The aim of this study is to investigate the distributions of polycyclic aromatic hydrocarbons (PAHs) in sediment and water (suspended particles and dissolved phase) samples collected from Dapeng Bay(coast¡Bbay¡Bwetland and mangrove). Chemical fingerprinting techniques and statistical analysis were applied to delineate the possible sources of PAHs in sediment and water samples. The average concentrations of total PAHs (£U51PAHs) ranged from 143 to 1595 ng/g dry weight (dw) in the sediments. Total PAH (£U46PAHs) concentrations varied from 11 to 38 ng/L in dissolved phase and from 1.4 to 15ng/L (252 to 772 ng/g dw) in suspended particulate phase, respectively. Comparing with sediment quality guidelines (SQGs), the total PAH concentrations in all sediment samples were below the criteria, suggesting that no adverse biological effects would arise from the PAHs in these sediments. The partition coefficients¡]KOC¡^values of PAHs were higher than predicted values. It might be attributed to soot particles which have extremely high sorption capacities. Total organic carbon¡]POC¡^and black carbon (BC) were significantly correlated with combustion PAH concentrations in Dapeng Bay. Combustion PAHs (Flt¡ÏPyr¡ÏBaA¡ÏChr¡ÏBbF¡ÏBkFa¡ÏBeP¡ÏBaP¡ÏIP¡ÏBghiP) concentrations were significantly correlated with black carbon (BC) in mangroves sediment cores and wetland A. In addition, total PAH concentrations were significantly correlated with combustion PAHs concentrations in dissolved phase. In suspended particulate phase, total PAH concentrations and combustion PAHs concentrations were significantly correlated with suspended solid (SS). Results from diagnostic ratios and hierarchical cluster analysis (HCA) both indicate that PAHs in the coast of Dapeng Bay were mainly from petrogenic sources, but from petrogenic and pyrogenic mixed sources in the wetland and mangrove inside the Dapeng Bay. In addition, the origin of perylene in Dapeng Bay and coastal sediments was mainly from the biogenic and pyrogenic, while it was from biogenic origin in wetland A and wetland B. However, the origin of perylene in mangrove M1 and mangrove M2 tended to be diagenetic.

Different approaches have been developed for TCP/IP fingerprinting, but none of these approaches is suited for Internet-wide fingerprinting. In this work, we develop approaches that rigorously tackle the issue of noise and packet loss while carrying out Internet-wide fingerprinting. We then carry out an Internet-wide scan to determine the distribution of different operating systems on the Internet. The results of our scan indicate that there are approximately 8.9 million publicly accessible web-servers on the Internet running Linux, while there are nearly 9.6 million web-servers with different embedded operating systems.

Water, suspended particle and sediment samples from Kao-ping estuary were collected and measured for concentrations of polycyclic aromatic hydrocarbons (PAHs) during March 2004 and April 2005. In addition, sediments from neighboring coastal area were also analyzed to estimate distribution, transportation and possible sources of PAHs. Total PAH concentrations varied from 33.0 to 910 ng/g dry weight (dw) in coastal sediments, and diagnostic ratios reflect a mixed sources of petrogenic and pyrolytic inputs. Due to the contribution of Kao-ping River, spatial distribution of PAH concentrations at coastal sediments near river mouth varied dramatically. Results of hierachical cluster analysis showed that PAH concentration distribution was influenced by Kao-ping canyon, and biogenic source might be the major PAH source for offshore sediments. Total PAH concentrations in river sediment varied from 63.0 to 720 ng/g dw. Higher concentration was measured between the Water Main pipe and Shuang-yuan Bridge, and possible sources were from both petrogenic and pyrolytic sources. Sediment of Dung-gang harbour had highest concentration, 28,000ng/g dw, in this study, which was contributed from petrogenic sources due to its intensive boating activities. Except fluorene and phenanthrene in harbour sediments, individual PAH concentrations of other sediments are lower or near the Effect Range Low value, concentrations might lead to possible adverse effects upon organism. Total PAH concentrations varied from 5.0 to 82.0 ng/L in suspended particulate phase and from 5.5ng/L to 46.0ng/L in dissolved phase, respectively. Most of high molecular weight PAH concentrations (>5-ring PAHs) in dissolved phase were below method detection limits. The partition coefficients¡]Koc¡^values of PAHs were 1 to 2 orders higher than predicted values. It might be attributed to soot particles which have extremely high sorption capacities. Correlation coefficients between total PAH concentrations in sediments versus total organic carbon¡]TOC¡^ and fine particle content¡]<63£gm%¡^were significant ¡]R=0.575, 0.800, 0.851 and 0.657, P<0.01¡^. In addition, PAHs in suspended particulate phase and dissolved phase were also significantly correlated to particulate organic carbon¡]POC¡^ and dissolved organic carbon¡]DOC¡^, respectively. The distribution of calculated PAH concentrations from organic carbon was higher in surface water than bottom water. Unlike salinity, there was no decreasing or increasing trend of these concentrations among river samples. It is possible that contamination was not come from upstream, but from estuary area where plume was lifted and diffused upstream by neat seawater. The flux in Wan-da Bridge was higher than downstream estuary area that might be due to PAH concentrations reduction by sedimentation or degradation.

