961 resultados para GEOCHEMICAL SURVEYS
Resumo:
Administrators of writing programs are regularly faced with the problem of assessing the learning that students gain in their coursework. Many methods of assessment exist, but most have some problems associated with them related to the amount of time it takes to perform the study or the scope of the knowledge gained relative to number of participants or volume of information collected. This pilot study investigates the use of surveys of student opinion for their potential to assess composition instruction at Michigan Technological University. The primary goal of this pilot study is to test the effectiveness of using data collected in surveys to make recommendations for improvement of the composition program at Michigan Tech. The report concludes with recommendations for additional study and refinements to the instruments used.
Resumo:
Maderas volcano is a small, andesitic stratovolcano located on the island of Ometepe, in Lake Nicaragua, Nicaragua with no record of historic activity. Twenty-one samples were collected from lava flows from Maderas in 2010. Selected samples were analyzed for whole-rock geochemical data using ICP-AES and/or were dated using the 40Ar/39Ar method. The results of these analyses were combined with previously collected data from Maderas as well as field observations to determine the eruptive history of the volcano and create a geologic map. The results of the geochemical analyses indicate that Maderas is a typical Central American andesitic volcano similar to other volcanoes in Nicaragua and Costa Rica and to its nearest neighbor, Concepción volcano. It is different from Concepción in one important way – higher incompatible elements. Determined age dates range from 176.8 ± 6.1 ka to 70.5 ± 6.1 ka. Based on these ages and the geomorphology of the volcano which is characterized by a bisecting graben, it is proposed that Maderas experienced two clear generations of development with three separate phases of volcanism: initial build-up of the older cone, pre-graben lava flows, and post-graben lava flows. The ages also indicate that Maderas is markedly older than Concepción which is historically active. Results were also analyzed regarding geologic hazards. The 40Ar/39Ar ages indicate that Maderas has likely been inactive for tens of thousands of years and the risk of future volcanic eruptions is low. However, earthquake, lahar and landslide hazards exist for the communities around the volcano. The steep slopes of the eroded older cone are the most likely source of landslide and lahar hazards.
Resumo:
Our study evaluates the dimensionality and equivalence of social trust across cultural contexts, using new data from Switzerland and the World Values Survey 2005–2008. Whereas some scholars assert that trust should be regarded as a coherent concept, others claim that trust is better conceived of as a multidimensional concept. In contrast to the conventional dichotomy of the forms of social trust, we identify three distinct forms of trust, namely, particularized, generalized, and identity-based trust. Moreover, we dispute the view that respondents understand the wording of survey questions regarding social trust differently between different cultural contexts, which would imply that comparative research on trust is a pointless endeavor. Applying multiple-group confirmatory factor analysis to the various constructs of social trust, we conclude that one may study relationships among the three forms of trust and other theoretical constructs as well as compare latent means across cultural contexts. Our analyses therefore provide an optimistic outlook for future comparative analyses that investigate forms of social trust across cultural contexts.
Resumo:
In der empirischen Antisemitismusforschung ist die standardisierte Befragung die populärste Methode der Datenerhebung. Ihre Verwendung kann jedoch weder die von Befragten wahrgenommene Normativität des Themas noch die situative Kontextabhängigkeit antisemitischer Kommunikation angemessen berücksichtigen. Die Methode des faktoriellen Surveys (auch „Vignettenexperiment“) bietet die Möglichkeit, solche situativen Merkmale systematisch zu variieren und so ihren Einfluss zu ermitteln. Damit wird eine bessere Operationalisierung von Kommunikationslatenz möglich, einem einflussreichen Konzept in der Antisemitismusforschung, dessen empirische Plausibilität unsere Studie zeigt. Sowohl Konsensgruppen- als auch Umwegkommunikation sind in der vorliegenden Stichprobe von Bedeutung: Stimmt die Mehrheit der Anwesenden antisemitischen Vorurteilen zu, steigt der Grad der Zustimmung zu antisemitischen Aussagen ebenso, wie wenn bei einer antisemitischen Aussage der Begriff „Juden“ durch den Begriff „Israelis“ ersetzt wird. Wird auf die deutsche Vergangenheit Bezug genommen, steigt die Zustimmung zu antisemitischen Aussagen ebenfalls (sekundärer Antisemitismus). Konsensgruppenkommunikation ist besonders bei eher links eingestellten Befragten, Umwegkommunikation besonders bei Personen mit niedrigem sozialen Status zu beobachten.
Resumo:
Abstract. To date, terrestrial archives of long-term climatic change within the Arctic have widely been restricted to ice cores from Greenland and, more recently, sediments from Lake El’gygytgyn in northeast Arctic Russia. Sediments from this lake contain a paleoclimate record of glacialinterglacial cycles during the last three million years. Lowresolution studies at this lake have suggested that changes observed during Transition IV (the transition from marine isotope stage (MIS) 10 to MIS 9) are of greater amplitude than any observed since. In this study, geochemical parameters are used to infer past climatic conditions thus providing the first high-resolution analyses of Transition IV from a terrestrial Arctic setting. These results demonstrate that a significant shift in climate was subsequently followed by a rapid increase in biogenic silica (BSi) production. Following this sharp increase, bioproductivity remained high, but variable, for over a thousand years. This study reveals differences in the timing and magnitude of change within the ratio of silica to titanium (Si/Ti) and BSi records that would not be apparent in lower resolution studies. This has significant implications for the increasingly common use of Si/Ti data as an alternative to traditional BSi measurements.