Heavy metal contamination is a serious concern throughout the world. Increased concentrations in drinking water have many negative impacts on human health. Limestone is an inexpensive and simple media for removing high concentrations of heavy metals from drinking water supplies. Ferric based media is commonly used to remove zinc, cadmium, lead, arsenic and other heavy metals. The drinking water standards set by the US EPA for cadmium, zinc and arsenic are 0.005 mg/L, 5 mg/L and 0.010 mg/L respectively. Bangladesh, parts of India, China and the United States have high concentrations of arsenic in drinking water. Although many technologies exist for heavy metal removal, most of these are complicated and are associated with high costs making them ineffective and unfavorable to be used in impoverished areas. We propose a novel method that combines the benefits of limestone with the capacity of ferric media in an iron-coated limestone based material. Samples of water with various concentrations of zinc and cadmium were prepared and batch tests were performed using both uncoated and iron coated limestone and are compared in removal efficiency. Kinetics studies showed that zinc is removed to a maximum level after 24 hours, while cadmium takes only 15 minutes. The effect of pH on removal of heavy metals was also studied. Metals are analyzed using Inductively Coupled Plasma Emission Spectroscopy (ICP-ES). Limestone is readily available and is also easy to coat with iron, making this material a cost effective and affordable method to be used by developing countries.

Elevated levels of arsenic and other heavy metals like copper, aluminum, zinc, and selenium in drinking water are found to have deleterious effects on human health. Hence, finding methods for reducing their levels is critical. Iron-coated limestone is used as an adsorption material for the removal of heavy metals from drinking water. Removal of heavy metals by native or uncoated limestone was also observed and used for comparison to and evaluation of the improvement in removal efficiency from the ironcoated material. The removal efficiency with limestone was studied for different concentrations of heavy metals. Kinetic studies were done to determine the decrease in heavy metal concentration as a function of time using limestone. Inductively coupled plasma spectroscopy was used for metal analysis. The effective removal rate of copper and aluminum was found to be four hours and one hour, respectively. This method of removal by using limestone is cost effective, eco-friendly, and hence, of great potential importance for heavy metal removal. Iron-coated limestone is used as an adsorption material for the removal of heavy metals from drinking water. This project will investigate techniques to improve removal efficiency of heavy metals using limestone-based material through adsorption. This research will assist in the development of a granular adsorbent product that will remove metals and that can be manufactured and sold for use at the drinking water source, at point-of-use, or at point-of-entry. Limestone is readily available and its use for metals removal is relatively inexpensive. The technology can be adapted to small, rural water supply systems. Benefits of this research will include a low-cost treatment technology for source reduction that will reduce select metals to below drinking water standards.

As the capabilities of autonomous vehicles increase, their use in situations that are dangerous or dull for humans is becoming more popular. Autonomous systems are currently being used in several military and civilian domains, including search and rescue operations, disaster relief coordination, infrastructure inspection and surveillance missions. In order to perform high level mission autonomy tasks, a method is required for the vehicle to localize itself, as well as generate a map of the environment. Algorithms which allow the vehicle to concurrently localize and create a map of its surroundings are known as solutions to the Simultaneous Localization and Mapping (SLAM) problem. Certain high level tasks, such as drivability analysis and obstacle avoidance, benefit from the use of a dense map of the environment, and are typically generated with the use of point cloud data. The point cloud data is incorporated into SLAM algorithms with scan registration techniques, which determine the relative transformation between two sufficiently overlapping point clouds. The Normal Distributions Transform (NDT) algorithm is a promising method for scan registration, however many issues with the NDT approach exist, including a poor convergence basin, discontinuities in the NDT cost function, and unreliable pose estimation in sparse, outdoor environments. This thesis presents methods to overcome the shortcomings of the NDT algorithm, in both 2D and 3D scenarios. To improve the convergence basin of NDT for 2D scan registration, the Multi-Scale k-Means NDT (MSKM-NDT) algorithm is presented, which divides a 2D point cloud using k-means clustering and performs the scan registration optimization over multiple scales of clustering. The k-means clustering approach generates fewer Gaussian distributions when compared to the standard NDT algorithm, allowing for evaluation of the cost function across all Gaussian clusters. Cost evaluation across all the clusters guarantees that the optimization will converge, as it resolves the issue of discontinuities in the cost function found in the standard NDT algorithm. Experiments demonstrate that the MSKM-NDT approach can be used to register partially overlapping scans with large initial transformation error, and that the convergence basin of MSKM-NDT is superior to NDT for the same test data. As k-means clustering does not scale well to 3D, the Segmented Greedy Cluster NDT (SGC-NDT) method is proposed as an alternative approach to improve and guarantee convergence using 3D point clouds that contain points corresponding to the ground of the environment. The SGC-NDT algorithm segments the ground points using a Gaussian Process (GP) regression model and performs clustering of the non ground points using a greedy method. The greedy clustering extracts natural features in the environment and generates Gaussian clusters to be used within the NDT framework for scan registration. Segmentation of the ground plane and generation of the Gaussian distributions using natural features results in fewer Gaussian distributions when compared to the standard NDT algorithm. Similar to MSKM-NDT, the cost function can be evaluated across all the clusters in the scan, resulting in a smooth and continuous cost function that guarantees convergence of the optimization. Experiments demonstrate that the SGC-NDT algorithm results in scan registrations with higher accuracy and better convergence properties than other state-of-the-art methods for both urban and forested environments.

