Crinoids from the Silurian of Western Ohio and Indiana

A large section of the stratigraphic column of the Great Lakes Area is composed of carbonate rock from the Silurian Period (ca. 443-419 Ma). This limestone, which has been highly dolomitized, formed in association with an ancient reef system that was present in the epicontinental seas that prevailed during this time. The rock has been thoroughly studied for both economic and academic purposes. Silurian dolomites are used for industrial purposes, and they are a key oil producer. Study of these carbonate rock has also revealed much about the nature of ancient reef systems. However, there is still much to learn about these reef systems. Of particular interest is the biota that helped to form the reefs. Among the least understood Silurian reef contributors are the echinoderms, in particular the crinoids. Little research has been done on Silurian reef crinoids; the last major work was in 1900. This is in part due to the high dolomitization of the fossils that makes identification of these species more difficult. To develop a better understanding of these species, a systematic study is being undertaken to identify several specimens from five different quarries in the western Ohio and Indiana. The study of these crinoids has led to further advances in the understanding of Silurian reefs worldwide. Understanding these crinoids provides further insight into the phylogenetic history of the crinoid class, allowing also for a greater understanding of echinoderm evolution. The identification of these Silurian crinoids also aids in understanding of the organisms and the processes by which these reefs formed. There is much to be discovered yet in the Silurian reefs of the Great Lakes Area, and the identification of these crinoid species is a step toward more complete understanding.A one-year embargo was granted for this item.Academic Major: Earth Science

Computational Fluid Dynamics in a Terminal Alveolated Bronchiole Duct with Expanding Walls: Proof-of-Concept in OpenFOAM

Mathematical Biology has found recent success applying Computational Fluid Dynamics (CFD) to model airflow in the human lung. Detailed modeling of flow patterns in the alveoli, where the oxygen-carbon dioxide gas exchange occurs, has provided data that is useful in treating illnesses and designing drug-delivery systems. Unfortunately, many CFD software packages have high licensing fees that are out of reach for independent researchers. This thesis uses three open-source software packages, Gmsh, OpenFOAM, and ParaView, to design a mesh, create a simulation, and visualize the results of an idealized terminal alveolar sac model. This model successfully demonstrates that OpenFOAM can be used to model airflow in the acinar region of the lung under biologically relevant conditions

Two-stage solenoid design

Solenoid use and design is limited by the fact that as the gap increases, the force greatly decreases. However, by using a solenoid that contains three cores instead of one, it is possible to greatly increase this force. In such a designs, the 3 cores interact as follows: Core 1 is rigidly attached to core 3. At the beginning of the motion, core 3 is in a hole in core 2. Core 2 remains stationary until core 1 reaches it. When this occurs, all cores move until core 3 reaches the shell. To prove this design creates better results, models are created and compared against an equivalent regular solenoid. Models are created in MATLAB using an equivalent resistor circuit to model the solenoid. In this model all flux paths are assumed to be perpendicular to the surfaces they enter and exit. This method shows an improvement of 29 % in the best case scenario. Models are also created in Maxwell 2D Field Solver by Ansoft, a finite elements program. Both models calculate the force that the solenoid can produce as it moves from the open to closed position. Data is collected when various parts of the geometry are varied. It is found that the diameter of core 3, the geometry of core 3,and the length of the connector rod connecting core 1 and core 3 have the greatest impact on the force output through the entire motion. Also it is found that the area with the greatest increase in force can be moved, by changing the initial gap between core 2 and the shell. The best results from the finite element code were found for a solenoid with a 10 mm gap. The results showed an average improvement of 48%. A smaller total stroke yields better results. This is because most of the improvement is localized to area only one area of the stroke path

Portfolio optimization with transaction costs and preconceived portfolio weights

Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2009.Cataloged from PDF version of thesis.Includes bibliographical references (p. 87-88).In the financial world, many quantitative investment managers have developed sophisticated statistical techniques to generate signals about expected returns from previous market data. However, the manner in which they apply this information to rebalancing their portfolios is often ad-hoc, trading off between rebalancing their assets into an allocation that generates the greatest expected return based on the generated signals and the incurred transaction costs that the reallocation will require. In this thesis, we develop an approximation to our investor's true value function which incorporates both return predictability and transaction costs. By optimizing our approximate value function at each time step, we will generate a portfolio strategy that closely emulates the optimal portfolio strategy, which is based on the true value function. In order to determine the optimal set of parameters for our approximate function which will generate the best overall portfolio performance, we develop a simulation-based method. Our computational implementation is verified against well-known base cases. We determine the optimal parameters for our approximate function in the single stock and bond case. In addition, we determine a confidence level on our simulation results. Our approximate function gives us useful insight into the optimal portfolio allocation in complex higher dimensional cases. Our function derivation and simulation methodology extend easily to portfolio allocation in higher dimensional cases, and we implement the modifications required to run these simulations. Simple cases are tested and more complex tests are specified for testing when appropriate dedicated computing resources are available.by Jeremy D. Myers.M.Eng

