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Battlefield communication networks consist of various heterogeneous networking technologies. Heterogeneity can create problems of interoperability and challenges in creating a unified network. Two of the challenges in making heterogeneous networks interoperate seamlessly are the existence of disparate Media Access Control (MAC) layers and control plane protocols. A network model that can abstract disparate MAC layers in heterogeneous networks and interconnect them using a unified and centralized connection broker could potentially solve the problems preventing seamless connectivity in heterogeneous networks. The controller can accept signals from a variety of access technologies and convert them to the appropriate form before forwarding. Using C++, we modeled the behavior of a unified access controller for heterogeneous wireless networks in the ns-3 environment. We allowed 2 simulated wireless networks with 2 different access technologies to communicate with one another via a virtual network device acting as the controller. The conversion process was performed using the ns-3 emulated net device model, which can change an ns-3 simulation signal of any particular access technology into a virtual packet and vice versa. Our simulated model validated the unified access control design for heterogeneous networks. It can be used as a framework for further testing and also as the foundation for a new physical design over which the heterogeneous networks operate seamlessly., Prepared in collaboration with Secure Mission Solutions, Charleston, SC. The original document contains color images.

One goal of the US Army Research Laboratory's Robotic Collaborative Technology Alliance is to develop a cognitive architecture that would allow a robot to operate on both the semantic and metric levels . As such, both symbolic and metric information would be interpreted within the robot's world-model with subsystems providing or interpreting the appropriate type of information. In December 2013, an integrated research assessment was conducted to evaluate progress toward this goal. The robot's ability to receive instructions in structured text, and to interpret those instructions in the context , in both camera and laser detection and ranging images, was applied to the goal of navigating around a building. In this report, the robot's performance is evaluated with 3 measures: 1) grading of the robot's performance during real-time operation, 2) evaluation of planning given the perceptual data within the world model after the testing , and 3) after- the- fact diagnosis of the cause of failed runs by developers of the technology., The original document contains color images.

This report documents the extensive work done on the lower leg finite element model, specifically on the sensitivity of injury prediction on linear elastic material parameters that are chosen within a range of values typically used for biological tissues. Using simple criteria, we predict a variety of injuries typically observed in theater. We find a strong dependence of these predicted injuries on the soft tissue properties included in our model. We also report on a potential oversensitivity in our model to predicting talus injuries. We conclude that biological variability in measured material parameters will need to be accounted for in future models., Prepared in collaboration with TKC Global, LLC. The original document contains color images.

A 3-phase design-of-experiment approach was used to investigate hydrogen re-embrittlement effects of common aviation maintenance chemicals and coatings. Both material and geometry were examined to uncover the best constraints for a novel method. While traditional testing uses a pass/fail approach, the developed method employed load monitoring cells over a range of material strength, hydrogen-emitting environment, and applied load. This method allowed prospective solvent replacement chemicals and cadmium replacement coatings to be finely delineated in terms of performance and formed the basis of a tool for predicting time to failure under any combination of parameters. In the aviation community, heavy restriction on using alternative chemicals and coatings could therefore be eased, and applications could be expanded for using highstrength steel., The original document contains color images. Prepared in collaboration with Bowhead Science and Technology, LLC, Alexandria, VA, and The Boeing Company.

We develop a mathematical model of the ear s response to intense sounds (over 120 dB) that starts with pressure in the freefield, accounts for the effects of the head, external ear, middle ear, and cochlea, and ends with predictions of basilar membrane motion. The model s structure parallels the ear s anatomy and function and fits hearing loss data for weapons impulses that are not explainable by any other mechanism. The model suggests that upward movements of the basilar membrane produce the stresses that are the primary cause of damage., The original document contains color images. Published in Proceedings of the 3rd Workshop on Launch Blast Overpressure, 1987. Presented at the 3rd Workshop on Launch Blast Overpressure, held at Aberdeen Proving Ground, MD in 1987.

Ballistic Research Laboratory Computer-Aided Design (BRL-CAD) is an open-source computer-aided design tool that uses constructive solid geometry (CSG) to create models of primitive shapes. However, no database of all (primitive) shapes exists in BRl-CAD. The goal of this project was to create a database containing one instance of every primitive shape supported by BRL-CAD. The database includes special cases of other primitive shapes , such as a rectangular parallelepiped ( rpp ), an arbitrary convex solid with 8 vertices (arb8) . After the database was completed, a tool was created to perform the same task automatically. The primitive-shape database provides the target describers of BRL-CAD with a representative example of each primitives shape and its properties. In addition to the database, part of BRL-CAD's large code base was debugged, specifically the hypersampling feature in rtarea and the error checking in rtweight were corrected by taking into account the sampling rate., The original document contains color images.

