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Sample records for advanced fabrication process

  1. Recent advancements in optical microstructure fabrication through glass molding process

    NASA Astrophysics Data System (ADS)

    Zhou, Tianfeng; Liu, Xiaohua; Liang, Zhiqiang; Liu, Yang; Xie, Jiaqing; Wang, Xibin

    2017-02-01

    Optical microstructures are increasingly applied in several fields, such as optical systems, precision measurement, and microfluid chips. Microstructures include microgrooves, microprisms, and microlenses. This paper presents an overview of optical microstructure fabrication through glass molding and highlights the applications of optical microstructures in mold fabrication and glass molding. The glass-mold interface friction and adhesion are also discussed. Moreover, the latest advancements in glass molding technologies are detailed, including new mold materials and their fabrication methods, viscoelastic constitutive modeling of glass, and microstructure molding process, as well as ultrasonic vibrationassisted molding technology.

  2. Advanced composites: Fabrication processes for selected resin matrix materials

    NASA Technical Reports Server (NTRS)

    Welhart, E. K.

    1976-01-01

    This design note is based on present state of the art for epoxy and polyimide matrix composite fabrication technology. Boron/epoxy and polyimide and graphite/epoxy and polyimide structural parts can be successfully fabricated. Fabrication cycles for polyimide matrix composites have been shortened to near epoxy cycle times. Nondestructive testing has proven useful in detecting defects and anomalies in composite structure elements. Fabrication methods and tooling materials are discussed along with the advantages and disadvantages of different tooling materials. Types of honeycomb core, material costs and fabrication methods are shown in table form for comparison. Fabrication limits based on tooling size, pressure capabilities and various machining operations are also discussed.

  3. Advanced materials and fabrication processes for supersonic cruise aircraft

    NASA Technical Reports Server (NTRS)

    Guess, M. K.; Kaneko, R. S.; Wald, G. G.

    1981-01-01

    Research and development programs to develop high-strength aluminum alloys and low-cost materials and fabrication techniques for titanium alloys are being conducted. Thirteen aluminum alloy compositions are being evaluated. A section of a production component was fabricated using superplastic forming and diffusion bonding (SPF/DB) and fabrication studies are being conducted on three low temperature forming beta titanium alloys. Cost studies indicate substantial structural cost reduction potentials resulting from the use of both aluminum alloys and low-cost titanium fabrication techniques. Lowest overall costs are indicated for a composite/aluminum or composite titanium structure.

  4. Fabrication of advanced electrochemical energy materials using sol-gel processing techniques

    NASA Technical Reports Server (NTRS)

    Chu, C. T.; Chu, Jay; Zheng, Haixing

    1995-01-01

    Advanced materials play an important role in electrochemical energy devices such as batteries, fuel cells, and electrochemical capacitors. They are being used as both electrodes and electrolytes. Sol-gel processing is a versatile solution technique used in fabrication of ceramic materials with tailored stoichiometry, microstructure, and properties. The application of sol-gel processing in the fabrication of advanced electrochemical energy materials will be presented. The potentials of sol-gel derived materials for electrochemical energy applications will be discussed along with some examples of successful applications. Sol-gel derived metal oxide electrode materials such as V2O5 cathodes have been demonstrated in solid-slate thin film batteries; solid electrolytes materials such as beta-alumina for advanced secondary batteries had been prepared by the sol-gel technique long time ago; and high surface area transition metal compounds for capacitive energy storage applications can also be synthesized with this method.

  5. Fabrication of advanced electrochemical energy materials using sol-gel processing techniques

    NASA Technical Reports Server (NTRS)

    Chu, C. T.; Chu, Jay; Zheng, Haixing

    1995-01-01

    Advanced materials play an important role in electrochemical energy devices such as batteries, fuel cells, and electrochemical capacitors. They are being used as both electrodes and electrolytes. Sol-gel processing is a versatile solution technique used in fabrication of ceramic materials with tailored stoichiometry, microstructure, and properties. The application of sol-gel processing in the fabrication of advanced electrochemical energy materials will be presented. The potentials of sol-gel derived materials for electrochemical energy applications will be discussed along with some examples of successful applications. Sol-gel derived metal oxide electrode materials such as V2O5 cathodes have been demonstrated in solid-slate thin film batteries; solid electrolytes materials such as beta-alumina for advanced secondary batteries had been prepared by the sol-gel technique long time ago; and high surface area transition metal compounds for capacitive energy storage applications can also be synthesized with this method.

  6. Advanced ACTPol Multichroic Polarimeter Array Fabrication Process for 150 mm Wafers

    NASA Technical Reports Server (NTRS)

    Duff, S. M.; Austermann, J.; Beall, J. A.; Becker, D.; Datta, R.; Gallardo, P. A.; Henderson, S. W.; Hilton, G. C.; Ho, S. P.; Hubmayr, J.; Koopman, B. J.; Li, D.; McMahon, J.; Nati, F.; Niemack, M. D.; Pappas, C. G.; Salatino, M.; Schmitt, B. L.; Simon, S. M.; Staggs, S. T.; Stevens, J. R.; Van Lanen, J.; Vavagiakis, E. M.; Ward, J. T.; Wollack, E. J.

    2016-01-01

    Advanced ACTPol (AdvACT) is a third-generation cosmic microwave background receiver to be deployed in 2016 on the Atacama Cosmology Telescope (ACT). Spanning five frequency bands from 25 to 280 GHz and having just over 5600 transition-edge sensor (TES) bolometers, this receiver will exhibit increased sensitivity and mapping speed compared to previously fielded ACT instruments. This paper presents the fabrication processes developed by NIST to scale to large arrays of feedhorn-coupled multichroic AlMn-based TES polarimeters on 150-mm diameter wafers. In addition to describing the streamlined fabrication process which enables high yields of densely packed detectors across larger wafers, we report the details of process improvements for sensor (AlMn) and insulator (SiN(sub x)) materials and microwave structures, and the resulting performance improvements.

  7. Advanced ACTPol Multichroic Polarimeter Array Fabrication Process for 150 mm Wafers

    NASA Astrophysics Data System (ADS)

    Duff, S. M.; Austermann, J.; Beall, J. A.; Becker, D.; Datta, R.; Gallardo, P. A.; Henderson, S. W.; Hilton, G. C.; Ho, S. P.; Hubmayr, J.; Koopman, B. J.; Li, D.; McMahon, J.; Nati, F.; Niemack, M. D.; Pappas, C. G.; Salatino, M.; Schmitt, B. L.; Simon, S. M.; Staggs, S. T.; Stevens, J. R.; Van Lanen, J.; Vavagiakis, E. M.; Ward, J. T.; Wollack, E. J.

    2016-08-01

    Advanced ACTPol (AdvACT) is a third-generation cosmic microwave background receiver to be deployed in 2016 on the Atacama Cosmology Telescope (ACT). Spanning five frequency bands from 25 to 280 GHz and having just over 5600 transition-edge sensor (TES) bolometers, this receiver will exhibit increased sensitivity and mapping speed compared to previously fielded ACT instruments. This paper presents the fabrication processes developed by NIST to scale to large arrays of feedhorn-coupled multichroic AlMn-based TES polarimeters on 150-mm diameter wafers. In addition to describing the streamlined fabrication process which enables high yields of densely packed detectors across larger wafers, we report the details of process improvements for sensor (AlMn) and insulator (SiN_x) materials and microwave structures, and the resulting performance improvements.

  8. Advanced ACTPol Multichroic Polarimeter Array Fabrication Process for 150 mm Wafers

    NASA Technical Reports Server (NTRS)

    Duff, S. M.; Austermann, J.; Beall, J. A.; Becker, D.; Datta, R.; Gallardo, P. A.; Henderson, S. W.; Hilton, G. C.; Ho, S. P.; Hubmayr, J.; hide

    2016-01-01

    Advanced ACTPol (AdvACT) is a third-generation cosmic microwave background receiver to be deployed in 2016 on the Atacama Cosmology Telescope (ACT). Spanning five frequency bands from 25 to 280 GHz and having just over 5600 transition-edge sensor (TES) bolometers, this receiver will exhibit increased sensitivity and mapping speed compared to previously fielded ACT instruments. This paper presents the fabrication processes developed by NIST to scale to large arrays of feedhorn-coupled multichroic AlMn-based TES polarimeters on 150-mm diameter wafers. In addition to describing the streamlined fabrication process which enables high yields of densely packed detectors across larger wafers, we report the details of process improvements for sensor (AlMn) and insulator (SiN(sub x)) materials and microwave structures, and the resulting performance improvements.

  9. FABRICATION PROCESS AND PRODUCT QUALITY IMPROVEMENTS IN ADVANCED GAS REACTOR UCO KERNELS

    SciTech Connect

    Charles M Barnes

    2008-09-01

    A major element of the Advanced Gas Reactor (AGR) program is developing fuel fabrication processes to produce high quality uranium-containing kernels, TRISO-coated particles and fuel compacts needed for planned irradiation tests. The goals of the AGR program also include developing the fabrication technology to mass produce this fuel at low cost. Kernels for the first AGR test (“AGR-1) consisted of uranium oxycarbide (UCO) microspheres that werre produced by an internal gelation process followed by high temperature steps tot convert the UO3 + C “green” microspheres to first UO2 + C and then UO2 + UCx. The high temperature steps also densified the kernels. Babcock and Wilcox (B&W) fabricated UCO kernels for the AGR-1 irradiation experiment, which went into the Advance Test Reactor (ATR) at Idaho National Laboratory in December 2006. An evaluation of the kernel process following AGR-1 kernel production led to several recommendations to improve the fabrication process. These recommendations included testing alternative methods of dispersing carbon during broth preparation, evaluating the method of broth mixing, optimizing the broth chemistry, optimizing sintering conditions, and demonstrating fabrication of larger diameter UCO kernels needed for the second AGR irradiation test. Based on these recommendations and requirements, a test program was defined and performed. Certain portions of the test program were performed by Oak Ridge National Laboratory (ORNL), while tests at larger scale were performed by B&W. The tests at B&W have demonstrated improvements in both kernel properties and process operation. Changes in the form of carbon black used and the method of mixing the carbon prior to forming kernels led to improvements in the phase distribution in the sintered kernels, greater consistency in kernel properties, a reduction in forming run time, and simplifications to the forming process. Process parameter variation tests in both forming and sintering steps led

  10. Development of a Batch Fabrication Process for Chemical Nanosensors: Recent Advancements at NASA Glenn Research Center

    NASA Technical Reports Server (NTRS)

    Biaggi-Labiosa, Azlin M.

    2014-01-01

    A major objective in aerospace sensor development is to produce sensors that are small in size, easy to batch fabricate and low in cost, and have low power consumption. Chemical sensors involving nanostructured materials can provide these characteristics as well as the potential for the development of sensor systems with unique properties and improved performance. However, the fabrication and processing of nanostructures for sensor applications currently is limited by the ability to control their location on the sensor platform, which in turn hinders the progress for batch fabrication. This presentation will discuss the following: the development of a novel room temperature methane (CH4) sensor fabricated using porous tin oxide (SnO2) nanorods as the sensing material, the advantages of using nanomaterials in sensor designs, the challenges encountered with the integration of nanostructures into microsensordevices, and the different methods that have been attempted to address these challenges. An approach for the mass production of sensors with nanostructures using a method developed by our group at the NASA Glenn Research Center to control the alignment of nanostructures onto a sensor platform will also be described.

  11. Innovative fabrication processing of advanced composite materials concepts for primary aircraft structures

    NASA Technical Reports Server (NTRS)

    Kassapoglou, Christos; Dinicola, Al J.; Chou, Jack C.

    1992-01-01

    The autoclave based THERM-X(sub R) process was evaluated by cocuring complex curved panels with frames and stiffeners. The process was shown to result in composite parts of high quality with good compaction at sharp radius regions and corners of intersecting parts. The structural properties of the postbuckled panels fabricated were found to be equivalent to those of conventionally tooled hand laid-up parts. Significant savings in bagging time over conventional tooling were documented. Structural details such as cocured shear ties and embedded stiffener flanges in the skin were found to suppress failure modes such as failure at corners of intersecting members and skin stiffeners separation.

  12. Advanced inductively coupled plasma etching processes for fabrication of resonator-quantum well infrared photodetector

    NASA Astrophysics Data System (ADS)

    Sun, J.; Choi, K. K.; Jhabvala, M. D.; Jhabvala, C. A.; Waczynski, A.; Olver, K.

    2015-05-01

    Resonator-quantum well infrared photodetectors (R-QWIPs) are the next generation of QWIP detectors that use resonances to increase the quantum efficiency (QE). To achieve the expected performance, the detector geometry must be produced in precise specification. In particular, the height of the diffractive elements (DE) and the thickness of the active resonator must be uniformly and accurately realized to within 0.05 μm accuracy and the substrates of the detectors have to be removed totally. To achieve these specifications, two optimized inductively coupled plasma (ICP) etching processes are developed. Using these etching techniques, we have fabricated a number of R-QWIP test detectors and FPAs with the required dimensions and completely removed the substrates of the test detectors and FPAs. Their QE spectra were tested to be in close agreement with the theoretical predictions. The operability and spectral non-uniformity of the FPA is about 99.57% and 3% respectively.

  13. Controlled fabrication of advanced functional structures on the nanoscale by means of electron beam-induced processing

    NASA Astrophysics Data System (ADS)

    Schmidt, Sebastian W.; Foucher, Johann; Penzkofer, Christian; Irmer, Bernd

    2013-05-01

    The controlled deposition of materials by means of electron beam induced processing (EBIP) is a well-established patterning method, which allows for the fabrication of nanostructures with high spatial resolution in a highly precise and flexible manner. Applications range from the production of ultrathin coatings and nanoscaled conductivity probes to super sharp atomic force microscopy (AFM) tips, to name but a few. The latter are typically deposited at the very end of silicon or silicon-nitride tips, which are fabricated with MEMS technologies. EBIP therefore provides the unique ability to converge MEMS to NEMS in a highly controllable way, and thus represents an encouraging opportunity to refine or even develop further MEMS-based features with advanced functionality and applicability. In this paper, we will present and discuss exemplary application solutions, where we successfully applied EBIP to overcome dimensional and/or functional limitations. We therefore show the fabrication stability and accuracy of "T-like-shaped" AFM tips made from high density, diamond-like carbon (HDC/DLC) for the investigation of undercut structures on the base of CDR30-EBD tips. Such aggressive CD-AFM tip dimensions are mandatory to fulfill ITRS requirements for the inspection of sub-28nm nodes, but are unattainable with state-of-art Si-based MEMS technologies today. In addition to that, we demonstrate the ability of EBIP to realize field enhancement in sensor applications and the fabrication of cold field emitters (CFE). For example: applying the EBIP approach allows for the production of CFEs, which are characterized by considerably enhanced imaging resolution compared to standard thermal field emitters and stable operation properties at room temperature without the need for periodic cathode flashing - unlike typical CFEs. Based on these examples, we outline the strong capabilities of the EBIP approach to further downscale functional structures in order to meet future demands in the

  14. Containerless Processing: Fabrication of Advanced Functional Materials from Undercooled Oxide Melt

    NASA Astrophysics Data System (ADS)

    Kumar, M. S. Vijaya; Ishikawa, Takehiko; Yoda, Shinichi; Kuribayashi, Kazuhiko

    2012-07-01

    Materials science in Microgravity condition is one of newly established cutting edge science field. After the effort of space development and space utilization, microgravity of space environment has been considered as one of novel tools for materials science because it assures containerless levitation. Containerless processing is a promising technique to explore the technologically important materials using rapid solidification of an undercooled melt. Recently, rare-earth ferrites and manganites have attracted great interest towards their wide applications in the field of electronic industry. Among these new hexagonal phases with a space group of P6 _{3}cm are technologically important materials because of multiferroic characteristics, i.e., the coexistence of ferroelectricity and magnetism in one compound. In the present study, containerless solidification of the R-Fe-O, and R-Mn-O melts were carried out to fabricate multiferroics under the controlled Po _{2}. Containerless processing is a promising technique to explore the new materials using rapid solidification of an undercooled melt because it provides large undercooling prior to nucleation. In order to undercool the melt deeply below the melting temperature under a precisely controlled oxygen partial pressure, an aerodynamic levitator (ADL) combined with ZrO _{2} oxygen sensor was designed. A spherical RFeO _{3} and RMnO _{3} sample was levitated by an ADL and completely melted by a CO _{2} laser in an atmosphere with predetermined Po _{2}.The surface temperature of the levitated droplet was monitored by a two-color pyrometer. Then, the droplet was cooled by turning off the CO _{2} laser. The XRD results of the rapidly solidified LuFeO _{3} and LuMnO _{3} samples at Po _{2} of 1x10 ^{5} Pa confirms the existence of the hexagonal metastable LuFeO _{3} phase. On the other hand, orthorhombic RFeO _{3} (R=Yb, Er, Y and Dy)and hexagonal RMnO _{3} (R=Ho-Lu)phases were identified. The cross-sectioned scanning

  15. Advanced fabrication of hyperbolic metamaterials

    NASA Astrophysics Data System (ADS)

    Shkondin, Evgeniy; Sukham, Johneph; Panah, Mohammad E. Aryaee; Takayama, Osamu; Malureanu, Radu; Jensen, Flemming; Lavrinenko, Andrei V.

    2017-09-01

    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 is expected to exhibit hyperbolic properties in the visible range. As the second approach we apply the atomic layer deposition technique to arrange vertical alignment of layers or pillars of heavily doped ZnO or TiN, which enables us to produce hyperbolic metamaterials for the near- and mid-infrared ranges.

  16. 3D printed electromagnetic transmission and electronic structures fabricated on a single platform using advanced process integration techniques

    NASA Astrophysics Data System (ADS)

    Deffenbaugh, Paul Issac

    3D printing has garnered immense attention from many fields including in-office rapid prototyping of mechanical parts, outer-space satellite replication, garage functional firearm manufacture, and NASA rocket engine component fabrication. 3D printing allows increased design flexibility in the fabrication of electronics, microwave circuits and wireless antennas and has reached a level of maturity which allows functional parts to be printed. Much more work is necessary in order to perfect the processes of 3D printed electronics especially in the area of automation. Chapter 1 shows several finished prototypes of 3D printed electronics as well as newly developed techniques in fabrication. Little is known about the RF and microwave properties and applications of the standard materials which have been developed for 3D printing. Measurement of a wide variety of materials over a broad spectrum of frequencies up to 10 GHz using a variety of well-established measurement methods is performed throughout chapter 2. Several types of high frequency RF transmission lines are fabricated and valuable model-matched data is gathered and provided in chapter 3 for future designers' use. Of particular note is a fully 3D printed stripline which was automatically fabricated in one process on one machine. Some core advantages of 3D printing RF/microwave components include rapid manufacturing of complex, dimensionally sensitive circuits (such as antennas and filters which are often iteratively tuned) and the ability to create new devices that cannot be made using standard fabrication techniques. Chapter 4 describes an exemplary fully 3D printed curved inverted-F antenna.

  17. Mask fabrication process

    DOEpatents

    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.

