrate components for this fuzing application [Ruff, et al. 1994; Stann, et al. 1996; Simonis, et al. 2000; Liu, et al. 2000]. The technologies employed in the optical fuze design are vertical cavity surface-emitting lasers (VCSELs), the p-i-n or metal-semiconductor-metal (MSM) photodetectors, and miniature lenses optics. This work will culminate in a robust, fully integrated, g-hardened component design suitable for proximity fuzing applications. This compact sensor will replace costly assemblies that are based on discrete lasers, photodetectors, and bulk optics. It will be mass manufacturable and impart huge savings for such applications. The specific application under investigation is for gun-fired munitions. Nevertheless, numerous civilian uses exist for this proximity sensor in automotive, robotics and aerospace applications. This technology is also applicable to robotic ladar and short-range 3-D imaging.
https://doi.org/10.1142/9789812772572_0021
In this paper, we address the problem of finding concertina wire in three-dimensional (3-D) data. Wire entanglements constitute a major obstacle to the mobility of Unmanned Ground Vehicle because of their widespread use and the difficulty to detect them. We pose the problem in term of finding thin structures organized in complex patterns. Such problem did not received as much attention as linear and planar structures segmentation. We are interested especially in the problems posed by repetitive and symmetric structures acquired with a laser range finder. The method relies on 3-D data projections along specific directions and 2-D histograms comparison. The sensitivity of the classification algorithm to the parameter settings is evaluated and a segmentation method proposed.
https://doi.org/10.1142/9789812772572_0022
In order for a team of autonomous robots to perform a complex mission effectively, an efficient assignment of tasks to robots must be determined. Existing multirobot task allocation algorithms treat tasks as simple, indivisible entities. However, when dealing with complex tasks, the structure and semantics of the tasks can be exploited to produce more efficient team plans by giving individual robots the ability to come up with new ways to perform a task, or by allowing multiple robots to cooperate by sharing the subcomponents of a task, or both. In this paper we detail a method for efficiently allocating a set of complex tasks to a robot team. The advantages of explicitly modeling complex tasks during the allocation process is demonstrated by a comparison of our approach with existing task allocation allocation algorithms in an area reconnaissance scenario. An implementation on a team of outdoor robots further validates our approach.
https://doi.org/10.1142/9789812772572_0023
Detecting water hazards is a significant challenge to unmanned ground vehicle autonomous off-road navigation. This paper focuses on detecting the presence of water during the daytime using color cameras. A multi-cue approach is taken. Evidence of the presence of water is generated from color, texture, and the detection of reflections in stereo range data. A rule base for fusing water cues was developed by evaluating detection results from an extensive archive of data collection imagery containing water. This software has been implemented into a run-time passive perception subsystem and tested thus far under Linux on a Pentium based processor.
https://doi.org/10.1142/9789812772572_0024
The current state-of-the-art in active-twist rotor control is discussed using representative examples from analytical and experimental studies, and the application to rotary-wing UAVs is considered. Topics include vibration and noise reduction, rotor performance improvement, active blade tracking, stability augmentation, and rotor blade de-icing. A review of the current status of piezoelectric fiber composite actuator technology, the class of piezoelectric actuators implemented in active-twist rotor systems, is included.
https://doi.org/10.1142/9789812772572_0025
Military and security operations often require that participants move as quickly as possible, while avoiding harm. Humans judge how fast they can drive, how sharply they can turn and how hard they can brake, based on a subjective assessment of vehicle handling, which results from responsiveness to driving commands, ride quality, and prior experience in similar conditions. Vehicle handling is a product of the vehicle dynamics and the vehicle-terrain interaction. Near real-time methods are needed for unmanned ground vehicles to assess their handling limits on the current terrain in order to plan and execute extreme maneuvers. This paper describes preliminary research to develop on-the-fly procedures to capture vehicle-terrain interaction data and simple models of vehicle response to driving commands, given the vehicle-terrain interaction data.
https://doi.org/10.1142/9789812772572_0026
The U.S. Department of Defense is constantly pursuing new technologies to improve the capabilities of protective structures in defeating current and emerging threats thus providing a safer environment in which its soldiers must work and fight. Exploiting innovative uses of cement-based materials, the U. S. Army Engineer Research and Development Center (ERDC) is developing several high-performance concretes to mitigate the effects of blast and ballistic threats from conventional and asymmetric weapons. This paper presents the theory, development, and preliminary laboratory and field experimental results of two distinctly different classes of high-performance concretes.
The first material presented in this paper is a very-high-strength concrete engineered for low-cost structural armoring applications. Innovative application of particle selection and distribution, advanced fiber selection in multiple magnitudes of scale, and modified curing techniques are being developed to increase the strength and toughness of this high-performance composite beyond current state-of-the-art performance.
At the other end of the performance envelope, this paper discusses the development of a material with an innovative combination of mechanical properties that are engineered for mitigation of debris hazards generated by high intensity blast loadings. This material shows great promise for construction applications for barricades and non-load-bearing walls where improvised explosive devices could be employed to inflict human casualties.
https://doi.org/10.1142/9789812772572_0027
Computational methods are currently available to perform vulnerability assessments of conventional structures and fixed facilities that are exposed to the effects of large-yield blast events. However, the same capabilities do not exist for expeditionary structures and field fortifications, which are integral parts of current US military base camps. Therefore, the United States Army Corps of Engineers (USACE), Engineer Research and Development Center (ERDC), has begun a research and development initiative directed towards developing this type of vulnerability assessment capability for field fortifications. As a part of the experimental program, attention will also be focused on identification of field expedient methods to modify these structures for the purpose of further protection from blast effects.