A copper rotating band is the munition component responsible for both obturation and transfer of torque from the gun barrel's rifling to the munition, thereby causing the projectile to spin. Pure copper, copper alloy, and brass rotating bands are typically fabricated to steel munitions using the weld-overlay process, a radial-pressing process, or a thermal shrink fit. This paper documents the initial development and demonstration of a cold-sprayed copper rotating band in a 155-mm artillery system., The original document contains color images.

The ability to understand the reasoning behind an intelligent agent s actions can help to increase operator performance as the use of human-agent teams for military operations grows. This experiment tested the effect of display design to convey environment and intelligent agent information in a simulation-based unmanned ground vehicle monitoring task. Three groups were tested with visual displays representing 1 of 3 types of information: current status only (group 1); current status with reasoning information (group 2); and current status, reasoning information, and projected information (group 3). Performance measures included comprehension of situation awareness probes, operator trust based on 3 different surveys, workload, and system usability. Results indicated a significant interaction between conditions and pre- and postadministration of a trust survey modified from Jian et al. (2000), with only group 2 increasing in trust preexperiment in comparison with postexperiment. The situation awareness probes failed to yield any significant differences among the conditions. No significant effects of operator workload or individual difference factors were observed across conditions. This research demonstrates the potential of agent transparency displays to improve Soldier trust and situation awareness., The original document contains color images.

In this report, we discuss the application of human factors and ergonomics to developing effective simulation training in health care. Simulation provides a safe, effective method for training and assessing human performance. In aviation, simulation-based training and assessment has been widely used, significantly improving safety. This progress would have been impossible without the involvement of human factors and ergonomics. Although aviation and health care have similarities, there also are differences that complicate the widespread implementation of simulation in health care., The original document contains color images. Pub in Human Factors and Ergonomics, v8 p191-234, 2013.

This cooperative research program emphasizes collaborative research between The Johns Hopkins University and the US Army Research Laboratory toward well-defined common goals: the understanding and development of advanced lightweight materials for vehicular protection, focusing on high-strain-rate/high-stress testing, determining the operative deformation and failure mechanisms, and developing relevant models to allow for materials design. This report summarizes the research carried out during 1 July 2011 through 30 June 2012 in the following areas: 1) nanomicro aluminum, 2) dynamic failure and damage mechanisms, 3) nanostructured magnesium, 4) modeling of body-centered-cubic nanostructures, 5) high-rate loading of piezoelectric ceramics research thrust, 6) continuum modeling of dynamic deformation mechanisms, 7) density functional theory modeling and transmission electron microscopy characterization of nonstoichiometric oxides and carbides (B6Ox and B4C), 8) administration, education, training, and collaborative structures, and 9) list of theses, publications, and presentations from the various thrust areas., The original document contains color images. Prepared in collaboration with the Hopkins Extreme Materials Institute, The Johns Hopkins University, Baltimore, MD.

A large number of the Survivability/Lethality Analysis Directorate s (SLAD s) software tools need to display geometric data. This project explored options for improving the speed and clarity with which SLAD s tools can display geometry. The goal was to reduce the amount of human effort and elapsed time necessary to prepare complex models for use in analysis and visualization tasks. We investigated several avenues for high-speed visualization and worked to update BRL-CAD s graphics display system to support more modern display layers. While additional work remains, we identified high-performance techniques and achieved the first stages of display system improvements., The original document contains color images.

This report describes the work underway in establishing a database of environmental sounds for research at the US Army Research Laboratory. This report reviews the current status of research on environmental sound perception as well as the challenges associated with characterizing such a broad stimulus class. One of the goals of this report is to establish what properties of environmental sounds are important to document for the purposes of a database. We end this discussion by providing a path forward for implementing the criteria highlighted here. The current document provides a summary of high-impact research on environmental sound perception as well as documentation on the sound source acquisition process. A list of environmental sounds used in previous research is included with this report, and many of the sound files are available by request., The original document contains color images. Prepared in collaboration with the Science and Engineering Apprentice Program, Harford Community College, Bel Air, MD.

In the past, robot operation has been a high-cognitive-workload task requiring human operators to dedicate a large amount of their cognitive resources to maintaining awareness about a robot s state and functioning. This technical report describes research of operator-knowledge-management aids, in the form of visual display-screen overlays, used to help increase performance and reduce perceived workload. The aids were overlays displaying what an autonomous robot perceived in the environment and the subsequent course of action planned by the robot. Eight active-duty, US Army Soldiers completed 16 scenario missions using an operator interface called the Warfighter Machine Interface. The simulated missions included various display configurations, with combinations with and without 3 operator aids: Travel Planner, Obstacle Map, and Rerouting Alert. During the simulations, participants managed the autonomously navigating robot, taking teleoperation control when needed, while completing a reconnaissance to detect simulated improvised explosive devices. Results of this study showed that the use of operator aids resulted in less use of manual teleoperation control, suggesting that operators were better able to predict robot actions, understand the projected robot paths, and have less need to manually intervene in autonomous robot behavior. The use of operator aids did not, however, contribute to improved target detection., The original document contains color images. Prepared in collaboration with 2DCS Corporation.