  18. Fabrication of Pd/Pd-Alloy Films by Surfactant Induced Electroless Plating for Hydrogen Separation from Advanced Coal Gasification Processes

    SciTech Connect

    Ilias, Shamsuddin; Kumar, Dhananjay

    2012-07-31

    Dense Pd, Pd-Cu and Pd-Ag composite membranes on microporous stainless steel substrate (MPSS) were fabricated by a novel electroless plating (EP) process. In the conventional Pd-EP process, the oxidation-reduction reactions between Pd-complex and hydrazine result in an evolution of NH{sub 3} and N{sub 2} gas bubbles. When adhered to the substrate surface and in the pores, these gas bubbles hinder uniform Pd-film deposition which results in dendrite growth leading to poor film formation. This problem was addressed by introducing cationic surfactant in the electroless plating process known as surfactant induced electroless plating (SIEP). The unique features of this innovation provide control of Pd-deposition rate, and Pd-grain size distribution. The surfactant molecules play an important role in the EP process by tailoring grain size and the process of agglomeration by removing tiny gas bubbles through adsorption at the gas-liquid interface. As a result surfactant can tailor a nanocrystalline Pd, Cu and Ag deposition in the film resulting in reduced membrane film thickness. Also, it produces a uniform, agglomerated film structure. The Pd-Cu and Pd-Ag membranes on MPSS support were fabricated by sequential deposition using SIEP method. The pre- and post-annealing characterizations of these membranes (Pd, Pd-Cu and Pd-Ag on MPSS substrate) were carried out by SEM, EDX, XRD, and AFM studies. The SEM images show significant improvement of the membrane surface morphology, in terms of metal grain structures and grain agglomeration compared to the membranes fabricated by conventional EP process. The SEM images and helium gas-tightness studies indicate that dense and thinner films of Pd, Pd-Cu and Pd-Ag membranes can be produced with shorter deposition time using surfactant. H{sub 2} Flux through the membranes fabricated by SIEP shows large improvement compared to those by CEP with comparable permselectivity. Pd-MPSS composite membrane was subjected to test for long term

  19. Advances on the fabrication process of Er3+/Yb3+:GeO2-PbO pedestal waveguides for integrated photonics

    NASA Astrophysics Data System (ADS)

    Bomfim, F. A.; da Silva, D. M.; Kassab, L. R. P.; de Assumpção, T. A. A.; Del Cacho, V. D.; Alayo, M. I.

    2015-11-01

    The present work reports the fabrication, passive and active characterization of Yb3+/Er3+ codoped GeO2-PbO pedestal waveguides. We show the advances obtained in pedestal fabrication by comparing waveguides obtained under different processes parameters. The thin films were deposited on previously oxidized silicon wafers in Ar plasma at 5 mTorr; pedestal waveguides, with 1-100 μm width range were defined by conventional lithography procedure, followed by reactive ion etching (RIE). A comparison between the results of propagation losses and internal gain is presented in order to show that the improvement of fabrication process contributed to enhance the performance of the pedestal waveguides. Reduction of about 50% was observed for the propagation losses at 632 and 1068 nm, whereas enhancement of approximately 50% was obtained for the internal gain at 1530 nm (4 and 6 dB/cm, for 70 μm waveguide width), under 980 nm excitation. The present results demonstrate the possibility of using Yb3+/Er3+ codoped GeO2-PbO as pedestal waveguide amplifiers.

  20. Process for fabrication of cermets

    DOEpatents

    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.

  1. Fabrication Process for Electroabsorption Modulators

    DTIC Science & Technology

    2007-03-01

    EAM) with high saturation optical power is currently of interest because of its size, efficiency, bandwidth and ease to monolithically integrate with...AFRL-SN-RS-TR-2007-57 In-House Interim Technical Report March 2007 FABRICATION PROCESS FOR ELECTROABSORPTION MODULATORS...SUBTITLE FABRICATION PROCESS FOR ELECTROABSORPTION MODULATORS 5c. PROGRAM ELEMENT NUMBER 62204F 5d. PROJECT NUMBER SEMI 5e. TASK NUMBER SN 6

  2. Process optimization in optical fabrication

    NASA Astrophysics Data System (ADS)

    Faehnle, Oliver

    2016-03-01

    Predictable and stable fabrication processes are essential for reliable cost and quality management in optical fabrication technology. This paper reports on strategies to generate and control optimum sets of process parameters for, e.g., subaperture polishing of small optics (featuring clear apertures smaller than 2 mm). Emphasis is placed on distinguishing between machine and process optimization, demonstrating that it is possible to set up the ductile mode grinding process by means other than controlling critical depth of cut. Finally, a recently developed in situ testing technique is applied to monitor surface quality on-machine while abrasively working the surface under test enabling an online optimization of polishing processes eventually minimizing polishing time and fabrication cost.

  3. Process control in optical fabrication

    NASA Astrophysics Data System (ADS)

    Faehnle, Oliver

    2015-09-01

    Predictable and stable fabrication processes are essential for reliable cost and quality management in optical fabrication technology. This paper reports on strategies to generate and control optimum sets of process parameters for e.g. sub-aperture polishing of small optics (featuring clear apertures smaller than 2 mm). Emphasis is placed to distinguish between machine and process optimization demonstrating, that e.g. it is possible setting up ductile mode grinding process by other means than controlling critical depth of cut. Finally, a recently developed in situ testing technique is applied to monitor surface quality on-machine while abrasively working the surface under test enabling an on-line optimization of polishing processes eventually minimizing polishing time and fabrication cost.

  4. Metallic parts fabrication using the SIS process

    NASA Astrophysics Data System (ADS)

    Mojdeh, Mehdi

    Since early 1980s, quite a few techniques of Rapid Prototyping (RP), also known as Layered Manufacturing, have been developed. By building three-dimensional parts in a layer-by-layer additive manner, these techniques allow freeform fabrication of parts of complex geometry. Despite recent advances in fabrication of polymer parts, most of the existing rapid prototyping processes are still not capable of fabrication of accurate metallic parts with acceptable mechanical properties. Insufficient dimensional accuracy, limited number of materials, proper mechanical properties, required post machining and lack of repeatability between builds have greatly limited the market penetration of these techniques. This dissertation presents an innovative layered manufacturing technique for fabrication of dense metallic parts called Selective Inhibition Sintering (SIS), developed at the University of Southern California. The SIS-Metal technology adapts RP capabilities and extends them to the field of fabrication of metallic parts for a variety of applications such as tooling and low volume production. Using this process, a metallic part, with varying 3 dimensional geometries, can be automatically constructed from a wide range of materials. SIS-Metal is the only RP process which is suitable for fabrication of dense, complex shaped, accurate objects using a variety of materials. In the SIS-Metal process a metallic part is built layer by layer by deposition for each layer of an inhibitor material which defines the corresponding layer boundary and then filling the voids of the created geometry with metal powder; and compacting the layer formed to reach a high powder density. The resulting green part is then sintered in a furnace to yield the final functional part. In this research different inhibition techniques were explored and a series of single and multi layer parts was fabricated using the most promising inhibition technique, namely, macro-mechanical inhibition. Dimensional

  5. Advanced Safeguards Approaches for New TRU Fuel Fabrication Facilities

    SciTech Connect

    Durst, Philip C.; Ehinger, Michael H.; Boyer, Brian; Therios, Ike; Bean, Robert; Dougan, A.; Tolk, K.

    2007-12-15

    This second report in a series of three reviews possible safeguards approaches for the new transuranic (TRU) fuel fabrication processes to be deployed at AFCF – specifically, the ceramic TRU (MOX) fuel fabrication line and the metallic (pyroprocessing) line. The most common TRU fuel has been fuel composed of mixed plutonium and uranium dioxide, referred to as “MOX”. However, under the Advanced Fuel Cycle projects custom-made fuels with higher contents of neptunium, americium, and curium may also be produced to evaluate if these “minor actinides” can be effectively burned and transmuted through irradiation in the ABR. A third and final report in this series will evaluate and review the advanced safeguards approach options for the ABR. In reviewing and developing the advanced safeguards approach for the new TRU fuel fabrication processes envisioned for AFCF, the existing international (IAEA) safeguards approach at the Plutonium Fuel Production Facility (PFPF) and the conceptual approach planned for the new J-MOX facility in Japan have been considered as a starting point of reference. The pyro-metallurgical reprocessing and fuel fabrication process at EBR-II near Idaho Falls also provided insight for safeguarding the additional metallic pyroprocessing fuel fabrication line planned for AFCF.

  6. Monolithic Fuel Fabrication Process Development

    SciTech Connect

    C. R. Clark; N. P. Hallinan; J. F. Jue; D. D. Keiser; J. M. Wight

    2006-05-01

    The pursuit of a high uranium density research reactor fuel plate has led to monolithic fuel, which possesses the greatest possible uranium density in the fuel region. Process developments in fabrication development include friction stir welding tool geometry and cooling improvements and a reduction in the length of time required to complete the transient liquid phase bonding process. Annealing effects on the microstructures of the U-10Mo foil and friction stir welded aluminum 6061 cladding are also examined.

  7. Advances in metals processing

    NASA Technical Reports Server (NTRS)

    Bales, T. T.; Royster, D. M.

    1982-01-01

    Research on metals processing being conducted to develop improved forming and joining methods with the potential of reducing the weight and cost of future aerospace structures is discussed. The approach followed is to assess the state of the art for fabricating a given structural system, define candidate methods for improving processing, evaluate the merits of each, fabricate and test subelement components, and then scale up the process to demonstrate validity. The development and the state of the art of weldbrazing, superplastic forming (SPF), superplastic forming and codiffusion bonding and superplastic forming and weldbrazing for titanium and the SPF of aluminum is discussed.

  8. Fabrication of advanced design (grooved) cermet anodes

    NASA Astrophysics Data System (ADS)

    Windisch, C. F., Jr.; Huettig, F. R.

    1993-05-01

    Attempts were made to fabricate full-size anodes with advanced, or grooved, design using isostatic pressing, slip casting injection molding. Of the three approaches, isostatic pressing produced an anode with dimensions nearest to the target specifications, without serious macroscopic flaws. This approach is considered the most promising for making advanced anodes for aluminum smelting. However, significant work still remains to optimize the physical properties and microstructure of the anode, both of which were significantly different from that of previous anodes. Injection molding and slip casting yielded anode materials with serious deficiencies, including cracks and holes. Injection molding gave cermet material with the best intrinsic microstructure, i.e., the microstructure of the material between macroscopic flaws was very similar to that of anodes previously made at PNL. The reason for the similarity may have to do with amount of residual binder in the material prior to sintering.

  9. Fabrication of advanced design (grooved) cermet anodes

    SciTech Connect

    Windisch, C.F. Jr.; Huettig, F.R.

    1993-05-01

    Attempts were made to fabricate full-size anodes with advanced, or grooved, design using isostatic pressing, slip casting injection molding. Of the three approaches, isostatic pressing produced an anode with dimensions nearest to the target specifications, without serious macroscopic flaws. This approach is considered the most promising for making advanced anodes for aluminum smelting. However, significant work still remains to optimize the physical properties and microstructure of the anode, both of which were significantly different from that of previous anodes. Injection molding and slip casting yielded anode materials with serious deficiencies, including cracks and holes. Injection molding gave cermet material with the best intrinsic microstructure, i.e., the microstructure of the material between macroscopic flaws was very similar to that of anodes previously made at PNL. Reason for the similarity may have to do with amount of residual binder in the material prior to sintering.

  10. Fabrication of advanced design (grooved) cermet anodes

    SciTech Connect

    Windisch, C.F. Jr. ); Huettig, F.R. )

    1993-05-01

    Attempts were made to fabricate full-size anodes with advanced, or grooved, design using isostatic pressing, slip casting injection molding. Of the three approaches, isostatic pressing produced an anode with dimensions nearest to the target specifications, without serious macroscopic flaws. This approach is considered the most promising for making advanced anodes for aluminum smelting. However, significant work still remains to optimize the physical properties and microstructure of the anode, both of which were significantly different from that of previous anodes. Injection molding and slip casting yielded anode materials with serious deficiencies, including cracks and holes. Injection molding gave cermet material with the best intrinsic microstructure, i.e., the microstructure of the material between macroscopic flaws was very similar to that of anodes previously made at PNL. Reason for the similarity may have to do with amount of residual binder in the material prior to sintering.

  11. Plasma Processes for Semiconductor Fabrication

    NASA Astrophysics Data System (ADS)

    Hitchon, W. N. G.

    1999-01-01

    Plasma processing is a central technique in the fabrication of semiconductor devices. This self-contained book provides an up-to-date description of plasma etching and deposition in semiconductor fabrication. It presents the basic physics and chemistry of these processes, and shows how they can be accurately modeled. The author begins with an overview of plasma reactors and discusses the various models for understanding plasma processes. He then covers plasma chemistry, addressing the effects of different chemicals on the features being etched. Having presented the relevant background material, he then describes in detail the modeling of complex plasma systems, with reference to experimental results. The book closes with a useful glossary of technical terms. No prior knowledge of plasma physics is assumed in the book. It contains many homework exercises and serves as an ideal introduction to plasma processing and technology for graduate students of electrical engineering and materials science. It will also be a useful reference for practicing engineers in the semiconductor industry.

  12. Strength and flexibility properties of advanced ceramic fabrics

    NASA Technical Reports Server (NTRS)

    Sawko, P. M.; Tran, H. K.

    1985-01-01

    The mechanical properties of four advanced ceramic fabrics are measured at a temperature range of 23 C to 1200 C. The fabrics evaluated are silica, high-and low-boria content aluminoborosilicate, and silicon carbide. Properties studied include fabric break strengths from room temperature to 1200 C, and bending durability after temperature conditioning at 1200 C and 1400 C. The interaction of the fabric and ceramic insulation is also studied for shrinkage, appearance, bend resistance, and fabric-to-insulation bonding. Based on these tests, the low-boria content aluminoborosilicate fabric retains more strength and fabric durability than the other fabrics studied at high temperature.

  13. Strength and flexibility properties of advanced ceramic fabrics

    NASA Technical Reports Server (NTRS)

    Sawko, P. M.; Tran, H. K.

    1985-01-01

    The mechanical properties of four advanced ceramic fabrics were measured at a temperature range of 23C to 1200C. The fabrics evaluated were silica, high and low-boria content aluminoborosilicate, and silicon carbide. Properties studied included fabric break strengths from room temperature to 1200C, and bending durability after temperature conditioning at 1200C and 1400C. The interaction of the fabric and ceramic insulation was also studied for shrinkage, appearance, bend resistance, and fabric-to-insulation bonding. Based on these tests, the low-boria content aluminoborosilicate fabric retained more strength and fabric durability than the other fabrics studied at high temperature.

  14. Advances in Process Control.

    ERIC Educational Resources Information Center

    Morrison, David L.; And Others

    1982-01-01

    Advances in electronics and computer science have enabled industries (pulp/paper, iron/steel, petroleum/chemical) to attain better control of their processes with resulting increases in quality, productivity, profitability, and compliance with government regulations. (JN)

  15. Advances in Process Control.

    ERIC Educational Resources Information Center

    Morrison, David L.; And Others

    1982-01-01

    Advances in electronics and computer science have enabled industries (pulp/paper, iron/steel, petroleum/chemical) to attain better control of their processes with resulting increases in quality, productivity, profitability, and compliance with government regulations. (JN)

  16. Advanced fabrication techniques for cooled engine structures

    NASA Technical Reports Server (NTRS)

    Buchmann, O. A.

    1978-01-01

    An improved design for regeneratively cooled engine structures was identified. This design uses photochemically machined (PCM) coolant passages. It permits the braze joint to be placed in a relatively cool area, remote from the critical hot face sheet. The geometry of the passages at the face sheet also minimizes stress concentration and, therefore, enhances the low cycle fatigue performance. The two most promising alloys identified for this application are Inconel 617 and Nickel 201. Inconel 617 was selected because it has excellent creep rupture properties, while Nickel 201 was selected because of its predicted good performance under low cycle fatigue loading. The fabrication of the PCM coolant passages in both Inconel 617 and Nickel 201 was successfully developed. During fabrication of Inconel 617, undesirable characteristics were observed in the braze joints. A development program to resolve this condition was undertaken and led to definition of an isothermal solidification process for joining Inconel 617 panels. This process produced joints which approach parent metal strength and homogeneity.

  17. Advancements in Binder Systems for Solid Freeform Fabrication

    NASA Technical Reports Server (NTRS)

    Cooper, Ken; Munafo, Paul (Technical Monitor)

    2002-01-01

    Paper will present recent developments in advanced material binder systems for solid freeform fabrication (SFF) technologies. The advantage of SFF is the capability to custom fabricate complex geometries directly from computer aided design data in layer- by-layer fashion, eliminated the need for traditional fixturing and tooling. Binders allow for the low temperature processing of 'green' structural materials, either metal, ceramic or composite, in traditional rapid prototyping machines. The greatest obstacle comes when green parts must then go through a sintering or burnout process to remove the binders and fully densify the parent material, without damaging or distorting the original part geometry. Critical issues and up-to-date assessments will be delivered on various material systems.

  18. Advancements in Binder Systems for Solid Freeform Fabrication

    NASA Technical Reports Server (NTRS)

    Cooper, Ken; Munafo, Paul (Technical Monitor)

    2002-01-01

    Paper will present recent developments in advanced material binder systems for solid freeform fabrication (SFF) technologies. The advantage of SFF is the capability to custom fabricate complex geometries directly from computer aided design data in layer- by-layer fashion, eliminated the need for traditional fixturing and tooling. Binders allow for the low temperature processing of 'green' structural materials, either metal, ceramic or composite, in traditional rapid prototyping machines. The greatest obstacle comes when green parts must then go through a sintering or burnout process to remove the binders and fully densify the parent material, without damaging or distorting the original part geometry. Critical issues and up-to-date assessments will be delivered on various material systems.

  19. Advanced Polymer Processing Facility

    SciTech Connect

    Muenchausen, Ross E.

    2012-07-25

    Some conclusions of this presentation are: (1) Radiation-assisted nanotechnology applications will continue to grow; (2) The APPF will provide a unique focus for radiolytic processing of nanomaterials in support of DOE-DP, other DOE and advanced manufacturing initiatives; (3) {gamma}, X-ray, e-beam and ion beam processing will increasingly be applied for 'green' manufacturing of nanomaterials and nanocomposites; and (4) Biomedical science and engineering may ultimately be the biggest application area for radiation-assisted nanotechnology development.

  20. Advances in superconducting quantum electronic microcircuit fabrication

    NASA Technical Reports Server (NTRS)

    Kirschman, R. K.; Notarys, H. A.; Mercereau, J. E.

    1975-01-01

    Standard microelectronic fabrication techniques have been utilized to produce batch quantities of superconducting quantum electronic devices and circuits. The overall goal is a fabrication technology yielding circuits that are rugged and stable and capable of being fabricated controllably and reproducibly in sizeable quantities. Our progress toward this goal is presented, with primary emphasis on the most recent work, which includes the use of electron-beam lithography and techniques of hybrid microelectronics. Several prototype microcircuits have been successfully fabricated. These microcircuits are formed in a thin-film parent material consisting of layers of superconducting and normal metals, and use proximity-effect structures as the active circuit elements.

  1. Advanced information processing system

    NASA Technical Reports Server (NTRS)

    Lala, J. H.

    1984-01-01

    Design and performance details of the advanced information processing system (AIPS) for fault and damage tolerant data processing on aircraft and spacecraft are presented. AIPS comprises several computers distributed throughout the vehicle and linked by a damage tolerant data bus. Most I/O functions are available to all the computers, which run in a TDMA mode. Each computer performs separate specific tasks in normal operation and assumes other tasks in degraded modes. Redundant software assures that all fault monitoring, logging and reporting are automated, together with control functions. Redundant duplex links and damage-spread limitation provide the fault tolerance. Details of an advanced design of a laboratory-scale proof-of-concept system are described, including functional operations.