IEEE 802.16 is a point to multipoint broadband wireless access standard, designed from ground up for fast and reliable mobile networking. Several location-related MAC layer fields specified in the standard indicate that WiMAX networks can be convenient backbones for future positioning systems. Information encapsulated in MAC headers is especially important for single base station positioning systems which require fewer network resources than multiple reference station location systems, but need more location-related input data. In this thesis, an algorithm for positioning mobile stations in a single base station network is presented to investigate location capability of WiMAX systems. The algorithm makes use of fingerprinting to create a training database and seeks to find locations of mobile stations by tracking them according to their signal parameters. Experimental results give an idea about how a single base station positioning system performs in the absence of sufficient location-related data, and suggest that better results can be obtained if MAC headers specified in IEEE 802.16 standard can be accessed.

The vision of ubiquitous computing is to seamlessly integrate information processing into everyday objects and activities. Part of this integration is an awareness on the part of a system of its user's context. Context can be composed of several variables --- such as a user's current activity, goals, or state of mind --- but location (both past and present) is almost always a key component. Determining location outdoors has become quite simple and pervasive with today's low-cost handheld Global Positioning System (GPS) receivers. Technologies enabling the location of people and objects to be determined while indoors, however, have lagged due to their extensive infrastructure requirements and associated cost. Just as GPS receivers utilize radio signals from satellites to triangulate their position, an indoor real-time locating system (RTLS) must also make use of some feature of the environment to determine the location of mobile units. Since the signal from GPS satellites is not sufficiently strong to penetrate the structure of a building, indoor RTLS systems must either use some existing feature of the environment or generate a new one. This typically requires a large amount of infrastructure (e.g. specialized RF receivers, additional 802.11 access points, RFID readers, etc.) to be deployed, making indoor RTLSs impractical for the home. While numerous techniques have been proposed for locating people and objects within a building, none of these has yet proven to be a viable option in terms of cost, complexity of installation, and accuracy for home users. This dissertation builds on work by Patel et al. in which the home power lines are used to radiate a low-frequency wireless RF signal that mobile tags use for location fingerprinting. Leveraging the existing power line permits this system to operate on far less additional infrastructure than existing solutions such as cellular (GSM and CDMA), 802.11b/g, and FM radio based systems. The contributions of this research to indoor power line-based RTLS are threefold. First, I examine the temporal stability of a power line based RTLS system's output. Fingerprinting-based RTLS relies upon some feature of the environment, such as the amplitude of an RF signal, to be stable over time at a particular location (temporal stability), but to change in space (spatial differentiability). I show that a power line-based RTLS can be made much more resistant to temporal instability in individual fingerprint components by utilizing a wide-band RF fingerprint. Next, I directly compare the temporal stability of the raw features used by various fingerprinting based indoor RTLSs, such as cellular, 802.11b/g, and FM radio. In doing so, I show that a power line based indoor RTLS has an inherent advantage in temporal stability over these other methods. Finally, I characterize the power line as a receiving antenna for low-powered wireless devices within the home, thus allowing the power line to not only transmit the RF signals used for fingerprinting, but also to receive the sensed features reported by location tags. Here, I show that the powerline is a viable receiver for these devices and that the globally available 27.12 MHz ISM band is a good choice of frequency for communications.

Thesis (Ph. D.)--University of North Texas, 2002. / Title from PDF title page (viewed on Dec. 9, 2004). Includes bibliographical references (p. 350-356).

Siesta Key Beach, located on the Gulf Coast of Florida, is frequently mentioned among the top ten beaches in the US. In summer 2004, high levels of indicator bacteria caused health warnings to be posted, and a storm drainage system was implicated as a possible source of microbial contamination. A study was initiated to determine whether indicator bacteria that persisted in the stormwater system could contribute to high microbial loads in receiving waters. Two sampling events, one within 48 hours of a rain event and the other during dry conditions, were conducted. Water and sediment samples were taken at various sites from the storm drainage system to the beach. Fecal coliforms and Enterococcus spp. were enumerated, and genotypic fingerprints of E. coli and Enterococcus spp. were generated by BOX-PCR. Diversity of E. coli and Enterococcus populations was calculated with the Shannon-Weiner diversity index. Similarity of E. coli and Enterococcus populations was calculated with the population similarity coefficient. After the rain event, levels of fecal coliforms and Enterococcus spp. were high in sediments and exceeded the regulatory standard for all water samples. In dry conditions, levels were lower in water samples, but still high in sediment samples. Significantly greater population diversity was observed in the rain event compared to the dry event for both E. coli and Enterococcus populations, and greater population similarity was vi observed in dry conditions. Enterococcus population diversity was significantly higher in untreated sewage and the Siesta Key rain event when compared to dry conditions, and to a site on the Myakka River (no known human input or urban stormwater runoff). Siesta Key populations in dry conditions were most similar to Myakka, and sewage was the least similar to all other populations. Increased population similarity for E. coli and Enterococcus spp. during dry conditions suggests that a portion of the population is composed of “survivor” isolates. Persistence of survivor isolates in the storm drainage system, where urban runoff can sit for days, suggests a reservoir for indicator bacteria that can be flushed through the system to the Gulf, causing high levels of indicator bacteria in receiving waters.