Investigations were conducted in the optimization of a lift-off photolithography technique using thick negative photoresist (PR) NR9-8000 to achieve and optimize micron-scale interdigitated capacitor (IDC) structures by lift-off process for use in high-frequency electrical characterization measurements. Target feature resolution was in the range of 3 20 m, with PR thickness in the range of 6 20 m. Systematic deviations were made from manufacturer-recommended PR processing conditions to investigate a processing-structure relationship for optimizing of IDC fabrication including PR response to manipulation of substrate material, spin-speed, postexposure bake, exposure dose, and development process conditions. Postexposure bake temperature was found to be the most sensitive and critical parameter for the optimization of PR structures., The original document contains color images.

In critical and life threatening situations faced by Soldiers on the battlefield, timely response to complex information is required. In such situations, battlefield computation can help to distill data into actionable information that can lead to better decision-making and outcomes. However, computing power is limited on the tactical edge due to size, weight, and power constraints of a Soldier s mobile device. One potential solution to this problem is to offload the computation to a more powerful computer to obtain an answer as fast as possible. However, this strategy comes at the cost of the introduction of a delay due to communication latency. It is therefore important to design the offloading mechanism intelligently. This report, presents a model to estimate the performance of offloading systems in current and future scenarios. The modularity of this model allows system designers to replace model components with the accuracy and level of detail necessary for their analyses. This report examines how this type of model is useful for making decisions about when and where to offload jobs, as well as making hardware acquisition decisions for improving the system over time., The original document contains color images.

The Lightweight and Specialty Metals Branch (LSMB) lies within the Materials and Manufacturing Science Division of the Weapons and Materials Research Directorate of the US Army Research Laboratory (ARL). LSMB s mission is to perform the fundamental and applied research and development in metals to create transformational metallic systems to enable battlefield overmatch; and to protect and defend our country by empowering, unburdening, and safeguarding our servicemen and women. LSMB s vision is to be the leading metals research and development facility for the US Army, which is achieved by attracting and retaining world-class researchers with exceptional credentials; building the necessary infrastructure for metals research; and integrating research with Army-relevant applications to enable game-changing, competitive capability. LSMB s strategy is to balance in-house capability, talent, resources, and infrastructure with external agencies/facilities to drive foundational materials research that meets the needs of the US Army. This report is a summary of published research within FY14 for LSMB., The original document contains color images.

Traumatic brain injury (TBI) is frequently caused by blasts that trigger a series of neuronal biochemical changes. Diagnosis of mild TBI caused by blast is challenging, since the damage to brain tissue progresses slowly over time. It is largely unknown how structural damage at tissue level from blast loading impact affects functional activity at variable time scales after the TBI event. This report describes the experimental approach and preliminary results of our study of cultured hippocampal brain slices impacted by explosively generated blast waves with single or multiple impacts in water. The initial results showed that a single blast had no effect on the immunoreactivity level of GluR1, an integral membrane protein belonging to the glutamate-gated ion channel family, whereas a triple blast insult caused a significant reduction in the GluR1synaptic marker compared to submerged control slices. This might be an indication of a dose-dependent effect and warrants further investigation with hippocampal slice samples to better understand blast-induced brain damage., The original document contains color images.

Stiffness and strength predictions of undulated composites (filament-wound cylinders, braids, plain weaves, etc.) using traditional laminated composite theories are complicated by complex fiber architecture. Undulations consisting of fibers passing over and under each other result from the interweaving process. In the current investigation, full-field strain measurements were used to evaluate local strain distributions in the region of a 0 undulated ply in a [0n/90n]s laminate (n = 2,4,6) and a 30 undulated ply in a [30n/ 60n]s laminate (n = 2,4). Specimens were manufactured with carbon fibers, various amplitudes of undulation, and matrix materials with moduli ranging from 300 to 3,000 MPa. Two-dimensional digital image correlation was used on the free edges of the compressively loaded specimens. The observed strain fields were highly influenced by the undulation geometry. The axial modulus (Ex) of a [0n/90n]s laminate was more sensitive to reinforcement undulation for flexible matrixes (300 MPa) rather than rigid (3,000 MPa). Fiber undulation was observed to elevate out-of-plane shear and through-thickness normal strains in regions eventually involved in the fiber microbuckling failure process., The original document contains color images. Prepared in collaboration with the Weapons and Materials Research Directorate, ARL, APG, MD, and the Pennsylvania State University, University Park.

