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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.
21

An Economic History and Analysis of the Great Feeder Canal of Southeastern Idaho

Gneiting, Gary Wayne 01 May 1972 (has links)
The purpose of this paper is to relate the economic history of the Great Feeder Canal and preform an analysis on its flow of water. Historical chapters are portrayed chronologically and reveal in sight into the rustic irrigation problems that faced those individuals who developed the Great Feeder Canal. The latter part of the paper entails an economic analysis indicating that the Great Feeder Canal is unique in that it uses nearly twice as much irrigation water per acre as other canals in Southeastern Idaho, yet it tends to maximize net social benefits.
22

The influence of eutrophic conditions on the activity of the suspension-feeding barnacle Semibalanus balanoides

Kunzel, Theresa January 2008 (has links)
<p>Eutrophication is a current problem on coastal lines worldwide. Cirripedia like the northern acorn barnacle Semibalanus balanoides actively help to prevent high amounts of plankton in the coastal zones by filtering plankton out of the surrounding water. This investigation focuses on the movements of Semibalanus balanoides in comparison to increasing concentrations of plankton in the water (between 33mg and 110 mg particles per litre) which simulate eutrophication. The four factors feeding activity, pumping activity, isolation time and clogging of the feeding apparatus in relation to the plankton concentration of the water were examined. </p><p>The results show significant interaction between pumping movement and the plankton concentration. The feeding activity, the isolation time and the clogging compared to the plankton concentration get no statistical results. </p><p>Less feeding activity and an increase in pumping behaviour will not decrease the amount of plankton in the coastal waters which will increase the problems of eutrophication. The paper shows that more investigation on suspension feeders and their surroundings needs to be done to be able to understand the dangers fully.</p>
23

Molecular and functional bases of coordination in early branching metazoans insights from physiology and investigations of potassium channels in the Porifera

Tompkins MacDonald, Gabrielle Jean 11 1900 (has links)
Sponges are filter feeders that lack nerves and muscle but are nonetheless able to respond to changes in the ambient environment to control their feeding current. Cellular sponges undergo coordinated contractions that effectively expel debris. Syncytial sponges propagate action potentials through their tissue, causing immediate flagellar arrest. Understanding the basis of this coordination in sponges is of interest for the insight it provides on mechanisms of coordination in early branching animals. However, when I began this thesis no ion channels had been described from the Porifera. I adopted a multifaceted approach to studying the conduction system of sponges. This included cloning and characterizing potassium channels as a means to understanding the underlying ionic currents, and monitoring regulation of the sponge feeding current in response to environmental stimuli. The latter experiments provided a functional context. The glass sponges Rhabdocalyptus dawsoni and Aphrocallistes vastus arrest feeding in response to mechanical disturbance and to sediment in the incurrent water suggesting a protective role. Monitoring patterns of feeding current arrests also revealed several features of the glass sponge conduction system: pacemaker activity, mechanosensitivity, distinct excitability thresholds, and tolerance to repeated stimuli. With access to the genome of the demosponge Amphimedon queenslandica I have also cloned and characterized the first sponge ion channels. Inward rectifier potassium (Kir) channels were prioritized for their role in regulating excitability. Kir channels cloned from A. queenslandica shared critical residues and a strong rectifying phenotype with Kir channels typically expressed in excitable cells. A variety of potassium channels from A. queenslandica indicate great diversity and a foundation for coordination at the dawn of the Metazoa / Physiology, Cell and Developmental Biology
24

The influence of eutrophic conditions on the activity of the suspension-feeding barnacle Semibalanus balanoides

Kunzel, Theresa January 2008 (has links)
Eutrophication is a current problem on coastal lines worldwide. Cirripedia like the northern acorn barnacle Semibalanus balanoides actively help to prevent high amounts of plankton in the coastal zones by filtering plankton out of the surrounding water. This investigation focuses on the movements of Semibalanus balanoides in comparison to increasing concentrations of plankton in the water (between 33mg and 110 mg particles per litre) which simulate eutrophication. The four factors feeding activity, pumping activity, isolation time and clogging of the feeding apparatus in relation to the plankton concentration of the water were examined. The results show significant interaction between pumping movement and the plankton concentration. The feeding activity, the isolation time and the clogging compared to the plankton concentration get no statistical results. Less feeding activity and an increase in pumping behaviour will not decrease the amount of plankton in the coastal waters which will increase the problems of eutrophication. The paper shows that more investigation on suspension feeders and their surroundings needs to be done to be able to understand the dangers fully.
25