  2. Advanced Fibre Bragg Grating and Microfibre Bragg Grating Fabrication Techniques

    NASA Astrophysics Data System (ADS)

    Chung, Kit Man

    Fibre Bragg gratings (FBGs) have become a very important technology for communication systems and fibre optic sensing. Typically, FBGs are less than 10-mm long and are fabricated using fused silica uniform phase masks which become more expensive for longer length or non-uniform pitch. Generally, interference UV laser beams are employed to make long or complex FBGs, and this technique introduces critical precision and control issues. In this work, we demonstrate an advanced FBG fabrication system that enables the writing of long and complex gratings in optical fibres with virtually any apodisation profile, local phase and Bragg wavelength using a novel optical design in which the incident angles of two UV beams onto an optical fibre can be adjusted simultaneously by moving just one optical component, instead of two optics employed in earlier configurations, to vary the grating pitch. The key advantage of the grating fabrication system is that complex gratings can be fabricated by controlling the linear movements of two translation stages. In addition to the study of advanced grating fabrication technique, we also focus on the inscription of FBGs written in optical fibres with a cladding diameter of several ten's of microns. Fabrication of microfibres was investigated using a sophisticated tapering method. We also proposed a simple but practical technique to filter out the higher order modes reflected from the FBG written in microfibres via a linear taper region while the fundamental mode re-couples to the core. By using this technique, reflection from the microfibre Bragg grating (MFBG) can be effectively single mode, simplifying the demultiplexing and demodulation processes. MFBG exhibits high sensitivity to contact force and an MFBG-based force sensor was also constructed and tested to investigate their suitability for use as an invasive surgery device. Performance of the contact force sensor packaged in a conforming elastomer material compares favourably to one

  3. Electrochromic Windows: Advanced Processing Technology

    SciTech Connect

    SAGE Electrochromics, Inc

    2006-12-13

    This project addresses the development of advanced fabrication capabilities for energy saving electrochromic (EC) windows. SAGE EC windows consist of an inorganic stack of thin films deposited onto a glass substrate. The window tint can be reversibly changed by the application of a low power dc voltage. This property can be used to modulate the amount of light and heat entering buildings (or vehicles) through the glazings. By judicious management of this so-called solar heat gain, it is possible to derive significant energy savings due to reductions in heating lighting, and air conditioning (HVAC). Several areas of SAGE’s production were targeted during this project to allow significant improvements to processing throughput, yield and overall quality of the processing, in an effort to reduce the cost and thereby improve the market penetration. First, the overall thin film process was optimized to allow a more robust set of operating points to be used, thereby maximizing the yield due to the thin film deposition themselves. Other significant efforts aimed at improving yield were relating to implementing new procedures and processes for the manufacturing process, to improve the quality of the substrate preparation, and the quality of the IGU fabrication. Furthermore, methods for reworking defective devices were developed, to enable devices which would otherwise be scrapped to be made into useful product. This involved the in-house development of some customized equipment. Finally, the improvements made during this project were validated to ensure that they did not impact the exceptional durability of the SageGlass® products. Given conservative estimates for cost and market penetration, energy savings due to EC windows in residences in the US are calculated to be of the order 0.026 quad (0.026×1015BTU/yr) by the year 2017.

  4. Polymer micromold and fabrication process

    DOEpatents

    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.

  5. Polymer micromold and fabrication process

    DOEpatents

    Lee, Abraham P.; Northrup, M. Allen; Ahre, Paul E.; Dupuy, Peter C.

    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.

  6. Fabrication and application of advanced functional materials from lignincellulosic biomass

    NASA Astrophysics Data System (ADS)

    Hu, Sixiao

    This dissertation explored the conversion of lignocellulosic biomass into advanced functional materials and their potential applications. Lignocellulosic biomass represents an as-of-yet underutilized renewable source for not only biofuel production but also functional materials fabrication. This renewable source is a great alternative for fossil fuel based chemicals, which could be one of the solutions to energy crisis. In this work, it was demonstrated a variety of advanced materials including functional carbons, metal and silica nanoparticles could be derived from lignocellulosic biomass. Chapter 1 provided overall reviewed of the lignin structures, productions and its utilizations as plastics, absorbents and carbons, as well as the preparation of nano-structured silver, silica and silicon carbide/nitride from biomass. Chapter 2, 3 and 4 discussed the fabrication of highly porous carbons from isolated lignin, and their applications as electric supercapacitors for energy storage. In chapter 2, ultrafine porous carbon fibers were prepared via electrospinning followed by simultaneous carbonization and activation. Chapter 3 covered the fabrication of supercapacitor based on the porous carbon fibers and the investigation of their electrochemical performances. In chapter 4, porous carbon particulates with layered carbon nano plates structures were produced by simple oven-drying followed by simultaneous carbonization and activation. The effects of heat processing parameters on the resulting carbon structures and their electrochemical properties were discussed in details. Chapter 5 and 6 addressed the preparation of silver nanoparticles using lignin. Chapter 5 reported the synthesis, underlying kinetics and mechanism of monodispersed silver nanospheres with diameter less than 25 nm in aqueous solutions using lignin as dual reducing and capping agents. Chapter 6 covered the preparation of silver nanoparticles on electrospun celluloses ultrafine fibers using lignin as both

  7. Advanced powder processing

    SciTech Connect

    Janney, M.A.

    1997-04-01

    Gelcasting is an advanced powder forming process. It is most commonly used to form ceramic or metal powders into complex, near-net shapes. Turbine rotors, gears, nozzles, and crucibles have been successfully gelcast in silicon nitride, alumina, nickel-based superalloy, and several steels. Gelcasting can also be used to make blanks that can be green machined to near-net shape and then high fired. Green machining has been successfully applied to both ceramic and metal gelcast blanks. Recently, the authors have used gelcasting to make tooling for metal casting applications. Most of the work has centered on H13 tool steel. They have demonstrated an ability to gelcast and sinter H13 to near net shape for metal casting tooling. Also, blanks of H13 have been cast, green machined into complex shape, and fired. Issues associated with forming, binder burnout, and sintering are addressed.

  8. Advanced microwave processing concepts

    SciTech Connect

    Lauf, R.J.; McMillan, A.D.; Paulauskas, F.L.

    1997-04-01

    The purpose of this work is to explore the feasibility of several advanced microwave processing concepts to develop new energy-efficient materials and processes. The project includes two tasks: (1) commercialization of the variable-frequency microwave furnace; and (2) microwave curing of polymeric materials. The variable frequency microwave furnace, whose initial conception and design was funded by the AIM Materials Program, allows the authors, for the first time, to conduct microwave processing studies over a wide frequency range. This novel design uses a high-power traveling wave tube (TWT) originally developed for electronic warfare. By using this microwave source, one can not only select individual microwave frequencies for particular experiments, but also achieve uniform power densities over a large area by the superposition of many different frequencies. Microwave curing of various thermoset resins will be studied because it holds the potential of in-situ curing of continuous-fiber composites for strong, lightweight components or in-situ curing of adhesives, including metal-to-metal. Microwave heating can shorten curing times, provided issues of scaleup, uniformity, and thermal management can be adequately addressed.

  9. Advanced microwave processing concepts

    SciTech Connect

    Lauf, R.J.; McMillan, A.D.; Paulauskas, F.L.

    1995-05-01

    The purpose of this work is to explore the feasibility of several advanced microwave processing concepts to develop new energy-efficient materials and processes. The project includes two tasks: (1) commercialization of the variable-frequency microwave furnace; and (2) microwave curing of polymer composites. The variable frequency microwave furnace, whose initial conception and design was funded by the AIC Materials Program, will allow us, for the first time, to conduct microwave processing studies over a wide frequency range. This novel design uses a high-power traveling wave tube (TWT) originally developed for electronic warfare. By using this microwave source, one can not only select individual microwave frequencies for particular experiments, but also achieve uniform power densities over a large area by the superposition of many different frequencies. Microwave curing of thermoset resins will be studied because it hold the potential of in-situ curing of continuous-fiber composites for strong, lightweight components. Microwave heating can shorten curing times, provided issues of scaleup, uniformity, and thermal management can be adequately addressed.

  10. Fabrication and evaluation of advanced titanium and composite structural panels

    NASA Technical Reports Server (NTRS)

    Bales, T. T.; Hoffman, E. L.; Payne, L.; Carter, A. L.

    1976-01-01

    Advanced manufacturing methods for titanium and composite material structures are being developed and evaluated. The focus for the manufacturing effort is the fabrication of full-scale structural panels which replace an existing shear panel on the upper wing surface of the NASA YF-12 aircraft. The program involves design, fabrication, ground testing, and Mach 3 flight service of full-scale structural panels and laboratory testing of representative structural element specimens.

  11. Statistical quality control for VLSIC fabrication processes

    SciTech Connect

    Mozumder, P.K.

    1989-01-01

    As the complexity of VLSICs increase and the device dimension shrink, random fluctuations become the main reason limiting the par metric yield. Whenever a new process is developed, the initial yield are low. The rate of climbing the learning curve is slow, i.e., the time necessary to bring the yield above an economically acceptable value can be unacceptably long, resulting in lost revenue and competitive edge in the market. The slow rates of climbing the learning curve and the low initial yields can be countered by using design methodologies that take into account the random fluctuations in the fabrication processes, and using statistical on-line and off-line control during the wafer fabrication. An integrated CAD-CAM approach with profit maximization as the objective is necessary to design and fabricate present day VLSICs. In this thesis the author proposes a methodology for monitoring and statistically controlling VLSIC manufacturing processes as part of an integrated CAD-CAM system. Present day statistical quality control systems fail to function satisfactorily due to lack of in-situ and in-line data, and absence of statistical techniques that take into account the multi-dimensionality of the data. A concerted effort has to be made to increase the number of in-situ parameters that are measured during the fabrication process using new generation equipment and sensors. Algorithms for identifying the minimal set of observable in-situ and in-line parameters that have to be measured to monitor the fabrication process are presented. The methodology for statistical quality control is based on the exploration of the multivariate distribution of the observed in-process parameters in the region of acceptability specified by the customer. Criteria for comparing the distributions of the normal process to that of the process under control are used to make the quality control decisions.

  12. Technology development of fabrication techniques for advanced solar dynamic concentrators

    NASA Technical Reports Server (NTRS)

    Richter, Scott W.

    1991-01-01

    The objective of the advanced concentrator program is to develop the technology that will lead to lightweight, highly reflective, accurate, scaleable, and long lived space solar dynamic concentrators. The advanced concentrator program encompasses new and innovative concepts, fabrication techniques, materials selection, and simulated space environmental testing. Fabrication techniques include methods of fabricating the substrates and coating substrate surfaces to produce high-quality optical surfaces, acceptable for further coating with vapor deposited optical films. The selected materials to obtain a high quality optical surface include microsheet glass and Eccocoat EP-3 epoxy, with DC-93-500 selected as a candidate silicone adhesive and levelizing layer. The following procedures are defined: cutting, cleaning, forming, and bonding microsheet glass. Procedures are also defined for surface cleaning, and EP-3 epoxy application. The results and analyses from atomic oxygen and thermal cycling tests are used to determine the effects of orbital conditions in a space environment.

  13. Technology development of fabrication techniques for advanced solar dynamic concentrators

    NASA Technical Reports Server (NTRS)

    Richter, Scott W.

    1991-01-01

    The objective of the advanced concentrator program is to develop the technology that will lead to lightweight, highly reflective, accurate, scaleable, and long lived space solar dynamic concentrators. The advanced concentrator program encompasses new and innovative concepts, fabrication techniques, materials selection, and simulated space environmental testing. Fabrication techniques include methods of fabricating the substrates and coating substrate surfaces to produce high quality optical surfaces, acceptable for further coating with vapor deposited optical films. The selected materials to obtain a high quality optical surface include microsheet glass and Eccocoat EP-3 epoxy, with DC-93-500 selected as a candidate silicone adhesive and levelizing layer. The following procedures are defined: cutting, cleaning, forming, and bonding microsheet glass. Procedures are also defined for surface cleaning, and EP-3 epoxy application. The results and analyses from atomic oxygen and thermal cycling tests are used to determine the effects of orbital conditions in a space environment.

  14. ADVANCED ELECTROSTATIC STIMULATION OF FABRIC FILTRATION: PERFORMANCE AND ECONOMICS

    EPA Science Inventory

    The paper discusses the performance and economics of advanced electrostatic stimulation of fabric filtration (AESFF), in which a high-voltage electrode is placed coaxially inside a filter bag to establish an electric field between the electrode and the bag surface. The electric f...

  15. ADVANCED ELECTROSTATIC STIMULATION OF FABRIC FILTRATION: PERFORMANCE AND ECONOMICS

    EPA Science Inventory

    The paper discusses the performance and economics of advanced electrostatic stimulation of fabric filtration (AESFF), in which a high-voltage electrode is placed coaxially inside a filter bag to establish an electric field between the electrode and the bag surface. The electric f...

  16. Establishing a Scientific Basis for Optimizing Compositions, Process Paths and Fabrication Methods for Nanostructured Ferritic Alloys for Use in Advanced Fission Energy Systems

    SciTech Connect

    Odette, G Robert; Cunningham, Nicholas J., Wu, Yuan; Etienne, Auriane; Stergar, Erich; Yamamoto, Takuya

    2012-02-21

    The broad objective of this NEUP was to further develop a class of 12-15Cr ferritic alloys that are dispersion strengthened and made radiation tolerant by an ultrahigh density of Y-Ti-O nanofeatures (NFs) in the size range of less than 5 nm. We call these potentially transformable materials nanostructured ferritic alloys (NFAs). NFAs are typically processed by ball milling pre-alloyed rapidly solidified powders and yttria (Y2O3) powders. Proper milling effectively dissolves the Ti, Y and O solutes that precipitate as NFs during hot consolidation. The tasks in the present study included examining alternative processing paths, characterizing and optimizing the NFs and investigating solid state joining. Alternative processing paths involved rapid solidification by gas atomization of Fe, 14% Cr, 3% W, and 0.4% Ti powders that are also pre-alloyed with 0.2% Y (14YWT), where the compositions are in wt.%. The focus is on exploring the possibility of minimizing, or even eliminating, the milling time, as well as producing alloys with more homogeneous distributions of NFs and a more uniform, fine grain size. Three atomization environments were explored: Ar, Ar plus O (Ar/O) and He. The characterization of powders and alloys occurred through each processing step: powder production by gas atomization; powder milling; and powder annealing or hot consolidation by hot isostatic pressing (HIPing) or hot extrusion. The characterization studies of the materials described here include various combinations of: a) bulk chemistry; b) electron probe microanalysis (EPMA); c) atom probe tomography (APT); d) small angle neutron scattering (SANS); e) various types of scanning and transmission electron microscopy (SEM and TEM); and f) microhardness testing. The bulk chemistry measurements show that preliminary batches of gas-atomized powders could be produced within specified composition ranges. However, EPMA and TEM showed that the Y is heterogeneously distributed and phase separated, but

  17. Fabrication and evaluation of advanced titanium structural panels for supersonic cruise aircraft

    NASA Technical Reports Server (NTRS)

    Payne, L.

    1977-01-01

    Flightworthy primary structural panels were designed, fabricated, and tested to investigate two advanced fabrication methods for titanium alloys. Skin-stringer panels fabricated using the weldbraze process, and honeycomb-core sandwich panels fabricated using a diffusion bonding process, were designed to replace an existing integrally stiffened shear panel on the upper wing surface of the NASA YF-12 research aircraft. The investigation included ground testing and Mach 3 flight testing of full-scale panels, and laboratory testing of representative structural element specimens. Test results obtained on full-scale panels and structural element specimens indicate that both of the fabrication methods investigated are suitable for primary structural applications on future civil and military supersonic cruise aircraft.

  18. Advanced Hydrogen Liquefaction Process

    SciTech Connect

    Schwartz, Joseph; Kromer, Brian; Neu, Ben; Jankowiak, Jerome; Barrett, Philip; Drnevich, Raymond

    2011-09-28

    The project identified and quantified ways to reduce the cost of hydrogen liquefaction, and reduce the cost of hydrogen distribution. The goal was to reduce the power consumption by 20% and then to reduce the capital cost. Optimizing the process, improving process equipment, and improving ortho-para conversion significantly reduced the power consumption of liquefaction, but by less than 20%. Because the efficiency improvement was less than the target, the program was stopped before the capital cost was addressed. These efficiency improvements could provide a benefit to the public to improve the design of future hydrogen liquefiers. The project increased the understanding of hydrogen liquefaction by modeling different processes and thoroughly examining ortho-para separation and conversion. The process modeling provided a benefit to the public because the project incorporated para hydrogen into the process modeling software, so liquefaction processes can be modeled more accurately than using only normal hydrogen. Adding catalyst to the first heat exchanger, a simple method to reduce liquefaction power, was identified, analyzed, and quantified. The demonstrated performance of ortho-para separation is sufficient for at least one identified process concept to show reduced power cost when compared to hydrogen liquefaction processes using conventional ortho-para conversion. The impact of improved ortho-para conversion can be significant because ortho para conversion uses about 20-25% of the total liquefaction power, but performance improvement is necessary to realize a substantial benefit. Most of the energy used in liquefaction is for gas compression. Improvements in hydrogen compression will have a significant impact on overall liquefier efficiency. Improvements to turbines, heat exchangers, and other process equipment will have less impact.

  19. End-of-fabrication CMOS process monitor

    NASA Technical Reports Server (NTRS)

    Buehler, M. G.; Allen, R. A.; Blaes, B. R.; Hannaman, D. J.; Lieneweg, U.; Lin, Y.-S.; Sayah, H. R.

    1990-01-01

    A set of test 'modules' for verifying the quality of a complementary metal oxide semiconductor (CMOS) process at the end of the wafer fabrication is documented. By electrical testing of specific structures, over thirty parameters are collected characterizing interconnects, dielectrics, contacts, transistors, and inverters. Each test module contains a specification of its purpose, the layout of the test structure, the test procedures, the data reduction algorithms, and exemplary results obtained from 3-, 2-, or 1.6-micrometer CMOS/bulk processes. The document is intended to establish standard process qualification procedures for Application Specific Integrated Circuits (ASIC's).

  20. Advanced Containerless Processing Technology

    NASA Technical Reports Server (NTRS)

    Wang, T. G.

    1985-01-01

    Breadboards for high temperature containerless processing systems are to be developed, the principles of operation are to be studied, the performance is to be characterized, the limitations identified, and the influence of the acoustic field on the samples established. The subjects to be addressed are experimental and theoretical studies of: (1) acoustic positioning and manipulation capabilities in a high temperature gradient environment (from 26 C to 990 C); (2) acoustic waveforms, harmonic contents, power transfer, sample transport and stability associated with high temperature gradient system; (3) high temperature ground based levitation systems which will allow melting, processing, and solidifying samples without crucibles in the laboratory, (4) KC-135 and laboratory tests of various acoustic geometries which may have spherical applications in the Materials Processing in Space Program; and (5) provide technical information to Acoustics Containerless Experimental System (ACES) engineering team and establish the operation conditions for ACES.

  1. Development of an advanced mask and its fabrication system

    NASA Astrophysics Data System (ADS)

    Takigawa, Tadahiro; Tojo, Toru; Ogawa, Yoji; Koyama, Kiyomi; Ono, Akira; Inoue, Soichi; Ito, Shinichi; Goto, Mineo

    1995-07-01

    Masks and their fabrication technologies are keys to the further advancement of optical lithography. A stable SiNx single layer attenuated masks for DUV have been developed. A 0.2 micrometers contact hole pattern was fabricated using a KrF stepper with the SiNx attenuated mask. Toshiba mask fabrication system, including an electron beam writing system, a data base inspection system, and a data conversion system, has been developed for 64 Mbit DRAM class. Required mask improvements for increasing optical lithography resolution include better critical dimension (CD) uniformity, higher mask writing system resolution, and automatic shifter patten generation of alternating phase shifting masks. In addition, improved mask pattern positioning accuracy is also required. In this paper, experimental CD uniformity and resolution improvements, automatic phase shifter assignment method, and improvement in positioning accuracy, are described. The future development of masks will incorporate these key technologies.

