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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.
1

Vodní svět - rekreační zóna Vyškov / Water World - Zone of Recreation Vyškov

Vesely, Michal January 2011 (has links)
It is a self-standing restaurant building. The basement contained storage needed for restaurant operations. The first floor is the kitchen which has placed kitchen for seating on both sides of the building. Also found here are also toilets and lift to upper floor. The first floor is the actual operation of the restaurant terrace.
2

Effect of historical land-use on lake-water carbon and geochemistry: : A multi-proxy study of two lake sediment profiles in Dalarna throughout the Holocene

Muthreich, Florian January 2016 (has links)
This study examines changes in lake-water total organic carbon (LW-TOC) and lake sediment geochemistry in two lakes, Stångtjärnen and Holtjärnen in (Dalarna, Sweden), during the Holocene and the role of the historic forest grazing and farming (fäbod-system). The aims of the study were to: 1. Discern the effects of natural processes on the lake’s biogeochemistry in different position in the landscape. 2. Identify the effects and differences in intensity of historic land-use on the lakes. A multi-proxy study was conducted encompassing multi-element (15) geochemistry, biogenic silica, LW-TOC, chlorophyll a and published pollen records. The first lake, Stångtjärnen, is shaped and influenced by surrounding mires, which developed shortly after deglaciation and stabilized the LW-TOC at 19 mg L-1 throughout most of the Holocene, while Holtjärnen, a small upland lake, changed from a productive lake (BSi: 35 %), low humic (LW-TOC: 8 mg L-1) to a less productive (BSi: 4 %) more humic lake (LW-TOC: 12 mg L-1) in 7300 BP. The intensification of agricultural land-use (e.g. hay-making) in Stångtjärnen reduced the concentrations of organic associated elements (Br, Cl) and LW-TOC and increased lithogenic elements (K, Ti), while Holtjärnen showed less anthropogenic influence. The comparison between the two lakes displayed the intensive influence of land-use on the Stångtjärnen catchment, showcased by changes in the sediment geochemistry, vegetation composition and the extent of the forest-grazing system in a landscape perspective. In response to the changes of the Holocene, Stångtjärnen’s mires became the main influence, while Holtjärnen was more sensitive to changes.
3

Tracing late Holocene changes in lake-water total organic carbon : A multi-proxy approach based on sediment bio-geochemistry and a faecal biomarker

Jonsson, Sofia January 2015 (has links)
Long-term dynamics of lake-water total organic carbon (LW-TOC) concentrations in freshwater lakes provide an important perspective on the recent increases in LW-TOC observed in many of these systems and may assist with the identification of natural and anthropogenic drivers of change. This study examines how LW-TOC in Dragsjön, a lake situated in an area with a long history of anthropogenic land use, has changed in response to natural and anthropogenic perturbations throughout the Holocene. To provide a better understanding of the processes involved, a multi-proxy study was conducted and included multi-element geochemistry (17 major and trace elements), biogenic silica, organic matter (OM) content and composition, and the faecal biomarker “coprostanol”. The direct biomarker for anthropogenic presence, “coprostanol”, and a detailed characterisation of OM composition are for the first time applied for tracing changes in LW-TOC. Natural processes contributed to stable LW-TOC concentrations in Dragsjön for most part of the Holocene. Humans were present in the catchment from AD 100 as indicated by coprostanol, but did not begin to affect LW-TOC until c. AD 1500. In the last 500 years LW-TOC steadily declined from 17 to 10 mg L-1 in response to anthropogenic alterations to the terrestrial biomass balance. The increase in LW-TOC during the last 70 years likely represents a recovery from anthropogenic disturbance rather than a baseline shift in response to any of the number of proposed recent stressors. The faecal biomarker coprostanol and OM composition provided information essential for identifying and characterising the effects of anthropogenic disturbance.
4

Investigating the potential of remote sensing for long-term limnological analysis at pan-continental scales

