Brochu C.A.,University of Iowa |
Parris D.C.,Bureau of Natural History |
Grandstaff B.S.,University of Pennsylvania |
Denton R.K.,Vista Engineering, Inc. |
Gallagher W.B.,Rider University
Journal of Vertebrate Paleontology | Year: 2012
A lower jaw and associated postcranial remains from the Late Cretaceous-early Paleocene Hornerstown Formation of New Jersey form the basis of a new crocodyliform species, Borealosuchus threeensis. Although one of the oldest known species of Borealosuchus, phylogenetic analysis supports a closer relationship to Borealosuchus from the early Eocene than with other Late Cretaceous or early Paleocene forms. This is based on the shared presence of a short mandibular symphysis excluding the splenial, a small external mandibular fenestra, and ventral osteoderms composed of two sutured ossifications. It is also similar to Borealosuchus material from the Paleocene of western Texas, though conspecificity cannot be demonstrated at present. A close relationship with the basal alligatoroids Leidyosuchus or Diplocynodontinae is not supported. The distribution of lower jaws with very small slit-like external mandibular fenestrae, or no fenestrae at all, among basal crocodylian lineages (including Borealosuchus) and close crocodylian relatives suggests the fenestrae may have been ancestrally absent in Crocodylia and regained two or more times. Current phylogenetic hypotheses are consistent with dispersal of more-derived species of Borealosuchus to the Western Interior during the Paleocene, and they indicate the presence of several unsampled lineages crossing the Cretaceous-Paleogene boundary. © 2012 Copyright Taylor and Francis Group, LLC.
Booth L.,University of Alabama at Birmingham |
Catledge S.A.,University of Alabama at Birmingham |
Nolen D.,Vista Engineering, Inc. |
Thompson R.G.,Vista Engineering, Inc. |
Vohra Y.K.,University of Alabama at Birmingham
Materials | Year: 2010
With incredible hardness and excellent wear-resistance, nanocrystalline diamond (NCD) coatings are gaining interest in the biomedical community as articulating surfaces of structural implant devices. The focus of this study was to deposit multilayered diamond coatings of alternating NCD and microcrystalline diamond (MCD) layers on Ti-6Al-4V alloy surfaces using microwave plasma chemical vapor deposition (MPCVD) and validate the multilayer coating's effect on toughness and adhesion. Multilayer samples were designed with varying NCD to MCD thickness ratios and layer numbers. The surface morphology and structural characteristics of the coatings were studied with X-ray diffraction (XRD), Raman spectroscopy, and atomic force microscopy (AFM). Coating adhesion was assessed by Rockwell indentation and progressive load scratch adhesion tests. Multilayered coatings shown to exhibit the greatest adhesion, comparable to single-layered NCD coatings, were the multilayer samples having the lowest average grain sizes and the highest titanium carbide to diamond ratios.© 2011 by the authors.