  2. Diffraction grating interferometers for mechanical characterisations of advanced fabric laminates

    NASA Astrophysics Data System (ADS)

    Lee, Jung-Ryul; Molimard, Jérôme; Vautrin, Alain; Surrel, Yves

    2006-02-01

    It is demonstrated that two grating interferometers with high spatial resolutions can successfully be applied for the mechanical characterisation of the advanced fabric composite materials. Based on these two techniques, the mechanical properties of two kinds of fabric laminates are obtained without assumption of uniform strain fields to be used in the characterisation approaches using the local strain sensors. The degree of the yarn crimp effects of the two laminates is compared in terms of the out-of-plane displacement derivatives. Especially, it is shown that the grating shearing interferometer is appropriate for the crimped fabric structure requiring a three-dimensional analysis. The modification from moiré interferometer to grating shearing interferometer is performed by introducing a Michelson interferometer modified for image shearing.

  3. Advanced deformation process modeling

    SciTech Connect

    Kocks, U.F.; Embury, J.D.; Beaudoin, A.J.; Dawson, P.R.; MacEwen, S.R.; Mecking, H.J.

    1997-08-01

    Progress was made in achieving a comprehensive and coherent description of material behavior in deformation processing. The materials included were metals, alloys, intermetallic compounds, arbitrary lattice structure, and metal matrix composites. Aspects of behavior modeled included kinetics of flow and strain hardening, as well as recrystallization and the various anisotropies of strength and compliance. Highlights include a new prediction of the limiting strength of materials at high temperature, a new understanding of the generation of new grain boundaries during forming operations, and a quantitatively verified computer simulation of texture development and the resulting behavioral anisotropies.

  4. Rapid prototype fabrication processes for high-performance thrust cells

    NASA Technical Reports Server (NTRS)

    Hunt, K.; Chwiedor, T.; Diab, J.; Williams, R.

    1994-01-01

    The Thrust Cell Technologies Program (Air Force Phillips Laboratory Contract No. F04611-92-C-0050) is currently being performed by Rocketdyne to demonstrate advanced materials and fabrication technologies which can be utilized to produce low-cost, high-performance thrust cells for launch and space transportation rocket engines. Under Phase 2 of the Thrust Cell Technologies Program (TCTP), rapid prototyping and investment casting techniques are being employed to fabricate a 12,000-lbf thrust class combustion chamber for delivery and hot-fire testing at Phillips Lab. The integrated process of investment casting directly from rapid prototype patterns dramatically reduces design-to-delivery cycle time, and greatly enhances design flexibility over conventionally processed cast or machined parts.

  5. Advanced Sulfur Control Processing

    SciTech Connect

    Gangwal, S.K.; Portzer, J.W.; Turk, B.S.; Gupta, R.

    1996-12-31

    The primary objective of this project is to determine the feasibility of an alternate concept for the regeneration of high temperature desulfurization sorbents in which elemental sulfur, instead of SO{sub 2}, is produced. If successful, this concept will eliminate or alleviate problems caused by the highly exothermic nature of the regeneration reaction, the tendency for metal sulfate formation, and the need to treat the regeneration off-gas to prevent atmospheric SO{sub 2}, emissions. Iron and cerium-based sorbents were chosen on the basis of thermodynamic analysis to determine the feasibility of elemental sulfur production. The ability of both to remove H{sub 2}S during the sulfidation phase is less than that of zinc-based sorbents, and a two-stage desulfurization process will likely be required. Preliminary experimental work used electrobalance reactors to compare the relative rates of reaction of O{sub 2} and H{sub 2}O with FeS. More detailed studies of the regeneration of FeS as well as the sulfidation of CeO{sub 2} and regeneration of Ce{sub 2}O{sub 2}S are being carried out in a laboratory-scale fixed-bed reactor equipped with a unique analytical system which permits semi-continuous analysis of the distribution of elemental sulfur, H{sub 2}S, and SO{sub 2} in the reaction product gas.

  6. ADVANCED OXIDATION PROCESS

    SciTech Connect

    Dr. Colin P. Horwitz; Dr. Terrence J. Collins

    2003-11-04

    The removal of recalcitrant sulfur species, dibenzothiophene and its derivatives, from automotive fuels is an integral component in the development of cleaner burning and more efficient automobile engines. Oxidative desulfurization (ODS) wherein the dibenzothiophene derivative is converted to its corresponding sulfoxide and sulfone is an attractive approach to sulfur removal because the oxidized species are easily extracted or precipitated and filtered from the hydrocarbon phase. Fe-TAML{reg_sign} activators of hydrogen peroxide (TAML is Tetra-Amido-Macrocyclic-Ligand) catalytically convert dibenzothiophene and its derivatives rapidly and effectively at moderate temperatures (50-60 C) and ambient pressure to the corresponding sulfoxides and sulfones. The oxidation process can be performed in both aqueous systems containing alcohols such as methanol, ethanol, or t-butanol, and in a two-phase hydrocarbon/aqueous system containing tert-butanol or acetonitrile. In the biphasic system, essentially complete conversion of the DBT to its oxidized products can be achieved using slightly longer reaction times than in homogeneous solution. Among the key features of the technology are the mild reaction conditions, the very high selectivity where no over oxidation of the sulfur compounds occurs, the near stoichiometric use of hydrogen peroxide, the apparent lack of degradation of sensitive fuel components, and the ease of separation of oxidized products.

  7. Development of the Direct Fabrication Process for Plutonium Immobilization

    SciTech Connect

    Congdon, J.W.

    2001-07-10

    The current baseline process for fabricating pucks for the Plutonium Immobilization Program includes granulation of the milled feed prior to compaction. A direct fabrication process was demonstrated that eliminates the need for granulation.

  8. Improved Process for Fabricating Carbon Nanotube Probes

    NASA Technical Reports Server (NTRS)

    Stevens, R.; Nguyen, C.; Cassell, A.; Delzeit, L.; Meyyappan, M.; Han, Jie

    2003-01-01

    An improved process has been developed for the efficient fabrication of carbon nanotube probes for use in atomic-force microscopes (AFMs) and nanomanipulators. Relative to prior nanotube tip production processes, this process offers advantages in alignment of the nanotube on the cantilever and stability of the nanotube's attachment. A procedure has also been developed at Ames that effectively sharpens the multiwalled nanotube, which improves the resolution of the multiwalled nanotube probes and, combined with the greater stability of multiwalled nanotube probes, increases the effective resolution of these probes, making them comparable in resolution to single-walled carbon nanotube probes. The robust attachment derived from this improved fabrication method and the natural strength and resiliency of the nanotube itself produces an AFM probe with an extremely long imaging lifetime. In a longevity test, a nanotube tip imaged a silicon nitride surface for 15 hours without measurable loss of resolution. In contrast, the resolution of conventional silicon probes noticeably begins to degrade within minutes. These carbon nanotube probes have many possible applications in the semiconductor industry, particularly as devices are approaching the nanometer scale and new atomic layer deposition techniques necessitate a higher resolution characterization technique. Previously at Ames, the use of nanotube probes has been demonstrated for imaging photoresist patterns with high aspect ratio. In addition, these tips have been used to analyze Mars simulant dust grains, extremophile protein crystals, and DNA structure.

  9. Advanced composite materials and processes

    NASA Technical Reports Server (NTRS)

    Baucom, Robert M.

    1991-01-01

    Composites are generally defined as two or more individual materials, which, when combined into a single material system, results in improved physical and/or mechanical properties. The freedom of choice of the starting components for composites allows the generation of materials that can be specifically tailored to meet a variety of applications. Advanced composites are described as a combination of high strength fibers and high performance polymer matrix materials. These advanced materials are required to permit future aircraft and spacecraft to perform in extended environments. Advanced composite precursor materials, processes for conversion of these materials to structures, and selected applications for composites are reviewed.

  10. Process for producing advanced ceramics

    DOEpatents

    Kwong, Kyei-Sing

    1996-01-01

    A process for the synthesis of homogeneous advanced ceramics such as SiC+AlN, SiAlON, SiC+Al.sub.2 O.sub.3, and Si.sub.3 N.sub.4 +AlN from natural clays such as kaolin, halloysite and montmorillonite by an intercalation and heat treatment method. Included are the steps of refining clays, intercalating organic compounds into the layered structure of clays, drying the intercalated mixture, firing the treated atmospheres and grinding the loosely agglomerated structure. Advanced ceramics produced by this procedure have the advantages of homogeneity, cost effectiveness, simplicity of manufacture, ease of grind and a short process time. Advanced ceramics produced by this process can be used for refractory, wear part and structure ceramics.

  11. Prediction of Corrosion of Advanced Materials and Fabricated Components

    SciTech Connect

    A. Anderko; G. Engelhardt; M.M. Lencka; M.A. Jakab; G. Tormoen; N. Sridhar

    2007-09-29

    The goal of this project is to provide materials engineers, chemical engineers and plant operators with a software tool that will enable them to predict localized corrosion of process equipment including fabricated components as well as base alloys. For design and revamp purposes, the software predicts the occurrence of localized corrosion as a function of environment chemistry and assists the user in selecting the optimum alloy for a given environment. For the operation of existing plants, the software enables the users to predict the remaining life of equipment and help in scheduling maintenance activities. This project combined fundamental understanding of mechanisms of corrosion with focused experimental results to predict the corrosion of advanced, base or fabricated, alloys in real-world environments encountered in the chemical industry. At the heart of this approach is the development of models that predict the fundamental parameters that control the occurrence of localized corrosion as a function of environmental conditions and alloy composition. The fundamental parameters that dictate the occurrence of localized corrosion are the corrosion and repassivation potentials. The program team, OLI Systems and Southwest Research Institute, has developed theoretical models for these parameters. These theoretical models have been applied to predict the occurrence of localized corrosion of base materials and heat-treated components in a variety of environments containing aggressive and non-aggressive species. As a result of this project, a comprehensive model has been established and extensively verified for predicting the occurrence of localized corrosion as a function of environment chemistry and temperature by calculating the corrosion and repassivation potentials.To support and calibrate the model, an experimental database has been developed to elucidate (1) the effects of various inhibiting species as well as aggressive species on localized corrosion of nickel

  12. Advanced fabrication technology for high speed aircraft structures

    NASA Technical Reports Server (NTRS)

    Bales, T. T.; Hoffman, E. K.; Bird, R. K.

    1990-01-01

    An overview of the development of the weld-brazing process for fabricating Ti-6Al-4V skin-stiffened panels, a brazing process for fabricating Bsc/Al titanium honeycomb core panels, and the enhanced diffusion bonding (EDB) process for fabricating Ti-14Al-21Nb titanium aluminide structural elements are presented. Data presented include the shear strengths of full-scale weldbrazed Ti-6Al-4V skin stiffened and Bsc/Al titanium honeycomb core sandwich panels designed to meet the requirements of an upper wing panel on the NASA YF-12. These results verified that the materials, fabrication processes, and structural concepts were qualified for Mach 3 flight. Shear strengths of each of the panel concepts following flight service evaluation are also reported. Comparisons made with the cost and weight of the original wing panel indicated that the weldbrazed titanium panels resulted in a 15-20 percent cost savings and the brazed Bsc/Al panel showed a 30 percent weight savings. It was also shown that the strengths of the EDB joints were sufficient to develop stresses in the Ti-14Al-21Nb face sheets of the sandwich structure which were above the yield strength of the material.

  13. A scalable fabrication process of polymer microneedles.

    PubMed

    Yang, Sixing; Feng, Yan; Zhang, Lijun; Chen, Nixiang; Yuan, Weien; Jin, Tuo

    2012-01-01

    While polymer microneedles may easily be fabricated by casting a solution in a mold, either centrifugation or vacuumizing is needed to pull the viscous polymer solution into the microholes of the mold. We report a novel process to fabricate polymer microneedles with a one-sided vacuum using a ceramic mold that is breathable but water impermeable. A polymer solution containing polyvinyl alcohol and polysaccharide was cast in a ceramic mold and then pulled into the microholes by a vacuum applied to the opposite side of the mold. After cross-linking and solidification through freeze-thawing, the microneedle patch was detached from the mold and transferred with a specially designed instrument for the drying process, during which the patch shrank evenly to form an array of regular and uniform needles without deformation. Moreover, the shrinkage of the patches helped to reduce the needles' size to ease microfabrication of the male mold. The dried microneedle patches were finally punched to the desired sizes to achieve various properties, including sufficient strength to penetrate skin, microneedles-absorbed water-swelling ratios, and drug-release kinetics. The results showed that the microneedles were strong enough to penetrate pigskin and that their performance was satisfactory in terms of swelling and drug release.

  14. Fabric geometry distortion during composites processing

    NASA Technical Reports Server (NTRS)

    Chen, Julie

    1994-01-01

    Waviness and tow misalignment are often cited as possible causes of data scatter and lower compression stiffness and strength in textile composites. Strength differences of as much as 40 percent have been seen in composites that appear to have the same basic material and structural properties -- i.e., yarn orientation, yarn size, interlacing geometry. Fabric geometry distortion has been suggested as a possible reason for this discrepancy, but little quantitative data or substantial evidence exists. The focus of this research is to contribute to the present understanding of the causes and effects of geometric distortion in textile composites. The initial part of the study was an attempt to gather qualitative information on a variety of textile structures. Existing and new samples confirmed that structures with a significant direction presence would be more susceptible to distortion due to the compaction process. Thus, uniweaves (fiber vol frac: 54-72 percent) biaxial braids (vf: 34-58 percent) demonstrated very little fabric geometry distortion. In stitched panels, only slight buckling of z-direction stitches was observed, primarily near the surface. In contrast, for structures with high compaction ratios -- e.g., large cylindrical yarns (2.5:1) orpowder towpreg (4:1) -- there were visible distortions where previously smooth and periodic undulations were transformed to abrupt changes in direction. A controlled study of the effect of forming pressure on distortion was conducted on type 162 glass plain weave fabrics. Panels (6 x 6 in) were produced via a resin infusion type setup, but with an EPON 815 epoxy resin. Pressures ranging from hand layup to 200 psi were used (vf: 34-54 percent). Photomicrographs indicated that at pressures up to 50 psi, large changes in thickness were due primarily to resin squeeze out. At higher pressures, when intimate contact was made between the layers, there was some tow flattening and in-plane shifting to optimize nesting. However

  15. Laser-assisted advanced assembly for MEMS fabrication

    NASA Astrophysics Data System (ADS)

    Atanasov, Yuriy Andreev

    Micro Electro-Mechanical Systems (MEMS) are currently fabricated using methods originally designed for manufacturing semiconductor devices, using minimum if any assembly at all. The inherited limitations of this approach narrow the materials that can be employed and reduce the design complexity, imposing limitations on MEMS functionality. The proposed Laser-Assisted Advanced Assembly (LA3) method solves these problems by first fabricating components followed by assembly of a MEMS device. Components are micro-machined using a laser or by photolithography followed by wet/dry etching out of any material available in a thin sheet form. A wide range of materials can be utilized, including biocompatible metals, ceramics, polymers, composites, semiconductors, and materials with special properties such as memory shape alloys, thermoelectric, ferromagnetic, piezoelectric, and more. The approach proposed allows enhancing the structural and mechanical properties of the starting materials through heat treatment, tribological coatings, surface modifications, bio-functionalization, and more, a limited, even unavailable possibility with existing methods. Components are transferred to the substrate for assembly using the thermo-mechanical Selective Laser Assisted Die Transfer (tmSLADT) mechanism for microchips assembly, already demonstrated by our team. Therefore, the mechanical and electronic part of the MEMS can be fabricated using the same equipment/method. The viability of the Laser-Assisted Advanced Assembly technique for MEMS is demonstrated by fabricating magnetic switches for embedding in a conductive carbon-fiber metamaterial for use in an Electromagnetic-Responsive Mobile Cyber-Physical System (E-RMCPS), which is expected to improve the wireless communication system efficiency within a battery-powered device.

  16. Advances in high-rate uncooled detector fabrication at Raytheon

    NASA Astrophysics Data System (ADS)

    Black, S. H.; Kraft, R.; Medrano, A.; Kocian, T.; Bradstreet, D.; Williams, R.; Yang, T.

    2010-04-01

    Over the past two years Raytheon has made a major investment aimed at establishing a high volume uncooled manufacturing capability. This effort has addressed three elements of the uncooled value stream, namely bolometer fabrication, packaging and calibration/test. To facilitate a low cost / high volume source of bolometers Raytheon has formed a partnership with a high volume 200mm commercial silicon wafer fabrication. Over a 12 month period Raytheon has installed 200mm VOx deposition equipment, matched the metrology used on the Raytheon 150mm line, transferred the process flow used to fabricate Raytheon's double layer bolometer process and qualified the product. In this paper we will review the process transfer methodology and bolometer performance. To reduce bolometer packaging cost and increase production rates, Raytheon has implemented an automated packaging line. This line utilizes automated adhesive dispense, component pick and place, wire bonding and solder seal. In this paper we will review the process flow, qualification process and line capacity Calibration and test has traditionally been performed using a number of temperature chambers, with increased throughput being obtained by adding more chambers. This comes at the expense of increased test labor required to feed the chambers and an increased energy and floor space foot print. To avoid these collateral costs, Raytheon has implemented an automated robotic calibration cell capable of performing in excess of 5,000 calibrations a month. In this paper we will provide an overview of the calibration cell along with takt time and throughput data.

  17. Fundamentals and advances in the development of remote welding fabrication systems

    NASA Technical Reports Server (NTRS)

    Agapakis, J. E.; Masubuchi, K.; Von Alt, C.

    1986-01-01

    Operational and man-machine issues for welding underwater, in outer space, and at other remote sites are investigated, and recent process developments are described. Probable remote welding missions are classified, and the essential characteristics of fundamental remote welding tasks are analyzed. Various possible operational modes for remote welding fabrication are identified, and appropriate roles for humans and machines are suggested. Human operator performance in remote welding fabrication tasks is discussed, and recent advances in the development of remote welding systems are described, including packaged welding systems, stud welding systems, remotely operated welding systems, and vision-aided remote robotic welding and autonomous welding systems.

  18. 0-G experiments with advanced ceramic fabric wick structures

    SciTech Connect

    Antoniak, Z.I.; Webb, B.J.; Bates, J.M.; Cooper, M.F.; Pauley, K.A.

    1991-07-01

    Both Air Force and NASA future spacecraft thermal management needs span the temperature range from cryogenic to liquid metals. Many of these needs are changing and not well defined and will remain so until goals, technology, and missions converge. Nevertheless, it is certain that high-temperature (> 800 K) and medium-temperature (about 450 K) radiator systems will have to be developed that offer significant improvements over current designs. This paper discusses experiments performed in the lower temperature regime as part of a comprehensive advanced ceramic fabric (ACF) heat pipe development program. These experiments encompassed wicking tests with various ceramic fabric samples, and heat transfer tests with a 1-m long prototype ACF water heat pipe. A prototype ceramic fabric/titanium water heat pipe has been constructed and tested; it transported up to 60 W of power at about 390 K. Startup and operation both with and against gravity examined. Wick testing was begun to aid in the design and construction of an improved prototype heat pipe, with a 38-{mu}m stainless steel linear covered by a biaxially-braided Nextel (trademark of the 3M Co., St. Paul, Minnesota) sleeve that is approximately 300-{mu}m thick. Wick testing took place in 1-g; limited testing in 0-g was initiated, and results to date suggest that in 0-g, wick performance improves over that in 1-g.

