Mucin Dynamics in Intestinal Bacterial Infection

Bacterial gastroenteritis causes morbidity and mortality in humans worldwide. Murine Citrobacter rodentium infection is a model for gastroenteritis caused by the human pathogens enteropathogenic Escherichia coli and enterohaemorrhagic E. coli. Mucin glycoproteins are the main component of the first barrier that bacteria encounter in the intestinal tract.Using Immunohistochemistry, we investigated intestinal expression of mucins (Alcian blue/PAS, Muc1, Muc2, Muc4, Muc5AC, Muc13 and Muc3/17) in healthy and C. rodentium infected mice. The majority of the C. rodentium infected mice developed systemic infection and colitis in the mid and distal colon by day 12. C. rodentium bound to the major secreted mucin, Muc2, in vitro, and high numbers of bacteria were found in secreted MUC2 in infected animals in vivo, indicating that mucins may limit bacterial access to the epithelial surface. In the small intestine, caecum and proximal colon, the mucin expression was similar in infected and non-infected animals. In the distal colonic epithelium, all secreted and cell surface mucins decreased with the exception of the Muc1 cell surface mucin which increased after infection (p<0.05). Similarly, during human infection Salmonella St Paul, Campylobacter jejuni and Clostridium difficile induced MUC1 in the colon.Major changes in both the cell-surface and secreted mucins occur in response to intestinal infection

The Influence of Manga on the Graphic Novel

This material has been published in The Cambridge History of the Graphic Novel edited by Jan Baetens, Hugo Frey, Stephen E. Tabachnick. This version is free to view and download for personal use only. Not for re-distribution, re-sale or use in derivative works. © Cambridge University PressProviding a range of cogent examples, this chapter describes the influences of the Manga genre of comics strip on the Graphic Novel genre, over the last 35 years, considering the functions of domestication, foreignisation and transmedia on readers, markets and forms

Multiphysics Modeling of Surface Finishing Performance in Pulsed-Waveform Electrochemical Machining

Electrochemical machining (ECM) is a manufacturing technology that allows metal to be precisely removed by electrochemical oxidation and dissolution into an electrolyte solution. ECM is suited for machining parts fabricated from “difficult to cut” materials and/or parts with complicated and intricate geometries. In ECM, the workpiece is the anode and the tool is the cathode in an electrochemical cell; by relative movement of the shaped tool into the workpiece, the mirror image of the tool is “copied” or machined into the workpiece. One notable difficulty with ECM is an inability to predict a priori the tool and process parameters required in order to satisfy the final specifications of the fabricated part [[1]]. Accordingly, there is potential value in development of a physical phenomenon-based design platform to predict optimal ECM tool shape. Such a capability is anticipated to dramatically shorten the process/tooling development cycle. A further goal of ECM is to simultaneously achieve a target surface finish on the machined part. It is thus of interest to develop the capability also to predict the distribution of local surface finish resulting from ECM processing. Modeling of the changes in local surface finish intrinsically operates on a different length scale from that of bulk material removal (μm, versus mm or cm), and thus is most easily treated separately. The physicochemical phenomena involved in the evolution of surface finish during ECM processing are strongly coupled, and include the electric field itself (primary current distribution), surface polarization and electrochemical kinetics (secondary current distribution), and fluid flow and mass transfer (tertiary current distribution). Of particular interest is modeling of pulsed-waveform ECM, for which significant practical advantages have been demonstrated [[2],[3],[4]]. While an extensive body of literature exists analyzing pulsed electrodeposition [[5],[6]], comparatively little work has been published to date on pulsed ECM [[7],[8]]. This talk will discuss recent modeling work seeking to develop a solid foundation for a predictive understanding of the surface finishing aspects of ECM processes. The work described herein encompasses time-dependent modeling of concentration profiles and other relevant physical quantities under the application of pulse(-reverse) current ECM waveforms, starting from simulations assuming a locally flat surface and working toward quantitative descriptions of the transient and steady-periodic behavior on structured substrates. Prior work (see, e.g., Ref. 3) has demonstrated the value in differential pulsed-ECM processing of surfaces with features of size comparable to or larger than the hydrodynamic boundary layer thickness (“macroprofiles”) versus surfaces with features much smaller than the boundary layer thickness (“microprofiles”). Figure 1 (left) plots a schematic of the pulsating concentration profiles at the end of the pulse on-time in forward-only pulsed ECM, assuming 100% current efficiency. Here, the pulse period (ton + toff) and the peak applied current density (jpeak) are assumed constant, with the curves corresponding to different values of ton. The saturation concentration of the dissolved metal is Cs, and the bulk metal concentration Cb equals zero. The quantity τ is the “transition time,” which is the value for ton for which the metal concentration at the surface rises exactly to Cs at the end of the forward pulse. As can be seen, for ton &lt; τ, metal dissolution is not mass transfer limited, but for any ton &gt; τ the rate of dissolution is constrained by the diffusion of the dissolved material, approaching the DC mass transfer rate for sufficiently high ton. Figure 1 (right) illustrates that preliminary simulations performed with COMSOL Multiphysics® exhibit behavior consistent with this qualitative concept. References [1]. Rajurkar, K.P. et al. Annals of the CIRP 82(2), 1999. [2]. Taylor, E.J. et al. “Breaking the Chemical Paradigm in Electrochemical Engineering: Case Studies and Lessons Learned from Plating to Polishing,” in Advances in Electrochemical Science &amp; Engineering: The Path from Discovery to Product, x, y Eds. In press. [3]. Taylor, E.J. and M. Inman. “Electrochemical Surface Finishing.” ECS Interface, Fall 2014: 57-61. [4]. Taylor, E.J. et al. U.S. Patent 9,006,147, 14 Apr 2015. [5]. Puippe, J.C. and F. Leaman, eds. “Theory and Practice of Pulse Plating.” Orlando, FL: AESF, 1986. [6]. Hansel, W.E.G. and S. Roy. “Pulse Plating.” Bad Saulgau, Germany: Leuze Verlag KG, 2012. [7]. Sautebin, R. et al. J Electrochem Soc 127(5): 1096, 1980. [8]. Sautebin, R. and D. Landolt. J Electrochem Soc 129(5): 946, 1982. Figure 1 <jats:p /

