Advanced Acoustic Concepts (United States)

The Program Manager, Supply and Maintenance Systems (PM SMS), along with the Electronics Software Calibration Test (ESCT) Division of Marine Depot Maintenance Command, execute the engineering support and development for the United States Marine Corps (USMC) General Purpose Automatic Test System (GPATS). The GPATS provides Intermediate and Depot level test capabilities for multiple communication and ground weapon systems. It utilizes commercial VXI analog instruments from several vendors; all are obsolete with no VXI replacements available. These include the digital multi-meter, counter/timer, digital storage oscilloscope, and arbitrary waveform generator. Most commercial vendors no longer produce or support the aforementioned VXI analog instruments. They only produce them utilizing PXI or PXIe bus architecture. PXI and PXIe instruments have the same physical form, and neither is directly compatible with a VXI chassis. There are three USMC GPATS configurations in use today. They are the Third Echelon Test System (TETS) and two variants of Virtual Instrument Portable Equipment Repair/Tester (VIPER/T). They incorporate Digital Test Systems (DTSs), Analog Instruments, High/Medium/Low Frequency Switching, and Programmable Power Supplies. All three GPATS have obsolete VXI analog instruments. The USMC GPATS DTS variant is also obsolete, but there are Commercial Off the Shelf (COTS) VXI DTS replacements available. There is still a need for VXI based DTSs, as moving to a PXI or PXIe DTS results in a 50% reduction of channels per card. Reducing total available channels or channels per card may result in a follow-on cost to rewrite the Test Program Sets that utilize them. Instead of an all-new PXI or PXIe based GPATS, PM SMS/ESCT explored combining the existing VXI DTS, the existing VXI High/Medium/Low Frequency Switching, and new PXIe analog instruments in the same VXI chassis. This approach utilizes a COTS PXIe Instrumentation Insertion Kit (PXIe Insert). The PXIe Insert acts as a VXI to PXIe chassis adapter, allowing PXIe instruments to fit and obtain power from a VXI chassis. The end goal of this effort is full functionality of PXIe bus architecture instruments in the existing VXI chassis. In addition to solving the GPATS analog instrument obsolescence problem, the PXI Insert has two benefits. First, the TETS and two VIPER/T can transform into a “Single” sustainable GPATS configuration; and in this particular case, it reduces the required GPATS VXI chassis from Two to “One.” This aligns with USMC concepts for lighter and smaller footprints, while remaining modular and scalable. The objectives of this initial USMC VXI/PXIe integration effort were finding fully suitable PXIe replacement instruments, and then demonstrating complete functionality for each, utilizing the GPATS system software. This was successful. Future testing involves regression testing of Application Program Set (APS) software. In summary, the PXIe Insert technology allows COTS PXIe instrument insertion into the existing VXI chassis, mitigating the impacts of VXI Analog instrument obsolescence. It can also allow future replacement of PXIe instrumentation as USMC GPATS test requirements change. Leveraging PXIe Insert technology into the TETS and VIPER/T VXI chassis is the most direct and potentially cost-effective means to replace older VXI analog instruments.

We report on the production of a flame-resistant xanthan gum (XG)-based hydrogel formulation, which could be directly applied onto the skin for protection against burning projectiles. The hydrogel cream represents an efficient use of XG and starch, both of which are biodegradable, reusable natural materials and are also GRAS-certified. The flame-retardant agent resorcinol bis(diphenyl phosphate) (RDP) was shown to be nontoxic to cells in vitro when adsorbed directly onto the starch delivery vehicle. Three hydrogel formulations were studied, the pure XG hydrogel, commercial FireIce hydrogel, and RDP-XG/RDP-starch hydrogel. After application of a direct flame for 150 s, the RDP-XG/RDP-starch hydrogel produced a thick char layer, which was easily removed, showing undamaged chicken skin and tissue underneath. In contrast, complete burning of skin and tissue was observed on untreated control samples and those covered with FireIce and pure XG hydrogels. The thermal protective performance test was also performed, where the heat transfer was measured as a function of time for all three hydrogels. The RDP-XG/RDP-starch hydrogel was able to prolong the protection time before obtaining a second-degree burn for 103 s, which is double that for FireIce and triple that for the pure XG hydrogel. The model proposed involves endothermic reactions, producing char and burning "cold", as opposed to simply relying on the adsorbed water in the hydrogel for burn protection.