  19. Advanced Microstructured Semiconductor Neutron Detectors: Design, Fabrication, and Performance

    NASA Astrophysics Data System (ADS)

    Bellinger, Steven Lawrence

    The microstructured semiconductor neutron detector (MSND) was investigated and previous designs were improved and optimized. In the present work, fabrication techniques have been refined and improved to produce three-dimensional microstructured semiconductor neutron detectors with reduced leakage current, reduced capacitance, highly anisotropic deep etched trenches, and increased signal-to-noise ratios. As a result of these improvements, new MSND detection systems function with better gamma-ray discrimination and are easier to fabricate than previous designs. In addition to the microstructured diode fabrication improvement, a superior batch processing backfill-method for 6LiF neutron reactive material, resulting in a nearly-solid backfill, was developed. This method incorporates a LiF nano-sizing process and a centrifugal batch process for backfilling the nanoparticle LiF material. To better transition the MSND detector to commercialization, the fabrication process was studied and enhanced to better facilitate low cost and batch process MSND production. The research and development of the MSND technology described in this work includes fabrication of variant microstructured diode designs, which have been simulated through MSND physics models to predict performance and neutron detection efficiency, and testing the operational performance of these designs in regards to neutron detection efficiency, gamma-ray rejection, and silicon fabrication methodology. The highest thermal-neutron detection efficiency reported to date for a solid-state semiconductor detector is presented in this work. MSNDs show excellent neutron to gamma-ray (n/γ) rejection ratios, which are on the order of 106, without significant loss in thermal-neutron detection efficiency. Individually, the MSND is intrinsically highly sensitive to thermal neutrons, but not extrinsically sensitive because of their small size. To improve upon this, individual MSNDs were tiled together into a 6x6-element array

  20. Advanced Technology Composite Fuselage - Materials and Processes

    NASA Technical Reports Server (NTRS)

    Scholz, D. B.; Dost, E. F.; Flynn, B. W.; Ilcewicz, L. B.; Nelson, K. M.; Sawicki, A. J.; Walker, T. H.; Lakes, R. S.

    1997-01-01

    The goal of Boeing's Advanced Technology Composite Aircraft Structures (ATCAS) program was to develop the technology required for cost and weight efficient use of composite materials in transport fuselage structure. This contractor report describes results of material and process selection, development, and characterization activities. Carbon fiber reinforced epoxy was chosen for fuselage skins and stiffening elements and for passenger and cargo floor structures. The automated fiber placement (AFP) process was selected for fabrication of monolithic and sandwich skin panels. Circumferential frames and window frames were braided and resin transfer molded (RTM'd). Pultrusion was selected for fabrication of floor beams and constant section stiffening elements. Drape forming was chosen for stringers and other stiffening elements. Significant development efforts were expended on the AFP, braiding, and RTM processes. Sandwich core materials and core edge close-out design concepts were evaluated. Autoclave cure processes were developed for stiffened skin and sandwich structures. The stiffness, strength, notch sensitivity, and bearing/bypass properties of fiber-placed skin materials and braided/RTM'd circumferential frame materials were characterized. The strength and durability of cocured and cobonded joints were evaluated. Impact damage resistance of stiffened skin and sandwich structures typical of fuselage panels was investigated. Fluid penetration and migration mechanisms for sandwich panels were studied.

  1. Integrating optical fabrication and metrology into the optical design process.

    PubMed

    Harvey, James E

    2015-03-20

    The recent validation of a generalized linear systems formulation of surface scatter theory and an analysis of image degradation due to surface scatter in the presence of aberrations has provided credence to the development of a systems engineering analysis of image quality as degraded not only by diffraction effects and geometrical aberrations, but to scattering effects due to residual optical fabrication errors as well. This generalized surface scatter theory provides insight and understanding by characterizing surface scatter behavior with a surface transfer function closely related to the modulation transfer function of classical image formation theory. Incorporating the inherently band-limited relevant surface roughness into the surface scatter theory provides mathematical rigor into surface scatter analysis, and implementing a fast Fourier transform algorithm with logarithmically spaced data points facilitates the practical calculation of scatter behavior from surfaces with a large dynamic range of relevant spatial frequencies. These advances, combined with the continuing increase in computer speed, leave the optical design community in a position to routinely derive the optical fabrication tolerances necessary to satisfy specific image quality requirements during the design phase of a project; i.e., to integrate optical metrology and fabrication into the optical design process.

  2. Computer modeling of complete IC fabrication process

    NASA Astrophysics Data System (ADS)

    Dutton, Robert W.

    1987-05-01

    The development of fundamental algorithms for process and device modeling as well as novel integration of the tools for advanced Integrated Circuit (IC) technology design is discussed. The development of the first complete 2D process simulator, SUPREM 4, is reported. The algorithms are discussed as well as application to local-oxidation and extrinsic diffusion conditions which occur in CMOS AND BiCMOS technologies. The evolution of 1D (SEDAN) and 2D (PISCES) device analysis is discussed. The application of SEDAN to a variety of non-silicon technologies (GaAs and HgCdTe) are considered. A new multi-window analysis capability for PISCES which exploits Monte Carlo analysis of hot carriers has been demonstrated and used to characterize a variety of silicon MOSFET and GaAs MESFET effects. A parallel computer implementation of PISCES has been achieved using a Hypercube architecture. The PISCES program has been used for a range of important device studies including: latchup, analog switch analysis, MOSFET capacitance studies and bipolar transient device for ECL gates. The program is broadly applicable to RAM and BiCMOS technology analysis and design. In the analog switch technology area this research effort has produced a variety of important modeling and advances.

  3. Advanced Integrated Optical Signal Processing Components.

    NASA Astrophysics Data System (ADS)

    Rastani, Kasra

    This research was aimed at the development of advanced integrated optical components suitable for devices capable of processing multi-dimensional inputs. In such processors, densely packed waveguide arrays with low crosstalk are needed to provide dissection of the information that has been partially processed. Waveguide arrays also expand the information in the plane of the processor while maintaining its coherence. Rib waveguide arrays with low loss, high mode confinement and highly uniform surface quality (660 elements, 8 μm wide, 1 μm high, and 1 cm long with 2 mu m separations) were fabricated on LiNbO _3 substrates through the ion beam milling technique. A novel feature of the multi-dimensional IO processor architecture proposed herein is the implementation of large area uniform outcoupling (with low to moderate outcoupling efficiencies) from rib waveguide arrays in order to access the third dimension of the processor structure. As a means of outcoupling, uniform surface gratings (2 μm and 4 μm grating periods, 0.05 μm high and 1 mm long) with low outcoupling efficiencies (of approximately 2-18%/mm) were fabricated on the nonuniform surface of the rib waveguide arrays. As a practical technique of modulating the low outcoupling efficiencies of the surface gratings, it was proposed to alter the period of the grating as a function of position along each waveguide. Large aperture (2.5 mm) integrated lenses with short positive focal lengths (1.2-2.5 cm) were developed through a modification of the titanium-indiffused proton exchanged (TIPE) technique. Such integrated lenses were fabricated by increasing the refractive index of the slab waveguides by the TIPE process while maintaining the refractive index of the lenses at the lower level of Ti:LiNbO _3 waveguide. By means of curvature reversal of the integrated lenses, positive focal length lenses have been fabricated while providing high mode confinement for the slab waveguide. The above elements performed as

  4. Plasma Processing of Advanced Materials

    SciTech Connect

    Heberlein, Joachim, V.R.; Pfender, Emil; Kortshagen, Uwe

    2005-02-28

    Plasma Processing of Advanced Materials The project had the overall objective of improving our understanding of the influences of process parameters on the properties of advanced superhard materials. The focus was on high rate deposition processes using thermal plasmas and atmospheric pressure glow discharges, and the emphasis on superhard materials was chosen because of the potential impact of such materials on industrial energy use and on the environment. In addition, the development of suitable diagnostic techniques was pursued. The project was divided into four tasks: (1) Deposition of superhard boron containing films using a supersonic plasma jet reactor (SPJR), and the characterization of the deposition process. (2) Deposition of superhard nanocomposite films in the silicon-nitrogen-carbon system using the triple torch plasma reactor (TTPR), and the characterization of the deposition process. (3) Deposition of films consisting of carbon nanotubes using an atmospheric pressure glow discharge reactor. (4) Adapting the Thomson scattering method for characterization of atmospheric pressure non-uniform plasmas with steep spatial gradients and temporal fluctuations. This report summarizes the results.

  5. Silicon solar cell process development, fabrication, and analysis

    NASA Technical Reports Server (NTRS)

    Yoo, H. I.; Iles, P. A.; Leung, D. C.

    1981-01-01

    Work has progressed in fabrication and characterization of solar cells from ubiquitous crystallization process (UCP) wafers and LASS ribbons. Gettering tests applied to UCP wafers made little change on their performance compared with corresponding baseline data. Advanced processes such as shallow junction (SJ), back surface field (BSF), and multilayer antireflection (MLAR) were also applied. While BSF by Al paste had shunting problems, cells with SJ and BSF by evaporated Al, and MLAR did achieve 14.1% AMI on UCP silicon. The study of LASS material was very preliminary. Only a few cells with SJ, BSR, (no BSF) and MLAR were completed due to mechanical yield problems after lapping the material. Average efficiency was 10.7% AMI with 13.4% AMI for CZ controls. Relatively high minority carrier diffusion lengths were obtained. The lower than expected Jsc could be partially explained by low active area due to irregular sizes.

  6. Advanced System for Process Engineering

    SciTech Connect

    Williams, K. E.; Saus, L. S.; Regenhardt, P. A.

    1992-02-01

    ASPEN (Advanced System for Process Engineering) is a state of the art process simulator and economic evaluation package which was designed for use in engineering fossil energy conversion processes. ASPEN can represent multiphase streams including solids, and handle complex substances such as coal. The system can perform steady state material and energy balances, determine equipment size and cost, and carry out preliminary economic evaluations. It is supported by a comprehensive physical property system for computation of major properties such as enthalpy, entropy, free energy, molar volume, equilibrium ratio, fugacity coefficient, viscosity, thermal conductivity, and diffusion coefficient for specified phase conditions; vapor, liquid, or solid. The properties may be computed for pure components, mixtures, or components in a mixture, as appropriate. The ASPEN Input Language is oriented towards process engineers.

  7. Electrochemical/Pyrometallurgical Waste Stream Processing and Waste Form Fabrication

    SciTech Connect

    Steven Frank; Hwan Seo Park; Yung Zun Cho; William Ebert; Brian Riley

    2015-07-01

    This report summarizes treatment and waste form options being evaluated for waste streams resulting from the electrochemical/pyrometallurgical (pyro ) processing of used oxide nuclear fuel. The technologies that are described are South Korean (Republic of Korea – ROK) and United States of America (US) ‘centric’ in the approach to treating pyroprocessing wastes and are based on the decade long collaborations between US and ROK researchers. Some of the general and advanced technologies described in this report will be demonstrated during the Integrated Recycle Test (IRT) to be conducted as a part of the Joint Fuel Cycle Study (JFCS) collaboration between US Department of Energy (DOE) and ROK national laboratories. The JFCS means to specifically address and evaluated the technological, economic, and safe guard issues associated with the treatment of used nuclear fuel by pyroprocessing. The IRT will involve the processing of commercial, used oxide fuel to recover uranium and transuranics. The recovered transuranics will then be fabricated into metallic fuel and irradiated to transmutate, or burn the transuranic elements to shorter lived radionuclides. In addition, the various process streams will be evaluated and tested for fission product removal, electrolytic salt recycle, minimization of actinide loss to waste streams and waste form fabrication and characterization. This report specifically addresses the production and testing of those waste forms to demonstrate their compatibility with treatment options and suitability for disposal.

  8. A Rapid Process for Fabricating Gas Sensors

    PubMed Central

    Hsiao, Chun-Ching; Luo, Li-Siang

    2014-01-01

    Zinc oxide (ZnO) is a low-toxicity and environmentally-friendly material applied on devices, sensors or actuators for “green” usage. A porous ZnO film deposited by a rapid process of aerosol deposition (AD) was employed as the gas-sensitive material in a CO gas sensor to reduce both manufacturing cost and time, and to further extend the AD application for a large-scale production. The relative resistance change (ΔR/R) of the ZnO gas sensor was used for gas measurement. The fabricated ZnO gas sensors were measured with operating temperatures ranging from 110 °C to 180 °C, and CO concentrations ranging from 100 ppm to 1000 ppm. The sensitivity and the response time presented good performance at increasing operating temperatures and CO concentrations. AD was successfully for applied for making ZnO gas sensors with great potential for achieving high deposition rates at low deposition temperatures, large-scale production and low cost. PMID:25010696

  9. Processes of particle deposition in membrane operation and fabrication.

    PubMed

    Wiesner, M R; Tarabara, V; Cortalezzi, M

    2005-01-01

    The processes that control particle deposition on surfaces that are of interest in understanding operational aspects of membrane filtration, also hold significance in controlling the morphology of particle deposits as intermediate steps in membrane fabrication. This paper summarizes processes controlling particle deposit morphology. The implications of these processes for understanding membrane fouling by particles and in fabricating membranes are then considered.

  10. Advanced Information Processing System (AIPS)

    NASA Technical Reports Server (NTRS)

    Pitts, Felix L.

    1993-01-01

    Advanced Information Processing System (AIPS) is a computer systems philosophy, a set of validated hardware building blocks, and a set of validated services as embodied in system software. The goal of AIPS is to provide the knowledgebase which will allow achievement of validated fault-tolerant distributed computer system architectures, suitable for a broad range of applications, having failure probability requirements of 10E-9 at 10 hours. A background and description is given followed by program accomplishments, the current focus, applications, technology transfer, FY92 accomplishments, and funding.

  11. Practical Advances in Petroleum Processing

    NASA Astrophysics Data System (ADS)

    Hsu, Chang S.; Robinson, Paul R.

    "This comprehensive book by Robinson and Hsu will certainly become the standard text book for the oil refining business...[A] must read for all who are associated with oil refining." - Dr. Walter Fritsch, Senior Vice President Refining, OMV "This book covers a very advanced horizon of petroleum processing technology. For all refiners facing regional and global environmental concerns, and for those who seek a more sophisticated understanding of the refining of petroleum resources, this book has been long in coming." - Mr. Naomasa Kondo, Cosmo Oil Company, Ltd.

  12. Advances in natural language processing.

    PubMed

    Hirschberg, Julia; Manning, Christopher D

    2015-07-17

    Natural language processing employs computational techniques for the purpose of learning, understanding, and producing human language content. Early computational approaches to language research focused on automating the analysis of the linguistic structure of language and developing basic technologies such as machine translation, speech recognition, and speech synthesis. Today's researchers refine and make use of such tools in real-world applications, creating spoken dialogue systems and speech-to-speech translation engines, mining social media for information about health or finance, and identifying sentiment and emotion toward products and services. We describe successes and challenges in this rapidly advancing area.

  13. Fabrication of Advanced Thermoelectric Materials by Hierarchical Nanovoid Generation

    NASA Technical Reports Server (NTRS)

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

    2011-01-01

    A novel method to prepare an advanced thermoelectric material has hierarchical structures embedded with nanometer-sized voids which are key to enhancement of the thermoelectric performance. Solution-based thin film deposition technique enables preparation of stable film of thermoelectric material and void generator (voigen). A subsequent thermal process creates hierarchical nanovoid structure inside the thermoelectric material. Potential application areas of this advanced thermoelectric material with nanovoid structure are commercial applications (electronics cooling), medical and scientific applications (biological analysis device, medical imaging systems), telecommunications, and defense and military applications (night vision equipments).

  14. Fabrication process of Si microlenses for OCT systems

    NASA Astrophysics Data System (ADS)

    Jovic, A.; Pandraud, G.; Zinoviev, K.; Rubio, J. L.; Margallo, E.; Sarro, P. M.

    2016-04-01

    We present Si microlenses fabricated using dry ICP plasma etching of silicon and thermal photoresist reflow. The process is insensitive to thermal reflow time and it can be easily incorporated into fabrication flows for complex optical systems. Using this process, we were able to fabricate microlenses with diameter of 150 μm, radius of curvature of 682 μm and with a surface roughness of only 25 nm.

  15. A New Fabrication Process for Thin-Film Multijunction Thermal Converters

    SciTech Connect

    WUNSCH,THOMAS F.; KINARD,J.R.; MANGINELL,RONALD P.; SOLOMON JR.,OTIS M.; LIPE,T.E.; JUNGLING,KENNETH CORNEAL

    2000-12-08

    Advanced thin film processing and packaging technologies are employed in the fabrication of new planar thin-film multifunction thermal converters. The processing, packaging, and design features build on experience gained from prior NIST demonstrations of thin-film converters and are optimized for improved sensitivity, bandwidth, manufacturability, and reliability.

  16. Advanced fabrication techniques for hydrogen-cooled engine structures

    NASA Technical Reports Server (NTRS)

    Buchmann, O. A.; Arefian, V. V.; Warren, H. A.; Vuigner, A. A.; Pohlman, M. J.

    1985-01-01

    Described is a program for development of coolant passage geometries, material systems, and joining processes that will produce long-life hydrogen-cooled structures for scramjet applications. Tests were performed to establish basic material properties, and samples constructed and evaluated to substantiate fabrication processes and inspection techniques. Results of the study show that the basic goal of increasing the life of hydrogen-cooled structures two orders of magnitude relative to that of the Hypersonic Research Engine can be reached with available means. Estimated life is 19000 cycles for the channels and 16000 cycles for pin-fin coolant passage configurations using Nickel 201. Additional research is required to establish the fatigue characteristics of dissimilar-metal coolant passages (Nickel 201/Inconel 718) and to investigate the embrittling effects of the hydrogen coolant.

  17. Advances in LIGA-Based Post-Mold Fabrication

    SciTech Connect

    Christenson, T.R.

    1998-10-21

    The establishment of a process to allow planarization of deep x-ray lithography based microfabncated metal components via diamond lapping has enabled examination of three additional microfabrication issues. The areas of improvement that are discussed include materials, microassembly and packaging, and multilevel fabrication. New materials work has centered on magnetic materials including precision micromagnets and surface treatments of electrodeposited materials. Assembly and packaging has been aided by deep silicon etch processing and the use of conventional precision milling equipment combined with press-tit assembly. Diffhsion bonding is shown to be a particularly important approach to achieving multilevel metal mechanisms and furthermore shows promise for achieving batch assembled and packaged high aspect-ratio metal micromechanics,

  18. Disc resonator gyroscope fabrication process requiring no bonding alignment

    NASA Technical Reports Server (NTRS)

    Shcheglov, Kirill V. (Inventor)

    2010-01-01

    A method of fabricating a resonant vibratory sensor, such as a disc resonator gyro. A silicon baseplate wafer for a disc resonator gyro is provided with one or more locating marks. The disc resonator gyro is fabricated by bonding a blank resonator wafer, such as an SOI wafer, to the fabricated baseplate, and fabricating the resonator structure according to a pattern based at least in part upon the location of the at least one locating mark of the fabricated baseplate. MEMS-based processing is used for the fabrication processing. In some embodiments, the locating mark is visualized using optical and/or infrared viewing methods. A disc resonator gyroscope manufactured according to these methods is described.

  19. Integrating optical fabrication and metrology into the optical design process

    NASA Astrophysics Data System (ADS)

    Harvey, James E.

    2014-12-01

    Image degradation due to scattered radiation from residual optical fabrication errors is a serious problem in many short wavelength (X-ray/EUV) imaging systems. Most commercially-available image analysis codes (ZEMAX, Code V, ASAP, FRED, etc.) currently require the scatter behavior (BSDF data) to be provided as input in order to calculate the image quality of such systems. This BSDF data is difficult to measure and rarely available for the operational wavelengths of interest. Since the smooth-surface approximation is often not satisfied at these short wavelengths, the classical Rayleigh-Rice expression that indicates the BRDF is directly proportional to the surface PSD cannot be used to calculate BRDFs from surface metrology data for even slightly rough surfaces. However, an FFTLog numerical Hankel transform algorithm enables the practical use of the computationally intensive Generalized Harvey-Shack (GHS) surface scatter theory [1] to calculate BRDFs from surface PSDs for increasingly short wavelengths that violate the smooth surface approximation implicit in the Rayleigh-Rice surface scatter theory [2-3]. The recent numerical validation [4] of the GHS theory (a generalized linear systems formulation of surface scatter theory), and an analysis of image degradation due to surface scatter in the presence of aberrations [5] has provided credence to the development of a systems engineering analysis of image quality as degraded not only by diffraction effects and geometrical aberrations, but to scattering effects due to residual optical fabrication errors as well. These advances, combined with the continuing increase in computer speed, leave us poised to fully integrate optical metrology and fabrication into the optical design process.