Fluid Flow and Current Distribution during Pulse-Reverse Electropolishing of Niobium Superconducting RF Cavities

The International Linear Collider (ILC) is a 200–500 GeV center-of-mass linear electron-positron collider, based on 1.3 GHz superconducting radio-frequency accelerating technology. This installation will require ~16,000 RF superconducting cavities operating within two linear accelerators at near absolute zero [[1]]. These SRF cavities are fabricated from pure Nb; to take full advantage of the Nb superconducting properties, the inner surface must be polished to a microscale roughness, and cleaned to be free of impurities that could degrade performance. Current methods use high viscosity electrolytes containing hydrofluoric acid, which is not conducive to low-cost, high volume manufacturing and is potentially harmful to workers. Faraday is developing an electropolishing process for niobium SRF cavities, based on a new and evolving paradigm of non-viscous dilute acid processing, enabled by a pulse-reverse electric field. Based on our understanding to date [[2]], we have speculated that the process works via oxide film formation controlled during a designed anodic pulse, followed by an off-time to remove heat and waste byproducts, followed by a cathodic pulse that removes the oxide film from the surface. This cycle is repeated many times per second, effectively removing niobium. The waveform design is such that the niobium is preferentially removed from the peaks on the surface, thus smoothing the surface. This talk will describe two recent efforts undertaken to improve understanding of various factors influencing the uniformity and speed of pulse-reverse electropolishing of niobium SRF cavities. The first is a flow study performed in a transparent plastic model of a single-cell (single-bell) cavity (Figure 1, left), to examine the flow dynamics in the absence and presence of an axisymmetric baffle fixed to the rod counter-electrode within the cavity bell. High-speed photography clearly shows the presence of a slow-moving eddy in the equatorial region of the bell (Figure 1, right), which is appreciably reduced in size when the baffle is present. Furthermore, rapid clearance of electrolysis gases and niobium oxide precipitates from the bell is expected to be strongly dependent on a proper configuration of flow throughout the bell. The second effort to be discussed comprises multiphysics modeling of the actual distribution of material removal in the EP process, as a function of position within the cavity. Modeling of EP of passive materials is complex, as numerous coupled phenomena must be accounted for, including: primary, secondary and tertiary current distributions; multi-phase effects, including fluid flow; and oxide formation/removal at the working surface. The strongest effects appear to be the primary and secondary current distributions, along with the surface oxide dynamics, inclusion of these physics (or semi-empirical approximations thereof) provides a significantly improved match between the model to the experimentally observed distribution of material removal, as compared to simulations incorporating only the primary current distribution. Figure 1 Caption (Left) Photograph of the transparent SRF cavity model, showing flow direction and early dye injection streaming pattern. (Right) High-speed photograph with annotations for bypass and eddy flows observed in a representative flow study test. References [[1]] http://www.linearcollider.org/ILC/What-is-the-ILC/The-project [[2]] M. Inman et al “Electropolishing of Passive Materials in HF-Free Low Viscosity Aqueous Electrolytes, J. Electrochem. Soc., 160 (9) E94-E98 (2013). Figure 1 <jats:p /

