Spelling suggestions: "subject:"site aanalysis"" "subject:"site 2analysis""
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Evaluation and Application of Microextraction Techniques Coupled with Portable Analytical Instrumentation for On-site AnalysisReyes-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.
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Evaluation and Application of Microextraction Techniques Coupled with Portable Analytical Instrumentation for On-site AnalysisReyes-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.
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Exploratory making: site inspired making as a tool for site analysis and designMoore, Wesley January 1900 (has links)
Master of Landscape Architecture / Landscape Architecture/Regional and Community Planning / Jon D. Hunt / Design tools (the method of making a designer uses to conceptualize or communicate the assembly of an object) are not simply secondary instruments to communicate designs through, but are the primary media through which designers contemplate and process design problems. Designers should utilize tools, whether digital or analog, with an awareness of each tool’s limitations and advantages and the possibilities they provide to each step of the design process. The intent of this report is to study how site inspired making methods can be used to observe and reveal information about a site, and thus contribute to the site analysis phase of design. Site inspired making methods are developed in this report through an exploratory research process. Exploratory research is a qualitative method used to provide flexibility in developing knowledge about a topic. An exploratory process was chosen to allow my focuses to shift as I make and reflect so my findings arise as I conduct the studies, not just from an initial hypothesis. Through an exploratory research process of making and reflecting this report answers the question:
How do various methods of making develop and document my understanding of the site?
Exploratory methods of drawing and sculpting are used to observe and reveal site information, and develop site-inspired artistic works. The site is a small, wooded lot and cove of Tuttle Creek Lake located northwest of Manhattan, Kansas. The research process is divided into an investigation phase in which I explored initial drawing and sculpting methods and an application phase in which I created a sculpture and series of drawings inspired by the site.
I documented site conditions through observational drawing; revealed patterns and textures by drawing with and on site materials; developed parametric studies of balancing sculptures; discovered crystallization patterns by splattering ink on a frozen lake; designed a balancing sculpture inspired by the motion of ice sheets and driftwood on water; and created frost drawings by applying ink to soaked and frozen watercolor paper. Each method revealed different site qualities and informed my understanding of the site.
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High Throughput Analysis for On-site SamplingGomez-Rios, German Augusto January 2012 (has links)
Until recently, multiple SPME fibres could not be automatically evaluated in a single sequence without manual intervention. This drawback had been a critical issue until recently, particularly during the analysis of numerous on-site samples. Recently, GERSTEL® has developed and commercialized a Multi-Fibre Exchanger (MFX) system designed to overcome this drawback. In this research, a critical evaluation of the MFX performance in terms of storage stability and long term operation is presented. It was established in the course of our research that the MFX can operate continuously and precisely for over 200 extraction/injection cycles. However, when the effect of residence time of commercial fibres on the MFX tray was evaluated, the results have shown that amongst the evaluated fibre coatings, carboxen/polydimethylsiloxane (CAR/PDMS) was the only coating capable of efficient storage on the MFX tray for up to 24 hours after field sampling without suffering significant loss of analytes. Additionally, the MFX system capability for high-throughput analysis was demonstrated by the unattended desorption of multiple fibres after on-site sampling of two different systems, indoor air and biogenic emissions. Subsequently, a protocol based on a new, fast, reproducible, reusable and completely automated method that enables quick assessment of SPME coatings was developed. The protocol consists of an innovative in-vial standard generator containing vacuum pump oil doped with McReynolds probes and subsequently mixed with a polystyrene-divinylbenzene resin. According to our results, the protocol has proven to be a useful tool for the quick assessment of inter-fibre reproducibility prior to their application in on-site analysis. The implications of such protocols include, but are not limited to: time-saving, assurance of reliable and reproducible data, and a dependable guide for novice users of the technique.
Finally, an innovative, reusable and readily deployable pen-like diffusive sampler for needle traps (PDS-NT) is proposed. Results have shown that the new PDS-NT is effective for air analysis of benzene, toluene, and o-xylene (BTX). In addition, no statistically significant effects of pen geometry on the uptake of analytes were found.