Initial efforts, begun in FY 2004, are focused on methodology development and gathering of a representative experimental data set that would be required to support computational assessments. The experimental processes used to gather data are tri-fold, and include high-performance computing simulations, scaled modeling and full scale validations. The results of initial activities in each of these areas are presented herein.
https://doi.org/10.1142/9789812772572_0028
ARL is pursuing the goal of developing a finite-element-based design methodology for thoracic body armor. We describe progress in modeling two essential ingredients, a Kevlar vest and the human thorax.
https://doi.org/10.1142/9789812772572_0029
Polymeric materials exhibit a wide range in all aspects of mechanical behavior including elastic stiffness, yield stress, crazing versus yielding, post-yield deformation, and failure mechanisms. Recent developments to further manipulate the microstructure of polymers by the incorporation of nanoscale particles further expand the ability to tailor mechanical behavior. Exploitation of the differences in mechanical response of different polymers provides the potential to design multiscale heterogeneous material assemblies that provide dramatic enhancements in energy absorption of projectile impacts while maintaining the light weight of the homopolymer. This paper presents recent research conducted at the MIT Institute for Soldier Nanotechnologies on a study of the high rate deformation and projectile impact behavior of two amorphous polymers which exhibit significantly contrasting deformation and failure behavior: polycarbonate (PC) and polymethylmethacrylate (PMMA). Projectile impact tests were conducted on 6.35 mm thickness plates using a single stage gas-gun. Small (1.4 gm) round-nosed projectiles (5.46 mm diameter) made of 4340 AISI steel were projected into the polymeric plates at velocities ranging from 300 to 550 m/s. High-speed photography was used to visualize the sequence of dynamic deformation and failure events. Numerical simulations of the projectile impact events were conducted using a new constitutive model which captures the high rate behavior of polymers together with finite element analysis. These simulations provide information on the stress and deformation fields in the polymer during projectile impact loading conditions. A new hierarchical material assembly was then designed to alter the stress and deformation fields during impact loading conditions and thus enable greater energy absorption; the new design capitalizes on the contrast in mechanical response between PC and PMMA, in particular on the differences in their inelastic deformation and failure mechanisms, and also takes into account the length-scales of the stress and deformation disturbances resulting from the projectile impact. The new material assembly designs were fabricated, tested, and found to provide strong improvements in the energy absorption of the projectile impact with no weight penalty.
https://doi.org/10.1142/9789812772572_0030
The study described here examines the kinetics of GB vapor exposure dosage as it relates to systemic concentrations of agent (internal dose) and the pharmacodynamics/time course of effects (from first evidence of agent in the systemic circulation, to onset of signs, to progression from mild to moderate to severe signs, to death) and compartmental distribution. The current study utilizes technological advances that allow the collection of electrocardiogram (ECG), electroencephalogram (EEG), electromyogram (EMG), pupil constriction and blood chemistry data in real-time during a whole body inhalation exposure to vapor GB.
https://doi.org/10.1142/9789812772572_0031
We present a methodology for the efficient calculation of the shock Hugoniot using standard molecular simulation techniques. The method is an extension of an equation of state methodology proposed by Erpenbeck [J. J. Erpenbeck, Phys. Rev. A 46, 6406 (1992)] and is considered as an alternative to other methods that generate Hugoniot properties. We illustrate the methodology for shocked liquid N2 using two different simulation methods: (a) the Reaction Ensemble Monte Carlo method for a reactive system; and (b) the molecular dynamics method for a non-reactive system. The method is shown to be accurate, stable and generally independent of the algorithm parameters. We find excellent agreement with results calculated by other previous simulation studies. The results show that the methodology provides a simulation tool capable of determining points on the shock Hugoniot from a single simulation in an efficient, straightforward manner.
https://doi.org/10.1142/9789812772572_0032
This research combined continuum mechanics modeling, materials design, materials fabrication/processing, and experimental testing/characterization to promote a materials solution for passive damping of undesirable extrinsic vibrations in microelectromechanical-systems-based devices. Shape memory alloy, nickel titanium (NiTi) thin films were deposited by an in-situ reactive DC magnetron sputtering process and piezoelectric, barium strontium titanate (Ba0.80Sr0.20TiO3) were fabricated using pulsed laser deposition and metal organic solution deposition techniques. These films were integrated as a bi-layer structure on n+ platinum silicon substrates to form a vibration-damping pedestal module known as "active materials". The optimized post deposition annealing temperatures for the shape memory alloy and piezoelectric thin films were determined to be 500 and 750°C, respectively. Crystalline, pinhole-free, and crack-free films of 250-400 nm thickness were fabricated. The surface roughness of the films was around 2.2 nm with average grain size of approximately 50 nm. Cross-sectional microscopy affirmed the dense and uniform microstructure. The bilayer pedestal design concept offers a solution for passive damping.
https://doi.org/10.1142/9789812772572_0033
A new family of quinary, hafnium-based, bulk-metallic-glass-forming alloys has been developed for use in composite kinetic-energy penetrators. The alloys are based on an invariant point identified in the hafnium-copper-nickel ternary system. They are denser than zirconium-based glass-forming compositions, and exhibit a higher reduced glass-transition temperature than alloys prepared by 1:1 hafnium substitution into the zirconium-based alloys. The combination of density and glass-forming ability exhibited by this alloy moves the composite technology closer to being a viable substitute for depleted-uranium penetrators.
https://doi.org/10.1142/9789812772572_0034
The stab resistance of shear thickening fluid (STF)-Kevlar and STF-Nylon fabric composites are investigated and found to exhibit significant improvements over neat fabric targets of equivalent areal density. Specifically, dramatic improvements in puncture resistance (spike threat) are observed under high and low speed loading conditions, while slight increases in cut protection are also observed. These results, combined with improvements in ballistic properties reported in earlier studies (Lee et al., 2002, Lee et al. 2003), indicate that these novel materials could be used to fabricate flexible body armors which provide improved protection against both stab and ballistic threats.
https://doi.org/10.1142/9789812772572_0035
Tunable ferroelectric ceramic capacitors have shown great promise in reducing the size, weight, and power (SWAP) of traditional varactor-based devices. Ferroelectric devices fabricated from Barium Strontium Titanate (BST) have been demonstrated in the laboratory and are just now becoming available for commercial narrowband applications. This paper presents some of the tradeoffs in designing a small form factor (SFF), easily manufacturable, broadband tunable filter utilizing high volume, low-cost BST devices. Development status for filters that cover the 225 MHz to 2.7 GHz frequency range with superior narrowband performance, low in-band insertion loss, and high out-of-band rejection that is directly applicable to the stringent requirements of Joint Tactical Radio System (JTRS) Cluster 5 Software Defined Radio (SDR) is also presented. These Manufacturing Readiness Level (MRL) 4 filters currently provide a 50% reduction in size over traditional approaches, and future short-term plans promise further reductions in unit production cost (UPC) and SWAP.
