Science.gov

Sample records for rapid prototyping models

  1. Utilizing Rapid Prototyping for Architectural Modeling

    ERIC Educational Resources Information Center

    Kirton, E. F.; Lavoie, S. D.

    2006-01-01

    This paper will discuss our approach to, success with and future direction in rapid prototyping for architectural modeling. The premise that this emerging technology has broad and exciting applications in the building design and construction industry will be supported by visual and physical evidence. This evidence will be presented in the form of…

  2. Rapid prototype modeling in a multimodality world

    NASA Astrophysics Data System (ADS)

    Bidaut, Luc; Madewell, John; Yasko, Alan

    2006-03-01

    Introduction: Rapid prototype modeling (RPM) has been used in medicine principally for bones - that are easily extracted from CT data sets - for planning orthopaedic, plastic or maxillo-facial interventions, and/or for designing custom prostheses and implants. Based on newly available technology, highly valuable multimodality approaches can now be applied to RPM, particularly for complex musculo-skeletal (MSK) tumors where multimodality often transcends CT alone. Methods: CT data sets are acquired for primary evaluation of MSK tumors in parallel with other modalities (e.g., MR, PET, SPECT). In our approach, CT is first segmented to provide bony anatomy for RPM and all other data sets are then registered to the CT reference. Parametric information relevant to the tumor's characterization is then extracted from the multimodality space and merged with the CT anatomy to produce a hybrid RPM-ready model. This model - that also accommodates digital multimodality visualization - is then produced on the latest generation of 3D printers, which permits both shapes and colors. Results: Multimodality models of complex MSK tumors have been physically produced on modern RPM equipment. This new approach has been found to be a clear improvement over the previously disconnected physical RPM and digital multimodality visualization. Conclusions: New technical developments keep opening doors to sophisticated medical applications that can directly impact the quality of patient care. Although this early work still deals with bones as base models for RPM, its use to encompass soft tissues is already envisioned for future approaches.

  3. Rapid prototyping and AI programming environments applied to payload modeling

    NASA Technical Reports Server (NTRS)

    Carnahan, Richard S., Jr.; Mendler, Andrew P.

    1987-01-01

    This effort focused on using artificial intelligence (AI) programming environments and rapid prototyping to aid in both space flight manned and unmanned payload simulation and training. Significant problems addressed are the large amount of development time required to design and implement just one of these payload simulations and the relative inflexibility of the resulting model to accepting future modification. Results of this effort have suggested that both rapid prototyping and AI programming environments can significantly reduce development time and cost when applied to the domain of payload modeling for crew training. The techniques employed are applicable to a variety of domains where models or simulations are required.

  4. Femur Model Reconstruction Based on Reverse Engineering and Rapid Prototyping

    NASA Astrophysics Data System (ADS)

    Tang, Tongming; Zhang, Zheng; Ni, Hongjun; Deng, Jiawen; Huang, Mingyu

    Precise reconstruction of 3D models is fundamental and crucial to the researches of human femur. In this paper we present our approach towards tackling this problem. The surface of a human femur was scanned using a hand-held 3D laser scanner. The data obtained, in the form of point cloud, was then processed using the reverse engineering software Geomagic and the CAD/CAM software CimatronE to reconstruct a digital 3D model. The digital model was then used by the rapid prototyping machine to build a physical model of human femur using 3D printing. The geometric characteristics of the obtained physical model matched that of the original femur. The process of "physical object - 3D data - digital 3D model - physical model" presented in this paper provides a foundation of precise modeling for the digital manufacturing, virtual assembly, stress analysis, and simulated surgery of artificial bionic femurs.

  5. Rapid prototyping techniques for anatomical modelling in medicine.

    PubMed Central

    McGurk, M.; Amis, A. A.; Potamianos, P.; Goodger, N. M.

    1997-01-01

    The rapid advances in computer technology, often driven by the demands of industry, have created new possibilities in surgery which previous generations of surgeons could only have imagined. Improved imaging with computerised tomography (CT) has been followed by magnetic resonance imaging (MRI) and, more recently, it has become possible to reformat the data as three-dimensional images. Computer technology has new moved forward with the advent of rapid prototyping techniques (RPT) which allow both the production of models of the hard tissues and custom-made prostheses from computerised scanning data. In this article we review the development and current technologies available in RPT and the applications of this advance in surgery and illustrate this with two case reports. Images Figure 1 Figure 2 Figure 3 Figure 4 PMID:9196336

  6. Analysis of errors in medical rapid prototyping models.

    PubMed

    Choi, J Y; Choi, J H; Kim, N K; Kim, Y; Lee, J K; Kim, M K; Lee, J H; Kim, M J

    2002-02-01

    Rapid prototyping (RP) is a relatively new technology that produces physical models by selectively solidifying UV-sensitive liquid resin using a laser beam. The technology has gained a great amount of attention, particularly in oral and maxillofacial surgery. An important issue in RP applications in this field is how to obtain RP models of the required accuracy. We investigated errors generated during the production of medical RP models, and identified the factors that caused dimensional errors in each production phase. The errors were mainly due to the volume-averaging effect, threshold value, and difficulty in the exact replication of landmark locations. We made 16 linear measurements on a dry skull, a replicated three-dimensional (3-D) visual (STL) model, and an RP model. The results showed that the absolute mean deviation between the original dry skull and the RP model over the 16 linear measurements was 0.62 +/- 0.35 mm (0.56 +/- 0.39%), which is smaller than values reported in previous studies. A major emphasis is placed on the dumb-bell effect. Classifying measurements as internal and external measurements, we observed that the effect of an inadequate threshold value differs with the type of measurement.

  7. Procedural Modeling for Rapid-Prototyping of Multiple Building Phases

    NASA Astrophysics Data System (ADS)

    Saldana, M.; Johanson, C.

    2013-02-01

    RomeLab is a multidisciplinary working group at UCLA that uses the city of Rome as a laboratory for the exploration of research approaches and dissemination practices centered on the intersection of space and time in antiquity. In this paper we present a multiplatform workflow for the rapid-prototyping of historical cityscapes through the use of geographic information systems, procedural modeling, and interactive game development. Our workflow begins by aggregating archaeological data in a GIS database. Next, 3D building models are generated from the ArcMap shapefiles in Esri CityEngine using procedural modeling techniques. A GIS-based terrain model is also adjusted in CityEngine to fit the building elevations. Finally, the terrain and city models are combined in Unity, a game engine which we used to produce web-based interactive environments which are linked to the GIS data using keyhole markup language (KML). The goal of our workflow is to demonstrate that knowledge generated within a first-person virtual world experience can inform the evaluation of data derived from textual and archaeological sources, and vice versa.

  8. Vibrational testing of trabecular bone architectures using rapid prototype models.

    PubMed

    Mc Donnell, P; Liebschner, M A K; Tawackoli, Wafa; Mc Hugh, P E

    2009-01-01

    The purpose of this study was to investigate if standard analysis of the vibrational characteristics of trabecular architectures can be used to detect changes in the mechanical properties due to progressive bone loss. A cored trabecular specimen from a human lumbar vertebra was microCT scanned and a three-dimensional, virtual model in stereolithography (STL) format was generated. Uniform bone loss was simulated using a surface erosion algorithm. Rapid prototype (RP) replicas were manufactured from these virtualised models with 0%, 16% and 42% bone loss. Vibrational behaviour of the RP replicas was evaluated by performing a dynamic compression test through a frequency range using an electro-dynamic shaker. The acceleration and dynamic force responses were recorded and fast Fourier transform (FFT) analyses were performed to determine the response spectrum. Standard resonant frequency analysis and damping factor calculations were performed. The RP replicas were subsequently tested in compression beyond failure to determine their strength and modulus. It was found that the reductions in resonant frequency with increasing bone loss corresponded well with reductions in apparent stiffness and strength. This suggests that structural dynamics has the potential to be an alternative diagnostic technique for osteoporosis, although significant challenges must be overcome to determine the effect of the skin/soft tissue interface, the cortex and variabilities associated with in vivo testing. PMID:18555727

  9. Rapid prototype and test

    SciTech Connect

    Gregory, D.L.; Hansche, B.D.

    1996-06-01

    In order to support advanced manufacturing, Sandia has acquired the capability to produce plastic prototypes using stereolithography. Currently, these prototypes are used mainly to verify part geometry and ``fit and form`` checks. This project investigates methods for rapidly testing these plastic prototypes, and inferring from prototype test data actual metal part performance and behavior. Performances examined include static load/stress response, and structural dynamic (modal) and vibration behavior. The integration of advanced non-contacting measurement techniques including scanning laser velocimetry, laser holography, and thermoelasticity into testing of these prototypes is described. Photoelastic properties of the epoxy prototypes to reveal full field stress/strain fields are also explored.

  10. Rapid Prototyping Reconsidered

    ERIC Educational Resources Information Center

    Desrosier, James

    2011-01-01

    Continuing educators need additional strategies for developing new programming that can both reduce the time to market and lower the cost of development. Rapid prototyping, a time-compression technique adapted from the high technology industry, represents one such strategy that merits renewed evaluation. Although in higher education rapid…

  11. Rapid Prototyping in PVS

    NASA Technical Reports Server (NTRS)

    Munoz, Cesar A.; Butler, Ricky (Technical Monitor)

    2003-01-01

    PVSio is a conservative extension to the PVS prelude library that provides basic input/output capabilities to the PVS ground evaluator. It supports rapid prototyping in PVS by enhancing the specification language with built-in constructs for string manipulation, floating point arithmetic, and input/output operations.

  12. Aerodynamic Properties Analysis of Rapid Prototyped Models Versus Conventional Machined Models

    NASA Technical Reports Server (NTRS)

    Springer, A.; Cooper, K.

    1998-01-01

    Initial studies of the aerodynamic characteristics of proposed launch vehicles can be made more accurately if lower cost, high fidelity aerodynamic models are available for wind tunnel testing early in the design phase. This paper discusses the results of a study undertaken at NASA's Marshall Space Flight Center to determine if four rapid prototyping methods using a variety of materials are suitable for the design and manufacturing of high speed wind tunnel models in direct testing applications. It also gives an analysis of whether these materials and processes are of sufficient strength and fidelity to withstand the testing environment. In addition to test data, costs and turn-around times for the various models are given. Based on the results of this study, it can be concluded that rapid prototyping models show promise in limited direct application for preliminary aerodynamic development studies at subsonic, transonic, and supersonic speeds.

  13. Teaching Tip: Using Rapid Game Prototyping for Exploring Requirements Discovery and Modeling

    ERIC Educational Resources Information Center

    Dalal, Nikunj

    2012-01-01

    We describe the use of rapid game prototyping as a pedagogic technique to experientially explore and learn requirements discovery, modeling, and specification in systems analysis and design courses. Students have a natural interest in gaming that transcends age, gender, and background. Rapid digital game creation is used to build computer games…

  14. Advances in rapid prototyping

    SciTech Connect

    Atwood, C.L.; McCarty, G.D.; Pardo, B.T.; Bryce, E.A.

    1993-12-31

    Recent advances in stereolithography and selective laser sintering have had a significant impact on the overall quality of parts produced using these rapid prototyping processes. The development and implementation of 3D System`s QuickCast{trademark} resin and software for building investment casting patterns have proven to be major steps toward fabricating highly accurate patterns with very good surface finishes. Sandia uses patterns generated from rapid prototyping processes to reduce the cycle time and cost of fabricating prototype parts in support of a Sandia National Laboratories managed program called FASTCAST. As participants in the Beta test program for QuickCast{trademark} resin and software, they experienced a steep learning curve and were able to build accurate parts in a short period of time. It is now possible, using this technology, to produce highly accurate prototype parts as well as acceptable firs article and small lots size production parts. They use the Selective Laser Sintering (SLS) process to fabricate prototype wax patterns for investment casting. DTM Corporation recently introduced the use of their polycarbonate material for fabricating investment casting patterns. The polycarbonate material is processed significantly faster, with improved strength, dimensional stability, and without a support structure during the build process. Sandia is currently changing from investment casting wax to polycarbonate for the fabrication of investment casting patterns using the SLS process. This presentation will focus on the successes with these new materials from the standpoints of application, accuracy, surface finish, and post processing. Also presented will be examples of parts manufactured by these processes.

  15. Knowledge-based visual image processing IDE model for algorithm and system rapid prototyping

    NASA Astrophysics Data System (ADS)

    Zhang, Biyin; Chen, Wei; Wang, Yuanbin

    2009-10-01

    A novel intelligent model for Image Processing (IP) research integrated development environment (IDE) is presented for rapid converting conceptual model of IP algorithm into computational model and program implementation. Considering psychology of IP and computer programming, this model presents a cycle model of IP research process and establishes an improved expert system prototype. Visualization approaches are introduced into visualizing three phases of IP development. An intelligent methodology is applied to reuse algorithms, graphical user interfaces (GUI) and data visualizing tools. Thus, researchers are allowed to fix more attention only on their own interest algorithm models. Experimental results show that the development based the new model enhances rapid algorithm prototype modeling with great efficiency and speed.

  16. A Three-Dimensional Mediastinal Model Created with Rapid Prototyping in a Patient with Ectopic Thymoma

    PubMed Central

    Nakada, Takeo; Inagaki, Takuya

    2014-01-01

    Preoperative three-dimensional (3D) imaging of a mediastinal tumor using two-dimensional (2D) axial computed tomography is sometimes difficult, and an unexpected appearance of the tumor may be encountered during surgery. In order to evaluate the preoperative feasibility of a 3D mediastinal model that used the rapid prototyping technique, we created a model and report its results. The 2D image showed some of the relationship between the tumor and the pericardium, but the 3D mediastinal model that was created using the rapid prototyping technique showed the 3D lesion in the outer side of the extrapericardium. The patient underwent a thoracoscopic resection of the tumor, and the pathological examination showed a rare middle mediastinal ectopic thymoma. We believe that the construction of mediastinal models is useful for thoracoscopic surgery and other complicated surgeries of the chest diseases. PMID:24633133

  17. Application of 3-D printing (rapid prototyping) for creating physical models of pediatric orthopedic disorders.

    PubMed

    Starosolski, Zbigniew A; Kan, J Herman; Rosenfeld, Scott D; Krishnamurthy, Rajesh; Annapragada, Ananth

    2014-02-01

    Three-dimensional printing called rapid prototyping, a technology that is used to create physical models based on a 3-D computer representation, is now commercially available and can be created from CT or MRI datasets. This technical innovation paper reviews the specific requirements and steps necessary to apply biomedical 3-D printing of pediatric musculoskeletal disorders. We discuss its role for the radiologist, orthopedist and patient. PMID:24202430

  18. Rapid prototyping modelling in oral and maxillofacial surgery: A two year retrospective study

    PubMed Central

    Stoor, Patricia; Mesimäki, Karri; Kontio, Risto K.

    2015-01-01

    Background The use of rapid prototyping (RP) models in medicine to construct bony models is increasing. Material and Methods The aim of the study was to evaluate retrospectively the indication for the use of RP models in oral and maxillofacial surgery at Helsinki University Central Hospital during 2009-2010. Also, the used computed tomography (CT) examination – multislice CT (MSCT) or cone beam CT (CBCT) - method was evaluated. Results In total 114 RP models were fabricated for 102 patients. The mean age of the patients at the time of the production of the model was 50.4 years. The indications for the modelling included malignant lesions (29%), secondary reconstruction (25%), prosthodontic treatment (22%), orthognathic surgery or asymmetry (13%), benign lesions (8%), and TMJ disorders (4%). MSCT examination was used in 92 and CBCT examination in 22 cases. Most of the models (75%) were conventional hard tissue models. Models with colored tumour or other structure(s) of interest were ordered in 24%. Two out of the 114 models were soft tissue models. Conclusions The main benefit of the models was in treatment planning and in connection with the production of pre-bent plates or custom made implants. The RP models both facilitate and improve treatment planning and intraoperative efficiency. Key words:Rapid prototyping, radiology, computed tomography, cone beam computed tomography. PMID:26644837

  19. Customer-experienced rapid prototyping

    NASA Astrophysics Data System (ADS)

    Zhang, Lijuan; Zhang, Fu; Li, Anbo

    2008-12-01

    In order to describe accurately and comprehend quickly the perfect GIS requirements, this article will integrate the ideas of QFD (Quality Function Deployment) and UML (Unified Modeling Language), and analyze the deficiency of prototype development model, and will propose the idea of the Customer-Experienced Rapid Prototyping (CE-RP) and describe in detail the process and framework of the CE-RP, from the angle of the characteristics of Modern-GIS. The CE-RP is mainly composed of Customer Tool-Sets (CTS), Developer Tool-Sets (DTS) and Barrier-Free Semantic Interpreter (BF-SI) and performed by two roles of customer and developer. The main purpose of the CE-RP is to produce the unified and authorized requirements data models between customer and software developer.

  20. Creation of an in vitro biomechanical model of the trachea using rapid prototyping.

    PubMed

    Walenga, Ross L; Longest, P Worth; Sundaresan, Gobalakrishnan

    2014-06-01

    Previous in vitro models of the airways are either rigid or, if flexible, have not matched in vivo compliance characteristics. Rapid prototyping provides a quickly evolving approach that can be used to directly produce in vitro airway models using either rigid or flexible polymers. The objective of this study was to use rapid prototyping to directly produce a flexible hollow model that matches the biomechanical compliance of the trachea. The airway model consisted of a previously developed characteristic mouth-throat region, the trachea, and a portion of the main bronchi. Compliance of the tracheal region was known from a previous in vivo imaging study that reported cross-sectional areas over a range of internal pressures. The compliance of the tracheal region was matched to the in vivo data for a specific flexible resin by iteratively selecting the thicknesses and other dimensions of tracheal wall components. Seven iterative models were produced and illustrated highly non-linear expansion consisting of initial rapid size increase, a transition region, and continued slower size increase as pressure was increased. Thickness of the esophageal interface membrane and initial trachea indention were identified as key parameters with the final model correctly predicting all phases of expansion within a value of 5% of the in vivo data. Applications of the current biomechanical model are related to endotracheal intubation and include determination of effective mucus suctioning and evaluation of cuff sealing with respect to gases and secretions. PMID:24735504

  1. The use of a block diagram simulation language for rapid model prototyping

    NASA Technical Reports Server (NTRS)

    Whitlow, Jonathan E.

    1995-01-01

    The research performed this summer focussed on the development of a predictive model for the loading of liquid oxygen (LO2) into the external tank (ET) of the shuttle prior to launch. A predictive model can greatly aid the operational personnel since instrumentation aboard the orbiter and ET is limited due to weight constraints. The model, which focuses primarily on the orbiter section of the system was developed using a block diagram based simulation language known as VisSim. Simulations were run on LO2 loading data for shuttle flights STS50 and STS55 and the model was demonstrated to accurately predict the sensor data recorded for these flights. As a consequence of the simulation results, it can be concluded that the software tool can be very useful for rapid prototyping of complex models.

  2. Physical human lumen carotid reconstruction: life-size models by rapid prototyping

    NASA Astrophysics Data System (ADS)

    Pili, Piero; Murgia, Fabrizio; Pusceddu, Gabriella; Franzoni, Gregorio; Tuveri, Massimiliano

    2003-05-01

    Rapid Prototyping (RP) is a technique used in industry for manufacturing prototypes. Its capability to physically reproduce geometrical complex shapes is getting increasing interest in many fields of medicine. In the field of vascular surgery, replicas of artery lumen have utility in complex cases or when standard imaging is felt to be equivocal. Replicas can also facilitate experimental studies of computational vascular fluid-dynamics permitting in-vitro reproductions of blood flow in living subjects before and after surgery. The VIrtual VAscular (VIVA) project at CRS4, developed a system able to process three-dimensional (3D) datasets extracted from a Computer Tomography (CT) apparatus, visualize them, reconstruct the geometry of arteries of specific patients, and simulate blood flow in them. In this paper, the applicability of RP techniques to VIVA's real size replicas of an autoptic carotid vessel lumen is presented and an overview of the RP based system developed is provided. The techniques used in our prototype are discussed and experimental results for the creation of a human carotid lumen replica are analyzed. We discuss in detail the pipeline of manufacturing process: 3D geometric reconstruction from segmented points, geometry tessellation, STL (Stereo Lithography format) conversion. Moreover we illustrate some technical details of the specific RP technique used to build the lumen replicas, which is called Fused Deposition Modelling (FDM), the materials used for prototypes, throughput time and costs of the FDM models realized. The system is totally based on open-source software. This enables us to control each step of the pipeline, from data acquisition to STL export file. In this context, we present main sources of error encountered during all manufacturing process stages.

  3. Comparative evaluation of dimension and surface detail accuracy of models produced by three different rapid prototype techniques.

    PubMed

    Murugesan, K; Anandapandian, Ponsekar Abraham; Sharma, Sumeet Kumar; Vasantha Kumar, M

    2012-03-01

    Rapid prototyping (RP) is a technology that produces physical models by selectively solidifying ultra violet (UV) sensitive liquid resin using a laser beam. These models can be formed using various techniques. A study was undertaken to compare the dimensional accuracy and surface details of three prototype models with a 3D STL (standard template library) image. In this study the STL file was used to produce three different rapid prototype models namely; model 1-fused deposition model (FDM) using ABS (acrylonitrile butadiene styrene), model 2-Polyjet using a clear resin and model 3-a 3 dimensional printing using a composite material. Measurements were made at various anatomical points. For surface detail reproductions the models were subjected to scanning electron microscopy analysis. The dimensions of the model created by Polyjet were closest to the 3D STL virtual image followed by the 3DP model and FDM. SEM analysis showed uniform smooth surface on Polyjet model with adequate surface details.

  4. Preliminary Component Integration Using Rapid Prototyping Techniques

    NASA Technical Reports Server (NTRS)

    Cooper, Ken; Salvail, Pat; Gordon, Gail (Technical Monitor)

    2001-01-01

    Rapid prototyping is a very important tool that should be used by both design and manufacturing disciplines during the development of elements for the aerospace industry. It helps prevent lack of adequate communication between design and manufacturing engineers (which could lead to costly errors) through mutual consideration of functional models generated from drawings. Rapid prototyping techniques are used to test hardware for design and material compatibility at Marshall Space Flight Center.

  5. D Modelling and Rapid Prototyping for Cardiovascular Surgical Planning - Two Case Studies

    NASA Astrophysics Data System (ADS)

    Nocerino, E.; Remondino, F.; Uccheddu, F.; Gallo, M.; Gerosa, G.

    2016-06-01

    In the last years, cardiovascular diagnosis, surgical planning and intervention have taken advantages from 3D modelling and rapid prototyping techniques. The starting data for the whole process is represented by medical imagery, in particular, but not exclusively, computed tomography (CT) or multi-slice CT (MCT) and magnetic resonance imaging (MRI). On the medical imagery, regions of interest, i.e. heart chambers, valves, aorta, coronary vessels, etc., are segmented and converted into 3D models, which can be finally converted in physical replicas through 3D printing procedure. In this work, an overview on modern approaches for automatic and semiautomatic segmentation of medical imagery for 3D surface model generation is provided. The issue of accuracy check of surface models is also addressed, together with the critical aspects of converting digital models into physical replicas through 3D printing techniques. A patient-specific 3D modelling and printing procedure (Figure 1), for surgical planning in case of complex heart diseases was developed. The procedure was applied to two case studies, for which MCT scans of the chest are available. In the article, a detailed description on the implemented patient-specific modelling procedure is provided, along with a general discussion on the potentiality and future developments of personalized 3D modelling and printing for surgical planning and surgeons practice.

  6. Rapid Prototyping Enters Mainstream Manufacturing.

    ERIC Educational Resources Information Center

    Winek, Gary

    1996-01-01

    Explains rapid prototyping, a process that uses computer-assisted design files to create a three-dimensional object automatically, speeding the industrial design process. Five commercially available systems and two emerging types--the 3-D printing process and repetitive masking and depositing--are described. (SK)

  7. Rapid prototyping and stereolithography in dentistry.

    PubMed

    Nayar, Sanjna; Bhuminathan, S; Bhat, Wasim Manzoor

    2015-04-01

    The word rapid prototyping (RP) was first used in mechanical engineering field in the early 1980s to describe the act of producing a prototype, a unique product, the first product, or a reference model. In the past, prototypes were handmade by sculpting or casting, and their fabrication demanded a long time. Any and every prototype should undergo evaluation, correction of defects, and approval before the beginning of its mass or large scale production. Prototypes may also be used for specific or restricted purposes, in which case they are usually called a preseries model. With the development of information technology, three-dimensional models can be devised and built based on virtual prototypes. Computers can now be used to create accurately detailed projects that can be assessed from different perspectives in a process known as computer aided design (CAD). To materialize virtual objects using CAD, a computer aided manufacture (CAM) process has been developed. To transform a virtual file into a real object, CAM operates using a machine connected to a computer, similar to a printer or peripheral device. In 1987, Brix and Lambrecht used, for the first time, a prototype in health care. It was a three-dimensional model manufactured using a computer numerical control device, a type of machine that was the predecessor of RP. In 1991, human anatomy models produced with a technology called stereolithography were first used in a maxillofacial surgery clinic in Viena.

  8. Rapid prototyping and stereolithography in dentistry.

    PubMed

    Nayar, Sanjna; Bhuminathan, S; Bhat, Wasim Manzoor

    2015-04-01

    The word rapid prototyping (RP) was first used in mechanical engineering field in the early 1980s to describe the act of producing a prototype, a unique product, the first product, or a reference model. In the past, prototypes were handmade by sculpting or casting, and their fabrication demanded a long time. Any and every prototype should undergo evaluation, correction of defects, and approval before the beginning of its mass or large scale production. Prototypes may also be used for specific or restricted purposes, in which case they are usually called a preseries model. With the development of information technology, three-dimensional models can be devised and built based on virtual prototypes. Computers can now be used to create accurately detailed projects that can be assessed from different perspectives in a process known as computer aided design (CAD). To materialize virtual objects using CAD, a computer aided manufacture (CAM) process has been developed. To transform a virtual file into a real object, CAM operates using a machine connected to a computer, similar to a printer or peripheral device. In 1987, Brix and Lambrecht used, for the first time, a prototype in health care. It was a three-dimensional model manufactured using a computer numerical control device, a type of machine that was the predecessor of RP. In 1991, human anatomy models produced with a technology called stereolithography were first used in a maxillofacial surgery clinic in Viena. PMID:26015715

  9. Rapid prototyping and stereolithography in dentistry

    PubMed Central

    Nayar, Sanjna; Bhuminathan, S.; Bhat, Wasim Manzoor

    2015-01-01

    The word rapid prototyping (RP) was first used in mechanical engineering field in the early 1980s to describe the act of producing a prototype, a unique product, the first product, or a reference model. In the past, prototypes were handmade by sculpting or casting, and their fabrication demanded a long time. Any and every prototype should undergo evaluation, correction of defects, and approval before the beginning of its mass or large scale production. Prototypes may also be used for specific or restricted purposes, in which case they are usually called a preseries model. With the development of information technology, three-dimensional models can be devised and built based on virtual prototypes. Computers can now be used to create accurately detailed projects that can be assessed from different perspectives in a process known as computer aided design (CAD). To materialize virtual objects using CAD, a computer aided manufacture (CAM) process has been developed. To transform a virtual file into a real object, CAM operates using a machine connected to a computer, similar to a printer or peripheral device. In 1987, Brix and Lambrecht used, for the first time, a prototype in health care. It was a three-dimensional model manufactured using a computer numerical control device, a type of machine that was the predecessor of RP. In 1991, human anatomy models produced with a technology called stereolithography were first used in a maxillofacial surgery clinic in Viena. PMID:26015715

  10. Parametric Modeling as a Technology of Rapid Prototyping in Light Industry

    NASA Astrophysics Data System (ADS)

    Tomilov, I. N.; Grudinin, S. N.; Frolovsky, V. D.; Alexandrov, A. A.

    2016-04-01

    The paper deals with the parametric modeling method of virtual mannequins for the purposes of design automation in clothing industry. The described approach includes the steps of generation of the basic model on the ground of the initial one (obtained in 3D-scanning process), its parameterization and deformation. The complex surfaces are presented by the wireframe model. The modeling results are evaluated with the set of similarity factors. Deformed models are compared with their virtual prototypes. The results of modeling are estimated by the standard deviation factor.

  11. Classroom Evaluation of a Rapid Prototyping System.

    ERIC Educational Resources Information Center

    Tennyson, Stephen A.; Krueger, Thomas J.

    2001-01-01

    Introduces rapid prototyping which creates virtual models through a variety of automated material additive processes. Relates experiences using JP System 5 in freshman and sophomore engineering design graphics courses. Analyzes strengths and limitations of the JP System 5 and discusses how to use it effectively. (Contains 15 references.)…

  12. Aeroelastic characteristics of a rapid prototype multi-material wind tunnel model of a mechanically deployable aerodynamic decelerator

    NASA Astrophysics Data System (ADS)

    Raskin, Boris

    Scaled wind tunnel models are necessary for the development of aircraft and spacecraft to simulate aerodynamic behavior. This allows for testing multiple iterations of a design before more expensive full-scale aircraft and spacecraft are built. However, the cost of building wind tunnel models can still be high because they normally require costly subtractive manufacturing processes, such as machining, which can be time consuming and laborious due to the complex surfaces of aerodynamic models. Rapid prototyping, commonly known as 3D printing, can be utilized to save on wind tunnel model manufacturing costs. A rapid prototype multi-material wind tunnel model was manufactured for this thesis to investigate the possibility of using PolyJet 3D printing to create a model that exhibits aeroelastic behavior. The model is of NASA's Adaptable Deployable entry and Placement (ADEPT) aerodynamic decelerator, used to decelerate a spacecraft during reentry into a planet's atmosphere. It is a 60° cone with a spherically blunted nose that consists of a 12 flexible panels supported by a rigid structure of nose, ribs, and rim. The novel rapid prototype multi-material model was instrumented and tested in two flow conditions. Quantitative comparisons were made of the average forces and dynamic forces on the model, demonstrating that the model matched expected behavior for average drag, but not Strouhal number, indicating that there was no aeroelastic behavior in this particular case. It was also noted that the dynamic properties (e.g., resonant frequency) associated with the mounting scheme are very important and may dominate the measured dynamic response.

  13. Integration of rapid prototyping into product development

    SciTech Connect

    Atwood, C.L.; McCarty, G.D.; Pardo, B.T.; Bryce, E.A.

    1993-12-31

    Sandia National Laboratories is a vertically multi-disciplined research and development laboratory with a long history of designing and developing d electro-mechanical products in the national interest. Integrating new technologies into the prototyping phase of our development cycle is necessary to reduce the cycle time from initial design to finished product. The introduction of rapid prototyping machines into the marketplace promises to revolutionize the process of producing prototype parts with relative speed and production-like quality. Issues of accuracy, feature definition, and surface finish continue to drive research and development of these processes. Sandia uses Stereolithography (SL) and Selective Laser Sintering (SLS) capabilities to support internal product development efforts. The primary use of SL and SLS is to produce patterns for investment casting in support of a Sandia managed program called FASTCAST that integrates computational technologies and experimental data into the investment casting process. These processes are also used in the design iteration process to produce proof-of-concept models, hands-on models for design reviews, fit-check models, visual aids for manufacturing, and functional parts in assemblies. This presentation will provide an overview of the SL and SLS processes and an update of our experience and success in integrating these technologies into the product development cycle. Also presented will be several examples of prototype parts manufactured using SL and SLS with a focus on application, accuracy, surface and feature definition.

  14. Rapid Prototyping of Mobile Learning Games

    ERIC Educational Resources Information Center

    Federley, Maija; Sorsa, Timo; Paavilainen, Janne; Boissonnier, Kimo; Seisto, Anu

    2014-01-01

    This position paper presents the first results of an on-going project, in which we explore rapid prototyping method to efficiently produce digital learning solutions that are commercially viable. In this first phase, rapid game prototyping and an iterative approach was tested as a quick and efficient way to create learning games and to evaluate…

  15. Web tools for rapid experimental visualization prototyping

    NASA Astrophysics Data System (ADS)

    Decker, Jonathan W.; Livingstion, Mark A.

    2013-01-01

    Quite often a researcher finds themselves looking at spreadsheets of high-dimensional data generated by experimental models and user studies. We can use analysis to challenge or confirm hypothesis, but unexpected results can easily be lost in the shuffle. For this reason, it would be useful to visualize the results so we can explore our data and make new discoveries. Web browsers have become increasingly capable for creating complex, multi-view applications. Javascript is quickly becoming a de facto standard for scripting, online and offline. This work demonstrates the use of web technologies as a powerful tool for rapid visualization prototyping. We have developed two prototypes: One for high-dimensional results of the abELICIT - multi-agent version of the ELICIT platform tasked with collaborating to identify the parameters of a pending attack. Another prototype displays responses to a user study on the effectiveness of multi-layer visualization techniques. We created coordinated multiple views prototypes in the Google Chrome web browser written in Javascript, CSS and HTML. We will discuss the benefits and shortcomings of this approach.

  16. Preliminary Component Integration Utilizing Rapid Prototyping Techniques

    NASA Technical Reports Server (NTRS)

    Cooper, K.; Salvail, P.

    2001-01-01

    One of the most costly errors committed during the development of an element to be used in the space industry is the lack of communication between design and manufacturing engineers. A very important tool that should be utilized in the development stages by both design and manufacturing disciplines is rapid prototyping. Communication levels are intensified with the injection of functional models that are generated from a drawing. At the Marshall Space Flight Center, this discipline is utilized on a more frequent basis as a manner by which hardware may be tested for design and material compatibility.

  17. Simulink based behavioural modelling of a pulse oximeter for deployment in rapid development, prototyping and verification.

    PubMed

    Shokouhian, M; Morling, R C S; Kale, I

    2012-01-01

    The pulse oximeter is a well-known device for measuring the level of oxygen in blood. Since their invention, pulse oximeters have been under constant development in both aspects of hardware and software; however there are still unsolved problems that limit their performance [6], [7]. Many fresh algorithms and new design techniques are being suggested every year by industry and academic researchers which claim that they can improve accuracy of measurements [8], [9]. With the lack of an accurate computer-based behavioural model for pulse oximeters, the only way for evaluation of these newly developed systems and algorithms is through hardware implementation which can be both expensive and time consuming. This paper presents an accurate Simulink based behavioural model for a pulse oximeter that can be used by industry and academia alike working in this area, as an exploration as well as productivity enhancement tool during their research and development process. The aim of this paper is to introduce a new computer-based behavioural model which provides a simulation environment from which new ideas can be rapidly evaluated long before the real implementation. PMID:23367190

  18. Application of Rapid Prototyping Pelvic Model for Patients with DDH to Facilitate Arthroplasty Planning: A Pilot Study.

    PubMed

    Xu, Jie; Li, Deng; Ma, Ruo-fan; Barden, Bertram; Ding, Yue

    2015-11-01

    Total hip arthroplasty (THA) is challenging in cases of osteoarthritis secondary to developmental dysplasia of the hip (DDH). Acetabular deficiency makes the positioning of the acetabular component difficult. Computer tomography based, patient-individual three dimensional (3-D) rapid prototype technology (RPT)-models were used to plan the placement of acetabular cup so that a surgeon was able to identify pelvic structures, assess the ideal extent of reaming and determine the size of cup after a reconstructive procedure. Intraclass correlation coefficients (ICCs) were used to analyze the agreement between the sizes of chosen components on the basis of preoperative planning and the actual sizes used in the operation. The use of the 3-D RPT-model facilitates the surgical procedures due to better planning and improved orientation. PMID:26129852

  19. Rapid Prototyping in Technology Education.

    ERIC Educational Resources Information Center

    Flowers, Jim; Moniz, Matt

    2002-01-01

    Describes how technology education majors are using a high-tech model builder, called a fused deposition modeling machine, to develop their models directly from computer-based designs without any machining. Gives examples of applications in technology education. (JOW)

  20. Lumped Parameter Modeling for Rapid Vibration Response Prototyping and Test Correlation for Electronic Units

    NASA Technical Reports Server (NTRS)

    Van Dyke, Michael B.

    2013-01-01

    Present preliminary work using lumped parameter models to approximate dynamic response of electronic units to random vibration; Derive a general N-DOF model for application to electronic units; Illustrate parametric influence of model parameters; Implication of coupled dynamics for unit/board design; Demonstrate use of model to infer printed wiring board (PWB) dynamics from external chassis test measurement.

  1. Fluorescence Imaging and Streamline Visualization of Hypersonic Flow over Rapid Prototype Wind-Tunnel Models

    NASA Technical Reports Server (NTRS)

    Danehy, Paul M.; Alderfer, David W.; Inman, Jennifer A.; Berger, Karen T.; Buck, Gregory M.; Schwartz, Richard J.

    2008-01-01

    Reentry models for use in hypersonic wind tunnel tests were fabricated using a stereolithography apparatus. These models were produced in one day or less, which is a significant time savings compared to the manufacture of ceramic or metal models. The models were tested in the NASA Langley Research Center 31-Inch Mach 10 Air Tunnel. Only a few of the models survived repeated tests in the tunnel, and several failure modes of the models were identified. Planar laser-induced fluorescence (PLIF) of nitric oxide (NO) was used to visualize the flowfields in the wakes of these models. Pure NO was either seeded through tubes plumbed into the model or via a tube attached to the strut holding the model, which provided localized addition of NO into the model s wake through a porous metal cylinder attached to the end of the tube. Models included several 2- inch diameter Inflatable Reentry Vehicle Experiment (IRVE) models and 5-inch diameter Crew Exploration Vehicle (CEV) models. Various model configurations and NO seeding methods were used, including a new streamwise visualization method based on PLIF. Virtual Diagnostics Interface (ViDI) technology, developed at NASA Langley Research Center, was used to visualize the data sets in post processing. The use of calibration "dotcards" was investigated to correct for camera perspective and lens distortions in the PLIF images.

  2. Rapid Prototyping of Composite Structures

    NASA Technical Reports Server (NTRS)

    Colton, Jonathan S.

    1998-01-01

    This progress report for the project Rapid Production of Composite Structures covers the period from July 14, 1997 to June 30, 1998. It will present a short overview of the project, followed by the results to date and plans for the future. The goal of this research is to provide a minimum 100x reduction in the time required to produce arbitrary, laminated products without the need for a separate mold or an autoclave. It will accomplish this by developing the science underlying the rapid production of composite structures, specifically those of carbon fiber-epoxy materials. This scientific understanding will be reduced to practice in a demonstration device that will produce a part on the order of 12" by 12" by 6". Work in the past year has focussed on developing an understanding of the materials issues and of the machine design issues. Our initial goal was to use UV cureable resins to accomplish full cure on the machine. Therefore, we have centered our materials work around whether or not UV cureable resins will work. Currently, the answer seems to be that they will not work, because UV light cannot penetrate the carbon fibers, and because no "shadow" curing seems to occur. As a result, non-UV cureable resins are being investigated. This has resulted in a change in the machine design focus. We are now looking into a "dip and place" machine design, whereby a prepreg layer would have one side coated with a curing agent, and then would be placed onto the previous layer. This would lead to cure at the interface, but not to the top of the layer. The formulation of the resins to accomplish this task at room or slightly elevated temperatures is being investigated, as is the machine design needed to apply the curing agent and then cure or partially cure the part. A final, out-of-autoclave, post-cure may be needed with this strategy, as final cure on the machine may not be possible, as it was for the initial UV cure strategy. The remainder of this report details the progress

  3. Fluorescence Visualization of Hypersonic Flow over Rapid Prototype Wind-Tunnel Models

    NASA Technical Reports Server (NTRS)

    Alderfer, D. W.; Danehy, P. M.; Inma, J. A.; Berger, K. T.; Buck, G. M.; Schwartz, R J.

    2007-01-01

    Reentry models for use in hypersonic wind tunnel tests were fabricated using a stereolithography apparatus. These models were produced in one day or less, which is a significant time savings compared to the manufacture of ceramic or metal models. The models were tested in the NASA Langley Research Center 31-Inch Mach 10 Air Tunnel. Most of the models did not survive repeated tests in the tunnel, and several failure modes of the models were identified. Planar laser-induced fluorescence (PLIF) of nitric oxide (NO) was used to visualize the flowfields in the wakes of these models. Pure NO was either seeded through tubes plumbed into the model or via a tube attached to the strut holding the model, which provided localized addition of NO into the model s wake through a porous metal cylinder attached to the end of the tube. Models included several 2-inch diameter Inflatable Reentry Vehicle Experiment (IRVE) models and 5-inch diameter Crew Exploration Vehicle (CEV) models. Various configurations were studied including different sting placements relative to the models, different model orientations and attachment angles, and different NO seeding methods. The angle of attack of the models was also varied and the location of the laser sheet was scanned to provide three-dimensional flowfield information. Virtual Diagnostics Interface technology, developed at NASA Langley, was used to visualize the data sets in post processing. The use of calibration "dotcards" was investigated to correct for camera perspective and lens distortions in the PLIF images. Lessons learned and recommendations for future experiments are discussed.

  4. Rapid Prototyping of Composite Structures

    NASA Technical Reports Server (NTRS)

    Colton, Jonathan S.

    1998-01-01

    This final report for the project Rapid Production of Composite Structures covers the period from July 14, 1997 to September 30, 1998. It will present a short overview of the project, followed by the results to date and plans for the future. The goal of this research is to provide a minimum 100x reduction in the time required to produce arbitrary, laminated products without the need for a separate mold or an autoclave. It will accomplish this by developing the science underlying the rapid production of composite structures, specifically those of carbon fiber-epoxy materials. This scientific understanding will be reduced to practice in a demonstration device that will produce a part on the order of 12in. by 12in. by 6in. Work in the past year has focussed on developing an understanding of the materials issues and of the machine design issues. Our initial goal was to use UV cureable resins to accomplish full cure on the machine. Therefore, we have centered our materials work around whether or not UV cureable resins will work. Currently, the answer seems to be that they will not work, because UV light cannot penetrate the carbon fibers, and because no "shadow" curing seems to occur. As a result, non-UV cureable resins are being investigated. This has resulted in a change in the machine design focus. We are now looking into a "dip and place" machine design, whereby a prepreg layer would have one side coated with a curing agent, and then would be placed onto the previous layer. This would lead to cure at the interface, but not to the top of the layer. The formulation of the resins to accomplish this task at room or slightly elevated temperatures is being investigated, as is the machine design needed to apply the curing agent and then cure or partially cure the part. A final, out-of-autoclave, post-cure may be needed with this strategy, as final cure on the machine may not be possible, as it was for the initial UV cure strategy. The remainder of this report details the

  5. Rapid prototyping in aortic surgery.

    PubMed

    Bangeas, Petros; Voulalas, Grigorios; Ktenidis, Kiriakos

    2016-04-01

    3D printing provides the sequential addition of material layers and, thus, the opportunity to print parts and components made of different materials with variable mechanical and physical properties. It helps us create 3D anatomical models for the better planning of surgical procedures when needed, since it can reveal any complex anatomical feature. Images of abdominal aortic aneurysms received by computed tomographic angiography were converted into 3D images using a Google SketchUp free software and saved in stereolithography format. Using a 3D printer (Makerbot), a model made of polylactic acid material (thermoplastic filament) was printed. A 3D model of an abdominal aorta aneurysm was created in 138 min, while the model was a precise copy of the aorta visualized in the computed tomographic images. The total cost (including the initial cost of the printer) reached 1303.00 euros. 3D imaging and modelling using different materials can be very useful in cases when anatomical difficulties are recognized through the computed tomographic images and a tactile approach is demanded preoperatively. In this way, major complications during abdominal aorta aneurysm management can be predicted and prevented. Furthermore, the model can be used as a mould; the development of new, more biocompatible, less antigenic and individualized can become a challenge in the future. PMID:26803324

  6. The Use of a Block Diagram Simulation Language for Rapid Model Prototyping

    NASA Technical Reports Server (NTRS)

    Whitlow, Johnathan E.; Engrand, Peter

    1996-01-01

    The research performed this summer was a continuation of work performed during the 1995 NASA/ASEE Summer Fellowship. The focus of the work was to expand previously generated predictive models for liquid oxygen (LOX) loading into the external fuel tank of the shuttle. The models which were developed using a block diagram simulation language known as VisSim, were evaluated on numerous shuttle flights and found to well in most cases. Once the models were refined and validated, the predictive methods were integrated into the existing Rockwell software propulsion advisory tool (PAT). Although time was not sufficient to completely integrate the models developed into PAT, the ability to predict flows and pressures in the orbiter section and graphically display the results was accomplished.

  7. PyTrilinos Rapid Prototyping Package

    2005-03-01

    PyTrilinos provides access to selected Trilinos packages from the python scripting language. This allows interactive and dynamic creation of Trilinos objects, rapid prototyping that does not require compilation, and "gluing" Trilinos scripts to other python modules, such as plotting, etc. The currently supported packages are Epetra, EpetraExt, and NOX.

  8. Integrating Rapid Prototyping into Graphic Communications

    ERIC Educational Resources Information Center

    Xu, Renmei; Flowers, Jim

    2015-01-01

    Integrating different science, technology, engineering, and mathematics (STEM) areas can help students learn and leverage both the equipment and expertise at a single school. In comparing graphic communications classes with classes that involve rapid prototyping (RP) technologies like 3D printing, there are sufficient similarities between goals,…

  9. Review, Selection and Installation of a Rapid Prototype Machine

    NASA Technical Reports Server (NTRS)

    McEndree, Caryl

    2008-01-01

    The objective of this paper is to impress upon the reader the benefits and advantages of investing in rapid prototyping (additive manufacturing) technology thru the procurement of one or two new rapid prototyping machines and the creation of a new Prototype and Model Lab at the Kennedy Space Center (KSC). This new resource will be available to all of United Space Alliance, LLC (USA), enabling engineers from around the company to pursue a more effective means of communication and design with our co-workers, and our customer, the National Aeronautics and Space Administration (NASA). The Rapid Protoyping/3D printing industry mirrors the transition the CAD industry made several years ago, when companies were trying to justify the expenditure of converting to a 3D based system from a 2D based system. The advantages of using a 3D system seemed to be outweighed by the cost it would take to convert not only legacy 2D drawings into 3D models but the training of personnel to use the 3D CAD software. But the reality was that when a 3D CAD system is employed, it gives engineers a much greater ability to conceive new designs and the ability to engineer new tools and products much more effectively. Rapid Prototyping (RP) is the name given to a host of related technologies that are used to fabricate physical objects directly from Computer Aided Design (CAD) data sources. These methods are generally similar to each other in that they add and bond materials in a layer wise-fashion to form objects, instead of machining away material. The machines used in Rapid Prototyping are also sometimes referred to as Rapid Manufacturing machines due to the fact that some of the parts fabricated in a RP machine can be used as the finished product. The name "Rapid Prototyping" is really a misnomer. It is much more than prototypes and it is not always rapid.

  10. Rapid prototyping--when virtual meets reality.

    PubMed

    Beguma, Zubeda; Chhedat, Pratik

    2014-01-01

    Rapid prototyping (RP) describes the customized production of solid models using 3D computer data. Over the past decade, advances in RP have continued to evolve, resulting in the development of new techniques that have been applied to the fabrication of various prostheses. RP fabrication technologies include stereolithography (SLA), fused deposition modeling (FDM), computer numerical controlled (CNC) milling, and, more recently, selective laser sintering (SLS). The applications of RP techniques for dentistry include wax pattern fabrication for dental prostheses, dental (facial) prostheses mold (shell) fabrication, and removable dental prostheses framework fabrication. In the past, a physical plastic shape of the removable partial denture (RPD) framework was produced using an RP machine, and then used as a sacrificial pattern. Yet with the advent of the selective laser melting (SLM) technique, RPD metal frameworks can be directly fabricated, thereby omitting the casting stage. This new approach can also generate the wax pattern for facial prostheses directly, thereby reducing labor-intensive laboratory procedures. Many people stand to benefit from these new RP techniques for producing various forms of dental prostheses, which in the near future could transform traditional prosthodontic practices.

  11. Rapid prototyping--when virtual meets reality.

    PubMed

    Beguma, Zubeda; Chhedat, Pratik

    2014-01-01

    Rapid prototyping (RP) describes the customized production of solid models using 3D computer data. Over the past decade, advances in RP have continued to evolve, resulting in the development of new techniques that have been applied to the fabrication of various prostheses. RP fabrication technologies include stereolithography (SLA), fused deposition modeling (FDM), computer numerical controlled (CNC) milling, and, more recently, selective laser sintering (SLS). The applications of RP techniques for dentistry include wax pattern fabrication for dental prostheses, dental (facial) prostheses mold (shell) fabrication, and removable dental prostheses framework fabrication. In the past, a physical plastic shape of the removable partial denture (RPD) framework was produced using an RP machine, and then used as a sacrificial pattern. Yet with the advent of the selective laser melting (SLM) technique, RPD metal frameworks can be directly fabricated, thereby omitting the casting stage. This new approach can also generate the wax pattern for facial prostheses directly, thereby reducing labor-intensive laboratory procedures. Many people stand to benefit from these new RP techniques for producing various forms of dental prostheses, which in the near future could transform traditional prosthodontic practices. PMID:25643461

  12. Relatively Inexpensive Rapid Prototyping of Small Parts

    NASA Technical Reports Server (NTRS)

    Swan, Scott A.

    2003-01-01

    Parts with complex three-dimensional shapes and with dimensions up to 8 by 8 by 10 in. (20.3 by 20.3 by 25.4 cm) can be made as unitary pieces of a room-temperature-curing polymer, with relatively little investment in time and money, by a process now in use at Johnson Space Center. The process is one of a growing number of processes and techniques that are known collectively as the art of rapid prototyping. The main advantages of this process over other rapid-prototyping processes are greater speed and lower cost: There is no need to make paper drawings and take them to a shop for fabrication, and thus no need for the attendant paperwork and organizational delays. Instead, molds for desired parts are made automatically on a machine that is guided by data from a computer-aided design (CAD) system and can reside in an engineering office.

  13. Rapid Prototyping Of Layered Composite Parts

    NASA Technical Reports Server (NTRS)

    Wolff, Edwin D.

    1992-01-01

    Numerically controlled cutting accelerates fabrication of layers. Proposed method derived from stereoscopic lithography. CATIA or CAEDS computer program used to generate three-dimensional mathematical model of prototype part. In model, geometry of part specified in layers, as in stereoscopic lithography. Model data for each layer fed to computer-numerically-controlled ultrasonic cutting machine. Sheet of prepreg (uncured composite material) of specified layer thickness placed in machine and cut, under control of model data, to specified shape of layer.

  14. Rapid Prototyping Integrated With Nondestructive Evaluation and Finite Element Analysis

    NASA Technical Reports Server (NTRS)

    Abdul-Aziz, Ali; Baaklini, George Y.

    2001-01-01

    Most reverse engineering approaches involve imaging or digitizing an object then creating a computerized reconstruction that can be integrated, in three dimensions, into a particular design environment. Rapid prototyping (RP) refers to the practical ability to build high-quality physical prototypes directly from computer aided design (CAD) files. Using rapid prototyping, full-scale models or patterns can be built using a variety of materials in a fraction of the time required by more traditional prototyping techniques (refs. 1 and 2). Many software packages have been developed and are being designed to tackle the reverse engineering and rapid prototyping issues just mentioned. For example, image processing and three-dimensional reconstruction visualization software such as Velocity2 (ref. 3) are being used to carry out the construction process of three-dimensional volume models and the subsequent generation of a stereolithography file that is suitable for CAD applications. Producing three-dimensional models of objects from computed tomography (CT) scans is becoming a valuable nondestructive evaluation methodology (ref. 4). Real components can be rendered and subjected to temperature and stress tests using structural engineering software codes. For this to be achieved, accurate high-resolution images have to be obtained via CT scans and then processed, converted into a traditional file format, and translated into finite element models. Prototyping a three-dimensional volume of a composite structure by reading in a series of two-dimensional images generated via CT and by using and integrating commercial software (e.g. Velocity2, MSC/PATRAN (ref. 5), and Hypermesh (ref. 6)) is being applied successfully at the NASA Glenn Research Center. The building process from structural modeling to the analysis level is outlined in reference 7. Subsequently, a stress analysis of a composite cooling panel under combined thermomechanical loading conditions was performed to validate

  15. Integration of rapid prototyping into design and manufacturing

    SciTech Connect

    Atwood, C.L.; McCarty, G.D.; Pardo, B.T.; Bryce, E.A.

    1993-10-01

    The introduction of rapid prototyping machines into the marketplace promises to revolutionize the process of producing prototype parts with production-like quality. In the age of concurrent engineering and agile manufacturing, it is necessary to exploit applicable new technologies as soon as they become available. The driving force behind integrating these evolutionary processes into the design and manufacture of prototype parts is the need to reduce lead times and fabrication costs, improve efficiency, and increase flexibility without sacrificing quality. Sandia utilizes Stereolithography (SL) and Selective Laser Sintering (SLS) capabilities to support internal design and manufacturing efforts. SL is used in the design iteration process to produce proof-of-concept models, hands-on models for design reviews, fit-check models, visual aids for manufacturing, and functional parts in assemblies. SLS is used to produce wax patterns for the lost wax process of investment casting in support of an internal Sandia National Laboratories program called FASTCAST which integrates experimental and computational technologies into the investment casting process. This presentation will provide a brief overview of the SL and SLS processes and address our experiences with these technologies from the standpoints of application, accuracy, surface finish, and feature definition. Also presented will be several examples of prototype parts manufactured by the Stereolithography and Selective Laser Sintering rapid prototyping machines.

  16. Integration of rapid prototyping into design and manufacturing

    SciTech Connect

    Atwood, C.L.; McCarty, G.D.; Pardo, B.T.

    1993-04-01

    The introduction of rapid prototyping machines into the market place promises to revolutionize the process of producing prototype parts with production-like quality. In the age of concurrent engineering and agile manufacturing, it is necessary to exploit applicable new technologies as soon as they become available. The driving force behind integrating these evolutionary processes into the design and manufacture of prototype parts is the need to reduce lead times and fabrication costs improve efficiency, and increase flexibility without sacrificing quality. Sandia Utilizes stereolithography and selective laser sintering capabilities to support internal design and manufacturing efforts. Stereolithography (SLA) is used in the design iteration process to produce proof-of-concept models, hands-on models for design reviews, fit check models, visual aids for manufacturing, and functional parts in assemblies. Selective laser sintering (SLS) is used to produce wax patterns for the lost wax process of investment casting in support of an internal Sandia National Laboratories program called FASTCAST which integrates experimental and computational technologies into the investment casting process. This presentation will provide a brief overview of the SLA and SLS processes and address our experiences with these technologies from the standpoints of application, accuracy, surface finish, and feature definition. Also presented will be several examples of prototype parts manufactured by the stereolithography and selective laser sintering rapid prototyping machines.

  17. Rapid prototyping of ossicular replacement prostheses

    NASA Astrophysics Data System (ADS)

    Ovsianikov, A.; Chichkov, B.; Adunka, O.; Pillsbury, H.; Doraiswamy, A.; Narayan, R. J.

    2007-05-01

    Materials used in ossicular replacement prostheses must demonstrate appropriate biological compatibility, acoustic transmission, stability, and stiffness properties. Prostheses prepared using Teflon ®, titanium, Ceravital and other conventional materials have demonstrated several problems, including migration, perforation of the tympanic membrane, difficulty in shaping the prostheses, and reactivity with the surrounding tissues. We have used two-photon polymerization for rapid prototyping of Ormocer ® middle-ear bone replacement prostheses. Ormocer ® surfaces fabricated using two-photon polymerization exhibited acceptable cell viability and cell growth profiles. The Ormocer ® prosthesis was able to be inserted and removed from the site of use in the frozen human head without fracture. Our results demonstrate that two-photon polymerization is able to create ossicular replacement prostheses and other medical devices with a larger range of sizes, shapes and materials than other microfabrication techniques.

  18. Rapid Prototyping of Patterned Multifunctional Nanostructures

    SciTech Connect

    FAN,HONGYOU; LU,YUNFENG; LOPEZ,GABRIEL P.; BRINKER,C. JEFFREY

    2000-07-18

    The ability to engineer ordered arrays of objects on multiple length scales has potential for applications such as microelectronics, sensors, wave guides, and photonic lattices with tunable band gaps. Since the invention of surfactant templated mesoporous sieves in 1992, great progress has been made in controlling different mesophases in the form of powders, particles, fibers, and films. To date, although there have been several reports of patterned mesostructures, materials prepared have been limited to metal oxides with no specific functionality. For many of the envisioned applications of hierarchical materials in micro-systems, sensors, waveguides, photonics, and electronics, it is necessary to define both form and function on several length scales. In addition, the patterning strategies utilized so far require hours or even days for completion. Such slow processes are inherently difficult to implement in commercial environments. The authors present a series of new methods of producing patterns within seconds. Combining sol-gel chemistry, Evaporation-Induced Self-Assembly (EISA), and rapid prototyping techniques like pen lithography, ink-jet printing, and dip-coating on micro-contact printed substrates, they form hierarchically organized silica structures that exhibit order and function on multiple scales: on the molecular scale, functional organic moieties are positioned on pore surfaces, on the mesoscale, mono-sized pores are organized into 1-, 2-, or 3-dimensional networks, providing size-selective accessibility from the gas or liquid phase, and on the macroscale, 2-dimensional arrays and fluidic or photonic systems may be defined. These rapid patterning techniques establish for the first time a link between computer-aided design and rapid processing of self-assembled nanostructures.

  19. Rapid prototyping fabrication of focused ultrasound transducers.

    PubMed

    Kim, Yohan; Maxwell, Adam D; Hall, Timothy L; Xu, Zhen; Lin, Kuang-Wei; Cain, Charles A

    2014-09-01

    Rapid prototyping (RP) fabrication techniques are currently widely used in diverse industrial and medical fields, providing substantial advantages in development time and costs in comparison to more traditional manufacturing processes. This paper presents a new method for the fabrication of high-intensity focused ultrasound transducers using RP technology. The construction of a large-aperture hemispherical transducer designed by computer software is described to demonstrate the process. The transducer was conceived as a modular design consisting of 32 individually focused 50.8-mm (2-in) PZT-8 element modules distributed in a 300-mm hemispherical scaffold with a geometric focus of 150 mm. The entire structure of the array, including the module housings and the hemispherical scaffold was fabricated through a stereolithography (SLA) system using a proprietary photopolymer. The PZT elements were bonded to the lenses through a quarter-wave tungsten-epoxy matching layer developed in-house specifically for this purpose. Modules constructed in this manner displayed a high degree of electroacoustic consistency, with an electrical impedance mean and standard deviation of 109 ± 10.2 Ω for the 32 elements. Time-of-flight measurements for individually pulsed modules mounted on the hemispherical scaffold showed that all pulses arrived at the focus within a 350 ns range, indicating a good degree of element alignment. Pressure profile measurements of the fully assembled transducer also showed close agreement with simulated results. The measured focal beam FWHM dimensions were 1.9 × 4.0 mm (1.9 × 3.9 mm simulated) in the transversal and axial directions respectively. Total material expenses associated with the construction of the transducer were approximately 5000 USD (as of 2011). The versatility and lower fabrication costs afforded by RP methods may be beneficial in the development of complex transducer geometries suitable for a variety of research and clinical applications

  20. Rapid Production of Composite Prototype Hardware

    NASA Technical Reports Server (NTRS)

    DeLay, T. K.

    2000-01-01

    The objective of this research was to provide a mechanism to cost-effectively produce composite hardware prototypes. The task was to take a hands-on approach to developing new technologies that could benefit multiple future programs.

  1. Rapid prototyping of patterned functional nanostructures

    SciTech Connect

    FAN,HONGYOU; LU,YUNFENG; STUMP,AARON; REED,SCOTT T.; BAER,THOMAS A.; SCHUNK,P. RANDALL; PEREZ-LUNA,VICTOR; LOPEZ,GABRIEL P.; BRINKER,C. JEFFREY

    2000-02-09

    Living systems exhibit form and function on multiple length scales, and the prospect of imparting life-like qualities to man-made materials has inspired many recent efforts to devise hierarchical materials assembly strategies. For example, Yang et al. grew surfactant-templated mesoporous silica on hydrophobic patterns prepared by micro-contact printing {micro}CP{sup 3}. Trau et al. formed oriented mesoporous silica patterns, using a micro-molding in capillaries MIMIC technique, and Yang et al. combined MIMIC, polystyrene sphere templating, and surfactant-templating to create oxides with three levels of structural order. Overall, great progress has been made to date in controlling structure on scales ranging from several nanometers to several micrometers. However, materials prepared have been limited to oxides with no specific functionality, whereas for many of the envisioned applications of hierarchical materials in micro-systems, sensors, waveguides, photonics, and electronics, it is necessary to define both form and function on several length scales. In addition, the patterning strategies employed thus far require hours or even days for completion. Such slow processes are inherently difficult to implement in commercial environments. The authors have combined evaporation-induced (silica/surfactant) self-assembly EISA with rapid prototyping techniques like pen lithography, ink-jet printing, and dip-coating on micro-contact printed substrates to form hierarchically organized structures in seconds. In addition, by co-condensation of tetrafunctional silanes (Si(OR){sub 4}) with tri-functional organosilanes ((RO){sub 3}SiR{prime}){sup 12--14} or by inclusion of organic additives, the authors have selectively derivatized the silica framework with functional R{prime} ligands or molecules. The resulting materials exhibit form and function on multiple length scales: on the molecular scale, functional organic moieties are positioned on pore surfaces, on the mesoscale

  2. 3D Rapid Prototyping for Otolaryngology—Head and Neck Surgery: Applications in Image-Guidance, Surgical Simulation and Patient-Specific Modeling

    PubMed Central

    Chan, Harley H. L.; Siewerdsen, Jeffrey H.; Vescan, Allan; Daly, Michael J.; Prisman, Eitan; Irish, Jonathan C.

    2015-01-01

    The aim of this study was to demonstrate the role of advanced fabrication technology across a broad spectrum of head and neck surgical procedures, including applications in endoscopic sinus surgery, skull base surgery, and maxillofacial reconstruction. The initial case studies demonstrated three applications of rapid prototyping technology are in head and neck surgery: i) a mono-material paranasal sinus phantom for endoscopy training ii) a multi-material skull base simulator and iii) 3D patient-specific mandible templates. Digital processing of these phantoms is based on real patient or cadaveric 3D images such as CT or MRI data. Three endoscopic sinus surgeons examined the realism of the endoscopist training phantom. One experienced endoscopic skull base surgeon conducted advanced sinus procedures on the high-fidelity multi-material skull base simulator. Ten patients participated in a prospective clinical study examining patient-specific modeling for mandibular reconstructive surgery. Qualitative feedback to assess the realism of the endoscopy training phantom and high-fidelity multi-material phantom was acquired. Conformance comparisons using assessments from the blinded reconstructive surgeons measured the geometric performance between intra-operative and pre-operative reconstruction mandible plates. Both the endoscopy training phantom and the high-fidelity multi-material phantom received positive feedback on the realistic structure of the phantom models. Results suggested further improvement on the soft tissue structure of the phantom models is necessary. In the patient-specific mandible template study, the pre-operative plates were judged by two blinded surgeons as providing optimal conformance in 7 out of 10 cases. No statistical differences were found in plate fabrication time and conformance, with pre-operative plating providing the advantage of reducing time spent in the operation room. The applicability of common model design and fabrication techniques

  3. 3D Rapid Prototyping for Otolaryngology-Head and Neck Surgery: Applications in Image-Guidance, Surgical Simulation and Patient-Specific Modeling.

    PubMed

    Chan, Harley H L; Siewerdsen, Jeffrey H; Vescan, Allan; Daly, Michael J; Prisman, Eitan; Irish, Jonathan C

    2015-01-01

    The aim of this study was to demonstrate the role of advanced fabrication technology across a broad spectrum of head and neck surgical procedures, including applications in endoscopic sinus surgery, skull base surgery, and maxillofacial reconstruction. The initial case studies demonstrated three applications of rapid prototyping technology are in head and neck surgery: i) a mono-material paranasal sinus phantom for endoscopy training ii) a multi-material skull base simulator and iii) 3D patient-specific mandible templates. Digital processing of these phantoms is based on real patient or cadaveric 3D images such as CT or MRI data. Three endoscopic sinus surgeons examined the realism of the endoscopist training phantom. One experienced endoscopic skull base surgeon conducted advanced sinus procedures on the high-fidelity multi-material skull base simulator. Ten patients participated in a prospective clinical study examining patient-specific modeling for mandibular reconstructive surgery. Qualitative feedback to assess the realism of the endoscopy training phantom and high-fidelity multi-material phantom was acquired. Conformance comparisons using assessments from the blinded reconstructive surgeons measured the geometric performance between intra-operative and pre-operative reconstruction mandible plates. Both the endoscopy training phantom and the high-fidelity multi-material phantom received positive feedback on the realistic structure of the phantom models. Results suggested further improvement on the soft tissue structure of the phantom models is necessary. In the patient-specific mandible template study, the pre-operative plates were judged by two blinded surgeons as providing optimal conformance in 7 out of 10 cases. No statistical differences were found in plate fabrication time and conformance, with pre-operative plating providing the advantage of reducing time spent in the operation room. The applicability of common model design and fabrication techniques

  4. Rapid Tooling via Investment Casting and Rapid Prototype Patterns

    SciTech Connect

    Baldwin, Michael D.

    1999-06-01

    The objective of this work to develop the materials processing and design technologies required to reduce the die development time for metal mold processes from 12 months to 3 months, using die casting of Al and Mg as the example process. Sandia demonstrated that investment casting, using rapid prototype patterns produced from Stereo lithography or Selective laser Sintering, was a viable alternative/supplement to the current technology of machining form wrought stock. A demonstration die insert (ejector halt) was investment cast and subsequently tested in the die casting environment. The stationary half of the die insert was machined from wrought material to benchmark the cast half. The two inserts were run in a die casting machine for 3,100 shots of aluminum and at the end of the run no visible difference could be detected between the cast and machined inserts. Inspection concluded that the cast insert performed identically to the machined insert. Both inserts had no indications of heat checking or degradation.

  5. Rapid prototyping for biomedical engineering: current capabilities and challenges.

    PubMed

    Lantada, Andrés Díaz; Morgado, Pilar Lafont

    2012-01-01

    A new set of manufacturing technologies has emerged in the past decades to address market requirements in a customized way and to provide support for research tasks that require prototypes. These new techniques and technologies are usually referred to as rapid prototyping and manufacturing technologies, and they allow prototypes to be produced in a wide range of materials with remarkable precision in a couple of hours. Although they have been rapidly incorporated into product development methodologies, they are still under development, and their applications in bioengineering are continuously evolving. Rapid prototyping and manufacturing technologies can be of assistance in every stage of the development process of novel biodevices, to address various problems that can arise in the devices' interactions with biological systems and the fact that the design decisions must be tested carefully. This review focuses on the main fields of application for rapid prototyping in biomedical engineering and health sciences, as well as on the most remarkable challenges and research trends.

  6. Materials Selection and Their Characteristics as Used in Rapid Prototyping

    NASA Technical Reports Server (NTRS)

    Cooper, K.; Salvail, P.; Vesely, E.; Wells, D.

    1999-01-01

    NASA's Marshall Space Flight Center (MSFC) conducted a program to evaluate six technologies used in Rapid Prototyping (RP) to produce investment casting patterns. In this paper, RP refers to the collective additive fabrication technologies known as Solid Free-Form Fabrication. Such technologies are being used with increasing frequency in manufacturing applications, due in part to their rapidly expanding capabilities to fabricate models from many types of materials. This study used ABS plastic, polycarbonate, TrueForm PM6, epoxy resin, paper, starch, and wax. The baseline model was a semi-complex prototype fuel pump housing, intended for use in the X-33 reusable launch vehicle. All models were shelled in a production- grade colloidal silica ceramic. Primary coats were zircon-base flour with zircon backup, while secondary coats were silica grains with a tabular alumina backup. Each model was shelled in an identical manner, using the same atmospheric conditions and drying times, as well as the same number of layers. Bake-outs and firing cycles were consistent with the leach ability of each material. Preheat and bath temperatures were also kept consistent. All molds were cast in vacuum using a hydrogen-resistant superalloy (NASA- 23) that was developed in-house. The final technical evaluation included detailed measurements of the model and the final casting, in order to determine any dimensional changes caused by different pattern materials, as well as documentation of all defects and any obvious refractory/model reactions. Prototype production costs were estimated for each method and taken into consideration during trade-off analysis.

  7. SOT: A rapid prototype using TAE windows

    NASA Technical Reports Server (NTRS)

    Stephens, Mark; Eike, David; Harris, Elfrieda; Miller, Dana

    1986-01-01

    The development of the window interface extension feature of the Transportable Applications Executive (TAE) is discussed. This feature is being used to prototype a space station payload interface in order to demonstrate and assess the benefits of using windows on a bit mapped display and also to convey the concept of telescience, the control and operation of space station payloads from remote sites. The prototype version of the TAE with windows operates on a DEC VAXstation 100. This workstation has a high resolution 19 inch bit mapped display, a keyboard and a three-button mouse. The VAXstation 100 is not a stand-alone workstation, but is controlled by software executing on a VAX/8600. A short scenario was developed utilizing the Solar Optical Telescope (SOT) as an example payload. In the scenario the end-user station includes the VAXstation 100 plus an image analysis terminal used to display the CCD images. The layout and use of the prototype elements, i.e., the root menu, payload status window, and target acquisition menu is described.

  8. Automated Rapid Prototyping of 3D Ceramic Parts

    NASA Technical Reports Server (NTRS)

    McMillin, Scott G.; Griffin, Eugene A.; Griffin, Curtis W.; Coles, Peter W. H.; Engle, James D.

    2005-01-01

    An automated system of manufacturing equipment produces three-dimensional (3D) ceramic parts specified by computational models of the parts. The system implements an advanced, automated version of a generic rapid-prototyping process in which the fabrication of an object having a possibly complex 3D shape includes stacking of thin sheets, the outlines of which closely approximate the horizontal cross sections of the object at their respective heights. In this process, the thin sheets are made of a ceramic precursor material, and the stack is subsequently heated to transform it into a unitary ceramic object. In addition to the computer used to generate the computational model of the part to be fabricated, the equipment used in this process includes: 1) A commercially available laminated-object-manufacturing machine that was originally designed for building woodlike 3D objects from paper and was modified to accept sheets of ceramic precursor material, and 2) A machine designed specifically to feed single sheets of ceramic precursor material to the laminated-object-manufacturing machine. Like other rapid-prototyping processes that utilize stacking of thin sheets, this process begins with generation of the computational model of the part to be fabricated, followed by computational sectioning of the part into layers of predetermined thickness that collectively define the shape of the part. Information about each layer is transmitted to rapid-prototyping equipment, where the part is built layer by layer. What distinguishes this process from other rapid-prototyping processes that utilize stacking of thin sheets are the details of the machines and the actions that they perform. In this process, flexible sheets of ceramic precursor material (called "green" ceramic sheets) suitable for lamination are produced by tape casting. The binder used in the tape casting is specially formulated to enable lamination of layers with little or no applied heat or pressure. The tape is cut

  9. Characteristics of products generated by selective sintering and stereolithography rapid prototyping processes

    NASA Technical Reports Server (NTRS)

    Cariapa, Vikram

    1993-01-01

    The trend in the modern global economy towards free market policies has motivated companies to use rapid prototyping technologies to not only reduce product development cycle time but also to maintain their competitive edge. A rapid prototyping technology is one which combines computer aided design with computer controlled tracking of focussed high energy source (eg. lasers, heat) on modern ceramic powders, metallic powders, plastics or photosensitive liquid resins in order to produce prototypes or models. At present, except for the process of shape melting, most rapid prototyping processes generate products that are only dimensionally similar to those of the desired end product. There is an urgent need, therefore, to enhance the understanding of the characteristics of these processes in order to realize their potential for production. Currently, the commercial market is dominated by four rapid prototyping processes, namely selective laser sintering, stereolithography, fused deposition modelling and laminated object manufacturing. This phase of the research has focussed on the selective laser sintering and stereolithography rapid prototyping processes. A theoretical model for these processes is under development. Different rapid prototyping sites supplied test specimens (based on ASTM 638-84, Type I) that have been measured and tested to provide a data base on surface finish, dimensional variation and ultimate tensile strength. Further plans call for developing and verifying the theoretical models by carefully designed experiments. This will be a joint effort between NASA and other prototyping centers to generate a larger database, thus encouraging more widespread usage by product designers.

