Reviewing Martha Zierden’s distinguished career in the Carolina Lowcountry, I was struck by the many times Martha brought research from the Chesapeake region to bear on findings from Charleston. I build on the ground Martha prepared by comparing Indigenous ceramics recovered from late 17th-century trading post/station archaeological sites in Virginia and Carolina. This preliminary analysis identifies similarities and differences between these sites with implications for understanding the many forms colonialism took in English North America.

after South arrived at SCIAA, in 1972, Leland Ferguson began his own career there, finding in the analysis of colonoware ceramics a point of entry into the experiences of enslaved Africans along the South Carolina coast and their stewardship of rice culture, a principal source of the region's stupendous wealth. 2 Other archaeologists took on some of the broad research questions South and Ferguson pursued, but none perhaps as persistent, or with the longevity, of Martha Zierden at the Charleston Museum. 3 The Society for Historical Archaeology (SHA) recognized Martha's contributions to the archaeology of Charleston and its Lowcountry environs at its 2022 annual meeting in Philadelphia, where she received the J. C.

Rheological modifiers enable direct ink writing of polymers with low viscosity such as epoxy without requiring light or heat. Modifiers that conduct electrons and phonons impart multifunctional properties to 3D printed polymers. Here, we report the development of printable nanocomposite inks comprised of epoxy, carbon fibers (CFs), and carbon nanotubes (CNTs) to achieve excellent mechanical properties and multifunctionality via high electrical conductivity required for next -generation light weight aerospace, electronics, and energy applications. CF and CNT concentrations of 8.5 and 1.7 wt%, respectively, render the material shear -thinning with a high yield stress, hence printable and self-supporting after being printed. An average electrical conductivity of 10-2 S/cm and thermal conductivity of 0.3 W/m.K were measured for the 3D -printed multi -layer structures. Furthermore, tensile modulus, tensile strength, flexural modulus, and flexural strength were measured to be 5.8, 0.08, 6.0, and 0.1 GPa, respectively. Compared with other 3D printed conductive polymer nanocomposites with reported electrical conductivity and elastic modulus, the structures here have the highest specific elastic modulus. They also possess the highest electrical conductivity among the 3D printed polymeric composites of carbon nanomaterials with an elastic modulus above 1 GPa. This is due to the outstanding combination of CNTs, CFs, and epoxy. The results expand the range of polymer properties for multifunctional applications.

It is well-known that all-atom molecular dynamics (MD) predictions of mechanical properties of thermoset resins suffer from multiple accuracy issues associated with their viscoelastic nature. The nanosecond simulation times of MD simulations do not allow for the direct simulation of the molecular conformational relaxations that occur under laboratory time scales. This adversely affects the prediction of mechanical properties at realistic strain rates, intermediate degrees of cure, and elevated temperatures. While some recent studies have utilized a time-temperature superposition approach to relate MD predictions to expected laboratory observations, such an approach becomes prohibitively difficult when simulating thermosets with a combination of strain rates, intermediate degrees of cure, and temperatures. In this study, a phenomenological approach is developed to map the predictions of Young's modulus and Poisson's ratio for a DGEBF/DETDA epoxy system to the corresponding laboratory-based properties for intermediate degrees of cure and temperatures above and below the glass transition temperature. The approach uses characterization data from dynamical mechanical analysis temperature sweep experiments. The mathematical formulation and experimental characterization of the mapping is described, and the resulting mapping of computationally-predicted to experimentally-observed elastic properties for various degrees of cure and temperatures are demonstrated and validated. This mapping is particularly important to mitigate the strain-rate effect associated with MD predictions, as well as to accurately predict mechanical properties at elevated temperatures and intermediate degrees of cure to facilitate accurate and efficient composite material process modeling.

Glassy carbon (GC) material derived from pyrolyzed furan resin was modeled by using reactive molecular dynamics (MD) simulations. The MD polymerization simulation protocols to cure the furan resin precursor material are validated via comparison of the predicted density and Young's modulus with experimental values. The MD pyrolysis simulations protocols to pyrolyze the furan resin precursor is validated by comparison of calculated density, Young's modulus, carbon content, sp(2) carbon content, the in-plane crystallite size, out-of-plane crystallite stacking height, and interplanar crystallite spacing with experimental results from the literature for furan resin derived GC. The modeling methodology established in this work can provide a powerful tool for the modeling-driven design of next-generation carbon-carbon composite precursor chemistries for thermal protection systems and other high-temperature applications.