Efficient Electrochemical Stripping of WC-Co Wear Coatings from Inconel® 718 Substrates

A significant cost driver in maintenance operations for aerospace parts is the stripping of functional coatings either due to damage or to allow for periodic inspection/maintenance of the parts. Typical coating processes include electroplating of metals such as chrome, nickel, zinc-nickel, cadmium and silver, and thermal processes such as plasma/flame spray or high-velocity oxygen fuel (HVOF) for deposition of tungsten, cobalt, chrome and carbide-based alloys/composites. The coatings must be stripped in as efficient and rapid a fashion as possible, while leaving the underlying part undamaged and ready for re-coating and return to service. The ideal coating stripping process will be fast, inexpensive, and innocuous to the base material; electrochemical stripping processes are well established for various applications [[1],[2],[3],[4]]. An additional consideration is that functional coatings often contain valuable elements, and recovery of these materials as part of the stripping operation is thus desirable. For metals that remain soluble in the stripping solution, electrowinning is a viable recovery method; filtration, centrifugation, and other approaches are available for retrieval of insoluble materials. This talk will present data generated from stripping of WC-Co HVOF wear coatings from Inconel® 718 (IN718) substrates using a citrate-percarbonate electrolytic system. The subject study was motivated by difficulty expressed by a client in achieving rapid, complete stripping of WC-Co coatings with this system. Electrolytic stripping tests on pristine and thermally aged (60 h at 500 °C in air) commercial WC-Co coatings were performed on individual IN718 coupons and on sets of four coupons (see Figure 1) to examine the effect of apparatus configuration on stripping efficacy. The experiments performed indicate proper design of part racking/fixturing to be crucial for efficient stripping, and highlight an appreciable effect of thermal aging on stripping performance. Significant, rapid decomposition of the hydrogen peroxide constituent of the stripping solution was observed, though this decomposition minimally affected stripping performance. The potential for in situ electrowinning to enable recovery of the cobalt and solubilized tungsten constituents of the dissolved coatings will be briefly discussed, and preliminary data will be presented suggesting that the use of pulsed electrolytic waveforms may afford appreciable process enhancement. Figure 1 Caption (Top) WC-Co coated IN718 part. (Bottom) Electrode configuration in the four-part electrolytic stripping tests. Each part was staged at a different distance from the SS316 counterelectrode. The parts were wired in parallel with split leads to allow individual measurement of the current passed to each part. References [1]. F. Passal. “Electrolytic method of stripping nickel, chromium, copper, zinc, cadmium, silver, tin, and lead electrodeposits from ferrous basis metals, and compositions for use therein.” United States Patent No. 2,561,222 (1948). [2]. Capt. Matthew Whitaker. “Speed is good: New cleaning process nets huge gains in efficiency.” Air Force Print News Today (9 Jan 2015). Available online: http://www.tinker.af.mil/news/story_print.asp?id=123435922. Accessed 16 Dec 2015. [3]. D.C. Fairbourn, M. Sorenson. “Apparatus, methods, and compositions for removing coatings from a metal component.” United States Patent No. 8,262,870 (2012). [4]. D.R. Gabe. “Metal strippers: their science and technology.” Trans Inst Metal Finishing 85(2): 72 (2007). Figure 1 <jats:p /

Pulsed Electrophoretic Deposition of Carbon Nanotubes for Anti-Reflective Coatings

