Passive air sampling techniques are an attractive alternative to active air sampling because of the lower costs, simple deployment and retrieval methods, minimum training requirements, no need for power sources, etc.. Because of their advantages, passive samplers are now widely used not only for water and indoor, outdoor and workplace air analysis, but also for soil-gas sampling required for various purposes, including vapor intrusion studies, contamination mapping and remediation. A simple and cost effective permeation-type passive sampler, invented in our laboratory, was further developed and validated during this project. The sampler is based on a 1.8 mL crimp-cap gas chromatography autosampler vial equipped with a polydimethylsiloxane (PDMS) membrane and filled with a carbon based adsorbent. Apart from the low material costs of the sampler and ease of fabrication, the design allows for potential automation of the extraction and chromatographic analysis for high-throughput analysis. The use of highly non-polar PDMS reduces water uptake into the sampler and reduces early adsorbent saturation. The thermodynamic properties of PDMS result in moderately low sampling rate effects with temperature variations. Further, the use of PDMS allows for easy estimation of the uptake-rates based on the physicochemical properties of the analytes such as retention indices determined using capillary columns coated with PDMS stationary phase. In the thesis, the theoretical and practical aspects of the new design with regards to uptake kinetics modeling and the dependence of the calibration constants on temperature, humidity, linear flow velocity of air across the sampler surface, sampler geometry, sampling duration, and analyte concentrations are discussed. The permeability of polydimethylsiloxane toward various analytes, as well as thermodynamic parameters such as the energy of activation of permeation through PDMS membranes was determined. Finally, many applications of the passive samplers developed in actual field locations, vital for the field validation and future regulatory acceptance are presented. The areas of application of the samplers include indoor and outdoor air monitoring, horizontal and vertical soil-gas contamination profiling and vapour intrusion studies.

Passive air sampling techniques are an attractive alternative to active air sampling because of the lower costs, simple deployment and retrieval methods, minimum training requirements, no need for power sources, etc.. Because of their advantages, passive samplers are now widely used not only for water and indoor, outdoor and workplace air analysis, but also for soil-gas sampling required for various purposes, including vapor intrusion studies, contamination mapping and remediation. A simple and cost effective permeation-type passive sampler, invented in our laboratory, was further developed and validated during this project. The sampler is based on a 1.8 mL crimp-cap gas chromatography autosampler vial equipped with a polydimethylsiloxane (PDMS) membrane and filled with a carbon based adsorbent. Apart from the low material costs of the sampler and ease of fabrication, the design allows for potential automation of the extraction and chromatographic analysis for high-throughput analysis. The use of highly non-polar PDMS reduces water uptake into the sampler and reduces early adsorbent saturation. The thermodynamic properties of PDMS result in moderately low sampling rate effects with temperature variations. Further, the use of PDMS allows for easy estimation of the uptake-rates based on the physicochemical properties of the analytes such as retention indices determined using capillary columns coated with PDMS stationary phase. In the thesis, the theoretical and practical aspects of the new design with regards to uptake kinetics modeling and the dependence of the calibration constants on temperature, humidity, linear flow velocity of air across the sampler surface, sampler geometry, sampling duration, and analyte concentrations are discussed. The permeability of polydimethylsiloxane toward various analytes, as well as thermodynamic parameters such as the energy of activation of permeation through PDMS membranes was determined. Finally, many applications of the passive samplers developed in actual field locations, vital for the field validation and future regulatory acceptance are presented. The areas of application of the samplers include indoor and outdoor air monitoring, horizontal and vertical soil-gas contamination profiling and vapour intrusion studies.

Proof of concept lidar research has, to date, examined wall-to-wall models of forest ecosystems. While these studies have been important for verifying lidars efficacy for forest surveys, complete coverage is likely not the most cost effective means of using lidar as auxiliary data for operational surveys; sampling of some sort being the better alternative. This study examines the effectiveness of sampling with high point-density scanning lidar data and shows that systematic sampling is a better alternative to simple random sampling. It examines the bias and mean squared error of various estimators, and concludes that a linear-trend-based and especially an autocorrelation-assisted variance estimator perform better than the commonly used simple random sampling based-estimator when sampling is systematic.