This Materials Center of Excellence program has been conducted as a seamless, synergistic collaboration among the following institutions: Rutgers Malcolm G McLaren Center for Ceramic Research, Penn State Particulate Research Center, the Johns Hopkins Center for Advanced Metal and Ceramic Systems, and the US Army Research Laboratory s Weapons and Materials Research Directorate. The following tasks are reviewed: Nanostructured Armor Ceramics: Focus on Boron Carbide; The Role of Microstructure in the Impact Resistance for Silicon Carbide; Education and Outreach; Defining Microstructural Tolerance Limits of Defects for Silicon Carbide Armor Ceramics; and Nondestructive Ultrasound Characterization of High-Density, High-Hardness Ceramics., The original document contains color images. Prepared in collaboration with the Center for Ceramic Research, Rutgers, The State University of New Jersey, Piscataway.

Physical impairment of a Soldier during a mission will inevitably change the Soldier's ability to perform various mission-essential tasks. This study examined the effects of an artificially impaired hand and arm on grenade throwing and weapon loading performance. The grenade task examined distance and accuracy while throwing a grenade from the kneeling, standing, and supine positions, with and without physical impairment. The weapon loading task examined time to change a magazine on an already loaded weapon as well as loading an unloaded weapon under conditions with and without physical impairment. The grenade throwing distance data revealed (for each of the throwing postures) a significant main effect for the physical impairment condition (p less than 0.01, differences of up to 46 inches). There were no significant effects or interactions of the physical impairment condition relative to mean accuracy in any of the throwing conditions. Also, main effects for physical impairment were found for mean times to complete individual subtasks in throwing the grenade (i.e., pull grenade from pouch, pull pin, and throw grenade). In both weapon loading tasks, a main effect of physical impairment was revealed (p less than 0.01). The results of this study will be used to verify and validate capability requirements used in human performance modeling for grenade throws and weapon loading under conditions of physical impairment., The original document contains color images.

The purpose of this research is to formulate polyurethane 1) for use in composites or coatings that contain isosorbide as part or all of the polyol phase and 2) that can be easily molded or cast into a film at ambient conditions. Solubility studies were conducted to determine the maximum amount of isosorbide that could remain in solution with other diols. Formulation of polyurethanes using isosorbide as part or all of the polyol phase combined with monomers such as toluene diisocyanate (TDI) and isophorone diisocyanate (IPDI) in the isocyanate phase. TDI reactivity at ambient conditions was too extreme, while IPDI was not reactive enough. Prepolymerized polyisocyanates were studied with isosorbide and compared with a commercial polyurethane coating. The dynamic mechanical analysis showed that isosorbide as a drop-in replacement for the commercial polyol increased the Tg 17 C. However, ultraviolet exposure revealed that the polyurethane containing isosorbide does not perform as well as the commercial product with defects such as brittleness and delamination., The original document contains color images.

The US Army Research Laboratory conducted an initial study to characterize the material properties and armor performance of low-density ceramic composite tiles manufactured by the Ukrainian National Academy of Science, under a US Army International Technology Center contract. These ceramic formulations were compared with standard armor-grade boron carbide and silicon carbide tiles versus the 12.7-mm armor-piercing APM2 projectile.

The representation of human aspects within Soldier-centered modeling and simulation (M&S) environments presents significant challenges in affect model availability, accessibility, and applicability within the condition-specific, parameter-driven Soldier representation and performance trade space. Furthermore, the increasing complexity of affect models poses substantial and often unsupportable systems integration effort for timely and efficient use. The Distributed Soldier Representation (DSR) project, led by the U.S. Army Research Laboratory (ARL) Human Research and Engineering Directorate (HRED) Simulation & Training Technology Center (STTC), aims to develop a service-oriented distributed M&S capability and provide performance factor representation of various degrees of fidelity within entity-level simulation environments in support of Soldier training and mission rehearsal., The original document contains color images.

Ballistic Research Laboratory Computer-Aided Design (BRL CAD) is a solid modeling system used by the Army for ballistics analysis. US Army Research Laboratory (ARL) target describers use the BRL CAD Geometry Difference (GDiff) tool to determine the differences between their target models. GDiff is currently a command-line-only utility lacking a graphical user interface (GUI). To improve the usability of the tool and to increase target describers productivity, a GUI for the tool is being created. Various differencing-type GUIs were researched to create an initial GUI design. Several possible designs were sketched and then made, and an initial design concept was reviewed by ARL target describers who provided feedback that improved the GUI design. A final sketch of the GUI was then created. The GUI is being implemented using the Tcl/Tk tookit in the form of an extension to Archer, which is a GUI for BRL CAD itself. Previous plug-ins for Archer are being examined to determine how to best implement the new GUI that is being written and tested., The original document contains color images.

Urea nitrate (UN) was synthesized and analyzed to determine the rate of mass loss of the material at various temperatures. The sensitivity of the material to external impact was also determined. From the results of the study, UN is safe to store under normal operating conditions., The original document contains color images.