  10. Rapid prototyping of database systems in human genetics data collection.

    PubMed

    Gersting, J M

    1987-06-01

    This work examines some of the problems encountered in developing small and large database application systems involving human genetics data collection efforts that include data on individuals as well as family pedigree data. Rapid prototyping of a database application requires software tools to produce the application with little or no programming. Features of MEGADATS-4 that provide for rapid prototyping and for producing stand-alone applications are examined. PMID:3668405

  11. Rapid prototyping of database systems in human genetics data collection.

    PubMed

    Gersting, J M

    1987-06-01

    This work examines some of the problems encountered in developing small and large database application systems involving human genetics data collection efforts that include data on individuals as well as family pedigree data. Rapid prototyping of a database application requires software tools to produce the application with little or no programming. Features of MEGADATS-4 that provide for rapid prototyping and for producing stand-alone applications are examined.

  12. FROM REQUIREMENTS CAPTURE TO SILICON: A MODEL-DRIVEN SYSTEMS ENGINEERING APPROACH TO RAPID DESIGN, PROTOTYPING AND DEVELOPMENT USED IN THE OAK RIDGE NATIONAL LABORATORY'S COGNITIVE RADIO PROGRAM

    SciTech Connect

    Buckner, Mark A; Kaldenbach, Brian J; Nory, Nakhaee; Moore, Michael Roy; Bouldin, Donald; Mills, Jonathan

    2008-01-01

    The performance and complexity of the signal processing hardware accessible to SDR/CR/RADAR designers has quickly out-paced the available design tools. The advances in Digital Signal Processors (DSP) both fixed- and floating-point, Field Programmable Gate Arrays (FPGA), and multicore processors have enabled rapid prototyping and deployment of platforms that can be dynamically reconfigured in the field to implement a variety of SDR/CR/RADAR waveforms. Until recently the process of creating waveforms meant starting with high-level mathematical models and simulations and then creating production quality code that can operate on this variety of specialized hardware using either hand coding or vendor specific tools, which are typically limited to single processor solutions. This paper discusses an integrated model-driven design process and tool-flow used in ORNL's Cognitive Radio Program. It describes how the process and tool-flow are used on a variety of SDR and CR projects and in the development of a software-defined RADAR environment simulator. It describes how, from a single Simulink model, a single deadlock free real-time multiprocessor application is created and executed on a network of heterogeneous processors. We also describe recent progress on extending the process/tool-flow to design digital ASICs and our plans for future extensions. We close by highlighting the benefits being realized from applying this design flow to SDR/CR/RADAR projects at ORNL: (1) a significant reduction in the time required to develop, prototype, implement and test SDR/CR/RADAR waveforms, (2) increased reusability/retargetabilty of SDR/CR/RADAR designs and signal processing library components, (3) the ability to quickly port SDR/CR/RADAR waveforms to different hardware systems and processor types, (4) improvements in documentation, and (5) traceability of system components back to original requirements.

  13. Accuracy and precision of polyurethane dental arch models fabricated using a three-dimensional subtractive rapid prototyping method with an intraoral scanning technique

    PubMed Central

    Kim, Jae-Hong; Kim, Ki-Baek; Kim, Woong-Chul; Kim, Ji-Hwan

    2014-01-01

    Objective This study aimed to evaluate the accuracy and precision of polyurethane (PUT) dental arch models fabricated using a three-dimensional (3D) subtractive rapid prototyping (RP) method with an intraoral scanning technique by comparing linear measurements obtained from PUT models and conventional plaster models. Methods Ten plaster models were duplicated using a selected standard master model and conventional impression, and 10 PUT models were duplicated using the 3D subtractive RP technique with an oral scanner. Six linear measurements were evaluated in terms of x, y, and z-axes using a non-contact white light scanner. Accuracy was assessed using mean differences between two measurements, and precision was examined using four quantitative methods and the Bland-Altman graphical method. Repeatability was evaluated in terms of intra-examiner variability, and reproducibility was assessed in terms of inter-examiner and inter-method variability. Results The mean difference between plaster models and PUT models ranged from 0.07 mm to 0.33 mm. Relative measurement errors ranged from 2.2% to 7.6% and intraclass correlation coefficients ranged from 0.93 to 0.96, when comparing plaster models and PUT models. The Bland-Altman plot showed good agreement. Conclusions The accuracy and precision of PUT dental models for evaluating the performance of oral scanner and subtractive RP technology was acceptable. Because of the recent improvements in block material and computerized numeric control milling machines, the subtractive RP method may be a good choice for dental arch models. PMID:24696823

  14. Rapid prototyping: A paradigm shift in investment casting

    SciTech Connect

    Atwood, C.L.; Maguire, M.C.; Baldwin, M.D.; Pardo, B.T.

    1996-09-01

    The quest for fabricating complex metal parts rapidly and with minimal cost has brought rapid prototyping (RP) processes to the forefront of the investment casting industry. Relatively recent advances in DTM Corporation`s selective laser sintering (SLS) and 3D Systems stereolithography (SL) processes have had a significant impact on the overall quality of patterns produced using these rapid prototyping processes. Sandia National Laboratories uses patterns generated from rapid prototyping processes to reduce the cycle time and cost of fabricating prototype and small lot production parts in support of a program called FASTCAST. The SLS process is used to fabricate patterns from materials such as investment casting wax, polycarbonate, and a new material called TrueForm PM{trademark}. With the timely introduction of each of these materials, the quality of patterns fabricated has improved. The development and implementation of SL QuickCast{trademark} software has enabled this process to produce highly accurate patterns for use in investment casting. This paper focuses on the successes with these new pattern materials and the infrastructure required to cast rapid prototyping patterns successfully. In addition, a brief overview of other applications of rapid prototyping at Sandia will be discussed.

  15. Inspection, 3D modelling, and rapid prototyping of cultural heritage by means of a 3D optical digitiser

    NASA Astrophysics Data System (ADS)

    Docchio, F.; Sansoni, G.; Trebeschi, M.

    2005-06-01

    This paper presents the activity carried out to perform the three-dimensional acquisition of the "Vittoria Alata", a 2m-high, bronze statue, symbol of our City, located at the Civici Musei di Arte e Storia (S. Giulia) of Brescia. The acquisition of the statue has been performed by using a three-dimensional vision system based on active triangulation and on the projection of non-coherent light. This system, called OPL-3D, represents one of the research products of our Laboratory, which has been active for years in the development of techniques and systems for the contactless acquisition of free-form, complex shapes. The study, originally motivated by the need to explore a new hypothesis on the origin of the "Vittoria Alata", led to its complete digitization and description in terms of both polygonal and NURBS-based models. A suite of copies of the whole statue has been obtained in the framework of the collaboration between the City Museum and the EOS Electro Optical Systems GmbH, located in Munich, Germany. As a first step, one 30 cm-high replica of the whole statue has been produced using a low-resolution triangle model of the statue (3.5 millions of triangles). As a second step, two 1:1 scale copies of the statue have been produced. For them, the Laboratory has provided the high resolution STL file (16 millions of triangles). The paper discusses in detail the hardware and the software facilities used to implement the whole process, and gives a comprehensive description of the results.

  16. Minimizing the extra-oral time in autogeneous tooth transplantation: use of computer-aided rapid prototyping (CARP) as a duplicate model tooth

    PubMed Central

    Lee, Seung-Jong

    2012-01-01

    Objectives The maintenance of the healthy periodontal ligament cells of the root surface of donor tooth and intimate surface contact between the donor tooth and the recipient bone are the key factors for successful tooth transplantation. In order to achieve these purposes, a duplicated donor tooth model can be utilized to reduce the extra-oral time using the computer-aided rapid prototyping (CARP) technique. Materials and Methods Briefly, a three-dimensional digital imaging and communication in medicine (DICOM) image with the real dimensions of the donor tooth was obtained from a computed tomography (CT), and a life-sized resin tooth model was fabricated. Dimensional errors between real tooth, 3D CT image model and CARP model were calculated. And extra-oral time was recorded during the autotransplantation of the teeth. Results The average extra-oral time was 7 min 25 sec with the range of immediate to 25 min in cases which extra-oral root canal treatments were not performed while it was 9 min 15 sec when extra-oral root canal treatments were performed. The average radiographic distance between the root surface and the alveolar bone was 1.17 mm and 1.35 mm at mesial cervix and apex; they were 0.98 mm and 1.26 mm at the distal cervix and apex. When the dimensional errors between real tooth, 3D CT image model and CARP model were measured in cadavers, the average of absolute error was 0.291 mm between real teeth and CARP model. Conclusions These data indicate that CARP may be of value in minimizing the extra-oral time and the gap between the donor tooth and the recipient alveolar bone in tooth transplantation. PMID:23431083

  17. Thermal Modeling and Simulation of Electron Beam Melting for Rapid Prototyping on Ti6Al4V Alloys

    NASA Astrophysics Data System (ADS)

    Neira Arce, Alderson

    To be a viable solution for contemporary engineering challenges, the use of titanium alloys in a wider range of applications requires the development of new techniques and processes that are able to decrease production cost and delivery times. As a result, the use of material consolidation in a near-net-shape fashion, using dynamic techniques like additive manufacturing by electron beam selective melting EBSM represents a promising method for part manufacturing. However, a new product material development can be cost prohibitive, requiring the use of computer modeling and simulation as a way to decrease turnaround time. To ensure a proper representation of the EBSM process, a thermophysical material characterization and comparison was first performed on two Ti6Al4V powder feedstock materials prepared by plasma (PREP) and gas atomized (GA) processes. This evaluation comprises an evaluation on particle size distribution, density and powder surface area, collectively with the temperature dependence on properties such as heat capacity, thermal diffusivity, thermal conductivity and surface emissivity. Multiple techniques were employed in this evaluation, including high temperature differential scanning calorimetry (HT-DSC), laser flash analysis (LFA), infrared remote temperature analysis (IR-Thermography), laser diffraction, liquid and gas pycnometry using mercury and krypton adsorption respectively. This study was followed by the review of complementary strategies to simulate the temperature evolution during the EBSM process, using a finite element analysis package called COMSOL Multiphysics. Two alternatives dedicated to representing a moving heat source (electron beam) and the powder bed were developed using a step-by-step approximation initiative. The first method consisted of the depiction of a powder bed discretized on an array of domains, each one representing a static melt pool, where the moving heat source was illustrated by a series of time dependant selective

  18. TOPAZ II Anti-Criticality Device Rapid Prototype

    NASA Astrophysics Data System (ADS)

    Campbell, Donald R.; Otting, William D.

    1994-07-01

    The Ballistic Missile Defense Organization (BMDO) has been working on a Nuclear Electric Propulsion Space Test Project (NEPSTP) using an existing Russian Topaz II reactor system to power the NEPSTP satellite. Safety investigations have shown that it will be possible to safely launch the Topaz II system in the United States with some modification to preclude water flooded criticality. A ``fuel-out'' water subcriticality concept was selected by the Los Alamos National Laboratory (LANL) as the baseline concept. A fuel-out anti-criticality device (ACD) conceptual design was developed by Rockwell. The concept functions to hold the fuel from the four centermost thermionic fuel elements (TFEs) outside the reactor during launch and reliably inserts the fuel into the reactor once the operational orbit is achieved. A four-tenths scale ACD rapid prototype model, fabricated from the CATIA solids design model, clearly shows in three dimensions the relative size and spatial relationship of the ACD components.

  19. Rapid prototyping in the development of image processing systems

    NASA Astrophysics Data System (ADS)

    von der Fecht, Arno; Kelm, Claus Thomas

    2004-08-01

    This contribution presents a rapid prototyping approach for the real-time demonstration of image processing algorithms. As an example EADS/LFK has developed a basic IR target tracking system implementing this approach. Traditionally in research and industry time-independent simulation of image processing algorithms on a host computer is processed. This method is good for demonstrating the algorithms' capabilities. Rarely done is a time-dependent simulation or even a real-time demonstration on a target platform to prove the real-time capabilities. In 1D signal processing applications time-dependent simulation and real-time demonstration has already been used for quite a while. For time-dependent simulation Simulink from The MathWorks has established as an industry standard. Combined with The MathWorks' Real-Time Workshop the simulation model can be transferred to a real-time target processor. The executable is generated automatically by the Real-Time Workshop directly out of the simulation model. In 2D signal processing applications like image processing The Mathworks' Matlab is commonly used for time-independent simulation. To achieve time-dependent simulation and real-time demonstration capabilities the algorithms can be transferred to Simulink, which in fact runs on top of Matlab. Additionally to increase the performance Simulink models or parts of them can be transferred to Xilinx FPGAs using Xilinx' System Generator. With a single model and the automatic workflow both, a time-dependant simulation and the real-time demonstration, are covered leading to an easy and flexible rapid prototyping approach. EADS/LFK is going to use this approach for a wider spectrum of IR image processing applications like automatic target recognition or image based navigation or imaging laser radar target recognition.

  20. Microgravity Manufacturing: Extending Rapid Prototyping Past the Horizon

    NASA Technical Reports Server (NTRS)

    Cooper, Ken

    2003-01-01

    Over the last decade, rapid prototyping (RP) technologies have continued to advance in all aspects of operation and application. From continuously advanced materials and processes development to more hard-core manufacturing uses, the RP realm has stretched considerably past its original expectations as a prototyping capability. This paper discusses the unique applications for which NASA has chosen these manufacturing techniques to be utilized in outer space.

  1. Methods and systems for rapid prototyping of high density circuits

    DOEpatents

    Palmer, Jeremy A.; Davis, Donald W.; Chavez, Bart D.; Gallegos, Phillip L.; Wicker, Ryan B.; Medina, Francisco R.

    2008-09-02

    A preferred embodiment provides, for example, a system and method of integrating fluid media dispensing technology such as direct-write (DW) technologies with rapid prototyping (RP) technologies such as stereolithography (SL) to provide increased micro-fabrication and micro-stereolithography. A preferred embodiment of the present invention also provides, for example, a system and method for Rapid Prototyping High Density Circuit (RPHDC) manufacturing of solderless connectors and pilot devices with terminal geometries that are compatible with DW mechanisms and reduce contact resistance where the electrical system is encapsulated within structural members and manual electrical connections are eliminated in favor of automated DW traces. A preferred embodiment further provides, for example, a method of rapid prototyping comprising: fabricating a part layer using stereolithography and depositing thermally curable media onto the part layer using a fluid dispensing apparatus.

  2. Additive Manufacturing: From Rapid Prototyping to Flight

    NASA Technical Reports Server (NTRS)

    Prater, Tracie

    2015-01-01

    Additive manufacturing (AM) offers tremendous promise for the rocket propulsion community. Foundational work must be performed to ensure the safe performance of AM parts. Government, industry, and academia must collaborate in the characterization, design, modeling, and process control to accelerate the certification of AM parts for human-rated flight.

  3. Rapid algorithm prototyping and implementation for power quality measurement

    NASA Astrophysics Data System (ADS)

    Kołek, Krzysztof; Piątek, Krzysztof

    2015-12-01

    This article presents a Model-Based Design (MBD) approach to rapidly implement power quality (PQ) metering algorithms. Power supply quality is a very important aspect of modern power systems and will become even more important in future smart grids. In this case, maintaining the PQ parameters at the desired level will require efficient implementation methods of the metering algorithms. Currently, the development of new, advanced PQ metering algorithms requires new hardware with adequate computational capability and time intensive, cost-ineffective manual implementations. An alternative, considered here, is an MBD approach. The MBD approach focuses on the modelling and validation of the model by simulation, which is well-supported by a Computer-Aided Engineering (CAE) packages. This paper presents two algorithms utilized in modern PQ meters: a phase-locked loop based on an Enhanced Phase Locked Loop (EPLL), and the flicker measurement according to the IEC 61000-4-15 standard. The algorithms were chosen because of their complexity and non-trivial development. They were first modelled in the MATLAB/Simulink package, then tested and validated in a simulation environment. The models, in the form of Simulink diagrams, were next used to automatically generate C code. The code was compiled and executed in real-time on the Zynq Xilinx platform that combines a reconfigurable Field Programmable Gate Array (FPGA) with a dual-core processor. The MBD development of PQ algorithms, automatic code generation, and compilation form a rapid algorithm prototyping and implementation path for PQ measurements. The main advantage of this approach is the ability to focus on the design, validation, and testing stages while skipping over implementation issues. The code generation process renders production-ready code that can be easily used on the target hardware. This is especially important when standards for PQ measurement are in constant development, and the PQ issues in emerging smart

  4. Can MODIS Data Calibrate and Validate Coastal Sediment Transport Models? Rapid Prototyping Using 250 m Data and the ECOMSED Model for Lake Pontchartrain, LA USA

    NASA Technical Reports Server (NTRS)

    Miller, Richard L.; Georgiou, Ioannis; Glorioso, Mark V.; McCorquodale, J. Alex; Crowder, Keely

    2006-01-01

    Field measurements from small boats and sparse arrays of instrumented buoys often do not provide sufficient data to capture the dynamic nature of biogeophysical parameters in may coastal aquatic environments. Several investigators have shown the MODIS 250 m images can provide daily synoptic views of suspended sediment concentration in coastal waters to determine sediment transport and fate. However, the use of MODIS for coastal environments can be limited due to a lack of cloud-free images. Sediment transport models are not constrained by sky conditions but often suffer from a lack of in situ observations for model calibration or validation. We demonstrate here the utility of MODIS 250 m to calibrate (set model parameters), validate output, and set or reset initial conditions of a hydrodynamic and sediment transport model (ECOMSED) developed for Lake Pontchartrain, LA USA. We present our approach in the context of how to quickly assess of 'prototype' an application of NASA data to support environmental managers and decision makers. The combination of daily MODIS imagery and model simulations offer a more robust monitoring and prediction system of suspended sediments than available from either system alone.

  5. Rapid Prototyping of NASA's Solar and Meteorological Data For Regional Level Modeling of Agricultural and Bio-fuel Crop Phenology and Yield Potential

    NASA Astrophysics Data System (ADS)

    Hoell, J. M.; Stackhouse, P. W.; Eckman, R. S.

    2006-12-01

    fluxes (4 to 7 day lag) produced via the NASA FLASHFlux (Fast Longwave and SHortwave radiative Fluxes) project. We will also discuss a Rapid Prototype Project designed to demonstrate the viability of using the resulting 1-degree resolution regional-to-global meteorological and solar radiation data products as inputs to agricultural based Decision Support Systems for improved production of food, feedstock and bio- fuel crops. The data requirements of these DSS's are discussed including the requirements for timeliness and spatial resolution. These have ramifications for future remote sensing, data analysis and modeling systems to support agricultural applications.

  6. Rapid prototyping polymers for microfluidic devices and high pressure injections.

    PubMed

    Sollier, Elodie; Murray, Coleman; Maoddi, Pietro; Di Carlo, Dino

    2011-11-21

    Multiple methods of fabrication exist for microfluidic devices, with different advantages depending on the end goal of industrial mass production or rapid prototyping for the research laboratory. Polydimethylsiloxane (PDMS) has been the mainstay for rapid prototyping in the academic microfluidics community, because of its low cost, robustness and straightforward fabrication, which are particularly advantageous in the exploratory stages of research. However, despite its many advantages and its broad use in academic laboratories, its low elastic modulus becomes a significant issue for high pressure operation as it leads to a large alteration of channel geometry. Among other consequences, such deformation makes it difficult to accurately predict the flow rates in complex microfluidic networks, change flow speed quickly for applications in stop-flow lithography, or to have predictable inertial focusing positions for cytometry applications where an accurate alignment of the optical system is critical. Recently, other polymers have been identified as complementary to PDMS, with similar fabrication procedures being characteristic of rapid prototyping but with higher rigidity and better resistance to solvents; Thermoset Polyester (TPE), Polyurethane Methacrylate (PUMA) and Norland Adhesive 81 (NOA81). In this review, we assess these different polymer alternatives to PDMS for rapid prototyping, especially in view of high pressure injections with the specific example of inertial flow conditions. These materials are compared to PDMS, for which magnitudes of deformation and dynamic characteristics are also characterized. We provide a complete and systematic analysis of these materials with side-by-side experiments conducted in our lab that also evaluate other properties, such as biocompatibility, solvent compatibility, and ease of fabrication. We emphasize that these polymer alternatives, TPE, PUMA and NOA, have some considerable strengths for rapid prototyping when bond

  7. The Requirements and Design of the Rapid Prototyping Capabilities System

    NASA Astrophysics Data System (ADS)

    Haupt, T. A.; Moorhead, R.; O'Hara, C.; Anantharaj, V.

    2006-12-01

    The Rapid Prototyping Capabilities (RPC) system will provide the capability to rapidly evaluate innovative methods of linking science observations. To this end, the RPC will provide the capability to integrate the software components and tools needed to evaluate the use of a wide variety of current and future NASA sensors, numerical models, and research results, model outputs, and knowledge, collectively referred to as "resources". It is assumed that the resources are geographically distributed, and thus RPC will provide the support for the location transparency of the resources. The RPC system requires providing support for: (1) discovery, semantic understanding, secure access and transport mechanisms for data products available from the known data provides; (2) data assimilation and geo- processing tools for all data transformations needed to match given data products to the model input requirements; (3) model management including catalogs of models and model metadata, and mechanisms for creation environments for model execution; and (4) tools for model output analysis and model benchmarking. The challenge involves developing a cyberinfrastructure for a coordinated aggregate of software, hardware and other technologies, necessary to facilitate RPC experiments, as well as human expertise to provide an integrated, "end-to-end" platform to support the RPC objectives. Such aggregation is to be achieved through a horizontal integration of loosely coupled services. The cyberinfrastructure comprises several software layers. At the bottom, the Grid fabric encompasses network protocols, optical networks, computational resources, storage devices, and sensors. At the top, applications use workload managers to coordinate their access to physical resources. Applications are not tightly bounded to a single physical resource. Instead, they bind dynamically to resources (i.e., they are provisioned) via a common grid infrastructure layer. For the RPC system, the

  8. Rapid prototyping with optical 3D measurement systems

    NASA Astrophysics Data System (ADS)

    Gaessler, J.; Blount, G. N.; Jones, R. M.

    1994-11-01

    One of the important tools for speeding up the prototyping of an new industrial or consumer product is the rapid generation of CAD data from hand-made styling models and moulds. We present a new optical 3D digitizing system which produces in a fully automatic way non- ambiguous, absolute and complete surface coordinate data of very complex objects in a short time. The system named `OptoShape' is based on a projection of sinusoidal fringes with a true grey-level matrix projector. The system measures both non-ambiguous and absolute XYZ surface data with a pronounced robustness towards optical surface properties. By moving the 3D sensor head around the object to be digitized with a 3/5 axes manipulator, multiple range images are obtained and automatically merged into a unified cloud of point coordinates. This set of surface coordinates are transferred to a software package where interactive manipulation, sectioning and semi-automatic generation of CAD surface descriptions are performed. CNC data can also be directly generated from the point surface coordinate data set.

  9. Rapid prototyping: practical approach to enabling reverse engineering

    NASA Astrophysics Data System (ADS)

    Onuh, Spencer; Bennett, Nick; Baker, Jim

    2001-10-01

    It has been reported that Rapid Prototyping (RP) is one of the enablers of Reverse Engineering (RE). Two separate studies have been carried out to verify the degree of the activities of RP as an enabler of RE. These studies which, are both experimental and theoretical in nature, considered two different components that were reversed engineered using CMM, 3D-laser Scanner and ProEngineer CAD package for final model in Stereolithography system. This involves the redesigning of parts using the original component as a template to retrieve the dimensional information required to rebuild the component on a Computer Aided Design (CAD) based program before the alterations can be made to improve it. The main area of studies is concerned with the interlinking of the two processes stated above. More accurately the computer data transfer of the dimensions of the component straight from the CMM or laser scanning machine on to the CAD based program considered, ProEngineer was used for this application. This would produce the model directly from the data transfer without any necessary physical drawing onto ProEngineer. The model production is generated at a considerable speed at minimal cost to ensure the components suitability for its specific use, giving the designer a physical model of the part. The purpose of doing this is to find a way of transferring data from the CMM or Laser Scanner to the RP system without the use of any other software and to cut down on the time and cost of Product development cycle. In this study these have been achieved.

  10. Rapid Prototyping of High Performance Signal Processing Applications

    NASA Astrophysics Data System (ADS)

    Sane, Nimish

    Advances in embedded systems for digital signal processing (DSP) are enabling many scientific projects and commercial applications. At the same time, these applications are key to driving advances in many important kinds of computing platforms. In this region of high performance DSP, rapid prototyping is critical for faster time-to-market (e.g., in the wireless communications industry) or time-to-science (e.g., in radio astronomy). DSP system architectures have evolved from being based on application specific integrated circuits (ASICs) to incorporate reconfigurable off-the-shelf field programmable gate arrays (FPGAs), the latest multiprocessors such as graphics processing units (GPUs), or heterogeneous combinations of such devices. We, thus, have a vast design space to explore based on performance trade-offs, and expanded by the multitude of possibilities for target platforms. In order to allow systematic design space exploration, and develop scalable and portable prototypes, model based design tools are increasingly used in design and implementation of embedded systems. These tools allow scalable high-level representations, model based semantics for analysis and optimization, and portable implementations that can be verified at higher levels of abstractions and targeted toward multiple platforms for implementation. The designer can experiment using such tools at an early stage in the design cycle, and employ the latest hardware at later stages. In this thesis, we have focused on dataflow-based approaches for rapid DSP system prototyping. This thesis contributes to various aspects of dataflow-based design flows and tools as follows: 1. We have introduced the concept of topological patterns, which exploits commonly found repetitive patterns in DSP algorithms to allow scalable, concise, and parameterizable representations of large scale dataflow graphs in high-level languages. We have shown how an underlying design tool can systematically exploit a high

  11. Optimizing the Zilog Z8 FORTH microcontroller for rapid prototyping

    SciTech Connect

    Edwards, R.

    1987-09-01

    This report presents techniques for modifying and extending Zilog Z8 FORTH microcontroller system software to improve its suitability for rapid prototyping, an increasingly popular method of developing new products and services. Rapid prototyping requires special product development methods and tools because it often mandates short term, radical changes in the concept being developed. Use of a high-performance, easily adaptable microcontroller can greatly facilitate a laboratory evaluation of Smart House product prototypes. Such a device can meet numerous sensing and testing needs, including the important function of simulating the operation of Smart House components associated with the one being tested. The techniques described in this report improve Z8 execution rates up to 300% by replacing selected parts of the vendor-supplied FORTH software with routines optimized for speed rather than program size. Also, the report shows how to exploit an unusual Z8 FORTH system feature to simulate a multitasking environment (concurrent execution of several tasks). This information is provided to project participants to help them select development and test equipment for Smart House products. The material is technical in nature and assumes considerable experience in microcontroller technology and microcomputer programming. 6 refs.

  12. Extending NASA Research Results to Benefit Society: Rapid Prototyping for Coastal Applications

    NASA Technical Reports Server (NTRS)

    Glorioso, Mark V.; Miller, Richard L.; Hall, Callie M.; McPherson, Terry R.

    2006-01-01

    The mission of the NASA Applied Sciences Program is to expand and accelerate the use of NASA research results to benefit society in 12 application areas of national priority. ONe of the program's major challenges is to perform a quick, efficient, and detailed review (i.e., prototyping) of the large number of combinations of NASA observations and results from Earth system models that may be used by a wide range of decision support tools. A Rapid Prototyping Capacity (RPC) is being developed to accelerate the use of NASA research results. Here, we present the conceptual framework of the Rapid Prototyping Capacity within the context of quickly assessing the efficacy of NASA research results and technologies to support the Coastal Management application. An initial RPC project designed to quickly evaluate the utility of moderate-resolution MODIS products for calibrating/validating coastal sediment transport models is also presented.

  13. Rapid Prototyping of Nanofluidic Slits in a Silicone Bilayer

    PubMed Central

    Kole, Thomas P.; Liao, Kuo-Tang; Schiffels, Daniel; Ilic, B. Robert; Strychalski, Elizabeth A.; Kralj, Jason G.; Liddle, J. Alexander; Dritschilo, Anatoly; Stavis, Samuel M.

    2015-01-01

    This article reports a process for rapidly prototyping nanofluidic devices, particularly those comprising slits with microscale widths and nanoscale depths, in silicone. This process consists of designing a nanofluidic device, fabricating a photomask, fabricating a device mold in epoxy photoresist, molding a device in silicone, cutting and punching a molded silicone device, bonding a silicone device to a glass substrate, and filling the device with aqueous solution. By using a bilayer of hard and soft silicone, we have formed and filled nanofluidic slits with depths of less than 400 nm and aspect ratios of width to depth exceeding 250 without collapse of the slits. An important attribute of this article is that the description of this rapid prototyping process is very comprehensive, presenting context and details which are highly relevant to the rational implementation and reliable repetition of the process. Moreover, this process makes use of equipment commonly found in nanofabrication facilities and research laboratories, facilitating the broad adaptation and application of the process. Therefore, while this article specifically informs users of the Center for Nanoscale Science and Technology (CNST) at the National Institute of Standards and Technology (NIST), we anticipate that this information will be generally useful for the nanofabrication and nanofluidics research communities at large, and particularly useful for neophyte nanofabricators and nanofluidicists. PMID:26958449

  14. [A rapid prototype fabrication method of dental splint based on 3D simulation and technology].

    PubMed

    Lin, Yanping; Chen, Xiaojun; Zhang, Shilei; Wang, Chengtao

    2006-04-01

    The conventional design and fabrication of the dental splint (in orthognathic surgery) is based on the preoperative planning and model surgery so this process is of low precision and efficiency. In order to solve the problems and be up to the trend of computer-assisted surgery, we have developed a novel method to design and fabricate the dental splint--computer-generated dental splint, which is based on three-dimensional model simulation and rapid prototype technology. After the surgical planning and simulation of 3D model, we can modify the model to be superior in chewing action (functional) and overall facial appearance (aesthetic). Then, through the Boolean operation of the dental splint blank and the maxillofacial bone model the model of dental splint is formed. At last, the dental splint model is fabricated through rapid prototype machine and applied in clinic. The result indicates that, with the use of this method, the surgical precision and efficiency are improved.

  15. Application of Rapid Prototyping Methods to High-Speed Wind Tunnel Testing

    NASA Technical Reports Server (NTRS)

    Springer, A. M.

    1998-01-01

    This study was undertaken in MSFC's 14-Inch Trisonic Wind Tunnel to determine if rapid prototyping methods could be used in the design and manufacturing of high speed wind tunnel models in direct testing applications, and if these methods would reduce model design/fabrication time and cost while providing models of high enough fidelity to provide adequate aerodynamic data, and of sufficient strength to survive the test environment. Rapid prototyping methods utilized to construct wind tunnel models in a wing-body-tail configuration were: fused deposition method using both ABS plastic and PEEK as building materials, stereolithography using the photopolymer SL-5170, selective laser sintering using glass reinforced nylon, and laminated object manufacturing using plastic reinforced with glass and 'paper'. This study revealed good agreement between the SLA model, the metal model with an FDM-ABS nose, an SLA nose, and the metal model for most operating conditions, while the FDM-ABS data diverged at higher loading conditions. Data from the initial SLS model showed poor agreement due to problems in post-processing, resulting in a different configuration. A second SLS model was tested and showed relatively good agreement. It can be concluded that rapid prototyping models show promise in preliminary aerodynamic development studies at subsonic, transonic, and supersonic speeds.

  16. Rapid laser prototyping of valves for microfluidic autonomous systems

    NASA Astrophysics Data System (ADS)

    Mohammed, M. I.; Abraham, E.; Y Desmulliez, M. P.

    2013-03-01

    Capillary forces in microfluidics provide a simple yet elegant means to direct liquids through flow channel networks. The ability to manipulate the flow in a truly automated manner has proven more problematic. The majority of valves require some form of flow control devices, which are manually, mechanically or electrically driven. Most demonstrated capillary systems have been manufactured by photolithography, which, despite its high precision and repeatability, can be labour intensive, requires a clean room environment and the use of fixed photomasks, limiting thereby the agility of the manufacturing process to readily examine alternative designs. In this paper, we describe a robust and rapid CO2 laser manufacturing process and demonstrate a range of capillary-driven microfluidic valve structures embedded within a microfluidic network. The manufacturing process described allows for advanced control and manipulation of fluids such that flow can be halted, triggered and delayed based on simple geometrical alterations to a given microchannel. The rapid prototyping methodology has been employed with PMMA substrates and a complete device has been created, ready for use, within 2-3 h. We believe that this agile manufacturing process can be applied to produce a range of complex autonomous fluidic platforms and allows subsequent designs to be rapidly explored.

  17. Evaluation of a complete denture trial method applying rapid prototyping.

    PubMed

    Inokoshi, Masanao; Kanazawa, Manabu; Minakuchi, Shunsuke

    2012-02-01

    A new trial method for complete dentures using rapid prototyping (RP) was compared with the conventional method. Wax dentures were fabricated for 10 edentulous patients. Cone-beam CT was used to scan the wax dentures. Using 3D computer-aided design software, seven 3D denture images with different artificial teeth arrangements were made and seven trial dentures per patient were fabricated accordingly. Two prosthodontists performed a denture try-in for one patient using both conventional and RP methods. The prosthodontists and patients rated satisfaction for both methods using a visual analogue scale. Satisfaction ratings with both conventional and RP methods were compared using the Wilcoxon signed-rank test. Regarding prosthodontist's ratings, esthetics and stability were rated significantly higher with the conventional method than with the RP method, whereas chair time was rated significantly longer with the RP method than with the conventional method. Although further improvements are needed, the trial method applying RP seems promising.

  18. Advanced Propulsion and TPS for a Rapidly-Prototyped CEV

    NASA Astrophysics Data System (ADS)

    Hudson, Gary C.

    2005-02-01

    Transformational Space Corporation (t/Space) is developing for NASA the initial designs for the Crew Exploration Vehicle family, focusing on a Launch CEV for transporting NASA and civilian passengers from Earth to orbit. The t/Space methodology is rapid prototyping of major vehicle systems, and deriving detailed specifications from the resulting hardware, avoiding "written-in-advance" specs that can force the costly invention of new capabilities simply to meet such specs. A key technology shared by the CEV family is Vapor Pressurized propulsion (Vapak) for simplicity and reliability, which provides electrical power, life support gas and a heat sink in addition to propulsion. The CEV family also features active transpiration cooling of re-entry surfaces (for reusability) backed up by passive thermal protection.

  19. Micromachining Lithium Niobate for Rapid Prototyping of Resonant Biosensors

    NASA Astrophysics Data System (ADS)

    Abdoon Al-Shibaany, Zeyad Yousif; Hedley, John; Huo, Dehong; Hu, Zhongxu

    2014-07-01

    Lithium niobate material is widely used in MEMS application due to its piezoelectric properties. This paper presents the micromachining process of lithium niobate to rapid prototype a resonant biosensor design. A high precision CNC machine was used to machine a sample of lithium niobate material at 5 different spindle speeds to find out the best conditions to machine this brittle material. A qualitative visual check of the surface was performed by using scanning electron microscopy, surface roughness was quantitatively investigated using an optical surface profiler and Raman spectroscopy to check the strain of the surface. Results show that the surface quality of the lithium niobate was significantly affected by the spindle speed with optimum conditions at 70k rpm giving a strained surface with 500 nm rms roughness.

  20. Modeling mechanical signals on the surface of µCT and CAD based rapid prototype scaffold models to predict (early stage) tissue development.

    PubMed

    Hendrikson, W J; van Blitterswijk, C A; Verdonschot, N; Moroni, L; Rouwkema, J

    2014-09-01

    In the field of tissue engineering, mechano-regulation theories have been applied to help predict tissue development in tissue engineering scaffolds in the past. For this, finite element models (FEMs) were used to predict the distribution of strains within a scaffold. However, the strains reported in these studies are volumetric strains of the material or strains developed in the extracellular matrix occupying the pore space. The initial phase of cell attachment and growth on the biomaterial surface has thus far been neglected. In this study, we present a model that determines the magnitude of biomechanical signals on the biomaterial surface, enabling us to predict cell differentiation stimulus values at this initial stage. Results showed that magnitudes of the 2D strain--termed surface strain--were lower when compared to the 3D volumetric strain or the conventional octahedral shear strain as used in current mechano-regulation theories. Results of both µCT and CAD derived FEMs from the same scaffold were compared. Strain and fluid shear stress distributions, and subsequently the cell differentiation stimulus, were highly dependent on the pore shape. CAD models were not able to capture the distributions seen in the µCT FEM. The calculated mechanical stimuli could be combined with current mechanobiological models resulting in a tool to predict cell differentiation in the initial phase of tissue engineering. Although experimental data is still necessary to properly link mechanical signals to cell behavior in this specific setting, this model is an important step towards optimizing scaffold architecture and/or stimulation regimes. PMID:24824318

  1. Modeling mechanical signals on the surface of µCT and CAD based rapid prototype scaffold models to predict (early stage) tissue development.

    PubMed

    Hendrikson, W J; van Blitterswijk, C A; Verdonschot, N; Moroni, L; Rouwkema, J

    2014-09-01

    In the field of tissue engineering, mechano-regulation theories have been applied to help predict tissue development in tissue engineering scaffolds in the past. For this, finite element models (FEMs) were used to predict the distribution of strains within a scaffold. However, the strains reported in these studies are volumetric strains of the material or strains developed in the extracellular matrix occupying the pore space. The initial phase of cell attachment and growth on the biomaterial surface has thus far been neglected. In this study, we present a model that determines the magnitude of biomechanical signals on the biomaterial surface, enabling us to predict cell differentiation stimulus values at this initial stage. Results showed that magnitudes of the 2D strain--termed surface strain--were lower when compared to the 3D volumetric strain or the conventional octahedral shear strain as used in current mechano-regulation theories. Results of both µCT and CAD derived FEMs from the same scaffold were compared. Strain and fluid shear stress distributions, and subsequently the cell differentiation stimulus, were highly dependent on the pore shape. CAD models were not able to capture the distributions seen in the µCT FEM. The calculated mechanical stimuli could be combined with current mechanobiological models resulting in a tool to predict cell differentiation in the initial phase of tissue engineering. Although experimental data is still necessary to properly link mechanical signals to cell behavior in this specific setting, this model is an important step towards optimizing scaffold architecture and/or stimulation regimes.

  2. Rapid Prototyping of Continuous Fiber Reinforced Ceramic Matrix Composites

    NASA Technical Reports Server (NTRS)

    Vaidyanathan, R.; Green, C.; Phillips, T.; Cipriani, R.; Yarlagadda, S.; Gillespie, J.; Effinger, M.; Cooper, K. C.; Gordon, Gail (Technical Monitor)

    2002-01-01

    For ceramics to be used as structural components in high temperature applications, their fracture toughness is improved by embedding continuous ceramic fibers. Ceramic matrix composite (CMC) materials allow increasing the overall operating temperature, raising the temperature safety margins, avoiding the need for cooling, and improving the damping capacity, while reducing the weight at the same time. They also need to be reliable and available in large quantities as well. In this paper, an innovative rapid prototyping technique to fabricate continuous fiber reinforced ceramic matrix composites is described. The process is simple, robust and will be widely applicable to a number of high temperature material systems. This technique was originally developed at the University of Delaware Center for Composite Materials (UD-CCM) for rapid fabrication of polymer matrix composites by a technique called automated tow placement or ATP. The results of mechanical properties and microstructural characterization are presented, together with examples of complex shapes and parts. It is believed that the process will be able to create complex shaped parts at an order of magnitude lower cost than current CVI and PIP processes.

  3. Rapid prototyping of PDMS devices using SU-8 lithography.

    PubMed

    Jenkins, Gareth

    2013-01-01

    This protocol describes the fabrication of single and multi-layer SU-8 microstructures for generating microfluidic devices via PDMS (polymethyldisiloxane) casting. SU-8 is a negative, thick-film, epoxy based photoresist that has become widespread in the MEMS industry for producing durable, high aspect ratio microstructures for a variety of applications. It has become especially popular with microfluidics researchers to produce molds for PDMS casting since such molds allow for the rapid replication of prototype microfluidic structures made from PDMS. Although SU-8 processing does allow for rapid and straightforward development of devices it is prone to numerous pitfalls which have gained it a reputation of being somewhat of a "black art." This protocol attempts to give as full an account as possible of all the tricks and tips the author has learned over the years for processing SU-8. It also describes the casting of PDMS and plasma bonding for the generation of complete microfluidic devices ready for use in the lab.

  4. Rapid Prototyping of Continuous Fiber Reinforced Ceramic Matrix Composites

    NASA Technical Reports Server (NTRS)

    Vaidyanathan, R.; Green, C.; Phillips, T.; Cipriani, R.; Yarlagadda, S.; Gillespie, J. W., Jr.; Effinger, M.; Cooper, K. C.

    2003-01-01

    For ceramics to be used as structural components in high temperature applications, their fracture toughness is improved by embedding continuous ceramic fibers. Ceramic matrix composite (CMC) materials allow increasing the overall operating temperature, raising the temperature safety margins, avoiding the need for cooling, and improving the damping capacity, while reducing the weight at the same time. They also need to be reliable and available in large quantities as well. In this paper, an innovative rapid prototyping technique to fabricate continuous fiber reinforced ceramic matrix composites is described. The process is simple, robust and will be widely applicable to a number of high temperature material systems. This technique was originally developed at the University of Delaware Center for Composite Materials (UD-CCM) for rapid fabrication of polymer matrix composites by a technique called automated tow placement or ATP. The results of mechanical properties and microstructural characterization are presented, together with examples of complex shapes and parts. It is believed that the process will be able to create complex shaped parts at an order of magnitude lower cost than current chemical vapor infiltration (CVI) and polymer impregnation and pyrolysis (PIP) processes.

  5. An Example of Economic Value in Rapid Prototyping

    NASA Technical Reports Server (NTRS)

    Hauer, R. L.; Braunscheidel, E. P.

    2001-01-01

    Today's modern machining projects are composed more and more of complicated and intricate structure due to a variety of reasons including the ability to computer model complex surfaces and forms. The cost of producing these forms can be extremely high not only in dollars but in time to complete. Changes are even more difficult to incorporate. The subject blade shown is an excellent example. Its complex form would have required hundreds of hours in fabrication for just a simple prototype. The procurement would have taken in the neighborhood of six weeks to complete. The actual fabrication would have been an equal amount of time to complete. An alternative to this process would have been a wood model. Although cheaper than a metal fabrication, it would be extremely time intensive and require in the neighborhood of a month to produce in-house.

  6. Preliminary work toward the development of a dimensional tolerance standard for rapid prototyping

    NASA Technical Reports Server (NTRS)

    Kennedy, W. J.

    1996-01-01

    Rapid prototyping is a new technology for building parts quickly from CAD models. It works by slicing a CAD model into layers, then by building a model of the part one layer at a time. Since most parts can be sliced, most parts can be modeled using rapid prototyping. The layers themselves are created in a number of different ways - by using a laser to cure a layer of an epoxy or a resin, by depositing a layer of plastic or wax upon a surface, by using a laser to sinter a layer of powder, or by using a laser to cut a layer of paper. Rapid prototyping (RP) is new, and a standard part for use in comparing dimensional tolerances has not yet been chosen and accepted by ASTM (the American Society for Testing Materials). Such a part is needed when RP is used to build parts for investment casting or for direct use. The objective of this project was to start the development of a standard part by using statistical techniques to choose the features of the part which show curl - the vertical deviation of a part from its intended horizontal plane.

  7. Rapid Prototyping Technology in Orbital Floor Reconstruction: Application in Three Patients

    PubMed Central

    Lim, Christopher G. T.; Campbell, Duncan I.; Clucas, Don M.

    2014-01-01

    Rapid prototyping entails the fabrication of three-dimensional anatomical models which provide an accurate and cost-effective method to visualize complex anatomical structures. Our unit has been using this to assist in the diagnosis, planning, and preoperative titanium plate adaptation for orbital reconstruction surgery following traumatic injury. The aim of this article is to demonstrate the potential clinical and cost-saving benefits of this technology. PMID:25050149

  8. Airplane numerical simulation for the rapid prototyping process

    NASA Astrophysics Data System (ADS)

    Roysdon, Paul F.

    Airplane Numerical Simulation for the Rapid Prototyping Process is a comprehensive research investigation into the most up-to-date methods for airplane development and design. Uses of modern engineering software tools, like MatLab and Excel, are presented with examples of batch and optimization algorithms which combine the computing power of MatLab with robust aerodynamic tools like XFOIL and AVL. The resulting data is demonstrated in the development and use of a full non-linear six-degrees-of-freedom simulator. The applications for this numerical tool-box vary from un-manned aerial vehicles to first-order analysis of manned aircraft. A Blended-Wing-Body airplane is used for the analysis to demonstrate the flexibility of the code from classic wing-and-tail configurations to less common configurations like the blended-wing-body. This configuration has been shown to have superior aerodynamic performance -- in contrast to their classic wing-and-tube fuselage counterparts -- and have reduced sensitivity to aerodynamic flutter as well as potential for increased engine noise abatement. Of course without a classic tail elevator to damp the nose up pitching moment, and the vertical tail rudder to damp the yaw and possible rolling aerodynamics, the challenges in lateral roll and yaw stability, as well as pitching moment are not insignificant. This thesis work applies the tools necessary to perform the airplane development and optimization on a rapid basis, demonstrating the strength of this tool through examples and comparison of the results to similar airplane performance characteristics published in literature.

  9. Risk D&D Rapid Prototype: Scenario Documentation and Analysis Tool

    SciTech Connect

    Unwin, Stephen D.; Seiple, Timothy E.

    2009-05-28

    Report describes process and methodology associated with a rapid prototype tool for integrating project risk analysis and health & safety risk analysis for decontamination and decommissioning projects.

  10. Rapid prototyping for radio-frequency geolocation applications

    SciTech Connect

    Briles, S. C.; Arrowood, J. L.; Braun, T. R.; Turcotte, D.; Fiset, E.

    2004-01-01

    Previous space-to-ground, single-platform geolocation experiments exploiting time-difference-of arrival (TDOA) via interferometry were successful at separating and quantitatively characterizing interfering radio frequency (RF) signals from expected RF transmissions. Much of the success of these experiments rested on the use of embedded processors to perform the required signal processing. The experiments handled data in a 'snapshot' fashion: digitized data was collected, the data was processed via a digital signal processing (DSP) microprocessor to yield differential phase measurements, and these measurements were transmitted to the Earth for geolocation processing. With the utilization of FPGAs (field programmable gate arrays) for the intensive number-crunching algorithms, the processing of streaming real-time data is feasible for bandwidths on the order of 20 MHz. By partitioning the signal processing algorithm so there is a significant reduction in the data rate as data flows through the FPGA, a DSP microprocessor can now be employed to perform further decision-oriented processing on the FPGA output. This hybrid architecture, employing both FPGAs and DSPs, typically requires an expensive and lengthy development cycle. However, the use of graphical development environments with auto-code generation and hardware-in-the-loop testing can result in rapid prototyping for geolocation experiments, which enables adaptation to emerging signals of interest in a cost and time effective manner.

  11. Integrated flexible manufacturing program for manufacturing automation and rapid prototyping

    NASA Technical Reports Server (NTRS)

    Brooks, S. L.; Brown, C. W.; King, M. S.; Simons, W. R.; Zimmerman, J. J.

    1993-01-01

    The Kansas City Division of Allied Signal Inc., as part of the Integrated Flexible Manufacturing Program (IFMP), is developing an integrated manufacturing environment. Several systems are being developed to produce standards and automation tools for specific activities within the manufacturing environment. The Advanced Manufacturing Development System (AMDS) is concentrating on information standards (STEP) and product data transfer; the Expert Cut Planner system (XCUT) is concentrating on machining operation process planning standards and automation capabilities; the Advanced Numerical Control system (ANC) is concentrating on NC data preparation standards and NC data generation tools; the Inspection Planning and Programming Expert system (IPPEX) is concentrating on inspection process planning, coordinate measuring machine (CMM) inspection standards and CMM part program generation tools; and the Intelligent Scheduling and Planning System (ISAPS) is concentrating on planning and scheduling tools for a flexible manufacturing system environment. All of these projects are working together to address information exchange, standardization, and information sharing to support rapid prototyping in a Flexible Manufacturing System (FMS) environment.

  12. Rapid prototyping of biomimetic vascular phantoms for hyperspectral reflectance imaging.

    PubMed

    Ghassemi, Pejhman; Wang, Jianting; Melchiorri, Anthony J; Ramella-Roman, Jessica C; Mathews, Scott A; Coburn, James C; Sorg, Brian S; Chen, Yu; Pfefer, T Joshua

    2015-01-01

    The emerging technique of rapid prototyping with three-dimensional (3-D) printers provides a simple yet revolutionary method for fabricating objects with arbitrary geometry. The use of 3-D printing for generating morphologically biomimetic tissue phantoms based on medical images represents a potentially major advance over existing phantom approaches. Toward the goal of image-defined phantoms, we converted a segmented fundus image of the human retina into a matrix format and edited it to achieve a geometry suitable for printing. Phantoms with vessel-simulating channels were then printed using a photoreactive resin providing biologically relevant turbidity, as determined by spectrophotometry. The morphology of printed vessels was validated by x-ray microcomputed tomography. Channels were filled with hemoglobin (Hb) solutions undergoing desaturation, and phantoms were imaged with a near-infrared hyperspectral reflectance imaging system. Additionally, a phantom was printed incorporating two disjoint vascular networks at different depths, each filled with Hb solutions at different saturation levels. Light propagation effects noted during these measurements—including the influence of vessel density and depth on Hb concentration and saturation estimates, and the effect of wavelength on vessel visualization depth—were evaluated. Overall, our findings indicated that 3-D-printed biomimetic phantoms hold significant potential as realistic and practical tools for elucidating light–tissue interactions and characterizing biophotonic system performance. PMID:26662064

  13. Rapid prototyping of biomimetic vascular phantoms for hyperspectral reflectance imaging

    NASA Astrophysics Data System (ADS)

    Ghassemi, Pejhman; Wang, Jianting; Melchiorri, Anthony J.; Ramella-Roman, Jessica C.; Mathews, Scott A.; Coburn, James C.; Sorg, Brian S.; Chen, Yu; Joshua Pfefer, T.

    2015-12-01

    The emerging technique of rapid prototyping with three-dimensional (3-D) printers provides a simple yet revolutionary method for fabricating objects with arbitrary geometry. The use of 3-D printing for generating morphologically biomimetic tissue phantoms based on medical images represents a potentially major advance over existing phantom approaches. Toward the goal of image-defined phantoms, we converted a segmented fundus image of the human retina into a matrix format and edited it to achieve a geometry suitable for printing. Phantoms with vessel-simulating channels were then printed using a photoreactive resin providing biologically relevant turbidity, as determined by spectrophotometry. The morphology of printed vessels was validated by x-ray microcomputed tomography. Channels were filled with hemoglobin (Hb) solutions undergoing desaturation, and phantoms were imaged with a near-infrared hyperspectral reflectance imaging system. Additionally, a phantom was printed incorporating two disjoint vascular networks at different depths, each filled with Hb solutions at different saturation levels. Light propagation effects noted during these measurements-including the influence of vessel density and depth on Hb concentration and saturation estimates, and the effect of wavelength on vessel visualization depth-were evaluated. Overall, our findings indicated that 3-D-printed biomimetic phantoms hold significant potential as realistic and practical tools for elucidating light-tissue interactions and characterizing biophotonic system performance.

  14. Improved rapid prototyping methodology for MPEG-4 IC development

    NASA Astrophysics Data System (ADS)

    Tang, Clive K. K.; Moseler, Kathy; Levi, Sami

    1998-12-01

    One important factor in deciding the success of a new consumer product or integrated circuit is minimized time-to- market. A rapid prototyping methodology that encompasses algorithm development in the hardware design phase will have great impact on reducing time-to-market. In this paper, a proven hardware design methodology and a novel top-down design methodology based on Frontier Design's DSP Station tool are described. The proven methodology was used during development of the MC149570 H.261/H.263 video codec manufactured by Motorola. This paper discusses an improvement to this method to create an integrated environment for both system and hardware development, thereby further reducing the time-to-market. The software tool chosen is DSP Station tool by Frontier Design. The rich features of DSP Station tool will be described and then it will be shown how these features may be useful in designing from algorithm to silicon. How this methodology may be used in the development of a new MPEG4 Video Communication ASIC will be outlined. A brief comparison with a popular tool, Signal Processing WorkSystem tool by Cadence, will also be given.

  15. Numerical and experimental investigation of molten metal droplet deposition applied to rapid prototyping

    NASA Astrophysics Data System (ADS)

    Li, SuLi; Wei, ZhengYing; Du, Jun; Zhao, Guangxi; Wang, Xin; Lu, BingHeng

    2016-08-01

    Rapid prototyping based on molten metal droplets deposition is an additive process in which parts are produced from molten materials in a single operation without the use of any mold or other tooling. Near-net shaped parts are fabricated by sequentially depositing molten droplets layer by layer. This paper presents a systematic numerical and experimental investigation of the transient transport phenomenon during the droplets impinging onto a substrate surface. The 3D models based on a volume of fluid (VOF) method were developed to investigate the deposition of molten metal droplets on a horizontally aluminum substrate surface. Based on the above research, a semiquantitative relationship between external morphology and internal microstructure was proposed, which was further certified by investigating the piled vertical columns and the three-dimensional parts. The works should be helpful for the process optimization and non-destructive detection of drop-based rapid prototyping techniques.

  16. Rapid optimization and prototyping for therapeutic antibody-like molecules

    PubMed Central

    Xu, Lihui; Kohli, Neeraj; Rennard, Rachel; Jiao, Yang; Razlog, Maja; Zhang, Kathy; Baum, Jason; Johnson, Bryan; Tang, Jian; Schoeberl, Birgit; Fitzgerald, Jonathan; Nielsen, Ulrik; Lugovskoy, Alexey A.

    2013-01-01

    Multispecific antibody-like molecules have the potential to advance the standard-of-care in many human diseases. The design of therapeutic molecules in this class, however, has proven to be difficult and, despite significant successes in preclinical research, only one trivalent antibody, catumaxomab, has demonstrated clinical utility. The challenge originates from the complexity of the design space where multiple parameters such as affinity, avidity, effector functions, and pharmaceutical properties need to be engineered in concurrent fashion to achieve the desired therapeutic efficacy. Here, we present a rapid prototyping approach that allows us to successfully optimize these parameters within one campaign cycle that includes modular design, yeast display of structure focused antibody libraries and high throughput biophysical profiling. We delineate this approach by presenting a design case study of MM-141, a tetravalent bispecific antibody targeting two compensatory signaling growth factor receptors: insulin-like growth factor 1 receptor (IGF-1R) and v-erb-b2 erythroblastic leukemia viral oncogene homolog 3 (ErbB3). A MM-141 proof-of-concept (POC) parent molecule did not meet initial design criteria due to modest bioactivity and poor stability properties. Using a combination of yeast display, structured-guided antibody design and library-scale thermal challenge assay, we discovered a diverse set of stable and active anti-IGF-1R and anti-ErbB3 single-chain variable fragments (scFvs). These optimized modules were reformatted to create a diverse set of full-length tetravalent bispecific antibodies. These re-engineered molecules achieved complete blockade of growth factor induced pro-survival signaling, were stable in serum, and had adequate activity and pharmaceutical properties for clinical development. We believe this approach can be readily applied to the optimization of other classes of bispecific or even multispecific antibody-like molecules. PMID:23392215

  17. Permeability of rapid prototyped artificial bone scaffold structures.

    PubMed

    Lipowiecki, Marcin; Ryvolová, Markéta; Töttösi, Ákos; Kolmer, Niels; Naher, Sumsun; Brennan, Stephen A; Vázquez, Mercedes; Brabazon, Dermot

    2014-11-01

    In this work, various three-dimensional (3D) scaffolds were produced via micro-stereolithography (µ-SLA) and 3D printing (3DP) techniques. This work demonstrates the advantages and disadvantages of these two different rapid prototyping methods for production of bone scaffolds. Compared to 3DP, SLA provides for smaller feature production with better dimensional resolution and accuracy. The permeability of these structures was evaluated experimentally and via numerical simulation utilizing a newly derived Kozeny-Carman based equation for intrinsic permeability. Both experimental and simulation studies took account of porosity percentage, pore size, and pore geometry. Porosity content was varied from 30% to 70%, pore size from 0.34 mm to 3 mm, and pore geometries of cubic and hexagonal closed packed were examined. Two different fluid viscosity levels of 1 mPa · s and 3.6 mPa · s were used. The experimental and theoretical results indicated that permeability increased when larger pore size, increased fluid viscosity, and higher percentage porosity were utilized, with highest to lowest degree of significance following the same order. Higher viscosity was found to result in permeabilities 2.2 to 3.3 times higher than for water. This latter result was found to be independent of pore morphology type. As well as demonstrating method for determining design parameters most beneficial for scaffold structure design, the results also illustrate how the variations in patient's blood viscosity can be extremely important in allowing for permeability through the bone and scaffold structures.

  18. Using Rapid Prototyping to Design a Smoking Cessation Website with End-Users.

    PubMed

    Ronquillo, Charlene; Currie, Leanne; Rowsell, Derek; Phillips, J Craig

    2016-01-01

    Rapid prototyping is an iterative approach to design involving cycles of prototype building, review by end-users and refinement, and can be a valuable tool in user-centered website design. Informed by various user-centered approaches, we used rapid prototyping as a tool to collaborate with users in building a peer-support focused smoking-cessation website for gay men living with HIV. Rapid prototyping was effective in eliciting feedback on the needs of this group of potential end-users from a smoking cessation website. PMID:27332420

  19. An application generator for rapid prototyping of Ada real-time control software

    NASA Technical Reports Server (NTRS)

    Johnson, Jim; Biglari, Haik; Lehman, Larry

    1990-01-01

    The need to increase engineering productivity and decrease software life cycle costs in real-time system development establishes a motivation for a method of rapid prototyping. The design by iterative rapid prototyping technique is described. A tool which facilitates such a design methodology for the generation of embedded control software is described.

  20. Simulation of the Fissureless Technique for Thoracoscopic Segmentectomy Using Rapid Prototyping

    PubMed Central

    Nakada, Takeo; Inagaki, Takuya

    2014-01-01

    The fissureless lobectomy or anterior fissureless technique is a novel surgical technique, which avoids dissection of the lung parenchyma over the pulmonary artery during lobectomy by open thoracotomy approach or direct vision thoracoscopic surgery. This technique is indicated for fused lobes. We present two cases where thoracoscopic pulmonary segmentectomy was performed using the fissureless technique simulated by three-dimensional (3D) pulmonary models. The 3D model and rapid prototyping provided an accurate anatomical understanding of the operative field in both cases. We believe that the construction of these models is useful for thoracoscopic and other complicated surgeries of the chest. PMID:24633132

  1. The application of rapid prototyping techniques in cranial reconstruction and preoperative planning in neurosurgery.

    PubMed

    Müller, Adolf; Krishnan, Kartik G; Uhl, Eberhard; Mast, Gerson

    2003-11-01

    The value of rapid prototype models of the skull in our craniofacial and neurosurgical practice was analyzed. Individual skull models of 52 patients were produced by means of rapid prototyping techniques and used in various procedures. Patients were divided into three groups as follows: group I (26 patients) requiring corrective cranioplasty 1) after resection of osseous tumors (15 patients) and 2) with congenital and posttraumatic craniofacial deformities (11 patients), group II (10 patients) requiring reconstructive cranioplasty, and group III (16 patients) requiring planning of difficult skull base approaches. The utility of the stereolithographic models was assessed using the Gillespie scoring system. The esthetic and clinical outcomes were assessed by means of the esthetic outcome score and the Glasgow Outcome Score, respectively. Simulation of osteotomies for advancement plasty and craniofacial reassembly in the model before surgery in group I reduced operating time and intraoperative errors. In group II, the usefulness of the models depended directly on the size and configuration of the cranial defect. The planning of approaches to uncommon and complex skull base tumors (group III) was significantly influenced by the stereolithographic models. The esthetic outcome was pleasing. The indications for the manufacture of individual three-dimensional models could be cases of craniofacial dysmorphism that require meticulous preoperative planning and skull base surgery with difficult anatomical and reconstructive problems. The stereolithographic models provide 1) better understanding of the anatomy, 2) presurgical simulation, 3) intraoperative accuracy in localization of lesions, 4) accurate fabrication of implants, and 5) improved education of trainees. PMID:14600634

  2. Concept of using a benchmark part to evaluate rapid prototype processes

    NASA Technical Reports Server (NTRS)

    Cariapa, Vikram

    1994-01-01

    A conceptual benchmark part for guiding manufacturers and users of rapid prototyping technologies is proposed. This is based on a need to have some tool to evaluate the development of this technology and to assist the user in judiciously selecting a process. The benchmark part is designed to have unique product details and features. The extent to which a rapid prototyping process can reproduce these features becomes a measure of the capability of the process. Since rapid prototyping is a dynamic technology, this benchmark part should be used to continuously monitor process capability of existing and developing technologies. Development of this benchmark part is, therefore, based on an understanding of the properties required from prototypes and characteristics of various rapid prototyping processes and measuring equipment that is used for evaluation.

  3. Modeling rapidly rotating stars

    NASA Astrophysics Data System (ADS)

    Rieutord, M.

    2006-06-01

    We review the quest of modeling rapidly rotating stars during the past 40 years and detail the challenges to be taken up by models facing new data from interferometry, seismology, spectroscopy... We then present the progress of the ESTER project aimed at giving a physically self-consistent model for the structure and evolution of rapidly rotating stars.

  4. A pilot biomedical engineering course in rapid prototyping for mobile health.

    PubMed

    Stokes, Todd H; Venugopalan, Janani; Hubbard, Elena N; Wang, May D

    2013-01-01

    Rapid prototyping of medically assistive mobile devices promises to fuel innovation and provides opportunity for hands-on engineering training in biomedical engineering curricula. This paper presents the design and outcomes of a course offered during a 16-week semester in Fall 2011 with 11 students enrolled. The syllabus covered a mobile health design process from end-to-end, including storyboarding, non-functional prototypes, integrated circuit programming, 3D modeling, 3D printing, cloud computing database programming, and developing patient engagement through animated videos describing the benefits of a new device. Most technologies presented in this class are open source and thus provide unlimited "hackability". They are also cost-effective and easily transferrable to other departments.

  5. On the Application of Rapid Prototyping Technology for the Fabrication of Flapping Wings for Micro Air Vehicles

    NASA Astrophysics Data System (ADS)

    Kraemer, Kurtis Leigh

    Micro air vehicles (MAV) are a class of small uninhabited aircraft with dimensions less than 15 cm (6 in) and mass less than 500g (1.1 lbs). The aim of this research was to develop a fast, accurate, low-cost, and repeatable fabrication process for flapping MAV wings. Through the use of the RepRap Mendel open-source fused-deposition modeling (FDM) rapid prototyping machine ("3-D printer"), various wing prototypes were designed and fabricated using a bio-inspired approach. Testing of the aerodynamic performance of both real locust wings and the 3-D printed wing prototypes was performed through axial spin testing. Bending stiffness measurements were also performed on the 3-D printed wings. Through the use of open-source rapid prototyping technology, a fast and low-cost fabrication process for flapping MAV wings has been developed, out of which further understanding of flapping wing design and fabrication has been gained.

  6. Low-cost rapid prototyping of flexible microfluidic devices using a desktop digital craft cutter.

    PubMed

    Yuen, Po Ki; Goral, Vasiliy N

    2010-02-01

    Low-cost and straight forward rapid prototyping of flexible microfluidic devices using a desktop digital craft cutter is presented. This rapid prototyping method can consistently achieve microchannels as thin as 200 microm in width and can be used to fabricate three-dimensional (3D) microfluidic devices using only double-sided pressure sensitive adhesive (PSA) tape and laser printer transparency film. Various functional microfluidic devices are demonstrated with this rapid prototyping method. The complete fabrication process from device design concept to working device can be completed in minutes without the need of expensive equipment. PMID:20091012

  7. Rapid prototyping of electrochemical lateral flow devices: stencilled electrodes.

    PubMed

    Aller Pellitero, Miguel; Kitsara, Maria; Eibensteiner, Friedrich; del Campo, F Javier

    2016-04-21

    A straightforward and very cost effective method is proposed to prototype electrodes using pressure sensitive adhesives (PSA) and a simple cutting technique. Two cutting methods, namely blade cutting and CO2 laser ablation, are compared and their respective merits are discussed. The proposed method consists of turning the protective liner on the adhesive into a stencil to apply screen-printing pastes. After the electrodes have been printed, the liner is removed and the PSA can be used as a backing material for standard lateral flow membranes. We present the fabrication of band electrodes down to 250 μm wide, and their characterization using microscopy techniques and cyclic voltammetry. The prototyping approach presented here facilitates the development of new electrochemical devices even if very limited fabrication resources are available. Here we demonstrate the fabrication of a simple lateral-flow device capable of determining glucose in blood. The prototyping approach presented here is highly suitable for the development of novel electroanalytical tools. PMID:26998899

  8. Weapon identification using antemortem computed tomography with virtual 3D and rapid prototype modeling--a report in a case of blunt force head injury.

    PubMed

    Woźniak, Krzysztof; Rzepecka-Woźniak, Ewa; Moskała, Artur; Pohl, Jerzy; Latacz, Katarzyna; Dybała, Bogdan

    2012-10-10

    A frequent request of a prosecutor referring to forensic autopsy is to determine the mechanism of an injury and to identify the weapons used to cause those injuries. This task could be problematic in many ways, including changes in the primary injury caused by medical intervention and the process of healing. To accomplish this task, the forensic pathologist has to gather all possible information during the post-mortem examination. The more data is collected, the easier it is to obtain an accurate answer to the prosecutor's question. The authors present a case of head injuries that the victim sustained under unknown circumstances. The patient underwent neurosurgical treatment which resulted in alteration of the bone fracture pattern. The only way to evaluate this injury was to analyze antemortem clinical data, especially CT scans, with virtual 3D reconstruction of the fractured skull. A physical model of a part of the broken skull was created with the use of 3D printing. These advanced techniques, applied for the first time in Poland for forensic purposes, allowed investigators to extract enough data to develop a hypothesis about the mechanism of injury and the weapon most likely used.

  9. Creation of bioactive glass (13-93) scaffolds for structural bone repair using a combined finite element modeling and rapid prototyping approach.

    PubMed

    Xiao, Wei; Zaeem, Mohsen Asle; Bal, B Sonny; Rahaman, Mohamed N

    2016-11-01

    There is a clinical need for synthetic bioactive materials that can reliably repair intercalary skeletal tissue loss in load-bearing bones. Bioactive glasses have been investigated as one such material but their mechanical response has been a concern. Previously, we created bioactive silicate glass (13-93) scaffolds with a uniform grid-like microstructure which showed a compressive strength comparable to human cortical bone but a much lower flexural strength. In the present study, finite element modeling (FEM) was used to re-design the scaffold microstructure to improve its flexural strength without significantly lowering its compressive strength and ability to support bone infiltration in vivo. Then scaffolds with the requisite microstructures were created by a robotic deposition method and tested in four-point bending and compression to validate the FEM simulations. In general, the data validated the predictions of the FEM simulations. Scaffolds with a porosity gradient, composed of a less porous outer region and a more porous inner region, showed a flexural strength (34±5MPa) that was more than twice the value for the uniform grid-like microstructure (15±5MPa) and a higher compressive strength (88±20MPa) than the grid-like microstructure (72±10MPa). Upon implantation of the scaffolds for 12weeks in rat calvarial defects in vivo, the amount of new bone that infiltrated the pore space of the scaffolds with the porosity gradient (37±16%) was similar to that for the grid-like scaffolds (35±6%). These scaffolds with a porosity gradient that better mimics the microstructure of human long bone could provide more reliable implants for structural bone repair. PMID:27524065

  10. Creation of bioactive glass (13-93) scaffolds for structural bone repair using a combined finite element modeling and rapid prototyping approach.

    PubMed

    Xiao, Wei; Zaeem, Mohsen Asle; Bal, B Sonny; Rahaman, Mohamed N

    2016-11-01

    There is a clinical need for synthetic bioactive materials that can reliably repair intercalary skeletal tissue loss in load-bearing bones. Bioactive glasses have been investigated as one such material but their mechanical response has been a concern. Previously, we created bioactive silicate glass (13-93) scaffolds with a uniform grid-like microstructure which showed a compressive strength comparable to human cortical bone but a much lower flexural strength. In the present study, finite element modeling (FEM) was used to re-design the scaffold microstructure to improve its flexural strength without significantly lowering its compressive strength and ability to support bone infiltration in vivo. Then scaffolds with the requisite microstructures were created by a robotic deposition method and tested in four-point bending and compression to validate the FEM simulations. In general, the data validated the predictions of the FEM simulations. Scaffolds with a porosity gradient, composed of a less porous outer region and a more porous inner region, showed a flexural strength (34±5MPa) that was more than twice the value for the uniform grid-like microstructure (15±5MPa) and a higher compressive strength (88±20MPa) than the grid-like microstructure (72±10MPa). Upon implantation of the scaffolds for 12weeks in rat calvarial defects in vivo, the amount of new bone that infiltrated the pore space of the scaffolds with the porosity gradient (37±16%) was similar to that for the grid-like scaffolds (35±6%). These scaffolds with a porosity gradient that better mimics the microstructure of human long bone could provide more reliable implants for structural bone repair.

  11. Product Development and its Comparative Analysis by SLA, SLS and FDM Rapid Prototyping Processes

    NASA Astrophysics Data System (ADS)

    Choudhari, C. M.; Patil, V. D.

    2016-09-01

    To grab market and meeting deadlines has increased the scope of new methods in product design and development. Industries continuously strive to optimize the development cycles with high quality and cost efficient products to maintain market competitiveness. Thus the need of Rapid Prototyping Techniques (RPT) has started to play pivotal role in rapid product development cycle for complex product. Dimensional accuracy and surface finish are the corner stone of Rapid Prototyping (RP) especially if they are used for mould development. The paper deals with the development of part made with the help of Selective Laser Sintering (SLS), Stereo-lithography (SLA) and Fused Deposition Modelling (FDM) processes to benchmark and investigate on various parameters like material shrinkage rate, dimensional accuracy, time, cost and surface finish. This helps to conclude which processes can be proved to be effective and efficient in mould development. In this research work the emphasis was also given to the design stage of a product development to obtain an optimum design solution for an existing product.

  12. Rapid Prototyping of Simulated VIIRS Data in the SERVIR Fire Rapid Response System

    NASA Astrophysics Data System (ADS)

    Easson, G.; Kuszmaul, J. S.; Yarbrough, L. D.; Irwin, D.; Cherrington, E.

    2006-12-01

    A rapid prototyping capability experiment has been established involving the application of the SERVIR (Sistema Regional de Visualización y Monitoreo) decision support tool, which is NASA's and its partner agencies' tool to monitor groundcover and climatic conditions in Mesoamerica. As an information system, the SERVIR tool processes data products from multiple sources and the outcome is visualized through interactive digital maps, standard view map outputs or 3D real-time visualization. The focus of this research is one of the SERVIR Fire Rapid Response products known as the MODIS SERVIR Fire Extent Product, which was developed to meet the requirements of the Guatemalan Park Service. The credibility of SERVIR's monitoring tools currently depends upon NASA's MODIS data, which is nearing the end of its availability. This will make it necessary to transition to the planned replacement sensor, VIIRS. The impact of this transition on the performance of SERVIR's fire detection tools is the current focus of our investigation. A quantitative assessment of fire conditions in Guatemala is made using MODIS data and is compared to the anticipated performance using simulated data that would have been produced by a VIIRS-like sensor. Using a low-density geospatial database, the comparison is made for a number of dates from the 2003 Guatemalan fire season, where ground validation data is available. A comparative assessment is also made using the kappa statistic applied to the land classifications resulting from both the MODIS- and VIIRS- based fire detection algorithms.

  13. [Application status of rapid prototyping technology in artificial bone based on reverse engineering].

    PubMed

    Fang, Ao; Zheng, Min; Fan, Ding

    2015-02-01

    Artificial bone replacement has made an important contribution to safeguard human health and improve the quality of life. The application requirements of rapid prototyping technology based on reverse engineering in individualized artificial bone with individual differences are particularly urgent. This paper reviewed the current research and applications of rapid prototyping and reverse engineering in artificial bone. The research developments and the outlook of bone kinematics and dynamics simulation are also introduced.