  20. Method for Fabricating Composite Structures Using Pultrusion Processing

    NASA Technical Reports Server (NTRS)

    Farley, Gary L. (Inventor)

    2000-01-01

    A method for fabricating composite structures at a low-cost, moderate-to-high production rate. A first embodiment of the method includes employing a continuous press forming fabrication process. A second embodiment of the method includes employing a pultrusion process for obtaining composite structures. The methods include coating yarns with matrix material, weaving the yarn into fabric to produce a continuous fabric supply and feeding multiple layers of net-shaped fabrics having optimally oriented fibers into a debulking tool to form an undebulked preform. The continuous press forming fabrication process includes partially debulking the preform, cutting the partially debulked preform and debulking the partially debulked preform to form a net-shape. An electron-beam or similar technique then cures the structure. The pultrusion fabric process includes feeding the undebulked preform into a heated die and gradually debulking the undebulked preform. The undebulked preform in the heated die changes dimension until a desired cross-sectional dimension is achieved. This process further includes obtaining a net-shaped infiltrated uncured preform, cutting the uncured preform to a desired length and electron-beam curing (or similar technique) the uncured preform. These fabrication methods produce superior structures formed at higher production rates, resulting in lower cost and high structural performance.

  1. Method for Fabricating Composite Structures Using Pultrusion Processing

    NASA Technical Reports Server (NTRS)

    Farley, Gary L. (Inventor)

    2000-01-01

    A method for fabricating composite structures at a low-cost, moderate-to-high production rate. A first embodiment of the method includes employing a continuous press forming fabrication process. A second embodiment of the method includes employing a pultrusion process for obtaining composite structures. The methods include coating yarns with matrix material, weaving the yarn into fabric to produce a continuous fabric supply and feeding multiple layers of net-shaped fabrics having optimally oriented fibers into a debulking tool to form an undebulked preform. The continuous press forming fabrication process includes partially debulking the preform, cutting the partially debulked preform and debulking the partially debulked preform to form a netshape. An electron-beam or similar technique then cures the structure. The pultrusion fabric process includes feeding the undebulked preform into a heated die and gradually debulking the undebulked preform. The undebulked preform in the heated die changes dimension until a desired cross-sectional dimension is achieved. This process further includes obtaining a net-shaped infiltrated uncured preform, cutting the uncured preform to a desired length and electronbeam curing (or similar technique) the uncured preform. These fabrication methods produce superior structures formed at higher production rates, resulting in lower cost and high structural performance.

  2. Process for fabrication of metal oxide films

    SciTech Connect

    Tracy, C.E.; Benson, D.; Svensson, S.

    1990-07-17

    This invention is comprised of a method of fabricating metal oxide films from a plurality of reactants by inducing a reaction by plasma deposition among the reactants. The plasma reaction is effective for consolidating the reactants and producing thin films of metal oxides, e.g. electro-optically active transition metal oxides, at a high deposition rate. The presence of hydrogen during the plasma reaction enhances the deposition rate of the metal oxide. Various types of metal oxide films can be produced.

  3. PMMA microlens array fabricated by indentation process

    NASA Astrophysics Data System (ADS)

    Cirino, Giuseppe A.; Jasinevicius, Renato G.

    2017-02-01

    This work reports the fabrication of a PMMA-based spherical microlens array (MLA), targeting application of Shack-Hartmann wavefront sensor for lens characterization. The array present 10 by 10 elements, with f-number f/# = f/10 (1 mm diameter, 10 mm focal length). The fabrication method employs a computer-controlled mechanical indentation for the fabrication of an insert mold, and subsequent replication by injection molding on PMMA. After replication and de-molding, the PMMA surface containing the negative of the phase profile of the lens array was evaluated by optical profilometry technique, in terms of the surface quality as well as the replication fidelity. The RMS surface roughness level of approximately (λ/10) was found, considering operation in the visible range of spectrum. Optical characterization was based on the evaluation of the sharpness, FWHM, and maximum intensity, IMAX, values associated to the profiles of each of the 100 generated light spots, obtained in the back focal plane of the MLA. An average sharpness of FWHMAVG = 13.9 +/- 8% μm, and average maximum intensity of IMAX AVG = 0.72 +/- 7% a.u. was obtained.

  4. Advances in fabrication of Ag-clad Bi-2223 superconductors.

    SciTech Connect

    Balachandran, U.

    1998-09-04

    Powder-in-tube (PIT) processing was used to fabricate multifilamentary Ag-clad Bi{sub 2}Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub y} (Bi-2223) superconductors for various electric power applications. Enhancements in the transport current properties of long lengths of multifilament tapes were achieved by increasing the packing density of the precursor powder, improving the mechanical deformation, and adjusting the cooling rate. The dependence of the critical current density on magnetic field and temperature for the optimally processed tapes was measured. J{sub c} was greater than 10{sup 4} (A/cm{sup 2}) at 20 K for magnetic field up to 3 T and parallel to the c-axis which is of interest for use in refrigerator coded magnets. An attempt was made to combine the good alignment of Bi-2223 grains in Ag-sheathed superconducting tapes to obtain high J{sub c} values at high temperature and low field, and good intrinsic pinning of YBa{sub 2}Cu{sub 3}O{sub 7{minus}d} (Y-123) thin film to maintain high J{sub c} values in high fields. A new composite multifilament tape was fabricated such that the central part contained Bi-2223 filaments, with the primary function of conducting the transport current. The central Bi-2223 filaments were surrounded by Y-123 thin film to shield the applied magnetic field and protect the Bi-2223 filaments. The J{sub c} values of the composite tape were better than those of an uncoated tape. In the case of 77 K applications, an I{sub c} of about 60 A was obtained in a 150 m long tape and zero applied magnetic field. In-situ strain characteristics of the mono- and multifilament tapes were conducted.

  5. Ceramic component processing development for advanced gas-turbine engines

    NASA Technical Reports Server (NTRS)

    Mcentire, B. J.; Hengst, R. R.; Collins, W. T.; Taglialavore, A. P.; Yeckley, R. L.; Bright, E.; Bingham, M. G.

    1991-01-01

    A review of ceramic component advancements directed at developing manufacturing technologies for rotors, stators, vane-seat platforms and scrolls is presented. The first three components are being produced from HIPed Si3N4, while scrolls were prepared from a series of siliconized silicon-carbide materials. Developmental work has been conducted on all aspects of the fabrication process utilizing Taguchi experimental design methods. An assessment of material properties for various components from each process and material are made.

  6. Advanced Information Processing System - Fault detection and error handling

    NASA Technical Reports Server (NTRS)

    Lala, J. H.

    1985-01-01

    The Advanced Information Processing System (AIPS) is designed to provide a fault tolerant and damage tolerant data processing architecture for a broad range of aerospace vehicles, including tactical and transport aircraft, and manned and autonomous spacecraft. A proof-of-concept (POC) system is now in the detailed design and fabrication phase. This paper gives an overview of a preliminary fault detection and error handling philosophy in AIPS.

  7. Advances in cardiac processing software.

    PubMed

    Gordon DePuey, Ernest

    2014-07-01

    New software methods that incorporate iterative reconstruction, resolution recovery, and noise compensation now provide the ability to maintain or improve myocardial perfusion SPECT image quality with conventional sodium iodide cameras. Despite lower image counting statistics associated with significantly decreased injected radiopharmaceutical doses or shortened acquisition times or both, image quality is preserved or even improved compared with conventional processing methods. The ability to prescribe a desired myocardial count density by preselecting a SPECT acquisition time now avoids additional patient radiation exposure associated with "weight-based" dosing. More recent advancements, including temporal correlation among the gated perfusion frames and higher resolution SPECT acquisitions, hold promise to further improve image quality and diagnostic accuracy. Phase analysis of gated perfusion SPECT provides the ability to assess cardiac dyssynchrony and to select those patients who will most benefit from resynchronization therapy. In combination with the higher counting statistics afforded by the new solid-state dedicated cardiac cameras, these software advancements allow for even further decreased patient radiation doses or acquisition times or both. List-mode software allows for refinement of myocardial perfusion SPECT by interrogating particular data from selected cardiac cycles. Rejection of frames degraded by arrhythmic cardiac cycles or excessive extracardiac uptake can be excluded for reconstruction. Respiratory gating, which diminishes cardiac motion and potentially decreases diaphragmatic attenuation, has been demonstrated to improve diagnostic specificity. With high-count first-pass list-mode acquisitions at rest and during pharmacologic vasodilatation, it may be possible to measure global and regional myocardial perfusion reserve to more accurately diagnose coronary artery disease and avoid false-negative studies owing to balanced ischemia.

  8. 3D Printed Surgical Instruments: The Design and Fabrication Process.

    PubMed

    George, Mitchell; Aroom, Kevin R; Hawes, Harvey G; Gill, Brijesh S; Love, Joseph

    2017-01-01

    3D printing is an additive manufacturing process allowing the creation of solid objects directly from a digital file. We believe recent advances in additive manufacturing may be applicable to surgical instrument design. This study investigates the feasibility, design and fabrication process of usable 3D printed surgical instruments. The computer-aided design package SolidWorks (Dassault Systemes SolidWorks Corp., Waltham MA) was used to design a surgical set including hemostats, needle driver, scalpel handle, retractors and forceps. These designs were then printed on a selective laser sintering (SLS) Sinterstation HiQ (3D Systems, Rock Hill SC) using DuraForm EX plastic. The final printed products were evaluated by practicing general surgeons for ergonomic functionality and performance, this included simulated surgery and inguinal hernia repairs on human cadavers. Improvements were identified and addressed by adjusting design and build metrics. Repeated manufacturing processes and redesigns led to the creation of multiple functional and fully reproducible surgical sets utilizing the user feedback of surgeons. Iterative cycles including design, production and testing took an average of 3 days. Each surgical set was built using the SLS Sinterstation HiQ with an average build time of 6 h per set. Functional 3D printed surgical instruments are feasible. Advantages compared to traditional manufacturing methods include no increase in cost for increased complexity, accelerated design to production times and surgeon specific modifications.

  9. Chemical Thinning Process for Fabricating UV-Imaging CCDs

    NASA Technical Reports Server (NTRS)

    Jones, TOdd; Grunthaner, Paula; Nikzad, Shouleh; Wilson, Rick

    2004-01-01

    The thinning stage of the postfabrication process reported in the immediately preceding article is notable in its own right. Although the thinning process was described in the preceding article as part of an overall process of fabrication of a supported charge-coupled device (CCD), it is more generally applicable to both free-standing and supported devices that have been fabricated in die and wafer formats. Like the thermocompression bonding process described in the preceding article, the thinning process is compatible with CCD-fabrication processes, as well as postfabrication processes that enhance the response of CCDs to ultraviolet (UV) light, including the delta-doping process. CCDs that are thinned by this process and then delta-doped exhibit high quantum efficiencies that are stable with time and with exposure to the environment.

  10. Ultrasonic imaging system for in-process fabric defect detection

    DOEpatents

    Sheen, Shuh-Haw; Chien, Hual-Te; Lawrence, William P.; Raptis, Apostolos C.

    1997-01-01

    An ultrasonic method and system are provided for monitoring a fabric to identify a defect. A plurality of ultrasonic transmitters generate ultrasonic waves relative to the fabric. An ultrasonic receiver means responsive to the generated ultrasonic waves from the transmitters receives ultrasonic waves coupled through the fabric and generates a signal. An integrated peak value of the generated signal is applied to a digital signal processor and is digitized. The digitized signal is processed to identify a defect in the fabric. The digitized signal processing includes a median value filtering step to filter out high frequency noise. Then a mean value and standard deviation of the median value filtered signal is calculated. The calculated mean value and standard deviation are compared with predetermined threshold values to identify a defect in the fabric.

  11. Computer Modeling of Complete IC Fabrication Process.

    DTIC Science & Technology

    1987-05-28

    Packard Richard Gurtler Motorola Joseph Chapley GTE Microcircuits Peter A. Habitz IBM King-Shan Chan Commodore Sameer Haddad Advanced Micro Devk Raymond...Forsythe National Semiconductor Nadim I. Maluf Siliconix Inc. Jorge Garcia-Colevatti AT&T Bell Labs Deborah D. Maracas Motorola Sidney C. Garrison Motorola

  12. Fabrication process for a gradient index x-ray lens

    DOEpatents

    Bionta, Richard M.; Makowiecki, Daniel M.; Skulina, Kenneth M.

    1995-01-01

    A process for fabricating high efficiency x-ray lenses that operate in the 0.5-4.0 keV region suitable for use in biological imaging, surface science, and x-ray lithography of integrated circuits. The gradient index x-ray optics fabrication process broadly involves co-sputtering multi-layers of film on a wire, followed by slicing and mounting on block, and then ion beam thinning to a thickness determined by periodic testing for efficiency. The process enables the fabrication of transmissive gradient index x-ray optics for the 0.5-4.0 keV energy range. This process allows the fabrication of optical elements for the next generation of imaging and x-ray lithography instruments m the soft x-ray region.

  13. Fabrication process for a gradient index x-ray lens

    DOEpatents

    Bionta, R.M.; Makowiecki, D.M.; Skulina, K.M.

    1995-01-17

    A process is disclosed for fabricating high efficiency x-ray lenses that operate in the 0.5-4.0 keV region suitable for use in biological imaging, surface science, and x-ray lithography of integrated circuits. The gradient index x-ray optics fabrication process broadly involves co-sputtering multi-layers of film on a wire, followed by slicing and mounting on block, and then ion beam thinning to a thickness determined by periodic testing for efficiency. The process enables the fabrication of transmissive gradient index x-ray optics for the 0.5-4.0 keV energy range. This process allows the fabrication of optical elements for the next generation of imaging and x-ray lithography instruments in the soft x-ray region. 13 figures.

  14. 43. PROCESS WELDING SHEDS (FABRICATION SHOPS) ON RIGHT, AND TANK ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    43. PROCESS WELDING SHEDS (FABRICATION SHOPS) ON RIGHT, AND TANK BARGE, CRANES, PAINT SHOP AND PIPE/MACHINE SHOP IN BACKGROUND, LOOKING NORTHEAST - Hillman Barge & Construction Company, Paul Thomas Boulevard, Brownsville, Fayette County, PA

  15. Advanced Materials and Processing 2010

    NASA Astrophysics Data System (ADS)

    Zhang, Yunfeng; Su, Chun Wei; Xia, Hui; Xiao, Pengfei

    2011-06-01

    Strain sensors made from MWNT/polymer nanocomposites / Gang Yin, Ning Hu and Yuan Li -- Shear band evolution and nanostructure formation in titanium by cold rolling / Dengke Yang, Peter D. Hodgson and Cuie Wen -- Biodegradable Mg-Zr-Ca alloys for bone implant materials / Yuncang Li ... [et al.] -- Hydroxyapatite synthesized from nanosized calcium carbonate via hydrothermal method / Yu-Shiang Wu, Wen-Ku Chang and Min Jou -- Modeling of the magnetization process and orthogonal fluxgate sensitivity of ferromagnetic micro-wire arrays / Fan Jie ... [et al.] -- Fabrication of silicon oxide nanowires on Ni coated silicon substrate by simple heating process / Bo Peng and Kwon-Koo Cho -- Deposition of TiOxNy thin films with various nitrogen flow rate: growth behavior and structural properties / S.-J. Cho ... [et al.] -- Observation on photoluminescence evolution in 300 KeV self-ion implanted and annealed silicon / Yu Yang ... [et al.] -- Facile synthesis of lithium niobate from a novel precursor H[symbol] / Meinan Liu ... [et al.] -- Effects of the buffer layers on the adhesion and antimicrobial properties of the amorphous ZrAlNiCuSi films / Pai-Tsung Chiang ... [et al.] -- Fabrication of ZnO nanorods by electrochemical deposition process and its photovoltaic properties / Jin-Hwa Kim ... [et al.] -- Cryogenic resistivities of NbTiAlVTaLax, CoCrFeNiCu and CoCrFeNiAl high entropy alloys / Xiao Yang and Yong Zhang -- Modeling of centrifugal force field and the effect on filling and solidification in centrifugal casting / Wenbin Sheng, Chunxue Ma and Wanli Gu -- Electrochemical properties of TiO[symbol] nanotube arrays film prepared by anodic oxidation / Young-Jin Choi ... [et al.] -- Effect of Ce additions on high temperature properties of Mg-5Sn-3Al-1Zn alloy / Byoung Soo Kang ... [et al.] -- Sono-electroless plating of Ni-Mo-P film / Atsushi Chiba, Masato Kanou and Wen-Chang Wu -- Diameter dependence of giant magneto-impedance effect in co-based melt extracted amorphous

  16. Optical processing for semiconductor device fabrication

    NASA Technical Reports Server (NTRS)

    Sopori, Bhushan L.

    1994-01-01

    A new technique for semiconductor device processing is described that uses optical energy to produce local heating/melting in the vicinity of a preselected interface of the device. This process, called optical processing, invokes assistance of photons to enhance interface reactions such as diffusion and melting, as compared to the use of thermal heating alone. Optical processing is performed in a 'cold wall' furnace, and requires considerably lower energies than furnace or rapid thermal annealing. This technique can produce some device structures with unique properties that cannot be produced by conventional thermal processing. Some applications of optical processing involving semiconductor-metal interfaces are described.

  17. Optimizing The DSSC Fabrication Process Using Lean Six Sigma

    NASA Astrophysics Data System (ADS)

    Fauss, Brian

    Alternative energy technologies must become more cost effective to achieve grid parity with fossil fuels. Dye sensitized solar cells (DSSCs) are an innovative third generation photovoltaic technology, which is demonstrating tremendous potential to become a revolutionary technology due to recent breakthroughs in cost of fabrication. The study here focused on quality improvement measures undertaken to improve fabrication of DSSCs and enhance process efficiency and effectiveness. Several quality improvement methods were implemented to optimize the seven step individual DSSC fabrication processes. Lean Manufacturing's 5S method successfully increased efficiency in all of the processes. Six Sigma's DMAIC methodology was used to identify and eliminate each of the root causes of defects in the critical titanium dioxide deposition process. These optimizations resulted with the following significant improvements in the production process: 1. fabrication time of the DSSCs was reduced by 54 %; 2. fabrication procedures were improved to the extent that all critical defects in the process were eliminated; 3. the quantity of functioning DSSCs fabricated was increased from 17 % to 90 %.

  18. Fabrication of Separator Demonstration Facility process vessel

    SciTech Connect

    Oberst, E.F.

    1985-01-15

    The process vessel system is the central element in the Separator Development Facility (SDF). It houses the two major process components, i.e., the laser-beam folding optics and the separators pods. This major subsystem is the critical-path procurement for the SDF project. Details of the vaious parts of the process vessel are given.