Exo-atmospheric optical sensors, seeker telescopes, and some other space-borne instruments require low reflectivity surfaces to minimize stray and reflected light across the visible and infrared wavebands. For example, in order to improve the sensitivity of missile-defense sensors and seekers, baffles are used within optical telescopes to reduce stray light. Some materials (e.g., aluminum, beryllium, etc.) are too reflective to use as absorptive baffles without surface processing, although they have lightweight and good thermo-structural properties, and survive harsh environments. Black surface coating treatments have been demonstrated as effective approaches to obtain low reflective surfaces. The surface features and intrinsic properties of the coating materials play an important role for scattering, absorbing, or trapping light. The excellent optical absorption performance and light weight of carbon nanotubes (CNTs) make them as ideal coating materials for obtaining low reflectivity surfaces. Within this context, Faraday Technology demonstrated the feasibility of a low-cost, efficient and scalable manufacturing process for the deposition of durable, low reflectivity carbon nanotube black coatings based on the use of pulse and pulse reverse electrophoretic deposition. As shown in Figure 1 A, the uniform CNT coatings are formed on stainless steel substrate (Figure 1 A, Inset), and the diffuse reflectance of the CNT coatings is ~ 1% over the visible range. We also demonstrated the potential to apply CNT coating on the internal diameter of cylinders at room temperature (Figure 1 B). Faraday are currently working on developing CNT coatings on the surface of absorptive baffle materials, such as beryllium and aluminum. The economic and scalable technology for producing CNT black coatings on desired substrates can not only be used for minimizing stray and reflected light for space-borne instruments, but also offer potential applications in other optical related devices which request low reflective surfaces, such as solar cells. Acknowledgements: The financial support of NASA Contract No. 80NNSC18P2062 and DOD MDA Contract No. HQ0147-19-C-7065 are acknowledged. Figure 1 <jats:p /

Accelerated Electrochemical Machining Tool Design Via Multiphysics Modeling

Electrochemical machining (ECM) is a manufacturing technology that allows metal to be precisely removed by electrochemical oxidation and dissolution into an electrolyte solution. ECM is suited for machining parts fabricated from “difficult to cut” materials and/or parts with complicated and intricate geometries. In ECM, the workpiece is the anode and the tool is the cathode in an electrochemical cell; by relative movement of the shaped tool into the workpiece, the mirror image of the tool is “copied” or machined into the workpiece. Figure 1 shows a schematic and photograph of a shaped ECM tool (cathode) and the resulting part (anode) surface after machining. Compared to mechanical or thermal machining processes where metal is removed by cutting or electric discharge/laser machining, respectively, ECM does not suffer from tool wear or result in a thermally damaged surface layer on the workpiece. Consequently, ECM has strong utility as a manufacturing technology for fabrication of a wide variety of metallic parts and components, and includes machining, deburring, boring, radiusing and polishing processes. ECM provides particular value in that application is straightforward to high strength/tough and/or work-hardening materials such as high strength steel, chrome-copper alloy (C18200), nickel alloy (IN718), cobalt-chrome alloy (Stellite 25) and tantalum-tungsten alloy (Ta10W), since the material removal process involves no mechanical interaction between the tool and the part. A variety of commercial and military production applications are envisioned as well suited for ECM techniques. One notable difficulty with ECM, common to a variety of manufacturing operations, is an inability to predict a priori the tool and process parameters required in order to satisfy the final specifications of the fabricated part. In this talk, Faraday will present preliminary results from a Phase I SBIR program aiming to demonstrate the potential for a phenomena-based design platform to predict optimal ECM tool shape using commercially available multiphysics simulation software. This capability is anticipated to dramatically shorten the process/tooling development cycle, eliminating much or all of the iterative prototyping necessary in the absence of a predictive tool. The validation argument will be presented via comparison of simulation results with data from parallel ECM experiments. The initial validation work encompasses a small subset of experimental parameters: electrolyte salt (“active” NaCl vs “passive” NaNO3) and electrolyte flow/tool geometry (“cross flow” past a solid tool, and “through-flow” in a tubular tool). The initial feasibility demonstration of the tool design platform will include only ECM based on potentiostatic direct currents, constant tool advancement rates, and simulations including only primary current distributions. Reasonable agreement between the simulated and experimentally derived profiles is observed. Eventually, however, the goal is to extend the model to other modes of ECM processing, including: 1) pulse-current ECM (PECM), where the tool is withdrawn from the workpiece during pulse current off-times to flush the gap; and also 2) pulse/pulse-reverse ECM (P/PR ECM) in metal-solubilizing electrolytes, where the tool gap is maintained relatively constant. An approach to modeling the optimal inter electrode gap dimension during PECM has been reported by Rajurkar and collaborators [[1]]; to our knowledge no modeling has been performed on constant-gap pulse/pulse-reverse ECM in solubilizing electrolytes. Faraday has developed and patented novel approaches to ECM based on pulse reverse currents [[2],[3],[4]] that do not require complicated electrolytes and results in improved surface finishes and better process control; application of the predictive model to these approaches is anticipated to provide substantial gains in both manufacturing logistics and economics. The authors acknowledge the financial support of U.S. Army Contract No. W15QKN-16-C-0070. References [[1]] B. Wei, K.P. Rajurkar, S. Talpallikar. “Identification of Interelectrode Gap Sizes in Pulse Electrochemical Machining.” J. Electrochemical Society 144(11): 3913-19, 1997. [[2]] C. Zhou, E.J. Taylor, J. Sun, L. Gebhart, R. Renz. “Electrochemical Machining using Modulated Reverse Electric Fields.” U.S. Patent No. 6,402,931, issued 11 June 2002. [[3]] E.J. Taylor. “Sequential Electromachining and Electropolishing of Metals and the like using Modulated Electric Fields.” U.S. Patent No. 6,558,231, issued 6 May 2003. [[4]] E.J. Taylor, M. Inman. “Method and Apparatus for Pulsed Electrochemical Grinding.” U.S. Patent No. 9,403,228, issued 2 August 2016. Figure 1 <jats:p /