During the manufacturing of composite structures, cure shrinkage of the thermoset matrix and differential thermal contraction mismatch between the matrix and fiber reinforcement cause the formation of residual stresses, which can result in a loss in structural durability. New multiscale computational process modeling is essential for linking material chemistry, processing parameters, residual stress evolution, and optimizing mechanical performance. This study establishes a new multiscale process modeling method to accurately predict residual stresses in a unidirectional carbon fiber/epoxy composite using molecular dynamics and finite element analysis simulation techniques. The results of this work demonstrate that process-induced residual stresses have a significant impact on the composite strength in transverse tension, out-of-plane shear, and in-plane shear, with a maximum reduction in strength of 35%. Moving forward, this method can be used as a design and optimization tool for future composite structures for specific engineering applications and can provide processing parameters that can maximize desirable composite properties and/or minimize composite manufacturing energy and cost.

For more than a century, researchers have used the distribution of Indigenous Rappahannock River settlements shown on John Smith’s 1608 map of Virginia to frame the river valley’s Native communities as unwilling subjects of the Powhatan chiefdom to their south. The map depicts the majority of Native settlements on the river’s north bank, a pattern interpreted as evidence that the Rappahannock communities physically distanced themselves as much as possible from Powhatan political control. Rappahannock tribal oral history, however, holds that the Rappahannock polities and the Powhatans enjoyed a political relationship as equals and neighbors, not as subjects or adversaries. Tribal historical and ecological knowledge, publicly available environmental information, and the distribution of known archaeological sites indicate that desirable factors for settlement—including level sandy loam soils, access to marshes, proximity to navigable waterways, and wide viewsheds—occur more frequently and in closer association with one another on the river’s north bank. This analysis’s mixed-methods and materials approach reveals the unevenly distributed and often highly contingent nature of Indigenous political authority at the time of European invasion.

To enable the design and development of the next generation of high-performance composite materials, there is a need to establish improved computational simulation protocols for accurate and efficient prediction of physical, mechanical, and thermal properties of thermoset resins. This is especially true for the prediction of glass transition temperature (Tg), as there are many discrepancies in the literature regarding simulation protocols and the use of cooling rate correction factors for predicting values using molecular dynamics (MD) simulation. The objectives of this study are to demonstrate accurate prediction the Tg with MD without the use of cooling rate correction factors and to establish the influence of simulated conformational state and heating/cooling cycles on physical, mechanical, and thermal properties predicted with MD. The experimentally-validated MD results indicate that accurate predictions of Tg, elastic modulus, strength, and coefficient of thermal expansion are highly reliant upon establishing MD models with mass densities that match experiment within 2%. The results also indicate the cooling rate correction factors, model building within different conformational states, and the choice of heating/cooling simulation runs do not provide statistically significant differences in the accurate prediction of Tg values, given the typical scatter observed in MD predictions of amorphous polymer properties.

Huntsman–Merrimack MIRALON® carbon nanotubes (CNTs) are a novel, highly entangled, commercially available, and scalable format of nanotubes. As-received and acid-treated CNTs were added to aerospace grade epoxy (CYCOM® 977-3), and the composites were characterized. The epoxy resin is expected to infiltrate the network of the CNTs and could improve mechanical properties. Epoxy composites were tested for flexural and viscoelastic properties and the as-received and acid treated CNTs were characterized using Field-Emission Scanning and Transmission Electron Microscopy, X-Ray Photoelectron Spectroscopy, and Thermogravimetric Analysis. Composites containing 0.4 wt% as-received CNTs showed an increase in flexural strength, from 136.9 MPa for neat epoxy to 147.5 MPa. In addition, the flexural modulus increased from 3.88 GPa for the neat epoxy to 4.24 GPa and 4.49 GPa for the 2.0 wt% and 3.0 wt% as-received CNT/epoxy composites, respectively. FE-SEM micrographs indicated good dispersion of the CNTs in the as-received CNT/epoxy composites and the 10 M nitric acid 6 h treatment at 120 °C CNT/epoxy composites. CNTs treated with 10 M nitric acid for 6 h at 120 °C added oxygen containing functional groups (C–O, C=O, and O=C–O) and removed iron catalyst present on the as-received CNTs, but the flexural properties were not improved compared to the as-received CNT/epoxy composites.

Thermoset resin-based composite materials are widely used in the aerospace industry, mainly due to their high stiffness-to-weight and strength-to-weight ratios. A major issue with the use of thermoset resins in fiber composites is the process-induced residual stresses that are formed from resin chemical shrinkage during the curing process. These residual stresses within the composite material ultimately result in reduced durability and residual deformations of the final product. Polybenzoxazine (PBZ) polymer resins have demonstrated near-zero volumetric shrinkage during the curing process. Although the low shrinkage of PBZ is promising in terms of reduced process-induced residual stresses, little is known about the physical causes. In this work, Molecular Dynamics (MD) simulations are performed with a reactive force field to predict physical properties (gelation point, evolution of network, mass density, volumetric shrinkage) and mechanical properties (Bulk modulus, Shear modulus, Young's modulus, Poisson's ratio, Yield strength) as a function of crosslinking density. The MD modeling procedure is validated herein using experimental measurements of the modeled PBZ resin. The results of this study are used to provide a physical understanding of the zero-shrinkage phenomenon of PBZ. This information is also a critical input to future process modeling efforts for PBZ composites.