  19. Fabrication of SiC mat by radiation processing

    NASA Astrophysics Data System (ADS)

    Kang, Phil-Hyun; Jeun, Joon-Pyo; Seo, Dong-Kwon; Nho, Young-Chang

    2009-07-01

    Silicon carbide (SiC) exhibits many important properties, such as high intrinsic strength, stiffness, and high temperature stability. Therein, it is considered to be one of the most promising candidates for reinforcement of advanced ceramic matrix composites. The use of preceramic polymers presents the possibility of solving the intricacies involved in obtaining a new generation of ceramic materials. In this study, a radiation processing method was used to fabricate a cured polycarbosilane mat as a preceramic polymer. The polycarbosilane mat was cured by electron beam (e-beam) irradiation up to 10 MGy in an inert gas atmosphere. Next, the e-beam-cured PCS mat, as green fiber, was carbonized to produce the SiC mat. The conversion process of the PCS mat into the SiC mat was investigated by SEM, FT-IR, XRD, and TGA. According to FT-IR analysis, the Si-H peak intensity was observed to decrease as the polymer structure changed from polycarbosilane to SiC. The XRD patterns of SiC showed the diffraction peaks at (1 1 1), (2 2 0), and (3 1 1) which indicated the emergence of β-SiC. TGA curve shows that weight percent of residue of electrospun PCS mat, e-beam-cured PCS mat and pyrolyzed SiC mat up to 1000 °C were 72.5%, 88.3%, and 99.2%, respectively.

  20. Advances in the fabrication of graphene transistors on flexible substrates

    PubMed Central

    Lo Verso, Stella; Di Marco, Silvestra; Vinciguerra, Vincenzo; Schilirò, Emanuela; Di Franco, Salvatore; Lo Nigro, Raffaella; Roccaforte, Fabrizio; Zurutuza, Amaia; Centeno, Alba; Ravesi, Sebastiano; Giannazzo, Filippo

    2017-01-01

    Graphene is an ideal candidate for next generation applications as a transparent electrode for electronics on plastic due to its flexibility and the conservation of electrical properties upon deformation. More importantly, its field-effect tunable carrier density, high mobility and saturation velocity make it an appealing choice as a channel material for field-effect transistors (FETs) for several potential applications. As an example, properly designed and scaled graphene FETs (Gr-FETs) can be used for flexible high frequency (RF) electronics or for high sensitivity chemical sensors. Miniaturized and flexible Gr-FET sensors would be highly advantageous for current sensors technology for in vivo and in situ applications. In this paper, we report a wafer-scale processing strategy to fabricate arrays of back-gated Gr-FETs on poly(ethylene naphthalate) (PEN) substrates. These devices present a large-area graphene channel fully exposed to the external environment, in order to be suitable for sensing applications, and the channel conductivity is efficiently modulated by a buried gate contact under a thin Al2O3 insulating film. In order to be compatible with the use of the PEN substrate, optimized deposition conditions of the Al2O3 film by plasma-enhanced atomic layer deposition (PE-ALD) at a low temperature (100 °C) have been developed without any relevant degradation of the final dielectric performance. PMID:28326237

  1. Advanced Manufacturing Techniques Demonstrated for Fabricating Developmental Hardware

    NASA Technical Reports Server (NTRS)

    Redding, Chip

    2004-01-01

    NASA Glenn Research Center's Engineering Development Division has been working in support of innovative gas turbine engine systems under development by Glenn's Combustion Branch. These one-of-a-kind components require operation under extreme conditions. High-temperature ceramics were chosen for fabrication was because of the hostile operating environment. During the designing process, it became apparent that traditional machining techniques would not be adequate to produce the small, intricate features for the conceptual design, which was to be produced by stacking over a dozen thin layers with many small features that would then be aligned and bonded together into a one-piece unit. Instead of using traditional machining, we produced computer models in Pro/ENGINEER (Parametric Technology Corporation (PTC), Needham, MA) to the specifications of the research engineer. The computer models were exported in stereolithography standard (STL) format and used to produce full-size rapid prototype polymer models. These semi-opaque plastic models were used for visualization and design verification. The computer models also were exported in International Graphics Exchange Specification (IGES) format and sent to Glenn's Thermal/Fluids Design & Analysis Branch and Applied Structural Mechanics Branch for profiling heat transfer and mechanical strength analysis.

  2. Advanced Manufacturing Techniques Demonstrated for Fabricating Developmental Hardware

    NASA Technical Reports Server (NTRS)

    Redding, Chip

    2004-01-01

    NASA Glenn Research Center's Engineering Development Division has been working in support of innovative gas turbine engine systems under development by Glenn's Combustion Branch. These one-of-a-kind components require operation under extreme conditions. High-temperature ceramics were chosen for fabrication was because of the hostile operating environment. During the designing process, it became apparent that traditional machining techniques would not be adequate to produce the small, intricate features for the conceptual design, which was to be produced by stacking over a dozen thin layers with many small features that would then be aligned and bonded together into a one-piece unit. Instead of using traditional machining, we produced computer models in Pro/ENGINEER (Parametric Technology Corporation (PTC), Needham, MA) to the specifications of the research engineer. The computer models were exported in stereolithography standard (STL) format and used to produce full-size rapid prototype polymer models. These semi-opaque plastic models were used for visualization and design verification. The computer models also were exported in International Graphics Exchange Specification (IGES) format and sent to Glenn's Thermal/Fluids Design & Analysis Branch and Applied Structural Mechanics Branch for profiling heat transfer and mechanical strength analysis.

  3. Silicon solar cell process. Development, fabrication and analysis

    NASA Technical Reports Server (NTRS)

    Yoo, H. I.; Iles, P. A.; Tanner, D. P.

    1978-01-01

    Solar cells were fabricated from unconventional silicon sheets, and the performances were characterized with an emphasis on statistical evaluation. A number of solar cell fabrication processes were used and conversion efficiency was measured under AMO condition at 25 C. Silso solar cells using standard processing showed an average efficiency of about 9.6%. Solar cells with back surface field process showed about the same efficiency as the cells from standard process. Solar cells from grain boundary passivation process did not show any improvements in solar cell performance.

  4. Batch fabrication process development for ferrite logic conductors

    NASA Technical Reports Server (NTRS)

    Heckler, C. H., Jr.; Bhiwandker, N. C.

    1972-01-01

    A process for fabricating ultrareliable magnetic ferrite logic circuits is described in which the conductors are formed by a combination of two batch type processes - photolithography and electroplating - and a mechanized writing process for completing conductors in the third dimension. Up to 4 turns, through an aperture 1 mm in diameter, are formed by the described process. The number of joints in the conductors is reduced by use of this process to only those which are required for input, output and power connections of a logic block. To demonstrate feasibility, 8-stage magnetic ring counter circuits have been fabricated.

  5. Electrochromic Windows: Process and Fabrication Improvements for Lower Total Costs

    SciTech Connect

    Mark Burdis; Neil Sbar

    2007-03-31

    The overall goal with respect to the U.S. Department of Energy (DOE) is to achieve significant national energy savings through maximized penetration of EC windows into existing markets so that the largest cumulative energy reduction can be realized. The speed with which EC windows can be introduced and replace current IGU's (and current glazings) is clearly a strong function of cost. Therefore, the aim of this project was to investigate possible improvements to the SageGlass{reg_sign} EC glazing products to facilitate both process and fabrication improvements resulting in lower overall costs. The project was split into four major areas dealing with improvements to the electrochromic layer, the capping layer, defect elimination and general product improvements. Significant advancements have been made in each of the four areas. These can be summarized as follows: (1) Plasma assisted deposition for the electrochromic layer was pursued, and several improvements made to the technology for producing a plasma beam were made. Functional EC devices were produced using the new technology, but there are still questions to be answered regarding the intrinsic properties of the electrochromic films produced by this method. (2) The capping layer work was successfully implemented into the existing SageGlass{reg_sign} product, thereby providing a higher level of transparency and somewhat lower reflectivity than the 'standard' product. (3) Defect elimination is an ongoing effort, but this project spurred some major defect reduction programs, which led to significant improvements in yield, with all the implicit benefits afforded. In particular, major advances were made in the development of a new bus bar application process aimed at reducing the numbers of 'shorts' developed in the finished product, as well as making dramatic improvements in the methods used for tempering the glass, which had previously been seen to produce a defect which appeared as a pinhole. (4) Improvements have

  6. Development and fabrication of an advanced liquid cooling garment

    NASA Technical Reports Server (NTRS)

    Hixon, C. W.

    1978-01-01

    A tube/fin concept liquid cooling garment head cooler was developed, fabricated and delivered to NASA-ARC. The head cooler was fabricated from polyurethane film which sandwiches the transport fluid tubing and a thermally conductive fin material. The head cooler garment is sewn to form a skull cap and covered with a comfort liner. In addition, two Neonate heating garments were fabricated and supplied to NASA for further finishing and use in medical tests. The resulting garment is flexible, elastic and conforms to the head comfortably. Tests on a tube/fin element of identical construction as the head cooler demonstrated good thermal effectiveness. Use of commercially available materials and development of relatively simple fabrication techniques give the potential for a low garment cost.

  7. Mechanical design and fabrication processes for the ALS third-harmonic cavities

    SciTech Connect

    Franks, M; Henderson, T; Hernandez, K; Otting, D; Plate, D; Rimmer, R

    1999-03-25

    It is planned to install five third-harmonic (1.5 GHz) RF Cavities in May/June 1999 as an upgrade to the Advanced Light Source (ALS) at Lawrence Berkeley National Laboratory (LBNL). This paper presents mechanical design features, their experiences in using electronic design models to expedite the manufacturing process, and the fabrication processes employed to produce these cavities for the ALS. They discuss some of the lessons learned from the PEP-II RF Cavity design and fabrication, and outline the improvements incorporated in the new design. They also report observations from the current effort.

  8. Process for fabricating a microelectromechanical structure

    DOEpatents

    Sniegowski, Jeffry J.; Krygowski, Thomas W.; Mani, Seethambal S.; Habermehl, Scott D.; Hetherington, Dale L.; Stevens, James E.; Resnick, Paul J.; Volk, Steven R.

    2004-10-26

    A process is disclosed for forming a microelectromechanical (MEM) structure on a substrate having from 5 to 6 or more layers of deposited and patterned polysilicon. The process is based on determining a radius of curvature of the substrate which is bowed due to accumulated stress in the layers of polysilicon and a sacrificial material used to buildup the MEM structure, and then providing one or more stress-compensation layers on a backside of the substrate to flatten the substrate and allow further processing.

  9. MEMS product engineering using fabrication process development tools

    NASA Astrophysics Data System (ADS)

    Hahn, K.; Schmidt, T.; Ortloff, D.; Popp, J.; Wagener, A.; Brück, R.

    2008-12-01

    The development of MEMS devices differs substantially from product engineering methods used in more traditional industries. The approach is characterized by a close customer involvement and product specific fabrication processes. A large number interdependencies between device design on the one hand and manufacturing process development on the other hand make product engineering in the MEMS area a rather tedious and complicated task. In this paper we discuss a comprehensive customer-oriented MEMS product engineering methodology. Both MEMS design and fabrication process development are analyzed with regard to procedures and interfaces used in order to develop an appropriate CAD support either in terms of existing tools or by specifying individual tools to be implemented. The manufacturing process development is part of this holistic approach and is supported by a CAD environment for the management and the design of thin-film MEMS fabrication processes. This environment has been developed by the authors and became recently commercially available.

  10. Novel Fabrication Process for Micro Thermoelectric Generators (μTEGs)

    NASA Astrophysics Data System (ADS)

    Pelz, U.; Jaklin, J.; Rostek, R.; Kröner, M.; Woias, P.

    2015-12-01

    A cost effective bottom-up process for the fabrication of micro thermoelectric generators (μTEGs) was developed. It is based on a novel fabrication method involving a selectively sacrificial photoresist for the sequential galvanostatic electrodeposition of thermoelectric materials. The use of an industrial pick and placer (P&P) for dispensing the second photoresist allows for accurate and flexible μTEG designs. The process makes use of Ordyl® as a negative dry film photoresist template and sequential lamination steps for shaping all thermoelectric legs and contacts. All structures of the μTEG are generated in one photoresist multi-layer - this represents the most significant advantage of the process. The process uses a minimum of clean room processing for the preparation of pre-structured substrates for electrodeposition and therefore provides a cost-effective, highly flexible fabrication platform for research and development.

  11. Process for fabricating continuous lengths of superconductor

    DOEpatents

    Kroeger, Donald M.; List, III, Frederick A.

    1998-01-01

    A process for manufacturing a superconductor. The process is accomplished by depositing a superconductor precursor powder on a continuous length of a first substrate ribbon, overlaying a continuous length of a second substrate ribbon on said first substrate ribbon, and applying sufficient pressure to form a bound layered superconductor precursor between said first substrate ribbon and said second substrates ribbon. The layered superconductor precursor is then heat treated to form a super conductor layer.

  12. In process monitoring of optics fabrication

    NASA Astrophysics Data System (ADS)

    Faehnle, O.

    2017-06-01

    During polishing of optical surfaces, light scattering from within the sample under test enables on machine monitoring of surface roughness levels during polishing. Surface roughness levels of 0.6 nm rms have been detected and the influence of different pH values of polishing slurries on the surface quality being generated have been monitored. In addition, iIRM's capability to function as in process contamination control of industrial polishing processes has been demonstrated.

  13. MEMS pressure sensor fabricated by advanced bulk micromachining techniques

    NASA Astrophysics Data System (ADS)

    Vanko, Gabriel; Hudek, Peter; Zehetner, Johann; Dzuba, Jaroslav; Choleva, Pavlina; Vallo, Martin; Rýger, Ivan; Lalinský, Tibor

    2013-05-01

    We present the design and implementation of a MEMS pressure sensor with an operation potential under harsh conditions at high temperatures (T = 300 - 800°C). The sensor consists of a circular HEMT (C-HEMT) integrated on a circular AlGaN/GaN membrane. In order to realize MEMS for extreme conditions using AlGaN/GaN material system, two key issues should be solved: (a) realization of MEMS structures by etching of the substrate material and (b) formation of metallic contacts (both ohmic and Schottky) to be able to withstand high thermal loads. In this design concept the piezoresistive and piezoelectric effect of AlGaN/GaN heterostructure is used to sense the pressure under static and/or dynamic conditions. The backside bulk micromachining of our SiC wafer in the first experiment started with FS-laser ablation down to ~200 -270μm deep holes of 500μm in diameter. Because no additional intermediate layer can stop the ablation process, the number of laser pulses has to be optimized in order to reach the required ablation depth. 2D structural-mechanical and piezoelectric analyses were performed to verify the mechanical and piezoelectric response of the circular membrane pressure sensor to static pressure load (in the range between 20 and 100kPa). We suggested that suppressing the residual stress in the membrane can improve the sensor response. The parameters of the same devices previously fabricated on bulk substrates and/or membranes were compared. The maxima of drain currents of our C-HEMT devices on SiC exhibit more than four times higher values compared to those measured on silicon substrates.

  14. An infiltration/cure model for manufacture of fabric composites by the resin infusion process

    NASA Technical Reports Server (NTRS)

    Weideman, Mark H.; Loos, Alfred C.; Dexter, H. Benson; Hasko, Gregory H.

    1992-01-01

    A 1-D infiltration/cure model was developed to simulate fabrication of advanced textile composites by the resin film infusion process. The simulation model relates the applied temperature and pressure processing cycles, along with the experimentally measured compaction and permeability characteristics of the fabric preforms, to the temperature distribution, the resin degree of cure and viscosity, and the infiltration flow front position as a function of time. The model also predicts the final panel thickness, fiber volume fraction, and resin mass for full saturation as a function of compaction pressure. Composite panels were fabricated using the RTM (Resin Transfer Molding) film infusion technique from knitted, knitted/stitched, and 2-D woven carbon preforms and Hercules 3501-6 resin. Fabric composites were fabricated at different compaction pressures and temperature cycles to determine the effects of the processing on the properties. The composites were C-scanned and micrographed to determine the quality of each panel. Advanced cure cycles, developed from the RTM simulation model, were used to reduce the total cure cycle times by a factor of 3 and the total infiltration times by a factor of 2.

  15. Fabrication of High Thermal Conductivity NARloy-Z-Diamond Composite Combustion Chamber Liner for Advanced Rocket Engines

    NASA Technical Reports Server (NTRS)

    Bhat, Biliyar N.; Greene, Sandra E.; Singh, Jogender

    2016-01-01

    NARloy-Z alloy (Cu-3 percent, Ag-0.5 percent, Zr) is a state of the art alloy currently used for fabricating rocket engine combustion chamber liners. Research conducted at NASA-MSFC and Penn State – Applied Research Laboratory has shown that thermal conductivity of NARloy-Z can be increased significantly by adding diamonds to form a composite (NARloy-Z-D). NARloy-Z-D is also lighter than NARloy-Z. These attributes make this advanced composite material an ideal candidate for fabricating combustion chamber liner for an advanced rocket engine. Increased thermal conductivity will directly translate into increased turbopump power and increased chamber pressure for improved thrust and specific impulse. This paper describes the process development for fabricating a subscale high thermal conductivity NARloy-Z-D combustion chamber liner using Field Assisted Sintering Technology (FAST). The FAST process uses a mixture of NARloy-Z and diamond powders which is sintered under pressure at elevated temperatures. Several challenges were encountered, i.e., segregation of diamonds, machining the super hard NARloy-Z-D composite, net shape fabrication and nondestructive examination. The paper describes how these challenges were addressed. Diamonds coated with copper (CuD) appear to give the best results. A near net shape subscale combustion chamber liner is being fabricated by diffusion bonding cylindrical rings of NARloy-Z-CuD using the FAST process.

  16. Molecular sieving silica membrane fabrication process

    DOEpatents

    Raman, Narayan K.; Brinker, Charles Jeffrey

    1998-01-01

    A process for producing a molecular sieve silica membrane comprising depositing a hybrid organic-inorganic polymer comprising at least one organic constituent and at least one inorganic constituent on a porous substrate material and removing at least a portion of the at least one organic constituent of the hybrid organic-inorganic polymer, forming a porous film.

  17. Molecular sieving silica membrane fabrication process

    DOEpatents

    Raman, Narayan K.; Brinker, Charles Jeffrey

    1999-01-01

    A process for producing a molecular sieve silica membrane comprising depositing a hybrid organic-inorganic polymer comprising at least one organic constituent and at least one inorganic constituent on a porous substrate material and removing at least a portion of the at least one organic constituent of the hybrid organic-inorganic polymer, forming a porous film.

  18. Molecular sieving silica membrane fabrication process

    DOEpatents

    Raman, N.K.; Brinker, C.J.

    1999-08-10

    A process is described for producing a molecular sieve silica membrane comprising depositing a hybrid organic-inorganic polymer comprising at least one organic constituent and at least one inorganic constituent on a porous substrate material and removing at least a portion of the at least one organic constituent of the hybrid organic-inorganic polymer, forming a porous film. 11 figs.

  19. Fabrication development of Li 2O pebbles by wet process

    NASA Astrophysics Data System (ADS)

    Tsuchiya, Kunihiko; Fuchinoue, Katsuhiro; Saito, Shigeru; Watarumi, Kazutoshi; Furuya, Takemi; Kawamura, Hiroshi

    1998-03-01

    Lithium oxide (Li 2O) is one of the best tritium breeding materials. A small sphere of Li 2O is proposed in some designs of fusion blankets. Recently, reprocessing technology on irradiated ceramic tritium breeders was developed from the viewpoint of effective use of resources and reduction of radioactive wastes. The wet process is advantageous for fabricating small Li 2O pebbles from the reprocessed lithium-bearing solutions. Preliminary fabrication tests of Li 2O pebbles by the wet process were carried out. However, the density of the pebbles obtained was only 55%. Therefore, process improvement tests were performed in order to increase the density of Li 2O pebbles fabricated by this method. The improved process yielded Li 2O pebbles in the target range of 80-85% T.D.

  20. Development and fabrication of an advanced liquid cooling garment

    NASA Technical Reports Server (NTRS)

    Leith, J. R.; Hixon, C. W.