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Surfacing: a guide for approaching landscapeKennedy, Andrea C. 21 January 2008 (has links)
This work is a compilation of ideas intended as a framework for an alternative approach to engaging ‘site’ in the design process, an approach that maintains and explores the complexities and subtleties of a landscape, of a place.
Through two parallel explorations - one that considers an expanded and inclusive interpretation of landscape as the frame through which we engage with, and design, our surroundings, and one that examines the specific nature of this engagement as exchange between the self and the milieu - such an approach has been developed.
This approach is called RECONNAISSANCE. Through encouragement of explicit, conscious consideration of how we perceive and experience a landscape, how this contributes to an understanding of a particular place and how this relates to and informs the practice of landscape architecture (both the process and the outcome), RECONNAISSANCE contributes to a strengthening of our abilities and actions as landscape architects. / February 2008
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Further Development of Atmospheric Pressure, Self-Igniting Microplasma Devices (MPDs) for Elemental Analysis of Liquid Microsamples Using Atomic Emission Spectrometry (AES)Weagant, Scott Richard January 2011 (has links)
The present elemental analysis workhorse worldwide is Inductively Coupled Plasma (ICP) Atomic Emission Spectrometry (AES) and Mass Spectrometry (MS). Due to the high power requirements, large gas consumption and the more obvious attribute, size, the ICP is tethered to the lab. Usually, samples must be collected, bottled, sometimes stabilized by acids and then shipped back to the lab for analysis (hours to days to weeks turnover rate). Due to the demand for a portable analyzer this thesis will focus on further development of microplasma devices (MPDs) for portable on-site analysis, in (near) real-time.
Mini-In-Torch Vapourization (mini-ITV) is the sample introduction method for MPDs which removes the need for sample preparation (further necessitates portability). Mini-ITV introduces the sample into the MPD via electrothermal vapourization of a dry (water-free) nano- to micro- volume sample. Pneumatic nebulization, the commercially available ICP sample introduction method would extinguish the microplasma.
Microplasma stability is the first issue addressed by confining the microplasma to a quartz tube (“wall-stabilized”) in hopes of a more stable MPD background emission. Once stabilized MPD conditions were found key microplasma parameters were studied including MPD power, HVac frequency, operating mode, inter-electrode distance (IED) and observation location, in hopes of improved MPD analytical performance.
Microplasma excitation mechanism and maximum energy available in the microplasma for analyte are discussed. Some fundamental characteristics such as excitation temperature (Texc) and changes in atom/ion population with variation in some of the key MPD parameters were also determined.
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Fragment Based Protein Active Site Analysis Using Markov Random Field Combinations of Stereochemical Feature-Based ClassificationsPai Karkala, Reetal 2009 May 1900 (has links)
Recent improvements in structural genomics efforts have greatly increased the
number of hypothetical proteins in the Protein Data Bank. Several computational
methodologies have been developed to determine the function of these proteins but
none of these methods have been able to account successfully for the diversity in
the sequence and structural conformations observed in proteins that have the same
function. An additional complication is the
flexibility in both the protein active site
and the ligand.
In this dissertation, novel approaches to deal with both the ligand flexibility
and the diversity in stereochemistry have been proposed. The active site analysis
problem is formalized as a classification problem in which, for a given test protein,
the goal is to predict the class of ligand most likely to bind the active site based
on its stereochemical nature and thereby define its function. Traditional methods
that have adapted a similar methodology have struggled to account for the
flexibility
observed in large ligands. Therefore, I propose a novel fragment-based approach to
dealing with larger ligands. The advantage of the fragment-based methodology is
that considering the protein-ligand interactions in a piecewise manner does not affect
the active site patterns, and it also provides for a way to account for the problems
associated with
flexible ligands. I also propose two feature-based methodologies to account for the diversity observed
in sequences and structural conformations among proteins with the same function.
The feature-based methodologies provide detailed descriptions of the active site
stereochemistry and are capable of identifying stereochemical patterns within the
active site despite the diversity.
