The bloating of Missouri\u27s shales

The first objective of this investigation was to determine which deposits of clays, shales, and loesses in Missouri are suitable for use in the production of lightweight aggregate by virtue of their expanding characteristics upon heating. The second objective was to determine, if possible, commercially feasible additions that will produce the bloating property in shales that do not naturally bloat. There are two conditions which must be met in firing in order to bloat a clay or shale. First, a gas must be formed and evolved during firing. Second, enough glass of the proper viscosity must be formed to trap the gas and permit expansion. There has been a good deal of research conducted in an effort to determine the bloating agents. The only conclusion one can draw in general from this work is that the bloating agents vary and it is difficult to tie down specifically the agents and reactions involved, and in this regard each clay and shale is a separate problem. It is a matter of record, however, that the majority of shales show some bloating, this was also found true of Missouri shales. In this work, no direct attempt was made to determine gas producing agents since in the majority of cases these agents occurred naturally in the shales. Therefore, the second part of this work was concerned with finding a suitable additive which would promote the formation of glass of the proper viscosity at the right temperatures. This problem is of considerable economic importance since there is an acute demand for lightweight concrete aggregate. Lightweight concrete aggregate is very popular for use in the production of concrete blocks because of its lightweight, insulating and acoustic properties. In large concrete structures the use of lightweight aggregate can effect a very worth while saving in structural steel and thus justify its slightly higher cost. Previous to this work very little had been known as to the bloating characteristics of the clays and shales in Missouri. In the process of this investigation, firing behaviors have been run on all the samples collected and these data might in the future be valuable to the structural clay products industry --Introduction, pages 1-2

MEMS 411 Morphing Wing RC Glider Senior Design Project

The problem we spent a semester working on was building a remote controlled glider which used morphing wings rather than traditional control surfaces. After interviewing our customer, we discovered a few metrics guiding the size of our project as well as the requirements of gliding and control. After brainstorming several ideas, we settled on a bat wing design keying in on the flexible wing material. The wing skin material we used ended up being made from one layer of plastic sandwiched by two layers of elastic fabric. The elastic skin was stretched over airfoil cross sections which rotated over a controlling torsion bar. The result were controllable, morphing surfaces for the main wings of our RC glider. The report contains several photos of the construction and videos of the operation of the wings. During testing we ran in to problems with weather which limited the results we could obtain. This meant we fell short on some of our design metrics such as flight time and glide ratio. However, we were able to successfully demonstrate control in the air by using the morphing wings. In the future, we would like to build upon our success by cutting down on weight in the parts used for construction, the addition of pitch control through controllable rear elevator surfaces, the addition of landing gear, and finally by ensuring proper weather conditions before flying

Model for floodplain management in urbanizing areas

A target land use pattern found using a dynamic programming model is shown to be a useful reference for comparing the success of floodplain management policies. At least in the test case, there is interdependence in the land use allocation for floodplain management--that is, a good solution includes some reduction of current land use in the floodplain and some provision of detention storage. For the test case, current floodplain management policies are not sufficient; some of the existing floodplain use should be removed. Although specific land use patterns are in part sensitive to potential error in land value data and to inaccuracy in the routing model, the general conclusion that some existing use must be removed is stable within the range of likely error. Trend surface analysis is shown to be a potentially useful way of generating bid price data for use in land use allocation models. Sensitivity analysis of the dynamic programming model with respect to routing of hydrographs is conducted through simulation based on expected distributions of error.U.S. Geological SurveyU.S. Department of the InteriorOpe

Direct Comparison of Inverted and Non-Inverted Growths of GaInP Solar Cells: Preprint

The inverted growth of III-V solar cells presents some specific challenges that are not present in regular, non-inverted growths. Because the highly doped top contact layer is grown first, followed by the lengthy high-temperature growth of the remainder of the structure, there is ample time for the dopants in the contact layer to diffuse away. This leads to an increase in the contact resistance to the top layer, and a corresponding drop in voltage. The diffusion of dopants in other layers is similarly altered with respect to the non-inverted configuration because of the change in growth sequence. We compare the dopant profiles of inverted and non-inverted structures by using secondary ion mass spectroscopy and correlate the results with the observed performance of the devices. We also describe a technique for growing a GaInAsN contact layer in the inverted configuration and show that it achieves a specific contact resistance comparable to what is normally observed in non-inverted cells

Abstract: Analysis of acute skin rejection in non-human primate models of face and hand allotransplantation

