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Impact of Distributed Generation on Power Network OperationPregelj, Aleksandar 11 December 2003 (has links)
Tools and algorithms are proposed that are useful for planning, designing, and operating a distribution network with a significant penetration of distributed generation (DG). In Task 1, a PV system simulation program is developed, which incorporates the most rigorous models for the calculation of insolation, module temperature, and DC and AC power output of a PV system. The effect of random inverter failures is incorporated in the model of a PV system, and a novel performance-derating coefficient is introduced. Furthermore, a novel inverter control algorithm is presented for systems with multiple inverters. The algorithm is designed to increase overall DC/AC conversion efficiency by selectively shutting down some of the inverters during periods of low insolation, thus forcing the remaining inverters to operate at higher efficiency. In Task 2, a procedure is developed to incorporate the uncertainties imposed by stochastic, renewable DG into the conventional tools for analysis of distribution systems. A clustering algorithm is proposed to reduce large input data sets that result from the interaction of stochastic processes that drive DG output with field measurements of feeder load profiles. In addition, a procedure is proposed to determine the boundary points of the original data set, which yield feeder extreme operating conditions. Finally, a Monte Carlo analysis using a reduced data set is presented, to determine the effects of deploying a large number of renewable DG systems on a distribution feeder. In Task 3, the reliability model of an asymmetric, three--phase, non-radial distribution feeder equipped with capacity-constrained DGs is developed and used to quantify the potential reliability improvements due to the intentional islanded operation of parts of the feeder. A procedure for finding optimal positions for DG and protection devices is presented using a custom-tailored adaptive genetic algorithm.
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Evaluation of Early Measures of Body Composition as Related to Beef Carcass TraitsMaulsby, Richard Paul. 2009 December 1900 (has links)
Two similarly managed trials were conducted to investigate serial ultrasound
measures of body composition (longissimus muscle area (ULMA), 12th - rib fat
thickness (UFAT), and percentage of intramuscular fat (UIMF)) early in the lives of
feeder calves as they compared to carcass traits. Group 1 cattle were Charolais-sired by
Brahman-British crossbred dams whereas Group 2 cattle were purebred Beefmaster.
Both groups were fed at the same commercial feedlot (Graham Land and Cattle Co.) in
Gonzales, Texas. In both data sets classifications were developed for ribeye area of
Lower (less than 70.95 cm2, Middle (between 70.95 cm2 and 90.3 cm2) and Upper (over
90.3 cm2) based on a range that fit within the ribeye specifications of such branded beef
programs as Certified Angus Beef and Nolan Ryan?s Tender Aged Beef. Differences
among ribeye area and quality grade (Choice vs. Select) categories were evaluated for
ultrasound and carcass traits. As reported previously, correlations between ultrasound
measures and carcass traits became larger at times closer to harvest. In both sets of
cattle, there were no differences in fat thickness or intramuscular fat at the ultrasound
scan sessions or in these carcass traits due to ribeye area category. The same trend for quality grade classification was not seen across both groups of cattle however. In Group
1, there were no differences in early measures of body composition between carcass
quality grade classes except for ultrasound fat thickness at weaning. However, in Group
2 cattle there were differences in ultrasound fat at times 1 and 2, IMF at time 1, and
ribeye area at time 2 between cattle that graded choice verses those that graded select.
Correlations between ultrasound measures of REA (r of .26 to .50) and ultrasound REA
and carcass REA (r of .16 to .81) appeared to be lower in Group 1 vs. Group 2 (r of .55,
and .64 to 81 respectively). Results from this project imply that changes in ribeye area
will not automatically result in changes of marbling and vice versa. Furthermore, these
results also show that ultrasound is useful to help predict beef carcass traits, but that
early measures of body composition used alone do not explain a large portion of the
variation in the carcass measures and specific methods should be developed by different
biological cattle types.
