Mountain Scholar

Mountain Scholar is an open access repository service that collects, preserves, and provides access to digitized library collections and other scholarly and creative works from Colorado State University and the University Press of Colorado. It also serves as a dark archive for the Open Textbook Library.

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Colorado State University, Fort Collins 27760
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Open Textbook Library Archive 25
A limited number of titles are available here. To see all OTL titles, please visit the Open Textbook Library at https://open.umn.edu/opentextbooks. Only Open Textbook Library staff have access to all OTL Archive titles held in Mountain Scholar.
University Press of Colorado 1088
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Recent Submissions

Access status: Open Access ,
Planning reservoir operations with imprecise objectives
(1999) Moncada, Enrique, author; Gates, Timothy K., advisor; Fontane, Darrell G., advisor; Grigg, Neil S., committee member; Ramírez, Jorge, committee member
Inclusion of soft elements in the formulation of water resource system problems has always received attention by water resource researchers and planners. In the case of reservoir operation, its multipurpose characteristic has been approached through the formulation of a multiobjective optimization problem. However, the non-quantitative nature of some objectives, like environmental and recreational objectives, has always represented a complex issue to deal with either in simulation or optimization models. Imprecise objectives and constraints have not been easily incorporated into a classical crisp model. Fuzzy sets theory allows us to deal with information which is valuable but not precise. Systems analysis tools such as dynamic programming provide the way to find optimal operational policies of a multipurpose reservoir. Hence, a fuzzy dynamic programming technique should allow finding a set of optimal controls or releases when the problem is addressed as a multidecision problem with imprecise objectives. A methodology is developed based on Bellman and Zadeh's approach. The methodology is tested through its application in a case study. Two cases are considered: deterministic and implicit stochastic. Grey Mountain Reservoir, a proposed water resource project in the Cache La Poudre River basin, is considered as the case study. The fuzzy goal is represented by the stored volume that the reservoir may have at the end of its yearly operation, and the fuzzy constraints are represented by the water uses or objectives, like municipal and industrial water supply, flood control space, hydropower, rafting, kayaking, angling and fish habitat, embedded with a subjective linguistic term. Membership functions of the fuzzy goal and fuzzy constraints are developed. In the deterministic case, fuzzy dynamic programming results show monthly releases and storage levels behaved as expected for reservoir operation problems. The achievement of the fuzzy goal was acceptable and in case of the water uses or objectives, the most achievable were flood control, fish habitat and water supply, while the less achievable ones were rafting, kayaking, angling and hydropower, with a high relative variability in the degree of their achievement. In the stochastic case, the results show the expected degree of satisfaction for the fuzzy goal was higher than for the deterministic case. In case of the water uses or objectives, the level of the expected achievement was in general similar to the deterministic case results; the most achievable objectives were also flood control, water supply and fish habitat, and the less achievable ones were again rafting, kayaking, angling and hydropower, and the relative variability of the degree of satisfaction was also high in several cases. Monthly storage levels were fit to linear models to obtain operating rules and the estimated values were further used in a simulation model to obtain monthly storage levels and releases. The comparison of simulated and optimal results reveals a good fit. Thus, operating rules can be used to make decisions about monthly releases from the reservoir. Finally, the results reveal that with the fuzzy approach it is possible to incorporate imprecision and non-commensurate issues in the formulation of objectives and constraints of water resources problems. In addition, the form of the results directly indicates the expected values and the variability in the degree of achievement of those objectives and constraints, providing commensurable and easily-interpreted measures of comparison among diverse and difficult-to-quantify objectives.
Access status: Open Access ,
The effects of school desegregation and resegregation on gifted African American inner city elementary school students
(1999) Harmon, Deborah A., author; Nelson, Barbara J., advisor; Timpson, William, committee member; Paccione, Angela, committee member; Presley, Cheryl, committee member; Shaefer, Bradford W., committee member
The purpose of this qualitative study was to understand the experiences of gifted African American, inner city elementary school students who were bused to desegregate a predominantly White school and then returned to their neighborhood. Students were interviewed about their experiences at both elementary schools and were asked to compare their experiences focusing on the trip to school, the classroom environment, classmates, and school resources. Three teachers, who were identified as exemplary, were interviewed about their education philosophies, teaching methods, classroom management strategies, classroom curriculum, and experience with resegregation. Students were selected for this study after participating in bibliotherapy using literature that dealt with discrimination and prejudice. Student interviews were video and audio taped to capture both verbal and nonverbal communication. The teachers' interviews were audio taped. The results of this study indicated that the students involved in this study experienced considerable anger with their experience with desegregation. The results of this study also had several implications including the need for the preparation of students and teachers participating in desegregation and resegregation, the importance of teachers being culturally competent and using culturally relevant teaching strategies, and the need for cultural competency when researching African American students.