  14. The development of an autonomous rendezvous and docking simulation using rapid integration and prototyping technology

    NASA Technical Reports Server (NTRS)

    Shackelford, John H.; Saugen, John D.; Wurst, Michael J.; Adler, James

    1991-01-01

    A generic planar 3 degree of freedom simulation was developed that supports hardware in the loop simulations, guidance and control analysis, and can directly generate flight software. This simulation was developed in a small amount of time utilizing rapid prototyping techniques. The approach taken to develop this simulation tool, the benefits seen using this approach to development, and on-going efforts to improve and extend this capability are described. The simulation is composed of 3 major elements: (1) Docker dynamics model, (2) Dockee dynamics model, and (3) Docker Control System. The docker and dockee models are based on simple planar orbital dynamics equations using a spherical earth gravity model. The docker control system is based on a phase plane approach to error correction.

  15. Rapid and cheap prototyping of a microfluidic cell sorter.

    PubMed

    Islam, M Z; McMullin, J N; Tsui, Y Y

    2011-05-01

    Development of a microfluidic device is generally based on fabrication-design-fabrication loop, as, unlike the microelectronics design, there is no rigorous simulation-based verification of the chip before fabrication. This usually results in extremely long, and hence expensive, product development cycle if micro/nano fabrication facilities are used from the beginning of the cycle. Here, we illustrate a novel approach of device prototyping that is fast, cheap, reliable, and most importantly, this technique can be adopted even if no state-of-the-art microfabrication facility is available. A water-jet machine is used to cut the desired microfluidic channels into a thin steel plate which is then used as a template to cut the channels into a thin sheet of a transparent and cheap polymer material named Surlyn® by using a Hot Knife™. The feature-inscribed Surlyn sheet is bonded in between two microscope glass slides by utilizing the techniques which has been being used in curing polymer film between dual layer automotive glasses for years. Optical fibers are inserted from the sides of chip and are bonded by UV epoxy. To study the applicability of this prototyping approach, we made a basic microfluidic sorter and tested its functionalities. Sample containing microparticles is injected into the chip. Light from a 532-nm diode laser is coupled into the optical fiber that delivers light to the interrogation region in the channel. The emitted light from the particle is collected by a photodiode (PD) placed over the detection window. The device sorts the particles into the sorted or waste outlets depending on the level of the PD signal. We used fluorescent latex beads to test the detection and sorting functionalities of the device. We found that the system could detect all the beads that passed through its geometric observation region and could sort almost all the beads it detected.

  16. Rapid and cheap prototyping of a microfluidic cell sorter.

    PubMed

    Islam, M Z; McMullin, J N; Tsui, Y Y

    2011-05-01

    Development of a microfluidic device is generally based on fabrication-design-fabrication loop, as, unlike the microelectronics design, there is no rigorous simulation-based verification of the chip before fabrication. This usually results in extremely long, and hence expensive, product development cycle if micro/nano fabrication facilities are used from the beginning of the cycle. Here, we illustrate a novel approach of device prototyping that is fast, cheap, reliable, and most importantly, this technique can be adopted even if no state-of-the-art microfabrication facility is available. A water-jet machine is used to cut the desired microfluidic channels into a thin steel plate which is then used as a template to cut the channels into a thin sheet of a transparent and cheap polymer material named Surlyn® by using a Hot Knife™. The feature-inscribed Surlyn sheet is bonded in between two microscope glass slides by utilizing the techniques which has been being used in curing polymer film between dual layer automotive glasses for years. Optical fibers are inserted from the sides of chip and are bonded by UV epoxy. To study the applicability of this prototyping approach, we made a basic microfluidic sorter and tested its functionalities. Sample containing microparticles is injected into the chip. Light from a 532-nm diode laser is coupled into the optical fiber that delivers light to the interrogation region in the channel. The emitted light from the particle is collected by a photodiode (PD) placed over the detection window. The device sorts the particles into the sorted or waste outlets depending on the level of the PD signal. We used fluorescent latex beads to test the detection and sorting functionalities of the device. We found that the system could detect all the beads that passed through its geometric observation region and could sort almost all the beads it detected. PMID:21491584

  17. Prototype-based models in machine learning.

    PubMed

    Biehl, Michael; Hammer, Barbara; Villmann, Thomas

    2016-01-01

    An overview is given of prototype-based models in machine learning. In this framework, observations, i.e., data, are stored in terms of typical representatives. Together with a suitable measure of similarity, the systems can be employed in the context of unsupervised and supervised analysis of potentially high-dimensional, complex datasets. We discuss basic schemes of competitive vector quantization as well as the so-called neural gas approach and Kohonen's topology-preserving self-organizing map. Supervised learning in prototype systems is exemplified in terms of learning vector quantization. Most frequently, the familiar Euclidean distance serves as a dissimilarity measure. We present extensions of the framework to nonstandard measures and give an introduction to the use of adaptive distances in relevance learning.

  18. A novel 3D template for mandible and maxilla reconstruction: Rapid prototyping using stereolithography

    PubMed Central

    Kumta, Samir; Kumta, Monica; Jain, Leena; Purohit, Shrirang; Ummul, Rani

    2015-01-01

    Introduction: Replication of the exact three-dimensional (3D) structure of the maxilla and mandible is now a priority whilst attempting reconstruction of these bones to attain a complete functional and aesthetic rehabilitation. We hereby present the process of rapid prototyping using stereolithography to produce templates for modelling bone grafts and implants for maxilla/mandible reconstructions, its applications in tumour/trauma, and outcomes for primary and secondary reconstruction. Materials and Methods: Stereolithographic template-assisted reconstruction was used on 11 patients for the reconstruction of the mandible/maxilla primarily following tumour excision and secondarily for the realignment of post-traumatic malunited fractures or deformity corrections. Data obtained from the computed tomography (CT) scans with 1-mm resolution were converted into a computer-aided design (CAD) using the CT Digital Imaging and Communications in Medicine (DICOM) data. Once a CAD model was constructed, it was converted into a stereolithographic format and then processed by the rapid prototyping technology to produce the physical anatomical model using a resin. This resin model replicates the native mandible, which can be thus used off table as a guide for modelling the bone grafts. Discussion: This conversion of two-dimensional (2D) data from CT scan into 3D models is a very precise guide to shaping the bone grafts. Further, this CAD can reconstruct the defective half of the mandible using the mirror image principle, and the normal anatomical model can be created to aid secondary reconstructions. Conclusion: This novel approach allows a precise translation of the treatment plan directly to the surgical field. It is also an important teaching tool for implant moulding and fixation, and helps in patient counselling. PMID:26933279

  19. Rapid Prototyping Technologies and their Applications in Prosthodontics, a Review of Literature

    PubMed Central

    Torabi, Kianoosh; Farjood, Ehsan; Hamedani, Shahram

    2015-01-01

    The early computer-aided design/computer-aided manufacturing (CAD/CAM) systems were relied exclusively on subtractive methods. In recent years, additive methods by employing rapid prototyping (RP) have progressed rapidly in various fields of dentistry as they have the potential to overcome known drawbacks of subtractive techniques such as fit problems. RP techniques have been exploited to build complex 3D models in medicine since the 1990s. RP has recently proposed successful applications in various dental fields, such as fabrication of implant surgical guides, frameworks for fixed and removable partial dentures, wax patterns for the dental prosthesis, zirconia prosthesis and molds for metal castings, and maxillofacial prosthesis and finally, complete dentures. This paper aimed to offer a comprehensive literature review of various RP methods, particularly in dentistry, that are expected to bring many improvements to the field. A search was made through MEDLINE database and Google scholar search engine. The keywords; ‘rapid prototyping’ and ‘dentistry’ were searched in title/abstract of publications; limited to 2003 to 2013, concerning past decade. The inclusion criterion was the technical researches that predominately included laboratory procedures. The exclusion criterion was meticulous clinical and excessive technical procedures. A total of 106 articles were retrieved, recited by authors and only 50 met the specified inclusion criteria for this review. Selected articles had used rapid prototyping techniques in various fields in dentistry through different techniques. This review depicted the different laboratory procedures employed in this method and confirmed that RP technique have been substantially feasible in dentistry. With advancement in various RP systems, it is possible to benefit from this technique in different dental practices, particularly in implementing dental prostheses for different applications. PMID:25759851

  20. Rapid prototyping of multiphase microfluidics with robotic cutters

    NASA Astrophysics Data System (ADS)

    Li, Zidong; Zhao, Zhengtuo; Lo, Joe Fu-jiou

    2014-03-01

    Microfluidic devices offer novel techniques to address biological and biomedical issues. Standard microfluidic fabrication uses photolithography to pattern channels on silicon wafers with high resolution. Even the relatively straightforward SU8 and soft lithography in microfluidics require investing and training in photolithography, which is also time consuming due to complicated thick resist procedures, including sensitive substrate pretreatment, coating, soft bake, expose, post-exposure bake, and developing steps. However, for applications where low resolution (>200 μm) and high turn-around (> 4 designs/day) prototyping are met with little or no lithography infrastructure, robotic cutters [1] offer flexible options for making glass and PDMS microfluidics. We describe the use of robotics cutters for designing microfluidic geometries, and compliment it with safe glass etching, with depths down to 60 μm. Soft lithography patterning of 200 μm thick PDMS membrane was also explored. Without high equipment investment and lengthy student training, both glass and PDMS microfluidics can be achieved in small facilities using this technique.

  1. Prototyping of cerebral vasculature physical models

    PubMed Central

    Khan, Imad S.; Kelly, Patrick D.; Singer, Robert J.

    2014-01-01

    Background: Prototyping of cerebral vasculature models through stereolithographic methods have the ability to accurately depict the 3D structures of complicated aneurysms with high accuracy. We describe the method to manufacture such a model and review some of its uses in the context of treatment planning, research, and surgical training. Methods: We prospectively used the data from the rotational angiography of a 40-year-old female who presented with an unruptured right paraclinoid aneurysm. The 3D virtual model was then converted to a physical life-sized model. Results: The model constructed was shown to be a very accurate depiction of the aneurysm and its associated vasculature. It was found to be useful, among other things, for surgical training and as a patient education tool. Conclusion: With improving and more widespread printing options, these models have the potential to become an important part of research and training modalities. PMID:24678427

  2. RETRACTED: Auricular prosthesis fabrication using computer-aided design and rapid prototyping technologies.

    PubMed

    Shah, Mayank

    2016-06-01

    At the request of the editorMayank Shah 'Auricular prosthesis fabrication using computer-aided design and rapid prototyping technologies' Prosthetics and Orthotics International, published online before print on October 8, 2013 as doi:10.1177/0309364613504779has been retracted. This is because it contains unattributed overlap withK. Subburaj, C. Nair, S. Rajesh, S. M. Meshram, B. Ravi 'Rapid development of auricular prosthesis using CAD and rapid prototyping technologies' International Journal of Oral & Maxillofacial Surgery 2007; 36: 938-943 doi:10.1016/j.ijom.2007.07.013.

  3. Reverse engineering--rapid prototyping of the skull in forensic trauma analysis.

    PubMed

    Kettner, Mattias; Schmidt, Peter; Potente, Stefan; Ramsthaler, Frank; Schrodt, Michael

    2011-07-01

    Rapid prototyping (RP) comprises a variety of automated manufacturing techniques such as selective laser sintering (SLS), stereolithography, and three-dimensional printing (3DP), which use virtual 3D data sets to fabricate solid forms in a layer-by-layer technique. Despite a growing demand for (virtual) reconstruction models in daily forensic casework, maceration of the skull is frequently assigned to ensure haptic evidence presentation in the courtroom. Owing to the progress in the field of forensic radiology, 3D data sets of relevant cases are usually available to the forensic expert. Here, we present a first application of RP in forensic medicine using computed tomography scans for the fabrication of an SLS skull model in a case of fatal hammer impacts to the head. The report is intended to show that this method fully respects the dignity of the deceased and is consistent with medical ethics but nevertheless provides an excellent 3D impression of anatomical structures and injuries.

  4. Test Structures Applied to the Rapid Prototyping of Sensors

    NASA Technical Reports Server (NTRS)

    Buehler, M.; Chang, L-J.; Martin, D.

    1997-01-01

    Recently, test structures were used to aid in the rapid development of a gas sensor and pressure sensor. These sensors were fabricated using co-fired ceramic technology and a multiproject approach. This talk will describe results obtained from a ceramic substrate which contained 36 chips with six variants including the sensors, process control monitors, and an interconnect chip. As far as the authors know, this is the first implementation of multi-projects in co-fired ceramic substrate. The gas sensor is being developed for the Space Shuttle and the pressure gage is being developed as a Martian barometer.

  5. Motion Planning for a Direct Metal Deposition Rapid Prototyping System

    SciTech Connect

    AMES,ARLO L.; HENSINGER,DAVID M.; KUHLMANN,JOEL L.

    1999-10-18

    A motion planning strategy was developed and implemented to generate motion control instructions from solid model data for controlling a robotically driven solid free-form fabrication process. The planning strategy was tested using a PUMA type robot arm integrated into a LENS{trademark} (Laser Engineered Net Shape) system. Previous systems relied on a series of x, y, and z stages, to provide a minimal coordinated motion control capability. This limited the complexity of geometries that could be constructed. With the coordinated motion provided by a robotic arm, the system can produce three dimensional parts by ''writing'' material onto any face of existing material. The motion planning strategy relied on solid model geometry evaluation and exploited robotic positioning flexibility to allow the construction of geometrically complex parts. The integration of the robotic manipulator into the LENS{trademark} system was tested by producing metal parts directly from CAD models.

  6. Fabrication of a Cranial Prosthesis Combined with an Ocular Prosthesis Using Rapid Prototyping: A Case Report.

    PubMed

    Shankaran, Gayatri; Deogade, Suryakant Chhagan; Dhirawani, Rajesh

    2016-01-01

    Rapid prototyping (RP) is a technique of manufacturing parts by the additive layer manufacturing technology; where, a three-dimensional (3D) model created in a computer aided design (CAD) system is sectioned into 2D profiles, which are further constructed by RP layer by layer. Its use is not limited to industrial or engineering fields and has extended to the medical field for the manufacturing of custom implants and prostheses, the study of anatomy and surgical planning. Nowadays, dentists are more frequently encountered with the individuals affected with craniofacial defects due to trauma. In such cases, the craniomaxillofacial rehabilitation is a real challenge to bring the patients back to society and promote their well-being. The conventional impression technique for facial prosthesis fabrication has the disadvantage of deforming the soft tissue and causing discomfort for the patient. Herein, we describe the fabrication of a cranial prosthesis combined with an ocular prosthesis with RP and stereolithography.

  7. Production of new 3D scaffolds for bone tissue regeneration by rapid prototyping.

    PubMed

    Fradique, R; Correia, T R; Miguel, S P; de Sá, K D; Figueira, D R; Mendonça, A G; Correia, I J

    2016-04-01

    The incidence of bone disorders, whether due to trauma or pathology, has been trending upward with the aging of the worldwide population. The currently available treatments for bone injuries are rather limited, involving mainly bone grafts and implants. A particularly promising approach for bone regeneration uses rapid prototyping (RP) technologies to produce 3D scaffolds with highly controlled structure and orientation, based on computer-aided design models or medical data. Herein, tricalcium phosphate (TCP)/alginate scaffolds were produced using RP and subsequently their physicochemical, mechanical and biological properties were characterized. The results showed that 60/40 of TCP and alginate formulation was able to match the compression and present a similar Young modulus to that of trabecular bone while presenting an adequate biocompatibility. Moreover, the biomineralization ability, roughness and macro and microporosity of scaffolds allowed cell anchoring and proliferation at their surface, as well as cell migration to its interior, processes that are fundamental for osteointegration and bone regeneration.

  8. Fabrication of a Cranial Prosthesis Combined with an Ocular Prosthesis Using Rapid Prototyping: A Case Report

    PubMed Central

    Shankaran, Gayatri; Dhirawani, Rajesh

    2016-01-01

    Rapid prototyping (RP) is a technique of manufacturing parts by the additive layer manufacturing technology; where, a three-dimensional (3D) model created in a computer aided design (CAD) system is sectioned into 2D profiles, which are further constructed by RP layer by layer. Its use is not limited to industrial or engineering fields and has extended to the medical field for the manufacturing of custom implants and prostheses, the study of anatomy and surgical planning. Nowadays, dentists are more frequently encountered with the individuals affected with craniofacial defects due to trauma. In such cases, the craniomaxillofacial rehabilitation is a real challenge to bring the patients back to society and promote their well-being. The conventional impression technique for facial prosthesis fabrication has the disadvantage of deforming the soft tissue and causing discomfort for the patient. Herein, we describe the fabrication of a cranial prosthesis combined with an ocular prosthesis with RP and stereolithography. PMID:27536331

  9. Fabrication of a Cranial Prosthesis Combined with an Ocular Prosthesis Using Rapid Prototyping: A Case Report.

    PubMed

    Shankaran, Gayatri; Deogade, Suryakant Chhagan; Dhirawani, Rajesh

    2016-01-01

    Rapid prototyping (RP) is a technique of manufacturing parts by the additive layer manufacturing technology; where, a three-dimensional (3D) model created in a computer aided design (CAD) system is sectioned into 2D profiles, which are further constructed by RP layer by layer. Its use is not limited to industrial or engineering fields and has extended to the medical field for the manufacturing of custom implants and prostheses, the study of anatomy and surgical planning. Nowadays, dentists are more frequently encountered with the individuals affected with craniofacial defects due to trauma. In such cases, the craniomaxillofacial rehabilitation is a real challenge to bring the patients back to society and promote their well-being. The conventional impression technique for facial prosthesis fabrication has the disadvantage of deforming the soft tissue and causing discomfort for the patient. Herein, we describe the fabrication of a cranial prosthesis combined with an ocular prosthesis with RP and stereolithography. PMID:27536331

  10. A rapid prototyping/artificial intelligence approach to space station-era information management and access

    NASA Technical Reports Server (NTRS)

    Carnahan, Richard S., Jr.; Corey, Stephen M.; Snow, John B.

    1989-01-01

    Applications of rapid prototyping and Artificial Intelligence techniques to problems associated with Space Station-era information management systems are described. In particular, the work is centered on issues related to: (1) intelligent man-machine interfaces applied to scientific data user support, and (2) the requirement that intelligent information management systems (IIMS) be able to efficiently process metadata updates concerning types of data handled. The advanced IIMS represents functional capabilities driven almost entirely by the needs of potential users. Space Station-era scientific data projected to be generated is likely to be significantly greater than data currently processed and analyzed. Information about scientific data must be presented clearly, concisely, and with support features to allow users at all levels of expertise efficient and cost-effective data access. Additionally, mechanisms for allowing more efficient IIMS metadata update processes must be addressed. The work reported covers the following IIMS design aspects: IIMS data and metadata modeling, including the automatic updating of IIMS-contained metadata, IIMS user-system interface considerations, including significant problems associated with remote access, user profiles, and on-line tutorial capabilities, and development of an IIMS query and browse facility, including the capability to deal with spatial information. A working prototype has been developed and is being enhanced.

  11. A cell-free framework for rapid biosynthetic pathway prototyping and enzyme discovery.

    PubMed

    Karim, Ashty S; Jewett, Michael C

    2016-07-01

    Speeding up design-build-test (DBT) cycles is a fundamental challenge facing biochemical engineering. To address this challenge, we report a new cell-free protein synthesis driven metabolic engineering (CFPS-ME) framework for rapid biosynthetic pathway prototyping. In our framework, cell-free cocktails for synthesizing target small molecules are assembled in a mix-and-match fashion from crude cell lysates either containing selectively enriched pathway enzymes from heterologous overexpression or directly producing pathway enzymes in lysates by CFPS. As a model, we apply our approach to n-butanol biosynthesis showing that Escherichia coli lysates support a highly active 17-step CoA-dependent n-butanol pathway in vitro. The elevated degree of flexibility in the cell-free environment allows us to manipulate physiochemical conditions, access enzymatic nodes, discover new enzymes, and prototype enzyme sets with linear DNA templates to study pathway performance. We anticipate that CFPS-ME will facilitate efforts to define, manipulate, and understand metabolic pathways for accelerated DBT cycles without the need to reengineer organisms. PMID:26996382

  12. Development of Experimental Setup of Metal Rapid Prototyping Machine using Selective Laser Sintering Technique

    NASA Astrophysics Data System (ADS)

    Patil, S. N.; Mulay, A. V.; Ahuja, B. B.

    2016-08-01

    Unlike in the traditional manufacturing processes, additive manufacturing as rapid prototyping, allows designers to produce parts that were previously considered too complex to make economically. The shift is taking place from plastic prototype to fully functional metallic parts by direct deposition of metallic powders as produced parts can be directly used for desired purpose. This work is directed towards the development of experimental setup of metal rapid prototyping machine using selective laser sintering and studies the various parameters, which plays important role in the metal rapid prototyping using SLS technique. The machine structure in mainly divided into three main categories namely, (1) Z-movement of bed and table, (2) X-Y movement arrangement for LASER movements and (3) feeder mechanism. Z-movement of bed is controlled by using lead screw, bevel gear pair and stepper motor, which will maintain the accuracy of layer thickness. X-Y movements are controlled using timing belt and stepper motors for precise movements of LASER source. Feeder mechanism is then developed to control uniformity of layer thickness metal powder. Simultaneously, the study is carried out for selection of material. Various types of metal powders can be used for metal RP as Single metal powder, mixture of two metals powder, and combination of metal and polymer powder. Conclusion leads to use of mixture of two metals powder to minimize the problems such as, balling effect and porosity. Developed System can be validated by conducting various experiments on manufactured part to check mechanical and metallurgical properties. After studying the results of these experiments, various process parameters as LASER properties (as power, speed etc.), and material properties (as grain size and structure etc.) will be optimized. This work is mainly focused on the design and development of cost effective experimental setup of metal rapid prototyping using SLS technique which will gives the feel of

  13. Technical note: rapid prototyping of 3D grid arrays for image guided therapy quality assurance.

    PubMed

    Kittle, David; Holshouser, Barbara; Slater, James M; Guenther, Bob D; Pitsianis, Nikos P; Pearlstein, Robert D

    2008-12-01

    Three dimensional grid phantoms offer a number of advantages for measuring imaging related spatial inaccuracies for image guided surgery and radiotherapy. The authors examined the use of rapid prototyping technology for directly fabricating 3D grid phantoms from CAD drawings. We tested three different fabrication process materials, photopolymer jet with acrylic resin (PJ/AR), selective laser sintering with polyamide (SLS/P), and fused deposition modeling with acrylonitrile butadiene styrene (FDM/ABS). The test objects consisted of rectangular arrays of control points formed by the intersections of posts and struts (2 mm rectangular cross section) and spaced 8 mm apart in the x, y, and z directions. The PJ/AR phantom expanded after immersion in water which resulted in permanent warping of the structure. The surface of the FDM/ABS grid exhibited a regular pattern of depressions and ridges from the extrusion process. SLS/P showed the best combination of build accuracy, surface finish, and stability. Based on these findings, a grid phantom for assessing machine-dependent and frame-induced MR spatial distortions was fabricated to be used for quality assurance in stereotactic neurosurgical and radiotherapy procedures. The spatial uniformity of the SLS/P grid control point array was determined by CT imaging (0.6 x 0.6 x 0.625 mm3 resolution) and found suitable for the application, with over 97.5% of the control points located within 0.3 mm of the position specified in CAD drawing and none of the points off by more than 0.4 mm. Rapid prototyping is a flexible and cost effective alternative for development of customized grid phantoms for medical physics quality assurance. PMID:19175128

  14. Technical Note: Rapid prototyping of 3D grid arrays for image guided therapy quality assurance

    SciTech Connect

    Kittle, David; Holshouser, Barbara; Slater, James M.; Guenther, Bob D.; Pitsianis, Nikos P.; Pearlstein, Robert D.

    2008-12-15

    Three dimensional grid phantoms offer a number of advantages for measuring imaging related spatial inaccuracies for image guided surgery and radiotherapy. The authors examined the use of rapid prototyping technology for directly fabricating 3D grid phantoms from CAD drawings. We tested three different fabrication process materials, photopolymer jet with acrylic resin (PJ/AR), selective laser sintering with polyamide (SLS/P), and fused deposition modeling with acrylonitrile butadiene styrene (FDM/ABS). The test objects consisted of rectangular arrays of control points formed by the intersections of posts and struts (2 mm rectangular cross section) and spaced 8 mm apart in the x, y, and z directions. The PJ/AR phantom expanded after immersion in water which resulted in permanent warping of the structure. The surface of the FDM/ABS grid exhibited a regular pattern of depressions and ridges from the extrusion process. SLS/P showed the best combination of build accuracy, surface finish, and stability. Based on these findings, a grid phantom for assessing machine-dependent and frame-induced MR spatial distortions was fabricated to be used for quality assurance in stereotactic neurosurgical and radiotherapy procedures. The spatial uniformity of the SLS/P grid control point array was determined by CT imaging (0.6x0.6x0.625 mm{sup 3} resolution) and found suitable for the application, with over 97.5% of the control points located within 0.3 mm of the position specified in CAD drawing and none of the points off by more than 0.4 mm. Rapid prototyping is a flexible and cost effective alternative for development of customized grid phantoms for medical physics quality assurance.

  15. A Method to Represent Heterogeneous Materials for Rapid Prototyping: The Matryoshka Approach

    PubMed Central

    Lei, Shuangyan; Frank, Matthew C.; Anderson, Donald D.; Brown, Thomas D.

    2015-01-01

    Purpose The purpose of this paper is to present a new method for representing heterogeneous materials using nested STL shells, based, in particular, on the density distributions of human bones. Design/methodology/approach Nested STL shells, called Matryoshka models, are described, based on their namesake Russian nesting dolls. In this approach, polygonal models, such as STL shells, are “stacked” inside one another to represent different material regions. The Matryoshka model addresses the challenge of representing different densities and different types of bone when reverse engineering from medical images. The Matryoshka model is generated via an iterative process of thresholding the Hounsfield Unit (HU) data using computed tomography (CT), thereby delineating regions of progressively increasing bone density. These nested shells can represent regions starting with the medullary (bone marrow) canal, up through and including the outer surface of the bone. Findings The Matryoshka approach introduced can be used to generate accurate models of heterogeneous materials in an automated fashion, avoiding the challenge of hand-creating an assembly model for input to multi-material additive or subtractive manufacturing. Originality/Value This paper presents a new method for describing heterogeneous materials: in this case, the density distribution in a human bone. The authors show how the Matryoshka model can be used to plan harvesting locations for creating custom rapid allograft bone implants from donor bone. An implementation of a proposed harvesting method is demonstrated, followed by a case study using subtractive rapid prototyping to harvest a bone implant from a human tibia surrogate. PMID:26120277

  16. Virtual prototype model for lunar rover missions

    NASA Astrophysics Data System (ADS)

    Lu, Desheng; Hong, Bingrong; Tang, Haoxuan

    2004-11-01

    By means of virtual prototype technolgy, the virtual enviroment of the lunar rover is established on graphics workstation. The model of virtual lunar rover based on rocker and redirector is derived for full six degree of freedom motions enabling movements in three directions, as well as pith, roll and yaw rotations. In order to make the operator see and believe the virtual enviroment of the scene while controlling the rover, a self-calibration system is developed by the method of transforming 3-D CAD models into 2-D graphics and superimposing the model built on the computer onto the image taken by the CCD camera, which can calibrate the figure of virtual enviroment. For the purpose of dispelling the time delay impact on the stability of the teleoperation system during lunar missions, a two-level control frame of teleoperation based on virtual reality preview, which can lay communication time delay out of the control loops, is applied to the simulation system. A man-machine interface based on six degree Space ball is developed so as to control the virtual lunar rover efficiently. The effectiveness and the feasibility of the model are verified by the climb simulation experiments of the virtual lunar rover.

  17. A Rapidly Prototyped Vegetation Dryness Index Developed for Wildfire Risk Assessment at Stennis Space Center

    NASA Technical Reports Server (NTRS)

    Ross, Kenton; Graham, William D.; Prados, Donald; Spruce, Joseph

    2006-01-01

    A remote sensing index was developed to allow improved monitoring of vegetation dryness conditions on a regional basis. This remote sensing index was rapidly prototyped at Stennis Space Center in response to drought conditions in the local area in spring 2006.

  18. Low-Cost Rapid Prototyping of Whole-Glass Microfluidic Devices

    ERIC Educational Resources Information Center

    Yuen, Po Ki; Goral, Vasiliy N.

    2012-01-01

    A low-cost, straightforward, rapid prototyping of whole-glass microfluidic devices is presented using glass-etching cream that can be easily purchased in local stores. A self-adhered vinyl stencil cut out by a desktop digital craft cutter was used as an etching mask for patterning microstructures in glass using the glass-etching cream. A specific…

  19. Rapid Prototyping of Chemical Microsensors Based on Molecularly Imprinted Polymers Synthesized by Two-Photon Stereolithography.

    PubMed

    Gomez, Laura Piedad Chia; Spangenberg, Arnaud; Ton, Xuan-Anh; Fuchs, Yannick; Bokeloh, Frank; Malval, Jean-Pierre; Tse Sum Bui, Bernadette; Thuau, Damien; Ayela, Cédric; Haupt, Karsten; Soppera, Olivier

    2016-07-01

    Two-photon stereolithography is used for rapid prototyping of submicrometre molecularly imprinted polymer-based 3D structures. The structures are evaluated as chemical sensing elements and their specific recognition properties for target molecules are confirmed. The 3D design capability is exploited and highlighted through the fabrication of an all-organic molecularly imprinted polymeric microelectromechanical sensor.

  20. Rapid Prototyping of Chemical Microsensors Based on Molecularly Imprinted Polymers Synthesized by Two-Photon Stereolithography.

    PubMed

    Gomez, Laura Piedad Chia; Spangenberg, Arnaud; Ton, Xuan-Anh; Fuchs, Yannick; Bokeloh, Frank; Malval, Jean-Pierre; Tse Sum Bui, Bernadette; Thuau, Damien; Ayela, Cédric; Haupt, Karsten; Soppera, Olivier

    2016-07-01

    Two-photon stereolithography is used for rapid prototyping of submicrometre molecularly imprinted polymer-based 3D structures. The structures are evaluated as chemical sensing elements and their specific recognition properties for target molecules are confirmed. The 3D design capability is exploited and highlighted through the fabrication of an all-organic molecularly imprinted polymeric microelectromechanical sensor. PMID:27145145

  1. Rapid Prototyping of Computer-Based Presentations Using NEAT, Version 1.1.

    ERIC Educational Resources Information Center

    Muldner, Tomasz

    NEAT (iNtegrated Environment for Authoring in ToolBook) provides templates and various facilities for the rapid prototyping of computer-based presentations, a capability that is lacking in current authoring systems. NEAT is a specialized authoring system that can be used by authors who have a limited knowledge of computer systems and no…

  2. Plan to procedure: combining 3D templating with rapid prototyping to enhance pedicle screw placement

    NASA Astrophysics Data System (ADS)

    Augustine, Kurt E.; Stans, Anthony A.; Morris, Jonathan M.; Huddleston, Paul M.; Matsumoto, Jane M.; Holmes, David R., III; Robb, Richard A.

    2010-02-01

    Spinal fusion procedures involving the implantation of pedicle screws have steadily increased over the past decade because of demonstrated improvement in biomechanical stability of the spine. However, current methods of spinal fusion carries a risk of serious vascular, visceral, and neurological injury caused by inaccurate placement or inappropriately sized instrumentation, which may lead to patient paralysis or even fatality. 3D spine templating software developed by the Biomedical Imaging Resource (BIR) at Mayo Clinic allows the surgeon to virtually place pedicle screws using pre-operative 3D CT image data. With the template plan incorporated, a patient-specific 3D anatomic model is produced using a commercial rapid prototyping system. The pre-surgical plan and the patient-specific model then are used in the procedure room to provide real-time visualization and quantitative guidance for accurate placement of each pedicle screw, significantly reducing risk of injury. A pilot study was conducted at Mayo Clinic by the Department of Radiology, the Department of Orthopedics, and the BIR, involving seven complicated pediatric spine cases. In each case, pre-operative 3D templating was carried out and patient specific models were generated. The plans and the models were used intra-operatively, providing precise pedicle screw starting points and trajectories. Postoperative assessment by the surgeon confirmed all seven operations were successful. Results from the study suggest that patient-specific, 3D anatomic models successfully acquired from 3D templating tools are valuable for planning and conducting pedicle screw insertion procedures.

  3. Compact form fitting small antennas using three-dimensional rapid prototyping

    NASA Astrophysics Data System (ADS)

    Willis, Bryan Jon

    Three-dimensional (3D) rapid prototyping holds significant promise for future antenna designs. Many complex designs that would be unmanufacturable or costly are realizable on a 3D printing machine. The ability to create 3D designs of virtually any configuration makes it possible to build compact antennas that can form fit to any space. These antennas build on the concept that small antennas can best reach the ideal operating limit when utilizing the entire 3D space in a sphere surrounding the antenna. Antennas require a combination of dielectric and conductive materials. 3D rapid prototyping is already well advanced for plastics and dielectric materials (with more options coming online). Prototyping with conductive materials has lagged behind; due mainly to their higher melting points, but this is advancing as well. This dissertation focuses on 3D rapid prototyping for antenna design. A 3D antenna made from small cubical cells is optimized for 2.4--3GHz using a genetic algorithm (GA). The antennas are built using 3D printing of plastic covered by conductive paint. The effects of the conductivity of the paint and number of layers on the resonance and gain of the antenna are evaluated. These results demonstrate the feasibility of using 3D rapid prototyping for antenna design. A 3D dipole is also optimized using a GA to function from 510--910MHz. The antenna was built using 3D rapid prototyping from plastic. The 3D antenna was covered with a conductive coating and measured, showing good agreement with simulation. The 3D GA is used to design 3D antennas of random shape to fit inside the empty space in a cell phone case and optimized for cell phone bands 800--900MHz and 1.6--3.7GHz. The research also evaluates methods and materials that can be used to produce 3D antennas. In addition to the flexibility that 3D prototyping brings to antenna design, this paper describes how this new and emerging method for building antennas can provide fast and affordable antennas for

  4. Computer-aided 3D-shape construction of hearts from CT images for rapid prototyping

    NASA Astrophysics Data System (ADS)

    Fukuzawa, Masayuki; Kato, Yutaro; Nakamori, Nobuyuki; Ozawa, Seiichiro; Shiraishi, Isao

    2012-03-01

    By developing a computer-aided modeling system, the 3D shapes of infant's heart have been constructed interactively from quality-limited CT images for rapid prototyping of biomodels. The 3D model was obtained by following interactive steps: (1) rough region cropping, (2) outline extraction in each slice with locally-optimized threshold, (3) verification and correction of outline overlap, (4) 3D surface generation of inside wall, (5) connection of inside walls, (6) 3D surface generation of outside wall, (7) synthesis of self-consistent 3D surface. The manufactured biomodels revealed characteristic 3D shapes of heart such as left atrium and ventricle, aortic arch and right auricle. Their real shape of cavity and vessel is suitable for surgery planning and simulation. It is a clear advantage over so-called "blood-pool" model which is massive and often found in 3D visualization of CT images as volume rendering perspective. The developed system contributed both to quality improvement and to modeling-time reduction, which may suggest a practical approach to establish a routine process for manufacturing heart biomodels. Further study on the system performance is now still in progress.

  5. Justification of rapid prototyping in the development cycle of thermoplastic-based lab-on-a-chip.

    PubMed

    Preywisch, Regina; Ritzi-Lehnert, Marion; Drese, Klaus S; Röser, Tina

    2011-11-01

    During the developmental cycle of lab-on-a-chip devices, various microstructuring techniques are required. While in the designing and assay implementation phase direct structuring or so-called rapid-prototyping methods such as milling or laser ablation are applied, replication methods like hot embossing or injection moulding are favourable for large quantity manufacturing. This work investigated the applicability of rapid-prototyping techniques for thermoplastic chip development in general, and the reproducibility of performances in dependency of the structuring technique. A previously published chip for prenatal diagnosis that preconcentrates DNA via electrokinetic trapping and field-amplified-sample-stacking and afterwards separates it in CGE was chosen as a model. The impact of structuring, sealing, and the integration of membranes on the mobility of the EOF, DNA preconcentration, and DNA separation was studied. Structuring methods were found to significantly change the location where preconcentration of DNA occurs. However, effects on the mobility of the EOF and the separation quality of DNA were not observed. Exchange of the membrane has no effect on the chip performance, whereas the sealing method impairs the separation of DNA within the chip. The overall assay performance is not significantly influenced by different structuring methods; thus, the application of rapid-prototyping methods during a chip development cycle is well justified. PMID:22102495

  6. Rapid prototyping and evaluation of programmable SIMD SDR processors in LISA

    NASA Astrophysics Data System (ADS)

    Chen, Ting; Liu, Hengzhu; Zhang, Botao; Liu, Dongpei

    2013-03-01

    With the development of international wireless communication standards, there is an increase in computational requirement for baseband signal processors. Time-to-market pressure makes it impossible to completely redesign new processors for the evolving standards. Due to its high flexibility and low power, software defined radio (SDR) digital signal processors have been proposed as promising technology to replace traditional ASIC and FPGA fashions. In addition, there are large numbers of parallel data processed in computation-intensive functions, which fosters the development of single instruction multiple data (SIMD) architecture in SDR platform. So a new way must be found to prototype the SDR processors efficiently. In this paper we present a bit-and-cycle accurate model of programmable SIMD SDR processors in a machine description language LISA. LISA is a language for instruction set architecture which can gain rapid model at architectural level. In order to evaluate the availability of our proposed processor, three common baseband functions, FFT, FIR digital filter and matrix multiplication have been mapped on the SDR platform. Analytical results showed that the SDR processor achieved the maximum of 47.1% performance boost relative to the opponent processor.

  7. New Design for Rapid Prototyping of Digital Master Casts for Multiple Dental Implant Restorations

    PubMed Central

    Romero, Luis; Jiménez, Mariano; Espinosa, María del Mar; Domínguez, Manuel

    2015-01-01

    Aim This study proposes the replacement of all the physical devices used in the manufacturing of conventional prostheses through the use of digital tools, such as 3D scanners, CAD design software, 3D implants files, rapid prototyping machines or reverse engineering software, in order to develop laboratory work models from which to finish coatings for dental prostheses. Different types of dental prosthetic structures are used, which were adjusted by a non-rotatory threaded fixing system. Method From a digital process, the relative positions of dental implants, soft tissue and adjacent teeth of edentulous or partially edentulous patients has been captured, and a maser working model which accurately replicates data relating to the patients oral cavity has been through treatment of three-dimensional digital data. Results Compared with the conventional master cast, the results show a significant cost savings in attachments, as well as an increase in the quality of reproduction and accuracy of the master cast, with the consequent reduction in the number of patient consultation visits. The combination of software and hardware three-dimensional tools allows the optimization of the planning of dental implant-supported rehabilitations protocol, improving the predictability of clinical treatments and the production cost savings of master casts for restorations upon implants. PMID:26696528

  8. Rapid prototyping facility for flight research in artificial-intelligence-based flight systems concepts

    NASA Technical Reports Server (NTRS)

    Duke, E. L.; Regenie, V. A.; Deets, D. A.

    1986-01-01

    The Dryden Flight Research Facility of the NASA Ames Research Facility of the NASA Ames Research Center is developing a rapid prototyping facility for flight research in flight systems concepts that are based on artificial intelligence (AI). The facility will include real-time high-fidelity aircraft simulators, conventional and symbolic processors, and a high-performance research aircraft specially modified to accept commands from the ground-based AI computers. This facility is being developed as part of the NASA-DARPA automated wingman program. This document discusses the need for flight research and for a national flight research facility for the rapid prototyping of AI-based avionics systems and the NASA response to those needs.

  9. Design Principles for Rapid Prototyping Forces Sensors using 3D Printing.

    PubMed

    Kesner, Samuel B; Howe, Robert D

    2011-07-21

    Force sensors provide critical information for robot manipulators, manufacturing processes, and haptic interfaces. Commercial force sensors, however, are generally not adapted to specific system requirements, resulting in sensors with excess size, cost, and fragility. To overcome these issues, 3D printers can be used to create components for the quick and inexpensive development of force sensors. Limitations of this rapid prototyping technology, however, require specialized design principles. In this paper, we discuss techniques for rapidly developing simple force sensors, including selecting and attaching metal flexures, using inexpensive and simple displacement transducers, and 3D printing features to aid in assembly. These design methods are illustrated through the design and fabrication of a miniature force sensor for the tip of a robotic catheter system. The resulting force sensor prototype can measure forces with an accuracy of as low as 2% of the 10 N measurement range.

  10. Design Principles for Rapid Prototyping Forces Sensors using 3D Printing

    PubMed Central

    Kesner, Samuel B.; Howe, Robert D.

    2011-01-01

    Force sensors provide critical information for robot manipulators, manufacturing processes, and haptic interfaces. Commercial force sensors, however, are generally not adapted to specific system requirements, resulting in sensors with excess size, cost, and fragility. To overcome these issues, 3D printers can be used to create components for the quick and inexpensive development of force sensors. Limitations of this rapid prototyping technology, however, require specialized design principles. In this paper, we discuss techniques for rapidly developing simple force sensors, including selecting and attaching metal flexures, using inexpensive and simple displacement transducers, and 3D printing features to aid in assembly. These design methods are illustrated through the design and fabrication of a miniature force sensor for the tip of a robotic catheter system. The resulting force sensor prototype can measure forces with an accuracy of as low as 2% of the 10 N measurement range. PMID:21874102

  11. Reconstruction of Frontal Bone With Custom-Made Prosthesis Using Rapid Prototyping.

    PubMed

    Florentino, Vinícius Gabriel Barros; Mendonça, Diego Santiago de; Bezerra, Ariel Valente; Silva, Leonardo de Freitas; Pontes, Rafael Figueirêdo; Melo, Carlos Vinícius Mota de; Mello, Manoel de Jesus Rodrigues; de Aguiar, Andréa Silvia Walter

    2016-06-01

    Frontal bone fracture treatment is still an issue of research in craniofacial surgery and neurosurgery. The aims of the treatment are to reduce the complication risks and to keep the aesthetic of the face. Before the management of this fracture type, it is necessary to consider the permanence or not of the frontal sinus function. Rapid prototyping has been an aid tool on planning and simulation of the surgical procedure, improving the diagnostic quality and the implant manufacture, beyond reducing the operative time. Among the used materials on treatment of these fractures, titanium mesh shows large versatility and ease of handling. Poly(methyl methacrylate) has been used in defects of partial thickness or irregularities on cranial surface. The aim of this study is to report a case of a patient presenting sequelae of large fracture of anterior wall of frontal bone, treated by a titanium mesh associated with the customized poly(methyl methacrylate) implant from the rapid prototyping. It could be concluded that the use of this technique showed itself effective on patient treatment, and rapid prototyping demonstrated being a valuable tool showing predictable and satisfactory results. PMID:27285896

  12. Enhancements to ASHRAE Standard 90.1 Prototype Building Models

    SciTech Connect

    Goel, Supriya; Athalye, Rahul A.; Wang, Weimin; Zhang, Jian; Rosenberg, Michael I.; Xie, YuLong; Hart, Philip R.; Mendon, Vrushali V.

    2014-04-16

    This report focuses on enhancements to prototype building models used to determine the energy impact of various versions of ANSI/ASHRAE/IES Standard 90.1. Since the last publication of the prototype building models, PNNL has made numerous enhancements to the original prototype models compliant with the 2004, 2007, and 2010 editions of Standard 90.1. Those enhancements are described here and were made for several reasons: (1) to change or improve prototype design assumptions; (2) to improve the simulation accuracy; (3) to improve the simulation infrastructure; and (4) to add additional detail to the models needed to capture certain energy impacts from Standard 90.1 improvements. These enhancements impact simulated prototype energy use, and consequently impact the savings estimated from edition to edition of Standard 90.1.

  13. Novel grinding stone used for polishing 3D plastic replica with rapid prototyping technology

    NASA Astrophysics Data System (ADS)

    Feng, Wang; Niikura, Yoshihiro; Sato, Toshio; Kawashima, Norimichi

    2006-01-01

    Rapid prototyping (RP) apparatus accepts a specific format translated from CAD data (patient's CT) and "slices" it into two-dimensional cross sections for laser photo curing. Surgeon can conduct safer surgery by reappearing on an actual model using 3D plastic replica in the preoperative. Polishing has to be used to eliminate the marks after removal of supports and the build layer pitches. Complicated and narrow areas of the 3D replica are difficult to be polished with the conventional grinding stone. This study proposes a novel grinding stone and introduces its producing process and characteristics. The novel grinding stone has many advantages as follows; (1) Preparation is possible of grinding stone that follows the complicated shape. (2) Grinding stone with uniformly dispersed abrasive grains can be prepared using magnetic particles and magnetic field. (3) Reshaping of grinding stone by heating is possible since the binder is made of a thermoplastic resin. (4) Every process can easily be carried out. We could polish to eliminate the marks after removal of supports and the build layer pitches on 3D plastic replica surface with the grinding stone.

  14. Rapid prototyping of coupled photonic cavities by focused ion beam/photolithography hybrid technique

    NASA Astrophysics Data System (ADS)

    Viegas, Jaime; Xing, Peng

    2014-03-01

    Hybrid photolithography and focused ion beam (FIB) patterning of coupled photonic cavities is reported. This technique is used for rapid prototyping of nanophotonic devices, where previously mass-produced devices by conventional lithography steps, such as photolithography, projection lithography or nano/micro-imprinting can be customized by a versatile approach on a focused ion beam microscope. This requires accurate positioning of the FIB pattern relative to the pre-patterned devices and minimal drift during the writing phase. Various fabrication parameters that mimic process variability can be studied and the obtained experimental results compared with numerical simulations of the fabricated devices. This allows the calibration of the simulation models for more accurate design to manufacturing predictability. As a proof of concept, the experimental optimization of the localized modes in a photonic molecule formed by placing two one-dimensional photonic crystal cavities on a nanowire coupler is reported. The effects of different photonic crystal geometry, material removal depth and rate, sidewall profile and roughness, patterning drift on the performance of the photonic molecule resonator are investigated. These fabricated photonic molecule devices can be used as refractive index sensors with measured sensitivities on the order of 400 nm/RIU with a sensing volume as low as 18 femtoliters. The dimensions of the fabricated devices and the understanding of their optical behavior on environmental influence open the door for near-field optical spectroscopy of single bacterial specimens.

  15. Processing of pure Ti by rapid prototyping based on laser cladding

    NASA Astrophysics Data System (ADS)

    Arias-González, F.; del Val, J.; Comesaña, R.; Lusquiños, F.; Quintero, F.; Riveiro, A.; Boutinguiza, M.; Pou, J.

    2013-11-01

    Rapid prototyping based on laser cladding is an additive manufacturing (AM) process based on the overlapping of cladding tracks to produce functional components. Powder or wire are fed into a melting pool created using laser radiation as a heat source and the relative movement between the beam and the work piece makes possible to generate pieces layer-by-layer. This technique can be applied for any material which can be melted and the components can be manufactured directly according to a computer aided design (CAD) model. Additive manufacturing is particularly interesting to produce titanium components because, in this case, the loss of material produced by subtractive manufacturing methods is highly costly. Moreover, titanium and its alloys are widely used in biomedical, aircraft, chemical and marine industries due to their biocompatibility, excellent corrosion resistance and superior strength-to-weight ratio. In this research work, a near-infrared laser delivering a maximum power of 500W is used to produce pure titanium thin parts. Dimensions and surface morphology are characterized using Optical Microscopy (OM) and Scanning Electron Microscopy (SEM), the hardness by nanoindentation and the composition by X-Ray Diffraction (XRD) and Energy Dispersive X-Ray Spectroscopy (EDS). The aim of this work is to establish the conditions under which satisfactory properties are obtained and to understand the relationship between microstructure/properties and deposition parameters.

  16. The development of a rapid prototyping prosthetic socket coated with a resin layer for transtibial amputees.

    PubMed

    Hsu, L H; Huang, G F; Lu, C T; Hong, D Y; Liu, S H

    2010-03-01

    This article proposes a type of transtibial socket composed of an inner layer fabricated by a rapid prototyping (RP) machine and an outer layer coated with unsaturated polyester resin. This work integrates contemporary technologies including a handheld scanner and CAD systems, to design a thin primary socket shape and then manufactures the socket using a fused deposition-modeling machine. To prevent breakage caused by the layer-based forming process and to reinforce flexural strength, the current research coats the preliminary RP socket with a layer of unsaturated polyester resin. After shaping the proximal brim of the resin-reinforced RP socket to match the specific stump, this study assembles and aligns a shank and a prosthetic foot to form a prosthesis set. After completing a trial safety walk wearing the prosthesis, which is satisfactory to the amputee and a registered prosthetist, this research measures interface pressures between the stump and the resin-reinforced RP socket. Experiment results demonstrate that the resin-reinforced RP socket is applicable for transtibial amputees. In addition to strengthening the FDM socket and producing consistent socket fit, this study also demonstrates a feasible procedure that employs current technologies to design and manufacture transtibial sockets without plaster moulds.

  17. Rapid prototyping amphiphilic polymer/hydroxyapatite composite scaffolds with hydration-induced self-fixation behavior.

    PubMed

    Kutikov, Artem B; Gurijala, Anvesh; Song, Jie

    2015-03-01

    Two major factors hampering the broad use of rapid prototyped biomaterials for tissue engineering applications are the requirement for custom-designed or expensive research-grade three-dimensional (3D) printers and the limited selection of suitable thermoplastic biomaterials exhibiting physical characteristics desired for facile surgical handling and biological properties encouraging tissue integration. Properly designed thermoplastic biodegradable amphiphilic polymers can exhibit hydration-dependent hydrophilicity changes and stiffening behavior, which may be exploited to facilitate the surgical delivery/self-fixation of the scaffold within a physiological tissue environment. Compared to conventional hydrophobic polyesters, they also present significant advantages in blending with hydrophilic osteoconductive minerals with improved interfacial adhesion for bone tissue engineering applications. Here, we demonstrated the excellent blending of biodegradable, amphiphilic poly(D,L-lactic acid)-poly(ethylene glycol)-poly(D,L-lactic acid) (PLA-PEG-PLA) (PELA) triblock co-polymer with hydroxyapatite (HA) and the fabrication of high-quality rapid prototyped 3D macroporous composite scaffolds using an unmodified consumer-grade 3D printer. The rapid prototyped HA-PELA composite scaffolds and the PELA control (without HA) swelled (66% and 44% volume increases, respectively) and stiffened (1.38-fold and 4-fold increases in compressive modulus, respectively) in water. To test the hypothesis that the hydration-induced physical changes can translate into self-fixation properties of the scaffolds within a confined defect, a straightforward in vitro pull-out test was designed to quantify the peak force required to dislodge these scaffolds from a simulated cylindrical defect at dry versus wet states. Consistent with our hypothesis, the peak fixation force measured for the PELA and HA-PELA scaffolds increased 6-fold and 15-fold upon hydration, respectively. Furthermore, we showed that

  18. Rapid Prototyping Amphiphilic Polymer/Hydroxyapatite Composite Scaffolds with Hydration-Induced Self-Fixation Behavior

    PubMed Central

    Kutikov, Artem B.; Gurijala, Anvesh

    2015-01-01

    Two major factors hampering the broad use of rapid prototyped biomaterials for tissue engineering applications are the requirement for custom-designed or expensive research-grade three-dimensional (3D) printers and the limited selection of suitable thermoplastic biomaterials exhibiting physical characteristics desired for facile surgical handling and biological properties encouraging tissue integration. Properly designed thermoplastic biodegradable amphiphilic polymers can exhibit hydration-dependent hydrophilicity changes and stiffening behavior, which may be exploited to facilitate the surgical delivery/self-fixation of the scaffold within a physiological tissue environment. Compared to conventional hydrophobic polyesters, they also present significant advantages in blending with hydrophilic osteoconductive minerals with improved interfacial adhesion for bone tissue engineering applications. Here, we demonstrated the excellent blending of biodegradable, amphiphilic poly(D,L-lactic acid)-poly(ethylene glycol)-poly(D,L-lactic acid) (PLA-PEG-PLA) (PELA) triblock co-polymer with hydroxyapatite (HA) and the fabrication of high-quality rapid prototyped 3D macroporous composite scaffolds using an unmodified consumer-grade 3D printer. The rapid prototyped HA-PELA composite scaffolds and the PELA control (without HA) swelled (66% and 44% volume increases, respectively) and stiffened (1.38-fold and 4-fold increases in compressive modulus, respectively) in water. To test the hypothesis that the hydration-induced physical changes can translate into self-fixation properties of the scaffolds within a confined defect, a straightforward in vitro pull-out test was designed to quantify the peak force required to dislodge these scaffolds from a simulated cylindrical defect at dry versus wet states. Consistent with our hypothesis, the peak fixation force measured for the PELA and HA-PELA scaffolds increased 6-fold and 15-fold upon hydration, respectively. Furthermore, we showed that

  19. Office-based rapid prototyping in orthopedic surgery: a novel planning technique and review of the literature.

    PubMed

    Schwartz, Adam; Money, Kyle; Spangehl, Mark; Hattrup, Steven; Claridge, Richard J; Beauchamp, Christopher

    2015-01-01

    Three-dimensional (3-D) prototyping, based on high-quality axial images, may allow for more accurate and extensive preoperative planning and may even allow surgeons to perform procedures as part of preoperative preparation. In this article, we describe 7 cases of complex orthopedic disorders that were surgically treated after preoperative planning that was based on both industry-provided models and use of our in-house 3-D printer. Commercially available 3-D printers allow for rapid in-office production of a high-quality realistic prototype at relatively low per-case cost. Using this technique, surgeons can assess the accuracy of their original surgical plans and, if necessary, correct them preoperatively. The ability to "perform surgery preoperatively" adds another element to surgeons' perceptions of the potential issues that may arise. PMID:25566552

  20. Investigation of rapid freeze prototyping and investment casting with ice patterns

    NASA Astrophysics Data System (ADS)

    Liu, Qingbin

    Rapid Freeze Prototyping (RFP) can generate three-dimensional ice patterns from CAD models by depositing and solidifying water droplets layer by layer. The waiting time between two successive layers is a critical factor. Finite Element Analysis (FEA) is employed to predict the solidification time of a newly deposited water layer in order to develop a better understanding of heat transfer during the RFP process. The result is used to investigate the effects of various process parameters on the solidification time of an ice column and a vertical ice wall. Experiments are conducted and the measured results are shown to agree well with simulation results. Investment casting with ice patterns is similar to that with wax patterns but with significant process differences. An interface agent can be coated around the ice pattern to protect it from damage during the process. To compensate for the thickness of the interface agent, analytical models have been constructed to predict the thickness of the interface agent for a large ice cylinder and for a small ice part. The dimensional accuracy of the generated metal castings for small parts can be much improved by compensating the interface layer thickness. Due to the use of ice, canned models must be made at sub-freezing temperatures. Success of this process depends significantly on curing kinetics of the slurries and the fracture toughness of mold materials. The curing kinetics of the slurries and mold material fracture toughness from different compositions are examined and the effects of various processing parameters on the results are examined and discussed.

  1. Habitat Demonstration Unit Project: Leadership and Management Strategies for a Rapid Prototyping Project

    NASA Technical Reports Server (NTRS)

    Kennedy, Kriss J.; Toup, Larry; Gill, Tracy; Tri, Terry; Howe, Scott; Smitherman, David

    2011-01-01

    This paper gives an overview of the National Aeronautics and Space Administration (NASA) led multi-center Habitat Demonstration Unit (HDU) project leadership and management strategies being used by the NASA HDU team for a rapid prototyping project. The HDU project team constructed and tested an analog prototype lunar surface habitat/laboratory called the Pressurized Excursion Module (PEM) during 2010. The prototype unit subsystems were integrated in a short amount of time, utilizing a tiger team rapid prototyping approach that brought together over 20 habitation-related technologies and innovations from a variety of NASA centers. This paper describes the leadership and management strategies as well as lessons learned pertaining to leading and managing a multi-center diverse team in a rapid prototype environment. The PEM configuration went from a paper design to an operational surface habitat demonstration unit in less than 12 months. The HDU project is part of the strategic plan from the Exploration Systems Mission Directorate (ESMD) Directorate Integration Office (DIO) and the Exploration Mission Systems Office (EMSO) to test destination elements in analog environments. The 2011 HDU-Deep Space Habitat (DSH) configuration will build upon the PEM work, and emphasize validity of crew operations (remote working and living), EVA operations, mission operations, logistics operations, and science operations that might be required in a deep space context for Near Earth Object (NEO) exploration mission architectures. The 2011 HDU-DSH will be field-tested during the 2011 Desert Research and Technologies Studies (DRaTS) field tests. The HDU project is a "technology-pull" project that integrates technologies and innovations from multiple NASA centers. This project will repurpose the HDU 2010 demo unit that was field tested in the 2010 DRaTS, adding habitation functionality to the prototype unit. This paper will describe the strategy of establishing a multi-center project

  2. Engineering Models Ease and Speed Prototyping

    NASA Technical Reports Server (NTRS)

    2008-01-01

    NASA astronauts plan to return to the Moon as early as 2015 and establish a lunar base, from which 6-month flights to Mars would be launched by 2030. Essential to this plan is the Ares launch vehicle, NASA s next-generation spacecraft that will, in various iterations, be responsible for transporting all equipment and personnel to the Moon, Mars, and beyond for the foreseeable future. The Ares launch vehicle is powered by the J-2X propulsion system, with what will be the world s largest rocket nozzles. One of the conditions that engineers carefully consider in designing rocket nozzles particularly large ones is called separation phenomenon, which occurs when outside ambient air is sucked into the nozzle rim by the relatively low pressures of rapidly expanding exhaust gasses. This separation of exhaust gasses from the side-wall imparts large asymmetric transverse loads on the nozzle, deforming the shape and thus perturbing exhaust flow to cause even greater separation. The resulting interaction can potentially crack the nozzle or break actuator arms that control thrust direction. Side-wall loads are extremely difficult to measure directly, and, until now, techniques were not available for accurately predicting the magnitude and frequency of the loads. NASA researchers studied separation phenomenon in scale-model rocket nozzles, seeking to use measured vibration on these nozzle replicas to calculate the unknown force causing the vibrations. Key to this approach was the creation of a computer model accurately representing the nozzle as well as the test cell.

  3. Rapid prototyping of robust and versatile microfluidic components using adhesive transfer tapes.

    PubMed

    Nath, Pulak; Fung, Derek; Kunde, Yuliya A; Zeytun, Ahmet; Branch, Brittany; Goddard, Greg

    2010-09-01

    A rapid prototyping technique of microfluidic devices is presented using adhesive transfer tapes. Lab on a chip systems can integrate multiple microfluidic functions in a single platform. Therefore, any rapid prototyping technique should be flexible and robust to accommodate different aspects of microfluidic integrations. In this work, the versatility of using adhesive transfer tapes for microfluidic applications is demonstrated by fabricating a wide range of platform. Prototypes demonstrating microfluidic mixing, dielectrophoretic trapping, complex microchannel networks and biologically relevant high temperature reactions were fabricated in less than 30 min. A novel ready to use world-to-chip interface was also developed using the same fabrication platform. All components (e.g. tapes, electrodes, acoustic sources or heaters) were obtained as finished products alleviating any chemical or clean-room specific processing. Only a 2D CAD software, a CO2 laser cutter and a seam roller was utilized to fabricate the devices. Adhesive transfer tapes provide additional flexibility compared to common double sided tapes as they do not contain any carrier material layer. Demonstrated ability to sustain in a wide range of dynamic physical processes (mechanical, electrical, or thermal) validates the robustness and the versatility of adhesive transfer tapes as an option for developing integrated lab on a chip systems. PMID:20593077

  4. SOAR telescope control system: a rapid prototype and development in LabVIEW

    NASA Astrophysics Data System (ADS)

    Ashe, Michael C.; Schumacher, German

    2000-06-01

    A Rapid Prototype and full development plan of the SOAR TCS is reviewed to show advances in: (1) Prototyping speed, which makes implementation and test of features faster than specification under older methods. This allows the development environment and prototype modules to become partners with and part of the specification documents. (2) Real-Time performance and reliability through use of RT Linux. (3) Visually Rich GUI development that allows an emphasis on `seeing' versus `reading'. (4) Long-Term DataLogging and Internet subscription service of all desired variables with instant recall of historical trend data. (5) A `plug-in' software architecture which enables rapid reconfiguration and reuse of the system and/or plug-ins utilizing LabVIEW graphical modules, a scripting language engine (in LabVIEW) and encapsulation of interfaces in `instrument-driver' style `plug-in' modules. (6) A platform- independent development environment and distributed architecture allowing secure internet observation and control via every major OS and hardware platform.

  5. Rapid and low-cost prototyping of medical devices using 3D printed molds for liquid injection molding.

    PubMed

    Chung, Philip; Heller, J Alex; Etemadi, Mozziyar; Ottoson, Paige E; Liu, Jonathan A; Rand, Larry; Roy, Shuvo

    2014-01-01

    Biologically inert elastomers such as silicone are favorable materials for medical device fabrication, but forming and curing these elastomers using traditional liquid injection molding processes can be an expensive process due to tooling and equipment costs. As a result, it has traditionally been impractical to use liquid injection molding for low-cost, rapid prototyping applications. We have devised a method for rapid and low-cost production of liquid elastomer injection molded devices that utilizes fused deposition modeling 3D printers for mold design and a modified desiccator as an injection system. Low costs and rapid turnaround time in this technique lower the barrier to iteratively designing and prototyping complex elastomer devices. Furthermore, CAD models developed in this process can be later adapted for metal mold tooling design, enabling an easy transition to a traditional injection molding process. We have used this technique to manufacture intravaginal probes involving complex geometries, as well as overmolding over metal parts, using tools commonly available within an academic research laboratory. However, this technique can be easily adapted to create liquid injection molded devices for many other applications. PMID:24998993

  6. Rapid and Low-cost Prototyping of Medical Devices Using 3D Printed Molds for Liquid Injection Molding

    PubMed Central

    Chung, Philip; Heller, J. Alex; Etemadi, Mozziyar; Ottoson, Paige E.; Liu, Jonathan A.; Rand, Larry; Roy, Shuvo

    2014-01-01

    Biologically inert elastomers such as silicone are favorable materials for medical device fabrication, but forming and curing these elastomers using traditional liquid injection molding processes can be an expensive process due to tooling and equipment costs. As a result, it has traditionally been impractical to use liquid injection molding for low-cost, rapid prototyping applications. We have devised a method for rapid and low-cost production of liquid elastomer injection molded devices that utilizes fused deposition modeling 3D printers for mold design and a modified desiccator as an injection system. Low costs and rapid turnaround time in this technique lower the barrier to iteratively designing and prototyping complex elastomer devices. Furthermore, CAD models developed in this process can be later adapted for metal mold tooling design, enabling an easy transition to a traditional injection molding process. We have used this technique to manufacture intravaginal probes involving complex geometries, as well as overmolding over metal parts, using tools commonly available within an academic research laboratory. However, this technique can be easily adapted to create liquid injection molded devices for many other applications. PMID:24998993

  7. Rapid and low-cost prototyping of medical devices using 3D printed molds for liquid injection molding.

    PubMed

    Chung, Philip; Heller, J Alex; Etemadi, Mozziyar; Ottoson, Paige E; Liu, Jonathan A; Rand, Larry; Roy, Shuvo

    2014-06-27

    Biologically inert elastomers such as silicone are favorable materials for medical device fabrication, but forming and curing these elastomers using traditional liquid injection molding processes can be an expensive process due to tooling and equipment costs. As a result, it has traditionally been impractical to use liquid injection molding for low-cost, rapid prototyping applications. We have devised a method for rapid and low-cost production of liquid elastomer injection molded devices that utilizes fused deposition modeling 3D printers for mold design and a modified desiccator as an injection system. Low costs and rapid turnaround time in this technique lower the barrier to iteratively designing and prototyping complex elastomer devices. Furthermore, CAD models developed in this process can be later adapted for metal mold tooling design, enabling an easy transition to a traditional injection molding process. We have used this technique to manufacture intravaginal probes involving complex geometries, as well as overmolding over metal parts, using tools commonly available within an academic research laboratory. However, this technique can be easily adapted to create liquid injection molded devices for many other applications.

  8. Rapid prototyping of zirconium diboride/copper electrical discharge machining electrodes

    NASA Astrophysics Data System (ADS)

    Stucker, Brent Eric

    The acceptance of rapid prototyping (RP) as the predominant technique for producing polymer and paper parts directly from computer-aided design (CAD) models has led many corporations and universities to try to extend its capabilities to more robust materials. In addition to producing prototype metal and ceramic parts, a significant effort has been made to create parts that are useful as tools and dies or that reduce the time necessary to create tools and dies. Most materials used for tools and dies are very hard, because they need to be able to withstand millions of cycles before failing. Electrical discharge machining (EDM) is the most common method used to machine tools and dies out of hard materials. A method for producing EDM electrodes using RP could greatly reduce the time and cost involved in creating tools and dies. A new EDM electrode material made up of zirconium diboride and copper (ZrBsb2/Cu) that is superior to traditional EDM electrodes has been investigated. The processing techniques necessary for creating Zrsb2/Cu electrodes from powders of ZrB2 and copper have been developed. These ZrBsb2/Cu electrodes have a better wear ratio and a faster sink rate than graphite, copper or tungsten/copper EDM electrodes. Performance variables that were tracked are: (1) wear ratio, (2) sink rate and (3) surface finish, where ZrBsb2/Cu, copper, graphite and W/Cu were used as anodes (electrodes) and stainless steel as cathodes (workpieces). The ZrBsb2/Cu electrode material system retains its superior EDM electrode performance across a number of materials processing and compositional variations. Scanning electron microscopy (SEM) was used to study the electrodes after EDM. These SEM observations facilitated an understanding of the superior EDM electrode performance characteristics of ZrBsb2/Cu to traditional EDM electrode material systems. A method for creating geometrically-complex ZrBsb2/Cu EDM electrodes using the selective laser sintering (SLS) RP technique was

  9. Ultra-rapid prototyping of flexible, multi-layered microfluidic devices via razor writing.

    PubMed

    Cosson, Steffen; Aeberli, Luc G; Brandenberg, Nathalie; Lutolf, Matthias P

    2015-01-01

    The fabrication of microfluidic devices is often still a time-consuming and costly process. Here we introduce a very simple and cheap microfabrication process based on "razor writing", also termed xurography, for the ultra-rapid prototyping of microfluidic devices. Thin poly(dimethylsiloxane) (PDMS) membranes are spin-coated on flexible plastic foil and cut into user-defined shapes with a bench-top cutter plotter. The PDMS membranes can then be assembled into desirable microdevices via plasma bonding. The plastic foil allows manipulation of exceptionally thin (30-300 μm) PDMS layers and can be readily peeled after fabrication. This versatile technique can be used to produce a wide variety of microfluidic device prototypes within just a few hours.

  10. Rapid prototyping and inclined plane technique in the treatment of maxillofacial malformations in a fox

    PubMed Central

    Freitas, Elisangela P.; Rahal, Sheila C.; Teixeira, Carlos R.; Silva, Jorge V.L.; Noritomi, Pedro Y.; Villela, Carlos H.S.; Yamashita, Seizo

    2010-01-01

    An approximately 9-month-old fox (Pseudalopex vetulus) was presented with malocclusion and deviation of the lower jaw to the right side. Orthodontic treatment was performed using the inclined plane technique. Virtual 3D models and prototypes of the head were based on computed tomography (CT) image data to assist in diagnosis and treatment. PMID:20514249

  11. Rapid prototyping and inclined plane technique in the treatment of maxillofacial malformations in a fox.

    PubMed

    Freitas, Elisangela P; Rahal, Sheila C; Teixeira, Carlos R; Silva, Jorge V L; Noritomi, Pedro Y; Villela, Carlos H S; Yamashita, Seizo

    2010-03-01

    An approximately 9-month-old fox (Pseudalopex vetulus) was presented with malocclusion and deviation of the lower jaw to the right side. Orthodontic treatment was performed using the inclined plane technique. Virtual 3D models and prototypes of the head were based on computed tomography (CT) image data to assist in diagnosis and treatment.

  12. Rapid prototyping of biodegradable microneedle arrays by integrating CO2 laser processing and polymer molding

    NASA Astrophysics Data System (ADS)

    Tu, K. T.; Chung, C. K.

    2016-06-01

    An integrated technology of CO2 laser processing and polymer molding has been demonstrated for the rapid prototyping of biodegradable poly-lactic-co-glycolic acid (PLGA) microneedle arrays. Rapid and low-cost CO2 laser processing was used for the fabrication of a high-aspect-ratio microneedle master mold instead of conventional time-consuming and expensive photolithography and etching processes. It is crucial to use flexible polydimethylsiloxane (PDMS) to detach PLGA. However, the direct CO2 laser-ablated PDMS could generate poor surfaces with bulges, scorches, re-solidification and shrinkage. Here, we have combined the polymethyl methacrylate (PMMA) ablation and two-step PDMS casting process to form a PDMS female microneedle mold to eliminate the problem of direct ablation. A self-assembled monolayer polyethylene glycol was coated to prevent stiction between the two PDMS layers during the peeling-off step in the PDMS-to-PDMS replication. Then the PLGA microneedle array was successfully released by bending the second-cast PDMS mold with flexibility and hydrophobic property. The depth of the polymer microneedles can range from hundreds of micrometers to millimeters. It is linked to the PMMA pattern profile and can be adjusted by CO2 laser power and scanning speed. The proposed integration process is maskless, simple and low-cost for rapid prototyping with a reusable mold.

  13. Linear DNA for rapid prototyping of synthetic biological circuits in an Escherichia coli based TX-TL cell-free system.

    PubMed

    Sun, Zachary Z; Yeung, Enoch; Hayes, Clarmyra A; Noireaux, Vincent; Murray, Richard M

    2014-06-20

    Accelerating the pace of synthetic biology experiments requires new approaches for rapid prototyping of circuits from individual DNA regulatory elements. However, current testing standards require days to weeks due to cloning and in vivo transformation. In this work, we first characterized methods to protect linear DNA strands from exonuclease degradation in an Escherichia coli based transcription-translation cell-free system (TX-TL), as well as mechanisms of degradation. This enabled the use of linear DNA PCR products in TX-TL. We then compared expression levels and binding dynamics of different promoters on linear DNA and plasmid DNA. We also demonstrated assembly technology to rapidly build circuits entirely in vitro from separate parts. Using this strategy, we prototyped a four component genetic switch in under 8 h entirely in vitro. Rapid in vitro assembly has future applications for prototyping multiple component circuits if combined with predictive computational models.

  14. Research and application of multimode tapered optical fiber use in desktop rapid prototyping system

    NASA Astrophysics Data System (ADS)

    Yang, Jiquan; Hou, Liya; Zhang, Weiyi; Yin, Zhidong; Chen, Li

    2001-10-01

    A new non-communication optical fiber--Multimode Tapered Optical Fiber (MTOF) is designed for Desktop Rapid Prototyping System(DRPS), which delivers much greater output energy than non-MTOF of the same output diameter. Its transmission ratio much increased. The DRPS' process is introduced, followed by the choose and design of MTOF, coupling and focusing of UV light. MTOF has some advantages, such as flexibility,low cost,high efficiency. The application of MTOF in DRPS that requires low cost will make concrete fundamental for populating the system.

  15. A Rapidly Prototyped Vegetation Dryness Index Evaluated for Wildfire Risk Assessment at Stennis Space Center

    NASA Technical Reports Server (NTRS)

    Ross, Kenton; Graham, William; Prados, Don; Spruce, Joseph

    2007-01-01

    MVDI, which effectively involves the differencing of NDMI and NDVI, appears to display increased noise that is consistent with a differencing technique. This effect masks finer variations in vegetation moisture, preventing MVDI from fulfilling the requirement of giving decision makers insight into spatial variation of fire risk. MVDI shows dependencies on land cover and phenology which also argue against its use as a fire risk proxy in an area of diverse and fragmented land covers. The conclusion of the rapid prototyping effort is that MVDI should not be implemented for SSC decision support.

  16. New technologies applied to surgical processes: Virtual Reality and rapid prototyping.

    PubMed

    Suárez-Mejías, Cristina; Gomez-Ciriza, Gorka; Valverde, Israel; Parra Calderón, Carlos; Gómez-Cía, Tomás

    2015-01-01

    AYRA is software of virtual reality for training, planning and optimizing surgical procedures. AYRA was developed under a research, development and innovation project financed by the Andalusian Ministry of Health, called VirSSPA. Nowadays AYRA has been successfully used in more than 1160 real cases and after proving its efficiency it has been introduced in the clinical practice at the Virgen del Rocío University Hospital . Furthermore, AYRA allows generating physical 3D biomodels using rapid prototyping technology. They are used for surgical planning support, intraoperative reference or defect reconstruction. In this paper, some of these tools and some real cases are presented.

