793 research outputs found

    Glass in the submarine section of the HSDP2 drill core, Hilo, Hawaii

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    The Hawaii Scientific Drilling Project recovered ~3 km of basalt by coring into the flank of Mauna Kea volcano at Hilo, Hawaii. Rocks recovered from deeper than ~1 km were deposited below sea level and contain considerable fresh glass. We report electron microprobe analyses of 531 glasses from the submarine section of the core, providing a high-resolution record of petrogenesis over ca. 200 Kyr of shield building of a Hawaiian volcano. Nearly all the submarine glasses are tholeiitic. SiO2 contents span a significant range but are bimodally distributed, leading to the identification of low-SiO2 and high-SiO2 magma series that encompass most samples. The two groups are also generally distinguishable using other major and minor elements and certain isotopic and incompatible trace element ratios. On the basis of distributions of high- and low-SiO2 glasses, the submarine section of the core is divided into four zones. In zone 1 (1079–~1950 mbsl), most samples are degassed high-SiO2 hyaloclastites and massive lavas, but there are narrow intervals of low-SiO2 hyaloclastites. Zone 2 (~1950–2233 mbsl), a zone of degassed pillows and hyaloclastites, displays a continuous decrease in silica content from bottom to top. In zone 3 (2233–2481 mbsl), nearly all samples are undegassed low-SiO2 pillows. In zone 4 (2481–3098 mbsl), samples are mostly high-SiO2 undegassed pillows and degassed hyaloclastites. This zone also contains most of the intrusive units in the core, all of which are undegassed and most of which are low-SiO2. Phase equilibrium data suggest that parental magmas of the low-SiO2 suite could be produced by partial melting of fertile peridotite at 30–40 kbar. Although the high-SiO2 parents could have equilibrated with harzburgite at 15–20 kbar, they could have been produced neither simply by higher degrees of melting of the sources of the low-SiO2 parents nor by mixing of known dacitic melts of pyroxenite/eclogite with the low-SiO2 parents. Our hypothesis for the relationship between these magma types is that as the low-SiO2 magmas ascended from their sources, they interacted chemically and thermally with overlying peridotites, resulting in dissolution of orthopyroxene and clinopyroxene and precipitation of olivine, thereby generating high-SiO2 magmas. There are glasses with CaO, Al2O3, and SiO2 contents slightly elevated relative to most low-SiO2 samples; we suggest that these differences reflect involvement of pyroxene-rich lithologies in the petrogenesis of the CaO-Al2O3-enriched glasses. There is also a small group of low-SiO2 glasses distinguished by elevated K2O and CaO contents; the sources of these samples may have been enriched in slab-derived fluid/melts. Low-SiO2 glasses from the top of zone 3 (2233–2280 mbsl) are more alkaline, more fractionated, and incompatible-element-enriched relative to other glasses from zone 3. This excursion at the top of zone 3, which is abruptly overlain by more silica-rich tholeiitic magmas, is reminiscent of the end of Mauna Kea shield building higher in the core

    Team Dinners: Considering Trends, Traditions, and Impacts beyond Sport

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    Team dinners persist as an enduring tradition merging sport and food. Encompassing sportsmanship, superstition, and sometimes even classically trained chefs, team dinners are enjoyed by youth and professional athletes alike worldwide. However, the role and impacts of such rituals remain poorly understood. This paper contends that team dinners represent a unique gastronomic phenomenon that has lasting effects beyond sport. Given that sport and food are often both culturally entrenched and emotionally bound, team dinners are likely influential in molding adolescence athletes’ notions of nutrition, food choice, and acceptable dining behaviors. In the U.S., pre- and post-game dinners are used as a means of recruiting student-athletes to elite collegiate teams and some programs have even constructed facilities dedicated to the procurement, production, and distribution of meals to athletes in turn shaping supply-lines and campus skylines and introducing students to elevated food experiences likely not had before. At the professional level, some of the most decorated athletes adhere to pre-game meal superstitions, while others use the meals to tout their status. In short, team dinners are seemingly significant to both sport and food in a myriad of ways. Thus, they deserve further academic consideration and offers avenues for future scholarly exploration