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Optimal Design of Demand-Responsive Feeder Transit ServicesLi, Xiugang 2009 August 1900 (has links)
The general public considers Fixed-Route Transit (FRT) to be inconvenient
while Demand-Responsive Transit (DRT) provides much of the desired flexibility with a
door-to-door type of service. However, FRT is typically more cost efficient than DRT to
deploy. Therefore, there is an increased interest in flexible transit services including all
types of hybrid services that combine FRT and pure DRT. The demand-responsive
feeder transit, also known as Demand-Responsive Connector (DRC), is a flexible transit
service because it operates in a demand-responsive fashion within a service area and
moves customers to/from a transfer point that connects to a FRT network. In this
research we develop analytical models, validated by simulation, to design the DRC
system.
Feeder transit services are generally operated with a DRC policy which might be
converted to a traditional FRT policy for higher demand. By using continuous
approximations, we provide an analytical modeling framework to help planners and
operators in their choice of the two policies. We compare utility functions of the two policies to derive rigorous analytical and approximate closed-form expressions of critical
demand densities. They represent the switching conditions, that are functions of the
parameters of each considered scenario, such as the geometry of the service area, the
vehicle speed and also the weights assigned to each term contributing to the utility
function: walking time, waiting time and riding time.
We address the problem faced by planners in determining the optimal number of
zones for dividing a service area. We develop analytical models representing the total
cost functions balancing customer service quality and vehicle operating cost. We obtain
close-form expressions for the FRT and approximation formulas for the DRC to
determine the optimal number of zones.
Finally we develop a real-case application with collected customer demand data
and road network data of El Cenizo, Texas. With our analytical formulas, we obtain the
optimal number of zones, and the times for switching FRT and DRC policies during a
day. Simulation results considering the road network of El Cenizo demonstrate that our
analytical formulas provide good estimates for practical use.
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The Effects of Mandatory Country-of-Origin Labeling on Canadian/U.S. Live Hog and Feeder Pig TradeThevenaz, Shad Arthur Michel 2011 December 1900 (has links)
The final implementation of Mandatory Country-of-Origin Labeling has caused some U.S. packing plants and finishing operations to discontinue using Canadian live hogs and feeder pigs in their operations thereby reducing trade. Using a system of simultaneous equations representing U.S. import demand and U.S. price, this thesis estimates the reduction in trade and any possible price effects in both live hogs and feeder pigs associated with the implementation of the final rule of Mandatory Country of Origin Labeling in the United States.
It was found that the implementation of Mandatory Country of Origin Labeling reduced the trade of live hogs between the United States and Canada by 37.8 percent. The reduction in feeder pigs was 24.1 percent. It was also found that the implementation of Mandatory Country of Origin Labeling had no effect on the price of both live hogs and feeder pigs in the U.S. market.
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A Barkhausen Noise Testing System for CANDU Feeder PipesWHITE, STEVEN ANDREW 22 July 2009 (has links)
A Barkhausen noise (BN) testing system was developed for the non-destructive evaluation (NDE) of residual stresses in CANDU reactor feeder pipes. The system consists of a four-channel arbitrary waveform flux control system (FCS), and the spring-loaded tetrapole prototype (SL4P) BN probe. The combination of the FCS and SL4P was shown to provide repeatable BN measurements on feeder pipe samples, with variations in air gaps between the SL4P poles and the sample from 0.43 mm to 1.29 mm, and typical pickup coil coupling uncertainties for the total BN energy from ±2% to ±7%. Precision for elastic strain estimation in feeder pipes was found to be between ±7 MPa and ±9 MPa in tension, depending on the excitation field configuration, and negligible in compression. Modelling of the BN penetration depth as a function of the excitation field was used to estimate the BN penetration depth between 5 μm at 300 kHz to a maximum of 500 μm at 3 kHz. The modelling, engineering, and procedures developed for this BN testing system provide an improved basis for the future advancement of BN testing, and ferromagnetic NDE in general. / Thesis (Ph.D, Physics, Engineering Physics and Astronomy) -- Queen's University, 2009-07-22 15:34:28.967
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BASIS VARIABILITY AND ITS EFFECTS ON HEDGING EFFICIENCY FOR KENTUCKY FEEDER CATTLERoutt, Nathaniel J. 01 January 2006 (has links)
Kentucky plays a vital role in the beef supply chain. The cow/calf producers,back-grounding operations, and order buying industry are important parts of Kentucky'sagricultural economy. Basis risk is an issue that affects these groups in a negative way. Agood estimate of the expected basis must be available to make hedging efficient.Simulations were performed on Kentucky price data to determine the effectiveness ofshort hedging for Kentucky producers. A model was also used to describe some of thefactors that determine basis levels. The research revealed that it is difficult to predictbasis within an acceptable range to make short hedging with futures efficient. Eventhough short hedging reduced variability in net price, it was difficult to lock in a profit.Various options and spread strategies were presented as alternative hedging tools thatwould protect cattle producers from unexpected price declines.
