Scientific Management in Research Libraries

published or submitted for publicatio

Prediction of Acoustical Response of Three-dimensional Cavities Using an Indirect Boundary Element Method

A technique which characterizes the acoustics of generalized cavities with the minimum model possible is developed. All boundary element methods have two advantages over finite element methods: (1) the models are smaller; and (2) the assumed variable behavior, inherent in the method to allow discretization, is harmonic rather than polynomial. Further, IBEM often requires one rather than two numerical boundary integrals as required by DBEM. Thus, a quadratic, isoparametric IBEM program was developed. The source distribution in this solution is continuous and quadratically variable rather than continuous and constant. The program was also formulated to include the additional capability of interior point sources and impedance boundary conditions. To test the quadratic, isoparametric IBEM program, several simple cavity enclosure problems where studied. Results are shown

A Comparison of Cheddar Cheese Yields and Composition Using Conventional Bulk Set Cultures and Superstart Concentrated Cultures

The cheese industry has become by far the largest user of milk for manufacturing. In 1978, cheese production utilized a fourth of the total market supply of milk, up from less than an eighth in 1960 (4). Rising consumer incomes and changing lifestyles and eating habits have increased cheese consumption and sales by 60% since 1960 (21). In the last ten years, annual per capita consumption of cured cheese has increased from 11.6 lb to 17.1 lb (45). Economists state that the cheese market will continue to expand through the 1980\u27s (7, 21, 68). Manufacturing cultured dairy products can be a very profitable business, or sustained losses can occur. Over the past two decades, retail cheese prices have increased faster than prices of other foods and dairy products; while consumption has doubled. However, rising labor, raw material, and equipment costs have forced cheese producers into a very narrow profit margin. Maximizing product yields often makes the difference whether a manufacturer-processor is successful. And since yields and profits can be synonymous, it is imperative that maximum yields are obtained. However, in recent years, cheesemakers have observed a gradual decrease in product yields (81). One of the primary reasons cheese yields have been steadily on the decline is the change in the predominant breed of cow (67). Years ago, Jersey and Guernsey numbers were higher than now. These breeds traditionally produce milk with higher solids-not-fat to total solids ratios than Holstein milk (50). Thus, more protein was available for cheesemaking on a unit volume basis. Yee (81) stated that since 1957 the solids content of milk has decreased, due mostly to increased breeding emphasis on high milk production and increase in number of the Holstein breed. Consequently, the current lower solids milk is resulting in less than 9 to 10% cheese yields that were common twenty years ago (2). In order to obtain the best yield and quality of cheddar cheese, the optimum casein-to-fat ratio in milk should be at least .70 parts casein to 1.00 parts fat (32). In South Dakota, the actual ratio is approximately .62, with total protein levels as low as 2.80% (81). Commercial cheesemaking studies have indicated a possible increase in yield when using direct-to-the-vat concentrated cultures (44). Supporting this is the fact that the whey generally contains a lower level of solids when these cultures are used. The reason for a possible increase in yield may be higher pH during ripening, renneting, and cooking of the cheese curd prior to drawing the whey. At higher pH, calcium salts and associated compounds are more insoluble, resulting in less acid soluble material being drawn off with the whey (57). However, the benefits claimed for Superstart cultures have not been substantiated under controlled conditions. Therefore, one objective of this research was to determine yield differences, if any, when using Superstart concentrated cultures vs conventional bulk set cultures. Another objective was to evaluate and compare compositional and organoleptic characteristics in cheese manufactured using both types of starter cultures

Interpolation in waveform space: enhancing the accuracy of gravitational waveform families using numerical relativity

Matched-filtering for the identification of compact object mergers in gravitational-wave antenna data involves the comparison of the data stream to a bank of template gravitational waveforms. Typically the template bank is constructed from phenomenological waveform models since these can be evaluated for an arbitrary choice of physical parameters. Recently it has been proposed that singular value decomposition (SVD) can be used to reduce the number of templates required for detection. As we show here, another benefit of SVD is its removal of biases from the phenomenological templates along with a corresponding improvement in their ability to represent waveform signals obtained from numerical relativity (NR) simulations. Using these ideas, we present a method that calibrates a reduced SVD basis of phenomenological waveforms against NR waveforms in order to construct a new waveform approximant with improved accuracy and faithfulness compared to the original phenomenological model. The new waveform family is given numerically through the interpolation of the projection coefficients of NR waveforms expanded onto the reduced basis and provides a generalized scheme for enhancing phenomenological models.Comment: 10 pages, 7 figure