Several finite elastic strain measures are evaluated for use in constitutive models of crystalline elasticity and elastoplasticity. These include the Green material strain tensor, the Eulerian material strain tensor, and the logarithmic material strain tensor, all of which are referred to locally relaxed coordinates invariant under spatial rotations. Solutions to the planar shock problem from previous work are summarized, and new applications of logarithmic strain-based theory toward shock compression of aluminum, copper, and magnesium single crystals and polycrystals are presented. Consideration of these new results in conjunction with previous analysis for metals, ceramics, and minerals suggests that Eulerian strain-based theory is preferred for typical ductile metallic crystals, while logarithmic strain-based theory is recommended for modeling shocks in ceramics and minerals with larger ratios of shear modulus to bulk modulus., The original document contains color images.

There is a strong need for real-world neuroimaging tools that could provide the hardware substrates supporting the rapidly expanding work in developing optimized brain computer interactive technologies in a fieldable format. It may be possible to support these needs with electroencephalography (EEG); however, current designs require too much power for long-term operation. Nonconventional, ultra-low power design will be necessary to achieve wear and forget systems for on-line, long-term neurological monitoring. One challenge to this goal is the relatively large dynamic range of EEG relative to a comparably low signal-to-noise ratio; this report demonstrates the initial design, simulation, and validation of an EEG data-acquisition, single-integrated-circuit system design that addresses this challenge using an analog front end that adapts on-line to keep the digitized signal within a much smaller dynamic range. This is accomplished through a combination of a voltage-offset controller, low-noise amplifier, low-bit rate analog-to-digital conversion, and a hardware-accelerated digital processor consuming less than 300 nW per channel. At that consumption, it is very feasible to design an entire system capable of operating solely on locally harvested power. Follow-up simulations demonstrate the approaches described here should still provide sufficient signal quality for targeted state monitoring applications., The original document contains color images. Prepared in collaboration with the Sensors and Electron Devices Directorate, ARL, Aberdeen, MD.

Tetranitroglycoluril (TNGU) was prepared according to the US Army Research Laboratory s (ARL s) method by the nitration of imidazo-[4,5-d]-imidazole nitrate using trifluoroacetic anhydride and 100% nitric acid. This resulting material was then subjected to hydrolytic stability studies in which it was placed into a temperature and humidity chamber set to 23 C and 85% relative humidity and the change in concentration of TNGU was measured over time through the use of nuclear magnetic resonance spectroscopy., The original document contains color images.

Given that it is not always feasible to reach an affected area via land or sea within the first week following a natural disaster, aerial delivery provides the primary means to rapidly supply the affected population. When direct airdrop systems are used to deliver large quantities of individually wrapped food and water items, dispersion among the affected disaster relief population will occur more quickly. In this project, we proffer a multiple criteria decision analysis (MCDA) framework to optimize the military humanitarian assistance/disaster relief (HA/DR) aerial delivery supply chain network. The model uses stochastic, mixed-integer, weighted goal programming to optimize network design, logistics costs, staging locations, procurement amounts, and inventory levels. The MCDA framework enables decision makers to explore the trade-offs between military HA/DR aerial delivery supply chain efficiency and responsiveness while optimizing across a wide range of real-world probabilistic scenarios to account for the inherent uncertainty in the location of global humanitarian disasters as well as the amount of demand to be met., The original document contains color images. Prepared in collaboration with the Department of Industrial & Manufacturing Engineering, The Pennsylvania State University, University Park, the School of Industrial & Systems Engineering, Georgia Institute of Technology, Atlanta, and the Rawls College of Business Administraion, Texas Tech University, Lubbock.

The objective of this research is to create an interface that is tailored to individual Soldiers' cognitive styles, individual differences, and expertise while at the same time reduces the interface complexity perceived by the Soldier. This interface design will improve upon existing adaptive interfaces by going beyond adaptation to the individual's prior actions and tailoring the interface to how each user perceives, processes, and filters information without the added complexity of current adaptive interfaces. The field of adaptive user interfaces and human-computer interaction will be extended by this tailored interface innovation to investigate Soldier performance benefits of speed, accuracy, understanding, coordination, and the reduction of workload., The original document contains color images.

A computational study was performed as an initial evaluation of the Lagrangian marker method recently implemented in the CTH shock physics code. A set of Taylor impact experiments served as the basis of this initial evaluation of the method. Numerical simulations of Taylor impact were performed with the CTH marker method, and the final shapes of the impacting cylinders were compared to experimental results. Additional CTH simulations were performed using the legacy Eulerian solver to isolate the influence of the CTH solver on the computational results. Finally, a set of Arbitrary Lagrangian-Eulerian (ALE) finite element simulations was performed for further comparison. The study revealed that the Lagrangian marker method reproduces the Taylor impact results with a degree of fidelity on par with the CTH legacy Eulerian and ALE methods. This study provides a critical first step toward the application of the CTH Lagrangian marker method to ballistic impact problems relevant to defense applications., The original document contains color images.

