Matching Items (8)
Description
This research addresses human adaptive decisions made at the Pleistocene-Holocene transition - the transition from the Last Glacial Maximum (LGM) to the climate regime in which humankind now lives - in the Mediterranean region of southeast Spain. Although on a geological time scale the Pleistocene-Holocene transition is the latest in a series of widespread environmental transformations due to glacial-interglacial cycles, it is the only one for which we have a record of the response by modern humans. Mediterranean Spain lay outside the refugium areas of late Pleistocene Europe, in which advancing ice sheets limited the land available for subsistence and caused relative demographic packing of hunter-gatherers. Therefore, the archaeological records of Mediterranean Spain contain more generally applicable states of the Pleistocene-Holocene transition, making it a natural laboratory for research on human adaptation to an environmental transformation. Foragers in Mediterranean Spain appear to have primarily adapted to macroclimatic change by extending their social networks to access new subsistence resources and by changing the mix of traditional relationships. Comparing faunal records from two cave sites near the Mediterranean coast with Geographic Information System (GIS) reconstructions of the coastal littoral plain from the LGM to the Holocene indicates the loss of the large ungulate species (mainly Bos primigenius and Equus) at one site coincided with the associated littoral disappearing due to sea level rise in the late Upper Paleolithic. Farther north, where portions of the associated littoral remained due to a larger initial mass and a more favorable topography, the species represented in the faunal record were constant through time. Social boundary defense definitions of territory require arranging social relationships in order to access even this lightly populated new hunting area on the interior plain. That the values of the least-cost-paths fit the parameters of two models equating varying degrees of social alliance with direct travel distances also helps support the hypothesis that foragers in Mediterranean Spain adapted to the consequences of macroclimatic change by extending their social networks to gain access to new subsistence resources Keeping these relationships stable and reliable was a mitigating factor in the mobility patterns of foragers during this period from direct travel to more distant down-the-line exchange. Information about changing conditions and new circumstances flowed along these same networks of social relationships. The consequences of climate-induced environmental changes are already a concern in the world, and human decisions in regard to future conditions are built upon past precedents. As the response to environmental risk centers on increasing the resilience of vulnerable smallholders, archaeology has an opportunity to apply its long-term perspective in the search for answers
ContributorsSchmich, Steven A (Author) / Clark, Geoffrey A. (Thesis advisor) / Barton, Michael (Thesis advisor) / Bearat, Hamdallah (Committee member) / Jochim, Michael A. (Committee member) / Arizona State University (Publisher)
Created2013
Description
Inductors are fundamental components that do not scale well. Their physical limitations to scalability along with their inherent losses make them the main obstacle in achieving monolithic system-on-chip platform (SoCP). For past decades researchers focused on integrating magnetic materials into on-chip inductors in the quest of achieving high inductance density and quality factor (QF). The state of the art on-chip inductor is made of an enclosed magnetic thin-film around the current carrying wire for maximum flux amplification. Though the integration of magnetic materials results in enhanced inductor characteristics, this approach has its own challenges and limitations especially in power applications. The current-induced magnetic field (HDC) drives the magnetic film into its saturation state. At saturation, inductance and QF drop to that of air-core inductors, eliminating the benefits of integrating magnetic materials. Increasing the current carrying capability without substantially sacrificing benefits brought on by the magnetic material is an open challenge in power applications. Researchers continue to address this challenge along with the continuous improvement in inductance and QF for RF and power applications.
In this work on-chip inductors incorporating magnetic Co-4%Zr-4%Ta -8%B thin films were fabricated and their characteristics were examined under the influence of an externally applied DC magnetic field. It is well established that spins in magnetic materials tend to align themselves in the same direction as the applied field. The resistance of the inductor resulting from the ferromagnetic film can be changed by manipulating the orientation of magnetization. A reduction in resistance should lead to decreases in losses and an enhancement in the QF. The effect of externally applied DC magnetic field along the easy and hard axes was thoroughly investigated. Depending on the strength and orientation of the externally applied field significant improvements in QF response were gained at the expense of a relative reduction in inductance. Characteristics of magnetic-based inductors degrade with current-induced stress. It was found that applying an externally low DC magnetic field across the on-chip inductor prevents the degradation in inductance and QF responses. Examining the effect of DC magnetic field on current carrying capability under low temperature is suggested.