https://doi.org/10.1142/9789812772572_0036
Today's coolant system consists mainly of technologies that have remained virtually unchanged for almost a century, yet modern day engines have advanced significantly in almost all other areas. A large amount of the engines horsepower goes into this antiquated and inefficient thermal system. Recent testing has shown that by properly controlling pumps, valves and fans, significant efficiency and emission improvements can be realized. Along with these benefits are improvements in packaging, life, and even operator comfort. These technologies can help the military decrease inventories, improve serviceability and decrease operating cost while increasing cooling capability. EMP has developed a family of products in order to help expedite this paradigm shift in thermal management. EMP, in partnership with the NAC, has successfully demonstrated these technologies on several military and commercial vehicles. This paper will summarize the products, systems and results to-date.
https://doi.org/10.1142/9789812772572_0037
One of the key challenges facing diesel engine system modelers lies in adequately predicting the fuel burning rate profile given the direct relationship between energy release and key performance parameters such as fuel economy, torque, and exhaust emissions. Current state-of-the-art combustion sub-models employed in such system simulation codes rely heavily on empiricism and successful application of such sub-models for new engine designs is highly dependent on past experience with similar combustion systems. One common approach to address this issue is to expend great effort choosing associated empirical coefficients over a range of similar combustion system designs thus improving the potential predictive capability of a given empirical model. But, continual combustion system development and design changes limit the extrapolation and application of such generic combustion system dependent coefficients to new designs due to various reasons including advancements in fuel injection systems, engine control strategy encompassing multiple injections, and combustion chamber geometry.
In order to address these very difficult challenges, an extensive effort has been applied toward developing a physically based, simplified combustion model for military-relevant diesel engines known as the Large Scale Combustion Model (LSCM). Recent effort has been spent further refining the first stage of the LSCM two stage combustion model that is known as the premixed phase sub-model. This particular sub-model has been compared with high-speed cylinder pressure data acquired from two relevant direct injection diesel engines with much success based on a user defined parameter referred to as the laminar flame speed by the combustion community. It is a physically significant parameter that is highly dependent on local temperature, pressure, and oxygen concentration but little experimental effort has been spent determining its behavior for diesel fuel due to ignition constraints. This submission will discuss one approach of indirectly determining this key combustion parameter.
https://doi.org/10.1142/9789812772572_0038
U.S. Army systems increasingly require novel methods of high density, fast charging power sources. In this study, a novel alternative to traditional batteries, catalytic microcombustors utilizing hydrocarbon fuels, are fabricated and characterized. These devices are found to be robust, easy to start up, operable over a wide range of compositions and temperatures, and able to support complete combustion over a range of fuels and fuel/air ratios. Various materials of construction are investigated in order to yield good temperature uniformity. Successful integration with thermoelectric devices is achieved, resulting in electrical power generation from catalytic microcombustion with a thermal efficiency of ~1%.
https://doi.org/10.1142/9789812772572_0039
This paper describes an innovative solution for a low cost, compact, lightweight (i.e. <500g), see-through, deployable head-mounted projection display (HMPD) system for embedded training simulation of out-the-window (OTW) scenes for Future Combat System ground vehicles. A unique capability is that virtual images are visible only when the user is looking at strategically located screens that simulate windows in the real environment. The display is inherently see-through with the physical surroundings visible through the display optics. This provides users with unencumbered access to the vehicle's controls while viewing the simulated OTW scene. In this paper we shall detail the underlying principle of the display, its optical design and assessment, and show an early integration of the optics in a HMPD prototype for demonstration.
https://doi.org/10.1142/9789812772572_0040
Embedded virtual simulation has the potential to provide more realistic and effective training for dismounted Soldiers, particularly in operations in urban areas, and in the operation and tactics, techniques and procedures for using Future Force systems. This paper describes an assessment of wearable virtual simulators (WSs) for Infantry Soldiers. The assessment focused on the capabilities and limitations of the WSs as they were used by Soldiers in a realistic training situation: the capability to support the performance of Soldier tasks, side effects, and human interface issues. Three vendors developed different WSs. Each was based on the Quantum 3D Thermite wearable computer, but the vendors used different software and interface hardware. Each permitted a Soldier to view a simulated virtual environment and to interact with other simulated and real entities within it. The SVS, an immersive but non-wearable 3D virtual simulator was used for comparison purposes and to provide enough simulators to fill out a full Infantry squad. OneSAF TestBed was used to provide a simulated enemy force and civilians. Six WS, four SVSs, the Dismounted Infantry Virtual After Action Review System (DIVAARS), and OneSAF were networked to provide a collective training situation in a shared environment. Squads of Soldiers each participated in a series of simulated tactical exercises using the simulators. They then completed questionnaires to report simulator sickness symptoms and to rate the ease with which they could perform 54 Soldier tasks in the simulator. The WSs were able to connect with each other and the SVSs. The major drawbacks to the use of WSs for training appear to be the current lack of graphic processing power of the Thermite computer. Reliability was also a problem. The activities that Soldiers reported they could perform well did not differ substantially from those reported previously with the SVS. The more highly rated tasks consisted of identification of types of people and tactically significant areas, imprecise movement, and communication. The lower rated tasks consisted of precise or rapid movement, distance estimation, and locating the source of enemy fire using either visual or auditory cues. Most of the problems identified should be correctible in the near term.
https://doi.org/10.1142/9789812772572_0041
The purpose of this presentation is to describe the highlights of a research program designed to investigate the feasibility of creating a motion base driving simulator in a Cave Automatic Virtual Environment (CAVE). The goal of the project was to create the most effective simulator possible using a compact, portable motion system. In addition to reviews of state-of-the-art simulation technology, two human factors studies were conducted to determine the impacts of design trade-offs on off-road driving performance in the simulator. In the first study, field of view (FOV), display system, and motion cueing algorithm were evaluated. In the second study, the optimum configuration from the first study was compared to off-road driving performance in TACOM's Ride Motion Simulator (RMS). In addition to performance evaluation, several simulator sickness mitigation techniques were also tested. The important findings from each of these evaluations will be discussed.
