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Sample records for freeform fabrication ebf3

  1. Metallurgical Mechanisms Controlling Mechanical Properties of Aluminum Alloy 2219 Produced By Electron Beam Freeform Fabrication

    Science.gov (United States)

    Domack, Marcia S.; Taminger, Karen M. B.; Begley, Matthew

    2006-01-01

    The electron beam freeform fabrication (EBF3) layer-additive manufacturing process has been developed to directly fabricate complex geometry components. EBF3 introduces metal wire into a molten pool created on the surface of a substrate by a focused electron beam. Part geometry is achieved by translating the substrate with respect to the beam to build the part one layer at a time. Tensile properties have been demonstrated for electron beam deposited aluminum and titanium alloys that are comparable to wrought products, although the microstructures of the deposits exhibit features more typical of cast material. Understanding the metallurgical mechanisms controlling mechanical properties is essential to maximizing application of the EBF3 process. In the current study, mechanical properties and resulting microstructures were examined for aluminum alloy 2219 fabricated over a range of EBF3 process variables. Material performance was evaluated based on tensile properties and results were compared with properties of Al 2219 wrought products. Unique microstructures were observed within the deposited layers and at interlayer boundaries, which varied within the deposit height due to microstructural evolution associated with the complex thermal history experienced during subsequent layer deposition. Microstructures exhibited irregularly shaped grains, typically with interior dendritic structures, which were described based on overall grain size, morphology, distribution, and dendrite spacing, and were correlated with deposition parameters. Fracture features were compared with microstructural elements to define fracture paths and aid in definition of basic processing-microstructure-property correlations.

  2. Tensile Properties and Microstructure of Inconel 718 Fabricated with Electron Beam Freeform Fabrication (EBF(sup 3))

    Science.gov (United States)

    Bird, R. Keith; Hibberd, Joshua

    2009-01-01

    Electron beam freeform fabrication (EBF3) direct metal deposition processing was used to fabricate two Inconel 718 single-bead-width wall builds and one multiple-bead-width block build. Specimens were machined to evaluate microstructure and room temperature tensile properties. The tensile strength and yield strength of the as-deposited material from the wall and block builds were greater than those for conventional Inconel 718 castings but were less than those for conventional cold-rolled sheet. Ductility levels for the EBF3 material were similar to those for conventionally-processed sheet and castings. An unexpected result was that the modulus of the EBF3-deposited Inconel 718 was significantly lower than that of the conventional material. This low modulus may be associated with a preferred crystallographic orientation resultant from the deposition and rapid solidification process. A heat treatment with a high solution treatment temperature resulted in a recrystallized microstructure and an increased modulus. However, the modulus was not increased to the level that is expected for Inconel 718.

  3. Solid freeform fabrication of biomaterials

    Science.gov (United States)

    Chu, Tien-Min Gabriel

    1999-12-01

    The biological performance of porous Hydroxyapatite (HA) is closely related to the pore architecture in the implants. The study on the effect of architecture to the biological performance of porous HA requires new manufacturing methods that can fabricate implants with controlled pores channels. In this thesis, four highly loaded HA and alumina suspensions were formulated and three different processes involving Solid Freeform Fabrication (SFF) were developed. An aqueous HA suspension in acrylamides was first formulated and the UV-curing properties were evaluated. With a medical grade HA powder, two non-aqueous HA suspensions were formulated: a 40 vol.% HA suspension in Hexanediol Diacrylate (HDDA) and a 40 vol.% HA suspension in 1:1 mix of Propoxylated Neopentyl Glycol Diacrylate (PNPGDA) and Isobomyl Acrylate (EBA). A 50 vol.% Alumina suspension in PNPGDA/IBA was also formulated. The effect of dispersant to the viscosity of the suspensions was characterized. In the Stereolithography (SL) method, the curing parameters of HA/HDDA and HA/PNPGDA/IBA were determined. Prototype HA implants with 1,700 mum internal channels were built directly on an SL Apparatus (SLA). The designed internal channel patterns were preserved after sintering. In the Ink-jet printing method, the high temperature flow behaviors of the suspensions were characterized. The effects of solids loading to the viscosity of the suspensions were modeled with Krieger-Dougherty equation. Leveling theory developed in paint industry was employed to analyze the self-leveling capability of the suspensions. In the indirect SL method, the thermal curing behavior of HA and alumina suspensions were characterized. The total cure time was measured and the curing kinetics was modeled. Negative molds for the implants were designed and built on SLA with epoxy resin. HA/PNPGDA/IBA was cast into the mold and cured in an oven. The binders and the epoxy mold were pyrolyzed and the green bodies sintered. Internal channels

  4. Solid freeform fabrication of biological materials

    Science.gov (United States)

    Wang, Jiwen

    This thesis investigates solid freeform fabrication of biological materials for dental restoration and orthopedic implant applications. The basic approach in this study for solid freeform fabrication of biological materials is micro-extrusion of single or multiple slurries for 3D components and inkjet color printing of multiple suspensions for functionally graded materials (FGMs). Common issues associated with micro-extrusion and inkjet color printing are investigated. These common issues include (i) formulation of stable slurries with a pseudoplastic property, (ii) cross-sectional geometry of the extrudate as a function of the extrusion parameters, (iii) fabrication path optimization for extrusion process, (iv) extrusion optimization for multi-layer components, (v) composition control in functionally graded materials, and (vi) sintering optimization to convert the freeform fabricated powder compact to a dense body for biological applications. The present study clearly shows that the rheological and extrusion behavior of dental porcelain slurries depend strongly on the pH value of the slurry and extrusion conditions. A slurry with pseudoplastic properties is a basic requirement for obtaining extruded lines with rectangular cross-sections. The cross-sectional geometry of the extrudate is also strongly affected by extrusion parameters including the extrusion nozzle height, nozzle moving speed, extrusion rate, and critical nozzle height. Proper combinations of these extrusion parameters are necessary in order to obtain single line extrudates with near rectangular cross-sections and 3D objects with dimensional accuracy, uniform wall thickness, good wall uprightness, and no wall slumping. Based on these understandings, single-wall, multi-wall, and solid teeth have been fabricated via micro-extrusion of the dental slurry directly from a CAD digital model in 30 min. Inkjet color printing using stable Al2O3 and ZrO 2 aqueous suspensions has been developed to fabricate

  5. Propulsion Design With Freeform Fabrication (PDFF)

    Science.gov (United States)

    Barnes, Daudi; McKinnon, James; Priem, Richard

    2010-01-01

    The nation is challenged to decrease the cost and schedule to develop new space transportation propulsion systems for commercial, scientific, and military purposes. Better design criteria and manufacturing techniques for small thrusters are needed to meet current applications in missile defense, space, and satellite propulsion. The requirements of these systems present size, performance, and environmental demands on these thrusters that have posed significant challenges to the current designers and manufacturers. Designers are limited by manufacturing processes, which are complex, costly, and time consuming, and ultimately limited in their capabilities. The PDFF innovation vastly extends the design opportunities of rocket engine components and systems by making use of the unique manufacturing freedom of solid freeform rapid prototype manufacturing technology combined with the benefits of ceramic materials. The unique features of PDFF are developing and implementing a design methodology that uses solid freeform fabrication (SFF) techniques to make propulsion components with significantly improved performance, thermal management, power density, and stability, while reducing development and production costs. PDFF extends the design process envelope beyond conventional constraints by leveraging the key feature of the SFF technique with the capability to form objects with nearly any geometric complexity without the need for elaborate machine setup. The marriage of SFF technology to propulsion components allows an evolution of design practice to harmonize material properties with functional design efficiency. Reduced density of materials when coupled with the capability to honeycomb structure used in the injector will have significant impact on overall mass reduction. Typical thrusters in use for attitude control have 60 90 percent of its mass in the valve and injector, which is typically made from titanium. The combination of material and structure envisioned for use in

  6. Fabrication and correction of freeform surface based on Zernike polynomials by slow tool servo

    Science.gov (United States)

    Cheng, Yuan-Chieh; Hsu, Ming-Ying; Peng, Wei-Jei; Hsu, Wei-Yao

    2017-10-01

    Recently, freeform surface widely using to the optical system; because it is have advance of optical image and freedom available to improve the optical performance. For freeform optical fabrication by integrating freeform optical design, precision freeform manufacture, metrology freeform optics and freeform compensate method, to modify the form deviation of surface, due to production process of freeform lens ,compared and provides more flexibilities and better performance. This paper focuses on the fabrication and correction of the free-form surface. In this study, optical freeform surface using multi-axis ultra-precision manufacturing could be upgrading the quality of freeform. It is a machine equipped with a positioning C-axis and has the CXZ machining function which is also called slow tool servo (STS) function. The freeform compensate method of Zernike polynomials results successfully verified; it is correction the form deviation of freeform surface. Finally, the freeform surface are measured experimentally by Ultrahigh Accurate 3D Profilometer (UA3P), compensate the freeform form error with Zernike polynomial fitting to improve the form accuracy of freeform.

  7. Friction Freeform Fabrication of Superalloy Inconel 718: Prospects and Problems

    Science.gov (United States)

    Dilip, J. J. S.; Janaki Ram, G. D.

    2014-01-01

    Friction Freeform Fabrication is a new solid-state additive manufacturing process. The present investigation reports a detailed study on the prospects of this process for additive part fabrication in superalloy Inconel 718. Using a rotary friction welding machine and employing alloy 718 consumable rods in solution treated condition, cylindrical-shaped multi-layer friction deposits (10 mm diameter) were successfully produced. In the as-deposited condition, the deposits showed very fine grain size with no grain boundary δ phase. The deposits responded well to direct aging and showed satisfactory room-temperature tensile properties. However, their stress rupture performance was unsatisfactory because of their layered microstructure with very fine grain size and no grain boundary δ phase. The problem was overcome by heat treating the deposits first at 1353 K (1080 °C) (for increasing the grain size) and then at 1223 K (950 °C) (for precipitating the δ phase). Overall, the current study shows that Friction Freeform Fabrication is a very useful process for additive part fabrication in alloy 718.

  8. Electron Beam Freeform Fabrication of Titanium Alloy Gradient Structures

    Science.gov (United States)

    Brice, Craig A.; Newman, John A.; Bird, Richard Keith; Shenoy, Ravi N.; Baughman, James M.; Gupta, Vipul K.

    2014-01-01

    Historically, the structural optimization of aerospace components has been done through geometric methods. A monolithic material is chosen based on the best compromise between the competing design limiting criteria. Then the structure is geometrically optimized to give the best overall performance using the single material chosen. Functionally graded materials offer the potential to further improve structural efficiency by allowing the material composition and/or microstructural features to spatially vary within a single structure. Thus, local properties could be tailored to the local design limiting criteria. Additive manufacturing techniques enable the fabrication of such graded materials and structures. This paper presents the results of a graded material study using two titanium alloys processed using electron beam freeform fabrication, an additive manufacturing process. The results show that the two alloys uniformly mix at various ratios and the resultant static tensile properties of the mixed alloys behave according to rule-of-mixtures. Additionally, the crack growth behavior across an abrupt change from one alloy to the other shows no discontinuity and the crack smoothly transitions from one crack growth regime into another.

  9. Solid freeform fabrication of piezoelectric actuators by a micro-casting method

    NARCIS (Netherlands)

    Bos, B.; Gorter, H.; Dortmans, L.J.M.G.

    2004-01-01

    In recent years, there has been much interest in the manufacturing of piezoceramic actuators by Solid Freeform Fabrication (SFF) methods, following developments in polymer and metal shaping. With these methods, actuator shapes can be realized that are impossible or very difficult to obtain by

  10. Solid Freeform and Additive Fabrication - 2000: Symposium Held in San Francisco, California on April 23-26, 2000

    National Research Council Canada - National Science Library

    Danforth, Stephen

    2000-01-01

    Solid freeform (SFF) and additive fabrication processes are defining a revolutionary new approach for materials manufacturing that is leading to a capability for producing parts quicker, cheaper and with more...

  11. Design and Fabrication of a Free-Form Reciprocal Roof

    DEFF Research Database (Denmark)

    Parigi, Dario

    2015-01-01

    The paper presents the framework and the design and construction process of a freeform reciprocal pavilion realized during a one-week long workshop with the students of the 1st semester of the Master of Science in Architecture and Design, fall 2014, at Aalborg University. The workshop didactic...... of relations between design parameters and a wide array of measurable performances. Due to the reciprocal structures geometric complexity, the shape generation process is handled using the Reciprocalizer, a software tool developed by the author that embeds in a computational environment the constructional...... logic of reciprocal structures. It enables to engage in real time in iterative processes that allows unfolding the geometric complexity and turn it into a source of inspiration for expanding the design space and triggering the development of unique, adapted and integrated design solutions. Reciprocal...

  12. Grain Refinement of Freeform Fabricated Ti-6Al-4V Alloy Using Beam/Arc Modulation

    Science.gov (United States)

    Mitzner, Scott; Liu, Stephen; Domack, Marcia S.; Hafley, Robert A.

    2012-01-01

    Grain refinement can significantly improve the mechanical properties of freeform-fabricated Ti-6Al-4V alloy, promoting increased strength and enhanced isotropy compared with coarser grained material. Large beta-grains can lead to a segregated microstructure, in regard to both alpha-phase morphology and alpha-lath orientation. Beam modulation, which has been used in conventional fusion welding to promote grain refinement, is explored in this study for use in additive manufacturing processes including electron beam freeform fabrication (EBF(sup 3)) and gas-tungsten arc (GTA) deposition to alter solidification behavior and produce a refined microstructure. The dynamic molten pool size induced by beam modulation causes rapid heat flow variance and results in a more competitive grain growth environment, reducing grain size. Consequently, improved isotropy and strength can be achieved with relatively small adjustments to deposition parameters.

  13. Advances in Design and Fabrication of Free-Form Reciprocal Structures

    DEFF Research Database (Denmark)

    Parigi, Dario

    2016-01-01

    The paper presents the advances in design and fabrication of free-form Reciprocal Structures, and their application a during a one-week long workshop with the students of the 1st semester of the Master of Science in Architecture and Design, fall 2015, at Aalborg University. Two new factors were...... introduced and tested: a new version of the software Reciprocalizer, and an evolution of the Reciprocalizer Robot. The workshop didactic framework Performance Aided/Assisted Design (PAD) is presented....

  14. Fabrication of high precision metallic freeform mirrors with magnetorheological finishing (MRF)

    Science.gov (United States)

    Beier, Matthias; Scheiding, Sebastian; Gebhardt, Andreas; Loose, Roman; Risse, Stefan; Eberhardt, Ramona; Tünnermann, Andreas

    2013-09-01

    The fabrication of complex shaped metal mirrors for optical imaging is a classical application area of diamond machining techniques. Aspherical and freeform shaped optical components up to several 100 mm in diameter can be manufactured with high precision in an acceptable amount of time. However, applications are naturally limited to the infrared spectral region due to scatter losses for shorter wavelengths as a result of the remaining periodic diamond turning structure. Achieving diffraction limited performance in the visible spectrum demands for the application of additional polishing steps. Magnetorheological Finishing (MRF) is a powerful tool to improve figure and finish of complex shaped optics at the same time in a single processing step. The application of MRF as a figuring tool for precise metal mirrors is a nontrivial task since the technology was primarily developed for figuring and finishing a variety of other optical materials, such as glasses or glass ceramics. In the presented work, MRF is used as a figuring tool for diamond turned aluminum lightweight mirrors with electroless nickel plating. It is applied as a direct follow-up process after diamond machining of the mirrors. A high precision measurement setup, composed of an interferometer and an advanced Computer Generated Hologram with additional alignment features, allows for precise metrology of the freeform shaped optics in short measuring cycles. Shape deviations less than 150 nm PV / 20 nm rms are achieved reliably for freeform mirrors with apertures of more than 300 mm. Characterization of removable and induced spatial frequencies is carried out by investigating the Power Spectral Density.

  15. Stem cell niche-specific Ebf3 maintains the bone marrow cavity.

    Science.gov (United States)

    Seike, Masanari; Omatsu, Yoshiki; Watanabe, Hitomi; Kondoh, Gen; Nagasawa, Takashi

    2018-03-01

    Bone marrow is the tissue filling the space between bone surfaces. Hematopoietic stem cells (HSCs) are maintained by special microenvironments known as niches within bone marrow cavities. Mesenchymal cells, termed CXC chemokine ligand 12 (CXCL12)-abundant reticular (CAR) cells or leptin receptor-positive (LepR + ) cells, are a major cellular component of HSC niches that gives rise to osteoblasts in bone marrow. However, it remains unclear how osteogenesis is prevented in most CAR/LepR + cells to maintain HSC niches and marrow cavities. Here, using lineage tracing, we found that the transcription factor early B-cell factor 3 (Ebf3) is preferentially expressed in CAR/LepR + cells and that Ebf3-expressing cells are self-renewing mesenchymal stem cells in adult marrow. When Ebf3 is deleted in CAR/LepR + cells, HSC niche function is severely impaired, and bone marrow is osteosclerotic with increased bone in aged mice. In mice lacking Ebf1 and Ebf3 , CAR/LepR + cells exhibiting a normal morphology are abundantly present, but their niche function is markedly impaired with depleted HSCs in infant marrow. Subsequently, the mutants become progressively more osteosclerotic, leading to the complete occlusion of marrow cavities in early adulthood. CAR/LepR + cells differentiate into bone-producing cells with reduced HSC niche factor expression in the absence of Ebf1/Ebf3 Thus, HSC cellular niches express Ebf3 that is required to create HSC niches, to inhibit their osteoblast differentiation, and to maintain spaces for HSCs. © 2018 Seike et al.; Published by Cold Spring Harbor Laboratory Press.

  16. New paradigms in internal architecture design and freeform fabrication of tissue engineering porous scaffolds.

    Science.gov (United States)

    Yoo, Dongjin

    2012-07-01

    Advanced additive manufacture (AM) techniques are now being developed to fabricate scaffolds with controlled internal pore architectures in the field of tissue engineering. In general, these techniques use a hybrid method which combines computer-aided design (CAD) with computer-aided manufacturing (CAM) tools to design and fabricate complicated three-dimensional (3D) scaffold models. The mathematical descriptions of micro-architectures along with the macro-structures of the 3D scaffold models are limited by current CAD technologies as well as by the difficulty of transferring the designed digital models to standard formats for fabrication. To overcome these difficulties, we have developed an efficient internal pore architecture design system based on triply periodic minimal surface (TPMS) unit cell libraries and associated computational methods to assemble TPMS unit cells into an entire scaffold model. In addition, we have developed a process planning technique based on TPMS internal architecture pattern of unit cells to generate tool paths for freeform fabrication of tissue engineering porous scaffolds. Copyright © 2012 IPEM. Published by Elsevier Ltd. All rights reserved.

  17. Closed-Loop Process Control for Electron Beam Freeform Fabrication and Deposition Processes

    Science.gov (United States)

    Taminger, Karen M. (Inventor); Hafley, Robert A. (Inventor); Martin, Richard E. (Inventor); Hofmeister, William H. (Inventor)

    2013-01-01

    A closed-loop control method for an electron beam freeform fabrication (EBF(sup 3)) process includes detecting a feature of interest during the process using a sensor(s), continuously evaluating the feature of interest to determine, in real time, a change occurring therein, and automatically modifying control parameters to control the EBF(sup 3) process. An apparatus provides closed-loop control method of the process, and includes an electron gun for generating an electron beam, a wire feeder for feeding a wire toward a substrate, wherein the wire is melted and progressively deposited in layers onto the substrate, a sensor(s), and a host machine. The sensor(s) measure the feature of interest during the process, and the host machine continuously evaluates the feature of interest to determine, in real time, a change occurring therein. The host machine automatically modifies control parameters to the EBF(sup 3) apparatus to control the EBF(sup 3) process in a closed-loop manner.

  18. Development of a hybrid scaffold with synthetic biomaterials and hydrogel using solid freeform fabrication technology

    International Nuclear Information System (INIS)

    Shim, Jin-Hyung; Park, Min; Park, Jaesung; Cho, Dong-Woo; Kim, Jong Young

    2011-01-01

    Natural biomaterials such as hyaluronic acid, gelatin and collagen provide excellent environments for tissue regeneration. Furthermore, gel-state natural biomaterials are advantageous for encapsulating cells and growth factors. In cell printing technology, hydrogel which contains cells was printed directly to form three-dimensional (3D) structures for tissue or organ regeneration using various types of printers. However, maintaining the 3D shape of the printed structure, which is made only of the hydrogel, is very difficult due to its weak mechanical properties. In this study, we developed a hybrid scaffold consisting of synthetic biomaterials and natural hydrogel using a multi-head deposition system, which is useful in solid freeform fabrication technology. The hydrogel was intentionally infused into the space between the lines of a synthetic biomaterial-based scaffold. The cellular efficacy of the hybrid scaffold was validated using rat primary hepatocytes and a mouse pre-osteoblast MC3T3-E1 cell line. In addition, the collagen hydrogel, which encapsulates cells, was dispensed and the viability of the cells observed. We demonstrated superior effects of the hybrid scaffold on cell adhesion and proliferation and showed the high viability of dispensed cells.

  19. Solid freeform-fabricated scaffolds designed to carry multicellular mesenchymal stem cell spheroids for cartilage regeneration

    Directory of Open Access Journals (Sweden)

    G-S Huang

    2013-10-01

    Full Text Available Three-dimensional (3D cellular spheroids have recently emerged as a new trend to replace suspended single cells in modern cell-based therapies because of their greater regeneration capacities in vitro. They may lose the 3D structure during a change of microenvironment, which poses challenges to their translation in vivo. Besides, the conventional microporous scaffolds may have difficulty in accommodating these relatively large spheroids. Here we revealed a novel design of microenvironment for delivering and sustaining the 3D spheroids. Biodegradable scaffolds with macroporosity to accommodate mesenchymal stem cell (MSC spheroids were made by solid freeform fabrication (SFF from the solution of poly(D,L-lactide-co-glycolide. Their internal surface was modified with chitosan following air plasma treatment in order to preserve the morphology of the spheroids. It was demonstrated that human MSC spheroids loaded in SFF scaffolds produced a significantly larger amount of cartilage-associated extracellular matrix in vitro and in NOD/SCID mice compared to single cells in the same scaffolds. Implantation of MSC spheroid-loaded scaffolds into the chondral defects of rabbit knees showed superior cartilage regeneration. This study establishes new perspectives in designing the spheroid-sustaining microenvironment within a tissue engineering scaffold for in vivo applications.

  20. Interactive Modeling of Architectural Freeform Structures - Combining Geometry with Fabrication and Statics

    KAUST Repository

    Jiang, Caigui

    2014-09-01

    This paper builds on recent progress in computing with geometric constraints, which is particularly relevant to architectural geometry. Not only do various kinds of meshes with additional properties (like planar faces, or with equilibrium forces in their edges) become available for interactive geometric modeling, but so do other arrangements of geometric primitives, like honeycomb structures. The latter constitute an important class of geometric objects, with relations to “Lobel” meshes, and to freeform polyhedral patterns. Such patterns are particularly interesting and pose research problems which go beyond what is known for meshes, e.g. with regard to their computing, their flexibility, and the assessment of their fairness.

  1. Paneling architectural freeform surfaces

    KAUST Repository

    Eigensatz, Michael; Kilian, Martin; Schiftner, Alexander; Mitra, Niloy J.; Pottmann, Helmut; Pauly, Mark

    2010-01-01

    The emergence of large-scale freeform shapes in architecture poses big challenges to the fabrication of such structures. A key problem is the approximation of the design surface by a union of patches, socalled panels, that can be manufactured with a

  2. Characterization of New PEEK/HA Composites with 3D HA Network Fabricated by Extrusion Freeforming

    Directory of Open Access Journals (Sweden)

    Mohammad Vaezi

    2016-05-01

    Full Text Available Addition of bioactive materials such as calcium phosphates or Bioglass, and incorporation of porosity into polyetheretherketone (PEEK has been identified as an effective approach to improve bone-implant interfaces and osseointegration of PEEK-based devices. In this paper, a novel production technique based on the extrusion freeforming method is proposed that yields a bioactive PEEK/hydroxyapatite (PEEK/HA composite with a unique configuration in which the bioactive phase (i.e., HA distribution is computer-controlled within a PEEK matrix. The 100% interconnectivity of the HA network in the biocomposite confers an advantage over alternative forms of other microstructural configurations. Moreover, the technique can be employed to produce porous PEEK structures with controlled pore size and distribution, facilitating greater cellular infiltration and biological integration of PEEK composites within patient tissue. The results of unconfined, uniaxial compressive tests on these new PEEK/HA biocomposites with 40% HA under both static and cyclic mode were promising, showing the composites possess yield and compressive strength within the range of human cortical bone suitable for load bearing applications. In addition, preliminary evidence supporting initial biological safety of the new technique developed is demonstrated in this paper. Sufficient cell attachment, sustained viability in contact with the sample over a seven-day period, evidence of cell bridging and matrix deposition all confirmed excellent biocompatibility.

  3. Characterization of New PEEK/HA Composites with 3D HA Network Fabricated by Extrusion Freeforming.

    Science.gov (United States)

    Vaezi, Mohammad; Black, Cameron; Gibbs, David M R; Oreffo, Richard O C; Brady, Mark; Moshrefi-Torbati, Mohamed; Yang, Shoufeng

    2016-05-26

    Addition of bioactive materials such as calcium phosphates or Bioglass, and incorporation of porosity into polyetheretherketone (PEEK) has been identified as an effective approach to improve bone-implant interfaces and osseointegration of PEEK-based devices. In this paper, a novel production technique based on the extrusion freeforming method is proposed that yields a bioactive PEEK/hydroxyapatite (PEEK/HA) composite with a unique configuration in which the bioactive phase (i.e., HA) distribution is computer-controlled within a PEEK matrix. The 100% interconnectivity of the HA network in the biocomposite confers an advantage over alternative forms of other microstructural configurations. Moreover, the technique can be employed to produce porous PEEK structures with controlled pore size and distribution, facilitating greater cellular infiltration and biological integration of PEEK composites within patient tissue. The results of unconfined, uniaxial compressive tests on these new PEEK/HA biocomposites with 40% HA under both static and cyclic mode were promising, showing the composites possess yield and compressive strength within the range of human cortical bone suitable for load bearing applications. In addition, preliminary evidence supporting initial biological safety of the new technique developed is demonstrated in this paper. Sufficient cell attachment, sustained viability in contact with the sample over a seven-day period, evidence of cell bridging and matrix deposition all confirmed excellent biocompatibility.

  4. Processing parameters investigation for the fabrication of self-supported and freeform polymeric microstructures using ultraviolet-assisted three-dimensional printing

    International Nuclear Information System (INIS)

    Farahani, R D; Lebel, L L; Therriault, D

    2014-01-01

    Ultraviolet-assisted three-dimensional (3D) printing (UV-3DP) was used to manufacture photopolymer-based microdevices with 3D self-supported and freeform features. The UV-3DP technique consists of the robotized deposition of extruded filaments, which are rapidly photopolymerized under UV illumination during the deposition process. This paper systematically studies the processing parameters of the UV-3DP technique using two photo-curable polymers and their associated nanocomposite materials. The main processing parameters including materials' rheological behavior, deposition speed and extrusion pressure, and UV illumination conditions were thoroughly investigated. A processing map was then defined in order to help choosing the proper parameters for the UV-3DP of microstructures with various geometries. Compared to self-supported features, the accurate fabrication of 3D freeform structures was found to take place in a narrower processing region since a higher rigidity of the extruded filament was required for structural stability. Finally, various 3D self-supported and freeform microstructures with high potential in micro electromechanical systems, micro-systems and organic electronics were fabricated to show the capability of the technique. (paper)

  5. Free-form processing of near-net shapes using directed light fabrication

    International Nuclear Information System (INIS)

    Thoma, D.J.; Lewis, G.K.; Milewski, J.O.; Nemec, R.B.

    1997-05-01

    Directed light fabrication (DLF) is a rapid fabrication process that fuses gas delivered metal powders within a focal zone of a laser beam to produce fully dense, near-net shape, three-dimensional metal components from a computer generated solid model. Computer controls dictate the metal deposition pathways, and no preforms or molds are required to generate complex sample geometries with accurate and precise tolerances. The DLF technique offers unique advantages over conventional thermomechanical processes or thermal spray processes in that many labor and equipment intensive steps can be avoided to produce components with fully dense microstructures. Moreover, owing to the flexibility in power distributions of lasers, a variety of materials have been processed, ranging from aluminum alloys to tungsten, and including intermetallics such as Mo 5 Si 3 . Since DLF processing offers unique capabilities and advantages for the rapid fabrication of complex metal components, an examination of the microstructural development has been performed in order to define and optimize the processed materials. Solidification studies of DLF processing have demonstrated that a continuous liquid/solid interface is maintained while achieving high constant cooling rates that can be varied between 10 to 10 5 K s -1 and solidification growth rates ranging up to the 10 -2 m s -1

  6. A comprehensive review of select smart polymeric and gel actuators for soft mechatronics and robotics applications: fundamentals, freeform fabrication, and motion control

    Science.gov (United States)

    Carrico; Tyler; Leang

    2017-10-01

    Smart polymeric and gel actuators change shape or size in response to stimuli like electricity, heat, or light. These smart polymeric- and gel-based actuators are compliant and well suited for development of soft mechatronic and robotic devices. This paper provides a thorough review of select smart polymeric and gel actuator materials where an automated and freeform fabrication process, like 3D printing, is exploited to create custom shaped monolithic devices. In particular, the advantages and limitations, examples of applications, manufacturing and fabrication techniques, and methods for actuator control are discussed. Finally, a rigorous comparison and analysis of some of the advantages and limitations, as well as manufacturing processes, for these materials, are presented.

  7. Elevated temperature characterization of electron beam freeform fabricated Ti–6Al–4V and dispersion strengthened Ti–8Al–1Er

    International Nuclear Information System (INIS)

    Bush, R.W.; Brice, C.A.

    2012-01-01

    Highlights: ► Electron beam freeform fabrication process. ► Ti–6Al–4V and rare-earth dispersion Ti alloy. ► Tensile, creep, and oxidation properties comparable to alloys made with conventional fabrication methods. ► Fabrication process allows use of rare-earth dispersion Ti alloy. - Abstract: Electron beam freeform fabrication is an additive manufacturing process that can be used to build fully dense, structural metallic parts directly from a three-dimensional computer model. This technique can replace conventional fabrication methods, such as forging or machining from plate, and enable significant cost, time, and tool savings. Additionally, this method enables the fabrication of alloys with novel compositions that are not well suited to production via ingot metallurgy processes. Ti–8Al–1Er is an experimental dispersion strengthened titanium alloy composition that requires rapid cooling to achieve optimal properties and thus is not amenable to ingot metallurgy production methods. Oxide dispersion strengthened alloys, such as Ti–8Al–1Er are known to have excellent thermal stability and improved high temperature properties. In this work, the room temperature tensile, elevated temperature tensile, creep properties and oxidation resistance of electron beam additive manufactured Ti–6Al–4V and Ti–8Al–1Er were measured and compared to those of laser beam additive manufactured Ti–8Al–1Er and wrought Ti–6Al–4V. Elevated temperature tensile properties were measured between 93° and 538 °C. Creep tests were performed between 425° and 455 °C at stresses between 345 and 483 MPa. It was found that the elevated temperature properties of the electron beam additive manufactured products are comparable to those of wrought forms. The elevated temperature strengths of Ti–8Al–1Er are comparable to those of Ti–6Al–4V in percentage of room temperature strength retained at temperature. Based on a Larson–Miller analysis of the creep test

  8. Elevated temperature characterization of electron beam freeform fabricated Ti-6Al-4V and dispersion strengthened Ti-8Al-1Er

    Energy Technology Data Exchange (ETDEWEB)

    Bush, R.W., E-mail: ralph.bush@usafa.edu [Department of Engineering Mechanics, 2354 Fairchild Dr., U.S. Air Force Academy, USAF Academy, CO 80840 (United States); Brice, C.A. [Lockheed Martin Aeronautics Co., Fort Worth, TX (United States)

    2012-09-30

    Highlights: Black-Right-Pointing-Pointer Electron beam freeform fabrication process. Black-Right-Pointing-Pointer Ti-6Al-4V and rare-earth dispersion Ti alloy. Black-Right-Pointing-Pointer Tensile, creep, and oxidation properties comparable to alloys made with conventional fabrication methods. Black-Right-Pointing-Pointer Fabrication process allows use of rare-earth dispersion Ti alloy. - Abstract: Electron beam freeform fabrication is an additive manufacturing process that can be used to build fully dense, structural metallic parts directly from a three-dimensional computer model. This technique can replace conventional fabrication methods, such as forging or machining from plate, and enable significant cost, time, and tool savings. Additionally, this method enables the fabrication of alloys with novel compositions that are not well suited to production via ingot metallurgy processes. Ti-8Al-1Er is an experimental dispersion strengthened titanium alloy composition that requires rapid cooling to achieve optimal properties and thus is not amenable to ingot metallurgy production methods. Oxide dispersion strengthened alloys, such as Ti-8Al-1Er are known to have excellent thermal stability and improved high temperature properties. In this work, the room temperature tensile, elevated temperature tensile, creep properties and oxidation resistance of electron beam additive manufactured Ti-6Al-4V and Ti-8Al-1Er were measured and compared to those of laser beam additive manufactured Ti-8Al-1Er and wrought Ti-6Al-4V. Elevated temperature tensile properties were measured between 93 Degree-Sign and 538 Degree-Sign C. Creep tests were performed between 425 Degree-Sign and 455 Degree-Sign C at stresses between 345 and 483 MPa. It was found that the elevated temperature properties of the electron beam additive manufactured products are comparable to those of wrought forms. The elevated temperature strengths of Ti-8Al-1Er are comparable to those of Ti-6Al-4V in percentage of room

  9. Effect of pore architecture and stacking direction on mechanical properties of solid freeform fabrication-based scaffold for bone tissue engineering.

    Science.gov (United States)

    Lee, Jung-Seob; Cha, Hwang Do; Shim, Jin-Hyung; Jung, Jin Woo; Kim, Jong Young; Cho, Dong-Woo

    2012-07-01

    Fabrication of a three-dimensional (3D) scaffold with increased mechanical strength may be an essential requirement for more advanced bone tissue engineering scaffolds. Various material- and chemical-based approaches have been explored to enhance the mechanical properties of engineered bone tissue scaffolds. In this study, the effects of pore architecture and stacking direction on the mechanical and cell proliferation properties of a scaffold were investigated. The 3D scaffold was prepared using solid freeform fabrication technology with a multihead deposition system. Various types of scaffolds with different pore architectures (lattice, stagger, and triangle types) and stacking directions (horizontal and vertical directions) were fabricated with a blend of polycaprolactone and poly lactic-co-glycolic acid. In compression tests, the triangle-type scaffold was the strongest among the experimental groups. Stacking direction affected the mechanical properties of scaffolds. An in vitro cell counting kit-8 assay showed no significant differences in optical density depending on the different pore architectures and stacking directions. In conclusion, mechanical properties of scaffolds can be enhanced by controlling pore architecture and stacking direction. Copyright © 2012 Wiley Periodicals, Inc.

  10. Paneling architectural freeform surfaces

    KAUST Repository

    Eigensatz, Michael

    2010-07-26

    The emergence of large-scale freeform shapes in architecture poses big challenges to the fabrication of such structures. A key problem is the approximation of the design surface by a union of patches, socalled panels, that can be manufactured with a selected technology at reasonable cost, while meeting the design intent and achieving the desired aesthetic quality of panel layout and surface smoothness. The production of curved panels is mostly based on molds. Since the cost of mold fabrication often dominates the panel cost, there is strong incentive to use the same mold for multiple panels. We cast the major practical requirements for architectural surface paneling, including mold reuse, into a global optimization framework that interleaves discrete and continuous optimization steps to minimize production cost while meeting user-specified quality constraints. The search space for optimization is mainly generated through controlled deviation from the design surface and tolerances on positional and normal continuity between neighboring panels. A novel 6-dimensional metric space allows us to quickly compute approximate inter-panel distances, which dramatically improves the performance of the optimization and enables the handling of complex arrangements with thousands of panels. The practical relevance of our system is demonstrated by paneling solutions for real, cutting-edge architectural freeform design projects. © 2010 ACM.

  11. Paneling architectural freeform surfaces

    KAUST Repository

    Eigensatz, Michael

    2010-07-25

    The emergence of large-scale freeform shapes in architecture poses big challenges to the fabrication of such structures. A key problem is the approximation of the design surface by a union of patches, so-called panels, that can be manufactured with a selected technology at reasonable cost, while meeting the design intent and achieving the desired aesthetic quality of panel layout and surface smoothness. The production of curved panels is mostly based on molds. Since the cost of mold fabrication often dominates the panel cost, there is strong incentive to use the same mold for multiple panels. We cast the major practical requirements for architectural surface paneling, including mold reuse, into a global optimization framework that interleaves discrete and continuous optimization steps to minimize production cost while meeting user-specified quality constraints. The search space for optimization is mainly generated through controlled deviation from the design surface and tolerances on positional and normal continuity between neighboring panels. A novel 6-dimensional metric space allows us to quickly compute approximate inter-panel distances, which dramatically improves the performance of the optimization and enables the handling of complex arrangements with thousands of panels. The practical relevance of our system is demonstrated by paneling solutions for real, cutting-edge architectural freeform design projects.

  12. Bio-composites composed of a solid free-form fabricated polycaprolactone and alginate-releasing bone morphogenic protein and bone formation peptide for bone tissue regeneration.

    Science.gov (United States)

    Kim, MinSung; Jung, Won-Kyo; Kim, GeunHyung

    2013-11-01

    Biomedical scaffolds should be designed with highly porous three-dimensional (3D) structures that have mechanical properties similar to the replaced tissue, biocompatible properties, and biodegradability. Here, we propose a new composite composed of solid free-form fabricated polycaprolactone (PCL), bone morphogenic protein (BMP-2) or bone formation peptide (BFP-1), and alginate for bone tissue regeneration. In this study, PCL was used as a mechanical supporting component to enhance the mechanical properties of the final biocomposite and alginate was used as the deterring material to control the release of BMP-2 and BFP-1. A release test revealed that alginate can act as a good release control material. The in vitro biocompatibilities of the composites were examined using osteoblast-like cells (MG63) and the alkaline phosphatase (ALP) activity and calcium deposition were assessed. The in vitro test results revealed that PCL/BFP-1/Alginate had significantly higher ALP activity and calcium deposition than the PCL/BMP-2/Alginate composite. Based on these findings, release-controlled BFP-1 could be a good growth factor for enhancement of bone tissue growth and the simple-alginate coating method will be a useful tool for fabrication of highly functional biomaterials through release-control supplementation.

  13. Acylinder and freeform optical manufacturing

    Science.gov (United States)

    Fess, Edward; Wolfs, Frank; DeFisher, Scott; Ross, James

    2015-10-01

    Aspheric cylinders have the ability to improve optical performance over standard cylindrical surfaces. Over the last several years there has also been development into the application and functionality of utilizing freeform surfaces to improve optical performance. Freeforms have the ability to not only improve image quality over a greater field of view, but can open up the design space of an optical system making it more compact. Freeform geometries, much like aspheric cylinders, may not have an axis of rotation to spin the optic about during manufacturing. This leads to costly fabrication processes and custom metrology set ups, which may inhibit their use. Over the last several years, OptiPro Systems has developed and optimized our eSX grinding, UFF and USF polishing, UltraSurf metrology, and ProSurf software programming technologies to make the processing of these complex geometries much easier and deterministic. In this paper we will discuss the challenges associated with manufacturing complex shapes like aspheric cylinders as well as freeform geometries, and how several technologies working together can overcome them. The technologies focus on metrology feedback to a grinding and polishing machine that is controlled through an iterative computer aided manufacturing software system. We will also present examples of these hard to manufacture shapes with results.

  14. Freeform micromachining of an infrared Alvarez lens

    Science.gov (United States)

    Smilie, Paul J.; Dutterer, Brian S.; Lineberger, Jennifer L.; Davies, Matthew A.; Suleski, Thomas J.

    2011-02-01

    In 1967, Luis Alvarez introduced a novel concept for a focusing lens whereby two transmitting elements with cubic polynomial surfaces yield a composite lens of variable focal length with small lateral shifts. Computer simulations have demonstrated the behavior of these devices, but fabricating the refractive cubic surfaces of the types needed with adequate precision and depth modulation has proven to be challenging using standard methods, and, to the authors' knowledge, Alvarez lens elements have not been previously machined in infrared materials. Recent developments in freeform diamond machining capability have enabled the fabrication of such devices. In this paper, we discuss the fabrication of freeform refractive Alvarez elements in germanium using diamond micro-milling on a five-axis Moore Nanotech® 350FG Freeform Generator. Machining approaches are discussed, and measurements of surface figure and finish are presented. Initial experimental tests of optical performance are also discussed.

  15. Solid Freeform and Additive Fabrication - 2000: Symposium Held in San Francisco, California on April 23-26, 2000

    National Research Council Canada - National Science Library

    Danforth, Stephen

    2000-01-01

    ... functionality than previously thought possible. The key aspect of these direct fabrication techniques is the ability to deposit or build up material only where it is required to produce finished parts...

  16. Zometool Rationalization of Freeform Surfaces.

    Science.gov (United States)

    Zimmer, Henrik; Kobbelt, Leif

    2014-10-01

    An ever broader availability of freeform designs together with an increasing demand for product customization has lead to a rising interest in efficient physical realization of such designs, the trend toward personal fabrication. Not only large-scale architectural applications are (becoming increasingly) popular but also different consumer-level rapid-prototyping applications, including toy and 3D puzzle creation. In this work we present a method for do-it-yourself reproduction of freeform designs without the typical limitation of state-of-the-art approaches requiring manufacturing custom parts using semi-professional laser cutters or 3D printers. Our idea is based on a popular mathematical modeling system (Zometool) commonly used for modeling higher dimensional polyhedra and symmetric structures such as molecules and crystal lattices. The proposed method extends the scope of Zometool modeling to freeform, disk-topology surfaces. While being an efficient construction system on the one hand (consisting only of a single node type and nine different edge types), this inherent discreteness of the Zometool system, on the other hand gives rise to a hard approximation problem. We base our method on a marching front approach, where elements are not added in a greedy sense, but rather whole regions on the front are filled optimally, using a set of problem specific heuristics to keep complexity under control.

  17. Novel de novo variant in EBF3 is likely to impact DNA binding in a patient with a neurodevelopmental disorder and expanded phenotypes: patient report, in silico functional assessment, and review of published cases.

    Science.gov (United States)

    Blackburn, Patrick R; Barnett, Sarah S; Zimmermann, Michael T; Cousin, Margot A; Kaiwar, Charu; Pinto E Vairo, Filippo; Niu, Zhiyv; Ferber, Matthew J; Urrutia, Raul A; Selcen, Duygu; Klee, Eric W; Pichurin, Pavel N

    2017-05-01

    Pathogenic variants in EBF3 were recently described in three back-to-back publications in association with a novel neurodevelopmental disorder characterized by intellectual disability, speech delay, ataxia, and facial dysmorphisms. In this report, we describe an additional patient carrying a de novo missense variant in EBF3 (c.487C>T, p.(Arg163Trp)) that falls within a conserved residue in the zinc knuckle motif of the DNA binding domain. Without a solved structure of the DNA binding domain, we generated a homology-based atomic model and performed molecular dynamics simulations for EBF3, which predicted decreased DNA affinity for p.(Arg163Trp) compared with wild-type protein and control variants. These data are in agreement with previous experimental studies of EBF1 showing the paralogous residue is essential for DNA binding. The conservation and experimental evidence existing for EBF1 and in silico modeling and dynamics simulations to validate comparable behavior of multiple variants in EBF3 demonstrates strong support for the pathogenicity of p.(Arg163Trp). We show that our patient presents with phenotypes consistent with previously reported patients harboring EBF3 variants and expands the phenotypic spectrum of this newly identified disorder with the additional feature of a bicornuate uterus.

  18. Solid Freeform Fabrication Proceedings -1999

    Science.gov (United States)

    1999-08-11

    with a Coordinate Measuring Machine Irenee Tyvaerf, Georges Fader, Emannuelle Rouhaud", "Universite de Technologie de Troyes , bClemson University...de Troyes , France Prof. Georges Fadel, Clemson University Prof. Emannuelle Rouhaud, Universite de Technologie de Troyes , France Abstract Industries

  19. A three-dimensional hierarchical collagen scaffold fabricated by a combined solid freeform fabrication (SFF) and electrospinning process to enhance mesenchymal stem cell (MSC) proliferation

    International Nuclear Information System (INIS)

    Ahn, SeungHyun; Kim, GeunHyung; Koh, Young Ho

    2010-01-01

    Collagen has the advantage of being very similar to macromolecular substances that can be recognized and metabolized in the biological environment. Although the natural material has superior property for this purpose, its use to fabricate reproducible and pore-structure-controlled 3D structures, which are designed to allow the entry of sufficient cells and the easy diffusion of nutrients, has been limited due to its low processability. Here, we propose a hybrid technology that combines a cryogenic plotting system with an electrospinning process. Using this technique, an easily pore-size-controllable hierarchical 3D scaffold consisting of micro-sized highly porous collagen strands and micro/nano-sized collagen fibers was fabricated. The pore structure of the collagen scaffold was controlled by the collagen micro/nanofibers, which were layered in the scaffold. The hierarchical scaffolds were characterized with respect to initial cell attachment and proliferation of bone marrow-derived mesenchymal stem cells within the scaffolds. The hierarchical scaffold exhibited incredibly enhanced initial cell attachment and cell compactness between pores of the plotted scaffold relative to the normally designed 3D collagen scaffold.

  20. Freeform Honeycomb Structures

    KAUST Repository

    Jiang, Caigui

    2014-07-01

    Motivated by requirements of freeform architecture, and inspired by the geometry of hexagonal combs in beehives, this paper addresses torsion-free structures aligned with hexagonal meshes. Since repetitive geometry is a very important contribution to the reduction of production costs, we study in detail “honeycomb structures”, which are defined as torsion-free structures where the walls of cells meet at 120 degrees. Interestingly, the Gauss-Bonnet theorem is useful in deriving information on the global distribution of node axes in such honeycombs. This paper discusses the computation and modeling of honeycomb structures as well as applications, e.g. for shading systems, or for quad meshing. We consider this paper as a contribution to the wider topic of freeform patterns, polyhedral or otherwise. Such patterns require new approaches on the technical level, e.g. in the treatment of smoothness, but they also extend our view of what constitutes aesthetic freeform geometry.

  1. Enhanced resolution and accuracy of freeform metrology through Subaperture Stitching Interferometry

    Science.gov (United States)

    Supranowitz, Chris; Maloney, Chris; Murphy, Paul; Dumas, Paul

    2017-10-01

    Recent advances in polishing and metrology have addressed many of the challenges in the fabrication and metrology of freeform surfaces, and the manufacture of these surfaces is possible today. However, achieving the form and mid-spatial frequency (MSF) specifications that are typical of visible imaging systems remains a challenge. Interferometric metrology for freeform surfaces is thus highly desirable for such applications, but the capability is currently quite limited for freeforms. In this paper, we provide preliminary results that demonstrate accurate, high-resolution measurements of freeform surfaces using prototype software on QED's ASI™ (Aspheric Stitching Interferometer).

  2. 3D freeform printing of silk fibroin.

    Science.gov (United States)

    Rodriguez, Maria J; Dixon, Thomas A; Cohen, Eliad; Huang, Wenwen; Omenetto, Fiorenzo G; Kaplan, David L

    2018-04-15

    Freeform fabrication has emerged as a key direction in printing biologically-relevant materials and structures. With this emerging technology, complex structures with microscale resolution can be created in arbitrary geometries and without the limitations found in traditional bottom-up or top-down additive manufacturing methods. Recent advances in freeform printing have used the physical properties of microparticle-based granular gels as a medium for the submerged extrusion of bioinks. However, most of these techniques require post-processing or crosslinking for the removal of the printed structures (Miller et al., 2015; Jin et al., 2016) [1,2]. In this communication, we introduce a novel method for the one-step gelation of silk fibroin within a suspension of synthetic nanoclay (Laponite) and polyethylene glycol (PEG). Silk fibroin has been used as a biopolymer for bioprinting in several contexts, but chemical or enzymatic additives or bulking agents are needed to stabilize 3D structures. Our method requires no post-processing of printed structures and allows for in situ physical crosslinking of pure aqueous silk fibroin into arbitrary geometries produced through freeform 3D printing. 3D bioprinting has emerged as a technology that can produce biologically relevant structures in defined geometries with microscale resolution. Techniques for fabrication of free-standing structures by printing into granular gel media has been demonstrated previously, however, these methods require crosslinking agents and post-processing steps on printed structures. Our method utilizes one-step gelation of silk fibroin within a suspension of synthetic nanoclay (Laponite), with no need for additional crosslinking compounds or post processing of the material. This new method allows for in situ physical crosslinking of pure aqueous silk fibroin into defined geometries produced through freeform 3D printing. Copyright © 2018 Acta Materialia Inc. Published by Elsevier Ltd. All rights

  3. Geometric Computing for Freeform Architecture

    KAUST Repository

    Wallner, J.; Pottmann, Helmut

    2011-01-01

    Geometric computing has recently found a new field of applications, namely the various geometric problems which lie at the heart of rationalization and construction-aware design processes of freeform architecture. We report on our work in this area

  4. Geometric Rationalization for Freeform Architecture

    KAUST Repository

    Jiang, Caigui

    2016-01-01

    The emergence of freeform architecture provides interesting geometric challenges with regards to the design and manufacturing of large-scale structures. To design these architectural structures, we have to consider two types of constraints. First

  5. Freeform Fabrication of Magnetophotonic Crystals with Diamond Lattices of Oxide and Metallic Glasses for Terahertz Wave Control by Micro Patterning Stereolithography and Low Temperature Sintering

    Directory of Open Access Journals (Sweden)

    Maasa Nakano

    2013-04-01

    Full Text Available Micrometer order magnetophotonic crystals with periodic arranged metallic glass and oxide glass composite materials were fabricated by stereolithographic method to reflect electromagnetic waves in terahertz frequency ranges through Bragg diffraction. In the fabrication process, the photo sensitive acrylic resin paste mixed with micrometer sized metallic glass of Fe72B14.4Si9.6Nb4 and oxide glass of B2O3·Bi2O3 particles was spread on a metal substrate, and cross sectional images of ultra violet ray were exposed. Through the layer by layer stacking, micro lattice structures with a diamond type periodic arrangement were successfully formed. The composite structures could be obtained through the dewaxing and sintering process with the lower temperature under the transition point of metallic glass. Transmission spectra of the terahertz waves through the magnetophotonic crystals were measured by using a terahertz time domain spectroscopy.

  6. 3D printed plano-freeform optics for non-coherent discontinuous beam shaping

    Science.gov (United States)

    Assefa, Bisrat G.; Saastamoinen, Toni; Biskop, Joris; Kuittinen, Markku; Turunen, Jari; Saarinen, Jyrki

    2018-06-01

    The design, fabrication, and characterization of freeform optics for LED-based complex target irradiance distribution are challenging. Here, we investigate a 3D printing technology called Printoptical® technology in order to relax or push forward both the fabrication limits and LED-based applications of thick freeform lenses with small slope features. The freeform designs are carried out with an assumption of small-sized LED source using an existing point-source-based Tailoring method, which is available in the semi-commercial software. The numerical methods of the designs are characterized by ray-tracing software. The irradiance patterns of the 3D printed freeform lenses are promising considering the average shape conformity deviation of around ± 40 µm and center area surface roughness around ± 12 nm, which is to our knowledge by far the best result reported for 3D printed freeform lenses with a thickness greater than 1 mm. Applications of freeform lenses with discontinuous target irradiance distribution patterns are expected in eco-friendly energy efficient lighting such as in zebra-cross lighting.

  7. 3D printed plano-freeform optics for non-coherent discontinuous beam shaping

    Science.gov (United States)

    Assefa, Bisrat G.; Saastamoinen, Toni; Biskop, Joris; Kuittinen, Markku; Turunen, Jari; Saarinen, Jyrki

    2018-03-01

    The design, fabrication, and characterization of freeform optics for LED-based complex target irradiance distribution are challenging. Here, we investigate a 3D printing technology called Printoptical® technology in order to relax or push forward both the fabrication limits and LED-based applications of thick freeform lenses with small slope features. The freeform designs are carried out with an assumption of small-sized LED source using an existing point-source-based Tailoring method, which is available in the semi-commercial software. The numerical methods of the designs are characterized by ray-tracing software. The irradiance patterns of the 3D printed freeform lenses are promising considering the average shape conformity deviation of around ± 40 µm and center area surface roughness around ± 12 nm, which is to our knowledge by far the best result reported for 3D printed freeform lenses with a thickness greater than 1 mm. Applications of freeform lenses with discontinuous target irradiance distribution patterns are expected in eco-friendly energy efficient lighting such as in zebra-cross lighting.

  8. Freeform electronics for advanced healthcare

    KAUST Repository

    Hussain, Muhammad Mustafa

    2017-02-16

    Freeform (physically flexible, stretchable and reconfigurable) electronics can be critical enabler for advanced personalized healthcare. With increased global population and extended average lifetime of mankind, it is more important than ever to integrate advanced electronics into our daily life for advanced personalized healthcare. In this paper, we discuss some critical criteria to design such electronics with enabling applications.

  9. Freeform electronics for advanced healthcare

    KAUST Repository

    Hussain, Muhammad Mustafa; Hussain, Aftab M.; Nassar, Joanna M.; Kutbee, Arwa T.; Gumus, Abdurrahman; Hanna, Amir

    2017-01-01

    Freeform (physically flexible, stretchable and reconfigurable) electronics can be critical enabler for advanced personalized healthcare. With increased global population and extended average lifetime of mankind, it is more important than ever to integrate advanced electronics into our daily life for advanced personalized healthcare. In this paper, we discuss some critical criteria to design such electronics with enabling applications.

  10. Freeform optics for photovoltaic concentration

    OpenAIRE

    Benitez Gimenez, Pablo; Miñano Dominguez, Juan Carlos

    2012-01-01

    Freeform surfaces are the key of the state-of-the-art nonimaging optics to solve the challenges in concentration photovoltaics. Different families (FK, XR, FRXI) will be presented, based on the SMS 3D design method and Köhler homogenization.

  11. Paneling architectural freeform surfaces

    KAUST Repository

    Eigensatz, Michael; Kilian, Martin; Schiftner, Alexander; Mitra, Niloy J.; Pottmann, Helmut; Pauly, Mark

    2010-01-01

    with a selected technology at reasonable cost, while meeting the design intent and achieving the desired aesthetic quality of panel layout and surface smoothness. The production of curved panels is mostly based on molds. Since the cost of mold fabrication

  12. Experimental characterization of variable output refractive beamshapers using freeform elements

    Science.gov (United States)

    Shultz, Jason A.; Smilie, Paul J.; Dutterer, Brian S.; Davies, Matthew A.; Suleski, Thomas J.

    2014-09-01

    We present experimental results from variable output refractive beam shapers based on freeform optical surfaces. Two freeform elements in close proximity comprise a beam shaper that maps a circular Gaussian input to a circular `flat-top' output. Different lateral relative shifts between the elements result in a varying output diameter while maintaining the uniform irradiance distribution. We fabricated the beam shaping elements in PMMA using multi-axis milling on a Moore Nanotech 350FG diamond machining center and tested with a 632.8 nm Gaussian input. Initial optical testing confirmed both the predicted beam shaping and variable functionality, but with poor output uniformity. The effects of surface finish on optical performance were investigated using LightTrans VirtualLabTM to perform physical optics simulations of the milled freeform surfaces. These simulations provided an optimization path for determining machining parameters to improve the output uniformity of the beam shaping elements. A second variable beam shaper based on a super-Gaussian output was designed and fabricated using the newly determined machining parameters. Experimental test results from the second beam shaper showed outputs with significantly higher quality, but also suggest additional areas of study for further improvements in uniformity.

  13. Smart Materials by Extrusion Solid Freeform Fabrication

    National Research Council Canada - National Science Library

    Calvert, Paul

    2000-01-01

    .... For fiber-reinforced composites it has been shown that orientation can be controlled by the writing process, allowing stiffness and strength to be varied from point to point within a component...

  14. Geometric Rationalization for Freeform Architecture

    KAUST Repository

    Jiang, Caigui

    2016-06-20

    The emergence of freeform architecture provides interesting geometric challenges with regards to the design and manufacturing of large-scale structures. To design these architectural structures, we have to consider two types of constraints. First, aesthetic constraints are important because the buildings have to be visually impressive. Sec- ond, functional constraints are important for the performance of a building and its e cient construction. This thesis contributes to the area of architectural geometry. Specifically, we are interested in the geometric rationalization of freeform architec- ture with the goal of combining aesthetic and functional constraints and construction requirements. Aesthetic requirements typically come from designers and architects. To obtain visually pleasing structures, they favor smoothness of the building shape, but also smoothness of the visible patterns on the surface. Functional requirements typically come from the engineers involved in the construction process. For exam- ple, covering freeform structures using planar panels is much cheaper than using non-planar ones. Further, constructed buildings have to be stable and should not collapse. In this thesis, we explore the geometric rationalization of freeform archi- tecture using four specific example problems inspired by real life applications. We achieve our results by developing optimization algorithms and a theoretical study of the underlying geometrical structure of the problems. The four example problems are the following: (1) The design of shading and lighting systems which are torsion-free structures with planar beams based on quad meshes. They satisfy the functionality requirements of preventing light from going inside a building as shad- ing systems or reflecting light into a building as lighting systems. (2) The Design of freeform honeycomb structures that are constructed based on hex-dominant meshes with a planar beam mounted along each edge. The beams intersect without

  15. Advances in the production of freeform optical surfaces

    Science.gov (United States)

    Tohme, Yazid E.; Luniya, Suneet S.

    2007-05-01

    Recent market demands for free-form optics have challenged the industry to find new methods and techniques to manufacture free-form optical surfaces with a high level of accuracy and reliability. Production techniques are becoming a mix of multi-axis single point diamond machining centers or deterministic ultra precision grinding centers coupled with capable measurement systems to accomplish the task. It has been determined that a complex software tool is required to seamlessly integrate all aspects of the manufacturing process chain. Advances in computational power and improved performance of computer controlled precision machinery have driven the use of such software programs to measure, visualize, analyze, produce and re-validate the 3D free-form design thus making the process of manufacturing such complex surfaces a viable task. Consolidation of the entire production cycle in a comprehensive software tool that can interact with all systems in design, production and measurement phase will enable manufacturers to solve these complex challenges providing improved product quality, simplified processes, and enhanced performance. The work being presented describes the latest advancements in developing such software package for the entire fabrication process chain for aspheric and free-form shapes. It applies a rational B-spline based kernel to transform an optical design in the form of parametrical definition (optical equation), standard CAD format, or a cloud of points to a central format that drives the simulation. This software tool creates a closed loop for the fabrication process chain. It integrates surface analysis and compensation, tool path generation, and measurement analysis in one package.

  16. Null testing of nonrotational symmetry transmission optical freeform: design, modeling, and inspection on the basis of Fermat principles

    Science.gov (United States)

    Qiu, Gufeng; Cui, Xudong

    2015-11-01

    We present a general design method for a type of transmission freeforms without rotational symmetry and achieve the null testing by putting a well-designed Fermat reflector on the transmitting optical path. The design principle of the reflector is given, and an eccentric spherical surface with 1-mm deviation is used as an example of testing freeform. We fabricated the reflector and the freeform with the single-point diamond turning machine. Both conventional interference inspection and our approach give consistent results. The design error is less than 106 mm, and the measurement accuracy is nearly completely determined by the fabrication precision. This approach can also be applied to the inspections of reflecting freeforms with low costs.