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Estudio comparativo de la satisfacción de los usuarios del distrito de Los Olivos del sistema de transporte metropolitano e informalTello Gamarra, Antonio Raúl, Ramírez Martín, Alfredo January 2015 (has links)
En la presente tesis se realizó un estudio comparativo de la satisfacción de los usuarios del distrito de los Olivos, del sistema de transporte Metropolitano con el transporte informal. Se requirió dentro de este estudio el método de las encuestas para comparar las diferencias existentes, basándonos en los puntos de cobertura, comodidad, seguridad, y tiempos. Las encuestas obtenidas de una muestra de 300 encuestados nos mostraron una buena aceptación al sistema de transporte Metropolitano.
El Metropolitano es un sistema de transporte ordenado que cumple con los puntos de la encuesta contraponiendo a los informales. Sin embargo, dentro del análisis se determinó que aun siendo un sistema innovador no cumple con unos puntos como la cobertura y tiempos de espera en los paraderos en que los informales tienen aceptación. Este estudio según los resultados obtenidos determina que falta para cubrir la demanda de usuarios en este distrito por el Metropolitano y reducir los tiempos de espera en los paraderos.
Se recomienda incrementar el abastecimiento de unidades así como reducir los tiempos de espera en cada paradero, para que la informalidad del transporte se termine.
In this thesis a comparative study of user satisfaction in the district of Los Olivos of the metropolitan transportation system with informal transport was conducted on survey method required in this study to compare the differences, based on points of comfort, safety, coverage, and time. Surveys obtained from a sample of 300 respondents showed us a good acceptance to the metropolitan transport system.
The Metropolitan is an orderly transport system that complies with the points of the survey opposing the informal. However, the analysis it was determined that even being an innovative system does not meet some points, such as coverage and waiting times at bus stops that have informal acceptance. This study according to the results obtained, determined to need improvement to meet the demand from users in this district by Metropolitan to reduce waiting times at bus stops.
It is recommended to increase the supply of units and reduce waiting times at every bus stop, so that the informality of transport disappears.
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Reprogramming peripheral blood mononuclear cells using an efficient feeder-free, non-integration method to generate iPS cells and the effect of immunophenotype and epigenetic state on HSPC fateLiu, Jing January 2014 (has links)
Background and objectives: In 2006 Shinya Yamanaka successfully reprogrammed mouse fibroblasts back to an embryonic stem cell-like state (called induced pluripotent cells, iPS cells) using retrovirus to introduce four genes that encode critical transcription factor proteins (Oct4, Sox2, KLF4, and c-Myc). This ability to reprogram has promising future applications in clinical and biomedical research for study of diseases, development of candidate drugs and to support therapeutic treatments in regenerative medicine. However, the clinical applications have to meet GMP requirements without the risk of insertional mutagenesis associated with retrovirus. Chromatin modifying agents are widely used in many protocols to generate iPS cells and culture of blood CD34+ cells with chromatin-modifying agents can lead to an increase in marrow repopulating cells and in the case of valproic acid increased erythroid cell colony formation. We undertook research to help understand what effects these reagents have on mobilised peripheral blood (mPB) CD34+ cells and optimised the expansion medium protocol to facilitate reprogramming work. This project aims to utilize peripheral blood mononuclear cells (MNC), one of the most easily accessible tissues to generate iPS cells using an efficient non-viral, feeder cell free methodology, with the ultimate goal of moving this methodology towards clinical use. Materials and Methods: G-CSF mobilised peripheral blood, buffy coat, cord blood and fetal liver were obtained from patients and donors under informed consent and ethics committee approval. Haematopoietic stem/progenitor cells CD34+ or CD133+) isolated by magnetic separation were flow cytometry sorted into CD34+/CD133+, CD34+/CD133-, and CD34-/CD133+ sub-populations and their lineage potential were assessed in colony forming unit assays. The effect of epigenetic modifiers