https://doi.org/10.1142/9789812772572_0042
Pre-recorded video segments can be very compelling for a variety of immersive training purposes, including providing answers to questions in after-action reviews. Answering questions fluently using pre-recorded video poses challenges, however. When humans interact, answers are constructed after questions are posed. When answers are pre-recorded, even if a correct answer exists in a library of video segments, the answer may be phrased in a way that is not coherent with the question. This paper reports on basic research experiments with short "linking dialogues" that mediate between the question and answer to reduce (or eliminate) the incoherence, resulting in more natural human-system interaction. A set of experiments were performed in which links were elicited to bridge between questions from users of an existing training application and selected answers from the system, and then comparisons made with unlinked answers. The results show that a linking dialogue can significantly increase the perceived relevance of the system's answers.
https://doi.org/10.1142/9789812772572_0043
Mixed Reality (MR), and its predecessor Virtual Reality (VR), has been primarily viewed as a visual science, with much less attention given to the other senses, despite clear evidence of their importance, especially audio. In fact, in military operation in urban environments, audio is often a more primary sense than vision, providing a soldier with an early warning system that needs to be honed and trained. Our research program, in contrast, treats the auditory sense as an equal to the visual. The consequences are MR experiences that have much greater impact than those in which audio is just an after thought. However, given the depth and breadth of graphics research, we are compelled to learn from this mature area. Thus, we are constantly striving to find results from graphics research that have useful analogies in the audio domain. Lessons learned from these analogies, especially as concern people's perception and expectations, are the focus of this paper.
https://doi.org/10.1142/9789812772572_0044
Motion Picture sets are traditionally built using decorated modular wall components called "flats". The FlatWorld project (Pair et al., 2003) at the University of Southern California Institute for Creative Technologies merges this practice with immersive technology by creating a system of displays coupled with physical props which can be scaled to simulate entire buildings and Streets. A single room prototype FlatWorld system was developed in 2001. The software developed for this prototype was not scalable beyond the simulation of a single room environment. In 2003, the FlatWorld Simulation Control Architecture (FSCA) was developed to support multiple digital flats in arbitrary configurations. The FSCA facilitates digital flat training scenarios which can be scaled from the simulation of a single room up to a complete city block. The architecture's flexibility allows it to easily interface with a variety of 3D graphics engines and display devices.
https://doi.org/10.1142/9789812772572_0045
Historically, Army acquisition has had difficulty conducting an adequate early assessment of the human dimension in system performance. Proactive research on human performance, however, is vital to achieving the unprecedented alliance of humans and machines anticipated with Future Combat Systems (FCS). This paper summarizes research methods and findings across four exploratory experiments focused on the command group of a small combined arms unit composed primarily of unmanned air and ground vehicles. Results are based on highly detailed objective measures of verbal and human-computer interaction and an array of subjective measures from expert and novice participants. Findings underscore potential problems in training and workload with FCS, and potential solutions through user-based involvement and proactive research to ensure technology complements human performance.
https://doi.org/10.1142/9789812772572_0046
The purpose of this research was to investigate dynamic cortical processes of soldiers during simulated shooting scenarios as a function of task demand. Task demand was varied among three two-level factors: task load (single, dual), decision load (no-decision, decision), and target exposure time (short, long). Dependent variables were measured at subjective, behavioral, and physiological levels. Subjective measures were self-reports of workload and stress, behavioral measures were primary and secondary task performance, and physiological measures were event-related spectral perturbation (ERSP, where event-related refers to target onset times) in theta (4-7 Hz) and alpha (11-13 Hz) frequency bands. Results from analyses of the subjective report data revealed that time stress and decision load main effects significantly influenced workload perceptions. Analyses of the shooting performance data revealed that the time stress main effect was significant for decision accuracy, shooting accuracy, and response time, and analyses of secondary task performance data revealed a time stress main effect for arithmetic accuracy. The interaction between time stress and decision load was also significant for shooting accuracy and arithmetic accuracy. Results from analyses of the ERSP data revealed that peak theta power differed as a function of time stress and peak alpha power differed as a function of task load and decision load. Overall, the results suggest that time stress had the most profound and widespread effects on workload perceptions and performance. Cortical responses exhibited different oscillatory patterns of communication at different frequencies and topographic regions in response to the different task demand factors.
https://doi.org/10.1142/9789812772572_0047
Research regarding the effects of encapsulation on soldier performance is critical for achieving effective mission performance as well as the survivability capabilities of dismounted soldiers of the Future Force. Soldier encapsulation is defined as enclosing the soldier's body in such a manner that all skin is protected from exposure to the elements of the battlefield. The objective of this research is to identify the effects of encapsulation on mission performance and to develop methods for further research on encapsulation effects of Future Force soldier systems. This research investigated the effects of three equipment configurations (baseline and two encapsulation configurations) on soldier performance during three mission related scenarios. Encapsulation effects on soldier's cognitive functioning and stress perceptions are discussed here. The characterization of cognitive performance and psychological state during military operations affords better understanding of human performance capabilities and opportunities to find predictors of future performance effectiveness.
https://doi.org/10.1142/9789812772572_0048
This study was designed to evaluate the effectiveness of caffeine gum in maintaining performance on a variety of military tasks during a 55 hr field training exercise with restricted sleep. A secondary goal was to correlate performance on a hand held computerized Psychomotor Vigilance Test (PVT) with actual performance of a field task. Thirty Canadian soldiers volunteered to participate in this study and were divided into 4 sections. After receiving 3 hours of sleep during the first night, they were awake for 30 hours. Two of the four sections received caffeine gum (CAF) and the other two groups a placebo gum (PLA). On the evening of Day 2 and morning of Day 3 subjects in CAF received 100 mg @ 2145 (Day 2), 200 mg @ 2345 (Day 2), 100 mg @ 0145 (Day 3), and 200 mg @ 0345 (Day 3). The placebo group always received the placebo gum. There were two test blocks from 2200-0200 (early night) and from 0200-0600 (late night). In each of the two test blocks subjects completed a live fire marksmanship/vigilance task and an Urban Operations Vigilance Task (UOVT). The PVT was administered prior to and after marksmanship and the UOVT. Performance on all of the field tasks significantly declined during the second night of the exercise with placebo. In contrast, subjects who received the caffeine gum maintained their performance on the marksmanship task and in the FIBUA task. These results demonstrate the potential utility of caffeine as a fatigue countermeasure in the operational environment.