  17. Rapid tooling for functional prototyping of metal mold processes: Literature review on cast tooling

    SciTech Connect

    Baldwin, M.D.; Hochanadel, P.W.

    1995-11-01

    This report is a literature review on cast tooling with the general focus on AISI H13 tool steel. The review includes processing of both wrought and cast H13 steel along with the accompanying microstructures. Also included is the incorporation of new rapid prototyping technologies, such as Stereolithography and Selective Laser Sintering, into the investment casting of tool steel. The limiting property of using wrought or cast tool steel for die casting is heat checking. Heat checking is addressed in terms of testing procedures, theories regarding the mechanism, and microstructural aspects related to the cracking.

  18. Interactive visual steering--rapid visual prototyping of a common rail injection system.

    PubMed

    Matković, Kresimir; Gracanin, Denis; Jelović, Mario; Hauser, Helwig

    2008-01-01

    Interactive steering with visualization has been a common goal of the visualization research community for twenty years, but it is rarely ever realized in practice. In this paper we describe a successful realization of a tightly coupled steering loop, integrating new simulation technology and interactive visual analysis in a prototyping environment for automotive industry system design. Due to increasing pressure on car manufacturers to meet new emission regulations, to improve efficiency, and to reduce noise, both simulation and visualization are pushed to their limits. Automotive system components, such as the powertrain system or the injection system have an increasing number of parameters, and new design approaches are required. It is no longer possible to optimize such a system solely based on experience or forward optimization. By coupling interactive visualization with the simulation back-end (computational steering), it is now possible to quickly prototype a new system, starting from a non-optimized initial prototype and the corresponding simulation model. The prototyping continues through the refinement of the simulation model, of the simulation parameters and through trial-and-error attempts to an optimized solution. The ability to early see the first results from a multidimensional simulation space--thousands of simulations are run for a multidimensional variety of input parameters--and to quickly go back into the simulation and request more runs in particular parameter regions of interest significantly improves the prototyping process and provides a deeper understanding of the system behavior. The excellent results which we achieved for the common rail injection system strongly suggest that our approach has a great potential of being generalized to other, similar scenarios. PMID:18989028

  19. Effects of Hydrocarbon-Based Grease on Rapid Prototype Material Used for Grease Retention Shrouds

    NASA Technical Reports Server (NTRS)

    Zakrajsek, Andrew J.; Valco, Daniel J.; Street, Kenneth W., Jr.

    2010-01-01

    Effects of hydrocarbon-based greases on specific rapid prototype (RP) materials used to fabricate grease retention shrouds (GRS) were explored in this study. Grease retention shrouds are being considered as a way to maintain adequate grease lubrication at the gear mesh in a prototype research transmission system. Due to their design and manufacturing flexibility, rapid prototype materials were chosen for the grease retention shrouds. In order to gain a better understanding of the short and long term effects grease pose on RP materials, research was conducted on the interaction of hydrocarbon-based grease with RP materials. The materials used in this study were durable polyamide (nylon), acrylonitrile butadiene styrene (ABS), and WaterClear 10120. Testing was conducted using Mobilgrease 28 and Syn-Tech 3913G grease (gear coupling grease). These greases were selected due to their regular use with mechanical components. To investigate the effect that grease has on RP materials, the following methods were used to obtain qualitative and quantitative data: Fourier transform infrared spectroscopy (FT-IR), interference profilometer measurements, digital camera imaging, physical shape measurement, and visual observations. To record the changes in the RP materials due to contact with the grease, data was taken before and after the grease application. Results showed that the WaterClear 10120 RP material provided the best resistance to grease penetration as compared to nylon and ABS RP materials. The manufacturing process, and thus resulting surface conditions of the RP material, played a key role in the grease penetration properties and resilience of these materials.

  20. Embedding VTK and ITK into a visual programming and rapid prototyping platform

    NASA Astrophysics Data System (ADS)

    Koenig, Matthias; Spindler, Wolf; Rexilius, Jan; Jomier, Julien; Link, Florian; Peitgen, Heinz-Otto

    2006-03-01

    Visualization and image processing of medical datasets has become an essential task for clinical diagnosis support as well as for treatment planning. In order to enable a physician to use and evaluate algorithms within a clinical setting, easily applicable software prototypes with a dedicated user interface are essential. However, substantial programming knowledge is still required today when using powerful open source libraries such as the Visualization Toolkit (VTK) or the Insight Toolkit (ITK). Moreover, these toolkits provide only limited graphical user interface functionality. In this paper, we present the visual programming and rapid prototyping platform MeVisLab which provides flexible and simple handling of visualization and image processing algorithms of VTK/ITK, Open Inventor and the MeVis Image Library by modular visual programming. No programming knowledge is required to set up image processing and visualization pipelines. Complete applications including user interfaces can be easily built within a general framework. In addition to the VTK/ITK features, MeVisLab provides a full integration of the Open Inventor library and offers a state-of-the-art integrated volume renderer. The integration of VTK/ITK algorithms is performed automatically: an XML structure is created from the toolkits' source code followed by an automatic module generation from this XML description. Thus, MeVisLab offers a one stop solution integrating VTK/ITK as modules and is suited for rapid prototyping as well as for teaching medical visualization and image analysis. The VTK/ITK integration is available as package of the free version of MeVisLab.

  1. Fastcast: Integration and application of rapid prototyping and computational simulation to investment casting

    SciTech Connect

    Maguire, M.C.; Baldwin, M.D.; Atwood, C.L.

    1996-09-01

    The emergence of several rapid prototyping and manufacturing (RP and M) technologies is having a dramatic impact on investment casting. While the most successful of the rapid prototyping technologies are almost a decade old, relatively recent process advances in their application have produced some remarkable success in utilizing their products as patterns for investment castings. Sandia National Laboratories has been developed highly coupled experimental and computational capabilities to examine the investment casting process with the intention of reducing the amount of time required to manufacture castings, and to increase the quality of the finished product. This presentation will begin with process aspects of RP and M pattern production and handling, shell fabrication, burnout, and casting. The emphasis will be on how the use of Stereolithography (SL) or Selective Laser Sintered (SLS) patterns differs from more traditional wax pattern processes. Aspects of computational simulation to couple design, thermal analysis, and mold filling will be discussed. Integration of these topics is probably the greatest challenge to the use of concurrent engineering principles with investment casting. Sandia has conducted several experiments aimed at calibrating computer codes and providing data for input into these simulations. Studies involving materials as diverse as stainless steel and gold have been conducted to determine liquid metal behavior in molds via real time radiography. The application of these experiments to predictive simulations will be described.

  2. The Java Image Science Toolkit (JIST) for Rapid Prototyping and Publishing of Neuroimaging Software

    PubMed Central

    Lucas, Blake C.; Bogovic, John A.; Carass, Aaron; Bazin, Pierre-Louis; Prince, Jerry L.; Pham, Dzung

    2010-01-01

    Non-invasive neuroimaging techniques enable extraordinarily sensitive and specific in vivo study of the structure, functional response and connectivity of biological mechanisms. With these advanced methods comes a heavy reliance on computer-based processing, analysis and interpretation. While the neuroimaging community has produced many excellent academic and commercial tool packages, new tools are often required to interpret new modalities and paradigms. Developing custom tools and ensuring interoperability with existing tools is a significant hurdle. To address these limitations, we present a new framework for algorithm development that implicitly ensures tool interoperability, generates graphical user interfaces, provides advanced batch processing tools, and, most importantly, requires minimal additional programming or computational overhead. Java-based rapid prototyping with this system is an efficient and practical approach to evaluate new algorithms since the proposed system ensures that rapidly constructed prototypes are actually fully-functional processing modules with support for multiple GUI's, a broad range of file formats, and distributed computation. Herein, we demonstrate MRI image processing with the proposed system for cortical surface extraction in large cross-sectional cohorts, provide a system for fully automated diffusion tensor image analysis, and illustrate how the system can be used as a simulation framework for the development of a new image analysis method. The system is released as open source under the Lesser GNU Public License (LGPL) through the Neuroimaging Informatics Tools and Resources Clearinghouse (NITRC). PMID:20077162

  3. Rapid prototyping of microfluidic systems using a PDMS/polymer tape composite.

    PubMed

    Kim, Jungkyu; Surapaneni, Rajesh; Gale, Bruce K

    2009-05-01

    Rapid prototyping of microfluidic systems using a combination of double-sided tape and PDMS (polydimethylsiloxane) is introduced. PDMS is typically difficult to bond using adhesive tapes due to its hydrophobic nature and low surface energy. For this reason, PDMS is not compatible with the xurography method, which uses a knife plotter and various adhesive coated polymer tapes. To solve these problems, a PDMS/tape composite was developed and demonstrated in microfluidic applications. The PDMS/tape composite was created by spinning it to make a thin layer of PDMS over double-sided tape. Then the PDMS/tape composite was patterned to create channels using xurography, and bonded to a PDMS slab. After removing the backing paper from the tape, a complete microfluidic system could be created by placing the construct onto nearly any substrate; including glass, plastic or metal-coated glass/silicon substrates. The bond strength was shown to be sufficient for the pressures that occur in typical microfluidic channels used for chemical or biological analysis. This method was demonstrated in three applications: standard microfluidic channels and reactors, a microfluidic system with an integrated membrane, and an electrochemical biosensor. The PDMS/tape composite rapid prototyping technique provides a fast and cost effective fabrication method and can provide easy integration of microfluidic channels with sensors and other components without the need for a cleanroom facility.

  4. A new UV-curing elastomeric substrate for rapid prototyping of microfluidic devices

    NASA Astrophysics Data System (ADS)

    Alvankarian, Jafar; Yeop Majlis, Burhanuddin

    2012-03-01

    Rapid prototyping in the design cycle of new microfluidic devices is very important for shortening time-to-market. Researchers are facing the challenge to explore new and suitable substrates with simple and efficient microfabrication techniques. In this paper, we introduce and characterize a UV-curing elastomeric polyurethane methacrylate (PUMA) for rapid prototyping of microfluidic devices. The swelling and solubility of PUMA in different chemicals is determined. Time-dependent measurements of water contact angle show that the native PUMA is hydrophilic without surface treatment. The current monitoring method is used for measurement of the electroosmotic flow mobility in the microchannels made from PUMA. The optical, physical, thermal and mechanical properties of PUMA are evaluated. The UV-lithography and molding process is used for making micropillars and deep channel microfluidic structures integrated to the supporting base layer. Spin coating is characterized for producing different layer thicknesses of PUMA resin. A device is fabricated and tested for examining the strength of different bonding techniques such as conformal, corona treating and semi-curing of two PUMA layers in microfluidic application and the results show that the bonding strengths are comparable to that of PDMS. We also report fabrication and testing of a three-layer multi inlet/outlet microfluidic device including a very effective fluidic interconnect for application demonstration of PUMA as a promising new substrate. A simple micro-device is developed and employed for observing the pressure deflection of membrane made from PUMA as a very effective elastomeric valve in microfluidic devices.

  5. Advances in three-dimensional rapid prototyping of microfluidic devices for biological applications.

    PubMed

    O'Neill, P F; Ben Azouz, A; Vázquez, M; Liu, J; Marczak, S; Slouka, Z; Chang, H C; Diamond, D; Brabazon, D

    2014-09-01

    The capability of 3D printing technologies for direct production of complex 3D structures in a single step has recently attracted an ever increasing interest within the field of microfluidics. Recently, ultrafast lasers have also allowed developing new methods for production of internal microfluidic channels within the bulk of glass and polymer materials by direct internal 3D laser writing. This review critically summarizes the latest advances in the production of microfluidic 3D structures by using 3D printing technologies and direct internal 3D laser writing fabrication methods. Current applications of these rapid prototyped microfluidic platforms in biology will be also discussed. These include imaging of cells and living organisms, electrochemical detection of viruses and neurotransmitters, and studies in drug transport and induced-release of adenosine triphosphate from erythrocytes.

  6. Innovative Applications of Laser Scanning and Rapid Prototype Printing to Rock Breakdown Experiments

    NASA Technical Reports Server (NTRS)

    Bourke, Mary; Viles, Heather; Nicoll, Joe; Lyew-Ayee, Parris; Ghent, Rebecca; Holmlund, James

    2008-01-01

    We present the novel application of two technologies for use in rock breakdown experiments, i.e. close-range, ground-based 3D triangulation scanning and rapid prototype printing. These techniques aid analyses of form-process interactions across the range of scales relevant to breakdown (micron-m). This is achieved through (a) the creation of DEMs (which permit quantitative description and analysis of rock surface morphology and morphological change) and (b) the production of more realistically-shaped experimental blocks. We illustrate the use of these techniques, alongside appropriate data analysis routines, in experiments designed to investigate the persistence of fluvially-derived features in the face of subsequent wind abrasion and weathering. These techniques have a range of potential applications in experimental field and lab-based geomorphic studies beyond those specifically outlined here.

  7. Rapid prototyping of three-dimensional microstructures from multiwalled carbon nanotubes

    SciTech Connect

    Hung, W.H.; Kumar, Rajay; Bushmaker, Adam; Cronin, Stephen B.; Bronikowski, Michael J.

    2007-08-27

    The authors report a method for creating three-dimensional carbon nanotube structures, whereby a focused laser beam is used to selectively burn local regions of a dense forest of multiwalled carbon nanotubes. Raman spectroscopy and scanning electron microscopy are used to quantify the threshold for laser burnout and depth of burnout. The minimum power density for burning carbon nanotubes in air is found to be 244 {mu}W/{mu}m{sup 2}. We create various three-dimensional patterns using this method, illustrating its potential use for the rapid prototyping of carbon nanotube microstructures. Undercut profiles, changes in nanotube density, and nanoparticle formation are observed after laser surface treatment and provide insight into the dynamic process of the burnout mechanism.

  8. Lab on a Biomembrane: rapid prototyping and manipulation of 2D fluidic lipid bilayers circuits.

    PubMed

    Ainla, Alar; Gözen, Irep; Hakonen, Bodil; Jesorka, Aldo

    2013-09-25

    Lipid bilayer membranes are among the most ubiquitous structures in the living world, with intricate structural features and a multitude of biological functions. It is attractive to recreate these structures in the laboratory, as this allows mimicking and studying the properties of biomembranes and their constituents, and to specifically exploit the intrinsic two-dimensional fluidity. Even though diverse strategies for membrane fabrication have been reported, the development of related applications and technologies has been hindered by the unavailability of both versatile and simple methods. Here we report a rapid prototyping technology for two-dimensional fluidic devices, based on in-situ generated circuits of phospholipid films. In this "lab on a molecularly thin membrane", various chemical and physical operations, such as writing, erasing, functionalization, and molecular transport, can be applied to user-defined regions of a membrane circuit. This concept is an enabling technology for research on molecular membranes and their technological use.

  9. Advances in three-dimensional rapid prototyping of microfluidic devices for biological applications

    PubMed Central

    O'Neill, P. F.; Ben Azouz, A.; Vázquez, M.; Liu, J.; Marczak, S.; Slouka, Z.; Chang, H. C.; Diamond, D.; Brabazon, D.

    2014-01-01

    The capability of 3D printing technologies for direct production of complex 3D structures in a single step has recently attracted an ever increasing interest within the field of microfluidics. Recently, ultrafast lasers have also allowed developing new methods for production of internal microfluidic channels within the bulk of glass and polymer materials by direct internal 3D laser writing. This review critically summarizes the latest advances in the production of microfluidic 3D structures by using 3D printing technologies and direct internal 3D laser writing fabrication methods. Current applications of these rapid prototyped microfluidic platforms in biology will be also discussed. These include imaging of cells and living organisms, electrochemical detection of viruses and neurotransmitters, and studies in drug transport and induced-release of adenosine triphosphate from erythrocytes. PMID:25538804

  10. A system for rapid prototyping of hearts with congenital malformations based on the medical imaging interaction toolkit (MITK)

    NASA Astrophysics Data System (ADS)

    Wolf, Ivo; Böttger, Thomas; Rietdorf, Urte; Maleike, Daniel; Greil, Gerald; Sieverding, Ludger; Miller, Stephan; Mottl-Link, Sibylle; Meinzer, Hans-Peter

    2006-03-01

    Precise knowledge of the individual cardiac anatomy is essential for diagnosis and treatment of congenital heart disease. Complex malformations of the heart can best be comprehended not from images but from anatomic specimens. Physical models can be created from data using rapid prototyping techniques, e.g., lasersintering or 3D-printing. We have developed a system for obtaining data that show the relevant cardiac anatomy from high-resolution CT/MR images and are suitable for rapid prototyping. The challenge is to preserve all relevant details unaltered in the produced models. The main anatomical structures of interest are the four heart cavities (atria, ventricles), the valves and the septum separating the cavities, and the great vessels. These can be shown either by reproducing the morphology itself or by producing a model of the blood-pool, thus creating a negative of the morphology. Algorithmically the key issue is segmentation. Practically, possibilities allowing the cardiologist or cardiac surgeon to interactively check and correct the segmentation are even more important due to the complex, irregular anatomy and imaging artefacts. The paper presents the algorithmic and interactive processing steps implemented in the system, which is based on the open-source Medical Imaging Interaction Toolkit (MITK, www.mitk.org). It is shown how the principles used in MITK enable to assemble the system from modules (functionalities) developed independently from each other. The system allows to produce models of the heart (and other anatomic structures) of individual patients as well as to reproduce unique specimens from pathology collections for teaching purposes.

  11. Quantitative assessment of biophotonic imaging system performance with phantoms fabricated by rapid prototyping

    NASA Astrophysics Data System (ADS)

    Wang, Jianting; Coburn, James; Woolsey, Nicholas; Liang, Chia-Pin; Ramella-Roman, Jessica; Chen, Yu; Pfefer, Joshua

    2014-03-01

    In biophotonic imaging, turbid phantoms that are low-cost, biologically-relevant, and durable are desired for standardized performance assessment. Such phantoms often contain inclusions of varying depths and sizes in order to quantify key image quality characteristics such as penetration depth, sensitivity and contrast detectability. The emerging technique of rapid prototyping with three-dimensional (3D) printers provides a potentially revolutionary way to fabricate these structures. Towards this goal, we have characterized the optical properties and morphology of phantoms fabricated by two 3D printing approaches: thermosoftening and photopolymerization. Material optical properties were measured by spectrophotometry while the morphology of phantoms incorporating 0.2-1.0 mm diameter channels was studied by μCT, optical coherence tomography (OCT) and optical microscopy. A near-infrared absorbing dye and nanorods at several concentrations were injected into channels to evaluate detectability with a near-infrared hyperspectral reflectance imaging (HRI) system (650-1100 nm). Phantoms exhibited biologically-relevant scattering and low absorption across visible and near-infrared wavelengths. Although limitations in resolution were noted, channels with diameters of 0.4 mm or more could be reliably fabricated. The most significant problem noted was the porosity of phantoms generated with the thermosoftening-based printer. The aforementioned three imaging methods provided a valuable mix of insights into phantom morphology and may also be useful for detailed structural inspection of medical devices fabricated by rapid prototyping, such as customized implants. Overall, our findings indicate that 3D printing has significant potential as a method for fabricating well-characterized, standard phantoms for medical imaging modalities such as HRI.

  12. Novel CAD/CAM rapid prototyping of next-generation biomedical devices

    NASA Astrophysics Data System (ADS)

    Doraiswamy, Anand

    An aging population with growing healthcare needs demands multifaceted tools for diagnosis and treatment of health conditions. In the near-future, drug-administration devices, implantable devices/sensors, enhanced prosthesis, artificial and unique functional tissue constructs will become increasingly significant. Conventional technologies for mass-produced implants do not adequately take individual patient anatomy into consideration. Development of novel CAD/CAM rapid prototyping techniques may significantly accelerate progress of these devices for next-generation patient-care. In this dissertation, several novel rapid prototyping techniques have been introduced for next-generation biomedical applications. Two-photon polymerization was developed to microfabricate scaffolds for tissue engineering, microneedles for drug-delivery and ossicular replacement prostheses. Various photoplymers were evaluated for feasibility, mechanical properties, cytotoxicity, and surface properties. Laser direct write using MDW was utilized for developing microstructures of bioceramics such as hydroxyapatite, and viable mammalian osteosarcoma cells. CAD/CAM laser micromachining (CLM) was developed to engineer biointerfaces as surface recognition regions for differential adherence of cells and growth into tissue-like networks. CLM was also developed for engineering multi-cellular vascular networks. Cytotoxic evaluations and growth studies demonstrated VEGF-induced proliferation of HAAE-1 human aortic endothelial cells with inhibition of HA-VSMC human aortic smooth muscle cells. Finally, piiezoelectric inkjet printing was developed for controlled administration of natural and synthetic adhesives to overcome several problems associated with conventional tissue bonding materials, and greatly improve wound-repair in next generation eye repair, fracture fixation, organ fixation, wound closure, tissue engineering, and drug delivery devices.

  13. A microcontroller platform for the rapid prototyping of functional electrical stimulation-based gait neuroprostheses.

    PubMed

    Luzio de Melo, Paulo; da Silva, Miguel Tavares; Martins, Jorge; Newman, Dava

    2015-05-01

    Functional electrical stimulation (FES) has been used over the last decades as a method to rehabilitate lost motor functions of individuals with spinal cord injury, multiple sclerosis, and post-stroke hemiparesis. Within this field, researchers in need of developing FES-based control solutions for specific disabilities often have to choose between either the acquisition and integration of high-performance industry-level systems, which are rather expensive and hardly portable, or develop custom-made portable solutions, which despite their lower cost, usually require expert-level electronic skills. Here, a flexible low-cost microcontroller-based platform for rapid prototyping of FES neuroprostheses is presented, designed for reduced execution complexity, development time, and production cost. For this reason, the Arduino open-source microcontroller platform was used, together with off-the-shelf components whenever possible. The developed system enables the rapid deployment of portable FES-based gait neuroprostheses, being flexible enough to allow simple open-loop strategies but also more complex closed-loop solutions. The system is based on a modular architecture that allows the development of optimized solutions depending on the desired FES applications, even though the design and testing of the platform were focused toward drop foot correction. The flexibility of the system was demonstrated using two algorithms targeting drop foot condition within different experimental setups. Successful bench testing of the device in healthy subjects demonstrated these neuroprosthesis platform capabilities to correct drop foot. PMID:25919579

  14. Assessment of Data Assimilation with the Prototype High Resolution Rapid Refresh for Alaska (HRRRAK)

    NASA Technical Reports Server (NTRS)

    Harrison, Kayla; Morton, Don; Zavodsky, Brad; Chou, Shih

    2012-01-01

    The Arctic Region Supercomputing Center has been running a quasi-operational prototype of a High Resolution Rapid Refresh for Alaska (HRRRAK) at 3km resolution, initialized by the 13km Rapid Refresh (RR). Although the RR assimilates a broad range of observations into its analyses, experiments with the HRRRAK suggest that there may be added value in assimilating observations into the 3km initial conditions, downscaled from the 13km RR analyses. The NASA Short-term Prediction Research and Transition (SPoRT) group has been using assimilated data from the Atmospheric Infrared Sounder (AIRS) in WRF and WRF-Var simulations since 2004 with promising results. The sounder is aboard NASA s Aqua satellite, and provides vertical profiles of temperature and humidity. The Gridpoint Statistical Interpolation (GSI) system is then used to assimilate these vertical profiles into WRF forecasts. In this work, we assess the use of AIRS data in combination with other global data assimilation products on non-assimilated HRRRAK case studies. Two separate weather events will be assessed to qualitatively and quantitatively assess the impacts of AIRS data on HRRRAK forecasts.

  15. From Prototypes to Caricatures: Geometrical Models for Concept Typicality

    ERIC Educational Resources Information Center

    Ameel, Eef; Storms, Gert

    2006-01-01

    In three studies, we investigated to what extent a geometrical representation in a psychological space succeeds in predicting typicality in animal, natural food and artifact concepts and whether contrast categories contribute to the prediction. In Study 1, we compared the predictive value of a family resemblance-based prototype model with a…

  16. A frame-based domain-specific language for rapid prototyping of FPGA-based software-defined radios

    NASA Astrophysics Data System (ADS)

    Ouedraogo, Ganda Stephane; Gautier, Matthieu; Sentieys, Olivier

    2014-12-01

    The field-programmable gate array (FPGA) technology is expected to play a key role in the development of software-defined radio (SDR) platforms. As this technology evolves, low-level designing methods for prototyping FPGA-based applications did not change throughout the decades. In the outstanding context of SDR, it is important to rapidly implement new waveforms to fulfill such a stringent flexibility paradigm. At the current time, different proposals have defined, through software-based approaches, some efficient methods to prototype SDR waveforms in a processor-based running environment. This paper describes a novel design flow for FPGA-based SDR applications. This flow relies upon high-level synthesis (HLS) principles and leverages the nascent HLS tools. Its entry point is a domain-specific language (DSL) which handles the complexity of programming an FPGA and integrates some SDR features so as to enable automatic waveform control generation from a data frame model. Two waveforms (IEEE 802.15.4 and IEEE 802.11a) have been designed and explored via this new methodology, and the results are highlighted in this paper.

  17. Using rapid prototyping for new products development: application to jewelery design

    NASA Astrophysics Data System (ADS)

    Suret, S.; Bernard, Alain; Bocquet, Jean Claud

    1997-01-01

    The goal of this paper is to present the methodology for the development of new rings, from the physical prototype built by the designer. We show the problems related to 3D shape digitizing, surface modeling from clouds of points, and the building of the different rings corresponding to the fingers diameters. The role of stereolithography is shown in a first way as a mean for the reproduction of the CAD model, and in a second way, as the link to the industrial molds for gold casting. In the second part of this paper, we propose to give some other examples of case studies to complete the application of our methodologies in the jewelry field.

  18. Planar array stack design aided by rapid prototyping in development of air-breathing PEMFC

    NASA Astrophysics Data System (ADS)

    Chen, Chen-Yu; Lai, Wei-Hsiang; Weng, Biing-Jyh; Chuang, Huey-Jan; Hsieh, Ching-Yuan; Kung, Chien-Chih

    The polymer electrolyte membrane fuel cell (PEMFC) is one of the most important research topics in the new and clean energy area. The middle or high power PEMFCs can be applied to the transportation or the distributed power system. But for the small power application, it is needed to match the power requirement of the product generally. On the other hand, the direct methanol fuel cell (DMFC) is one of the most common type that researchers are interested in, but recently the miniature or the micro-PEMFCs attract more attention due to their advantages of high open circuit voltage and high power density. The objective of this study is to develop a new air-breathing planar array fuel cell stacked from 10 cells made by rapid prototyping technology which has potential for fast commercial design, low cost manufacturing, and even without converters/inverters for the system. In this paper, the main material of flow field plates is acrylonitrile-butadiene-styrene (ABS) which allows the fuel cell be mass-manufactured by plastic injection molding technology. The rapid prototyping technology is applied to construct the prototype and verify the practicability of the proposed stack design. A 10-cell air-breathing miniature PEMFC stack with a volume of 6 cm × 6 cm × 0.9 cm is developed and tested. Its segmented membrane electrode assembly (MEA) is designed with the active surface area of 1.3 cm × 1.3 cm in each individual MEA. The platinum loading at anode and cathode are 0.2 mg cm -2 and 0.4 mg cm -2, respectively. Results show that the peak power densities of the parallel connected and serial connected stack are 99 mW cm -2 at 0.425 V and 92 mW cm -2 at 4.25 V, respectively under the conditions of 70 °C relative saturated humidity (i.e., dew point temperature), ambient temperature and free convection air. Besides, the stack performance is increased under forced convection. If the cell surface air is blown by an electric fan, the peak power densities of parallel connected and

  19. Extrusion based rapid prototyping technique: an advanced platform for tissue engineering scaffold fabrication.

    PubMed

    Hoque, M Enamul; Chuan, Y Leng; Pashby, Ian

    2012-02-01

    Advances in scaffold design and fabrication technology have brought the tissue engineering field stepping into a new era. Conventional techniques used to develop scaffolds inherit limitations, such as lack of control over the pore morphology and architecture as well as reproducibility. Rapid prototyping (RP) technology, a layer-by-layer additive approach offers a unique opportunity to build complex 3D architectures overcoming those limitations that could ultimately be tailored to cater for patient-specific applications. Using RP methods, researchers have been able to customize scaffolds to mimic the biomechanical properties (in terms of structural integrity, strength, and microenvironment) of the organ or tissue to be repaired/replaced quite closely. This article provides intensive description on various extrusion based scaffold fabrication techniques and review their potential utility for TE applications. The extrusion-based technique extrudes the molten polymer as a thin filament through a nozzle onto a platform layer-by-layer and thus building 3D scaffold. The technique allows full control over pore architecture and dimension in the x- and y- planes. However, the pore height in z-direction is predetermined by the extruding nozzle diameter rather than the technique itself. This review attempts to assess the current state and future prospects of this technology.

  20. Rapid prototyping: porous titanium alloy scaffolds produced by selective laser melting for bone tissue engineering.

    PubMed

    Warnke, Patrick H; Douglas, Timothy; Wollny, Patrick; Sherry, Eugene; Steiner, Martin; Galonska, Sebastian; Becker, Stephan T; Springer, Ingo N; Wiltfang, Jörg; Sivananthan, Sureshan

    2009-06-01

    Selective laser melting (SLM), a method used in the nuclear, space, and racing industries, allows the creation of customized titanium alloy scaffolds with highly defined external shape and internal structure using rapid prototyping as supporting external structures within which bone tissue can grow. Human osteoblasts were cultured on SLM-produced Ti6Al4V mesh scaffolds to demonstrate biocompatibility using scanning electron microscopy (SEM), fluorescence microscopy after cell vitality staining, and common biocompatibility tests (lactate dihydrogenase (LDH), 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT), 5-bromo-2-deoxyuridine (BrdU), and water soluble tetrazolium (WST)). Cell occlusion of pores of different widths (0.45-1.2 mm) was evaluated. Scaffolds were tested for resistance to compressive force. SEM investigations showed osteoblasts with well-spread morphology and multiple contact points. Cell vitality staining and biocompatibility tests confirmed osteoblast vitality and proliferation on the scaffolds. Pore overgrowth increased during 6 weeks' culture at pore widths of 0.45 and 0.5 mm, and in the course of 3 weeks for pore widths of 0.55, 0.6, and 0.7 mm. No pore occlusion was observed on pores of width 0.9-1.2 mm. Porosity and maximum compressive load at failure increased and decreased with increasing pore width, respectively. In summary, the scaffolds are biocompatible, and pore width influences pore overgrowth, resistance to compressive force, and porosity.

  1. Rapid prototyping of tissue-engineering constructs, using photopolymerizable hydrogels and stereolithography.

    PubMed

    Dhariwala, Busaina; Hunt, Elaine; Boland, Thomas

    2004-01-01

    One of the most important aspects of tissue engineering is the design of the scaffold providing the mechanical strength and access to nutrients for the new tissue. For customized tissue engineering, it is essential to be able to fabricate three-dimensional scaffolds of various geometric shapes, in order to repair defects caused by accidents, surgery, or birth. Rapid prototyping or solid free-form fabrication (SFF) techniques hold great promise for designing three-dimensional customized scaffolds, yet traditional cell-seeding techniques may not provide enough cell mass for larger constructs. This article presents a novel attempt to fabricate three-dimensional scaffolds, using hydrogels combined with cell encapsulation to fabricate high-density tissue constructs. A commercially available stereolithography technique was applied to fabricate scaffolds using poly(ethylene oxide) and poly(ethylene glycol)dimethacrylate photopolymerizable hydrogels. Mechanical characterization shows the constructs to be comparable with soft tissues in terms of elasticity. High cell viability was achieved and high-density constructs fabricated.

  2. Rapid prototyping of multi-scale biomedical microdevices by combining additive manufacturing technologies.

    PubMed

    Hengsbach, Stefan; Lantada, Andrés Díaz

    2014-08-01

    The possibility of designing and manufacturing biomedical microdevices with multiple length-scale geometries can help to promote special interactions both with their environment and with surrounding biological systems. These interactions aim to enhance biocompatibility and overall performance by using biomimetic approaches. In this paper, we present a design and manufacturing procedure for obtaining multi-scale biomedical microsystems based on the combination of two additive manufacturing processes: a conventional laser writer to manufacture the overall device structure, and a direct-laser writer based on two-photon polymerization to yield finer details. The process excels for its versatility, accuracy and manufacturing speed and allows for the manufacture of microsystems and implants with overall sizes up to several millimeters and with details down to sub-micrometric structures. As an application example we have focused on manufacturing a biomedical microsystem to analyze the impact of microtextured surfaces on cell motility. This process yielded a relevant increase in precision and manufacturing speed when compared with more conventional rapid prototyping procedures.

  3. Rapid Prototyping of a High Sensitivity Graphene Based Glucose Sensor Strip

    PubMed Central

    Tehrani, Farshad; Reiner, Lisa; Bavarian, Behzad

    2015-01-01

    A rapid prototyping of an inexpensive, disposable graphene and copper nanocomposite sensor strip using polymeric flexible substrate for highly sensitive and selective nonenzymatic glucose detection has been developed and tested for direct oxidization of glucose. The CuNPs were electrochemically deposited on to the graphene sheets to improve electron transfer rates and to enhance electrocatalytic activity toward glucose. The graphene based electrode with CuNPs demonstrated a high degree of sensitivity (1101.3±56 μA/mM.cm2), excellent selectivity (without an interference with Ascorbic Acid, Uric Acid, Dopamine, and Acetaminophen), good stability with a linear response to glucose ranging from 0.1 mM to 0.6 mM concentration, and detection limits of 0.025 mM to 0.9 mM. Characterization of the electrodes was performed by scanning electron microscopy (FESEM and SEM). The electrochemical properties of the modified graphene electrodes were inspected by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and amperometry. PMID:26678700

  4. Porous titanium scaffolds fabricated using a rapid prototyping and powder metallurgy technique.

    PubMed

    Ryan, Garrett E; Pandit, Abhay S; Apatsidis, Dimitrios P

    2008-09-01

    One of the main issues in orthopaedic implant design is the fabrication of scaffolds that closely mimic the biomechanical properties of the surrounding bone. This research reports on a multi-stage rapid prototyping technique that was successfully developed to produce porous titanium scaffolds with fully interconnected pore networks and reproducible porosity and pore size. The scaffolds' porous characteristics were governed by a sacrificial wax template, fabricated using a commercial 3D-printer. Powder metallurgy processes were employed to generate the titanium scaffolds by filling around the wax template with titanium slurry. In the attempt to optimise the powder metallurgy technique, variations in slurry concentration, compaction pressure and sintering temperature were investigated. By altering the wax design template, pore sizes ranging from 200 to 400 microm were achieved. Scaffolds with porosities of 66.8 +/- 3.6% revealed compression strengths of 104.4+/-22.5 MPa in the axial direction and 23.5 +/- 9.6 MPa in the transverse direction demonstrating their anisotropic nature. Scaffold topography was characterised using scanning electron microscopy and microcomputed tomography. Three-dimensional reconstruction enabled the main architectural parameters such as pore size, interconnecting porosity, level of anisotropy and level of structural disorder to be determined. The titanium scaffolds were compared to their intended designs, as governed by their sacrificial wax templates. Although discrepancies in architectural parameters existed between the intended and the actual scaffolds, overall the results indicate that the porous titanium scaffolds have the properties to be potentially employed in orthopaedic applications.

  5. Rapid Prototyping of a High Sensitivity Graphene Based Glucose Sensor Strip.

    PubMed

    Tehrani, Farshad; Reiner, Lisa; Bavarian, Behzad

    2015-01-01

    A rapid prototyping of an inexpensive, disposable graphene and copper nanocomposite sensor strip using polymeric flexible substrate for highly sensitive and selective nonenzymatic glucose detection has been developed and tested for direct oxidization of glucose. The CuNPs were electrochemically deposited on to the graphene sheets to improve electron transfer rates and to enhance electrocatalytic activity toward glucose. The graphene based electrode with CuNPs demonstrated a high degree of sensitivity (1101.3 ± 56 μA/mM.cm2), excellent selectivity (without an interference with Ascorbic Acid, Uric Acid, Dopamine, and Acetaminophen), good stability with a linear response to glucose ranging from 0.1 mM to 0.6 mM concentration, and detection limits of 0.025 mM to 0.9 mM. Characterization of the electrodes was performed by scanning electron microscopy (FESEM and SEM). The electrochemical properties of the modified graphene electrodes were inspected by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and amperometry. PMID:26678700

  6. Rapid prototyping: porous titanium alloy scaffolds produced by selective laser melting for bone tissue engineering.

    PubMed

    Warnke, Patrick H; Douglas, Timothy; Wollny, Patrick; Sherry, Eugene; Steiner, Martin; Galonska, Sebastian; Becker, Stephan T; Springer, Ingo N; Wiltfang, Jörg; Sivananthan, Sureshan

    2009-06-01

    Selective laser melting (SLM), a method used in the nuclear, space, and racing industries, allows the creation of customized titanium alloy scaffolds with highly defined external shape and internal structure using rapid prototyping as supporting external structures within which bone tissue can grow. Human osteoblasts were cultured on SLM-produced Ti6Al4V mesh scaffolds to demonstrate biocompatibility using scanning electron microscopy (SEM), fluorescence microscopy after cell vitality staining, and common biocompatibility tests (lactate dihydrogenase (LDH), 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT), 5-bromo-2-deoxyuridine (BrdU), and water soluble tetrazolium (WST)). Cell occlusion of pores of different widths (0.45-1.2 mm) was evaluated. Scaffolds were tested for resistance to compressive force. SEM investigations showed osteoblasts with well-spread morphology and multiple contact points. Cell vitality staining and biocompatibility tests confirmed osteoblast vitality and proliferation on the scaffolds. Pore overgrowth increased during 6 weeks' culture at pore widths of 0.45 and 0.5 mm, and in the course of 3 weeks for pore widths of 0.55, 0.6, and 0.7 mm. No pore occlusion was observed on pores of width 0.9-1.2 mm. Porosity and maximum compressive load at failure increased and decreased with increasing pore width, respectively. In summary, the scaffolds are biocompatible, and pore width influences pore overgrowth, resistance to compressive force, and porosity. PMID:19072196

  7. Rapid prototyping of reflectors for vehicle lighting using laser activated remote phosphor

    NASA Astrophysics Data System (ADS)

    Lachmayer, Roland; Kloppenburg, Gerolf; Wolf, Alexander

    2015-03-01

    Bright white light sources are of significant importance for automotive front lighting systems. Today's upper class vehicles mainly use HID or LED as light source. As a further step in this development laser diode based systems offer high luminance, efficiency and allow the realization of new styling concepts and new dynamic lighting functions. These white laser diode systems can either be realized by mixing different spectral sources or by combining diodes with specific phosphors. Based on the approach of generating light using a laser and remote phosphor, lighting modules are manufactured. Four blue laser diodes (450 nm) are used to activate a phosphor coating and thus to achieve white light. A segmented paraboloid reflector generates the desired light distribution for an additional car headlamp. We use high speed milling and selective laser melting to build the reflector system for this lighting module. We compare the spectral reflection grade of these materials. Furthermore the generated modules are analyzed regarding their efficiency and light distribution. The use of Rapid Prototyping technologies allows an early validation of the chosen concept and is supposed to reduce cost and time in the product development process significantly. Therefor we discuss costs and times of the applied manufacturing technologies.

  8. Using CamiTK for rapid prototyping of interactive Computer Assisted Medical Intervention applications

    PubMed Central

    Promayon, Emmanuel; Fouard, Celine; Bailet, Mathieu; Deram, Aurelien; Fiard, Gaelle; Hungr, Nikolai; Luboz, Vincent; Payan, Yohan; Sarrazin, Johan; Saubat, Nicolas; Selmi, Sonia Yuki; Voros, Sandrine; Cinquin, Philippe; Troccaz, Jocelyne

    2013-01-01

    Computer Assisted Medical Intervention (CAMI hereafter) is a complex multi-disciplinary field. CAMI research requires the collaboration of experts in several fields as diverse as medicine, computer science, mathematics, instrumentation, signal processing, mechanics, modeling, automatics, optics, etc. CamiTK1 is a modular framework that helps researchers and clinicians to collaborate together in order to prototype CAMI applications by regrouping the knowledge and expertise from each discipline. It is an open-source, cross-platform generic and modular tool written in C++ which can handle medical images, surgical navigation, biomedicals simulations and robot control. This paper presents the Computer Assisted Medical Intervention ToolKit (CamiTK) and how it is used in various applications in our research team. PMID:24110841

  9. Rapid Model Fabrication and Testing for Aerospace Vehicles

    NASA Technical Reports Server (NTRS)

    Buck, Gregory M.

    2000-01-01

    Advanced methods for rapid fabrication and instrumentation of hypersonic wind tunnel models are being developed and evaluated at NASA Langley Research Center. Rapid aeroheating model fabrication and measurement techniques using investment casting of ceramic test models and thermographic phosphors are reviewed. More accurate model casting techniques for fabrication of benchmark metal and ceramic test models are being developed using a combination of rapid prototype patterns and investment casting. White light optical scanning is used for coordinate measurements to evaluate the fabrication process and verify model accuracy to +/- 0.002 inches. Higher-temperature (<210C) luminescent coatings are also being developed for simultaneous pressure and temperature mapping, providing global pressure as well as global aeroheating measurements. Together these techniques will provide a more rapid and complete experimental aerodynamic and aerothermodynamic database for future aerospace vehicles.

  10. Rapid world modelling for robotics

    SciTech Connect

    Littile, C.Q.; Wilson, C.W.

    1996-04-01

    The ability to use an interactive world model, whether it is for robotics simulation or most other virtual graphical environments, relies on the users ability to create an accurate world model. Typically this is a tedious process, requiring many hours to create 3-D CAD models of the surfaces within a workspace. The goal of this ongoing project is to develop usable methods to rapidly build world models of real world workspaces. This brings structure to an unstructured environment and allows graphical based robotics control to be accomplished in a reasonable time frame when traditional CAD modelling is not enough. To accomplish this, 3D range sensors are deployed to capture surface data within the workspace. This data is then transformed into surface maps, or models. A 3D world model of the workspace is built quickly and accurately, without ever having to put people in the environment.

  11. Rapid prototyping 3D virtual world interfaces within a virtual factory environment

    NASA Technical Reports Server (NTRS)

    Kosta, Charles Paul; Krolak, Patrick D.

    1993-01-01

    On-going work into user requirements analysis using CLIPS (NASA/JSC) expert systems as an intelligent event simulator has led to research into three-dimensional (3D) interfaces. Previous work involved CLIPS and two-dimensional (2D) models. Integral to this work was the development of the University of Massachusetts Lowell parallel version of CLIPS, called PCLIPS. This allowed us to create both a Software Bus and a group problem-solving environment for expert systems development. By shifting the PCLIPS paradigm to use the VEOS messaging protocol we have merged VEOS (HlTL/Seattle) and CLIPS into a distributed virtual worlds prototyping environment (VCLIPS). VCLIPS uses the VEOS protocol layer to allow multiple experts to cooperate on a single problem. We have begun to look at the control of a virtual factory. In the virtual factory there are actors and objects as found in our Lincoln Logs Factory of the Future project. In this artificial reality architecture there are three VCLIPS entities in action. One entity is responsible for display and user events in the 3D virtual world. Another is responsible for either simulating the virtual factory or communicating with the real factory. The third is a user interface expert. The interface expert maps user input levels, within the current prototype, to control information for the factory. The interface to the virtual factory is based on a camera paradigm. The graphics subsystem generates camera views of the factory on standard X-Window displays. The camera allows for view control and object control. Control or the factory is accomplished by the user reaching into the camera views to perform object interactions. All communication between the separate CLIPS expert systems is done through VEOS.

  12. Validation of thermal models for a prototypical MEMS thermal actuator.

    SciTech Connect

    Gallis, Michail A.; Torczynski, John Robert; Piekos, Edward Stanley; Serrano, Justin Raymond; Gorby, Allen D.; Phinney, Leslie Mary

    2008-09-01

    This report documents technical work performed to complete the ASC Level 2 Milestone 2841: validation of thermal models for a prototypical MEMS thermal actuator. This effort requires completion of the following task: the comparison between calculated and measured temperature profiles of a heated stationary microbeam in air. Such heated microbeams are prototypical structures in virtually all electrically driven microscale thermal actuators. This task is divided into four major subtasks. (1) Perform validation experiments on prototypical heated stationary microbeams in which material properties such as thermal conductivity and electrical resistivity are measured if not known and temperature profiles along the beams are measured as a function of electrical power and gas pressure. (2) Develop a noncontinuum gas-phase heat-transfer model for typical MEMS situations including effects such as temperature discontinuities at gas-solid interfaces across which heat is flowing, and incorporate this model into the ASC FEM heat-conduction code Calore to enable it to simulate these effects with good accuracy. (3) Develop a noncontinuum solid-phase heat transfer model for typical MEMS situations including an effective thermal conductivity that depends on device geometry and grain size, and incorporate this model into the FEM heat-conduction code Calore to enable it to simulate these effects with good accuracy. (4) Perform combined gas-solid heat-transfer simulations using Calore with these models for the experimentally investigated devices, and compare simulation and experimental temperature profiles to assess model accuracy. These subtasks have been completed successfully, thereby completing the milestone task. Model and experimental temperature profiles are found to be in reasonable agreement for all cases examined. Modest systematic differences appear to be related to uncertainties in the geometric dimensions of the test structures and in the thermal conductivity of the

  13. Application of Rapid Prototyping to the Investment Casting of Test Hardware (MSFC Center Director's Discretionary Fund Final Report, Project No. 98-08)

    NASA Technical Reports Server (NTRS)

    Cooper, K. G.; Wells, D.

    2000-01-01

    Investment casting masters of a selected propulsion hardware component, a fuel pump housing, were rapid prototyped on the several processes in-house, along with the new Z-Corp process acquired through this project. Also, tensile samples were prototyped and cast using the same significant parameters. The models were then shelled in-house using a commercial grade zircon-based slurry and stucco technique. Next, the shelled models were fired and cast by our in-house foundry contractor (IITRI), with NASA-23, a commonly used test hardware metal. The cast models are compared by their surface finish and overall appearance (i.e., the occurrence of pitting, warping, etc.), as well as dimensional accuracy.

  14. Key elements to successful rapid prototyping and building of a Michelson interferometer for space-based sensing applications

    NASA Astrophysics Data System (ADS)

    Webb, Merritt; Cordray, David; Cronin, Shaun; Walker, Gary

    2004-02-01

    The Crosstrack Infrared Sounder (CrIS) is one of the sensors now under development for the National Polar-orbiting Operational Environmental Satellite System (NPOESS) program. In order to reduce program risk and verify instrument performance rapid prototyping of the sensor and critical subsystems has been utilized. Key among these was a prototype instrument and a prototype interferometer. This prototype instrument is referred to as the EDU1 (Engineering Development Unit). A second effort was the build of a prototype interferometer as a part of an internal ITT effort. This was an uncompensated version of the CrIS interferometer. This was referred to as the Aluminum Prototype Interferometer. The idea was to move rapidly to hardware while exploring new technologies. This was built in 4 months. There were key success factors for both efforts. A set of clear cardinal requirements was established. The layout and the cardinal requirements therefore provided a conceptual overview and a basis for deriving lower level requirements. These requirements remained basically unchanged throughout the effort. Vendors were closely worked with but; key to this was the GD&T dimensions and datum"s that were established. These enabled sub systems to be independently produced and "snapped together" to produce a final assembly in a minimum time. Essentially many of the critical optical alignments were built in to the individual parts so the subsequent shiming was not required. Electronics to control the porchswing and Dynamic Alignment Mechanism were developed in existing servo control test beds and designed to be FPGA based. This allowed a high degree of flexibility. Success was also based on continuity of the key engineering leadership and effective communications between the team and a clear understanding of the technical issues by the engineering leadership team.

  15. Using the prototype willingness model to predict doping in sport.

    PubMed

    Whitaker, L; Long, J; Petróczi, A; Backhouse, S H

    2014-10-01

    To enable preventive measures to be designed, it is important to identify modifiable distal and proximal factors underlying doping behavior. This study investigated aspects of the prototype willingness model in relation to doping. A cross-sectional study was conducted involving 729 competitive athletes. Following ethical approval, athletes (mean age = 28.8 ± 10.1 years; 63% male) completed an online questionnaire, which assessed doping-related attitudes, norms, prototype perceptions, outcome expectancies, and behavioral willingness. Using hierarchical multiple regression analysis, 54.4% of the total variance in willingness to dope was explained. Specifically, past doping, attitudes, and favorability of performance enhancing substance user prototypes were the strongest unique predictors of willingness to dope. Athletes appeared most willing to dope if they were to suffer an injury, a dip in performance, or think others are doping and getting away with it. National-level athletes displayed significantly greater willingness to dope (Kruskal-Wallis γ2 = 35.9, P < 0.001) and perceived themselves as significantly more similar to a doper (Kruskal-Wallis γ2 = 13.4, P = 0.004) than athletes competing at any other level. The findings highlight the importance of extending anti-doping provision beyond elite-level sport and the need to target athletes' doping-related perceptions.

  16. CartaBlanca-rapid prototyping development environment for non-linear systems on unstructured grids.

    SciTech Connect

    VanderHeyden, W. B.; Livescu, D.; Padial-Collins, N. T.

    2002-01-01

    This talk describes a component-based nonlinear physical system simulation prototyping package written entirely in Java using objectoriented design, The package provides scientists and engineers a 'developer-friendly' software environment for large-scale computational algorithm and physical model development, on the Jacobian-Free Newton-Krylov solution method surrounding a finite-volume treatment of conservation equations. This enables a clean component-like implementation. We first provide motivation for the development of the software and then discuss software structure. Discussion .includes a description of the use of Java's built-in thread facility that enables parallel, shared-memory computations on a wide variety of unstructured grids with triangular, quadrilateral, tetrahedral and hexahedral elements. We also discuss the use of Java's inheritance mechanism in the construction of a hierarchy of physics systems objects and linear and nonlinear solver objects that simplify development and foster software re-use. Following this, we show results from example calculations and then discuss plans including the extension of the software to distributed memory computer systems.

  17. The use of an automated flight test management system in the development of a rapid-prototyping flight research facility

    NASA Technical Reports Server (NTRS)

    Duke, Eugene L.; Hewett, Marle D.; Brumbaugh, Randal W.; Tartt, David M.; Antoniewicz, Robert F.; Agarwal, Arvind K.

    1988-01-01

    An automated flight test management system (ATMS) and its use to develop a rapid-prototyping flight research facility for artificial intelligence (AI) based flight systems concepts are described. The ATMS provides a flight test engineer with a set of tools that assist in flight planning and simulation. This system will be capable of controlling an aircraft during the flight test by performing closed-loop guidance functions, range management, and maneuver-quality monitoring. The rapid-prototyping flight research facility is being developed at the Dryden Flight Research Facility of the NASA Ames Research Center (Ames-Dryden) to provide early flight assessment of emerging AI technology. The facility is being developed as one element of the aircraft automation program which focuses on the qualification and validation of embedded real-time AI-based systems.

  18. The Effect of Jetting Parameters on the Performance of Droplet Formation for Ink-Jet Rapid Prototyping

    NASA Technical Reports Server (NTRS)

    Helmer, Wayne

    1998-01-01

    Heinzl et al. (1985) reports that experiments in ink-jets to produce drawings or signals occurred as early as 1930. Various companies such as IBM and Pitney-Bowes have conducted extensive studies on these devices for many years. Many such reports are available in such journals as the IBM Journal of Research and Development. While numerous articles have been published on the jetting characteristics of ink and water, the literature is rather limited on fluids such as waxes (Gao & Sonin 1994) or non-water based fluids (Passow, et al. 1993). This present study extends the knowledge base to determine the performance of molten waxes in "ink-jet" type printers for rapid prototyping. The purpose of this research was to qualitatively and quantitatively study the droplet formation of a drop-on-demand ink-jet type nozzle system for rapid prototyping.

  19. Rapid prototyping and the ASME B5.54 standard for evaluation of machine tool performance

    SciTech Connect

    Lewis, G.K.; Rhorer, D.

    1998-03-01

    The Directed Light Fabrication (DLF) process has shown feasibility for rapid fabrication of metal to full density. Structural properties equivalent to those of conventionally processed material have been achieved. The process is performed without the use of stereolithography files using a more conventional CNC approach to developing the motion path from the CAD solid model and using multi-axis positioning to deposit material in any plane, not just the horizontal plane used in many current processes. The important criteria for evaluating a solid free-form deposit were suggested and used to evaluate a part produced by DLF example presented here.

  20. Development of Rapid, Continuous Calibration Techniques and Implementation as a Prototype System for Civil Engineering Materials Evaluation

    NASA Astrophysics Data System (ADS)

    Scott, M. L.; Gagarin, N.; Mekemson, J. R.; Chintakunta, S. R.

    2011-06-01

    Until recently, civil engineering material calibration data could only be obtained from material sample cores or via time consuming, stationary calibration measurements in a limited number of locations. Calibration data are used to determine material propagation velocities of electromagnetic waves in test materials for use in layer thickness measurements and subsurface imaging. Limitations these calibration methods impose have been a significant impediment to broader use of nondestructive evaluation methods such as ground-penetrating radar (GPR). In 2006, a new rapid, continuous calibration approach was designed using simulation software to address these measurement limitations during a Federal Highway Administration (FHWA) research and development effort. This continuous calibration method combines a digitally-synthesized step-frequency (SF)-GPR array and a data collection protocol sequence for the common midpoint (CMP) method. Modeling and laboratory test results for various data collection protocols and materials are presented in this paper. The continuous-CMP concept was finally implemented for FHWA in a prototype demonstration system called the Advanced Pavement Evaluation (APE) system in 2009. Data from the continuous-CMP protocol is processed using a semblance/coherency analysis to determine material propagation velocities. Continuously calibrated pavement thicknesses measured with the APE system in 2009 are presented. This method is efficient, accurate, and cost-effective.

  1. Comparison of Conventional Methods and Laser-Assisted Rapid Prototyping for Manufacturing Fixed Dental Prostheses: An In Vitro Study.

    PubMed

    Pompa, Giorgio; Di Carlo, Stefano; De Angelis, Francesca; Cristalli, Maria Paola; Annibali, Susanna

    2015-01-01

    This study assessed whether there are differences in marginal fit between laser-fusion and conventional techniques to produce fixed dental prostheses (FDPs). A master steel die with 2 abutments was produced to receive a posterior 4-unit FDPs and single copings. These experimental models were divided into three groups (n = 20/group) manufactured: group 1, Ni-Cr alloy, with a lost-wax casting technique; group 2, Co-Cr alloy, with selective laser melting (SLM); and group 3, yttria-tetragonal zirconia polycrystal (Y-TZP), with a milling system. All specimens were cut along the longitudinal axis and their adaptation was measured at the marginal and shoulder areas on the right and left sides of each abutment. Measurements were made using a stereomicroscope (×60 magnification) and a scanning electron microscope (×800 magnification). The data were analyzed using one-way analysis of variance and the Bonferroni post hoc test, with a significance cutoff of 5%. Significant differences (P < 0.05) were observed between group 3 and the other groups. The marginal opening was smallest with Co-Cr alloy substructures, while the shoulder opening was smallest with Ni-Cr alloy substructures. Within the limitations of this study, the marginal fit of an FDP is better with rapid prototyping (RP) via SLM than conventional manufacturing systems.

  2. Comparison of Conventional Methods and Laser-Assisted Rapid Prototyping for Manufacturing Fixed Dental Prostheses: An In Vitro Study.

    PubMed

    Pompa, Giorgio; Di Carlo, Stefano; De Angelis, Francesca; Cristalli, Maria Paola; Annibali, Susanna

    2015-01-01

    This study assessed whether there are differences in marginal fit between laser-fusion and conventional techniques to produce fixed dental prostheses (FDPs). A master steel die with 2 abutments was produced to receive a posterior 4-unit FDPs and single copings. These experimental models were divided into three groups (n = 20/group) manufactured: group 1, Ni-Cr alloy, with a lost-wax casting technique; group 2, Co-Cr alloy, with selective laser melting (SLM); and group 3, yttria-tetragonal zirconia polycrystal (Y-TZP), with a milling system. All specimens were cut along the longitudinal axis and their adaptation was measured at the marginal and shoulder areas on the right and left sides of each abutment. Measurements were made using a stereomicroscope (×60 magnification) and a scanning electron microscope (×800 magnification). The data were analyzed using one-way analysis of variance and the Bonferroni post hoc test, with a significance cutoff of 5%. Significant differences (P < 0.05) were observed between group 3 and the other groups. The marginal opening was smallest with Co-Cr alloy substructures, while the shoulder opening was smallest with Ni-Cr alloy substructures. Within the limitations of this study, the marginal fit of an FDP is better with rapid prototyping (RP) via SLM than conventional manufacturing systems. PMID:26576419

  3. Comparison of Conventional Methods and Laser-Assisted Rapid Prototyping for Manufacturing Fixed Dental Prostheses: An In Vitro Study

    PubMed Central

    Pompa, Giorgio; Di Carlo, Stefano; De Angelis, Francesca; Cristalli, Maria Paola; Annibali, Susanna

    2015-01-01

    This study assessed whether there are differences in marginal fit between laser-fusion and conventional techniques to produce fixed dental prostheses (FDPs). A master steel die with 2 abutments was produced to receive a posterior 4-unit FDPs and single copings. These experimental models were divided into three groups (n = 20/group) manufactured: group 1, Ni-Cr alloy, with a lost-wax casting technique; group 2, Co-Cr alloy, with selective laser melting (SLM); and group 3, yttria-tetragonal zirconia polycrystal (Y-TZP), with a milling system. All specimens were cut along the longitudinal axis and their adaptation was measured at the marginal and shoulder areas on the right and left sides of each abutment. Measurements were made using a stereomicroscope (×60 magnification) and a scanning electron microscope (×800 magnification). The data were analyzed using one-way analysis of variance and the Bonferroni post hoc test, with a significance cutoff of 5%. Significant differences (P < 0.05) were observed between group 3 and the other groups. The marginal opening was smallest with Co-Cr alloy substructures, while the shoulder opening was smallest with Ni-Cr alloy substructures. Within the limitations of this study, the marginal fit of an FDP is better with rapid prototyping (RP) via SLM than conventional manufacturing systems. PMID:26576419

  4. Development of rapid, continuous calibration techniques and implementation as a prototype system for civil engineering materials evaluation

    SciTech Connect

    Scott, M. L.; Gagarin, N.; Mekemson, J. R.; Chintakunta, S. R.

    2011-06-23

    Until recently, civil engineering material calibration data could only be obtained from material sample cores or via time consuming, stationary calibration measurements in a limited number of locations. Calibration data are used to determine material propagation velocities of electromagnetic waves in test materials for use in layer thickness measurements and subsurface imaging. Limitations these calibration methods impose have been a significant impediment to broader use of nondestructive evaluation methods such as ground-penetrating radar (GPR). In 2006, a new rapid, continuous calibration approach was designed using simulation software to address these measurement limitations during a Federal Highway Administration (FHWA) research and development effort. This continuous calibration method combines a digitally-synthesized step-frequency (SF)-GPR array and a data collection protocol sequence for the common midpoint (CMP) method. Modeling and laboratory test results for various data collection protocols and materials are presented in this paper. The continuous-CMP concept was finally implemented for FHWA in a prototype demonstration system called the Advanced Pavement Evaluation (APE) system in 2009. Data from the continuous-CMP protocol is processed using a semblance/coherency analysis to determine material propagation velocities. Continuously calibrated pavement thicknesses measured with the APE system in 2009 are presented. This method is efficient, accurate, and cost-effective.

  5. Prototype Software for a Federal Planning Model for Analysis of Accessibility to Higher Education.

    ERIC Educational Resources Information Center

    Weldon, Kent; Huckfeldt, Vaughn

    This report presents the prototype software resulting from an initial research effort in the development of a comprehensive national planning model for higher education. The software for the prototype model requires as input existing or derivable institutional and student data and is designed to permit prototype planning studies to examine the…

  6. An Embedded Systems Laboratory to Support Rapid Prototyping of Robotics and the Internet of Things

    ERIC Educational Resources Information Center

    Hamblen, J. O.; van Bekkum, G. M. E.

    2013-01-01

    This paper describes a new approach for a course and laboratory designed to allow students to develop low-cost prototypes of robotic and other embedded devices that feature Internet connectivity, I/O, networking, a real-time operating system (RTOS), and object-oriented C/C++. The application programming interface (API) libraries provided permit…

  7. Fused Deposition Modelling as Rapid Prototyping for Structural Material Improvement: Analytical Solution / Ātrās Prototipēšanas Ar Kausēšanas Metodi Strukturālā Uzlabojuma Analītisks Risinājums

    NASA Astrophysics Data System (ADS)

    Brensons, I.; Polukoshko, S.

    2013-10-01

    Fused deposition modelling (FDM) is one of the most effective rapid prototyping (RP) techniques due to its low cost, available materials and versatility. In FDM, a part of material (usually plastic) is made by heating this material to the molten state, and from the melt it is extruded through a nozzle and deposited on a surface. In the article, an alternative RP method is considered for improvement of the mechanical properties of a rapid prototype. The authors propose an analytical solution which allows for achievement of this purpose via advanced technologies. The base materials applied in RP technology can be combined with liquid resin which solidifies after a definite time. This makes it possible to create a channel through the prototype and fill it with another material having better mechanical properties. The optimal channel sizes can be chosen in order to raise the strength of material parts. Darbā tiek apskatīts ātrās prototipēšanas veids, kura pamatā ir detaļas veidošana, izmantojot kausētu materiālu parasti plastmasu. Šī detaļu veidošanas metode ir kļuvusi par vienu no visizplatītākajām tās zemo izmaksu, pieejamo materiālu un daudzpusības dēļ. Šī raksta mērķis ir izpētīt alternatīvu veidu, kā uzlabot prototipu mehāniskās īpašības, tādējādi palielinot printētu detaļu izmantošanu kā gala produktu. Raksts piedāvā analītisku risinājumu, kā uzlabot ātro prototipu mehāniskās īpašības, uzlabojot tehnoloģiskos procesus, kas iesaistīti detaļu izgatavošanā. Darba pamatā tiek izmantota 3D printēšanas tehnoloģijas iespēja veidot iekšējus kanālus bez ģeometriskiem ierobežojumiem, kā rezultātā ir iespējams izveidot iekšēju kanālu shēmu, ko pēc tam piepilda ar citu materiālu, kam ir labākas mehāniskās īpašības kā pamata materiālam. Pildīšanai izmantotais materiāls ir epoksīda sveķi, kas pieļauj vieglu iepildīšanu šķidrā fāzē, un sniedz labas mehāniskās īpašības p

  8. Rapid prototyping for in vitro knee rig investigations of prosthetized knee biomechanics: comparison with cobalt-chromium alloy implant material.

    PubMed

    Schröder, Christian; Steinbrück, Arnd; Müller, Tatjana; Woiczinski, Matthias; Chevalier, Yan; Weber, Patrick; Müller, Peter E; Jansson, Volkmar

    2015-01-01

    Retropatellar complications after total knee arthroplasty (TKA) such as anterior knee pain and subluxations might be related to altered patellofemoral biomechanics, in particular to trochlear design and femorotibial joint positioning. A method was developed to test femorotibial and patellofemoral joint modifications separately with 3D-rapid prototyped components for in vitro tests, but material differences may further influence results. This pilot study aims at validating the use of prostheses made of photopolymerized rapid prototype material (RPM) by measuring the sliding friction with a ring-on-disc setup as well as knee kinematics and retropatellar pressure on a knee rig. Cobalt-chromium alloy (standard prosthesis material, SPM) prostheses served as validation standard. Friction coefficients between these materials and polytetrafluoroethylene (PTFE) were additionally tested as this latter material is commonly used to protect pressure sensors in experiments. No statistical differences were found between friction coefficients of both materials to PTFE. UHMWPE shows higher friction coefficient at low axial loads for RPM, a difference that disappears at higher load. No measurable statistical differences were found in knee kinematics and retropatellar pressure distribution. This suggests that using polymer prototypes may be a valid alternative to original components for in vitro TKA studies and future investigations on knee biomechanics. PMID:25879019

  9. Rapid Prototyping for In Vitro Knee Rig Investigations of Prosthetized Knee Biomechanics: Comparison with Cobalt-Chromium Alloy Implant Material

    PubMed Central

    Schröder, Christian; Steinbrück, Arnd; Müller, Tatjana; Woiczinski, Matthias; Chevalier, Yan; Müller, Peter E.; Jansson, Volkmar

    2015-01-01

    Retropatellar complications after total knee arthroplasty (TKA) such as anterior knee pain and subluxations might be related to altered patellofemoral biomechanics, in particular to trochlear design and femorotibial joint positioning. A method was developed to test femorotibial and patellofemoral joint modifications separately with 3D-rapid prototyped components for in vitro tests, but material differences may further influence results. This pilot study aims at validating the use of prostheses made of photopolymerized rapid prototype material (RPM) by measuring the sliding friction with a ring-on-disc setup as well as knee kinematics and retropatellar pressure on a knee rig. Cobalt-chromium alloy (standard prosthesis material, SPM) prostheses served as validation standard. Friction coefficients between these materials and polytetrafluoroethylene (PTFE) were additionally tested as this latter material is commonly used to protect pressure sensors in experiments. No statistical differences were found between friction coefficients of both materials to PTFE. UHMWPE shows higher friction coefficient at low axial loads for RPM, a difference that disappears at higher load. No measurable statistical differences were found in knee kinematics and retropatellar pressure distribution. This suggests that using polymer prototypes may be a valid alternative to original components for in vitro TKA studies and future investigations on knee biomechanics. PMID:25879019

  10. [Computer-aided method and rapid prototyping for the personalized fabrication of a silicone bandage digital prosthesis].

    PubMed

    Ventura Ferreira, Nuno; Leal, Nuno; Correia Sá, Inês; Reis, Ana; Marques, Marisa

    2014-01-01

    The fabrication of digital prostheses has acquired growing importance not only for the possibility for the patient to overcome psychosocial trauma but also to promote grip functionality. An application method of three dimensional-computer-aided design technologies for the production of passive prostheses is presented by means of a fifth finger amputee clinical case following bilateral hand replantation.Three-dimensional-computerized tomography was used for the collection of anthropometric images of the hands. Computer-aided design techniques were used to develop the digital file-based prosthesis from the reconstruction images by inversion and superimposing the contra-lateral finger images. The rapid prototyping manufacturing method was used for the production of a silicone bandage prosthesis prototype. This approach replaces the traditional manual method by a virtual method that is basis for the optimization of a high speed, accurate and innovative process.

  11. A highly miniaturized electron and ion energy spectrometer prototype for the rapid analysis of space plasmas

    SciTech Connect

    Bedington, R.; Kataria, D. O.; Smith, A.

    2014-02-15

    MEMS (Micro Electro-Mechanical Systems) plasma analyzers are a promising possibility for future space missions but conventional instrument designs are not necessarily well suited to micro-fabrication. Here, a candidate design for a MEMS-based instrument has been prototyped using electron-discharge machining. The device features 10 electrostatic analyzers that, with a single voltage applied to it, allow five different energies of electron and five different energies of positive ion to be simultaneously sampled. It has been simulated using SIMION and the electron response characteristics tested in an instrument calibration chamber. Small deviations found in the electrode spacing of the as-built prototype were found to have some effect on the electron response characteristics but do not significantly impede its performance.

  12. Advanced product realization through model-based design and virtual prototyping

    SciTech Connect

    Andreas, R.D.

    1995-03-01

    Several government agencies and industrial sectors have recognized the need for, and payoff of, investing in the methodologies and associated technologies for improving the product realization process. Within the defense community as well as commercial industry, there are three major needs. First, they must reduce the cost of military products, of related manufacturing processes, and of the enterprises that have to be maintained. Second, they must reduce the time required to realize products while still applying the latest technologies. Finally, they must improve the predictability of process attributes, product performance, cost, schedule and quality. They must continue to advance technology, quickly incorporate their innovations in new products and in processes to produce them, and they need to capitalize on the raw computational power and communications bandwidth that continues to become available at decreasing cost. Sandia National Laboratories initiative is pursuing several interrelated, key concepts and technologies in order to enable such product realization process improvements: model-based design; intelligent manufacturing processes; rapid virtual and physical prototyping; and agile people/enterprises. While progress in each of these areas is necessary, this paper only addresses a portion of the overall initiative. First a vision of a desired future capability in model-based design and virtual prototyping is presented. This is followed by a discussion of two specific activities parametric design analysis of Synthetic Aperture Radars (SARs) and virtual prototyping of miniaturized high-density electronics -- that exemplify the vision as well as provide a status report on relevant work in progress.

  13. Eagle II: A prototype for multi-resolution combat modeling

    SciTech Connect

    Powell, D.R.; Hutchinson, J.L.

    1993-02-01

    Eagle 11 is a prototype analytic model derived from the integration of the low resolution Eagle model with the high resolution SIMNET model. This integration promises a new capability to allow for a more effective examination of proposed or existing combat systems that could not be easily evaluated using either Eagle or SIMNET alone. In essence, Eagle II becomes a multi-resolution combat model in which simulated combat units can exhibit both high and low fidelity behavior at different times during model execution. This capability allows a unit to behave in a highly manner only when required, thereby reducing the overall computational and manpower requirements for a given study. In this framework, the SIMNET portion enables a highly credible assessment of the performance of individual combat systems under consideration, encompassing both engineering performance and crew capabilities. However, when the assessment being conducted goes beyond system performance and extends to questions of force structure balance and sustainment, then SISMNET results can be used to ``calibrate`` the Eagle attrition process appropriate to the study at hand. Advancing technologies, changes in the world-wide threat, requirements for flexible response, declining defense budgets, and down-sizing of military forces motivate the development of manpower-efficient, low-cost, responsive tools for combat development studies. Eagle and SIMNET both serve as credible and useful tools. The integration of these two models promises enhanced capabilities to examine the broader, deeper, more complex battlefield of the future with higher fidelity, greater responsiveness and low overall cost.

  14. Development of the prototype Munitions Case Moisture Meter, Model ORNL-1

    SciTech Connect

    Agouridis, D.C.; Gayle, T.M.; Griest, W.H.

    1993-02-24

    There is a great need for a rapid and simple means of determining the moisture content in combustible cartridge case (ccc) munitions. Previous studies have demonstrated that accumulation of moisture in ccc rounds, such as the M829, leads to softening of the case wall and weakening of the adhesive joint. Moisture in the ccc can lead to incomplete combustion of the case upon firing the round. Currently, there are no facile methods for measuring the moisture content. A prototype portable meter for non-destructive and rapid estimation of moisture in ccc has been developed. The Munitions Case Moisture Meter Model ORNL-1 demonstrates the feasibility of developing an instrument based on the moisture dependence of dielectric properties, to measure moisture in ccc munitions in storage and in the field. These instruments are simple, inexpensive, lightweight, portable, low-power battery operated, and intrinsically safe. They provide nondestructive, noninvasive, and rapid measurements. Calibration data for the prototype are not available at this time. Therefore, calibration of the meter and the development of a scale reading directly moisture content in munitions rounds could not be completed. These data will be supplied by the US Army from its tests of the meter with actual munitions. However, experimental results on empty cccs in laboratory conditions demonstrate satisfactory performance of the instrument. Additional work is needed to bring the prototype to its optimum usefulness and accuracy for field measurements. This includes: Calibration of the meter scale with full-up munitions; Data and evaluation procedures to adjust the performance of the meter for different environmental conditions such as temperature and humidity; and Studies of the dielectric properties of moist ccc materials, as a function of frequency and temperature, are needed for adjustment of the meter for optimal performance.

  15. Development of the prototype Munitions Case Moisture Meter, Model ORNL-1. Final report

    SciTech Connect

    Agouridis, D.C.; Gayle, T.M.; Griest, W.H.

    1993-02-24

    There is a great need for a rapid and simple means of determining the moisture content in combustible cartridge case (ccc) munitions. Previous studies have demonstrated that accumulation of moisture in ccc rounds, such as the M829, leads to softening of the case wall and weakening of the adhesive joint. Moisture in the ccc can lead to incomplete combustion of the case upon firing the round. Currently, there are no facile methods for measuring the moisture content. A prototype portable meter for non-destructive and rapid estimation of moisture in ccc has been developed. The Munitions Case Moisture Meter Model ORNL-1 demonstrates the feasibility of developing an instrument based on the moisture dependence of dielectric properties, to measure moisture in ccc munitions in storage and in the field. These instruments are simple, inexpensive, lightweight, portable, low-power battery operated, and intrinsically safe. They provide nondestructive, noninvasive, and rapid measurements. Calibration data for the prototype are not available at this time. Therefore, calibration of the meter and the development of a scale reading directly moisture content in munitions rounds could not be completed. These data will be supplied by the US Army from its tests of the meter with actual munitions. However, experimental results on empty cccs in laboratory conditions demonstrate satisfactory performance of the instrument. Additional work is needed to bring the prototype to its optimum usefulness and accuracy for field measurements. This includes: Calibration of the meter scale with full-up munitions; Data and evaluation procedures to adjust the performance of the meter for different environmental conditions such as temperature and humidity; and Studies of the dielectric properties of moist ccc materials, as a function of frequency and temperature, are needed for adjustment of the meter for optimal performance.

