Defense Logistics Agency

Trade tensions, resource nationalism, and various other factors are increasing concerns regarding the supply reliability of nonfuel mineral commodities. This is especially the case for commodities required for new and emerging technologies ranging from electric vehicles to wind turbines. In this analysis, we use a conventional risk-modeling framework to develop and apply a new methodology for assessing the supply risk to the U.S. manufacturing sector. Specifically, supply risk is defined as the confluence of three factors: the likelihood of a foreign supply disruption, the dependency of U.S. manufacturers on foreign supplies, and the ability of U.S. manufacturers to withstand a supply disruption. The methodology is applied to 52 commodities for the decade spanning 2007-2016. The results indicate that a subset of 23 commodities, including cobalt, niobium, rare earth elements, and tungsten, pose the greatest supply risk. This supply risk is dynamic, shifting with changes in global market conditions.

Abstract An explicit predictor‐corrector algorithm is derived from the implicit α‐method. This explicit algorithm is shown to have better stability and accuracy properties than its Newmark‐based predecessor. This algorithm is then combined with the implicit α‐method, resulting in an implicit‐explicit α‐method which can be effectively utilized for linear and non‐linear structural dynamics calculations.

Edgerton VR, Roy RR, Allen DL, Monti RJ: Adaptations in skeletal muscle disuse or decreased-use atrophy. Am J Phys Med Rehabil 2002;81(Suppl):S127–S147. Those factors that seem to play some role in inducing adaptations of skeletal muscle in vivo are discussed. The role of myogenesis in maintaining and repairing muscle during atrophic and hypertrophic states is discussed, including pointing out that the modulation of myonuclear number is one means of adapting to varying chronic levels of neuromuscular activity. Finally, we point out the potential consequences of muscle atrophy on the control of movement and the susceptibility to fatigue.

Abstract Energy systems and manufacturing processes of the 21st century are becoming increasingly dynamic and interconnected, which require new capabilities to effectively model and optimize their design and operations. Such next generation computational tools must leverage state‐of‐the‐art techniques in optimization and be able to rapidly incorporate new advances. To address these requirements, we have developed the Institute for the Design of Advanced Energy Systems (IDAES) Integrated Platform, which builds on the strengths of both process simulators (model libraries) and algebraic modeling languages (advanced solvers). This paper specifically presents the IDAES Core Modeling Framework (IDAES‐CMF), along with a case study demonstrating the application of the framework to solve process optimization problems. Capabilities provided by this framework include a flexible, modifiable, open‐source platform for optimization of process flowsheets utilizing state‐of‐the‐art solvers and solution techniques, fully open and extensible libraries of dynamic unit operations models and thermophysical property models, and integrated support for superstructure‐based conceptual design and optimization under uncertainty.

This review discusses the fabrication, deployment, challenges, and future directions of metal–organic framework thin film sensing platforms, which are of particular interest due to their tunable porosity, chemical functionalities, optical and electrical properties.

Abstract Underground hydrogen storage is a long‐duration energy storage option for a low‐carbon economy. Although research into the technical feasibility of underground hydrogen storage is ongoing, existing underground gas storage (UGS) facilities are appealing candidates for the technology because of their ability to store and deliver natural gas. We estimate that UGS facilities in the United States (U.S.) can store 327 TWh (9.8 MMT) of pure hydrogen. A complete transition to hydrogen storage would reduce the collective working‐gas energy of UGS facilities by ∼75%; however, most (73.2%) UGS facilities could maintain current energy demand using a 20% hydrogen‐natural gas blend. U.S. UGS facilities can buffer 23.9%–44.6% of the high and low hydrogen demand projected for 2050, respectively, which exceeds the current percentage of natural gas demand buffered by storage. Thus, transitioning UGS infrastructure to hydrogen could substantially reduce the number of new hydrogen storage facilities needed to support a hydrogen economy.

The prevalence of tick-borne encephalitis virus (TBEV) in southern Korea was determined by collecting ticks using tick drags. A total of 4,077 of 6,788 ticks collected were pooled (649 pools) according to collection site, species, and developmental stage and assayed for TBEV. The TBEV protein E and NS5 gene fragments were detected using RT-nested PCR in six pools of nymphs collected from Jeju Island (2,491 ticks). The minimum field detection rates for TBEV were 0.17% and 0.14% for Haemaphysalis longicornis and Haemayphysalis. flava nymphs, respectively. The 252 bp NS5 and 477 bp protein E gene amplicons were sequenced. Phylogenetic analysis showed that the NS5 and protein E genes of the Jeju strain were clustered with Western subtype (98.0% and 99.4% identity, respectively). The Western subtype of TBEV is endemic in Korea, including Jeju Island. The study of vector and zoonotic host susceptibility to TBEV is required to better understand its potential impact on public health.