Six types of aerosol samplers were evaluated experimentally in a test chamber with polydisperse fly ash. The Andersen sampler overestimates the mass of small particles due to particle bounce between stages and therefore provides a conservative estimate of respirable particulate mass and thoracic particulate mass. The TSP sampler provides an unbiased estimate of total particulate mass. TSP/CCM provides no information below ESD 2 µm and therefore underestimates respirable particulate mass. The PM10 sampler provides a reasonable estimate of the thoracic particulate fraction. The RespiCon sampler provides an unbiased estimate of respirable, thoracic, and inhalable fractions. DustTrak and SidePak monitors provide relative particle concentrations instead of absolute concentrations because it could not be calibrated for absolute particle concentrations with varying particle shape, composition, and density. Six sampler technologies were used to evaluate airborne dust concentrations released from oilfield pipe rattling operations. The task sampled was the removal of scale deposited on the inner wall of the pipe before it was removed from service in a producing well. The measured mass concentrations of the aerosol samplers show that a Gaussian plume model is applicable to the data of pipe rattling operations for finding an attainment area. It is estimated that workers who remain within 1 m of the machine centerline and directly downwind have an 8-hour TWA exposure opportunity of (13.3 ± 9.7) mg/m3 for the Mud Lake pipe scale and (11.4 ± 9.7) mg/m3 for the Lake Sand pipe scale at 95 % confidence. At distances more than 4 m downwind from the machine centerline, dust concentrations are below the TWA-TLV of 10 mg/m3 for the worker in both scales. At positions crosswind or upwind from the machine centerline there is no measurable exposure. Available data suggest that the attainment area for the public starts at about 9 m downwind from the machine centerline in both scales, as 24 hour average concentrations at these distances are smaller than the 0.15 mg/m3, the NAAQS for unrestricted public access. The PSD of the suspended plume is dominated by particles smaller than ESD 50 µm.

When carrying out sampling tasks close to the ocean bottom, a ROV keeps station at a fixed position and compensates the tether effects and currents. However, the operation of ROV thrust propellers for station keeping might stir up sediment and cause poor visibility, which forces ROV operators to stop work until the sediment clears. The purpose of this thesis, therefore, is to design and fabricate a seafloor moving platform able to approach steadily to sampling objects without stirring up much sediment. This moving platform must be combined with the second generation NCKU-NSYSU ROV, a sampling manipulator, and a sample storage apparatus. Also, the moving platform requires some capabilities for travel over relatively smooth seafloor. A wheel-driven mobile platform, as a result, is developed, in which the front wheels and rear wheels are respectively driven by two separately provided DC motors. The required power and serial command signals are transmitted to the platform via the second generation NCKU-NSYSU ROV. A four-bar linkage for steering font wheels is designed to work close to the Ackerman condition, and a chain-and-sprocket drive train is used to transfer power to the rear wheels. The motor controllers used for controlling DC motors are constructed based on MSP430 MCU (Micro Controller Unit). The preliminary driving performance of the platform is tested. The testing results indicate that the moving platform can drive steadily and behave as expected.

To expand the ability of collecting underwater targets of "Remotely Operated Vehicle II", developed by National Sun Yat-sen University and National Cheng Kung University, this research will develop an underwater manipulator system which can be integrated with ROV II to have enough degrees of freedom to carry out sampling. The goal will focus on mechanism design and to distinguish the assemble restrictions from other mechanism modules. To avoid use of hydraulic pressure apparatus, the manipulator system will use electric motors as the source of drive, which feeds on ROV II's electricity. In mechanical design, water tightness of underwater manipulator system is first considered to avoid damage of internal electric components. Therefore, in this research, suitable waterproof components will be selected separately for static and dynamic machine parts, and dimension and tolerance of assembly of waterproof components will be analyzed. Then, according to decided design conditions, the number of degrees of freedom of the manipulator and range of length of the arm will be decided. The final design model will be constructed, and selection of motors will be finished by 3D Computer Aided Solid Drawing Software. To have a manipulator system which can deal with different targets, the gripper design needs to consider to easily replacement. In the aspect of systematic control, commercial motor control card and motor driver chip are used to carry out the structure of the entire control system, and develop control interface by C language to easily control each joint of the manipulator system.

For amanipulator to carry outmultiple sampling tasks in a single ROV dive, the samples collected need to be stored temporarily in a secure space to free the gripper for the next sampling. The goal of this research is to design and fabricate a sample holding device to improve the efficient of the ROV which was developed jointly by National Sun Yat-sen University and National Cheng-Kung University. The sample bay mounted on a linear track, moves forward to be in the workspace of the manipulator for the storage service. Upon completion of the sample storage tasks, it retrieves back into the ROV frame to prevent itself from being hit or damaged when the ROV is in motion. The development includes the design for a linear track, an underwater motor and its controller, and sample holder. The design of the sample holder was implemented by decision weighting matrix to choose the most appropriate prototype. The efficacy of the system was verified by several joint tests with the manipulator.

This thesis is an investigation into the appropriation and assimilation of meaning by examining the relationship between the technique and meaning of the musical sample and meaning and memory in architecture. As a previously recorded sound integrated into a new work, the sample has a dual identity as both detail and artifact. It is a detail of two or more wholes: an original condition and the new condition, and an artifact from the context of the work from which it was taken. In architectural design, each recognizable form and spatial arrangement is a sample from a prototype with its own context and history. Each time a known form or spatial arrangement is sampled meaning is communicated from the prototype to the new work. The decontextualization of the sample, its manipulation and recontextualization into a new work provides the architect a means for reinterpretation and reinvention. Through an exploration of the use of the sample in music, art and architecture this thesis shows how sampling can alter the meaning of the physical environment.

Thesis (M.A.)--University of South Florida, 2002. / Title from PDF of title page. Includes bibliographical references.

Thesis (M. Phil.)--University of Hong Kong, 2001. / Includes bibliographical references (leaves 66-70).