  17. Freeform aberrations in phase space: an example.

    Science.gov (United States)

    Babington, James

    2017-06-01

    We consider how optical propagation and aberrations of freeform systems can be formulated in phase space. As an example system, a freeform prism is analyzed and discussed. Symmetry considerations and their group theory descriptions are given some importance. Numerical aberrations are also highlighted and put into the context of the underlying aberration theory.

  18. Freeform surface descriptions. Part I: Mathematical representations

    Science.gov (United States)

    Broemel, Anika; Lippmann, Uwe; Gross, Herbert

    2017-10-01

    Optical systems can benefit strongly from freeform surfaces; however, the choice of the right surface representation is not trivial and many aspects must be considered. In this work, we discuss the general approach classical globally defined representations, as well as the basic mathematics and properties of the most commonly used descriptions and present a new description developed by us for describing freeform surfaces.

  19. Geometric Computing for Freeform Architecture

    KAUST Repository

    Wallner, J.

    2011-06-03

    Geometric computing has recently found a new field of applications, namely the various geometric problems which lie at the heart of rationalization and construction-aware design processes of freeform architecture. We report on our work in this area, dealing with meshes with planar faces and meshes which allow multilayer constructions (which is related to discrete surfaces and their curvatures), triangles meshes with circle-packing properties (which is related to conformal uniformization), and with the paneling problem. We emphasize the combination of numerical optimization and geometric knowledge.

  20. Freeform inkjet printing of cellular structures with bifurcations.

    Science.gov (United States)

    Christensen, Kyle; Xu, Changxue; Chai, Wenxuan; Zhang, Zhengyi; Fu, Jianzhong; Huang, Yong

    2015-05-01

    Organ printing offers a great potential for the freeform layer-by-layer fabrication of three-dimensional (3D) living organs using cellular spheroids or bioinks as building blocks. Vascularization is often identified as a main technological barrier for building 3D organs. As such, the fabrication of 3D biological vascular trees is of great importance for the overall feasibility of the envisioned organ printing approach. In this study, vascular-like cellular structures are fabricated using a liquid support-based inkjet printing approach, which utilizes a calcium chloride solution as both a cross-linking agent and support material. This solution enables the freeform printing of spanning and overhang features by providing a buoyant force. A heuristic approach is implemented to compensate for the axially-varying deformation of horizontal tubular structures to achieve a uniform diameter along their axial directions. Vascular-like structures with both horizontal and vertical bifurcations have been successfully printed from sodium alginate only as well as mouse fibroblast-based alginate bioinks. The post-printing fibroblast cell viability of printed cellular tubes was found to be above 90% even after a 24 h incubation, considering the control effect. © 2014 Wiley Periodicals, Inc.

  1. Four-Mirror Freeform Reflective Imaging Systems

    Data.gov (United States)

    National Aeronautics and Space Administration — Central Objectives: The research involves a revelation of the solution space for revolutionary families of four-mirror freeform reflective imaging systems. A...

  2. New strategies and developments in transparent free-form design: From facetted to nearly smooth envelopes

    KAUST Repository

    Baldassini, Niccolo

    2009-09-01

    Free-form geometries in architecture pose new challenges to designers and engineers. Form, structure and fabrication processes are closely linked, which makes the realization of complex architectural free-form structures even harder. Free-form transparent design today is mainly based on triangularly facetted forms or quadrilateral meshes supported by a structure composed of rectilinear bars, with strong shape restrictions. After a brief review of the history, we report on some very recent progress in this area. Beginning with a presentation of improved methods for triangle mesh design, we also discuss experiences in coupling triangular glass panels with continuous curved structures, seeking an optimised structural behaviour and simplified connections. Furthermore, we present how the results of research on planar quadrilateral (PQ) meshes lead the way to optimized beam layouts and the breakdown of free-form shapes using planar quadrilateral panels. PQ meshes are rooted in discrete differential geometry, an active area of mathematical research. Using recent projects as examples, we discuss how transparent free-form envelopes with a smooth visual appearance are achievable if the structure is designed to adhere to the limits of current glazing technology and the surfaces are reasonably simple (e.g. rotational, overall developable, or of a small scale). In section 6 we show how the latter restriction can be relaxed: the theoretical and computational methodology for PQ meshes can easily be extended to create nearly smooth approximations of free-form surfaces by single-curved panels. This has a strong impact on glass panelling design, since it avoids expensive double-curvature glass and exploits cold-bending technology. We elaborate on how this discretisation technique goes hand in hand with the technology for construction of the structure, glazing system and structural joints. Our approach has been tested in three case studies, each one validating a particular aspect of

  3. Functional webs for freeform architecture

    KAUST Repository

    Deng, Bailin

    2011-08-01

    Rationalization and construction-aware design dominate the issue of realizability of freeform architecture. The former means the decomposition of an intended shape into parts which are sufficiently simple and efficient to manufacture; the latter refers to a design procedure which already incorporates rationalization. Recent contributions to this topic have been concerned mostly with small-scale parts, for instance with planar faces of meshes. The present paper deals with another important aspect, namely long-range parts and supporting structures. It turns out that from the pure geometry viewpoint this means studying families of curves which cover surfaces in certain well-defined ways. Depending on the application one has in mind, different combinatorial arrangements of curves are required. We here restrict ourselves to so-called hexagonal webs which correspond to a triangular or tri-hex decomposition of a surface. The individual curve may have certain special properties, like being planar, being a geodesic, or being part of a circle. Each of these properties is motivated by manufacturability considerations and imposes constraints on the shape of the surface. We investigate the available degrees of freedom, show numerical methods of optimization, and demonstrate the effectivity of our approach and the variability of construction solutions derived from webs by means of actual architectural designs.

  4. Nodal aberration theory applied to freeform surfaces

    Science.gov (United States)

    Fuerschbach, Kyle; Rolland, Jannick P.; Thompson, Kevin P.

    2014-12-01

    When new three-dimensional packages are developed for imaging optical systems, the rotational symmetry of the optical system is often broken, changing its imaging behavior and making the optical performance worse. A method to restore the performance is to use freeform optical surfaces that compensate directly the aberrations introduced from tilting and decentering the optical surfaces. In order to effectively optimize the shape of a freeform surface to restore optical functionality, it is helpful to understand the aberration effect the surface may induce. Using nodal aberration theory the aberration fields induced by a freeform surface in an optical system are explored. These theoretical predications are experimentally validated with the design and implementation of an aberration generating telescope.

  5. Active control of residual tool marks for freeform optics functionalization by novel biaxial servo assisted fly cutting.

    Science.gov (United States)

    Zhu, Zhiwei; To, Suet; Zhang, Shaojian

    2015-09-01

    The inherent residual tool marks (RTM) with particular patterns highly affect optical functions of the generated freeform optics in fast tool servo or slow tool servo (FTS/STS) diamond turning. In the present study, a novel biaxial servo assisted fly cutting (BSFC) method is developed for flexible control of the RTM to be a functional micro/nanotexture in freeform optics generation, which is generally hard to achieve in FTS/STS diamond turning. In the BSFC system, biaxial servo motions along the z-axis and side-feeding directions are mainly adopted for primary surface generation and RTM control, respectively. Active control of the RTM from the two aspects, namely, undesired effect elimination or effective functionalization, are experimentally demonstrated by fabricating a typical F-theta freeform surface with scattering homogenization and two functional microstructures with imposition of secondary phase gratings integrating both reflective and diffractive functions.

  6. Multi-Scalar Modelling for Free-form Timber Structures

    DEFF Research Database (Denmark)

    Poinet, Paul; Nicholas, Paul; Tamke, Martin

    2016-01-01

    .The research explores the design probe of free-form structures composed of glue-laminated timber beams and looks at the different types of data that need to be shared among each discipline and across multiple scales from which different levels of resolution can be defined. A particular focus lies...... in the segmentation strategy of glue-laminated timber structures that depend on structural requirements and the different types of constraints related to fabrication, transportation and assembly. Where current working practices decouple segmentation processes within a discrete digital workflow, this research aims...... and techniques as a means to work within a continuous design environment in which an abstract network of timber beams is iteratively updated through geometrical and structural optimizations at different levels of resolution....

  7. Towards Free-Form Kinetic Structures

    DEFF Research Database (Denmark)

    Parigi, Dario; Kirkegaard, Poul Henning

    2012-01-01

    of pin-slot paths starting from the local displacements of element [2] [3]. In the design of kinetic structures, in particular when complex three dimensional and non regular configurations are involved, the functionality is frequently related to a global displacement capability of the assembly rather...... for the generation of free-form kinetic structures....

  8. Detection and reconstruction of freeform sweeps

    KAUST Repository

    Barton, Michael; Pottmann, Helmut; Wallner, Johannes

    2014-01-01

    We study the difficult problem of deciding if parts of a freeform surface can be generated, or approximately generated, by the motion of a planar profile through space. While this task is basic for understanding the geometry of shapes as well

  9. Freeform optics applications in photovoltaic concentration

    OpenAIRE

    Miñano Dominguez, Juan Carlos; Benitez Gimenez, Pablo; Zamora Herranz, Pablo; Mendes Lopes, Joao; Buljan, Marina; Santamaria Galdon, Maria Asuncion

    2012-01-01

    Freeform surfaces are the key of the state-of-the-art nonimaging optics to solve the challenges in concentration photovoltaics. Different families (FK, XR, FRXI) will be presented, based on the SMS 3D design method and Köhler homogenization.

  10. Three-dimensional printing of freeform helical microstructures: a review.

    Science.gov (United States)

    Farahani, R D; Chizari, K; Therriault, D

    2014-09-21

    Three-dimensional (3D) printing is a fabrication method that enables creation of structures from digital models. Among the different structures fabricated by 3D printing methods, helical microstructures attracted the attention of the researchers due to their potential in different fields such as MEMS, lab-on-a-chip systems, microelectronics and telecommunications. Here we review different types of 3D printing methods capable of fabricating 3D freeform helical microstructures. The techniques including two more common microfabrication methods (i.e., focused ion beam chemical vapour deposition and microstereolithography) and also five methods based on computer-controlled robotic direct deposition of ink filament (i.e., fused deposition modeling, meniscus-confined electrodeposition, conformal printing on a rotating mandrel, UV-assisted and solvent-cast 3D printings) and their advantages and disadvantages regarding their utilization for the fabrication of helical microstructures are discussed. Focused ion beam chemical vapour deposition and microstereolithography techniques enable the fabrication of very precise shapes with a resolution down to ∼100 nm. However, these techniques may have material constraints (e.g., low viscosity) and/or may need special process conditions (e.g., vacuum chamber) and expensive equipment. The five other techniques based on robotic extrusion of materials through a nozzle are relatively cost-effective, however show lower resolution and less precise features. The popular fused deposition modeling method offers a wide variety of printable materials but the helical microstructures manufactured featured a less precise geometry compared to the other printing methods discussed in this review. The UV-assisted and the solvent-cast 3D printing methods both demonstrated high performance for the printing of 3D freeform structures such as the helix shape. However, the compatible materials used in these methods were limited to UV-curable polymers and

  11. ‘Action’ on structured freeform surfaces

    Science.gov (United States)

    Whitehouse, David J.

    2018-06-01

    Surfaces are becoming more complex partly due to the more complicated function required of them and partly due to the introduction of different manufacturing processes. These have thrown into relief the need to consider new ways of measuring and characterizing such surfaces and more importantly to make such characterization more relevant by tying together the geometry and the function more closely. The surfaces which have freeform and structure have been chosen to be a carrier for this investigation because so far there has been little work carried out in this neglected but potentially important area. This necessitates the development of a strategy for their characterization. In this article, some ways have been found of identifying possible strategies for tackling this characterization problem but also linking this characterization to performance and manufacture, based in part on the principles of least action and on the way that nature has evolved to solve the marriage of flexible freeform geometry, structure and function. Recommendations are made for the most suitable surface parameter to use which satisfies the requirement for characterizing structured freeform surfaces as well as utilizing ‘Action’ to predict functionality.

  12. Imaging Freeform Optical Systems Designed with NURBS Surfaces

    Science.gov (United States)

    2015-12-01

    reflective, anastigmat 1 Introduction The imaging freeform optical systems described here are designed using non-uniform rational basis-spline (NURBS...code, but to succeed in designing NURBS freeform optical systems an optimization code is required. The motivation for developing the optical design

  13. Quantitative optimization of solid freeform deposition of aqueous hydrogels

    International Nuclear Information System (INIS)

    Kang, K H; Hockaday, L A; Butcher, J T

    2013-01-01

    Many soft tissues exhibit complex anatomical geometry that is challenging to replicate for regenerative medicine applications. Solid freeform fabrication (SFF) has emerged as an attractive approach for creating 3D tissues, but a detailed understanding of how specific fabrication parameters affect accuracy and viability has not been established to date. In this study, we evaluate the effects of printing parameters of the Fab-Home 3D printing system on accuracy using alginate, photocrosslinkable polyethylene-glycol diacrylate (PEG-DA) and gelatin as commonly used model hydrogel materials. Print accuracy and resolution along the length, width and height were determined based on quantitative image analysis. The effects of extrusion parameters on cell viability were assessed using porcine aortic valve interstitial cells (PAVIC) as a model cell type. We observed that pressure, pathheight and pathspace all significantly affected print accuracy and resolution. Printing conditions did not affect PAVIC viability within the ranges applied. We predicted that optimal pressure, pathheight and pathspace values would be increased linearly with increasing nozzle diameter, and we confirmed that the predicted values generate accurate 3D geometries while poorly chosen parameters yield inaccurate, unpredictable geometries. This systematic optimization strategy therefore improves the accuracy of 3D printing platforms for biofabrication and tissue engineering applications. (paper)

  14. Design and evaluation of a freeform lens by using a method of luminous intensity mapping and a differential equation

    Science.gov (United States)

    Essameldin, Mahmoud; Fleischmann, Friedrich; Henning, Thomas; Lang, Walter

    2017-02-01

    Freeform optical systems are playing an important role in the field of illumination engineering for redistributing the light intensity, because of its capability of achieving accurate and efficient results. The authors have presented the basic idea of the freeform lens design method at the 117th annual meeting of the German Society of Applied Optics (DGAOProceedings). Now, we demonstrate the feasibility of the design method by designing and evaluating a freeform lens. The concepts of luminous intensity mapping, energy conservation and differential equation are combined in designing a lens for non-imaging applications. The required procedures to design a lens including the simulations are explained in detail. The optical performance is investigated by using a numerical simulation of optical ray tracing. For evaluation, the results are compared with another recently published design method, showing the accurate performance of the proposed method using a reduced number of mapping angles. As a part of the tolerance analyses of the fabrication processes, the influence of the light source misalignments (translation and orientation) on the beam-shaping performance is presented. Finally, the importance of considering the extended light source while designing a freeform lens using the proposed method is discussed.

  15. A novel method of freeform surface grinding with a soft wheel based on industrial robots

    Science.gov (United States)

    Sha, Sheng-chun; Guo, Xiao-ling

    2011-08-01

    In order to meet the growing demand for high-quality images, optical elements of freeform surface are more and more applied to imaging system. However the fabrication of freeform surface optical elements is much more difficult than that of traditional spherical ones. Recent research on freeform surface manufacture often deals with precision machine tools which have limitations on dimensions and are always expensive. Little has been researched on industrial robots. In this paper, a new method of freeform surface grinding based on industrial robots was found. This method could be applied to both whole surface grinding as well as partial surface grinding. The diameter of lenses to be ground would not be restricted to the machine tool's size. In this method a high-speed-rotating soft wheel was used. The relation between removing amount and grinding time which could be called removing function was established and measured. The machining precision was achieved by means of controlling the grinding time instead of the machine tool or industrial robot itself. There are two main factors affecting the removing function: i).rotating speed of the soft wheel; ii).pressure between the wheel and the work piece. In this paper, two groups of experiments have been conducted. One is the removing function tested at constant rotating speed while under different pressure. The other is that tested under a certain pressure with variable speed. Tables and curves which can show the effect of speed and pressure on the removing efficiency have been obtained. Cause for inaccuracy between experiment data and calculated result according to the theory and the non-linearity in the curves was analyzed. Through these analyses the removing function could be concluded under certain condition including rotating speed and pressure. Finally several experiments were performed to verify the appropriateness of the removing function. It could also be concluded that this method was more efficient in comparison

  16. Freeform lens design for LED collimating illumination.

    Science.gov (United States)

    Chen, Jin-Jia; Wang, Te-Yuan; Huang, Kuang-Lung; Liu, Te-Shu; Tsai, Ming-Da; Lin, Chin-Tang

    2012-05-07

    We present a simple freeform lens design method for an application to LED collimating illumination. The method is derived from a basic geometric-optics analysis and construction approach. By using this method, a highly collimating lens with LED chip size of 1.0 mm × 1.0 mm and optical simulation efficiency of 86.5% under a view angle of ± 5 deg is constructed. To verify the practical performance of the lens, a prototype of the collimator lens is also made, and an optical efficiency of 90.3% with a beam angle of 4.75 deg is measured.

  17. Alignment engineering in liquid crystalline elastomers: Free-form microstructures with multiple functionalities

    Energy Technology Data Exchange (ETDEWEB)

    Zeng, Hao; Cerretti, Giacomo; Wiersma, Diederik S., E-mail: camilla.parmeggiani@lens.unifi.it, E-mail: wiersma@lens.unifi.it [European Laboratory for Non Linear Spectroscopy (LENS), University of Florence, via Nello Carrara 1, 50019 Sesto Fiorentino (Italy); Wasylczyk, Piotr [European Laboratory for Non Linear Spectroscopy (LENS), University of Florence, via Nello Carrara 1, 50019 Sesto Fiorentino (Italy); Faculty of Physics, Institute of Experimental Physics, University of Warsaw, ul. Hoza 69, Warszawa 00-681 (Poland); Martella, Daniele [European Laboratory for Non Linear Spectroscopy (LENS), University of Florence, via Nello Carrara 1, 50019 Sesto Fiorentino (Italy); Dipartimento di Chimica “Ugo Schiff,” University of Florence, via della Lastruccia 3-13, 50019 Sesto Fiorentino (Italy); Parmeggiani, Camilla, E-mail: camilla.parmeggiani@lens.unifi.it, E-mail: wiersma@lens.unifi.it [European Laboratory for Non Linear Spectroscopy (LENS), University of Florence, via Nello Carrara 1, 50019 Sesto Fiorentino (Italy); CNR-INO, via Nello Carrara 1, 50019 Sesto Fiorentino (Italy)

    2015-03-16

    We report a method to fabricate polymer microstructures with local control over the molecular orientation. Alignment control is achieved on molecular level in a structure of arbitrary form that can be from 1 to 100 μm in size, by fixing the local boundary conditions with micro-grating patterns. The method makes use of two-photon polymerization (Direct Laser Writing) and is demonstrated specifically in liquid-crystalline elastomers. This concept allows for the realization of free-form polymeric structures with multiple functionalities which are not possible to realize with existing techniques and which can be locally controlled by light in the micrometer scale.

  18. Detection and reconstruction of freeform sweeps

    KAUST Repository

    Barton, Michael

    2014-05-01

    We study the difficult problem of deciding if parts of a freeform surface can be generated, or approximately generated, by the motion of a planar profile through space. While this task is basic for understanding the geometry of shapes as well as highly relevant for manufacturing and building construction, previous approaches were confined to special cases like kinematic surfaces or "moulding" surfaces. The general case remained unsolved so far. We approach this problem by a combination of local and global methods: curve analysis with regard to "movability", curve comparison by common substring search in curvature plots, an exhaustive search through all planar cuts enhanced by quick rejection procedures, the ordering of candidate profiles and finally, global optimization. The main applications of our method are digital reconstruction of CAD models exhibiting sweep patches, and aiding in manufacturing freeform surfaces by pointing out those parts which can be approximated by sweeps. © 2014 The Author(s) Computer Graphics Forum © 2014 The Eurographics Association and John Wiley & Sons Ltd. Published by John Wiley & Sons Ltd.

  19. Cartesian oval representation of freeform optics in illumination systems.

    Science.gov (United States)

    Michaelis, D; Schreiber, P; Bräuer, A

    2011-03-15

    The geometrical method for constructing optical surfaces for illumination purpose developed by Oliker and co-workers [Trends in Nonlinear Analysis (Springer, 2003)] is generalized in order to obtain freeform designs in arbitrary optical systems. The freeform is created by a set of primitive surface elements, which are generalized Cartesian ovals adapted to the given optical system. Those primitives are determined by Hamiltonian theory of ray optics. The potential of this approach is demonstrated by some examples, e.g., freeform lenses with collimating front elements.

  20. Macroporous hydroxyapatite bioceramics by solid freeform fabrication: towards custom implants

    CSIR Research Space (South Africa)

    Richter, PW

    1999-08-01

    Full Text Available structure that would be impossible to make by conventional manufacturing methods. Application of this technology to the manufacture of macro porous hydroxyapatite bio ceramics for bone substitute applications is discussed. A new design is described...

  1. Efficient Design And Fabrication Of Free-Form Reciprocal Structures

    DEFF Research Database (Denmark)

    Parigi, Dario; Kirkegaard, Poul Henning

    2013-01-01

    Structures based on the principle of reciprocity have been autonomously studied and used since the antiquity on the basis of different needs and purposes. The application of the principle of reciprocity requires the presence of at least two elements, at the same time both supporting and being sup...

  2. Additive manufacturing for freeform mechatronics design: from concepts to applications

    NARCIS (Netherlands)

    Baars, G. van; Smeltink, J.; Werff, J. van der; Limpens, M.; Barink, M.; Berg, D. van den; Vreugd, J. de; Witvoet, G.; Galaktionov, O.S.

    2015-01-01

    This article presents developments of freeform mechatronics concepts, enabled by industrial Additive Manufacturing (AM), aiming at breakthroughs for precision engineering challenges such as lightweight, advanced thermal control, and integrated design. To assess potential impact in future

  3. Geometric Modeling and Reasoning of Human-Centered Freeform Products

    CERN Document Server

    Wang, Charlie C L

    2013-01-01

    The recent trend in user-customized product design requires the shape of products to be automatically adjusted according to the human body’s shape, so that people will feel more comfortable when wearing these products.  Geometric approaches can be used to design the freeform shape of products worn by people, which can greatly improve the efficiency of design processes in various industries involving customized products (e.g., garment design, toy design, jewel design, shoe design, and design of medical devices, etc.). These products are usually composed of very complex geometric shapes (represented by free-form surfaces), and are not driven by a parameter table but a digital human model with free-form shapes or part of human bodies (e.g., wrist, foot, and head models).   Geometric Modeling and Reasoning of Human-Centered Freeform Products introduces the algorithms of human body reconstruction, freeform product modeling, constraining and reconstructing freeform products, and shape optimization for improving...

  4. Reconstruction of freeform surfaces for metrology

    International Nuclear Information System (INIS)

    El-Hayek, N; Nouira, H; Anwer, N; Damak, M; Gibaru, O

    2014-01-01

    The application of freeform surfaces has increased since their complex shapes closely express a product's functional specifications and their machining is obtained with higher accuracy. In particular, optical surfaces exhibit enhanced performance especially when they take aspheric forms or more complex forms with multi-undulations. This study is mainly focused on the reconstruction of complex shapes such as freeform optical surfaces, and on the characterization of their form. The computer graphics community has proposed various algorithms for constructing a mesh based on the cloud of sample points. The mesh is a piecewise linear approximation of the surface and an interpolation of the point set. The mesh can further be processed for fitting parametric surfaces (Polyworks ® or Geomagic ® ). The metrology community investigates direct fitting approaches. If the surface mathematical model is given, fitting is a straight forward task. Nonetheless, if the surface model is unknown, fitting is only possible through the association of polynomial Spline parametric surfaces. In this paper, a comparative study carried out on methods proposed by the computer graphics community will be presented to elucidate the advantages of these approaches. We stress the importance of the pre-processing phase as well as the significance of initial conditions. We further emphasize the importance of the meshing phase by stating that a proper mesh has two major advantages. First, it organizes the initially unstructured point set and it provides an insight of orientation, neighbourhood and curvature, and infers information on both its geometry and topology. Second, it conveys a better segmentation of the space, leading to a correct patching and association of parametric surfaces

  5. Advanced free-form micro tooling

    DEFF Research Database (Denmark)

    Tosello, Guido; Gavillet, J.

    2011-01-01

    -beam lithography and nano imprinting lithography [Che05][Che09] have high manufacturing cost and a low throughput. The aim was obtain large tool area with nano structures patterning without using energy intensive nano machining (e.g. focus ion beam, X-ray lithography, etc) but, instead, by exploiting the advantage......The present deliverable contains the report of the work and results achieved within the framework of WP 2.2 in Tasks 2.2.4 “Advanced free-form micro tooling” in experimental research done regarding practical applications of methods of applying nano structures to tooling solutions. As part of Task 2.......2.4, tests based on three different chemical-based-batch techniques to establish surface nano (i.e. sub-μm) structures on large tools area were performed. The three approached regarded: o Scheme 1  The use of Ø500nm nanobeads deposition for direct patterning of a Ø4inch. silicon wafer and subsequent nickel...

  6. Freeform object design and simultaneous manufacturing

    Science.gov (United States)

    Zhang, Wei; Zhang, Weihan; Lin, Heng; Leu, Ming C.

    2003-04-01

    Today's product design, especially the consuming product design, focuses more and more on individuation, originality, and the time to market. One way to meet these challenges is using the interactive and creationary product design methods and rapid prototyping/rapid tooling. This paper presents a novel Freeform Object Design and Simultaneous Manufacturing (FODSM) method that combines the natural interaction feature in the design phase and simultaneous manufacturing feature in the prototyping phase. The natural interactive three-dimensional design environment is achieved by adopting virtual reality technology. The geometry of the designed object is defined through the process of "virtual sculpting" during which the designer can touch and visualize the designed object and can hear the virtual manufacturing environment noise. During the designing process, the computer records the sculpting trajectories and automatically translates them into NC codes so as to simultaneously machine the designed part. The paper introduced the principle, implementation process, and key techniques of the new method, and compared it with other popular rapid prototyping methods.

  7. Characterisation of surface roughness for ultra-precision freeform surfaces

    International Nuclear Information System (INIS)

    Li Huifen; Cheung, C F; Lee, W B; To, S; Jiang, X Q

    2005-01-01

    Ultra-precision freeform surfaces are widely used in many advanced optics applications which demand for having surface roughness down to nanometer range. Although a lot of research work has been reported on the study of surface generation, reconstruction and surface characterization such as MOTIF and fractal analysis, most of them are focused on axial symmetric surfaces such as aspheric surfaces. Relative little research work has been found in the characterization of surface roughness in ultra-precision freeform surfaces. In this paper, a novel Robust Gaussian Filtering (RGF) method is proposed for the characterisation of surface roughness for ultra-precision freeform surfaces with known mathematic model or a cloud of discrete points. A series of computer simulation and measurement experiments were conducted to verify the capability of the proposed method. The experimental results were found to agree well with the theoretical results

  8. Freeform Optics: current challenges for future serial production

    Science.gov (United States)

    Schindler, C.; Köhler, T.; Roth, E.

    2017-10-01

    One of the major developments in optics industry recently is the commercial manufacturing of freeform surfaces for optical mid- and high performance systems. The loss of limitation on rotational symmetry enables completely new optical design solutions - but causes completely new challenges for the manufacturer too. Adapting the serial production from radial-symmetric to freeform optics cannot be done just by the extension of machine capabilities and software for every process step. New solutions for conventional optics productions or completely new process chains are necessary.

  9. Optimization of freeform lightpipes for light-emitting-diode projectors.

    Science.gov (United States)

    Fournier, Florian; Rolland, Jannick

    2008-03-01

    Standard nonimaging components used to collect and integrate light in light-emitting-diode-based projector light engines such as tapered rods and compound parabolic concentrators are compared to optimized freeform shapes in terms of transmission efficiency and spatial uniformity. We show that the simultaneous optimization of the output surface and the profile shape yields transmission efficiency within the étendue limit up to 90% and spatial uniformity higher than 95%, even for compact sizes. The optimization process involves a manual study of the trends for different shapes and the use of an optimization algorithm to further improve the performance of the freeform lightpipe.

  10. Structural optimization of free-form reciprocal structures

    DEFF Research Database (Denmark)

    Parigi, Dario

    2014-01-01

    This paper presents an optimization algorithm for the design of structurally efficient free-form reciprocal structures. Because of the geometric complexity of reciprocal structures, only a few structural studies have been carried out so far, and we have a limited knowledge of the relation between...

  11. Non-contact measurement machine for freeform optics

    NARCIS (Netherlands)

    Henselmans, R.

    2009-01-01

    The performance of high-precision optical systems using spherical optics is limited by aberrations. By applying aspherical and freeform optics, the geometrical aberrations can be reduced or eliminated while at the same time also reducing the required number of components, the size and the weight of

  12. Validation of calibration procedures for freeform parts on CMMs

    DEFF Research Database (Denmark)

    Savio, Enrico; De Chiffre, Leonardo

    2003-01-01

    The paper describes the validation of a new method for establishment of traceability of freeform measurements on coordinate measuring machines currently being considered for development as a new ISO standard. The method deals with calibration by: i) repeated measurements of a given uncalibrated...

  13. Adaptive Robotic Fabrication for Conditions of Material Inconsistency

    DEFF Research Database (Denmark)

    Nicholas, Paul; Zwierzycki, Mateusz; Clausen Nørgaard, Esben

    2017-01-01

    This paper describes research that addresses the variable behaviour of industrial quality metals and the extension of computational techniques into the fabrication process. It describes the context of robotic incremental sheet metal forming, a freeform method for imparting 3D form onto a 2D thin ...... is an offline predictive strategy based on machine learning. Rigidisation of thin metal skins......This paper describes research that addresses the variable behaviour of industrial quality metals and the extension of computational techniques into the fabrication process. It describes the context of robotic incremental sheet metal forming, a freeform method for imparting 3D form onto a 2D thin...

  14. Mechanical design implementation and mathematical considerations for ultra precise diamond turning of multiple freeform mirrors on a common substrate

    Science.gov (United States)

    Hartung, Johannes; Beier, Matthias; Peschel, Thomas; Gebhardt, Andreas; Risse, Stefan

    2015-09-01

    For optical systems consisting of metal (in general freeform) mirrors there exist several diamond turning fabrication approaches. These are distuingished by the effort in manufacturing and integration of the later system. The more work one puts into the manufacturing stage the less complicated is the alignment and integration afterwards. For example the most degrees of freedom have to be aligned in integration phase if every mirror of the system is fabricated as a single optical component. For a three mirror anastigmat with three freeform mirrors the degrees of freedom sum up to 18. Therefore the mirror fabrication itself is more or less easy, but the integration is very difficult. There are three major parts in the design and manufacturing process chain to be considered for tackling this integration problem. At the first position in the process chain there is the optical design occuring. At this stage a negotiation between manufacturing and design could improve manufacturability because of more possible integration approaches. The second stage is the mechanical design. Here the appropriate manufacturing approach is already chosen, but may be revisited due to incompatiblities with, e.g., stress specifications. The third level is the manufacturing stage. Here are different clamping approaches and fabrication methods possible. The current article will focus on an approach ("snap-together") where two mirrors are fabricated on one substrate and therefore a reduction of the number of degrees of freedom to be aligned are reduced to six. This improves the amount of time needed for the system integration significantly in contrast to a single mirror fabrication.

  15. Digitally switchable multi-focal lens using freeform optics.

    Science.gov (United States)

    Wang, Xuan; Qin, Yi; Hua, Hong; Lee, Yun-Han; Wu, Shin-Tson

    2018-04-16

    Optical technologies offering electrically tunable optical power have found a broad range of applications, from head-mounted displays for virtual and augmented reality applications to microscopy. In this paper, we present a novel design and prototype of a digitally switchable multi-focal lens (MFL) that offers the capability of rapidly switching the optical power of the system among multiple foci. It consists of a freeform singlet and a customized programmable optical shutter array (POSA). Time-multiplexed multiple foci can be obtained by electrically controlling the POSA to switch the light path through different segments of the freeform singlet rapidly. While this method can be applied to a broad range of imaging and display systems, we experimentally demonstrate a proof-of-concept prototype for a multi-foci imaging system.

  16. Towards freeform curved blazed gratings using diamond machining

    Science.gov (United States)

    Bourgenot, C.; Robertson, D. J.; Stelter, D.; Eikenberry, S.

    2016-07-01

    Concave blazed gratings greatly simplify the architecture of spectrographs by reducing the number of optical components. The production of these gratings using diamond-machining offers practically no limits in the design of the grating substrate shape, with the possibility of making large sag freeform surfaces unlike the alternative and traditional method of holography and ion etching. In this paper, we report on the technological challenges and progress in the making of these curved blazed gratings using an ultra-high precision 5 axes Moore-Nanotech machine. We describe their implementation in an integral field unit prototype called IGIS (Integrated Grating Imaging Spectrograph) where freeform curved gratings are used as pupil mirrors. The goal is to develop the technologies for the production of the next generation of low-cost, compact, high performance integral field unit spectrometers.

  17. Electron beam freeforming of stainless steel using solid wire feed

    International Nuclear Information System (INIS)

    Wanjara, P.; Brochu, M.; Jahazi, M.

    2007-01-01

    The use of electron beam technology for freeforming build-ups on 321 stainless steel substrates was investigated in this work by using 347 stainless steel as a filler metal. The electron beam freeforming studies indicated that line build-ups could be deposited on the substrate material for optimized processing conditions and a slight linear thickening of the re-build occurred as a function of the deposited layer. The evolution in the formation of the Ti (C, N) (Nb, Ti) carbonitrides and Nb (C, N) precipitates was demonstrated to counteract the formation of detrimental Cr-carbides usually observed during welding stainless steels. The mechanical properties of the re-build were similar to the properties of the base metal, showing that homogeneous properties can be expected in the repaired components

  18. APPROXIMATION OF FREE-FORM CURVE – AIRFOIL SHAPE

    Directory of Open Access Journals (Sweden)

    CHONG PERK LIN

    2013-12-01

    Full Text Available Approximation of free-form shape is essential in numerous engineering applications, particularly in automotive and aircraft industries. Commercial CAD software for the approximation of free-form shape is based almost exclusively on parametric polynomial and rational parametric polynomial. The parametric curve is defined by vector function of one independent variable R(u = (x(u, y(u, z(u, where 0≤u≤1. Bézier representation is one of the parametric functions, which is widely used in the approximating of free-form shape. Given a string of points with the assumption of sufficiently dense to characterise airfoil shape, it is desirable to approximate the shape with Bézier representation. The expectation is that the representation function is close to the shape within an acceptable working tolerance. In this paper, the aim is to explore the use of manual and automated methods for approximating section curve of airfoil with Bézier representation.

  19. Theory of aberration fields for general optical systems with freeform surfaces.

    Science.gov (United States)

    Fuerschbach, Kyle; Rolland, Jannick P; Thompson, Kevin P

    2014-11-03

    This paper utilizes the framework of nodal aberration theory to describe the aberration field behavior that emerges in optical systems with freeform optical surfaces, particularly φ-polynomial surfaces, including Zernike polynomial surfaces, that lie anywhere in the optical system. If the freeform surface is located at the stop or pupil, the net aberration contribution of the freeform surface is field constant. As the freeform optical surface is displaced longitudinally away from the stop or pupil of the optical system, the net aberration contribution becomes field dependent. It is demonstrated that there are no new aberration types when describing the aberration fields that arise with the introduction of freeform optical surfaces. Significantly it is shown that the aberration fields that emerge with the inclusion of freeform surfaces in an optical system are exactly those that have been described by nodal aberration theory for tilted and decentered optical systems. The key contribution here lies in establishing the field dependence and nodal behavior of each freeform term that is essential knowledge for effective application to optical system design. With this development, the nodes that are distributed throughout the field of view for each aberration type can be anticipated and targeted during optimization for the correction or control of the aberrations in an optical system with freeform surfaces. This work does not place any symmetry constraints on the optical system, which could be packaged in a fully three dimensional geometry, without fold mirrors.

  20. Machining and metrology systems for free-form laser printer mirrors

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    optical systems were designed and manufactured for the individual laser wavelength to be ... The design objective in utilizing a free-form mirror has resulted in a corresponding ... Since mass production of these free-form mirrors is required, the ...

  1. Aberration analysis for freeform surface terms overlay on general decentered and tilted optical surfaces.

    Science.gov (United States)

    Yang, Tong; Cheng, Dewen; Wang, Yongtian

    2018-03-19

    Aberration theory helps designers to better understand the nature of imaging systems. However, the existing aberration theory of freeform surfaces has many limitations. For example, it only works in the special case when the central area of the freeform surface is used. In addition, the light footprint is limited to a circle, which does not match the case of an elliptical footprint for general systems. In this paper, aberrations generated by freeform surface term overlay on general decentered and tilted optical surfaces are analyzed. For the case when the off-axis section of a freeform surface is used, the aberration equation for using stop and nonstop surfaces is discussed, and the aberrations generated by Zernike terms up to Z 17/18 are analyzed in detail. To solve the problem of the elliptical light footprint for tilted freeform surfaces, the scaled pupil vector is used in the aberration analysis. The mechanism of aberration transformation is discovered, and the aberrations generated by different Zernike terms in this case are calculated. Finally we proposed aberration equations for freeform terms on general decentered and tilted freeform surfaces. The research result given in this paper offers an important reference for optical designers and engineers, and it is of great importance in developing analytical methods for general freeform system design, tolerance analysis, and system assembly.

  2. Freeform drop-on-demand laser printing of 3D alginate and cellular constructs

    International Nuclear Information System (INIS)

    Xiong, Ruitong; Zhang, Zhengyi; Chai, Wenxuan; Huang, Yong; Chrisey, Douglas B

    2015-01-01

    Laser printing is an orifice-free printing approach and has been investigated for the printing of two-dimensional patterns and simple three-dimensional (3D) constructs. To demonstrate the potential of laser printing as an effective bioprinting technique, both straight and Y-shaped tubes have been freeform printed using two different bioinks: 8% alginate solution and 2% alginate-based mouse fibroblast suspension. It has been demonstrated that 3D cellular tubes, including constructs with bifurcated overhang structures, can be adequately fabricated under optimal printing conditions. The post-printing cell viabilities immediately after printing as well as after 24 h incubation are above 60% for printed straight and Y-shaped fibroblast tubes. During fabrication, overhang and spanning structures can be printed using a dual-purpose crosslinking solution, which also functions as a support material. The advancement distance of gelation reaction front after a cycle time of the receiving platform downward motion should be estimated for experimental planning. The optimal downward movement step size of receiving platform should be chosen to be equal to the height of ungelled portion of a previously printed layer. (paper)

  3. Design of a novel freeform lens for LED uniform illumination and conformal phosphor coating.

    Science.gov (United States)

    Hu, Run; Luo, Xiaobing; Zheng, Huai; Qin, Zong; Gan, Zhiqiang; Wu, Bulong; Liu, Sheng

    2012-06-18

    A conformal phosphor coating can realize a phosphor layer with uniform thickness, which could enhance the angular color uniformity (ACU) of light-emitting diode (LED) packaging. In this study, a novel freeform lens was designed for simultaneous realization of LED uniform illumination and conformal phosphor coating. The detailed algorithm of the design method, which involves an extended light source and double refractions, was presented. The packaging configuration of the LED modules and the modeling of the light-conversion process were also presented. Monte Carlo ray-tracing simulations were conducted to validate the design method by comparisons with a conventional freeform lens. It is demonstrated that for the LED module with the present freeform lens, the illumination uniformity and ACU was 0.89 and 0.9283, respectively. The present freeform lens can realize equivalent illumination uniformity, but the angular color uniformity can be enhanced by 282.3% when compared with the conventional freeform lens.

  4. Freeform Deposition Method for Coolant Channel Closeout

    Science.gov (United States)

    Gradl, Paul R. (Inventor); Reynolds, David Christopher (Inventor); Walker, Bryant H. (Inventor)

    2017-01-01

    A method is provided for fabricating a coolant channel closeout jacket on a structure having coolant channels formed in an outer surface thereof. A line of tangency relative to the outer surface is defined for each point on the outer surface. Linear rows of a metal feedstock are directed towards and deposited on the outer surface of the structure as a beam of weld energy is directed to the metal feedstock so-deposited. A first angle between the metal feedstock so-directed and the line of tangency is maintained in a range of 20-90.degree.. The beam is directed towards a portion of the linear rows such that less than 30% of the cross-sectional area of the beam impinges on a currently-deposited one of the linear rows. A second angle between the beam and the line of tangency is maintained in a range of 5-65 degrees.

  5. Inspection of freeform surfaces considering uncertainties in measurement, localization and surface reconstruction

    International Nuclear Information System (INIS)

    Mehrad, Vahid; Xue, Deyi; Gu, Peihua

    2013-01-01

    Inspection of a manufactured freeform surface can be conducted by building its surface model and comparing this manufactured surface model with the ideal design surface model and its tolerance requirement. The manufactured freeform surface model is usually achieved by obtaining measurement points on the manufactured surface, transforming these measurement points from the measurement coordinate system to the design coordinate system through localization, and reconstructing the surface model using the localized measurement points. In this research, a method was developed to estimate the locations and their variances of any selected points on the reconstructed freeform surface considering different sources of uncertainties in measurement, localization and surface reconstruction processes. In this method, first locations and variances of the localized measurement points are calculated considering uncertainties of the measurement points and uncertainties introduced in the localization processes. Then locations and variances of points on the reconstructed freeform surface are obtained considering uncertainties of the localized measurement points and uncertainties introduced in the freeform surface reconstruction process. Two case studies were developed to demonstrate how these three different uncertainty sources influence the quality of the reconstructed freeform curve and freeform surface in inspection. (paper)

  6. Partial null astigmatism-compensated interferometry for a concave freeform Zernike mirror

    Science.gov (United States)

    Dou, Yimeng; Yuan, Qun; Gao, Zhishan; Yin, Huimin; Chen, Lu; Yao, Yanxia; Cheng, Jinlong

    2018-06-01

    Partial null interferometry without using any null optics is proposed to measure a concave freeform Zernike mirror. Oblique incidence on the freeform mirror is used to compensate for astigmatism as the main component in its figure, and to constrain the divergence of the test beam as well. The phase demodulated from the partial nulled interferograms is divided into low-frequency phase and high-frequency phase by Zernike polynomial fitting. The low-frequency surface figure error of the freeform mirror represented by the coefficients of Zernike polynomials is reconstructed from the low-frequency phase, applying the reverse optimization reconstruction technology in the accurate model of the interferometric system. The high-frequency surface figure error of the freeform mirror is retrieved from the high-frequency phase adopting back propagating technology, according to the updated model in which the low-frequency surface figure error has been superimposed on the sag of the freeform mirror. Simulations verified that this method is capable of testing a wide variety of astigmatism-dominated freeform mirrors due to the high dynamic range. The experimental result using our proposed method for a concave freeform Zernike mirror is consistent with the null test result employing the computer-generated hologram.

  7. A Sketching Interface for Freeform 3D Modeling

    Science.gov (United States)

    Igarashi, Takeo

    This chapter introduces Teddy, a sketch-based modeling system to quickly and easily design freeform models such as stuffed animals and other rotund objects. The user draws several 2D freeform strokes interactively on the screen and the system automatically constructs plausible 3D polygonal surfaces. Our system supports several modeling operations, including the operation to construct a 3D polygonal surface from a 2D silhouette drawn by the user: it inflates the region surrounded by the silhouette making a wide area fat, and a narrow area thin. Teddy, our prototype system, is implemented as a Java program, and the mesh construction is done in real-time on a standard PC. Our informal user study showed that a first-time user masters the operations within 10 minutes, and can construct interesting 3D models within minutes. We also report the result of a case study where a high school teacher taught various 3D concepts in geography using the system.

  8. RAPID FREEFORM SHEET METAL FORMING: TECHNOLOGY DEVELOPMENT AND SYSTEM VERIFICATION

    Energy Technology Data Exchange (ETDEWEB)

    Kiridena, Vijitha [Ford Scientific Research Lab., Dearborn, MI (United States); Verma, Ravi [Boeing Research and Technology (BR& T), Seattle, WA (United States); Gutowski, Timothy [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Roth, John [Pennsylvania State Univ., University Park, PA (United States)

    2018-03-31

    The objective of this project is to develop a transformational RApid Freeform sheet metal Forming Technology (RAFFT) in an industrial environment, which has the potential to increase manufacturing energy efficiency up to ten times, at a fraction of the cost of conventional technologies. The RAFFT technology is a flexible and energy-efficient process that eliminates the need for having geometry-specific forming dies. The innovation lies in the idea of using the energy resource at the local deformation area which provides greater formability, process control, and process flexibility relative to traditional methods. Double-Sided Incremental Forming (DSIF), the core technology in RAFFT, is a new concept for sheet metal forming. A blank sheet is clamped around its periphery and gradually deformed into a complex 3D freeform part by two strategically aligned stylus-type tools that follow a pre-described toolpath. The two tools, one on each side of the blank, can form a part with sharp features for both concave and convex shapes. Since deformation happens locally, the forming force at any instant is significantly decreased when compared to traditional methods. The key advantages of DSIF are its high process flexibility, high energy-efficiency, low capital investment, and the elimination of the need for massive amounts of die casting and machining. Additionally, the enhanced formability and process flexibility of DSIF can open up design spaces and result in greater weight savings.

  9. Worthwhile optical method for free-form mirrors qualification

    Science.gov (United States)

    Sironi, G.; Canestrari, R.; Toso, G.; Pareschi, G.

    2013-09-01

    We present an optical method for free-form mirrors qualification developed by the Italian National Institute for Astrophysics (INAF) in the context of the ASTRI (Astrofisica con Specchi a Tecnologia Replicante Italiana) Project which includes, among its items, the design, development and installation of a dual-mirror telescope prototype for the Cherenkov Telescope Array (CTA) observatory. The primary mirror panels of the telescope prototype are free-form concave mirrors with few microns accuracy required on the shape error. The developed technique is based on the synergy between a Ronchi-like optical test performed on the reflecting surface and the image, obtained by means of the TraceIT ray-tracing proprietary code, a perfect optics should generate in the same configuration. This deflectometry test allows the reconstruction of the slope error map that the TraceIT code can process to evaluate the measured mirror optical performance at the telescope focus. The advantages of the proposed method is that it substitutes the use of 3D coordinates measuring machine reducing production time and costs and offering the possibility to evaluate on-site the mirror image quality at the focus. In this paper we report the measuring concept and compare the obtained results to the similar ones obtained processing the shape error acquired by means of a 3D coordinates measuring machine.

  10. Integrating optical, mechanical, and test software (with applications to freeform optics)

    Science.gov (United States)

    Genberg, Victor; Michels, Gregory; Myer, Brian

    2017-10-01

    Optical systems must perform under environmental conditions including thermal and mechanical loading. To predict the performance in the field, integrated analysis combining optical and mechanical software is required. Freeform and conformal optics offer many new opportunities for optical design. The unconventional geometries can lead to unconventional, and therefore unintuitive, mechanical behavior. Finite element (FE) analysis offers the ability to predict the deformations of freeform optics under various environments and load conditions. To understand the impact on optical performance, the deformations must be brought into optical analysis codes. This paper discusses several issues related to the integrated optomechanical analysis of freeform optics.

  11. Investigation of uniformity field generated from freeform lens with UV LED exposure system

    Science.gov (United States)

    Ciou, F. Y.; Chen, Y. C.; Pan, C. T.; Lin, P. H.; Lin, P. H.; Hsu, F. T.

    2015-03-01

    In the exposure process, the intensity and uniformity of light in the exposure area directly influenced the precision of products. UV-LED (Ultraviolet Light-Emitting Diode) exposure system was established to reduce the radiation leakage and increase the energy efficiency for energy saving. It is a trend that conventional mercury lamp could be replaced with UV-LED exposure system. This study was based on the law of conservation of energy and law of refraction of optical field distributing on the target plane. With these, a freeform lens with uniform light field of main exposure area could be designed. The light outside the exposure area could be concentrated into the area to improve the intensity of light. The refraction index and UV transmittance of Polydimethylsiloxane (PDMS) is 1.43 at 385 nm wavelength and 85-90%, respectively. The PDMS was used to fabricate the optics lens for UV-LEDs. The average illumination and the uniformity could be obtained by increasing the number of UV-LEDs and the spacing of different arrangement modes. After exposure process with PDMS lens, about 5% inaccuracy was obtained. Comparing to 10% inaccuracy of general exposure system, it shows that it is available to replace conventional exposure lamp with using UV-LEDs.

  12. T-Spline Based Unifying Registration Procedure for Free-Form Surface Workpieces in Intelligent CMM

    Directory of Open Access Journals (Sweden)

    Zhenhua Han

    2017-10-01

    Full Text Available With the development of the modern manufacturing industry, the free-form surface is widely used in various fields, and the automatic detection of a free-form surface is an important function of future intelligent three-coordinate measuring machines (CMMs. To improve the intelligence of CMMs, a new visual system is designed based on the characteristics of CMMs. A unified model of the free-form surface is proposed based on T-splines. A discretization method of the T-spline surface formula model is proposed. Under this discretization, the position and orientation of the workpiece would be recognized by point cloud registration. A high accuracy evaluation method is proposed between the measured point cloud and the T-spline surface formula. The experimental results demonstrate that the proposed method has the potential to realize the automatic detection of different free-form surfaces and improve the intelligence of CMMs.

  13. Freeform optics: a non-contact "test plate" for manufacturing, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The goal of this NASA SBIR Phase I study is to determine the feasibility of measuring precision (fractional wave) freeform optics using non-contact areal (imaging)...

  14. The Purdue Mechanics Freeform Classroom: A New Approach to Engineering Mechanics Education

    OpenAIRE

    Rhoads, Jeffrey F.; Nauman, Eric; Holloway, Beth M; Krousgrill, Charles Morton

    2014-01-01

    The [REMOVED] Mechanics Freeform Classroom: A New Approach to Engineering Mechanics EducationMotivated by the need to address the broad spectrum of learning styles embraced by today’sengineering students, a desire to encourage active, peer-to-peer, and self-learning, and a goal ofinteracting with every student despite ever-expanding enrollments, the mechanics faculty at[REMOVED] University have developed the [REMOVED] Mechanics Freeform Classroom(PMFC) -- a new approach to engineering mechani...

  15. User-Generated Free-Form Gestures for Authentication: Security and Memorability

    OpenAIRE

    Sherman, Michael; Clark, Gradeigh; Yang, Yulong; Sugrim, Shridatt; Modig, Arttu; Lindqvist, Janne; Oulasvirta, Antti; Roos, Teemu

    2014-01-01

    This paper studies the security and memorability of free-form multitouch gestures for mobile authentication. Towards this end, we collected a dataset with a generate-test-retest paradigm where participants (N=63) generated free-form gestures, repeated them, and were later retested for memory. Half of the participants decided to generate one-finger gestures, and the other half generated multi-finger gestures. Although there has been recent work on template-based gestures, there are yet no metr...

  16. Adaptive Robotic Fabrication for Conditions of Material Inconsistency

    DEFF Research Database (Denmark)

    Nicholas, Paul; Zwierzycki, Mateusz; Clausen Nørgaard, Esben

    2017-01-01

    This paper describes research that addresses the variable behaviour of industrial quality metals and the extension of computational techniques into the fabrication process. It describes the context of robotic incremental sheet metal forming, a freeform method for imparting 3D form onto a 2D thin...... and the fabrication process? Here, two adaptive methods are presented that aim to increase forming accuracy with only a minimum increase in fabrication time, and that maintain ongoing input from the results of the fabrication process. The first method is an online sensor-based strategy and the second method...

  17. Architectural Geometry and Fabrication-Aware Design

    KAUST Repository

    Pottmann, Helmut

    2013-04-27

    Freeform shapes and structures with a high geometric complexity play an increasingly important role in contemporary architecture. While digital models are easily created, the actual fabrication and construction remains a challenge. This is the source of numerous research problems many of which fall into the area of Geometric Computing and form part of a recently emerging research area, called "Architectural Geometry". The present paper provides a short survey of research in Architectural Geometry and shows how this field moves towards a new direction in Geometric Modeling which aims at combining shape design with important aspects of function and fabrication. © 2013 Kim Williams Books, Turin.

  18. Freeform Compliant CMOS Electronic Systems for Internet of Everything Applications

    KAUST Repository

    Shaikh, Sohail F.

    2017-01-17

    The state-of-the-art electronics technology has been an integral part of modern advances. The prevalent rise of the mobile device and computational technology in the age of information technology offers exciting applications that are attributed to sophisticated, enormously reliable, and most mature CMOS-based electronics. We are accustomed to high performance, cost-effective, multifunctional, and energy-efficient scaled electronics. However, they are rigid, bulky, and brittle. The convolution of flexibility and stretchability in electronics for emerging Internet of Everything application can unleash smart application horizon in unexplored areas, such as robotics, healthcare, smart cities, transport, and entertainment systems. While flexible and stretchable device themes are being remarkably chased, the realization of the fully compliant electronic system is unaddressed. Integration of data processing, storage, communication, and energy management devices complements a compliant system. Here, a comprehensive review is presented on necessity and design criteria for freeform (physically flexible and stretchable) compliant high-performance CMOS electronic systems.

  19. Freeform surface measurement and characterisation using a toolmakers microscope

    International Nuclear Information System (INIS)

    Wong, Francis Seung-yin; Chauh, Kong-Bieng; Venuvinod, Patri K

    2014-01-01

    Current freeform surface (FFS) characterization systems mainly cover aspects related to computer-aided design/manufacture (CAD/CAM). This paper describes a new approach that extends into computer-aided inspection (CAI).The following novel features are addressed: - ◼ Feature recognition and extraction from surface data; - ◼ Characterisation of properties of the surface's M and N vectors at individual vertex; - ◼ Development of a measuring plan using a toolmakers microscope for the inspection of the FFS; - ◼ Inspection of the actual FFS produced by CNC milling; - ◼ Verification of the measurement results and comparison with the CAD design data; Tests have shown that the deviations between the CAI and CAD data were within the estimated uncertainty limits

  20. Novel freeform optical surface design with spiral symmetry

    Science.gov (United States)

    Zamora, Pablo; Benítez, Pablo; Miñano, Juan C.; Vilaplana, Juan

    2011-10-01

    Manufacturing technologies as injection molding or embossing specify their production limits for minimum radii of the vertices or draft angle for demolding, for instance. These restrictions may limit the system optical efficiency or affect the generation of undesired artifacts on the illumination pattern when dealing with optical design. A novel manufacturing concept is presented here, in which the optical surfaces are not obtained from the usual revolution symmetry with respect to a central axis (z axis), but they are calculated as free-form surfaces describing a spiral trajectory around z axis. The main advantage of this new concept lies in the manufacturing process: a molded piece can be easily separated from its mold just by applying a combination of rotational movement around axis z and linear movement along axis z, even for negative draft angles. The general designing procedure will be described in detail.

  1. IR-laser assisted additive freeform optics manufacturing.

    Science.gov (United States)

    Hong, Zhihan; Liang, Rongguang

    2017-08-02

    Computer-controlled additive manufacturing (AM) processes, also known as three-dimensional (3D) printing, create 3D objects by the successive adding of a material or materials. While there have been tremendous developments in AM, the 3D printing of optics is lagging due to the limits in materials and tight requirements for optical applicaitons. We propose a new precision additive freeform optics manufacturing (AFOM) method using an pulsed infrared (IR) laser. Compared to ultraviolet (UV) curable materials, thermally curable optical silicones have a number of advantages, such as strong UV stability, non-yellowing, and high transmission, making it particularly suitable for optical applications. Pulsed IR laser radiation offers a distinct advantage in processing optical silicones, as the high peak intensity achieved in the focal region allows for curing the material quickly, while the brief duration of the laser-material interaction creates a negligible heat-affected zone.

  2. Freeform manufacturing of a microoptical lens array on a steep curved substrate by use of a voice coil fast tool servo.

    Science.gov (United States)

    Scheiding, Sebastian; Yi, Allen Y; Gebhardt, Andreas; Li, Lei; Risse, Stefan; Eberhardt, Ramona; Tünnermann, Andreas

    2011-11-21

    We report what is to our knowledge the first approach to diamond turn microoptical lens array on a steep curved substrate by use of a voice coil fast tool servo. In recent years ultraprecision machining has been employed to manufacture accurate optical components with 3D structure for beam shaping, imaging and nonimaging applications. As a result, geometries that are difficult or impossible to manufacture using lithographic techniques might be fabricated using small diamond tools with well defined cutting edges. These 3D structures show no rotational symmetry, but rather high frequency asymmetric features thus can be treated as freeform geometries. To transfer the 3D surface data with the high frequency freeform features into a numerical control code for machining, the commonly piecewise differentiable surfaces are represented as a cloud of individual points. Based on this numeric data, the tool radius correction is calculated to account for the cutting-edge geometry. Discontinuities of the cutting tool locations due to abrupt slope changes on the substrate surface are bridged using cubic spline interpolation.When superimposed with the trajectory of the rotationally symmetric substrate the complete microoptical geometry in 3D space is established. Details of the fabrication process and performance evaluation are described. © 2011 Optical Society of America

  3. 3D Printing PDMS Elastomer in a Hydrophilic Support Bath via Freeform Reversible Embedding.

    Science.gov (United States)

    Hinton, Thomas J; Hudson, Andrew; Pusch, Kira; Lee, Andrew; Feinberg, Adam W

    2016-10-10

    Polydimethylsiloxane (PDMS) elastomer is used in a wide range of biomaterial applications including microfluidics, cell culture substrates, flexible electronics, and medical devices. However, it has proved challenging to 3D print PDMS in complex structures due to its low elastic modulus and need for support during the printing process. Here we demonstrate the 3D printing of hydrophobic PDMS prepolymer resins within a hydrophilic Carbopol gel support via freeform reversible embedding (FRE). In the FRE printing process, the Carbopol support acts as a Bingham plastic that yields and fluidizes when the syringe tip of the 3D printer moves through it, but acts as a solid for the PDMS extruded within it. This, in combination with the immiscibility of hydrophobic PDMS in the hydrophilic Carbopol, confines the PDMS prepolymer within the support for curing times up to 72 h while maintaining dimensional stability. After printing and curing, the Carbopol support gel releases the embedded PDMS prints by using phosphate buffered saline solution to reduce the Carbopol yield stress. As proof-of-concept, we used Sylgard 184 PDMS to 3D print linear and helical filaments via continuous extrusion and cylindrical and helical tubes via layer-by-layer fabrication. Importantly, we show that the 3D printed tubes were manifold and perfusable. The results demonstrate that hydrophobic polymers with low viscosity and long cure times can be 3D printed using a hydrophilic support, expanding the range of biomaterials that can be used in additive manufacturing. Further, by implementing the technology using low cost open-source hardware and software tools, the FRE printing technique can be rapidly implemented for research applications.