In this work, Molecular Dynamics (MD) simulations are performed to predict the physical properties (gelation point, mass density, volumetric shrinkage) and mechanical properties (Bulk modulus, Shear modulus, Young’s Modulus, Poisson’s ratio) of a PolyBenzoxazine (PBZ) resin system as a function of crosslinking density. The molecular models are developed using the Reactive Interface Force Field (IFF-R). The results obtained from MD are in good agreement with the experimental data.

NOTE: The first page of text has been automatically extracted and included below in lieu of an abstract Engineering Education in Alternative Energy Abstract This paper describes education and research efforts in alternative energy at Michigan Technological University (MTU). A particular emphasis will be placed on the multidisciplinary education of chemical engineering undergraduate students in alternative energy. Experiences can involve enrollment in an interdisciplinary design project, an elective fuel cell course, a hydrogen fuel cell “electrochemical engineering” laboratory, or performing basic or applied research with university faculty and staff. Teaching and mentoring opportunities are also available to doctoral students. The major aspect of the experience is the Alternative Fuels and Fuel Cell Enterprise (AFE). This is a multidisciplinary, research-oriented undergraduate research project which is run as a business with student management and faculty / staff oversight. The students are currently working on the development of a hybrid, alternative fuel military transport and a transportable alternative energy demonstration unit. Furthermore, these students are involved in minor projects studying other forms of alternative energy, alternative energy applications, or energy integration. This project is in its fourth year and typically enrolls about thirty chemical, mechanical, and electrical engineering undergraduates. Introduction Alternative energy is a topic of current interest due to rising oil costs due to increased worldwide demand and political instability in the Middle East. During the 2004 election campaigns, both President George W. Bush and Senator John Kerry discussed as part of their platforms an increased focus on alternative energy research and development. Furthermore, within the State of Michigan there has been increased emphasis on fuel cell applications to motor vehicles. To prepare our students to create the future, faculty and staff at MTU have developed a wide range of interdisciplinary courses and projects in alternative energy. After describing the structure of the MTU enterprise program, the AFE enterprise and its projects will be presented. This program allows for a unique, multidisciplinary integration of research into teaching. Following this will be a description of the elective course, laboratory, and focused research projects. The MTU Enterprise Program MTU students can pursue a minor or concentration (curriculum shown in Table 1 with elective modules listed in Table 2) in the Enterprise program as part of their respective accredited degree program. A vertical (sophomores, juniors, and seniors) and horizontal (various engineering and business disciplines) integration makes the program a unique experience for students. Over 10% of students enrolled in the College of Engineering are involved in (mostly) industry-sponsored enterprise projects, in one of twenty enterprises.

The objective of this study is to design a new nano graphenecarbon fiberpolymer hybrid composite that can be used for the NASA SLS Composite Exploration Upper Stage (CEUS) forward skirt structure. The new material will improve the resistance to open-hole compression failure of the structure relative to traditional polymer fiber composites. The material is designed rapidly and with little cost using the Integrated Computational Materials Engineering (ICME) approach. Multiscale modeling and experiments are used to synergistically optimize the material design to yield improved properties and performance by controlling key processing parameters for manufacturing nano-enhanced materials. Specifically, the nanocomposite panel showed a 22 reduction in mass relative to the traditional composite panel, while both designs are equal in terms of ease of manufacture. This potential mass savings corresponds to an estimated 45 savings in materials and manufacturing costs. The multiscale ICME workflow developed for this project can be readily applied to the development of nano-enhanced composite materials and large aerospace structures. In addition, all key aspects of ICME were employed to complete this project including multiscale modeling, experimental characterization and visualization, data management, visualization, error and uncertainty quantification, and education. The results presented herein indicate a dramatic level of success, as well as the power and potential of ICME approach and multiscale modeling for composite materials.

Archaeological collections repositories have two principal aims: preserving collections while also making them accessible. This accessibility is critical for the growing number of researchers turning to collections to study the past. This article describes steps that repositories can take to enhance access to collections in their custody, based on the experience of the Maryland Archaeological Conservation Laboratory, the state's public archaeological curation facility. These steps include the identification of stakeholders-archaeologists, Native American tribes, and stakeholder communities; creation of a detailed and prioritized collection inventory including artifacts and records; development of finding aids; reconstruction of provenience systems; and exploration of the digital delivery of collection information. For repositories ill equipped to hold archaeological collections, consideration should be given to transferring the collection to one with the appropriate resources and expertise.