Agency: Department of Health and Human Services | Branch: | Program: STTR | Phase: Phase II | Award Amount: 746.37K | Year: 2011
DESCRIPTION (provided by applicant): Temporomandibular Disorders (TMD) represent a collection of medical and dental conditions affecting the temporomandibular joint (TMJ) and/or the muscles of mastication, as well as contiguous tissue structures. For somepatients with severe TMJ degeneration, a prosthetic replacement may be required. However, long-term success and functioning of current implant designs remains a serious problem due, in large part, to the deterioration of the implant and surrounding tissueresulting from wear debris. During Phase I of this project, the UAB and Vista Engineering team developed novel nanotechnology diamond coatings with enhanced adhesion and wear properties for articulation components in TMJ devices. This new technology willbe used in the proposed Phase II to enable new total replacement TMJ prostheses of smaller size and longer life. The smaller sized prosthesis designs will enable minimally invasive clinical pathways targeted for a single-incision implantation. The new TMJprostheses will be designed using finite element modeling and analysis to minimize the device size based on the use of nanostructured diamond on the articulating surfaces. The prototype designs will be manufactured and tested in a TMJ, mandibular wear simulator. Successful designs will be carried to clinical translation studies using a miniature pig animal model. Commercialization potential for the product will be developed through prosthesis design, prototype wear testing and clinical translation. Lettersof support for this Phase II project have come from biomedical and venture capital companies in support of our commercialization plan. UAB and Vista Engineering have a strong track record of collaboration culminating in the licensing (to Vista Engineering)of a UAB patent involving this technology: Process for Ultra Smooth Diamond Coating on Metals and Uses Thereof , Patent # 6,183,818. Our specific aims are as follows: Specific Aim 1: Optimize New Designs for Minimally Invasive TMJ Total Replacement Prosthesis by Computer Modeling and Analysis. Specific Aim 2: Manufacture Prototype Prostheses of Promising Minimally Invasive Designs. Specific Aim 3: Rank and Revise Computer-Optimized Designs Based on Test Results from Mandibular Wear Simulator Specific Aim4: Conduct Clinical Translation Studies on Two Most Promising Designs PUBLIC HEALTH RELEVANCE: We propose the use of a nanotechnology approach, using nanostructured diamond for controlling interfaces between Temporomandibular Joint (TMJ) implants and the surrounding tissues, to improve the fixation, durability and osseointegration for long-term implant success. As many as 60,000 Americans could benefit from the nanostructured diamond-diamond components that will facilitate reductions in implant device size and enable a clinically less- invasive route to joint restoration. We also propose a clear pathway for commercialization of the nanotechnology enabled TMJ prosthesis.
PubMed | Vista Engineering, Inc. and University of Alabama at Birmingham
Type: Journal Article | Journal: Journal of coatings technology and research | Year: 2016
Using microwave-plasma Chemical Vapor Deposition (CVD), a 3-micron thick nanostructured-diamond (NSD) layer was deposited onto polished, convex and concave components that were machined from Ti-6Al-4V alloy. These components had the same radius of curvature, 25.4mm. Wear testing of the surfaces was performed by rotating articulation of the diamond-deposited surfaces (diamond-on-diamond) with a load of 225N for a total of 5 million cycles in bovine serum resulting in polishing of the diamond surface and formation of very shallow, linear wear grooves of less than 50nm depth. The two diamond surfaces remained adhered to the components and polished each other to an average surface roughness that was reduced by as much as a factor of 80 for the most polished region located at the center of the condyle. Imaging of the surfaces showed that the initial wearing-in phase of diamond was only beginning at the end of the 5 million cycles. Atomic force microscopy, scanning electron microscopy, Raman spectroscopy, and surface profilometry were used to characterize the surfaces and verify that the diamond remained intact and uniform over the surface, thereby protecting the underlying metal. These wear simulation results show that diamond deposition on Ti alloy has potential application for joint replacement devices with improved longevity over existing devices made of cobalt chrome and ultra-high molecular weight polyethylene (UHMWPE).
Upadhyaya S.,Vista Engineering, Inc. |
Goulias D.,University of Maryland University College |
Obla K.,Technical Services
Journal of Materials in Civil Engineering | Year: 2014
The use of fly ash in concrete has received significant attention during recent years, owing to environmental concerns regarding its disposal and to its potential use as a supplementary cementitious material owing to its ability to improve concrete performance. Although a fly ash content of less than 25% of the total cementitious content is routinely used in concrete, high-volume fly ash (HVFA) concrete is not commonly used because of perceived lower early age strengths. The objective of this research was to use maturity based modeling to demonstrate that the beneficial effects of high temperatures observed in structural elements such as slabs and concrete beams during the hydration process associated with the mass features of such elements may compensate for the slower rate of strength gain of fly ash concrete that is typically observed in standard laboratory cured cylinders. Match cured cylinders were used during this process to estimate the early age in-place strength of HVFA concrete and to confirm the predicted mature strengths. The results have shown that standard and field cured cylinder strengths underestimate the in-place concrete strength. High in-place temperatures owing to the mass characteristics of structural elements result in increased and satisfactory in-place early age strengths for construction, measured by match cured cylinders and pullout testing, and predicted by maturity modeling. © 2014 American Society of Civil Engineers.