  16. New layer-based imaging and rapid prototyping techniques for computer-aided design and manufacture of custom dental restoration.

    PubMed

    Lee, M-Y; Chang, C-C; Ku, Y C

    2008-01-01

    Fixed dental restoration by conventional methods greatly relies on the skill and experience of the dental technician. The quality and accuracy of the final product depends mostly on the technician's subjective judgment. In addition, the traditional manual operation involves many complex procedures, and is a time-consuming and labour-intensive job. Most importantly, no quantitative design and manufacturing information is preserved for future retrieval. In this paper, a new device for scanning the dental profile and reconstructing 3D digital information of a dental model based on a layer-based imaging technique, called abrasive computer tomography (ACT) was designed in-house and proposed for the design of custom dental restoration. The fixed partial dental restoration was then produced by rapid prototyping (RP) and computer numerical control (CNC) machining methods based on the ACT scanned digital information. A force feedback sculptor (FreeForm system, Sensible Technologies, Inc., Cambridge MA, USA), which comprises 3D Touch technology, was applied to modify the morphology and design of the fixed dental restoration. In addition, a comparison of conventional manual operation and digital manufacture using both RP and CNC machining technologies for fixed dental restoration production is presented. Finally, a digital custom fixed restoration manufacturing protocol integrating proposed layer-based dental profile scanning, computer-aided design, 3D force feedback feature modification and advanced fixed restoration manufacturing techniques is illustrated. The proposed method provides solid evidence that computer-aided design and manufacturing technologies may become a new avenue for custom-made fixed restoration design, analysis, and production in the 21st century.

  17. New layer-based imaging and rapid prototyping techniques for computer-aided design and manufacture of custom dental restoration.

    PubMed

    Lee, M-Y; Chang, C-C; Ku, Y C

    2008-01-01

    Fixed dental restoration by conventional methods greatly relies on the skill and experience of the dental technician. The quality and accuracy of the final product depends mostly on the technician's subjective judgment. In addition, the traditional manual operation involves many complex procedures, and is a time-consuming and labour-intensive job. Most importantly, no quantitative design and manufacturing information is preserved for future retrieval. In this paper, a new device for scanning the dental profile and reconstructing 3D digital information of a dental model based on a layer-based imaging technique, called abrasive computer tomography (ACT) was designed in-house and proposed for the design of custom dental restoration. The fixed partial dental restoration was then produced by rapid prototyping (RP) and computer numerical control (CNC) machining methods based on the ACT scanned digital information. A force feedback sculptor (FreeForm system, Sensible Technologies, Inc., Cambridge MA, USA), which comprises 3D Touch technology, was applied to modify the morphology and design of the fixed dental restoration. In addition, a comparison of conventional manual operation and digital manufacture using both RP and CNC machining technologies for fixed dental restoration production is presented. Finally, a digital custom fixed restoration manufacturing protocol integrating proposed layer-based dental profile scanning, computer-aided design, 3D force feedback feature modification and advanced fixed restoration manufacturing techniques is illustrated. The proposed method provides solid evidence that computer-aided design and manufacturing technologies may become a new avenue for custom-made fixed restoration design, analysis, and production in the 21st century. PMID:18183523

  18. High-Throughput Generation of Emulsions and Microgels in Parallelized Microfluidic Drop-Makers Prepared by Rapid Prototyping.

    PubMed

    Femmer, Tim; Jans, Alexander; Eswein, Rudi; Anwar, Naveed; Moeller, Martin; Wessling, Matthias; Kuehne, Alexander J C

    2015-06-17

    We describe the preparation of rapid prototyped parallelized microfluidic drop-maker devices. The manufacturing technique facilitates stacking of the drop-makers vertically on top of each other allowing for a reduced footprint and minimized dead-volume through efficient design of the distribution channels. We showcase the potential of the additive manufacturing technique for microfluidics and the performance of the parallelized device by producing large amounts of microgels with a diameter of ca. 500 μm, a size that is inaccessible using traditional synthetic approaches. PMID:26040198

  19. Application of Rapid Prototyping and Wire Arc Spray to the Fabrication of Injection Mold Tools (MSFC Center Director's Discretionary Fund)

    NASA Technical Reports Server (NTRS)

    Cooper, K. G.

    2000-01-01

    Rapid prototyping (RP) is a layer-by-layer-based additive manufacturing process for constructing three-dimensional representations of a computer design from a wax, plastic, or similar material. Wire arc spray (WAS) is a metal spray forming technique, which deposits thin layers of metal onto a substrate or pattern. Marshall Space Flight Center currently has both capabilities in-house, and this project proposed merging the two processes into an innovative manufacturing technique, in which intermediate injection molding tool halves were to be fabricated with RP and WAS metal forming.

  20. Rapid prototyping of pneumatically actuated hydrocarbon gel valves for centrifugal microfluidic devices.

    PubMed

    Swayne, Laura; Kazarine, Alexei; Templeton, Erin J; Salin, Eric D

    2015-03-01

    A novel, easy to prototype hydrocarbon gel-based active valve was developed for use in centrifugal microfluidic devices. The valve has been demonstrated to restrict flow by an additional 1000 revolutions per minute (RPM) when compared to a passive capillary valve of the same size located at the same radius. Opening of the valve is accomplished in a contactless manner using a stream of focused compressed air. The ease of fabrication, low cost and small dimensions of the gel valve offer the potential for integration of multiple valves of this type into multi-process centrifugal microfluidic systems.

  1. Open-Source Wax RepRap 3-D Printer for Rapid Prototyping Paper-Based Microfluidics.

    PubMed

    Pearce, J M; Anzalone, N C; Heldt, C L

    2016-08-01

    The open-source release of self-replicating rapid prototypers (RepRaps) has created a rich opportunity for low-cost distributed digital fabrication of complex 3-D objects such as scientific equipment. For example, 3-D printable reactionware devices offer the opportunity to combine open hardware microfluidic handling with lab-on-a-chip reactionware to radically reduce costs and increase the number and complexity of microfluidic applications. To further drive down the cost while improving the performance of lab-on-a-chip paper-based microfluidic prototyping, this study reports on the development of a RepRap upgrade capable of converting a Prusa Mendel RepRap into a wax 3-D printer for paper-based microfluidic applications. An open-source hardware approach is used to demonstrate a 3-D printable upgrade for the 3-D printer, which combines a heated syringe pump with the RepRap/Arduino 3-D control. The bill of materials, designs, basic assembly, and use instructions are provided, along with a completely free and open-source software tool chain. The open-source hardware device described here accelerates the potential of the nascent field of electrochemical detection combined with paper-based microfluidics by dropping the marginal cost of prototyping to nearly zero while accelerating the turnover between paper-based microfluidic designs. PMID:26763294

  2. Beyond PDMS: off-stoichiometry thiol-ene (OSTE) based soft lithography for rapid prototyping of microfluidic devices.

    PubMed

    Carlborg, Carl Fredrik; Haraldsson, Tommy; Öberg, Kim; Malkoch, Michael; van der Wijngaart, Wouter

    2011-09-21

    In this article we introduce a novel polymer platform based on off-stoichiometry thiol-enes (OSTEs), aiming to bridge the gap between research prototyping and commercial production of microfluidic devices. The polymers are based on the versatile UV-curable thiol-ene chemistry but takes advantage of off-stoichiometry ratios to enable important features for a prototyping system, such as one-step surface modifications, tuneable mechanical properties and leakage free sealing through direct UV-bonding. The platform exhibits many similarities with PDMS, such as rapid prototyping and uncomplicated processing but can at the same time mirror the mechanical and chemical properties of both PDMS as well as commercial grade thermoplastics. The OSTE-prepolymer can be cast using standard SU-8 on silicon masters and a table-top UV-lamp, the surface modifications are precisely grafted using a stencil mask and the bonding requires only a single UV-exposure. To illustrate the potential of the material we demonstrate key concepts important in microfluidic chip fabrication such as patterned surface modifications for hydrophobic stops, pneumatic valves using UV-lamination of stiff and rubbery materials as well as micromachining of chip-to-world connectors in the OSTE-materials. PMID:21804987

  3. Beyond PDMS: off-stoichiometry thiol-ene (OSTE) based soft lithography for rapid prototyping of microfluidic devices.

    PubMed

    Carlborg, Carl Fredrik; Haraldsson, Tommy; Öberg, Kim; Malkoch, Michael; van der Wijngaart, Wouter

    2011-09-21

    In this article we introduce a novel polymer platform based on off-stoichiometry thiol-enes (OSTEs), aiming to bridge the gap between research prototyping and commercial production of microfluidic devices. The polymers are based on the versatile UV-curable thiol-ene chemistry but takes advantage of off-stoichiometry ratios to enable important features for a prototyping system, such as one-step surface modifications, tuneable mechanical properties and leakage free sealing through direct UV-bonding. The platform exhibits many similarities with PDMS, such as rapid prototyping and uncomplicated processing but can at the same time mirror the mechanical and chemical properties of both PDMS as well as commercial grade thermoplastics. The OSTE-prepolymer can be cast using standard SU-8 on silicon masters and a table-top UV-lamp, the surface modifications are precisely grafted using a stencil mask and the bonding requires only a single UV-exposure. To illustrate the potential of the material we demonstrate key concepts important in microfluidic chip fabrication such as patterned surface modifications for hydrophobic stops, pneumatic valves using UV-lamination of stiff and rubbery materials as well as micromachining of chip-to-world connectors in the OSTE-materials.

  4. Open-Source Wax RepRap 3-D Printer for Rapid Prototyping Paper-Based Microfluidics.

    PubMed

    Pearce, J M; Anzalone, N C; Heldt, C L

    2016-08-01

    The open-source release of self-replicating rapid prototypers (RepRaps) has created a rich opportunity for low-cost distributed digital fabrication of complex 3-D objects such as scientific equipment. For example, 3-D printable reactionware devices offer the opportunity to combine open hardware microfluidic handling with lab-on-a-chip reactionware to radically reduce costs and increase the number and complexity of microfluidic applications. To further drive down the cost while improving the performance of lab-on-a-chip paper-based microfluidic prototyping, this study reports on the development of a RepRap upgrade capable of converting a Prusa Mendel RepRap into a wax 3-D printer for paper-based microfluidic applications. An open-source hardware approach is used to demonstrate a 3-D printable upgrade for the 3-D printer, which combines a heated syringe pump with the RepRap/Arduino 3-D control. The bill of materials, designs, basic assembly, and use instructions are provided, along with a completely free and open-source software tool chain. The open-source hardware device described here accelerates the potential of the nascent field of electrochemical detection combined with paper-based microfluidics by dropping the marginal cost of prototyping to nearly zero while accelerating the turnover between paper-based microfluidic designs.

  5. Rapid prototyping of microfluidic devices with integrated wrinkled gold micro-/nano textured electrodes for electrochemical analysis.

    PubMed

    Gabardo, C M; Adams-McGavin, R C; Vanderfleet, O M; Soleymani, L

    2015-08-21

    Fully-integrated electro-fluidic systems with micro-/nano-scale features have a wide range of applications in lab-on-a-chip systems used for biosensing, biological sample processing, and environmental monitoring. Rapid prototyping of application-specific electro-fluidic systems is envisioned to facilitate the testing, validation, and market translation of several lab-on-a-chip systems. Towards this goal, we developed a rapid prototyping process for creating wrinkled micro-/nano-textured electrodes on shrink memory polymers, fabricating microfluidics using molds patterned by a craft-cutter, and bonding electrical and fluidic circuitries using a PDMS partial curing method optimized for creating void-free bonds at the side walls and surfaces of tall (>5 μm) micro-/nano-textured wrinkled electrodes. The resulting electro-fluidic devices, featuring closely spaced high topography electrodes for electrochemical analysis, can withstand flow-rates and burst pressures larger than 25 mL min(-1) and 125 kPa, respectively. In addition, the fully-integrated electrochemical flow-cell developed here demonstrates excellent electrochemical behaviour, with negligible scan to scan variation for over 100 cyclic voltammetry scans, and expected redox signatures measured under various voltage scan rates and fluidic flow rates.

  6. Rapid prototyping of microfluidic devices with integrated wrinkled gold micro-/nano textured electrodes for electrochemical analysis.

    PubMed

    Gabardo, C M; Adams-McGavin, R C; Vanderfleet, O M; Soleymani, L

    2015-08-21

    Fully-integrated electro-fluidic systems with micro-/nano-scale features have a wide range of applications in lab-on-a-chip systems used for biosensing, biological sample processing, and environmental monitoring. Rapid prototyping of application-specific electro-fluidic systems is envisioned to facilitate the testing, validation, and market translation of several lab-on-a-chip systems. Towards this goal, we developed a rapid prototyping process for creating wrinkled micro-/nano-textured electrodes on shrink memory polymers, fabricating microfluidics using molds patterned by a craft-cutter, and bonding electrical and fluidic circuitries using a PDMS partial curing method optimized for creating void-free bonds at the side walls and surfaces of tall (>5 μm) micro-/nano-textured wrinkled electrodes. The resulting electro-fluidic devices, featuring closely spaced high topography electrodes for electrochemical analysis, can withstand flow-rates and burst pressures larger than 25 mL min(-1) and 125 kPa, respectively. In addition, the fully-integrated electrochemical flow-cell developed here demonstrates excellent electrochemical behaviour, with negligible scan to scan variation for over 100 cyclic voltammetry scans, and expected redox signatures measured under various voltage scan rates and fluidic flow rates. PMID:26178719

  7. Performance Evaluation of the Prototype Model NEXT Ion Thruster

    NASA Technical Reports Server (NTRS)

    Herman, Daniel A.; Soulas, George C.; Patterson, Michael J.

    2008-01-01

    The performance testing results of the first prototype model NEXT ion engine, PM1, are presented. The NEXT program has developed the next generation ion propulsion system to enhance and enable Discovery, New Frontiers, and Flagship-type NASA missions. The PM1 thruster exhibits operational behavior consistent with its predecessors, the engineering model thrusters, with substantial mass savings, enhanced thermal margins, and design improvements for environmental testing compliance. The dry mass of PM1 is 12.7 kg. Modifications made in the thruster design have resulted in improved performance and operating margins, as anticipated. PM1 beginning-of-life performance satisfies all of the electric propulsion thruster mission-derived technical requirements. It demonstrates a wide range of throttleability by processing input power levels from 0.5 to 6.9 kW. At 6.9 kW, the PM1 thruster demonstrates specific impulse of 4190 s, 237 mN of thrust, and a thrust efficiency of 0.71. The flat beam profile, flatness parameters vary from 0.66 at low-power to 0.88 at full-power, and advanced ion optics reduce localized accelerator grid erosion and increases margins for electron backstreaming, impingement-limited voltage, and screen grid ion transparency. The thruster throughput capability is predicted to exceed 750 kg of xenon, an equivalent of 36,500 hr of continuous operation at the full-power operating condition.

  8. Rapid prototyping for tissue-engineered bone scaffold by 3D printing and biocompatibility study

    PubMed Central

    He, Hui-Yu; Zhang, Jia-Yu; Mi, Xue; Hu, Yang; Gu, Xiao-Yu

    2015-01-01

    The prototyping of tissue-engineered bone scaffold (calcined goat spongy bone-biphasic ceramic composite/PVA gel) by 3D printing was performed, and the biocompatibility of the fabricated bone scaffold was studied. Pre-designed STL file was imported into the GXYZ303010-XYLE 3D printing system, and the tissue-engineered bone scaffold was fabricated by 3D printing using gel extrusion. Rabbit bone marrow stromal cells (BMSCs) were cultured in vitro and then inoculated to the sterilized bone scaffold obtained by 3D printing. The growth of rabbit BMSCs on the bone scaffold was observed under the scanning electron microscope (SEM). The effect of the tissue-engineered bone scaffold on the proliferation and differentiation of rabbit BMSCs using MTT assay. Universal testing machine was adopted to test the tensile strength of the bone scaffold. The leachate of the bone scaffold was prepared and injected into the New Zealand rabbits. Cytotoxicity test, acute toxicity test, pyrogenic test and intracutaneous stimulation test were performed to assess the biocompatibility of the bone scaffold. Bone scaffold manufactured by 3D printing had uniform pore size with the porosity of about 68.3%. The pores were well interconnected, and the bone scaffold showed excellent mechanical property. Rabbit BMSCs grew and proliferated on the surface of the bone scaffold after adherence. MTT assay indicated that the proliferation and differentiation of rabbit BMSCs on the bone scaffold did not differ significantly from that of the cells in the control. In vivo experiments proved that the bone scaffold fabricated by 3D printing had no acute toxicity, pyrogenic reaction or stimulation. Bone scaffold manufactured by 3D printing allows the rabbit BMSCs to adhere, grow and proliferate and exhibits excellent biomechanical property and high biocompatibility. 3D printing has a good application prospect in the prototyping of tissue-engineered bone scaffold. PMID:26380018

  9. Rapid prototyping for tissue-engineered bone scaffold by 3D printing and biocompatibility study.

    PubMed

    He, Hui-Yu; Zhang, Jia-Yu; Mi, Xue; Hu, Yang; Gu, Xiao-Yu

    2015-01-01

    The prototyping of tissue-engineered bone scaffold (calcined goat spongy bone-biphasic ceramic composite/PVA gel) by 3D printing was performed, and the biocompatibility of the fabricated bone scaffold was studied. Pre-designed STL file was imported into the GXYZ303010-XYLE 3D printing system, and the tissue-engineered bone scaffold was fabricated by 3D printing using gel extrusion. Rabbit bone marrow stromal cells (BMSCs) were cultured in vitro and then inoculated to the sterilized bone scaffold obtained by 3D printing. The growth of rabbit BMSCs on the bone scaffold was observed under the scanning electron microscope (SEM). The effect of the tissue-engineered bone scaffold on the proliferation and differentiation of rabbit BMSCs using MTT assay. Universal testing machine was adopted to test the tensile strength of the bone scaffold. The leachate of the bone scaffold was prepared and injected into the New Zealand rabbits. Cytotoxicity test, acute toxicity test, pyrogenic test and intracutaneous stimulation test were performed to assess the biocompatibility of the bone scaffold. Bone scaffold manufactured by 3D printing had uniform pore size with the porosity of about 68.3%. The pores were well interconnected, and the bone scaffold showed excellent mechanical property. Rabbit BMSCs grew and proliferated on the surface of the bone scaffold after adherence. MTT assay indicated that the proliferation and differentiation of rabbit BMSCs on the bone scaffold did not differ significantly from that of the cells in the control. In vivo experiments proved that the bone scaffold fabricated by 3D printing had no acute toxicity, pyrogenic reaction or stimulation. Bone scaffold manufactured by 3D printing allows the rabbit BMSCs to adhere, grow and proliferate and exhibits excellent biomechanical property and high biocompatibility. 3D printing has a good application prospect in the prototyping of tissue-engineered bone scaffold.

  10. Binary Encoded-Prototype Tree for Probabilistic Model Building GP

    NASA Astrophysics Data System (ADS)

    Yanase, Toshihiko; Hasegawa, Yoshihiko; Iba, Hitoshi

    In recent years, program evolution algorithms based on the estimation of distribution algorithm (EDA) have been proposed to improve search ability of genetic programming (GP) and to overcome GP-hard problems. One such method is the probabilistic prototype tree (PPT) based algorithm. The PPT based method explores the optimal tree structure by using the full tree whose number of child nodes is maximum among possible trees. This algorithm, however, suffers from problems arising from function nodes having different number of child nodes. These function nodes cause intron nodes, which do not affect the fitness function. Moreover, the function nodes having many child nodes increase the search space and the number of samples necessary for properly constructing the probabilistic model. In order to solve this problem, we propose binary encoding for PPT. In this article, we convert each function node to a subtree of binary nodes where the converted tree is correct in grammar. Our method reduces ineffectual search space, and the binary encoded tree is able to express the same tree structures as the original method. The effectiveness of the proposed method is demonstrated through the use of two computational experiments.

  11. Rapid prototyping of microchannels with surface patterns for fabrication of polymer fibers

    SciTech Connect

    Goodrich, Payton J.; Sharifi, Farrokh; Hashemi, Nastaran

    2015-08-14

    Microfluidic technology has provided innovative solutions to numerous problems, but the cost of designing and fabricating microfluidic channels is impeding its expansion. In this study, Shrinky-Dink thermoplastic sheets are used to create multilayered complex templates for microfluidic channels. We also used inkjet and laserjet printers to raise a predetermined microchannel geometry by depositing several layers of ink for each feature consecutively. We achieved feature heights over 100 μm, which were measured and compared with surface profilometry. Templates closest to the target geometry were then used to create microfluidic devices from soft-lithography with the molds as a template. These microfluidic devices were, futhermore used to fabricate polymer microfibers using the microfluidic focusing approach to demonstrate the potential that this process has for microfluidic applications. Finally, an economic analysis was conducted to compare the price of common microfluidic template manufacturing methods. We showed that multilayer microchannels can be created significantly quicker and cheaper than current methods for design prototyping and point-of-care applications in the biomedical area.

  12. Rapid prototyping of microchannels with surface patterns for fabrication of polymer fibers

    DOE PAGESBeta

    Goodrich, Payton J.; Sharifi, Farrokh; Hashemi, Nastaran

    2015-08-14

    Microfluidic technology has provided innovative solutions to numerous problems, but the cost of designing and fabricating microfluidic channels is impeding its expansion. In this study, Shrinky-Dink thermoplastic sheets are used to create multilayered complex templates for microfluidic channels. We also used inkjet and laserjet printers to raise a predetermined microchannel geometry by depositing several layers of ink for each feature consecutively. We achieved feature heights over 100 μm, which were measured and compared with surface profilometry. Templates closest to the target geometry were then used to create microfluidic devices from soft-lithography with the molds as a template. These microfluidic devicesmore » were, futhermore used to fabricate polymer microfibers using the microfluidic focusing approach to demonstrate the potential that this process has for microfluidic applications. Finally, an economic analysis was conducted to compare the price of common microfluidic template manufacturing methods. We showed that multilayer microchannels can be created significantly quicker and cheaper than current methods for design prototyping and point-of-care applications in the biomedical area.« less

  13. Proliferation Risk Characterization Model Prototype Model - User and Programmer Guidelines

    SciTech Connect

    Dukelow, J.S.; Whitford, D.

    1998-12-01

    A model for the estimation of the risk of diversion of weapons-capable materials was developed. It represents both the threat of diversion and site vulnerability as a product of a small number of variables (two to eight), each of which can take on a small number (two to four) of qualitatively defined (but quantitatively implemented) values. The values of the overall threat and vulnerability variables are then converted to threat and vulnerability categories. The threat and vulnerability categories are used to define the likelihood of diversion, also defined categorically. The evaluator supplies an estimate of the consequences of a diversion, defined categorically, but with the categories based on the IAEA Attractiveness levels. Likelihood and Consequences categories are used to define the Risk, also defined categorically. The threat, vulnerability, and consequences input provided by the evaluator contains a representation of his/her uncertainty in each variable assignment which is propagated all the way through to the calculation of the Risk categories. [Appendix G available on diskette only.

  14. Maximizing modern distribution of complex anatomical spatial information: 3D reconstruction and rapid prototype production of anatomical corrosion casts of human specimens.

    PubMed

    Li, Jianyi; Nie, Lanying; Li, Zeyu; Lin, Lijun; Tang, Lei; Ouyang, Jun

    2012-01-01

    Anatomical corrosion casts of human specimens are useful teaching aids. However, their use is limited due to ethical dilemmas associated with their production, their lack of perfect reproducibility, and their consumption of original specimens in the process of casting. In this study, new approaches with modern distribution of complex anatomical spatial information were explored to overcome these limitations through the digitalization of anatomical casts of human specimens through three-dimensional (3D) reconstruction, rapid prototype production, and Web-based 3D atlas construction. The corrosion cast of a lung, along with its associated arteries, veins, trachea, and bronchial tree was CT-scanned, and the data was then processed by Mimics software. Data from the lung casts were then reconstructed into 3D models using a hybrid method, utilizing both "image threshold" and "region growing." The fine structures of the bronchial tree, arterial, and venous network of the lung were clearly displayed and demonstrated their distinct relationships. The multiple divisions of bronchi and bronchopulmonary segments were identified. The 3D models were then uploaded into a rapid prototype 3D printer to physically duplicate the cast. The physically duplicated model of the lung was rescanned by CT and reconstructed to detect its production accuracy. Gross observation and accuracy detection were used to evaluate the duplication and few differences were found. Finally, Virtual Reality Modeling Language (VRML) was used to edit the 3D casting models to construct a Web-based 3D atlas accessible through Internet Explorer with 3D display and annotation functions.

  15. 3D imaging acquisition, modeling, and prototyping for facial defects reconstruction

    NASA Astrophysics Data System (ADS)

    Sansoni, Giovanna; Trebeschi, Marco; Cavagnini, Gianluca; Gastaldi, Giorgio

    2009-01-01

    A novel approach that combines optical three-dimensional imaging, reverse engineering (RE) and rapid prototyping (RP) for mold production in the prosthetic reconstruction of facial prostheses is presented. A commercial laser-stripe digitizer is used to perform the multiview acquisition of the patient's face; the point clouds are aligned and merged in order to obtain a polygonal model, which is then edited to sculpture the virtual prothesis. Two physical models of both the deformed face and the 'repaired' face are obtained: they differ only in the defect zone. Depending on the material used for the actual prosthesis, the two prototypes can be used either to directly cast the final prosthesis or to fabricate the positive wax pattern. Two case studies are presented, referring to prostetic reconstructions of an eye and of a nose. The results demonstrate the advantages over conventional techniques as well as the improvements with respect to known automated manufacturing techniques in the mold construction. The proposed method results into decreased patient's disconfort, reduced dependence on the anaplasthologist skill, increased repeatability and efficiency of the whole process.

  16. Updates on the Construction of an Eyeglass-Supported Nasal Prosthesis Using Computer-Aided Design and Rapid Prototyping Technology.

    PubMed

    Ciocca, Leonardo; Tarsitano, Achille; Marchetti, Claudio; Scotti, Roberto

    2016-01-01

    This study was undertaken to design an updated connection system for an eyeglass-supported nasal prosthesis using rapid prototyping techniques. The substructure was developed with two main endpoints in mind: the connection to the silicone and the connection to the eyeglasses. The mold design was also updated; the mold was composed of various parts, each carefully designed to allow for easy release after silicone processing and to facilitate extraction of the prosthesis without any strain. The approach used in this study enabled perfect transfer of the reciprocal position of the prosthesis with respect to the eyeglasses, from the virtual to the clinical environment. Moreover, the reduction in thickness improved the flexibility of the prosthesis and promoted adaptation to the contours of the skin, even during functional movements. The method described here is a simplified and viable alternative to standard construction techniques for nasal prostheses and offers improved esthetic and functional results when no bone is available for implant-supported prostheses.

  17. Consistent quasistatic and acoustic elasticity determination of poly-L-lactide-based rapid-prototyped tissue engineering scaffolds.

    PubMed

    Luczynski, Krzysztof W; Brynk, Tomasz; Ostrowska, Barbara; Swieszkowski, Wojciech; Reihsner, Roland; Hellmich, Christian

    2013-01-01

    This paper is concerned with reliable and physically sound elasticity determination of rapid-prototyped tissue engineering scaffolds made of poly-L-lactide (PLLA), with and without small portions of tricalcium phosphate (TCP) inclusions. At the level of overall scaffolds, that is, that of several millimeters, multiple uniaxial loading-unloading (quasistatic) tests were performed, giving access to the scaffolds' Young's moduli, through stress-strain characteristics during unloading. In addition, acoustic tests with 0.05 MHz frequency delivered an independent access to elastic properties, in terms of the normal components of the scaffolds' stiffness tensors. The latter strongly correlate, in a linear fashion, with the Young's moduli from the unloading tests, revealing porosity independence of Poisson's ratio. The magnitude of the latter is in full agreement with literature data on polymers. Both of these facts underline that both ultrasound tests and quasistatic unloading tests reliably provide the elastic properties of tissue engineering scaffolds.

  18. Liquid on Paper: Rapid Prototyping of Soft Functional Components for Paper Electronics

    PubMed Central

    Long Han, Yu; Liu, Hao; Ouyang, Cheng; Jian Lu, Tian; Xu, Feng

    2015-01-01

    This paper describes a novel approach to fabricate paper-based electric circuits consisting of a paper matrix embedded with three-dimensional (3D) microchannels and liquid metal. Leveraging the high electric conductivity and good flowability of liquid metal, and metallophobic property of paper, it is possible to keep electric and mechanical functionality of the electric circuit even after a thousand cycles of deformation. Embedding liquid metal into paper matrix is a promising method to rapidly fabricate low-cost, disposable, and soft electric circuits for electronics. As a demonstration, we designed a programmable displacement transducer and applied it as variable resistors and pressure sensors. The unique metallophobic property, combined with softness, low cost and light weight, makes paper an attractive alternative to other materials in which liquid metal are currently embedded. PMID:26129723

  19. Rapid prototyping of multichannel microfluidic devices for single-molecule DNA curtain imaging.

    PubMed

    Robison, Aaron D; Finkelstein, Ilya J

    2014-05-01

    Single-molecule imaging and manipulation of biochemical reactions continues to reveal numerous biological insights. To facilitate these studies, we have developed and implemented a high-throughput approach to organize and image hundreds of individual DNA molecules at aligned diffusion barriers. Nonetheless, obtaining statistically relevant data sets under a variety of reaction conditions remains challenging. Here, we present a method for integrating high-throughput single-molecule "DNA curtain" imaging with poly(dimethylsiloxane) (PDMS)-based microfluidics. Our benchtop fabrication method can be accomplished in minutes with common tools found in all molecular biology laboratories. We demonstrate the utility of this approach by simultaneous imaging of two independent biochemical reaction conditions in a laminar flow device. In addition, five different reaction conditions can be observed concurrently in a passive linear gradient generator. Combining rapid microfluidic fabrication with high-throughput DNA curtains greatly expands our capability to interrogate complex biological reactions. PMID:24734940

  20. Reverse engineering and rapid prototyping for solid free-form fabrication

    NASA Astrophysics Data System (ADS)

    Stanley, James H.; Yancey, Robert N.; Cao, Qizhi; Dusaussoy, Nicolas J.

    1995-07-01

    Computed tomography (CT) systems have the ability to rapidly and nondestructively scan parts and extract part contours, independent of material type and/or surface condition. Under the correct conditions, these part contours are dimensionally correct and can be used to extract metrological information suitable for determining dimensional conformance or creating files readable by computer-aided-design (CAD) systems. Important CT-assisted reverse engineering and part characterization capabilities are being developed by ARACOR for the Advanced Research Projects Administration (ARPA) to support its solid freeform fabrication (SFF) initiative. SFF refers to the machine capability to convert an electronic master of a part into a solid object of near-net shape without part-specific tooling or other specialized operator intervention. Application software specific to advanced composite materials in general, and ceramic materials in particular, is being developed for the SFF program. The new software will run on a variety of common workstation platforms, accept data from different CT scanners, and output results in various formats to support a variety of engineering and manufacturing needs. An overview of CT-to-CAD technology is presented, and work in progress relevant to emerging aerospace composites is reported.

  1. Interoperable Geoprocessing for Rapid Prototyping of Landuse/Landcover, Topographical and Meteorological Datasets for Hydrological Simulation

    NASA Astrophysics Data System (ADS)

    Alarcon, V. J.; O'Hara, C. G.; Viger, R.; Shrestha, B.; Mali, P.; Toll, D. L.; Engman, T.

    2007-12-01

    Geoprocessing of landuse/landcover, topographical, and meteorological datasets is ubiquitous in the initial set- up of environmental models' applications. Geoprocessing provides parameterized geographic/meteorological information to models, organized per geographic sub-region or in the form of time-series. Environmental models use the summarized information for simulation of past, present or future events of interest. Traditionally, geoprocessing is performed following protocols and methodologies built-in into the environmental models. Each geoprocessing routine is tailored by the model's developers and is not re-usable or transferable to other models. Furthermore, metadata documenting the geoprocessing steps are usually not detailed. This paper proposes the use of the Geospatial Object Library for Environmental Modeling (GEOLEM) as an alternative or complementary tool for calculating land use, topographical, and meteorological parameters and time-series. GEOLEM has the capability of providing re-usable and transferable geoprocessed information to environmental models. Although this research focuses on the calculation of the geographical parameters and time-series needed by the Hydrological Simulation Program Fortran (HSPF), potential uses of GEOLEM in other environmental modeling frameworks are also addressed. The project area is located in the Saint Louis Bay watershed in the Mississippi Gulf coast. Interferometric Synthetic Aperture Radar (IFSAR) Digital Surface Model (5-m horizontal, 0.01-m vertical resolution), NASA's Shuttle Radar Topography Mission (SRTM) DTED Level 2 (30- m horizontal, 0.01-m vertical), National Elevation Data (NED) (30-m horizontal, 1-m vertical), and USGS DEM (300- m horizontal, 1-m vertical) topographical datasets were used in this research. Additionally, three landuse/landcover datasets were included: Geographic Retrieval and Analysis System (GIRAS), National Land Cover Dataset (NLCD), and NASA's Moderate Resolution Imaging

  2. Rapid serial prototyping of magnet-tipped attonewton-sensitivity cantilevers by focused ion beam manipulation1

    PubMed Central

    Longenecker, Jonilyn G.; Moore, Eric W.; Marohn, John A.

    2011-01-01

    The authors report a method for rapidly prototyping attonewton-sensitivity cantilevers with custom-fabricated tips and illustrate the method by preparing tips consisting of a magnetic nanorod overhanging the leading edge of the cantilevers. Micron-long nickel nanorods with widths of 120–220 nm were fabricated on silicon chips by electron beam lithography, deposition, and lift-off. Each silicon chip, with its integral nanomagnet, was attached serially to a custom-fabricated attonewton-sensitivity cantilever using focused ion beam manipulation. The magnetic nanorod tips were prepared with and without an alumina capping layer, and the minimum detectable force and tip magnetic moment of the resulting cantilevers was characterized by cantilever magnetometry. The results indicate that this serial but high-yield approach is an effective way to rapidly prepare and characterize magnetic tips for the proposed single-electron-spin and single-proton magnetic resonance imaging experiments. The approach also represents a versatile route for affixing essentially any vacuum-compatible sample to the leading edge of an attonewton-sensitivity cantilever. PMID:23028212

  3. A Rapid Prototyping Look at NASA's Next Generation Earth-Observing Satellites; Opportunities for Global Change Research and Applications

    NASA Astrophysics Data System (ADS)

    Cecil, L.; Young, D. F.; Parker, P. A.; Eckman, R. S.

    2006-12-01

    biological productivity. NASA's Applied Sciences Program is taking a scientifically rigorous systems engineering approach to facilitate rapid prototyping of potential uses of the projected research capabilities of these new missions into decision support systems. This presentation includes an example of a prototype experiment that focuses on two of the Applied Sciences Program's twelve National Applications focus areas, Water Management and Energy Management. This experiment is utilizing research results and associated uncertainties from existing Earth-observation missions as well as from several of NASA's nine next generation missions. This prototype experiment is simulating decision support analysis and research results leading to priority management and/or policy issues concentrating on climate change and uncertainties in alpine areas on the watershed scale.

  4. A review of rapid prototyped surgical guides for patient-specific total knee replacement.

    PubMed

    Krishnan, S P; Dawood, A; Richards, R; Henckel, J; Hart, A J

    2012-11-01

    Improvements in the surgical technique of total knee replacement (TKR) are continually being sought. There has recently been interest in three-dimensional (3D) pre-operative planning using magnetic resonance imaging (MRI) and CT. The 3D images are increasingly used for the production of patient-specific models, surgical guides and custom-made implants for TKR. The users of patient-specific instrumentation (PSI) claim that they allow the optimum balance of technology and conventional surgery by reducing the complexity of conventional alignment and sizing tools. In this way the advantages of accuracy and precision claimed by computer navigation techniques are achieved without the disadvantages of additional intra-operative inventory, new skills or surgical time. This review describes the terminology used in this area and debates the advantages and disadvantages of PSI.

  5. Application of 3D rapid prototyping technology in posterior corrective surgery for Lenke 1 adolescent idiopathic scoliosis patients.

    PubMed

    Yang, Mingyuan; Li, Chao; Li, Yanming; Zhao, Yingchuan; Wei, Xianzhao; Zhang, Guoyou; Fan, Jianping; Ni, Haijian; Chen, Ziqiang; Bai, Yushu; Li, Ming

    2015-02-01

    A retrospective study to evaluate the effectiveness of 3-dimensional rapid prototyping (3DRP) technology in corrective surgery for Lenke 1 adolescent idiopathic scoliosis (AIS) patients. 3DRP technology has been widely used in medical field; however, no study has been performed on the effectiveness of 3DRP technology in corrective surgery for Lenke 1 AIS patients. Lenke 1 AIS patients who were preparing to undergo posterior corrective surgery from a single center between January 2010 and January 2012 were included in this analysis. Patients were divided into 2 groups. In group A, 3-dimensional (3D) printing technology was used to create subject-specific spine models in the preoperative planning process. Group B underwent posterior corrective surgery as usual (by free hand without image guidance). Perioperative and postoperative clinical outcomes were compared between 2 groups, including operation time, perioperative blood loss, transfusion volume, postoperative hemoglobin (Hb), postoperative complications, and length of hospital stay. Radiological outcomes were also compared, including the assessment of screw placement, postoperative Cobb angle, coronal balance, sagittal vertical axis, thoracic kyphosis, and lumbar lordosis. Subgroup was also performed according to the preoperative Cobb angle: mean Cobb angle <50° and mean Cobb angle >50°. Besides, economic evaluation was also compared between 2 groups. A total of 126 patients were included in this study (group A, 50 and group B, 76). Group A had significantly shorter operation time, significantly less blood loss and transfusion volume, and higher postoperative Hb (all, P < 0.001). However, no significant differences were observed in complication rate, length of hospital stay, and postoperative radiological outcomes between 2 groups (all, P>0.05). There was also no significant difference in misplacement of screws in total populations (16.90% vs 18.82%, P = 0.305), whereas a low misplacement rate of

  6. Application of 3D Rapid Prototyping Technology in Posterior Corrective Surgery for Lenke 1 Adolescent Idiopathic Scoliosis Patients

    PubMed Central

    Yang, Mingyuan; Li, Chao; Li, Yanming; Zhao, Yingchuan; Wei, Xianzhao; Zhang, Guoyou; Fan, Jianping; Ni, Haijian; Chen, Ziqiang; Bai, Yushu; Li, Ming

    2015-01-01

    Abstract A retrospective study to evaluate the effectiveness of 3-dimensional rapid prototyping (3DRP) technology in corrective surgery for Lenke 1 adolescent idiopathic scoliosis (AIS) patients. 3DRP technology has been widely used in medical field; however, no study has been performed on the effectiveness of 3DRP technology in corrective surgery for Lenke 1 AIS patients. Lenke 1 AIS patients who were preparing to undergo posterior corrective surgery from a single center between January 2010 and January 2012 were included in this analysis. Patients were divided into 2 groups. In group A, 3-dimensional (3D) printing technology was used to create subject-specific spine models in the preoperative planning process. Group B underwent posterior corrective surgery as usual (by free hand without image guidance). Perioperative and postoperative clinical outcomes were compared between 2 groups, including operation time, perioperative blood loss, transfusion volume, postoperative hemoglobin (Hb), postoperative complications, and length of hospital stay. Radiological outcomes were also compared, including the assessment of screw placement, postoperative Cobb angle, coronal balance, sagittal vertical axis, thoracic kyphosis, and lumbar lordosis. Subgroup was also performed according to the preoperative Cobb angle: mean Cobb angle <50° and mean Cobb angle >50°. Besides, economic evaluation was also compared between 2 groups. A total of 126 patients were included in this study (group A, 50 and group B, 76). Group A had significantly shorter operation time, significantly less blood loss and transfusion volume, and higher postoperative Hb (all, P < 0.001). However, no significant differences were observed in complication rate, length of hospital stay, and postoperative radiological outcomes between 2 groups (all, P>0.05). There was also no significant difference in misplacement of screws in total populations (16.90% vs 18.82%, P = 0.305), whereas a low misplacement rate

  7. Prototyping the Future

    NASA Technical Reports Server (NTRS)

    1998-01-01

    Advanced Ceramics Research (ACR) of Tucson, Arizona, researches transforming scientific concepts into technological achievement. Through the SBIR (Small Business Innovative Research) program, ACR developed a high pressure and temperature fused deposition system, a prototyping system that is known as extrusion freeform fabrication. This system is useful in manufacturing prosthetics. ACR also developed a three-dimensional rapid prototyping process in which physical models are quickly created directly from computer generated models. Marshall Space Flight Center also contracted ACR to fabricate a set of ceramic engines to be appraised for a solar thermal rocket engine test program.

  8. Deep Proton Writing for the rapid prototyping of polymer micro-components for optical interconnects and optofluidics

    NASA Astrophysics Data System (ADS)

    Van Erps, Jürgen; Vervaeke, Michael; Ottevaere, Heidi; Hermanne, Alex; Thienpont, Hugo

    2013-07-01

    The use of photonics in data communication and numerous other industrial applications brought plenty of prospects for innovation and opened up different unexplored market opportunities. This is a major driving force for the fabrication of micro-optical and micro-mechanical structures and their accurate alignment and integration into opto-mechanical modules and systems. To this end, we present Deep Proton Writing (DPW) as a powerful rapid prototyping technology for such micro-components. The DPW process consists of bombarding polymer samples (PMMA or SU-8) with swift protons, which results after chemical processing steps in high-quality micro-optical components. One of the strengths of the DPW micro-fabrication technology is the ability to fabricate monolithic building blocks that include micro-optical and mechanical functionalities which can be precisely integrated into more complex photonic systems. In this paper we comment on how we shifted from using 8.3 to 16.5 MeV protons for DPW and give some examples of micro-optical and micro-mechanical components recently fabricated through DPW, targeting applications in optical interconnections and in optofluidics.

  9. Fabrication of novel Si-doped hydroxyapatite/gelatine scaffolds by rapid prototyping for drug delivery and bone regeneration.

    PubMed

    Martínez-Vázquez, F J; Cabañas, M V; Paris, J L; Lozano, D; Vallet-Regí, M

    2015-03-01

    Porous 3-D scaffolds consisting of gelatine and Si-doped hydroxyapatite were fabricated at room temperature by rapid prototyping. Microscopic characterization revealed a highly homogeneous structure, showing the pre-designed porosity (macroporosity) and a lesser in-rod porosity (microporosity). The mechanical properties of such scaffolds are close to those of trabecular bone of the same density. The biological behavior of these hybrid scaffolds is greater than that of pure ceramic scaffolds without gelatine, increasing pre-osteoblastic MC3T3-E1 cell differentiation (matrix mineralization and gene expression). Since the fabrication process of these structures was carried out at mild conditions, an antibiotic (vancomycin) was incorporated in the slurry before the extrusion of the structures. The release profile of this antibiotic was measured in phosphate-buffered saline solution by high-performance liquid chromatography and was adjusted to a first-order release kinetics. Vancomycin released from the material was also shown to inhibit bacterial growth in vitro. The implications of these results for bone tissue engineering applications are discussed. PMID:25560614

  10. Fabrication and characterization of a rapid prototyped tissue engineering scaffold with embedded multicomponent matrix for controlled drug release

    PubMed Central

    Chen, Muwan; Le, Dang QS; Hein, San; Li, Pengcheng; Nygaard, Jens V; Kassem, Moustapha; Kjems, Jørgen; Besenbacher, Flemming; Bünger, Cody

    2012-01-01

    Bone tissue engineering implants with sustained local drug delivery provide an opportunity for better postoperative care for bone tumor patients because these implants offer sustained drug release at the tumor site and reduce systemic side effects. A rapid prototyped macroporous polycaprolactone scaffold was embedded with a porous matrix composed of chitosan, nanoclay, and β-tricalcium phosphate by freeze-drying. This composite scaffold was evaluated on its ability to deliver an anthracycline antibiotic and to promote formation of mineralized matrix in vitro. Scanning electronic microscopy, confocal imaging, and DNA quantification confirmed that immortalized human bone marrow-derived mesenchymal stem cells (hMSC-TERT) cultured in the scaffold showed high cell viability and growth, and good cell infiltration to the pores of the scaffold. Alkaline phosphatase activity and osteocalcin staining showed that the scaffold was osteoinductive. The drug-release kinetics was investigated by loading doxorubicin into the scaffold. The scaffolds comprising nanoclay released up to 45% of the drug for up to 2 months, while the scaffold without nanoclay released 95% of the drug within 4 days. Therefore, this scaffold can fulfill the requirements for both bone tissue engineering and local sustained release of an anticancer drug in vitro. These results suggest that the scaffold can be used clinically in reconstructive surgery after bone tumor resection. Moreover, by changing the composition and amount of individual components, the scaffold can find application in other tissue engineering areas that need local sustained release of drug. PMID:22904634

  11. Rapid and low-cost prototyping of 3D nanostructures with multi-layer hydrogen silsesquioxane scaffolds.

    PubMed

    Varghese, Leo T; Fan, Li; Wang, Jian; Xuan, Yi; Qi, Minghao

    2013-12-20

    A layer-by-layer (LBL) method can generate or approximate any three-dimensional (3D) structure, and has been the approach for the manufacturing of complementary metal-oxide-semiconductor (CMOS) devices. However, its high cost precludes the fabrication of anything other than CMOS-compatible devices, and general 3D nanostructures have been difficult to prototype in academia and small businesses, due to the lack of expensive facility and state-of-the-art tools. It is proposed and demonstrated that a novel process that can rapidly fabricate high-resolution three-dimensional (3D) nanostructures at low cost, without requiring specialized equipment. An individual layer is realized through electron-beam lithography patterning of hydrogen silsesquioxane (HSQ) resist, followed by planarization via spinning SU-8 resist and etch-back. A 4-layer silicon inverse woodpile photonic crystal with a period of 650 nm and a 7-layer HSQ scaffold with a period of 300 nm are demonstrated. This process provides a versatile and accessible solution to the fabrication of highly complex 3D nanostructures.

  12. A Prototypicality Validation of the Comprehensive Assessment of Psychopathic Personality (CAPP) Model Spanish Version.

    PubMed

    Flórez, Gerardo; Casas, Alfonso; Kreis, Mette K F; Forti, Leonello; Martínez, Joaquín; Fernández, Juan; Conde, Manuel; Vázquez-Noguerol, Raúl; Blanco, Tania; Hoff, Helge A; Cooke, David J

    2015-10-01

    The Comprehensive Assessment of Psychopathic Personality (CAPP) is a newly developed, lexically based, conceptual model of psychopathy. The content validity of the Spanish language CAPP model was evaluated using prototypicality analysis. Prototypicality ratings were collected from 187 mental health experts and from samples of 143 health professionals and 282 community residents. Across the samples the majority of CAPP items were rated as highly prototypical of psychopathy. The Self, Dominance, and Attachment domains were evaluated as being more prototypical than the Behavioral and Cognitive domains. These findings are consistent with findings from similar studies in other languages and provide further support for the content validation of the CAPP model across languages and the lexical approach.

  13. Rapid Modeling and Analysis Tools: Evolution, Status, Needs and Directions

    NASA Technical Reports Server (NTRS)

    Knight, Norman F., Jr.; Stone, Thomas J.; Ransom, Jonathan B. (Technical Monitor)

    2002-01-01

    Advanced aerospace systems are becoming increasingly more complex, and customers are demanding lower cost, higher performance, and high reliability. Increased demands are placed on the design engineers to collaborate and integrate design needs and objectives early in the design process to minimize risks that may occur later in the design development stage. High performance systems require better understanding of system sensitivities much earlier in the design process to meet these goals. The knowledge, skills, intuition, and experience of an individual design engineer will need to be extended significantly for the next generation of aerospace system designs. Then a collaborative effort involving the designer, rapid and reliable analysis tools and virtual experts will result in advanced aerospace systems that are safe, reliable, and efficient. This paper discusses the evolution, status, needs and directions for rapid modeling and analysis tools for structural analysis. First, the evolution of computerized design and analysis tools is briefly described. Next, the status of representative design and analysis tools is described along with a brief statement on their functionality. Then technology advancements to achieve rapid modeling and analysis are identified. Finally, potential future directions including possible prototype configurations are proposed.

  14. Greenbrier Prototype

    SciTech Connect

    2010-06-18

    This case study describes a prototype home that is the model home for the Homes at Greenbrier in Oakdale, Connecticut, and demonstrates the builder's concept of “attainable sustainable” of offering high performance homes at mid-market prices.

  15. Exemplar and prototype models revisited: response strategies, selective attention, and stimulus generalization.

    PubMed

    Nosofsky, Robert M; Zaki, Safa R

    2002-09-01

    J. D. Smith and colleagues (J. P. Minda & J. D. Smith, 2001; J. D. Smith & J. P. Minda, 1998,2000; J. D. Smith, M. J. Murray, & J. P. Minda, 1997) presented evidence that they claimed challenged the predictions of exemplar models and that supported prototype models. In the authors' view, this evidence confounded the issue of the nature of the category representation with the type of response rule (probabilistic vs. deterministic) that was used. Also, their designs did not test whether the prototype models correctly predicted generalization performance. The present work demonstrates that an exemplar model that includes a response-scaling mechanism provides a natural account of all of Smith et al.'s experimental results. Furthermore, the exemplar model predicts classification performance better than the prototype models when novel transfer stimuli are included in the experimental designs.

  16. Simulation Model of Bus Rapid Transit

    NASA Astrophysics Data System (ADS)

    Gunawan, Fergyanto E.; Suharjito; Gunawan, Alexander A. S.

    2014-03-01

    Bus rapid transit system is modern solution for mass transportation system. The system, in comparison to the rail-based transportation system, is significantly cheaper and requires shorter development time, but lower performance. The BRT system performance strongly depends on variables related to station design and infrastructure. A numerical model offers an effective and efficient means to evaluate the system performance. This article offers a detailed numerical model on the basis of the discrete-event approach and demonstrates its application.

  17. Francis turbine draft tube modelling for prediction of pressure fluctuations on prototype

    NASA Astrophysics Data System (ADS)

    Alligné, S.; Landry, C.; Favrel, A.; Nicolet, C.; Avellan, F.

    2015-12-01

    The prediction of pressure fluctuations amplitudes on Francis turbine prototype is a challenge for hydro-equipment industry since it is subjected to guarantees to ensure smooth and reliable operation of the hydro units. The European FP7 research project Hyperbole aims to setup a methodology to transpose the pressure fluctuations measured on the reduced scale model to the prototype generating units. This paper presents this methodology which relies on an advanced modelling of the draft tube cavitation flow, and focuses on the transposition to the prototype of the draft tube model parameters identified on the reduced scale model. Different modelling assumptions of the draft tube are considered and their influence on the eigenmodes and the forced response of the system are presented.

  18. Interactive Effects within the Prototype Willingness Model: Predicting the Drinking Behavior of Indigenous Early Adolescents

    PubMed Central

    Armenta, Brian E.; Whitbeck, Les B.; Gentzler, Kari C.

    2016-01-01

    Drawing on the Prototype/Willingness Model of Adolescent Risk Behavior we used longitudinal data collected from North American Indigenous early adolescents (ages 10–12 years) to examine the interactive effects of favorable drinker prototypes, perceived drinking norms, and past year drinking behavior on subsequent drinking behavior (i.e., drinking behavior 1 year later and growth in drinking behavior from 1–5 years later). We found that the positive association between favorable drinker prototypes and drinking one year later was strongest for adolescents who were high in past year drinking and perceived low drinking norms. The interaction pattern for growth in drinking was more complex and suggested an important pattern; specifically, favorable drinker prototypes were positively associated with drinking five years later, but only for adolescents who reported no past year drinking and perceived low drinking norms. The theoretical and practical implications of these results are discussed. PMID:26999351

  19. Low Cost Rapid Response Spacecraft, (LCRRS): A Research Project in Low Cost Spacecraft Design and Fabrication in a Rapid Prototyping Environment

    NASA Technical Reports Server (NTRS)

    Spremo, Stevan; Bregman, Jesse; Dallara, Christopher D.; Ghassemieh, Shakib M.; Hanratty, James; Jackson, Evan; Kitts, Christopher; Klupar, Pete; Lindsay, Michael; Ignacio, Mas; Mayer, David; Quigley, Emmett; Rasay, Mike; Swank, Aaron; Vandersteen, Jeroen

    2009-01-01

    The Low Cost Rapid Response Spacecraft (LCRRS) is an ongoing research development project at NASA Ames Research Center (ARC), Moffett Field, California. The prototype spacecraft, called Cost Optimized Test for Spacecraft Avionics and Technologies (COTSAT) is the first of what could potentially be a series of rapidly produced low-cost satellites. COTSAT has a target launch date of March 2009 on a SpaceX Falcon 9 launch vehicle. The LCRRS research system design incorporates use of COTS (Commercial Off The Shelf), MOTS (Modified Off The Shelf), and GOTS (Government Off The Shelf) hardware for a remote sensing satellite. The design concept was baselined to support a 0.5 meter Ritchey-Chretien telescope payload. This telescope and camera system is expected to achieve 1.5 meter/pixel resolution. The COTSAT team is investigating the possibility of building a fully functional spacecraft for $500,000 parts and $2,000,000 labor. Cost is dramatically reduced by using a sealed container, housing the bus and payload subsystems. Some electrical and RF designs were improved/upgraded from GeneSat-1 heritage systems. The project began in January 2007 and has yielded two functional test platforms. It is expected that a flight-qualified unit will be finished in December 2008. Flight quality controls are in place on the parts and materials used in this development with the aim of using them to finish a proto-flight satellite. For LEO missions the team is targeting a mission class requiring a minimum of six months lifetime or more. The system architecture incorporates several design features required by high reliability missions. This allows for a true skunk works environment to rapidly progress toward a flight design. Engineering and fabrication is primarily done in-house at NASA Ames with flight certifications on materials. The team currently employs seven Full Time Equivalent employees. The success of COTSATs small team in this effort can be attributed to highly cross trained

  20. Model prototype utilization in the analysis of fault tolerant control and data processing systems

    NASA Astrophysics Data System (ADS)

    Kovalev, I. V.; Tsarev, R. Yu; Gruzenkin, D. V.; Prokopenko, A. V.; Knyazkov, A. N.; Laptenok, V. D.

    2016-04-01

    The procedure assessing the profit of control and data processing system implementation is presented in the paper. The reasonability of model prototype creation and analysis results from the implementing of the approach of fault tolerance provision through the inclusion of structural and software assessment redundancy. The developed procedure allows finding the best ratio between the development cost and the analysis of model prototype and earnings from the results of this utilization and information produced. The suggested approach has been illustrated by the model example of profit assessment and analysis of control and data processing system.

  1. Development of a Prototype Model-Form Uncertainty Knowledge Base

    NASA Technical Reports Server (NTRS)

    Green, Lawrence L.

    2016-01-01

    Uncertainties are generally classified as either aleatory or epistemic. Aleatory uncertainties are those attributed to random variation, either naturally or through manufacturing processes. Epistemic uncertainties are generally attributed to a lack of knowledge. One type of epistemic uncertainty is called model-form uncertainty. The term model-form means that among the choices to be made during a design process within an analysis, there are different forms of the analysis process, which each give different results for the same configuration at the same flight conditions. Examples of model-form uncertainties include the grid density, grid type, and solver type used within a computational fluid dynamics code, or the choice of the number and type of model elements within a structures analysis. The objectives of this work are to identify and quantify a representative set of model-form uncertainties and to make this information available to designers through an interactive knowledge base (KB). The KB can then be used during probabilistic design sessions, so as to enable the possible reduction of uncertainties in the design process through resource investment. An extensive literature search has been conducted to identify and quantify typical model-form uncertainties present within aerospace design. An initial attempt has been made to assemble the results of this literature search into a searchable KB, usable in real time during probabilistic design sessions. A concept of operations and the basic structure of a model-form uncertainty KB are described. Key operations within the KB are illustrated. Current limitations in the KB, and possible workarounds are explained.

  2. Accuracy of fibular sectioning and insertion into a rapid-prototyped bone plate, for mandibular reconstruction using CAD-CAM technology.

    PubMed

    Ciocca, Leonardo; Marchetti, Claudio; Mazzoni, Simona; Baldissara, Paolo; Gatto, Maria Rosaria Antonella; Cipriani, Riccardo; Scotti, Roberto; Tarsitano, Achille

    2015-01-01

    Modern techniques of mandibular reconstruction, such as CAD-CAM technology and rapid prototyping, offer new means by which reconstructive surgery can be planned to optimise aesthetic outcomes and prosthetic rehabilitation. The high degree of accuracy afforded by these approaches is principally attributable to high-precision fibular sectioning and insertion of the bone into a customised bone plate. CAD-CAM mandibular reconstruction procedures using vascularised bone free-flap transfers were performed on 10 patients with benign or malignant neoplasms. Five were not treated with the aid of CAD-CAM technology, and served as the control group. Five were scheduled for maxillofacial surgery using surgical cutting guides and customised bone plates. A generalised linear model for linear measures was used to compare the accuracy of reconstruction between the two groups. A difference, even though not significant, in the lateral shift of the mesial and distal positions of the fibular units was evident between groups. CAD-CAM-generated fibular surgical guides afford improved accuracy when used to restore native anatomy, especially in the context of mandibular arch restoration, and both operating room time and related costs are reduced during fibular sectioning. PMID:25434288

  3. GEM System: automatic prototyping of cell-wide metabolic pathway models from genomes

    PubMed Central

    Arakawa, Kazuharu; Yamada, Yohei; Shinoda, Kosaku; Nakayama, Yoichi; Tomita, Masaru

    2006-01-01

    Background Successful realization of a "systems biology" approach to analyzing cells is a grand challenge for our understanding of life. However, current modeling approaches to cell simulation are labor-intensive, manual affairs, and therefore constitute a major bottleneck in the evolution of computational cell biology. Results We developed the Genome-based Modeling (GEM) System for the purpose of automatically prototyping simulation models of cell-wide metabolic pathways from genome sequences and other public biological information. Models generated by the GEM System include an entire Escherichia coli metabolism model comprising 968 reactions of 1195 metabolites, achieving 100% coverage when compared with the KEGG database, 92.38% with the EcoCyc database, and 95.06% with iJR904 genome-scale model. Conclusion The GEM System prototypes qualitative models to reduce the labor-intensive tasks required for systems biology research. Models of over 90 bacterial genomes are available at our web site. PMID:16553966

  4. Final report on LDRD project: Low-cost Pd-catalyzed metallization technology for rapid prototyping of electronic substrates and devices

    SciTech Connect

    Chen, K.S.; Morgan, W.P.; Zich, J.L.

    1998-02-01

    A low-cost, thermally-activated, palladium-catalyzed metallization process was developed for rapid prototyping of polymeric electronic substrates and devices. The process was successfully applied in producing adhesiveless copper/polyimide laminates with high peel strengths and thick copper coating; copper/polyimide laminates are widely used in fabricating interconnects such as printed wiring boards (PWBs) and flexible circuits. Also successfully metallized using this low-cost metallization process were: (1) scaled-down models of radar-and-communication antenna and waveguide; (2) scaled-down model of pulsed-power-accelerator electrode; (3) three-dimensional micro-porous, open-cell vitreous carbon foams. Moreover, additive patterned metallization was successfully achieved by selectively printing or plotting the catalyst ink only on areas where metallization is desired, and by uniform thermal activation. Additive patterned metallization eliminates the time-consuming, costly and environmentally-unfriendly etching process that is routinely carried out in conventional subtractive patterned metallization. A metallization process via ultraviolet (UV) irradiation activation was also demonstrated. In this process palladium-catalyst solution is first uniformly coated onto the substrate. A masking pattern is used to cover the areas where metallization is not wanted. UV irradiation is applied uniformly to activate the palladium catalyst and to cure the polymer carrier in areas that are not covered by the mask. Metal is then deposited by electroless plating only or by a combination of electroless and electrolytic plating. This UV-activation technique is particularly useful in additive fine-line patterned metallization. Lastly, computer models for electrolytic and electroless plating processes were developed to provide guidance in plating-process design.

  5. Boron-10 ABUNCL Prototype Models And Initial Active Testing

    SciTech Connect

    Kouzes, Richard T.; Ely, James H.; Lintereur, Azaree T.; Siciliano, Edward R.

    2013-04-23

    The Department of Energy Office of Nuclear Safeguards and Security (NA-241) is supporting the project Coincidence Counting With Boron-Based Alternative Neutron Detection Technology at Pacific Northwest National Laboratory (PNNL) for the development of a 3He proportional counter alternative neutron coincidence counter. The goal of this project is to design, build and demonstrate a system based upon 10B-lined proportional tubes in a configuration typical for 3He-based coincidence counter applications. This report provides results from MCNPX model simulations and initial testing of the active mode variation of the Alternative Boron-Based Uranium Neutron Coincidence Collar (ABUNCL) design built by General Electric Reuter-Stokes. Initial experimental testing of the as-delivered passive ABUNCL was previously reported.

  6. NE Ohio Urban Growth Monitoring and Modeling Prototype. Revised

    NASA Technical Reports Server (NTRS)

    Siebert, Loren; Klosterman, Richard E.

    2001-01-01

    At the University of Akron, Dr. Loren Siebert, Dr. Richard Klosterman, and their graduate research assistants (Jung-Wook Kim, Mohammed Hoque, Aziza Parveen, and Ben Stabler) worked on the integration of remote sensing and GIs-based planning support systems. The primary goal of the project was to develop methods that use remote sensing land cover mapping and GIs-based modeling to monitor and project urban growth and farmland loss in northeast Ohio. Another research goal has been to use only GIS data that are accessible via the World Wide Web, to determine whether Ohio's small counties and townships that do not currently have parcel-level GIS systems can apply these techniques. The project was jointly funded by NASA and USGS OhioView grants during the 2000-2001 academic year; the work is now being continued under a USGS grant.

  7. A review method for UML requirements analysis model employing system-side prototyping.

    PubMed

    Ogata, Shinpei; Matsuura, Saeko

    2013-12-01

    User interface prototyping is an effective method for users to validate the requirements defined by analysts at an early stage of a software development. However, a user interface prototype system offers weak support for the analysts to verify the consistency of the specifications about internal aspects of a system such as business logic. As the result, the inconsistency causes a lot of rework costs because the inconsistency often makes the developers impossible to actualize the system based on the specifications. For verifying such consistency, functional prototyping is an effective method for the analysts, but it needs a lot of costs and more detailed specifications. In this paper, we propose a review method so that analysts can verify the consistency among several different kinds of diagrams in UML efficiently by employing system-side prototyping without the detailed model. The system-side prototype system does not have any functions to achieve business logic, but visualizes the results of the integration among the diagrams in UML as Web pages. The usefulness of our proposal was evaluated by applying our proposal into a development of Library Management System (LMS) for a laboratory. This development was conducted by a group. As the result, our proposal was useful for discovering the serious inconsistency caused by the misunderstanding among the members of the group.

  8. Design and modeling of a prototype fiber scanning CARS endoscope

    NASA Astrophysics Data System (ADS)

    Veilleux, Isra"l.; Doucet, Michel; Coté, Patrice; Verreault, Sonia; Fortin, Michel; Paradis, Patrick; Leclair, Sébastien; Da Costa, Ralph S.; Wilson, Brian C.; Seibel, Eric; Mermut, Ozzy; Cormier, Jean-François

    2010-02-01

    An endoscope capable of Coherent Anti-Stokes Raman scattering (CARS) imaging would be of significant clinical value for improving early detection of endoluminal cancers. However, developing this technology is challenging for many reasons. First, nonlinear imaging techniques such as CARS are single point measurements thus requiring fast scanning in a small footprint if video rate is to be achieved. Moreover, the intrinsic nonlinearity of this modality imposes several technical constraints and limitations, mainly related to pulse and beam distortions that occur within the optical fiber and the focusing objective. Here, we describe the design and report modeling results of a new CARS endoscope. The miniature microscope objective design and its anticipated performance are presented, along with its compatibility with a new spiral scanningfiber imaging technology developed at the University of Washington. This technology has ideal attributes for clinical use, with its small footprint, adjustable field-of-view and high spatial-resolution. This compact hybrid fiber-based endoscopic CARS imaging design is anticipated to have a wide clinical applicability.

  9. Assessing the Utility of the Willingness/Prototype Model in Predicting Help-Seeking Decisions

    ERIC Educational Resources Information Center

    Hammer, Joseph H.; Vogel, David L.

    2013-01-01

    Prior research on professional psychological help-seeking behavior has operated on the assumption that the decision to seek help is based on intentional and reasoned processes. However, research on the dual-process prototype/willingness model (PWM; Gerrard, Gibbons, Houlihan, Stock, & Pomery, 2008) suggests health-related decisions may also…

  10. Development of an Adolescent Alcohol Misuse Intervention Based on the Prototype Willingness Model: A Delphi Study

    ERIC Educational Resources Information Center

    Davies, Emma; Martin, Jilly; Foxcroft, David

    2016-01-01

    Purpose: The purpose of this paper is to report on the use of the Delphi method to gain expert feedback on the identification of behaviour change techniques (BCTs) and development of a novel intervention to reduce adolescent alcohol misuse, based on the Prototype Willingness Model (PWM) of health risk behaviour. Design/methodology/approach: Four…

  11. Rapid implementation of advanced constitutive models

    NASA Astrophysics Data System (ADS)

    Starman, Bojan; Halilovič, Miroslav; Vrh, Marko; Štok, Boris

    2013-12-01

    This paper presents a methodology based on the NICE integration scheme [1, 2] for simple and rapid numerical implementation of a class of plasticity constitutive models. In this regard, an algorithm is purposely developed for the implementation of newly developed advanced constitutive models into explicit finite element framework. The methodology follows the organization of the problem state variables into an extended form, which allows the constitutive models' equations to be organized in such a way, that the algorithm can be optionally extended with minimal effort to integrate also evolution equations related to a description of other specific phenomena, such as damage, distortional hardening, phase transitions, degradation etc. To confirm simplicity of the program implementation, computational robustness, effectiveness and improved accuracy of the implemented integration algorithm, a deep drawing simulation of the cylindrical cup is considered as the case study, performed in ABAQUS/Explicit. As a fairly complex considered model, the YLD2004-18p model [3, 4] is first implemented via external subroutine VUMAT. Further, to give additional proof of the simplicity of the proposed methodology, a combination of the YLD2004-18p model and Gurson-Tvergaard-Needleman model (GTN) is considered. As demonstrated, the implementation is really obtained in a very simple way.

  12. Predictors of Non- Hookah Smoking Among High-School Students Based On Prototype/Willingness Model

    PubMed Central

    Abedini, Sedigheh; MorowatiSharifabad, MohammadAli; Chaleshgar Kordasiabi, Mosharafeh; Ghanbarnejad, Amin

    2014-01-01

    Background: The aim of the study was to determine predictors of refraining from hookah smoking among high-school students in Bandar Abbas, southern Iran based on Prototype/Willingness model. Methods: This cross- sectional with analytic approach was performed on 240 high-school students selected by a cluster random sampling. The data of demographic and Prototype-Willingness Model constructs were acquired via a self-administrated questionnaire. Data were analyzed by mean, frequency, correlation, liner and logistic regression statistical tests. Results: Statistically significant determinants of the intention to refrain from hookah smoking were subjective norms, willingness, and attitude. Regression model indicated that the three items together explained 46.9% of the non-smoking hookah intention variance. Attitude and subjective norms predicted 36.0% of the non-smoking hookah intention variance. There was a significant relationship between the participants’ negative prototype about the hookah smokers and the willingness to avoid from hookah smoking (P=0.002). Also willingness predicted non-smoking hookah better than the intention (P<0.001). Conclusion: Deigning intervention to increase negative prototype about the hookah smokers and reducing situations and conditions which facilitate hookah smoking, such as easy access to tobacco products in the cafés, beaches can be useful results among adolescents to hookah smoking prevention. PMID:25097836

  13. RRTM: A rapid radiative transfer model

    SciTech Connect

    Mlawer, E.J.; Taubman, S.J.; Clough, S.A.

    1996-04-01

    A rapid radiative transfer model (RRTM) for the calculation of longwave clear-sky fluxes and cooling rates has been developed. The model, which uses the correlated-k method, is both accurate and computationally fast. The foundation for RRTM is the line-by-line radiative transfer model (LBLRTM) from which the relevant k-distributions are obtained. LBLRTM, which has been extensively validated against spectral observations e.g., the high-resolution sounder and the Atmospheric Emitted Radiance Interferometer, is used to validate the flux and cooling rate results from RRTM. Validations of RRTM`s results have been performed for the tropical, midlatitude summer, and midlatitude winter atmospheres, as well as for the four Intercomparison of Radiation Codes in Climate Models (ICRCCM) cases from the Spectral Radiance Experiment (SPECTRE). Details of some of these validations are presented below. RRTM has the identical atmospheric input module as LBLRTM, facilitating intercomparisons with LBLRTM and application of the model at the Atmospheric Radiation Measurement Cloud and Radiation Testbed sites.

  14. The prototype effect revisited: Evidence for an abstract feature model of face recognition.

    PubMed

    Wallis, Guy; Siebeck, Ulrike E; Swann, Kellie; Blanz, Volker; Bülthoff, Heinrich H

    2008-01-01

    Humans typically have a remarkable memory for faces. Nonetheless, in some cases they can be fooled. Experiments described in this paper provide new evidence for an effect in which observers falsely "recognize" a face that they have never seen before. The face is a chimera (prototype) built from parts extracted from previously viewed faces. It is known that faces of this kind can be confused with truly familiar faces, a result referred to as the prototype effect. However, recent studies have failed to find evidence for a full effect, one in which the prototype is regarded not only as familiar, but as more familiar than faces which have been seen before. This study sought to reinvestigate the effect. In a pair of experiments, evidence is reported for the full effect based on both an old/new discrimination task and a familiarity ranking task. The results are shown to be consistent with a recognition model in which faces are represented as combinations of reusable, abstract features. In a final experiment, novel predictions of the model are verified by comparing the size of the prototype effect for upright and upside-down faces. Despite the fundamentally piecewise nature of the model, an explanation is provided as to how it can also account for the sensitivity of observers to configural and holistic cues. This discussion is backed up with the use of an unsupervised network model. Overall, the paper describes how an abstract feature-based model can reconcile a range of results in the face recognition literature and, in turn, lessen currently perceived differences between the representation of faces and other objects. PMID:18484826

  15. Magnetostrictive wire-bonding clamp for semiconductor packaging: initial prototype design, modeling, and experiments

    NASA Astrophysics Data System (ADS)

    Dozor, David M.

    1998-06-01

    A magnetostrictive wire-bonding clamp for use in semiconductor packaging applications has been developed by Mechatronic Technology Co. Semiconductor industry trends, requiring high process throughput on increasing lead count packaging, make the magnetostrictive material Terfenol-D a candidate for this application. To construct this small, lightweight device, small samples of Terfenol-D were prepared by ETREMA Products, Inc. This paper reports the initial design, mathematical modeling, and experiments related to this initial prototype.

  16. Computer-aided design and manufacturing and rapid prototyped nanoscale hydroxyapatite/polyamide (n-HA/PA) construction for condylar defect caused by mandibular angle ostectomy.

    PubMed

    Li, Jihua; Hsu, Yuchun; Luo, En; Khadka, Ashish; Hu, Jing

    2011-08-01

    The fracture or defect of the mandibular condyle is one of the serious complications during angle-reduction ostectomy. Reconstruction of such defects also is a daunting task. The case report describes a method based on computer-aided design/computer-aided manufacturing (CAD/CAM) and rapid prototyping nanoscale hydroxyapatite/polyamide (n-HA/PA) for individual design, fabrication, and implantation of a mandibular condyle. A 27-year-old woman with a square-shaped face who had previously undergone mandibular angle reduction reported with malocclusion, deviated mouth, collapse of the right side of the face, and masticatory problems. The reason for the problems was the unintended removal of the condyle during the ostectomy procedure. Using computed tomography (CT) data, a biomimetic n-HA/PA scaffold, and CAD/CAM for rapid prototyping by three-dimensional (3D) printing, a perfect-fitting condylar implant was fabricated. A surgical guide system also was developed to reproduce the procedures accurately so a perfect fit could be obtained during surgery. The patient ultimately regained reasonable jaw contour and appearance, as well as appreciable temporomandibular joint (TMJ) function.