  4. Comparison of optical design methods of freeform surfaces for imaging applications

    Science.gov (United States)

    Agócs, Tibor

    2015-09-01

    Optical systems based on freeform optical components offer many advantages over conventional systems in imaging applications, e.g. superior image quality, compact and lightweight designs. There are a few well established manufacturing method that can be used for the generation of freeform surfaces with low surface form error and low surface roughness, in the case of freeform mirrors e.g. diamond turning, nickel plating and post-polishing. Metrology is evolving rapidly, although developments are still needed in order to verify the manufactured surface with the necessary accuracy. Optical design methods of freeform surfaces are also lagging behind, many algorithms address non-imaging applications, but in the field of imaging (image-forming) only a few exists and works with various limitations. We compare the available techniques in freeform optical design for imaging and explore the advantages, disadvantages and boundary conditions of the different methods. We also intend to identify the most useful concepts and investigate how they can be embedded into commercially available optical design software.

  5. Parametric design of a part with free-form surfaces

    Institute of Scientific and Technical Information of China (English)

    KIM Yeoung-il; KIM Li-ra; JUN Cha-soo

    2006-01-01

    3D solid models for parts with regular-form surfaces (PRFSs) are effectively generated using traditional parametric design techniques. A new model is obtained by changing some parameters defining the model. The parts with free-form surfaces(PFFSs), however, cannot be defined by several parameters. Usually they are defined by some geometric elements like profile curves. The traditional parametric design approaches have not easily dealt with the PFFSs. A method for generating a solid model and an engineering drawing for PFFSs is proposed in this paper: First, the new profiles are generated from input point data. Second,the profile information is extracted from the existing model. Last, the old profiles are replaced with the new profiles. This method can preserve the associative information of the existing model and automatically generate the drawing including views, dimensions, and annotations. The proposed method has been implemented using a commercial CAD/CAM system, Unigraphics, and API functions written in C-language, and were applied to the blades of a turbine generator. Some illustrative examples are provided in order to show the effectiveness of the proposed method.

  6. Efficient free-form surface representation with application in orthodontics

    Science.gov (United States)

    Yamany, Sameh M.; El-Bialy, Ahmed M.

    1999-03-01

    Orthodontics is the branch of dentistry concerned with the study of growth of the craniofacial complex. The detection and correction of malocclusion and other dental abnormalities is one of the most important and critical phases of orthodontic diagnosis. This paper introduces a system that can assist in automatic orthodontics diagnosis. The system can be used to classify skeletal and dental malocclusion from a limited number of measurements. This system is not intended to deal with several cases but is aimed at cases more likely to be encountered in epidemiological studies. Prior to the measurement of the orthodontics parameters, the position of the teeth in the jaw model must be detected. A new free-form surface representation is adopted for the efficient and accurate segmentation and separation of teeth from a scanned jaw model. THe new representation encodes the curvature and surface normal information into a 2D image. Image segmentation tools are then sued to extract structures of high/low curvature. By iteratively removing these structures, individual teeth surfaces are obtained.

  7. Fast free-form deformable registration via calculus of variations

    International Nuclear Information System (INIS)

    Lu Weiguo; Chen Mingli; Olivera, Gustavo H; Ruchala, Kenneth J; Mackie, Thomas R

    2004-01-01

    In this paper, we present a fully automatic, fast and accurate deformable registration technique. This technique deals with free-form deformation. It minimizes an energy functional that combines both similarity and smoothness measures. By using calculus of variations, the minimization problem was represented as a set of nonlinear elliptic partial differential equations (PDEs). A Gauss-Seidel finite difference scheme is used to iteratively solve the PDE. The registration is refined by a multi-resolution approach. The whole process is fully automatic. It takes less than 3 min to register two three-dimensional (3D) image sets of size 256 x 256 x 61 using a single 933 MHz personal computer. Extensive experiments are presented. These experiments include simulations, phantom studies and clinical image studies. Experimental results show that our model and algorithm are suited for registration of temporal images of a deformable body. The registration of inspiration and expiration phases of the lung images shows that the method is able to deal with large deformations. When applied to the daily CT images of a prostate patient, the results show that registration based on iterative refinement of displacement field is appropriate to describe the local deformations in the prostate and the rectum. Similarity measures improved significantly after the registration. The target application of this paper is for radiotherapy treatment planning and evaluation that incorporates internal organ deformation throughout the course of radiation therapy. The registration method could also be equally applied in diagnostic radiology

  8. High Brightness HDR Projection Using Dynamic Freeform Lensing

    KAUST Repository

    Damberg, Gerwin

    2016-05-03

    Cinema projectors need to compete with home theater displays in terms of image quality. High frame rate and spatial resolution as well as stereoscopic 3D are common features today, but even the most advanced cinema projectors lack in-scene contrast and, more important, high peak luminance, both of which are essential perceptual attributes of images appearing realistic. At the same time, HDR image statistics suggest that the average image intensity in a controlled ambient viewing environment such as the cinema can be as low as 1% for cinematic HDR content and not often higher than 18%, middle gray in photography. Traditional projection systems form images and colors by blocking the source light from a lamp, therefore attenuating between 99% and 82% of light, on average. This inefficient use of light poses significant challenges for achieving higher peak brightness levels. In this work, we propose a new projector architecture built around commercially available components, in which light can be steered to form images. The gain in system efficiency significantly reduces the total cost of ownership of a projector (fewer components and lower operating cost), and at the same time increases peak luminance and improves black level beyond what is practically achievable with incumbent projector technologies. At the heart of this computational display technology is a new projector hardware design using phase modulation in combination with a new optimization algorithm that is capable of on-the-fly computation of freeform lens surfaces. © 2016 ACM.

  9. Precision reconstruction of manufactured free-form components

    Science.gov (United States)

    Ristic, Mihailo; Brujic, Djordje; Ainsworth, Iain

    2000-03-01

    Manufacturing needs in many industries, especially the aerospace and the automotive, involve CAD remodeling of manufactured free-form parts using NURBS. This is typically performed as part of 'first article inspection' or 'closing the design loop.' The reconstructed model must satisfy requirements such as accuracy, compatibility with the original CAD model and adherence to various constraints. The paper outlines a methodology for realizing this task. Efficiency and quality of the results are achieved by utilizing the nominal CAD model. It is argued that measurement and remodeling steps are equally important. We explain how the measurement was optimized in terms of accuracy, point distribution and measuring speed using a CMM. Remodeling steps include registration, data segmentation, parameterization and surface fitting. Enforcement of constraints such as continuity was performed as part of the surface fitting process. It was found necessary that the relevant algorithms are able to perform in the presence of measurement noise, while making no special assumptions about regularity of data distribution. In order to deal with real life situations, a number of supporting functions for geometric modeling were required and these are described. The presented methodology was applied using real aeroengine parts and the experimental results are presented.

  10. Multi-scale freeform surface texture filtering using a mesh relaxation scheme

    International Nuclear Information System (INIS)

    Jiang, Xiangqian; Abdul-Rahman, Hussein S; Scott, Paul J

    2013-01-01

    Surface filtering algorithms using Fourier, Gaussian, wavelets, etc, are well-established for simple Euclidean geometries. However, these filtration techniques cannot be applied to today's complex freeform surfaces, which have non-Euclidean geometries, without distortion of the results. This paper proposes a new multi-scale filtering algorithm for freeform surfaces that are represented by triangular meshes based on a mesh relaxation scheme. The proposed algorithm is capable of decomposing a freeform surface into different scales and separating surface roughness, waviness and form from each other, as will be demonstrated throughout the paper. Results of applying the proposed algorithm to computer-generated as well as real surfaces are represented and compared with a lifting wavelet filtering algorithm. (paper)

  11. Evaluating the performance of free-formed surface parts using an analytic network process

    Science.gov (United States)

    Qian, Xueming; Ma, Yanqiao; Liang, Dezhi

    2018-03-01

    To successfully design parts with a free-formed surface, the critical issue of how to evaluate and select a favourable evaluation strategy before design is raised. The evaluation of free-formed surface parts is a multiple criteria decision-making (MCDM) problem that requires the consideration of a large number of interdependent factors. The analytic network process (ANP) is a relatively new MCDM method that can systematically deal with all kinds of dependences. In this paper, the factors, which come from the life-cycle and influence the design of free-formed surface parts, are proposed. After analysing the interdependence among these factors, a Hybrid ANP (HANP) structure for evaluating the part’s curved surface is constructed. Then, a HANP evaluation of an impeller is presented to illustrate the application of the proposed method.

  12. Non-uniformly sampled grids in double pole coordinate system for freeform reflector construction

    Science.gov (United States)

    Ma, Donglin; Pacheco, Shaun; Feng, Zexin; Liang, Rongguang

    2015-08-01

    We propose a new method to design freeform reflectors by nonuniformly sampling the source intensity distribution in double pole coordinate system. In double pole coordinate system, there is no pole for the whole hemisphere because both poles of the spherical coordinate system are moved to southernmost point of the sphere and overlapped together. With symmetric definition of both angular coordinates in the modified double pole coordinate system, a better match between the source intensity distribution and target irradiance distribution can be achieved for reflectors with large acceptance solid angle, leading to higher light efficiency and better uniformity on the target surface. With non-uniform sampling of the source intensity, we can design circular freeform reflector to obtain uniform rectangular illumination pattern. Aided by the feedback optimization, the freeform reflector can achieve the collection efficiency for ideal point source over 0.7 and relative standard deviation (RSD) less than 0.1.

  13. Design of multisegmented freeform lens for LED fishing/working lamp with high efficiency.

    Science.gov (United States)

    Lai, Min-Feng; Anh, Nguyen Doan Quoc; Gao, Jia-Zhi; Ma, Hsin-Yi; Lee, Hsiao-Yi

    2015-10-01

    A novel LED fishing/working light is proposed to enhance the lighting efficiency of a fishing boat. The study is focused on the freeform secondary lens design so as to create a lamp that attracts fish and sheds light on the deck for the crew's work. The experimental results show that the proposed multisegmented freeform lens can deliver the proposed aim, giving 3 times as much illuminating power as the traditional high-intensity discharge fishing lamp does with the same input of electrical power.

  14. Analytic free-form lens design for imaging applications with high aspect ratio

    Science.gov (United States)

    Duerr, Fabian; Benítez, Pablo; Miñano, Juan Carlos; Meuret, Youri; Thienpont, Hugo

    2012-10-01

    A new three-dimensional analytic optics design method is presented that enables the coupling of three ray sets with only two free-form lens surfaces. Closely related to the Simultaneous Multiple Surface method in three dimensions (SMS3D), it is derived directly from Fermat's principle, leading to multiple sets of functional differential equations. The general solution of these equations makes it possible to calculate more than 80 coefficients for each implicit surface function. Ray tracing simulations of these free-form lenses demonstrate superior imaging performance for applications with high aspect ratio, compared to conventional rotational symmetric systems.

  15. Wavelet based free-form deformations for nonrigid registration

    Science.gov (United States)

    Sun, Wei; Niessen, Wiro J.; Klein, Stefan

    2014-03-01

    In nonrigid registration, deformations may take place on the coarse and fine scales. For the conventional B-splines based free-form deformation (FFD) registration, these coarse- and fine-scale deformations are all represented by basis functions of a single scale. Meanwhile, wavelets have been proposed as a signal representation suitable for multi-scale problems. Wavelet analysis leads to a unique decomposition of a signal into its coarse- and fine-scale components. Potentially, this could therefore be useful for image registration. In this work, we investigate whether a wavelet-based FFD model has advantages for nonrigid image registration. We use a B-splines based wavelet, as defined by Cai and Wang.1 This wavelet is expressed as a linear combination of B-spline basis functions. Derived from the original B-spline function, this wavelet is smooth, differentiable, and compactly supported. The basis functions of this wavelet are orthogonal across scales in Sobolev space. This wavelet was previously used for registration in computer vision, in 2D optical flow problems,2 but it was not compared with the conventional B-spline FFD in medical image registration problems. An advantage of choosing this B-splines based wavelet model is that the space of allowable deformation is exactly equivalent to that of the traditional B-spline. The wavelet transformation is essentially a (linear) reparameterization of the B-spline transformation model. Experiments on 10 CT lung and 18 T1-weighted MRI brain datasets show that wavelet based registration leads to smoother deformation fields than traditional B-splines based registration, while achieving better accuracy.

  16. Advanced freeform optics enabling ultra-compact VR headsets

    Science.gov (United States)

    Benitez, Pablo; Miñano, Juan C.; Zamora, Pablo; Grabovičkić, Dejan; Buljan, Marina; Narasimhan, Bharathwaj; Gorospe, Jorge; López, Jesús; Nikolić, Milena; Sánchez, Eduardo; Lastres, Carmen; Mohedano, Ruben

    2017-06-01

    We present novel advanced optical designs with a dramatically smaller display to eye distance, excellent image quality and a large field of view (FOV). This enables headsets to be much more compact, typically occupying about a fourth of the volume of a conventional headset with the same FOV. The design strategy of these optics is based on a multichannel approach, which reduces the distance from the eye to the display and the display size itself. Unlike conventional microlens arrays, which are also multichannel devices, our designs use freeform optical surfaces to produce excellent imaging quality in the entire field of view, even when operating at very oblique incidences. We present two families of compact solutions that use different types of lenslets: (1) refractive designs, whose lenslets are composed typically of two refractive surfaces each; and (2) light-folding designs that use prism-like three-surface lenslets, in which rays undergo refraction, reflection, total internal reflection and refraction again. The number of lenslets is not fixed, so different configurations may arise, adaptable for flat or curved displays with different aspect ratios. In the refractive designs the distance between the optics and the display decreases with the number of lenslets, allowing for displaying a light-field when the lenslet becomes significantly small than the eye pupil. On the other hand, the correlation between number of lenslets and the optics to display distance is broken in light-folding designs, since their geometry permits achieving a very short display to eye distance with even a small number of lenslets.

  17. Solid Freeform Fabrication Symposium Proceedings Held in Austin, Texas on August 9-11, 1993

    Science.gov (United States)

    1993-09-01

    di Produzione 1611 Headway Circle, Bldg 2 Austin TX 78712 Ed Economia DeirAzienda Austin TX 78754 Corso Duca Abruzzi 24 512 339-2922J fax: 512 339...Street Aeronautical Engineering & Mechanics Ed Economia DellAzienda Tucson AZ 85713 Troy NY 12180 Corso Duca Abruzzi 24 602 792-2616/ fax: 602 792

  18. In-chip fabrication of free-form 3D constructs for directed cell migration analysis

    DEFF Research Database (Denmark)

    Olsen, Mark Holm; Hjortø, Gertrud Malene; Hansen, Morten

    2013-01-01

    with a range of pore sizes from 5 × 5 μm to 15 × 15 μm and prefilled with fibrillar collagen. Dendritic cells seeded into the polymer chip in a concentration gradient of the chemoattractant CCL21 efficiently negotiated the microporous maze structure for pore sizes of 8 × 8 μm or larger. The cells migrating...... through smaller pore sizes made significantly more turns than those through larger pores. The introduction of additional defined barriers in the microporous structure resulted in dendritic cells making more turns while still being able to follow the chemoattractant concentration gradient....

  19. Finite Element Models for Electron Beam Freeform Fabrication Process, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — This Small Business Innovation Research Phase II proposal offers to develop a comprehensive computer simulation methodology based on the finite element method for...

  20. Piezoelectric Composites by Solid Freeform Fabrication: A Nature-Inspired Approach

    Science.gov (United States)

    Safari, A.; Akdoğan, E. K.

    Piezoelectrics and electrostrictors are indispensable materials for use in transducer technology, as they inherently possess both direct (sensing) and converse (actuation) effects. A piezoelectric/electrostrictive sensor converts a mechanical input (displacement or force) into a measurable electrical output through piezoelectric/electrostrictive energy conversion. In the case of a piezoelectric, an applied mechanical force (stress) induces a voltage across the terminals of the transducer. On the other hand, an applied mechanical force induces a change in the capacitance of an electrostrictive transducer that could be electrically detected. Hence, the mechanical to electrical energy conversion is accomplished directly when a piezoelectric is used, while the same is obtained indirectly if the electroactive material of choice is an electrostrictor. Conversely, both piezoelectric and electrostrictive materials develop an elastic strain under an applied electric field. The said elastic strain is linearly proportional to the applied field in a piezoelectric, whereas electrostrictive coupling involves the second-order (quadratic) coupling of electric field with elastic strain. While piezoelectricity is possible only in noncentrosymetric point groups, electrostriction is observed in all solids, which make it a much more general solid-state phenomenon. Sensing and actuation functions can coexist in a given transducer by the intelligent use of such materials. Piezoelectrics and electrostrictors, therefore, constitute the backbone of modern transducer technology, as mechanical to electric energy (and vice versa) conversion can be accomplished with great efficiency in a way that is second to none among all phenomena known to date [1,2].

  1. Solid Freeform Fabrication Proceedings (9th) Held in Austin, Texas on August 10-12 1998

    Science.gov (United States)

    1998-08-01

    through a CaFl viewport in the LENS glovebox using a 12 bit digital camera equipped with a telephoto lens and 650nm broad band filter. A total of 2048 ...SLS of investment casting shells - rapidly to metal parts 5 References König, W. (1990) Fertigungsverfahren Band 4, Massivumformung, VDI -Verlag

  2. Student Evaluation of Teaching: A Study Exploring Student Rating Instrument Free-Form Text Comments

    Science.gov (United States)

    Stupans, Ieva; McGuren, Therese; Babey, Anna Marie

    2016-01-01

    Student rating instruments are recognised to be valid indicators of effective instruction, providing a valuable tool to improve teaching. However, free-form text comments obtained from the open-ended question component of such surveys are only infrequently analysed comprehensively. We employed an innovative, systematic approach to the analysis of…

  3. Integrated Front–Rear-Grid Optimization of Free-Form Solar Cells

    NARCIS (Netherlands)

    Gupta, D.K.; Barink, M.; Galagan, Y.; Langelaar, M.

    2016-01-01

    Free-form solar cells expand solar power beyond traditional rectangular geometries. With the flexibility of being installed on objects of daily use, they allow making better use of available space and are expected to bring in new possibilities of generating solar power in the coming future. In

  4. Design, realization and testing of the nanomefos non-contact measurement machine for freeform optics

    NARCIS (Netherlands)

    Henselmans, R.; Cacace, L.; Rosielle, P.C.J.N.; Steinbuch, M.

    2008-01-01

    By applying freeform optics (figure 1) in high-end optical systems such as used in space, science and lithography applications, system performance can be improved while decreasing the system mass, size and number of required components (for instance [1]). The applicability of classical metrology

  5. A numerical method for the design of free-form reflectors for lighting applications

    NARCIS (Netherlands)

    Prins, C.R.; Thije Boonkkamp, ten J.H.M.; Roosmalen, van J.; IJzerman, W.L.; Tukker, T.W.

    2013-01-01

    In this article we present a method for the design of fully free-form reflectors for illumination systems. We derive an elliptic partial differential equation of the Monge-Ampère type for the surface of a reflector that converts an arbitrary parallel beam of light into a desired intensity output

  6. Adaptive Sampling based 3D Profile Measuring Method for Free-Form Surface

    Science.gov (United States)

    Duan, Xianyin; Zou, Yu; Gao, Qiang; Peng, Fangyu; Zhou, Min; Jiang, Guozhang

    2018-03-01

    In order to solve the problem of adaptability and scanning efficiency of the current surface profile detection device, a high precision and high efficiency detection approach is proposed for surface contour of free-form surface parts based on self- adaptability. The contact mechanical probe and the non-contact laser probe are synthetically integrated according to the sampling approach of adaptive front-end path detection. First, the front-end path is measured by the non-contact laser probe, and the detection path is planned by the internal algorithm of the measuring instrument. Then a reasonable measurement sampling is completed according to the planned path by the contact mechanical probe. The detection approach can effectively improve the measurement efficiency of the free-form surface contours and can simultaneously detect the surface contours of unknown free-form surfaces with different curvatures and even different rate of curvature. The detection approach proposed in this paper also has important reference value for free-form surface contour detection.

  7. Optically Clear and Resilient Free-Form µ-Optics 3D-Printed via Ultrafast Laser Lithography.

    Science.gov (United States)

    Jonušauskas, Linas; Gailevičius, Darius; Mikoliūnaitė, Lina; Sakalauskas, Danas; Šakirzanovas, Simas; Juodkazis, Saulius; Malinauskas, Mangirdas

    2017-01-02

    We introduce optically clear and resilient free-form micro-optical components of pure (non-photosensitized) organic-inorganic SZ2080 material made by femtosecond 3D laser lithography (3DLL). This is advantageous for rapid printing of 3D micro-/nano-optics, including their integration directly onto optical fibers. A systematic study of the fabrication peculiarities and quality of resultant structures is performed. Comparison of microlens resiliency to continuous wave (CW) and femtosecond pulsed exposure is determined. Experimental results prove that pure SZ2080 is ∼20 fold more resistant to high irradiance as compared with standard lithographic material (SU8) and can sustain up to 1.91 GW/cm² intensity. 3DLL is a promising manufacturing approach for high-intensity micro-optics for emerging fields in astro-photonics and atto-second pulse generation. Additionally, pyrolysis is employed to homogeneously shrink structures up to 40% by removing organic SZ2080 constituents. This opens a promising route towards downscaling photonic lattices and the creation of mechanically robust glass-ceramic microstructures.

  8. Optically Clear and Resilient Free-Form µ-Optics 3D-Printed via Ultrafast Laser Lithography

    Directory of Open Access Journals (Sweden)

    Linas Jonušauskas

    2017-01-01

    Full Text Available We introduce optically clear and resilient free-form micro-optical components of pure (non-photosensitized organic-inorganic SZ2080 material made by femtosecond 3D laser lithography (3DLL. This is advantageous for rapid printing of 3D micro-/nano-optics, including their integration directly onto optical fibers. A systematic study of the fabrication peculiarities and quality of resultant structures is performed. Comparison of microlens resiliency to continuous wave (CW and femtosecond pulsed exposure is determined. Experimental results prove that pure SZ2080 is ∼20 fold more resistant to high irradiance as compared with standard lithographic material (SU8 and can sustain up to 1.91 GW/cm2 intensity. 3DLL is a promising manufacturing approach for high-intensity micro-optics for emerging fields in astro-photonics and atto-second pulse generation. Additionally, pyrolysis is employed to homogeneously shrink structures up to 40% by removing organic SZ2080 constituents. This opens a promising route towards downscaling photonic lattices and the creation of mechanically robust glass-ceramic microstructures.

  9. Optically Clear and Resilient Free-Form μ-Optics 3D-Printed via Ultrafast Laser Lithography

    Science.gov (United States)

    Jonušauskas, Linas; Gailevičius, Darius; Mikoliūnaitė, Lina; Sakalauskas, Danas; Šakirzanovas, Simas; Juodkazis, Saulius; Malinauskas, Mangirdas

    2017-01-01

    We introduce optically clear and resilient free-form micro-optical components of pure (non-photosensitized) organic-inorganic SZ2080 material made by femtosecond 3D laser lithography (3DLL). This is advantageous for rapid printing of 3D micro-/nano-optics, including their integration directly onto optical fibers. A systematic study of the fabrication peculiarities and quality of resultant structures is performed. Comparison of microlens resiliency to continuous wave (CW) and femtosecond pulsed exposure is determined. Experimental results prove that pure SZ2080 is ∼20 fold more resistant to high irradiance as compared with standard lithographic material (SU8) and can sustain up to 1.91 GW/cm2 intensity. 3DLL is a promising manufacturing approach for high-intensity micro-optics for emerging fields in astro-photonics and atto-second pulse generation. Additionally, pyrolysis is employed to homogeneously shrink structures up to 40% by removing organic SZ2080 constituents. This opens a promising route towards downscaling photonic lattices and the creation of mechanically robust glass-ceramic microstructures. PMID:28772389

  10. Design a freeform microlens array module for any arbitrary-shape collimated beam shaping and color mixing

    Science.gov (United States)

    Chen, Enguo; Wu, Rengmao; Guo, Tailiang

    2014-06-01

    Collimated beam shaping with freeform surface usually employs a predefined mapping to tailor one or multiple freeform surfaces. Limitation on those designs is that the source, the freeform optics and the target are in fixed one-to-one correspondence with each other. To overcome this drawback, this paper presents a kind of freeform microlens array module integrated with an ultra-thin freeform microlens array and a condenser lens to reshape any arbitrary-shape collimated beam into a prescribed uniform rectangular illumination and achieve color mixing. The design theory is explicitly given, and some key issues are addressed. Several different application examples are given, and the target is obtained with high uniformity and energy efficiency. This freeform microlens array module, which shows better flexibility and practicality than the regular designs, can be used not only to reshape any arbitrary-shape collimated beam (or a collimated beam integrated with several sub-collimated beams), but also most importantly to achieve color mixing. With excellent optical performance and ultra-compact volume, this optical module together with the design theory can be further introduced into other applications and will have a huge market potential in the near future.

  11. Automated inspection of gaps on the free-form shape parts by laser scanning technologies

    Science.gov (United States)

    Zhou, Sen; Xu, Jian; Tao, Lei; An, Lu; Yu, Yan

    2018-01-01

    In industrial manufacturing processes, the dimensional inspection of the gaps on the free-form shape parts is critical and challenging, and is directly associated with subsequent assembly and terminal product quality. In this paper, a fast measuring method for automated gap inspection based on laser scanning technologies is presented. The proposed measuring method consists of three steps: firstly, the relative position is determined according to the geometric feature of measuring gap, which considers constraints existing in a laser scanning operation. Secondly, in order to acquire a complete gap profile, a fast and effective scanning path is designed. Finally, the range dimension of the gaps on the free-form shape parts including width, depth and flush, correspondingly, is described in a virtual environment. In the future, an appliance machine based on the proposed method will be developed for the on-line dimensional inspection of gaps on the automobile or aerospace production line.

  12. Compact illumination optic with three freeform surfaces for improved beam control.

    Science.gov (United States)

    Sorgato, Simone; Mohedano, Rubén; Chaves, Julio; Hernández, Maikel; Blen, José; Grabovičkić, Dejan; Benítez, Pablo; Miñano, Juan Carlos; Thienpont, Hugo; Duerr, Fabian

    2017-11-27

    Multi-chip and large size LEDs dominate the lighting market in developed countries these days. Nevertheless, a general optical design method to create prescribed intensity patterns for this type of extended sources does not exist. We present a design strategy in which the source and the target pattern are described by means of "edge wavefronts" of the system. The goal is then finding an optic coupling these wavefronts, which in the current work is a monolithic part comprising up to three freeform surfaces calculated with the simultaneous multiple surface (SMS) method. The resulting optic fully controls, for the first time, three freeform wavefronts, one more than previous SMS designs. Simulations with extended LEDs demonstrate improved intensity tailoring capabilities, confirming the effectiveness of our method and suggesting that enhanced performance features can be achieved by controlling additional wavefronts.

  13. Integrated manufacture of a freeform off-axis multi-reflective imaging system without optical alignment.

    Science.gov (United States)

    Li, Zexiao; Liu, Xianlei; Fang, Fengzhou; Zhang, Xiaodong; Zeng, Zhen; Zhu, Linlin; Yan, Ning

    2018-03-19

    Multi-reflective imaging systems find wide applications in optical imaging and space detection. However, it is faced with difficulties in adjusting the freeform mirrors with high accuracy to guarantee the optical function. Motivated by this, an alignment-free manufacture approach is proposed to machine the optical system. The direct optical performance-guided manufacture route is established without measuring the form error of freeform optics. An analytical model is established to investigate the effects of machine errors to serve the error identification and compensation in machining. Based on the integrated manufactured system, an ingenious self-designed testing configuration is constructed to evaluate the optical performance by directly measuring the wavefront aberration. Experiments are carried out to manufacture a three-mirror anastigmat, surface topographical details and optical performance shows agreement to the designed expectation. The final system works as an off-axis infrared imaging system. Results validate the feasibility of the proposed method to achieve excellent optical application.

  14. Synthesis of freeform refractive surfaces forming various radiation patterns using interpolation

    Science.gov (United States)

    Voznesenskaya, Anna; Mazur, Iana; Krizskiy, Pavel

    2017-09-01

    Optical freeform surfaces are very popular today in such fields as lighting systems, sensors, photovoltaic concentrators, and others. The application of such surfaces allows to obtain systems with a new quality with a reduced number of optical components to ensure high consumer characteristics: small size, weight, high optical transmittance. This article presents the methods of synthesis of refractive surface for a given source and the radiation pattern of various shapes using a computer simulation cubic spline interpolation.

  15. Automatic fitting of conical envelopes to free-form surfaces for flank CNC machining

    OpenAIRE

    Bo P.; Bartoň M.; Pottmann H.

    2017-01-01

    We propose a new algorithm to detect patches of free-form surfaces that can be well approximated by envelopes of a rotational cone under a rigid body motion. These conical envelopes are a preferable choice from the manufacturing point of view as they are, by-definition, manufacturable by computer numerically controlled (CNC) machining using the efficient flank (peripheral) method with standard conical tools. Our geometric approach exploits multi-valued vector fields that consist of vectors in...

  16. 3D Printing PDMS Elastomer in a Hydrophilic Support Bath via Freeform Reversible Embedding

    OpenAIRE

    Hinton, Thomas J.; Hudson, Andrew; Pusch, Kira; Lee, Andrew; Feinberg, Adam W.

    2016-01-01

    Polydimethylsiloxane (PDMS) elastomer is used in a wide range of biomaterial applications including microfluidics, cell culture substrates, flexible electronics, and medical devices. However, it has proved challenging to 3D print PDMS in complex structures due to its low elastic modulus and need for support during the printing process. Here we demonstrate the 3D printing of hydrophobic PDMS prepolymer resins within a hydrophilic Carbopol gel support via freeform reversible embedding (FRE). In...

  17. Why are freeform telescopes less alignment sensitive than a traditional unobscured TMA?

    Science.gov (United States)

    Thompson, Kevin P.; Schiesser, Eric; Rolland, Jannick P.

    2015-10-01

    As freeform optical systems emerge as interesting and innovative solutions for imaging in 3D packages there is an assumption they are going to be more sensitive particularly at assembly. While it is true that the clocking of the component becomes a relatively weak new tolerance, for the most effective new class of freeform systems the alignment sensitivity is actually lower in most cases than for a comparable traditional unobscured three mirror anastigmatic (TMA) telescope. Traditional unobscured TMA telescopes, whose designs emerged in the mid-70s and which begin to appear as hardware in the literature in the early 90s, are based on using increasingly offset apertures with otherwise coaxial rotationally symmetric mirrors. The mirrors (typically 3 to correct spherical, coma, and astigmatism) have evolved to contain more high order terms as the designs are pushed to more compact and wider field packages - the NIRCAM camera for the JWST is an excellent example of this [1]. As the higher order terms are added, the mirrors become increasingly sensitive to decenters and tilts. An emerging class of freeform telescopes that provide wider field of view and/or faster f/numbers than the traditional TMA are based on a strategy where the surface shape remains a low order Zernike-type surface even in compact, unobscured packages. This optical design strategy results in an optical form that is not only higher performance but simultaneously less sensitive to alignment.

  18. Virtual-stereo fringe reflection technique for specular free-form surface testing

    Science.gov (United States)

    Ma, Suodong; Li, Bo

    2016-11-01

    Due to their excellent ability to improve the performance of optical systems, free-form optics have attracted extensive interest in many fields, e.g. optical design of astronomical telescopes, laser beam expanders, spectral imagers, etc. However, compared with traditional simple ones, testing for such kind of optics is usually more complex and difficult which has been being a big barrier for the manufacture and the application of these optics. Fortunately, owing to the rapid development of electronic devices and computer vision technology, fringe reflection technique (FRT) with advantages of simple system structure, high measurement accuracy and large dynamic range is becoming a powerful tool for specular free-form surface testing. In order to obtain absolute surface shape distributions of test objects, two or more cameras are often required in the conventional FRT which makes the system structure more complex and the measurement cost much higher. Furthermore, high precision synchronization between each camera is also a troublesome issue. To overcome the aforementioned drawback, a virtual-stereo FRT for specular free-form surface testing is put forward in this paper. It is able to achieve absolute profiles with the help of only one single biprism and a camera meanwhile avoiding the problems of stereo FRT based on binocular or multi-ocular cameras. Preliminary experimental results demonstrate the feasibility of the proposed technique.

  19. Isogeometric analysis of free-form Timoshenko curved beams including the nonlinear effects of large deformations

    Science.gov (United States)

    Hosseini, Seyed Farhad; Hashemian, Ali; Moetakef-Imani, Behnam; Hadidimoud, Saied

    2018-03-01

    In the present paper, the isogeometric analysis (IGA) of free-form planar curved beams is formulated based on the nonlinear Timoshenko beam theory to investigate the large deformation of beams with variable curvature. Based on the isoparametric concept, the shape functions of the field variables (displacement and rotation) in a finite element analysis are considered to be the same as the non-uniform rational basis spline (NURBS) basis functions defining the geometry. The validity of the presented formulation is tested in five case studies covering a wide range of engineering curved structures including from straight and constant curvature to variable curvature beams. The nonlinear deformation results obtained by the presented method are compared to well-established benchmark examples and also compared to the results of linear and nonlinear finite element analyses. As the nonlinear load-deflection behavior of Timoshenko beams is the main topic of this article, the results strongly show the applicability of the IGA method to the large deformation analysis of free-form curved beams. Finally, it is interesting to notice that, until very recently, the large deformations analysis of free-form Timoshenko curved beams has not been considered in IGA by researchers.

  20. Portable waveguide display system with a large field of view by integrating freeform elements and volume holograms.

    Science.gov (United States)

    Han, Jian; Liu, Juan; Yao, Xincheng; Wang, Yongtian

    2015-02-09

    A compact waveguide display system integrating freeform elements and volume holograms is presented here for the first time. The use of freeform elements can broaden the field of view, which limits the applications of a holographic waveguide. An optimized system can achieve a diagonal field of view of 45° when the thickness of the waveguide planar is 3mm. Freeform-elements in-coupler and the volume holograms out-coupler were designed in detail in our study, and the influence of grating configurations on diffraction efficiency was analyzed thoroughly. The off-axis aberrations were well compensated by the in-coupler and the diffraction efficiency of the optimized waveguide display system could reach 87.57%. With integrated design, stability and reliability of this monochromatic display system were achieved and the alignment of the system was easily controlled by the record of the volume holograms, which makes mass production possible.

  1. Design of an off-axis visual display based on a free-form projection screen to realize stereo vision

    Science.gov (United States)

    Zhao, Yuanming; Cui, Qingfeng; Piao, Mingxu; Zhao, Lidong

    2017-10-01

    A free-form projection screen is designed for an off-axis visual display, which shows great potential in applications such as flight training for providing both accommodation and convergence cues for pilots. The method based on point cloud is proposed for the design of the free-form surface, and the design of the point cloud is controlled by a program written in the macro-language. In the visual display based on the free-form projection screen, when the error of the screen along Z-axis is 1 mm, the error of visual distance at each filed is less than 1%. And the resolution of the design for full field is better than 1‧, which meet the requirement of resolution for human eyes.

  2. Towards efficient 5-axis flank CNC machining of free-form surfaces via fitting envelopes of surfaces of revolution

    OpenAIRE

    Bo P.; Bartoň M.; Plakhotnik D.; Pottmann H.

    2016-01-01

    We introduce a new method that approximates free-form surfaces by envelopes of one-parameter motions of surfaces of revolution. In the context of 5-axis computer numerically controlled (CNC) machining, we propose a flank machining methodology which is a preferable scallop-free scenario when the milling tool and the machined free-form surface meet tangentially along a smooth curve. We seek both an optimal shape of the milling tool as well as its optimal path in 3D space and propose an optimiza...

  3. Design of off-axial Gregory telescope design with freeform mirror corrector

    Science.gov (United States)

    Bazhanov, Yu.; Vlakhko, V.

    2017-08-01

    In this paper a well-known approach is used for calculation of off-axis three-mirror telescope. It includes usage of conic cross-sections properties, each of the sections forming a stigmatic image. To create a compact optical system, a flat mirror aberration corrector is introduced, which is at later stage transformed into a free-form surface in order to compensate field aberrations. Similarly, one can introduce such a corrector in finalized layout for its further optimization and getting a suitable form, including the conversion of multimirrors axial optical system into decentered one. As an example, off-axial Gregory telescope embodiment is used for infrared waveband region, due to the fact that, unlike the Cassegrain telescope, it provides a real exit pupil, and usage of the mirror corrector brings several advantages. Firstly, this feature may be used to include cold stop or adaptive mirror in the exit pupil, wherein corrector is introduced into a converging beam before the focus of the first mirror. Secondly, when placing corrector in the exit pupil of the optical system it is possible to eliminate high and low order aberrations of center point, which in turn improves optical system f-number, and minimize field aberrations. As another example, off-axial Ritchey-Chretien telescope embodiment is used as a good fit for visible region systems. Analysis and calculation results of optical systems with free-form correctors with surfaces, defined by Power polynomial series are presented in this paper. Advantages of different freeform surfaces usage depends on optical system layouts specifics.

  4. High-efficiency free-form condenser overcoming rotational symmetry limitations.

    Science.gov (United States)

    Miñano, Juan C; Benítez, Pablo; Blen, José; Santamaría, Asunción

    2008-12-08

    Conventional condensers using rotational symmetric devices perform far from their theoretical limits when transferring optical power from sources such as arc lamps or halogen bulbs to the rectangular entrance of homogenizing prisms (target). We present a free-form condenser design (calculated with the SMS method) that overcomes the limitations inherent to rotational devices and can send to the target 1.8 times the power sent by an equivalent elliptical condenser for a 4:1 target aspect ratio and 1.5 times for 16:9 target and for practical values of target etendue.

  5. Design of compact freeform lens for application specific Light-Emitting Diode packaging.

    Science.gov (United States)

    Wang, Kai; Chen, Fei; Liu, Zongyuan; Luo, Xiaobing; Liu, Sheng

    2010-01-18

    Application specific LED packaging (ASLP) is an emerging technology for high performance LED lighting. We introduced a practical design method of compact freeform lens for extended sources used in ASLP. A new ASLP for road lighting was successfully obtained by integrating a polycarbonate compact freeform lens of small form factor with traditional LED packaging. Optical performance of the ASLP was investigated by both numerical simulation based on Monte Carlo ray tracing method and experiments. Results demonstrated that, comparing with traditional LED module integrated with secondary optics, the ASLP had advantages of much smaller size in volume (approximately 1/8), higher system lumen efficiency (approximately 8.1%), lower cost and more convenience for customers to design and assembly, enabling possible much wider applications of LED for general road lighting. Tolerance analyses were also conducted. Installation errors of horizontal and vertical deviations had more effects on the shape and uniformity of radiation pattern compared with rotational deviation. The tolerances of horizontal, vertical and rotational deviations of this lens were 0.11 mm, 0.14 mm and 2.4 degrees respectively, which were acceptable in engineering.

  6. LED surgical lighting system with multiple free-form surfaces for highly sterile operating theater application.

    Science.gov (United States)

    Liu, Peng; Zhang, Yaqin; Zheng, Zhenrong; Li, Haifeng; Liu, Xu

    2014-06-01

    Although the ventilation system is widely employed in the operating theater, a strictly sterile surgical environment still cannot be ensured because of laminar disturbance, which is mainly caused by the surgical lighting system. Abandoning traditional products, we propose an LED surgical lighting system, which can alleviate the laminar disturbance and provide an appropriate lighting condition for surgery. It contains a certain amount of LED lens units, which are embedded in the ceiling and arranged around the air supply smallpox. The LED lens unit integrated with an LED light source and a free-form lens is required to produce a uniform circular illumination with a large tolerance to the change of lighting distance. To achieve such a dedicated lens, two free-form refractive surfaces, which are converted into two ordinary differential equations by the design method presented in this paper, are used to deflect the rays. The results show that the LED surgical lighting system can provide an excellent illumination environment for surgery, and, apparently, the laminar disturbance also can be relieved.

  7. An Integrated Reverse Engineering Approach for Accuracy Control of Free-Form Objects

    Directory of Open Access Journals (Sweden)

    Pathak Vimal Kumar

    2016-12-01

    Full Text Available Computer-aided tools help in shortening and eradicating numerous repetitive tasks that reduces the gap between digital model and actual product. Use of these tools assists in realizing free-form objects such as custom fit products as described by a stringent interaction with the human body. Development of such a model presents a challenging situation for reverse engineering (RE which is not analogous with the requirement for generating simple geometric models. Hence, an alternating way of producing more accurate three-dimensional models is proposed. For creating accurate 3D models, point clouds are processed through filtering, segmentation, mesh smoothing and surface generation. These processes help in converting the initial unorganized point data into a 3D digital model and simultaneously influence the quality of model. This study provides an optimum balance for the best accuracy obtainable with maximum allowable deviation to lessen computer handling and processing time. A realistic non trivial case study of free-form prosthetic socket is considered. The accuracy obtained for the developed model is acceptable for the use in medical applications and FEM analysis.

  8. Free-form analysis of the cosmological evolution of radio sources

    International Nuclear Information System (INIS)

    Robertson, J.G.

    1980-01-01

    This paper extends an iterative scheme for calculation of free-form evolution functions able to reconcile observed radio source counts with the standard General Relativistic cosmological models. It is assumed that the luminosity dependence of the evolution consists of a gradual turn-on of evolution above a certain luminosity. No particular functional form is assumed for the redshift dependence of the evolution (i.e. it is free-form). The extension concerns the use of the luminosity distribution to supply an effective luminosity function, thus overcoming a problem of consistency at the high-luminosity end of the luminosity function, where the evolution function has to be known. This method also guarantees that the correct average redshifts will be predicted where they are known observationally at high flux densities. The new iterative scheme has been applied to the source counts at 408 MHz from the Molonglo Cross telescope, using the Einstein-de Sitter cosmology and a recent determination of the luminosity distribution for sources of S 408 > 10 Jy. (author)

  9. Design of an ultra-thin near-eye display with geometrical waveguide and freeform optics.

    Science.gov (United States)

    Cheng, Dewen; Wang, Yongtian; Xu, Chen; Song, Weitao; Jin, Guofan

    2014-08-25

    Small thickness and light weight are two important requirements for a see-through near-eye display which are achieved in this paper by using two advanced technologies: geometrical waveguide and freeform optics. A major problem associated with the geometrical waveguide is the stray light which can severely degrade the display quality. The causes and solutions to this problem are thoroughly studied. A mathematical model of the waveguide is established and a non-sequential ray tracing algorithm is developed, which enable us to carefully examine the stray light of the planar waveguide and explore a global searching method to find an optimum design with the least amount of stray light. A projection optics using freeform surfaces on a wedge shaped prism is also designed. The near-eye display integrating the projection optics and the waveguide has a field of view of 28°, an exit pupil diameter of 9.6mm and an exit pupil distance of 20mm. In our final design, the proportion of the stray light energy over the image output energy of the waveguide is reduced to 2%, the modulation transfer function values across the entire field of the eyepiece are above 0.5 at 30 line pairs/mm (lps/mm). A proof-of-concept prototype of the proposed geometrical waveguide near-eye display is developed and demonstrated.

  10. New reversing freeform lens design method for LED uniform illumination with extended source and near field

    Science.gov (United States)

    Zhao, Zhili; Zhang, Honghai; Zheng, Huai; Liu, Sheng

    2018-03-01

    In light-emitting diode (LED) array illumination (e.g. LED backlighting), obtainment of high uniformity in the harsh condition of the large distance height ratio (DHR), extended source and near field is a key as well as challenging issue. In this study, we present a new reversing freeform lens design algorithm based on the illuminance distribution function (IDF) instead of the traditional light intensity distribution, which allows uniform LED illumination in the above mentioned harsh conditions. IDF of freeform lens can be obtained by the proposed mathematical method, considering the effects of large DHR, extended source and near field target at the same time. In order to prove the claims, a slim direct-lit LED backlighting with DHR equal to 4 is designed. In comparison with the traditional lenses, illuminance uniformity of LED backlighting with the new lens increases significantly from 0.45 to 0.84, and CV(RMSE) decreases dramatically from 0.24 to 0.03 in the harsh condition. Meanwhile, luminance uniformity of LED backlighting with the new lens is obtained as high as 0.92 at the condition of extended source and near field. This new method provides a practical and effective way to solve the problem of large DHR, extended source and near field for LED array illumination.

  11. Optimization of freeform surfaces using intelligent deformation techniques for LED applications

    Science.gov (United States)

    Isaac, Annie Shalom; Neumann, Cornelius

    2018-04-01

    For many years, optical designers have great interests in designing efficient optimization algorithms to bring significant improvement to their initial design. However, the optimization is limited due to a large number of parameters present in the Non-uniform Rationaly b-Spline Surfaces. This limitation was overcome by an indirect technique known as optimization using freeform deformation (FFD). In this approach, the optical surface is placed inside a cubical grid. The vertices of this grid are modified, which deforms the underlying optical surface during the optimization. One of the challenges in this technique is the selection of appropriate vertices of the cubical grid. This is because these vertices share no relationship with the optical performance. When irrelevant vertices are selected, the computational complexity increases. Moreover, the surfaces created by them are not always feasible to manufacture, which is the same problem faced in any optimization technique while creating freeform surfaces. Therefore, this research addresses these two important issues and provides feasible design techniques to solve them. Finally, the proposed techniques are validated using two different illumination examples: street lighting lens and stop lamp for automobiles.

  12. A method of LED free-form tilted lens rapid modeling based on scheme language

    Science.gov (United States)

    Dai, Yidan

    2017-10-01

    According to nonimaging optical principle and traditional LED free-form surface lens, a new kind of LED free-form tilted lens was designed. And a method of rapid modeling based on Scheme language was proposed. The mesh division method was applied to obtain the corresponding surface configuration according to the character of the light source and the desired energy distribution on the illumination plane. Then 3D modeling software and the Scheme language programming are used to generate lens model respectively. With the help of optical simulation software, a light source with the size of 1mm*1mm*1mm in volume is used in experiment, and the lateral migration distance of illumination area is 0.5m, in which total one million rays are computed. We could acquire the simulated results of both models. The simulated output result shows that the Scheme language can prevent the model deformation problems caused by the process of the model transfer, and the degree of illumination uniformity is reached to 82%, and the offset angle is 26°. Also, the efficiency of modeling process is greatly increased by using Scheme language.

  13. Design method of freeform light distribution lens for LED automotive headlamp based on DMD

    Science.gov (United States)

    Ma, Jianshe; Huang, Jianwei; Su, Ping; Cui, Yao

    2018-01-01

    We propose a new method to design freeform light distribution lens for light-emitting diode (LED) automotive headlamp based on digital micro mirror device (DMD). With the Parallel optical path architecture, the exit pupil of the illuminating system is set in infinity. Thus the principal incident rays of micro lens in DMD is parallel. DMD is made of high speed digital optical reflection array, the function of distribution lens is to distribute the emergent parallel rays from DMD and get a lighting pattern that fully comply with the national regulation GB 25991-2010.We use DLP 4500 to design the light distribution lens, mesh the target plane regulated by the national regulation GB 25991-2010 and correlate the mesh grids with the active mirror array of DLP4500. With the mapping relations and the refraction law, we can build the mathematics model and get the parameters of freeform light distribution lens. Then we import its parameter into the three-dimensional (3D) software CATIA to construct its 3D model. The ray tracing results using Tracepro demonstrate that the Illumination value of target plane is easily adjustable and fully comply with the requirement of the national regulation GB 25991-2010 by adjusting the exit brightness value of DMD. The theoretical optical efficiencies of the light distribution lens designed using this method could be up to 92% without any other auxiliary lens.

  14. Production of Curved Precast Concrete Elements for Shell Structures and Free-form Architecture using the Flexible Mould Method

    NARCIS (Netherlands)

    Schipper, H.R.; Grünewald, S.; Eigenraam, P.; Raghunath, P.; Kok, M.A.D.

    2014-01-01

    Free-form buildings tend to be expensive. By optimizing the production process, economical and well-performing precast concrete structures can be manufactured. In this paper, a method is presented that allows producing highly accurate double curved-elements without the need for milling two expensive

  15. Evaluation of antinociceptive activity of nanoliposome-encapsulated and free-form diclofenac in rats and mice.

    Science.gov (United States)

    Goh, Jun Zheng; Tang, Sook Nai; Chiong, Hoe Siong; Yong, Yoke Keong; Zuraini, Ahmad; Hakim, Muhammad Nazrul

    2015-01-01

    Diclofenac is a nonsteroidal anti-inflammatory drug (NSAID) that exhibits anti-inflammatory, antinociceptive, and antipyretic activities. Liposomes have been shown to improve the therapeutic efficacy of encapsulated drugs. The present study was conducted to compare the antinociceptive properties between liposome-encapsulated and free-form diclofenac in vivo via different nociceptive assay models. Liposome-encapsulated diclofenac was prepared using the commercialized proliposome method. Antinociceptive effects of liposome-encapsulated and free-form diclofenac were evaluated using formalin test, acetic acid-induced abdominal writhing test, Randall-Selitto paw pressure test, and plantar test. The results of the writhing test showed a significant reduction of abdominal constriction in all treatment groups in a dose-dependent manner. The 20 mg/kg liposome-encapsulated diclofenac demonstrated the highest antinociceptive effect at 78.97% compared with 55.89% in the free-form group at equivalent dosage. Both liposome-encapsulated and free-form diclofenac produced significant results in the late phase of formalin assay at a dose of 20 mg/kg, with antinociception percentages of 78.84% and 60.71%, respectively. Significant results of antinociception were also observed in both hyperalgesia assays. For Randall-Sellito assay, the highest antinociception effect of 71.38% was achieved with 20 mg/kg liposome-encapsulated diclofenac, while the lowest antinociceptive effect of 17.32% was recorded with 0 mg/kg liposome formulation, whereas in the plantar test, the highest antinociceptive effect was achieved at 56.7% with 20 mg/kg liposome-encapsulated diclofenac, and the lowest effect was shown with 0 mg/kg liposome formulation of 8.89%. The present study suggests that liposome-encapsulated diclofenac exhibits higher antinociceptive efficacy in a dose-dependent manner in comparison with free-form diclofenac.

  16. Fabrication Facilities

    Data.gov (United States)

    Federal Laboratory Consortium — The Fabrication Facilities are a direct result of years of testing support. Through years of experience, the three fabrication facilities (Fort Hood, Fort Lewis, and...

  17. Additively Manufactured Low Cost Upper Stage Combustion Chamber

    Science.gov (United States)

    Protz, Christopher; Cooper, Ken; Ellis, David; Fikes, John; Jones, Zachary; Kim, Tony; Medina, Cory; Taminger, Karen; Willingham, Derek

    2016-01-01

    Over the past two years NASA's Low Cost Upper Stage Propulsion (LCUSP) project has developed Additive Manufacturing (AM) technologies and design tools aimed at reducing the costs and manufacturing time of regeneratively cooled rocket engine components. High pressure/high temperature combustion chambers and nozzles must be regeneratively cooled to survive their operating environment, causing their design fabrication to be costly and time consuming due to the number of individual steps and different processes required. Under LCUSP, AM technologies in Sintered Laser Melting (SLM) GRCop-84 and Electron Beam Freeform Fabrication (EBF3) Inconel 625 have been significantly advanced, allowing the team to successfully fabricate a 25k-class regenerative chamber. Estimates of the costs and schedule of future builds indicate cost reductions and significant schedule reductions will be enabled by this technology. Characterization of the microstructural and mechanical properties of the SLM-produced GRCop-84, EBF3 Inconel 625 and the interface layer between the two has been performed and indicates the properties will meet the design requirements. The LCUSP chamber is to be tested with a previously demonstrated SLM injector in order to advance the Technology Readiness Level (TRL) and demonstrate the capability of the application of these processes. NASA is advancing these technologies to reduce cost and schedule for future engine applications and commercial needs.

  18. Research on fabrication of aspheres at the Center of Optics Technology (University of Applied Science in Aalen); Techical Digest

    Science.gov (United States)

    Boerret, Rainer; Burger, Jochen; Bich, Andreas; Gall, Christoph; Hellmuth, Thomas

    2005-05-01

    The Center of Optics Technology at the University of Applied Science, founded in 2003, is part of the School of Optics and Mechatronics. It completes the existing optical engineering department with a full optical fabrication and metrology chain and serves in parallel as a technology transfer center, to provide area industries with the most up-to-date technology in optical fabrication and engineering. Two examples of research work will be presented. The first example is the optimizing of the grinding process for high precision aspheres, the other is generating and polishing of a freeform optical element which is used as a phase plate.

  19. Proceedings of the Solid Freeform Fabrication Symposium (3rd) Held in Austin, Texas on 3-5 August 1992

    Science.gov (United States)

    1992-09-01

    to accept; Manufacturing the desk could be only a very small facility for manufacturing Instant In every manufacturing process Manufacturing will be...produced " instant " parts Layer Characterized most, but not all Manufacturing of the new principles Material Deposit Includes the geometrical...using the NOODLES CAD environment [4]. Next, the CAD model is sliced, and the slices are used to generate files that control the laser mask cutting

  20. Freeform fabrication of tissue-simulating phantom for potential use of surgical planning in conjoined twins separation surgery.

    Science.gov (United States)

    Shen, Shuwei; Wang, Haili; Xue, Yue; Yuan, Li; Zhou, Ximing; Zhao, Zuhua; Dong, Erbao; Liu, Bin; Liu, Wendong; Cromeens, Barrett; Adler, Brent; Besner, Gail; Xu, Ronald X

    2017-09-08

    Preoperative assessment of tissue anatomy and accurate surgical planning is crucial in conjoined twin separation surgery. We developed a new method that combines three-dimensional (3D) printing, assembling, and casting to produce anatomic models of high fidelity for surgical planning. The related anatomic features of the conjoined twins were captured by computed tomography (CT), classified as five organ groups, and reconstructed as five computer models. Among these organ groups, the skeleton was produced by fused deposition modeling (FDM) using acrylonitrile-butadiene-styrene. For the other four organ groups, shell molds were prepared by FDM and cast with silica gel to simulate soft tissues, with contrast enhancement pigments added to simulate different CT and visual contrasts. The produced models were assembled, positioned firmly within a 3D printed shell mold simulating the skin boundary, and cast with transparent silica gel. The produced phantom was subject to further CT scan in comparison with that of the patient data for fidelity evaluation. Further data analysis showed that the produced model reassembled the geometric features of the original CT data with an overall mean deviation of less than 2 mm, indicating the clinical potential to use this method for surgical planning in conjoined twin separation surgery.

  1. 3D Printing, Additive Manufacturing, and Solid Freeform Fabrication: The Technologies of the Past, Present and Future

    Science.gov (United States)

    Beaman, Joseph

    2015-03-01

    Starting in the late 1980's, several new technologies were created that have the potential to revolutionize manufacturing. These technologies are, for the most part, additive processes that build up parts layer by layer. In addition, the processes that are being touted for hard-core manufacturing are primarily laser or e-beam based processes. This presentation gives a brief history of Additive Manufacturing and gives an assessment for these technologies. These technologies initially grew out of a commercial need for rapid prototyping. This market has a different requirement for process and quality control than traditional manufacturing. The relatively poor process control of the existing commercial Additive Manufacturing equipment is a vestige of this history. This presentation discusses this history and improvements in quality over time. The emphasis will be on Additive Manufacturing processes that are being considered for direct manufacturing, which is a different market than the 3D Printing ``Makerbot'' market. Topics discussed include past and present machine sensors, materials, and operational methods that were used in the past and those that are used today to create manufactured parts. Finally, a discussion of new methods and future directions of AM is presented.

  2. Sub-micrometre accurate free-form optics by three-dimensional printing on single-mode fibres

    Science.gov (United States)

    Gissibl, Timo; Thiele, Simon; Herkommer, Alois; Giessen, Harald

    2016-01-01

    Micro-optics are widely used in numerous applications, such as beam shaping, collimation, focusing and imaging. We use femtosecond 3D printing to manufacture free-form micro-optical elements. Our method gives sub-micrometre accuracy so that direct manufacturing even on single-mode fibres is possible. We demonstrate the potential of our method by writing different collimation optics, toric lenses, free-form surfaces with polynomials of up to 10th order for intensity beam shaping, as well as chiral photonic crystals for circular polarization filtering, all aligned onto the core of the single-mode fibres. We determine the accuracy of our optics by analysing the output patterns as well as interferometrically characterizing the surfaces. We find excellent agreement with numerical calculations. 3D printing of microoptics can achieve sufficient performance that will allow for rapid prototyping and production of beam-shaping and imaging devices. PMID:27339700

  3. A task specific uncertainty analysis method for least-squares-based form characterization of ultra-precision freeform surfaces

    International Nuclear Information System (INIS)

    Ren, M J; Cheung, C F; Kong, L B

    2012-01-01

    In the measurement of ultra-precision freeform surfaces, least-squares-based form characterization methods are widely used to evaluate the form error of the measured surfaces. Although many methodologies have been proposed in recent years to improve the efficiency of the characterization process, relatively little research has been conducted on the analysis of associated uncertainty in the characterization results which may result from those characterization methods being used. As a result, this paper presents a task specific uncertainty analysis method with application in the least-squares-based form characterization of ultra-precision freeform surfaces. That is, the associated uncertainty in the form characterization results is estimated when the measured data are extracted from a specific surface with specific sampling strategy. Three factors are considered in this study which include measurement error, surface form error and sample size. The task specific uncertainty analysis method has been evaluated through a series of experiments. The results show that the task specific uncertainty analysis method can effectively estimate the uncertainty of the form characterization results for a specific freeform surface measurement

  4. Two-step design method for highly compact three-dimensional freeform optical system for LED surface light source.

    Science.gov (United States)

    Mao, Xianglong; Li, Hongtao; Han, Yanjun; Luo, Yi

    2014-10-20

    Designing an illumination system for a surface light source with a strict compactness requirement is quite challenging, especially for the general three-dimensional (3D) case. In accordance with the two key features of an expected illumination distribution, i.e., a well-controlled boundary and a precise illumination pattern, a two-step design method is proposed in this paper for highly compact 3D freeform illumination systems. In the first step, a target shape scaling strategy is combined with an iterative feedback modification algorithm to generate an optimized freeform optical system with a well-controlled boundary of the target distribution. In the second step, a set of selected radii of the system obtained in the first step are optimized to further improve the illuminating quality within the target region. The method is quite flexible and effective to design highly compact optical systems with almost no restriction on the shape of the desired target field. As examples, three highly compact freeform lenses with ratio of center height h of the lens and the maximum dimension D of the source ≤ 2.5:1 are designed for LED surface light sources to form a uniform illumination distribution on a rectangular, a cross-shaped and a complex cross pierced target plane respectively. High light control efficiency of η > 0.7 as well as low relative standard illumination deviation of RSD < 0.07 is obtained simultaneously for all the three design examples.