The VXIbus (IEEE-STD-1155) was the first widely adopted modular standard in the test and measurement industry. The adoption of the VXIbus standard led the way for the industry system integrators to achieve tremendous reductions in instrument size, ATS footprint, power consumption, cooling and overall cost. Automated Test Systems (ATS) designed and delivered for more than the last 20 years were fielded with a high percentage of VXI instrumentation. During that same time period, the test and measurement industry developed their new product lines leveraging advanced technologies from the PC industries leaving very limited resources to contend with product supportability issues for their VXI instruments. Unfortunately, as the VXIbus standard and its instrument support declines, system sustainment challenges grow exponentially. Today the VXI user's ability to maintain and support their ATS inventory is being challenged. With the large sums of money that have been invested in the ATS and TPS, to support operational objectives, the using organizations must deal with this evolving support problem. User organizations are experiencing lifetime management struggles to mitigate the impacts to their capabilities caused by critical vendors obsoleting VXI instruments and ending their support. The removal of VXIbus instrumentation increases risk impact to the ATS system dramatically since most ATS systems were principally fielded utilizing VXIbus instruments. The ratio of the VXIbus architecture instrumentation as compared to the total number of instruments in the test system is high. This ratio, in effect, amplifies the risk to the system due to obsolescence. Sustainment solutions to facilitate integrating merging industry standards seamlessly with the VXI standard can ease the transition impact by relegating the scope of a change to the INSTRUMENT level and away from the STANDARD level risk impact. In the case of VXI to PXI, or VXI to PXIe, a bridge technology that can identify and provide a path to resolve the impact to the instrument level will allow the ATS managers to accurately plan costs and manage risk while sustaining operational capability.

PurposeThe prevalence of individuals with an autism spectrum disorder (ASD) being associated with terroristic threats, lone wolf terrorism or affiliating with terroristic groups is rare. This paper aims to discuss this issue.Design/methodology/approachHowever, several cases are presented, where individuals with autism are involved in making a naïve, empty terroristic threat or uttering serious serial terroristic threats. Other cases are also presented of individuals being at risk for an abduction or being used by a terrorist group, and finally committing an act of domestic lone wolf terrorism.FindingsEssential to the analysis was establishing a functional connection between autism-based deficits and the terroristic threats, terrorism, and when to not criminalize naïve, empty terroristic threats or acts.Originality/valueCurrently, tools available to law enforcement and prosecutors exploit the vulnerabilities and liabilities which arise as a result of group interactions, a “preventive” approach to terrorism that is not applicable to the solitary, “lone wolf” terrorist. There has been relatively little research (including case studies) examining individuals with ASD who engage in terrorism. For instance, when dealing with an individual with ASD who is charged with terrorism, it is crucial to consider how the diagnosis of autism may have presented as a contextual vulnerability, and to make sure that justice, rehabilitation and management, are informed by an understanding of the person’s diagnosis of ASD.

This paper presents a novel system capable of simultaneous high-power and high data-rate transmission through solid metal barriers using ultrasound. By co-axially aligning a pair of piezoelectric transducers on opposite sides of a metal wall and acoustically coupling them to the barrier, an acoustic-electric transmission channel is formed which prevents the need for physical penetrations. Independent data and power channels are utilized, but they are only separated by 25.4 mm (1 in) to reduce the system's form factor. Commercial off-the-shelf components and evaluation boards are used to create real-time prototype hardware and the full system is capable of transmitting data at 12.4 Mbps and delivering 50 W of power through a 63.5 mm (2.5 in) thick steel wall. A synchronous multi-carrier communication scheme (OFDM) is used to achieve a very high spectral efficiency and to ensure that there is only minor interference between the power and data channels. Also presented is a discussion of many potential enhancements that could be made to greatly improve the power and data-rate capabilities of the system. This system could have a tremendous impact on improving safety and preserving structural integrity in many military applications (submarines, surface ships, UUVs, armored vehicles, planes, etc.) as well as in a wide range of commercial, industrial, and nuclear systems.