Operation Planning of Distribution Feeders with Electric Vehicle Loads

Chan, Chieh-Min 13 July 2012 (has links)
In the next decade, electric vehicles (EV) will be heading to the road in a fast speed. Utility company would have no control over the future EV charging points or stations, and no direct control over periods and frequency of EV charging that could cause great effects to the existing distribution network operations if not well planned. Distribution system operation and expansion planning would become more complicated due to the high degree of uncertainty of the EV charging demand. Markov model is used in this study to calculate the probabilities and locations of EV charging. To mitigate the loading and voltage quality problem, feeder reconfiguration is proposed. The problem is formulated as an stochastic programming program with an objective function of minimizing total switching and system loss costs, and subject to radial structure of the distribution network and security constraints. The problem is solved by a binary particle swarm optimization technique. Test results indicate that feeder reconfiguration can be exercised to match loading patterns of different types of feeders (residential, commercial and industrial) with various stochastic charging scenarios, and consequently, reduce the impacts of EV charging and optimize the use of the existing network.
26

Window Based Digital Mapping And Feeder Management Decision Support System

Chen, Sheng-Wuen 06 June 2001 (has links)
With the performance enhancement of personal computers and the popularity of Microsoft Windowing Geographic Information System (GIS), it is becoming more viable in performing the distribution automated mapping and facility management (AM/FM). In this thesis, the relative structure of the graphic and attribute data of the distribution system with four feeders (LB33, LB34, LB35 and LB38) of the Taiwan Power Company (TPC) were built according to the true geography, referring to the street background. The related applications of the GIS included Distribution Information System (DIS) and Feeder Management Decision Support (FMDS) system by using MS Visual Basic object oriented programming. The proposed DIS links graphic objects and facility attribute data through the DDE connect and WinGIS Software, and provides a user-friendly Man-Machine Interface to manage the distribution database. As for FMDS, it is complicated to operate with colossal system information of the distribution systems. To enhance the operational efficiency and reduce cost, a fast and effective Feeder Management Decision Support is critical. With a user-friendly graphical user interface provided by mapping, effective database interface and related distribution system management algorithms, it is capable of providing the decision support, so a good decision can be made both normal and emergency conditions: 1. Decision support under the normal operation The decision system can reduce the line loss and maintain bus voltages with load transferal through feeder reconfiguration strategy. 2. Decision support under the emergency operation With fuzzy reasoning algorithm, security analysis will examine network security and an optimal switching strategy can solve the load recovery problem fast and effectively.
27

A Study on Switching Operation Decision Making by Using Petri Nets for Power Distribution Systems

Ke, Yu-Lung 23 June 2001 (has links)
In this dissertation, the artificial intelligent Petri nets is applied to find the optimal switching operation for service restoration and feeder loading balance for 18-feeders distribution systems that containing the whole 24-hours load profiles of service zones. After the fault location has been identified and isolated for a system fault contingency, the Petri nets model with inference mechanism is derived and applied to solve the optimal load transfer among distribution feeders. For system normal operation condition, the load balancing among distribution feeders is obtained by the Petri nets model to enhance the operation efficiency of distribution systems. The switching operation, which will result in the loading balance among distribution feeders, is derived by the Petri nets model according to the loading cost of distribution systems. To determine the effectiveness of the proposed methodology, a Taipower (Taiwan Power Company) distribution system which serves a mixed types of customers is selected to perform the computer simulation. It is found that the Petri nets approach can enhance the solution process of fault restoration with proper load transfer and improve feeder load balance for distribution systems by considering the load characteristics of the service customers.
28

Distribution Feeders Scheduling Considering Variable Load Profiles and Outage Costs

Yin, Shih-An 10 September 2008 (has links)
In a deregulated power market, customers would have more choices for their power service and the improvement of service quality has become a challenge to power transmission and distribution companies. Distribution system reliability that was traditionally considered within the planning activities, is now incorporated in the operational environment. This dissertation presents study results of a multi-objective feeder operation optimization problem that considers how to balance network efficiency, switching and reliability costs in a distribution network. The proposed method divides annual feeder load curve into multi periods of load levels and optimizes the feeder configurations for different load levels in annual operation planning. Customer load profiles and seasonal varying data of feeder section failure rates and customer interruption costs are considered. Simulations results demonstrate the time varying effects on the optimal distribution feeder reconfiguration and operation costs. A binary particle swarm optimization (BPSO) search is adopted to determine the feeder configuration in each time period. Test results indicate that not considering time varying effects and using only simplified fixed load and reliability parameters could underestimate the total loss to the utility and its customers.
29

Molecular and functional bases of coordination in early branching metazoans – insights from physiology and investigations of potassium channels in the Porifera

Tompkins MacDonald, Gabrielle Jean Unknown Date
No description available.
30

Fault Section Identification for Power Distribution Systems Using Online Measurements

Chen, Jie 01 January 2015 (has links)
Fault location is very important for distribution systems, and quickly identifying the fault and restoring the system can help reduce the outage time and make the system more reliable. In this thesis, a method for locating faults on distribution systems is introduced to quickly identify the faulted feeder sections by using the overcurrent information from the switches in the system. Fuzzy logic is utilized. The proposed method can quickly and accurately locate faulted sections with different fault locations, fault types and fault resistances. The method is applicable to cases with single-faults or multi-faults, and is applicable to networks with multi-sources. The case study has demonstrated the effectiveness of the proposed method.

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