In this work on-chip inductors incorporating magnetic Co-4%Zr-4%Ta -8%B thin films were fabricated and their characteristics were examined under the influence of an externally applied DC magnetic field. It is well established that spins in magnetic materials tend to align themselves in the same direction as the applied field. The resistance of the inductor resulting from the ferromagnetic film can be changed by manipulating the orientation of magnetization. A reduction in resistance should lead to decreases in losses and an enhancement in the QF. The effect of externally applied DC magnetic field along the easy and hard axes was thoroughly investigated. Depending on the strength and orientation of the externally applied field significant improvements in QF response were gained at the expense of a relative reduction in inductance. Characteristics of magnetic-based inductors degrade with current-induced stress. It was found that applying an externally low DC magnetic field across the on-chip inductor prevents the degradation in inductance and QF responses. Examining the effect of DC magnetic field on current carrying capability under low temperature is suggested.
ContributorsKhdour, Mahmoud (Author) / Yu, Hongbin (Thesis advisor) / Pan, George (Committee member) / Goryll, Michael (Committee member) / Bearat, Hamdallah (Committee member) / Arizona State University (Publisher)
Created2014
Description
This dissertation explores the interrelationships between periods of rapid social change and regional-scale social identities. Using archaeological data from the Cibola region of the U.S. Southwest, I examine changes in the nature and scale of social identification across a period of demographic and social upheaval (A.D. 1150-1325) marked by a shift from dispersed hamlets, to clustered villages, and eventually, to a small number of large nucleated towns. This transformation in settlement organization entailed a fundamental reconfiguration of the relationships among households and communities across an area of over 45,000 km2. This study draws on contemporary social theory focused on political mobilization and social movements to investigate how changes in the process of social identification can influence the potential for such widespread and rapid transformations. This framework suggests that social identification can be divided into two primary modes; relational identification based on networks of interaction among individuals, and categorical identification based on active expressions of affiliation with social roles or groups to which one can belong. Importantly, trajectories of social transformations are closely tied to the interrelationships between these two modes of identification. This study has three components: Social transformation, indicated by rapid demographic and settlement transitions, is documented through settlement studies drawing on a massive, regional database including over 1,500 sites. Relational identities, indicated by networks of interaction, are documented through ceramic compositional analyses of over 2,100 potsherds, technological characterizations of over 2,000 utilitarian ceramic vessels, and the distributions of different types of domestic architectural features across the region. Categorical identities are documented through stylistic comparisons of a large sample of polychrome ceramic vessels and characterizations of public architectural spaces. Contrary to assumptions underlying traditional approaches to social identity in archaeology, this study demonstrates that relational and categorical identities are not necessarily coterminous. Importantly, however, the strongest patterns of relational connections prior to the period of social transformation in the Cibola region largely predict the scale and structure of changes associated with that transformation. This suggests that the social transformation in the Cibola region, despite occurring in a non-state setting, was governed by similar dynamics to well-documented contemporary examples.
ContributorsPeeples, Matthew A. (Author) / Kintigh, Keith W. (Thesis advisor) / Hegmon, Michelle (Thesis advisor) / Spielmann, Katherine A. (Committee member) / Arizona State University (Publisher)
Created2011
Description
In recent years, southern Africa has figured prominently in the modern human origins debate due to increasing evidence for precocious behaviors considered to be unique to our species. These significant findings have included bone tools, shell beads, engraved ostrich eggshell, and heavily ground and engraved ochre fragments. The presence of ochre in Middle Stone Age (MSA, ~250-40kya) archaeological sites in southern Africa is often proposed as indirect evidence for the emergence of symbolic or artistic behavior, a uniquely modern human trait. However, there is no remaining artwork from this period and there is significant debate about what the ochre may have been used for. With a few exceptions, ochre has gone largely unstudied. This project tested competing models for ochre use within the Pinnacle Point (PP), South Africa research area. Combined results from characterization and sourcing analyses, color classification, heat treatment analysis, and hafting experiments suggest MSA ochre is tied to early symbolic or ritual behavior.