Allen V.,CONTECH Stormwater Solutions |
Walker T.,Vista Engineering, Inc. |
Schemper T.,Vista Engineering, Inc.
Low Impact Development 2010: Redefining Water in the City - Proceedings of the 2010 International Low Impact Development Conference | Year: 2010
The push for low impact development (LID) by the EPA, State and local stormwater regulators has increased emphasis on pollution source reduction and site design elements of stormwater management planning. Emerging regulations and project review priorities encourage project designs that minimize the impact to the predevelopment hydrologic balance by reducing the amount of imperviousness created, and by integrating small-scale, distributed retention and treatment facilities into the landscape. This LID based approach stands in contrast to more conventional approaches, which generally seek to efficiently convey runoff to central detention and treatment facilities. Successful projects will require developers or their representatives to coordinate the efforts of planners, architects, civil engineers, landscape architects and geotechnical engineers around a development plan that includes specific stormwater runoff reduction and treatment recommendations. In order to establish the feasibility of a proposed development project, it is necessary to estimate the land requirements, capital costs and ongoing operation and maintenance costs for potential stormwater management measures. However, BMP design criteria and associated cost information are highly variable. To add to the uncertainty, a developer's proposal of a suite of BMPs that constitute treatment to the "maximum extent practicable" (MEP) may be rejected by plan reviewers. As stormwater regulations evolve, developers may find themselves facing delays and cost overruns as they are forced to redesign their sites to fit those regulations late in the project development process. Avoiding this costly situation requires early consideration of stormwater management elements and a detailed understanding of local regulatory requirements, site constraints and BMP design requirements. CONTECH has developed the LID Site Planner, a modular planning tool that incorporates this information into a preliminary stormwater mitigation plan. The plan provides a list of BMPs that are expected to satisfy the MEP criteria for a specific proposed development and their approximate sizes and costs. © 2010 ASCE.
Chou Y.K.,University of Alabama |
Thompson R.G.,Vista Engineering, Inc. |
Kumar A.,University of South Florida
Thin Solid Films | Year: 2010
CVD-diamond for dry drilling applications is reported. Specifically, the fabrication of nanostructured diamond-coated drills is outlined. Tool life is evaluated by dry drilling of aluminum alloy and nanostructured diamond-coated drills show a superior performance to uncoated drills. In addition, different surface treatments have been studied with the effects on diamond film deposition and delamination investigated. Moreover, drill edge geometry has been evaluated. Major findings indicate that the drill edge radius plays a critical role to the drilling performance. A slightly honed edge may lead to improved performance due to the reduction of deposition stresses at the tool edge. © 2010 Elsevier B.V. All rights reserved.
Hu J.,University of Alabama |
Chou Y.K.,Vista Engineering, Inc. |
Thompson R.G.,Vista Engineering, Inc.
International Journal of Machining and Machinability of Materials | Year: 2010
The stress state of a diamond coated tool is interrelatedly influenced by coating and subsequent machining. Moreover, the cutting edge geometry strongly impacts the stress fields around the tool tip in both processes. In this study, finite element modelling and cutting simulations were applied to investigate stress evolutions in a coated tool from deposition to machining, with the edge radius effect emphasised. For the deposition residual stress, edge sharpness results in significant stress concentrations at the edge rounding area. In machining, the thermal load is more dominant to the stress evolutions than the mechanical load. Increasing the edge radius generally results in increased stress reversal. Moreover, the edge hone effects on stress reversal are more prominent at a small uncut chip thickness. Since the edge radius has conflicting effects on the deposition stresses and machining loads, there may exist an optimal edge radius for the tool stress conditions. Copyright © 2010 Inderscience Enterprises Ltd.