https://doi.org/10.1142/9789812772572_0049
The purpose of the study was to investigate the effects of load weight and load configurations upon postural sway of Soldiers. Measuring postural sway may complement analyses of walking with loads, allowing for quick and efficient determination of how load carriage gear will impact the Soldier. Fourteen Army enlisted men participated in the study. Postural sway was measured while participants stood on a force platform. Soldiers were tested under four load weight configurations comprised of Army clothing and equipment: unloaded (6 kg), fighting load (16 kg), and march load (40 kg) with rucksack weight located close to the body and high in the pack, and a second march load (40 kg) with rucksack weight located far from the body and low in the pack. With an increase in weight, center of pressure excursions increased and Soldiers had to exert more control of the load to maintain balance. As the pack load weight position moved from high and close to low and away from the body, center of pressure excursions continued to increase and the rucksack became quite difficult for a load carrier to control precisely. This study demonstrated that an increase in load weight and a change in rucksack weight position changes both the individual's postural sway and the structure of the sway.
https://doi.org/10.1142/9789812772572_0050
A novel research approach was investigated to improve sample preparation for complex food matrices, generating high surface area nanofibrous membranes with covalently attached molecular recognition elements (MREs, e.g. antibodies, peptides/DNA) for the selective binding/capture of target biological agents using the electrospinning fabrication technique. Two types of electrospun capture membranes were fabricated containing either carboxyl (COOH) or amine (NH2) functional groups for covalent attachment of antibodies. The carboxylated electrospun polymer used in this study was polyvinyl chloride formulated to be 1.8% carboxylated. The amine functional membrane was made by co-electrospinning two polymers, water-soluble polyamine and water insoluble polyurethane. Linking of molecular recognition groups, antibodies, to the carboxylated PVC was performed using established crosslinking chemistries. Antigen/antibody experiments were performed on the electrospun membranes containing primary antibodies covalently attached on the membranes with different secondary antibody specificity. Results showed that electropun membranes, treated with the secondary antibody, reacted only with its complement as indicated with a chemi-luminescent signal versus those membranes having bound a different, or non-complementary primary antibody. Toxin studies with Staphylococcal enterotoxin B (SEB) were conducted using avidin/biotin chemistries on the electrospun membranes. Experiments were performed using a sandwich assay (avidin-SEB biotinylated antibody–SEB toxin-SEB antibody-HRP). Results showed that 1ng-100ng/ml concentration of toxin were detected in a non-optimized experiment.
https://doi.org/10.1142/9789812772572_0051
Despite years of treating trauma patients, the optimal fluid and strategy for the resuscitation of hemorrhagic hypovolemia remains unknown. Hypotensive resuscitation is a rational approach for the military due to logistic constraints to treat casualties on the battlefield, and to minimize rebleeding from penetrating injuries. In the present study anesthetized, splenectomized and instrumented 40 kg swine (n=8-10/gp) were subjected to a controlled hemorrhage of 20 ml/kg over about 5 min that duplicated the blood loss profile of an uncontrolled hemorrhage. After 30 min, fluid resuscitation was initiated along with a second hemorrhage of 8 ml/kg. Fluid infusion was controlled to return systolic blood pressure to 80 mmHg, as necessary throughout the experiment. Hemodynamic and metabolic variables were monitored continuously and blood samples were drawn at baseline (BL), and at select times throughout the 3.5 hr experimental period or until death. Tissues were collected at necropsy, homogenized and the content of total and phosphorylated EGF-R was determined by Western blot analysis. Evidence for lipid peroxidation or free radical generation was also determined. Hemorrhage reduced MAP to about 36 mmHg and lowered cardiac output (CO) to 36% of BL in all groups. CO improved the most in the Hextend group. PolyHeme infusion resulted in the highest blood pressure and lowest CO in surviving animals compared with the other fluids, but differences were not statistically significant among groups. Base deficit and plasma lactate increased during the 3.5 hr experiment in all groups. In the PolyHeme and Hextend groups, duodenal EGF-R levels were 73% and 33%, respectively, of the levels observed in LR treated pigs. EGF-R activation was about 50% higher in Hextend treated pigs compared to the LR and PolyHeme groups. As a result, about 60% of the EGF-R in duodenum from PolyHeme treated pigs was in the activated form compared to 37% and 18% in the Hextend and LR groups, respectively. In summary, all fluids improved hemodynamics and resulted in similar short term survival in this model of severe hemorrhage. Biochemical analyses suggest that resuscitation fluids can have different effects on signal transduction mediators that should be considered in designing the optimal fluid for long term improved outcome.
https://doi.org/10.1142/9789812772572_0052
The Walter Reed Army Institute of Research Whole Blood (WRAIR WB, U.S. Patent #6,746,850, 2004) cholinesterase assay (a) rapidly determines the activity of both AChE and BChE in unprocessed (uncentrifuged) whole blood, (b) uses a minimally invasive blood sampling technique (e.g., blood from a finger prick), and (c) is semi-automated for high-throughput using the Biomek 2000 robotic system (see Figure 1). The method measures ChE activity in whole blood in the presence of the chro-mophore 4, 4' dithidiopyridine (DTP) and three thiocholine substrates, from which the individual AChE and BChE activities are calculated.