Previous work by our research group demonstrated that quantitative chemical analysis of analytes, such as mercury and chromium species, in environmental matrices could be successfully carried out without using calibration curves and with correction for species interconversion by using EPA Method 6800A. This method encompasses isotope dilution mass spectrometry (IDMS) and speciated isotope dilution mass spectrometry (SIDMS), both of which are described in detail in chapter 1. Research described in this dissertation expands upon our earlier work by applying the method to the speciation of mercury in biological matrices, the speciation of glutathione in red blood cells and whole blood, and the analysis of enzyme activity in mammalian tissue. / Bayer School of Natural and Environmental Sciences; / Chemistry and Biochemistry; / PhD; / Dissertation;

Abstract Methods for tephrochronology are evaluated, in the following way: Lake sediments <500 years old from three small Antarctic lakes were analysed for identification of tephras. Subsamples were analysed for a) grain size, and identification and concentration of volcanogenic grains, b) identification of tephra horizons, c) element abundance by EPMA WDS/EDS and LA-ICP-MS, and d) possible correlations between lakes and volcanoes. Volcanogenic minerals and shards were found all through the sediment cores in all three lakes, in different abundances. A high background population of volcanogenic mineral grains, in all samples, made the identification of tephra horizons difficult, and shards could only be distinguished by certainty after chemical analysis of elements. The tephra layers commonly could not be seen by the naked eye, and, hence they are regarded as cryptotephras. Because of the small size of recent eruptions in the research area, and the travel distance of ash, most shards are small and difficult to analyse. Nine possible tephra horizons have been recorded in the three lakes, and preliminary correlations have been made. But because of analytical problems, the proposed correlations between the lakes and possible volcanic sources are preliminary.

Syftet med föreliggande studie var att ta reda på vårdpersonal och närståendes upplevelser vad gäller vanlig palliativ vård och strukturerade vårdplaner så som LCP/ICP. Studien genomfördes som en systematisk litteraturstudie där underlaget inhämtades genom att med specifika sökord söka i Högskolan Dalarnas databas ELIN@ efter vetenskapliga artiklar. En artikel har även sökts från en annan referenslista där artikelnamnet använts som sökord. Vid sökningarna har sökorden använts var för sig och i kombination med varandra varvid 13 stycken artiklar valdes ut till resultatet. Resultatet visade att det fanns brister i den ordinarie palliativa vården vad det gäller kommunikation, symtomlindring och anhörigvård. Tidsbrist och stress var också utmärkande i den ordinarie palliativa vården. Vad gäller patienter som vårdats under LCP/ICP så upplevde närstående och vårdpersonal att både kommunikation och symtomkontroll var avsevärt bättre än i den ordinarie palliativa vården. Tiden för det goda samtalet fanns i betydligt större utsträckning vid vård under LCP/ICP. En orsak var att sjuksköterskan istället för att lägga ner tid på dokumentationen hade möjlighet att vara där för patienten och dess närstående. De närstående hade också möjlighet att vara delaktiga i vården på grund av att de hade tillgång till dokumentationen kring patienten.

The purpose of this research is to develop a rapid determination method for heavy metals in soil. Using X-ray fluorescence to obtain soil metals decision limit (CC£\) and detection capability (CC£]), to establish the scope of soil metal concentration selection. Then aqua regia digestion digestion and ICP-OES analysis of Pb, Cd, Zn, Ni, Cr, Cu area to check the accuracy of screening. Operating conditions; First, the soil standard samples for the Establishment and assessment of the applicability of the standard. Finally,using of the soil near the control standard establish methods and explore ways to establish the applicability and potential impact. I hope this research can provide a fast, accurate, and sensitivity of soil heavy metal screening, to achieve savings of cost. The results show that the standard reference soil Cu: screening rate was 79.7%, sensitivity was 43.6% and an specificity of 87.7%; reference standard soil Pb: screening rate was 91.5%, a sensitivity of 8.3% specificity 91.5%;reference standard soil Cr:screening rate was 100%, sensitivity was 0%, 100% specificity; reference standard soil Ni: screening rate was 96.1%, sensitivity was 0%, specificity 92.4%; reference standard soil Zn: screening rate was 82.4%, sensitivity was 69.2%, specificity 87.1%; reaching control values of soil Cu: screening rate was 83.0%, sensitivity was 30.8%, specificity of 84.3%. Screening rate and specificity with 80%, the sensitivity poor areas, water was the major disturbance factor.

The electro-optical properties of the ZnO/Si heterojunction embedded with self-assembled gold nanoparticles on patterned silicon substrate are investigated in this master thesis. High quality n-type ZnO film is deposited on patterned p-type silicon substrate by radio-frequency sputtering to form a ZnO/Si pn junction. The patterned silicon substrates are prepared by ICP-RIE using self-assembled nickel metal dot and silicon dioxide as etching mask. The optimum ICP process conditions of silicon nanopillars are CF4/Ar ~ 40/40 sccm and bias/RF power 400/400 W. Silicon nanopillars of diameter ~ 50 nm and height 100~400 nm are formed on the substrate surface. ZnO film is then deposited of a growth rate ~ 12 nm/min at the substrate temperature = 200oC. The plasmonic effects on the electro-optical properties, including photoluminescence (PL), reflection, and electrical characteristics, are studied by adding self-assembled gold nanoparticles within the ZnO film. The self-assembled gold nanoparticles are formed by thermal deposition and rapid thermal annealing at 700oC. The gold nanoparticles are observed by scanning electron microscopy (SEM) and particles of diameter about 100 nm. The PL intensity of ZnO is enhanced more than ten times at the peak wavelength = 380 nm by adding the gold nanoparticles and silicon nanopillars. Strong blue emission light could be saw with the naked eyes. For the electric characteristics, self-assembled gold nanoparticles in patterned ZnO/Si heterojunction show photoelectric conversion phenomenon because of high electromagnetic absorption and plasmonic effects.

none

none