Politi, Eirini January 2010 (has links)
Lakes are key indicators of environmental change and major repositories of biodiversity and ecosystem services. However, studies of lake response to drivers of change at a pan-European scale are exceptionally rare. The need for such studies has been given renewed impetus by concerns over climate change and because of international policyrelated schemes, such as the EU Water Framework Directive that has made it legal requirement to repeatedly assess and monitor the ecological status of European lakes toward their effective management and sustainable use. This has introduced the need for methods that can be widely applied across large spatial and temporal scales and produce comparable results. Remote sensing is a promising method for providing such information, but the spatial transferability and temporal repeatability of methods and relationships observed remains untested. In this project, an extensive dataset of field measurements was compiled covering temperature, chlorophyll a and Secchi disk depth in 23 European lakes spanning the last 30 years. The characteristics of these lake systems were explored and similarities in their ecological behavior identified, thus providing the basis for their grouping. Then the potential of remote sensing for estimating and monitoring lake water quality at wide spatial and temporal scales was assessed and thus the long remote sensing archive at the NEODAAS DSRS was fundamental for the purposes of this project. Using NOAA AVHRR, Terra/Aqua MODIS and field data from lakes that represented three main lake groups, the spatial and temporal reliability of 26 existing water quality estimation algorithms was assessed. Following this, the best performing algorithms were applied to all study sites and the effect of scale and spatial resolution upon reliable estimation of key water quality parameters was evaluated. It was demonstrated that the NOAA AVHRR and Terra/Aqua MODIS were both capable of producing highly accurate (R2 > 0.9) lake surface temperature estimates in lakes with variable characteristics and a variety of thermal spatial features, and longterm patterns within the study sites could be studied with NOAA AVHRR data despite the relatively coarse spatial resolution of the sensor. Restricting factors to the latter were the size and shape of lakes and the frequency of cloud cover. By contrast, the development of a universal Terra/Aqua MODIS algorithm for the estimation of chlorophyll a and Secchi disk depth in variable lakes was more challenging due to the optical complexity of Case II waters. Terra/Aqua MODIS data showed a potential, but the use of a different technique (e.g. multivariate regression or neural networks) and/or a different sensor (e.g. Envisat MERIS) could potentially improve the predictive accuracy of the algorithms.
5

Environmental change during the Holocene : A comparative multi-proxy study of landscape disturbances in Northern Sweden

Capel, Mégane January 2019 (has links)
Varved lake sediments were used to provide information on how a landscape is affected by disturbances of different scales, from global (i.e. climatic) to local (i.e. fires), as well as anthropogenic activities. Geochemical and pollen data, biogenic silica (bSi), lake-water total organic carbon (LWTOC) and chlorophyll a were used as proxies to infer past changes in lake-conditions. The goal was to evaluate the response to scale different disturbances and how it differs among sites. By comparing different lake records, it became possible to isolate the climatic signal from the effect of soil development and vegetation establishment, and differences emerging from different catchment characteristics. Climatic trends were reconstructed based on the pollen and geochemical data. The sediment records were then compared to identify the effect of each disturbance on individual lakes. One of the most prominent event observed was the immigration of spruce at about 3000 BP which considerably affected sedimentation trends. The presence of spruce within the catchment appears to promote the input of fine-grained material to the lakes. The timing and intensification of anthropogenic activities was established and it was possible to differentiate the effects of human disturbance from changes caused by natural processes such as climate or landscape vegetation cover changes. The results show that farming practices started earlier in more southern locations and that this timing is site-dependent. Two phases were identified, corresponding to the start of slash and burn farming and later to the expansion of agricultural practices, with a more profound transformation of the landscape.
6

Using of PCR-DGGE Technique to Analyze the Microbial Diversity in Biofiltration System of Water Treatment Plant

Shiu, Chih-ping 23 August 2007 (has links)
This study investigated the microbiota in ten different drinking water treatment pools, particles in the Biological Activated Carbon Filtration (BACF) bed, and two mimic columns in the Cheng-Ching Lake Water Treatment Plant. Assimilable organic carbon (AOC) is one of the main nutrition sources for microbes to survive in tap water. Over growing microbes not only decrease the water quality, but also contaminate the water treatment system and distribution system. In this study, we used two molecular biology techniques, the polymerase chain reaction (PCR) and denaturing gradient gel electrophoresis (DGGE), to analyze the dynamic microbial communities and biodiversities in the drinking water cleaning system and the micorbiota that exist in the BAC and anthracite filtration pellets. The bacterial 16S rDNA sequences resulted from PCR-DGGE were compared with the data in the Ribosomal Database Project Bank to construct a phylogenetic tree which allowed us to understand the microbial communities and biodiversities in the drinking water treatment pools and the filtration pellets. The total bacterial count and PCR-DGGE profiles showed that the drinking water quality had been improved during the treating processes and most of the microbes in raw water were removed. The scanning electron microscopy clearly indicated the biofilms were developed on the pellet surface. From the mimic column studies, the PCR-DGGE profiles suggested that various microbial communities were present on different depth of the columns samples. In comparing the 16S rDNA sequences with Gene Bank, many are new category bacteria were found and most of them are unculturable. Most of these microbes belong to the beta-proteobacterium. Although many bacteria were located on the surface of the filtration pellet, the BAC and anthracite could still absorb AOC efficiently to enhance the bacteria growth. The over growing bacteria might release out and contaminate the drinking water. Therefore, we suggest that it is important to backwash the filter bed frequently in order to diminish microbes of the filtration pellet and avoid re-contaminate the drinking water.
7