The purpose of this study was to evaluate perceived annoyance for vibrotactile signals applied to the head. A head-mounted tactile display, integrated with a bone conduction system (dual-use, tactile-bone conduction communication system), is considered for military applications, but previous studies have reported unfavorable user reviews for vibrotactile signals applied to the head. Vibrotactile signals from 32 to 250 Hz were sent to the foreheads of 30 participants who rated the perceived annoyance of each signal. Higher frequency signals were rated more annoying than lower frequency signals. Consequently, higher frequency signals will most likely not be preferred on the head and generally may be associated with annoyance and other feelings of unsettledness. We are not advocating that higher signal frequencies should never be used on the head, because there are times when they may be appropriate, especially for various military applications. However, we must be systematic in how we use them to maintain user acceptance., The original document contains color images.

This report will cover the testing of the Ballistic Research Laboratory Computer-Aided Design s (BRL CAD s) ray-tracer on the primitive Bag of Triangles (BoTs). Two programs were created to accommodate each component of this project. The first program created all possible triangles (BoTs) given a bounding box and step size that is specified by the user. The second program fired multiple rays toward various locations on each triangle in the database. The results of these tests were classified as a success or failure; the percentages of success were graphed against the different tolerance levels to determine the accuracy of the ray-tracer on BoTs. These data could be useful in understanding how BRL CAD s ray-tracer performs in comparison to the Air Force s ray-tracer, FASTGEN, on BoTs., The original document contains color images.

Complex metabolic networks contain many essential enzymes that cannot be genetically altered or deleted without adverse impact on the host cell. We have developed an alternate strategy to modulate metabolite flow through these essential enzymes with the goal of more efficient production of commodity chemicals (i.e., biofuels), better waste remediation, and novel antibiotics. In this report we tackle the first of 2 goals to computationally discover and design small molecules and modified bacterial genes (for producing peptide tails to a common bacterial protein) that will inhibit native bacterial metabolic enzymes and alter metabolic output. We computationally screened the million-compound ChemDiv catalogue and identified and purchased 20 candidate inhibitors to 2 sites of the Fe-Fe hydrogenase protein in Clostridium acetobutylicum. During this effort, we developed a novel assay for detecting gas production in ultrasmall bacterial cultures and verified this assay with TNT as a positive control. After testing all of the candidate molecules in this assay, we found some that moderately reduced hydrogen gas production as desired and some that reduced overall cell viability., The original document contains color images.

The US Army Research Laboratory s (ARL s) Human Research and Engineering Directorate (HRED) launched a research program entitled Relevant Information for Social Cultural Depiction (RISC-D). The RISC-D program is concentrated on understanding and modeling the sociocultural factors that affect Soldier and Commander decision making, specially addressing how a Soldier s own cultural background influences their own decision making. This report discusses the development of a taxonomy of sociocultural factors that influence decision making to include the development process, the elements of the taxonomy, the proposed model and general framework., The original document contains color images.

Aluminum 5083 powder was milled through cryogenic attrition for 8, 16, and 24 h with graphite as a hydrogen-free process control agent. The powders were degassed to remove moisture and other impurities. The degassed powders have a relatively low hydrogen concentration. The morphology, grain sizes, and stability of the milled powders were compared, and it was found that while there was little difference in grain size between the 3 milling times, powders milled for 16 and 24 h showed more grain stability than powders milled for 8 h., The original document contains color images.

We investigate inertial effects in torsional Kolsky bar tests on nearly incompressible, soft materials. The results are relevant for materials with instantaneous elastic shear modulus on the order of 1 1000 kPa and density on the order of water. Examples include brain tissue and many other soft tissues and tissue surrogates. We have conducted one- and three-dimensional analyses and simulations to understand the stress and strain states that exist in these materials in a torsional Kolsky bar test. We demonstrate that the short loading pulses typically used for high strain-rate (e.g., 700 = s) tests do not allow the softer specimens to ring-up to uniform stress and strain states and that consequently the shear stress versus shear strain data reported in the literature are erroneous. We also show that normal stress components, which are present even in quasistatic torsion of nonlinear elastic materials, can be amplified in dynamic torsion tests on soft materials. Kolsky bar tests are widely used to study strain-rate effects in inelastic solids [Gray 2000; Chen and Song 2011]. In a compression Kolsky bar test, a relatively thin specimen is sandwiched between two bars. Impact at one end of the incident bar generates a compressive wave that travels along the bar, through the specimen, and into a transmission bar. The goal of this test is to subject the specimen to uniform uniaxial stress and uniform (biaxial) strain at a prescribed axial strain-rate. These uniform conditions can often be achieved after an initial ring-up period involving multiple wave reflections from the specimentransmission bar and specimen-incident bar interfaces. Once uniform conditions have been achieved in the specimen, the axial stress, axial strain, and axial strain-rate histories in the specimen can be deduced from strain gage measurements on the elastic bars: the axial stress is proportional to the strain in the transmission bar, and the axial strain-rate is proportional to the strain in t, The original document contains color images. Pub in Journal of Mechanics of Materials and Structures, v9 n5 p515 555, 2014.