We combined ultrahigh vacuum surface science techniques, electrochemical measurements, density functional theory, and microkinetic modeling to finely resolve the size-dependent transition between the CO2 reduction reaction (CO2RR) and H2 evolution reaction (HER) selectivity for Ag nanoparticle electrocatalysts in the sub-5 nm range. We experimentally measured activity and selectivity trends with sub-nm size resolution using a series of Ag nanoparticles with average diameters between 2 and 6 nm. CO2RR activity increased with particle sizes between 2 nm and ∼4 nm, and 3.7 ± 0.7 nm-diameter particles demonstrated the highest combination of CO2RR activity and selectivity. Computational modeling of 1–10 nm Ag particles predicted a nearly identical size-dependent trend with maximum CO2RR activity predicted for 3.7 nm-diameter particles. Smaller diameter particles were predicted to favor HER due to a high population of Ag edge sites. CO2RR activity was predicted to increase for larger diameter particles as the population of Ag(100) surface sites grew, but a growing population of electrochemically inaccessible, interior atoms eventually decreased catalyst utilization for particle diameters above ∼4 nm. Our results resolve the CO2RR behavior of Ag in the critical sub-5 nm range, establish an effective minimum size limit for selective and active Ag catalysts, and provide insights to help guide future catalyst development efforts.

We demonstrate that electronic metal–support interactions (EMSIs) between silver and carbon can dramatically improve the CO2 reduction reaction (CO2RR) performance of the small Ag nanoparticles. Ag–C EMSIs were created by ultrahigh vacuum deposition of Ag onto defect-containing (sputtered) highly oriented pyrolytic graphite, and calculations predicted that 1.02 e was transferred from Ag to carbon, which stabilized the *COOH reaction intermediate, lowered the potential-limiting CO2RR step, and improved the predicted CO2-to-CO performance. Experimentally, we identified a scaling relationship between particle size and the relative Ag–C EMSI strength, which improved the CO2-to-CO Faradaic efficiency of sub-2 nm Ag particles from 2 to ∼100% and increased the CO turnover frequency ∼15-fold compared with similarly sized Ag particles grown in the absence of Ag–C EMSIs. We extended this concept to grow sub-2 nm Ag electrocatalysts on commonly used carbon black catalyst supports and showed that the interaction with support defects could sustain CO selectivity comparable to larger particles, suggesting an approach for tailoring CO2RR electrocatalyst performance.

A comprehensive review of low-carbon hydrogen production via plastic waste gasification.

Seasonal storage of natural gas (NG), which primarily consists of methane (CH4), has been practiced for more than a hundred years at underground gas storage (UGS) facilities that use depleted hydrocarbon reservoirs, saline aquifers, and salt caverns. To support a transition to a hydrogen (H2) economy, similar facilities are envisioned for long-duration, underground H2 storage (UHS) of either H2 or H2/CH4 mixtures. Experience with UGS can be used to guide the deployment of UHS, so we identify and quantify factors (formation/fluid properties and engineering choices) that influence reservoir behavior (e.g., viscous fingering and gravity override), the required number of injection/withdrawal wells, and required storage volume, contrasting the differences between the storage of CH4, H2, and H2/CH4 mixtures. The most important engineering choices are found to be the H2 fraction in H2/CH4 mixtures, storage depth, and injection rate. Storage at greater depths (higher pressure), but with relatively lower temperature, is more favorable because it maximizes volumetric energy-storage density, while minimizing viscous fingering and gravity override due to buoyancy. To store an equivalent amount of energy, storing H2/CH4 mixtures in UHS facilities will require more wells and greater reservoir volume than corresponding UGS facilities. We use our findings to make recommendations about further research needed to guide deployment of UHS in porous reservoirs.

production with minimal carbon emissions.

The unique features of metal–organic frameworks (MOFs), such as their large surface areas and diversity of structures, make them suitable for a broad range of applications including storage, separation, and sensing of gases. Among all the MOFs, Mg-MOF-74 with the highest CO2 uptake at 1 bar and 25 °C would be particularly beneficial for CO2-related applications. One of the most critical enabling technologies for implementing Mg-MOF-74 is the preparation of dense and continuous films that would maximize the sorption behaviors. However, Mg-MOF-74 thin films present significant challenges in demonstrating large-scale coatings. Herein, we demonstrate for the first time high-quality Mg-MOF-74 films synthesized via a vapor-assisted crystallization (VAC) process. The VAC process described herein provides dense and highly crystalline layers of the Mg-MOF-74 thin film with a low coefficient of variation of film thickness below 7%. By minimizing the solvent use, the VAC process is also more environmentally friendly than conventional techniques. In this work, we first optimized a precursor solution for the VAC process and then investigated the effects of synthesis temperature, time, and droplet volume on the growth, crystallinity, and thickness of VAC Mg-MOF-74 films. The porosity of the MOF film was assessed by measuring the CO2 uptake at room temperature and 1 bar. The obtained VAC Mg-MOF-74 films possess a well-defined microporosity, as deduced from CO2 adsorption studies via quartz crystal microbalance (QCM) and comparison with bulk Mg-MOF-74 reference data. Furthermore, CO2 cyclic adsorption–desorption experiments on the VAC Mg-MOF-74 films showed scaled uptakes to a wide range of CO2 concentration without showing significant variations in the baseline. We specifically demonstrate how the film’s quality of the MOF affects adsorption behavior of CO2 on VAC Mg-MOF-74 and drop-cast Mg-MOF-74 films.