ContributorsBernatchez, Jocelyn A (Author) / Marean, Curtis W (Thesis advisor) / Bearat, Hamdallah (Committee member) / Abbott, David (Committee member) / Arizona State University (Publisher)
Created2012
Description
Foodways in societies at every social scale are linked in complex ways to processes of social change. This dissertation explores the interrelationship between foodways and processes of rapid social transformation. Drawing on a wide range of archaeological and ethnographic data from the Cibola region, I examine the role of foodways in processes of population aggregation and community formation and address how changes in the scale and diversity of social life interacted with the scale and organization of food production and consumption practices. To address the interrelationships between foodways and social transformations, I employ a conceptual framework focused on two social dimensions of food: cuisine and commensality. This study comparatively examines cuisine and commensality through time by investigating a range of interrelated food activities including: food production, storage, preparation, cooking, consumption and discard.
While settlement patterns and other more obvious manifestations of aggregation have been studied frequently, by examining foodways during periods of aggregation and social reorganization this study provides new insights into the micro-scalar processes of social transformation, cuisine change, and economic intensification associated with increases in settlement size, density, and social diversity. I document how food production and preparation intensified in conjunction with increases in the size of settlements and the scale of communal commensal events. I argue that foodways were a critical aspect of the social work of establishing and maintaining large, dense communities in the 13th and 14th centuries. At the same time, widespread changes in commensal practices placed a larger burden on household surplus and labor and women were likely the most affected as maize flatbreads and other foods made with finely ground flour were adopted and became central to cuisine. As such, this study provides insights into how rapid social transformations in the late 13th and 14th centuries were experienced differently by individuals, particularly along gendered lines. Studies of foodways, and specifically the social dimensions of food, offer a promising and often underutilized source of information about past processes of population aggregation, social integration, and transformations in the political economies of small-scale societies the past.
While settlement patterns and other more obvious manifestations of aggregation have been studied frequently, by examining foodways during periods of aggregation and social reorganization this study provides new insights into the micro-scalar processes of social transformation, cuisine change, and economic intensification associated with increases in settlement size, density, and social diversity. I document how food production and preparation intensified in conjunction with increases in the size of settlements and the scale of communal commensal events. I argue that foodways were a critical aspect of the social work of establishing and maintaining large, dense communities in the 13th and 14th centuries. At the same time, widespread changes in commensal practices placed a larger burden on household surplus and labor and women were likely the most affected as maize flatbreads and other foods made with finely ground flour were adopted and became central to cuisine. As such, this study provides insights into how rapid social transformations in the late 13th and 14th centuries were experienced differently by individuals, particularly along gendered lines. Studies of foodways, and specifically the social dimensions of food, offer a promising and often underutilized source of information about past processes of population aggregation, social integration, and transformations in the political economies of small-scale societies the past.
ContributorsOas, Sarah E (Author) / Hegmon, Michelle (Thesis advisor) / Kintigh, Keith W. (Thesis advisor) / Morehart, Christopher T. (Committee member) / Peeples, Matthew A. (Committee member) / Arizona State University (Publisher)
Created2019
Description
Calcium hydroxide carbonation processes were studied to investigate the potential for abiotic soil improvement. Different mixtures of common soil constituents such as sand, clay, and granite were mixed with a calcium hydroxide slurry and carbonated at approximately 860 psi. While the carbonation was successful and calcite formation was strong on sample exteriors, a 4 mm passivating boundary layer effect was observed, impeding the carbonation process at the center. XRD analysis was used to characterize the extent of carbonation, indicating extremely poor carbonation and therefore CO2 penetration inside the visible boundary. The depth of the passivating layer was found to be independent of both time and choice of aggregate. Less than adequate strength was developed in carbonated trials due to formation of small, weakly-connected crystals, shown with SEM analysis. Additional research, especially in situ analysis with thermogravimetric analysis would be useful to determine the causation of poor carbonation performance. This technology has great potential to substitute for certain Portland cement applications if these issues can be addressed.
ContributorsHermens, Stephen Edward (Author) / Bearat, Hamdallah (Thesis director) / Dai, Lenore (Committee member) / Mobasher, Barzin (Committee member) / Barrett, The Honors College (Contributor) / Chemical Engineering Program (Contributor)
Created2015-05
Description
I propose a new approach for the analysis of social transformations within the context of colonialism. Drawing on concepts used by historical sociologists, combined with insights from historians and archaeologists, I forge a synthesis of relational mechanisms that concatenated into processes of categorical change. Within the social sciences, mechanisms are formally defined as specific classes of events or social interactions that are causally linked and tend to repeat under specific conditions, potentially resulting in widespread social transformations. Examples of mechanisms include formal inscription through spatial segregation and adjustments in individual position through socioeconomic mobility.