  5. Evaluation of antinociceptive activity of nanoliposome-encapsulated and free-form diclofenac in rats and mice

    Directory of Open Access Journals (Sweden)

    Goh JZ

    2014-12-01

    Full Text Available Jun Zheng Goh,1 Sook Nai Tang,1 Hoe Siong Chiong,1,2 Yoke Keong Yong,3 Ahmad Zuraini,1 Muhammad Nazrul Hakim1,4 1Department of Biomedical Sciences, Universiti Putra Malaysia, Serdang, Selangor, Malaysia; 2InQpharm Group, Kuala Lumpur, Malaysia; 3Department of Human Anatomy, 4Halal Product Research Institute, Universiti Putra Malaysia, Serdang, Selangor, Malaysia Abstract: Diclofenac is a nonsteroidal anti-inflammatory drug (NSAID that exhibits anti-inflammatory, antinociceptive, and antipyretic activities. Liposomes have been shown to improve the therapeutic efficacy of encapsulated drugs. The present study was conducted to compare the antinociceptive properties between liposome-encapsulated and free-form diclofenac in vivo via different nociceptive assay models. Liposome-encapsulated diclofenac was prepared using the commercialized proliposome method. Antinociceptive effects of liposome-encapsulated and free-form diclofenac were evaluated using formalin test, acetic acid-induced abdominal writhing test, Randall–Selitto paw pressure test, and plantar test. The results of the writhing test showed a significant reduction of abdominal constriction in all treatment groups in a dose-dependent manner. The 20 mg/kg liposome-encapsulated diclofenac demonstrated the highest antinociceptive effect at 78.97% compared with 55.89% in the free-form group at equivalent dosage. Both liposome-encapsulated and free-form diclofenac produced significant results in the late phase of formalin assay at a dose of 20 mg/kg, with antinociception percentages of 78.84% and 60.71%, respectively. Significant results of antinociception were also observed in both hyperalgesia assays. For Randall–Sellito assay, the highest antinociception effect of 71.38% was achieved with 20 mg/kg liposome-encapsulated diclofenac, while the lowest antinociceptive effect of 17.32% was recorded with 0 mg/kg liposome formulation, whereas in the plantar test, the highest antinociceptive effect

  6. Integration Strategy for Free-form Lithium Ion Battery: Material, Design to System level Applications

    KAUST Repository

    Kutbee, Arwa T.

    2017-10-31

    Power supply in any electronic system is a crucial necessity. Especially so in fully compliant personalized advanced healthcare electronic self-powered systems where we envision seamless integration of sensors and actuators with data management components in a single freeform platform to augment the quality of our healthcare, smart living and sustainable future. However, the status-quo energy storage (battery) options require packaging to protect the indwelling toxic materials against harsh physiological environment and vice versa, compromising its mechanical flexibility, conformability and wearability at the highest electrochemical performance. Therefore, clean and safe energy storage solutions for wearable and implantable electronics are needed to replace the commercially used unsafe lithium-ion batteries. This dissertation discusses a highly manufacturable integration strategy for a free-form lithium-ion battery towards a genuine mechanically compliant wearable system. We sequentially start with the optimization process for the preparation of all solid-state material comprising a ‘’Lithium-free’’ lithium-ion microbattery with a focus on thin film texture optimization of the cathode material. State of the art complementary metal oxide semiconductor technology was used for the thin film based battery. Additionally, this thesis reports successful development of a transfer-less scheme for a flexible battery with small footprint and free form factor in a high yield production process. The reliable process for the flexible lithium-ion battery achieves an enhanced energy density by three orders of magnitude compared to the available rigid ones. Interconnection and bonding procedures of the developed batteries are discussed for a reliable back end of line process flexible, stretchable and stackable modules. Special attention is paid to the advanced bonding, handling and packaging strategies of flexible batteries towards system-level applications. Finally, this

  7. Digital fabrication

    CERN Document Server

    2012-01-01

    The Winter 2012 (vol. 14 no. 3) issue of the Nexus Network Journal features seven original papers dedicated to the theme “Digital Fabrication”. Digital fabrication is changing architecture in fundamental ways in every phase, from concept to artifact. Projects growing out of research in digital fabrication are dependent on software that is entirely surface-oriented in its underlying mathematics. Decisions made during design, prototyping, fabrication and assembly rely on codes, scripts, parameters, operating systems and software, creating the need for teams with multidisciplinary expertise and different skills, from IT to architecture, design, material engineering, and mathematics, among others The papers grew out of a Lisbon symposium hosted by the ISCTE-Instituto Universitario de Lisboa entitled “Digital Fabrication – A State of the Art”. The issue is completed with four other research papers which address different mathematical instruments applied to architecture, including geometric tracing system...

  8. Interferometry with flexible point source array for measuring complex freeform surface and its design algorithm

    Science.gov (United States)

    Li, Jia; Shen, Hua; Zhu, Rihong; Gao, Jinming; Sun, Yue; Wang, Jinsong; Li, Bo

    2018-06-01

    The precision of the measurements of aspheric and freeform surfaces remains the primary factor restrict their manufacture and application. One effective means of measuring such surfaces involves using reference or probe beams with angle modulation, such as tilted-wave-interferometer (TWI). It is necessary to improve the measurement efficiency by obtaining the optimum point source array for different pieces before TWI measurements. For purpose of forming a point source array based on the gradients of different surfaces under test, we established a mathematical model describing the relationship between the point source array and the test surface. However, the optimal point sources are irregularly distributed. In order to achieve a flexible point source array according to the gradient of test surface, a novel interference setup using fiber array is proposed in which every point source can be independently controlled on and off. Simulations and the actual measurement examples of two different surfaces are given in this paper to verify the mathematical model. Finally, we performed an experiment of testing an off-axis ellipsoidal surface that proved the validity of the proposed interference system.

  9. Generating Free-Form Grid Truss Structures from 3D Scanned Point Clouds

    Directory of Open Access Journals (Sweden)

    Hui Ding

    2017-01-01

    Full Text Available Reconstruction, according to physical shape, is a novel way to generate free-form grid truss structures. 3D scanning is an effective means of acquiring physical form information and it generates dense point clouds on surfaces of objects. However, generating grid truss structures from point clouds is still a challenge. Based on the advancing front technique (AFT which is widely used in Finite Element Method (FEM, a scheme for generating grid truss structures from 3D scanned point clouds is proposed in this paper. Based on the characteristics of point cloud data, the search box is adopted to reduce the search space in grid generating. A front advancing procedure suit for point clouds is established. Delaunay method and Laplacian method are used to improve the quality of the generated grids, and an adjustment strategy that locates grid nodes at appointed places is proposed. Several examples of generating grid truss structures from 3D scanned point clouds of seashells are carried out to verify the proposed scheme. Physical models of the grid truss structures generated in the examples are manufactured by 3D print, which solidifies the feasibility of the scheme.

  10. A Robot Trajectory Optimization Approach for Thermal Barrier Coatings Used for Free-Form Components

    Science.gov (United States)

    Cai, Zhenhua; Qi, Beichun; Tao, Chongyuan; Luo, Jie; Chen, Yuepeng; Xie, Changjun

    2017-10-01

    This paper is concerned with a robot trajectory optimization approach for thermal barrier coatings. As the requirements of high reproducibility of complex workpieces increase, an optimal thermal spraying trajectory should not only guarantee an accurate control of spray parameters defined by users (e.g., scanning speed, spray distance, scanning step, etc.) to achieve coating thickness homogeneity but also help to homogenize the heat transfer distribution on the coating surface. A mesh-based trajectory generation approach is introduced in this work to generate path curves on a free-form component. Then, two types of meander trajectories are generated by performing a different connection method. Additionally, this paper presents a research approach for introducing the heat transfer analysis into the trajectory planning process. Combining heat transfer analysis with trajectory planning overcomes the defects of traditional trajectory planning methods (e.g., local over-heating), which helps form the uniform temperature field by optimizing the time sequence of path curves. The influence of two different robot trajectories on the process of heat transfer is estimated by coupled FEM models which demonstrates the effectiveness of the presented optimization approach.

  11. In situ 3D nanoprinting of free-form coupling elements for hybrid photonic integration

    Science.gov (United States)

    Dietrich, P.-I.; Blaicher, M.; Reuter, I.; Billah, M.; Hoose, T.; Hofmann, A.; Caer, C.; Dangel, R.; Offrein, B.; Troppenz, U.; Moehrle, M.; Freude, W.; Koos, C.

    2018-04-01

    Hybrid photonic integration combines complementary advantages of different material platforms, offering superior performance and flexibility compared with monolithic approaches. This applies in particular to multi-chip concepts, where components can be individually optimized and tested. The assembly of such systems, however, requires expensive high-precision alignment and adaptation of optical mode profiles. We show that these challenges can be overcome by in situ printing of facet-attached beam-shaping elements. Our approach allows precise adaptation of vastly dissimilar mode profiles and permits alignment tolerances compatible with cost-efficient passive assembly techniques. We demonstrate a selection of beam-shaping elements at chip and fibre facets, achieving coupling efficiencies of up to 88% between edge-emitting lasers and single-mode fibres. We also realize printed free-form mirrors that simultaneously adapt beam shape and propagation direction, and we explore multi-lens systems for beam expansion. The concept paves the way to automated assembly of photonic multi-chip systems with unprecedented performance and versatility.

  12. Efficient color mixing through étendue conservation using freeform optics

    Science.gov (United States)

    Sorgato, Simone; Mohedano, Rubén.; Chaves, Julio; Cvetkovic, Aleksandra; Hernández, Maikel; Benitez, Pablo; Miñano, Juan C.; Thienpont, Hugo; Duerr, Fabian

    2015-08-01

    Today's SSL illumination market shows a clear trend to high flux packages with higher efficiency and higher CRI, realized by means of multiple color chips and phosphors. Such light sources require the optics to provide both near- and far-field color mixing. This design problem is particularly challenging for collimated luminaries, since traditional diffusers cannot be employed without enlarging the exit aperture and reducing brightness. Furthermore, diffusers compromise the light output ratio (efficiency) of the lamps to which they are applied. A solution, based on Köhler integration, consisting of a spherical cap comprising spherical microlenses on both its interior and exterior sides was presented in 2012. The diameter of this so-called Shell-Mixer was 3 times that of the chip array footprint. A new version of the Shell-Mixer, based on the Edge Ray Principle and conservation of etendue, where neither the outer shape of the cap nor the surfaces of the lenses are constrained to spheres or 2D Cartesian ovals will be shown in this work. The new shell is freeform, only twice as large as the original chip-array and equals the original model in terms of color uniformity, brightness and efficiency.

  13. Freeform étendue-preserving optics for light and color mixing

    Science.gov (United States)

    Sorgato, Simone; Mohedano, Rubén.; Chaves, Julio; Cvetkovic, Aleksandra; Hernández, Maikel; Benítez, Pablo; Miñano, Juan C.; Thienpont, Hugo; Duerr, Fabian

    2015-09-01

    Today's SSL illumination market shows a clear trend towards high flux packages with higher efficiency and higher CRI, realized by means of multiple color chips and phosphors. Such light sources require the optics to provide both near- and far-field color mixing. This design problem is particularly challenging for collimated luminaries, since traditional diffusers cannot be employed without enlarging the exit aperture and reducing brightness (so increasing étendue). Furthermore, diffusers compromise the light output ratio (efficiency) of the lamps to which they are applied. A solution, based on Köhler integration, consisting of a spherical cap comprising spherical microlenses on both its interior and exterior sides was presented in 2012. When placed on top of an inhomogeneous multichip Lambertian LED, this so-called Shell-Mixer creates a homogeneous (both spatially and angularly) virtual source, also Lambertian, where the images of the chips merge. The virtual source is located at the same position with essentially the same size of the original source. The diameter of this optics was 3 times that of the chip-array footprint. In this work, we present a new version of the Shell-Mixer, based on the Edge Ray Principle, where neither the overall shape of the cap nor the surfaces of the lenses are constrained to spheres or rotational Cartesian ovals. This new Shell- Mixer is freeform, only twice as large as the original chip-array and equals the original model in terms of brightness, color uniformity and efficiency.

  14. Mesh-free free-form lensing - I. Methodology and application to mass reconstruction

    Science.gov (United States)

    Merten, Julian

    2016-09-01

    Many applications and algorithms in the field of gravitational lensing make use of meshes with a finite number of nodes to analyse and manipulate data. Specific examples in lensing are astronomical CCD images in general, the reconstruction of density distributions from lensing data, lens-source plane mapping or the characterization and interpolation of a point spread function. We present a numerical framework to interpolate and differentiate in the mesh-free domain, defined by nodes with coordinates that follow no regular pattern. The framework is based on radial basis functions (RBFs) to smoothly represent data around the nodes. We demonstrate the performance of Gaussian RBF-based, mesh-free interpolation and differentiation, which reaches the sub-percent level in both cases. We use our newly developed framework to translate ideas of free-form mass reconstruction from lensing on to the mesh-free domain. By reconstructing a simulated mock lens we find that strong-lensing only reconstructions achieve <10 per cent accuracy in the areas where these constraints are available but provide poorer results when departing from these regions. Weak-lensing only reconstructions give <10 per cent accuracy outside the strong-lensing regime, but cannot resolve the inner core structure of the lens. Once both regimes are combined, accurate reconstructions can be achieved over the full field of view. The reconstruction of a simulated lens, using constraints that mimics real observations, yields accurate results in terms of surface-mass density, Navarro-Frenk-White profile (NFW) parameters, Einstein radius and magnification map recovery, encouraging the application of this method to real data.

  15. Fabrication challenges associated with conformal optics

    Science.gov (United States)

    Schaefer, John; Eichholtz, Richard A.; Sulzbach, Frank C.

    2001-09-01

    A conformal optic is typically an optical window that conforms smoothly to the external shape of a system platform to improve aerodynamics. Conformal optics can be on-axis, such as an ogive missile dome, or off-axis, such as in a free form airplane wing. A common example of conformal optics is the automotive head light window that conforms to the body of the car aerodynamics and aesthetics. The unusual shape of conformal optics creates tremendous challenges for design, manufacturing, and testing. This paper will discuss fabrication methods that have been successfully demonstrated to produce conformal missile domes and associated wavefront corrector elements. It will identify challenges foreseen with more complex free-form configurations. Work presented in this paper was directed by the Precision Conformal Optics Consortium (PCOT). PCOT is comprised of both industrial and academic members who teamed to develop and demonstrate conformal optical systems suitable for insertion into future military programs. The consortium was funded under DARPA agreement number MDA972-96-9-08000.

  16. Multi-optical-axis measurement of freeform progressive addition lenses using a Hartmann-Shack wavefront sensor

    Science.gov (United States)

    Xiang, Huazhong; Guo, Hang; Fu, Dongxiang; Zheng, Gang; Zhuang, Songlin; Chen, JiaBi; Wang, Cheng; Wu, Jie

    2018-05-01

    To precisely measure the whole-surface characterization of freeform progressive addition lenses (PALs), considering the multi-optical-axis conditions is becoming particularly important. Spherical power and astigmatism (cylinder) measurements for freeform PALs, using a Hartmann-Shack wavefront sensor (HSWFS) are proposed herein. Conversion formulas for the optical performance results were provided as HSWFS Zernike polynomial expansions. For each selected zone, the studied PALs were placed and tilted to simulate the multi-optical-axis conditions. The results of two tested PALs were analyzed using MATLAB programs and represented as contour plots of the spherical equivalent and cylinder of the whole-surface. The proposed experimental setup can provide a high accuracy as well as a possibility of choosing 12 lines and positions of 193 measurement zones on the entire surface. This approach to PAL analysis is potentially an efficient and useful method to objectively evaluate the optical performances, in which the full lens surface is defined and expressed as the contour plots of power in different regions (i.e., the distance region, progressive region, and near region) of the lens for regions of interest.

  17. A unified free-form representation applied to the shape optimization of the hohlraum with octahedral 6 laser entrance holes

    International Nuclear Information System (INIS)

    Jiang, Shaoen; Ding, Yongkun; Huang, Yunbao; Li, Haiyan; Jing, Longfei; Huang, Tianxuan

    2016-01-01

    The hohlraum is very crucial for indirect laser driven Inertial Confinement Fusion. Usually, its shape is designed as sphere, cylinder, or rugby with some kind of fixed functions, such as ellipse or parabola. Recently, a spherical hohlraum with octahedral 6 laser entrance holes (LEHs) has been presented with high flux symmetry [Lan et al., Phys. Plasmas 21, 010704 (2014); 21, 052704 (2014)]. However, there is only one shape parameter, i.e., the hohlraum to capsule radius ratio, being optimized. In this paper, we build the hohlraum with octahedral 6LEHs with a unified free-form representation, in which, by varying additional shape parameters: (1) available hohlraum shapes can be uniformly and accurately represented, (2) it can be used to understand why the spherical hohlraum has higher flux symmetry, (3) it allows us to obtain a feasible shape design field satisfying flux symmetry constraints, and (4) a synthetically optimized hohlraum can be obtained with a tradeoff of flux symmetry and other hohlraum performance. Finally, the hohlraum with octahedral 6LEHs is modeled, analyzed, and then optimized based on the unified free-form representation. The results show that a feasible shape design field with flux asymmetry no more than 1% can be obtained, and over the feasible design field, the spherical hohlraum is validated to have the highest flux symmetry, and a synthetically optimal hohlraum can be found with closing flux symmetry but larger volume between laser spots and centrally located capsule

  18. A unified free-form representation applied to the shape optimization of the hohlraum with octahedral 6 laser entrance holes

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Shaoen; Ding, Yongkun [Laser Fusion Research Center, China Academy of Engineering Physics, Mianyang 621900 (China); Center for Applied Physics and Technology, Peking University, Beijing 100871 (China); Huang, Yunbao, E-mail: Huangyblhy@gmail.com, E-mail: scmyking-2008@163.com; Li, Haiyan [Key Laboratory of Computer Integrated Manufacturing System, Guangdong University of Technology, Guangzhou 510006 (China); Jing, Longfei, E-mail: Huangyblhy@gmail.com, E-mail: scmyking-2008@163.com; Huang, Tianxuan [Laser Fusion Research Center, China Academy of Engineering Physics, Mianyang 621900 (China)

    2016-01-15

    The hohlraum is very crucial for indirect laser driven Inertial Confinement Fusion. Usually, its shape is designed as sphere, cylinder, or rugby with some kind of fixed functions, such as ellipse or parabola. Recently, a spherical hohlraum with octahedral 6 laser entrance holes (LEHs) has been presented with high flux symmetry [Lan et al., Phys. Plasmas 21, 010704 (2014); 21, 052704 (2014)]. However, there is only one shape parameter, i.e., the hohlraum to capsule radius ratio, being optimized. In this paper, we build the hohlraum with octahedral 6LEHs with a unified free-form representation, in which, by varying additional shape parameters: (1) available hohlraum shapes can be uniformly and accurately represented, (2) it can be used to understand why the spherical hohlraum has higher flux symmetry, (3) it allows us to obtain a feasible shape design field satisfying flux symmetry constraints, and (4) a synthetically optimized hohlraum can be obtained with a tradeoff of flux symmetry and other hohlraum performance. Finally, the hohlraum with octahedral 6LEHs is modeled, analyzed, and then optimized based on the unified free-form representation. The results show that a feasible shape design field with flux asymmetry no more than 1% can be obtained, and over the feasible design field, the spherical hohlraum is validated to have the highest flux symmetry, and a synthetically optimal hohlraum can be found with closing flux symmetry but larger volume between laser spots and centrally located capsule.

  19. Evaluation of Parameters Affecting Magnetic Abrasive Finishing on Concave Freeform Surface of Al Alloy via RSM Method

    Directory of Open Access Journals (Sweden)

    Mehrdad Vahdati

    2016-01-01

    Full Text Available The attempts of researchers in industries to obtain accurate and high quality surfaces led to the invention of new methods of finishing. Magnetic abrasive finishing (MAF is a relatively new type of finishing in which the magnetic field is used to control the abrasive tools. Applications such as the surface of molds are ones of the parts which require very high surface smoothness. Usually this type of parts has freeform surface. In this study, the effect of magnetic abrasive process parameters on freeform surfaces of parts made of aluminum is examined. This method is obtained through combination of magnetic abrasive process and Control Numerical Computer (CNC. The use of simple hemisphere for installation on the flat area of the magnets as well as magnets’ spark in curve form is a measure done during testing the experiments. The design of experiments is based on response surface methodology. The gap, the rotational speed of the spindle, and the feed rate are found influential and regression equations governing the process are also determined. The impact of intensity of the magnetic field is obtained using the finite element software of Maxwell. Results show that in concave areas of the surface, generally speaking, the surface roughness decreases to 0.2 μm from its initial 1.3 μm roughness. However, in some points the lowest surface roughness of 0.08 μm was measured.

  20. Fabricated Elastin.

    Science.gov (United States)

    Yeo, Giselle C; Aghaei-Ghareh-Bolagh, Behnaz; Brackenreg, Edwin P; Hiob, Matti A; Lee, Pearl; Weiss, Anthony S

    2015-11-18

    The mechanical stability, elasticity, inherent bioactivity, and self-assembly properties of elastin make it a highly attractive candidate for the fabrication of versatile biomaterials. The ability to engineer specific peptide sequences derived from elastin allows the precise control of these physicochemical and organizational characteristics, and further broadens the diversity of elastin-based applications. Elastin and elastin-like peptides can also be modified or blended with other natural or synthetic moieties, including peptides, proteins, polysaccharides, and polymers, to augment existing capabilities or confer additional architectural and biofunctional features to compositionally pure materials. Elastin and elastin-based composites have been subjected to diverse fabrication processes, including heating, electrospinning, wet spinning, solvent casting, freeze-drying, and cross-linking, for the manufacture of particles, fibers, gels, tubes, sheets and films. The resulting materials can be tailored to possess specific strength, elasticity, morphology, topography, porosity, wettability, surface charge, and bioactivity. This extraordinary tunability of elastin-based constructs enables their use in a range of biomedical and tissue engineering applications such as targeted drug delivery, cell encapsulation, vascular repair, nerve regeneration, wound healing, and dermal, cartilage, bone, and dental replacement. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. An Ethology of Urban Fabric(s)

    DEFF Research Database (Denmark)

    Fritsch, Jonas; Thomsen, Bodil Marie Stavning

    2014-01-01

    The article explores a non-metaphorical understanding of urban fabric(s), shifting the attention from a bird’s eye perspective to the actual, textural manifestations of a variety of urban fabric(s) to be studied in their real, processual, ecological and ethological complexity within urban life. We...... effectuate this move by bringing into resonance a range of intersecting fields that all deal with urban fabric(s) in complementary ways (interaction design and urban design activism, fashion, cultural theory, philosophy, urban computing)....

  2. Curcumin β-D-Glucuronide Plays an Important Role to Keep High Levels of Free-Form Curcumin in the Blood.

    Science.gov (United States)

    Ozawa, Hitomi; Imaizumi, Atsushi; Sumi, Yoshihiko; Hashimoto, Tadashi; Kanai, Masashi; Makino, Yuji; Tsuda, Takanori; Takahashi, Nobuaki; Kakeya, Hideaki

    2017-01-01

    Curcumin, a polyphenol derived from the rhizome of the naturally occurring plant Curcuma longa, has various pharmacological actions such as antioxidant and anti-inflammatory effects. In this paper, we evaluated the role of its internal metabolite, curcumin β-D-glucuronide (curcumin monoglucuronide, CMG), by investigating curcumin kinetics and metabolism in the blood. Firstly, we orally administered highly bioavailable curcumin to rats to elucidate its kinetics, and observed not only the free-form of curcumin, but also, curcumin in a conjugated form, within the portal vein. We confirmed that curcumin is conjugated when it passes through the intestinal wall. CMG, one of the metabolites, was then orally administered to rats. Despite its high aqueous solubility compared to free-form curcumin, it was not well absorbed. In addition, CMG was injected intravenously into rats in order to assess its metabolic behavior in the blood. Interestingly, high levels of free-form curcumin, thought to be sufficiently high to be pharmacologically active, were observed. The in vivo antitumor effects of CMG following intravenous injection were then evaluated in tumor-bearing mice with the HCT116 human colon cancer cell line. The tumor volume within the CMG group was significantly less than that of the control group. Moreover, there was no significant loss of body weight in the CMG group compared to the control group. These results suggest that CMG could be used as an anticancer agent without the serious side effects that most anticancer agents have.

  3. Fabrication and Prototyping Lab

    Data.gov (United States)

    Federal Laboratory Consortium — Purpose: The Fabrication and Prototyping Lab for composite structures provides a wide variety of fabrication capabilities critical to enabling hands-on research and...

  4. Fabrication of recyclable superhydrophobic cotton fabrics

    Science.gov (United States)

    Han, Sang Wook; Park, Eun Ji; Jeong, Myung-Geun; Kim, Il Hee; Seo, Hyun Ook; Kim, Ju Hwan; Kim, Kwang-Dae; Kim, Young Dok

    2017-04-01

    Commercial cotton fabric was coated with SiO2 nanoparticles wrapped with a polydimethylsiloxane (PDMS) layer, and the resulting material surface showed a water contact angle greater than 160°. The superhydrophobic fabric showed resistance to water-soluble contaminants and maintained its original superhydrophobic properties with almost no alteration even after many times of absorption-washing cycles of oil. Moreover, superhydrophobic fabric can be used as a filter to separate oil from water. We demonstrated a simple method of fabrication of superhydrophobic fabric with potential interest for use in a variety of applications.

  5. Automatic segmentation of phase-correlated CT scans through nonrigid image registration using geometrically regularized free-form deformation

    International Nuclear Information System (INIS)

    Shekhar, Raj; Lei, Peng; Castro-Pareja, Carlos R.; Plishker, William L.; D'Souza, Warren D.

    2007-01-01

    Conventional radiotherapy is planned using free-breathing computed tomography (CT), ignoring the motion and deformation of the anatomy from respiration. New breath-hold-synchronized, gated, and four-dimensional (4D) CT acquisition strategies are enabling radiotherapy planning utilizing a set of CT scans belonging to different phases of the breathing cycle. Such 4D treatment planning relies on the availability of tumor and organ contours in all phases. The current practice of manual segmentation is impractical for 4D CT, because it is time consuming and tedious. A viable solution is registration-based segmentation, through which contours provided by an expert for a particular phase are propagated to all other phases while accounting for phase-to-phase motion and anatomical deformation. Deformable image registration is central to this task, and a free-form deformation-based nonrigid image registration algorithm will be presented. Compared with the original algorithm, this version uses novel, computationally simpler geometric constraints to preserve the topology of the dense control-point grid used to represent free-form deformation and prevent tissue fold-over. Using mean squared difference as an image similarity criterion, the inhale phase is registered to the exhale phase of lung CT scans of five patients and of characteristically low-contrast abdominal CT scans of four patients. In addition, using expert contours for the inhale phase, the corresponding contours were automatically generated for the exhale phase. The accuracy of the segmentation (and hence deformable image registration) was judged by comparing automatically segmented contours with expert contours traced directly in the exhale phase scan using three metrics: volume overlap index, root mean square distance, and Hausdorff distance. The accuracy of the segmentation (in terms of radial distance mismatch) was approximately 2 mm in the thorax and 3 mm in the abdomen, which compares favorably to the

  6. Polymorphous computing fabric

    Science.gov (United States)

    Wolinski, Christophe Czeslaw [Los Alamos, NM; Gokhale, Maya B [Los Alamos, NM; McCabe, Kevin Peter [Los Alamos, NM

    2011-01-18

    Fabric-based computing systems and methods are disclosed. A fabric-based computing system can include a polymorphous computing fabric that can be customized on a per application basis and a host processor in communication with said polymorphous computing fabric. The polymorphous computing fabric includes a cellular architecture that can be highly parameterized to enable a customized synthesis of fabric instances for a variety of enhanced application performances thereof. A global memory concept can also be included that provides the host processor random access to all variables and instructions associated with the polymorphous computing fabric.

  7. Robust Spatial Approximation of Laser Scanner Point Clouds by Means of Free-form Curve Approaches in Deformation Analysis

    Science.gov (United States)

    Bureick, Johannes; Alkhatib, Hamza; Neumann, Ingo

    2016-03-01

    In many geodetic engineering applications it is necessary to solve the problem of describing a measured data point cloud, measured, e. g. by laser scanner, by means of free-form curves or surfaces, e. g., with B-Splines as basis functions. The state of the art approaches to determine B-Splines yields results which are seriously manipulated by the occurrence of data gaps and outliers. Optimal and robust B-Spline fitting depend, however, on optimal selection of the knot vector. Hence we combine in our approach Monte-Carlo methods and the location and curvature of the measured data in order to determine the knot vector of the B-Spline in such a way that no oscillating effects at the edges of data gaps occur. We introduce an optimized approach based on computed weights by means of resampling techniques. In order to minimize the effect of outliers, we apply robust M-estimators for the estimation of control points. The above mentioned approach will be applied to a multi-sensor system based on kinematic terrestrial laserscanning in the field of rail track inspection.

  8. A Gradient-Based Multistart Algorithm for Multimodal Aerodynamic Shape Optimization Problems Based on Free-Form Deformation

    Science.gov (United States)

    Streuber, Gregg Mitchell

    Environmental and economic factors motivate the pursuit of more fuel-efficient aircraft designs. Aerodynamic shape optimization is a powerful tool in this effort, but is hampered by the presence of multimodality in many design spaces. Gradient-based multistart optimization uses a sampling algorithm and multiple parallel optimizations to reliably apply fast gradient-based optimization to moderately multimodal problems. Ensuring that the sampled geometries remain physically realizable requires manually developing specialized linear constraints for each class of problem. Utilizing free-form deformation geometry control allows these linear constraints to be written in a geometry-independent fashion, greatly easing the process of applying the algorithm to new problems. This algorithm was used to assess the presence of multimodality when optimizing a wing in subsonic and transonic flows, under inviscid and viscous conditions, and a blended wing-body under transonic, viscous conditions. Multimodality was present in every wing case, while the blended wing-body was found to be generally unimodal.

  9. The design of an ultra-thin and multiple channels optical receiving antenna system with freeform lenses

    Science.gov (United States)

    Zhang, Lingyun; Cheng, Dewen; Hu, Yuan; Song, Weitao; Wang, Yongtian

    2014-11-01

    Visible Light Communications (VLC) has become an emerging area of research since it can provide higher data transmission speed and wider bandwidth. The white LEDs are very important components of the VLC system, because it has the advantages of higher brightness, lower power consumption, and a longer lifetime. More importantly, their intensity and color are modulatable. Besides the light source, the optical antenna system also plays a very important role in the VLC system since it determines the optical gain, effective working area and transmission rate of the VLC system. In this paper, we propose to design an ultra-thin and multiple channels optical antenna system by tiling multiple off-axis lenses, each of which consists of two reflective and two refractive freeform surfaces. The tiling of multiple systems and detectors but with different band filters makes it possible to design a wavelength division multiplexing VLC system to highly improve the system capacity. The field of view of the designed antenna system is 30°, the entrance pupil diameter is 1.5mm, and the thickness of the system is under 4mm. The design methods are presented and the results are discussed in the last section of this paper. Besides the optical gain is analyzed and calculated. The antenna system can be tiled up to four channels but without the increase of thickness.

  10. Fabrication of metal-matrix composites and adaptive composites using ultrasonic consolidation process

    International Nuclear Information System (INIS)

    Kong, C.Y.; Soar, R.C.

    2005-01-01

    Ultrasonic consolidation (UC) has been used to embed thermally sensitive and damage intolerant fibres within aluminium matrix structures using high frequency, low amplitude, mechanical vibrations. The UC process can induce plastic flow in the metal foils being bonded, to allow the embedding of fibres at typically 25% of the melting temperature of the base metal and at a fraction of the clamping force when compared to fusion processes. To date, the UC process has successfully embedded Sigma silicon carbide (SiC) fibres, shape memory alloy wires and optical fibres, which are presented in this paper. The eventual aim of this research is targeted at the fabrication of adaptive composite structures having the ability to measure external stimuli and respond by adapting their structure accordingly, through the action of embedded active and passive functional fibres within a freeform fabricated metal-matrix structure. This paper presents the fundamental studies of this research to identify embedding methods and working range for the fabrication of adaptive composite structures. The methods considered have produced embedded fibre specimens in which large amounts of plastic flow have been observed, within the matrix, as it is deformed around the fibres, resulting in fully consolidated specimens without damage to the fibres. The microscopic observation techniques and macroscopic functionality tests confirms that the UC process could be applied to the fabrication of metal-matrix composites and adaptive composites, where fusion techniques are not feasible and where a 'cold' process is necessary

  11. Blood-Vessel Mimicking Structures by Stereolithographic Fabrication of Small Porous Tubes Using Cytocompatible Polyacrylate Elastomers, Biofunctionalization and Endothelialization

    Directory of Open Access Journals (Sweden)

    Birgit Huber

    2016-04-01

    Full Text Available Blood vessel reconstruction is still an elusive goal for the development of in vitro models as well as artificial vascular grafts. In this study, we used a novel photo-curable cytocompatible polyacrylate material (PA for freeform generation of synthetic vessels. We applied stereolithography for the fabrication of arbitrary 3D tubular structures with total dimensions in the centimeter range, 300 µm wall thickness, inner diameters of 1 to 2 mm and defined pores with a constant diameter of approximately 100 µm or 200 µm. We established a rinsing protocol to remove remaining cytotoxic substances from the photo-cured PA and applied thio-modified heparin and RGDC-peptides to functionalize the PA surface for enhanced endothelial cell adhesion. A rotating seeding procedure was introduced to ensure homogenous endothelial monolayer formation at the inner luminal tube wall. We showed that endothelial cells stayed viable and adherent and aligned along the medium flow under fluid-flow conditions comparable to native capillaries. The combined technology approach comprising of freeform additive manufacturing (AM, biomimetic design, cytocompatible materials which are applicable to AM, and biofunctionalization of AM constructs has been introduced as BioRap® technology by the authors.

  12. Printed freeform lens arrays on multi-core fibers for highly efficient coupling in astrophotonic systems.

    Science.gov (United States)

    Dietrich, Philipp-Immanuel; Harris, Robert J; Blaicher, Matthias; Corrigan, Mark K; Morris, Tim M; Freude, Wolfgang; Quirrenbach, Andreas; Koos, Christian

    2017-07-24

    Coupling of light into multi-core fibers (MCF) for spatially resolved spectroscopy is of great importance to astronomical instrumentation. To achieve high coupling efficiencies along with fill-fractions close to unity, micro-optical elements are required to concentrate the incoming light to the individual cores of the MCF. In this paper we demonstrate facet-attached lens arrays (LA) fabricated by two-photon polymerization. The LA provide close to 100% fill-fraction along with efficiencies of up to 73% (down to 1.4 dB loss) for coupling of light from free space into an MCF core. We show the viability of the concept for astrophotonic applications by integrating an MCF-LA assembly in an adaptive-optics test bed and by assessing its performance as a tip/tilt sensor.

  13. A new optimization tool path planning for 3-axis end milling of free-form surfaces based on efficient machining intervals

    Science.gov (United States)

    Vu, Duy-Duc; Monies, Frédéric; Rubio, Walter

    2018-05-01

    A large number of studies, based on 3-axis end milling of free-form surfaces, seek to optimize tool path planning. Approaches try to optimize the machining time by reducing the total tool path length while respecting the criterion of the maximum scallop height. Theoretically, the tool path trajectories that remove the most material follow the directions in which the machined width is the largest. The free-form surface is often considered as a single machining area. Therefore, the optimization on the entire surface is limited. Indeed, it is difficult to define tool trajectories with optimal feed directions which generate largest machined widths. Another limiting point of previous approaches for effectively reduce machining time is the inadequate choice of the tool. Researchers use generally a spherical tool on the entire surface. However, the gains proposed by these different methods developed with these tools lead to relatively small time savings. Therefore, this study proposes a new method, using toroidal milling tools, for generating toolpaths in different regions on the machining surface. The surface is divided into several regions based on machining intervals. These intervals ensure that the effective radius of the tool, at each cutter-contact points on the surface, is always greater than the radius of the tool in an optimized feed direction. A parallel plane strategy is then used on the sub-surfaces with an optimal specific feed direction for each sub-surface. This method allows one to mill the entire surface with efficiency greater than with the use of a spherical tool. The proposed method is calculated and modeled using Maple software to find optimal regions and feed directions in each region. This new method is tested on a free-form surface. A comparison is made with a spherical cutter to show the significant gains obtained with a toroidal milling cutter. Comparisons with CAM software and experimental validations are also done. The results show the

  14. Determination of Free-Form and Peptide Bound Pyrraline in the Commercial Drinks Enriched with Different Protein Hydrolysates

    Directory of Open Access Journals (Sweden)

    Zhili Liang

    2016-07-01

    Full Text Available Pyrraline, a causative factor for the recent epidemics of diabetes and cardiovascular disease, is also employed as an indicator to evaluate heat damage and formation of advanced glycation end-products (AGEs in foods. Peptide-enriched drinks (PEDs are broadly consumed worldwide due to rapid rate of absorption and perceived health effects. It can be hypothesized that PED is an important source of pyrraline, especially peptide bound pyrraline (Pep-Pyr. In this study we determined free-form pyrraline (Free-Pyr and Pep-Pyr in drinks enriched with whey protein hydrolysate (WPH, soy protein hydrolysate (SPH and collagen protein hydrolysate (CPH. A detection method was developed using ultrahigh-performance liquid chromatography with UV-visible detector coupled with tandem mass spectrometry after solid-phase extraction (SPE. The SPE led to excellent recovery rates ranging between 93.2% and 98.5% and a high reproducibility with relative standard deviations (RSD of <5%. The limits of detection and quantification obtained were 30.4 and 70.3 ng/mL, respectively. Pep-Pyr was identified as the most abundant form (above 96 percent of total pyrraline, whereas Free-Pyr was present in a small proportion (less than four percent of total pyrraline. The results indicate that PED is an important extrinsic source of pyrraline, especially Pep-Pyr. As compared with CPH- and SPH-enriched drinks, WPH-enriched drinks contained high content of Pep-Pyr. The Pep-Pyr content is associated with the distribution of peptide lengths and the amino acid compositions of protein in PEDs.

  15. Magnetic resonance imaging-three-dimensional printing technology fabricates customized scaffolds for brain tissue engineering

    Institute of Scientific and Technical Information of China (English)

    Feng Fu; Chong Chen; Sai Zhang; Ming-liang Zhao; Xiao-hong Li; Zhe Qin; Chao Xu; Xu-yi Chen; Rui-xin Li; Li-na Wang; Ding-wei Peng; Hong-tao Sun; Yue Tu

    2017-01-01

    Conventional fabrication methods lack the ability to control both macro- and micro-structures of generated scaffolds. Three-dimensional printing is a solid free-form fabrication method that provides novel ways to create customized scaffolds with high precision and accuracy. In this study, an electrically controlled cortical impactor was used to induce randomized brain tissue defects. The overall shape of scaffolds was designed using rat-specific anatomical data obtained from magnetic resonance imaging, and the internal structure was created by computer- aided design. As the result of limitations arising from insufficient resolution of the manufacturing process, we magnified the size of the cavity model prototype five-fold to successfully fabricate customized collagen-chitosan scaffolds using three-dimensional printing. Results demonstrated that scaffolds have three-dimensional porous structures, high porosity, highly specific surface areas, pore connectivity and good internal characteristics. Neural stem cells co-cultured with scaffolds showed good viability, indicating good biocompatibility and biodegradability. This technique may be a promising new strategy for regenerating complex damaged brain tissues, and helps pave the way toward personalized medicine.

  16. Patient-specific surgical planning and hemodynamic computational fluid dynamics optimization through free-form haptic anatomy editing tool (SURGEM).

    Science.gov (United States)

    Pekkan, Kerem; Whited, Brian; Kanter, Kirk; Sharma, Shiva; de Zelicourt, Diane; Sundareswaran, Kartik; Frakes, David; Rossignac, Jarek; Yoganathan, Ajit P

    2008-11-01

    The first version of an anatomy editing/surgical planning tool (SURGEM) targeting anatomical complexity and patient-specific computational fluid dynamics (CFD) analysis is presented. Novel three-dimensional (3D) shape editing concepts and human-shape interaction technologies have been integrated to facilitate interactive surgical morphology alterations, grid generation and CFD analysis. In order to implement "manual hemodynamic optimization" at the surgery planning phase for patients with congenital heart defects, these tools are applied to design and evaluate possible modifications of patient-specific anatomies. In this context, anatomies involve complex geometric topologies and tortuous 3D blood flow pathways with multiple inlets and outlets. These tools make it possible to freely deform the lumen surface and to bend and position baffles through real-time, direct manipulation of the 3D models with both hands, thus eliminating the tedious and time-consuming phase of entering the desired geometry using traditional computer-aided design (CAD) systems. The 3D models of the modified anatomies are seamlessly exported and meshed for patient-specific CFD analysis. Free-formed anatomical modifications are quantified using an in-house skeletization based cross-sectional geometry analysis tool. Hemodynamic performance of the systematically modified anatomies is compared with the original anatomy using CFD. CFD results showed the relative importance of the various surgically created features such as pouch size, vena cave to pulmonary artery (PA) flare and PA stenosis. An interactive surgical-patch size estimator is also introduced. The combined design/analysis cycle time is used for comparing and optimizing surgical plans and improvements are tabulated. The reduced cost of patient-specific shape design and analysis process, made it possible to envision large clinical studies to assess the validity of predictive patient-specific CFD simulations. In this paper, model

  17. Fabric based supercapacitor

    International Nuclear Information System (INIS)

    Yong, S; Tudor, M J; Beeby, S P; Owen, J R

    2013-01-01

    Flexible supercapacitors with electrodes coated on inexpensive fabrics by the dipping technique. This paper present details of the design, fabrication and characterisation of fabric supercapacitor. The sandwich structured supercapacitors can achieve specific capacitances of 11.1F/g, area capacitance 105 mF.cm −2 and maintain 95% of the initial capacitance after cycling the device for more than 15000 times

  18. Fabrics in Function

    DEFF Research Database (Denmark)

    Bang, Anne Louise

    2007-01-01

    sensing of fabrics in function. It is proposed that tactile and visual sensing of fabrics is a way to investigate and express emotional utility values. The further purpose is to use experiments with repertory grid models as part of the mapping of the entire research project and also as a basis...

  19. Fabricating architectural volume

    DEFF Research Database (Denmark)

    Feringa, Jelle; Søndergaard, Asbjørn

    2015-01-01

    The 2011 edition of Fabricate inspired a number of collaborations, this article seeks to highlight three of these. There is a common thread amongst the projects presented: sharing the ambition to close the rift between design and fabrication while incorporating structural design aspects early on...

  20. Smart Fabrics Technology Development

    Science.gov (United States)

    Simon, Cory; Potter, Elliott; Potter, Elliott; McCabe, Mary; Baggerman, Clint

    2010-01-01

    Advances in Smart Fabrics technology are enabling an exciting array of new applications for NASA exploration missions, the biomedical community, and consumer electronics. This report summarizes the findings of a brief investigation into the state of the art and potential applications of smart fabrics to address challenges in human spaceflight.

  1. Optics fabrication technical challenges

    International Nuclear Information System (INIS)

    Chabassier, G.; Ferriou, N.; Lavastre, E.; Maunier, C.; Neauport, J.; Taroux, D.; Balla, D.; Fornerod, J.C.

    2004-01-01

    Before the production of all the LMJ (MEGAJOULE laser) optics, the CEA had to proceed with the fabrication of about 300 large optics for the LIL (laser integration line) laser. Thanks to a fruitful collaboration with high-tech optics companies in Europe, this challenge has been successfully hit. In order to achieve the very tight requirements for cleanliness, laser damage threshold and all the other high demanding fabrication specifications, it has been necessary to develop and to set completely new fabrication process going and to build special outsize fabrication equipment. Through a couple of examples, this paper gives an overview of the work which has been done and shows some of the results which have been obtained: continuous laser glass melting, fabrication of the laser slabs, rapid-growth KDP (potassium dihydrogen phosphate) technology, large diffractive transmission gratings engraving and characterization. (authors)

  2. New polymorphous computing fabric

    International Nuclear Information System (INIS)

    Wolinski, Christophe; Gokhale, Maya; McCabe, Kevin P.

    2002-01-01

    This paper introduces a new polymorphous computing Fabric well suited to DSP and Image Processing and describes its implementation on a Configurable System on a Chip (CSOC). The architecture is highly parameterized and enables customization of the synthesized Fabric to achieve high performance for a specific class of application. For this reason it can be considered to be a generic model for hardware accelerator synthesis from a high level specification. Another important innovation is the Fabric uses a global memory concept, which gives the host processor random access to all the variables and instructions on the Fabric. The Fabric supports different computing models including MIMD, SPMD and systolic flow and permits dynamic reconfiguration. We present a specific implementation of a bank of FIR filters on a Fabric composed of 52 cells on the Altera Excalibur ARM running at 33 MHz. The theoretical performance of this Fabric is 1.8 GMACh. For the FIR application we obtain 1.6 GMAC/s real performance. Some automatic tools have been developed like the tool to provide a host access utility and assembler.

  3. Deployment and evaluation of a dual-sensor autofocusing method for on-machine measurement of patterns of small holes on freeform surfaces.

    Science.gov (United States)

    Chen, Xiaomei; Longstaff, Andrew; Fletcher, Simon; Myers, Alan

    2014-04-01

    This paper presents and evaluates an active dual-sensor autofocusing system that combines an optical vision sensor and a tactile probe for autofocusing on arrays of small holes on freeform surfaces. The system has been tested on a two-axis test rig and then integrated onto a three-axis computer numerical control (CNC) milling machine, where the aim is to rapidly and controllably measure the hole position errors while the part is still on the machine. The principle of operation is for the tactile probe to locate the nominal positions of holes, and the optical vision sensor follows to focus and capture the images of the holes. The images are then processed to provide hole position measurement. In this paper, the autofocusing deviations are analyzed. First, the deviations caused by the geometric errors of the axes on which the dual-sensor unit is deployed are estimated to be 11 μm when deployed on a test rig and 7 μm on the CNC machine tool. Subsequently, the autofocusing deviations caused by the interaction of the tactile probe, surface, and small hole are mathematically analyzed and evaluated. The deviations are a result of the tactile probe radius, the curvatures at the positions where small holes are drilled on the freeform surface, and the effect of the position error of the hole on focusing. An example case study is provided for the measurement of a pattern of small holes on an elliptical cylinder on the two machines. The absolute sum of the autofocusing deviations is 118 μm on the test rig and 144 μm on the machine tool. This is much less than the 500 μm depth of field of the optical microscope. Therefore, the method is capable of capturing a group of clear images of the small holes on this workpiece for either implementation.

  4. A Comparative Evaluation of 3 Different Free-Form Deformable Image Registration and Contour Propagation Methods for Head and Neck MRI: The Case of Parotid Changes During Radiotherapy.

    Science.gov (United States)

    Broggi, Sara; Scalco, Elisa; Belli, Maria Luisa; Logghe, Gerlinde; Verellen, Dirk; Moriconi, Stefano; Chiara, Anna; Palmisano, Anna; Mellone, Renata; Fiorino, Claudio; Rizzo, Giovanna

    2017-06-01

    To validate and compare the deformable image registration and parotid contour propagation process for head and neck magnetic resonance imaging in patients treated with radiotherapy using 3 different approaches-the commercial MIM, the open-source Elastix software, and an optimized version of it. Twelve patients with head and neck cancer previously treated with radiotherapy were considered. Deformable image registration and parotid contour propagation were evaluated by considering the magnetic resonance images acquired before and after the end of the treatment. Deformable image registration, based on free-form deformation method, and contour propagation available on MIM were compared to Elastix. Two different contour propagation approaches were implemented for Elastix software, a conventional one (DIR_Trx) and an optimized homemade version, based on mesh deformation (DIR_Mesh). The accuracy of these 3 approaches was estimated by comparing propagated to manual contours in terms of average symmetric distance, maximum symmetric distance, Dice similarity coefficient, sensitivity, and inclusiveness. A good agreement was generally found between the manual contours and the propagated ones, without differences among the 3 methods; in few critical cases with complex deformations, DIR_Mesh proved to be more accurate, having the lowest values of average symmetric distance and maximum symmetric distance and the highest value of Dice similarity coefficient, although nonsignificant. The average propagation errors with respect to the reference contours are lower than the voxel diagonal (2 mm), and Dice similarity coefficient is around 0.8 for all 3 methods. The 3 free-form deformation approaches were not significantly different in terms of deformable image registration accuracy and can be safely adopted for the registration and parotid contour propagation during radiotherapy on magnetic resonance imaging. More optimized approaches (as DIR_Mesh) could be preferable for critical

  5. Fabrication and characterisation of fabric supercapacitor

    OpenAIRE

    Yong, Sheng

    2016-01-01

    Fabric supercapacitor is a flexible electrochemical device for energy storage application. It is designed to power up flexible electronic systems used for, for example, information sensing, data computation and communication. The development of a flexible supercapacitor is important for e-textiles since supercapacitor can achieve higher energy density than a standard parallel plate capacitor and a larger power density compared with a battery. This research area is currently facing barriers on...

  6. Fabrication of an infrared Shack-Hartmann sensor by combining high-speed single-point diamond milling and precision compression molding processes.

    Science.gov (United States)

    Zhang, Lin; Zhou, Wenchen; Naples, Neil J; Yi, Allen Y

    2018-05-01

    A novel fabrication method by combining high-speed single-point diamond milling and precision compression molding processes for fabrication of discontinuous freeform microlens arrays was proposed. Compared with slow tool servo diamond broaching, high-speed single-point diamond milling was selected for its flexibility in the fabrication of true 3D optical surfaces with discontinuous features. The advantage of single-point diamond milling is that the surface features can be constructed sequentially by spacing the axes of a virtual spindle at arbitrary positions based on the combination of rotational and translational motions of both the high-speed spindle and linear slides. By employing this method, each micro-lenslet was regarded as a microstructure cell by passing the axis of the virtual spindle through the vertex of each cell. An optimization arithmetic based on minimum-area fabrication was introduced to the machining process to further increase the machining efficiency. After the mold insert was machined, it was employed to replicate the microlens array onto chalcogenide glass. In the ensuing optical measurement, the self-built Shack-Hartmann wavefront sensor was proven to be accurate in detecting an infrared wavefront by both experiments and numerical simulation. The combined results showed that precision compression molding of chalcogenide glasses could be an economic and precision optical fabrication technology for high-volume production of infrared optics.

  7. Metrology for Freeform Optics

    Data.gov (United States)

    National Aeronautics and Space Administration — Science requirements for optical instrumentation are requiring larger fields of view and faster f-numbers to complete their objectives.   Additionally, opportunities...

  8. Freeform Phononic Waveguides

    Directory of Open Access Journals (Sweden)

    Georgios Gkantzounis

    2017-11-01

    Full Text Available We employ a recently introduced class of artificial structurally-disordered phononic structures that exhibit large and robust elastic frequency band gaps for efficient phonon guiding. Phononic crystals are periodic structures that prohibit the propagation of elastic waves through destructive interference and exhibit large band gaps and ballistic propagation of elastic waves in the permitted frequency ranges. In contrast, random-structured materials do not exhibit band gaps and favour localization or diffusive propagation. Here, we use structures with correlated disorder constructed from the so-called stealthy hyperuniform disordered point patterns, which can smoothly vary from completely random to periodic (full order by adjusting a single parameter. Such amorphous-like structures exhibit large band gaps (comparable to the periodic ones, both ballistic-like and diffusive propagation of elastic waves, and a large number of localized modes near the band edges. The presence of large elastic band gaps allows the creation of waveguides in hyperuniform materials, and we analyse various waveguide architectures displaying nearly 100% transmission in the GHz regime. Such phononic-circuit architectures are expected to have a direct impact on integrated micro-electro-mechanical filters and modulators for wireless communications and acousto-optical sensing applications.

  9. Junction and circuit fabrication

    International Nuclear Information System (INIS)

    Jackel, L.D.

    1980-01-01

    Great strides have been made in Josephson junction fabrication in the four years since the first IC SQUID meeting. Advances in lithography have allowed the production of devices with planar dimensions as small as a few hundred angstroms. Improved technology has provided ultra-high sensitivity SQUIDS, high-efficiency low-noise mixers, and complex integrated circuits. This review highlights some of the new fabrication procedures. The review consists of three parts. Part 1 is a short summary of the requirements on junctions for various applications. Part 2 reviews intergrated circuit fabrication, including tunnel junction logic circuits made at IBM and Bell Labs, and microbridge radiation sources made at SUNY at Stony Brook. Part 3 describes new junction fabrication techniques, the major emphasis of this review. This part includes a discussion of small oxide-barrier tunnel junctions, semiconductor barrier junctions, and microbridge junctions. Part 3 concludes by considering very fine lithography and limitations to miniaturization. (orig.)

  10. Construction, fabrication, and installation

    International Nuclear Information System (INIS)

    1992-05-01

    This standard specifies the construction, fabrication, and installation requirements that apply to concrete containment structures of a containment system designated as class containment components, parts and appurtenances for nuclear power plants

  11. Experimental Fabrication Facility

    Data.gov (United States)

    Federal Laboratory Consortium — Provides aviation fabrication support to special operations aircraft residing at Fort Eustis and other bases in the United States. Support is also provided to AATD...

  12. Alloy Fabrication Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — At NETL’s Alloy Fabrication Facility in Albany, OR, researchers conduct DOE research projects to produce new alloys suited to a variety of applications, from gas...

  13. Printing Outside the Box: Additive Manufacturing Processes for Fabrication of Large Aerospace Structures

    Science.gov (United States)

    Babai, Majid; Peters, Warren

    2015-01-01

    To achieve NASA's mission of space exploration, innovative manufacturing processes are being applied to the fabrication of propulsion elements. Liquid rocket engines (LREs) are comprised of a thrust chamber and nozzle extension as illustrated in figure 1 for the J2X upper stage engine. Development of the J2X engine, designed for the Ares I launch vehicle, is currently being incorporated on the Space Launch System. A nozzle extension is attached to the combustion chamber to obtain the expansion ratio needed to increase specific impulse. If the nozzle extension could be printed as one piece using free-form additive manufacturing (AM) processes, rather than the current method of forming welded parts, a considerable time savings could be realized. Not only would this provide a more homogenous microstructure than a welded structure, but could also greatly shorten the overall fabrication time. The main objective of this study is to fabricate test specimens using a pulsed arc source and solid wire as shown in figure 2. The mechanical properties of these specimens will be compared with those fabricated using the powder bed, selective laser melting technology at NASA Marshall Space Flight Center. As printed components become larger, maintaining a constant temperature during the build process becomes critical. This predictive capability will require modeling of the moving heat source as illustrated in figure 3. Predictive understanding of the heat profile will allow a constant temperature to be maintained as a function of height from substrate while printing complex shapes. In addition, to avoid slumping, this will also allow better control of the microstructural development and hence the properties. Figure 4 shows a preliminary comparison of the mechanical properties obtained.

  14. Applications for Gradient Metal Alloys Fabricated Using Additive Manufacturing

    Science.gov (United States)

    Hofmann, Douglas C.; Borgonia, John Paul C.; Dillon, Robert P.; Suh, Eric J.; Mulder, jerry L.; Gardner, Paul B.

    2013-01-01

    Recently, additive manufacturing (AM) techniques have been developed that may shift the paradigm of traditional metal production by allowing complex net-shaped hardware to be built up layer-by-layer, rather than being machined from a billet. The AM process is ubiquitous with polymers due to their low melting temperatures, fast curing, and controllable viscosity, and 3D printers are widely available as commercial or consumer products. 3D printing with metals is inherently more complicated than with polymers due to their higher melting temperatures and reactivity with air, particularly when heated or molten. The process generally requires a high-power laser or other focused heat source, like an electron beam, for precise melting and deposition. Several promising metal AM techniques have been developed, including laser deposition (also called laser engineered net shaping or LENS® and laser deposition technology (LDT)), direct metal laser sintering (DMLS), and electron beam free-form (EBF). These machines typically use powders or wire feedstock that are melted and deposited using a laser or electron beam. Complex net-shape parts have been widely demonstrated using these (and other) AM techniques and the process appears to be a promising alternative to machining in some cases. Rather than simply competing with traditional machining for cost and time savings, the true advantage of AM involves the fabrication of hardware that cannot be produced using other techniques. This could include parts with "blind" features (like foams or trusses), parts that are difficult to machine conventionally, or parts made from materials that do not exist in bulk forms. In this work, the inventors identify that several AM techniques can be used to develop metal parts that change composition from one location in the part to another, allowing for complete control over the mechanical or physical properties. This changes the paradigm for conventional metal fabrication, which relies on an

  15. Fabricating nuclear components

    International Nuclear Information System (INIS)

    Anon.

    1977-01-01

    Activities of the Nuclear Engineering Division of Vickers Ltd., particularly fabrication of long slim tubular components for power reactors and the construction of irradiation loops and rigs, are outlined. The processes include hydraulic forming for fabrication of various types of tubes and outer cases of fuel transfer buckets, various specialised welding operations including some applications of the TIG process, and induction brazing of specialised assemblies. (U.K.)

  16. Nuclear Fabrication Consortium

    Energy Technology Data Exchange (ETDEWEB)

    Levesque, Stephen [EWI, Columbus, OH (United States)

    2013-04-05

    This report summarizes the activities undertaken by EWI while under contract from the Department of Energy (DOE) Office of Nuclear Energy (NE) for the management and operation of the Nuclear Fabrication Consortium (NFC). The NFC was established by EWI to independently develop, evaluate, and deploy fabrication approaches and data that support the re-establishment of the U.S. nuclear industry: ensuring that the supply chain will be competitive on a global stage, enabling more cost-effective and reliable nuclear power in a carbon constrained environment. The NFC provided a forum for member original equipment manufactures (OEM), fabricators, manufacturers, and materials suppliers to effectively engage with each other and rebuild the capacity of this supply chain by : Identifying and removing impediments to the implementation of new construction and fabrication techniques and approaches for nuclear equipment, including system components and nuclear plants. Providing and facilitating detailed scientific-based studies on new approaches and technologies that will have positive impacts on the cost of building of nuclear plants. Analyzing and disseminating information about future nuclear fabrication technologies and how they could impact the North American and the International Nuclear Marketplace. Facilitating dialog and initiate alignment among fabricators, owners, trade associations, and government agencies. Supporting industry in helping to create a larger qualified nuclear supplier network. Acting as an unbiased technology resource to evaluate, develop, and demonstrate new manufacturing technologies. Creating welder and inspector training programs to help enable the necessary workforce for the upcoming construction work. Serving as a focal point for technology, policy, and politically interested parties to share ideas and concepts associated with fabrication across the nuclear industry. The report the objectives and summaries of the Nuclear Fabrication Consortium

  17. Development of a 3D bellows tracheal graft: mechanical behavior analysis, fabrication and an in vivo feasibility study

    International Nuclear Information System (INIS)

    Park, Jeong Hun; Jung, Jin Woo; Lee, Jung-Seob; Cho, Dong-Woo; Kang, Hyun-Wook; Joo, Young Hoon

    2012-01-01

    Artificial tracheal grafts should have not only enough compressive strength to maintain an open tracheal lumen, but also sufficient flexibility for stable mechanical behavior, similar to the native trachea at the implant site. In this study, we developed a new 3D artificial tracheal graft using a bellows design for considering its mechanical behavior. To investigate the mechanical behavior of the bellows structure, finite element method (FEM) analysis in terms of longitudinal tension/compression, bending and radial compression was conducted. The bellows structure was then compared with the cylinder structure generally used for artificial tracheal grafts. The FEM analysis showed that the bellows had outstanding flexibility in longitudinal tension/compression and bending. Moreover, the bellows kept the lumen open without severe luminal deformation in comparison with the cylinder structure. A three-dimensional artificial tracheal graft with a bellows design was fabricated using indirect solid freeform fabrication technology, and the actual mechanical test was conducted to investigate the actual mechanical behavior of the bellows graft. The fabricated bellows graft was then applied to segmental tracheal reconstruction in a rabbit model to assess its applicability. The bellows graft was completely incorporated into newly regenerated connective tissue and no obstruction at the implanted site was observed for up to 8 weeks after implantation. The data suggested that the developed bellows tracheal graft could be a promising alternative for tracheal reconstruction. (paper)

  18. Understanding core conductor fabrics

    International Nuclear Information System (INIS)

    Swenson, D E

    2011-01-01

    ESD Association standard test method ANSI/ESD STM2.1 - Garments (STM2.1), provides electrical resistance test procedures that are applicable for materials and garments that have surface conductive or surface dissipative properties. As has been reported in other papers over the past several years 1 fabrics are now used in many industries for electrostatic control purposes that do not have surface conductive properties and therefore cannot be evaluated using the procedures in STM2.1 2 . A study was conducted to compare surface conductive fabrics with samples of core conductor fibre based fabrics in order to determine differences and similarities with regards to various electrostatic properties. This work will be used to establish a new work item proposal within WG-2, Garments, in the ESD Association Standards Committee in the USA.