  17. Correction of facial asymmetry associated with vertical maxillary excess and mandibular prognathism by combined orthognathic surgery and guiding templates and splints fabricated by rapid prototyping technique.

    PubMed

    Ying, B; Ye, N; Jiang, Y; Liu, Y; Hu, J; Zhu, S

    2015-11-01

    The facial asymmetry associated with vertical maxillary excess and mandibular prognathism is one of the more complicated types in the field of oral and maxillofacial surgery. The purpose of this study was to investigate the efficacy of combined orthognathic surgeries, together with guiding templates and splints fabricated by rapid prototyping technique, for the correction of facial asymmetry. Fourteen patients with facial asymmetry associated with vertical maxillary excess and mandibular prognathism were included. A maxillary Le Fort I osteotomy, a sagittal split ramus osteotomy on the shorter side of the face, and an intraoral vertical ramus osteotomy on the longer side of the face were performed with the aid of guiding templates and splints fabricated by rapid prototyping technique. Parameters reflecting maxillary canting, ramal inclination, mandibular deviation, and chin inclination were measured before surgery, 7 days after surgery, and 1 year after surgery, and compared. Significant differences in these parameters were found between the two sides preoperatively, whereas no differences were observed postoperatively. Facial asymmetry was corrected in all patients with satisfactory outcomes. In conclusion, combined orthognathic surgery and guiding templates and splints can offer improvements in accuracy, complexity, and duration over traditional procedures for the correction of facial asymmetry associated with vertical maxillary excess and mandibular prognathism.

  18. A prototypicality validation of the Comprehensive Assessment of Psychopathic Personality model (CAPP).

    PubMed

    Hoff, Helge Andreas; Rypdal, Knut; Mykletun, Arnstein; Cooke, David J

    2012-06-01

    Cooke and colleagues recently developed the lexically based model of psychopathy named the Comprehensive Assessment of Psychopathic Personality (CAPP, Cooke, Hart, Logan, & Michie, 2004). The current study was the first to evaluate aspects of the validity of a translated version of the CAPP model, which comprises 33 symptoms from six domains of personality functioning. Prototypicality ratings from 796 Norwegian community residents, forensic mental health professionals, and corrections professionals were obtained. Most CAPP symptoms were evaluated as highly prototypical of psychopathy by all three groups. Symptoms from the Self, Dominance, and Attachment domains were perceived as more prototypical than those from the Behavioral domain. Confirmatory Factor Analysis (CFA) indicated that two CAPP domains were unidimensional whereas evidence of unidimensionality was somewhat weaker for the other domains, but improved substantially after removal of problematic symptoms. Overall, the findings support the content validity of the CAPP model. This may have relevance to the current considerations regarding reformulation of the criteria for Antisocial Personality Disorder in DSM-V.

  19. The Utility of the Prototype/Willingness Model in Predicting Alcohol Use among North American Indigenous Adolescents

    ERIC Educational Resources Information Center

    Armenta, Brian E.; Hautala, Dane S.; Whitbeck, Les B.

    2015-01-01

    In the present study, we considered the utility of the prototype/willingness model in predicting alcohol use among North-American Indigenous adolescents. Specifically, using longitudinal data, we examined the associations among subjective drinking norms, positive drinker prototypes, drinking expectations (as a proxy of drinking willingness), and…

  20. A low-cost rapid prototyping method for metal electrode fabrication using a CO2 laser cutter

    NASA Astrophysics Data System (ADS)

    Toossi, A.; Daneshmand, M.; Sameoto, D.

    2013-04-01

    In this note, a novel approach on the use of a low-power CO2 laser cutter is proposed to pattern thin metal electrode prototypes. Although low-power CO2 laser cutters have been used to etch and cut a wide range of materials, based on our knowledge, metal electrode patterning has not been previously explored. Using the proposed approach, metal electrodes can be patterned on the substrates that are good absorbers of CO2 wavelength. Here, polymethylmethacrylate substrates are selected and metal electrode patterning using the commercial CO2 laser cutter of VLS 3.50 Versa Laser is investigated. This approach has a wide range of applications, and two of those examples for microwave heating and antenna applications are presented.

  1. Addendum to `numerical modeling of an enhanced very early time electromagnetic (VETEM) prototype system'

    USGS Publications Warehouse

    Cui, T.J.; Chew, W.C.; Aydiner, A.A.; Wright, D.L.; Smith, D.V.; Abraham, J.D.

    2000-01-01

    Two numerical models to simulate an enhanced very early time electromagnetic (VETEM) prototype system that is used for buried-object detection and environmental problems are presented. In the first model, the transmitting and receiving loop antennas accurately analyzed using the method of moments (MoM), and then conjugate gradient (CG) methods with the fast Fourier transform (FFT) are utilized to investigate the scattering from buried conducting plates. In the second model, two magnetic dipoles are used to replace the transmitter and receiver. Both the theory and formulation are correct and the simulation results for the primary magnetic field and the reflected magnetic field are accurate.

  2. Characterizing Indoor Airflow and Pollutant Transport using Simulation Modeling for Prototypical Buildings. I. Office Buildings

    SciTech Connect

    Sohn, M.D.; Daisey, J.M.; Feustel, H.E.

    1999-06-01

    This paper describes the first efforts at developing a set of prototypical buildings defined to capture the key features affecting airflow and pollutant transport in buildings. These buildings will be used to model airflow and pollutant transport for emergency response scenarios when limited site-specific information is available and immediate decisions must be made, and to better understand key features of buildings controlling occupant exposures to indoor pollutant sources. This paper presents an example of this approach for a prototypical intermediate-sized, open style, commercial building. Interzonal transport due to a short-term source release, e.g., accidental chemical spill, in the bottom and the upper floors is predicted and corresponding HVAC system operation effects and potential responses are considered. Three-hour average exposure estimates are used to compare effects of source location and HVAC operation.

  3. Modeling Nitrogen Losses under Rapid Infiltration Basins

    NASA Astrophysics Data System (ADS)

    Akhavan, M.; Imhoff, P. T.; Andres, A. S.; Finsterle, S.

    2011-12-01

    Rapid Infiltration Basin System (RIBS) is one of the major land treatment techniques used for wastewater treatment and reuse of recovered treated wastewater. In this system, wastewater that is treated using primary, secondary, or advanced treatment techniques is applied at high rates to shallow basins constructed in permeable deposits of soil or sand, with further treatment occurring in soil and the vadose zone before the water recharges groundwater. Because the influent wastewater is usually enriched in nitrogen (N) compounds, there is particular concern that RIBS may contaminant groundwater or nearby surface waters if not designed and operated properly. In most of the new sequenced batch reactor (SBR) wastewater treatment plants, N is found in the form of nitrate in the discharged wastewater, so denitrification (DNF) is the main reaction in N removal. The absence of molecular oxygen is one of the required conditions for DNF. During RIBS operation, application of wastewater is cyclic and typically consists of a flooding period followed by days or weeks of drying. Key operational parameters include the ratio of wetting to drying time and the hydraulic loading rate, which affect water saturation and air content in the vadose zone and as a result have an impact on DNF. Wastewater is typically distributed at a limited number of discharge points in RIBS and basins are not usually completely flooded which result in non-homogeneous distribution of wastewater and unusual surface water flow patterns. For this reason, we couple overland flow within RIBS with subsurface flow to investigate the influence of non-uniform application of wastewater on DNF. No modeling effort has been done for understanding this aspect of RIBS performance previously. TOUGH2/ iTOUGH2, a general-purpose numerical simulation program for multi-phase fluid flow in porous media, is used for modeling fluid movement. Water saturation is used as a surrogate parameter to evaluate oxygen limitations in the

  4. A prototype symbolic model of canonical functional neuroanatomy of the motor system.

    PubMed

    Talos, Ion-Florin; Rubin, Daniel L; Halle, Michael; Musen, Mark; Kikinis, Ron

    2008-04-01

    Recent advances in bioinformatics have opened entire new avenues for organizing, integrating and retrieving neuroscientific data, in a digital, machine-processable format, which can be at the same time understood by humans, using ontological, symbolic data representations. Declarative information stored in ontological format can be perused and maintained by domain experts, interpreted by machines, and serve as basis for a multitude of decision support, computerized simulation, data mining, and teaching applications. We have developed a prototype symbolic model of canonical neuroanatomy of the motor system. Our symbolic model is intended to support symbolic look up, logical inference and mathematical modeling by integrating descriptive, qualitative and quantitative functional neuroanatomical knowledge. Furthermore, we show how our approach can be extended to modeling impaired brain connectivity in disease states, such as common movement disorders. In developing our ontology, we adopted a disciplined modeling approach, relying on a set of declared principles, a high-level schema, Aristotelian definitions, and a frame-based authoring system. These features, along with the use of the Unified Medical Language System (UMLS) vocabulary, enable the alignment of our functional ontology with an existing comprehensive ontology of human anatomy, and thus allow for combining the structural and functional views of neuroanatomy for clinical decision support and neuroanatomy teaching applications. Although the scope of our current prototype ontology is limited to a particular functional system in the brain, it may be possible to adapt this approach for modeling other brain functional systems as well.

  5. Prediction of a Francis turbine prototype full load instability from investigations on the reduced scale model

    NASA Astrophysics Data System (ADS)

    Alligné, S.; Maruzewski, P.; Dinh, T.; Wang, B.; Fedorov, A.; Iosfin, J.; Avellan, F.

    2010-08-01

    The growing development of renewable energies combined with the process of privatization, lead to a change of economical energy market strategies. Instantaneous pricings of electricity as a function of demand or predictions, induces profitable peak productions which are mainly covered by hydroelectric power plants. Therefore, operators harness more hydroelectric facilities at full load operating conditions. However, the Francis Turbine features an axi-symmetric rope leaving the runner which may act under certain conditions as an internal energy source leading to instability. Undesired power and pressure fluctuations are induced which may limit the maximum available power output. BC Hydro experiences such constraints in a hydroelectric power plant consisting of four 435 MW Francis Turbine generating units, which is located in Canada's province of British Columbia. Under specific full load operating conditions, one unit experiences power and pressure fluctuations at 0.46 Hz. The aim of the paper is to present a methodology allowing prediction of this prototype's instability frequency from investigations on the reduced scale model. A new hydro acoustic vortex rope model has been developed in SIMSEN software, taking into account the energy dissipation due to the thermodynamic exchange between the gas and the surrounding liquid. A combination of measurements, CFD simulations and computation of eigenmodes of the reduced scale model installed on test rig, allows the accurate calibration of the vortex rope model parameters at the model scale. Then, transposition of parameters to the prototype according to similitude laws is applied and stability analysis of the power plant is performed. The eigenfrequency of 0.39 Hz related to the first eigenmode of the power plant is determined to be unstable. Predicted frequency of the full load power and pressure fluctuations at the unit unstable operating point is found to be in general agreement with the prototype measurements.

  6. Are anticoagulant independent mechanical valves within reach—fast prototype fabrication and in vitro testing of innovative bi-leaflet valve models

    PubMed Central

    Siegel, Rolland

    2015-01-01

    Background Exploration for causes of prosthetic valve thrombogenicity has frequently focused on forward or post-closure flow detail. In prior laboratory studies, we uncovered high amplitude flow velocities of short duration close to valve closure implying potential for substantial shear stress with subsequent initiation of blood coagulation pathways. This may be relevant to widely accepted clinical disparity between mechanical and tissue valves vis-à-vis thrombogenicity. With a series of prototype bi-leaflet mechanical valves, we attempt reduction of closure related velocities with the objective of identifying a prototype valve with thrombogenic potential similar to our tissue valve control. This iterative design approach may find application in preclinical assessment of valves for anticoagulation independence. Methods Tested valves included: prototype mechanical bi-leaflet BVs (n=56), controls (n=2) and patented early prototype mechanicals (n=2) from other investigators. Pulsatile and quasi-steady flow systems were used for testing. Projected dynamic valve area (PDVA) was measured using previously described novel technology. Flow velocity over the open and closing periods was determined by volumetric flow rate/PDVA. For the closed valve interval, use was made of data obtained from quasi-steady back pressure/flow tests. Performance was ranked by a proposed thrombogenicity potential index (TPI) relative to tissue and mechanical control valves. Results Optimization of the prototype valve designs lead to a 3-D printed model (BV3D). For the mitral/aortic site, BV3D has lower TPI (1.10/1.47) relative to the control mechanical valve (3.44/3.93) and similar to the control tissue valve (ideal TPI ≤1.0). Conclusions Using unique technology, rapid prototyping and thrombogenicity ranking, optimization of experimental valves for reduced thrombogenic potential was expedited and simplified. Innovative mechanical valve configurations were identified that merit consideration

  7. Modeling Thermal and Environmental Effects of Prototype Scale Ocean Thermal Energy Conversion

    NASA Astrophysics Data System (ADS)

    Hamrick, J. M.

    2010-12-01

    Ocean thermal energy conversion (OTEC) utilizes the temperature difference between the mix lay and deep water electricity generation. The small temperature difference compared to other thermal-electric generation devises, typically between 20 and 25 C, requires the substantial volumetric flows on the order of hundreds of cubic meters per second to generate net energy and recover capital investments. This presentation described the use of a high resolution three-dimensional EFDC model with an embedded jet-plume model to simulate the thermal and environmental impacts of a number of prototype OTEC configurations on the southwest coast of Oahu, Hawaii. The EFDC model is one-way nested into a larger scale ROMS model to allow for realistic incorporation of region processes including external and internal tides and sub-tidal circulation. Impacts on local thermal structure and the potential for nutrient enrichment of the mixed layer are addressed with model and presented.

  8. The use of rapid prototyped implants to simulate knee joint abnormalities for in vitro testing: a validation study with replica implants of the native trochlea.

    PubMed

    Van Haver, Annemieke; De Roo, Karel; De Beule, Matthieu; Van Cauter, Sofie; Labey, Luc; De Baets, Patrick; Claessens, Tom; Verdonk, Peter

    2014-08-01

    To investigate the biomechanical effect of skeletal knee joint abnormalities, the authors propose to implant pathologically shaped rapid prototyped implants in cadaver knee specimens. This new method was validated by replacing the native trochlea by a replica implant on four cadaver knees with the aid of cadaver-specific guiding instruments. The accuracy of the guiding instruments was assessed by measuring the rotational errors of the cutting planes (on average 3.01° in extension and 1.18° in external/internal rotation). During a squat and open chain simulation, the patella showed small differences in its articulation with the native trochlea and the replica trochlea, which could partially be explained by the rotational errors of the implants. This study concludes that this method is valid to investigate the effect of knee joint abnormalities with a replica implant as a control condition to account for the influence of material properties and rotational errors of the implant.

  9. Business intelligence tools for radiology: creating a prototype model using open-source tools.

    PubMed

    Prevedello, Luciano M; Andriole, Katherine P; Hanson, Richard; Kelly, Pauline; Khorasani, Ramin

    2010-04-01

    Digital radiology departments could benefit from the ability to integrate and visualize data (e.g. information reflecting complex workflow states) from all of their imaging and information management systems in one composite presentation view. Leveraging data warehousing tools developed in the business world may be one way to achieve this capability. In total, the concept of managing the information available in this data repository is known as Business Intelligence or BI. This paper describes the concepts used in Business Intelligence, their importance to modern Radiology, and the steps used in the creation of a prototype model of a data warehouse for BI using open-source tools.

  10. Building and Calibration of a FAST Model of the SWAY Prototype Floating Wind Turbine: Preprint

    SciTech Connect

    Koh, J. H.; Robertson, A.; Jonkman, J.; Driscoll, F.; Ng, E. Y. K.

    2013-09-01

    Present efforts to verify and validate aero-hydro-servo-elastic numerical simulation tools that predict the dynamic response of a floating offshore wind turbine are primarily limited to code-to-code comparisons or code-to-data comparisons using data from wind-wave basin tests. In partnership with SWAY AS, the National Renewable Energy Laboratory (NREL) installed scientific wind, wave, and motion measurement equipment on the 1/6.5th-scale prototype SWAY floating wind system to collect data to validate a FAST model of the SWAY design in an open-water condition. Nanyang Technological University (NTU), through a collaboration with NREL, assisted in this validation.

  11. Dynamic Characteristics of a Model and Prototype for 3D-RC Structure

    NASA Astrophysics Data System (ADS)

    Moniuddin, Md. Khaja; Vasanthalakshmi, G.; Chethan, K.; Babu, R. Ramesh

    2016-06-01

    Infill walls provide durable and economical partitions that have relatively excellent thermal and sound insulation with high fire resistance. Monolithic infilled walls are provided within RC structures without being analyzed as a combination of concrete and brick elements, although in reality they act as a single unit during earthquakes. The performance of such structures during earthquakes has proved to be superior in comparison to bare frames in terms of stiffness, strength and energy dissipation. To know the dynamic characteristics of monolithic infill wall panels and masonry infill, modal, response spectrum and time history analyses have been carried out on a model and prototype of a 3D RC structure for a comparative study.

  12. Modeling and simulation of a beam emission spectroscopy diagnostic for the ITER prototype neutral beam injector

    SciTech Connect

    Barbisan, M. Zaniol, B.; Pasqualotto, R.

    2014-11-15

    A test facility for the development of the neutral beam injection system for ITER is under construction at Consorzio RFX. It will host two experiments: SPIDER, a 100 keV H{sup −}/D{sup −} ion RF source, and MITICA, a prototype of the full performance ITER injector (1 MV, 17 MW beam). A set of diagnostics will monitor the operation and allow to optimize the performance of the two prototypes. In particular, beam emission spectroscopy will measure the uniformity and the divergence of the fast particles beam exiting the ion source and travelling through the beam line components. This type of measurement is based on the collection of the H{sub α}/D{sub α} emission resulting from the interaction of the energetic particles with the background gas. A numerical model has been developed to simulate the spectrum of the collected emissions in order to design this diagnostic and to study its performance. The paper describes the model at the base of the simulations and presents the modeled H{sub α} spectra in the case of MITICA experiment.

  13. Modeling and simulation of a beam emission spectroscopy diagnostic for the ITER prototype neutral beam injector.

    PubMed

    Barbisan, M; Zaniol, B; Pasqualotto, R

    2014-11-01

    A test facility for the development of the neutral beam injection system for ITER is under construction at Consorzio RFX. It will host two experiments: SPIDER, a 100 keV H(-)/D(-) ion RF source, and MITICA, a prototype of the full performance ITER injector (1 MV, 17 MW beam). A set of diagnostics will monitor the operation and allow to optimize the performance of the two prototypes. In particular, beam emission spectroscopy will measure the uniformity and the divergence of the fast particles beam exiting the ion source and travelling through the beam line components. This type of measurement is based on the collection of the Hα/Dα emission resulting from the interaction of the energetic particles with the background gas. A numerical model has been developed to simulate the spectrum of the collected emissions in order to design this diagnostic and to study its performance. The paper describes the model at the base of the simulations and presents the modeled Hα spectra in the case of MITICA experiment.

  14. Modelling of helium-mediated quench propagation in the LHC prototype test string-1

    NASA Astrophysics Data System (ADS)

    Chorowski, M.; Grzegory, P.; Serio, L.; van Weelderen, R.

    2000-08-01

    The Large Hadron Collider (LHC) prototype test string-1, hereafter referred to as the string, is composed of three 10-m long prototype dipole magnets and one 6-m long prototype quadrupole magnet. The magnets are immersed in a pressurized static bath of superfluid helium that is maintained at a pressure of about 1 bar and at a temperature of about 1.9 K. This helium bath constitutes one single hydraulic unit, extending along 42.5 m of the string length. We have measured the triggering of quenches of the string magnets due to the quenching of a single dipole magnet located at the string's extremity, i.e., "quench propagation". Previously reported measurements enabled to establish that in this configuration the quench propagation is mediated by the helium and not by the inter-magnet bus bar connections [L. Coull, D. Hagedorn, G. Krainz, F. Rodriguez-Mateos, R. Schmidt, Quench propagation tests on the LHC superconducting magnet string, in: S. Myers, A. Pacheco, R. Pascual, C. Petit-Jean-Genaz, J. Poole (Eds.), Fifth European Particle Accelerator Conference - EPAC '96, Sitges, Barcelona, Spain, 10-14 June 1996, IOP, Bristol, 1996; F. Rodriguez-Mateos, R. Schmidt, L. Serio, Thermo-hydraulic quench propagation at the LHC superconducting magnet string, in: D. Dew-Hughes, R.G. Scurlock, J.H.P. Watson (Eds), 17th International Cryogenic Engineering Conference (ICEC-17), Bournemouth, UK, 14-17 July 1998, IOP, Bristol, 1998]. We present a model of helium-mediated quench propagation based on the qualitative conclusions of these two previous papers, and on additional information gained from a dedicated series of quench propagation measurements that were not previously reported. We will discuss the specific mechanisms and their main parameters involved at different timescales of the propagation process, and apply the model to make quantitative predictions.

  15. Reasoned versus reactive prediction of behaviour: a meta-analysis of the prototype willingness model.

    PubMed

    Todd, Jemma; Kothe, Emily; Mullan, Barbara; Monds, Lauren

    2016-01-01

    The prototype willingness model (PWM) was designed to extend expectancy-value models of health behaviour by also including a heuristic, or social reactive pathway, to better explain health-risk behaviours in adolescents and young adults. The pathway includes prototype, i.e., images of a typical person who engages in a behaviour, and willingness to engage in behaviour. The current study describes a meta-analysis of predictive research using the PWM and explores the role of the heuristic pathway and intentions in predicting behaviour. Eighty-one studies met inclusion criteria. Overall, the PWM was supported and explained 20.5% of the variance in behaviour. Willingness explained 4.9% of the variance in behaviour over and above intention, although intention tended to be more strongly related to behaviour than was willingness. The strength of the PWM relationships tended to vary according to the behaviour being tested, with alcohol consumption being the behaviour best explained. Age was also an important moderator, and, as expected, PWM behaviour was best accounted for within adolescent samples. Results were heterogeneous even after moderators were taken into consideration. This meta-analysis provides support for the PWM and may be used to inform future interventions that can be tailored for at-risk populations.

  16. Rapid prototyping, astronaut training, and experiment control and supervision: distributed virtual worlds for COLUMBUS, the European Space Laboratory module

    NASA Astrophysics Data System (ADS)

    Freund, Eckhard; Rossmann, Juergen

    2002-02-01

    In 2004, the European COLUMBUS Module is to be attached to the International Space Station. On the way to the successful planning, deployment and operation of the module, computer generated and animated models are being used to optimize performance. Under contract of the German Space Agency DLR, it has become IRF's task to provide a Projective Virtual Reality System to provide a virtual world built after the planned layout of the COLUMBUS module let astronauts and experimentators practice operational procedures and the handling of experiments. The key features of the system currently being realized comprise the possibility for distributed multi-user access to the virtual lab and the visualization of real-world experiment data. Through the capabilities to share the virtual world, cooperative operations can be practiced easily, but also trainers and trainees can work together more effectively sharing the virtual environment. The capability to visualize real-world data will be used to introduce measured data of experiments into the virtual world online in order to realistically interact with the science-reference model hardware: The user's actions in the virtual world are translated into corresponding changes of the inputs of the science reference model hardware; the measured data is than in turn fed back into the virtual world. During the operation of COLUMBUS, the capabilities for distributed access and the capabilities to visualize measured data through the use of metaphors and augmentations of the virtual world may be used to provide virtual access to the COLUMBUS module, e.g. via Internet. Currently, finishing touches are being put to the system. In November 2001 the virtual world shall be operational, so that besides the design and the key ideas, first experimental results can be presented.

  17. Prototype integration of the joint munitions assessment and planning model with the OSD threat methodology

    SciTech Connect

    Lynn, R.Y.S.; Bolmarcich, J.J.

    1994-06-01

    The purpose of this Memorandum is to propose a prototype procedure which the Office of Munitions might employ to exercise, in a supportive joint fashion, two of its High Level Conventional Munitions Models, namely, the OSD Threat Methodology and the Joint Munitions Assessment and Planning (JMAP) model. The joint application of JMAP and the OSD Threat Methodology provides a tool to optimize munitions stockpiles. The remainder of this Memorandum comprises five parts. The first is a description of the structure and use of the OSD Threat Methodology. The second is a description of JMAP and its use. The third discusses the concept of the joint application of JMAP and OSD Threat Methodology. The fourth displays sample output of the joint application. The fifth is a summary and epilogue. Finally, three appendices contain details of the formulation, data, and computer code.

  18. Electronic prototyping

    NASA Technical Reports Server (NTRS)

    Hopcroft, J.

    1987-01-01

    The potential benefits of automation in space are significant. The science base needed to support this automation not only will help control costs and reduce lead-time in the earth-based design and construction of space stations, but also will advance the nation's capability for computer design, simulation, testing, and debugging of sophisticated objects electronically. Progress in automation will require the ability to electronically represent, reason about, and manipulate objects. Discussed here is the development of representations, languages, editors, and model-driven simulation systems to support electronic prototyping. In particular, it identifies areas where basic research is needed before further progress can be made.

  19. State-and-transition prototype model of riparian vegetation downstream of Glen Canyon Dam, Arizona

    USGS Publications Warehouse

    Ralston, Barbara E.; Starfield, Anthony M.; Black, Ronald S.; Van Lonkhuyzen, Robert A.

    2014-01-01

    Facing an altered riparian plant community dominated by nonnative species, resource managers are increasingly interested in understanding how to manage and promote healthy riparian habitats in which native species dominate. For regulated rivers, managing flows is one tool resource managers consider to achieve these goals. Among many factors that can influence riparian community composition, hydrology is a primary forcing variable. Frame-based models, used successfully in grassland systems, provide an opportunity for stakeholders concerned with riparian systems to evaluate potential riparian vegetation responses to alternative flows. Frame-based, state-and-transition models of riparian vegetation for reattachment bars, separation bars, and the channel margin found on the Colorado River downstream of Glen Canyon Dam were constructed using information from the literature. Frame-based models can be simple spreadsheet models (created in Microsoft® Excel) or developed further with programming languages (for example, C-sharp). The models described here include seven community states and five dam operations that cause transitions between states. Each model divides operations into growing (April–September) and non-growing seasons (October–March) and incorporates upper and lower bar models, using stage elevation as a division. The inputs (operations) can be used by stakeholders to evaluate flows that may promote dynamic riparian vegetation states, or identify those flow options that may promote less desirable states (for example, Tamarisk [Tamarix sp.] temporarily flooded shrubland). This prototype model, although simple, can still elicit discussion about operational options and vegetation response.

  20. Modification of three-dimensional prototype temporal bone model for training in skull-base surgery.

    PubMed

    Mori, Kentaro; Yamamoto, Takuji; Oyama, Kazutaka; Nakao, Yasuaki

    2009-04-01

    Experience with dissection of the temporal bone is essential for training in skull-base surgery, but only a limited number of neurosurgical residents have the opportunity of cadaver dissection. A modification of a commercially available prototype three-dimensional (3D) temporal bone model is proposed to include artificial dura mater, venous sinuses, and cranial nerves for such surgical training. The base 3D temporal bone model incorporates the surface details and the inner ear structures and air cells. Model dural sinuses and dura mater made from silicone, cranial nerves made from rubber fibers, and internal carotid artery made from rubber tubes were added to the model. Posterior petrosectomy (transpetrosal approach) and transcondylar approach were performed on this model using a high-speed drill and ultrasonic bone curette under an operating microscope. The modified 3D temporal bone model provided good experience with the complicated 3D anatomy. The model could be dissected, and the dural sinuses and dura mater preserved by the eggshell peeling technique in almost the same way as real temporal bone. The modified 3D temporal bone model provides a good educational tool for training in skull-base surgery.

  1. A scenario-based approach to modeling development: a prototype model of C. elegans vulval fate specification.

    PubMed

    Kam, Na'aman; Kugler, Hillel; Marelly, Rami; Appleby, Lara; Fisher, Jasmin; Pnueli, Amir; Harel, David; Stern, Michael J; Hubbard, E Jane Albert

    2008-11-01

    Studies of developmental biology are often facilitated by diagram "models" that summarize the current understanding of underlying mechanisms. The increasing complexity of our understanding of development necessitates computational models that can extend these representations to include their dynamic behavior. Here we present a prototype model of Caenorhabditis elegans vulval precursor cell fate specification that represents many processes crucial for this developmental event but that are hard to integrate using other modeling methodologies. We demonstrate the integrative capabilities of our methodology by comprehensively incorporating the contents of three seminal papers, showing that this methodology can lead to comprehensive models of developmental biology. The prototype computational model was built and is run using a language (Live Sequence Charts) and tool (the Play-Engine) that facilitate the same conceptual processes biologists use to construct and probe diagram-type models. We demonstrate that this modeling approach permits rigorous tests of mutual consistency between experimental data and mechanistic hypotheses and can identify specific conflicting results, providing a useful approach to probe developmental systems. PMID:18706404

  2. A Comparison of the Validity of the Five-Factor Model (FFM) Personality Disorder Prototypes Using FFM Self-Report and Interview Measures

    ERIC Educational Resources Information Center

    Miller, Joshua D.; Bagby, R. Michael; Pilkonis, Paul A.

    2005-01-01

    Recent studies have demonstrated that personality disorders (PDs) can be assessed via a prototype-matching technique, which enables researchers and clinicians to match an individual's five-factor model (FFM) personality profile to an expert-generated prototype. The current study examined the relations between these prototype scores, using…

  3. Numerical modeling of an enhanced very early time electromagnetic (VETEM) prototype system

    USGS Publications Warehouse

    Cui, T.J.; Chew, W.C.; Aydiner, A.A.; Wright, D.L.; Smith, D.V.; Abraham, J.D.

    2000-01-01

    In this paper, two numerical models are presented to simulate an enhanced very early time electromagnetic (VETEM) prototype system, which is used for buried-object detection and environmental problems. Usually, the VETEM system contains a transmitting loop antenna and a receiving loop antenna, which run on a lossy ground to detect buried objects. In the first numerical model, the loop antennas are accurately analyzed using the Method of Moments (MoM) for wire antennas above or buried in lossy ground. Then, Conjugate Gradient (CG) methods, with the use of the fast Fourier transform (FFT) or MoM, are applied to investigate the scattering from buried objects. Reflected and scattered magnetic fields are evaluated at the receiving loop to calculate the output electric current. However, the working frequency for the VETEM system is usually low and, hence, two magnetic dipoles are used to replace the transmitter and receiver in the second numerical model. Comparing these two models, the second one is simple, but only valid for low frequency or small loops, while the first modeling is more general. In this paper, all computations are performed in the frequency domain, and the FFT is used to obtain the time-domain responses. Numerical examples show that simulation results from these two models fit very well when the frequency ranges from 10 kHz to 10 MHz, and both results are close to the measured data.

  4. Modified energy cascade model adapted for a multicrop Lunar greenhouse prototype

    NASA Astrophysics Data System (ADS)

    Boscheri, G.; Kacira, M.; Patterson, L.; Giacomelli, G.; Sadler, P.; Furfaro, R.; Lobascio, C.; Lamantea, M.; Grizzaffi, L.

    2012-10-01

    Models are required to accurately predict mass and energy balances in a bioregenerative life support system. A modified energy cascade model was used to predict outputs of a multi-crop (tomatoes, potatoes, lettuce and strawberries) Lunar greenhouse prototype. The model performance was evaluated against measured data obtained from several system closure experiments. The model predictions corresponded well to those obtained from experimental measurements for the overall system closure test period (five months), especially for biomass produced (0.7% underestimated), water consumption (0.3% overestimated) and condensate production (0.5% overestimated). However, the model was less accurate when the results were compared with data obtained from a shorter experimental time period, with 31%, 48% and 51% error for biomass uptake, water consumption, and condensate production, respectively, which were obtained under more complex crop production patterns (e.g. tall tomato plants covering part of the lettuce production zones). These results, together with a model sensitivity analysis highlighted the necessity of periodic characterization of the environmental parameters (e.g. light levels, air leakage) in the Lunar greenhouse.

  5. Slow manifold structure in explosive kinetics. 1. Bifurcations of points-at-infinity in prototypical models.

    PubMed

    Creta, F; Adrover, A; Cerbelli, S; Valorani, M; Giona, M

    2006-12-21

    This article analyzes in detail the global geometric properties (structure of the slow and fast manifolds) of prototypical models of explosive kinetics (the Semenov model for thermal explosion and the chain-branching model). The concepts of global or generalized slow manifolds and the notions of heterogeneity and alpha-omega inversion for invariant manifolds are introduced in order to classify the different geometric features exhibited by two-dimensional kinetic schemes by varying model parameters and to explain the phenomena that may occur in model reduction practice. This classification stems from the definition of suitable Lyapunov-type numbers and from the analysis of normal-to-tangent stretching rates. In the case of the Semenov model, we show that the existence of a global slow manifold and its properties are controlled by a transcritical bifurcation of the points-at-infinity, which can be readily identified by analyzing the Poincaré projected system. The issue of slow manifold uniqueness and the implications of the theory with regard to the practical definition of explosion limits are thoroughly addressed.

  6. Prototype Data Models and Data Dictionaries for Hanford Sediment Physical and Hydraulic Properties

    SciTech Connect

    Rockhold, Mark L.; Last, George V.; Middleton, Lisa A.

    2010-09-30

    The Remediation Decision Support (RDS) project, managed by the Pacific Northwest National Laboratory (PNNL) for the U.S. Department of Energy (DOE) and the CH2M HILL Plateau Remediation Company (CHPRC), has been compiling physical and hydraulic property data and parameters to support risk analyses and waste management decisions at Hanford. In FY09 the RDS project developed a strategic plan for a physical and hydraulic property database. This report documents prototype data models and dictionaries for these properties and associated parameters. Physical properties and hydraulic parameters and their distributions are required for any type of quantitative assessment of risk and uncertainty associated with predictions of contaminant transport and fate in the subsurface. The central plateau of the Hanford Site in southeastern Washington State contains most of the contamination at the Site and has up to {approx}100 m of unsaturated and unconsolidated or semi-consolidated sediments overlying the unconfined aquifer. These sediments contain a wide variety of contaminants ranging from organic compounds, such as carbon tetrachloride, to numerous radionuclides including technetium, plutonium, and uranium. Knowledge of the physical and hydraulic properties of the sediments and their distributions is critical for quantitative assessment of the transport of these contaminants in the subsurface, for evaluation of long-term risks and uncertainty associated with model predictions of contaminant transport and fate, and for evaluating, designing, and operating remediation alternatives. One of the goals of PNNL's RDS project is to work with the Hanford Environmental Data Manager (currently with CHPRC) to develop a protocol and schedule for incorporation of physical property and hydraulic parameter datasets currently maintained by PNNL into HEIS. This requires that the data first be reviewed to ensure quality and consistency. New data models must then be developed for HEIS that are

  7. Optimizing the translational value of animal models of glomerulonephritis: insights from recent murine prototypes.

    PubMed

    Foster, Mary H

    2016-09-01

    Animal models are indispensable for the study of glomerulonephritis, a group of diseases that destroy kidneys but for which specific therapies do not yet exist. Novel interventions are urgently needed, but their rational design requires suitable in vivo platforms to identify and test new candidates. Animal models can recreate the complex immunologic microenvironments that foster human autoimmunity and nephritis and provide access to tissue compartments not readily examined in patients. Study of rat Heymann nephritis identified fundamental disease mechanisms that ultimately revolutionized our understanding of human membranous nephropathy. Significant species differences in expression of a major target antigen, however, and lack of spontaneous autoimmunity in animals remain roadblocks to full exploitation of preclinical models in this disease. For several glomerulonephritides, humanized models have been developed to circumvent cross-species barriers and to study the effects of human genetic risk variants. Herein we review humanized mouse prototypes that provide fresh insight into mediators of IgA nephropathy and origins of antiglomerular basement membrane nephritis and Goodpasture's disease, as well as a means to test novel therapies for ANCA vasculitis. Additional and refined model systems are needed to mirror the full spectrum of human disease in a genetically diverse population, to facilitate development of patient-specific interventions, to determine the origin of nephritogenic autoimmunity, and to define the role of environmental exposures in disease initiation and relapse. PMID:27335377

  8. Bacterial inhibition potential of 3D rapid-prototyped magnesium-based porous composite scaffolds–an in vitro efficacy study

    PubMed Central

    Ma, Rui; Lai, Yu-xiao; Li, Long; Tan, Hong-lue; Wang, Jia-li; Li, Ye; Tang, Ting-ting; Qin, Ling

    2015-01-01

    Bone infections are common in trauma-induced open fractures with bone defects. Therefore, developing anti-infection scaffolds for repairing bone defects is desirable. This study develoepd novel Mg-based porous composite scaffolds with a basal matrix composed of poly(lactic-co-glycolicacid) (PLGA) and tricalcium phosphate (TCP). A unique low-temperature rapid prototyping technology was used to fabricate the scaffolds, including PLGA/TCP (PT), PLGA/TCP/5%Mg (PT5M), PLGA/TCP/10%Mg (PT10M), and PLGA/TCP/15%Mg (PT15M). The bacterial adhesion and biofilm formation of Staphylococcus aureus were evaluated. The results indicated that the Mg-based scaffolds significantly inhibited bacterial adhesion and biofilm formation compared to PT, and the PT10M and PT15M exhibited significantly stronger anti-biofilm ability than PT5M. In vitro degratation tests revealed that the degradation of the Mg-based scaffolds caused an increase of pH, Mg2+ concentration and osmolality, and the increased pH may be one of the major contributing factors to the antibacterial function of the Mg-based scaffolds. Additionally, the PT15M exhibited an inhibitory effect on cell adhesion and proliferation of MC3T3-E1 cells. In conclusion, the PLGA/TCP/Mg scaffolds could inhibit bacterial adhesion and biofilm formation, and the PT10M scaffold was considered to be an effective composition with considerable antibacterial ability and good cytocompatibility. PMID:26346217

  9. Shaping ability of Reciproc and TF Adaptive systems in severely curved canals of rapid microCT-based prototyping molar replicas

    PubMed Central

    ORDINOLA-ZAPATA, Ronald; BRAMANTE, Clovis Monteiro; DUARTE, Marco Antonio Húngaro; CAVENAGO, Bruno Cavalini; JARAMILLO, David; VERSIANI, Marco Aurélio

    2014-01-01

    Objective: To evaluate the shaping ability of Reciproc and Twisted-File Adaptive systems in rapid prototyping replicas. Material and Methods: Two mandibular molars showing S-shaped and 62-degree curvatures in the mesial root were scanned by using a microcomputed tomography (μCT) system. The data were exported in the stereolitograhic format and 20 samples of each molar were printed at 16 µm resolution. The mesial canals of 10 replicas of each specimen were prepared with each system. Transportation was measured by overlapping radiographs taken before and after preparation and resin thickness after instrumentation was measured by μCT. Results: Both systems maintained the original shape of the apical third in both anatomies (P>0.05). Overall, considering the resin thickness in the 62-degree replicas, no statistical difference was found between the systems (P>0.05). In the S-shaped curvature replica, Reciproc significantly decreased the thickness of the resin walls in comparison with TF Adaptive. Conclusions: The evaluated systems were able to maintain the original shape at the apical third of severely curved mesial canals of molar replicas. PMID:24918662

  10. Rapid prototype extruded conductive pathways

    DOEpatents

    Bobbitt, III, John T.

    2016-06-21

    A process of producing electrically conductive pathways within additively manufactured parts and similar parts made by plastic extrusion nozzles. The process allows for a three-dimensional part having both conductive and non-conductive portions and allows for such parts to be manufactured in a single production step.

  11. National Fire Fuels and Risks Assessment Using Remote Sensing and Ecological Modeling: Prototype Results

    NASA Astrophysics Data System (ADS)

    Zhu, Z.; Rollins, M.

    2003-12-01

    Hazardous fuel reduction, ecosystem rehabilitation and restoration, and firefighting safety, are land management priorities emphasized by recent national fire policies such as the National Fire Plan. Implementation of these policies requires geospatial data of vegetation conditions, fire fuels, risks, and ecosystem status developed consistently nationwide that can be used at multiple scales (i.e., local, regional, and national). A new research and development project called LANDFIRE has been conducted to develop an integrated methodology to produce geospatial fire data and predictive models for the land management community and a broad range of other applications. Main deliverables include mapped potential and existing vegetation types and structure variables, various biophysical data layers, fire fuels models, fire risk layers, as well as state-of-the-art computer models for assessing fire risk, behavior and effects. In this presentation, we will review research results and findings of the LANDFIRE project using results from a prototype study covering central Utah Uinta and Wasatch ecosystems. Particularly we will describe how a consistent and operational vegetation mapping component may be achieved by integrating machine-learning algorithms, field reference data, satellite imagery, and ecologically significant biophysical variables. We will discuss how remotely sensed vegetation cover types and structure can be successfully converted to fire fuel classes and risk layers which are necessary input into fire behavior and fire effect models. Finally we will discuss challenges and opportunities for national implementation of the methodology.

  12. [Efficient and rapid liquid reduction animal model].

    PubMed

    Han, Bing; Kou, Shu-ming; Chen, Biao; Peng, Yao-zong; Wang, Yue; Han, Yu-long; Ye, Xiao-li; Li, Xue-gang

    2015-11-01

    To investigate the practicability of establishing zebrafish lipid-lowering drug screening model and the effect of berberine (BBR) on hyperlipidemic zebrafish. Three-month-old zebrafishes were fed with 4% cholesterol for 0, 2, 4, 8, 14, 20, 25, 30 days, and the level of total cholesterol in serum was measured. Zebrafish were randomly divided into four groups: the control group, the high cholesterol diet group, the 0.01% simvastatin-treated group, the 0.1% berberine-treated group and the 0.2% berberine-treated group. The levels of total cholesterol (TC), triglyceride (TC), low density lipoprotein cholesterol (LDL-c) and high-density lipoprotein cholesterol (HDL-c) in serum were measured; the expression of hepatic HMGCR, LDLR and CYP7A1a mRNA expressions were detected by real time PCR. Oil red O staining was performed to observe the changes in fat content in the liver. According to the result, the level of serum TC in the 4% cholesterol diet group significantly was higher than that of the normal control group in a time-dependent manner and reached a stable level at the 20th day. The BBR group showed significant decreases in the levels of TC, TG and LDL-c, HMGCR mRNA expression and fat content and increases in LDLR and CYP7A1a mRNA. The hyperlipidemia zebrafish model was successfully established by feeding with 4% cholesterol for 20 days. The findings lay a foundation for further screenings on lipid-lowering drugs.

  13. A Primer on Prototyping.

    PubMed

    Lynch, Dylan; Biron, David

    2015-01-01

    Standard mechanical components, such as adapters or mounts, are ubiquitous in research laboratories, C. elegans labs included. Recently, in-house prototyping and fabricating both standard and custom mechanical parts has become simple and cost effective. Here we describe the basic steps, equipment, and considerations required for rapid prototyping of a handful of simple yet useful designs. These examples were chosen for their simplicity, as well as for demonstrating specific practicalities. They are thus appropriate as training exercises. PMID:26423979

  14. A Primer on Prototyping.

    PubMed

    Lynch, Dylan; Biron, David

    2015-01-01

    Standard mechanical components, such as adapters or mounts, are ubiquitous in research laboratories, C. elegans labs included. Recently, in-house prototyping and fabricating both standard and custom mechanical parts has become simple and cost effective. Here we describe the basic steps, equipment, and considerations required for rapid prototyping of a handful of simple yet useful designs. These examples were chosen for their simplicity, as well as for demonstrating specific practicalities. They are thus appropriate as training exercises.

  15. Assessing the utility of the willingness/prototype model in predicting help-seeking decisions.

    PubMed

    Hammer, Joseph H; Vogel, David L

    2013-01-01

    Prior research on professional psychological help-seeking behavior has operated on the assumption that the decision to seek help is based on intentional and reasoned processes. However, research on the dual-process prototype/willingness model (PWM; Gerrard, Gibbons, Houlihan, Stock, & Pomery, 2008) suggests health-related decisions may also involve social reaction processes that influence one's spontaneous willingness (rather than planned intention) to seek help, given conducive circumstances. The present study used structural equation modeling to evaluate the ability of these 2 information-processing pathways (i.e., the reasoned pathway and the social reaction pathway) to predict help-seeking decisions among 182 college students currently experiencing clinical levels of psychological distress. Results indicated that when both pathways were modeled simultaneously, only the social reaction pathway independently accounted for significant variance in help-seeking decisions. These findings argue for the utility of the PWM framework in the context of professional psychological help seeking and hold implications for future counseling psychology research, prevention, and practice. PMID:23106820

  16. Computer-Aided Designing and Manufacturing of Lingual Fixed Orthodontic Appliance Using 2D/3D Registration Software and Rapid Prototyping

    PubMed Central

    Kwon, Soon-Yong; Kim, Ki-Beom; Chung, Kyu-Rhim; Kim (Sunny), Seong-Hun

    2014-01-01

    The availability of 3D dental model scanning technology, combined with the ability to register CBCT data with digital models, has enabled the fabrication of orthognathic surgical CAD/CAM designed splints, customized brackets, and indirect bonding systems. In this study, custom lingual orthodontic appliances were virtually designed by merging 3D model images with lateral and posterior-anterior cephalograms. By exporting design information to 3D CAD software, we have produced a stereolithographic prototype and converted it into a cobalt-chrome alloy appliance as a way of combining traditional prosthetic investment and cast techniques. While the bonding procedure of the appliance could be reinforced, CAD technology simplified the fabrication process by eliminating the soldering phase. This report describes CAD/CAM fabrication of the complex anteroposterior lingual bonded retraction appliance for intrusive retraction of the maxillary anterior dentition. Furthermore, the CAD/CAM method eliminates the extra step of determining the lever arm on the lateral cephalograms and subsequent design modifications on the study model. PMID:24899895

  17. Computer-Aided Designing and Manufacturing of Lingual Fixed Orthodontic Appliance Using 2D/3D Registration Software and Rapid Prototyping.

    PubMed

    Kwon, Soon-Yong; Kim, Yong; Ahn, Hyo-Won; Kim, Ki-Beom; Chung, Kyu-Rhim; Kim Sunny, Seong-Hun

    2014-01-01

    The availability of 3D dental model scanning technology, combined with the ability to register CBCT data with digital models, has enabled the fabrication of orthognathic surgical CAD/CAM designed splints, customized brackets, and indirect bonding systems. In this study, custom lingual orthodontic appliances were virtually designed by merging 3D model images with lateral and posterior-anterior cephalograms. By exporting design information to 3D CAD software, we have produced a stereolithographic prototype and converted it into a cobalt-chrome alloy appliance as a way of combining traditional prosthetic investment and cast techniques. While the bonding procedure of the appliance could be reinforced, CAD technology simplified the fabrication process by eliminating the soldering phase. This report describes CAD/CAM fabrication of the complex anteroposterior lingual bonded retraction appliance for intrusive retraction of the maxillary anterior dentition. Furthermore, the CAD/CAM method eliminates the extra step of determining the lever arm on the lateral cephalograms and subsequent design modifications on the study model.

  18. Flow and transport modeling and isotope monitoring of a dug well SAT prototype in Shafdan, Israel

    NASA Astrophysics Data System (ADS)

    Kloppmann, Wolfram; Pettenati, Marie; Chikurel, Haim; Picot, Géraldine; Guttmann, Joseph; Aharoni, Avi

    2010-05-01

    The Shafdan case (Israel) offers the unique opportunity to investigate the long-term behaviour of a large scale Soil Aquifer Treatment system over a timescale of several decades. Specific problems occurred only after 20 years of successful operation, like the reduction of infiltration capacity, partly due to physical and chemical clogging, and the sudden appearance of significant concentrations of dissolved manganese in several wells. In the framework of the European FP6 ReclaimWater project, a new injection system through dug wells was developed and tested, destined to complete the existing infiltration basins, and the design and testing of the dug-well prototype was accompanied by different modelling activities. A preliminary 3D flow and conservative transport model was set up a the onset of the project to plan and design the dug well prototype and the monitoring wells. The radial pattern of solute transport obtained by the 3D model showed that a 2D radial model could satisfyingly describe the system so that a 2D flow and transport model was developed to model tracer tests and transfer scenarios of accidental peaks of organic contaminants. Boron and Li isotopes have been tested as environmental tracers of treated sewage injected into the sandy aquifer during a 38 days injection test in the newly dug injection well, a conservative artificial tracer (Br-) was monitored together with δ11B and δ7Li in the injectate, in the unsaturated soil zone (porous cup) and an observation well in the aquifer. Boron isotope ratios show a breakthrough curve delayed with respect to Br- breakthrough due to some reversible sorption on the aquifer material. No isotope fractionation was observed in the unsaturated or the saturated zone so that B-isotopes can be considered as conservative in the investigated part of the aquifer system. Lithium isotopes are strongly fractionated, probably due to sorption processes whereas Boron isotopes reveals a valuable tracer of artificial recharge

  19. The performance evaluation test for prototype model of Longwave Infrared Imager (LIR) onboard PLANET-C

    NASA Astrophysics Data System (ADS)

    Fukuhara, Tetsuya; Taguchi, Makoto; Imamura, Takeshi

    The PLANET-C mission, which is one of the future planetary missions of Japan, aims at understanding the atmospheric circulation of Venus. Meteorological information will be obtained by globally mapping clouds and minor constituents successively with four imagers at ultraviolet and infrared wavelengths, and radio occultation experiments will provide vertical profiles of the atmospheric temperature. These systematic, continuous remote observations will provide us with an unprecedented large data set of the Venusian atmospheric dynamics. The Longwave Infrared Imager (LIR), which mounts a commercial uncooled micro-bolometer array (UMBA), is one of four imagers onboard the spacecraft and detects thermal emission from the top of the sulfur dioxide cloud in a rather wide wavelength region of 8-12 µm to map the cloud-top temperature which is typically as low as 230 K. Unlike other imagers, LIR is able to take images of both dayside and nightside with equal quality and accuracy. The cloud-top temperature map will reflect the cloud height distribution in which a few hundred meters of difference in cloud height corresponds to temperature difference of 0.3 K. In order to detect the cloud height difference of a few hundred meters, LIR requires a noise equivalent temperature difference (NETD) of 0.3 K. The commercial UMBA camera is typically used for observing room-temperature targets, and thus the electronics and the driving parameters have been optimized for low temperature-targets. Images of blackbody targets in room temperature (˜300 K) and low temperature (˜230 K) have been acquired in a vacuum environment using a prototype model of LIR, showing that the NETD of 0.2 K and 0.8 K are achieved in room temperature and low temperature, respectively. Although the NETD at the low temperature is 4 times worse than the case for the room temperature, we expect that the requirement of N ET D < 0.3 K for a low-temperature target will be achieved by averaging several tens of images

  20. Modeling rapidly disseminating infectious disease during mass gatherings

    PubMed Central

    2012-01-01

    We discuss models for rapidly disseminating infectious diseases during mass gatherings (MGs), using influenza as a case study. Recent innovations in modeling and forecasting influenza transmission dynamics at local, regional, and global scales have made influenza a particularly attractive model scenario for MG. We discuss the behavioral, medical, and population factors for modeling MG disease transmission, review existing model formulations, and highlight key data and modeling gaps related to modeling MG disease transmission. We argue that the proposed improvements will help integrate infectious-disease models in MG health contingency plans in the near future, echoing modeling efforts that have helped shape influenza pandemic preparedness plans in recent years. PMID:23217051

  1. Biomimetically Ornamented Rapid Prototyping Fabrication of an Apatite-Collagen-Polycaprolactone Composite Construct with Nano-Micro-Macro Hierarchical Structure for Large Bone Defect Treatment.

    PubMed

    Wang, Jinbing; Wu, Dingyu; Zhang, Zhanzhao; Li, Jun; Shen, Yi; Wang, Zhenxing; Li, Yu; Zhang, Zhi-Yong; Sun, Jian

    2015-12-01

    Biomaterial-based bone graft substitute with favorable mechanical and biological properties could be used as an alternative to autograft for large defect treatment. Here, an apatite-collagen-polycaprolactone (Ap-Col-PCL) composite construct was developed with unique nano-micro-macro hierarchical architectures by combining rapid prototyping (RP) fabrication technology and a 3D functionalization strategy. Macroporous PCL framework was fabricated using RP technology, then functionalized by collagen incorporation and biomimetic deposition. Ap-Col-PCL composite construct was characterized with hierarchical architectures of a nanoscale (∼100 nm thickness and ∼1 μm length) platelike apatite coating on the microporous (126 ± 18 μm) collagen networks, which homogeneously filled the macroporous (∼1000 μm) PCL frameworks and possessed a favorable hydrophilic property and compressive modulus (68.75 ± 3.39 MPa) similar to that of cancellous bone. Moreover, in vitro cell culture assay and in vivo critical-sized bone defect implantation demonstrated that the Ap-Col-PCL construct could not only significantly increase the cell adhesion capability (2.0-fold) and promote faster cell proliferation but also successfully bridge the segmental long bone defect within 12 weeks with much more bone regeneration (5.2-fold), better osteointegration (7.2-fold), and a faster new bone deposition rate (2.9-fold). Our study demonstrated that biomimetically ornamented Ap-Col-PCL constructs exhibit a favorable mechanical property, more bone tissue ingrowth, and better osteointegration capability as an effective bone graft substitute for critical-sized bone defect treatment; meanwhile, it can also harness the advantages of RP technology, in particular, facilitating the customization of the shape and size of implants according to medical images during clinical application.

  2. Blood quantum and perceptions of black-white biracial targets: the black ancestry prototype model of affirmative action.

    PubMed

    Sanchez, Diana T; Good, Jessica J; Chavez, George

    2011-01-01

    The present study examined the causal role of amount of Black ancestry in targets' perceived fit with Black prototypes and perceivers' categorization of biracial targets. Greater Black ancestry increased the likelihood that perceivers categorized biracial targets as Black and perceived targets as fitting Black prototypes (e.g., experiencing racial discrimination, possessing stereotypic traits). These results persisted, controlling for perceptions of phenotype that stem from ancestry information. Perceivers' beliefs about how society would categorize the biracial targets predicted perceptions of discrimination, whereas perceivers' beliefs about the targets' self-categorization predicted trait perceptions. The results of this study support the Black ancestry prototype model of affirmative action, which reveals the downstream consequences of Black ancestry for the distribution of minority resources (e.g., affirmative action) to biracial targets. PMID:21088283

  3. Interactive Rapid Dose Assessment Model (IRDAM): user's guide

    SciTech Connect

    Poeton, R.W.; Moeller, M.P.; Laughlin, G.J.; Desrosiers, A.E.

    1983-05-01

    As part of the continuing emphasis on emergency preparedness the US Nuclear Regulatory Commission (NRC) sponsored the development of a rapid dose assessment system by Pacific Northwest Laboratory (PNL). This system, the Interactive Rapid Dose Assessment Model (IRDAM) is a micro-computer based program for rapidly assessing the radiological impact of accidents at nuclear power plants. This User's Guide provides instruction in the setup and operation of the equipment necessary to run IRDAM. Instructions are also given on how to load the magnetic disks and access the interactive part of the program. Two other companion volumes to this one provide additional information on IRDAM. Reactor Accident Assessment Methods (NUREG/CR-3012, Volume 2) describes the technical bases for IRDAM including methods, models and assumptions used in calculations. Scenarios for Comparing Dose Assessment Models (NUREG/CR-3012, Volume 3) provides the results of calculations made by IRDAM and other models for specific accident scenarios.

  4. Modeling of subglacial hydrological development following rapid supraglacial lake drainage

    PubMed Central

    Dow, C F; Kulessa, B; Rutt, I C; Tsai, V C; Pimentel, S; Doyle, S H; van As, D; Lindbäck, K; Pettersson, R; Jones, G A; Hubbard, A

    2015-01-01

    The rapid drainage of supraglacial lakes injects substantial volumes of water to the bed of the Greenland ice sheet over short timescales. The effect of these water pulses on the development of basal hydrological systems is largely unknown. To address this, we develop a lake drainage model incorporating both (1) a subglacial radial flux element driven by elastic hydraulic jacking and (2) downstream drainage through a linked channelized and distributed system. Here we present the model and examine whether substantial, efficient subglacial channels can form during or following lake drainage events and their effect on the water pressure in the surrounding distributed system. We force the model with field data from a lake drainage site, 70 km from the terminus of Russell Glacier in West Greenland. The model outputs suggest that efficient subglacial channels do not readily form in the vicinity of the lake during rapid drainage and instead water is evacuated primarily by a transient turbulent sheet and the distributed system. Following lake drainage, channels grow but are not large enough to reduce the water pressure in the surrounding distributed system, unless preexisting channels are present throughout the domain. Our results have implications for the analysis of subglacial hydrological systems in regions where rapid lake drainage provides the primary mechanism for surface-to-bed connections. Key Points Model for subglacial hydrological analysis of rapid lake drainage events Limited subglacial channel growth during and following rapid lake drainage Persistence of distributed drainage in inland areas where channel growth is limited PMID:26640746

  5. Prototype Near-Field/GIS Model for Sequestered-CO2 Risk Characterization and Management

    SciTech Connect

    Bogen, K T; Homann, S G; Gouveia, F J; Neher, L A

    2006-02-10

    Detecting unmapped abandoned wells thus remains a major carbon sequestration (CS) technology gap. Many (>10{sup 5}) abandoned wells are thought to lie in potential sequestration sites. For such wells, risk analysis to date has focused on aggregate long-term future impacts of seepage at rates < or << {approx}1 g m{sup 2} d{sup -1} on storage goals as sequestered plumes encroach upon wells with assumed distributions of seal ineffectiveness (Oldenburg and Unger, 2003; Saripali et al. 2003; Celia, 2005). However, unmapped abandoned wells include an unknown number without any effective seal at all, venting through which may dominate CO{sub 2}-loss scenarios. A model of such a well is Crystal Geyser (CG), a prospective oil well abandoned in the 1930s with no barrier installed after it encountered a natural CO{sub 2} reservoir rather than oil (Baer and Rigby, 1978; Rinehart, 1980). CG demonstrates how an unimpeded conduit to the surface now regularly vents from 10{sup 3} to >10{sup 4} kg of CO{sub 2} gas to the terrestrial surface (Figure 1). Unique field data recently gathered from Crystal Geyser (CG) in Utah (Gouveia et al. 2005) confirm that, although resulting surface CO{sub 2} concentrations resulting from CG-like eruptions would likely be safe in general, they could accumulate to pose lethal hazards under relatively rare meteorological and topographic (MT) conditions. This source of foreseeable risk needs to be managed if carbon sequestration is to be publicly accepted. To address this concern, we used CG field data to estimate the source term for a prototype model that identifies zones at relatively highly elevated risk for sequestered-CO{sub 2} casualties. Such a model could be applied both to design and comply with future regulatory requirements to survey high-risk zones in each proposed sequestration site for improperly sealed wells.

  6. COINSTAC: A Privacy Enabled Model and Prototype for Leveraging and Processing Decentralized Brain Imaging Data

    PubMed Central

    Plis, Sergey M.; Sarwate, Anand D.; Wood, Dylan; Dieringer, Christopher; Landis, Drew; Reed, Cory; Panta, Sandeep R.; Turner, Jessica A.; Shoemaker, Jody M.; Carter, Kim W.; Thompson, Paul; Hutchison, Kent; Calhoun, Vince D.

    2016-01-01

    The field of neuroimaging has embraced the need for sharing and collaboration. Data sharing mandates from public funding agencies and major journal publishers have spurred the development of data repositories and neuroinformatics consortia. However, efficient and effective data sharing still faces several hurdles. For example, open data sharing is on the rise but is not suitable for sensitive data that are not easily shared, such as genetics. Current approaches can be cumbersome (such as negotiating multiple data sharing agreements). There are also significant data transfer, organization and computational challenges. Centralized repositories only partially address the issues. We propose a dynamic, decentralized platform for large scale analyses called the Collaborative Informatics and Neuroimaging Suite Toolkit for Anonymous Computation (COINSTAC). The COINSTAC solution can include data missing from central repositories, allows pooling of both open and “closed” repositories by developing privacy-preserving versions of widely-used algorithms, and incorporates the tools within an easy-to-use platform enabling distributed computation. We present an initial prototype system which we demonstrate on two multi-site data sets, without aggregating the data. In addition, by iterating across sites, the COINSTAC model enables meta-analytic solutions to converge to “pooled-data” solutions (i.e., as if the entire data were in hand). More advanced approaches such as feature generation, matrix factorization models, and preprocessing can be incorporated into such a model. In sum, COINSTAC enables access to the many currently unavailable data sets, a user friendly privacy enabled interface for decentralized analysis, and a powerful solution that complements existing data sharing solutions.

  7. COINSTAC: A Privacy Enabled Model and Prototype for Leveraging and Processing Decentralized Brain Imaging Data.

    PubMed

    Plis, Sergey M; Sarwate, Anand D; Wood, Dylan; Dieringer, Christopher; Landis, Drew; Reed, Cory; Panta, Sandeep R; Turner, Jessica A; Shoemaker, Jody M; Carter, Kim W; Thompson, Paul; Hutchison, Kent; Calhoun, Vince D

    2016-01-01

    The field of neuroimaging has embraced the need for sharing and collaboration. Data sharing mandates from public funding agencies and major journal publishers have spurred the development of data repositories and neuroinformatics consortia. However, efficient and effective data sharing still faces several hurdles. For example, open data sharing is on the rise but is not suitable for sensitive data that are not easily shared, such as genetics. Current approaches can be cumbersome (such as negotiating multiple data sharing agreements). There are also significant data transfer, organization and computational challenges. Centralized repositories only partially address the issues. We propose a dynamic, decentralized platform for large scale analyses called the Collaborative Informatics and Neuroimaging Suite Toolkit for Anonymous Computation (COINSTAC). The COINSTAC solution can include data missing from central repositories, allows pooling of both open and "closed" repositories by developing privacy-preserving versions of widely-used algorithms, and incorporates the tools within an easy-to-use platform enabling distributed computation. We present an initial prototype system which we demonstrate on two multi-site data sets, without aggregating the data. In addition, by iterating across sites, the COINSTAC model enables meta-analytic solutions to converge to "pooled-data" solutions (i.e., as if the entire data were in hand). More advanced approaches such as feature generation, matrix factorization models, and preprocessing can be incorporated into such a model. In sum, COINSTAC enables access to the many currently unavailable data sets, a user friendly privacy enabled interface for decentralized analysis, and a powerful solution that complements existing data sharing solutions. PMID:27594820

  8. COINSTAC: A Privacy Enabled Model and Prototype for Leveraging and Processing Decentralized Brain Imaging Data.

    PubMed

    Plis, Sergey M; Sarwate, Anand D; Wood, Dylan; Dieringer, Christopher; Landis, Drew; Reed, Cory; Panta, Sandeep R; Turner, Jessica A; Shoemaker, Jody M; Carter, Kim W; Thompson, Paul; Hutchison, Kent; Calhoun, Vince D

    2016-01-01

    The field of neuroimaging has embraced the need for sharing and collaboration. Data sharing mandates from public funding agencies and major journal publishers have spurred the development of data repositories and neuroinformatics consortia. However, efficient and effective data sharing still faces several hurdles. For example, open data sharing is on the rise but is not suitable for sensitive data that are not easily shared, such as genetics. Current approaches can be cumbersome (such as negotiating multiple data sharing agreements). There are also significant data transfer, organization and computational challenges. Centralized repositories only partially address the issues. We propose a dynamic, decentralized platform for large scale analyses called the Collaborative Informatics and Neuroimaging Suite Toolkit for Anonymous Computation (COINSTAC). The COINSTAC solution can include data missing from central repositories, allows pooling of both open and "closed" repositories by developing privacy-preserving versions of widely-used algorithms, and incorporates the tools within an easy-to-use platform enabling distributed computation. We present an initial prototype system which we demonstrate on two multi-site data sets, without aggregating the data. In addition, by iterating across sites, the COINSTAC model enables meta-analytic solutions to converge to "pooled-data" solutions (i.e., as if the entire data were in hand). More advanced approaches such as feature generation, matrix factorization models, and preprocessing can be incorporated into such a model. In sum, COINSTAC enables access to the many currently unavailable data sets, a user friendly privacy enabled interface for decentralized analysis, and a powerful solution that complements existing data sharing solutions.

  9. COINSTAC: A Privacy Enabled Model and Prototype for Leveraging and Processing Decentralized Brain Imaging Data

    PubMed Central

    Plis, Sergey M.; Sarwate, Anand D.; Wood, Dylan; Dieringer, Christopher; Landis, Drew; Reed, Cory; Panta, Sandeep R.; Turner, Jessica A.; Shoemaker, Jody M.; Carter, Kim W.; Thompson, Paul; Hutchison, Kent; Calhoun, Vince D.

    2016-01-01

    The field of neuroimaging has embraced the need for sharing and collaboration. Data sharing mandates from public funding agencies and major journal publishers have spurred the development of data repositories and neuroinformatics consortia. However, efficient and effective data sharing still faces several hurdles. For example, open data sharing is on the rise but is not suitable for sensitive data that are not easily shared, such as genetics. Current approaches can be cumbersome (such as negotiating multiple data sharing agreements). There are also significant data transfer, organization and computational challenges. Centralized repositories only partially address the issues. We propose a dynamic, decentralized platform for large scale analyses called the Collaborative Informatics and Neuroimaging Suite Toolkit for Anonymous Computation (COINSTAC). The COINSTAC solution can include data missing from central repositories, allows pooling of both open and “closed” repositories by developing privacy-preserving versions of widely-used algorithms, and incorporates the tools within an easy-to-use platform enabling distributed computation. We present an initial prototype system which we demonstrate on two multi-site data sets, without aggregating the data. In addition, by iterating across sites, the COINSTAC model enables meta-analytic solutions to converge to “pooled-data” solutions (i.e., as if the entire data were in hand). More advanced approaches such as feature generation, matrix factorization models, and preprocessing can be incorporated into such a model. In sum, COINSTAC enables access to the many currently unavailable data sets, a user friendly privacy enabled interface for decentralized analysis, and a powerful solution that complements existing data sharing solutions. PMID:27594820

  10. Rapid installation of numerical models in multiple parent codes

    SciTech Connect

    Brannon, R.M.; Wong, M.K.

    1996-10-01

    A set of``model interface guidelines``, called MIG, is offered as a means to more rapidly install numerical models (such as stress-strain laws) into any parent code (hydrocode, finite element code, etc.) without having to modify the model subroutines. The model developer (who creates the model package in compliance with the guidelines) specifies the model`s input and storage requirements in a standardized way. For portability, database management (such as saving user inputs and field variables) is handled by the parent code. To date, NUG has proved viable in beta installations of several diverse models in vectorized and parallel codes written in different computer languages. A NUG-compliant model can be installed in different codes without modifying the model`s subroutines. By maintaining one model for many codes, MIG facilitates code-to-code comparisons and reduces duplication of effort potentially reducing the cost of installing and sharing models.

  11. Prompt and Precise Prototyping

    NASA Technical Reports Server (NTRS)

    2003-01-01

    For Sanders Design International, Inc., of Wilton, New Hampshire, every passing second between the concept and realization of a product is essential to succeed in the rapid prototyping industry where amongst heavy competition, faster time-to-market means more business. To separate itself from its rivals, Sanders Design aligned with NASA's Marshall Space Flight Center to develop what it considers to be the most accurate rapid prototyping machine for fabrication of extremely precise tooling prototypes. The company's Rapid ToolMaker System has revolutionized production of high quality, small-to-medium sized prototype patterns and tooling molds with an exactness that surpasses that of computer numerically-controlled (CNC) machining devices. Created with funding and support from Marshall under a Small Business Innovation Research (SBIR) contract, the Rapid ToolMaker is a dual-use technology with applications in both commercial and military aerospace fields. The advanced technology provides cost savings in the design and manufacturing of automotive, electronic, and medical parts, as well as in other areas of consumer interest, such as jewelry and toys. For aerospace applications, the Rapid ToolMaker enables fabrication of high-quality turbine and compressor blades for jet engines on unmanned air vehicles, aircraft, and missiles.

  12. Prototyping an online wetland ecosystem services model using open model sharing standards

    USGS Publications Warehouse

    Feng, M.; Liu, S.; Euliss, N.H.; Young, Caitlin; Mushet, D.M.

    2011-01-01

    Great interest currently exists for developing ecosystem models to forecast how ecosystem services may change under alternative land use and climate futures. Ecosystem services are diverse and include supporting services or functions (e.g., primary production, nutrient cycling), provisioning services (e.g., wildlife, groundwater), regulating services (e.g., water purification, floodwater retention), and even cultural services (e.g., ecotourism, cultural heritage). Hence, the knowledge base necessary to quantify ecosystem services is broad and derived from many diverse scientific disciplines. Building the required interdisciplinary models is especially challenging as modelers from different locations and times may develop the disciplinary models needed for ecosystem simulations, and these models must be identified and made accessible to the interdisciplinary simulation. Additional difficulties include inconsistent data structures, formats, and metadata required by geospatial models as well as limitations on computing, storage, and connectivity. Traditional standalone and closed network systems cannot fully support sharing and integrating interdisciplinary geospatial models from variant sources. To address this need, we developed an approach to openly share and access geospatial computational models using distributed Geographic Information System (GIS) techniques and open geospatial standards. We included a means to share computational models compliant with Open Geospatial Consortium (OGC) Web Processing Services (WPS) standard to ensure modelers have an efficient and simplified means to publish new models. To demonstrate our approach, we developed five disciplinary models that can be integrated and shared to simulate a few of the ecosystem services (e.g., water storage, waterfowl breeding) that are provided by wetlands in the Prairie Pothole Region (PPR) of North America. ?? 2010 Elsevier Ltd.

  13. Rapid Modeling, Assembly and Simulation in Design Optimization

    NASA Technical Reports Server (NTRS)

    Housner, Jerry

    1997-01-01

    A new capability for design is reviewed. This capability provides for rapid assembly of detail finite element models early in the design process where costs are most effectively impacted. This creates an engineering environment which enables comprehensive analysis and design optimization early in the design process. Graphical interactive computing makes it possible for the engineer to interact with the design while performing comprehensive design studies. This rapid assembly capability is enabled by the use of Interface Technology, to couple independently created models which can be archived and made accessible to the designer. Results are presented to demonstrate the capability.

  14. Kaiser Permanente/Sandia National health care model. Phase I prototype final report. Part 1 - model overview

    SciTech Connect

    Edwards, D.; Yoshimura, A.; Butler, D.; Judson, R.

    1996-11-01

    This report describes the results of a Cooperative Research and Development Agreement between Sandia National Laboratories and Kaiser Permanente Southern California to develop a prototype computer model of Kaiser Permanente`s health care delivery system. As a discrete event simulation, SimHCO models for each of 100,000 patients the progression of disease, individual resource usage, and patient choices in a competitive environment. SimHCO is implemented in the object-oriented programming language C++, stressing reusable knowledge and reusable software components. The versioned implementation of SimHCO showed that the object-oriented framework allows the program to grow in complexity in an incremental way. Furthermore, timing calculations showed that SimHCO runs in a reasonable time on typical workstations, and that a second phase model will scale proportionally and run within the system constraints of contemporary computer technology. This report is published as two documents: Model Overview and Domain Analysis. A separate Kaiser-proprietary report contains the Disease and Health Care Organization Selection Models.

  15. Development of Residential Prototype Building Models and Analysis System for Large-Scale Energy Efficiency Studies Using EnergyPlus

    SciTech Connect

    Mendon, Vrushali V.; Taylor, Zachary T.

    2014-09-10

    ABSTRACT: Recent advances in residential building energy efficiency and codes have resulted in increased interest in detailed residential building energy models using the latest energy simulation software. One of the challenges of developing residential building models to characterize new residential building stock is to allow for flexibility to address variability in house features like geometry, configuration, HVAC systems etc. Researchers solved this problem in a novel way by creating a simulation structure capable of creating fully-functional EnergyPlus batch runs using a completely scalable residential EnergyPlus template system. This system was used to create a set of thirty-two residential prototype building models covering single- and multifamily buildings, four common foundation types and four common heating system types found in the United States (US). A weighting scheme with detailed state-wise and national weighting factors was designed to supplement the residential prototype models. The complete set is designed to represent a majority of new residential construction stock. The entire structure consists of a system of utility programs developed around the core EnergyPlus simulation engine to automate the creation and management of large-scale simulation studies with minimal human effort. The simulation structure and the residential prototype building models have been used for numerous large-scale studies, one of which is briefly discussed in this paper.