valproic acid and 5-aza-2-deoxycytidine used singly or in combination with each other and with IL3 on phenotype and lineage potential of cultured CD34+ cells from mobilised peripheral blood were assessed by flow cytometry and colony-forming unit assays. Prior to reprogramming mononuclear cells from peripheral blood or CD34+ cells from blood were expanded in culture medium supplemented with stem cell factor (SCF), Fms-related tyrosine kinase 3 ligand (Flt3L) and Interleukin- 3 (IL-3) for several days. Actively proliferating cells were reprogrammed by electroporation using episomal vectors with an oriP/EBNA-1 backbone to deliver five reprogramming genes, Oct4, Sox2, Lin28, L-Myc, and Klf4. Electroporated cells were seeded onto matrigel coated plates immediately after transfection or were reseeded after three days’ culture. Subsequently, cells were cultured in specific medium on different days. When iPS colonies appeared, they were picked and cultured as for ES cells. Once established, iPS cell lines were immunophenotyped using flow cytometry and immunofluorescence and their potential to differentiate into the three germ layers was assessed in vitro. Results and Conclusion: The largest subpopulation of CD34+ cells was CD34+/CD133+ population which was essentially committed to myeloid colony production, while much smaller CD34+/CD133- subpopulation had a greater capacity to generate erythroid colonies. Optimised cytokine cocktail for expansion of CD34+ cells included IL-3, important in improving expansion and maintaining functionality of CD34+ cells. The optimised cytokine cocktail comprised 100 ng/ml SCF, 10 ng/ml Flt3L, and 20 ng/ml IL-3, which maintained CD34+ cells and MNC in an active proliferating state. In addition, valproic acid and IL3 were found to act synergistically, to increase the numbers of CD34+/CD36+ positive cells. However, we found that an apparent increase in red cell colony formation actually resulted from a decrease in white cell colonies, so no overall increase in red cell colonies was seen when equivalent numbers of CD34+ cells were plated. Proliferating MNC maintained in optimised cytokine cocktail were amenable to electroporation for the effective delivery of episomal transcription factors (Oct4, Sox2, Klf4, L-Myc, and Lin28) within a backbone of oriP/EBNA-1. We successfully developed an efficient and simple method for reprogramming MNC from fresh or frozen samples to generate induced pluripotent cells using episomal vectors in a feeder-free system without any requirement for small molecules and the highest reprogramming efficiency is 0.033% (65 colonies from 2 ◊ 105 seeding MNC). The cytokine cocktail and reprogramming methods work better in CD34+ cells from cord blood or fetal liver, and we obtained 148 iPS colonies from 105 seeding cells (0.148%) at most. In addition, fibroblasts from adult and fetal liver can be successfully reprogrammed using the same reprogramming method. The use of episomal vectors with an oriP/EBNA-1 backbone to deliver reprogramming genes, and efficient electroporation were the most important factors in efficiency of the reprogramming process. In addition, it is pivotal to initiate transfection when cells are actively proliferating. The iPS cell lines we generated maintained the successful expression of ES markers including Oct4, Nanog, SSEA3. SSEA4, TRA-1-60 and TRA-1-81, and had the capacity to successfully differentiate into cell types of ectoderm, mesoderm and endoderm layers in vitro.
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Návrh zásobníku s posuvem a orientací gumové ucpávky / Suggestion of case feeder for orientation gum plugLaurenc, Filip January 2012 (has links)
The main target of this diploma thesis was to make suggestion orientation and movement product, this solution describe, make calculation and draw drawings documentation.
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Konstrukce podavače tyčového materiálu pro CNC soustruh / Design of bar-feeder for CNC latheVoda, Pavel January 2013 (has links)
The aim of this thesis called Design of bar-feeder for CNC lathe is research about workpiece handling and bar feeders. But the most important aim is design of bar feeder by chosen parameters. The first part of thesis includes description of different types of workpiece handling. The second part is formed by bar feeders description and distribution and possibly construction solution. In the last part is performed choice of parameters for designed bar feeder and design of short bar feeder construction itself.
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