Due to the documented use of OPs by terrorists and in warfare around the globe, Federal, State, and local authorities need a reliable, fast, inexpensive, and standard method for confirming such an assault in order to initiate appropriate containment, decontamination, and treatment measures. Thus, the WRAIR whole blood cholinesterase assay, with its high-throughput robotic capability, is ideal for prescreening military personnel for ChE activities that might preclude their deployment to areas of potential CWA exposure. This assay fulfills the requirement for rapid and reliable monitoring of OP exposure in military and civilian populations.
https://doi.org/10.1142/9789812772572_0053
We have conducted studies with existing rapid HIV-1 serology technology for applicability in military operations. Studies on fresh and frozen serum and differing HIV subtypes have been conducted in both the research and field environments. Testing has been compared to reference technology for calculation of operating characteristics. Conclusion: Rapid HIV-1 testing technology is an evolving field subject to market demands. Several tests exist that support warfighter use in the field. However, these tests should still be utilized in the context of the medical risk decision making process.
https://doi.org/10.1142/9789812772572_0054
Recent advancements in technology have resulted in new biosensors and information processing capabilities that permit on-line, real-time measurement of physiological variables. This has, in turn, given rise to the possibility of developing soldier-specific, data-driven predictive models for assessing physiological status in the battlefield. This paper explores how the accuracy of a predictive model based on first principles physiology can be enhanced by data-driven "black box" techniques of modeling and predicting human physiological variables. Such hybrid techniques are employed here in the prediction of core temperature. Preliminary results show that the mean square error of prediction can be reduced by up to fifty percent for prediction horizons of up to 30 minutes.
https://doi.org/10.1142/9789812772572_0055
For over a decade following the end of the first Gulf War in 1991, there has been increasing concern to understand the immediate and persistent effects of sub-acute and low-level exposures to chemical warfare agents. Although low-level exposures may not cause obvious pathology at the time of exposure, they may cause molecular-level alterations in the brain and other vital organ systems.
The work described in this manuscript was designed to measure the gene and protein expression alterations in the brains of male and female rats exposed to sub- and peri-miotic levels of the aerosolized nerve agents sarin (GB) and cyclosarin (GF). Gene expression was assessed using DNA microarray analysis. The microarray data were verified by real-time RT-PCR and Western immunoblotting where possible.
The overall aim of this project is to measure and characterize the gene and protein level alterations that may reveal near term, operational risks as well as changes that may predispose an individual to injury or disease later in life. To date, our results indicate that: 1) low-level inhalation exposure to GB and GF results in the differential expression of a number of neuronal genes, including a group that participate in cellular processes critical to neurological injury and regeneration and 2) there are significant gender-associated differences in the level and type of gene expression response.
https://doi.org/10.1142/9789812772572_0056
We are studying the complex interaction between various biological pathogens and the host to understand the basis of infection or biothreat-induced diseases and to identify host defense strategies and the mechanisms by which they are regulated. Although gene response profiles show unique signatures quite rapidly after exposure, they also have the potential to reveal phases of progression of illness to a) provide stage-specific diagnosis and b) identification of potential molecular targets for stage-appropriate therapeutic interventions for intractable illness induced by unconventional pathogenic agents.
We have used a library of 20,000 human cDNA (~10,000 are known genes) to construct customized microarray chips used in these studies. We determined gene expression in human peripheral blood mononuclear cells (PBMC) in response to 15 pathogens at different time points in vitro (3-5 replicates). This provided a framework for us to then utilize responses in animal models that closely imitate the illness as it occurs in humans. For those studies, PBMC or whole blood were collected at various time points post exposure to track the primary, secondary and subsequent gene responses elicited by the pathogenic agents. The massive amounts of data are overwhelming but provide an incredibly rich source for both diagnostic and therapeutic approaches.
We have identified host gene expression patterns that can discriminate exposure to various biological threat agents. Each of these gene patterns regulated by a specific agent reveals the cascade of events that occurs after the host encounters a pathogenic agent. Even though these pathogens initially cause similar symptoms, such as malaise, fever, headache, and cough, the course of illness induced by each of them differs in time frame of illness patterns. Using these signature gene profiles to assess possible exposure to pathogenic agents or to differentiate them from non lethal illnesses when the classical identification of a pathogen is not conclusive may fill a gap in the arsenal of diagnostic tools. Rapid detection, before the symptoms appear or even at various stages of illness, offers the opportunity to initiate appropriate treatment. Furthermore, this technique may provide the means to identify new therapeutic approaches to ameliorate the devastating results of these pathogens.
https://doi.org/10.1142/9789812772572_0057
In this study fusion of lipid-peptide amphiphile vesicles is employed to form biomimetic coating materials that can modify cellular adhesion and growth on solid substrates. Ellipsometry has been used to monitor vesicle fusion at different concentrations on hydrophilic surfaces and to identify adsorption as its limiting step. Incorporation of small amounts of RGD containing peptide amphiphiles in cell adhesion resistant PC lipid membranes is shown to promote adhesion and growth only when a sufficiently long spacer is used to control the distance of the peptide ligand from the surface.
https://doi.org/10.1142/9789812772572_0058
Bacteriophage MS2 is currently the only virus widely accepted for low-level containment or field release in the development of BW detection methods. However, MS2 does not resemble orthopoxviruses, a group of viruses of particular concern. We describe here assays for the detection of baculoviruses as an alternative to MS2.
https://doi.org/10.1142/9789812772572_0059
This paper describes fabrication of glass and plastic microfluidic devices for protein separations. Although the long-term goal is to develop a microfluidic device for two-dimensional gel electrophoresis, this paper focuses on the first dimension–isoelectric focusing (IEF). A laser-induced fluorescence (LIF) imaging system has been built for imaging an entire channel in an IEF device. The whole-channel imaging eliminates the need to migrate focused protein bands, which is required if a single-point detector is used. Using the devices and the imaging system, we are able to perform IEF separations of proteins within minutes rather than hours in traditional bench-top instruments.
https://doi.org/10.1142/9789812772572_0060
A new class of nanometer-scale, low power, solid-state devices is being investigated for the detection of CW agents and other hazardous vapors. These nanoelectronic chemical vapor sensors, or "chemiresistors" are comprised of nanometer-sized gold particles (1.2-2.4nm) encapsulated by monomolecular layers of functionalized alkanethiols (R-SH) deposited as thin films on interdigitated microelectrodes. When chemical (agent, explosive) vapors reversibly absorb into these thin films, a large modulation of the electrical conductivity of the film is observed. The measured current between gold clusters is extremely sensitive to very small amounts of monolayer swelling or dielectric alteration caused by absorption of vapor molecules. For chemical agent simulants, a large dynamic range (5-logs) of sensitivities is observed and extends down to ppb (parts-per-billion) vapor concentrations. For explosive vapors of TNT/DNT detection limits in the femtogram range have been observed. Complete reversibility has been observed for all analyte vapors and the devices exhibit relatively low sensitivity to water vapor (a major interferent). Tailored selectivities of the sensors are accomplished by incorporation of chemical functionalities at the terminal structure of the alkanethiol or substitution of the entire alkane structure.