  19. Fabrication of multilayer nanowires

    Energy Technology Data Exchange (ETDEWEB)

    Kaur, Jasveer, E-mail: kaurjasveer89@gmail.com; Singh, Avtar; Kumar, Davinder [Department of Physics, Punjabi University Patiala, 147002, Punjab (India); Thakur, Anup; Kaur, Raminder, E-mail: raminder-k-saini@yahoo.com [Department of Basic and Applied Sciences, Punjabi University Patiala, 147002, Punjab (India)

    2016-05-06

    Multilayer nanowires were fabricated by potentiostate ectrodeposition template synthesis method into the pores of polycarbonate membrane. In present work layer by layer deposition of two different metals Ni and Cu in polycarbonate membrane having pore size of 600 nm were carried out. It is found that the growth of nanowires is not constant, it varies with deposition time. Scanning electron microscopy (SEM) is used to study the morphology of fabricated multilayer nanowires. An energy dispersive X-ray spectroscopy (EDS) results confirm the composition of multilayer nanowires. The result shows that multilayer nanowires formed is dense.

  20. MOX Fabrication Isolation Considerations

    Energy Technology Data Exchange (ETDEWEB)

    Eric L. Shaber; Bradley J Schrader

    2005-08-01

    This document provides a technical position on the preferred level of isolation to fabricate demonstration quantities of mixed oxide transmutation fuels. The Advanced Fuel Cycle Initiative should design and construct automated glovebox fabrication lines for this purpose. This level of isolation adequately protects the health and safety of workers and the general public for all mixed oxide (and other transmutation fuel) manufacturing efforts while retaining flexibility, allowing parallel development and setup, and minimizing capital expense. The basis regulations, issues, and advantages/disadvantages of five potential forms of isolation are summarized here as justification for selection of the preferred technical position.

  1. Fabrication of multilayer nanowires

    International Nuclear Information System (INIS)

    Kaur, Jasveer; Singh, Avtar; Kumar, Davinder; Thakur, Anup; Kaur, Raminder

    2016-01-01

    Multilayer nanowires were fabricated by potentiostate ectrodeposition template synthesis method into the pores of polycarbonate membrane. In present work layer by layer deposition of two different metals Ni and Cu in polycarbonate membrane having pore size of 600 nm were carried out. It is found that the growth of nanowires is not constant, it varies with deposition time. Scanning electron microscopy (SEM) is used to study the morphology of fabricated multilayer nanowires. An energy dispersive X-ray spectroscopy (EDS) results confirm the composition of multilayer nanowires. The result shows that multilayer nanowires formed is dense.

  2. Estimating 4D-CBCT from prior information and extremely limited angle projections using structural PCA and weighted free-form deformation for lung radiotherapy.

    Science.gov (United States)

    Harris, Wendy; Zhang, You; Yin, Fang-Fang; Ren, Lei

    2017-03-01

    To investigate the feasibility of using structural-based principal component analysis (PCA) motion-modeling and weighted free-form deformation to estimate on-board 4D-CBCT using prior information and extremely limited angle projections for potential 4D target verification of lung radiotherapy. A technique for lung 4D-CBCT reconstruction has been previously developed using a deformation field map (DFM)-based strategy. In the previous method, each phase of the 4D-CBCT was generated by deforming a prior CT volume. The DFM was solved by a motion model extracted by a global PCA and free-form deformation (GMM-FD) technique, using a data fidelity constraint and deformation energy minimization. In this study, a new structural PCA method was developed to build a structural motion model (SMM) by accounting for potential relative motion pattern changes between different anatomical structures from simulation to treatment. The motion model extracted from planning 4DCT was divided into two structures: tumor and body excluding tumor, and the parameters of both structures were optimized together. Weighted free-form deformation (WFD) was employed afterwards to introduce flexibility in adjusting the weightings of different structures in the data fidelity constraint based on clinical interests. XCAT (computerized patient model) simulation with a 30 mm diameter lesion was simulated with various anatomical and respiratory changes from planning 4D-CT to on-board volume to evaluate the method. The estimation accuracy was evaluated by the volume percent difference (VPD)/center-of-mass-shift (COMS) between lesions in the estimated and "ground-truth" on-board 4D-CBCT. Different on-board projection acquisition scenarios and projection noise levels were simulated to investigate their effects on the estimation accuracy. The method was also evaluated against three lung patients. The SMM-WFD method achieved substantially better accuracy than the GMM-FD method for CBCT estimation using extremely

  3. Precision extruding deposition (PED) fabrication of polycaprolactone (PCL) scaffolds for bone tissue engineering

    Energy Technology Data Exchange (ETDEWEB)

    Shor, Lauren; Gueceri, Selcuk; Chang, Robert; Sun Wei [Department of Mechanical Engineering and Mechanics, Drexel University, Philadelphia, PA (United States); Gordon, Jennifer; Kang Qian; Hartsock, Langdon; An Yuehuei [Department of Orthopedic Surgery, Medical University of South Carolina, Charleston, SC (United States)], E-mail: st963bya@drexel.edu, E-mail: guceri@drexel.edu, E-mail: rcc34@drexel.edu, E-mail: sunwei@drexel.edu, E-mail: kangqk@musc.edu, E-mail: hartsock@musc.edu, E-mail: any@musc.edu

    2009-03-01

    Bone tissue engineering is an emerging field providing viable substitutes for bone regeneration. Recent advances have allowed scientists and engineers to develop scaffolds for guided bone growth. However, success requires scaffolds to have specific macroscopic geometries and internal architectures conducive to biological and biophysical functions. Freeform fabrication provides an effective process tool to manufacture three-dimensional porous scaffolds with complex shapes and designed properties. A novel precision extruding deposition (PED) technique was developed to fabricate polycaprolactone (PCL) scaffolds. It was possible to manufacture scaffolds with a controlled pore size of 350 {mu}m with designed structural orientations using this method. The scaffold morphology, internal micro-architecture and mechanical properties were evaluated using scanning electron microscopy (SEM), micro-computed tomography (micro-CT) and mechanical testing, respectively. An in vitro cell-scaffold interaction study was carried out using primary fetal bovine osteoblasts. Specifically, the cell proliferation and differentiation was evaluated by Alamar Blue assay for cell metabolic activity, alkaline phosphatase activity and osteoblast production of calcium. An in vivo study was performed on nude mice to determine the capability of osteoblast-seeded PCL to induce osteogenesis. Each scaffold was implanted subcutaneously in nude mice and, following sacrifice, was explanted at one of a series of time intervals. The explants were then evaluated histologically for possible areas of osseointegration. Microscopy and radiological examination showed multiple areas of osseous ingrowth suggesting that the osteoblast-seeded PCL scaffolds evoke osteogenesis in vivo. These studies demonstrated the viability of the PED process to fabricate PCL scaffolds having the necessary mechanical properties, structural integrity, and controlled pore size and interconnectivity desired for bone tissue engineering.

  4. Precision extruding deposition (PED) fabrication of polycaprolactone (PCL) scaffolds for bone tissue engineering

    International Nuclear Information System (INIS)

    Shor, Lauren; Gueceri, Selcuk; Chang, Robert; Sun Wei; Gordon, Jennifer; Kang Qian; Hartsock, Langdon; An Yuehuei

    2009-01-01

    Bone tissue engineering is an emerging field providing viable substitutes for bone regeneration. Recent advances have allowed scientists and engineers to develop scaffolds for guided bone growth. However, success requires scaffolds to have specific macroscopic geometries and internal architectures conducive to biological and biophysical functions. Freeform fabrication provides an effective process tool to manufacture three-dimensional porous scaffolds with complex shapes and designed properties. A novel precision extruding deposition (PED) technique was developed to fabricate polycaprolactone (PCL) scaffolds. It was possible to manufacture scaffolds with a controlled pore size of 350 μm with designed structural orientations using this method. The scaffold morphology, internal micro-architecture and mechanical properties were evaluated using scanning electron microscopy (SEM), micro-computed tomography (micro-CT) and mechanical testing, respectively. An in vitro cell-scaffold interaction study was carried out using primary fetal bovine osteoblasts. Specifically, the cell proliferation and differentiation was evaluated by Alamar Blue assay for cell metabolic activity, alkaline phosphatase activity and osteoblast production of calcium. An in vivo study was performed on nude mice to determine the capability of osteoblast-seeded PCL to induce osteogenesis. Each scaffold was implanted subcutaneously in nude mice and, following sacrifice, was explanted at one of a series of time intervals. The explants were then evaluated histologically for possible areas of osseointegration. Microscopy and radiological examination showed multiple areas of osseous ingrowth suggesting that the osteoblast-seeded PCL scaffolds evoke osteogenesis in vivo. These studies demonstrated the viability of the PED process to fabricate PCL scaffolds having the necessary mechanical properties, structural integrity, and controlled pore size and interconnectivity desired for bone tissue engineering

  5. Text-Fabric

    NARCIS (Netherlands)

    Roorda, Dirk

    2016-01-01

    Text-Fabric is a Python3 package for Text plus Annotations. It provides a data model, a text file format, and a binary format for (ancient) text plus (linguistic) annotations. The emphasis of this all is on: data processing; sharing data; and contributing modules. A defining characteristic is that

  6. PIGMI mechanical fabrication

    International Nuclear Information System (INIS)

    Hart, V.E.

    1976-01-01

    A prime goal of the mechanical design effort associated with the PIGMI (Pion Generator for Medical Irradiations) program is to investigate new materials and fabrication techniques in an effort to obtain increased machine efficiency and reliability at a reasonable cost. The following discussion deals with the modeling program that LASL is pursuing for 450-MHz and 1350-MHz PIGMI development. (author)

  7. Micromechanical Structures Fabrication; FINAL

    International Nuclear Information System (INIS)

    Rajic, S

    2001-01-01

    Work in materials other than silicon for MEMS applications has typically been restricted to metals and metal oxides instead of more ''exotic'' semiconductors. However, group III-V and II-VI semiconductors form a very important and versatile collection of material and electronic parameters available to the MEMS and MOEMS designer. With these materials, not only are the traditional mechanical material variables (thermal conductivity, thermal expansion, Young's modulus, etc.) available, but also chemical constituents can be varied in ternary and quaternary materials. This flexibility can be extremely important for both friction and chemical compatibility issues for MEMS. In addition, the ability to continually vary the bandgap energy can be particularly useful for many electronics and infrared detection applications. However, there are two major obstacles associated with alternate semiconductor material MEMS. The first issue is the actual fabrication of non-silicon micro-devices and the second impediment is communicating with these novel devices. We have implemented an essentially material independent fabrication method that is amenable to most group III-V and II-VI semiconductors. This technique uses a combination of non-traditional direct write precision fabrication processes such as diamond turning, ion milling, laser ablation, etc. This type of deterministic fabrication approach lends itself to an almost trivial assembly process. We also implemented a mechanical, electrical, and optical self-aligning hybridization technique for these alternate-material MEMS substrates

  8. Fabrication activity for nanophotonics

    DEFF Research Database (Denmark)

    Malureanu, Radu; Chung, Il-Sug; Carletti, Luca

    We present the fabrication and characterization of new structures and materials to be used in nanophotonics. The first structure presented is a fractal metallic metasurface designed to be used as a high-sensitivity sensor for 810nm wavelength. A second structure is a high index contrast grating...

  9. Status report, canister fabrication

    Energy Technology Data Exchange (ETDEWEB)

    Andersson, Claes-Goeran; Eriksson, Peter; Westman, Marika [Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden); Emilsson, Goeran [CSM Materialteknik AB, Linkoeping (Sweden)

    2004-06-01

    The report gives an account of the development of material and fabrication technology for copper canisters with cast inserts during the period from 2000 until the start of 2004. The engineering design of the canister and the choice of materials in the constituent components described in previous status reports have not been significantly changed. In the reference canister, the thickness of the copper shell is 50 mm. Fabrication of individual components with a thinner copper thickness is done for the purpose of gaining experience and evaluating fabrication and inspection methods for such canisters. As a part of the development of cast inserts, computer simulations of the casting processes and techniques used at the foundries have been performed for the purpose of optimizing the material properties. These properties have been evaluated by extensive tensile testing and metallographic inspection of test material taken from discs cut at different points along the length of the inserts. The testing results exhibit a relatively large spread. Low elongation values in certain tensile test specimens are due to the presence of poorly formed graphite, porosities, slag or other casting defects. It is concluded in the report that it will not be possible to avoid some presence of observed defects in castings of this size. In the deep repository, the inserts will be exposed to compressive loading and the observed defects are not critical for strength. An analysis of the strength of the inserts and formulation of relevant material requirements must be based on a statistical approach with probabilistic calculations. This work has been initiated and will be concluded during 2004. An initial verifying compression test of a canister in an isostatic press has indicated considerable overstrength in the structure. Seamless copper tubes are fabricated by means of three methods: extrusion, pierce and draw processing, and forging. It can be concluded that extrusion tests have revealed a

  10. Status report, canister fabrication

    International Nuclear Information System (INIS)

    Andersson, Claes-Goeran; Eriksson, Peter; Westman, Marika; Emilsson, Goeran

    2004-06-01

    The report gives an account of the development of material and fabrication technology for copper canisters with cast inserts during the period from 2000 until the start of 2004. The engineering design of the canister and the choice of materials in the constituent components described in previous status reports have not been significantly changed. In the reference canister, the thickness of the copper shell is 50 mm. Fabrication of individual components with a thinner copper thickness is done for the purpose of gaining experience and evaluating fabrication and inspection methods for such canisters. As a part of the development of cast inserts, computer simulations of the casting processes and techniques used at the foundries have been performed for the purpose of optimizing the material properties. These properties have been evaluated by extensive tensile testing and metallographic inspection of test material taken from discs cut at different points along the length of the inserts. The testing results exhibit a relatively large spread. Low elongation values in certain tensile test specimens are due to the presence of poorly formed graphite, porosities, slag or other casting defects. It is concluded in the report that it will not be possible to avoid some presence of observed defects in castings of this size. In the deep repository, the inserts will be exposed to compressive loading and the observed defects are not critical for strength. An analysis of the strength of the inserts and formulation of relevant material requirements must be based on a statistical approach with probabilistic calculations. This work has been initiated and will be concluded during 2004. An initial verifying compression test of a canister in an isostatic press has indicated considerable overstrength in the structure. Seamless copper tubes are fabricated by means of three methods: extrusion, pierce and draw processing, and forging. It can be concluded that extrusion tests have revealed a

  11. In vitro dermal and epidermal cellular response to titanium alloy implants fabricated with electron beam melting.

    Science.gov (United States)

    Springer, Jessica Collins; Harrysson, Ola L A; Marcellin-Little, Denis J; Bernacki, Susan H

    2014-10-01

    Transdermal osseointegrated prostheses (TOPs) are emerging as an alternative to socket prostheses. Electron beam melting (EBM) is a promising additive manufacturing technology for manufacture of custom, freeform titanium alloy (Ti6Al4V) implants. Skin ongrowth for infection resistance and mechanical stability are critically important to the success of TOP, which can be influenced by material composition and surface characteristics. We assessed viability and proliferation of normal human epidermal keratinocytes (NHEK) and normal human dermal fibroblasts (NHDF) on several Ti6Al4V surfaces: solid polished commercial, solid polished EBM, solid unpolished EBM and porous unpolished EBM. Cell proliferation was evaluated at days 2 and 7 using alamarBlue(®) and cell viability was analyzed with a fluorescence-based live-dead assay after 1 week. NHDF and NHEK were viable and proliferated on all Ti6Al4V surfaces. NHDF proliferation was highest on commercial and EBM polished surfaces. NHEK was highest on commercial polished surfaces. All EBM Ti6Al4V discs exhibited an acceptable biocompatibility profile compared to solid Ti6Al4V discs from a commercial source for dermal and epidermal cells. EBM may be considered as an option for fabrication of custom transdermal implants. Copyright © 2014 IPEM. Published by Elsevier Ltd. All rights reserved.

  12. A measurement strategy and an error-compensation model for the on-machine laser measurement of large-scale free-form surfaces

    International Nuclear Information System (INIS)

    Li, Bin; Li, Feng; Liu, Hongqi; Cai, Hui; Mao, Xinyong; Peng, Fangyu

    2014-01-01

    This study presents a novel measurement strategy and an error-compensation model for the measurement of large-scale free-form surfaces in on-machine laser measurement systems. To improve the measurement accuracy, the effects of the scan depth, surface roughness, incident angle and azimuth angle on the measurement results were investigated experimentally, and a practical measurement strategy considering the position and orientation of the sensor is presented. Also, a semi-quantitative model based on geometrical optics is proposed to compensate for the measurement error associated with the incident angle. The normal vector of the measurement point is determined using a cross-curve method from the acquired surface data. Then, the azimuth angle and incident angle are calculated to inform the measurement strategy and error-compensation model, respectively. The measurement strategy and error-compensation model are verified through the measurement of a large propeller blade on a heavy machine tool in a factory environment. The results demonstrate that the strategy and the model are effective in increasing the measurement accuracy. (paper)

  13. Automated breeder fuel fabrication

    International Nuclear Information System (INIS)

    Goldmann, L.H.; Frederickson, J.R.

    1983-01-01

    The objective of the Secure Automated Fabrication (SAF) Project is to develop remotely operated equipment for the processing and manufacturing of breeder reactor fuel pins. The SAF line will be installed in the Fuels and Materials Examination Facility (FMEF). The FMEF is presently under construction at the Department of Energy's (DOE) Hanford site near Richland, Washington, and is operated by the Westinghouse Hanford Company (WHC). The fabrication and support systems of the SAF line are designed for computer-controlled operation from a centralized control room. Remote and automated fuel fabriction operations will result in: reduced radiation exposure to workers; enhanced safeguards; improved product quality; near real-time accountability, and increased productivity. The present schedule calls for installation of SAF line equipment in the FMEF beginning in 1984, with qualifying runs starting in 1986 and production commencing in 1987. 5 figures

  14. OPO fabric decontamination

    International Nuclear Information System (INIS)

    Severa, J.; Bar, J.; Grujbar, V.

    1978-01-01

    Samples of five polypropylene-based man-made fabrics were studied with regard to the degree of contamination and possibilities of decontamination in order to assess their suitability as material for protective clothing in the nuclear industry. The contamination degree of the fabrics in an aqueous solution of a fission product mixture was found to be low. Soaking in a mixture of the Sapon detergent and sodium hexametaphosphate at a concentration of both materials of 1 g/l with subsequent washing in a solution of the Zenit detergent at a concentration of 3 g/l was suggested as the most suitable decontamination procedure. It reduces the initial contamination by almost 99%. (Z.M.)

  15. Intentionally fabricated autobiographical memories

    OpenAIRE

    Justice, LV; Morrison, CM; Conway, MA

    2017-01-01

    Participants generated both autobiographical memories (AMs) that they believed to be true and intentionally fabricated autobiographical memories (IFAMs). Memories were constructed while a concurrent memory load (random 8-digit sequence) was held in mind or while there was no concurrent load. Amount and accuracy of recall of the concurrent memory load was reliably poorer following generation of IFAMs than following generation of AMs. There was no reliable effect of load on memory generation ti...

  16. Colored fused filament fabrication

    OpenAIRE

    Song, Haichuan; Lefebvre, Sylvain

    2017-01-01

    Filament fused fabrication is the method of choice for printing 3D models at low cost, and is the de-facto standard for hobbyists, makers and schools. Unfortunately, filament printers cannot truly reproduce colored objects. The best current techniques rely on a form of dithering exploiting occlusion, that was only demonstrated for shades of two base colors and that behaves differently depending on surface slope. We explore a novel approach for 3D printing colored objects, capable of creating ...

  17. Advanced fuel fabrication

    International Nuclear Information System (INIS)

    Bernard, H.

    1989-01-01

    This paper deals with the fabrication of advanced fuels, such as mixed oxides for Pressurized Water Reactors or mixed nitrides for Fast Breeder Reactors. Although an extensive production experience exists for the mixed oxides used in the FBR, important work is still needed to improve the theoretical and technical knowledge of the production route which will be introduced in the future European facility, named Melox, at Marcoule. Recently, the feasibility of nitride fuel fabrication in existing commercial oxide facilities was demonstrated in France. The process, based on carbothermic reduction of oxides with subsequent comminution of the reaction product, cold pressing and sintering provides (U, Pu)N pellets with characteristics suitable for irradiation testing. Two experiments named NIMPHE 1 and 2 fabricated in collaboration with ITU, Karlsruhe, involve 16 nitride and 2 carbide pins, operating at a linear power of 45 and 73 kW/m with a smear density of 75-80% TD and a high burn-up target of 15 at%. These experiments are currently being irradiated in Phenix, at Marcoule. (orig.)

  18. Intraocular lens fabrication

    Energy Technology Data Exchange (ETDEWEB)

    Salazar, Mike A. (Albuquerque, NM); Foreman, Larry R. (Los Alamos, NM)

    1997-01-01

    This invention describes a method for fabricating an intraocular lens made rom clear Teflon.TM., Mylar.TM., or other thermoplastic material having a thickness of about 0.025 millimeters. These plastic materials are thermoformable and biocompatable with the human eye. The two shaped lenses are bonded together with a variety of procedures which may include thermosetting and solvent based adhesives, laser and impulse welding, and ultrasonic bonding. The fill tube, which is used to inject a refractive filling material is formed with the lens so as not to damage the lens shape. A hypodermic tube may be included inside the fill tube.

  19. Intraocular lens fabrication

    Energy Technology Data Exchange (ETDEWEB)

    Salazar, M.A.; Foreman, L.R.

    1997-07-08

    This invention describes a method for fabricating an intraocular lens made from clear Teflon{trademark}, Mylar{trademark}, or other thermoplastic material having a thickness of about 0.025 millimeters. These plastic materials are thermoformable and biocompatable with the human eye. The two shaped lenses are bonded together with a variety of procedures which may include thermosetting and solvent based adhesives, laser and impulse welding, and ultrasonic bonding. The fill tube, which is used to inject a refractive filling material is formed with the lens so as not to damage the lens shape. A hypodermic tube may be included inside the fill tube. 13 figs.

  20. Mask fabrication process

    Science.gov (United States)

    Cardinale, Gregory F.

    2000-01-01

    A method for fabricating masks and reticles useful for projection lithography systems. An absorber layer is conventionally patterned using a pattern and etch process. Following the step of patterning, the entire surface of the remaining top patterning photoresist layer as well as that portion of an underlying protective photoresist layer where absorber material has been etched away is exposed to UV radiation. The UV-exposed regions of the protective photoresist layer and the top patterning photoresist layer are then removed by solution development, thereby eliminating the need for an oxygen plasma etch and strip and chances for damaging the surface of the substrate or coatings.

  1. Advanced fabrication technology

    International Nuclear Information System (INIS)

    Sheely, W.F.

    1986-01-01

    The Fuel Cycle Plant is a multipurpose nuclear facility located on the Hanford Nuclear Reservation in eastern Washington state. The facility is part of the Hanford Engineering Development Laboratory which is operated by Westinghouse Hanford Company for the Department of Energy. The Fuel Cycle Plant is currently being prepared to support the Liquid Metal Reactors Program with fuel fabrication services for the Fast Flux Test Facility and other LMR programs. This report describes the technical innovations to be utilized in the operation of this plant

  2. A new method of fabricating a blend scaffold using an indirect three-dimensional printing technique

    International Nuclear Information System (INIS)

    Jung, Jin Woo; Lee, Hyungseok; Hong, Jung Min; Park, Jeong Hun; Cho, Dong-Woo; Shim, Jung Hee; Choi, Tae Hyun

    2015-01-01

    Due to its simplicity and effectiveness, the physical blending of polymers is considered to be a practical strategy for developing a versatile scaffold having desirable mechanical and biochemical properties. In the present work, an indirect three-dimensional (i3D) printing technique was proposed to fabricate a 3D free-form scaffold using a blend of immiscible materials, such as polycaprolactone (PCL) and gelatin. The i3D printing technique includes 3D printing of a mold and a sacrificial molding process. PCL/chloroform and gelatin/water were physically mixed to prepare the blend solution, which was subsequently injected into the cavity of a 3D printed mold. After solvent removal and gelatin cross-linking, the mold was dissolved to obtain a PCL–gelatin (PG) scaffold, with a specific 3D structure. Scanning electron microscopy and Fourier transform infrared spectroscopy analysis indicated that PCL masses and gelatin fibers in the PG scaffold homogenously coexisted without chemical bonding. Compression tests confirmed that gelatin incorporation into the PCL enhanced its mechanical flexibility and softness, to the point of being suitable for soft-tissue engineering, as opposed to pure PCL. Human adipose-derived stem cells, cultured on a PG scaffold, exhibited enhanced in vitro chondrogenic differentiation and tissue formation, compared with those on a PCL scaffold. The i3D printing technique can be used to blend a variety of materials, facilitating 3D scaffold fabrication for specific tissue regeneration. Furthermore, this convenient and versatile technique may lead to wider application of 3D printing in tissue engineering. (paper)

  3. A new method of fabricating a blend scaffold using an indirect three-dimensional printing technique.

    Science.gov (United States)

    Jung, Jin Woo; Lee, Hyungseok; Hong, Jung Min; Park, Jeong Hun; Shim, Jung Hee; Choi, Tae Hyun; Cho, Dong-Woo

    2015-11-03

    Due to its simplicity and effectiveness, the physical blending of polymers is considered to be a practical strategy for developing a versatile scaffold having desirable mechanical and biochemical properties. In the present work, an indirect three-dimensional (i3D) printing technique was proposed to fabricate a 3D free-form scaffold using a blend of immiscible materials, such as polycaprolactone (PCL) and gelatin. The i3D printing technique includes 3D printing of a mold and a sacrificial molding process. PCL/chloroform and gelatin/water were physically mixed to prepare the blend solution, which was subsequently injected into the cavity of a 3D printed mold. After solvent removal and gelatin cross-linking, the mold was dissolved to obtain a PCL-gelatin (PG) scaffold, with a specific 3D structure. Scanning electron microscopy and Fourier transform infrared spectroscopy analysis indicated that PCL masses and gelatin fibers in the PG scaffold homogenously coexisted without chemical bonding. Compression tests confirmed that gelatin incorporation into the PCL enhanced its mechanical flexibility and softness, to the point of being suitable for soft-tissue engineering, as opposed to pure PCL. Human adipose-derived stem cells, cultured on a PG scaffold, exhibited enhanced in vitro chondrogenic differentiation and tissue formation, compared with those on a PCL scaffold. The i3D printing technique can be used to blend a variety of materials, facilitating 3D scaffold fabrication for specific tissue regeneration. Furthermore, this convenient and versatile technique may lead to wider application of 3D printing in tissue engineering.

  4. Fabrication of zein nanostructure

    Science.gov (United States)

    Luecha, Jarupat

    The concerns on the increase of polluting plastic wastes as well as the U.S. dependence on imported petrochemical products have driven an attention towards alternative biodegradable polymers from renewable resources. Zein protein, a co-product from ethanol production from corn, is a good candidate. This research project aims to increase zein value by adopting nanotechnology for fabricating advanced zein packaging films and zein microfluidic devices. Two nanotechnology approaches were focused: the polymer nanoclay nanocomposite technique where the nanocomposite structures were created in the zein matrix, and the soft lithography and the microfluidic devices where the micro and nanopatterns were created on the zein film surfaces. The polymer nanoclay nanocomposite technique was adopted in the commonly used zein film fabrication processes which were solvent casting and extrusion blowing methods. The two methods resulted in partially exfoliated nanocomposite structures. The impact of nanoclays on the physical properties of zein films strongly depended on the film preparation techniques. The impact of nanoclay concentration was more pronounced in the films made by extrusion blowing technique than by the solvent casting technique. As the processability limitation for the extrusion blowing technique of the zein sample containing hight nanoclay content, the effect of the nanoclay content on the rheological properties of zein hybrid resins at linear and nonlinear viscoelastic regions were further investigated. A pristine zein resin exhibited soft solid like behavior. On the other hand, the zein hybrid with nanoclay content greater than 5 wt.% showed more liquid like behavior, suggesting that the nanoclays interrupted the entangled zein network. There was good correspondence between the experimental data and the predictions of the Wagner model for the pristine zein resins. However, the model failed to predict the steady shear properties of the zein nanoclay nanocomposite

  5. Intentionally fabricated autobiographical memories.

    Science.gov (United States)

    Justice, Lucy V; Morrison, Catriona M; Conway, Martin A

    2018-02-01

    Participants generated both autobiographical memories (AMs) that they believed to be true and intentionally fabricated autobiographical memories (IFAMs). Memories were constructed while a concurrent memory load (random 8-digit sequence) was held in mind or while there was no concurrent load. Amount and accuracy of recall of the concurrent memory load was reliably poorer following generation of IFAMs than following generation of AMs. There was no reliable effect of load on memory generation times; however, IFAMs always took longer to construct than AMs. Finally, replicating previous findings, fewer IFAMs had a field perspective than AMs, IFAMs were less vivid than AMs, and IFAMs contained more motion words (indicative of increased cognitive load). Taken together, these findings show a pattern of systematic differences that mark out IFAMs, and they also show that IFAMs can be identified indirectly by lowered performance on concurrent tasks that increase cognitive load.

  6. NCSX Vacuum Vessel Fabrication

    International Nuclear Information System (INIS)

    Viola ME; Brown T; Heitzenroeder P; Malinowski F; Reiersen W; Sutton L; Goranson P; Nelson B; Cole M; Manuel M; McCorkle D.

    2005-01-01

    The National Compact Stellarator Experiment (NCSX) is being constructed at the Princeton Plasma Physics Laboratory (PPPL) in conjunction with the Oak Ridge National Laboratory (ORNL). The goal of this experiment is to develop a device which has the steady state properties of a traditional stellarator along with the high performance characteristics of a tokamak. A key element of this device is its highly shaped Inconel 625 vacuum vessel. This paper describes the manufacturing of the vessel. The vessel is being fabricated by Major Tool and Machine, Inc. (MTM) in three identical 120 o vessel segments, corresponding to the three NCSX field periods, in order to accommodate assembly of the device. The port extensions are welded on, leak checked, cut off within 1-inch of the vessel surface at MTM and then reattached at PPPL, to accommodate assembly of the close-fitting modular coils that surround the vessel. The 120 o vessel segments are formed by welding two 60 o segments together. Each 60 o segment is fabricated by welding ten press-formed panels together over a collapsible welding fixture which is needed to precisely position the panels. The vessel is joined at assembly by welding via custom machined 8-inch (20.3 cm) wide spacer ''spool pieces''. The vessel must have a total leak rate less than 5 X 10 -6 t-l/s, magnetic permeability less than 1.02(micro), and its contours must be within 0.188-inch (4.76 mm). It is scheduled for completion in January 2006

  7. Fabrication of superhydrophobic cotton fabrics using crosslinking polymerization method

    Science.gov (United States)

    Jiang, Bin; Chen, Zhenxing; Sun, Yongli; Yang, Huawei; Zhang, Hongjie; Dou, Haozhen; Zhang, Luhong

    2018-05-01

    With the aim of removing and recycling oil and organic solvent from water, a facile and low-cost crosslinking polymerization method was first applied on surface modification of cotton fabrics for water/oil separation. Micro-nano hierarchical rough structure was constructed by triethylenetetramine (TETA) and trimesoyl chloride (TMC) that formed a polymeric layer on the surface of the fabric and anchored Al2O3 nanoparticles firmly between the fabric surface and the polymer layer. Superhydrophobic property was further obtained through self-assembly grafting of hydrophobic groups on the rough surface. The as-prepared cotton fabric exhibited superoleophilicity in atmosphere and superhydrophobicity both in atmosphere and under oil with the water contact angle of 153° and 152° respectively. Water/oil separation test showed that the as-prepared cotton fabric can handle with various oil-water mixtures with a high separation efficiency over 99%. More importantly, the separation efficiency remained above 98% over 20 cycles of reusing without losing its superhydrophobicity which demonstrated excellent reusability in oil/water separation process. Moreover, the as-prepared cotton fabric possessed good contamination resistance ability and self-cleaning property. Simulation washing process test showed the superhydrophobic cotton fabric maintained high value of water contact angle above 150° after 100 times washing, indicating great stability and durability. In summary, this work provides a brand-new way to surface modification of cotton fabric and makes it a promising candidate material for oil/water separation.

  8. Process for fabrication of cermets

    Science.gov (United States)

    Landingham, Richard L [Livermore, CA

    2011-02-01

    Cermet comprising ceramic and metal components and a molten metal infiltration method and process for fabrication thereof. The light weight cermets having improved porosity, strength, durability, toughness, elasticity fabricated from presintered ceramic powder infiltrated with a molten metal or metal alloy. Alumina titanium cermets biocompatible with the human body suitable for bone and joint replacements.

  9. CW RFQ fabrication and engineering

    International Nuclear Information System (INIS)

    Schrage, D.; Young, L.; Roybal, P.

    1998-01-01

    The design and fabrication of a four-vane RFQ to deliver a 100 mA CW proton beam at 6.7 MeV is described. This linac is an Oxygen-Free Electrolytic (OFE) copper structure 8 m in length and was fabricated using hydrogen furnace brazing as the joining technology

  10. DRAPING SIMULATION OF WOVEN FABRICS

    Energy Technology Data Exchange (ETDEWEB)

    Rodgers, William [General Motors LLC; Jin, Xiaoshi [ESI Group NA; Zhu, Jiang [Optimal CAE; Wathen, Terrence [General Motors LLC; Doroudian2, Mark [ESI Group NA; Aitharaju, Venkat [General Motors LLC

    2016-09-07

    Woven fabric composites are extensively used in molding complex geometrical shapes due to their high conformability compared to other fabrics. Preforming is an important step in the overall process, where the two-dimensional fabric is draped to become the three-dimensional shape of the part prior to resin injection. During preforming, the orientation of the yarns may change significantly compared to the initial orientations. Accurate prediction of the yarn orientations after molding is important for evaluating the structural performance of the final part. This paper presents a systematic investigation of the angle changes during the preform operation for carbon fiber twill and satin weave fabrics. Preforming experiments were conducted using a truncated pyramid mold geometry designed and fabricated at the General Motors Research Laboratories. Predicted results for the yarn orientations were compared with experimental results and good agreement was observed

  11. Secure Automated Fabrication: an overview of remote breeder fuel fabrication

    International Nuclear Information System (INIS)

    Nyman, D.H.; Graham, R.A.

    1983-10-01

    The Secure Automated Fabrication (SAF) line is an automated, remotely controlled breeder fuel pin fabrication process which is to be installed in the Fuels and Materials Examination Facility (FMEF). The FMEF is presently under construction at Hanford and is scheduled for completion in 1984. The SAF line is scheduled for startup in 1987 and will produce mixed uranium-plutonium fuel pins for the Fast Flux Test Facility (FFTF) and the Clinch River Breeder Reactor Plant (CRBRP). The fabrication line and support systems are described

  12. MOX fuel fabrication at AECL

    International Nuclear Information System (INIS)

    Dimayuga, F.C.; Jeffs, A.T.

    1995-01-01

    Atomic Energy of Canada Limited's mixed-oxide (MOX) fuel fabrication activities are conducted in the Recycle Fuel Fabrication Laboratories (RFFL) at the Chalk River Laboratories. The RFFL facility is designed to produce experimental quantities of CANDU MOX fuel for reactor physics tests or demonstration irradiations. From 1979 to 1987, several MOX fuel fabrication campaigns were run in the RFFL, producing various quantities of fuel with different compositions. About 150 bundles, containing over three tonnes of MOX, were fabricated in the RFFL before operations in the facility were suspended. In late 1987, the RFFL was placed in a state of active standby, a condition where no fuel fabrication activities are conducted, but the monitoring and ventilation systems in the facility are maintained. Currently, a project to rehabilitate the RFFL and resume MOX fuel fabrication is nearing completion. This project is funded by the CANDU Owners' Group (COG). The initial fabrication campaign will consist of the production of thirty-eight 37-element (U,Pu)O 2 bundles containing 0.2 wt% Pu in Heavy Element (H.E.) destined for physics tests in the zero-power ZED-2 reactor. An overview of the Rehabilitation Project will be given. (author)

  13. Fabric circuits and method of manufacturing fabric circuits

    Science.gov (United States)

    Chu, Andrew W. (Inventor); Dobbins, Justin A. (Inventor); Scully, Robert C. (Inventor); Trevino, Robert C. (Inventor); Lin, Greg Y. (Inventor); Fink, Patrick W. (Inventor)

    2011-01-01

    A flexible, fabric-based circuit comprises a non-conductive flexible layer of fabric and a conductive flexible layer of fabric adjacent thereto. A non-conductive thread, an adhesive, and/or other means may be used for attaching the conductive layer to the non-conductive layer. In some embodiments, the layers are attached by a computer-driven embroidery machine at pre-determined portions or locations in accordance with a pre-determined attachment layout before automated cutting. In some other embodiments, an automated milling machine or a computer-driven laser using a pre-designed circuit trace as a template cuts the conductive layer so as to separate an undesired portion of the conductive layer from a desired portion of the conductive layer. Additional layers of conductive fabric may be attached in some embodiments to form a multi-layer construct.

  14. Fabrication of cotton fabric with superhydrophobicity and flame retardancy.

    Science.gov (United States)

    Zhang, Ming; Wang, Chengyu

    2013-07-25

    A simple and facile method for fabricating the cotton fabric with superhydrophobicity and flame retardancy is described in the present work. The cotton fabric with the maximal WCA of 160° has been prepared by the covalent deposition of amino-silica nanospheres and the further graft with (heptadecafluoro-1,1,2,2-tetradecyl) trimethoxysilane. The geometric microstructure of silica spheres was measured by transmission electron microscopy (TEM). The cotton textiles before and after treatment were characterized by using scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS). The wetting behavior of cotton samples was investigated by water contact angle measurement. Moreover, diverse performances of superhydrophobic cotton textiles have been evaluated as well. The results exhibited the outstanding superhydrophobicity, excellent waterproofing durability and flame retardancy of the cotton fabric after treatment, offering a good opportunity to accelerate the large-scale production of superhydrophobic textiles materials for new industrial applications. Copyright © 2013 Elsevier Ltd. All rights reserved.

  15. Fabrication of nanowires and nanostructures

    DEFF Research Database (Denmark)

    Mátéfi-Tempfli, Stefan; Mátéfi-Tempfli, M.; Piraux, L.

    2009-01-01

    We report on different approaches that we have adopted and developed for the fabrication of nanowires and nanostructures. Methods based on template synthesis and on self organization seem to be the most promising for the fabrication of nanomaterials and nanostructures due to their easiness and low...... cost. The development of a supported nanoporous alumina template and the possibility of using this template to combine electrochemical synthesis with lithographic methods open new ways for the fabrication of complex nanostructures. The numerous advantages of the supported template and its compatibility...

  16. Quantum Bridge Fabrication Using Photolithography

    International Nuclear Information System (INIS)

    Quinones, R.

    2001-01-01

    The need for high-speed performance electronics in computers integrated circuits and sensors, require the fabrication of low energy consumption diodes. Nano fabrication methods require new techniques and equipment. We are currently developing a procedure to fabricate a diode based on quantum-effects. The device will act like a traditional diode, but the nanometer scale will allow it to reach high speeds without over heating. This new diode will be on a nano-bridge so it can be attenuated by an electromagnetic wave. The goal is to obtain similar current vs voltage response as in a silicon diode

  17. Fabricating Copper Nanotubes by Electrodeposition

    Science.gov (United States)

    Yang, E. H.; Ramsey, Christopher; Bae, Youngsam; Choi, Daniel

    2009-01-01

    Copper tubes having diameters between about 100 and about 200 nm have been fabricated by electrodeposition of copper into the pores of alumina nanopore membranes. Copper nanotubes are under consideration as alternatives to copper nanorods and nanowires for applications involving thermal and/or electrical contacts, wherein the greater specific areas of nanotubes could afford lower effective thermal and/or electrical resistivities. Heretofore, copper nanorods and nanowires have been fabricated by a combination of electrodeposition and a conventional expensive lithographic process. The present electrodeposition-based process for fabricating copper nanotubes costs less and enables production of copper nanotubes at greater rate.

  18. Natural fabric of Hildegardia populifolia composites

    CSIR Research Space (South Africa)

    Guduri, BBR

    2006-12-01

    Full Text Available The influence of Hildegardia populofolia fabric content, fabric orientation, sodium hydroxide (NaOH) and silane coupling agent treatment on the surface properties of the fabric, mechanical and fracture properties of Hildegardia populifolia...

  19. Properties of natural fabric Polyalthia cerasoides

    CSIR Research Space (South Africa)

    Jayaramudu, J

    2009-06-01

    Full Text Available of this fabric were compared with those of two natural fabrics reported in the literature. This uniaxial fabric has sufficient tensile modulus and can be used as reinforcement in the development of green composites....

  20. Fabrication of integrated metallic MEMS devices

    DEFF Research Database (Denmark)

    Yalcinkaya, Arda Deniz; Ravnkilde, Jan Tue; Hansen, Ole

    2002-01-01

    A simple and complementary metal oxide semiconductor (CMOS) compatible fabrication technique for microelectromechanical (MEMS) devices is presented. The fabrication technology makes use of electroplated metal layers. Among the fabricated devices, high quality factor microresonators are characteri......A simple and complementary metal oxide semiconductor (CMOS) compatible fabrication technique for microelectromechanical (MEMS) devices is presented. The fabrication technology makes use of electroplated metal layers. Among the fabricated devices, high quality factor microresonators...

  1. SU-G-JeP3-04: Estimating 4D CBCT from Prior Information and Extremely Limited Angle Projections Using Structural PCA and Weighted Free-Form Deformation

    International Nuclear Information System (INIS)

    Harris, W; Yin, F; Zhang, Y; Ren, L

    2016-01-01

    Purpose: To investigate the feasibility of using structure-based principal component analysis (PCA) motion-modeling and weighted free-form deformation to estimate on-board 4D-CBCT using prior information and extremely limited angle projections for potential 4D target verification of lung radiotherapy. Methods: A technique for lung 4D-CBCT reconstruction has been previously developed using a deformation field map (DFM)-based strategy. In the previous method, each phase of the 4D-CBCT was generated by deforming a prior CT volume. The DFM was solved by a motion-model extracted by global PCA and a free-form deformation (GMM-FD) technique, using data fidelity constraint and the deformation energy minimization. In this study, a new structural-PCA method was developed to build a structural motion-model (SMM) by accounting for potential relative motion pattern changes between different anatomical structures from simulation to treatment. The motion model extracted from planning 4DCT was divided into two structures: tumor and body excluding tumor, and the parameters of both structures were optimized together. Weighted free-form deformation (WFD) was employed afterwards to introduce flexibility in adjusting the weightings of different structures in the data fidelity constraint based on clinical interests. XCAT (computerized patient model) simulation with a 30 mm diameter lesion was simulated with various anatomical and respirational changes from planning 4D-CT to onboard volume. The estimation accuracy was evaluated by the Volume-Percent-Difference (VPD)/Center-of-Mass-Shift (COMS) between lesions in the estimated and “ground-truth” on board 4D-CBCT. Results: Among 6 different XCAT scenarios corresponding to respirational and anatomical changes from planning CT to on-board using single 30° on-board projections, the VPD/COMS for SMM-WFD was reduced to 10.64±3.04%/1.20±0.45mm from 21.72±9.24%/1.80±0.53mm for GMM-FD. Using 15° orthogonal projections, the VPD/COMS was

  2. SU-G-JeP3-04: Estimating 4D CBCT from Prior Information and Extremely Limited Angle Projections Using Structural PCA and Weighted Free-Form Deformation

    Energy Technology Data Exchange (ETDEWEB)

    Harris, W; Yin, F; Zhang, Y; Ren, L [Duke University Medical Center, Durham, NC (United States)

    2016-06-15

    Purpose: To investigate the feasibility of using structure-based principal component analysis (PCA) motion-modeling and weighted free-form deformation to estimate on-board 4D-CBCT using prior information and extremely limited angle projections for potential 4D target verification of lung radiotherapy. Methods: A technique for lung 4D-CBCT reconstruction has been previously developed using a deformation field map (DFM)-based strategy. In the previous method, each phase of the 4D-CBCT was generated by deforming a prior CT volume. The DFM was solved by a motion-model extracted by global PCA and a free-form deformation (GMM-FD) technique, using data fidelity constraint and the deformation energy minimization. In this study, a new structural-PCA method was developed to build a structural motion-model (SMM) by accounting for potential relative motion pattern changes between different anatomical structures from simulation to treatment. The motion model extracted from planning 4DCT was divided into two structures: tumor and body excluding tumor, and the parameters of both structures were optimized together. Weighted free-form deformation (WFD) was employed afterwards to introduce flexibility in adjusting the weightings of different structures in the data fidelity constraint based on clinical interests. XCAT (computerized patient model) simulation with a 30 mm diameter lesion was simulated with various anatomical and respirational changes from planning 4D-CT to onboard volume. The estimation accuracy was evaluated by the Volume-Percent-Difference (VPD)/Center-of-Mass-Shift (COMS) between lesions in the estimated and “ground-truth” on board 4D-CBCT. Results: Among 6 different XCAT scenarios corresponding to respirational and anatomical changes from planning CT to on-board using single 30° on-board projections, the VPD/COMS for SMM-WFD was reduced to 10.64±3.04%/1.20±0.45mm from 21.72±9.24%/1.80±0.53mm for GMM-FD. Using 15° orthogonal projections, the VPD/COMS was

  3. Pilling Resistance of Knitted Fabrics

    Directory of Open Access Journals (Sweden)

    Gita BUSILIENĖ

    2011-09-01

    Full Text Available Knitted fabrics with different quantity of elastane, conspicuous by high viscosity and elasticity, having one of the most important performance properties - resistance to pilling are often used in the production of high quality sportswear. During technological process imitating operating conditions, the behaviour of knitted fabrics may be changed by different industrial softeners from 12 % to 20 % of active substance, for example fatty acid condensate (Tubingal 5051 or silicone micro emulsion (Tubingal SMF. The aim of this investigation is to define the influence of fibrous composition and chemical softeners to the propensity of fuzzing and pilling of plain and plated jersey pattern knitted fabrics. The results of investigations showed that fibrous composition and thickness of materials (up to 6 % and washing as well as softening (from 33 % to 67 % change the resistance of knitted fabrics to pilling.http://dx.doi.org/10.5755/j01.ms.17.3.597

  4. Geoacoustic Physical Model Fabrication Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Fabricates three-dimensional rough surfaces (e.g., fractals, ripples) out of materials such as PVC or wax to simulate the roughness properties associated...

  5. Fabricating plasmonic components for nanophotonics

    DEFF Research Database (Denmark)

    Boltasseva, Alexandra; Nielsen, Rasmus Bundgaard; Jeppesen, Claus

    2009-01-01

    We report on experimental realization of different metal-dielectric structures that are used as surface plasmon polariton waveguides and as plasmonic metamaterials. Fabrication approaches based on different lithographic and deposition techniques are discussed....

  6. Design and fabrication of human skin by three-dimensional bioprinting.

    Science.gov (United States)

    Lee, Vivian; Singh, Gurtej; Trasatti, John P; Bjornsson, Chris; Xu, Xiawei; Tran, Thanh Nga; Yoo, Seung-Schik; Dai, Guohao; Karande, Pankaj

    2014-06-01

    Three-dimensional (3D) bioprinting, a flexible automated on-demand platform for the free-form fabrication of complex living architectures, is a novel approach for the design and engineering of human organs and tissues. Here, we demonstrate the potential of 3D bioprinting for tissue engineering using human skin as a prototypical example. Keratinocytes and fibroblasts were used as constituent cells to represent the epidermis and dermis, and collagen was used to represent the dermal matrix of the skin. Preliminary studies were conducted to optimize printing parameters for maximum cell viability as well as for the optimization of cell densities in the epidermis and dermis to mimic physiologically relevant attributes of human skin. Printed 3D constructs were cultured in submerged media conditions followed by exposure of the epidermal layer to the air-liquid interface to promote maturation and stratification. Histology and immunofluorescence characterization demonstrated that 3D printed skin tissue was morphologically and biologically representative of in vivo human skin tissue. In comparison with traditional methods for skin engineering, 3D bioprinting offers several advantages in terms of shape- and form retention, flexibility, reproducibility, and high culture throughput. It has a broad range of applications in transdermal and topical formulation discovery, dermal toxicity studies, and in designing autologous grafts for wound healing. The proof-of-concept studies presented here can be further extended for enhancing the complexity of the skin model via the incorporation of secondary and adnexal structures or the inclusion of diseased cells to serve as a model for studying the pathophysiology of skin diseases.

  7. Silicone nanocomposite coatings for fabrics

    Science.gov (United States)

    Eberts, Kenneth (Inventor); Lee, Stein S. (Inventor); Singhal, Amit (Inventor); Ou, Runqing (Inventor)

    2011-01-01

    A silicone based coating for fabrics utilizing dual nanocomposite fillers providing enhanced mechanical and thermal properties to the silicone base. The first filler includes nanoclusters of polydimethylsiloxane (PDMS) and a metal oxide and a second filler of exfoliated clay nanoparticles. The coating is particularly suitable for inflatable fabrics used in several space, military, and consumer applications, including airbags, parachutes, rafts, boat sails, and inflatable shelters.

  8. Safeguards through secure automated fabrication

    International Nuclear Information System (INIS)

    DeMerschman, A.W.; Carlson, R.L.

    1982-01-01

    Westinghouse Hanford Company, a prime contractor for the U.S. Department of Energy, is constructing the Secure Automated Fabrication (SAF) line for fabrication of mixed oxide breeder fuel pins. Fuel processing by automation, which provides a separation of personnel from fuel handling, will provide a means whereby advanced safeguards concepts will be introduced. Remote operations and the inter-tie between the process computer and the safeguards computer are discussed

  9. ITER Central Solenoid Module Fabrication

    Energy Technology Data Exchange (ETDEWEB)

    Smith, John [General Atomics, San Diego, CA (United States)

    2016-09-23

    The fabrication of the modules for the ITER Central Solenoid (CS) has started in a dedicated production facility located in Poway, California, USA. The necessary tools have been designed, built, installed, and tested in the facility to enable the start of production. The current schedule has first module fabrication completed in 2017, followed by testing and subsequent shipment to ITER. The Central Solenoid is a key component of the ITER tokamak providing the inductive voltage to initiate and sustain the plasma current and to position and shape the plasma. The design of the CS has been a collaborative effort between the US ITER Project Office (US ITER), the international ITER Organization (IO) and General Atomics (GA). GA’s responsibility includes: completing the fabrication design, developing and qualifying the fabrication processes and tools, and then completing the fabrication of the seven 110 tonne CS modules. The modules will be shipped separately to the ITER site, and then stacked and aligned in the Assembly Hall prior to insertion in the core of the ITER tokamak. A dedicated facility in Poway, California, USA has been established by GA to complete the fabrication of the seven modules. Infrastructure improvements included thick reinforced concrete floors, a diesel generator for backup power, along with, cranes for moving the tooling within the facility. The fabrication process for a single module requires approximately 22 months followed by five months of testing, which includes preliminary electrical testing followed by high current (48.5 kA) tests at 4.7K. The production of the seven modules is completed in a parallel fashion through ten process stations. The process stations have been designed and built with most stations having completed testing and qualification for carrying out the required fabrication processes. The final qualification step for each process station is achieved by the successful production of a prototype coil. Fabrication of the first

  10. A facile method to fabricate superhydrophobic cotton fabrics

    Science.gov (United States)

    Zhang, Ming; Wang, Shuliang; Wang, Chengyu; Li, Jian

    2012-11-01

    A facile and novel method for fabricating superhydrophobic cotton fabrics is described in the present work. The superhydrophobic surface has been prepared by utilizing cationic poly (dimethyldiallylammonium chloride) and silica particles together with subsequent modification of (heptadecafluoro-1,1,2,2-tetradecyl) trimethoxysilane. The size distribution of silica particles was measured by Particle Size Analyzer. The cotton textiles before and after treatment were characterized by using scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS). The wetting behavior of cotton samples was investigated by water contact angle measurement. Moreover, the superhydrophobic durability of coated cotton textiles has been evaluated by exposure, immersion and washing tests. The results show that the treated cotton fabrics exhibited excellent chemical stability and outstanding non-wettability with the WCA of 155 ± 2°, which offers an opportunity to accelerate the large-scale production of superhydrophobic textiles materials for new industrial applications.

  11. Fabrication of Nanoimprint stamps for photonic crystals

    International Nuclear Information System (INIS)

    Kouba, J; Kubenz, M; Mai, A; Ropers, G; Eberhardt, W; Loechel, B

    2006-01-01

    We report on fabrication of nanoimprint stamps for fabrication of two dimensional photonic crystals in visible range of spectra. Nanoimprint stamps made of silicon and/or nickel were successfully fabricated using electron beam lithography and advanced dry etching techniques. The quality of the stamps was evaluated using scanning electron microscopy. The fabricated stamps were also evaluated by imprinting them into suitable polymer materials

  12. 14 CFR 23.605 - Fabrication methods.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Fabrication methods. 23.605 Section 23.605... Fabrication methods. (a) The methods of fabrication used must produce consistently sound structures. If a... fabrication method must be substantiated by a test program. [Doc. No. 4080, 29 FR 17955, Dec. 18, 1964; 30 FR...

  13. 14 CFR 29.605 - Fabrication methods.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Fabrication methods. 29.605 Section 29.605... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Design and Construction General § 29.605 Fabrication methods. (a) The methods of fabrication used must produce consistently sound structures. If a fabrication process...

  14. 14 CFR 27.605 - Fabrication methods.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Fabrication methods. 27.605 Section 27.605... STANDARDS: NORMAL CATEGORY ROTORCRAFT Design and Construction General § 27.605 Fabrication methods. (a) The methods of fabrication used must produce consistently sound structures. If a fabrication process (such as...

  15. 14 CFR 25.605 - Fabrication methods.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Fabrication methods. 25.605 Section 25.605... STANDARDS: TRANSPORT CATEGORY AIRPLANES Design and Construction General § 25.605 Fabrication methods. (a) The methods of fabrication used must produce a consistently sound structure. If a fabrication process...

  16. Functional webs for freeform architecture

    KAUST Repository

    Deng, Bailin; Pottmann, Helmut; Wallner, Johannes

    2011-01-01

    , namely long-range parts and supporting structures. It turns out that from the pure geometry viewpoint this means studying families of curves which cover surfaces in certain well-defined ways. Depending on the application one has in mind, different

  17. On Free-Form Gaming,

    Science.gov (United States)

    1985-08-01

    which the competitive interactions can occur simultaneously in several "arenas" (political, military, etc.). This gaming format has been used to...10 E . Post- Game Analysis .. ..................................... 13 F. Limitations ... ............................................ 15 III...preparation of game papers and an electronic message handling system for moving papers from room to room. This satisfies the requirement for legible, multiple

  18. Metallic Reactor Fuel Fabrication for SFR

    Energy Technology Data Exchange (ETDEWEB)

    Song, Hoon; Kim, Jong-Hwan; Ko, Young-Mo; Woo, Yoon-Myung; Kim, Ki-Hwan; Lee, Chan-Bock [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-05-15

    The metal fuel for an SFR has such advantages such as simple fabrication procedures, good neutron economy, high thermal conductivity, excellent compatibility with a Na coolant, and inherent passive safety 1. U-Zr metal fuel for SFR is now being developed by KAERI as a national R and D program of Korea. The fabrication technology of metal fuel for SFR has been under development in Korea as a national nuclear R and D program since 2007. The fabrication process for SFR fuel is composed of (1) fuel slug casting, (2) loading and fabrication of the fuel rods, and (3) fabrication of the final fuel assemblies. Fuel slug casting is the dominant source of fuel losses and recycled streams in this fabrication process. Fabrication on the rod type metallic fuel was carried out for the purpose of establishing a practical fabrication method. Rod-type fuel slugs were fabricated by injection casting. Metallic fuel slugs fabricated showed a general appearance was smooth.

  19. Electromagnetic micropores: fabrication and operation.

    Science.gov (United States)

    Basore, Joseph R; Lavrik, Nickolay V; Baker, Lane A

    2010-12-21

    We describe the fabrication and characterization of electromagnetic micropores. These devices consist of a micropore encompassed by a microelectromagnetic trap. Fabrication of the device involves multiple photolithographic steps, combined with deep reactive ion etching and subsequent insulation steps. When immersed in an electrolyte solution, application of a constant potential across the micropore results in an ionic current. Energizing the electromagnetic trap surrounding the micropore produces regions of high magnetic field gradients in the vicinity of the micropore that can direct motion of a ferrofluid onto or off of the micropore. This results in dynamic gating of the ion current through the micropore structure. In this report, we detail fabrication and characterize the electrical and ionic properties of the prepared electromagnetic micropores.

  20. Integrated Fabrication of a Microgripper

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    Successful implementation of simple mechanism on silicon chip is a prerequisite for monolithic microrobot-ic systems. This paper describes the integrated fabrication of polycrystalline silicon microgripper. Link, fixed andactive joint, and sliding flange structures with dimensions of micrometers have been fabricated on the substrate ofmonocrystalline silicon using silicon microfabrication technology. This microgripper, which may be applied to trans-ducers or sensors, can be batch-fabricated in IC-compatible process. The movable mechanical elements are built onlayers that are later removed, so that they are free for translation and rotation. Under external driving, a microgrip-per cut from substrate would be able to catch tiny filament or small particle with dimension of 10~ 200 micrometers.

  1. Cascade reactor: granule fabrication processes

    International Nuclear Information System (INIS)

    Erlandson, O.D.; Winkler, E.O.; Maya, I.; Pitts, J.H.

    1985-01-01

    A key feature of Cascade is the granular blanket. Of the many blanket material options open to Cascade, fabrication of Li 2 O granules was felt to offer the greatest challenge. The authors explored available methods for initial Li 2 O granule fabrication. They identified three cost-effective processes for fabricating Li 2 O granules: the VSM drop-melt furnace process, which is based on melting and spheroidizing irregularly shaped Li 2 O feed granules; the LiOH process, which spheroidizes liquefied LiOH and uses GA Technologies' sphere-forming procedures; and the Li 2 CO 3 sol-gel process, used for making spherical fuel particles for the high-temperature gas-cooled reactor (HTGR). Each process is described below

  2. SRF Cavity Fabrication and Materials

    CERN Document Server

    Singer, W

    2014-07-17

    The technological and metallurgical requirements of material for highgradient superconducting cavities are described. High-purity niobium, as the preferred metal for the fabrication of superconducting accelerating cavities, should meet exact specifications. The content of interstitial impurities such as oxygen, nitrogen, and carbon must be below 10μg/g. The hydrogen content should be kept below 2μg/g to prevent degradation of the Q-value under certain cool-down conditions. The material should be free of flaws (foreign material inclusions or cracks and laminations) that can initiate a thermal breakdown. Defects may be detected by quality control methods such as eddy current scanning and identified by a number of special methods. Conventional and alternative cavity fabrication methods are reviewed. Conventionally, niobium cavities are fabricated from sheet niobium by the formation of half-cells by deep drawing, followed by trim machining and Electron-Beam Welding (EBW). The welding of half-cells is a delicate...