This report describes the development, application, and results obtained from scenario-based structured interview items designed to support the concept development of autonomous and intelligent robot capabilities with a Soldier squad. Results will be used to validate and inform scenario development within a simulation platform. Eighteen Soldiers participated in these interviews and provided detailed feedback with regard to information and capability requirements, priorities of use, and recommendations for robot roles and responsibilities. The results are summarized in the report and detailed in appendixes sorted by topic area and Soldier group., The original document contains color images.

A computationally based study was conducted to assess the potential viability of schemes proposed for employing cucurbiturils as precursors for the synthesis of polycyclic nitramines (PCNAs). One scheme involved reducing cucurbiturils to cucurbitaminals, then nitrolyzing them. The other involved hydrolyzing the cucurbiturils, then nitrating the secondary amine groups of the product. To assess the schemes viabilities, an attempt was made to establish correlations between properties of equilibrium molecular structures and stability for known compounds, then employ the correlations to predict the stabilities of intermediates and targets. However, strong correlations were not found. Moreover, even if more evidence supporting hypothesized correlations had been found, results for the intermediates and targets of interest suggest that the yields of these schemes are likely to be low (at best) and that the targets will be unstable. The attempt to answer questions regarding the feasibility of producing PCNAs from cucurbiturils prompted the design and modeling of other notional PCNAs. Two appear to warrant further investigation. One is 2,6,7-trinitro-2,6,7-triaza[2.2.2]octane. It has a tris(nitramino) group. The other is a CL-20 analog with 4 C(H)C(H) groups and 4 nitramine groups., The original document contains color images.

Two modular helmet systems, consisting of helmet, eye, and mandible protection plus tactical communications via earmuffs (EMs), earplugs (EPs), or double hearing protection, developed under the Helmet Electronics and Display System-Upgradeable Protection program were evaluated for their effects on auditory perception. Measures of passive directional attenuation were made for the helmets alone, hearing protection alone, and in combination. The situation awareness (SA) microphones of the communications system compressed noise transmission when ambient levels exceeded 85 dB (A) so that at 110 dB (A) the noise level under the EPs was only 88 dB (A) for the highest microphone setting. For EMs, attenuation was limited to approximately 18.5 dB (A) of passive protection with additional amplification caused by the ear canal; therefore, with the microphones on the highest setting, the level under the EM at 110 dB (A) was 110 dB (A). Impulse noise attenuation for the systems was measured by presenting impulses at peak levels of 150 and 171 dB with the SA microphones turned off, on low, and on high. EPs, EMs, and double hearing protection provided impulse noise protection equivalent to the passive attenuation of the hearing protectors when the SA microphones were on., The original document contains color images.

The Legion programming system from Stanford University was developed to address the specific needs of portable parallel heterogeneous programming with emphasis on program data. Data-centric Legion abstracts the underlying hardware such that the focus is algorithmic development rather than the idiosyncrasies of different computing architectures. Legion is part of a small but growing movement to treat parallel programming design and development in a task-oriented fashion and, as of this writing, is the only one to address this paradigm dynamically. This work employs a gravitational n-body simulation as a vehicle to introduce Legion to a wider audience of parallel programmers., The original document contains color images.

An efficient method was needed to perform ballistic testing using 0.30-cal. Fragment Simulating Projectiles at or near subsonic velocity in order to screen new resin systems for advanced composite/ceramic armor scaled-down test coupons. This technical note outlines the custom gun system and testing methods developed to enable this ballistic testing., The original document contains color images.

A recent gun launch experimental program required that the pusher assembly of the launch package be diverted so that it would not follow behind the projectile being evaluated. Initial experiments showed that a subscale launch package fired from a 2-inch (51-mm)-diameter air gun exhibited similar sabot discard performance to the full-size projectile. The subscale launch package was assembled from parts built from plastic via rapid prototyping (3-dimensional printing). Subsequent evaluation of several sabot concepts revealed that the best design had one of the 4 sabot petals firmly attached to the pusher assembly so that the discarding sabot petal pulled the pusher assembly off of the line of fire. The modified assembly was fabricated and fired from the full-scale 8-inch (203-mm) gun. Sabot discard and pusher diversion occurred as expected, allowing the experimental program to proceed. The launch package modifications are described, and a simple analysis of basic equations of force and motion illustrates why a low-speed, subscale simulation can be used for first order evaluations of sabot discard phenomena., The original document contains color images.