https://doi.org/10.1142/9789812772572_0061
Nanocomposites made by adding nanoparticle reinforcement to polymers have been demonstrated to have significantly enhanced properties at relatively low levels of added reinforcement. The observed properties have in some cases been attributed to the shape of the reinforcing particle. Nanoparticle additives with a variety of particle morphologies and compositions have become commercially available in recent years. A study was carried out to examine the effects of varying nanoparticle morphology and composition on the mechanical and barrier properties of polymer nanocomposites made with natural rubber (NR). NR compounds were prepared containing different nanoparticles including montmorillonite layered silicate (MLS) clay, exfoliated graphite nanoparticles (EGN), carbon nanotubes (CNT) and conventional carbon black (CB). The cure behavior and mechanical properties of the prepared nanocomposites were investigated. Barrier property testing included permeation of selected organic compounds utilizing a recently developed fully flooded surface method. The relationships between these properties and nanoparticle composition and morphology are presented.
https://doi.org/10.1142/9789812772572_0062
The Nanostructured Origami™ 3D Fabrication and Assembly Process is a method of manufacturing 3D nanosystems using exclusively 2D lithography tools. The 3D structure is obtained by folding a nanopatterned 2D substrate. We report on the materials, actuation and modeling aspects of the manufacturing process, and present experimental results from fabricated structures.
https://doi.org/10.1142/9789812772572_0063
Recent research has examined the feasibility of detecting biological warfare agents by conjugating their antibodies (receptors) with taggant nanoparticles (also known as "quantum dots"), which subsequently fluoresce upon excitation, when they are bound to a specific biowarfare agent, or its simulant. Furthermore, when they react with their target bacteria, optically excited nanoparticle-receptor conjugates generate spectra in which the intensities of primary emission peaks are diminished, while the secondary emission peaks increase in intensities, i.e., energy is transferred from major peaks to minor peaks. These optical emission spectral signatures, with emission wavelength shifts of 140 nm in some cases, strongly suggest the possibility of homogeneous (one step) assays, leading to positive detection of bacterial agents, without wash steps using nanoparticle-receptor conjugates.
https://doi.org/10.1142/9789812772572_0064
Different polymer nanocomposites were prepared during this study. The polymer matrix, the nanoclay type and loadings were systematically varied. Processing conditions (screw speed, configuration, and temperature profile) were varied as well in order to find the optimum conditions for nanocomposite synthesis. Dispersion and exfoliation of nanoclays in the polymer nanocomposites were characterized via XRD and TEM. Single and multi layer films were prepared initially in lab scale and characterized. Subsequently, a 62" multilayer blown film was made and laminated into a fabric for tent applications. The liner material was characterized for chemical agent (HD/GB) barrier properties, flame retardant, and mechanical properties. Results showed that the new liner material offers up to 72 hours protection against HD and GB chemical agents. The new tent liner material showed good heat sealability. A full M28 tent liner was manufactured at the end and submitted for further testing. This technology has the potential to realize immediate utilization in currently used tentage systems, as well as long-term feasibility for its transition to future programs, including the Joint Expeditionary Collective Protection (JECP) program.
https://doi.org/10.1142/9789812772572_0065
The results of laboratory and field testing of a new large format infrared focal plane array based on quantum well infrared photodetector technology are presented. The array used had 1024 × 1024 pixels and is available commercially. from QWIP Technologies, Inc. The laboratory test results show that this array had high system-level performance. Imagery of military targets at ranges from 500 m to 5 km was acquired in the field with a sensor using this array. The results of the performance in the field are compared to that predicted by computer models and the performance of the large format QWIP FPA was evaluated in terms of the capabilities of a notional 3rd generation FLIR system.
https://doi.org/10.1142/9789812772572_0066
The U.S. Army's Future Combat Systems are designed to support the future force with three integrated transformation phases: Concept and Technology Development, Systems Design, Demonstration and Production. The Concept and Technology Developments phase is creating new challenges and opportunities for radio frequency and microwave applications in global positioning, navigation, timing, communications, improved radar target detection, and new forms of combat identification.
The merging of photonics and microwave electronics may revolutionize the traditional microwave technologies and explore many new technology fields. This merging has led to several significant developments such as higher frequency of operation and the capability to change frequency faster with greater agility, the ability to use larger bandwidths at higher frequencies, to improve the stability low phase noise oscillators (useful for low Doppler Radar target detection) and for novel methods of phase array antenna steering. In this paper we review two important system milestones by merging optoelectronics with microwaves, the injection locked dual opto-electronic-oscillator (OEO) and the optical controlled microwave phased array antenna.
https://doi.org/10.1142/9789812772572_0067
The application of polymer technology in integrated optical components provides a method of increasing the level of integration with the real potential of reducing unit cost. This paper describes the application of this technology in an integrated optical transceiver unit designed for an inertial sensor system, or more specifically, for an interferometric fiber optic gyroscope (IFOG) system. The design and fabrication of the optical polymer waveguide component and its integration with other discreet components to construct a transceiver is described.
https://doi.org/10.1142/9789812772572_0068
An efficient modeling of the electromagnetic scattering properties of symmetric lamellar periodic structures at normal incidence is discussed within the framework of the modal-field approach. By taking advantage of the inherent symmetry, a numerical computational speedup of up to 8 times can be achieved by explicitly ignoring anti-symmetric modes, which play no role in the scattering process at all.