  3. Stirling Microregenerators Fabricated and Tested

    Science.gov (United States)

    Moran, Matthew E.

    2004-01-01

    A mesoscale Stirling refrigerator patented by the NASA Glenn Research Center is currently under development. This refrigerator has a predicted efficiency of 30 percent of Carnot and potential uses in electronics, sensors, optical and radiofrequency systems, microarrays, and microsystems. The mesoscale Stirling refrigerator is most suited to volume-limited applications that require cooling below the ambient or sink temperature. Primary components of the planar device include two diaphragm actuators that replace the pistons found in traditional-scale Stirling machines and a microregenerator that stores and releases thermal energy to the working gas during the Stirling cycle. Diaphragms are used to eliminate frictional losses and bypass leakage concerns associated with pistons, while permitting reversal of the hot and cold sides of the device during operation to allow precise temperature control. Three candidate microregenerators were fabricated under NASA grants for initial evaluation: two constructed of porous ceramic, which were fabricated by Johns Hopkins Applied Physics Laboratory, and one made of multiple layers of nickel and photoresist, which was fabricated by Polar Thermal Technologies. The candidate regenerators are being tested by Johns Hopkins Applied Physics in a custom piezoelectric-actuated test apparatus designed to produce the Stirling refrigeration cycle. In parallel with the regenerator testing, Johns Hopkins is using deep reactive ion etching to fabricate electrostatically driven, comb-drive diaphragm actuators. These actuators will drive the Stirling cycle in the prototype device. The top photograph shows the porous ceramic microregenerators. Two microregenerators were fabricated with coarse pores and two with fine pores. The bottom photograph shows the test apparatus parts for evaluating the microregenerators, including the layered nickel-and-photoresist regenerator fabricated using LIGA techniques.

  4. Advanced fabrication of hyperbolic metamaterials

    DEFF Research Database (Denmark)

    Shkondin, Evgeniy; Sukham, Johneph; Panah, Mohammad Esmail Aryaee

    2017-01-01

    Hyperbolic metamaterials can provide unprecedented properties in accommodation of high-k (high wave vector) waves and enhancement of the optical density of states. To reach such performance the metamaterials have to be fabricated with as small imperfections as possible. Here we report on our...... advances in two approaches in fabrication of optical metamaterials. We deposit ultrathin ultrasmooth gold layers with the assistance of organic material (APTMS) adhesion layer. The technology supports the stacking of such layers in a multiperiod construction with alumina spacers between gold films, which...

  5. MQXFS1 Quadrupole Fabrication Report

    CERN Document Server

    Ambrosio, G; Bossert, R; Cavanna, E; Cheng, D; Chlachidize, G; Cooley, L D; Dietderich, D; Felice, H; Ferracin, P; Ghosh, A; Hafalia, R; Holik, E F; Izquierdo Bermudez, S; Juchno, M; Krave, S; Marchevsky, M; Muratore, J; Nobrega, F; Pan, H; Perez, J C; Pong, I; Prestemon, S; Ravaioli, E; Sabbi, G L; Santini, C; Schmalzle, J; Schmalzle, J; Stoynev, S; Strauss, T; Vallone, G; Wanderer, P; Wang, X; Yu, M

    2017-01-01

    This report presents the fabrication and QC data of MQXFS1, the first short model of the low-beta quadrupoles (MQXF) for the LHC High Luminosity Upgrade. It describes the conductor, the coils, and the structure that make the MQXFS1 magnet. Qualification tests and non-conformities are also presented and discussed. The fabrication of MQXFS1 was started before the finalization of conductor and coil design for MQXF magnets. Two strand design were used (RRP 108/127 and RRP 132/169). Cable and coil cross-sections were “first generation”.

  6. MQXFS1 Quadrupole Fabrication Report

    Energy Technology Data Exchange (ETDEWEB)

    Ambrosio, G. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Anerella, M. [Brookhaven National Lab. (BNL), Upton, NY (United States); Bossert, R. [European Organization for Nuclear Research (CERN), Geneva (Switzerland); Cavanna, E. [European Organization for Nuclear Research (CERN), Geneva (Switzerland); Cheng, D. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Chlachidize, G. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Cooley, L. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Dietderich, D. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Felice, H. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Ferracin, P. [European Organization for Nuclear Research (CERN), Geneva (Switzerland); Ghosh, A. [Brookhaven National Lab. (BNL), Upton, NY (United States); Hafalia, R. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Holik, E. F. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Bermudez, S. Izquierdo [European Organization for Nuclear Research (CERN), Geneva (Switzerland); Juchno, M. [European Organization for Nuclear Research (CERN), Geneva (Switzerland); Krave, S. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Marchevsky, M. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Muratore, J. [Brookhaven National Lab. (BNL), Upton, NY (United States); Nobrega, F. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Pan, H. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Perez, J. C. [European Organization for Nuclear Research (CERN), Geneva (Switzerland); Pong, I. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Prestemon, S. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Ravaioli, E. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Sabbi, G. L. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Santini, C. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Schmalzle, J. [Brookhaven National Lab. (BNL), Upton, NY (United States); Stoynev, S. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Strauss, T. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Vallone, G. [European Organization for Nuclear Research (CERN), Geneva (Switzerland); Wanderer, P. [Brookhaven National Lab. (BNL), Upton, NY (United States); Wang, X. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Yu, M. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)

    2017-07-16

    This report presents the fabrication and QC data of MQXFS1, the first short model of the low-beta quadrupoles (MQXF) for the LHC High Luminosity Upgrade. It describes the conductor, the coils, and the structure that make the MQXFS1 magnet. Qualification tests and non-conformities are also presented and discussed. The fabrication of MQXFS1 was started before the finalization of conductor and coil design for MQXF magnets. Two strand design were used (RRP 108/127 and RRP 132/169). Cable and coil cross-sections were “first generation”.

  7. The Flexible Fabric of Space

    Science.gov (United States)

    VanNorsdall, Erin Leigh

    2015-08-01

    This poster will clearly illustrate my understanding of how the fabric of space behaves. The poster will be on a large trampoline with a heavy bowling ball in the center. The observer will be able to clearly understand the much more complicated property of how an object in space, such as a star, literally bends the fabric of the space around as a result of its density. This will also help to explain, in very simple terms, how space-time is bendable, and therefore, travel in space can be as well.

  8. Fabrication Aware Form-finding

    DEFF Research Database (Denmark)

    Egholm Pedersen, Ole; Larsen, Niels Martin; Pigram, Dave

    2014-01-01

    This paper describes a design and construction method that combines two distinct material systems with fabrication aware form-finding and file-to-factory workflows. The method enables the fluent creation of complex materially efficient structures comprising high populations of geometrically uniqu...

  9. Nuclear fuel fabrication in India

    Energy Technology Data Exchange (ETDEWEB)

    Kondal Rao, N

    1975-01-01

    The important role of a nuclear power program in meeting the growing needs of power in India is explained. The successful installation of Tarapur Atomic Power Station and Rajasthan Atomic Power Station as well as the work at Madras Atomic Power Station are described. The development of the Atomic Fuels Division and the Nuclear Fuel Complex, Hyderabad which is mainly concerned with the fabrication of fuel elements and the reprocessing of fuels are explained. The N.F.C. essentially has the following constituent units : Zirconium Plant (ZP) comprising of Zirconium Oxide Plant, Zirconium Sponge Plant and Zirconium Fabrication Plant; Natural Uranium Oxide Plant (UOP); Ceramic Fuel Fabrication Plant (CFFP); Enriched Uranium Oxide Plant (EUOP); Enriched Fuel Fabrication Plant (EEFP) and Quality Control Laboratory for meeting the quality control requirements of all plants. The capacities of various plants at the NFC are mentioned. The work done on mixed oxide fuels and FBTR core with blanket assemblies, nickel and steel assemblies, thermal research reactor of 100 MW capacity, etc. are briefly mentioned.

  10. Fabrication of green polymeric membranes

    KAUST Repository

    Kim, Dooli; Nunes, Suzana Pereira

    2017-01-01

    Provided herein are methods of fabricating membranes using polymers with functionalized groups such as sulfone (e.g., PSf and PES), ether (e.g., PES), acrylonitrile (e.g., PAN), fluoride(e.g., pvdf and other fluoropolymers), and imide (e.g., extem) and ionic liquids. Also provided are membranes made by the provided methods.

  11. Gas-filled hohlraum fabrication

    International Nuclear Information System (INIS)

    Salazar, M.A.; Gobby, P.L.; Foreman, L.R.; Bush, H. Jr.; Gomez, V.M.; Moore, J.E.; Stone, G.F.

    1995-01-01

    Los Alamos National Laboratory (LANL) researchers have fabricated and fielded gas-filled hohlraums at the Lawrence Livermore National Laboratory (LLNL) Nova laser. Fill pressures of 1--5 atmospheres have been typical. We describe the production of the parts, their assembly and fielding. Emphasis is placed on the production of gas-tight polyimide windows and the fielding apparatus and procedure

  12. Nuclear fuel fabrication in India

    International Nuclear Information System (INIS)

    Kondal Rao, N.

    1975-01-01

    The important role of a nuclear power programme in meeting the growing needs of power in India is explained. The successful installation of Tarapur Atomic Power Station and Rajasthan Atomic Power Station as well as the work at Madras Atomic Power Station are described. The development of the Atomic Fuels Division and the Nuclear Fuel Complex, Hyderabad which is mainly concerned with the fabrication of fuel elements and the reprocessing of fuels are explained. The N.F.C. essentially has the following constituent units : Zirconium Plant (ZP) comprising of Zirconium Oxide Plant, Zirconium Sponge Plant and Zirconium Fabrication Plant; Natural Uranium Oxide Plant (UOP); Ceramic Fuel Fabrication Plant (CFFP); Enriched Uranium Oxide Plant (EUOP); Enriched Fuel Fabrication Plant (EEFP) and Quality Control Laboratory for meeting the quality control requirements of all plants. The capacities of various plants at the NFC are mentioned. The work done on mixed oxide fuels and FBTR core with blanket assemblies, nickel and steel assemblies, thermal research reactor of 100 MW capacity, etc. are briefly mentioned. (K.B.)

  13. Fabrication of green polymeric membranes

    KAUST Repository

    Kim, Dooli

    2017-06-16

    Provided herein are methods of fabricating membranes using polymers with functionalized groups such as sulfone (e.g., PSf and PES), ether (e.g., PES), acrylonitrile (e.g., PAN), fluoride(e.g., pvdf and other fluoropolymers), and imide (e.g., extem) and ionic liquids. Also provided are membranes made by the provided methods.

  14. The Fabrication of Qualified Citizens

    DEFF Research Database (Denmark)

    Andrade-Molina, Melissa

    2017-01-01

    a rhizomatic analytical move, a historization of the present is deployed to map the fabrication of the desired qualified citizen in Chile. The analysis evidences the (re)production of dominant narratives about the “qualified citizen” are and have been entangled with the functioning of school geometry...

  15. Fabrication of elliptical SRF cavities

    Science.gov (United States)

    Singer, W.

    2017-03-01

    The technological and metallurgical requirements of material for high-gradient superconducting cavities are described. High-purity niobium, as the preferred metal for the fabrication of superconducting accelerating cavities, should meet exact specifications. The content of interstitial impurities such as oxygen, nitrogen, and carbon must be below 10 μg g-1. The hydrogen content should be kept below 2 μg g-1 to prevent degradation of the quality factor (Q-value) under certain cool-down conditions. The material should be free of flaws (foreign material inclusions or cracks and laminations) that can initiate a thermal breakdown. Traditional and alternative cavity mechanical fabrication methods are reviewed. Conventionally, niobium cavities are fabricated from sheet niobium by the formation of half-cells by deep drawing, followed by trim machining and electron beam welding. The welding of half-cells is a delicate procedure, requiring intermediate cleaning steps and a careful choice of weld parameters to achieve full penetration of the joints. A challenge for a welded construction is the tight mechanical and electrical tolerances. These can be maintained by a combination of mechanical and radio-frequency measurements on half-cells and by careful tracking of weld shrinkage. The main aspects of quality assurance and quality management are mentioned. The experiences of 800 cavities produced for the European XFEL are presented. Another cavity fabrication approach is slicing discs from the ingot and producing cavities by deep drawing and electron beam welding. Accelerating gradients at the level of 35-45 MV m-1 can be achieved by applying electrochemical polishing treatment. The single-crystal option (grain boundary free) is discussed. It seems that in this case, high performance can be achieved by a simplified treatment procedure. Fabrication of the elliptical resonators from a seamless pipe as an alternative is briefly described. This technology has yielded good

  16. Fast and Scalable Fabrication of Microscopic Optical Surfaces and its Application for Optical Interconnect Devices

    Science.gov (United States)

    Summitt, Christopher Ryan

    slope to form the coupler surface. In this method, instead of using an entire exposure in a pixelated manner, only a portion of the Gaussian profile is used, allowing a reduced surface roughness and better control of the surface shape than previously possible with this low NA beam. The surface figure of the mirror is well controlled below 0.04 waves in root-mean-square (RMS) at 1.55 mum wavelength, with mirror angle of 45+/-1 degrees. The coupling efficiency is evaluated using a set of polymer waveguides fabricated on the same substrate as the complete proof of concept device. Device insertion loss was measured using a custom built optical test station and a detailed loss analysis was completed to characterize the optical coupling efficiency of the mirror. Surface roughness and angle were also experimentally confirmed. This process opens up a pathway towards large volume fabrication of free-form and high aspect ratio optical components which have not yet pursued, along with well-defined optical structures on a single substrate. In this dissertation, in Chapter 1, we provide an overview of optical surface fabrication in conjunction with current state of the art on fabrication of free form surfaces in macro and microscopic length scale. The need for optical interconnects is introduced and fabrication methods of micro-optical couplers are reviewed in Chapter 2. In Chapter 3, the complete fabrication process of a mirror based coupler is presented including a custom alignment procedure. In Chapter 4, we provide the integration procedure of the optical couplers with waveguides. In Chapter 5, the alignment of two-lithographic methods is discussed. In Chapter 6, we provide the fabrication procedure used for the waveguides. In Chapter 7, the experimental evaluation and testing of the optical coupler is described. We present a custom test station used for angle verification and optical coupler efficiency measurement. In Chapter 8, a detailed loss analysis of the device is

  17. Novel fabric pressure sensors: design, fabrication, and characterization

    International Nuclear Information System (INIS)

    Wang, Yangyong; Hua, Tao; Zhu, Bo; Li, Qiao; Yi, Weijing; Tao, Xiaoming

    2011-01-01

    Soft and pliable pressure sensors are essential elements in wearable electronics which have wide applications in modern daily lives. This paper presents a family of fabric pressure sensors made by sandwiching a piece of resistive fabric strain sensing element between two tooth-structured layers of soft elastomers. The pressure sensors are capable of measuring pressure from 0 to 2000 kPa, covering the whole range of human–machine interactions. A pressure sensitivity of up to 2.98 × 10 −3 kPa −1 was obtained. Theoretical modeling was conducted based on an energy method to predict the load–displacement relationship for various sensor configurations. By adjusting the Young's modulus of the two conversion layers, as well as the geometrical dimensions, the measurement ranges, and sensitivities of the sensors can be quantitatively determined. The sensors are being used for pressure measurements between the human body and garments, shoes, beds, and chairs

  18. Laser target fabrication, structure and method for its fabrication

    Science.gov (United States)

    Farnum, Eugene H.; Fries, R. Jay

    1985-01-01

    The disclosure is directed to a laser target structure and its method of fabrication. The target structure comprises a target plate containing an orifice across which a pair of crosshairs are affixed. A microsphere is affixed to the crosshairs and enclosed by at least one hollow shell comprising two hemispheres attached together and to the crosshairs so that the microsphere is juxtapositioned at the center of the shell.

  19. Preparation of activated carbon fabrics from cotton fabric precursor

    Science.gov (United States)

    Salehi, R.; Dadashian, F.; Abedi, M.

    2017-10-01

    The preparation of activated carbon fabrics (ACFs) from cotton fabric was performed by chemical activation with phosphoric acid (H3PO4). The operation conditions for obtaining the ACFs with the highest the adsorption capacity and process yield, proposed. Optimized conditions were: impregnation ratio of 2, the rate of temperature rising of 7.5 °C min-1, the activation temperature of 500 °C and the activation time of 30 min. The ACFs produced under optimized conditions was characterized by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX). The surface area and pore volume of carbon nanostructures was characterized by BET nitrogen adsorption isotherm at 77 °K. The pore size distribution calculated from the desorption branch according to BJH method. The iodine number of the prepared ACFs was determined by titration at 30 °C based on the ASTM D4607-94. The results showed the improvement of porous structure, fabric shape, surface area (690 m2/g), total pore volume (0.3216 cm3/g), and well-preserved fibers integrity.

  20. A comprehensive study on the fabrication and properties of biocomposites of poly(lactic acid)/ceramics for bone tissue engineering.

    Science.gov (United States)

    Tajbakhsh, Saeid; Hajiali, Faezeh

    2017-01-01

    The fabrication of a suitable scaffold material is one of the major challenges for bone tissue engineering. Poly(lactic acid) (PLA) is one of the most favorable matrix materials in bone tissue engineering owing to its biocompatibility and biodegradability. However, PLA suffers from some shortcomings including low degradation rate, low cell adhesion caused by its hydrophobic property, and inflammatory reactions in vivo due to its degradation product, lactic acid. Therefore, the incorporation of bioactive reinforcements is considered as a powerful method to improve the properties of PLA. This review presents a comprehensive study on recent advances in the synthesis of PLA-based biocomposites containing ceramic reinforcements, including various methods of production and the evaluation of the scaffolds in terms of porosity, mechanical properties, in vitro and in vivo biocompatibility and bioactivity for bone tissue engineering applications. The production routes range from traditional approaches such as the use of porogens to provide porosity in the scaffolds to novel methods such as solid free-form techniques. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Qualitative Investigation of Some Locally Produced Printed Fabrics ...

    African Journals Online (AJOL)

    The results obtained showed that the locally produced fabrics exhibited comparably better end – use performance characteristics in terms of fabric weight per square meter, fabric flammability, and linear density. While the foreign fabrics are better in terms of Crease recovery, fabric handle, fabric sett, fabric shrinkage, and ...

  2. Fabrication of superconducting niobium radio frequency structures

    International Nuclear Information System (INIS)

    Kirchgessner, J.; Amato, J.; Brawley, J.

    1983-01-01

    During the last several years a variety of superconducting radio frequency structures have been designed, fabricated and tested. The diverse structures and fabrication techniques are described. This paper is a description of the authors' experiences in this field

  3. Fabric quality issues related to apparel merchandising

    CSIR Research Space (South Africa)

    Das, Sonali

    2015-02-01

    Full Text Available The objectives of this study are to develop an understanding of fabric quality related issues and research gaps relevant to apparel manufacturing and merchandising within the South African context. The specific focus is on fabric objective...

  4. Quality in the fabrication process

    International Nuclear Information System (INIS)

    Romano, A.; Aguirre, F.

    2010-01-01

    Enusa commitment to quality in the manufacture process materializes in the application of the most advanced product quality control technologies such as not-destructive inspection techniques, like artificial vision, X-ray or UT inspection, or process parameter statistical control systems. Quality inspectors are trained and certified by the main National Quality Organizations and receive periodic training under a formal company training program that constantly updates their qualification. Fabrication quality control reliability is based on a strategy that prioritizes redundancy of critical inspection equipment's and inspection personnel knowledge polyvalence. Furthermore, improvement in fabrication quality is obtained by a systematic application of the six sigma methodology where added value is created in projects integrating crosscutting company knowledge, reinforcing the global company vision that the fuel business is based on quality. (Author)

  5. Device fabrication by plasma etching

    International Nuclear Information System (INIS)

    Mogab, C.J.

    1980-01-01

    Plasma etching as applied to many of the materials encountered in the fabrication of LSI's is complicated by loading effect-the dependence of etch rate on the integrated surface area to be etched. This problem is alleviated by appropriate choice of etchant and etching conditions. Appropriate choice of system parameters, generally most concerned with the inherent lifetime of etchant species, may also result in improvement of etch rate uniformity on a wafer-by-wafer basis

  6. Zircaloy 4 ingots' industrial fabrication

    International Nuclear Information System (INIS)

    Leyt, A.

    1987-01-01

    The technology developed for the industrial fabrication of Zircaloy-4 ingots is presented. According to the results obtained: a) the homogeneity of the ingots is analyzed, regarding the distribution of components (tin, iron, chromium, oxygen) and Brinell hardness as a function of different types of charge: zirconium sponge-recycling alloy material, sponge of zirconium-alloy; b) the distribution of the same parameters as a function of production is also analyzed. (Author)

  7. Nanocarbon materials fabricated using plasmas

    Science.gov (United States)

    Hatakeyama, Rikizo

    2017-12-01

    Since the discovery of fullerenes more than three decades ago, new kinds of nanoscale materials of carbon allotropes called "nanocarbons" have so far been discovered or synthesized at successive intervals as cases such as carbon nanotubes, carbon nanohorns, graphene, carbon nanowalls, and a carbon nanobelt, while nanodiamonds were actually discovered before then. Their attractively excellent mechanical, physical, and chemical properties have driven researchers to continuously create one of the hottest frontiers in materials science and technology. While plasma states have often been involved in their discovery, on the other hand, plasma-based approaches to this exciting field originally hold promising and enormous potentials for advancing and expanding industrial/biomedical applications of nanocarbons of great diversity. This article provides an extensive overview on plasma-fabricated nanocarbon materials, where the term "fabrication" is defined as synthesis, functionalization, and assembly of devices to cover a wide range of issues associated with the step-by-step plasma processes. Specific attention has been paid to the comparative examination between plasma-based and non-plasma methods for fabricating the nanocarobons with an emphasis on the advantages of plasma processing, such as low-temperature/large-scale fabrication and diversity-carrying structure controllability. The review ends with current challenges and prospects including a ripple effect of the nanocarbon studies on the development of related novel nanomaterials such as transition metal dichalcogenides. It contains not only the latest progress in the field for cutting-edge scientists and engineers, but also the introductory guidance to non-specialists such as lower-class graduate students.

  8. Nanodisk fabrication by nanosphere lithography

    Energy Technology Data Exchange (ETDEWEB)

    Lozhkina, O. A.; Lozhkin, M. S., E-mail: maksim.lozhkin@spbu.ru; Kapitonov, Yu. V. [St.Petersburg State University, 7/9 Universitetskaya nab., St. Petersburg, 199034 (Russian Federation)

    2016-06-17

    Top-down fabrication of regular nanodisk arrays from an A{sub 3}B{sub 5} epitaxial heterostructure containing quantum well is demonstrated. Dry ion etching through the mask was emloyed. The spin-coated monolayer of polystyrene nanospheres served as a mask. Nanodisk diameter could be precisely controlled by oxygen plasma resizing of spheres after deposition. Nanodisks with diameters down to 200 nm were made.

  9. Fabrication of sealed radiation sources

    International Nuclear Information System (INIS)

    Mars, Jean.

    1977-01-01

    The description is given for fabricating a sealed radiation source, consisting in depositing on a metal substrate a thin active coat of a radioelement, termed first coat, submitting this coated substrate to an oxidation treatment in order to obtain on the first coat an inactive coat of an oxide of the metal, termed second coat, and depositing a coat of varnish on this second inactive coat [fr

  10. Computational modelling of buckling of woven fabrics

    CSIR Research Space (South Africa)

    Anandjiwala, RD

    2006-02-01

    Full Text Available for reducing unit production cost is critically important if garment industries in developed countries are keen to improve their competitiveness vis-à-vis low labour cost countries. The mechanics of the buckling behaviour of woven fabric started... of woven fabric. INTRODUCTION The buckling, bending and drape behaviours of a woven fabric influence its performance during actual use and during the process of making-up into the end product. These properties are important, particularly when the fabric...

  11. Parallel fabrication of macroporous scaffolds.

    Science.gov (United States)

    Dobos, Andrew; Grandhi, Taraka Sai Pavan; Godeshala, Sudhakar; Meldrum, Deirdre R; Rege, Kaushal

    2018-07-01

    Scaffolds generated from naturally occurring and synthetic polymers have been investigated in several applications because of their biocompatibility and tunable chemo-mechanical properties. Existing methods for generation of 3D polymeric scaffolds typically cannot be parallelized, suffer from low throughputs, and do not allow for quick and easy removal of the fragile structures that are formed. Current molds used in hydrogel and scaffold fabrication using solvent casting and porogen leaching are often single-use and do not facilitate 3D scaffold formation in parallel. Here, we describe a simple device and related approaches for the parallel fabrication of macroporous scaffolds. This approach was employed for the generation of macroporous and non-macroporous materials in parallel, in higher throughput and allowed for easy retrieval of these 3D scaffolds once formed. In addition, macroporous scaffolds with interconnected as well as non-interconnected pores were generated, and the versatility of this approach was employed for the generation of 3D scaffolds from diverse materials including an aminoglycoside-derived cationic hydrogel ("Amikagel"), poly(lactic-co-glycolic acid) or PLGA, and collagen. Macroporous scaffolds generated using the device were investigated for plasmid DNA binding and cell loading, indicating the use of this approach for developing materials for different applications in biotechnology. Our results demonstrate that the device-based approach is a simple technology for generating scaffolds in parallel, which can enhance the toolbox of current fabrication techniques. © 2018 Wiley Periodicals, Inc.

  12. Fabricating customized hydrogel contact lens

    Science.gov (United States)

    Childs, Andre; Li, Hao; Lewittes, Daniella M.; Dong, Biqin; Liu, Wenzhong; Shu, Xiao; Sun, Cheng; Zhang, Hao F.

    2016-10-01

    Contact lenses are increasingly used in laboratories for in vivo animal retinal imaging and pre-clinical studies. The lens shapes often need modification to optimally fit corneas of individual test subjects. However, the choices from commercially available contact lenses are rather limited. Here, we report a flexible method to fabricate customized hydrogel contact lenses. We showed that the fabricated hydrogel is highly transparent, with refractive indices ranging from 1.42 to 1.45 in the spectra range from 400 nm to 800 nm. The Young’s modulus (1.47 MPa) and hydrophobicity (with a sessile drop contact angle of 40.5°) have also been characterized experimentally. Retinal imaging using optical coherence tomography in rats wearing our customized contact lenses has the quality comparable to the control case without the contact lens. Our method could significantly reduce the cost and the lead time for fabricating soft contact lenses with customized shapes, and benefit the laboratorial-used contact lenses in pre-clinical studies.

  13. Micro Machining Enhances Precision Fabrication

    Science.gov (United States)

    2007-01-01

    Advanced thermal systems developed for the Space Station Freedom project are now in use on the International Space Station. These thermal systems employ evaporative ammonia as their coolant, and though they employ the same series of chemical reactions as terrestrial refrigerators, the space-bound coolers are significantly smaller. Two Small Business Innovation Research (SBIR) contracts between Creare Inc. of Hanover, NH and Johnson Space Center developed an ammonia evaporator for thermal management systems aboard Freedom. The principal investigator for Creare Inc., formed Mikros Technologies Inc. to commercialize the work. Mikros Technologies then developed an advanced form of micro-electrical discharge machining (micro-EDM) to make tiny holes in the ammonia evaporator. Mikros Technologies has had great success applying this method to the fabrication of micro-nozzle array systems for industrial ink jet printing systems. The company is currently the world leader in fabrication of stainless steel micro-nozzles for this market, and in 2001 the company was awarded two SBIR research contracts from Goddard Space Flight Center to advance micro-fabrication and high-performance thermal management technologies.

  14. OpenSoC Fabric

    Energy Technology Data Exchange (ETDEWEB)

    2014-08-21

    Recent advancements in technology scaling have shown a trend towards greater integration with large-scale chips containing thousands of processors connected to memories and other I/O devices using non-trivial network topologies. Software simulation proves insufficient to study the tradeoffs in such complex systems due to slow execution time, whereas hardware RTL development is too time-consuming. We present OpenSoC Fabric, an on-chip network generation infrastructure which aims to provide a parameterizable and powerful on-chip network generator for evaluating future high performance computing architectures based on SoC technology. OpenSoC Fabric leverages a new hardware DSL, Chisel, which contains powerful abstractions provided by its base language, Scala, and generates both software (C++) and hardware (Verilog) models from a single code base. The OpenSoC Fabric2 infrastructure is modeled after existing state-of-the-art simulators, offers large and powerful collections of configuration options, and follows object-oriented design and functional programming to make functionality extension as easy as possible.

  15. The SMES model coil. Fabrication

    International Nuclear Information System (INIS)

    Hanai, Satoshi; Nakamoto, Kazunari; Takahashi, Nobuji

    1998-01-01

    A SMES model coil was fabricated as R and D item in the development of component technologies for a 480 MJ/20 MW SMES pilot plant. The coil consists of four double-pancake windings. The coil is the same diameter but half the number of pancakes that will be needed for a SMES pilot plant. The NbTi cable-in-conduit conductor and superconducting joints between the double pancakes are cooled by a forced flow of supercritical helium. Prior to fabrication, various characteristics of the cable-in-conduit were measured by full-sized short samples from actual conductors and by scaled short samples from scaled conductors. The critical current of the scaled short samples was in agreement with that calculated from one strand of the conductor. The impedance between arbitrary dual-oxide coated strands in the full-size conductor was measured to be smaller than that obtained from two Cr-plated strands, which showed a good degree of stability in another coil. It was estimated that oxide-coated conductors would have high stability. Through fabrication of a model coil, it was demonstrated that a large forced-flow coil for a small-scale 100 kWh SMES device could be manufactured. (author)

  16. The SMES model coil. Fabrication

    Energy Technology Data Exchange (ETDEWEB)

    Hanai, Satoshi; Nakamoto, Kazunari; Takahashi, Nobuji [Toshiba Corp., Yokohama, Kanagawa (Japan)] [and others

    1998-07-01

    A SMES model coil was fabricated as R and D item in the development of component technologies for a 480 MJ/20 MW SMES pilot plant. The coil consists of four double-pancake windings. The coil is the same diameter but half the number of pancakes that will be needed for a SMES pilot plant. The NbTi cable-in-conduit conductor and superconducting joints between the double pancakes are cooled by a forced flow of supercritical helium. Prior to fabrication, various characteristics of the cable-in-conduit were measured by full-sized short samples from actual conductors and by scaled short samples from scaled conductors. The critical current of the scaled short samples was in agreement with that calculated from one strand of the conductor. The impedance between arbitrary dual-oxide coated strands in the full-size conductor was measured to be smaller than that obtained from two Cr-plated strands, which showed a good degree of stability in another coil. It was estimated that oxide-coated conductors would have high stability. Through fabrication of a model coil, it was demonstrated that a large forced-flow coil for a small-scale 100 kWh SMES device could be manufactured. (author)

  17. Shock wave fabricated ceramic-metal nozzles

    NARCIS (Netherlands)

    Carton, E.P.; Stuivinga, M.E.C.; Keizers, H.L.J.; Verbeek, H.J.; Put, P.J. van der

    1999-01-01

    Shock compaction was used in the fabrication of high temperature ceramic-based materials. The materials' development was geared towards the fabrication of nozzles for rocket engines using solid propellants, for which the following metal-ceramic (cermet) materials were fabricated and tested: B4C-Ti

  18. Fabrication technology for ODS Alloy MA957

    International Nuclear Information System (INIS)

    ML Hamilton; DS Gelles; RJ Lobsinger; MM Paxton; WF Brown

    2000-01-01

    A successful fabrication schedule has been developed at Carpenter Technology Corporation for the production of MA957 fuel and blanket cladding. Difficulties with gun drilling, plug drawing and recrystallization were overcome to produce a pilot lot of tubing. This report documents the fabrication efforts of two qualified vendors and the support studies performed at WHC to develop the fabrication-schedule

  19. Fierce competition in the US fabrication market

    International Nuclear Information System (INIS)

    Schwartz, M.H.; Supko, E.M.

    1996-01-01

    The US fuel fabrication market has a clear international presence, but a future in which there is presently no expectation of growth in requirements. This market continues to be characterised by annual production capacity significantly exceeding current and anticipated fuel fabrication requirements, resulting in an extremely competitive market for LWR fuel fabrication services. (UK)

  20. 14 CFR 31.35 - Fabrication methods.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Fabrication methods. 31.35 Section 31.35 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: MANNED FREE BALLOONS Design Construction § 31.35 Fabrication methods. The methods of fabrication...

  1. High-Thermal-Conductivity Fabrics

    Science.gov (United States)

    Chibante, L. P. Felipe

    2012-01-01

    Heat management with common textiles such as nylon and spandex is hindered by the poor thermal conductivity from the skin surface to cooling surfaces. This innovation showed marked improvement in thermal conductivity of the individual fibers and tubing, as well as components assembled from them. The problem is centered on improving the heat removal of the liquid-cooled ventilation garments (LCVGs) used by astronauts. The current design uses an extensive network of water-cooling tubes that introduces bulkiness and discomfort, and increases fatigue. Range of motion and ease of movement are affected as well. The current technology is the same as developed during the Apollo program of the 1960s. Tubing material is hand-threaded through a spandex/nylon mesh layer, in a series of loops throughout the torso and limbs such that there is close, form-fitting contact with the user. Usually, there is a nylon liner layer to improve comfort. Circulating water is chilled by an external heat exchanger (sublimator). The purpose of this innovation is to produce new LCVG components with improved thermal conductivity. This was addressed using nanocomposite engineering incorporating high-thermalconductivity nanoscale fillers in the fabric and tubing components. Specifically, carbon nanotubes were added using normal processing methods such as thermoplastic melt mixing (compounding twin screw extruder) and downstream processing (fiber spinning, tubing extrusion). Fibers were produced as yarns and woven into fabric cloths. The application of isotropic nanofillers can be modeled using a modified Nielsen Model for conductive fillers in a matrix based on Einstein s viscosity model. This is a drop-in technology with no additional equipment needed. The loading is limited by the ability to maintain adequate dispersion. Undispersed materials will plug filtering screens in processing equipment. Generally, the viscosity increases were acceptable, and allowed the filled polymers to still be

  2. SRF Cavity Fabrication and Materials

    Energy Technology Data Exchange (ETDEWEB)

    Singer, W [DESY (Germany)

    2014-07-01

    The technological and metallurgical requirements of material for highgradient superconducting cavities are described. High-purity niobium, as the preferred metal for the fabrication of superconducting accelerating cavities, should meet exact specifications. The content of interstitial impurities such as oxygen, nitrogen, and carbon must be below 10μg/g. The hydrogen content should be kept below 2μg/g to prevent degradation of the Q-value under certain cool-down conditions. The material should be free of flaws (foreign material inclusions or cracks and laminations) that can initiate a thermal breakdown. Defects may be detected by quality control methods such as eddy current scanning and identified by a number of special methods. Conventional and alternative cavity fabrication methods are reviewed. Conventionally, niobium cavities are fabricated from sheet niobium by the formation of half-cells by deep drawing, followed by trim machining and Electron-Beam Welding (EBW). The welding of half-cells is a delicate procedure, requiring intermediate cleaning steps and a careful choice of weld parameters to achieve full penetration of the joints. The equator welds are particularly critical. A challenge for a welded construction is the tight mechanical and electrical tolerances. These can be maintained by a combination of mechanical and radio-frequency measurements on halfcells and by careful tracking of weld shrinkage. The established procedure is suitable for large series production. The main aspects of quality assurance management are mentioned. Another cavity fabrication approach is slicing discs from the ingot and producing cavities by deep drawing and EBW. Accelerating gradients at the level of 35–45 MV·m–1 can be achieved by applying Electropolishing (EP) treatment. Furthermore, the single-crystal option (grain boundary free) is promising. It seems that in this case, high performance can be achieved by a simplified treatment procedure. Fabrication of the

  3. Remote fabrication of nuclear fuel: a secure automated fabrication overview

    International Nuclear Information System (INIS)

    Nyman, D.H.; Benson, E.M.; Yatabe, J.M.; Nagamoto, T.T.

    1981-01-01

    An automated line for the fabrication of breeder reactor fuel pins is being developed. The line will be installed in the Fuels and Materials Examination Facility (FMEF) presently under construction at the Hanford site near Richland, Washington. The application of automation and remote operations to fuel processing technology is needed to meet program requirements of reduced personnel exposure, enhanced safeguards, improved product quality, and increased productivity. Commercially available robots are being integrated into operations such as handling of radioactive material within a process operation. These and other automated equipment and chemistry analyses systems under development are described

  4. Additive Manufacturing of Low Cost Upper Stage Propulsion Components

    Science.gov (United States)

    Protz, Christopher; Bowman, Randy; Cooper, Ken; Fikes, John; Taminger, Karen; Wright, Belinda

    2014-01-01

    NASA is currently developing Additive Manufacturing (AM) technologies and design tools aimed at reducing the costs and manufacturing time of regeneratively cooled rocket engine components. These Low Cost Upper Stage Propulsion (LCUSP) tasks are funded through NASA's Game Changing Development Program in the Space Technology Mission Directorate. The LCUSP project will develop a copper alloy additive manufacturing design process and develop and optimize the Electron Beam Freeform Fabrication (EBF3) manufacturing process to direct deposit a nickel alloy structural jacket and manifolds onto an SLM manufactured GRCop chamber and Ni-alloy nozzle. In order to develop these processes, the project will characterize both the microstructural and mechanical properties of the SLMproduced GRCop-84, and will explore and document novel design techniques specific to AM combustion devices components. These manufacturing technologies will be used to build a 25K-class regenerative chamber and nozzle (to be used with tested DMLS injectors) that will be tested individually and as a system in hot fire tests to demonstrate the applicability of the technologies. These tasks are expected to bring costs and manufacturing time down as spacecraft propulsion systems typically comprise more than 70% of the total vehicle cost and account for a significant portion of the development schedule. Additionally, high pressure/high temperature combustion chambers and nozzles must be regeneratively cooled to survive their operating environment, causing their design to be time consuming and costly to build. LCUSP presents an opportunity to develop and demonstrate a process that can infuse these technologies into industry, build competition, and drive down costs of future engines.

  5. Facile fabrication of a superhydrophobic fabric with mechanical stability and easy-repairability.

    Science.gov (United States)

    Zhu, Xiaotao; Zhang, Zhaozhu; Yang, Jin; Xu, Xianghui; Men, Xuehu; Zhou, Xiaoyan

    2012-08-15

    The poor mechanical stability of superhydrophobic fabrics severely hindered their use in practical applications. Herein, to address this problem, we fabricated a superhydrophobic fabric with both mechanical stability and easy-repairability by a simple method. The mechanical durability of the obtained superhydrophobic fabric was evaluated by finger touching and abrasion with sandpaper. The results show that rough surface textures of the fabric were retained, and the fabric surface still exhibited superhydrophobicity after tests. More importantly, when the fabric lost its superhydrophobicity after a long-time abrasion, it can be easily rendered with superhydrophobicity once more by a regeneration process. Copyright © 2012 Elsevier Inc. All rights reserved.

  6. Micro-fabricated all optical pressure sensors

    DEFF Research Database (Denmark)

    Havreland, Andreas Spandet; Petersen, Søren Dahl; Østergaard, Christian

    2017-01-01

    Optical pressure sensors can operate in certain harsh application areas where the electrical pressure sensors cannot. However, the sensitivity is often not as good for the optical sensors. This work presents an all optical pressure sensor, which is fabricated by micro fabrication techniques, where...... the sensitivity can be tuned in the fabrication process. The developed sensor design, simplifies the fabrication process leading to a lower fabrication cost, which can make the all optical pressure sensors more competitive towards their electrical counterpart. The sensor has shown promising results and a linear...... pressure response has been measured with a sensitivity of 0.6nm/bar....

  7. Design Thinking for Digital Fabrication in Education

    DEFF Research Database (Denmark)

    Smith, Rachel Charlotte; Iversen, Ole Sejer; Hjorth, Mikkel

    2015-01-01

    In this paper, we argue that digital fabrication in education may benefit from design thinking, to foster a more profound understanding of digital fabrication processes among students. Two related studies of digital fabrication in education are presented in the paper. In an observational study we...... found that students (eleven to fifteen) lacked an understanding of the complexity of the digital fabrication process impeding on the potentials of digital fabrication in education. In a second explorative research through design study, we investigated how a focus on design thinking affected the students...

  8. Innovative Application of Fabric Recycling in Fashion

    Directory of Open Access Journals (Sweden)

    Chenyang Lee

    2017-10-01

    Full Text Available With the continuous development of the socialist market economy, human aesthetic standards are constantly changing, the occurrence of this situation to the development of the garment industry challenges, that is a single fabric has long been unable to meet people's aesthetic needs, And then the art of fabric reengineering will be born. This paper elaborates the meaning of fabric reworking art. This paper systematically describes the meaning of fabric reengineering to garment designer and garment itself, and comprehensively summarizes the fabric recycling technique and its characteristics.

  9. Fabric Reconstruction Based on Sustainable Development: Take the Type of Fabric Recycling as an Example

    OpenAIRE

    Zhangting Guan

    2017-01-01

    Sustainable development is a very important concept of our time, it wants to do is to live in harmony with people, to protect the environment where our human survival. Fabric recycling refers to the use of a variety of traditional and high-tech means of the existing fabric fabric design and processing. So that the surface of a rich visual texture and tactile texture "through the fabric recycling approach. However, the fabric form and clothing design coordination between the clothing design is...

  10. Influence of Clothing Fabrics on Skin Microcirculation

    Institute of Scientific and Technical Information of China (English)

    CHENG Ling; PAN Ning; ZHAO Lian-ying; HUAUNG Gu

    2010-01-01

    This study investigated the effects of clothing fabric on human skin microcirculation. Once skin is covered with a clothing fabric, human sensations, namely, coolness, warmth, softness, and roughness, are amused immediately, and the cutaneous micrecireulation may be changed consequently. Since the complex relationships of the human skin, the environment, and the clothing, there is few publication focusing on the physiological responses of the skin to the fabrics. In this paper, a Laser Doppler Flowmetry (LDF) was used to test the dynamic responses of the skin blood flow when the fabric was placed on the skin. Effects of different fabrics on the skin blood flux were investigated. The results show that cold stimulation of fabric has remarkable influences on the skin blood flux, and the surface properties of fabric are of importance to affect the human skin blood flow.

  11. Structure and yarn sensor for fabric

    Science.gov (United States)

    Mee, D.K.; Allgood, G.O.; Mooney, L.R.; Duncan, M.G.; Turner, J.C.; Treece, D.A.

    1998-10-20

    A structure and yarn sensor for fabric directly determines pick density in a fabric thereby allowing fabric length and velocity to be calculated from a count of the picks made by the sensor over known time intervals. The structure and yarn sensor is also capable of detecting full length woven defects and fabric. As a result, an inexpensive on-line pick (or course) density measurement can be performed which allows a loom or knitting machine to be adjusted by either manual or automatic means to maintain closer fiber density tolerances. Such a sensor apparatus dramatically reduces fabric production costs and significantly improves fabric consistency and quality for woven or knitted fabric. 13 figs.

  12. DESIGN AND FABRICATION OF MICRONOZZLES

    Directory of Open Access Journals (Sweden)

    Kean How Cheah

    2011-05-01

    Full Text Available Normal 0 false false false EN-US ZH-CN X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:SimSun; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} Micronozzle, a key component in micropropulsion system, has been designed and fabricated. Quasi 1D inviscid theory was used in designing a series of conical micronozzles of different expander half-angles (10°-50°. Aerospike micronozzle, a promising candidate to achieve high performance propulsion system, was designed with Angelino method (or Approximate method. Both micronozzles were fabricated using soft lithography, an inexpensive and relatively simple technique comparing to well-established deep reactive ion etching (DRIE technique, with polydimethylsiloxane (PDMS as structural material. Micronozzles with two different nozzle throat width, 53.5µm and 107µm, were fabricated for comparison. Microscopic inspections reveal 107µm is the more producible nozzle throat width with current equipments. The PDMS-based micronozzle can be used as cold gas microthruster system for micro- and nanosatellites.

  13. Advanced fabrication of optical materials

    International Nuclear Information System (INIS)

    Hed, P.P.; Blaedel, K.L.

    1986-01-01

    The fabrication of high-precision optical elements for new generations of high-power lasers requires a deterministic method of generating precision optical surfaces entailing considerably less time, skill, and money than present optical techniques. Such a process would use precision computer-controlled machinery with ongoing in situ metrology to generate precise optical surfaces. The implementation of deterministic processes requires a better understanding of the glass-grinding process, especially the control of ductile material removal. This project is intended to develop the basic knowledge needed to implement a computer-controlled optics-manufacturing methodology

  14. Fabrication of elastomeric silk fibers.

    Science.gov (United States)

    Bradner, Sarah A; Partlow, Benjamin P; Cebe, Peggy; Omenetto, Fiorenzo G; Kaplan, David L

    2017-09-01

    Methods to generate fibers from hydrogels, with control over mechanical properties, fiber diameter, and crystallinity, while retaining cytocompatibility and degradability, would expand options for biomaterials. Here, we exploited features of silk fibroin protein for the formation of tunable silk hydrogel fibers. The biological, chemical, and morphological features inherent to silk were combined with elastomeric properties gained through enzymatic crosslinking of the protein. Postprocessing via methanol and autoclaving provided tunable control of fiber features. Mechanical, optical, and chemical analyses demonstrated control of fiber properties by exploiting the physical cross-links, and generating double network hydrogels consisting of chemical and physical cross-links. Structure and chemical analyses revealed crystallinity from 30 to 50%, modulus from 0.5 to 4 MPa, and ultimate strength 1-5 MPa depending on the processing method. Fabrication and postprocessing combined provided fibers with extensibility from 100 to 400% ultimate strain. Fibers strained to 100% exhibited fourth order birefringence, revealing macroscopic orientation driven by chain mobility. The physical cross-links were influenced in part by the drying rate of fabricated materials, where bound water, packing density, and microstructural homogeneity influenced cross-linking efficiency. The ability to generate robust and versatile hydrogel microfibers is desirable for bottom-up assembly of biological tissues and for broader biomaterial applications. © 2017 Wiley Periodicals, Inc.

  15. Fabrication of simulated DUPIC fuel

    Science.gov (United States)

    Kang, Kweon Ho; Song, Ki Chan; Park, Hee Sung; Moon, Je Sun; Yang, Myung Seung

    2000-12-01

    Simulated DUPIC fuel provides a convenient way to investigate the DUPIC fuel properties and behavior such as thermal conductivity, thermal expansion, fission gas release, leaching, and so on without the complications of handling radioactive materials. Several pellets simulating the composition and microstructure of DUPIC fuel are fabricated by resintering the powder, which was treated through OREOX process of simulated spent PWR fuel pellets, which had been prepared from a mixture of UO2 and stable forms of constituent nuclides. The key issues for producing simulated pellets that replicate the phases and microstructure of irradiated fuel are to achieve a submicrometre dispersion during mixing and diffusional homogeneity during sintering. This study describes the powder treatment, OREOX, compaction and sintering to fabricate simulated DUPIC fuel using the simulated spent PWR fuel. The homogeneity of additives in the powder was observed after attrition milling. The microstructure of the simulated spent PWR fuel agrees well with the other studies. The leading structural features observed are as follows: rare earth and other oxides dissolved in the UO2 matrix, small metallic precipitates distributed throughout the matrix, and a perovskite phase finely dispersed on grain boundaries.

  16. Fabrication and calibration of FORTIS

    Science.gov (United States)

    Fleming, Brian T.; McCandliss, Stephan R.; Kaiser, Mary Elizabeth; Kruk, Jeffery; Feldman, Paul D.; Kutyrev, Alexander S.; Li, Mary J.; Rapchun, David A.; Lyness, Eric; Moseley, S. H.; Siegmund, Oswald; Vallerga, John; Martin, Adrian

    2011-09-01

    The Johns Hopkins University sounding rocket group is entering the final fabrication phase of the Far-ultraviolet Off Rowland-circle Telescope for Imaging and Spectroscopy (FORTIS); a sounding rocket borne multi-object spectro-telescope designed to provide spectral coverage of 43 separate targets in the 900 - 1800 Angstrom bandpass over a 30' x 30' field-of- view. Using "on-the-fly" target acquisition and spectral multiplexing enabled by a GSFC microshutter array, FORTIS will be capable of observing the brightest regions in the far-UV of nearby low redshift (z ~ 0.002 - 0.02) star forming galaxies to search for Lyman alpha escape, and to measure the local gas-to-dust ratio. A large area (~ 45 mm x 170 mm) microchannel plate detector built by Sensor Sciences provides an imaging channel for targeting flanked by two redundant spectral outrigger channels. The grating is ruled directly onto the secondary mirror to increase efficiency. In this paper, we discuss the recent progress made in the development and fabrication of FORTIS, as well as the results of early calibration and characterization of our hardware, including mirror/grating measurements, detector performance, and early operational tests of the microshutter arrays.

  17. Polymer micromold and fabrication process

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Abraham P. (1428 Whitecliff Way, Walnut Creek, CA 94596); Northrup, M. Allen (923 Creston Rd., Berkeley, CA 94708); Ahre, Paul E. (1299 Gonzaga Ct., Livermore, CA 94550); Dupuy, Peter C. (1736 Waldo Ct., Modesto, CA 95358)

    1997-01-01

    A mold assembly with micro-sized features in which the hollow portion thereof is fabricated from a sacrificial mandrel which is surface treated and then coated to form an outer shell. The sacrificial mandrel is then selectively etched away leaving the outer shell as the final product. The sacrificial mandrel is fabricated by a precision lathe, for example, so that when removed by etching the inner or hollow area has diameters as small as 10's of micros (.mu.m). Varying the inside diameter contours of the mold can be accomplished with specified ramping slopes formed on the outer surface of the sacrificial mandrel, with the inside or hollow section being, for example, 275 .mu.m in length up to 150 .mu.m in diameter within a 6 mm outside diameter (o.d.) mold assembly. The mold assembly itself can serve as a micronozzle or microneedle, and plastic parts, such as microballoons for angioplasty, polymer microparts, and microactuators, etc., may be formed within the mold assembly.

  18. Polymer micromold and fabrication process

    Energy Technology Data Exchange (ETDEWEB)

    Lee, A.P.; Northrup, M.A.; Ahre, P.E.; Dupuy, P.C.

    1997-08-19

    A mold assembly is disclosed with micro-sized features in which the hollow portion thereof is fabricated from a sacrificial mandrel which is surface treated and then coated to form an outer shell. The sacrificial mandrel is then selectively etched away leaving the outer shell as the final product. The sacrificial mandrel is fabricated by a precision lathe, for example, so that when removed by etching the inner or hollow area has diameters as small as 10`s of micros ({micro}m). Varying the inside diameter contours of the mold can be accomplished with specified ramping slopes formed on the outer surface of the sacrificial mandrel, with the inside or hollow section being, for example, 275 {micro}m in length up to 150 {micro}m in diameter within a 6 mm outside diameter (o.d.) mold assembly. The mold assembly itself can serve as a micronozzle or microneedle, and plastic parts, such as microballoons for angioplasty, polymer microparts, and microactuators, etc., may be formed within the mold assembly. 6 figs.

  19. LEU fuel fabrication in Argentina

    International Nuclear Information System (INIS)

    Giorsetti, D.R.; Gomez, J.O.; Marajofsky, A.; Kohut, C.

    1985-01-01

    As an Institution, aiming to meet with its own needs, CNEA has been intensively developing reduced enriched fuel to use in its own research and test reactors. Development of the fabrication technology as well as the design, installation and operation of the manufacturing plant, have been carried out with its own funds. Irradiation and post-irradiation of test miniplates have been taking place within the framework of the RERTR program. During the last years, CNEA has developed three LEU fuel types. In the previous RERTR meetings, we presented the technological results obtained with these fuel types. This paper focuses on CNEA LEU fuel element manufacturing status and the trained personnel we can offer in design and manufacture fuel capability. CNEA has its own fuel manufacturing technology; the necessary facilities to start the fuel fabrication; qualified technicians and professionals for: fuel design and behaviour analysis; fuel manufacturing and QA; international recognition of its fuel development and manufacturing capability through its ORR miniplate irradiation; its own natural uranium and the future possibility to enrich up to 20% U 235 ; the probability to offer a competitive fuel manufacturing cost in the international market; the disposition to cooperate with all countries that wish to take part and aim to reach an self-sufficiency in their own fuel supply needs

  20. Optimization of Ultrasonic Fabric Cleaning

    Energy Technology Data Exchange (ETDEWEB)

    Hand, T.E.

    1998-05-13

    The fundamental purpose of this project was to research and develop a process that would reduce the cost and improve the environmental efficiency of the present dry-cleaning industry. This second phase of research (see report KCP-94-1006 for information gathered during the first phase) was intended to allow the optimal integration of all factors of ultrasonic fabric cleaning. For this phase, Garment Care performed an extensive literature search and gathered data from other researchers worldwide. The Garment Care-AlliedSignal team developed the requirements for a prototype cleaning tank for studies and acquired that tank and the additional equipment required to use it properly. Garment Care and AlliedSignal acquired the transducers and generators from Surftran Martin-Walter in Sterling Heights, Michigan. Amway's Kelly Haley developed the test protocol, supplied hundreds of test swatches, gathered the data on the swatches before and after the tests, assisted with the cleaning tests, and prepared the final analysis of the results. AlliedSignal personnel, in conjunction with Amway and Garment Care staff, performed all the tests. Additional planning is under way for future testing by outside research facilities. The final results indicated repeatable performance and good results for single layered fabric swatches. Swatches that were cleaned as a ''sandwich,'' that is, three or more layers.

  1. Porosity Prediction of Plain Weft Knitted Fabrics

    Directory of Open Access Journals (Sweden)

    Muhammad Owais Raza Siddiqui

    2014-12-01

    Full Text Available Wearing comfort of clothing is dependent on air permeability, moisture absorbency and wicking properties of fabric, which are related to the porosity of fabric. In this work, a plug-in is developed using Python script and incorporated in Abaqus/CAE for the prediction of porosity of plain weft knitted fabrics. The Plug-in is able to automatically generate 3D solid and multifilament weft knitted fabric models and accurately determine the porosity of fabrics in two steps. In this work, plain weft knitted fabrics made of monofilament, multifilament and spun yarn made of staple fibers were used to evaluate the effectiveness of the developed plug-in. In the case of staple fiber yarn, intra yarn porosity was considered in the calculation of porosity. The first step is to develop a 3D geometrical model of plain weft knitted fabric and the second step is to calculate the porosity of the fabric by using the geometrical parameter of 3D weft knitted fabric model generated in step one. The predicted porosity of plain weft knitted fabric is extracted in the second step and is displayed in the message area. The predicted results obtained from the plug-in have been compared with the experimental results obtained from previously developed models; they agreed well.

  2. Fabrication of flexible piezoelectric PZT/fabric composite.

    Science.gov (United States)

    Chen, Caifeng; Hong, Daiwei; Wang, Andong; Ni, Chaoying

    2013-01-01

    Flexible piezoelectric PZT/fabric composite material is pliable and tough in nature which is in a lack of traditional PZT patches. It has great application prospect in improving the sensitivity of sensor/actuator made by piezoelectric materials especially when they are used for curved surfaces or complicated conditions. In this paper, glass fiber cloth was adopted as carrier to grow PZT piezoelectric crystal particles by hydrothermal method, and the optimum conditions were studied. The results showed that the soft glass fiber cloth was an ideal kind of carrier. A large number of cubic-shaped PZT nanocrystallines grew firmly in the carrier with a dense and uniform distribution. The best hydrothermal condition was found to be pH 13, reaction time 24 h, and reaction temperature 200°C.

  3. Fabrication of superhydrophobic cotton fabrics by silica hydrosol and hydrophobization

    Science.gov (United States)

    Xu, Lihui; Zhuang, Wei; Xu, Bi; Cai, Zaisheng

    2011-04-01

    Superhydrophobic cotton fabrics were prepared by the incorporation of silica nanoparticles and subsequent hydrophobization with hexadecyltrimethoxysilane (HDTMS). The silica nanoparticles were synthesized via sol-gel reaction with methyl trimethoxy silane (MTMS) as the precursor in the presence of the base catalyst and surfactant in aqueous solution. As for the resulting products, characterization by particle size analyzer, scanning electron microscopy (SEM), scanning probe microscopy (SPM), X-ray photoelectron spectroscopy (XPS), and thermal gravimetric analysis (TGA) were performed respectively. The size of SiO2 nanoparticles can be controlled by adjusting the catalyst and surfactant concentrations. The wettability of cotton textiles was evaluated by the water contact angle (WCA) and water shedding angle (WSA) measurements. The results showed that the treated cotton sample displayed remarkable water repellency with a WCA of 151.9° for a 5 μL water droplet and a WSA of 13° for a 15 μL water droplet.

  4. Nanocrystal thin film fabrication methods and apparatus

    Science.gov (United States)

    Kagan, Cherie R.; Kim, David K.; Choi, Ji-Hyuk; Lai, Yuming

    2018-01-09

    Nanocrystal thin film devices and methods for fabricating nanocrystal thin film devices are disclosed. The nanocrystal thin films are diffused with a dopant such as Indium, Potassium, Tin, etc. to reduce surface states. The thin film devices may be exposed to air during a portion of the fabrication. This enables fabrication of nanocrystal-based devices using a wider range of techniques such as photolithography and photolithographic patterning in an air environment.

  5. Breeder reactor fuel fabrication system development

    International Nuclear Information System (INIS)

    Bennett, D.W.; Fritz, R.L.; McLemore, D.R.; Yatabe, J.M.

    1981-01-01

    Significant progress has been made in the design and development of remotely operated breeder reactor fuel fabrication and support systems (e.g., analytical chemistry). These activities are focused by the Secure Automated Fabrication (SAF) Program sponsored by the Department of Energy to provide: a reliable supply of fuel pins to support US liquid metal cooled breeder reactors and at the same time demonstrate the fabrication of mixed uranium/plutonium fuel by remotely operated and automated methods

  6. Hemp nanocellulose: fabrication, characterisation and application

    OpenAIRE

    Dasong, Dai

    2015-01-01

    This thesis was submitted for the award of Doctor of Philosophy and was awarded by Brunel University London Nanocellulose has gained lots of attentions in recent years due to the development of nanotechnology. Thousands of publications have been reported about the fabrication, characterization and application of nanocellulose, among which most of the nanocelluloses were fabricated from the microcrystalline cellulose (MCC) or pulp, and only two methods about the nanocellulose fabrication ha...

  7. Fabrication of Games and Learning

    DEFF Research Database (Denmark)

    Schoenau-Fog, Henrik; Reng, Lars; Kofoed, Lise

    2015-01-01

    The concept of Game based learning has proven to have many possibilities for supporting better learning outcomes, when using educational or commercial games in the classroom. However, there is also a great potential in using game development as a motivator in several other kinds of learning...... scenarios. Using game development as an approach for including game based learning in various educations has become more accessible due to more user friendly game development tools and systems. This study will thus focus on an exploration on how game development motivates students and what they learn when...... creating games. We exemplify the potential of using game fabrication as a learning environment with the investigation of a game production, which involved over 25 students across semesters. In order to investigate students’ experiences during this purposive game production, we set up an experiment where...