With the emergence of Matrix Assisted Laser Desorption/Ionization-Time-of-flight as a tool for diagnosis of diseases via proteomics, there is an increasing need for greater sensitivity. Analysis of peptides by MALDI-TOF-MS is affected by sample formulation and spotting onto a MALDI target. This dissertation investigates a novel MALDI sample preparation technique, Induction Based Fluidics (IBF), for depositing precise volumes (pL to nL) of samples onto the target. We have seen that while using IBF, the induced electric field accompanying deposition enhances matrix crystallization yielding smaller crystals with more homogeneity, as compared to conventional manual micropipette (MP) depositions. An investigation of the signal-to-noise (S/N) for IBF deposition of tryptic digested Bovine Serum Albumin (BSA) showed a significant improvement in the signal-to-noise ratio for 0.5 and 0.25 pmol/µL BSA sample compared to equivalent MP depositions. The S/N enhancement for IBF and MP depositions of BSA were studied using à-cyano-4-hydroycinnamic acid (CHCA) and 2,5-dihydroxybenzoic acid (DHB) matrices, and CHCA showed better results than DHB . The exciting results obtained by IBF prompted us to probe sample morphology more fully and to relate morphology to the detections level and hopefully, to increase the utility of MALDI-TOF-MS for detection of a larger range of peptides. Morphology results were correlated to sensitivity limits using both dispensing techniques. Because of dissimilar rates of evaporation, different or uneven deposition thickness, or crystal lattice morphology, discontinuous crystallization patterns were observed for MP depositions. However, IBF deposited samples occupied less planar area with uniform distribution of crystals, thereby reducing sample crystal heterogeneity and laborious hunt for a "sweet" or "hot" spot to produce high quality spectra. The application of IBF was extended to the tryptic digested BSA protein using peptide mass fingerprinting. IBF deposition resulted in a larger number of detectable peptides as well as higher sequence coverage as compared to equivalent MP depositions. In last few decades, advanced research and potential applications in the field of microelectronics have spurred interest in the development of reticulated doped polymer films. Bis (ethylenedioxy) tetrathiafulvalene (BEDO-TTF)/Polycarbonate (PC) films were synthesized and characterized for use in hand-held real time explosives sensors, capable of detecting nitro-based compounds (nitroaromatics, nitoamines and nitroesters), which are the main components of Improvised Explosive Devices or IEDs. Reticulated doped polymer films were prepared by exposing solid solutions of BEDO-TTF in PC to iodine to form conductive charge transfer complexes. The resulting films exhibited room temperature conductivities ranging from 6.33-90.4*10-5 S cm-1. The colored iodine complexes in the film were reduced by cyclic voltammetry yielding conductive, colorless, transparent films. Dielectric analysis (DEA) was used to probe relaxations in neat PC and BEDO-TTF/PC showed that BEDO-TTF plasticized the PC and decreased the glass transition temperature. Two secondary relaxations appeared in PC films, whereas the transitions merged in the doped film. DEA also revealed conductivity relaxations above 180°C, which were characterized by the electric modulus formalism and showed that BEDO-TTF increased the alternating current, (AC) conductivity in PC.

This dissertation combines various holographic techniques with application on the two- and three-dimensional imaging of ophthalmic tissue, fingerprints, and microsphere samples with micrometer resolution. Digital interference holography (DIH) uses scanned wavelengths to synthesize short-coherence interference tomographic images. We used DIH for in vitro imaging of human optic nerve head and retina. Tomographic images were produced by superposition of holograms. Holograms were obtained with a signal-to-noise ratio of approximately 50 dB. Optic nerve head characteristics (shape, diameter, cup depth, and cup width) were quantified with a few micron resolution (4.06 -4.8 microns). Multiple layers were distinguishable in cross-sectional images of the macula. To our knowledge, this is the first report of DIH use to image human macular and optic nerve tissue. Holographic phase microscopy is used to produce images of thin film patterns left by latent fingerprints. Two or more holographic phase images with different wavelengths are combined for optical phase unwrapping of images of patent prints. We demonstrated digital interference holography images of a plastic print, and latent prints. These demonstrations point to significant contributions to biometry by using digital interference holography to identify and quantify Level 1 (pattern), Level 2 (minutia points), and Level 3 (pores and ridge contours). Quantitative studies of physical and biological processes and precise non-contact manipulation of nanometer/micrometer trapped objects can be effectuated with nanometer accuracy due to the development of optical tweezers. A three-dimensional gradient trap is produced at the focus position of a high NA microscope objective. Particles are trapped axially and laterally due to the gradient force. The particle is confined in a potential well and the trap acts as a harmonic spring. The elastic constant or the stiffness along any axis is determined from the particle displacements in time along each specific axis. Thus, we report the sensing of small particles using optical trapping in combination with the digital Gabor holography to calibrate the optical force and the position and of the copolymer microsphere in the x, y, z direction with nm precision.

No description available.