We have been able to synthesize and characterize several synthetic cannabinoid-dark quencher (DQ) conjugates for the use in fluorescence-based cannabinoid detection platforms. The carboxylic acid reactive QSY 7 amine was reacted with the carboxylated metabolites of JWH 018 and JWH 073 via a simple peptide conjugation reaction with the catalyst O-benzotriazole-N,N,N',N'-tetramethyl-uronium-hexafluoro-phosphate to yield 3 new DQ conjugates. Thin layer chromatography and liquid chromatography coupled mass spectrometry show full conversion of the synthetic cannabinoid starting material to product with observed and expected masses of 1,097 g/mol for JWH 018 pentanoic acid QSY 7 amine and 1,081.4 g/mol for JWH 073 butanoic acid-QSY 7 amine. These characterized conjugates are now ready for cannabinoid-receptor-based binding assays., Prepared in collaboration with Oak Ridge Institute for Science and Education, Oak Ridge, TN. The original document contains color images.

A phase field theory for modeling deformation and fracture of single crystals, polycrystals, and grain boundaries is developed. Anisotropies of elastic coefficients and fracture surface energy are addressed, the latter enabling favorable cleavage on intrinsically weak planes in crystals. An order parameter increases in value as damage accumulates in an element of material. The shear elastic coefficients deteriorate with cumulative damage regardless of local strain state, while the effective bulk modulus degrades only under tensile volumetric deformation. Governing equations and boundary conditions are derived using variational methods. An incremental energy minimization approach is used to predict equilibrium crack morphologies in finite element simulations of deforming polycrystals. Thin layers of material, representative of glassy second phases near grain boundaries, are assigned possibly different properties than surrounding crystals. Results of simulations of polycrystals subjected to tensile loading are reported, with base properties representative of silicon carbide or zinc. Key findings include (i) a tendency for intergranular over transgranular fracture as the grain boundary surface energy is reduced or as cleavage anisotropy is increased and (ii) an increase in overall ductility and strength, the latter similar to Hall-Petch scaling, as the absolute size of the polycrystal is reduced while holding the ratio of phase field regularization length to grain size fixed., Journal article published in Computational Materials Science, v98, p158-169, 2015. The original document contains color images.

The US Army Research Laboratory (ARL) started several corporate initiatives to benchmark and improve upon strategic areas of the laboratory. These initiatives, designed to investigate a critical interest area, each began with a study led by a senior leader. The intent was to propose recommendations and an implementation plan for the next several years. One of these initiatives, Skills Assessment, was designed to examine the current state of the human capital of the organization. Dr Laurel Allender, director of the Human Research and Engineering Directorate, was tasked to lead a team of representatives from each of the other directorates in ARL and appropriate support functions in assessing the human capital of ARL. At the same time, ARL began a process to realign the long-term direct mission program to a set of science and technology campaigns. The ARL campaign plans would be collaborative and crosscutting focus areas for the mission program. The team used the campaign taxonomy to define the competencies for ARL and collected data for each ARL scientist or engineer, including all post docs and contractors based on the competency lists. A gap analysis was then completed. There were areas where ARL has little competency but planned to lead or collaborate in that area as well as areas where we had large numbers of people claiming competency yet we did not plan future efforts. Although the data were not exact, the study provides a place to begin to benchmark the ARL skill mix., The original document contains color images.

The Human Research and Engineering Directorate s Dismounted Warrior Branch conducted a live-fire research study where subjects were asked to engage targets at various ranges using an M4 carbine with and without a vertical grip. The objectives of the study were to quantify subjects shooting performance of the M4 carbine with and without a vertical grip and to determine subjects subjective responses on their perceived shooting performance and preferences while shooting the M4 carbine. Of the 18 subjects, 6 were US Army Soldiers and 12 were officers from the local Special Response Team (a local police force at Aberdeen Proving Ground). All 18 subjects fired both weapon conditions in the reflexive posture at 10-, 25-, and 50-m targets and aimed posture at 50-, 100-, and 150-m targets. For the reflexive posture, all subjects conducted 3 training trials with 24 rounds per trial, firing at 24 targets exposed for 3.5 s and later 3 record trials with 24 rounds per trial firing at 24 targets. A similar scenario was conducted in the aimed posture only using 6-s target exposure times. Shooting performance data were collated by the range computer and analyzed for significant differences between weapon configurations. The results of this study showed that for the mean number of targets hit, mean radial error (distance from the point of aim on the E-silhouette target), mean time to shoot, and mean time to hit the target, there were no significant differences in any of the weapon configurations (M4 with and without a vertical grip) in either the reflexive or aimed firing postures, suggesting that perhaps the use of a vertical grip should be left to the discretion of each user., The original document contains color images.

This report documents a set of functions, written in C++, that can be used to perform interpolations (nearest-neighbor, linear, and cubic) and to find coefficients for best-fit equations. Functions for working with periodic equations are included., The original document contains color images.

Being able to save screenshots directly to a file and to record activity on a desktop or within a specific window is extremely useful for a variety of reasons. Although third-party screen-recording software is readily available online from a variety of sources, such software often presents a security concern and would require administrative permissions to install. This report presents a software utility for capturing series of desktop or window screenshots using only original equipment manufacturer software on systems running Microsoft Windows., The original document contains color images.