Pulsed Electrodeposition of Tin Electrocatalysts Onto Gas Diffusion Layers for CO₂ Reduction to Formate

The performance of electrocatalysts for the electrochemical carbon dioxide (CO2) reduction reaction (eCO2RR) is largely dependent on the ability to efficiently deliver CO2 to the active sites. A variety of reactor configurations have been explored in the literature that can be broadly classified as based on either liquid- or gas-phase reactant delivery. These configurations utilize a range of electrode types including metal plates, meshes, packed granules, and gas diffusion electrodes (GDEs).[1] Amongst these methods, the use of gas-phase reactor designs employing GDEs enables a dramatic increase in current density (typically an order of magnitude or larger) over liquid-phase reactor designs, where the low solubility and aqueous diffusivity of CO2 result in severe mass transport limitations. However, per existing literature, the performance of GDEs in various CO2 electroreduction processes can be hampered by poor catalyst utilization and transport limitations within the catalyst layer. Prior reports have demonstrated electroreduction of CO2 to formate (FA) on commercial tin nanoparticle (150 nm) loaded gas diffusion layers (GDLs) at current densities of 200 mA/cm2, 80% selectivity to FA, and cathodic potentials of -0.8 V vs. RHE.[2, 3] However, these and other studies have also reported that at higher catalyst loadings (thicker catalyst layers), which are desirable for high production rates, conversion efficiencies drop and undesirable side product formation increases due to reactant starvation. Reducing particle size typically enhances both catalyst utilization and activity per unit mass. This, in turn, may enable thinner catalyst layers. While synthesis methods exist for generating smaller (&lt; 10 nm) particles, these particles must still be deposited on a GDL such that ionic and electronic contact can be maintained with the electrolyte and GDL, respectively. These critical interfaces are key to maximizing electrode performance in terms of product generation rate, selectivity, and catalyst utilization. Previous work directed towards platinum (Pt) catalyst utilization in polymer electrolyte fuel cell GDEs demonstrated an “electrocatalyzation” (EC) approach that used pulse and pulse-reverse electrodeposition to obtain highly dispersed and uniform Pt catalyst nanoparticles (~5 nm).[4-6] Moreover, since the catalyst was electroplated through an ionomer layer onto the bare GDL, the formed nanoparticles were inherently in both electronic and ionic contact within the GDE and, consequently, utilization was enhanced. Specifically, for the oxygen reduction reaction, the electrodeposited catalyst exhibited equivalent performance at 0.05 mg/cm2 loading compared to a conventionally prepared GDE with a loading of 0.5 mg/cm2.[6] Here we investigate the electrodeposition of tin (Sn) onto commercially available GDLs through an EC process and benchmark our results against a state-of-the-art Sn nanoparticle catalysts (150 nm) spray-coated on a GDL. Electrolysis experiments are conducted in a three compartment W-Cell setup using the Sn-coated GDEs as cathodes and Pt/H2 counter electrode. We demonstrate that the EC GDE samples can exhibit up to 388 mA/cm2 total current density and 76% selectivity to formate at cathodic potentials of -0.8 V vs. RHE, representing a two-fold improvement in current density over both our benchmark electrode and existing reports using Sn-loaded GDEs prepared by conventional methods.[2, 3] We hypothesize that this enhancement arises from improved catalyst utilization, leading to high electrode activity. Surprisingly, SEM imaging of the EC GDE reveals Sn particles no smaller than the micron scale (~10 μm). Thus, we anticipate further improvement in electrode activity may be realized through suitable tuning of the EC waveform to yield nanoscale Sn particles (&lt; 10 nm). In summary, the EC approach appears promising for fabricating active catalytic layers directly onto GDL substrates. References [1] I. Merino-Garcia, E. Alvarez-Guerra, J. Albo, A. Irabien, Chemical Engineering Journal, 305 (2016) 104-120. [2] D. Kopljar, N. Wagner, E. Klemm, Chemical Engineering &amp; Technology, 39 (2016) 2042-2050. [3] D. Kopljar, A. Inan, P. Vindayer, N. Wagner, E. Klemm, Journal of Applied Electrochemistry, 44 (2014) 1107-1116. [4] M. E. Inman, E.J. Taylor, in, U.S. Patent No. 6,080,504, 2000. [5] N .R.K. Vilambi Reddy, E. B. Anderson, E.J. Taylor, in, U.S. Patent No. 5,084,144, 1992. [6] E.J. Taylor, E.B. Anderson, N.R.K. Vilambi, Journal of The Electrochemical Society, 139 (1992) L45-L46. </jats:p