https://doi.org/10.1142/9789812772572_0069
This paper describes the photonic component development, which exploits pioneering work and unique expertise at Sandia National Laboratories, ARDEC and the Army Research Laboratory by combining key optoelectronic technologies to design and demonstrate components for this fuzing application. The technologies under investigation for the optical fuze design covered in this paper are vertical cavity surface emitting lasers (VECSELs), integrated resonant cavity photodetectors (RCPD), and diffractive micro-optics. The culmination of this work will be low cost, robust, fully integrated, g-hardened components designed suitable for proximity fuzing applications. The use of advanced photonic components will enable replacement of costly assemblies that employ discrete lasers, photodetectors, and bulk optics. The integrated devices will be mass produced and impart huge savings for a variety of Army applications.
https://doi.org/10.1142/9789812772572_0070
The Army has a requirement to develop methods of strengthening soil to support rapid runway and roadway construction. A study was undertaken on the use of DC current applied to soil to form cementing phases in the soil. Preliminary work was on the use of zinc, aluminum, and iron in a variety of granular materials. Metal ions primarily form soft metal hydroxide gels that produce no immediate soil strengthening. Passing current through soil mixed with an alkali-reactive silicate produces rapid hardening with strength to 2,000 psi.
https://doi.org/10.1142/9789812772572_0071
Georgia Tech is in the second year of a Multi-University Research Initiative designed to study the impact of environmental processes on optical signatures. In particular, this program is conducting phenomenological studies on hyperspectral and polarimetric signatures of various target classes in the visible and infrared wavebands. Initial research studies have focused on landmines and the impact of various environmental factors and processes (e.g., subsurface processes) on the resultant spectral infrared signatures. A variety of approaches have been employed in this research to gain a better understanding of the impact of the environment on the spectral and polarimetric characteristics of soil and landmine signatures. These approaches include theoretical analyses, physics-based signature modeling, field measurements, and laboratory studies. We will present results from our research into the use of a physics-based, hyperspectral signature model as an analysis tool for landmine-related phenomenology studies. Results from these studies will be presented that underscore the importance of incorporating the subsurface processes into the signature analyses and the impact of these processes on detection algorithm development. The results of these analyses have been propagated to algorithm developers to permit the creation of more robust processing techniques based on these physical analyses and models.
https://doi.org/10.1142/9789812772572_0072
The NTU/ Purdue nonhydrostatic numerical model has been developed over the last 6 years to predict atmospheric motions and conditions for both the mesoscale (200 m to 200 km) and large scale turbulence scale (20 m to 200 m). It is a fully explicit, compressible three-dimensional code and has compared quite to a wide variety of known analytical solution or observed situations including the Boulder Wind Storm, nonhydrostatic and hydrostatic mountain waves for flow over an isolated mountain and a 2-dimensional mountain barrier, and buoyant bubble.
The model has application to FCS requirements for providing fine scale weather information for small unit operations in near real-time. It will enable us to study and better understand the problems of diagnosing and predicting atmospheric flow and conditions in real terrain. It is also designed and being applied to simulate larger turbulent eddies particularly in stable atmospheric boundary layers which are important for night operations. Large scale turbulence is a key to accounting for small scale turbulence that affects electromagnetic and acoustic propagation and governs local diffusion.
This paper considers both idealized and real terrain simulations in which the model was applied at high resolution (Δx, Δy of 500 m to 1 km) to the Organ, San Andres and Franklin Mountains region on and near the White Sands Missile Range (WSMR) in New Mexico. We used DTED level 1 terrain data (3 arc second resolution) to generate the model's terrain fields.
https://doi.org/10.1142/9789812772572_0073
Millions of acres of former and currently used military training and testing ranges are potentially contaminated by surface and buried unexploded ordnance (UXO), giving rise to requirements for UXO environmental restoration of formerly used sites and for sustainable use and active range cleanup. Geophysical surveys are required to map the location of buried UXO. The major cost driver of current cleanup and restoration is the inability to discriminate between buried false alarm and UXO targets. Excavation of false alarm targets is the major cost driver of UXO cleanup. Application of complementary geophysical sensor systems increases the potential for discrimination of UXO targets from false alarm targets. Development of new and innovative data integration methods and cooperative geophysical inversion algorithms allows enhanced discrimination and gives potential for target classification.
https://doi.org/10.1142/9789812772572_0074
Through its influence on the mobility of troops and materiel, the interaction between weather and landscape is of primary importance to the effectiveness and timeliness of Army operations. More specifically, knowledge of the spatial and temporal variability in soil moisture over large areas, at the scale of tactical operations (∼100 m), has the potential to dramatically improve trafficability assessments. The majority of Army operations are conducted in regions where field observations of soil moisture are sparse in space and/or time or completely unavailable. However, remotely sensed information about the factors that affect the spatial variability in soil moisture over a range of spatial scales are available. We present here a framework by which we can fuse these remotely sensed data representing the various factors affecting soil moisture through the existing tRIBS hydrologic model to produce forecasts of the spatial distribution of soil moisture. Using data assimilation techniques these forecasts can be dynamically updated when remotely sensed observations of soil moisture using become available. When used in conjunction with tactical decision aids, such as IWEDA, the proposed fusion of data through tRIBS has the potential to improve trafficability assessments and other soil moisture dependent Army operations.
https://doi.org/10.1142/9789812772572_0075
Sonic booms are a barrier to progress in supersonic flight due to their harmful effect on humans, animals, and structures. This research developed a new empirical formulation for prediction of the magnitude of a sonic boom using a linear regression on a database of measurements of the sonic booms created by military aircraft at Edwards Air Force Base. This formulation employs a new form of the F function, based on prior theoretical work, that characterizes the effects of shape, lift, and speed on the sonic boom and also includes a new expression for lateral sonic boom prediction. The formulation's accuracy is within the resolution capability of the human ear. The entire method was incorporated into a user-friendly Matlab® Graphical User Interface that predicts the magnitude of the sonic boom and creates an animated graphical model of the shock wave and sonic boom footprint. This can be used to easily test new low-boom supersonic transport designs, determine the environmental impact of a supersonic flight, and educate the public about sonic booms.
https://doi.org/10.1142/9789812772572_bmatter
AUTHOR INDEX.
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Chapter 1: Kernel-Based Anomaly Detection in Hyperspectral Imagery (907 KB)
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9789812772572SM01.iso (64707 KB)
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