Thesis (M.S.)--University of Wisconsin--Madison, 1962. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 108-109).

M.Ing. / \Vith electrical power networks expanding beyond their original design limits and the various non-linear loads on the network, power quality has become an important issue in electrical engineering. Some of the largest non-linear loads on the power network are arc furnaces used to melt various metal orrs and scrap metal. In this study the focus is on fliCker as a power quality issue and more specifically the measurement and analysis methods of flicker at arc furnace installations. By measuring flicker and 3 phase voltage and current waveforms the effect of changes in arc furnace system parameters on flicker is determined. Various analysis methods based on statistical theory are described in this study. The aim is to gain a better understanding of flicker and arc furnaces to contribute to the current flicker knowledge base.

An investigation of a pulsed Hg arc has been undertaken to test the relation V α I°⁴ between the voltage and current of an arc discharge. Although the experimental V-I characteristic exhibited this tendency, further considerations strongly indicated that the agreement between theory and experiment was probably a coincidence. The Paschen breakdown curve was determined, and together with simultaneous measurements of the current and voltage, it was possible to measure the average column field strength as a function of current. As a result of an unexpected feature of the apparatus, namely an inherent motion of the electrodes, the voltage waveform could be used to obtain an approximate measurement of the combined thickness of the anode and cathode falls df, and also the average field strength in these regions Ef. The measurements df = 3x10⁻⁶ cm, and Ef = 2.4x10⁶ volt/om appear to be in agreement with the field emission theory. / Science, Faculty of / Physics and Astronomy, Department of / Graduate

Vortex stabilized argon arcs are of interest as sources of high intensity light. Previous workers in the field have found that the heat transported to the wall of the arc vessel greatly exceeded that predicted by theory. Two modifications to the theory have been proposed to account for the observed values of heat transport. This thesis describes a specialized arc vessel which has been constructed to allow the measurement of the axial profile of heat transported to the wall. The axial profile of radiation produced by the arc has also been measured. These experiments elucidate the mechanisms responsible for the large values of heat transported to the wall. In this work a 225 A d.c. arc was used. It was stabilized by an argon vortex at a pressure of 5.5 atm. It is found that the electrode regions of the arc contribute significantly to the total heat transported to the wall. Midway between the electrodes however, the profile is found to be quite flat. The experiments also indicate that some heat is transported upstream from the arc, and it has been shown that this is due to a reverse axial flow core in the gas vortex. The measured profile of radiation produced by the arc is found to be very uniform in the arc column. In the region midway between the electrodes the dependence of the radiation and heat transported to the wall on the gas flow rate in the vortex were examined. The measured radiation is found to be 30-35% less than predicted by theory. It is shown that this may be due to the axial transport of energy in the arc. The scaling of the amount of heat transported to the wall is found to be in good agreement with the predictions of a model for the arc which includes turbulent heat transport by using a mixing length model. The d.c. power supply used in this work produces a waveform with considerable ripple. Time dependent measurements were therefore made of the radiation produced by the arc and the electrical power input to the arc column. These results are compared with a time dependent theory of the arc column. / Science, Faculty of / Physics and Astronomy, Department of / Graduate

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Around the world, the eutrophication of freshwater lakes and streams by the excess loading of phosphorus (P) has become one of the most important water quality issues. In Vermont, P pollution from urban and agricultural non-point sources has led to severe blooms of toxic cyanobacteria in Lake Champlain, and the degradation of the lake’s value as a drinking water source and its recreation potential. Electric arc furnace (EAF) steel slag has been identified as an effective material for use as a filter media for the removal of P from both point and non-point sources of pollution. In order to further assess the feasibility of this technology for use in Vermont, several investigations were carried out starting in the winter of 2006. Three objectives for research were identified: 1) to construct 2 EAF steel slag filters in-series at the Constructed Wetlands Research Center (CWRC) and investigate their efficiency in P, TSS and metals reduction from dairy waste water in a cold climate; 2) investigate the potential for reuse of P saturated EAF steel slag as a soil amendment and plant fertilizer by testing bioavailability of sorbed P and quantities of P released to surface runoff; 3) To elucidate the principal mechanisms responsible for the removal of P in EAF slag filters when used for the treatment of dairy effluent. The results indicated that 2 EAF steel slag filters constructed in-series are an effective method to increase the treatment efficiency and longevity of a filter system. Additionally, parameters for the concentrations of total suspended solids (TSS) and biological oxygen demand (BOD) were developed, both important factors for design of filter systems. In greenhouse trials, Medicago sativa plants achieved greater above ground biomass growth with P fertilization by triple super phosphate (TSP) than EAF steel slag at the shorter growth period (5 weeks). However, by the end of the longer growth period (10 weeks) except at the highest amendment rate, the plants treated with EAF steel slag had a higher growth rate than the TSP, suggesting that EAF steel slag is an effective slow release P source. Using a rain simulator, the amount of P lost to surface runoff from both a saturated and a semi-saturated EAF steel slag was found to be negligible, and except for total P in the saturated slag, to be below 1 mg L-1. Voltammetric analysis and geochemical modeling were used to identify possible mechanisms for the removal of P from waste effluent. The Ca mineral hydroxyapaptite and the Fe(II) mineral vivianite were both shown to be likely mechanisms given the chemical conditions in EAF steel slag filters. This research represents the first investigation of cold weather performance of EAF steel slag filters for the treatment of dairy parlor and milk house waste effluent. Additionally, it was also the first research on the bioavailability of P sorbed to EAF steel slag, and of the possibility of its reuse as a soil amendment, and of the mechanisms involved in P removal from dairy waste effluent.

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Thesis (M.S.)--University of Wisconsin--Madison, 1968. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.