Two-Stage Solenoid

A proposed design for a solenoid-based electromechanical actuator would provide greater starting force than does a comparable conventional design. As used here, starting force signifies the magnetic force exerted by the actuator at one end of its stroke when the gap in its magnetic circuit is the widest. A solenoid of conventional design exerts a large force when its gap is closed. The magnetic force decreases as the gap increases. Hence, typically, the starting force exerted by a conventional solenoid is small; depending upon the specific application, the starting force may even be insufficient to initiate closure. Whereas a conventional solenoid design provides for only one core, the proposed design calls for three cores, two of these being fixed to one another with a separate core between these two. Analysis shows that in comparison with conventional solenoids, the solenoids of the proposed design would not have a cost impact, could have longer operational lives, and exhibit larger forces in an open position. It was also reported that the proposed design could be extended to multiple-staged solenoid design, which would yield increased force in the middle of the stroke as well

Effects of Mandatory Energy Efficiency Disclosure in Housing Markets

HealthCarePolicymakers are increasingly using mandated information disclosures as a way to increase market efficiency by providing information on quality to buyers. In the housing market in Austin, Texas, home sellers are required to perform a standardized energy audit and provide home efficiency information to prospective buyers. In working paper 1916, Steven Puller, PERC’s Professor of Free Enterprise, along with coauthors Erica Myers and Jeremy West investigate whether the audit and disclosure policies mandated by the City of Austin have the intended effect of improving the energy efficiency quality of homes. To read a summary of this working paper in the Winter 2020 issue of PERCspectives on Research, click on View or Download below

Historic Archeological Investigations at Roberts Cemetery Near Troy, Bell County, Texas

A preliminary archeological investigation was conducted in 2008 at Roberts Cemetery near Troy, Texas, as part of the Texas Department of Transportation’s planned expansion of Interstate Highway 35. Mechanical trenching discovered one unmarked grave near the highway right of way, and this led to an extensive mechanical search of the eastern edge of the cemetery in 2012. Following the removal of the southbound access road and thick layer of artificial fill, five additional unmarked graves were discovered. Of the six unmarked graves, two are located in the cemetery property and were left in place, but the four burials inside the highway right of way were exhumed. They were reinterred in a nearby plot in Roberts Cemetery. Analyses of the mortuary items and skeletal remains indicate that the three adult males and one child were interred between 1895 and the late 1930s. DNA analyses were used to try and match the four interred individuals with possible living relatives, but the results were negative or inconclusive. Archival research provided historical context for Roberts Cemetery and defined the sequence of road expansions that impacted the east side of the cemetery in the twentieth century

Genome Improvement at JGI-HAGSC

Since the completion of the sequencing of the human genome, the JGI has rapidly expanded its scientific goals in several DOE mission-relevant areas. At the JGI-HAGSC, we have kept pace with this rapid expansion of projects with our focus on assessing, assembling, improving and finishing eukaryotic whole genome shotgun (WGS) projects for which the shotgun sequence is generated at the Production Genomic Facility (JGI-PGF). We follow this by combining the draft WGS with genomic resources generated at JGI-HAGSC or in collaborator laboratories (including BAC end sequences, genetic maps and FLcDNA sequences) to produce an improved draft sequence. For eukaryotic genomes important to the DOE mission, we then add further information from directed experiments to produce reference genomic sequences that are publicly available for any scientific researcher. Also, we have continued our program for producing BAC-based finished sequence, both for adding information to JGI genome projects and for small BAC-based sequencing projects proposed through any of the JGI sequencing programs. We have now built our computational expertise in WGS assembly and analysis and have moved eukaryotic genome assembly from the JGI-PGF to JGI-HAGSC. We have concentrated our assembly development work on large plant genomes and complex fungal and algal genomes