Environmental geospatial data and adult and larval mosquito collection data for up to 106 sites throughout the Republic of Korea (ROK) were used to develop ecological niche models (ENMs) of the potential geographic distribution for eight anopheline species known to occur there. The areas predicted suitable for the Hyrcanus Group species were the most extensive for Anopheles sinensis Wiedemann, An. kleini Rueda, An. belenrae Rueda, and An. pullus Yamada, intermediate for An. sineroides Yamada, and the most restricted for An. lesteri Baisas and Hu and the non-Hyrcanus Group species An. koreicus Yamada and Watanabe and An. lindesayi Yamada. The relative vectorial importance of these species is unknown, and all, except An. koreicus and An. lindesayi, are predicted to occur widely in the northwest of the ROK where malaria transmission has been sporadic since its resurgence in 1993. Our ENMs suggest that it is unlikely that An. koreicus and An. lindesayi are vectors, but we do not document consistent geographic differentiation that might incriminate any of the other species as vectors. Because all species are predicted to occur in North Korea, we also cannot reject the hypothesis that malaria infected mosquitoes from North Korea may have been the cause of the resurgence of malaria in the ROK. Ecological differentiation of the eight species is inferred from collection locations and 34 environmental layers based on remote sensing and global climatic averages. Interspecific differences were noted, and characterizing mosquito habitats by ground-based and remote sensing methods is proposed.

Malaria was eradicated and the Republic of Korea (ROK) declared "malaria free" in 1979. However, in 1993, a temperate strain of vivax malaria, expressing both latent and nonlatent disease populations, re-emerged near the demilitarized zone (DMZ), rapidly spread to civilian sectors near the DMZ, and increased exponentially in ROK military, veteran, and civilian populations through 1998. Malaria among all ROK populations decreased 5-fold from a high of 4142 cases in 2000 to a low of 826 cases in 2004, before increasing again to 2180 cases by 2007. Each malaria case in the ROK is reported in the metropolitan area/province where the diagnosis is made, which may be at some distance from the area where infection occurred. Therefore, it is difficult to ascertain transmission sites since approximately 60% of vivax malaria in Korea is latent with symptoms occurring >1 month to 24 months after infection. A review of case diagnosis for civilian, veteran, and military populations shows that nearly all malaria south of Gyeonggi and Gangwon Provinces is the result of veterans exposed in malaria high-risk areas along the DMZ and returning to their hometowns where they later develop malaria. Thus, malaria currently remains localized near the DMZ with limited transmission in provinces south of Seoul and has not spread throughout Korea as previously hypothesized. This report describes the reemergence of vivax malaria cases in civilian and military ROK populations and U.S. military personnel and assesses variables related to its transmission and geographic distribution.

Malaria is a significant health threat to U.S. combat forces that are deployed to malaria-endemic regions. From 1979, when the Republic of Korea (ROK) was declared malaria free, malaria did not present a health threat to U.S. forces deployed to Korea until the early 1990s. In 1993, a temperate strain of vivax malaria expressing both latent (long prepatent incubation periods of usually 6-18 months after infection) and nonlatent (short prepatent incubation periods < 30 days after infection) disease reemerged near the demilitarized zone (DMZ) and once again presented a primary health threat to U.S. military populations in the ROK. Following its reemergence, malaria rates increased dramatically through 1998 and accounted for > 44% of all malaria cases among U.S. Army soldiers from 1997 to 2002. More than 60% of all Korean-acquired malaria among U.S. soldiers was identified as latent malaria. Nearly 80% of all latent malaria attributed to exposure in Korea was diagnosed in the U.S. or other countries where soldiers were deployed. These data illustrate the requirement for a comprehensive malaria education program, especially for those soldiers residing or training in malaria high-risk areas, to inform soldiers and providers of the risk of developing malaria after leaving Korea.