  8. The Danish fabricated metal industry:

    DEFF Research Database (Denmark)

    Hansen, Teis

    2010-01-01

    This paper aims to contribute to the knowledge on innovation processes in low- and medium-low-tech industries. Today, industries characterised as high-tech are perceived to be central to economic development, as the research intensity shields them from competition from low-wage countries....... This is less the case for low-tech industries, but their economic importance continues to be large, however. It is thus interesting to analyse how they manage to remain competitive. The analysis focuses on a case study of the fabricated metal industry by identifying the innovation strategies followed by firms...... located in a part of Jutland, where this industry has experienced growth. It is found that the ability to create tailor-made solutions is central to the competitiveness of these medium-low-tech firms. Knowledge is thus highly important, yet in different ways than for high-tech industries. This illustrates...

  9. Fabrication of Metallic Hollow Nanoparticles

    Science.gov (United States)

    Kim, Jae-Woo (Inventor); Choi, Sr., Sang H. (Inventor); Lillehei, Peter T. (Inventor); Chu, Sang-Hyon (Inventor); Park, Yeonjoon (Inventor); King, Glen C. (Inventor); Elliott, James R. (Inventor)

    2016-01-01

    Metal and semiconductor nanoshells, particularly transition metal nanoshells, are fabricated using dendrimer molecules. Metallic colloids, metallic ions or semiconductors are attached to amine groups on the dendrimer surface in stabilized solution for the surface seeding method and the surface seedless method, respectively. Subsequently, the process is repeated with additional metallic ions or semiconductor, a stabilizer, and NaBH.sub.4 to increase the wall thickness of the metallic or semiconductor lining on the dendrimer surface. Metallic or semiconductor ions are automatically reduced on the metallic or semiconductor nanoparticles causing the formation of hollow metallic or semiconductor nanoparticles. The void size of the formed hollow nanoparticles depends on the dendrimer generation. The thickness of the metallic or semiconductor thin film around the dendrimer depends on the repetition times and the size of initial metallic or semiconductor seeds.

  10. ATLAS facility fabrication and assembly

    CERN Document Server

    Ballard, E O; Davis, H A; Nielsen, K E; Parker, G V; Parsons, W M

    2001-01-01

    Summary form only given. Atlas is a pulsed-power facility recently completed at Los Alamos National Laboratory to drive hydrodynamic experiments. This new generation pulsed-power machine consists of a radial array of 24, 240-kV Marx modules and transmission lines supplying current to the load region at the machine center. The transmission lines, powered by the Marx modules, consist of cable headers, load protection switches and tri-plates interfacing to the center transition section through detachable current joints. A conical power-flow-channel attaches to the transition section providing an elevated interface to attach the experimental loads for diagnostic access. Fabrication and assembly of all components for the Atlas machine was completed in August 2000. The machine has also progressed through a test phase where the Marx module/transmission line units were fired, individually, into a test load. Progression continued with eight and sixteen lines being fired. Subsequently, an overall machine test was condu...

  11. Container Materials, Fabrication And Robustness

    International Nuclear Information System (INIS)

    Dunn, K.; Louthan, M.; Rawls, G.; Sindelar, R.; Zapp, P.; Mcclard, J.

    2009-01-01

    The multi-barrier 3013 container used to package plutonium-bearing materials is robust and thereby highly resistant to identified degradation modes that might cause failure. The only viable degradation mechanisms identified by a panel of technical experts were pressurization within and corrosion of the containers. Evaluations of the container materials and the fabrication processes and resulting residual stresses suggest that the multi-layered containers will mitigate the potential for degradation of the outer container and prevent the release of the container contents to the environment. Additionally, the ongoing surveillance programs and laboratory studies should detect any incipient degradation of containers in the 3013 storage inventory before an outer container is compromised.

  12. Photolithography and Micro-Fabrication/ Packaging Laboratories

    Data.gov (United States)

    Federal Laboratory Consortium — The Photolithography and Micro-Fabrication/Packaging laboratories provide research level semiconductor processing equipment and facilities that do not require a full...

  13. Fuel Fabrication Capability Research and Development Plan

    Energy Technology Data Exchange (ETDEWEB)

    Senor, David J.; Burkes, Douglas

    2013-06-28

    The purpose of this document is to provide a comprehensive review of the mission of the Fuel Fabrication Capability (FFC) within the Global Threat Reduction Initiative (GTRI) Convert Program, along with research and development (R&D) needs that have been identified as necessary to ensuring mission success. The design and fabrication of successful nuclear fuels must be closely linked endeavors.

  14. New Fabrication Strategies for Polymer Electrolyte Batteries

    National Research Council Canada - National Science Library

    Shriver, D

    1997-01-01

    .... The objective of this research was to fabricate lithium-polymer batteries by techniques that may produce a thin electrolyte and cathode films and with minimal contamination during fabrication. One such technique, ultrasonic spray was used. Another objective of this research was to test lithium cells that incorporate the new polymer electrolytes and polyelectrolytes.

  15. Quality assurance for breeder reactor fuel fabrication

    International Nuclear Information System (INIS)

    Marx, E.R.

    1978-01-01

    Fuel performance in the Fast Flux Test Facility (FFTF) depends on fabrication of fuel to rigorous quality standards. The quality program including Management, Procurement, Fabrication, Inspection, Records, and Audits is discussed as well as unique mixed oxide fuel inspections such as homogeneity inspection, analytical chemistry, and nondestructive fissile assay

  16. Process for fabricating mixed-oxide powders

    International Nuclear Information System (INIS)

    Elmaleh, D.; Giraudel, A.

    1975-01-01

    A physical-chemical process for fabricating homogeneous powders suitable for sintering is described. It can be applied to the synthesis of all mixed oxides having mutually compatible and water soluble salts. As a specific example, the fabrication of lead titanate-zirconate powders used to make hot pressed ceramics is described. These ceramics show improved piezoelectric properties [fr

  17. Remote fabrication of breeder reactor fuel

    International Nuclear Information System (INIS)

    Gerber, E.W.; Hoitink, N.C.; Graham, R.A.

    1984-06-01

    The Secure Automated Fabrication (SAF) Line, a remotely operable plutonium fuel fabrication facility, incorporates advanced automation techniques. Included in the plant are 24 robots used to perform complex operations, and to enhance equipment standardization and ease of maintenance. Automated equipment is controlled remotely from centrally located supervisory computer control consoles or alternatively from control consoles dedicated to individual systems

  18. Stainless steel fabrications: past and present

    International Nuclear Information System (INIS)

    Daniels, R.

    1986-01-01

    The paper deals with stainless steel fabrications of Fairey Engineering Company for the nuclear industry. The manufacture of stainless steel containers for Magnox and Advanced Gas Cooled Reactors, flexible fabrication facility, and welding development, are all briefly described. (U.K.)

  19. Cylindrical fabric-confined soil structures

    Science.gov (United States)

    Harrison, Richard A.

    A cylindrical fabric-soil structural concept for implementation on the moon and Mars which provides many advantages is proposed. The most efficient use of fabric is to fashion it into cylindrical tubes, creating cylindrical fabric-confined soil structures. The length, diameter, and curvature of the tubes will depend on the intended application. The cylindrical hoop forces provide radial confinement while end caps provide axial confinement. One of the ends is designed to allow passage of the soil into the fabric tube before sealing. Transportation requirements are reduced due to the low mass and volume of the fabric. Construction requirements are reduced due to the self-erection capability via the pneumatic exoskeleton. Maintenance requirements are reduced due to the passive nature of the concept. The structure's natural ductility is well suited for any seismic activity.

  20. Engineering Non-Wetting Antimicrobial Fabrics

    Science.gov (United States)

    van den Berg, Desmond

    This research presents novel techniques and a review of commercially available fabrics for their antimicrobial potential. Based on previous research into the advantages of superhydrophobic self-cleaning surfaces against bacterial contamination, insights into what can make a superhydrophobic fabric inherently antimicrobial were analyzed. Through comparing the characterization results of scanning electron microscopy (SEM) and optical profilometry to microbiology experiments, hypotheses into the relationship between the contact area of a bacterial solution and the extent of contamination is developed. Contact scenario experiments, involving the use of fluorescence microscopy and calculating colony forming units, proved that the contamination potential of any fabric is due to the wetting state exhibited by the fabric, as well as the extent of surface texturing. Transmission experiments, utilizing a novel technique of stamping a contaminated fabric, outlined the importance of retention of solutions or bacteria during interactions within the hospital environment on the extent of contamination.

  1. APT target-blanket fabrication development

    Energy Technology Data Exchange (ETDEWEB)

    Fisher, D.L.

    1997-06-13

    Concepts for producing tritium in an accelerator were translated into hardware for engineering studies of tritium generation, heat transfer, and effects of proton-neutron flux on materials. Small-scale target- blanket assemblies were fabricated and material samples prepared for these performance tests. Blanket assemblies utilize composite aluminum-lead modules, the two primary materials of the blanket. Several approaches are being investigated to produce large-scale assemblies, developing fabrication and assembly methods for their commercial manufacture. Small-scale target-blanket assemblies, designed and fabricated at the Savannah River Site, were place in Los Alamos Neutron Science Center (LANSCE) for irradiation. They were subjected to neutron flux for nine months during 1996-97. Coincident with this test was the development of production methods for large- scale modules. Increasing module size presented challenges that required new methods to be developed for fabrication and assembly. After development, these methods were demonstrated by fabricating and assembling two production-scale modules.

  2. Fabricating 3D figurines with personalized faces.

    Science.gov (United States)

    Tena, J Rafael; Mahler, Moshe; Beeler, Thabo; Grosse, Max; Hengchin Yeh; Matthews, Iain

    2013-01-01

    We present a semi-automated system for fabricating figurines with faces that are personalised to the individual likeness of the customer. The efficacy of the system has been demonstrated by commercial deployments at Walt Disney World Resort and Star Wars Celebration VI in Orlando Florida. Although the system is semi automated, human intervention is limited to a few simple tasks to maintain the high throughput and consistent quality required for commercial application. In contrast to existing systems that fabricate custom heads that are assembled to pre-fabricated plastic bodies, our system seamlessly integrates 3D facial data with a predefined figurine body into a unique and continuous object that is fabricated as a single piece. The combination of state-of-the-art 3D capture, modelling, and printing that are the core of our system provide the flexibility to fabricate figurines whose complexity is only limited by the creativity of the designer.

  3. Composite metal foil and ceramic fabric materials

    Science.gov (United States)

    Webb, Brent J.; Antoniak, Zen I.; Prater, John T.; DeSteese, John G.

    1992-01-01

    The invention comprises new materials useful in a wide variety of terrestrial and space applications. In one aspect, the invention comprises a flexible cloth-like material comprising a layer of flexible woven ceramic fabric bonded with a layer of metallic foil. In another aspect, the invention includes a flexible fluid impermeable barrier comprising a flexible woven ceramic fabric layer having metal wire woven therein. A metallic foil layer is incontinuously welded to the woven metal wire. In yet another aspect, the invention includes a material comprising a layer of flexible woven ceramic fabric bonded with a layer of an organic polymer. In still another aspect, the invention includes a rigid fabric structure comprising a flexible woven ceramic fabric and a resinous support material which has been hardened as the direct result of exposure to ultraviolet light. Inventive methods for producing such material are also disclosed.

  4. Large superconducting coil fabrication development

    International Nuclear Information System (INIS)

    Brown, R.L.; Allred, E.L.; Anderson, W.C.; Burn, P.B.; Deaderick, R.I.; Henderson, G.M.; Marguerat, E.F.

    1975-01-01

    Toroidal fields for some fusion devices will be produced by an array of large superconducting coils. Their size, space limitation, and field requirements dictate that they be high performance coils. Once installed, accessibility for maintenance and repairs is severely restricted; therefore, good reliability is an obvious necessity. Sufficient coil fabrication will be undertaken to develop and test methods that are reliable, fast, and economical. Industrial participation will be encouraged from the outset to insure smooth transition from development phases to production phases. Initially, practice equipment for three meter bore circular coils will be developed. Oval shape coil forms will be included in the practice facility later. Equipment that is more automated will be developed with the expectation of winding faster and obtaining good coil quality. Alternate types of coil construction, methods of winding and insulating, will be investigated. Handling and assembly problems will be studied. All technology developed must be feasible for scaling up when much larger coils are needed. Experimental power reactors may need coils having six meter or larger bores

  5. Influence of Fabric Parameters on Thermal Comfort Performance of Double Layer Knitted Interlock Fabrics

    Directory of Open Access Journals (Sweden)

    Afzal Ali

    2017-03-01

    Full Text Available The aim of this study was to analyse the effects of various fabric parameters on the thermal resistance, thermal conductivity, thermal transmittance, thermal absorptivity and thermal insulation of polyester/cotton double layer knitted interlock fabrics. It was found that by increasing fibre content with higher specific heat increases the thermal insulation while decreases the thermal transmittance and absorptivity of the fabric. It was concluded that double layer knitted fabrics developed with higher specific heat fibres, coarser yarn linear densities, higher knitting loop length and fabric thickness could be adequately used for winter clothing purposes.

  6. A facile fabrication of multifunctional knit polyester fabric based on chitosan and polyaniline polymer nanocomposite

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Xiaoning [College of Textiles, Qingdao University, Qingdao, Shandong 266071 (China); Laboratory of New Fiber Materials and Modern Textile, The Growing Base for State Key Laboratory, Qingdao University, Qingdao, Shandong 266071 (China); Tian, Mingwei [College of Textiles, Qingdao University, Qingdao, Shandong 266071 (China); Laboratory of New Fiber Materials and Modern Textile, The Growing Base for State Key Laboratory, Qingdao University, Qingdao, Shandong 266071 (China); Collaborative Innovation Center for Marine Biomass Fibers, Materials and Textiles of Shandong Province, Qingdao University, Qingdao, Shandong 266071 (China); Qu, Lijun, E-mail: lijunqu@126.com [College of Textiles, Qingdao University, Qingdao, Shandong 266071 (China); Laboratory of New Fiber Materials and Modern Textile, The Growing Base for State Key Laboratory, Qingdao University, Qingdao, Shandong 266071 (China); Collaborative Innovation Center for Marine Biomass Fibers, Materials and Textiles of Shandong Province, Qingdao University, Qingdao, Shandong 266071 (China); Zhu, Shifeng [College of Textiles, Qingdao University, Qingdao, Shandong 266071 (China); Laboratory of New Fiber Materials and Modern Textile, The Growing Base for State Key Laboratory, Qingdao University, Qingdao, Shandong 266071 (China); Guo, Xiaoqing [College of Textiles, Qingdao University, Qingdao, Shandong 266071 (China); Laboratory of New Fiber Materials and Modern Textile, The Growing Base for State Key Laboratory, Qingdao University, Qingdao, Shandong 266071 (China); Collaborative Innovation Center for Marine Biomass Fibers, Materials and Textiles of Shandong Province, Qingdao University, Qingdao, Shandong 266071 (China); Han, Guangting [Laboratory of New Fiber Materials and Modern Textile, The Growing Base for State Key Laboratory, Qingdao University, Qingdao, Shandong 266071 (China); Collaborative Innovation Center for Marine Biomass Fibers, Materials and Textiles of Shandong Province, Qingdao University, Qingdao, Shandong 266071 (China); and others

    2014-10-30

    Highlights: • Multifunctional knit polyester fabric was facile fabricated by the combination of pad-dry-cure process and in situ chemical polymerization route. • High electrical conductivity and efficient water-repellent properties were endowed to the polymer nanocomposite coated fabric. • The polymer nanocomposite coated fabric also performed efficient and durable photocatalytic activities under the illumination of ultraviolet light. - Abstract: Knit polyester fabric was successively modified and decorated with chitosan layer and polyaniline polymer nanocomposite layer in this paper. The fabric was firstly treated with chitosan to form a stable layer through the pad-dry-cure process, and then the polyaniline polymer nanocomposite layer was established on the outer layer by in situ chemical polymerization method using ammonium persulfate as oxidant and chlorhydric acid as dopant. The surface morphology of coated fabric was characterized by scanning electron microscopy (SEM), and the co-existence of chitosan layer and granular polyaniline polymer nanocomposite was confirmed and well dispersed on the fabric surface. The resultant fabric was endowed with remarkable electrical conductivity properties and efficient water-repellent capability, which also have been found stable after water laundering. In addition, the photocatalytic decomposition activity for reactive red dye was observed when the multifunctional knit polyester fabric was exposed to the illumination of ultraviolet lamp. These results indicated that chitosan and polyaniline polymer nanocomposite could form ideal multifunctional coatings on the surface of knit polyester fabric.

  7. A facile fabrication of multifunctional knit polyester fabric based on chitosan and polyaniline polymer nanocomposite

    International Nuclear Information System (INIS)

    Tang, Xiaoning; Tian, Mingwei; Qu, Lijun; Zhu, Shifeng; Guo, Xiaoqing; Han, Guangting

    2014-01-01

    Highlights: • Multifunctional knit polyester fabric was facile fabricated by the combination of pad-dry-cure process and in situ chemical polymerization route. • High electrical conductivity and efficient water-repellent properties were endowed to the polymer nanocomposite coated fabric. • The polymer nanocomposite coated fabric also performed efficient and durable photocatalytic activities under the illumination of ultraviolet light. - Abstract: Knit polyester fabric was successively modified and decorated with chitosan layer and polyaniline polymer nanocomposite layer in this paper. The fabric was firstly treated with chitosan to form a stable layer through the pad-dry-cure process, and then the polyaniline polymer nanocomposite layer was established on the outer layer by in situ chemical polymerization method using ammonium persulfate as oxidant and chlorhydric acid as dopant. The surface morphology of coated fabric was characterized by scanning electron microscopy (SEM), and the co-existence of chitosan layer and granular polyaniline polymer nanocomposite was confirmed and well dispersed on the fabric surface. The resultant fabric was endowed with remarkable electrical conductivity properties and efficient water-repellent capability, which also have been found stable after water laundering. In addition, the photocatalytic decomposition activity for reactive red dye was observed when the multifunctional knit polyester fabric was exposed to the illumination of ultraviolet lamp. These results indicated that chitosan and polyaniline polymer nanocomposite could form ideal multifunctional coatings on the surface of knit polyester fabric

  8. Heat Transfer in Directional Water Transport Fabrics

    Directory of Open Access Journals (Sweden)

    Chao Zeng

    2016-10-01

    Full Text Available Directional water transport fabrics can proactively transfer moisture from the body. They show great potential in making sportswear and summer clothing. While moisture transfer has been previously reported, heat transfer in directional water transport fabrics has been little reported in research literature. In this study, a directional water transport fabric was prepared using an electrospraying technique and its heat transfer properties under dry and wet states were evaluated, and compared with untreated control fabric and the one pre-treated with NaOH. All the fabric samples showed similar heat transfer features in the dry state, and the equilibrium temperature in the dry state was higher than for the wet state. Wetting considerably enhanced the thermal conductivity of the fabrics. Our studies indicate that directional water transport treatment assists in moving water toward one side of the fabric, but has little effect on thermal transfer performance. This study may be useful for development of “smart” textiles for various applications.

  9. MAGNETIC WOVEN FABRICS - PHYSICAL AND MAGNETIC PROPERTIES

    Directory of Open Access Journals (Sweden)

    GROSU Marian C

    2015-05-01

    Full Text Available A coated material is a composite structure that consists of at least two components: base material and coating layer. The purpose of coating is to provide special properties to base material, with potential to be applied in EMI shielding and diverse smart technical fields. This paper reports the results of a study about some physical and magnetic properties of coated woven fabrics made from cotton yarns with fineness of 17 metric count. For this aim, a plain woven fabric was coated with a solution hard magnetic polymer based. As hard magnetic powder, barium hexaferrite (BaFe12O19 was selected. The plain woven fabric used as base has been coated with five solutions having different amounts of hard magnetic powder (15% - 45% in order to obtain five different magnetic woven fabrics. A comparison of physical properties regarding weight (g/m2, thickness (mm, degree of charging (% and magnetic properties of magnetic woven samples were presented. Saturation magnetizing (emu/g, residual magnetizing (emu/g and coercive force (kA/m of pure hard magnetic powder and woven fabrics have been studied as hysteresis characteristics. The magnetic properties of the woven fabrics depend on the mass percentage of magnetic powder from coating solution. Also, the residual magnetism and coercive field of woven fabrics represents only a part of bulk barium hexafferite residual magnetism and coercive field.

  10. The fabrication of andean particularism

    Directory of Open Access Journals (Sweden)

    1989-01-01

    Full Text Available Ce travail aborde la question des liens que la société coloniale garde avec son passé. Plutôt que de concevoir cette relation en termes de survie d'une culture indigène authentique à travers le canal de la résistance, l'auteur met l'accent sur la fabrication de la tradition au sein de l'appareil étatique du régime colonial et montre comment la résistance politique tournée vers le passé réutilise cette tradition. Cette recherche part de l'étude de cas que présente un incident peu connu dans les Andes du nord, lié au 'culte à l'Inca' et survenu dans l'Audience de Quito, au XVIIème siècle. Un tel objet d'étude semble fort riche d'enseignements et nous laisse entrevoir le rapport existant entre l'autorité et la tradition, car il met en lumière les mécanismes de remémoration, conservation et de récupération du passé. Este trabajo aborda la problemática de la relación que la sociedad colonial mantiene con su pasado. En vez de concebir esta relación a través de la figura de la conservación de la cultura andina por la vía de la resistencia, enfoca la fabricación de la tradición (de la memoria y de las costumbres en el seno de los aparatos estatales del régimen colonial. Muestra como la resistencia política orientada hacia el pasado reutiliza la tradición inventada dentro de los dispositivos disciplinarios. La discusión de estos temas se lleva a cabo en base a un estudio de caso de un incidente del culto al Inca y de resistencia enfocada en el simbolismo del Inca, que tuvo lugar en la Audiencia de Quito a mediados del siglo diecisiete. La invocación del Inca en la época colonial ofrece un campo privilegiado para examinar la relación entre la autoridad y los orígenes, ya que implica la conmemoración, continuación y recuperación del pasado. This paper addresses the issue of the relationship that the colonial order keeps with its past. Instead of conceiving this relation in terms of the preservation of an

  11. Materials for microfluidic chip fabrication.

    Science.gov (United States)

    Ren, Kangning; Zhou, Jianhua; Wu, Hongkai

    2013-11-19

    Through manipulating fluids using microfabricated channel and chamber structures, microfluidics is a powerful tool to realize high sensitive, high speed, high throughput, and low cost analysis. In addition, the method can establish a well-controlled microenivroment for manipulating fluids and particles. It also has rapid growing implementations in both sophisticated chemical/biological analysis and low-cost point-of-care assays. Some unique phenomena emerge at the micrometer scale. For example, reactions are completed in a shorter amount of time as the travel distances of mass and heat are relatively small; the flows are usually laminar; and the capillary effect becomes dominant owing to large surface-to-volume ratios. In the meantime, the surface properties of the device material are greatly amplified, which can lead to either unique functions or problems that we would not encounter at the macroscale. Also, each material inherently corresponds with specific microfabrication strategies and certain native properties of the device. Therefore, the material for making the device plays a dominating role in microfluidic technologies. In this Account, we address the evolution of materials used for fabricating microfluidic chips, and discuss the application-oriented pros and cons of different materials. This Account generally follows the order of the materials introduced to microfluidics. Glass and silicon, the first generation microfluidic device materials, are perfect for capillary electrophoresis and solvent-involved applications but expensive for microfabriaction. Elastomers enable low-cost rapid prototyping and high density integration of valves on chip, allowing complicated and parallel fluid manipulation and in-channel cell culture. Plastics, as competitive alternatives to elastomers, are also rapid and inexpensive to microfabricate. Their broad variety provides flexible choices for different needs. For example, some thermosets support in-situ fabrication of

  12. Fabrication of seamless calandria tubes

    International Nuclear Information System (INIS)

    Saibaba, N.; Phanibabu, C.; Bhaskara Rao, C.V.; Kalidas, R.; Ganguly, C.

    2002-01-01

    Full text: Calandria tube is a large diameter, thin walled zircaloy-4 tube and is an important structural component of PHWR type of reactors. These tubes are lifetime components and remain during the full life of the reactor. Calandria tubes are classified as extremely thin walled tubes with a diameter to wall thickness ratio of around 96. Such thin walled tubes are conventionally produced by seam welded route comprising of extrusion of slabs followed by a series of hot and rolling passes, shaping into O-shape and eventual welding. An alternative and superior method of fabricating the calandria tubes, the seamless route, has been developed, which involves hot extrusion of mother blanks followed by three successive cold pilger reductions. Eccentricity correction of the extruded blanks is carried out on a special purpose grinding equipment to bring the wall thickness variation within permissible limits. Predominant wall thickness reductions are given during cold pilgering to ensure high Q-factor values. The texture in the finished tubes could be closely, controlled with an average f r value of 0.65. Pilgering parameters and tube guiding system have been specially designed to facilities rolling of thin walled tubes. Seamless calandria tubes have distinct advantages over welded tubes. In addition to the absence of weld, they are dimensionally more stable, lighter in weight and possess uniform grains with superior grain size. The cycle time from billet to finished product is substantially reduced and the product is amenable to high level of quality assurance. The most significant feature of the seamless route is its material recovery over welded route. Residual stresses measured in the tubes indicate that these are negligible and uniform along the length of the tube. In view of their superior quality, the first charge of seamless calandria tubes will be rolled into the first 500 MWe Pressurised Heavy Water Reactor at Tarapur

  13. Progress on KMRR fuel fabrication

    International Nuclear Information System (INIS)

    Kuk, I.H.; Lee, J.B.; Rhee, C.K.; Kim, K.W.

    1991-01-01

    In order to increase the practical applicability of powder heat-treatment in KMRR fuel fabrication, efforts were made to reduce the critical size. Primary U 3 Si 2 particle size was reviewed in terms of cooling rate. Temperature dependence of peritectoid reaction was reviewed as well. (1) Cooling rate of U 3 Si molten alloy was calculated by ADINA program. In practice, particle size of the primary U 3 Si 2 varies radially. U 3 Si 2 size increases as it goes deeper from the surface. As cooling rate increases, primary U 3 Si 2 size decreases. (2) Peritectoid reaction occurs in two unique groups of temperature; one is below 790 C where β-U and U 3 Si 2 reaction occurs, and the other above 790 C where γ-U and U 3 Si 2 reaction occurs. 780 C is most completely reacting temperature in β-U region, and 810 C is so in γ-U region. Reaction is completed more perfectly in γ-U region than in β-U region. 810 C is found to be the optimized heat-treatment temperature, but it is desirable not to approach to 790 C in heat-treatment. (3) The critical powder size in powder heat-treatment is dependent on the primary U 3 Si 2 particle size. The smaller the primary U 3 Si 2 particle size, the smaller the critical particle size of the powder. At present, the primary U 3 Si 2 particle size can be reduced to 3∝5 μm at 4∝5 mm deep from surface in Cu mold. This may be reduced further by rapid solidification process. (orig.)

  14. Overview of MOX fuel fabrication achievements

    International Nuclear Information System (INIS)

    Bairiot, H.; Vliet, J. van; Chiarelli, G.; Edwards, J.; Nagai, S.H.; Reshetnikov, F.

    2000-01-01

    Such overview having been adequately covered in an OECD/NEA publication providing the situation as of end 1994, this paper is mainly devoted to an update as of end 1998. The Belgian plant, Belgonucleaire/Dessel, is now dedicated exclusively to the fabrication of MOX fuel and has operated consistently around its nameplate capacity (35tHM/a) through the 1990s involving a large variety of PWR and BWR fuels. The two French plants have also achieved routine operation during the 1990s. CFCa, historically the largest FBR MOX fuel manufacturer, is utilizing the genuine COCA process for that type of fuel and the MIMAS process for LWR fuel: a nominal capacity (40 tHM/a) has been gradually approached. MELOX has operated at 100 tHM/a, as defined in the operating licence granted originally. The British plant, MDF/Sellafield with 8tHM/a nameplate capacity is devoted to fuel and has manufactured several small fabrication campaigns. In Japan, JNC operates three facilities located at Tokai: PFDF, devoted to basic research and fabrication of test fuels, PFFF/ATR line, for the fabrication of Fugen fuel and of corresponding fuel for the critical facility DCA, and PFPF for the fabrication of FBR fuel. In Russia, fabrication techniques have been developed to fuel four BN-800 FBRs contemplated to be constructed and be fuelled with the civilian Pu stockpile. Two demonstration facilities Paket (Mayak) and RIAR (Dimitrovgrad) fabricated respectively pellet and vipac type FBR MOX fuel for BR-5, BOR-60, BN-350 and BN-600. The paper includes a brief description of each of the fabrication routes mentioned, as well as the production of respectively LWR and FBR MOX fuel in each fabrication facility, since the start-up of the plant, since 1 January 1993 and since 1 January 1998 up to 31 December 1998. (author)

  15. Superamphiphobic cotton fabrics with enhanced stability

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Bi, E-mail: xubi@dhu.edu.cn [National Engineering Research Center for Dyeing and Finishing of Textiles, Donghua University, Shanghai 201620 (China); Key Laboratory of Science & Technology of Eco-Textile, Ministry of Education, Donghua University, Shanghai 201620 (China); College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai 201620 (China); Ding, Yinyan; Qu, Shaobo [College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai 201620 (China); Cai, Zaisheng, E-mail: zshcai@dhu.edu [College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai 201620 (China)

    2015-11-30

    Highlights: • Superamphiphobic cotton fabrics were prepared. • Water and hexadecane contact angels reach to 164.4° and 156.3°, respectively. • Nanoporous organically modified silica alcogel particles were synthesized. • The superamphiphobic cotton fabrics exhibit enhanced stability against abrasion, laundering and acid. - Abstract: Superamphiphobic cotton fabrics were prepared by alternately depositing organically modified silica alcogel (ormosil) particles onto chitosan precoated cotton fabrics and subsequent 1H, 1H, 2H, 2H-perfluorooctyltrimethoxysilane (PFOTMS) modification. Transmission electron microscopy and scanning electron microscopy images reveal that the ormosil particles display a fluffy, sponge-like nanoporous structure, and the entire cotton fiber surface is covered with highly porous networks. PFOTMS acts as not only a modifier to lower the surface energy of the cotton fabric but also a binder to enhance the coating stability against abrasion and washing. The treated cotton fabrics show highly liquid repellency with the water, cooking oil and hexadecane contact angels reaching to 164.4°, 160.1° and 156.3°, respectively. Meanwhile, the treated cotton fabrics exhibit good abrasion resistance and high laundering durability, which can withstand 10,000 cycles of abrasion and 30 cycles of machine wash without apparently changing the superamphiphobicity. The superamphiphobic cotton fabric also shows high acid stability, and can withstand 98% H{sub 2}SO{sub 4}. Moreover, the superamphiphobic coating has almost no influence on the other physical properties of the cotton fabrics including tensile strength, whiteness and air permeability. This durable non-wetting surface may provide a wide range of new applications in the future.

  16. Laser-assisted fabrication of materials

    CERN Document Server

    Manna, Indranil

    2013-01-01

    Laser assisted fabrication involves shaping of materials using laser as a source of heat. It can be achieved by removal of materials (laser assisted cutting, drilling, etc.), deformation (bending, extrusion), joining (welding, soldering) and addition of materials (surface cladding or direct laser cladding). This book on ´Laser assisted Fabrication’ is aimed at developing in-depth engineering concepts on various laser assisted macro and micro-fabrication techniques with the focus on application and a review of the engineering background of different micro/macro-fabrication techniques, thermal history of the treated zone and microstructural development and evolution of properties of the treated zone.

  17. Silicon fabric for multi-functional applications

    KAUST Repository

    Sevilla, Galo T.; Rojas, Jhonathan Prieto; Ahmed, Sally; Hussain, Aftab M.; Inayat, Salman Bin; Hussain, Muhammad Mustafa

    2013-01-01

    This paper reports a generic process flow to fabricate mechanically flexible and optically semi-transparent thermoelectric generators (TEGs), micro lithium-ion batteries (μLIB) and metal-oxide-semiconductor capacitors (MOSCAPs) on mono-crystalline silicon fabric platforms from standard bulk silicon (100) wafers. All the fabricated devices show outstanding mechanical flexibility and performance, making an important step towards monolithic integration of Energy Chip (self-powered devices) including energy harvesters and electronic devices on flexible platforms. We also report a recyclability process for the remaining bulk substrate after release, allowing us to achieve a low cost flexible platform for high performance applications. © 2013 IEEE.

  18. Fabricating solid carbon porous electrodes from powders

    Science.gov (United States)

    Kaschmitter, James L.; Tran, Tri D.; Feikert, John H.; Mayer, Steven T.

    1997-01-01

    Fabrication of conductive solid porous carbon electrodes for use in batteries, double layer capacitors, fuel cells, capacitive dionization, and waste treatment. Electrodes fabricated from low surface area (Electrodes having a higher surface area, fabricated from powdered carbon blacks, such as carbon aerogel powder, carbon aerogel microspheres, activated carbons, etc. yield high conductivity carbon compositives with excellent double layer capacity, and can be used in double layer capacitors, or for capacitive deionization and/or waste treatment of liquid streams. By adding metallic catalysts to be high surface area carbons, fuel cell electrodes can be produced.

  19. Silicon fabric for multi-functional applications

    KAUST Repository

    Sevilla, Galo T.

    2013-06-01

    This paper reports a generic process flow to fabricate mechanically flexible and optically semi-transparent thermoelectric generators (TEGs), micro lithium-ion batteries (μLIB) and metal-oxide-semiconductor capacitors (MOSCAPs) on mono-crystalline silicon fabric platforms from standard bulk silicon (100) wafers. All the fabricated devices show outstanding mechanical flexibility and performance, making an important step towards monolithic integration of Energy Chip (self-powered devices) including energy harvesters and electronic devices on flexible platforms. We also report a recyclability process for the remaining bulk substrate after release, allowing us to achieve a low cost flexible platform for high performance applications. © 2013 IEEE.

  20. Fabrication of biopolymer cantilevers using nanoimprint lithography

    DEFF Research Database (Denmark)

    Keller, Stephan Sylvest; Feidenhans'l, Nikolaj Agentoft; Fisker-Bødker, Nis

    2011-01-01

    The biodegradable polymer poly(l-lactide) (PLLA) was introduced for the fabrication of micromechanical devices. For this purpose, thin biopolymer films with thickness around 10 μm were spin-coated on silicon substrates. Patterning of microcantilevers is achieved by nanoimprint lithography. A major...... challenge was the high adhesion between PLLA and silicon stamp. Optimized stamp fabrication and the deposition of a 125 nm thick fluorocarbon anti-stiction coating on the PLLA allowed the fabrication of biopolymer cantilevers. Resonance frequency measurements were used to estimate the Young’s modulus...

  1. Design, fabrication and installation of irradiation facilities

    Energy Technology Data Exchange (ETDEWEB)

    Sim, Bong Shick; Kim, Y. S.; Lee, C. Y. and others

    1999-03-01

    The principal contents of this project are to design, fabricate and install the steady-state fuel test loop in HANARO for nuclear technology development. Procurement and fabrication of main equipment, licensing and technical review for fuel test loop have been performed during 2 years(1997, 1998) for this project. Following contents are described in the report. - Procurement and fabrication of the equipment, piping for OPS - IPS manufacture - License - Technical review and evaluation of the FTL facility. As besides, as these irradiation facilities will be installed in HANARO, review of safety concern, discussion with KINS for licensing and review ofHANARO interface have been performed respectively. (author)

  2. Toward an Active Fabric-Based Air Decontamination System

    National Research Council Canada - National Science Library

    Gaddy, G. A; Bratcher, Matthew S; Mills, G; Huang, S; Slaten, B. L; Debortoli, J

    2004-01-01

    ...) particles that were grafted on cotton fabric and on TiO2 particles that were embedded in glass fabric Modified TiO2 particles were grafted onto cotton fabric and irradiated in the presence of CHCl3...

  3. Fabric Reconstruction Based on Sustainable Development: Take the Type of Fabric Recycling as an Example

    Directory of Open Access Journals (Sweden)

    Zhangting Guan

    2017-07-01

    Full Text Available Sustainable development is a very important concept of our time, it wants to do is to live in harmony with people, to protect the environment where our human survival. Fabric recycling refers to the use of a variety of traditional and high-tech means of the existing fabric fabric design and processing. So that the surface of a rich visual texture and tactile texture "through the fabric recycling approach. However, the fabric form and clothing design coordination between the clothing design is essential to the link! Garment fabric is not only the material basis of clothing modeling But also an important form of plastic arts. Fabric recycling art has gradually become a new breakthrough point of fashion design! And become an important means to increase the added value of clothing products. But at the same time fabric recycling also follow the concept of sustainable development. This paper analyzes the relationship between fabric reengineering and sustainable development. Combined with practice to explore the fabric processing technology and its creative ideas and some of its environmental performance.

  4. Optimum processing parameters for the fabrication of twill flax fabric-reinforced polypropylene (PP) composites

    Science.gov (United States)

    Zuhudi, Nurul Zuhairah Mahmud; Minhat, Mulia; Shamsuddin, Mohd Hafizi; Isa, Mohd Dali; Nur, Nurhayati Mohd

    2017-12-01

    In recent years, natural fabric thermoplastic composites such as flax have received much attention due to its attractive capabilities for structural applications. It is crucial to study the processing of flax fabric materials in order to achieve good quality and cost-effectiveness in fibre reinforced composites. Though flax fabric has been widely utilized for several years in composite applications due to its high strength and abundance in nature, much work has been concentrated on short flax fibre and very little work focused on using flax fabric. The effectiveness of the flax fabric is expected to give higher strength performance due to its structure but the processing needs to be optimised. Flax fabric composites were fabricated using compression moulding due to its simplicity, gives good surface finish and relatively low cost in terms of labour and production. Further, the impregnation of the polymer into the fabric is easier in this process. As the fabric weave structure contributes to the impregnation quality which leads to the overall performance, the processing parameters of consolidation i.e. pressure, time, and weight fraction of fabric were optimized using the Taguchi method. This optimization enhances the consolidation quality of the composite by improving the composite mechanical properties, three main tests were conducted i.e. tensile, flexural and impact test. It is observed that the processing parameter significantly affected the consolidation and quality of composite.

  5. Fabrication Process Development for Light Deformable Mirrors

    Data.gov (United States)

    National Aeronautics and Space Administration — The project objective is to develop robust, reproductibble fabrication processes to realize functional deformable membrane mirrors (DM) for a space mission in which...

  6. Impediments for Digital Fabrication in Education

    DEFF Research Database (Denmark)

    Smith, Rachel Charlotte; Iversen, Ole Sejer; Veerasawmy, Rune

    2016-01-01

    with eight primary and lower secondary teachers, the findings point to four central impediments for integrating digital fabrication and design into school environments. The findings extend current perceptions of digital technology in education towards exploratory processes of investigation in which......Digital fabrication technologies are increasingly integrated across subjects in primary and secondary education. Focus on the potentials of these technologies has mainly been on the support to STEM oriented learning goals, while emphasis on teachers' roles with the new learning processes...... of technology and design is largely absent. The paper addresses the experiences and challenges that digital fabrication technology present for teachers in educational environments, and the impediments that are linked to the teachers' roles in design processes of digital fabrication. Based on a research study...

  7. Laminate mechanics for balanced woven fabrics

    NARCIS (Netherlands)

    Akkerman, Remko

    2006-01-01

    Laminate mechanics equations are presented for composites with balanced woven fabric reinforcements. It is shown that mimicking these textile composites with equivalent transversely isotropic (‘unidirectional’) layers requires disputable manipulations. Various micromechanics predictions of textile

  8. Fabrication of thick superconducting films by decantation

    Directory of Open Access Journals (Sweden)

    Julián Betancourt M.

    1991-07-01

    Full Text Available We have found superconducting behavior in thick films fabricated by decantation. In this paper we present the experimental method and results obtained using commercial copper substrates.

  9. Natural fabric sandwich laminate composites: development and ...

    Indian Academy of Sciences (India)

    3Department of Production Technology, MIT Campus, Anna University, Chennai 600044, India. MS received ... In this work, eco-friendly natural fabric sandwich laminate (NFSL) composites are formulated using ... and eco-friendly quality [22].

  10. Semiconductors detectors: basics principals, fabrication and repair

    International Nuclear Information System (INIS)

    Souza Coelho, L.F. de.

    1982-05-01

    The fabrication and repairing techniques of semiconductor detectors, are described. These methods are shown in the way they are applied by the semiconductor detector laboratory of the KFA-Julich, where they have been developed during the last 15 years. The history of the semiconductor detectors is presented here, being also described the detector fabrication experiences inside Brazil. The key problems of manufacturing are raised. In order to understand the fabrication and repairing techniques the working principles of these detectors, are described. The cases in which worked during the stay in the KFA-Julich, particularly the fabrication of a plane Ge (Li) detector, with side entry, and the repair of a coaxial Ge (Li) is described. The vanguard problems being researched in Julich are also described. Finally it is discussed a timetable for the semiconductor detector laboratory of the UFRJ, which laboratory is in the mounting stage now. (Author) [pt

  11. Flexible Thermoelectric Generators on Silicon Fabric

    KAUST Repository

    Sevilla, Galo T.

    2012-01-01

    In this work, the development of a Thermoelectric Generator on Flexible Silicon Fabric is explored to extend silicon electronics for flexible platforms. Low cost, easily deployable plastic based flexible electronics are of great interest for smart

  12. Diffractive optics: design, fabrication, and test

    National Research Council Canada - National Science Library

    O'Shea, Donald C

    2004-01-01

    This book provides the reader with the broad range of materials that were discussed in a series of short courses presented at Georgia Tech on the design, fabrication, and testing of diffractive optical elements (DOEs...

  13. Fabrication of LD-3 Polymer Directional Couplers

    National Research Council Canada - National Science Library

    Chen, Ray T

    1998-01-01

    .... LD-3 polymer directional couplers arc designed and fabricated to operate at 1.3 microns. Waveguide propagation losses, device characterization, demonstration of cross coupling and packaged device pictures are presented in this final report.

  14. Fabrication of 3D Silicon Sensors

    Energy Technology Data Exchange (ETDEWEB)

    Kok, A.; Hansen, T.E.; Hansen, T.A.; Lietaer, N.; Summanwar, A.; /SINTEF, Oslo; Kenney, C.; Hasi, J.; /SLAC; Da Via, C.; /Manchester U.; Parker, S.I.; /Hawaii U.

    2012-06-06

    Silicon sensors with a three-dimensional (3-D) architecture, in which the n and p electrodes penetrate through the entire substrate, have many advantages over planar silicon sensors including radiation hardness, fast time response, active edge and dual readout capabilities. The fabrication of 3D sensors is however rather complex. In recent years, there have been worldwide activities on 3D fabrication. SINTEF in collaboration with Stanford Nanofabrication Facility have successfully fabricated the original (single sided double column type) 3D detectors in two prototype runs and the third run is now on-going. This paper reports the status of this fabrication work and the resulted yield. The work of other groups such as the development of double sided 3D detectors is also briefly reported.

  15. Flame retardant treatments of PBI fabric.

    Science.gov (United States)

    Temin, S. C.

    1972-01-01

    Fabrics knitted or woven from polybenzimidazole (PBI) fibers were treated to reduce flammability in oxygen atmospheres, particularly that of 5 psia oxygen. Bromination to approximately 15% weight gain of such fabrics led to markedly lower burning rates; samples brominated to over 80% weight gain were self-extinguishing in 5 psia oxygen. The loss in tensile strength of fabrics due to bromination was negligible although shrinkage was observed. Free fibers showed negligible losses on bromination. Treatment of PBI fabric with organophosphorus compounds also achieved self-extinguishing character in 5 psia oxygen but the enhanced flameproofing was largely lost on leaching. Reaction with POCl3 in pyridine led to a permanent reduction in flammability.

  16. Fabricating plasmonic components for nano-and meta-photonics

    DEFF Research Database (Denmark)

    Boltasseva, Alexandra; Nielsen, Rasmus Bundgaard; Jeppesen, Claus

    2009-01-01

    Different fabrication approaches for realization of metal-dielectric structures supporting propagating and localized surface plasmons are described including fabrication of nanophotonic waveguides and plasmonic nanoantennae....

  17. The quality challenge for fuel fabrication

    International Nuclear Information System (INIS)

    Lannegrace, J.-P.

    1990-01-01

    Fuel fabrication is a key segment of the nuclear fuel cycle, since safe and economic operation of reactors is highly dependent on the quality of the fuel. Achieving and controlling quality is, therefore, of paramount importance to fuel fabricators dominating nearly every aspect of the business. The quality policy, concepts and assurance system at three French plants are outlined. The need for integrated inspection, process optimization and good employee motivation is stressed. (author)

  18. Interfacing robotics with plutonium fuel fabrication

    International Nuclear Information System (INIS)

    Bowen, W.W.; Moore, F.W.

    1986-01-01

    Interfacing robotic systems with nuclear fuel fabrication processes resulted in a number of interfacing challenges. The system not only interfaces with the fuel process, but must also interface with nuclear containment, radiation control boundaries, criticality control restrictions, and numerous other safety systems required in a fuel fabrication plant. The robotic system must be designed to allow operator interface during maintenance and recovery from an upset as well as normal operations

  19. FBR pellet fabrication - density and dimensional control

    International Nuclear Information System (INIS)

    Rasmussen, D.E.; Schaus, P.S.

    1982-01-01

    The fuel pellet fabricating experience described in this paper involved pellet processing tests using mixed oxide (PuO 2 -UO 2 ) powders to produce fast breeder reactor (FBR) fuel pellets. Objectives of the pellet processing tests were to establish processing parameters for sintered-to-size fuel pellets to be used in an irradiation test in the Fast Flux Test Facility and to establish baseline fabrication control information. 26 figures, 7 tables

  20. Fabrication of Polymer Optical Fibre (POF Gratings

    Directory of Open Access Journals (Sweden)

    Yanhua Luo

    2017-03-01

    Full Text Available Gratings inscribed in polymer optical fibre (POF have attracted remarkable interest for many potential applications due to their distinctive properties. This paper overviews the current state of fabrication of POF gratings since their first demonstration in 1999. In particular we summarize and discuss POF materials, POF photosensitivity, techniques and issues of fabricating POF gratings, as well as various types of POF gratings.

  1. Fabrication of off-axis parabolic mirrors

    International Nuclear Information System (INIS)

    Bezik, M.J.; Gerth, H.L.; Sladky, R.E.; Washington, C.A.

    1978-08-01

    The report describes the fabrication process, including metal preparation, copper electroplating, single-crystal-diamond turning, optical inspection, and polishing, used to manufacture the focusing mirrors for the 10-kJ laser fusion experiment being conducted by the Los Alamos Scientific Laboratory. Fabrication of these mirrors by the techniques described resulted in diffraction-limited optics at a 10.6 μm wavelength

  2. Silver Nanowire Arrays : Fabrication and Applications

    OpenAIRE

    Feng, Yuyi

    2016-01-01

    Nanowire arrays have increasingly received attention for their use in a variety of applications such as surface-enhanced Raman scattering (SERS), plasmonic sensing, and electrodes for photoelectric devices. However, until now, large scale fabrication of device-suitable metallic nanowire arrays on supporting substrates has seen very limited success. This thesis describes my work rst on the development of a novel successful processing route for the fabrication of uniform noble metallic (e.g. A...

  3. Quality assurance in the fuel fabrication

    International Nuclear Information System (INIS)

    Darmayan, P.

    1995-01-01

    The paper concentrates on the evolutions that FBFC Franco Belge de Fabrication de Combustible has initiated in order to make a further step in improving quality: 1. Improving each personnel's involment and responsability towards quality. 2. Incorporating quality assurance in a total quality management policy, involving both the fabrication teams of FBFC and the design teams of Framatome in order to improve quality. (orig./HP)

  4. Fabrication and Multiprobe Electrical Characterization of Nanostructures

    DEFF Research Database (Denmark)

    Klarskov, Mikkel Buster

    2013-01-01

    techniques, such as colloidal lithography or block copolymers lithography, which covers the entire sample. This project presents graphene devices with periodic holes fabricated by electron beam lithography. Only partial coverage of holes are fabricated by making from one to many rows of holes perpendicular......, such as nanograss and silver nanowires. Furthermore, antidot lattice of dierent sizes are made in graphene, to investigating the dependence of number of holes needed for modifying the electronic properties of graphene....

  5. Fabrication of ion source components by electroforming

    International Nuclear Information System (INIS)

    Schechter, D.E.; Sluss, F.

    1983-01-01

    Several components of the Oak Ridge National Laboratory (ORNL)/Magnetic Fusion Test Facility (MFTF-B) ion source have been fabricated utilizing an electroforming process. A procedure has been developed for enclosing coolant passages in copper components by electrodepositing a thick (greater than or equal to 0.75-mm) layer of copper (electroforming) over the top of grooves machined into the copper component base. Details of the procedure to fabricate acceleration grids and other ion source components are presented

  6. Kinetic Friction of Sport Fabrics on Snow

    Directory of Open Access Journals (Sweden)

    Werner Nachbauer

    2016-03-01

    Full Text Available After falls, skiers or snowboarders often slide on the slope and may collide with obstacles. Thus, the skier’s friction on snow is an important factor to reduce incidence and severity of impact injuries. The purpose of this study was to measure snow friction of different fabrics of ski garments with respect to roughness, speed, and contact pressure. Three types of fabrics were investigated: a commercially available ski overall, a smooth downhill racing suit, and a dimpled downhill racing suit. Friction was measured for fabrics taped on a short ski using a linear tribometer. The fabrics’ roughness was determined by focus variation microscopy. Friction coefficients were between 0.19 and 0.48. Roughness, friction coefficient, and friction force were highest for the dimpled race suit. The friction force of the fabrics was higher for the higher contact pressure than for the lower one at all speeds. It was concluded that the main friction mechanism for the fabrics was dry friction. Only the fabric with the roughest surface showed friction coefficients, which were high enough to sufficiently decelerate a sliding skier on beginner and intermediate slopes.

  7. EIT-based fabric pressure sensing.

    Science.gov (United States)

    Yao, A; Yang, C L; Seo, J K; Soleimani, M

    2013-01-01

    This paper presents EIT-based fabric sensors that aim to provide a pressure mapping using the current carrying and voltage sensing electrodes attached to the boundary of the fabric patch. Pressure-induced shape change over the sensor area makes a change in the conductivity distribution which can be conveyed to the change of boundary current-voltage data. This boundary data is obtained through electrode measurements in EIT system. The corresponding inverse problem is to reconstruct the pressure and deformation map from the relationship between the applied current and the measured voltage on the fabric boundary. Taking advantage of EIT in providing dynamical images of conductivity changes due to pressure induced shape change, the pressure map can be estimated. In this paper, the EIT-based fabric sensor was presented for circular and rectangular sensor geometry. A stretch sensitive fabric was used in circular sensor with 16 electrodes and a pressure sensitive fabric was used in a rectangular sensor with 32 electrodes. A preliminary human test was carried out with the rectangular sensor for foot pressure mapping showing promising results.

  8. EIT-Based Fabric Pressure Sensing

    Directory of Open Access Journals (Sweden)

    A. Yao

    2013-01-01

    Full Text Available This paper presents EIT-based fabric sensors that aim to provide a pressure mapping using the current carrying and voltage sensing electrodes attached to the boundary of the fabric patch. Pressure-induced shape change over the sensor area makes a change in the conductivity distribution which can be conveyed to the change of boundary current-voltage data. This boundary data is obtained through electrode measurements in EIT system. The corresponding inverse problem is to reconstruct the pressure and deformation map from the relationship between the applied current and the measured voltage on the fabric boundary. Taking advantage of EIT in providing dynamical images of conductivity changes due to pressure induced shape change, the pressure map can be estimated. In this paper, the EIT-based fabric sensor was presented for circular and rectangular sensor geometry. A stretch sensitive fabric was used in circular sensor with 16 electrodes and a pressure sensitive fabric was used in a rectangular sensor with 32 electrodes. A preliminary human test was carried out with the rectangular sensor for foot pressure mapping showing promising results.

  9. Fabrication of Durably Superhydrophobic Cotton Fabrics by Atmospheric Pressure Plasma Treatment with a Siloxane Precursor

    Directory of Open Access Journals (Sweden)

    Jing Yang

    2018-04-01

    Full Text Available The surface treatment of fabrics in an atmospheric environment may pave the way for commercially viable plasma modifications of fibrous matters. In this paper, we demonstrate a durably superhydrophobic cotton cellulose fabric prepared in a single-step graft polymerization of hexamethyldisiloxane (HMDSO by N2 and O2 atmospheric pressure plasma. We systematically investigated effects on contact angle (CA and surface morphology of the cotton fabric under three operational parameters: precursor value; ionization gas flow rate; and plasma cycle time. Surface morphology, element composition, chemical structure and hydrophobic properties of the treated fabric were characterized by scanning electron microscope (SEM, EDS, FTIR and CA on the fabrics. The results indicated that a layer of thin film and nano-particles were evenly deposited on the cotton fibers, and graft polymerization occurred between cellulose and HMDSO. The fabric treated by O2 plasma exhibited a higher CA of 162° than that treated by N2 plasma which was about 149°. Furthermore, the CA of treated fabrics decreased only 0°~10° after storing at the ambient conditions for four months, and treated fabrics could also endure the standard textile laundering procedure in AATCC 61-2006 with minimum change. Therefore, this single-step plasma treatment method is shown to be a novel and environment-friendly way to make durable and superhydrophobic cotton fabrics.

  10. Fabrication of fuel elements interplay between typical SNR Mark Ia specifications and the fuel element fabrication

    International Nuclear Information System (INIS)

    Biermann, W.K.; Heuvel, H.J.; Pilate, S.; Vanderborck, Y.; Pelckmans, E.; Vanhellemont, G.; Roepenack, H.; Stoll, W.

    1987-01-01

    The core and fuel were designed for the SNR-300 first core by Interatom GmbH and Belgonucleaire. The fuel was fabricated by Alkem/RBU and Belgonucleaire. Based on the preparation of drawings and specifications and on the results of the prerun fabrication, an extensive interplay took place between design requirements, specifications, and fabrication processes at both fuel plants. During start-up of pellet and pin fabrication, this solved such technical questions as /sup 239/Pu equivalent linear weight, pellet density, stoichiometry of the pellets, and impurity content. Close cooperation of designers and manufacturers has allowed manufacture of 205 fuel assemblies without major problems

  11. INFLUENCE OF FABRIC TIGHTNESS ON SPIRALITY OF WEFTKNITTED PLAIN COTTON FABRIC

    Directory of Open Access Journals (Sweden)

    A.K.M. Mobarok Hossain

    2011-01-01

    Full Text Available Global demand for knitted garments is growing at a faster rate than that of woven items.Currently around 50% of clothing needs in the developed countries is met by knit goods. So ensuring the required quality in a knitted fabric is a vital issue for the manufacturer. One of the major problems encountered in knitted fabric is spirality. It affects particularly single jersey fabric and presents a serious problem during garment confection and use. So controlling spirality is a basic requirement for producing quality knitted fabric. Though there are several factors that contribute to knitted fabric spirality, yarn twist and relative tightness of the fabric are said tobe the most significant ones. In this work the basic single jersey fabric, i.e. plain jersey cotton fabrics were produced by a Hosiery knitting machine and spirality values were observed for different yarn T.P.I. and tightness factor at relaxed state. It was found that tightness factor has a direct influence on knitted fabric spirality with a high degree of correlation. The work thus gives an idea to deal this problem by controlling the knitting parameters.

  12. Fabrication and characterization of active nanostructures

    Science.gov (United States)

    Opondo, Noah F.

    Three different nanostructure active devices have been designed, fabricated and characterized. Junctionless transistors based on highly-doped silicon nanowires fabricated using a bottom-up fabrication approach are first discussed. The fabrication avoids the ion implantation step since silicon nanowires are doped in-situ during growth. Germanium junctionless transistors fabricated with a top down approach starting from a germanium on insulator substrate and using a gate stack of high-k dielectrics and GeO2 are also presented. The levels and origin of low-frequency noise in junctionless transistor devices fabricated from silicon nanowires and also from GeOI devices are reported. Low-frequency noise is an indicator of the quality of the material, hence its characterization can reveal the quality and perhaps reliability of fabricated transistors. A novel method based on low-frequency noise measurement to envisage trap density in the semiconductor bandgap near the semiconductor/oxide interface of nanoscale silicon junctionless transistors (JLTs) is presented. Low-frequency noise characterization of JLTs biased in saturation is conducted at different gate biases. The noise spectrum indicates either a Lorentzian or 1/f. A simple analysis of the low-frequency noise data leads to the density of traps and their energy within the semiconductor bandgap. The level of noise in silicon JLT devices is lower than reported values on transistors fabricated using a top-down approach. This noise level can be significantly improved by improving the quality of dielectric and the channel interface. A micro-vacuum electron device based on silicon field emitters for cold cathode emission is also presented. The presented work utilizes vertical Si nanowires fabricated by means of self-assembly, standard lithography and etching techniques as field emitters in this dissertation. To obtain a high nanowire density, hence a high current density, a simple and inexpensive Langmuir Blodgett technique

  13. Fabrication of HTTR first loading fuel

    International Nuclear Information System (INIS)

    Kato, S.; Yoshimuta, S.; Hasumi, T.; Sato, K.; Sawa, K.; Suzuki, S.; Mogi, H.; Shiozawa, S.; Tanaka, T.

    2001-01-01

    This paper summarizes the fabrication of the first loading fuel for HTTR, High Temperature engineering Test Reactor constructed by JAERI, Japan Atomic Energy Research Institute. The fuel fabrication started at the HTR fuel facility of NFI, Nuclear Fuel Industries, Ltd., June 1995. 4,770 fuel rods were fabricated through the fuel kernel, coated fuel particle and fuel compaction process, then 150 fuel elements were assembled in the reactor building December 1997. Fabrication technology for the fuel was established through a lot of R and D activities and fabrication experience of irradiation examination samples spread over about 30 years. Most of all, very high quality and production efficiency of fuel were achieved by the development of the fuel kernel process using the vibration dropping technology, the continuous 4-layer coating process and the automatic compaction process. As for the inspection technology, the development of the automatic measurement equipment for coated layer thickness of a coated fuel particle and uranium content of a fuel compact contributed to the higher reliability and rationalization of the inspection process. The data processing system for the fabrication and quality control, which was originally developed by NFI, made possible not only quick feedback of statistical quality data to the fabrication processes, but also automatic document preparation, such as inspection certificates and accountability control reports. The quality of the first loading fuel fully satisfied the design specifications for the fuel. In particular, average bare uranium fraction and SiC defective fraction of fuel compacts were 2x10 -6 and 8x10 -5 , respectively. According to the preceding irradiation examinations being performed at JMTR, Japan Materials Testing Reactor of JAERI, the specimen sampled from the first loading fuel shows good irradiation performance. (author)

  14. Fabrication of miniaturized electrostatic deflectors using LIGA

    International Nuclear Information System (INIS)

    Jackson, K.H.; Khan-Malek, C.; Muray, L.P.