Agency: Department of Energy | Branch: | Program: SBIR | Phase: Phase I | Award Amount: 142.91K | Year: 2013
The research proposed under this effort is focused on addressing the need for improved real-time in-situ sensing approaches for monitoring radionuclide contamination in the soils surrounding waste disposal facilities. Specifically this proposal focuses on the development of an approach for detecting technetium-99, which is a major risk driver at the Hanford site. The sensing approach that is proposed will also detect other beta-emitting radionuclides and therefore will address characterization and monitoring needs for strontium-90 and other beta-emitting particles. The objective of the proposed research is to establish the feasibility of a method for detecting beta-emitting isotopes of technetium-99, strontium-90 and yttrium-90 in soil at concentrations on the order of 100 pCi/gm; the method should be suitable to be implemented for in-situ monitoring in sub-surface soils. Specifically, in Phase I we will experimentally fabricate and demonstrate a wireline CPT -sized integrated beta and gamma sensor for characterization of radiologically contaminated soils with both gamma and beta emitters. This will provide the basis for improved development and field testing of the sensor for 99Tc detection in Phase II. The technical approach proposed involves integrating a well-designed beta spectroscopy sensor with a gamma detecting crystal, which can be deployed using wireline Cone Penetrometer Technique (CPT) during retraction of the rods. The new sensor will extend beyond the end of the CPT rods during removal from the penetration, permitting the beta sensor to be in direct contact with the soil and make a complete, real time profile of the soil contamination as the rods are retracted. Commercial Application: The development of the proposed sensing approach will lead to significant cost savings for characterizing and monitoring subsurface soils for radioactive waste contamination. By utilizing the Cone Penetrometer Technique for deployment, the sensor will be able to provide real-time continuous profiles of the contaminated soil layers. In addition, less drilling waste and also less worker exposure will occur when fielding applications are conducted using this innovative approach as compared to traditional drilling and sampling techniques.
Agency: Department of Health and Human Services | Branch: National Institutes of Health | Program: SBIR | Phase: Phase I | Award Amount: 221.88K | Year: 2015
DESCRIPTION provided by applicant Millions of Americans suffer from the debilitating disease of temporomandibular joint TMJ disorder affecting their ability to eat talk and live their lives For the patients whose joints do not respond to basic treatments and continue to have long term problems a doctor may recommend to perform surgical procedures to correct underlying problems in the joint The last form of treatment available is the surgical replacement of the entire joint with an implanted prosthesis Often the patient that receives this final recommendation has endured years of suffering and many forms of partial treatment of the problem frequenting many different doctors from different fields such as neurosurgeons rheumatologists and dental surgeons Current guidance from the NIH suggests that all forms of treatment be exhausted before resorting to a non reversible surgical treatment the total joint replacement being the treatment of last resort There are a large number of people for whom this final treatment is necessary but doctors are reluctant to recommend that the surgery be performed Vista Engineering and the University of Alabama at Birmingham UAB have been developing a next generation diamond surfaced TMJ prosthesis implant in an attempt to revolutionize this market This device is less invasive with a reduced surgical procedure and greater biocompatibility The very nature of the device is innovative in that it is not a total joit replacement device but a resurfacing device where the majority of the existing joint is retained including all the joint stabilizing muscles The proposed research is innovative because an animal model for the TMJ has not been proven Furthermore the long term viability of diamond surfaces for implants is not well studied The proposed research will evaluate the performance of the UAB Vista diamond surfaced TMJ at the conclusion of a month animal trial involving diamond surfaced implants in miniature pigs plus a control device in an eighth The surgeon will examine the tissue and health of the TMJ prior to extraction Research on the explant devices will focus on the integration of the bone to the implant and a search for evidence of giant cell foreign body GCFB reactions The integrity of the diamond surfaces indications of articulation behavior and the fixation of the device to the bone will be determined through laboratory investigations PUBLIC HEALTH RELEVANCE This grant will be used to research and analyze the results of an animal study currently in progress where a next generation temporomandibular joint prosthesis is being tested in vivo The current reluctance by surgeons to perform a total joint replacement in patients with severe TMJ disorder needs to be overcome by introducing an alternative to current implant prosthesis designs The UAB Vista implant is more biocompatible reduces the surgical complexity of the procedure and preserves the patientandapos s joint functionality