  16. The Worm Process for the Ising Model is Rapidly Mixing

    NASA Astrophysics Data System (ADS)

    Collevecchio, Andrea; Garoni, Timothy M.; Hyndman, Timothy; Tokarev, Daniel

    2016-09-01

    We prove rapid mixing of the worm process for the zero-field ferromagnetic Ising model, on all finite connected graphs, and at all temperatures. As a corollary, we obtain a fully-polynomial randomized approximation scheme for the Ising susceptibility, and for a certain restriction of the two-point correlation function.

  17. Classification of geokhod units and systems based on product cost analysis and estimation for a prototype model production

    NASA Astrophysics Data System (ADS)

    Aksenov, V. V.; Walter, A. V.; Gordeyev, A. A.; Kosovets, A. V.

    2015-09-01

    The paper considers data systematization on a new shield-type heading machine - geokhod. The target of the paper is to classify geokhod components on the basis of their technical and economical production parameters. A prototype model reveals the structure of a geokhod as an assembly unit and identifies its basic characteristics. The paper overviews the methods of product cost estimations, justifies the application of an operation-based approach for a prototype model, provides the results containing product cost data for various geokhod components and technological processes, and gives the data for a material cost structure. Taking into consideration the product cost analysis, geokhod components are classified according to their technical and economical production parameters. Moreover the paper outlines the ways of a classification application for a geokhod manufacturing techniques improvement.

  18. Standardized data collection to build prediction models in oncology: a prototype for rectal cancer.

    PubMed

    Meldolesi, Elisa; van Soest, Johan; Damiani, Andrea; Dekker, Andre; Alitto, Anna Rita; Campitelli, Maura; Dinapoli, Nicola; Gatta, Roberto; Gambacorta, Maria Antonietta; Lanzotti, Vito; Lambin, Philippe; Valentini, Vincenzo

    2016-01-01

    The advances in diagnostic and treatment technology are responsible for a remarkable transformation in the internal medicine concept with the establishment of a new idea of personalized medicine. Inter- and intra-patient tumor heterogeneity and the clinical outcome and/or treatment's toxicity's complexity, justify the effort to develop predictive models from decision support systems. However, the number of evaluated variables coming from multiple disciplines: oncology, computer science, bioinformatics, statistics, genomics, imaging, among others could be very large thus making traditional statistical analysis difficult to exploit. Automated data-mining processes and machine learning approaches can be a solution to organize the massive amount of data, trying to unravel important interaction. The purpose of this paper is to describe the strategy to collect and analyze data properly for decision support and introduce the concept of an 'umbrella protocol' within the framework of 'rapid learning healthcare'. PMID:26674745

  19. Standardized data collection to build prediction models in oncology: a prototype for rectal cancer.

    PubMed

    Meldolesi, Elisa; van Soest, Johan; Damiani, Andrea; Dekker, Andre; Alitto, Anna Rita; Campitelli, Maura; Dinapoli, Nicola; Gatta, Roberto; Gambacorta, Maria Antonietta; Lanzotti, Vito; Lambin, Philippe; Valentini, Vincenzo

    2016-01-01

    The advances in diagnostic and treatment technology are responsible for a remarkable transformation in the internal medicine concept with the establishment of a new idea of personalized medicine. Inter- and intra-patient tumor heterogeneity and the clinical outcome and/or treatment's toxicity's complexity, justify the effort to develop predictive models from decision support systems. However, the number of evaluated variables coming from multiple disciplines: oncology, computer science, bioinformatics, statistics, genomics, imaging, among others could be very large thus making traditional statistical analysis difficult to exploit. Automated data-mining processes and machine learning approaches can be a solution to organize the massive amount of data, trying to unravel important interaction. The purpose of this paper is to describe the strategy to collect and analyze data properly for decision support and introduce the concept of an 'umbrella protocol' within the framework of 'rapid learning healthcare'.

  20. Elements of effective palliative care models: a rapid review

    PubMed Central

    2014-01-01

    Background Population ageing, changes to the profiles of life-limiting illnesses and evolving societal attitudes prompt a critical evaluation of models of palliative care. We set out to identify evidence-based models of palliative care to inform policy reform in Australia. Method A rapid review of electronic databases and the grey literature was undertaken over an eight week period in April-June 2012. We included policy documents and comparative studies from countries within the Organisation for Economic Co-operation and Development (OECD) published in English since 2001. Meta-analysis was planned where >1 study met criteria; otherwise, synthesis was narrative using methods described by Popay et al. (2006). Results Of 1,959 peer-reviewed articles, 23 reported systematic reviews, 9 additional RCTs and 34 non-randomised comparative studies. Variation in the content of models, contexts in which these were implemented and lack of detailed reporting meant that elements of models constituted a more meaningful unit of analysis than models themselves. Case management was the element most consistently reported in models for which comparative studies provided evidence for effectiveness. Essential attributes of population-based palliative care models identified by policy and addressed by more than one element were communication and coordination between providers (including primary care), skill enhancement, and capacity to respond rapidly to individuals’ changing needs and preferences over time. Conclusion Models of palliative care should integrate specialist expertise with primary and community care services and enable transitions across settings, including residential aged care. The increasing complexity of care needs, services, interventions and contextual drivers warrants future research aimed at elucidating the interactions between different components and the roles played by patient, provider and health system factors. The findings of this review are limited by its

  1. Quantitative myocardial perfusion imaging in a porcine ischemia model using a prototype spectral detector CT system

    NASA Astrophysics Data System (ADS)

    Fahmi, Rachid; Eck, Brendan L.; Levi, Jacob; Fares, Anas; Dhanantwari, Amar; Vembar, Mani; Bezerra, Hiram G.; Wilson, David L.

    2016-03-01

    We optimized and evaluated dynamic myocardial CT perfusion (CTP) imaging on a prototype spectral detector CT (SDCT) scanner. Simultaneous acquisition of energy sensitive projections on the SDCT system enabled projection-based material decomposition, which typically performs better than image-based decomposition required by some other system designs. In addition to virtual monoenergetic, or keV images, the SDCT provided conventional (kVp) images, allowing us to compare and contrast results. Physical phantom measurements demonstrated linearity of keV images, a requirement for quantitative perfusion. Comparisons of kVp to keV images demonstrated very significant reductions in tell-tale beam hardening (BH) artifacts in both phantom and pig images. In phantom images, consideration of iodine contrast to noise ratio and small residual BH artifacts suggested optimum processing at 70 keV. The processing pipeline for dynamic CTP measurements included 4D image registration, spatio-temporal noise filtering, and model-independent singular value decomposition deconvolution, automatically regularized using the L-curve criterion. In normal pig CTP, 70 keV perfusion estimates were homogeneous throughout the myocardium. At 120 kVp, flow was reduced by more than 20% on the BH-hypo-enhanced myocardium, a range that might falsely indicate actionable ischemia, considering the 0.8 threshold for actionable FFR. With partial occlusion of the left anterior descending (LAD) artery (FFR  <  0.8), perfusion defects at 70 keV were correctly identified in the LAD territory. At 120 kVp, BH affected the size and flow in the ischemic area; e.g. with FFR ≈ 0.65, the anterior-to-lateral flow ratio was 0.29  ±  0.01, over-estimating stenosis severity as compared to 0.42  ±  0.01 (p  <  0.05) at 70 keV. On the non-ischemic inferior wall (not a LAD territory), the flow ratio was 0.50  ±  0.04 falsely indicating an actionable ischemic condition in a healthy

  2. Quantitative myocardial perfusion imaging in a porcine ischemia model using a prototype spectral detector CT system.

    PubMed

    Fahmi, Rachid; Eck, Brendan L; Levi, Jacob; Fares, Anas; Dhanantwari, Amar; Vembar, Mani; Bezerra, Hiram G; Wilson, David L

    2016-03-21

    We optimized and evaluated dynamic myocardial CT perfusion (CTP) imaging on a prototype spectral detector CT (SDCT) scanner. Simultaneous acquisition of energy sensitive projections on the SDCT system enabled projection-based material decomposition, which typically performs better than image-based decomposition required by some other system designs. In addition to virtual monoenergetic, or keV images, the SDCT provided conventional (kVp) images, allowing us to compare and contrast results. Physical phantom measurements demonstrated linearity of keV images, a requirement for quantitative perfusion. Comparisons of kVp to keV images demonstrated very significant reductions in tell-tale beam hardening (BH) artifacts in both phantom and pig images. In phantom images, consideration of iodine contrast to noise ratio and small residual BH artifacts suggested optimum processing at 70 keV. The processing pipeline for dynamic CTP measurements included 4D image registration, spatio-temporal noise filtering, and model-independent singular value decomposition deconvolution, automatically regularized using the L-curve criterion. In normal pig CTP, 70 keV perfusion estimates were homogeneous throughout the myocardium. At 120 kVp, flow was reduced by more than 20% on the BH-hypo-enhanced myocardium, a range that might falsely indicate actionable ischemia, considering the 0.8 threshold for actionable FFR. With partial occlusion of the left anterior descending (LAD) artery (FFR < 0.8), perfusion defects at 70 keV were correctly identified in the LAD territory. At 120 kVp, BH affected the size and flow in the ischemic area; e.g. with FFR ≈ 0.65, the anterior-to-lateral flow ratio was 0.29 ± 0.01, over-estimating stenosis severity as compared to 0.42 ± 0.01 (p < 0.05) at 70 keV. On the non-ischemic inferior wall (not a LAD territory), the flow ratio was 0.50 ± 0.04 falsely indicating an actionable ischemic condition in a healthy territory. This ratio was 1.00 ± 0.08 at 70 ke

  3. Modeling of subglacial hydrological development following rapid supraglacial lake drainage

    NASA Astrophysics Data System (ADS)

    Dow, C. F.; Kulessa, B.; Rutt, I. C.; Tsai, V. C.; Pimentel, S.; Doyle, S. H.; As, D.; Lindbäck, K.; Pettersson, R.; Jones, G. A.; Hubbard, A.

    2015-06-01

    The rapid drainage of supraglacial lakes injects substantial volumes of water to the bed of the Greenland ice sheet over short timescales. The effect of these water pulses on the development of basal hydrological systems is largely unknown. To address this, we develop a lake drainage model incorporating both (1) a subglacial radial flux element driven by elastic hydraulic jacking and (2) downstream drainage through a linked channelized and distributed system. Here we present the model and examine whether substantial, efficient subglacial channels can form during or following lake drainage events and their effect on the water pressure in the surrounding distributed system. We force the model with field data from a lake drainage site, 70 km from the terminus of Russell Glacier in West Greenland. The model outputs suggest that efficient subglacial channels do not readily form in the vicinity of the lake during rapid drainage and instead water is evacuated primarily by a transient turbulent sheet and the distributed system. Following lake drainage, channels grow but are not large enough to reduce the water pressure in the surrounding distributed system, unless preexisting channels are present throughout the domain. Our results have implications for the analysis of subglacial hydrological systems in regions where rapid lake drainage provides the primary mechanism for surface-to-bed connections.

  4. A rapid radiative transfer model for reflection of solar radiation

    NASA Technical Reports Server (NTRS)

    Xiang, X.; Smith, E. A.; Justus, C. G.

    1994-01-01

    A rapid analytical radiative transfer model for reflection of solar radiation in plane-parallel atmospheres is developed based on the Sobolev approach and the delta function transformation technique. A distinct advantage of this model over alternative two-stream solutions is that in addition to yielding the irradiance components, which turn out to be mathematically equivalent to the delta-Eddington approximation, the radiance field can also be expanded in a mathematically consistent fashion. Tests with the model against a more precise multistream discrete ordinate model over a wide range of input parameters demonstrate that the new approximate method typically produces average radiance differences of less than 5%, with worst average differences of approximately 10%-15%. By the same token, the computational speed of the new model is some tens to thousands times faster than that of the more precise model when its stream resolution is set to generate precise calculations.

  5. A Rapid Radiative Transfer Model for Reflection of Solar Radiation.

    NASA Astrophysics Data System (ADS)

    Xiang, X.; Smith, E. A.; Justus, C. G.

    1994-07-01

    A rapid analytical radiative transfer model for reflection of solar radiation in plane-parallel atmospheres is developed based on the Sobolev approach and the delta function transformation technique. A distinct advantage of this model over alternative two-stream solutions is that in addition to yielding the irradiance components, which turn out to be mathematically equivalent to the delta-Eddington approximation, the radiance field can also be expanded in a mathematically consistent fashion. Tests with the model against a more precise multistream discrete ordinate model over a wide range of input parameters demonstrate that the new approximate method typically produces average radiance differences of less than 5%, with worst average differences of 10%-15%. By the same token, the computational speed of the new model is some tens to thousands times faster than that of the more precise model when its stream resolution is set to generate precise calculations.

  6. Rapid Automated Aircraft Simulation Model Updating from Flight Data

    NASA Technical Reports Server (NTRS)

    Brian, Geoff; Morelli, Eugene A.

    2011-01-01

    Techniques to identify aircraft aerodynamic characteristics from flight measurements and compute corrections to an existing simulation model of a research aircraft were investigated. The purpose of the research was to develop a process enabling rapid automated updating of aircraft simulation models using flight data and apply this capability to all flight regimes, including flight envelope extremes. The process presented has the potential to improve the efficiency of envelope expansion flight testing, revision of control system properties, and the development of high-fidelity simulators for pilot training.

  7. Model and prototype investigations of upper partial load unsteady phenomena on the Francis turbine designed for head up to 120 m

    NASA Astrophysics Data System (ADS)

    Kuznetsov, I.; Zakharov, A.; Arm, V.; Akulaev, R.

    2014-03-01

    The upper partial load unsteady phenomena are often observed at model tests for Francis turbine with high and middle specific speed. It is appears approximately between 7085% of optima point discharge for constant unit speed value and has accompanied by additional phenomenon with much higher frequency than draft tube vortex precession frequency and also runner rotational frequency. There are some discussions about nature of this phenomena and transposition of unsteady model test results to the prototype. In this paper are presented the results of above mentioned phenomena model investigations and some results of investigation at prototype turbine. Based on the results of model tests the following extensive data have been obtained: pressure fluctuation in the draft tube cone and spiral case, axial force fluctuations, it is demonstrated the significant influence of cavitation on upper partial load unsteady phenomena. The result of measurements of bearing vibrations and pressure pulsations are presented for prototype turbine at corresponded or very close operation points to model. In accordance with obtained data it is demonstrated that at upper partial load operation the unsteady phenomenon is observed as for the model also for the prototype turbine. On the base of model investigation has been demonstrated the influence of air admission and special design solutions to diminish unsteady phenomena at upper partial load range. All investigations were based on the physical experiment. Thus, based on model and prototype experimental investigations it is obtained additional information about upper partial load unsteady phenomenon and confirmed the transposition of model results to prototype turbine.

  8. Modeling rapid mass movements using the shallow water equations

    NASA Astrophysics Data System (ADS)

    Hergarten, S.; Robl, J.

    2014-11-01

    We propose a new method to model rapid mass movements on complex topography using the shallow water equations in Cartesian coordinates. These equations are the widely used standard approximation for the flow of water in rivers and shallow lakes, but the main prerequisite for their application - an almost horizontal fluid table - is in general not satisfied for avalanches and debris flows in steep terrain. Therefore, we have developed appropriate correction terms for large topographic gradients. In this study we present the mathematical formulation of these correction terms and their implementation in the open source flow solver GERRIS. This novel approach is evaluated by simulating avalanches on synthetic and finally natural topographies and the widely used Voellmy flow resistance law. The results are tested against analytical solutions and the commercial avalanche model RAMMS. The overall results are in excellent agreement with the reference system RAMMS, and the deviations between the different models are far below the uncertainties in the determination of the relevant fluid parameters and involved avalanche volumes in reality. As this code is freely available and open source, it can be easily extended by additional fluid models or source areas, making this model suitable for simulating several types of rapid mass movements. It therefore provides a valuable tool assisting regional scale natural hazard studies.

  9. Extending a prototype knowledge and object based image analysis model to coarser spatial resolution imagery: an example from the Missouri River

    USGS Publications Warehouse

    Strong, Laurence L.

    2012-01-01

    A prototype knowledge- and object-based image analysis model was developed to inventory and map least tern and piping plover habitat on the Missouri River, USA. The model has been used to inventory the state of sandbars annually for 4 segments of the Missouri River since 2006 using QuickBird imagery. Interpretation of the state of sandbars is difficult when images for the segment are acquired at different river stages and different states of vegetation phenology and canopy cover. Concurrent QuickBird and RapidEye images were classified using the model and the spatial correspondence of classes in the land cover and sandbar maps were analysed for the spatial extent of the images and at nest locations for both bird species. Omission and commission errors were low for unvegetated land cover classes used for nesting by both bird species and for land cover types with continuous vegetation cover and water. Errors were larger for land cover classes characterized by a mixture of sand and vegetation. Sandbar classification decisions are made using information on land cover class proportions and disagreement between sandbar classes was resolved using fuzzy membership possibilities. Regression analysis of area for a paired sample of 47 sandbars indicated an average positive bias, 1.15 ha, for RapidEye that did not vary with sandbar size. RapidEye has potential to reduce temporal uncertainty about least tern and piping plover habitat but would not be suitable for mapping sandbar erosion, and characterization of sandbar shapes or vegetation patches at fine spatial resolution.

  10. Extending a prototype knowledge- and object-based image analysis model to coarser spatial resolution imagery: an example from the Missouri River

    USGS Publications Warehouse

    Strong, Laurence L.

    2012-01-01

    A prototype knowledge- and object-based image analysis model was developed to inventory and map least tern and piping plover habitat on the Missouri River, USA. The model has been used to inventory the state of sandbars annually for 4 segments of the Missouri River since 2006 using QuickBird imagery. Interpretation of the state of sandbars is difficult when images for the segment are acquired at different river stages and different states of vegetation phenology and canopy cover. Concurrent QuickBird and RapidEye images were classified using the model and the spatial correspondence of classes in the land cover and sandbar maps were analysed for the spatial extent of the images and at nest locations for both bird species. Omission and commission errors were low for unvegetated land cover classes used for nesting by both bird species and for land cover types with continuous vegetation cover and water. Errors were larger for land cover classes characterized by a mixture of sand and vegetation. Sandbar classification decisions are made using information on land cover class proportions and disagreement between sandbar classes was resolved using fuzzy membership possibilities. Regression analysis of area for a paired sample of 47 sandbars indicated an average positive bias, 1.15 ha, for RapidEye that did not vary with sandbar size. RapidEye has potential to reduce temporal uncertainty about least tern and piping plover habitat but would not be suitable for mapping sandbar erosion, and characterization of sandbar shapes or vegetation patches at fine spatial resolution.

  11. A kinetic model of rapidly reversible nonphotochemical quenching

    PubMed Central

    Zaks, Julia; Amarnath, Kapil; Kramer, David M.; Niyogi, Krishna K.; Fleming, Graham R.

    2012-01-01

    Oxygen-evolving photosynthetic organisms possess nonphotochemical quenching (NPQ) pathways that protect against photo-induced damage. The majority of NPQ in plants is regulated on a rapid timescale by changes in the pH of the thylakoid lumen. In order to quantify the rapidly reversible component of NPQ, called qE, we developed a mathematical model of pH-dependent quenching of chlorophyll excitations in Photosystem II. Our expression for qE depends on the protonation of PsbS and the deepoxidation of violaxanthin by violaxanthin deepoxidase. The model is able to simulate the kinetics of qE at low and high light intensities. The simulations suggest that the pH of the lumen, which activates qE, is not itself affected by qE. Our model provides a framework for testing hypothesized qE mechanisms and for assessing the role of qE in improving plant fitness in variable light intensity. PMID:22891305

  12. Rapid isolation of intact, viable fetal cartilage models

    SciTech Connect

    Schmidt, R.R.; Chepenik, K.P.; Paynton, B.V.; Cotler, J.M.

    1982-04-01

    A rapid procedure is described for the isolation of viable, intact, femoral cartilage models (humeri and femora) obtained from pregnant rats on the 18th day of gestation. Viability of these models is demonstrated in an in vitro system where the incorporation of /sup 35/S-sulfate was linear with time of incubation and with numbers of cartilage models utilized. Treatment of cartilage models with ice-cold trichloroacetic acid and a boiling water bath prior to incubation with radiolabel, reduced the amount of radioactivity incorporated to 1.3% of that observed for models incubated by routine procedures. Furthermore, digestion of cartilage model homogenates with protease yielded a supernatant from which 51% to 57% of the radioactivity was precipitated as GAG. This method may also be used to isolate fetal cartilage models as early as the 16th day of gestation. with this system, specific biochemical parameters of mammalian fetal chondrogenesis may be surveyed in normally and abnormally developing fetal cartilage free of surrounding soft tissue.

  13. Application of expert system technology to nondestructive waste assay - initial prototype model

    SciTech Connect

    Becker, G.K.; Determan, J.C.

    1997-11-01

    Expert system technology has been identified as a technique useful for filling certain types of technology/capability gaps in existing waste nondestructive assay (NDA) applications. In particular, expert system techniques are being investigated with the intent of providing on-line evaluation of acquired data and/or directed acquisition of data in a manner that mimics the logic and decision making process a waste NDA expert would employ. The space from which information and data sources utilized in this process is much expanded with respect to the algorithmic approach typically utilized in waste NDA. Expert system technology provides a mechanism to manage and reason with this expanded information/data set. The material presented in this paper concerns initial studies and a resultant prototype expert system that incorporates pertinent information, and evaluation logic and decision processes, for the purpose of validating acquired waste NDA measurement assays. 6 refs., 6 figs.

  14. Universal Quantum Computing:. Third Gen Prototyping Utilizing Relativistic `Trivector' R-Qubit Modeling Surmounting Uncertainty

    NASA Astrophysics Data System (ADS)

    Amoroso, Richard L.; Kauffman, Louis H.; Giandinoto, Salvatore

    2013-09-01

    We postulate bulk universal quantum computing (QC) cannot be achieved without surmounting the quantum uncertainty principle, an inherent barrier by empirical definition in the regime described by the Copenhagen interpretation of quantum theory - the last remaining hurdle to bulk QC. To surmount uncertainty with probability 1, we redefine the basis for the qubit utilizing a unique form of M-Theoretic Calabi-Yau mirror symmetry cast in an LSXD Dirac covariant polarized vacuum with an inherent `Feynman synchronization backbone'. This also incorporates a relativistic qubit (r-qubit) providing additional degrees of freedom beyond the traditional Block 2-sphere qubit bringing the r-qubit into correspondence with our version of Relativistic Topological Quantum Field Theory (RTQFT). We present a 3rd generation prototype design for simplifying bulk QC implementation.

  15. Kaiser Permanente-Sandia National Health Care Model: Phase 1 prototype final report. Part 2 -- Domain analysis

    SciTech Connect

    Edwards, D.; Yoshimura, A.; Butler, D.; Judson, R.; Mason, W.; Napolitano, L.; Mariano, R.; Eddy, D.; Schlessinger, L.

    1996-11-01

    This report describes the results of a Cooperative Research and Development Agreement between Sandia National Laboratories and Kaiser Permanente Southern California to develop a prototype computer model of Kaiser Permanente`s health care delivery system. As a discrete event simulation, SimHCO models for each of 100,000 patients the progression of disease, individual resource usage, and patient choices in a competitive environment. SimHCO is implemented in the object-oriented programming language C{sup 2}, stressing reusable knowledge and reusable software components. The versioned implementation of SimHCO showed that the object-oriented framework allows the program to grow in complexity in an incremental way. Furthermore, timing calculations showed that SimHCO runs in a reasonable time on typical workstations, and that a second phase model will scale proportionally and run within the system constraints of contemporary computer technology.

  16. Wind-tunnel evaluation of a 21-percent-scale powered model of a prototype advanced scout helicopter

    NASA Technical Reports Server (NTRS)

    Phelps, A. E., III; Berry, J. D.

    1985-01-01

    An exploratory wind tunnel investigation of a 21 percent scale powered model of a prototype advanced scout helicopter was conducted in the Langley 4 by 7 Meter Tunnel. The investigation was conducted to define the overall aerodynamic characteristics of the Army Helicopter Improvement Program (AHIP), to determine the effects of the rotor on the aerodynamic characteristics and to evaluate the effect of a mast mounted sight on the aircraft stability characteristics. Tests covered a range of thrust coefficients, advance ratios, angles of attack and angles of sideslip and were run for both rotor on and rotor off configurations. Results of the investigation showed that the prototype configuration was longitudinally unstable with angle of attack for all configurations tested. The instability was due to unfavorable interference effects between the horizontal tail and the wake shed from the engine pylon and rotor hub, which caused a loss of horizontal tail effectiveness. The addition of the mast mounted sight had little effect on the stability of the model, but it caused an alteration in the rotor lift distribution that resulted in substantial interference drag for the sight.

  17. Rapid SAR target modeling through genetic inheritance mechanism

    NASA Astrophysics Data System (ADS)

    Bala, Jerzy; Pachowicz, Peter W.; Vafaie, Halleh

    1997-07-01

    The paper presents a methodology and GETP experimental system for rapid SAR target signature generation from limited initial sensory data. The methodology exploits and integrates the following four processes: (1) analysis of initial SAR image signatures and their transformation into higher-level blob representation, (2) blob modeling, (3) genetic inheritance modeling to generate new instances of a target model in blob representation, and (4) synthesis of new SAR signatures from genetically evolved blob data. The GETP system takes several SAR signatures of the target and transforms each signature into more general scattered blob graphs, where each blob represents local energy cluster. A single graph node is describe by blob relative position, confidence, and iconic data. Graph data is forwarded to the genetic modeling process while blob image is stored in a catalog. Genetic inheritance is applied to the initial population of graph data. New graph models of the target are generated and evaluated. Selected graph variations are forwarded to the synthesis process. The synthesis process restores target signature from a given graph and a catalog of blobs. The background is synthesized to complement the signature. Initial experimental results are illustrated with 64 X 32 image sections of a tank.

  18. 2D modeling and preliminary in vitro investigation of a prototype high gradient magnetic separator for biomedical applications.

    PubMed

    Chen, Haitao; Kaminski, Michael D; Rosengart, Axel J

    2008-01-01

    High gradient magnetic separation (HGMS) of magnetic materials from fluids or waste products has many established industrial applications. However, there is currently no technology employing HGMS for ex-vivo biomedical applications, such as for the removal of magnetic drug- or toxin-loaded spheres from the human blood stream. Importantly, human HGMS applications require special design modifications as, in contrast to conventional use where magnetic elements are permanently imbedded within the separation chambers, medical separators need to avoid direct contact between the magnetic materials and blood to reduce the risk of blood clotting and to facilitate convenient and safe treatment access for many individuals. We describe and investigate the performance of a magnetic separator prototype designed for biomedical applications. First, the capture efficiency of a prototype HGMS separator unit consisting of a short tubing segment and two opposing magnetizable fine wires along the outside of the tubing was investigated using 2D mathematical modeling. Second, the first-pass effectiveness to remove commercially available, magnetic polystyrene spheres from human blood using a single separator unit was experimentally verified. The theoretical and experimental data correlated well at low flow velocities (<5.0 cm/s) and high external magnetic fields (>0.05 T). This prototype separator unit removed >90% in a single pass of the magnetic spheres from water at mean flow velocity < or =8.0 cm/s and from blood mimic fluids (ethylene glycol-water solutions) at mean flow velocity < or =2.0 cm/s. In summary, we describe and prove the feasibility of a HGMS separator for biomedical applications.

  19. Rapidly recomputable EEG forward models for realistic head shapes.

    PubMed

    Ermer, J J; Mosher, J C; Baillet, S; Leah, R M

    2001-04-01

    With the increasing availability of surface extraction techniques for magnetic resonance and x-ray computed tomography images, realistic head models can be readily generated as forward models in the analysis of electroencephalography (EEG) and magnetoencephalography (MEG) data. Inverse analysis of this data, however, requires that the forward model be computationally efficient. We propose two methods for approximating the EEG forward model using realistic head shapes. The 'sensor-fitted sphere' approach fits a multilayer sphere individually to each sensor, and the 'three-dimensional interpolation' scheme interpolates using a grid on which a numerical boundary element method (BEM) solution has been precomputed. We have characterized the performance of each method in terms of magnitude and subspace error metrics, as well as computational and memory requirements. We have also made direct performance comparisons with traditional spherical models. The approximation provided by the interpolative scheme had an accuracy nearly identical to full BEM, even within 3 mm of the inner skull surface. Forward model computation during inverse procedures was approximately 30 times faster than for a traditional three-shell spherical model. Cast in this framework, high-fidelity numerical solutions currently viewed as computationally prohibitive for solving the inverse problem (e.g. linear Galerkin BEM) can be rapidly recomputed in a highly efficient manner. The sensor-fitting method has a similar one-time cost to the BEM method, and while it produces some improvement over a standard three-shell sphere, its performance does not approach that of the interpolation method. In both methods, there is a one-time cost associated with precomputing the forward solution over a set of grid points.

  20. Rapid world modeling: Fitting range data to geometric primitives

    SciTech Connect

    Feddema, J.; Little, C.

    1996-12-31

    For the past seven years, Sandia National Laboratories has been active in the development of robotic systems to help remediate DOE`s waste sites and decommissioned facilities. Some of these facilities have high levels of radioactivity which prevent manual clean-up. Tele-operated and autonomous robotic systems have been envisioned as the only suitable means of removing the radioactive elements. World modeling is defined as the process of creating a numerical geometric model of a real world environment or workspace. This model is often used in robotics to plan robot motions which perform a task while avoiding obstacles. In many applications where the world model does not exist ahead of time, structured lighting, laser range finders, and even acoustical sensors have been used to create three dimensional maps of the environment. These maps consist of thousands of range points which are difficult to handle and interpret. This paper presents a least squares technique for fitting range data to planar and quadric surfaces, including cylinders and ellipsoids. Once fit to these primitive surfaces, the amount of data associated with a surface is greatly reduced up to three orders of magnitude, thus allowing for more rapid handling and analysis of world data.

  1. High-pressure magnetostrictive pump development: a comparison of prototype and modeled performance

    NASA Astrophysics Data System (ADS)

    Bridger, Keith; Sewell, John M.; Cooke, Arthur V.; Lutian, Joseph L.; Kohlhafer, Dennis; Small, George E.; Kuhn, Philip M.

    2004-07-01

    Current efforts to extend the mission profile of Unmanned Aerial Vehicles (UAVs) have highlighted the need for scalable linear actuators. Typically, electrical power and control are specified for their high specific performance and ease of maintenance and replacement. Electro-Hydraulic Actuators (EHAs) provide the advantages of electrical power and control along with the proven reliability, robustness and graceful failure modes of hydraulic actuation. Current EHA technology, however, is not scalable to the degree required for projected UAVs and extension to other markets and applications. This paper will describe the measured and theoretical performance of a magnetostrictive hydraulic pump developed for one such EHA as part of the DARPA Compact Hybrid Actuator Program (CHAP). This work will focus on prototype pump designs utilizing a resonant magnetostrictive piston driver. The numerous design and operational parameters that have been tested and studied in an effort to produce an optimized pump design will be discussed. In particular, the measured and predicted performance of the resonant structure and fluidics will be compared and contrasted for several pump designs. The paper will also examine the interdependence of pump parameters and the balance required to produce a viable design with the required performance characteristics.

  2. A Model of Rapid Radicalization Behavior Using Agent-Based Modeling and Quorum Sensing

    NASA Technical Reports Server (NTRS)

    Schwartz, Noah; Drucker, Nick; Campbell, Kenyth

    2012-01-01

    Understanding the dynamics of radicalization, especially rapid radicalization, has become increasingly important to US policy in the past several years. Traditionally, radicalization is considered a slow process, but recent social and political events demonstrate that the process can occur quickly. Examining this rapid process, in real time, is impossible. However, recreating an event using modeling and simulation (M&S) allows researchers to study some of the complex dynamics associated with rapid radicalization. We propose to adapt the biological mechanism of quorum sensing as a tool to explore, or possibly explain, rapid radicalization. Due to the complex nature of quorum sensing, M&S allows us to examine events that we could not otherwise examine in real time. For this study, we employ Agent Based Modeling (ABM), an M&S paradigm suited to modeling group behavior. The result of this study was the successful creation of rapid radicalization using quorum sensing. The Battle of Mogadishu was the inspiration for this model and provided the testing conditions used to explore quorum sensing and the ideas behind rapid radicalization. The final product has wider applicability however, using quorum sensing as a possible tool for examining other catalytic rapid radicalization events.

  3. Development of a hybrid (numerical-hydraulic) circulatory model: prototype testing and its response to IABP assistance.

    PubMed

    Ferrari, G; Kozarski, M; De Lazzari, C; Górczyńska, K; Tosti, G; Darowski, M

    2005-07-01

    Merging numerical and physical models of the circulation makes it possible to develop a new class of circulatory models defined as hybrid. This solution reduces the costs, enhances the flexibility and opens the way to many applications ranging from research to education and heart assist devices testing. In the prototype described in this paper, a hydraulic model of systemic arterial tree is connected to a lumped parameters numerical model including pulmonary circulation and the remaining parts of systemic circulation. The hydraulic model consists of a characteristic resistance, of a silicon rubber tube to allow the insertion of an Intra-Aortic Balloon Pump (IABP) and of a lumped parameters compliance. Two electro-hydraulic interfaces, realized by means of gear pumps driven by DC motors, connect the numerical section with both terminals of the hydraulic section. The lumped parameters numerical model and the control system (including analog to digital and digital to analog converters)are developed in LabVIEW environment. The behavior of the model is analyzed by means of the ventricular pressure-volume loops and the time courses of arterial and ventricular pressures and flows in different circulatory conditions. A simulated pathological condition was set to test the IABP and verify the response of the system to this type of mechanical circulatory assistance. The results show that the model can represent hemodynamic relationships in different ventricular and circulatory conditions and is able to react to the IABP assistance.

  4. Modeling the rapid de-swelling of toroidal hydrogels

    NASA Astrophysics Data System (ADS)

    Nikolov, Svetoslav; Chang, Ya-Wen; Alexeev, Alexander; Fernandez de Las Nieves, Alberto

    2015-03-01

    The utilization of synthetic hydrogel networks as 3-D cell culture platforms has allowed researchers to more effectively study how epigenetic factors affect cell growth and physiology. As a whole, this has emphasized the biomechanical role of scaffold structures and led to a number of advances in tissue engineering. Our current research focuses on modeling temperature activated shape transformations of toroidal poly(N-isopropylacrylamide) pNIPAM gels. We use dissipative particle dynamics (DPD) to simulate the steady (slow heating rates) and unsteady (fast heating rates) de-swelling behavior of these thermo-sensitive gels. Our simulations show that for slow heating rates the aspect ratio of the tori remains constant during de-swelling. For rapid heating rates we observe buckling instabilities. Our simulations agree with the experimental observations. Financial support by NSF CAREER Award DMR-1255288 is gratefully acknowledged.

  5. Prototyping global Earth System Models at high resolution: Representation of climate, ecosystems, and acidification in Eastern Boundary Currents

    NASA Astrophysics Data System (ADS)

    Dunne, J. P.; John, J. G.; Stock, C. A.

    2013-12-01

    The world's major Eastern Boundary Currents (EBC) such as the California Current Large Marine Ecosystem (CCLME) are critically important areas for global fisheries. Computational limitations have divided past EBC modeling into two types: high resolution regional approaches that resolve the strong meso-scale structures involved, and coarse global approaches that represent the large scale context for EBCs, but only crudely resolve only the largest scales of their manifestation. These latter global studies have illustrated the complex mechanisms involved in the climate change and acidification response in these regions, with the CCLME response dominated not by local adjustments but large scale reorganization of ocean circulation through remote forcing of water-mass supply pathways. While qualitatively illustrating the limitations of regional high resolution studies in long term projection, these studies lack the ability to robustly quantify change because of the inability of these models to represent the baseline meso-scale structures of EBCs. In the present work, we compare current generation coarse resolution (one degree) and a prototype next generation high resolution (1/10 degree) Earth System Models (ESMs) from NOAA's Geophysical Fluid Dynamics Laboratory in representing the four major EBCs. We review the long-known temperature biases that the coarse models suffer in being unable to represent the timing and intensity of upwelling-favorable winds, along with lack of representation of the observed high chlorophyll and biological productivity resulting from this upwelling. In promising contrast, we show that the high resolution prototype is capable of representing not only the overall meso-scale structure in physical and biogeochemical fields, but also the appropriate offshore extent of temperature anomalies and other EBC characteristics. Results for chlorophyll were mixed; while high resolution chlorophyll in EBCs were strongly enhanced over the coarse resolution

  6. Making the procedure manual come alive: A prototype relational database and dynamic website model for the management of nursing information.

    PubMed

    Peace, Jane; Brennan, Patricia Flatley

    2006-01-01

    The nursing procedural manual is an essential resource for clinical practice, yet insuring its currency and availability at the point of care remains an unresolved information management challenge for nurses. While standard HTML-based web pages offer significant advantage over paper compilations, employing emerging computer science tools offers even greater promise. This paper reports on the creation of a prototypical dynamic web-based nursing procedure manual driven by a relational database. We created a relational database in MySQL to manage, store, and link the procedure information, and developed PHP files to guide content retrieval, content management, and display on demand in browser-viewable format. This database driven dynamic website model is an important innovation to meet the challenge of content management and dissemination of nursing information.

  7. Development of a Decision Aid for Cardiopulmonary Resuscitation Involving Intensive Care Unit Patients' and Health Professionals' Participation Using User-Centered Design and a Wiki Platform for Rapid Prototyping: A Research Protocol

    PubMed Central

    Heyland, Daren Keith; Ebell, Mark H; Dupuis, Audrey; Lavoie-Bérard, Carole-Anne; Légaré, France; Archambault, Patrick Michel

    2016-01-01

    Background Cardiopulmonary resuscitation (CPR) is an intervention used in cases of cardiac arrest to revive patients whose heart has stopped. Because cardiac arrest can have potentially devastating outcomes such as severe neurological deficits even if CPR is performed, patients must be involved in determining in advance if they want CPR in the case of an unexpected arrest. Shared decision making (SDM) facilitates discussions about goals of care regarding CPR in intensive care units (ICUs). Patient decision aids (DAs) are proven to support the implementation of SDM. Many patient DAs about CPR exist, but they are not universally implemented in ICUs in part due to lack of context and cultural adaptation. Adaptation to local context is an important phase of implementing any type of knowledge tool such as patient DAs. User-centered design supported by a wiki platform to perform rapid prototyping has previously been successful in creating knowledge tools adapted to the needs of patients and health professionals (eg, asthma action plans). This project aims to explore how user-centered design and a wiki platform can support the adaptation of an existing DA for CPR to the local context. Objective The primary objective is to use an existing DA about CPR to create a wiki-based DA that is adapted to the context of a single ICU and tailorable to individual patient’s risk factors while employing user-centered design. The secondary objective is to document the use of a wiki platform for the adaptation of patient DAs. Methods This study will be conducted in a mixed surgical and medical ICU at Hôtel-Dieu de Lévis, Quebec, Canada. We plan to involve all 5 intensivists and recruit at least 20 alert and oriented patients admitted to the ICU and their family members if available. In the first phase of this study, we will observe 3 weeks of daily interactions between patients, families, intensivists, and other allied health professionals. We will specifically observe 5 dyads of

  8. Prototype Development of the Intelligent Hydrogel Wound Dressing and Its Efficacy in the Detection of Model Pathogenic Wound Biofilms.

    PubMed

    Thet, N T; Alves, D R; Bean, J E; Booth, S; Nzakizwanayo, J; Young, A E R; Jones, B V; Jenkins, A Toby A

    2016-06-22

    The early detection of wound infection in situ can dramatically improve patient care pathways and clinical outcomes. There is increasing evidence that within an infected wound the main bacterial mode of living is a biofilm: a confluent community of adherent bacteria encased in an extracellular polymeric matrix. Here we have reported the development of a prototype wound dressing, which switches on a fluorescent color when in contact with pathogenic wound biofilms. The dressing is made of a hydrated agarose film in which the fluorescent dye containing vesicles were mixed with agarose and dispersed within the hydrogel matrix. The static and dynamic models of wound biofilms, from clinical strains of Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Enterococcus faecalis, were established on nanoporous polycarbonate membrane for 24, 48, and 72 h, and the dressing response to the biofilms on the prototype dressing evaluated. The dressing indicated a clear fluorescent/color response within 4 h, only observed when in contact with biofilms produced by a pathogenic strain. The sensitivity of the dressing to biofilms was dependent on the species and strain types of the bacterial pathogens involved, but a relatively higher response was observed in strains considered good biofilm formers. There was a clear difference in the levels of dressing response, when dressings were tested on bacteria grown in biofilm or in planktonic cultures, suggesting that the level of expression of virulence factors is different depending of the growth mode. Colorimetric detection on wound biofilms of prevalent pathogens (S. aureus, P. aeruginosa, and E. faecalis) is also demonstrated using an ex vivo porcine skin model of burn wound infection. PMID:26492095

  9. Prototype Development of the Intelligent Hydrogel Wound Dressing and Its Efficacy in the Detection of Model Pathogenic Wound Biofilms.

    PubMed

    Thet, N T; Alves, D R; Bean, J E; Booth, S; Nzakizwanayo, J; Young, A E R; Jones, B V; Jenkins, A Toby A

    2016-06-22

    The early detection of wound infection in situ can dramatically improve patient care pathways and clinical outcomes. There is increasing evidence that within an infected wound the main bacterial mode of living is a biofilm: a confluent community of adherent bacteria encased in an extracellular polymeric matrix. Here we have reported the development of a prototype wound dressing, which switches on a fluorescent color when in contact with pathogenic wound biofilms. The dressing is made of a hydrated agarose film in which the fluorescent dye containing vesicles were mixed with agarose and dispersed within the hydrogel matrix. The static and dynamic models of wound biofilms, from clinical strains of Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Enterococcus faecalis, were established on nanoporous polycarbonate membrane for 24, 48, and 72 h, and the dressing response to the biofilms on the prototype dressing evaluated. The dressing indicated a clear fluorescent/color response within 4 h, only observed when in contact with biofilms produced by a pathogenic strain. The sensitivity of the dressing to biofilms was dependent on the species and strain types of the bacterial pathogens involved, but a relatively higher response was observed in strains considered good biofilm formers. There was a clear difference in the levels of dressing response, when dressings were tested on bacteria grown in biofilm or in planktonic cultures, suggesting that the level of expression of virulence factors is different depending of the growth mode. Colorimetric detection on wound biofilms of prevalent pathogens (S. aureus, P. aeruginosa, and E. faecalis) is also demonstrated using an ex vivo porcine skin model of burn wound infection.

  10. Aircraft model prototypes which have specified handling-quality time histories

    NASA Technical Reports Server (NTRS)

    Johnson, S. H.

    1976-01-01

    Several techniques for obtaining linear constant-coefficient airplane models from specified handling-quality time histories are discussed. One technique, the pseudodata method, solves the basic problem, yields specified eigenvalues, and accommodates state-variable transfer-function zero suppression. The method is fully illustrated for a fourth-order stability-axis small-motion model with three lateral handling-quality time histories specified. The FORTRAN program which obtains and verifies the model is included and fully documented.

  11. Prototype casting fabrication by stereolithography

    SciTech Connect

    Cromwell, W.E.

    1992-03-01

    The evolution of the new technology of producing CAD models by ultraviolet solidification of resin materials (``STEREOLITHOGRAPHY``) continues to progress. The potential application area of rigid fabrication of prototype investment castings is becoming more feasible as we continue to successfully yield experimental castings by the ``SHELL`` processing method. This supplemental (to 11/90 publication) report briefly reviews the original project objectives, activities related to these objectives since November 1990, and progress made through December 1991. We discuss several new case studies involving new resin materials (and other materials) tested along with investment casting processing results. The most recent success, the processing of the highly complex ``C`` HOUSING design by the ``shell`` mold process in both aluminum and steel, will be discussed. This is considered a major breakthrough toward establishing this new technology as a viable approach to the rapid development of prototype investment castings, employing the most common aerospace (precision) cast process. Our future planning calls for expanding the study to help the investment casting industry in refining related processing techniques and to continue our evaluation of new resins suitable for the casting process. Present project planning calls for the completion of this study by the third quarter FY93 or sooner. We believe that with the continued excellent cooperation of our casting supplier study team and an accelerated effort by resin materials producers to further refine related materials, we can achieve all objectives during the planned time frame.

  12. Prototype casting fabrication by stereolithography

    SciTech Connect

    Cromwell, W.E.

    1992-03-01

    The evolution of the new technology of producing CAD models by ultraviolet solidification of resin materials ( STEREOLITHOGRAPHY'') continues to progress. The potential application area of rigid fabrication of prototype investment castings is becoming more feasible as we continue to successfully yield experimental castings by the SHELL'' processing method. This supplemental (to 11/90 publication) report briefly reviews the original project objectives, activities related to these objectives since November 1990, and progress made through December 1991. We discuss several new case studies involving new resin materials (and other materials) tested along with investment casting processing results. The most recent success, the processing of the highly complex C'' HOUSING design by the shell'' mold process in both aluminum and steel, will be discussed. This is considered a major breakthrough toward establishing this new technology as a viable approach to the rapid development of prototype investment castings, employing the most common aerospace (precision) cast process. Our future planning calls for expanding the study to help the investment casting industry in refining related processing techniques and to continue our evaluation of new resins suitable for the casting process. Present project planning calls for the completion of this study by the third quarter FY93 or sooner. We believe that with the continued excellent cooperation of our casting supplier study team and an accelerated effort by resin materials producers to further refine related materials, we can achieve all objectives during the planned time frame.

  13. Agile manufacturing prototyping system (AMPS)

    SciTech Connect

    Garcia, P.

    1998-05-09

    The Agile Manufacturing Prototyping System (AMPS) is being integrated at Sandia National Laboratories. AMPS consists of state of the industry flexible manufacturing hardware and software enhanced with Sandia advancements in sensor and model based control; automated programming, assembly and task planning; flexible fixturing; and automated reconfiguration technology. AMPS is focused on the agile production of complex electromechanical parts. It currently includes 7 robots (4 Adept One, 2 Adept 505, 1 Staubli RX90), conveyance equipment, and a collection of process equipment to form a flexible production line capable of assembling a wide range of electromechanical products. This system became operational in September 1995. Additional smart manufacturing processes will be integrated in the future. An automated spray cleaning workcell capable of handling alcohol and similar solvents was added in 1996 as well as parts cleaning and encapsulation equipment, automated deburring, and automated vision inspection stations. Plans for 1997 and out years include adding manufacturing processes for the rapid prototyping of electronic components such as soldering, paste dispensing and pick-and-place hardware.

  14. A Multi-Model Real Time Forecasting Prototype System in the Mara Basin (Kenya/Tanzania)

    NASA Astrophysics Data System (ADS)

    Serrat-Capdevila, A.; Valdes, J. B.; Valdes, R.; Demaria, E. M.; Durcik, M.; Maitaria, K.; Roy, T.

    2013-12-01

    Remote sensing data and hydrologic models can respond to monitoring and forecasting needs in Africa and other poorly gauged regions. We present here the progress to date in developing a multi-model platform to provide hydrologic monitoring and forecasting using real time remote sensing observations. Satellite precipitation products such as CMORPH, TMPA (at 0.25° resolution) and PERSIANN-CCS (at 4km resolution) are used to force two models of different structure. One model is physically based and distributed, and the other is conceptual and lumped at the sub-basin level. The performance of both models is evaluated using different metrics, and the uncertainty in their predictions based on the errors incurred during the historical simulations period is computed. The models were compared and the potential increase in performance from using both models versus a single one will be assessed. This work provides insights into the advantages of a multi-model platform over a single model, with respect to different management and decision-making purposes. The methods were applied to the Mara Basin (Kenya/Tanzania), where growing human demands on water and land use are likely to alter significantly the hydrologic balance of the basin and the ecosystems that depend on it. These efforts are part of the Applied Sciences Team of the NASA SERVIR Program in collaboration with its East Africa Hub at the Regional Center for Mapping of Resources for Development (Nairobi,Kenya).

  15. O the Use of a Gas-Cavitation Model to Generate Prototypal Air and Helium Decompression Schedules for Divers

    NASA Astrophysics Data System (ADS)

    Hoffman, Donald Clinton

    During the last several years, significant progress has been made in elucidating the bubble-nucleation phenomenon in aqueous media. According to the varying-permeability model, cavitation nuclei consist of spherical gas phases that are small enough to remain in solution, yet strong enough to resist collapse, their stability being provided by elastic skins or membranes consisting of surface-active molecules. By tracking the radial size of bubble nuclei during changes in ambient pressure, the model has provided precise quantitative descriptions of bubble-counting experiments in gelatin. It has also been used to trace levels of incidence for decompression sickness in several animal species, including fingerling salmon, rats, and humans. More recently, bubble nuclei have been observed directly in distilled water, gelatin, and blood using a variety of microscopic techniques. This work details the application of the varying -permeability model to the problem of decompression sickness through the construction of a prototypal set of decompression schedules. These schedules were generated by a short computer program based on the model equations. Once initialized with a group of tissue half-times and four free parameters selected to optimize decompression safety and speed, the program was used to calculate air diving tables for depths ranging from 30-300 fsw, requiring only the corresponding depth excursions and bottom times as input. Following the reevaluation and readjustment of the program and the model parameters, a similar set of decompression schedules for helium dives was produced.

  16. Model evaluation of denitrification under rapid infiltration basin systems

    NASA Astrophysics Data System (ADS)

    Akhavan, Maryam; Imhoff, Paul T.; Andres, A. Scott; Finsterle, Stefan

    2013-09-01

    Rapid Infiltration Basin Systems (RIBS) are used for disposing reclaimed wastewater into soil to achieve additional treatment before it recharges groundwater. Effluent from most new sequenced batch reactor wastewater treatment plants is completely nitrified, and denitrification (DNF) is the main reaction for N removal. To characterize effects of complex surface and subsurface flow patterns caused by non-uniform flooding on DNF, a coupled overland flow-vadose zone model is implemented in the multiphase flow and reactive transport simulator TOUGHREACT. DNF is simulated in two representative soils varying the application cycle, hydraulic loading rate, wastewater quality, water table depth, and subsurface heterogeneity. Simulations using the conventional specified flux boundary condition under-predict DNF by as much as 450% in sand and 230% in loamy sand compared to predictions from the coupled overland flow-vadose zone model, indicating that simulating coupled flow is critical for predicting DNF in cases where hydraulic loading rates are not sufficient to spread the wastewater over the whole basin. Smaller ratios of wetting to drying time and larger hydraulic loading rates result in greater water saturations, more anoxic conditions, and faster water transport in the vadose zone, leading to greater DNF. These results in combination with those from different water table depths explain why reported DNF varied with soil type and water table depth in previous field investigations. Across all simulations, cumulative percent DNF varies between 2 and 49%, indicating that NO3 removal in RIBS may vary widely depending on operational procedures and subsurface conditions. These modeling results improve understanding of DNF in RIBS and suggest operational procedures that may improve NO3 removal.

  17. Model evaluation of denitrification under rapid infiltration basin systems.

    PubMed

    Akhavan, Maryam; Imhoff, Paul T; Andres, A Scott; Finsterle, Stefan

    2013-09-01

    Rapid Infiltration Basin Systems (RIBS) are used for disposing reclaimed wastewater into soil to achieve additional treatment before it recharges groundwater. Effluent from most new sequenced batch reactor wastewater treatment plants is completely nitrified, and denitrification (DNF) is the main reaction for N removal. To characterize effects of complex surface and subsurface flow patterns caused by non-uniform flooding on DNF, a coupled overland flow-vadose zone model is implemented in the multiphase flow and reactive transport simulator TOUGHREACT. DNF is simulated in two representative soils varying the application cycle, hydraulic loading rate, wastewater quality, water table depth, and subsurface heterogeneity. Simulations using the conventional specified flux boundary condition under-predict DNF by as much as 450% in sand and 230% in loamy sand compared to predictions from the coupled overland flow-vadose zone model, indicating that simulating coupled flow is critical for predicting DNF in cases where hydraulic loading rates are not sufficient to spread the wastewater over the whole basin. Smaller ratios of wetting to drying time and larger hydraulic loading rates result in greater water saturations, more anoxic conditions, and faster water transport in the vadose zone, leading to greater DNF. These results in combination with those from different water table depths explain why reported DNF varied with soil type and water table depth in previous field investigations. Across all simulations, cumulative percent DNF varies between 2 and 49%, indicating that NO₃ removal in RIBS may vary widely depending on operational procedures and subsurface conditions. These modeling results improve understanding of DNF in RIBS and suggest operational procedures that may improve NO₃ removal.

  18. A Dual-Process Approach to Health Risk Decision Making: The Prototype Willingness Model

    ERIC Educational Resources Information Center

    Gerrard, Meg; Gibbons, Frederick X.; Houlihan, Amy E.; Stock, Michelle L.; Pomery, Elizabeth A.

    2008-01-01

    Although dual-process models in cognitive, personality, and social psychology have stimulated a large body of research about analytic and heuristic modes of decision making, these models have seldom been applied to the study of adolescent risk behaviors. In addition, the developmental course of these two kinds of information processing, and their…

  19. Prototype of an Integrated Hurricane Information System for Research: Description and Illustration of its Use in Evaluating WRF Model Simulations

    NASA Astrophysics Data System (ADS)

    Hristova-Veleva, S.; Chao, Y.; Vane, D.; Lambrigtsen, B.; Li, P. P.; Knosp, B.; Vu, Q. A.; Su, H.; Dang, V.; Fovell, R.; Tanelli, S.; Garay, M.; Willis, J.; Poulsen, W.; Fishbein, E.; Ao, C. O.; Vazquez, J.; Park, K. J.; Callahan, P.; Marcus, S.; Haddad, Z.; Fetzer, E.; Kahn, R.

    2007-12-01

    In spite of recent improvements in hurricane track forecast accuracy, currently there are still many unanswered questions about the physical processes that determine hurricane genesis, intensity, track and impact on large- scale environment. Furthermore, a significant amount of work remains to be done in validating hurricane forecast models, understanding their sensitivities and improving their parameterizations. None of this can be accomplished without a comprehensive set of multiparameter observations that are relevant to both the large- scale and the storm-scale processes in the atmosphere and in the ocean. To address this need, we have developed a prototype of a comprehensive hurricane information system of high- resolution satellite, airborne and in-situ observations and model outputs pertaining to: i) the thermodynamic and microphysical structure of the storms; ii) the air-sea interaction processes; iii) the larger-scale environment as depicted by the SST, ocean heat content and the aerosol loading of the environment. Our goal was to create a one-stop place to provide the researchers with an extensive set of observed hurricane data, and their graphical representation, together with large-scale and convection-resolving model output, all organized in an easy way to determine when coincident observations from multiple instruments are available. Analysis tools will be developed in the next step. The analysis tools will be used to determine spatial, temporal and multiparameter covariances that are needed to evaluate model performance, provide information for data assimilation and characterize and compare observations from different platforms. We envision that the developed hurricane information system will help in the validation of the hurricane models, in the systematic understanding of their sensitivities and in the improvement of the physical parameterizations employed by the models. Furthermore, it will help in studying the physical processes that affect

  20. Prototype casting fabrication by stereolithography

    SciTech Connect

    Cromwell, W.E.

    1990-11-01

    A new product development technology is emerging which could have a major impact on the investment casting industry. It's identified by several names, the most common of which is STEREOLITHOGRAPHY.'' This technology involves a three-dimensional printing process which will yield plastic parts (polymer models) from solid, surface, or wireframe CAD files. The concept links a CAD database to a process which guides a laser beam to solidify liquid photo-curable polymer into a programmed shaped. The process can produce models in far less time and at far less cost than can be done by other known (conventional) model producing methods. Parts that would normally require weeks or months to prototype with conventional processes can be produced in a matter of hours by Stereolithography. The Allied-Signal Inc., Kansas City Division, is engaged in a development project (funded by the Department of Energy) which is aimed at establishing this process as a practical, expedient, and cost-effective method fabricating prototype investment castings. The early phases of the project include procurement of a special designed test unit for several companies (Service Centers) involved in fabrication of models. These models are produced in various materials and used in experimental casting programs being conducted with four casting suppliers (two ferrous and two non-ferrous). This presentation will cover the objectives of the project and the results obtained up to this time. We will also briefly review future plans for the continuation of the project, until this new technology has been proven as a viable process for rapid development of investment castings.

  1. Digital Microdroplet Ejection Technology-Based Heterogeneous Objects Prototyping.

    PubMed

    Li, Na; Yang, Jiquan; Feng, Chunmei; Yang, Jianfei; Zhu, Liya; Guo, Aiqing

    2016-01-01

    An integrate fabrication framework is presented to build heterogeneous objects (HEO) using digital microdroplets injecting technology and rapid prototyping. The heterogeneous materials part design and manufacturing method in structure and material was used to change the traditional process. The net node method was used for digital modeling that can configure multimaterials in time. The relationship of material, color, and jetting nozzle was built. The main important contributions are to combine the structure, material, and visualization in one process and give the digital model for manufacture. From the given model, it is concluded that the method is effective for HEO. Using microdroplet rapid prototyping and the model given in the paper HEO could be gotten basically. The model could be used in 3D biomanufacturing. PMID:26981110

  2. Digital Microdroplet Ejection Technology-Based Heterogeneous Objects Prototyping

    PubMed Central

    Yang, Jiquan; Feng, Chunmei; Yang, Jianfei; Zhu, Liya; Guo, Aiqing

    2016-01-01

    An integrate fabrication framework is presented to build heterogeneous objects (HEO) using digital microdroplets injecting technology and rapid prototyping. The heterogeneous materials part design and manufacturing method in structure and material was used to change the traditional process. The net node method was used for digital modeling that can configure multimaterials in time. The relationship of material, color, and jetting nozzle was built. The main important contributions are to combine the structure, material, and visualization in one process and give the digital model for manufacture. From the given model, it is concluded that the method is effective for HEO. Using microdroplet rapid prototyping and the model given in the paper HEO could be gotten basically. The model could be used in 3D biomanufacturing. PMID:26981110

  3. Digital Microdroplet Ejection Technology-Based Heterogeneous Objects Prototyping.

    PubMed

    Li, Na; Yang, Jiquan; Feng, Chunmei; Yang, Jianfei; Zhu, Liya; Guo, Aiqing

    2016-01-01

    An integrate fabrication framework is presented to build heterogeneous objects (HEO) using digital microdroplets injecting technology and rapid prototyping. The heterogeneous materials part design and manufacturing method in structure and material was used to change the traditional process. The net node method was used for digital modeling that can configure multimaterials in time. The relationship of material, color, and jetting nozzle was built. The main important contributions are to combine the structure, material, and visualization in one process and give the digital model for manufacture. From the given model, it is concluded that the method is effective for HEO. Using microdroplet rapid prototyping and the model given in the paper HEO could be gotten basically. The model could be used in 3D biomanufacturing.

  4. Getting expert systems off the ground: Lessons learned from integrating model-based diagnostics with prototype flight hardware

    NASA Technical Reports Server (NTRS)

    Stephan, Amy; Erikson, Carol A.

    1991-01-01

    As an initial attempt to introduce expert system technology into an onboard environment, a model based diagnostic system using the TRW MARPLE software tool was integrated with prototype flight hardware and its corresponding control software. Because this experiment was designed primarily to test the effectiveness of the model based reasoning technique used, the expert system ran on a separate hardware platform, and interactions between the control software and the model based diagnostics were limited. While this project met its objective of showing that model based reasoning can effectively isolate failures in flight hardware, it also identified the need for an integrated development path for expert system and control software for onboard applications. In developing expert systems that are ready for flight, artificial intelligence techniques must be evaluated to determine whether they offer a real advantage onboard, identify which diagnostic functions should be performed by the expert systems and which are better left to the procedural software, and work closely with both the hardware and the software developers from the beginning of a project to produce a well designed and thoroughly integrated application.

  5. Drosophila provides rapid modeling of renal development, function, and disease.

    PubMed

    Dow, Julian A T; Romero, Michael F

    2010-12-01

    The evolution of specialized excretory cells is a cornerstone of the metazoan radiation, and the basic tasks performed by Drosophila and human renal systems are similar. The development of the Drosophila renal (Malpighian) tubule is a classic example of branched tubular morphogenesis, allowing study of mesenchymal-to-epithelial transitions, stem cell-mediated regeneration, and the evolution of a glomerular kidney. Tubule function employs conserved transport proteins, such as the Na(+), K(+)-ATPase and V-ATPase, aquaporins, inward rectifier K(+) channels, and organic solute transporters, regulated by cAMP, cGMP, nitric oxide, and calcium. In addition to generation and selective reabsorption of primary urine, the tubule plays roles in metabolism and excretion of xenobiotics, and in innate immunity. The gene expression resource FlyAtlas.org shows that the tubule is an ideal tissue for the modeling of renal diseases, such as nephrolithiasis and Bartter syndrome, or for inborn errors of metabolism. Studies are assisted by uniquely powerful genetic and transgenic resources, the widespread availability of mutant stocks, and low-cost, rapid deployment of new transgenics to allow manipulation of renal function in an organotypic context.

  6. System Modeling of Metabolic Heat Regenerated Temperature Swing Adsorption (MTSA) Subassembly for Prototype Design

    NASA Technical Reports Server (NTRS)

    Bower, Chad; Padilla, Sebastian; Iacomini, Christie; Paul, Heather L.

    2009-01-01

    This paper describes modeling methods for the three core components of a Metabolic heat regenerated Temperature Swing Adsorption (MTSA) subassembly: the sorbent bed, a sublimation (cooling) heat exchanger (SHX), and a condensing icing (warming) heat exchanger (CIHX). The primary function of the MTSA, removing carbon dioxide from a ventilation loop, is performed via the sorbent bed. The CIHX is used to heat the sorbent bed for desorption and to remove moisture from the ventilation loop while the SHX is alternately employed to cool the sorbent bed via sublimation of a spray of water at low pressure to prepare the reconditioned bed for the next cycle. This paper describes a system level model of the MTSA as developed in Thermal Desktop and SINDA/FLUINT including assumptions on geometry and physical phenomena, modeling methodology and relevant pa ra mete rizatio ns. Several areas of particular modeling interest are discussed. In the sorbent bed, capture of the translating CO2 saturation front and associated local energy and mass balance in both adsorbing and desorbing modes is covered. The CIHX poses particular challenges for modeling in SINDA/FLUINT as accounting for solids states in fluid submodels are not a native capability. Methods for capturing phase change and latent heat of ice as well as the transport properties across a layer of low density accreted frost are developed. This extended modeling capacity is applicable to temperatures greater than 258 K. To extend applicability to the minimum device temperature of 235 K, a method for a mapped transformation of temperatures from below the limit temperatures to some value above is given along with descriptions for associated material property transformations and the resulting impacts to total heat and mass transfer. Similar considerations are shown for the SHX along with assumptions for flow mechanics and resulting model methods for sublimation in a flow.

  7. Modeling Hydrologic and Geochemical Aspects of Rapid Infiltration Basins

    NASA Astrophysics Data System (ADS)

    Akhavan, M.; Imhoff, P. T.; Andres, S.; Finsterle, S.; Gu, C.; Maggi, F.

    2010-12-01

    Land-based wastewater treatment is the controlled application of wastewater to soil to remove wastewater constituents. A Rapid Infiltration Basin (RIB) is a major land treatment technique where treated wastewater is infiltrated at high rates in shallow basins, with further treatment occurring in soil and the vadose zone before the water recharges groundwater. Because the influent wastewater is usually enriched in nitrogen compounds, there is particular concern that a RIB may contaminant groundwater or nearby surface waters if not designed and operated properly. RIBs are operated in repetitive cycles of flooding, infiltration, and drying. Key operational parameters include the ratio of wetting to drying time and the hydraulic loading rate, which affect pollutant residence time and water table rise in shallow groundwater systems. They also alter water saturation and air content in the vadose zone, which have an impact on denitrification. Optimum values of the wetting-drying cycle ratio and the hydraulic loading rate are expected to vary with the quality of applied wastewater, soil type, treatment objective, and climate. Soil development within the basins may have an important effect on RIB performance. In this study, numerical modeling is used to obtain optimum values for the wetting-drying cycle ratio and hydraulic loading rate for different soil types and environmental conditions. TOUGH2/ iTOUGH2, a general-purpose numerical simulation program for multi-phase fluid flow in porous media, is used for modeling fluid movement. Overland flow within RIBs is coupled with subsurface flow to investigate the influence of non-uniform application of wastewater on hydraulic performance. TOUGHREACT v1.1 is used for modeling nitrogen fate and transport. Flow simulations indicate that using a long flooding cycle results in more water spreading over the basin and higher vadose zone water saturations than more frequent short-duration flooding events. Results of modeling fate and

  8. A prototype Global Drought Information System based on multiple land surface models

    NASA Astrophysics Data System (ADS)

    Nijssen, Bart; Shukla, Shrad; Lin, Chi-Yu; Lettenmaier, Dennis

    2013-04-01

    Droughts are pervasive natural hazards, which cause large economic losses and human suffering. While the absolute magnitude of these losses is greatest in the developed world, the relative impact is much higher in the developing world. Nonetheless, our ability to monitor and predict the development and occurrence of droughts at a global scale in near real-time is limited. This ability is of particular importance in estimating regional crop production and thus current and future prices of agricultural commodities, as well as the implementation of emergency measures in areas where the effects of drought threaten lives and livelihoods. We describe the implementation of a multi-model drought monitoring system, which provides near real-time estimates of soil moisture conditions for the global land areas between 50S and 50N with a latency of about one day. The system is an extension of similar systems developed by both the University of Washington and the National Centers for Environmental Prediction for use in the U.S. Drought Monitor. Global application of the protocols used in the U.S. systems poses new challenges, particularly with respect to the generation of meteorological forcings with which to drive the land surface models used in such a system. The global system we describe uses satellite-based precipitation (as contrasted with gridded station data in the U.S. systems) as well as temperature estimates based on global weather model analysis fields to track the evolution of soil moisture in near real-time at a spatial resolution of 0.5 degree using multiple land surface models. By comparing the modeled, near real-time soil moisture values with the results from long-term retrospective simulations, the model estimates can be placed in historic context (as soil moisture percentiles) and used to monitor the development of droughts around the world. We evaluate the performance of our system for historic droughts, and compare with other drought analyses and analytical

  9. A comparison of wake characteristics of model and prototype buildings in transverse winds

    NASA Technical Reports Server (NTRS)

    Logan, E., Jr.; Phataraphruk, P.; Chang, J.

    1978-01-01

    Previously measured mean velocity and turbulence intensity profiles in the wake of a 26.8-m long building 3.2 m high and transverse to the wind direction in an atmospheric boundary layer several hundred meters thick were compared with profiles at corresponding stations downstream of a 1/50-scale model on the floor of a large meteorological wind tunnel in a boundary layer 0.61 m in thickness. The validity of using model wake data to predict full scale data was determined. Preliminary results are presented which indicate that disparities result from differences in relative depth of logarithmic layers, surface roughness, and the proximity of upstream obstacles.

  10. MITRE sensor layer prototype

    NASA Astrophysics Data System (ADS)

    Duff, Francis; McGarry, Donald; Zasada, David; Foote, Scott

    2009-05-01

    The MITRE Sensor Layer Prototype is an initial design effort to enable every sensor to help create new capabilities through collaborative data sharing. By making both upstream (raw) and downstream (processed) sensor data visible, users can access the specific level, type, and quantities of data needed to create new data products that were never anticipated by the original designers of the individual sensors. The major characteristic that sets sensor data services apart from typical enterprise services is the volume (on the order of multiple terabytes) of raw data that can be generated by most sensors. Traditional tightly coupled processing approaches extract pre-determined information from the incoming raw sensor data, format it, and send it to predetermined users. The community is rapidly reaching the conclusion that tightly coupled sensor processing loses too much potentially critical information.1 Hence upstream (raw and partially processed) data must be extracted, rapidly archived, and advertised to the enterprise for unanticipated uses. The authors believe layered sensing net-centric integration can be achieved through a standardize-encapsulate-syndicateaggregate- manipulate-process paradigm. The Sensor Layer Prototype's technical approach focuses on implementing this proof of concept framework to make sensor data visible, accessible and useful to the enterprise. To achieve this, a "raw" data tap between physical transducers associated with sensor arrays and the embedded sensor signal processing hardware and software has been exploited. Second, we encapsulate and expose both raw and partially processed data to the enterprise within the context of a service-oriented architecture. Third, we advertise the presence of multiple types, and multiple layers of data through geographic-enabled Really Simple Syndication (GeoRSS) services. These GeoRSS feeds are aggregated, manipulated, and filtered by a feed aggregator. After filtering these feeds to bring just the type

  11. CMAQ MODELING FOR AIR TOXICS AT FINE SCALES: A PROTOTYPE STUDY

    EPA Science Inventory

    Toxic air pollutants (TAPs) or hazardous air pollutants (HAPs) exhibit considerable spatial and temporal variability across urban areas. Therefore, the ability of chemical transport models (CTMs), e.g. Community Multi-scale Air Quality (CMAQ), to reproduce the spatial and tempor...

  12. The "Research Audit" Model: A Prototype for Data-Driven Discovery of Interdisciplinary Biomedical Research

    ERIC Educational Resources Information Center

    Burnette, Margaret H.

    2015-01-01

    The increasing interdisciplinarity of scientific research creates both challenges and opportunities for librarians. The liaison model may be inadequate for supporting campus research that represents multiple disciplines and geographically dispersed departments. The identification of units, researchers, and projects is a first step in planning and…

  13. A Prototype Performance Assessment Model for Generic Deep Borehole Repository for High-Level Nuclear Waste - 12132

    SciTech Connect

    Lee, Joon H.; Arnold, Bill W.; Swift, Peter N.; Hadgu, Teklu; Freeze, Geoff; Wang, Yifeng

    2012-07-01

    A deep borehole repository is one of the four geologic disposal system options currently under study by the U.S. DOE to support the development of a long-term strategy for geologic disposal of commercial used nuclear fuel (UNF) and high-level radioactive waste (HLW). The immediate goal of the generic deep borehole repository study is to develop the necessary modeling tools to evaluate and improve the understanding of the repository system response and processes relevant to long-term disposal of UNF and HLW in a deep borehole. A prototype performance assessment model for a generic deep borehole repository has been developed using the approach for a mined geological repository. The preliminary results from the simplified deep borehole generic repository performance assessment indicate that soluble, non-sorbing (or weakly sorbing) fission product radionuclides, such as I-129, Se-79 and Cl-36, are the likely major dose contributors, and that the annual radiation doses to hypothetical future humans associated with those releases may be extremely small. While much work needs to be done to validate the model assumptions and parameters, these preliminary results highlight the importance of a robust seal design in assuring long-term isolation, and suggest that deep boreholes may be a viable alternative to mined repositories for disposal of both HLW and UNF. (authors)

  14. Modeling Of Metabolic Heat Regenerated Temperature Swing Adsorption (MTSA) Subassembly For Prototype Design

    NASA Technical Reports Server (NTRS)

    Bower, Chad E.; Padilla, Sebastian A.; Iacomini, Christie S.; Paul, Heather L.

    2010-01-01

    This paper describes modeling methods for the three core components of a Metabolic heat regenerated Temperature Swing Adsorption (MTSA) subassembly: a sorbent bed, a sublimation (cooling) heat exchanger (SHX), and a condensing icing (warming) heat exchanger (CIHX). The primary function of the MTSA, removing carbon dioxide from a space suit Portable Life Support System (PLSS) ventilation loop, is performed via the sorbent bed. The CIHX is used to heat the sorbent bed for desorption and to remove moisture from the ventilation loop while the SHX is alternately employed to cool the sorbent bed via sublimation of a spray of water at low pressure to prepare the reconditioned bed for the next cycle. This paper describes subsystem heat a mass transfer modeling methodologies relevant to the description of the MTSA subassembly in Thermal Desktop and SINDA/FLUINT. Several areas of particular modeling interest are discussed. In the sorbent bed, capture of the translating carbon dioxide (CO2) front and associated local energy and mass balance in both adsorbing and desorbing modes is covered. The CIHX poses particular challenges for modeling in SINDA/FLUINT as accounting for solids states in fluid submodels are not a native capability. Methods for capturing phase change and latent heat of ice as well as the transport properties across a layer of low density accreted frost are developed. This extended modeling capacity is applicable to temperatures greater than 258 K. To extend applicability to the minimum device temperature of 235 K, a method for a mapped transformation of temperatures from below the limit temperatures to some value above is given along with descriptions for associated material property transformations and the resulting impacts to total heat and mass transfer. Similar considerations are given for the SHX along with functional relationships for areal sublimation rates as limited by flow mechanics in t1he outlet duct.