Access status: Open Access ,
Experimental and theoretical development of a tracer gas method for measuring trapping efficiency in internal combustion engines
(1999) Olsen, Daniel B., author; Willson, Bryan, advisor; Mitchell, Charles E., advisor; Dandy, D. S., committee member; Kirkpatrick, Allan, committee member
An investigation into a tracer gas method for determining trapping efficiency in 4-stroke and 2-stroke cycle engines is described. Potential difficulties with the technique are identified and analyzed. These potential difficulties include incomplete cylinder tracer reaction, exhaust tracer instability, and inconsistent exhaust sampling. Tracer gas global chemical kinetic mechanisms are reviewed and used as a means for tracer gas selection. Multiple step chemical kinetic mechanisms are implemented to predict tracer destruction in the cylinder and tracer consumption in the exhaust. The tracer gases investigated are nitrous oxide (N20) and monomethylamine (CH3NH2). As a benchmark the oxygen tracer technique, where oxygen in the intake air is used as the tracer, is evaluated for application to 4-stroke cycle engines. Equations and procedures for performing tracer gas measurements and analysis are developed. Test results are presented for a GM 5.7 1, 8 cylinder, 4-stroke cycle, gasoline engine and a Cooper-Bessemer GMV-4TF 141 1, 4-cylinder, 2-stroke cycle, natural gas engine. Results include evaluation of tracer cylinder reaction efficiency, assessment of the extent of tracer exhaust reaction, and trapping efficiency measurements. Of the tracers considered, N20 is determined to be optimal for both applications. The tracer gas method is utilized to determine the engine speed at which maximum short-circuiting occurs in the 4-stroke cycle engine. Results of scavenging investigations using the tracer gas method are described for the 2-stroke cycle engine for various operating conditions. The scavenging investigations include evaluation of trapping efficiency, delivery ratio, scavenging efficiency, and trapped equivalence ratio. The engine operating condition variations investigated are changes in boost, speed, back pressure, and port restriction.
Access status: Open Access ,
Microbiological profiles of pork carcasses and pork variety meats and decontamination technologies for pork variety meats
(1999) Zerby, Henry N., author; Belk, Keith E., advisor; Tatum, J. Daryl, advisor; Kimberling, Cleon, committee member; Smith, Gary C., committee member; Schmidt, Glenn R., committee member; Sofos, John N., committee member
Experiments were designed and conducted to provide packers, producers, other members of the swine/pork industry and regulatory agencies with information about the microbiological status of pork carcasses and pork variety meats. Collectively, the results offer a snapshot of the occurrence of bacteria on pork carcasses and variety meats collected during only a brief period of time, but provide baseline information for identifying where the industry is and where it should be going in its quest to improve the wholesomeness of products for consumers. Experiment 1 developed microbiological baseline information for pork carcasses using a 3-site sponge sampling protocol. Experiment 2 compared a 3-site sponge sampling protocol with a 2-site sponge sampling protocol as a means for quantifying and characterizing microbiological populations on pork carcasses. Experiment 3 developed microbiological baseline information for 11 pork variety meats (cheek meat, salivary glands, tongues, livers, hearts, kidneys, stomachs, chitterlings, bungs and front feet). Experiment 4 evaluated the effectiveness of 10 decontamination technologies for their ability to reduce bacterial counts on pork variety meats. Experiment 5 evaluated the effectiveness of 7 decontamination technologies for their ability to reduce incidence of Salmonella spp., Listeria monocytogenes and Yersinia enterocolitica on pork variety meats. Results from experiment 1 demonstrated that C. jejuni/coli, with an incidence of 7.9%, was the most commonly found pathogen (of those tested) on pork carcasses in the cooler, followed by L. monocytogenes (5.0%), Salmonella spp. (4.6%) and Y. enterocolitica (0.9%). Mean (log CFU/cm2) APC, TCC and ECC were generally lower (P > 0.05) during the winter, when compared to the summer season. The results of experiment 2 indicated that mean (log CFU/cm2) TCC and ECC did not differ (P > 0.05) between the 3-site sponge sampling protocol and the 2-site sponge sampling protocol at