    1997-01-01

    Miniaturized electron beam columns (open-quotes microcolumnsclose quotes) have been demonstrated to be suitable candidates for scanning electron microscopy (SEM), e-beam lithography and other high resolution, low voltage applications. In the present technology, microcolumns consist of open-quotes selectively scaledclose quotes micro-sized lenses and apertures, fabricated from silicon membranes with e-beam lithography, reactive ion beam etching and other semiconductor thin-film techniques. These miniaturized electron-optical elements provide significant advantages over conventional optics in performance and ease of fabrication. Since lens aberrations scale roughly with size, it is possible to fabricate simple microcolumns with extremely high brightness sources and electrostatic objective lenses, with resolution and beam current comparable to conventional e-beam columns. Moreover since microcolumns typically operate at low voltages (1 KeV), the proximity effects encountered in e-beam lithography become negligible. For high throughput applications, batch fabrication methods may be used to build large parallel arrays of microcolumns. To date, the best reported performance with a 1 keV cold field emission cathode, is 30 nm resolution at a working distance of 2mm in a 3.5mm column. Fabrication of the microcolumn deflector and stigmator, however, have remained beyond the capabilities of conventional machining operations and semiconductor processing technology. This work examines the LIGA process as a superior alternative to fabrication of the deflectors, especially in terms of degree of miniaturization, dimensional control, placement accuracy, run-out, facet smoothness and choice of suitable materials. LIGA is a combination of deep X-ray lithography, electroplating, and injection molding processes which allow the fabrication of microstructures

  15. Functional electronic screen printing – electroluminescent smart fabric watch

    OpenAIRE

    de Vos, Marc; Torah, Russel; Beeby, Steve; Tudor, John

    2013-01-01

    Motivation for screen printed smart fabrics.Introduce functional electronic screen printing on fabrics.Printed smart fabric watch design.Printing process for electroluminescent watch.Demonstration video.Conclusions and further work.Examples of other screen printed smart fabrics.

  16. Technical study report on fuel fabrication system

    International Nuclear Information System (INIS)

    Kono, Shusaku; Tanaka, Kenya; Ono, Kiyoshi; Iwasa, Katsuyoshi; Hoshino, Yasushi; Shinkai, Yasuo

    2000-07-01

    The feasibility study of FBR and related fuel cycle is performed for developing the FBR recycle system which ensures safety, economic competitiveness, efficient utilization of resources, reduction of environmental burden and enhancement of nuclear non-proliferation under consistency of FBR reactor and fuel cycle systems. In this study, a conceptual design study and system characteristics evaluation are conducted for fuel fabrication systems of pellet process, vibropack process for oxide and nitride fuel and casting process for metal fuel. Technical issues in each process are also extracted. In 1999 fiscal year, a conceptual design study were conducted for the fuel fabrication plants adopting (1) the short pellet process which simplifies the conventional MOX pellet fabrication processes, (2) vibropack processes of aqueous gelation process, improved RIAR process, improved ANL process and fluoride volatility process, (3) casting processes of injection process, centrifuging process. As a result, attainable perspective was obtained for each fuel fabrication system through the evaluation of apparatuses, layout and facility volume, etc. In each fuel fabrication system, technical issues for practical use were made clear. Hereafter, more detailed study will be performed for each system, and research programs for phase II study will be planned. (author)

  17. Fabrication of preliminary fuel rods for SFR

    International Nuclear Information System (INIS)

    Kim, Sun Ki; Oh, Seok Jin; Ko, Young Mo; Woo, Youn Myung; Kim, Ki Hwan

    2012-01-01

    Metal fuels was selected for fueling many of the first reactors in the US, including the Experimental Breeder Reactor-I (EBR-I) and the Experimental Breeder Reactor-II (EBR-II) in Idaho, the FERMI-I reactor, and the Dounreay Fast Reactor (DFR) in the UK. Metallic U.Pu.Zr alloys were the reference fuel for the US Integral Fast Reactor (IFR) program. Metallic fuel has advantages such as simple fabrication procedures, good neutron economy, high thermal conductivity, excellent compatibility with a Na coolant and inherent passive safety. U-Zr-Pu alloy fuels have been used for SFR (sodium-cooled fast reactor) related to the closed fuel cycle for managing minor actinides and reducing a high radioactivity levels since the 1980s. Fabrication technology of metallic fuel for SFR has been in development in Korea as a national nuclear R and D program since 2007. For the final goal of SFR fuel rod fabrication with good performance, recently, three preliminary fuel rods were fabricated. In this paper, the preliminary fuel rods were fabricated, and then the inspection for QC(quality control) of the fuel rods was performed

  18. 3D bioprinting for vascularized tissue fabrication

    Science.gov (United States)

    Richards, Dylan; Jia, Jia; Yost, Michael; Markwald, Roger; Mei, Ying

    2016-01-01

    3D bioprinting holds remarkable promise for rapid fabrication of 3D tissue engineering constructs. Given its scalability, reproducibility, and precise multi-dimensional control that traditional fabrication methods do not provide, 3D bioprinting provides a powerful means to address one of the major challenges in tissue engineering: vascularization. Moderate success of current tissue engineering strategies have been attributed to the current inability to fabricate thick tissue engineering constructs that contain endogenous, engineered vasculature or nutrient channels that can integrate with the host tissue. Successful fabrication of a vascularized tissue construct requires synergy between high throughput, high-resolution bioprinting of larger perfusable channels and instructive bioink that promotes angiogenic sprouting and neovascularization. This review aims to cover the recent progress in the field of 3D bioprinting of vascularized tissues. It will cover the methods of bioprinting vascularized constructs, bioink for vascularization, and perspectives on recent innovations in 3D printing and biomaterials for the next generation of 3D bioprinting for vascularized tissue fabrication. PMID:27230253

  19. Composite fabrication via resin transfer molding technology

    Energy Technology Data Exchange (ETDEWEB)

    Jamison, G.M.; Domeier, L.A.

    1996-04-01

    The IMPReS (Integrated Modeling and Processing of Resin-based Structures) Program was funded in FY95 to consolidate, evaluate and enhance Sandia`s capabilities in the design and fabrication of composite structures. A key driver of this and related programs was the need for more agile product development processes and for model based design and fabrication tools across all of Sandia`s material technologies. A team of polymer, composite and modeling personnel was assembled to benchmark Sandia`s existing expertise in this area relative to industrial and academic programs and to initiate the tasks required to meet Sandia`s future needs. RTM (Resin Transfer Molding) was selected as the focus composite fabrication technology due to its versatility and growing use in industry. Modeling efforts focused on the prediction of composite mechanical properties and failure/damage mechanisms and also on the uncured resin flow processes typical of RTM. Appropriate molds and test composites were fabricated and model validation studies begun. This report summarizes and archives the modeling and fabrication studies carried out under IMPReS and evaluates the status of composite technology within Sandia. It should provide a complete and convenient baseline for future composite technology efforts within Sandia.

  20. Development of technology for fabrication of lithium CPS on basis of CNT-reinforced carboxylic fabric

    International Nuclear Information System (INIS)

    Tazhibayeva, Irina; Baklanov, Viktor; Ponkratov, Yuriy; Abdullin, Khabibulla; Kulsartov, Timur; Gordienko, Yuriy; Zaurbekova, Zhanna; Lyublinski, Igor; Vertkov, Alexey; Skakov, Mazhyn

    2017-01-01

    Highlights: • Preliminary study of carboxylic fabric wettability with liquid lithium is presented. • Preliminary studies of carboxylic fabric wettability with liquid lithium consist in carrying out of experiments at temperatures 673,773 and 873 К in vacuum during long time. • A scheme of experimental device for manufacturing of lithium CPS and matrix filling procedure with liquid lithium are presented. • The concept of lithium limiter with CPS on basis of CNT-reinforced carboxylic fabric is proposed. - Abstract: The paper describes the analysis of liquid lithium interaction with materials based on carbon, the manufacture technology of capillary-porous system (CPS) matrix on basis of CNT-reinforced carboxylic fabric. Preliminary study of carboxylic fabric wettability with liquid lithium is presented. The development of technology includes: microstructural studies of carboxylic fabric before its CNT-reinforcing; validation of CNT-reinforcing technology; mode validation of CVD-method for CNT synthesize; study of synthesized carbon structures. Preliminary studies of carboxylic fabric wettability with liquid lithium consist in carrying out of experiments at temperatures 673, 773 and 873 К in vacuum during long time. The scheme of experimental device for manufacturing of lithium CPS and matrix filling procedure with liquid lithium are presented. The concept of lithium limiter with CPS on basis of CNT-reinforced carboxylic fabric is proposed.

  1. Development of technology for fabrication of lithium CPS on basis of CNT-reinforced carboxylic fabric

    Energy Technology Data Exchange (ETDEWEB)

    Tazhibayeva, Irina, E-mail: tazhibayeva@ntsc.kz [Institute of Atomic Energy, National Nuclear Center of RK, Kurchatov (Kazakhstan); Baklanov, Viktor; Ponkratov, Yuriy [Institute of Atomic Energy, National Nuclear Center of RK, Kurchatov (Kazakhstan); Abdullin, Khabibulla [Institute of Experimental and Theoretical Physics of Kazakh National University, Almaty (Kazakhstan); Kulsartov, Timur; Gordienko, Yuriy; Zaurbekova, Zhanna [Institute of Atomic Energy, National Nuclear Center of RK, Kurchatov (Kazakhstan); Lyublinski, Igor [JSC «Red Star», Moscow (Russian Federation); NRNU «MEPhI», Moscow (Russian Federation); Vertkov, Alexey [JSC «Red Star», Moscow (Russian Federation); Skakov, Mazhyn [Institute of Atomic Energy, National Nuclear Center of RK, Kurchatov (Kazakhstan)

    2017-04-15

    Highlights: • Preliminary study of carboxylic fabric wettability with liquid lithium is presented. • Preliminary studies of carboxylic fabric wettability with liquid lithium consist in carrying out of experiments at temperatures 673,773 and 873 К in vacuum during long time. • A scheme of experimental device for manufacturing of lithium CPS and matrix filling procedure with liquid lithium are presented. • The concept of lithium limiter with CPS on basis of CNT-reinforced carboxylic fabric is proposed. - Abstract: The paper describes the analysis of liquid lithium interaction with materials based on carbon, the manufacture technology of capillary-porous system (CPS) matrix on basis of CNT-reinforced carboxylic fabric. Preliminary study of carboxylic fabric wettability with liquid lithium is presented. The development of technology includes: microstructural studies of carboxylic fabric before its CNT-reinforcing; validation of CNT-reinforcing technology; mode validation of CVD-method for CNT synthesize; study of synthesized carbon structures. Preliminary studies of carboxylic fabric wettability with liquid lithium consist in carrying out of experiments at temperatures 673, 773 and 873 К in vacuum during long time. The scheme of experimental device for manufacturing of lithium CPS and matrix filling procedure with liquid lithium are presented. The concept of lithium limiter with CPS on basis of CNT-reinforced carboxylic fabric is proposed.

  2. CMOS MEMS Fabrication Technologies and Devices

    Directory of Open Access Journals (Sweden)

    Hongwei Qu

    2016-01-01

    Full Text Available This paper reviews CMOS (complementary metal-oxide-semiconductor MEMS (micro-electro-mechanical systems fabrication technologies and enabled micro devices of various sensors and actuators. The technologies are classified based on the sequence of the fabrication of CMOS circuitry and MEMS elements, while SOI (silicon-on-insulator CMOS MEMS are introduced separately. Introduction of associated devices follows the description of the respective CMOS MEMS technologies. Due to the vast array of CMOS MEMS devices, this review focuses only on the most typical MEMS sensors and actuators including pressure sensors, inertial sensors, frequency reference devices and actuators utilizing different physics effects and the fabrication processes introduced. Moreover, the incorporation of MEMS and CMOS is limited to monolithic integration, meaning wafer-bonding-based stacking and other integration approaches, despite their advantages, are excluded from the discussion. Both competitive industrial products and state-of-the-art research results on CMOS MEMS are covered.

  3. Decontamination of polypropylene fabrics by dry cleaning

    International Nuclear Information System (INIS)

    Severa, J.; Knajfl, J.

    1983-01-01

    Polypropylene fabrics can efficiently be decontaminated by dry cleaning in benzine or perchloroethylene, this also in case the fabric was greased in addition to radioactive contamination. For heavily soiled fabric, it is advantageous to first dry clean it and then wash it. The positive effect was confirmed of intensifiers on the cleaning process, especially of benzine soap. In practice, its concentration should be selected within 1 and 10 g.dm - 3 . Decontamination by dry cleaning and subsequent washing is advantageous in that that the resulting activity of waste water from the laundry is low. Radioactive wastes from the dry cleaning process have a low weight and can be handled as solid waste. (M.D.)

  4. HIP technologies for fusion reactor blankets fabrication

    International Nuclear Information System (INIS)

    Le Marois, G.; Federzoni, L.; Bucci, P.; Revirand, P.

    2000-01-01

    The benefit of HIP techniques applied to the fabrication of fusion internal components for higher performances, reliability and cost savings are emphasized. To demonstrate the potential of the techniques, design of new blankets concepts and mock-ups fabrication are currently performed by CEA. A coiled tube concept that allows cooling arrangement flexibility, strong reduction of the machining and number of welds is proposed for ITER IAM. Medium size mock-ups according to the WCLL breeding blanket concept have been manufactured. The fabrication of a large size mock-up is under progress. These activities are supported by numerical calculations to predict the deformations of the parts during HIP'ing. Finally, several HIP techniques issues have been identified and are discussed

  5. Fabrication process of expanded cooling jackets

    International Nuclear Information System (INIS)

    Weber, C.M.

    1980-01-01

    The present invention concerns the fabrication process of heat exchangers and in particular, the fabrication and assembly process of cooling jackets of the system driving the control rods used in nuclear reactors. The cooling jackets are assembled for cooling the stator of a tubular motor displacing the control rods. The fabrication and assembling of the cooling jacket is made up by the following operations: - a sleeve has an inner fluid inlet and outlet ways, - an external socket is fitted to the sleeve, - on the external socket a continuous welding is realized, which join the socket to the sleeve, and define a serie of parallel welded turns, - a pressure is established between the sleeve and the socket by a fluid through the outlet or inlet ways of the sleeve. When the other way is sealed up, the socket expands between the welded turns, and the fluid can pass through the jacket [fr

  6. MITG test assembly design and fabrication

    International Nuclear Information System (INIS)

    Schock, A.

    1983-01-01

    The design, analysis, and evaluation of the Modular Isotopic Thermoelectric Generator (MITG), described in an earlier paper, led to a program to build and test prototypical, modules of that generator. Each test module duplicates the thermoelectric converters, thermal insulation, housing and radiator fins of a typical generator slice, and simulates its isotope heat source module by means of an electrical heater encased in a prototypical graphite box. Once the approx. 20-watt MITG module has been developed, it can be assembled in appropriate number to form a generator design yielding the desired power output. The present paper describes the design and fabrication of the MITG test assembly, which confirmed the fabricability of the multicouples and interleaved multifoil insulation called for by the design. Test plans, procedures, instrumentation, results, and post-test analyses, as well as revised designs, fabrication procedures, and performance estimates, are described in subsequent papers in these proceedings

  7. Design, fabrication and installation of irradiation facilities

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yong Sung; Lee, C. Y.; Kim, J. Y.; Chi, D. Y.; Kim, S. H.; Ahn, S. H.; Kim, S. J.; Kim, J. K.; Yang, S. H.; Yang, S. Y.; Kim, H. R.; Kim, H.; Lee, K. H.; Lee, B. C.; Park, C.; Lee, C. T.; Cho, S. W.; Kwak, K. K.; Suk, H. C. [and others

    1997-07-01

    The principle contents of this project are to design, fabricate and install the steady-state fuel test loop and non-instrumented capsule in HANARO for nuclear technology development. This project will be completed in 1999, the basic and detail design, safety analysis, and procurement of main equipment for fuel test loop have been performed and also the piping in gallery and the support for IPS piping in reactor pool have been installed in 1994. In the area of non-instrumented capsule for material irradiation test, the fabrication of capsule has been completed. Procurement, fabrication and installation of the fuel test loop will be implemented continuously till 1999. As besides, as these irradiation facilities will be installed in HANARO, review of safety concern, discussion with KINS for licensing and safety analysis report has been submitted to KINS to get a license and review of HANARO interface have been performed respectively. (author). 39 refs., 28 tabs., 21 figs.

  8. Fabrication of Josephson Junction without shadow evaporation

    Science.gov (United States)

    Wu, Xian; Ku, Hsiangsheng; Long, Junling; Pappas, David

    We developed a new method of fabricating Josephson Junction (Al/AlOX/Al) without shadow evaporation. Statistics from room temperature junction resistance and measurement of qubits are presented. Unlike the traditional ``Dolan Bridge'' technique, this method requires two individual lithographies and straight evaporations of Al. Argon RF plasma is used to remove native AlOX after the first evaporation, followed by oxidation and second Al evaporation. Junction resistance measured at room temperature shows linear dependence on Pox (oxidation pressure), √{tox} (oxidation time), and inverse proportional to junction area. We have seen 100% yield of qubits made with this method. This method is promising because it eliminates angle dependence during Junction fabrication, facilitates large scale qubits fabrication.

  9. Ion traps fabricated in a CMOS foundry

    Energy Technology Data Exchange (ETDEWEB)

    Mehta, K. K.; Ram, R. J. [Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Eltony, A. M.; Chuang, I. L. [Center for Ultracold Atoms, Research Laboratory of Electronics and Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Bruzewicz, C. D.; Sage, J. M., E-mail: jsage@ll.mit.edu; Chiaverini, J., E-mail: john.chiaverini@ll.mit.edu [Lincoln Laboratory, Massachusetts Institute of Technology, Lexington, Massachusetts 02420 (United States)

    2014-07-28

    We demonstrate trapping in a surface-electrode ion trap fabricated in a 90-nm CMOS (complementary metal-oxide-semiconductor) foundry process utilizing the top metal layer of the process for the trap electrodes. The process includes doped active regions and metal interconnect layers, allowing for co-fabrication of standard CMOS circuitry as well as devices for optical control and measurement. With one of the interconnect layers defining a ground plane between the trap electrode layer and the p-type doped silicon substrate, ion loading is robust and trapping is stable. We measure a motional heating rate comparable to those seen in surface-electrode traps of similar size. This demonstration of scalable quantum computing hardware utilizing a commercial CMOS process opens the door to integration and co-fabrication of electronics and photonics for large-scale quantum processing in trapped-ion arrays.

  10. The LHC Main Quadrupoles during Series Fabrication

    CERN Document Server

    Tortschanoff, Theodor; Durante, M; Hagen, P; Klein, U; Krischel, D; Payn, A; Rossi, L; Schellong, B; Schmidt, P; Simon, F; Schirm, K-M; Todesco, E

    2006-01-01

    By the end of August 2005 about 320 of the 400 main LHC quadrupole magnets have been fabricated and about 220 of them assembled into their cold masses, together with corrector magnets. About 130 of them have been cold tested in their cryostats and most of the quadrupoles exceeded their nominal excitation, i.e. 12,000 A, after no more than two training quenches. During this series fabrication, the quality of the magnets and cold masses was thoroughly monitored by means of warm magnetic field measurements, of strict geometrical checking, and of various electrical verifications. A number of modifications were introduced in order to improve the magnet fabrication, mainly correction of the coil geometry for achieving the specified field quality and measures for avoiding coil insulation problems. Further changes concern the electrical connectivity and insulation of instrumentation, and of the corrector magnets inside the cold masses. The contact resistances for the bus-bar connections to the quench protection diode...

  11. Gentrification and community fabric in Chicago.

    Science.gov (United States)

    Betancur, John

    2011-01-01

    Critical authors of gentrification point to its deleterious impacts on displaced residents. Research on the nature or actual forms of impacts has not advanced much, however. This paper attempts to specify impacts on low-income racial/ethnic groups (Latinos in particular) in five Chicago neighbourhoods, with a particular focus on neighbourhood-based fabrics of support and advancement. Limited in their mobility and exchange value resources, lower-income groups depend on such fabrics far more than do the higher income. In fact, they have fewer choices and are most vulnerable to place-based shifts. The case seems especially challenging for minorities who, like European immigrants before them, depend largely on place-based platforms/social fabrics but, unlike them, confront the added factors of race and urban restructuring.

  12. Design, fabrication and installation of irradiation facilities

    International Nuclear Information System (INIS)

    Kim, Yong Sung; Lee, C. Y.; Kim, J. Y.; Chi, D. Y.; Kim, S. H.; Ahn, S. H.; Kim, S. J.; Kim, J. K.; Yang, S. H.; Yang, S. Y.; Kim, H. R.; Kim, H.; Lee, K. H.; Lee, B. C.; Park, C.; Lee, C. T.; Cho, S. W.; Kwak, K. K.; Suk, H. C.

    1997-07-01

    The principle contents of this project are to design, fabricate and install the steady-state fuel test loop and non-instrumented capsule in HANARO for nuclear technology development. This project will be completed in 1999, the basic and detail design, safety analysis, and procurement of main equipment for fuel test loop have been performed and also the piping in gallery and the support for IPS piping in reactor pool have been installed in 1994. In the area of non-instrumented capsule for material irradiation test, the fabrication of capsule has been completed. Procurement, fabrication and installation of the fuel test loop will be implemented continuously till 1999. As besides, as these irradiation facilities will be installed in HANARO, review of safety concern, discussion with KINS for licensing and safety analysis report has been submitted to KINS to get a license and review of HANARO interface have been performed respectively. (author). 39 refs., 28 tabs., 21 figs

  13. Fabrication of CFRP/Al Active Laminates

    Science.gov (United States)

    Asanuma, Hiroshi; Haga, Osamu; Ohira, Junichiro; Takemoto, Kyosuke; Imori, Masataka

    This paper describes fabrication and evaluation of the active laminate. It was made by hot-pressing of an aluminum plate as a high CTE material, a unidirectional CFRP prepreg as a low CTE material and an electric resistance heater, a KFRP prepreg as a low CTE material and an insulator between them, and copper foils as electrodes. In this study, fabricating conditions and performances such as curvature change and output force were examined. Under optimized fabricating conditions, it became clear that 1) the curvature of the active laminate linearly changes as a function of temperature, between room temperature and its hot pressing temperature without hysteresis by electric resistance heating of carbon fiber in the CFRP layer and cooling, and 2) the output force against a fixed punch almost linearly increases with increasing temperature during heating from 313K up to around the glass transition temperature of the epoxy matrix.

  14. Scanning probe lithography for nanoimprinting mould fabrication

    International Nuclear Information System (INIS)

    Luo Gang; Xie Guoyong; Zhang Yongyi; Zhang Guoming; Zhang Yingying; Carlberg, Patrick; Zhu Tao; Liu Zhongfan

    2006-01-01

    We propose a rational fabrication method for nanoimprinting moulds by scanning probe lithography. By wet chemical etching, different kinds of moulds are realized on Si(110) and Si(100) surfaces according to the Si crystalline orientation. The structures have line widths of about 200 nm with a high aspect ratio. By reactive ion etching, moulds with patterns free from the limitation of Si crystalline orientation are also obtained. With closed-loop scan control of a scanning probe microscope, the length of patterned lines is more than 100 μm by integrating several steps of patterning. The fabrication process is optimized in order to produce a mould pattern with a line width about 10 nm. The structures on the mould are further duplicated into PMMA resists through the nanoimprinting process. The method of combining scanning probe lithography with wet chemical etching or reactive ion etching (RIE) provides a resistless route for the fabrication of nanoimprinting moulds

  15. Fabrication of tungsten wire reinforced nickel-base alloy composites

    Science.gov (United States)

    Brentnall, W. D.; Toth, I. J.

    1974-01-01

    Fabrication methods for tungsten fiber reinforced nickel-base superalloy composites were investigated. Three matrix alloys in pre-alloyed powder or rolled sheet form were evaluated in terms of fabricability into composite monotape and multi-ply forms. The utility of monotapes for fabricating more complex shapes was demonstrated. Preliminary 1093C (2000F) stress rupture tests indicated that efficient utilization of fiber strength was achieved in composites fabricated by diffusion bonding processes. The fabrication of thermal fatigue specimens is also described.

  16. Fabrication of submicron proteinaceous structures by direct laser writing

    Energy Technology Data Exchange (ETDEWEB)

    Serien, Daniela [Center for International Research on Integrative Biomedical Systems, Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, 153-8505 Tokyo (Japan); Takeuchi, Shoji, E-mail: takeuchi@iis.u-tokyo.ac.jp [Center for International Research on Integrative Biomedical Systems, Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, 153-8505 Tokyo (Japan); ERATO Takeuchi Biohybrid Innovation Project, Japan Science and Technology Agency, 4-6-1 Komaba, Meguro-ku, 153-8505 Tokyo (Japan)

    2015-07-06

    In this paper, we provide a characterization of truly free-standing proteinaceous structures with submicron feature sizes depending on the fabrication conditions by model-based analysis. Protein cross-linking of bovine serum albumin is performed by direct laser writing and two-photon excitation of flavin adenine dinucleotide. We analyze the obtainable fabrication resolution and required threshold energy for polymerization. The applied polymerization model allows prediction of fabrication conditions and resulting fabrication size, alleviating the application of proteinaceous structure fabrication.

  17. One-step fabrication of multifunctional micromotors

    Science.gov (United States)

    Gao, Wenlong; Liu, Mei; Liu, Limei; Zhang, Hui; Dong, Bin; Li, Christopher Y.

    2015-08-01

    Although artificial micromotors have undergone tremendous progress in recent years, their fabrication normally requires complex steps or expensive equipment. In this paper, we report a facile one-step method based on an emulsion solvent evaporation process to fabricate multifunctional micromotors. By simultaneously incorporating various components into an oil-in-water droplet, upon emulsification and solidification, a sphere-shaped, asymmetric, and multifunctional micromotor is formed. Some of the attractive functions of this model micromotor include autonomous movement in high ionic strength solution, remote control, enzymatic disassembly and sustained release. This one-step, versatile fabrication method can be easily scaled up and therefore may have great potential in mass production of multifunctional micromotors for a wide range of practical applications.Although artificial micromotors have undergone tremendous progress in recent years, their fabrication normally requires complex steps or expensive equipment. In this paper, we report a facile one-step method based on an emulsion solvent evaporation process to fabricate multifunctional micromotors. By simultaneously incorporating various components into an oil-in-water droplet, upon emulsification and solidification, a sphere-shaped, asymmetric, and multifunctional micromotor is formed. Some of the attractive functions of this model micromotor include autonomous movement in high ionic strength solution, remote control, enzymatic disassembly and sustained release. This one-step, versatile fabrication method can be easily scaled up and therefore may have great potential in mass production of multifunctional micromotors for a wide range of practical applications. Electronic supplementary information (ESI) available: Videos S1-S4 and Fig. S1-S3. See DOI: 10.1039/c5nr03574k

  18. Nuclear fuel elements design, fabrication and performance

    CERN Document Server

    Frost, Brian R T

    1982-01-01

    Nuclear Fuel Elements: Design, Fabrication and Performance is concerned with the design, fabrication, and performance of nuclear fuel elements, with emphasis on fast reactor fuel elements. Topics range from fuel types and the irradiation behavior of fuels to cladding and duct materials, fuel element design and modeling, fuel element performance testing and qualification, and the performance of water reactor fuels. Fast reactor fuel elements, research and test reactor fuel elements, and unconventional fuel elements are also covered. This volume consists of 12 chapters and begins with an overvie

  19. Nanowire and microwire fabrication technique and product

    Energy Technology Data Exchange (ETDEWEB)

    Sumant, Anirudha V.; Zach, Michael; Marten, Alan David

    2018-02-27

    A continuous or semi-continuous process for fabricating nanowires or microwires makes use of the substantially planar template that may be moved through electrochemical solution to grow nanowires or microwires on exposed conductive edges on the surface of that template. The planar template allows fabrication of the template using standard equipment and techniques. Adhesive transfer may be used to remove the wires from the template and in one embodiment to draw a continuous wire from the template to be wound around the drum.

  20. Deformation and Fabric in Compacted Clay Soils

    Science.gov (United States)

    Wensrich, C. M.; Pineda, J.; Luzin, V.; Suwal, L.; Kisi, E. H.; Allameh-Haery, H.

    2018-05-01

    Hydromechanical anisotropy of clay soils in response to deformation or deposition history is related to the micromechanics of platelike clay particles and their orientations. In this article, we examine the relationship between microstructure, deformation, and moisture content in kaolin clay using a technique based on neutron scattering. This technique allows for the direct characterization of microstructure within representative samples using traditional measures such as orientation density and soil fabric tensor. From this information, evidence for a simple relationship between components of the deviatoric strain tensor and the deviatoric fabric tensor emerge. This relationship may provide a physical basis for future anisotropic constitutive models based on the micromechanics of these materials.

  1. Design of the MOX fuel fabrication facility

    International Nuclear Information System (INIS)

    Johnson, J.V.; Brabazon, E.J.

    2001-01-01

    A consortium of Duke Engineering and Services, Inc., COGEMA, Inc. and Stone and Webster (DCS) are designing a mixed oxide fuel fabrication facility (MFFF) for the U.S. Department of Energy (DOE) to convert surplus plutonium to mixed oxide (MOX) fuel to be irradiated in commercial nuclear power plants based on the proven European technology of COGEMA and BELGONUCLEAIRE. This paper describes the MFFF processes, and how the proven MOX fuel fabrication technology is being adapted as required to comply with U.S. requirements. (author)

  2. A new RFQ linac fabrication technique

    International Nuclear Information System (INIS)

    Schrage, D.; Roybal, P.; Young, L.; Clark, W.; DePaula, R.; Martinez, F.

    1994-01-01

    The use of hydrogen furnace brazing has been applied as a joining technology to the fabrication of a Radio-Frequency-Quadrupole (RFQ) linac for the Los Alamos Accelerator Performance Demonstration Facility (APDF). The design concept provides a monolithic cavity with no longitudinal rf, vacuum, or mechanical joints. A 530 MHz, 0.46 meter long engineering model RFQ has been fabricated and tested at the Los Alamos National Laboratory as a technical demonstration of this concept. It is planned that two funneled RFQ's for the APDF (7 MeV, 350 MHz, 100 mAmp CW, each eight meters in length) will be manufactured by this method

  3. Antenna Fabrication using 3D printing techniques

    OpenAIRE

    Elibiary, Ahmed

    2017-01-01

    This thesis focuses to explore the use of additive manufacturing (AM) techniques to fabricate various radio frequency (RF) devices. 3D printing, a term used for AM has evolved to the point where it is being introduced into various industries, one of these, discussed in this thesis is the fabrication of antennas for the aim to reduce manufacturing costs and time.\\ud The aim is to investigate the performance and reliability of a modified low-cost 3D printer to print plastic and metal simultaneo...

  4. Design of the MOX fuel fabrication facility

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, J.V. [MFFF Technical Manager, U.S. dept. of Energy, Washington, DC (United States); Brabazon, E.J. [MFFF Engineering Manager, Duke Cogema Stone and Webster, Charlotte, NC (United States)

    2001-07-01

    A consortium of Duke Engineering and Services, Inc., COGEMA, Inc. and Stone and Webster (DCS) are designing a mixed oxide fuel fabrication facility (MFFF) for the U.S. Department of Energy (DOE) to convert surplus plutonium to mixed oxide (MOX) fuel to be irradiated in commercial nuclear power plants based on the proven European technology of COGEMA and BELGONUCLEAIRE. This paper describes the MFFF processes, and how the proven MOX fuel fabrication technology is being adapted as required to comply with U.S. requirements. (author)

  5. Lithography requirements in complex VLSI device fabrication

    International Nuclear Information System (INIS)

    Wilson, A.D.

    1985-01-01

    Fabrication of complex very large scale integration (VLSI) circuits requires continual advances in lithography to satisfy: decreasing minimum linewidths, larger chip sizes, tighter linewidth and overlay control, increasing topography to linewidth ratios, higher yield demands, increased throughput, harsher device processing, lower lithography cost, and a larger part number set with quick turn-around time. Where optical, electron beam, x-ray, and ion beam lithography can be applied to judiciously satisfy the complex VLSI circuit fabrication requirements is discussed and those areas that are in need of major further advances are addressed. Emphasis will be placed on advanced electron beam and storage ring x-ray lithography

  6. Fabrication of longitudinally arbitrary shaped fiber tapers

    Science.gov (United States)

    Nold, J.; Plötner, M.; Böhme, S.; Sattler, B.; deVries, O.; Schreiber, T.; Eberhardt, R.; Tünnermann, A.

    2018-02-01

    We present our current results on the fabrication of arbitrary shaped fiber tapers on our tapering rig using a CO2-laser as heat source. Single mode excitation of multimode fibers as well as changing the fiber geometry in an LPG-like fashion is presented. It is shown that this setup allows for reproducible fabrication of single-mode excitation tapers to extract the fundamental mode (M2 < 1.1) from a 30 μm core having an NA of 0.09.

  7. High yield fabrication of fluorescent nanodiamonds

    Energy Technology Data Exchange (ETDEWEB)

    Boudou, Jean-Paul; Curmi, Patrick A [Structure and Activity of Normal and Pathological Biomolecules-INSERM/UEVE U829, Universite d' Evry-Val d' Essonne, Batiment Maupertuis, Rue du pere Andre Jarlan, F-91025 Evry (France); Jelezko, Fedor; Wrachtrup, Joerg; Balasubramanian, Gopalakrischnan; Reuter, Rolf [3.Physikalisches Institut, University of Stuttgart, Pfaffenwaldring 57, D-70550 Stuttgart (Germany); Aubert, Pascal [Nanometric Media Laboratory, Universite d' Evry-Val d' Essonne, Batiment Maupertuis, Rue du pere Andre Jarlan, F-91025 Evry (France); Sennour, Mohamed; Thorel, Alain [Centre des Materiaux, Mines Paris, ParisTech, BP 87, F-91000 Evry (France); Gaffet, Eric [Nanomaterials Research Group-UMR 5060, CNRS, UTBM, Site de Sevenans, F-90010 Belfort (France)], E-mail: jpb.cnrs@free.fr, E-mail: pcurmi@univ-evry.fr, E-mail: f.jelezko@physik.uni-stuttgart.de

    2009-06-10

    A new fabrication method to produce homogeneously fluorescent nanodiamonds with high yields is described. The powder obtained by high energy ball milling of fluorescent high pressure, high temperature diamond microcrystals was converted in a pure concentrated aqueous colloidal dispersion of highly crystalline ultrasmall nanoparticles with a mean size less than or equal to 10 nm. The whole fabrication yield of colloidal quasi-spherical nanodiamonds was several orders of magnitude higher than those previously reported starting from microdiamonds. The results open up avenues for the industrial cost-effective production of fluorescent nanodiamonds with well-controlled properties.

  8. Fabrication of FFTF fuel pin wire wrap

    International Nuclear Information System (INIS)

    Epperson, E.M.

    1980-06-01

    Lateral spacing between FFTF fuel pins is required to provide a passageway for the sodium coolant to flow over each pin to remove heat generated by the fission process. This spacing is provided by wrapping each fuel pin with type 316 stainless steel wire. This wire has a 1.435mm (0.0565 in.) to 1.448mm (0.0570 in.) diameter, contains 17 +- 2% cold work and was fabricated and tested to exacting RDT Standards. About 500 kg (1100 lbs) or 39 Km (24 miles) of fuel pin wrap wire is used in each core loading. Fabrication procedures and quality assurance tests are described

  9. High yield fabrication of fluorescent nanodiamonds

    International Nuclear Information System (INIS)

    Boudou, Jean-Paul; Curmi, Patrick A; Jelezko, Fedor; Wrachtrup, Joerg; Balasubramanian, Gopalakrischnan; Reuter, Rolf; Aubert, Pascal; Sennour, Mohamed; Thorel, Alain; Gaffet, Eric

    2009-01-01

    A new fabrication method to produce homogeneously fluorescent nanodiamonds with high yields is described. The powder obtained by high energy ball milling of fluorescent high pressure, high temperature diamond microcrystals was converted in a pure concentrated aqueous colloidal dispersion of highly crystalline ultrasmall nanoparticles with a mean size less than or equal to 10 nm. The whole fabrication yield of colloidal quasi-spherical nanodiamonds was several orders of magnitude higher than those previously reported starting from microdiamonds. The results open up avenues for the industrial cost-effective production of fluorescent nanodiamonds with well-controlled properties.

  10. Simple process to fabricate nitride alloy powders

    International Nuclear Information System (INIS)

    Yang, Jae Ho; Kim, Dong-Joo; Kim, Keon Sik; Rhee, Young Woo; Oh, Jang-Soo; Kim, Jong Hun; Koo, Yang Hyun

    2013-01-01

    Uranium mono-nitride (UN) is considered as a fuel material [1] for accident-tolerant fuel to compensate for the loss of fissile fuel material caused by adopting a thickened cladding such as SiC composites. Uranium nitride powders can be fabricated by a carbothermic reduction of the oxide powders, or the nitriding of metal uranium. Among them, a direct nitriding process of metal is more attractive because it has advantages in the mass production of high-purity powders and the reusing of expensive 15 N 2 gas. However, since metal uranium is usually fabricated in the form of bulk ingots, it has a drawback in the fabrication of fine powders. The Korea Atomic Energy Research Institute (KAERI) has a centrifugal atomisation technique to fabricate uranium and uranium alloy powders. In this study, a simple reaction method was tested to fabricate nitride fuel powders directly from uranium metal alloy powders. Spherical powder and flake of uranium metal alloys were fabricated using a centrifugal atomisation method. The nitride powders were obtained by thermal treating the metal particles under nitrogen containing gas. The phase and morphology evolutions of powders were investigated during the nitriding process. A phase analysis of nitride powders was also part of the present work. KAERI has developed the centrifugal rotating disk atomisation process to fabricate spherical uranium metal alloy powders which are used as advanced fuel materials for research reactors. The rotating disk atomisation system involves the tasks of melting, atomising, and collecting. A nozzle in the bottom of melting crucible introduces melt at the center of a spinning disk. The centrifugal force carries the melt to the edge of the disk and throws the melt off the edge. Size and shape of droplets can be controlled by changing the nozzle size, the disk diameter and disk speed independently or simultaneously. By adjusting the processing parameters of the centrifugal atomiser, a spherical and flake shape

  11. A facile fabrication of multifunctional knit polyester fabric based on chitosan and polyaniline polymer nanocomposite

    Science.gov (United States)

    Tang, Xiaoning; Tian, Mingwei; Qu, Lijun; Zhu, Shifeng; Guo, Xiaoqing; Han, Guangting; Sun, Kaikai; Hu, Xili; Wang, Yujiao; Xu, Xiaoqi

    2014-10-01

    Knit polyester fabric was successively modified and decorated with chitosan layer and polyaniline polymer nanocomposite layer in this paper. The fabric was firstly treated with chitosan to form a stable layer through the pad-dry-cure process, and then the polyaniline polymer nanocomposite layer was established on the outer layer by in situ chemical polymerization method using ammonium persulfate as oxidant and chlorhydric acid as dopant. The surface morphology of coated fabric was characterized by scanning electron microscopy (SEM), and the co-existence of chitosan layer and granular polyaniline polymer nanocomposite was confirmed and well dispersed on the fabric surface. The resultant fabric was endowed with remarkable electrical conductivity properties and efficient water-repellent capability, which also have been found stable after water laundering. In addition, the photocatalytic decomposition activity for reactive red dye was observed when the multifunctional knit polyester fabric was exposed to the illumination of ultraviolet lamp. These results indicated that chitosan and polyaniline polymer nanocomposite could form ideal multifunctional coatings on the surface of knit polyester fabric.

  12. A review: fabrication of porous polyurethane scaffolds.

    Science.gov (United States)

    Janik, H; Marzec, M

    2015-03-01

    The aim of tissue engineering is the fabrication of three-dimensional scaffolds that can be used for the reconstruction and regeneration of damaged or deformed tissues and organs. A wide variety of techniques have been developed to create either fibrous or porous scaffolds from polymers, metals, composite materials and ceramics. However, the most promising materials are biodegradable polymers due to their comprehensive mechanical properties, ability to control the rate of degradation and similarities to natural tissue structures. Polyurethanes (PUs) are attractive candidates for scaffold fabrication, since they are biocompatible, and have excellent mechanical properties and mechanical flexibility. PU can be applied to various methods of porous scaffold fabrication, among which are solvent casting/particulate leaching, thermally induced phase separation, gas foaming, emulsion freeze-drying and melt moulding. Scaffold properties obtained by these techniques, including pore size, interconnectivity and total porosity, all depend on the thermal processing parameters, and the porogen agent and solvents used. In this review, various polyurethane systems for scaffolds are discussed, as well as methods of fabrication, including the latest developments, and their advantages and disadvantages. Copyright © 2014. Published by Elsevier B.V.

  13. Fabrication of Environmentally Biodegradable Lignin Nanoparticles

    NARCIS (Netherlands)

    Frangville, C.; Rutkevicius, M.; Richter, A.P.; Velev, O.D.; Stoyanov, S.D.; Paunov, V.N.

    2012-01-01

    We developed a method for the fabrication of novel biodegradable nanoparticles (NPs) from lignin which are apparently non-toxic for microalgae and yeast. We compare two alternative methods for the synthesis of lignin NPs which result in particles of very different stability upon change of pH. The

  14. Fabrication and characterization of a piezoelectric accelerometer

    DEFF Research Database (Denmark)

    Reus, Roger De; Gulløv, Jens; Scheeper, Patrick

    1999-01-01

    Zinc oxide based piezoelectric accelerometers were fabricated by bulk micromachining. A high yield was obtained in a relatively simple process sequence. For two electrode configurations a direction selectivity better than 100 was obtained for acceleration in the vertical direction and a selectivity...

  15. Fabrication of universal esthetic lingual button

    Directory of Open Access Journals (Sweden)

    Ramkishore Ratre

    2015-01-01

    Full Text Available Lingual buttons are used in many instances for labial, as well as lingual orthodontics. A simple method is demonstrated to fabricate the lingual buttons chair side. The buttons made are aesthetic as they are made from composite resin and can be successfully bonded anywhere on all tooth surfaces.

  16. 1-D nanochannels fabricated in polyimide

    NARCIS (Netherlands)

    Eijkel, Jan C.T.; Bomer, Johan G.; Tas, Niels Roelof; van den Berg, Albert

    2004-01-01

    A simple method using spin-deposition and sacrificial layer etching is used to fabricate all-polyimide nanochannels (100 and 500 nm channel height). Channels are characterized using spontaneous capillary filling with water, ethanol and isopropanol, and with electroosmotic flow. The channels can be

  17. Tunable metamaterials fabricated by fiber drawing

    DEFF Research Database (Denmark)

    Fleming, Simon; Stefani, Alessio; Tang, Xiaoli

    2017-01-01

    We demonstrate a practical scalable approach to the fabrication of tunable metamaterials. Designed for terahertz (THz) wavelengths, the metamaterial is comprised of polyurethane filled with an array of indium wires using the well-established fiber drawing technique. Modification of the dimensions...

  18. Woven fabric composites: Can we peel it?

    NARCIS (Netherlands)

    Sacchetti, Francisco; Grouve, Wouter Johannes Bernardus; Warnet, Laurent; Villegas, I. Fernandez

    2016-01-01

    The present work focuses on the applicability of the mandrel peel test to quantify the fracture toughness of woven fabric Carbon/PEEK composites. For this purpose, the mandrel peel test was compared to the standardized DCB test. Unstable crack propagation (stick-slip) was observed in both testing

  19. Computation, architectural design and fabrication logic

    DEFF Research Database (Denmark)

    Larsen, Niels Martin

    2016-01-01

    Digital fabrication and digital form generation can change the way different professions interact in relation to the development and construction of architecture. The technologies can provide a more integrated design process and expand the architectural vocabulary. At Aarhus School of Architectur...

  20. Chilean fuel elements fabrication progress report

    International Nuclear Information System (INIS)

    Baeza, J.; Contreras, H.; Chavez, J.; Klein, J.; Mansilla, R.; Marin, J.; Medina, R.

    1993-01-01

    Due to HEU-LEU core conversion necessity for the Chilean MTR reactors, the Fuel Elements Plant is being implemented to LEU nuclear fuel elements fabrication. A glove box line for powder-compact processing designed at CCHEN, which supposed to operate under an automatic control system, is at present under initial tests. Results of first natural uranium fuel plates manufacturing runs are shown

  1. Fabrication of internally instrumented reactor fuel rods

    International Nuclear Information System (INIS)

    Schmutz, J.D.; Meservey, R.H.

    1975-01-01

    Procedures are outlined for fabricating internally instrumented reactor fuel rods while maintaining the original quality assurance level of the rods. Instrumented fuel rods described contain fuel centerline thermocouples, ultrasonic thermometers, and pressure tubes for internal rod gas pressure measurements. Descriptions of the thermocouples and ultrasonic thermometers are also contained

  2. Layerless fabrication with continuous liquid interface production.

    Science.gov (United States)

    Janusziewicz, Rima; Tumbleston, John R; Quintanilla, Adam L; Mecham, Sue J; DeSimone, Joseph M

    2016-10-18

    Despite the increasing popularity of 3D printing, also known as additive manufacturing (AM), the technique has not developed beyond the realm of rapid prototyping. This confinement of the field can be attributed to the inherent flaws of layer-by-layer printing and, in particular, anisotropic mechanical properties that depend on print direction, visible by the staircasing surface finish effect. Continuous liquid interface production (CLIP) is an alternative approach to AM that capitalizes on the fundamental principle of oxygen-inhibited photopolymerization to generate a continual liquid interface of uncured resin between the growing part and the exposure window. This interface eliminates the necessity of an iterative layer-by-layer process, allowing for continuous production. Herein we report the advantages of continuous production, specifically the fabrication of layerless parts. These advantages enable the fabrication of large overhangs without the use of supports, reduction of the staircasing effect without compromising fabrication time, and isotropic mechanical properties. Combined, these advantages result in multiple indicators of layerless and monolithic fabrication using CLIP technology.

  3. Fabrication of a New Electrostatic Linear Actuator

    Science.gov (United States)

    Matsunaga, Takashi; Kondoh, Kazuya; Kumagae, Michihiro; Kawata, Hiroaki; Yasuda, Masaaki; Murata, Kenji; Yoshitake, Masaaki

    2000-12-01

    We propose a new electrostatic linear actuator with a large stroke and a new process for fabricating the actuator. A moving slider with many teeth on both sides is suspended above lower electrodes on a substrate by two bearings. A photoresist is used as a sacrificial layer. Both the slider and the bearings are fabricated by Ni electroplating. The bearings are fabricated by the self-alignment technique. Bearings with 0.6 μm clearance can be easily fabricated. All processes are performed at low temperatures up to 110°C. It is confirmed that the slider can be moved mechanically, and also can be moved by about 10 μm when a voltage pulse of 50 V is applied between the slider and the lower electrodes when the slider is upside down. However, the slider cannot move continuously because of friction. We also calculate the electrostatic force acting on one slider tooth. The simulation result shows that the reduction of the electrostatic force to the vertical direction is very important for mechanical movement of the actuator.

  4. Nuclear fuel conversion and fabrication chemistry

    International Nuclear Information System (INIS)

    Lerch, R.E.; Norman, R.E.

    1984-01-01

    Following irradiation and reprocessing of nuclear fuel, two operations are performed to prepare the fuel for subsequent reuse as fuel: fuel conversion, and fuel fabrication. These operations complete the classical nuclear fuel cycle. Fuel conversion involves generating a solid form suitable for fabrication into nuclear fuel. For plutonium based fuels, either a pure PuO 2 material or a mixed PuO 2 -UO 2 fuel material is generated. Several methods are available for preparation of the pure PuO 2 including: oxalate or peroxide precipitation; or direct denitration. Once the pure PuO 2 is formed, it is fabricated into fuel by mechanically blending it with ceramic grade UO 2 . The UO 2 can be prepared by several methods which include direct denitration. ADU precipitation, AUC precipitation, and peroxide precipitation. Alternatively, UO 2 -PuO 2 can be generated directly using coprecipitation, direct co-denitration, or gel sphere processes. In coprecipitation, uranium and plutonium are either precipitated as ammonium diuranate and plutonium hydroxide or as a mixture of ammonium uranyl-plutonyl carbonate, filtered and dried. In direct thermal denitration, solutions of uranium and plutonium nitrates are heated causing concentration and, subsequently, direct denitration. In gel sphere conversion, solutions of uranium and plutonium nitrate containing additives are formed into spherical droplets, gelled, washed and dried. Refabrication of these UO 3 -PuO 2 starting materials is accomplished by calcination-reduction to UO 2 -PuO 2 followed by pellet fabrication. (orig.)

  5. Sintering furnace for remote fuel fabrication

    International Nuclear Information System (INIS)

    Bowen, W.W.

    1978-10-01

    Component testing and evaluation of a chemical vapor deposition Re/W muffle has been initiated. Hydrogen permeation testing and thermal cycling behavior will be evaluated. Fabrication of prototype 10-12 Kg furnace is scheduled for completion late in 1979, at which time testing of the system will be initiated

  6. Text Fabric: What, How, and Why

    NARCIS (Netherlands)

    Erwich, C.M.; Kingham, Cody

    Text-Fabric (TF) is a promising new framework for the Eep Talstra Center for Bible and Computer corpus plus (linguistic) annotations. TF is a Python 3.x software package that provides scientific, accessible and reproducible ways of processing Biblical Hebrew text data. It also allows sharing the

  7. Flexible Thermoelectric Generators on Silicon Fabric

    KAUST Repository

    Sevilla, Galo T.

    2012-11-01

    In this work, the development of a Thermoelectric Generator on Flexible Silicon Fabric is explored to extend silicon electronics for flexible platforms. Low cost, easily deployable plastic based flexible electronics are of great interest for smart textile, wearable electronics and many other exciting applications. However, low thermal budget processing and fundamentally limited electron mobility hinders its potential to be competitive with well established and highly developed silicon technology. The use of silicon in flexible electronics involve expensive and abrasive materials and processes. In this work, high performance flexible thermoelectric energy harvesters are demonstrated from low cost bulk silicon (100) wafers. The fabrication of the micro- harvesters was done using existing silicon processes on silicon (100) and then peeled them off from the original substrate leaving it for reuse. Peeled off silicon has 3.6% thickness of bulk silicon reducing the thermal loss significantly and generating nearly 30% more output power than unpeeled harvesters. The demonstrated generic batch processing shows a pragmatic way of peeling off a whole silicon circuitry after conventional fabrication on bulk silicon wafers for extremely deformable high performance integrated electronics. In summary, by using a novel, low cost process, this work has successfully integrated existing and highly developed fabrication techniques to introduce a flexible energy harvester for sustainable applications.

  8. Elastocapillary fabrication of three-dimensional microstructures

    NARCIS (Netherlands)

    van Honschoten, J.W.; Berenschot, Johan W.; Ondarcuhu, T.; Sanders, Remco G.P.; Sundaram, J.; Elwenspoek, Michael Curt; Tas, Niels Roelof

    2010-01-01

    We describe the fabrication of three-dimensional microstructures by means of capillary forces. Using an origami-like technique, planar silicon nitride structures of various geometries are folded to produce three-dimensional objects of 50–100 m. Capillarity is a particularly effective mechanism since

  9. Fabrication of high efficacy selective solar absorbers

    CSIR Research Space (South Africa)

    Tile, N

    2012-03-01

    Full Text Available High efficiency tandem selective solar absorber materials of carbon in nickel oxide (C-NiO) composite were fabricated on an aluminium substrate using a simple and cost effective sol-gel process. The process involved preparation of carbon and nickel...

  10. Review of qualifications for fuel assembly fabrication

    International Nuclear Information System (INIS)

    Slabu, Dan; Zemek, Martin; Hellwig, Christian

    2013-01-01

    The required quality of nuclear fuel in industrial production can only be assured by applying processes in fabrication and inspection, which are well mastered and have been proven by an appropriate qualification. The present contribution shows the understanding and experiences of Axpo with respect to qualifications in the frame of nuclear fuel manufacturing and reflects some related expectations of the operator. (orig.)

  11. Internal Backpressure for Terabit Switch Fabrics

    DEFF Research Database (Denmark)

    Fagertun, Anna Manolova; Ruepp, Sarah Renée; Rytlig, Andreas

    2012-01-01

    This paper proposes and analyzes the efficiency of novel backpressure schemes for Terabit switch fabrics. The proposed schemes aim at buffer optimization under uniform traffic distribution with Bernoulli packet arrival process. Results show that a reduction of the needed maximum buffer capacity w...... with up to 47% can be achieved with switch-internal backpressure mechanisms at the expense of a small control overhead....

  12. Fuel fabrication and post-irradiation examination

    Energy Technology Data Exchange (ETDEWEB)

    Venter, P J; Aspeling, J C [Atomic Energy Corporation of South Africa Ltd., Pretoria (South Africa)

    1990-06-01

    This paper provides an overview of the A/c's Bevan and Eldopar facilities for the fabrication of nuclear fuel. It also describes the sophisticated Hot Cell Complex, which is capable of accommodating pressurised water reactor fuel and various other irradiated samples. Some interesting problems and their solutions are discussed. (author)

  13. Fuel fabrication and post-irradiation examination

    International Nuclear Information System (INIS)

    Venter, P.J.; Aspeling, J.C.

    1990-01-01

    This paper provides an overview of the A/c's Bevan and Eldopar facilities for the fabrication of nuclear fuel. It also describes the sophisticated Hot Cell Complex, which is capable of accommodating pressurised water reactor fuel and various other irradiated samples. Some interesting problems and their solutions are discussed. (author)

  14. Micro and nano fabrication tools and processes

    CERN Document Server

    Gatzen, Hans H; Leuthold, Jürg

    2015-01-01

    For Microelectromechanical Systems (MEMS) and Nanoelectromechanical Systems (NEMS) production, each product requires a unique process technology. This book provides a comprehensive insight into the tools necessary for fabricating MEMS/NEMS and the process technologies applied. Besides, it describes enabling technologies which are necessary for a successful production, i.e., wafer planarization and bonding, as well as contamination control.

  15. Fabrication of micro metallic valve and pump

    Science.gov (United States)

    Yang, Ming; Kabasawa, Yasunari; Ito, Kuniyoshi

    2010-03-01

    Fabrication of micro devices by using micro metal forming was proposed by the authors. We developed a desktop servo-press machine with precise tooling system. Precise press forming processes including micro forging and micro joining has been carried out in a progressive die. In this study, micro metallic valve and pump were fabricated by using the precise press forming. The components are made of sheet metals, and assembled in to a unit in the progressive die. A micro check-valve with a diameter of 3mm and a length of 3.2mm was fabricated, and the property of flow resistance was evaluated. The results show that the check valve has high property of leakage proof. Since the valve is a unit parts with dimensions of several millimeters, it has advantage to be adapted to various pump design. Here, two kinds of micro pumps with the check-valves were fabricated. One is diaphragm pump actuated by vibration of the diaphragm, and another is tube-shaped pump actuated by resonation. The flow quantities of the pumps were evaluated and the results show that both of the pumps have high pumping performance.

  16. Numerical Tools for Composite Woven Fabric Preforming

    Directory of Open Access Journals (Sweden)

    Abel Cherouat

    2013-01-01

    Full Text Available An important step in the manufacturing processes of thin composite components is the layingup of the reinforcement onto the mould surface. The prediction of the angular distortion of the reinforcement during draping and the changes in fibre orientation are essential for the understanding of the manufacture process and the evaluation of the mechanical properties of the composite structures. This paper presents an optimization-based method for the simulation of the forming processes of woven fabric reinforced composites. Two different approaches are proposed for the simulation of the draping of woven fabric onto complex geometries: geometrical and mechanical approaches. The geometrical approach is based on a fishnet model. It is well adapted to predimensioning fabrics and to give a suitable quantification of the resulting flat patterns. The mechanical approach is based on a mesostructural model. It allows us to take into account the mechanical properties of fibres and resin and the various dominating mode of deformation of woven fabrics during the forming process. Some numerical simulations of the forming process are proposed and compared with the experimental results in order to demonstrate the efficiency of our approaches.

  17. Dissolvable microneedle fabrication using piezoelectric dispensing technology.

    Science.gov (United States)

    Allen, Evin A; O'Mahony, Conor; Cronin, Michael; O'Mahony, Thomas; Moore, Anne C; Crean, Abina M

    2016-03-16

    Dissolvable microneedle (DMN) patches are novel dosage forms for the percutaneous delivery of vaccines. DMN are routinely fabricated by dispensing liquid formulations into microneedle-shaped moulds. The liquid formulation within the mould is then dried to create dissolvable vaccine-loaded microneedles. The precision of the dispensing process is critical to the control of formulation volume loaded into each dissolvable microneedle structure. The dispensing process employed must maintain vaccine integrity. Wetting of mould surfaces by the dispensed formulation is also an important consideration for the fabrication of sharp-tipped DMN. Sharp-tipped DMN are essential for ease of percutaneous administration. In this paper, we demonstrate the ability of a piezoelectric dispensing system to dispense picolitre formulation volumes into PDMS moulds enabling the fabrication of bilayer DMN. The influence of formulation components (trehalose and polyvinyl alcohol (PVA) content) and piezoelectric actuation parameters (voltage, frequency and back pressure) on drop formation is described. The biological integrity of a seasonal influenza vaccine following dispensing was investigated and maintained voltage settings of 30 V but undermined at higher settings, 50 and 80 V. The results demonstrate the capability of piezoelectric dispensing technology to precisely fabricate bilayer DMN. They also highlight the importance of identifying formulation and actuation parameters to ensure controlled droplet formulation and vaccine stabilisation. Copyright © 2015 Elsevier B.V. All rights reserved.

  18. Sandia National Laboratories: Fabrication, Testing and Validation

    Science.gov (United States)

    digital and analog elements. * Cadence Process-Design Kit. Structured ASIC Sandia National Laboratories demonstrate complex multilevel devices such as micro-mass-analysis systems up to 25 microns thick and novel possible to fabricate a wide very large variety of useful devices. Micro-Mass-Analysis Systems Applications

  19. FABRICATION AND CHARACTERIZATION OF FAST IGNITION TARGETS

    International Nuclear Information System (INIS)

    HILL, D.W; CASTILLO, E; CHEN, K.C; GRANT, S.E; GREENWOOD, A.L; KAAE, J.L; NIKROO, A; PAGUIO, S.P; SHEARER, C; SMITH, J.N Jr.; STEPHENS, R.B; STEINMAN, D.A; WALL, J.

    2003-09-01

    OAK-B135 Fast ignition is a novel scheme for achieving laser fusion. A class of these targets involves cone mounted CH shells. The authors have been fabricating such targets with shells with a wide variety of diameters and wall thicknesses for several years at General Atomics. In addition, recently such shells were needed for implosion experiments at Laboratory for Laser Energetics (LLE) that for the first time were required to be gas retentive. Fabrication of these targets requires producing appropriate cones and shells, assembling the targets, and characterization of the assembled targets. The cones are produced using micromachining and plating techniques. The shells are fabricated using the depolymerizable mandrel technique followed by micromachining a hole for the cone. The cone and the shell then need to be assembled properly for gas retention and precisely in order to position the cone tip at the desired position within the shell. Both are critical for the fast ignition experiments. The presence of the cone in the shell creates new challenges in characterization of the assembled targets. Finally, for targets requiring a gas fill, the cone-shell assembly needs to be tested for gas retention and proper strength at the glue joint. This paper presents an overview of the developmental efforts and technical issues addressed during the fabrication of fast ignition targets

  20. Porous Microfluidic Devices - Fabrication adn Applications

    NARCIS (Netherlands)

    de Jong, J.; Geerken, M.J.; Lammertink, Rob G.H.; Wessling, Matthias

    2007-01-01

    The major part of microfluidic devices nowadays consists of a dense material that defines the fluidic structure. A generic fabrication method enabling the production of completely porous micro devices with user-defined channel networks is developed. The channel walls can be used as a (selective)