Plasma reactor waste management systems

The University of North Dakota is developing a plasma reactor system for use in closed-loop processing that includes biological, materials, manufacturing, and waste processing. Direct-current, high-frequency, or microwave discharges will be used to produce plasmas for the treatment of materials. The plasma reactors offer several advantages over other systems, including low operating temperatures, low operating pressures, mechanical simplicity, and relatively safe operation. Human fecal material, sunflowers, oats, soybeans, and plastic were oxidized in a batch plasma reactor. Over 98 percent of the organic material was converted to gaseous products. The solids were then analyzed and a large amount of water and acid-soluble materials were detected. These materials could possibly be used as nutrients for biological systems

The construction and evaluation of a test on the concepts of informal geometry

Thesis (Ed.M.)--Boston UniversityThe primary purpose of constructing a test on informal geometry is to provide the eighth-grade mathematics teacher with an objective means of measuring the achievement of his students in geometry. A secondary purpose is to explore the possibility that this test alone, or in conjunction with other criteria, might have value in predicting the degree of success of a student in demonstrative geometry

Bayesian causal inference of cell signal transduction from proteomics experiments

Cell signal transduction describes how a cell senses and processes signals from the environment using networks of interacting proteins. In computational systems biology, investigators apply machine learning methods for causal inference to develop causal Bayesian network models of signal transduction from experimental data. Directed edges in the network represent causal regulatory relationships, and the model can be used to predict the effects of interventions to signal transduction. Causal inference approaches applied to proteomics experiments use statistical associations between observed signaling protein concentrations to infer a causal Bayesian network model, but there is no experimental and analysis framework for applying these methods to this experimental context. The goal of this dissertation is to provide a Bayesian experimental design and modeling framework for causal inference of signal transduction. We evaluate how different high-throughput experimental settings affect the performance of algorithms that detect conditional dependence relationships between proteins. We present a Bayesian active learning approach for designing intervention experiments that reveal the direction of causal influence between proteins. Finally, we present a Bayesian model for inferring the parameters of the conditional probability density functions in a causal Bayesian network. The parameters are directly interpretable as a function of the rate constants in the biochemical reactions between interacting proteins. The work pays special attention to analysis of single-cell snapshot data such as mass cytometry, where each cell is a multivariate cell-level replicate of signal transduction at a single time point. We also address the role of large-scale bulk experiments such as mass-spectrometry-based proteomics, and small-scale time-course experiments in causal inference

The Effect of Hydrogen Partial Pressure on Lignite Liquefaction in a Two-Stage Hot-Charge Batch Autoclave System

The effect of varying hydrogen partial pressure in a two-stage liquefaction process on conversion of North Dakota lignite to THF solubles was studied using the UND hot-charge, time sample, batch autoclave system. Approximately one hundred and fifty grams of moisture- and ash-free (MAF) Zap lignite, three hundred grams of AO4 (Anthracene oil) solvent and seventy five grams of water were reacted in the autoclave unit. Carbon monoxide was used as feed gas for the first stage and varying amounts of hydrogen and carbon monoxide were utilized in the second stage. First stage temperatures ranged from 358 C to 370 C while the second stage temperatures were 429 C to 444 C. Residence times in the first and second stages were 20 and 60 minutes, respectively. Liquid and gas samples were taken at one, three, six, ten, twenty, forty, and sixty minutes during the second stage run period. Overall conversion ranged from 68.7 to 85.0 percent while the distillate yield varied from -7.9 to 25.0 percent based on the MAF coal charge. The soluble residuum yield rose with increasing hydrogen partial pressure from 20.1 to 39.3 percent. Light and middle oil production increased directly with hydrogen partial pressure. When the second stage feed gas consisted of pure carbon monoxide, the heavy oil yield was -15.2 percent. With increasing hydrogen content of the feed gas, the heavy oil yield ranged from -15.2 to 3.2 percent and when 100 percent hydrogen feed gas was used in the second stage, a 3.9 percent yield was produced. Conversion reached a maximum after approximately ten minutes in the second stage. Results indicated that syngas may be a viable feed gas if yields can be increased, perhaps by adding hydrogen sulfide or using a hydrogen donating solvent

The Information Content of the 1999 Announcement of Funds from Operations (FFO) Changes for Real Estate Investment Trusts

This study examines the market response to the 1999 announcement of a change in accounting for Funds from Operations (FFO) for Real Estate Investment Trusts (REITs). This change provides an increase in transparency in the accounting statements of REITs regarding the calculation of FFO. An analysis of this announcement finds that shareholder wealth increases but the significance of that increase is questionable. Additionally, an analysis of the adverse selection component of the bid-ask spread finds weak evidence to support the conjecture that the amount of information asymmetry in REIT prices declines after the announcement of the FFO accounting change.