pre-wash, final wash or cooler sampling sites. However, the 2-site sponge sampling protocol was not as effective as the 3-site sponge sampling protocol in detecting Salmonella spp. In the cooler, the 2-site sponge sampling protocol only detected Salmonella spp. at a rate of 2.1% which was less than half of the 4.6% incidence detected using the 3-site sponge sampling protocol. Results of experiment 3 indicated that general microbiological contamination (APC) was relatively high, for most variety meats sampled, with a mean APC ranging between > 4 log CFU/g to < 7 log CFU/g (hearts were the exception, having a mean APC of 3.4 log CFU/g). Mean TCC and ECC ranged between 1.7 to 4.6 and 1.1 to 4.3 log CFU/g, respectively. There were no positive samples of Y. enterocolitica detected on variety meat samples. Less than 1% (4 out of 405) of the samples were positive for C. jejuni/coli. For Salmonella spp., 15% of the samples were positive and a greater number of positive samples were associated with the head (cheek meat, head meat, salivary gland and tongue) and intestinal tract (chitterlings and bung) than with other types of variety meats. Listeria monocytogenes occurred on 16% of samples and the highest incidence rates were associated with variety meat products from the head, the stomach and the front feet. Results from experiment 4 indicated that larger reductions in APC, TCC and ECC on pork variety meats were obtained using trisodium phosphate (12%), acetic acid (2%) and lactic acid (2%) decontamination interventions. Treatments such as hot water (75 to 80°C) or steam resulted in discoloration of red variety meat products due to high temperatures. The hydrogen peroxide (5%) treatment slightly discolored red variety meat products and produced a foam that was undesirable for working/packaging conditions. Results from experiment 5 indicated that lactic acid (2%) immersion was the most successful and consistent decontamination intervention treatment for reducing Salmonella, L. monocytogenes and Y. enterocolitica counts on variety meats tested. Additionally, a 10 sec application of lactic acid (2%) or acetic acid (2%) was more effective than a 5 sec application in reducing Salmonella, L. monocytogenes and Y. enterocolitica.
Access status: Open Access ,
Pollution control policy and social welfare: a theoretical and empirical analysis
(1999) White, Douglas Sloan, author; Loomis, John B., advisor; Davies, Stephen P., committee member; Fan, Chuen mei, committee member; Hoag, Dana L., committee member
The impact of pollution control policy upon social welfare is a central theme to the discipline of environmental economics. Theoretical analyses focus on minimizing social welfare losses when selecting a policy instrument. The efficiency of a price or quantity policy depends on the nature of the marginal benefit and marginal cost curves. Their relative slopes are key to the selection of the more efficient instrument. In addition, uncertainty of the curve estimates can affect policy instrument choice. Since policymakers and even polluters rarely have accurate estimates of the abatement benefits and costs, the nature of the marginal curves is not well known. Such complications and how to account for them can affect the choice of the more efficient policy instrument. Typically theoretical analysis assumes an additive and symmetric distribution about the marginal curves. While these assumptions provide ease of use, they can lead to the use of the improper instrument. In the first two chapters of this dissertation, the influence of these error assumptions is examined. Chapter 1 compares a simple additive error structure with a more complex and realistic multiplicative error. When the marginal benefit and marginal cost curved are relatively flat, the difference between selection criteria can be substantially different. The ability of the price instrument to efficiently minimize welfare losses is compromised with the multiplicative error assumption. Chapter 2 focuses upon the role of informational bias upon policy instrument choice. With biased estimates, the assumption of a symmetric distribution about the marginal curves becomes invalid. Chapter 3 is an empirical analysis of air pollution in forty metropolitan areas of the United States. The criteria pollutant ozone is used as the dependent variable. Two hypotheses are tested: that 1) automobile use and 2) economic sector composition affect ambient ozone levels. Econometric results strongly support the first hypothesis and weakly support the second.