ABSTRACT Introduction Unlike endoskeletal connectors and prosthetic feet, prosthetic sockets are not subjected to structural strength testing using internationally recognized test standards, such as International Organization for Standardization (ISO) 10328. Definitive prosthetic sockets fabricated in the traditional manner have been shown to be inconsistent in the ability to withstand the loads applied by these standards. Persistent concerns regarding the strength and durability of 3D-printed prosthetic sockets are a barrier to clinical adoption of 3D-printing technologies in prosthetic socket fabrication. To develop a robust prosthetic socket design based on 3D-printing technology, an iterative development process was used with integral validation testing using the ISO 10328 loading conditions performed independently by two testing centers. Materials and Methods Twenty-four 3D-printed transtibial prosthetic sockets were tested using ISO 10328 loading conditions designed to represent the greatest atypical elevated loads a 125-kg user would be expected to place on their prosthesis without failure (ultimate strength test at the P6 load level). Several design iterations and variations were tested. One socket of a design that withstood the ultimate strength loading was reprinted and subjected to cyclic testing, up to 3 million cycles. All tests were conducted under the forefoot loading condition (Condition II of the ISO 10328 standard), which generates greater moments at the distal end of the socket than the heel loading condition. Results Early socket designs were unable to withstand the ISO 10328 ultimate strength test to the P6 load level. Successive design improvements increased the strength until a robust final design was achieved. Variations of that final design for different suspension types and a different limb model demonstrated consistent performance. The final design was significantly stronger than the initial design ( P = 1.35 × 10 −7 ). The socket that was tested for durability completed the 3 million loading cycles at the P6 load level without damage and withstood the subsequent static proof loads. Conclusions An iterative design process with integral structural testing can result in strong, durable prosthetic sockets made using 3D-printing technology that may be robust to variations in limb size/shape and suspension type.

Threats to a nation's resources and forces are becoming increasingly lethal and mobile. Therefore, the ability to locate and interdict these threats is more important than ever. Search theory was developed during World War II (WWII), but remains an analytical tool vital to locating and countering the increasing threat. This paper presents results that demonstrate how simulation can be used to extend the analytical results of classic Search Theory. This paper presents a multi-agent simulation, built in the Java object-oriented programming language, and based on the Allied search for U-boats in the Bay of Biscay during WWII. Key components of the model are validated against historical data using statistical methods. The model is then used to empirically examine the utility of various modern search patterns particularly when rigid Search Theory assumptions are relaxed.

Abstract Estimating the material flows of rare earth elements (REEs) is essential to understanding which industries are most vulnerable to potential REE supply disruptions which, in turn, may inform policy recommendations aimed at reducing the supply risk. However, the REEs are a group of mineral commodities characterized by highly uncertain estimates of supply and demand due to the REE market's complexity, opacity, and small size. In this study, a streamlined methodology was applied to map mineral commodity first‐use to final‐use applications and to estimate total requirements at the national level based on available industrial data for final‐use finished goods. This analysis examines REEs both as a group and individually, showing that total US requirements are between 15% and 16.5% of world requirements for the year 2015, the latest year with the most complete information available. The findings shed light on US industrial capabilities by revealing the discrepancy between the types of REEs that go into US raw material consumption and those that are contained in embedded consumption. For instance, given the United States’ large oil refining industry, US raw material consumption of lanthanum is quite high. In contrast, US raw material consumption of neodymium is relatively low, whereas embedded demand is comparatively high. This reflects the lack of industrial capacity to process REE concentrates into magnet material combined with the US's high imports of products that contain rare earth permanent magnets.

Geologic carbon storage (GCS) is a rapidly evolving technology with the potential to reduce the environmental impact of fossil fuel usage. Saline aquifers, which comprise a sandstone matrix with brine contained in the pores, make up much of the pore space available for CO2 storage in the United States. When CO2 is injected in saline aquifers, however, capillary fingering occurs, and only a small percentage of the pore space is filled with CO2. This fingering effect is due to the low viscosity of CO2, which is roughly ten times less viscous than brine. To address this problem, we tested the ability of inexpensive, commercially available nonionic surfactants to be dissolved in injected CO2 and increase the apparent viscosity of CO2 by generating CO2-in-water foams in situ. We focused our study on nonionic tridecyl ethoxylate surfactants with the number of ethoxylate groups ranging from 11 to 18 (TDA-11, TDA-13, TDA-15, TDA-18). These surfactants exhibited sufficient CO2-solubility and were shown to reduce the CO2-brine interfacial tension (IFT), stabilize bulk CO2-in-brine foams, and reduce the mobility of CO2 during core floods of CO2 in brine-saturated Berea sandstone. The surfactants did not alter the wettability of the Berea sandstone. Modeling results showed that in a reservoir field injection scenario, the presence of TDA-11 (0.1 wt %) increased both the CO2 storage resource and storage efficiency by 17%. Simulations also showed that the lateral extension area of the plume was reduced by 23% and that CO2 saturation within the plume increased by 26%.