  15. Development of a Decision Aid for Cardiopulmonary Resuscitation Involving Intensive Care Unit Patients' and Health Professionals' Participation Using User-Centered Design and a Wiki Platform for Rapid Prototyping: A Research Protocol

    PubMed Central

    Heyland, Daren Keith; Ebell, Mark H; Dupuis, Audrey; Lavoie-Bérard, Carole-Anne; Légaré, France; Archambault, Patrick Michel

    2016-01-01

    Background Cardiopulmonary resuscitation (CPR) is an intervention used in cases of cardiac arrest to revive patients whose heart has stopped. Because cardiac arrest can have potentially devastating outcomes such as severe neurological deficits even if CPR is performed, patients must be involved in determining in advance if they want CPR in the case of an unexpected arrest. Shared decision making (SDM) facilitates discussions about goals of care regarding CPR in intensive care units (ICUs). Patient decision aids (DAs) are proven to support the implementation of SDM. Many patient DAs about CPR exist, but they are not universally implemented in ICUs in part due to lack of context and cultural adaptation. Adaptation to local context is an important phase of implementing any type of knowledge tool such as patient DAs. User-centered design supported by a wiki platform to perform rapid prototyping has previously been successful in creating knowledge tools adapted to the needs of patients and health professionals (eg, asthma action plans). This project aims to explore how user-centered design and a wiki platform can support the adaptation of an existing DA for CPR to the local context. Objective The primary objective is to use an existing DA about CPR to create a wiki-based DA that is adapted to the context of a single ICU and tailorable to individual patient’s risk factors while employing user-centered design. The secondary objective is to document the use of a wiki platform for the adaptation of patient DAs. Methods This study will be conducted in a mixed surgical and medical ICU at Hôtel-Dieu de Lévis, Quebec, Canada. We plan to involve all 5 intensivists and recruit at least 20 alert and oriented patients admitted to the ICU and their family members if available. In the first phase of this study, we will observe 3 weeks of daily interactions between patients, families, intensivists, and other allied health professionals. We will specifically observe 5 dyads of

  16. Modeling Engineered Approaches to Enhance Denitrification under Rapid Infiltration Basins

    NASA Astrophysics Data System (ADS)

    Imhoff, P. T.; Akhavan, M.; Finsterle, S.; Andres, S.

    2012-12-01

    Rapid Infiltration Basin Systems (RIBS) use the controlled application of treated wastewater to soil to remove wastewater constituents before recharging groundwater. Because wastewater from new wastewater treatment plants is often enriched in NO3, denitrification (DNF) is the most important process for nitrogen removal. Two key requirements for DNF in the subsurface are the absence of molecular oxygen and an adequate supply of carbon to serve as a substrate for heterotrophic bacteria. These requirements can be met by adjusting the wastewater application to maximize anaerobic conditions beneath the infiltration basin, and by incorporating a carbon source layer, where carbon is supplied to infiltrating wastewater by dissolution from a solid matrix, e.g., woodchips. To examine the interplay between alternative wastewater application approaches and the length and thickness of the carbon source layer on DNF, a series of simulations were conducted in two soil types using TOUGHREACT. Because RIBS are often overdesigned, basins may be only partially flooded such that overland flow within the basin controls the infiltration area. For this reason, TOUGHREACT was modified to include both overland and subsurface flow. Simulations with the coupled overland flow-vadose zone model predict uneven water distribution over the basins, a condition that significantly affects DNF. Smaller ratios of wetting to drying time, i.e., shorter but more intense flooding periods, result in greater water saturations, shorter residence times and lower oxygen concentrations in the vadose zone, ultimately resulting in greater DNF. While the addition of a carbon source layer at the bottom of the RIBS is essential for supplying needed carbon, flow bypassing around this carbon layer, which is typically of lower permeability than the surrounding soil, can be problematic. These simulations demonstrate the interplay between the selection of wastewater application approach and carbon source layer design on

  17. Regarding on the prototype solutions for the nonlinear fractional-order biological population model

    NASA Astrophysics Data System (ADS)

    Baskonus, Haci Mehmet; Bulut, Hasan

    2016-06-01

    In this study, we have submitted to literature a method newly extended which is called as Improved Bernoulli sub-equation function method based on the Bernoulli Sub-ODE method. The proposed analytical scheme has been expressed with steps. We have obtained some new analytical solutions to the nonlinear fractional-order biological population model by using this technique. Two and three dimensional surfaces of analytical solutions have been drawn by wolfram Mathematica 9. Finally, a conclusion has been submitted by mentioning important acquisitions founded in this study.

  18. Expo 86: An Escalation Prototype.

    ERIC Educational Resources Information Center

    Ross, Jerry; Staw, Barry M.

    1986-01-01

    British Columbia remained committed to its decision to host a world's fair (Expo 86) despite rapidly increasing deficit projections. Expo is examined as a prototypical example of the escalation of commitment. Theory is proposed that integrates determinants of escalation from several levels of analysis over time. (CJH)

  19. Millon's Evolutionary Model of Personality Assessment: A Case for Categorical/Dimensional Prototypes.

    PubMed

    Grossman, Seth D

    2015-01-01

    Theodore Millon (1928-2014) was arguably one of the most influential figures in conceptualizing and detailing personality styles and disorders in the latter 20th and early 21st centuries. A prominent member of the Axis II Work Group of DSM-III, III-R, and IV, Millon continued refining his evolutionary model long after his active involvement with these committees, and remained focused on the future of personality assessment until his death in 2014. This article is an exploration of his latter works, critiques of recent DSM-5 developments, and commentary on the usefulness of his deductive methodology as it continues to apply to the study, classification, and clinical application of personality assessment.

  20. Applications and development of communication models for the touchstone GAMMA and DELTA prototypes

    NASA Technical Reports Server (NTRS)

    Seidel, Steven R.

    1993-01-01

    The goal of this project was to develop models of the interconnection networks of the Intel iPSC/860 and DELTA multicomputers to guide the design of efficient algorithms for interprocessor communication in problems that commonly occur in CFD codes and other applications. Interprocessor communication costs of codes for message-passing architectures such as the iPSC/860 and DELTA significantly affect the level of performance that can be obtained from those machines. This project addressed several specific problems in the achievement of efficient communication on the Intel iPSC/860 hypercube and DELTA mesh. In particular, an efficient global processor synchronization algorithm was developed for the iPSC/860 and numerous broadcast algorithms were designed for the DELTA.

  1. Perspective: The Asakura Oosawa model: A colloid prototype for bulk and interfacial phase behavior

    SciTech Connect

    Binder, Kurt; Virnau, Peter; Statt, Antonia

    2014-10-14

    In many colloidal suspensions, the micrometer-sized particles behave like hard spheres, but when non-adsorbing polymers are added to the solution a depletion attraction (of entropic origin) is created. Since 60 years the Asakura-Oosawa model, which simply describes the polymers as ideal soft spheres, is an archetypical description for the statistical thermodynamics of such systems, accounting for many features of real colloid-polymer mixtures very well. While the fugacity of the polymers (which controls their concentration in the solution) plays a role like inverse temperature, the size ratio of polymer versus colloid radii acts as a control parameter to modify the phase diagram: when this ratio is large enough, a vapor-liquid like phase separation occurs at low enough colloid packing fractions, up to a triple point where a liquid-solid two-phase coexistence region takes over. For smaller size ratios, the critical point of the phase separation and the triple point merge, resulting in a single two-phase coexistence region between fluid and crystalline phases (of “inverted swan neck”-topology, with possibly a hidden metastable phase separation). Furthermore, liquid-crystalline ordering may be found if colloidal particles of non-spherical shape (e.g., rod like) are considered. Also interactions of the particles with solid surfaces should be tunable (e.g., walls coated by polymer brushes), and interfacial phenomena are particularly interesting experimentally, since fluctuations can be studied in the microscope on all length scales, down to the particle level. Due to its simplicity this model has become a workhorse for both analytical theory and computer simulation. Recently, generalizations addressing dynamic phenomena (phase separation, crystal nucleation, etc.) have become the focus of studies.

  2. Prototyping scalable digital signal processing systems for radio astronomy using dataflow models

    NASA Astrophysics Data System (ADS)

    Sane, N.; Ford, J.; Harris, A. I.; Bhattacharyya, S. S.

    2012-05-01

    There is a growing trend toward using high-level tools for design and implementation of radio astronomy digital signal processing (DSP) systems. Such tools, for example, those from the Collaboration for Astronomy Signal Processing and Electronics Research (CASPER), are usually platform-specific, and lack high-level, platform-independent, portable, scalable application specifications. This limits the designer's ability to experiment with designs at a high-level of abstraction and early in the development cycle. We address some of these issues using a model-based design approach employing dataflow models. We demonstrate this approach by applying it to the design of a tunable digital downconverter (TDD) used for narrow-bandwidth spectroscopy. Our design is targeted toward an FPGA platform, called the Interconnect Break-out Board (IBOB), that is available from the CASPER. We use the term TDD to refer to a digital downconverter for which the decimation factor and center frequency can be reconfigured without the need for regenerating the hardware code. Such a design is currently not available in the CASPER DSP library. The work presented in this paper focuses on two aspects. First, we introduce and demonstrate a dataflow-based design approach using the dataflow interchange format (DIF) tool for high-level application specification, and we integrate this approach with the CASPER tool flow. Secondly, we explore the trade-off between the flexibility of TDD designs and the low hardware cost of fixed-configuration digital downconverter (FDD) designs that use the available CASPER DSP library. We further explore this trade-off in the context of a two-stage downconversion scheme employing a combination of TDD or FDD designs.

  3. Perspective: The Asakura Oosawa model: A colloid prototype for bulk and interfacial phase behavior

    NASA Astrophysics Data System (ADS)

    Binder, Kurt; Virnau, Peter; Statt, Antonia

    2014-10-01

    In many colloidal suspensions, the micrometer-sized particles behave like hard spheres, but when non-adsorbing polymers are added to the solution a depletion attraction (of entropic origin) is created. Since 60 years the Asakura-Oosawa model, which simply describes the polymers as ideal soft spheres, is an archetypical description for the statistical thermodynamics of such systems, accounting for many features of real colloid-polymer mixtures very well. While the fugacity of the polymers (which controls their concentration in the solution) plays a role like inverse temperature, the size ratio of polymer versus colloid radii acts as a control parameter to modify the phase diagram: when this ratio is large enough, a vapor-liquid like phase separation occurs at low enough colloid packing fractions, up to a triple point where a liquid-solid two-phase coexistence region takes over. For smaller size ratios, the critical point of the phase separation and the triple point merge, resulting in a single two-phase coexistence region between fluid and crystalline phases (of "inverted swan neck"-topology, with possibly a hidden metastable phase separation). Furthermore, liquid-crystalline ordering may be found if colloidal particles of non-spherical shape (e.g., rod like) are considered. Also interactions of the particles with solid surfaces should be tunable (e.g., walls coated by polymer brushes), and interfacial phenomena are particularly interesting experimentally, since fluctuations can be studied in the microscope on all length scales, down to the particle level. Due to its simplicity this model has become a workhorse for both analytical theory and computer simulation. Recently, generalizations addressing dynamic phenomena (phase separation, crystal nucleation, etc.) have become the focus of studies.

  4. Perspective: The Asakura Oosawa model: a colloid prototype for bulk and interfacial phase behavior.

    PubMed

    Binder, Kurt; Virnau, Peter; Statt, Antonia

    2014-10-14

    In many colloidal suspensions, the micrometer-sized particles behave like hard spheres, but when non-adsorbing polymers are added to the solution a depletion attraction (of entropic origin) is created. Since 60 years the Asakura-Oosawa model, which simply describes the polymers as ideal soft spheres, is an archetypical description for the statistical thermodynamics of such systems, accounting for many features of real colloid-polymer mixtures very well. While the fugacity of the polymers (which controls their concentration in the solution) plays a role like inverse temperature, the size ratio of polymer versus colloid radii acts as a control parameter to modify the phase diagram: when this ratio is large enough, a vapor-liquid like phase separation occurs at low enough colloid packing fractions, up to a triple point where a liquid-solid two-phase coexistence region takes over. For smaller size ratios, the critical point of the phase separation and the triple point merge, resulting in a single two-phase coexistence region between fluid and crystalline phases (of "inverted swan neck"-topology, with possibly a hidden metastable phase separation). Furthermore, liquid-crystalline ordering may be found if colloidal particles of non-spherical shape (e.g., rod like) are considered. Also interactions of the particles with solid surfaces should be tunable (e.g., walls coated by polymer brushes), and interfacial phenomena are particularly interesting experimentally, since fluctuations can be studied in the microscope on all length scales, down to the particle level. Due to its simplicity this model has become a workhorse for both analytical theory and computer simulation. Recently, generalizations addressing dynamic phenomena (phase separation, crystal nucleation, etc.) have become the focus of studies. PMID:25318706

  5. Hyper-Resolution Large Scale Flood Inundation Modeling: Development of AutoRAPID Model

    NASA Astrophysics Data System (ADS)

    Tavakoly, A. A.; Follum, M. L.; Wahl, M.; Snow, A.

    2015-12-01

    Streamflow and the resultant flood inundation are defining elements in large scale flood analyses. High-fidelity predictive capabilities of flood inundation risk requires hydrologic and hydrodynamic modeling at hyper-resolution (<100 m) scales. Using spatiotemporal data from climate models as the driver, we couple a continental scale river routing model known as Routing Application for Parallel ComputatIon of Discharge (RAPID) with a regional scale flood delineation model called AutoRoute to estimate flood extents. We demonstrate how the coupled tool, referred to as AutoRAPID, can quickly and efficiently simulate flood extents using a high resolution dataset (~10 m) at the regional scale (> 100,000 km2). The AutoRAPID framework is implemented over 230,000 km2 in the Midwestern United States (between latitude 38°N and 44°N, and longitude 86°W to 91°W, approximately 8% of the Mississippi River Basin) using a 10 m DEM. We generate the flood inundation map over the entire area for a June 2008 flood event. The model is compared with observed data at five select locations: Spencer, IN; Newberry, IN; Gays Mills, WI; Ft. Atkinson, WI, and Janesville, WI. We show that the model results are generally satisfactory with observed flow and flood inundation data and suggest that the AutoRAPID model can be considered for several potential applications, such as: forecast flow and flood inundation information; generating flood recurrence maps using high resolution vector river data; and for emergency management applications to protect/evacuate large areas when time is limited and data are sparse.

  6. Prototyping of Computer-Based Training Materials.

    ERIC Educational Resources Information Center

    Gray, D. E.; Black, T. R.

    1994-01-01

    Defines prototyping as an original version or model on which a completed software system for computer-based training is formed; examines the development process of a prototype; describes how prototyping can assist in facilitating communication between educational technology, software engineering, and project management; and discusses why…

  7. Rapid Acquisition in Concurrent Chains: Evidence for a Decision Model

    ERIC Educational Resources Information Center

    Grace, Randolph C.; McLean, Anthony P.

    2006-01-01

    Pigeons' choice in concurrent chains can adapt to rapidly changing contingencies. Grace, Bragason, and McLean (2003) found that relative initial-link response rate was sensitive to the immediacy ratio in the current session when one of the terminal-link fixed-interval schedules was changed daily according to a pseudorandom binary sequence (e.g.,…

  8. Interactive Rapid Dose Assessment Model (IRDAM): scenarios for comparing dose-assessment models. Vol. 3

    SciTech Connect

    Poeton, R.W.; Moeller, M.P.; Laughlin, G.J.; Desrosiers, A.E.

    1983-05-01

    The Interactive Rapid Dose Assessment Model (IRDAM) is a micro-computer based program designed to provide rapid assessments of the radiological impact of accidents at nuclear power plants. The main body of this document consists of 28 examples of IRDAM input and output, representing various types of accidents and releases. These examples are intended to provide a basis for comparison with other models or for testing IRDAM itself. Figures are included which show dose rates calculated by IRDAM for each scenario. Figures are also included which show calculations made using the computer codes WRAITH (Scherpelz, Borst and Hoenes, 1980) and RADPUR (Dabbert, et. al., 1982). Two other companion volumes to this one provide additional information on IRDAM. The User's Guide (NUREG/CR-3012, Volume 1) describes the setup and operation of equipment necessary to run IRDAM. Reactor Accident Assessment Methods (NUREG/CR-3012, Volume 2) describes the technical bases for IRDAM including methods, models and assumptions used in calculations.

  9. The Prototypical Ranitidine Analog JWS-USC-75-IX Improves Information Processing and Cognitive Function in Animal Models

    PubMed Central

    Buccafusco, Jerry J.; Herman, Elizabeth J.; Callahan, Patrick M.; Beck, Wayne D.; Warner, Samantha; Vandenhuerk, Leah; Bouchard, Kristy; Schwarz, Gary M.; Gao, Jie; Chapman, James M.

    2011-01-01

    This study was designed to evaluate further a prototypical ranitidine analog, JWS-USC-75-IX, [(3-[[[2-[[(5-dimethylaminomethyl)-2-furanyl]methyl]thio]ethyl]amino]-4-nitropyridazine, JWS], for neuropharmacologic properties that would theoretically be useful for treating cognitive and noncognitive behavioral symptoms of neuropsychiatric disorders. JWS was previously found to inhibit acetylcholinesterase (AChE) activity, serve as a potent ligand at muscarinic M2 acetylcholine receptors, and elicit positive effects on spatial learning, passive avoidance, and working memory in rodents. In the current study, JWS was evaluated for binding activity at more than 60 neurotransmitter receptors, transporters, and ion channels, as well as for inhibitory activity at AChE and butyrylcholinesterase (BChE). The results indicate that JWS inhibits AChE and BChE at low (micromolar) concentrations and that it is a functional antagonist at M2 receptors (KB = 320 nM). JWS was subsequently evaluated orally across additional behavioral assays in rodents (dose range, 0.03–10.0 mg/kg) as well as nonhuman primates (dose range, 0.05–2.0 mg/kg). In rats, JWS improved prepulse inhibition (PPI) of the acoustic startle response in nonimpaired rats and attenuated PPI deficits in three pharmacologic impairment models. JWS also attenuated scopolamine and (−)-5-methyl-10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5,10-imine maleate (MK-801)-related impairments in a spontaneous novel object recognition task and a five-choice serial reaction time task, respectively. In monkeys, JWS elicited dose-dependent improvements of a delayed match-to-sample task as well as an attention-related version of the task where randomly presented (task-relevant) distractors were presented. Thus, JWS (potentially via effects at several drug targets) improves information processing, attention, and memory in animal models and could potentially treat the cognitive and behavioral symptoms of some neuropsychiatric illnesses

  10. Rapid Prototyping Platform for Robotics Applications

    ERIC Educational Resources Information Center

    Hwang, Kao-Shing; Hsiao, Wen-Hsu; Shing, Gaung-Ting; Chen, Kim-Joan

    2011-01-01

    For the past several years, a team in the Department of Electrical Engineering (EE), National Chung Cheng University, Taiwan, has been establishing a pedagogical approach to embody embedded systems in the context of robotics. To alleviate the burden on students in the robotics curriculum in their junior and senior years, a training platform on…

  11. Coupled Thermo-Hydro-Chemical (THC) Modeling of Hypogene Karst Evolution in a Prototype Mountain Hydrologic System

    NASA Astrophysics Data System (ADS)

    Chaudhuri, A.; Rajaram, H.; Viswanathan, H. S.; Zyvoloski, G.

    2011-12-01

    Hypogene karst systems are believed to develop when water flowing upward against the geothermal gradient dissolves limestone as it cools. We present a comprehensive THC model incorporating time-evolving fluid flow, heat transfer, buoyancy effects, multi-component reactive transport and aperture/permeability change to investigate the origin of hypogene karst systems. Our model incorporates the temperature and pressure dependence of the solubility and dissolution kinetics of calcite. It also allows for rigorous representation of temperature-dependent fluid density and its influence on buoyancy forces at various stages of karstification. The model is applied to investigate karstification over geological time scales in a prototype mountain hydrologic system. In this system, a high water table maintained by mountain recharge, drives flow downward through the country rock and upward via a high-permeability fault/fracture. The pressure boundary conditions are maintained constant in time. The fluid flux through the fracture remains nearly constant even though the fracture aperture and permeability increase by dissolution, largely because the permeability of the country rock is not altered significantly due to slower dissolution rates. However, karstification by fracture dissolution is not impeded even though the fluid flux stays nearly constant. Forced and buoyant convection effects arise due to the increased permeability of the evolving fracture system. Since in reality the aperture varies significantly within the fracture plane, the initial fracture aperture is modeled as a heterogeneous random field. In such a heterogeneous aperture field, the water initially flows at a significant rate mainly through preferential flow paths connecting the relatively large aperture zones. Dissolution is more prominent at early time along these flow paths, and the aperture grows faster within these paths. With time, the aperture within small sub-regions of these preferential flow paths

  12. 3-D subsurface modeling within the framework of an environmental restoration information system: Prototype results using earthvision

    SciTech Connect

    Goeltz, R.T.; Zondlo, T.F.

    1994-12-31

    As a result of the DOE Oak Ridge Reservation (DOE-ORR) placement on the EPA Superfund National Priorities List in December of 1989, all remedial activities, including characterization, remedial alternatives selection, and implementation of remedial measures, must meet the combined requirements of RCRA, CERCLA, and NEPA. The Environmental Restoration Program, therefore, was established with the mission of eliminating or reducing to prescribed safe levels the risks to the environment or to human health and safety posed by inactive and surplus DOE-ORR managed sites and facilities that have been contaminated by radioactive and surplus DOE-ORR managed sites and facilities that have been contaminated by radioactive, hazardous, or mixed wastes. In accordance with an established Federal Facilities Agreement (FFA), waste sites and facilities across the DOE-ORR have been inventoried, prioritized, and are being systematically investigated and remediated under the direction of Environmental Restoration. EarthVision, a product of Dynamic Graphics, Inc., that provides three-dimensional (3-D) modeling and visualization, was exercised within the framework of an environmental restoration (ER) decision support system. The goal of the prototype was to investigate framework integration issues including compatibility and value to decision making. This paper describes the ER program, study site, and information system framework; selected EarthVision results are shown and discussed. EarthVision proved effective in integrating complex data from disparate sources and in providing 3-D visualizations of the spatial relationships of the data, including contaminant plumes. Work is under way to expand the analysis to the full site, covering about 1600 acres, and to include data from new sources, particularly remote-sensing studies.

  13. Design and fabrication of a long-life Stirling cycle cooler for space application. Phase 3: Prototype model

    NASA Technical Reports Server (NTRS)

    Keung, C.; Patt, P. J.; Starr, M.; Sweet, R. C.; Bourdillon, L. A.; Figueroa, R.; Hartmann, M.; Mcfarlane, R.

    1990-01-01

    A second-generation, Stirling-cycle cryocooler (cryogenic refrigerator) for space applications, with a cooling capacity of 5 watts at 65 K, was recently completed. The refrigerator, called the Prototype Model, was designed with a goal of 5 year life with no degradation in cooling performance. The free displacer and free piston of the refrigerator are driven directly by moving-magnet linear motors with the moving elements supported by active magnetic bearings. The use of clearance seals and the absence of outgassing material in the working volume of the refrigerator enable long-life operation with no deterioration in performance. Fiber-optic sensors detect the radial position of the shafts and provide a control signal for the magnetic bearings. The frequency, phase, stroke, and offset of the compressor and expander are controlled by signals from precision linear position sensors (LVDTs). The vibration generated by the compressor and expander is cancelled by an active counter balance which also uses a moving-magnet linear motor and magnetic bearings. The driving signal for the counter balance is derived from the compressor and expander position sensors which have wide bandwidth for suppression of harmonic vibrations. The efficiency of the three active members, which operate in a resonant mode, is enhanced by a magnetic spring in the expander and by gas springs in the compressor and counterbalance. The cooling was achieved with a total motor input power of 139 watts. The magnetic-bearing stiffness was significantly increased from the first-generation cooler to accommodate shuttle launch vibrations.

  14. Do the eyes scan dream images during rapid eye movement sleep? Evidence from the rapid eye movement sleep behaviour disorder model.

    PubMed

    Leclair-Visonneau, Laurène; Oudiette, Delphine; Gaymard, Bertrand; Leu-Semenescu, Smaranda; Arnulf, Isabelle

    2010-06-01

    Rapid eye movements and complex visual dreams are salient features of human rapid eye movement sleep. However, it remains to be elucidated whether the eyes scan dream images, despite studies that have retrospectively compared the direction of rapid eye movements to the dream recall recorded after having awakened the sleeper. We used the model of rapid eye movement sleep behaviour disorder (when patients enact their dreams by persistence of muscle tone) to determine directly whether the eyes move in the same directions as the head and limbs. In 56 patients with rapid eye movement sleep behaviour disorder and 17 healthy matched controls, the eye movements were monitored by electrooculography in four (right, left, up and down) directions, calibrated with a target and synchronized with video and sleep monitoring. The rapid eye movement sleep behaviour disorder-associated behaviours occurred 2.1 times more frequently during rapid eye movement sleep with than without rapid eye movements, and more often during or after rapid eye movements than before. Rapid eye movement density, index and complexity were similar in patients with rapid eye movement sleep behaviour disorder and controls. When rapid eye movements accompanied goal-oriented motor behaviour during rapid eye movement sleep behaviour disorder (e.g. grabbing a fictive object, hand greetings, climbing a ladder), which happened in 19 sequences, 82% were directed towards the action of the patient (same plane and direction). When restricted to the determinant rapid eye movements, the concordance increased to 90%. Rapid eye movements were absent in 38-42% of behaviours. This directional coherence between limbs, head and eye movements during rapid eye movement sleep behaviour disorder suggests that, when present, rapid eye movements imitate the scanning of the dream scene. Since the rapid eye movements are similar in subjects with and without rapid eye movement sleep behaviour disorder, this concordance can be extended

  15. Five-factor model personality disorder prototypes in a community sample: self- and informant-reports predicting interview-based DSM diagnoses.

    PubMed

    Lawton, Erin M; Shields, Andrew J; Oltmanns, Thomas F

    2011-10-01

    The need for an empirically validated, dimensional system of personality disorders is becoming increasingly apparent. While a number of systems have been investigated in this regard, the five-factor model of personality has demonstrated the ability to adequately capture personality pathology. In particular, the personality disorder prototypes developed by Lynam and Widiger (2001) have been tested in a number of samples. The goal of the present study is to extend this literature by validating the prototypes in a large, representative community sample of later middle-aged adults using both self and informant reports. We found that the prototypes largely work well in this age group. Schizoid, Borderline, Histrionic, Narcissistic, and Avoidant personality disorders demonstrate good convergent validity, with a particularly strong pattern of discriminant validity for the latter four. Informant-reported prototypes show similar patterns to self reports for all analyses. This demonstrates that informants are not succumbing to halo representations of the participants, but are rather describing participants in nuanced ways. It is important that informant reports add significant predictive validity for Schizoid, Antisocial, Borderline, Histrionic, and Narcissistic personality disorders. Implications of our results and directions for future research are discussed.

  16. Evaluating Rapid Models for High-Throughput Exposure Forecasting (SOT)

    EPA Science Inventory

    High throughput exposure screening models can provide quantitative predictions for thousands of chemicals; however these predictions must be systematically evaluated for predictive ability. Without the capability to make quantitative, albeit uncertain, forecasts of exposure, the ...

  17. Rapid State Space Modeling Tool for Rectangular Wing Aeroservoelastic Studies

    NASA Technical Reports Server (NTRS)

    Suh, Peter M.; Conyers, Howard Jason; Mavris, Dimitri N.

    2015-01-01

    This report introduces a modeling and simulation tool for aeroservoelastic analysis of rectangular wings with trailing-edge control surfaces. The inputs to the code are planform design parameters such as wing span, aspect ratio, and number of control surfaces. Using this information, the generalized forces are computed using the doublet-lattice method. Using Roger's approximation, a rational function approximation is computed. The output, computed in a few seconds, is a state space aeroservoelastic model which can be used for analysis and control design. The tool is fully parameterized with default information so there is little required interaction with the model developer. All parameters can be easily modified if desired. The focus of this report is on tool presentation, verification, and validation. These processes are carried out in stages throughout the report. The rational function approximation is verified against computed generalized forces for a plate model. A model composed of finite element plates is compared to a modal analysis from commercial software and an independently conducted experimental ground vibration test analysis. Aeroservoelastic analysis is the ultimate goal of this tool, therefore, the flutter speed and frequency for a clamped plate are computed using damping-versus-velocity and frequency-versus-velocity analysis. The computational results are compared to a previously published computational analysis and wind-tunnel results for the same structure. A case study of a generic wing model with a single control surface is presented. Verification of the state space model is presented in comparison to damping-versus-velocity and frequency-versus-velocity analysis, including the analysis of the model in response to a 1-cos gust.

  18. Rapid State Space Modeling Tool for Rectangular Wing Aeroservoelastic Studies

    NASA Technical Reports Server (NTRS)

    Suh, Peter M.; Conyers, Howard J.; Mavris, Dimitri N.

    2015-01-01

    This paper introduces a modeling and simulation tool for aeroservoelastic analysis of rectangular wings with trailing-edge control surfaces. The inputs to the code are planform design parameters such as wing span, aspect ratio, and number of control surfaces. Using this information, the generalized forces are computed using the doublet-lattice method. Using Roger's approximation, a rational function approximation is computed. The output, computed in a few seconds, is a state space aeroservoelastic model which can be used for analysis and control design. The tool is fully parameterized with default information so there is little required interaction with the model developer. All parameters can be easily modified if desired. The focus of this paper is on tool presentation, verification, and validation. These processes are carried out in stages throughout the paper. The rational function approximation is verified against computed generalized forces for a plate model. A model composed of finite element plates is compared to a modal analysis from commercial software and an independently conducted experimental ground vibration test analysis. Aeroservoelastic analysis is the ultimate goal of this tool, therefore, the flutter speed and frequency for a clamped plate are computed using damping-versus-velocity and frequency-versus-velocity analysis. The computational results are compared to a previously published computational analysis and wind-tunnel results for the same structure. A case study of a generic wing model with a single control surface is presented. Verification of the state space model is presented in comparison to damping-versus-velocity and frequency-versus-velocity analysis, including the analysis of the model in response to a 1-cos gust.

  19. Rapid State Space Modeling Tool for Rectangular Wing Aeroservoelastic Studies

    NASA Technical Reports Server (NTRS)

    Suh, Peter M.; Conyers, Howard J.; Mavris, Dimitri N.

    2014-01-01

    This paper introduces a modeling and simulation tool for aeroservoelastic analysis of rectangular wings with trailing edge control surfaces. The inputs to the code are planform design parameters such as wing span, aspect ratio and number of control surfaces. A doublet lattice approach is taken to compute generalized forces. A rational function approximation is computed. The output, computed in a few seconds, is a state space aeroservoelastic model which can be used for analysis and control design. The tool is fully parameterized with default information so there is little required interaction with the model developer. Although, all parameters can be easily modified if desired.The focus of this paper is on tool presentation, verification and validation. This process is carried out in stages throughout the paper. The rational function approximation is verified against computed generalized forces for a plate model. A model composed of finite element plates is compared to a modal analysis from commercial software and an independently conducted experimental ground vibration test analysis. Aeroservoelastic analysis is the ultimate goal of this tool. Therefore the flutter speed and frequency for a clamped plate are computed using V-g and V-f analysis. The computational results are compared to a previously published computational analysis and wind tunnel results for the same structure. Finally a case study of a generic wing model with a single control surface is presented. Verification of the state space model is presented in comparison to V-g and V-f analysis. This also includes the analysis of the model in response to a 1-cos gust.

  20. A Rapid Approach to Modeling Species-Habitat Relationships

    NASA Technical Reports Server (NTRS)

    Carter, Geoffrey M.; Breinger, David R.; Stolen, Eric D.

    2005-01-01

    A growing number of species require conservation or management efforts. Success of these activities requires knowledge of the species' occurrence pattern. Species-habitat models developed from GIS data sources are commonly used to predict species occurrence but commonly used data sources are often developed for purposes other than predicting species occurrence and are of inappropriate scale and the techniques used to extract predictor variables are often time consuming and cannot be repeated easily and thus cannot efficiently reflect changing conditions. We used digital orthophotographs and a grid cell classification scheme to develop an efficient technique to extract predictor variables. We combined our classification scheme with a priori hypothesis development using expert knowledge and a previously published habitat suitability index and used an objective model selection procedure to choose candidate models. We were able to classify a large area (57,000 ha) in a fraction of the time that would be required to map vegetation and were able to test models at varying scales using a windowing process. Interpretation of the selected models confirmed existing knowledge of factors important to Florida scrub-jay habitat occupancy. The potential uses and advantages of using a grid cell classification scheme in conjunction with expert knowledge or an habitat suitability index (HSI) and an objective model selection procedure are discussed.

  1. A Rapid Compression Machine Modelling Study of the Heptane Isomers

    SciTech Connect

    Silke, E J; Curran, H J; Simmie, J M; Pitz, W J; Westbrook, C K

    2005-05-10

    Previously we have reported on the combustion behavior of all nine isomers of heptane in a rapid compression machine (RCM) with stoichiometric fuel and ''air'' mixtures at a compressed gas pressure of 15 atm. The dependence of autoignition delay times on molecular structure was illustrated. Here, we report some additional experimental work that was performed in order to address unusual results regarding significant differences in the ignition delay times recorded at the same fuel and oxygen composition, but with different fractions of nitrogen and argon diluent gases. Moreover, we have begun to simulate these experiments with detailed chemical kinetic mechanisms. These mechanisms are based on previous studies of other alkane molecules, in particular, n-heptane and iso-octane. We have focused our attention on n-heptane in order to systematically redevelop the chemistry and thermochemistry for this C{sub 7} isomer with the intention of extending our greater knowledge gained to the other eight isomers. The addition of new reaction types, that were not included previously, has had a significant impact on the simulations, particularly at low temperatures.

  2. Rapid evolution of mimicry following local model extinction

    PubMed Central

    Akcali, Christopher K.; Pfennig, David W.

    2014-01-01

    Batesian mimicry evolves when individuals of a palatable species gain the selective advantage of reduced predation because they resemble a toxic species that predators avoid. Here, we evaluated whether—and in which direction—Batesian mimicry has evolved in a natural population of mimics following extirpation of their model. We specifically asked whether the precision of coral snake mimicry has evolved among kingsnakes from a region where coral snakes recently (1960) went locally extinct. We found that these kingsnakes have evolved more precise mimicry; by contrast, no such change occurred in a sympatric non-mimetic species or in conspecifics from a region where coral snakes remain abundant. Presumably, more precise mimicry has continued to evolve after model extirpation, because relatively few predator generations have passed, and the fitness costs incurred by predators that mistook a deadly coral snake for a kingsnake were historically much greater than those incurred by predators that mistook a kingsnake for a coral snake. Indeed, these results are consistent with prior theoretical and empirical studies, which revealed that only the most precise mimics are favoured as their model becomes increasingly rare. Thus, highly noxious models can generate an ‘evolutionary momentum’ that drives the further evolution of more precise mimicry—even after models go extinct. PMID:24919704

  3. Rapid evolution of mimicry following local model extinction.

    PubMed

    Akcali, Christopher K; Pfennig, David W

    2014-06-01

    Batesian mimicry evolves when individuals of a palatable species gain the selective advantage of reduced predation because they resemble a toxic species that predators avoid. Here, we evaluated whether-and in which direction-Batesian mimicry has evolved in a natural population of mimics following extirpation of their model. We specifically asked whether the precision of coral snake mimicry has evolved among kingsnakes from a region where coral snakes recently (1960) went locally extinct. We found that these kingsnakes have evolved more precise mimicry; by contrast, no such change occurred in a sympatric non-mimetic species or in conspecifics from a region where coral snakes remain abundant. Presumably, more precise mimicry has continued to evolve after model extirpation, because relatively few predator generations have passed, and the fitness costs incurred by predators that mistook a deadly coral snake for a kingsnake were historically much greater than those incurred by predators that mistook a kingsnake for a coral snake. Indeed, these results are consistent with prior theoretical and empirical studies, which revealed that only the most precise mimics are favoured as their model becomes increasingly rare. Thus, highly noxious models can generate an 'evolutionary momentum' that drives the further evolution of more precise mimicry-even after models go extinct.

  4. A 12 GHz satellite video receiver: Low noise, low cost prototype model for TV reception from broadcast satellites

    NASA Technical Reports Server (NTRS)

    Hreha, M. A.; Baprawski, J. G.; Chamaneria, C. N.; Ferry, S. J.; Keithly, G.; Kuklin, H. S.; Lockyear, W. H.; Schifter, L. H.; Swanberg, N. E.; Swift, G. W.

    1978-01-01

    A 12-channel synchronous phase lock video receiver consisting of an outdoor downconverter unit and an indoor demodulator unit was developed to provide both low noise performance and low cost in production quantities of 1000 units. The prototype receiver can be mass produced at a cost under $1540 without sacrificing system performance. The receiver also has the capability of selecting any of the twelve assigned satellite broadcast channels in the frequency range 11.7 to 12.2 GHz.

  5. Prototype of calorimetric flow microsensor

    NASA Astrophysics Data System (ADS)

    Sazhin, Oleg

    2012-11-01

    An analytical model of calorimetric flow sensor has been developed. The results of the application of this model are utilized to develop a calorimetric flow microsensor with optimal functional characteristics. The technology to manufacture the microsensor is described. A prototype of the microsensor suitable to be used in the mass air flow meter has been designed. The basic characteristics of the microsensor are presented.

  6. Impulsive control of a financial model [rapid communication

    NASA Astrophysics Data System (ADS)

    Sun, Jitao; Qiao, Fei; Wu, Qidi

    2005-02-01

    In this Letter, several new theorems on the stability of impulsive control systems are presented. These theorem are then used to find the conditions under which an advertising strategy can be asymptotically control to the equilibrium point by using impulsive control. Given the parameters of the financial model and the impulsive control law, an estimation of the upper bound of the impulse interval is given, i.e., number of advert can been decreased (i.e., can decrease cost) for to obtain the equivalent advertising effect.The result is illustrated to be efficient through a numerical example.

  7. Rapid Discrimination Among Putative Mechanistic Models of Biochemical Systems

    PubMed Central

    Lomnitz, Jason G.; Savageau, Michael A.

    2016-01-01

    An overarching goal in molecular biology is to gain an understanding of the mechanistic basis underlying biochemical systems. Success is critical if we are to predict effectively the outcome of drug treatments and the development of abnormal phenotypes. However, data from most experimental studies is typically noisy and sparse. This allows multiple potential mechanisms to account for experimental observations, and often devising experiments to test each is not feasible. Here, we introduce a novel strategy that discriminates among putative models based on their repertoire of qualitatively distinct phenotypes, without relying on knowledge of specific values for rate constants and binding constants. As an illustration, we apply this strategy to two synthetic gene circuits exhibiting anomalous behaviors. Our results show that the conventional models, based on their well-characterized components, cannot account for the experimental observations. We examine a total of 40 alternative hypotheses and show that only 5 have the potential to reproduce the experimental data, and one can do so with biologically relevant parameter values. PMID:27578053

  8. Rapid Discrimination Among Putative Mechanistic Models of Biochemical Systems.

    PubMed

    Lomnitz, Jason G; Savageau, Michael A

    2016-01-01

    An overarching goal in molecular biology is to gain an understanding of the mechanistic basis underlying biochemical systems. Success is critical if we are to predict effectively the outcome of drug treatments and the development of abnormal phenotypes. However, data from most experimental studies is typically noisy and sparse. This allows multiple potential mechanisms to account for experimental observations, and often devising experiments to test each is not feasible. Here, we introduce a novel strategy that discriminates among putative models based on their repertoire of qualitatively distinct phenotypes, without relying on knowledge of specific values for rate constants and binding constants. As an illustration, we apply this strategy to two synthetic gene circuits exhibiting anomalous behaviors. Our results show that the conventional models, based on their well-characterized components, cannot account for the experimental observations. We examine a total of 40 alternative hypotheses and show that only 5 have the potential to reproduce the experimental data, and one can do so with biologically relevant parameter values. PMID:27578053

  9. Using the Synergy Model to guide the practice of rapid response teams.

    PubMed

    Arashin, Kelly A

    2010-01-01

    The goals of Rapid Response Teams are to provide interventional care upon recognizing a clinical change in a patient's condition and to prevent further progression of declining health. There are many clinical situations in which the critical care nurse or advanced practice nurse can apply the Synergy Model to patient care. Understanding how the Synergy Model can guide the Rapid Response Team interventions and practice by identifying and matching patient and nurse characteristics can possibly achieve improved patient outcomes.

  10. Elastic instability model of rapid beak closure in hummingbirds.

    PubMed

    Smith, M L; Yanega, G M; Ruina, A

    2011-08-01

    The hummingbird beak, specialized for feeding on floral nectars, is also uniquely adapted to eating flying insects. During insect capture the beak often appears to close at a rate that cannot be explained by direct muscular action alone. Here we show that the lower jaw of hummingbirds has a shape and compliance that allows for a controlled elastic snap. Furthermore, hummingbirds have the musculature needed to independently bend and twist the sides of the lower jaw. According to both our simple physical model and our elastic instability calculation, the jaw can be smoothly opened and then snapped closed through an appropriate sequence of bending and twisting actions by the muscles of the lower jaw.

  11. A prototype for cartographic human body analysis.

    PubMed

    Carvalho, Elizabeth; Marcos, Adérito; Santos, Maribel Yasmina; Espregueira-Mendes, João

    2008-01-01

    A cartographic-oriented model uses algebraic map operations to perform spatial analysis of medical data relative to the human body. A prototype system uses 3D visualization techniques to deliver analysis results. A prototype implementation suggests the model might provide the basis for a medical application tool that introduces new information insight.

  12. Nanoparticle detection limits of TNO's Rapid Nano: modeling and experimental results

    NASA Astrophysics Data System (ADS)

    van der Walle, Peter; Kumar, Pragati; Ityaksov, Dmitry; Versulis, Richard; Maas, Diederik J.; Kievit, Olaf; Janssen, Jochem; van der Donck, Jacques C. J.

    2012-11-01

    TNO has developed the Rapid Nano scanner to detect nanoparticles on EUVL mask blanks. This scanner was designed to be used in particle qualifications of EUV reticle handling equipment. In this paper we present an end-to-end model of the Rapid Nano detection process. All important design parameters concerning illumination, detection and noise are included in the model. The prediction from the model matches the performance that was experimentally determined (59 nm LSE). The model will be used to design and predict the performance of future generations of particle scanners.

  13. Modeling and development of INS-aided PLLs in a GNSS/INS deeply-coupled hardware prototype for dynamic applications.

    PubMed

    Zhang, Tisheng; Niu, Xiaoji; Ban, Yalong; Zhang, Hongping; Shi, Chuang; Liu, Jingnan

    2015-01-05

    A GNSS/INS deeply-coupled system can improve the satellite signals tracking performance by INS aiding tracking loops under dynamics. However, there was no literature available on the complete modeling of the INS branch in the INS-aided tracking loop, which caused the lack of a theoretical tool to guide the selections of inertial sensors, parameter optimization and quantitative analysis of INS-aided PLLs. This paper makes an effort on the INS branch in modeling and parameter optimization of phase-locked loops (PLLs) based on the scalar-based GNSS/INS deeply-coupled system. It establishes the transfer function between all known error sources and the PLL tracking error, which can be used to quantitatively evaluate the candidate inertial measurement unit (IMU) affecting the carrier phase tracking error. Based on that, a steady-state error model is proposed to design INS-aided PLLs and to analyze their tracking performance. Based on the modeling and error analysis, an integrated deeply-coupled hardware prototype is developed, with the optimization of the aiding information. Finally, the performance of the INS-aided PLLs designed based on the proposed steady-state error model is evaluated through the simulation and road tests of the hardware prototype.

  14. Modeling and development of INS-aided PLLs in a GNSS/INS deeply-coupled hardware prototype for dynamic applications.

    PubMed

    Zhang, Tisheng; Niu, Xiaoji; Ban, Yalong; Zhang, Hongping; Shi, Chuang; Liu, Jingnan

    2015-01-01

    A GNSS/INS deeply-coupled system can improve the satellite signals tracking performance by INS aiding tracking loops under dynamics. However, there was no literature available on the complete modeling of the INS branch in the INS-aided tracking loop, which caused the lack of a theoretical tool to guide the selections of inertial sensors, parameter optimization and quantitative analysis of INS-aided PLLs. This paper makes an effort on the INS branch in modeling and parameter optimization of phase-locked loops (PLLs) based on the scalar-based GNSS/INS deeply-coupled system. It establishes the transfer function between all known error sources and the PLL tracking error, which can be used to quantitatively evaluate the candidate inertial measurement unit (IMU) affecting the carrier phase tracking error. Based on that, a steady-state error model is proposed to design INS-aided PLLs and to analyze their tracking performance. Based on the modeling and error analysis, an integrated deeply-coupled hardware prototype is developed, with the optimization of the aiding information. Finally, the performance of the INS-aided PLLs designed based on the proposed steady-state error model is evaluated through the simulation and road tests of the hardware prototype. PMID:25569751

  15. Modeling and Development of INS-Aided PLLs in a GNSS/INS Deeply-Coupled Hardware Prototype for Dynamic Applications

    PubMed Central

    Zhang, Tisheng; Niu, Xiaoji; Ban, Yalong; Zhang, Hongping; Shi, Chuang; Liu, Jingnan

    2015-01-01

    A GNSS/INS deeply-coupled system can improve the satellite signals tracking performance by INS aiding tracking loops under dynamics. However, there was no literature available on the complete modeling of the INS branch in the INS-aided tracking loop, which caused the lack of a theoretical tool to guide the selections of inertial sensors, parameter optimization and quantitative analysis of INS-aided PLLs. This paper makes an effort on the INS branch in modeling and parameter optimization of phase-locked loops (PLLs) based on the scalar-based GNSS/INS deeply-coupled system. It establishes the transfer function between all known error sources and the PLL tracking error, which can be used to quantitatively evaluate the candidate inertial measurement unit (IMU) affecting the carrier phase tracking error. Based on that, a steady-state error model is proposed to design INS-aided PLLs and to analyze their tracking performance. Based on the modeling and error analysis, an integrated deeply-coupled hardware prototype is developed, with the optimization of the aiding information. Finally, the performance of the INS-aided PLLs designed based on the proposed steady-state error model is evaluated through the simulation and road tests of the hardware prototype. PMID:25569751

  16. SXI prototype mirror mount

    NASA Technical Reports Server (NTRS)

    1995-01-01

    The purpose of this contract was to provide optomechanical engineering and fabrication support to the Solar X-ray Imager (SXI) program in the areas of mirror, optical bench and camera assemblies of the telescope. The Center for Applied Optics (CAO) worked closely with the Optics and S&E technical staff of MSFC to develop and investigate the most viable and economical options for the design and fabrication of a number of parts for the various telescope assemblies. All the tasks under this delivery order have been successfully completed within budget and schedule. A number of development hardware parts have been designed and fabricated jointly by MSFC and UAH for the engineering model of SXI. The major parts include a nickel electroformed mirror and a mirror mount, plating and coating of the ceramic spacers, and gold plating of the contact rings and fingers for the camera assembly. An aluminum model of the high accuracy sun sensor (HASS) was also designed and fabricated. A number of fiber optic tapers for the camera assembly were also coated with indium tin oxide and phosphor for testing and evaluation by MSFC. A large number of the SXI optical bench parts were also redesigned and simplified for a prototype telescope. These parts include the forward and rear support flanges, front aperture plate, the graphite epoxy optical bench and a test fixture for the prototype telescope. More than fifty (50) drawings were generated for various components of the prototype telescope. Some of these parts were subsequently fabricated at UAH machine shop or at MSFC or by the outside contractors. UAH also provide technical support to MSFC staff for a number of preliminary and critical design reviews. These design reviews included PDR and CDR for the mirror assembly by United Technologies Optical Systems (UTOS), and the program quarterly reviews, and SXI PDR and CDR. UAH staff also regularly attended the monthly status reviews, and made a significant number of suggestions to improve

  17. SXI prototype mirror mount

    NASA Astrophysics Data System (ADS)

    1995-04-01

    The purpose of this contract was to provide optomechanical engineering and fabrication support to the Solar X-ray Imager (SXI) program in the areas of mirror, optical bench and camera assemblies of the telescope. The Center for Applied Optics (CAO) worked closely with the Optics and S&E technical staff of MSFC to develop and investigate the most viable and economical options for the design and fabrication of a number of parts for the various telescope assemblies. All the tasks under this delivery order have been successfully completed within budget and schedule. A number of development hardware parts have been designed and fabricated jointly by MSFC and UAH for the engineering model of SXI. The major parts include a nickel electroformed mirror and a mirror mount, plating and coating of the ceramic spacers, and gold plating of the contact rings and fingers for the camera assembly. An aluminum model of the high accuracy sun sensor (HASS) was also designed and fabricated. A number of fiber optic tapers for the camera assembly were also coated with indium tin oxide and phosphor for testing and evaluation by MSFC. A large number of the SXI optical bench parts were also redesigned and simplified for a prototype telescope. These parts include the forward and rear support flanges, front aperture plate, the graphite epoxy optical bench and a test fixture for the prototype telescope. More than fifty (50) drawings were generated for various components of the prototype telescope. Some of these parts were subsequently fabricated at UAH machine shop or at MSFC or by the outside contractors. UAH also provide technical support to MSFC staff for a number of preliminary and critical design reviews. These design reviews included PDR and CDR for the mirror assembly by United Technologies Optical Systems (UTOS), and the program quarterly reviews, and SXI PDR and CDR. UAH staff also regularly attended the monthly status reviews, and made a significant number of suggestions to improve

  18. Development of a prototype kinestatic platform for application to space and ground servicing tasks. Phase 1: Concept Modeling

    NASA Technical Reports Server (NTRS)

    Duffy, J.; Crane, C.

    1993-01-01

    The Center for Intelligent Machines and Robotics (CIMAR) of the University of Florida, in conjunction with Rockwell International is developing an electro-mechanical device called a Kinestatic Platform (KP) for aerospace applications. The goal of the current project is to develop a prototype KP which is capable of manipulating a 50 lb. payload. This prototype will demonstrate the feasibility of implementing a scaled up version to perform high precision manipulation of distributed systems and to control contact forces and allowable motions (rotations and translations), which is defined here as Kinestatic Control, in a six dimensional, partially constrained environment, simultaneously and independently. The objectives of the Phase 1 effort were as follows: (1) Identify specific NASA applications where the KP technology can be applied. (2) Select one application for development. (3) Develop a conceptual design of the KP specifically for the selected application. This includes the steps of developing a set of detailed performance criteria, establishing and making selection of the mechanism design parameters, and evaluating the expected system response. (4) Develop a computer graphics animation of the KP as it performs the selected application. This report will proceed by providing a technical description of the KP followed by how each of these objectives was addressed.

  19. Monte Carlo model for a prototype CT-compatible, anatomically adaptive, shielded intracavitary brachytherapy applicator for the treatment of cervical cancer

    SciTech Connect

    Price, Michael J.; Gifford, Kent A.; Horton, John L. Jr.; Eifel, Patricia J.; Gillin, Michael T.; Lawyer, Ann A.; Mourtada, Firas

    2009-09-15

    Purpose: Current, clinically applicable intracavitary brachytherapy applicators that utilize shielded ovoids contain a pair of tungsten-alloy shields which serve to reduce dose delivered to the rectum and bladder during source afterloading. After applicator insertion, these fixed shields are not necessarily positioned to provide optimal shielding of these critical structures due to variations in patient anatomies. The authors present a dosimetric evaluation of a novel prototype intracavitary brachytherapy ovoid [anatomically adaptive applicator (A{sup 3})], featuring a single shield whose position can be adjusted with two degrees of freedom: Rotation about and translation along the long axis of the ovoid. Methods: The dosimetry of the device for a HDR {sup 192}Ir was characterized using radiochromic film measurements for various shield orientations. A MCNPX Monte Carlo model was developed of the prototype ovoid and integrated with a previously validated model of a v2 mHDR {sup 192}Ir source (Nucletron Co.). The model was validated for three distinct shield orientations using film measurements. Results: For the most complex case, 91% of the absolute simulated and measured dose points agreed within 2% or 2 mm and 96% agreed within 10% or 2 mm. Conclusions: Validation of the Monte Carlo model facilitates future investigations into any dosimetric advantages the use of the A{sup 3} may have over the current state of art with respect to optimization and customization of dose delivery as a function of patient anatomical geometries.

  20. Report on the test and evaluation of the Chaparral Physics Model 4.1.1 prototype microbarograph for CTBT infrasound array application

    SciTech Connect

    Kromer, R.P.; McDonald, T.S.

    1998-01-01

    The Sandia National Laboratories has tested and evaluated the Chaparral Physics Model 4.1.1 prototype infrasound sensor to CTBT specifications. The sensor was characterized by using a piston-phone chamber to set and measure sensor sensitivity. Multiple sensor side-by-side coherence analysis testing provided a measure of sensor relative gain and phase; sensor self-noise was computed using this technique. The performance of the sensor calibration circuitry was evaluated. Sensor performance was compared to CTBT specifications. The Chaparral sensor met or exceeded all CTBT specifications.

  1. Limitations in the rapid extraction of evoked potentials using parametric modeling.

    PubMed

    De Silva, A C; Sinclair, N C; Liley, D T J

    2012-05-01

    The rapid extraction of variations in evoked potentials (EPs) is of great clinical importance. Parametric modeling using autoregression with an exogenous input (ARX) and robust evoked potential estimator (REPE) are commonly used methods for extracting EPs over the conventional moving time average. However, a systematic study of the efficacy of these methods, using known synthetic EPs, has not been performed. Therefore, the current study evaluates the restrictions of these methods in the presence of known and systematic variations in EP component latency and signal-to-noise ratios (SNR). In the context of rapid extraction, variations of wave V of the auditory brainstem in response to stimulus intensity were considered. While the REPE methods were better able to recover the simulated model of the EP, morphology and the latency of the ARX-estimated EPs was a closer match to the actual EP than than that of the REPE-estimated EPs. We, therefore, concluded that ARX rapid extraction would perform better with regards to the rapid tracking of latency variations. By tracking simulated and empirically induced latency variations, we conclude that rapid EP extraction using ARX modeling is only capable of extracting latency variations of an EP in relatively high SNRs and, therefore, should be used with caution in low-noise environments. In particular, it is not a suitable method for the rapid extraction of early EP components such as the auditory brainstem potential. PMID:22394572

  2. A Connectionist Modeling Approach to Rapid Analysis of Emergent Social Cognition Properties in Large-Populations

    SciTech Connect

    Perumalla, Kalyan S; Schryver, Jack C

    2009-01-01

    Traditional modeling methodologies, such as those based on rule-based agent modeling, are exhibiting limitations in application to rich behavioral scenarios, especially when applied to large population aggregates. Here, we propose a new modeling methodology based on a well-known "connectionist approach," and articulate its pertinence in new applications of interest. This methodology is designed to address challenges such as speed of model development, model customization, model reuse across disparate geographic/cultural regions, and rapid and incremental updates to models over time.

  3. Virtual prototype and experimental research on gear multi-fault diagnosis using wavelet-autoregressive model and principal component analysis method

    NASA Astrophysics Data System (ADS)

    Li, Zhixiong; Yan, Xinping; Yuan, Chengqing; Peng, Zhongxiao; Li, Li

    2011-10-01

    Gear systems are an essential element widely used in a variety of industrial applications. Since approximately 80% of the breakdowns in transmission machinery are caused by gear failure, the efficiency of early fault detection and accurate fault diagnosis are therefore critical to normal machinery operations. Reviewed literature indicates that only limited research has considered the gear multi-fault diagnosis, especially for single, coupled distributed and localized faults. Through virtual prototype simulation analysis and experimental study, a novel method for gear multi-fault diagnosis has been presented in this paper. This new method was developed based on the integration of Wavelet transform (WT) technique, Autoregressive (AR) model and Principal Component Analysis (PCA) for fault detection. The WT method was used in the study as the de-noising technique for processing raw vibration signals. Compared with the noise removing method based on the time synchronous average (TSA), the WT technique can be performed directly on the raw vibration signals without the need to calculate any ensemble average of the tested gear vibration signals. More importantly, the WT can deal with coupled faults of a gear pair in one operation while the TSA must be carried out several times for multiple fault detection. The analysis results of the virtual prototype simulation prove that the proposed method is a more time efficient and effective way to detect coupled fault than TSA, and the fault classification rate is superior to the TSA based approaches. In the experimental tests, the proposed method was compared with the Mahalanobis distance approach. However, the latter turns out to be inefficient for the gear multi-fault diagnosis. Its defect detection rate is below 60%, which is much less than that of the proposed method. Furthermore, the ability of the AR model to cope with localized as well as distributed gear faults is verified by both the virtual prototype simulation and

  4. Modeling and prototyping of a fiber Bragg grating-based dynamic micro-coordinate measuring machine probe

    NASA Astrophysics Data System (ADS)

    Liu, Fangfang; Chen, Lijuan; Wang, Jingfan; Xia, Haojie; Li, Ruijun; Yu, Liandong; Fei, Yetai

    2016-02-01

    Higher-accuracy measurements of the 3D metrology of nano- and micro-structures are increasingly demanded. This paper details the prototyping of a novel 3D micro-scale coordinate measuring machine probe based on fiber Bragg grating sensors for true 3D measurements at micro- and nanometer scales. A new manufacturing technique for the high-precision cantilever used in the probe is also reported. Simulations are performed during the design and testing to help to test important aspects of the probe and to gain understanding about the influence of the probe geometrical parameters on the sensor sensitivity. The initial performance of the probe has been tested in both the vertical and horizontal directions, and the characterization results are promising. Further experimental results demonstrate that the probe is not affected by surface interaction forces.

  5. A Climate Service Prototype for the Hydropower Industry: Using a Multi-Model Approach to Improve Seasonal Forecasts of the Spring Flood Period in Sweden.

    NASA Astrophysics Data System (ADS)

    Foster, K. L.; Uvo, C. B.; Olsson, J.; Bosshard, T.; Berg, P.; Södling, J.

    2015-12-01

    The Ångerman River is Sweden's third largest river with over 50 regulation reservoirs, 42 hydropower stations and accounts for nearly 20% of the country's hydropower production. In seasonally snow covered regions, such as the Ångerman river system, the winter precipitation is often temporarily stored in the snow pack during the colder months and released over a relatively short period of intense flows during in the warmer months. These spring flood events dominate the hydrology in these regions and as such reliable hydrological forecasts of these events are in great demand. However, it has been shown that the spread in the forecast error of operational hydrological forecasts in Sweden have not changed significantly over the last 25 years (Arheimer et al., 2012). Building on previous work by Foster et al. (2011) and Olsson et al. (2015), a multi-model hydrological seasonal forecast prototype has been developed for the Ångerman river system and applied to the spring flood season. The prototype employs different model-chain approaches: (1) a climatological forecast, where historical observations for the same period are selected to run the hydrological model, (2) a reduced historical ensemble, where analogue years from the historical observations dataset are selected to run the hydrological model, (3) using bias corrected meteorological seasonal forecasts from the ECMWF to force the hydrological model, and (4) statistical downscaling large-scale circulation variables from ECMWF seasonal forecasts directly to accumulated discharge. These different chains are combined into a multi-model ensemble forecast. The different approaches and the multi-model prototype are evaluated against the state-of-the-art operational system for the spring flood season for the period 1981-2014 in the Ångerman river system. References Arheimer, B., Lindström, G., and Olsson, J.: A systematic review of sensitivities in the Swedish flood-forecasting system, Atmos. Res., 100, 275-284, 2011

  6. Software Prototyping: Designing Systems for Users.

    ERIC Educational Resources Information Center

    Spies, Phyllis Bova

    1983-01-01

    Reports on major change in computer software development process--the prototype model, i.e., implementation of skeletal system that is enhanced during interaction with users. Expensive and unreliable software, software design errors, traditional development approach, resources required for prototyping, success stories, and systems designer's role…

  7. A Report of the Joint Development of a Prototype Communications Link to Share Nuclear Accident Dispersion and Dose Assessment Modeling Products Between JAERI/WSPEEDI and LLNL/NARAC

    SciTech Connect

    Sullivan, T J; Belles, R D; Ellis, J S; Chino, M; Nagai, H

    2001-05-01

    In June of 1997, under an umbrella Memorandum of Understanding between the Japan Atomic Energy Research Institute (JAERI) and the U.S. Department of Energy (US/DOE) concerning matters of nuclear research and development, a Specific Memorandum of Agreement (SMA) entitled ''A Collaborative Programme of Development of a Prototype Communication Link to Share Atmospheric Dispersion and Dose Assessment Modelling Products'' was signed. This SMA formalized an informal collaborative exchange between the DOE's Lawrence Livermore National Laboratory (LLNL) Atmospheric Release Advisory Capability (ARAC) center and the Japan Atomic Energy Research Institute (JAERI) Worldwide System for Prediction of Environmental Emergency Dose Information (WSPEEDI). The intended objective of this agreement was to explore various modes of information exchange, beyond facsimile transmission, which could provide for the quick exchange of information between two major nuclear emergency dose assessment and prediction national centers to provide consistency checks and data exchange before public release of their calculations. The extreme sensitivity of the general public to any nuclear accident information has been a strong motivation to seek peer preview prior to public release. Other intended objectives of this work are the development of an affordable/accessible system for distribution of prediction results to other countries having no prediction capabilities and utilization of the link for collaboration studies. To fulfill the objectives of this project JAERI and LLNL scientists determined to assess the evolving Internet and rapidly emerging communications application software. Our timing was a little early in 1997-1998 but nonetheless a few candidate software packages were found, evaluated and a selection was made for initial test and evaluation. Subsequently several new candidate software packages have arrived, albeit with limitations. This report outlines the ARAC and JAERI emergency response

  8. A rapid-distortion-theory turbulence model for developed unsteady wall-bounded flow

    NASA Technical Reports Server (NTRS)

    Brereton, G. J.; Mankbadi, R. R.

    1993-01-01

    A new approach to turbulence modeling in unsteady developed flows has recently been introduced, based on results of rapid distortion theory. The approach involves closing the k-epsilon equations for the organized unsteady component of the flow by modeling local unsteadiness as a rapid distortion of the local structure of the parent turbulent flow, in terms of an effective strain parameter alpha(sub eff). In this paper, the phase-conditioned equations of motion are developed to accommodate a new unsteady dissipation model and local effects of the slow-relaxation time scale of the parent flow. The model equations are tested against measurements of the response of a fully-developed turbulent pipe flow to the superposition of sinusoidal streamwise oscillation. Good agreement is found between measurements and predictions over a wide range of frequencies of unsteadiness, indicating that this approach may be particularly well suited to modeling of unsteady turbulent flows which are perturbations about a well characterized mean.

  9. An Active Area Model of Rapid Infiltration Response at Substantial Depth in the Unsaturated Zone

    NASA Astrophysics Data System (ADS)

    Mitchell, L.; Nimmo, J. R.

    2011-12-01

    In a porous medium subject to preferential flow, response to surface water infiltration can occur rapidly even at substantial depth in the unsaturated zone. In a ponding experiment at the Idaho National Laboratory (INL) the profile of undisturbed natural soil, seasonally dry at the start, was observed to approach field saturation throughout a 2 meter depth within 6 hours (Nimmo and Perkins, 2007). Traditional use of Richards' equation would require an unrealistically large unsaturated hydraulic conductivity of 40 m/day to capture the observed non-classic wetting behavior. Here we present a model for rapid flow using an active area concept similar to the active fracture model (Liu and others, 1998, WRR 34:2633-2646). The active area concept is incorporated within the preferential flow domain (which allows rapid downward movement) of a dual-domain model that also contains a diffuse-flow domain in which flow can be described by Richards' equation. Development of the active area model is motivated by observation of rapid wetting at substantial depth, as well as a phenomenon in which deep flow is observed before shallow flow. In this model water movement in the preferential domain can be physically conceptualized as laminar flow in free-surface films of constant average thickness. For a given medium, the preferential domain is characterized by an effective areal density (area per unit bulk volume) that describes the free-surface film capacity of the domain as a function of depth. The active area is defined as a portion of the effective areal density that dictates the depth and temporal distribution of domain-exchange and new infiltration within the preferential domain. With the addition of the active area concept, the model is capable of simulating non-diffusive vertical transport patterns. Advantages of the model include simulating rapid response for a variety of infiltration types, including ponding and rain events, as well as modeling relatively rapid aquifer

  10. Virtual acoustic prototyping

    NASA Astrophysics Data System (ADS)

    Johnson, Marty

    2003-10-01

    In this paper the re-creation of 3-D sound fields so the full psycho-acoustic impact of sound sources can be assessed before the manufacture of a product or environment is examined. Using head related transfer functions (HRTFs) coupled with a head tracked set of headphones the sound field at the left and right ears of a listener can be re-created for a set of sound sources. However, the HRTFs require that sources have a defined location and this is not the typical output from numerical codes which describe the sound field as a set of distributed modes. In this paper a method of creating a set of equivalent sources is described such that the standard set of HRTFs can be applied in real time. A structural-acoustic model of a cylinder driving an enclosed acoustic field will be used as an example. It will be shown that equivalent sources can be used to recreate all of the reverberation of the enclosed space. An efficient singular value decomposition technique allows the large number of sources required to be simulated in real time. An introduction to the requirements necessary for 3-D virtual prototyping using high frequency Statistical Energy Analysis models will be presented. [Work supported by AuSim and NASA.

  11. Interactive Rapid Dose Assessment Model (IRDAM): reactor-accident assessment methods. Vol. 2

    SciTech Connect

    Poeton, R.W.; Moeller, M.P.; Laughlin, G.J.; Desrosiers, A.E.

    1983-05-01

    As part of the continuing emphasis on emergency preparedness, the US Nuclear Regulatory Commission (NRC) sponsored the development of a rapid dose assessment system by Pacific Northwest Laboratory (PNL). This system, the Interactive Rapid Dose Assessment Model (IRDAM) is a micro-computer based program for rapidly assessing the radiological impact of accidents at nuclear power plants. This document describes the technical bases for IRDAM including methods, models and assumptions used in calculations. IRDAM calculates whole body (5-cm depth) and infant thyroid doses at six fixed downwind distances between 500 and 20,000 meters. Radionuclides considered primarily consist of noble gases and radioiodines. In order to provide a rapid assessment capability consistent with the capacity of the Osborne-1 computer, certain simplifying approximations and assumptions are made. These are described, along with default values (assumptions used in the absence of specific input) in the text of this document. Two companion volumes to this one provide additional information on IRDAM. The user's Guide (NUREG/CR-3012, Volume 1) describes the setup and operation of equipment necessary to run IRDAM. Scenarios for Comparing Dose Assessment Models (NUREG/CR-3012, Volume 3) provides the results of calculations made by IRDAM and other models for specific accident scenarios.

  12. A model for rapid synthesis of large volume InP melts

    SciTech Connect

    Iseler, G.; Anselmo, A.P.; Bliss, D.F.; Bryant, G.

    1996-12-31

    The rapid synthesis of InP is routinely carried out in the laboratory by subliming phosphorus into encapsulated liquid In. The authors have constructed the first model of this process by considering the equilibrium vapor pressure over red phosphorus as its temperature increases, and that over In{sub 1{minus}x}P{sub x} as its phosphorus content increases.

  13. Rapid E-learning Development Strategies and a Multimedia Project Design Model

    ERIC Educational Resources Information Center

    Sözcü, Ömer Faruk; Ipek, Ismail

    2014-01-01

    The purpose of the study is to discuss e-learning design strategies which can be used for multimedia projects as a design model. Recent advances in instructional technologies have been found to be very important in the design of training courses by using rapid instructional design (ID) approaches. The approaches were developed to use in training…

  14. PRMS Data Warehousing Prototype

    NASA Technical Reports Server (NTRS)

    Guruvadoo, Eranna K.

    2002-01-01

    Project and Resource Management System (PRMS) is a web-based, mid-level management tool developed at KSC to provide a unified enterprise framework for Project and Mission management. The addition of a data warehouse as a strategic component to the PRMS is investigated through the analysis, design and implementation processes of a data warehouse prototype. As a proof of concept, a demonstration of the prototype with its OLAP's technology for multidimensional data analysis is made. The results of the data analysis and the design constraints are discussed. The prototype can be used to motivate interest and support for an operational data warehouse.

  15. PRMS Data Warehousing Prototype

    NASA Technical Reports Server (NTRS)

    Guruvadoo, Eranna K.

    2001-01-01

    Project and Resource Management System (PRMS) is a web-based, mid-level management tool developed at KSC to provide a unified enterprise framework for Project and Mission management. The addition of a data warehouse as a strategic component to the PRMS is investigated through the analysis design and implementation processes of a data warehouse prototype. As a proof of concept, a demonstration of the prototype with its OLAP's technology for multidimensional data analysis is made. The results of the data analysis and the design constraints are discussed. The prototype can be used to motivate interest and support for an operational data warehouse.

  16. Evaluation of a prototype infrasound system

    SciTech Connect

    Whitaker, R.; Sandoval, T.; Breding, D.; Kromer, D.

    1997-08-01

    Under Department of Energy sponsorship, Sandia National Laboratories and Los Alamos National Laboratory cooperated to develop a prototype infrasonic array, with associated documentation, that could be used as part of the International Monitoring System. The United States Government or foreign countries could procure commercially available systems based on this prototype to fulfill their Comprehensive Test Ban Treaty (CTBT) obligations. The prototype is a four-element array in a triangular layout as recommended in CD/NTB/WP.224 with an element at each corner and one in the center. The prototype test configuration utilize an array spacing of 1 km. The prototype infrasound system has the following objectives: (1) Provide a prototype that reliably acquires and transmits near real-time infrasonic data to facilitate the rapid location and identification of atmospheric events. (2) Provide documentation that could be used by the United States and foreign countries to procure infrasound systems commercially to fulfill their CTBT responsibilities. Infrasonic monitoring is an effective, low cost technology for detecting atmospheric explosions. The low frequency components of explosion signals propagate to long ranges (few thousand kilometers) where they can be detected with an array of sensors. Los Alamos National Laboratory`s expertise in infrasound systems and phenomenology when combined with Sandia`s expertise in providing verification quality system for treaty monitoring make an excellent team to provide the prototype infrasound sensor system. By September 1997, the prototype infrasound system will have been procured, integrated, evaluated and documented. Final documentation will include a system requirements document, an evaluation report and a hardware design document. The hardware design document will describe the various hardware components used in the infrasound prototype and their interrelationships.

  17. Viscous effects in rapidly rotating stars with application to white-dwarf models. I, II.

    NASA Technical Reports Server (NTRS)

    Durisen, R. H.

    1973-01-01

    A general approximate numerical technique is proposed for constructing evolutionary sequences of rapidly rotating axisymmetric barytropic equilibrium configurations, with allowance for angular momentum transfer by a nonconstant isotropic viscosity. The principal physical assumption involved is the constancy of the angular momentum per unit mass on cylinders about the axis of rotation. Rapidly rotating nonmagnetic white-dwarf models with a zero-temperature degenerate-electron equation of state are considered as a particular application. The viscosity used in the analysis is that of the degenerate electrons.

  18. Resource Allocation Modelling in Vocational Rehabilitation: A Prototype Developed with the Michigan and Rhode Island VR Agencies.

    ERIC Educational Resources Information Center

    Leff, H. Stephen; Turner, Ralph R.

    This report focuses on the use of linear programming models to address the issues of how vocational rehabilitation (VR) resources should be allocated in order to maximize program efficiency within given resource constraints. A general introduction to linear programming models is first presented that describes the major types of models available,…

  19. Ceramic subsurface marker prototypes

    SciTech Connect

    Lukens, C.E.

    1985-05-02

    The client submitted 5 sets of porcelain and stoneware subsurface (radioactive site) marker prototypes (31 markers each set). The following were determined: compressive strength, thermal shock resistance, thermal crazing resistance, alkali resistance, color retention, and chemical resistance.

  20. Colleyville Eco House Prototype

    SciTech Connect

    2009-06-16

    This case study describes the construction of a prototype high-performance home that includes a high efficiency ground source heat pump, unvented roof with low density spray foam insulation, and supplemental dehumidification.