Parameter-free predictions of the viscoelastic response of glassy polymers from non-affine lattice dynamics

We study the viscoelastic response of amorphous polymers using theory and simulations. By accounting for internal stresses and considering instantaneous normal modes (INMs) within athermal non-affine theory, we make parameter-free predictions of the dynamic viscoelastic moduli obtained in coarse-grained simulations of polymer glasses at non-zero temperatures. The theoretical results show very good correspondence with rheology data collected from molecular dynamics simulations over five orders of magnitude in frequency, with some instabilities that accumulate in the low-frequency part on approach to the glass transition. These results provide evidence that the mechanical glass transition itself is continuous and thus represents a crossover rather than a true phase transition. The relatively sharp drop of the low-frequency storage modulus across the glass transition temperature can be explained mechanistically within the proposed theory: the proliferation of low-eigenfrequency vibrational excitations (boson peak and nearly-zero energy excitations) is directly responsible for the rapid growth of a negative non-affine contribution to the storage modulus.Comment: 10 pages, 7 figure

LONG-TERM CHANGES IN CANADA GOOSE NEST SUCCESS AND NEST DENSITIES AT AN IOWA WETLAND COMPLEX

Giant Canada geese (Branta canadensis maxima) were extirpated from Iowa by the early 1900s due to unregulated hunting, egg gathering, and wetland drainage in the nineteenth century (Bishop 1978). Ef- forts to reintroduce Canada geese in Iowa began in 1964 (Bishop and Howing 1972) and involved releasing flightless adults and goslings at nearly 30 sites across the state (Zenner and LaGrange 1998a). In 1972, 13 flightless pairs were released at Rice Lake Wildlife Management Area (WMA; Bishop 1978). By 1989, the breeding population of Canada geese at Rice Lake WMA had increased to 420 nesting adults (G. G. Zenner, Iowa Department of Natural Resources, unpublished data). Canada goose nest success and nest densities were documented from 1989–1991 on extant islands at Rice Lake WMA (Zenner and LaGrange 1998b). Rice Lake WMA (43.379497, –93.472715) is located in north-central Iowa and lies within the southernmost portion of the Prairie Pothole Region. This wetland complex consists of Rice Lake, a 409-ha shallow, natural lake with a maximum depth of 3 m and 20 natural islands ranging in size from 0.04 to 3.9 ha, and Joice Slough, a 73-ha marsh with a maximum depth of 1 m and 15 natural islands ranging in size from 0.02 to 3.19 ha (Zenner and LaGrange 1998b). During 1989–1991, potential Canada goose nest sites included islands, elevated structures, and muskrat houses. Over the course of that study, drought conditions left Joice Slough completely dry and dramatically lowered water levels at Rice Lake, exposing islands to increased predator activity. Despite the drought, nest densities were high (68–158 nests/ha) and nest success ranged from 40–58% (Zenner and LaGrange 1998b)

Cost Comparisons between Home- and Clinic-Based Testing for Sexually Transmitted Diseases in High-Risk Young Women

Home testing for chlamydia and gonorrhea increases screening rates, but the cost consequences of this intervention are unclear. We examined the cost differences between home-based and clinic-based testing and the cost-effectiveness of home testing based on the DAISY study, a randomized controlled trial. Direct and indirect costs were estimated for home and clinic testing, and cost-effectiveness was calculated as cost per additional test performed. In the clinic testing group, direct costs were 49/test and indirect costs (the costs of seeking or receiving care) were 62/test. Home testing cost was 25/test. We found that home testing was cost saving when all testing for all patients was considered. However cost savings were not seen when only asymptomatic tests or when patient subgroups were considered. A home testing program could be cost saving, depending on whether changes in clinic testing frequency occur when home testing is available