Lake condition changes of a boreal lake over the past ca. 6500 years based on varve geochemistry

Ligtenberg, Jora January 2017 (has links)
The purpose of this study was to assess changes in the in-lake conditions of lake Kassjön, northern Sweden, in response to environmental and climate changes over the past ca. 6500 years. Sediment concentrations of different elements and biogenic silica (bSi) were measured with wavelength dispersive X-ray fluorescence spectrometry (XRF) and Fourier transform infrared spectroscopy (FTIR), respectively. The lake-water total organic carbon (LWTOC) content was inferred based on near-infrared spectroscopy (NIRS). The marine sediment was distinguished from the lacustrine sediment by higher dry bulk density, lithogenic element concentrations and Br content, and lower bSi concentrations. After lake formation, the dry bulk density, lithogenic element concentrations and metal contents decreased, while organic matter (OM), bSi and LWTOC increased. The main reasons for these changes are soil development and vegetation establishment. Spruce immigration around 3000 BP induced considerable changes to the sediment concentrations indicative of increased erosion versus weathering, and LWTOC declined. These changes are mainly related the different characteristics of spruce compared to birch. Human influences in the catchment were also clearly visible, but the rest of the sediment sequence demonstrated that natural changes can be of a similar magnitude. Overall, relatively small-scale, catchment specific processes seem to be more important for changes in the lake conditions than general climate change.
8

Differential Sensitivity of Bacterial Strains to Protozoan Predation in Lake Water

Lin, J., Scheuerman, Phillip R. 01 January 1989 (has links)
No description available.
9

Hydrolysis of Condensed Phosphates in Lake Water and Wastewater

Heinke, Gerhard William 05 1900 (has links)
<p> Nutrient enrichment through pollution causes intense aquatic growth in many of our lakes, which results in their deterioration for man's use. Phosphorus is suspected as possibly the most important element in this problem since it often is the limiting nutrient for growth. Condensed phosphates from detergents in wastewater are a major supply of phosphorus to surface waters. They hydrolyze to orthophosphate, the form most readily available to plants and organisms. The removal of phosphorus in treatment plants has therefore been suggested. </p> <p> The chemical industry has carried our many studies on the rate of hydrolysis of condensed phosphate in distilled water. However few investigations have been made on this effect in natural water and wastewater. This work concentrates on studies on the rate of hydrolysis of condensed phosphates in wastewater and lake water under conditions of temperature, pH and concentration levels actually occurring in the environment. </p> / Thesis / Doctor of Philosophy (PhD)
10

Changes in lake-water organic carbon over recent centuries in northern Sweden, Västerbotten : Past and present mechanisms, and the potential implications on mercury

Petter, Magnusson January 2023 (has links)
Due to the current increase in lake water total organic carbon (LW-TOC), many studies have investigated the long-term dynamics using lake sediments. However, these have mainly been focused on Sweden’s south and south-central parts. Thus, this study aimed to investigate how LW-TOC concentrations in northern freshwater systems have changed over the recent few centuries and what effect potential trends or patterns may have on mercury (Hg). A multi-proxy study was conducted that included geochemical characteristics, inferred LW-TOC, chlorophyll a, and land-use observations acting as a supplement to modern land-use changes. The results show that LW-TOC concentrations display tendencies to a decreasing trend in the deepest part of the sediment, which could be related to traditional land-use activities. This is followed by a more rapid decrease reaching equally low LW-TOC concentrations as in southern and south-central Sweden, here suggested being caused by catchment disturbances superimposed by acid deposition. During the recent decades, LW-TOC displayed increasing concentrations, possibly due to the combined effect of the reduction of the abovementioned factors, but also likely to be superimposed by an increase in temperature similar to what has been shown for Canadian lakes. These results align broadly with lakes in southern and south-central Sweden, although with potentially different forcings in the earliest part of the sediment. This contemporary increase in LW-TOC is accompanied by an increase in Hg in two lakes, with both LW-TOC and Chl-a show possible relations.

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