Introduction: The incidence of acute rejection (AR) of the skin within the first year after hand or face transplantation is approximately 85% and up to 56% of patients experience multiple episodes1. Significant immunosuppression is required to prevent allograft loss, and recent studies suggest that repeated AR episodes can lead to VCA dysfunction and loss2. The mechanisms underlying variability in AR presentation remain poorly defined however. Materials and Methods: 8 cynomolgus monkeys received either an orthotopic hand (n=2) or heterotopic face VCA (n=6) from MHC-mismatched donors following induction with anti-thymocyte globulin. Post-operatively, triple immunosuppression – tacrolimus, mycophenolate mofetil, methylprednisolone – was maintained for up to 120 days before bone marrow transplantation (BMT) was performed. Protocol biopsies of VCA skin were performed at 30-day intervals for histopathology and flow cytometric analysis of resident skin leukocyte populations; VCA-resident cells were differentiated by H38 status (mouse antihuman HLA class I monoclonal antibody that cross reacts with cynomolgus monkeys) for donor or recipient derivation. Clinical AR was treated with steroids and further biopsies were taken for histologic confirmation; corresponding anti-donor responses were evaluated by mixed lymphocyte reaction (MLR) and allo-antibody formation. Results: Up to three episodes of AR (from POD 14, Banff I to II) developed while recipient animals were maintained on triple immunosuppression. Corresponding flow cytometric analyses demonstrate > 80% of skin-resident T lymphocytes (CD4+, CD8+) within VCA dermis were of recipient origin, suggesting rapid immigration of various lineages into the VCA. These observations coincided with the first episode of AR in fully mismatched recipients but haplomatched animals remained rejection-free. All but one episode of AR were successfully treated. No allo-antibodies were detected and anti-donor responses by MLR were comparable to that against third-party. Following BMT, mixed chimerism was detected and enabled immunosuppression withdrawal. However, this was transient and once lost, clinical AR developed and nearly 100% of both dermal and epidermal lymphocytes were recipient-derived. Conclusion: We report a clinically-relevant model for studying AR in VCA. Our results suggest that further understanding of the relative importance of MHC differences in transplant pairs may lead to differences in outcomes for VCA recipients maintained under standard immunosuppression. Immunosuppression-free tolerance of non-hematopoietic antigens in composite tissues can be achieved, but require additional strategies to achieve stable, rather than transient mixed chimerism following BMT

Direct Comparison of Inverted and Non-inverted Growths of GaInP Solar Cells

The motivation for this presentation is that growing inverted cells may enable technological advances in solar cell fabrication, leading to higher efficiencies. Differences in dopant diffusion during inverted vs. upright growths may lead to differences in atomic depth profiles; changes in carrier concentrations; higher contact resistance and lower overall performance. This presentation summarizes that excellent performance is achievable in both upright and inverted configurations with proper consideration; subtle differences in depth profile QE and JV between upright and inverted growths due to dopant diffusion; and GaInAsN contact layer is resilient to length annealing and more work is necessary to determine why

The Incidence of Highly-Obscured Star-Forming Regions in SINGS Galaxies

Using the new capabilities of the Spitzer Space Telescope and extensive multiwavelength data from the Spitzer Infrared Nearby Galaxies Survey (SINGS), it is now possible to study the infrared properties of star formation in nearby galaxies down to scales equivalent to large HII regions. We are therefore able to determine what fraction of large, infrared-selected star-forming regions in normal galaxies are highly obscured and address how much of the star formation we miss by relying solely on the optical portion of the spectrum. Employing a new empirical method for deriving attenuations of infrared-selected star-forming regions we investigate the statistics of obscured star formation on 500pc scales in a sample of 38 nearby galaxies. We find that the median attenuation is 1.4 magnitudes in H-alpha and that there is no evidence for a substantial sub-population of uniformly highly-obscured star-forming regions. The regions in the highly-obscured tail of the attenuation distribution (A_H-alpha > 3) make up only ~4% of the sample of nearly 1800 regions, though very embedded infrared sources on the much smaller scales and lower luminosities of compact and ultracompact HII regions are almost certainly present in greater numbers. The highly-obscured cases in our sample are generally the bright, central regions of galaxies with high overall attenuation but are not otherwise remarkable. We also find that a majority of the galaxies show decreasing radial trends in H-alpha attenuation. The small fraction of highly-obscured regions seen in this sample of normal, star-forming galaxies suggests that on 500pc scales the timescale for significant dispersal or break up of nearby, optically-thick dust clouds is short relative to the lifetime of a typical star-forming region.Comment: Accepted for publication in ApJ; emulateapj style, 30 pages, 18 figures (compressed versions), 3 table

A method for the reconstruction of unknown non-monotonic growth functions in the chemostat

We propose an adaptive control law that allows one to identify unstable steady states of the open-loop system in the single-species chemostat model without the knowledge of the growth function. We then show how one can use this control law to trace out (reconstruct) the whole graph of the growth function. The process of tracing out the graph can be performed either continuously or step-wise. We present and compare both approaches. Even in the case of two species in competition, which is not directly accessible with our approach due to lack of controllability, feedback control improves identifiability of the non-dominant growth rate.Comment: expansion of ideas from proceedings paper (17 pages, 8 figures), proceedings paper is version v

Global parameter identification of stochastic reaction networks from single trajectories

We consider the problem of inferring the unknown parameters of a stochastic biochemical network model from a single measured time-course of the concentration of some of the involved species. Such measurements are available, e.g., from live-cell fluorescence microscopy in image-based systems biology. In addition, fluctuation time-courses from, e.g., fluorescence correlation spectroscopy provide additional information about the system dynamics that can be used to more robustly infer parameters than when considering only mean concentrations. Estimating model parameters from a single experimental trajectory enables single-cell measurements and quantification of cell--cell variability. We propose a novel combination of an adaptive Monte Carlo sampler, called Gaussian Adaptation, and efficient exact stochastic simulation algorithms that allows parameter identification from single stochastic trajectories. We benchmark the proposed method on a linear and a non-linear reaction network at steady state and during transient phases. In addition, we demonstrate that the present method also provides an ellipsoidal volume estimate of the viable part of parameter space and is able to estimate the physical volume of the compartment in which the observed reactions take place.Comment: Article in print as a book chapter in Springer's "Advances in Systems Biology