Polyether ether ketone (PEEK) is a high-performance, semi-crystalline thermoplastic that is used in a wide range of engineering applications, including some structural components of aircraft. The design of new PEEK-based materials requires a precise understanding of the multiscale structure and behavior of semi-crystalline PEEK. Molecular dynamics (MD) modeling can efficiently predict bulk-level properties of single phase polymers, and micromechanics can be used to homogenize those phases based on the overall polymer microstructure. In this study, MD modeling was used to predict the mechanical properties of the amorphous and crystalline phases of PEEK. The hierarchical microstructure of PEEK, which combines the aforementioned phases, was modeled using a multiscale modeling approach facilitated by NASA's MSGMC. The bulk mechanical properties of semi-crystalline PEEK predicted using MD modeling and MSGMC agree well with vendor data, thus validating the multiscale modeling approach.

Reviewed by: Blackbeard's Sunken Prize: The 300-Year Voyage of Queen Anne's Revenge by Mark U. Wilde-Ramsing and Linda F. Carnes-McNaughton Julia A. King Blackbeard's Sunken Prize: The 300-Year Voyage of Queen Anne's Revenge. By Mark U. Wilde-Ramsing and Linda F. Carnes-McNaughton. ( Chapel Hill: University of North Carolina Press, 2018. Pp. xiv, 205. Paper, $28.00, ISBN 978-1-4696-4052-5.) Blackbeard's Sunken Prize: The 300-Year Voyage of Queen Anne's Revenge is a well-illustrated study of the ship that Edward Thache, the pirate better known as Blackbeard, ran aground off the North Carolina coast in 1718. The skeletal remains of the Queen Anne's Revenge (QAR), along with tens of thousands of artifacts, were ultimately recovered and analyzed by a vast interdisciplinary research team, shedding light on the material world of piracy in the late-seventeenth- and early-eighteenth-century Atlantic world. The book is organized into eight chapters, with maps, graphs, tables, and dozens of photographs, many of them of artifacts. The Queen Anne's Revenge, originally a French privateer and slaver captured near Martinique in 1717 by Thache, soon became a heavily armed pirate ship engaging in a "six-month spree" of pillage and plunder along the coast of North America (p. 3). The shipwreck yielded not only the artifacts of Thache's pirate flagship but also artifacts and snippets of Akan gold jewelry from when the ship sailed under the French flag. Mark U. Wilde-Ramsing and Linda F. Carnes-McNaughton use the artifacts to present a compelling teaser of life aboard a pirate ship, finding that "Captain Thache maintained traditional [End Page 663] hierarchal control from his cabin in the stern" (p. 160). The area of the ship that housed the officers, including Thache, yielded fancy dinnerware, coins, gold dust, and tellingly, most of the lead shot recovered from the wreck. Other findings include the extent of wear and repair of the ship's arms and armament, suggesting that the ship's gunsmiths kept busy managing stolen weapons. Preservation of the ship and its contents was extraordinary, with a wide range of materials recovered, including (to name but a few) ship's timbers and hardware, lamps, navigational equipment, weapons of all kinds, medical tools, ceramics, glass, clothing, and even remnants of cloth sails. Still, the authors argue, only with "full recovery" will the "real treasure" of the ship be finally realized by answering unspecified "broader questions" (p. 164). The authors go on to suggest that the QAR's significance lies "first and foremost" in its contributions to the conservation of materials recovered through underwater archaeology (p. 164). Archaeological conservation, especially for materials from submerged contexts, is no small (or inexpensive) undertaking. The lessons conservators can take from the QAR will no doubt be of value to the future work of shipwreck recovery. But what of the so-called broader questions? What can the recovered evidence suggest about the economic, social, and cultural significance of piracy? Answers can be partially found in the book's detailed discussions of the artifacts. Missing from the book, however, is a section or chapter synthesizing the findings of these individual discussions, relating them to the documentary evidence, and contextualizing them in the growing body of scholarship on early Atlantic piracy, such as Marcus Rediker's Villains of All Nations: Atlantic Pirates in the Golden Age (Boston, 2004). There are two stories at play in this book. The first is about Edward Thache, the pirate known as Blackbeard, and the things found aboard his flagship. This story brings a unique body of evidence to bear on the understanding of early modern piracy. The second story—the epic narrative of the discovery, recovery, and analysis of the three-hundred-year-old shipwreck—nearly swamps the first. No doubt this undertaking was a complex project, but its recounting is overdone. For example, the three-page table in the main body of the text that lists every participant, research topic, institutional affiliation, region, and publication date is information better suited to a bibliography. Nonetheless, the results of the project are published, which is no small achievement, and the material has been...