Finally, I propose a Markov Random Field approach to combine the individual
ligand fragment classifications (based on the stereochemical descriptors) into a single
multi-fragment ligand class. This probabilistic framework combines the information
provided by stereochemical features with the information regarding geometric constraints
between ligand fragments to make a final ligand class prediction.
The feature-based fragment identification methodology had an accuracy of 84%
across a diverse set of ligand fragments and the mrf analysis was able to succesfully
combine the various ligand fragments (identified by feature-based analysis) into one
final ligand based on statistical models of ligand fragment distances. This novel
approach to protein active site analysis was additionally tested on 3 proteins with very
low sequence and structural similarity to other proteins in the PDB (a challenge for
traditional methods) and in each of these cases, this approach successfully identified
the cognate ligand. This approach addresses the two main issues that affect the
accuracy of current automated methodologies in protein function assignment.
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Surfacing: a guide for approaching landscapeKennedy, Andrea C. 21 January 2008 (has links)
This work is a compilation of ideas intended as a framework for an alternative approach to engaging ‘site’ in the design process, an approach that maintains and explores the complexities and subtleties of a landscape, of a place.
Through two parallel explorations - one that considers an expanded and inclusive interpretation of landscape as the frame through which we engage with, and design, our surroundings, and one that examines the specific nature of this engagement as exchange between the self and the milieu - such an approach has been developed.
This approach is called RECONNAISSANCE. Through encouragement of explicit, conscious consideration of how we perceive and experience a landscape, how this contributes to an understanding of a particular place and how this relates to and informs the practice of landscape architecture (both the process and the outcome), RECONNAISSANCE contributes to a strengthening of our abilities and actions as landscape architects.
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Surfacing: a guide for approaching landscapeKennedy, Andrea C. 21 January 2008 (has links)
This work is a compilation of ideas intended as a framework for an alternative approach to engaging ‘site’ in the design process, an approach that maintains and explores the complexities and subtleties of a landscape, of a place.
Through two parallel explorations - one that considers an expanded and inclusive interpretation of landscape as the frame through which we engage with, and design, our surroundings, and one that examines the specific nature of this engagement as exchange between the self and the milieu - such an approach has been developed.
This approach is called RECONNAISSANCE. Through encouragement of explicit, conscious consideration of how we perceive and experience a landscape, how this contributes to an understanding of a particular place and how this relates to and informs the practice of landscape architecture (both the process and the outcome), RECONNAISSANCE contributes to a strengthening of our abilities and actions as landscape architects.
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Further Development of Atmospheric Pressure, Self-Igniting Microplasma Devices (MPDs) for Elemental Analysis of Liquid Microsamples Using Atomic Emission Spectrometry (AES)Weagant, Scott Richard January 2011 (has links)
The present elemental analysis workhorse worldwide is Inductively Coupled Plasma (ICP) Atomic Emission Spectrometry (AES) and Mass Spectrometry (MS). Due to the high power requirements, large gas consumption and the more obvious attribute, size, the ICP is tethered to the lab. Usually, samples must be collected, bottled, sometimes stabilized by acids and then shipped back to the lab for analysis (hours to days to weeks turnover rate). Due to the demand for a portable analyzer this thesis will focus on further development of microplasma devices (MPDs) for portable on-site analysis, in (near) real-time.
Mini-In-Torch Vapourization (mini-ITV) is the sample introduction method for MPDs which removes the need for sample preparation (further necessitates portability). Mini-ITV introduces the sample into the MPD via electrothermal vapourization of a dry (water-free) nano- to micro- volume sample. Pneumatic nebulization, the commercially available ICP sample introduction method would extinguish the microplasma.
Microplasma stability is the first issue addressed by confining the microplasma to a quartz tube (“wall-stabilized”) in hopes of a more stable MPD background emission. Once stabilized MPD conditions were found key microplasma parameters were studied including MPD power, HVac frequency, operating mode, inter-electrode distance (IED) and observation location, in hopes of improved MPD analytical performance.
Microplasma excitation mechanism and maximum energy available in the microplasma for analyte are discussed. Some fundamental characteristics such as excitation temperature (Texc) and changes in atom/ion population with variation in some of the key MPD parameters were also determined.
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