The salt expulsion caused by the freezing of seawater and the drainage of brine from the ice creates a convectively mixed layer, which extends to the bottom in shallow coastal regions. This buoyancy flux at the surface was simulated in laboratory experiments by percolating salt water through a porous membrane into a tank. Shadowgraph images show that a down-slope flow is induced when the bottom of the tank is set at an angle. Velocity maxima in the slope flow, measured from the movement of injected dye ranged from 0.09 to 0.66 cm/s. Fluid densities were determined using thermistors and small-volume conductivity micro-cells developed for this purpose. For bottom slope angles between 2.2° and 5.5°, and at computed salt fluxes between 1.82★10⁻⁵ and 1.63★10⁻⁶ g/cm²/s, the salinity profiles showed slope flow depths between 7 and 17 mm with a rise in salinity of 0.24 to 0.92 ppt above those in the mixed layer. Entrainment at a density interface without shear, using this experimental arrangement, agreed closely with predicted results by Bo Pedersen. Using the entrainment model for a turbulent gravity current, entrainment factors computed from the data of the slope flow experiments were up to two orders of magnitude larger than those predicted for flows in a quiescent environment. This is contrary to visual evidence of the experiments or to Arctic field data, which indicate low rates of entrainment. This suggests that a different model is required to explain the interaction between such flows and the turbulent environment. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate

The purpose of this master thesis is to analyze legal instruments of the water quality protection with the emphasis on the management of waste waters and also on the special treatment of some water bodies. The Czech legislation is influenced by the regulation of the European Union. The thesis is composed of seven chapters. Chapter One is introductory and defines the quality of fresh waters in the Czech Republic as well as the main sources of their pollution. The following chapters examine the subject of the regulation, aims and the planning process, individual sources of pollution, special protection and the problem of the liability. Powered by TCPDF (www.tcpdf.org)

Thesis (M.D.) - Queen's College, New Jersey.

Many drinking water treatment facilities face problems with algal organic matter (AOM) due to eutrophication of the environment and frequent occurrence of algal blooms. AOM can cause deterioration of water organoleptic properties, but the main threat is the potential for acting as a precursor of toxic disinfection by-products (DBPs). The presented master thesis deals with the possibility of using electrocoagulation (EC) - an innovative electrochemical method - to remove cellular organic matter (COM) produced by cyanobacteria Microcystis aeruginosa from drinking water. EC is similar to widely used chemical coagulation, the difference is that during EC the coagulant is produced by electrochemical dissolution of an iron or an aluminum electrode. Synthetic water with COM concentration of 5.5 and 8.5 mg/L of TOC was used for the experiments. The target value of conductivity (4.5 mS/cm) was reached by addition of NaCl. pH of the solution was adjusted by HCl and NaOH. During some of the experiments, NaHCO3 was added to increase the ANC4.5. The experiments were conducted in a batch mode with a stainless-steel cathode and an aluminum or an iron anode. The coagulant dosage was regulated by applied electric current passing through the electrodes. Flocs were separated by sedimentation and centrifugation. COM...

published_or_final_version / abstract / Civil Engineering / Master / Master of Philosophy

No description available.

No description available.

Thesis (doctoral)--Universität, Hamburg, 2005. / "International Max Planck Research School for Maritime Affairs at the University of Hamburg"--Cover. Description based on print version record. Includes bibliographical references (p. [461]-476) and index.

Thesis (M.A.)--Guo li Taiwan da xue. / Cover title. Mimeo, copy. Includes bibliographical references.

The overall goal of this study is to determine the resolution and type of proxy that any one drip site can provide for the determination of past climate. The study examines surface conditions (effective rainfall, temperature, PDSI), cave characteristics (cave geometry, cave air CO2, location), drip site characteristics (drip rate, drip rate response to rainfall), and drip water characteristics (pH, trace element ratios, alkalinity, temperature). The study encompasses two distinctly different caves, Inner Space Cavern (Chapter 2) and Westcave (Chapter 3). A goal of Chapter 2 is to identify drip sites where there is an intra-annual climate signal, which can assist with high resolution paleo-drought reconstructions when extended to speleothem studies. To be considered an intra-annual climate sensitive drip site, a site should display statistically significant correlations between (1) effective rainfall and drip rate; (2) effective rainfall and Mg/Ca; (3) drip rate and Mg/Ca; (4) Palmer Drought Severity Index (PDSI) and drip rate; and (5) PDSI and Mg/Ca. These relationships can be explained by the extent to which water flux in the karst overburden influences flow path characteristics, water residence time, and water-rock interactions. The data in Chapter 3 will indicate that (1) variations in trace element/Ca values in cave drip waters are temperature dependent and vary on a seasonal time scale, (2) the standardization of trace element/Ca values allows for between drip site comparisons, (3) the standardization of trace element/Ca values can add statistical power to statistical analyses by increasing the sample size, (4) calcite growth rates follow a seasonal pattern based on variations in surface temperature, (5) a regional drought indicator provides correlation with trace element/Ca values at some drip sites and this relationship is most likely dependent upon temperature. / text