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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
101

Evaluation and Application of Microextraction Techniques Coupled with Portable Analytical Instrumentation for On-site Analysis

Reyes-Garces, Nathaly January 2012 (has links)
In recent years, on-site analysis has garnered increased interest from the scientific community. The development of smaller, more sophisticated analytical instruments, and the establishment of new environmental regulations have encouraged the application of new methodologies for field analysis. Prominent advantages of on-site analysis include elimination of error sources due to sample transportation and matrix modification, considerable reduction in analysis time, and more accurate and precise analytical results. Several techniques suitable for on-site analysis, which integrate sampling and sample preparation in one step, have demonstrated high versatility and throughput in field applications. This research was focused on the application and evaluation of three microextraction techniques: solid phase microextraction (SPME), needle trap devices (NTD) and membrane extraction with sorbent interface (MESI), which were then coupled with various portable instruments for on-site analysis of different systems. Additionally, the conducted project involved the development of an approach using ion mobility spectrometry detection (IMS) coupled with a miniaturized gas chromatograph (GC) as a powerful system for field analysis. This proposed GC-IMS exhibited satisfactory performance in terms of retention time (inter-day variation < 3%) and response stability (intra and inter-day relative standard deviations (RSDs) < 10 %). Moreover, when coupled with NTD, it showed limits of detection comparable to those provided by conventional benchtop instruments. Other portable GC instruments employed in this project included flame ionization and mass spectrometry detection. Three different sample systems were investigated using SPME and NTD together with these portable instruments: emissions of a pine branch, breath samples, and indoor pollutants in a polymer synthesis laboratory. Consequently, the feasibility of using SPME and NTD for determination of free and total concentrations was investigated. Finally, MESI was successfully coupled with the newly proposed GC-IMS system, and its functionality was evaluated by analyzing acetone in breath samples.
102

A comparison of prediction models for cover type transitions and their effects on harvest schedules in coastal Oregon /

Eng, Helge. January 1992 (has links)
Thesis (Ph. D.)--Oregon State University, 1992. / Typescript (photocopy). Includes bibliographical references (leaves 122-125). Also available on the World Wide Web.
103

The dating of La Quemada and theory of its development /

Salinas, Christopher. January 2007 (has links)
Thesis (B.S.)--University of Wisconsin -- La Crosse, 2007. / Also available online. Includes bibliographical references.
104

Site-specific dance the place it takes /

Dodge, Lila Ann Millberry. January 2009 (has links)
Honors Project--Smith College, Northampton, Mass., 2009. / Includes bibliographical references.
105

Height-diameter and volume equations, growth intercept and needle length site quality indicators, and yield equations for young ponderosa pine plantations in Neuquén, Patagonia, Argentina /

Gonda, Héctor Eduardo. January 1900 (has links)
Thesis (Ph. D.)--Oregon State University, 1999. / Typescript (photocopy). Includes bibliographical references. Also available on the World Wide Web.
106

Webangebote und ihre Klassifikation : typische Merkmale aus Experten- und Rezipientenperspektive /

Brandl, Annette. January 2002 (has links) (PDF)
Univ., Magisterarbeit--München, 2001. / Literaturverz. S. 167 - 172.
107

On the feasibility of using FSM approaches to test large web applications

Mallery, Christopher Jerry, January 2005 (has links) (PDF)
Thesis (M.S.)--Washington State University. / Includes bibliographical references.
108

Material and meaning : a contextual examination of select portable material culture from Colha, Belize /

Buttles, Palma Jeanne, January 2002 (has links)
Thesis (Ph. D.)--University of Texas at Austin, 2002. / Vita. Includes bibliographical references (leaves 355-408). Available also in an electronic version.
109

Site indices and rates of conversion in northern Wisconsin quaking aspen

Fralish, James S. January 1900 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1970. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.
110

Creating Erie Simple Sites : starting a company dedicated to assisting local businesses get online /

Sullivan, Nicholas Patrick, January 2009 (has links)
Thesis (M.S.)--Edinboro University of Pennsylvania, 2009. / Typescript, photocopy. Includes bibliographical references.

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