3 resultados para Lenses
em University of Washington
Resumo:
Thesis (Ph.D.)--University of Washington, 2016-06
Resumo:
Population growth, urban development, and increased commercial and industrial activity in the south-central Puget Lowlands of Washington State has led to an increased demand for groundwater. The Vashon till is a glacially consolidated, low-permeability unit comprising unstratified clay, silt, cobbles and boulders with ubiquitous coarse-grained lenses and is an extensive surficial unit throughout the south-central Puget Lowland. Thus, understanding the physical and hydrological characteristics – specifically, the hydraulic conductivity – of this unit is a necessary component of a groundwater model. This study provides (1) a record of the physical characteristics of Vashon till deposits within the study area; and (2) an estimate of the highest, lowest, and average value of saturated hydraulic conductivity based on the grain-size distribution of Vashon till samples collected from six field sites in the Puyallup River Watershed. Analysis shows that the average moisture content ranges between about 1 and 6%, average dry bulk density is about 2.20 g/cm3, and average porosity is about 17%. Grain-size distributions show that half of the samples analyzed are well graded, while the other half is poorly graded. Grain-size distributions also show an average d10 value of about 0.20 mm, and average ff values ≤ 16%, which are key values in estimating the saturated hydraulic conductivity of over-consolidated glacial deposits. Based on these observed values, the estimates of hydraulic conductivity range from a minimum of 0.02 m/d to a maximum of 1.38 m/d in within the general Vashon till.
Resumo:
The work of knowledge organization requires a particular set of tools. For instance we need standards of content description like Anglo-American Cataloging Rules Edition 2, Resource Description and Access (RDA), Cataloging Cultural Objects, and Describing Archives: A Content Standard. When we intellectualize the process of knowledge organization – that is when we do basic theoretical research in knowledge organization we need another set of tools. For this latter exercise we need constructs. Constructs are ideas with many conceptual elements, largely considered subjective. They allow us to be inventive as well as allow us to see a particular point of view in knowledge organization. For example, Patrick Wilson’s ideas of exploitative control and descriptive control, or S. R. Ranganathan’s fundamental categories are constructs. They allow us to identify functional requirements or operationalizations of functional requirements, or at least come close to them for our systems and schemes. They also allow us to carry out meaningful evaluation.What is even more interesting, from a research point of view, is that constructs once offered to the community can be contested and reinterpreted and this has an affect on how we view knowledge organization systems and processes. Fundamental categories are again a good example in that some members of the Classification Research Group (CRG) argued against Ranganathan’s point of view. The CRG posited more fundamental categories than Ranganathan’s five, Personality, Matter, Energy, Space, and Time (Ranganathan, 1967). The CRG needed significantly more fundamental categories for their work.1 And these are just two voices in this space we can also consider the fundamental categories of Johannes Kaiser (1911), Shera and Egan, Barbara Kyle (Vickery, 1960), and Eric de Grolier (1962). We can also reference contemporary work that continues comparison and analysis of fundamental categories (e.g., Dousa, 2011).In all these cases we are discussing a construct. The fundamental category is not discovered; it is constructed by a classificationist. This is done because it is useful in engaging in the act of classification. And while we are accustomed to using constructs or debating their merit in one knowledge organization activity or another, we have not analyzed their structure, nor have we created a typology. In an effort to probe the epistemological dimension of knowledge organization, we think it would be a fruitful exercise to do this. This is because we might benefit from clarity around not only our terminology, but the manner in which we talk about our terminology. We are all creative workers examining what is available to us, but doing so through particular lenses (constructs) identifying particular constructs. And by knowing these and being able to refer to these we would consider a core competency for knowledge organization researchers.