Eliminating the Formation of Hexavalent Chromium in Chrome Stripping Operations Using Pulse Reverse Processes

Chromium electrodeposits are commonly applied to aeronautical and automotive components as protective coatings from harsh and/or corrosive operational environments. Through normal use, these coatings may become damaged. During repair and refurbishment of these components, the parts are stripped of the existing chromium deposit before being recoated and reinstalled into various systems. Traditionally, the chrome stripping process has been facilitated by applying a potential bias to a workpiece in an alkaline electrolyte per MIL-STD-871B. While the alkaline pH may help to protect the underlying steel surface from corrosion, it preferentially favors the formation of the hexavalent chromium species, which is a carcinogen and an environmental toxin. In the conventional stripping process, hexavalent chromium ions build up in the stripping electrolyte over time, resulting in decreased stripping rates, high energy consumption and possible damage to the part. To minimize these effects, the bath must be purified or discarded and replaced. Prior to waste disposal all hexavalent chromium in the electrolytes must be reduced to trivalent form as the trivalent species is non-toxic, non-hazardous and more stable compared to the hexavalent species. Therefore, if the oxidation of chromium metal can be limited to the trivalent species during stripping operations, air quality regulations will be easier to meet and working conditions personnel would be greatly improved. Faraday is working to develop an electrolytic stripping process intended as a drop-in replacement for the conventional stripping process. The process seeks to eliminate the formation of hexavalent chromium while maintaining the material properties of the underlying substrate. Faraday will present work that demonstrates removal of chrome from high strength steel substrates using a weak acid electrolyte that results in the dissolution of the metal to its trivalent state. The effect of pulse and pulse/reverse electric fields on the efficacy of the stripping process will be presented in comparison to operation under constant voltage electric fields. The stripping process based on use of a weak acid electrolyte in conjunction with pulse/pulse reverse electric fields was demonstrated for flat and round specimens in a pilot scale cell using a simple oxalic acid electrolyte. In addition, studies were conducted to assess how age of the oxalic acid electrolyte impacts the stripping process using constant voltage electric fields. Faraday also developed a process for the recycling of spent alkaline stripping electrolytes loaded with hexavalent chromium ions. This process relies on the use of catalytic Au-Pd-Cu cathodes and pulse reverse process conditions. Results of the process in bench scale validation studies and lessons in the scaling of this technology are discussed. Acknowledgement: Funding for this work is gratefully acknowledged from Air Force SBIR Contract Number FA8222-16-C-0006. </jats:p