Doctor of Philosophy

dissertationThe forefront of current nanoscience initiatives includes the investigation and development of semiconducting colloidal nanocrystals for optoelectronic device concepts. Being highly facile in their synthesis, a wide range of sizes, morphologies, materials, interactions, and effects can easily be engineered by current synthetic chemists. Their solution-processability also makes available the use of long established industrial fabrication techniques such as reel-to-reel processing or even simple inkjet printing, offering the prospect of extremely cheap device manufacturing. Aside from anticipated technologies, this material class also makes available a type of "playground" for generating and observing novel quantum effects within reduced dimensions. Since the surface-to-volume ratio is very large in these systems, unsatisfied surface states are able to dominate the energetics of these particles. Although simple methods for satisfying such states are usually employed, they have proven to be only semieffective, often due to a significant change in surface stoichiometry caused by complex atomic reorganization. Serving as charge "trap" states, their effect on observables is readily seen, for instance, in single particle photoluminescence (PL) blinking. Unfortunately, most methods used to observe their influence are inherently blind to the chemical identity of these sites. In absence of such structural information, systematically engineering a robust passivation system becomes problematic. The development of pulsed optically detected magnetic resonance (pODMR) as a method for directly addressing the chemical nature of optically active charges while under trapping conditions is the primary tenet of this thesis. By taking advantage of this technique, a great wealth of knowledge becomes immediately accessible to the researcher. The first chapter of this work imparts the relevant background needed to pursue spin resonance studies in colloidal nanocrystals; the second chapter addresses technical aspects of these studies. In Chapter 3, pODMR is used to explore shallow trap states that dominate the charge transfer process in CdSe/CdS heterostructure nanocrystals. Several trapping channels are observed, while two in particular are correlated, demonstrating for the first time that both electrons and holes are able to be trapped within the same nanoparticle at the same time. The intrinsically long spin coherence lifetime for these states allows for the spin multiplicity and degree of isolation to be explored. Demonstration of novel effects is also performed, such as coherent control of the light-harvesting process and remote readout of spin information. The study presented in Chapter 4 focuses on the spin-dependencies observed in the historically ill-described emissive CdS defect. By monitoring deep-level emission from nanorods of this material, it is shown that the cluster defect can ultimately be fed by the same shallow trap states explored in Chapter 3. The degree of interaction between trap states and the cluster defect is probed. Also, a surprisingly long spin coherence lifetime (T2 « 1.6 /is) for the defect itself is observed, which opens the possibility of highly precise chemical fingerprinting through electron spin echo envelop modulation (ESEEM). This dissertation lays the groundwork for further use of these, and more powerful magnetic resonance probes of the states that fundamentally limit the practical utility of colloidal nanocrystal optoelectronics devices. Furthermore, by gaining access to these optically active electronic states, novel methods of coherent quantum control may be exerted on the energetics of this material system

Crop-phenology and LANDSAT-based irrigated lands inventory in the high plains

Optimal LANDSAT image dates for 1980 were identified based on the weekly crop-weather reports for Colorado, New Mexico, South Dakota, Texas, Oklahoma, Kansas, Nebraska, and Wyoming. The 1979 agricultural statistics data were entered into computer files and a revised questionnaire was developed and mailed to ASCS county agents. A set of computer programs was developed to allow the preparation of computer-assisted graphic displays of much of the collected data

Crop phenology and LANDSAT-based irrigated lands inventory in the high plains

The activity concentrated on identifying crop and irrigation data sources for the eight states within the High Plains Aquifer and making contacts concerning the nature of these data. A mail questionnaire was developed to gather specific data not routinely reported through standard data collection channels. Input/output routines were designed for High Plains crop and irrigation data and initial statistical data on crops were input to computer files

Aerothermodynamic Assessment of Corrugated Panel Thermal Protection Systems

The feasibility of using corrugated panels as a thermal protection system for an advanced space transportation vehicle was investigated. The study consisted of two major tasks: development of improved correlations for wind tunnel heat transfer and pressure data to yield design techniques, and application of the design techniques to determine if corrugated panels have application future aerospace vehicles. A single-stage-to-orbit vehicle was used to assess advantages and aerothermodynamic penalties associated with use of such panels. In the correlation task, experimental turbulent heat transfer and pressure data obtained on corrugation roughened surfaces during wind tunnel testing were analyzed and compared with flat plate data. The correlations and data comparisons included the effects of a large range of geometric, inviscid flow, internal boundary layer, and bulk boundary layer parameters in supersonic and hypersonic flow

Mechanical Demands of the Hang Power Clean and Jump Shrug: A Joint-level Perspective

The purpose of this study was to investigate the joint- and load-dependent changes in the mechanical demands of the lower extremity joints during the hang power clean (HPC) and the jump shrug (JS). Fifteen male lacrosse players were recruited from an NCAA DI team, and completed three sets of the HPC and JS at 30%, 50%, and 70% of their HPC 1-Repetition Maximum (1-RM HPC) in a counterbalanced and randomized order. Motion analysis and force plate technology were used to calculate the positive work, propulsive phase duration, and peak concentric power at the hip, knee, and ankle joints. Separate three-way analysis of variances were used to determine the interaction and main effects of joint, load, and lift type on the three dependent variables. The results indicated that the mechanics during the HPC and JS exhibit joint-, load-, and lift-dependent behavior. When averaged across joints, the positive work during both lifts increased progressively with external load, but was greater during the JS at 30% and 50% of 1-RM HPC than during the HPC. The JS was also characterized by greater hip and knee work when averaged across loads. The joint-averaged propulsive phase duration was lower at 30% than at 50% and 70% of 1-RM HPC for both lifts. Furthermore, the load-averaged propulsive phase duration was greater for the hip than the knee and ankle joint. The jointaveraged peak concentric power was the greatest at 70% of 1-RM for the HPC and at 30% to 50% of 1-RM for the JS. In addition, the joint-averaged peak concentric power of the JS was greater than that of the HPC. Furthermore, the load-averaged peak knee and ankle concentric joint powers were greater during the execution of the JS than the HPC. However, the loadaveraged power of all joints differed only during the HPC, but was similar between the hip and knee joints for the JS. Collectively, these results indicate that compared to the HPC the JS is characterized by greater hip and knee positive joint work, and greater knee and ankle peak concentric joint power, especially if performed at 30 and 50% of 1-RM HPC. This study provides important novel information about the mechanical demands of two commonly used exercises and should be considered in the design of resistance training programs that aim to improve the explosiveness of the lower extremity joints