    A multiple objective optimization approach to quality control

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    The use of product quality as the performance criteria for manufacturing system control is explored. The goal in manufacturing, for economic reasons, is to optimize product quality. The problem is that since quality is a rather nebulous product characteristic, there is seldom an analytic function that can be used as a measure. Therefore standard control approaches, such as optimal control, cannot readily be applied. A second problem with optimizing product quality is that it is typically measured along many dimensions: there are many apsects of quality which must be optimized simultaneously. Very often these different aspects are incommensurate and competing. The concept of optimality must now include accepting tradeoffs among the different quality characteristics. These problems are addressed using multiple objective optimization. It is shown that the quality control problem can be defined as a multiple objective optimization problem. A controller structure is defined using this as the basis. Then, an algorithm is presented which can be used by an operator to interactively find the best operating point. Essentially, the algorithm uses process data to provide the operator with two pieces of information: (1) if it is possible to simultaneously improve all quality criteria, then determine what changes to the process input or controller parameters should be made to do this; and (2) if it is not possible to improve all criteria, and the current operating point is not a desirable one, select a criteria in which a tradeoff should be made, and make input changes to improve all other criteria. The process is not operating at an optimal point in any sense if no tradeoff has to be made to move to a new operating point. This algorithm ensures that operating points are optimal in some sense and provides the operator with information about tradeoffs when seeking the best operating point. The multiobjective algorithm was implemented in two different injection molding scenarios: tuning of process controllers to meet specified performance objectives and tuning of process inputs to meet specified quality objectives. Five case studies are presented

    Volatiles in glasses from the HSDP2 drill core

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    H2O, CO2, S, Cl, and F concentrations are reported for 556 glasses from the submarine section of the 1999 phase of HSDP drilling in Hilo, Hawaii, providing a high-resolution record of magmatic volatiles over ~200 kyr of a Hawaiian volcano's lifetime. Glasses range from undegassed to having lost significant volatiles at near-atmospheric pressure. Nearly all hyaloclastite glasses are degassed, compatible with formation from subaerial lavas that fragmented on entering the ocean and were transported by gravity flows down the volcano flank. Most pillows are undegassed, indicating submarine eruption. The shallowest pillows and most massive lavas are degassed, suggesting formation by subaerial flows that penetrated the shoreline and flowed some distance under water. Some pillow rim glasses have H2O and S contents indicating degassing but elevated CO2 contents that correlate with depth in the core; these tend to be more fractionated and could have formed by mixing of degassed, fractionated magmas with undegassed magmas during magma chamber overturn or by resorption of rising CO2-rich bubbles by degassed magmas. Intrusive glasses are undegassed and have CO2 contents similar to adjacent pillows, indicating intrusion shallow in the volcanic edifice. Cl correlates weakly with H2O and S, suggesting loss during low-pressure degassing, although most samples appear contaminated by seawater-derived components. F behaves as an involatile incompatible element. Fractionation trends were modeled using MELTS. Degassed glasses require fractionation at pH2O β‰ˆ 5–10 bars. Undegassed low-SiO2 glasses require fractionation at pH2O β‰ˆ 50 bars. Undegassed and partially degassed high-SiO2 glasses can be modeled by coupled crystallization and degassing. Eruption depths of undegassed pillows can be calculated from their volatile contents assuming vapor saturation. The amount of subsidence can be determined from the difference between this depth and the sample's depth in the core. Assuming subsidence at 2.5 mm/y, the amount of subsidence suggests ages of ~500 ka for samples from the lower 750 m of the core, consistent with radiometric ages. H2O contents of undegassed low-SiO2 HSDP2 glasses are systematically higher than those of high-SiO2 glasses, and their H2O/K2O and H2O/Ce ratios are higher than typical tholeiitic pillow rim glasses from Hawaiian volcanoes

    Music Around Noon

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    Emergence of Pentecostalism in Oklahoma: 1909-1930

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    This thesis examines the development of the Pentecostal Holiness Church in the Twin Territories and early Oklahoma, from sectarian movement to formalized institution, that helped lay the foundations for the denomination's national and global development. Looking at the background as an eccentric holiness sect to a loosely organized Pentecostal denomination in 1909, built by part-time administrators and a predominately lay pastorate. The Pentecostal Holiness Church evolved into a traditionally structured evangelical denomination with salaried executive staff and professional clergy. The church faced social demonization for its distinct theologies including the belief in glossolalia or speaking in unknown tongues and other ecstatic methods of worship. In the earliest years of the movement the adherents held countercultural social beliefs, with many practitioners objecting to the participation in World War I and some ministers preaching socialism from their pulpit. While they abandoned many of their radical leanings by the 1920s, their eschatological beliefs led them to allowing women pastors despite their conservative views regarding women's domestic and societal roles. The people of the Pentecostal Holiness Church in Oklahoma from 1909-1930, were predominately rural, lacking access to power structures, but established the western most stronghold for the budding denomination.Histor

    The Arts in Basic Curriculum Project : a ten year evaluation

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    The Arts in Basic Curriculum Project is an initiative begun in the state of South Carolina in 1987. It is a collaborative effort funded and run by the South Carolina Arts Commission, the South Carolina Department of Education, and Winthrop University. The stated goal of the Project is "to ensure that every child in South Carolina, from preschool through college levels, has access to a quality, comprehensive education in the arts, including dance, drama, music, visual arts, and creative writing." The primary findings of this evaluation are (1) that the ABC Project has built and supported a strong network that measurably strengthens arts education, and (2) for the reform to continue, there must be new initiatives
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