For New Spain, historians have identified at least three macroscale shifts in the social structure of the viceroyalty. I examine the mechanisms that led to these changes in two distinct contexts. The Port of Veracruz (Mexico), located along the main axis of colonial exchange, offers a shifting baseline for comparison of the long-term trajectory of colonial interaction and categorical change. I undertake a finer grain study at the borderland presidios of Northwest Florida, where three presidios were sequentially occupied (AD 1698-1763) and historically linked to Veracruz through formal recruitment and governmental supply.
My analysis draws on two independent lines of evidence. Historically, I examine census records, maps, and other colonial documents. Archaeologically, I assess change in interaction mainly through technological style analysis, compositional characterization, and the distribution of low visibility plain and lead-glazed utilitarian wares. I document the active expression of social categories through changing consumption of highly visible serving vessels.
This study demonstrates that colonial transformations were driven locally from the bottom up and through the top-down responses of local and imperial elites who attempted to maintain control over labor and resources. Social changes in Florida and Veracruz were distinct based upon initial conditions and historical contingencies, yet simultaneously were influenced by and contributed to broad trajectories of macroscale colonial transformations.
For New Spain, historians have identified at least three macroscale shifts in the social structure of the viceroyalty. I examine the mechanisms that led to these changes in two distinct contexts. The Port of Veracruz (Mexico), located along the main axis of colonial exchange, offers a shifting baseline for comparison of the long-term trajectory of colonial interaction and categorical change. I undertake a finer grain study at the borderland presidios of Northwest Florida, where three presidios were sequentially occupied (AD 1698-1763) and historically linked to Veracruz through formal recruitment and governmental supply.
My analysis draws on two independent lines of evidence. Historically, I examine census records, maps, and other colonial documents. Archaeologically, I assess change in interaction mainly through technological style analysis, compositional characterization, and the distribution of low visibility plain and lead-glazed utilitarian wares. I document the active expression of social categories through changing consumption of highly visible serving vessels.
This study demonstrates that colonial transformations were driven locally from the bottom up and through the top-down responses of local and imperial elites who attempted to maintain control over labor and resources. Social changes in Florida and Veracruz were distinct based upon initial conditions and historical contingencies, yet simultaneously were influenced by and contributed to broad trajectories of macroscale colonial transformations.
ContributorsEschbach, Krista (Author) / Stark, Barbara L. (Thesis advisor) / Smith, Michael E. (Thesis advisor) / Alexander, Rani T (Committee member) / Worth, John E. (Committee member) / Bearat, Hamdallah (Committee member) / Peeples, Matthew A. (Committee member) / Arizona State University (Publisher)
Created2019
Description
This research combines traditional archaeological analysis with lidar data to investigate infrastructure, residential architecture, and neighborhoods in a completely new way. Taken together, these analyses show the shape and form of this city during its apogee in CE 650, while providing a deeper understanding of its civic administration through the use of multiple urban levels (citywide, district, neighborhood, and residential/plazuela). Independently, any one of these results may provide an incomplete picture or inaccurate conclusion, but, when conjoined, the analyses interdigitate to shed light on the city as a whole. This research showcases the physical infrastructural power of this city through the widespread distribution of its urban services among the city’s districts while still highlighting tiers of urban services among districts. It reinforces the idea of household architectural autonomy through the lack of standardization in the built environment, while also highlighting the relative equality of residences. And, it emphasizes both citywide and neighborhood-based similarities in categorical identities that would have facilitated collective action among individuals in the past by reducing the friction to initiate collective endeavors. Taken together, these results suggest both autocratic and collective governance, and views from different urban levels when combined provide a more detailed perspective on the multiple interacting and concurrent processes that determined urban life and structure in the past. These analyses also hold the potential to shed light on other governance practices in future comparative urban research on archaeological, historical, and modern cities. However, the initial findings reported in this dissertation suggest that Caracol enjoyed a more collective system of governance processes despite the hieroglyphic record of a lineage of rulers.
ContributorsChase, Adrian Sylvanus Zaino (Author) / Smith, Michael E. (Thesis advisor) / Nelson, Ben A. (Committee member) / York, Abigail M. (Committee member) / Peeples, Matthew A. (Committee member) / Arizona State University (Publisher)
Created2021