    1976-01-01

    The elastomeric film fin/tube concept which was developed is a composite of polyurethane film, fine expanded silver mesh, a serpentine pattern polyurethane transport tubing and an integral comfort liner, all bonded via adhesive application and vacuum-bagged for final cure. As demonstrated by thermal analysis, the composite garment material is capable of removing a 293 watt (1000 BTU/hr) metabolic load through a head and torso cooling area of .46 sq m (5 sq ft) with tube spacing of slightly under one inch. A total of 60 test elements, each .15m x .15m (6 in. x 6 in.) were fabricated in support of the liquid cooling garment concept development. In parallel with the fabrication of these elements a continuing series of laboratory tests to support the fabrication techniques was carried out. The elements and supporting tests are described.

  1. Fabrication Processes and Mechanical Behavior of CNT/Metal Nanocomposites

    DTIC Science & Technology

    2013-12-01

    process, were investigated and applied for fabrication of CNT/Cu and CNT/Ni nanocomposite powders. The spark plasma sintering process was applied... spark plasma sintering process to fabricate CNT/NiTi and CNT/Al-Cu nanocomposites. It is confirmed that the CNTs were homogeneously dispersed in NiTi...can be seen in Figure 1-1. The CNT/NiTi composite powders were consolidated by spark plasma sintering (SPS, Dr. Sinter Lab., Sumitomo). The CNT/NiTi

  2. Potential of mask production process for finer pattern fabrication

    NASA Astrophysics Data System (ADS)

    Yagawa, Keisuke; Ugajin, Kunihiro; Suenaga, Machiko; Kobayashi, Yoshihito; Motokawa, Takeharu; Hagihara, Kazuki; Saito, Masato; Itoh, Masamitsu

    2013-09-01

    Photomask used for optical lithography has been developed for purpose of fabrication a pattern along with finer designed rules and increase the productivity. With regard to pattern fabrication on mask, EB (Electron beam) mask writer has been used because it has high resolution beam. But in producing photomask, minimum pattern size on mask is hits a peak around 40nm by the resolution limit of ArF immersion systems. This value is easy to achieve by current EB writer. So, photomask process with EB writer has gotten attached to increase turnaround time. In next generation lithography such as EUV (Extreme ultraviolet) lithography and Nano-imprint lithography, it is enable to fabricate finer pattern beyond the resolution limit of ArF immersion systems. Thereby the pattern on a mask becomes finer rapidly. According to ITRS 2012, fabrication of finer patterns less than 20nm will be required on EUV mask and on NIL template. Especially in NIL template, less than 15nm pattern will be required half a decade later. But today's development of EB writer is aiming to increase photomask's productivity, so we will face a difficulty to fabricate finer pattern in near future. In this paper, we examined a potential of mask production process with EB writer from the view of finer pattern fabrication performances. We succeeded to fabricate hp (half-pitch) 17nm pattern on mask plate by using VSB (Variable Shaped Beam) type EB mask writer with CAR (Chemically Amplified Resist). This result suggests that the photomask fabrication process has the potential for sub-20nm generation mask production.

  3. Process for fabricating ZNO-based varistors

    SciTech Connect

    Lauf, R. J.

    1985-04-09

    The invention is a process for producing ZnO-based varistors incorporating a metal oxide dopant. In one form, the invention comprises providing a varistor powder mix of colloidal particles of ZnO and metal-oxide dopants including Bi/sub 2/O/sub 3/. The mix is hot-pressed to form a compact at temperatures below 850/sup 0/ C. and under conditions effecting reduction of the ZnO to sub-stoichiometric oxide. This promotes densification while restricting liquid formation and grain growth. The compact then is heated under conditions restoring the zinc oxide to stoichiometric composition, thus improving the varistor properties of the compact. The process produces fine-grain varistors characterized by a high actual breakdown voltage and a high average breakdown voltage per individual grain boundary.

  4. Process for fabrication of large titanium diboride ceramic bodies

    DOEpatents

    Moorhead, Arthur J.; Bomar, E. S.; Becher, Paul F.

    1989-01-01

    A process for manufacturing large, fully dense, high purity TiB.sub.2 articles by pressing powders with a sintering aid at relatively low temperatures to reduce grain growth. The process requires stringent temperature and pressure applications in the hot-pressing step to ensure maximum removal of sintering aid and to avoid damage to the fabricated article or the die.

  5. Advanced methods for processing ceramics

    SciTech Connect

    Carter, W.B.

    1995-05-01

    Combustion chemical vapor deposition (CCVD) is a flame assisted, open air chemical vapor deposition (CVD) process. The process is capable of producing textured, epitaxial coatings on single crystal substrates using low cost reagents. Combustion chemical vapor deposition is a relatively inexpensive, alternative thin film deposition process with potential to replace conventional coating technologies for certain applications. The goals of this project are to develop the CCVD process to the point that potential industrial applications can be identified and reliably assessed.

  6. Advanced concepts in joining by conventional processes

    SciTech Connect

    Edwards, G.R.; Fasching-James, A.A.; Onsoien, M.I.; Allen, J.W.

    1994-12-31

    Innovations which can be made to conventional arc welding processes so that advanced materials can be more efficiently joined are considered. Three examples are discussed: (1) GTA welding of iron aluminides, (2) GMA welding of advanced steels, and (3) SMA welding of structural steels. Advanced materials present new challenges for the materials joining specialist. The three examples discussed in this paper demonstrate, however, that modest but creative alterations of conventional GTAW, GMAW, or SMAW processes can provide new and better controls for solving advanced materials joining problems.

  7. Processes for fabricating and load testing NASA scatterometer antenna assemblies

    NASA Technical Reports Server (NTRS)

    Barth, James R.

    1988-01-01

    The purpose of this paper is to present the processes used to fabricate and load test the NASA Scatterometer Antenna Assemblies. The fabrication processes include layup, curing and machining of antenna components, and the bonding and assembly of the components into the final antenna configuration. The design of each antenna consists of an aluminum waveguide bonded to a sandwich structure of Nomex honeycomb core with graphite/epoxy skins. A titanium end fitting with fiberglass/epoxy transitions is bonded into one end of each antenna. Several antenna components are fabricated using a process where aluminum foil is co-cured to a composite surface. The antenna assemblies are radiographically inspected, thermally cycled, and load tested prior to shipment.

  8. Trapped rubber processing for advanced composites

    NASA Technical Reports Server (NTRS)

    Marra, P. J.

    1976-01-01

    Trapped rubber processing is a molding technique for composites in which precast silicone rubber is placed within a closed cavity where it thermally expands against the composite's surface supported by the vessel walls. The method has been applied by the Douglas Aircraft Company, under contract to NASA-Langley, to the design and fabrication of 10 DC-10 graphite/epoxy upper aft rudder assemblies. A three-bay development tool form mold die has been designed and manufactured, and tooling parameters have been established. Fabrication procedures include graphite layup, assembly of details in the tool, and a cure cycle. The technique has made it possible for the cocured fabrication of complex primary box structures otherwise impracticable via standard composite material processes.

  9. Ultrastructure Processing of Advanced Materials.

    DTIC Science & Technology

    1992-11-01

    As a continuation of our efforts to improve the molecular level understanding of the sol-gel process , we have recently carried out several studies...using various experimental techniques are necessary to improve our molecular-level understanding of the gelation process . 22 UNDERSTANDING OF THE SOL...present in the solution. They are sometimes added in order to improve the process such as catalysts [4], stabilizing additives [5], or drying control

  10. Development and fabrication of a solar cell junction processing system

    NASA Technical Reports Server (NTRS)

    Bunker, S.

    1981-01-01

    A solar cell junction processing system was developed and fabricated. A pulsed electron beam for the four inch wafers is being assembled and tested, wafers were successfully pulsed, and solar cells fabricated. Assembly of the transport locks is completed. The transport was operated successfully but not with sufficient reproducibility. An experiment test facility to examine potential scaleup problems associated with the proposed ion implanter design was constructed and operated. Cells were implanted and found to have efficiency identical to the normal Spire implant process.

  11. Selective niobium anodization process for fabricating Josephson tunnel junctions

    SciTech Connect

    Kroger, H.; Smith, L.N.; Jillie, D.W.

    1981-08-01

    A novel process for fabricating refractory sperconducting tunnel junctions is described, which is useful with both deposited and native oxide barriers. The distinguishing feature of the method is that the entire superconductor-barrier-superconductor sandwich is formed before the patterning of any layer. Isolated Josephson junctions are then formed by anodizing through the upper electrode, while the devices themselves are protected by a photoresist mask. Using this process, Nb-Si:H-Nb junctions have been fabricated, whose product of critical current and subgap resistance exceeds 10 mV and whose critical current density varies by about 50% over a 2-in. diameter wafer.

  12. Enabling advanced mirror blank design through modern optical fabrication technology

    NASA Astrophysics Data System (ADS)

    Wilson, Timothy J.; Genberg, Victor L.

    1994-02-01

    Mirror blanks used in high-reliability optical systems for airborne and spaceborne applications have many requirements in terms of weight, stiffness and moment of inertia, as well as mounting and gravitational influences. Lightweight and ultra-lightweight mirror blank design techniques have been enhanced by recent technological developments in mirror blank fabrication and optical figuring. This paper briefly reviews traditional mirror blank design considerations in light of new fabrication technologies such as abrasive water jet machining of mirror cores and ion figuring of optical surfaces. The impact of these new technologies on mirror blank design is also discussed, as well as new design and analytical techniques using NASTRAN. Actual production data using these techniques are presented.

  13. Advances in the Fabrication of Antimicrobial Hydrogels for Biomedical Applications

    PubMed Central

    González-Henríquez, Carmen M.; Sarabia-Vallejos, Mauricio A.; Rodriguez-Hernandez, Juan

    2017-01-01

    This review describes, in an organized manner, the recent developments in the elaboration of hydrogels that possess antimicrobial activity. The fabrication of antibacterial hydrogels for biomedical applications that permits cell adhesion and proliferation still remains as an interesting challenge, in particular for tissue engineering applications. In this context, a large number of studies has been carried out in the design of hydrogels that serve as support for antimicrobial agents (nanoparticles, antibiotics, etc.). Another interesting approach is to use polymers with inherent antimicrobial activity provided by functional groups contained in their structures, such as quaternary ammonium salt or hydrogels fabricated from antimicrobial peptides (AMPs) or natural polymers, such as chitosan. A summary of the different alternatives employed for this purpose is described in this review, considering their advantages and disadvantages. Finally, more recent methodologies that lead to more sophisticated hydrogels that are able to react to external stimuli are equally depicted in this review. PMID:28772591

  14. Advances in the Fabrication of Antimicrobial Hydrogels for Biomedical Applications.

    PubMed

    González-Henríquez, Carmen M; Sarabia-Vallejos, Mauricio A; Rodriguez-Hernandez, Juan

    2017-02-26

    This review describes, in an organized manner, the recent developments in the elaboration of hydrogels that possess antimicrobial activity. The fabrication of antibacterial hydrogels for biomedical applications that permits cell adhesion and proliferation still remains as an interesting challenge, in particular for tissue engineering applications. In this context, a large number of studies has been carried out in the design of hydrogels that serve as support for antimicrobial agents (nanoparticles, antibiotics, etc.). Another interesting approach is to use polymers with inherent antimicrobial activity provided by functional groups contained in their structures, such as quaternary ammonium salt or hydrogels fabricated from antimicrobial peptides (AMPs) or natural polymers, such as chitosan. A summary of the different alternatives employed for this purpose is described in this review, considering their advantages and disadvantages. Finally, more recent methodologies that lead to more sophisticated hydrogels that are able to react to external stimuli are equally depicted in this review.

  15. Advanced methods for processing ceramics

    SciTech Connect

    Carter, W.B.

    1997-04-01

    Combustion chemical vapor deposition (combustion CVD) is being developed for the deposition of high temperature oxide coatings. The process is being evaluated as an alternative to more capital intensive conventional coating processes. The thrusts during this reporting period were the development of the combustion CVD process for depositing lanthanum monazite, the determination of the influence of aerosol size on coating morphology, the incorporation of combustion CVD coatings into thermal barrier coatings (TBCs) and related oxidation research, and continued work on the deposition of zirconia-yttria coatings.

  16. 3D nanostructures fabricated by advanced stencil lithography

    NASA Astrophysics Data System (ADS)

    Yesilkoy, F.; Flauraud, V.; Rüegg, M.; Kim, B. J.; Brugger, J.

    2016-02-01

    This letter reports on a novel fabrication method for 3D metal nanostructures using high-throughput nanostencil lithography. Aperture clogging, which occurs on the stencil membranes during physical vapor deposition, is leveraged to create complex topographies on the nanoscale. The precision of the 3D nanofabrication method is studied in terms of geometric parameters and material types. The versatility of the technique is demonstrated by various symmetric and chiral patterns made of Al and Au.

  17. 3D nanostructures fabricated by advanced stencil lithography.

    PubMed

    Yesilkoy, F; Flauraud, V; Rüegg, M; Kim, B J; Brugger, J

    2016-03-07

    This letter reports on a novel fabrication method for 3D metal nanostructures using high-throughput nanostencil lithography. Aperture clogging, which occurs on the stencil membranes during physical vapor deposition, is leveraged to create complex topographies on the nanoscale. The precision of the 3D nanofabrication method is studied in terms of geometric parameters and material types. The versatility of the technique is demonstrated by various symmetric and chiral patterns made of Al and Au.

  18. Hybrid polymer fabrication process for electro-enzymatic glucose sensor

    NASA Astrophysics Data System (ADS)

    Patel, Jasbir N.; Kaminska, Bozena; Gray, Bonnie L.; Gates, Byron D.

    2008-02-01

    We present a novel self-aligned and hybrid polymer fabrication process for an electro-enzymatic glucose sensor. The self-aligned fabrication process is performed using polydimethylsiloxane (PDMS) as a process substrate material, SU-8 as a sensor structural material, and gold as an electrode material. PDMS has many advantages as a process substrate over conventional substrates such as bare silicon or glass. During the fabrication process, SU-8 has good adhesion to the PDMS. However, after completion of all fabrication steps, the SU-8 based sensors can be easily peeled-off from the PDMS. The PDMS is prepared on a glass handle wafer, and is reusable for many process cycles. Such an SU-8 release technique from a PDMS substrate has never been proposed before. The novel process is employed to realize a glucose sensor with active and reference gold electrodes that are sandwiched between two SU-8 layers with contact pad openings and the active area opening to the top SU-8 layer. The enzyme glucose oxidase is immobilized within the confined active area opening to provide an active electrode sensing surface. After successful fabrication using the hybrid process, the overall thickness of the sensors is measured between 166.15 μm and 210.15 μm. The sensor area and the electrode area are 2mm x 3mm and 2mm x 2mm respectively. The resulting glucose sensors are mechanically flexible. A linear response is observed for the glucose sensors, typically between 50mg/dl and 600mg/dl glucose concentrations.

  19. Advanced digital SAR processing study

    NASA Technical Reports Server (NTRS)

    Martinson, L. W.; Gaffney, B. P.; Liu, B.; Perry, R. P.; Ruvin, A.

    1982-01-01

    A highly programmable, land based, real time synthetic aperture radar (SAR) processor requiring a processed pixel rate of 2.75 MHz or more in a four look system was designed. Variations in range and azimuth compression, number of looks, range swath, range migration and SR mode were specified. Alternative range and azimuth processing algorithms were examined in conjunction with projected integrated circuit, digital architecture, and software technologies. The advaced digital SAR processor (ADSP) employs an FFT convolver algorithm for both range and azimuth processing in a parallel architecture configuration. Algorithm performace comparisons, design system design, implementation tradeoffs and the results of a supporting survey of integrated circuit and digital architecture technologies are reported. Cost tradeoffs and projections with alternate implementation plans are presented.

  20. Advanced lift-off planarization process for Josephson integrated circuits

    SciTech Connect

    Ishida, I.; Tahara, S.; Wada, Y.

    1988-07-25

    An advanced lift-off planarization process utilizing an undercut technique of a photoresist etching mask has been developed to achieve planarization of thin-sputtered and fine-patterned films that are necessary for high-performance Josephson integrated circuits (IC's). A stack of the same kind of photoresist layers, including the modified layer between them, has been utilized as an etching mask providing fine-patterned film profiles with minimized resist degradation by the top photoresist protection layer. This advanced planarization process brings about smooth surfaces having no residues and no grooves along pattern edges. 30 nm deviation from planarity has been demonstrated on a 200-nm-thick planarized Nb superconducting layer. A four-level interconnection of Josephson IC's was successfully fabricated by this process.

  1. Preparation, Fabrication, and Evaluation of Advanced Polymeric and Composite Materials

    NASA Technical Reports Server (NTRS)

    Orwoll, Robert A.

    1997-01-01

    The thesis titles are given below: physical and mechanical behavior of amorphous poly(arylene ether-co-imidasole)s and poly(arylene ether-co-imidasole) modification epoxies; the requirements of patentability as applied to the chemical arts; fabrication of thermoplastic polymer composite ribbon; blend of reactive diluents with phenylethynyl-terminated arylene ether oligomers; the synthesis, characterization, and application of ether-containing polyimides; the synthesis of reflective and electrically conductive polyimide films via an in-situ self-metalization procedure using silver (I) complexes; the thermal cure of phenylethynyl terminated polyimides and selected model compounds; and the synthesis, characterization, and molecular modeling of cyclic arylene ether oligomers.

  2. Processing - Property Relationship in Advanced Intermetallics

    DTIC Science & Technology

    1994-07-01

    AD-A285 262 - IlE I !!III Illl iIII c.,. Processing- Property Relationship I in Advanced Intermetallics Final Report For Period March 4,1991 through...through 03-03-94 4. TITLE AND SUBTITLE 5. FUNDING NUMBERS Processing- Property Relationship in Advanced Intermetallics; 4. AUTHOR(S) D.A. Hardwick and P.L...2 M echanical Properties ......................................................................... 9 3 C

  3. Fabrication

    NASA Astrophysics Data System (ADS)

    Angel, Roger; Helms, Richard; Bilbro, Jim; Brown, Norman; Eng, Sverre; Hinman, Steve; Hull-Allen, Greg; Jacobs, Stephen; Keim, Robert; Ulmer, Melville

    1992-08-01

    What aspects of optical fabrication technology need to be developed so as to facilitate existing planned missions, or enable new ones? Throughout the submillimeter to UV wavelengths, the common goal is to push technology to the limits to make the largest possible apertures that are diffraction limited. At any one wavelength, the accuracy of the surface must be better than lambda/30 (rms error). The wavelength range is huge, covering four orders of magnitude from 1 mm to 100 nm. At the longer wavelengths, diffraction limited surfaces can be shaped with relatively crude techniques. The challenge in their fabrication is to make as large as possible a reflector, given the weight and volume constraints of the launch vehicle. The limited cargo diameter of the shuttle has led in the past to emphasis on deployable or erectable concepts such as the Large Deployable Reflector (LDR), which was studied by NASA for a submillimeter astrophysics mission. Replication techniques that can be used to produce light, low-cost reflecting panels are of great interest for this class of mission. At shorter wavelengths, in the optical and ultraviolet, optical fabrication will tax to the limit the most refined polishing methods. Methods of mechanical and thermal stabilization of the substrate will be severely stressed. In the thermal infrared, the need for large aperture is tempered by the even stronger need to control the telescope's thermal emission by cooled or cryogenic operation. Thus, the SIRTF mirror at 1 meter is not large and does not require unusually high accuracy, but the fabrication process must produce a mirror that is the right shape at a temperature of 4 K. Future large cooled mirrors will present more severe problems, especially if they must also be accurate enough to work at optical wavelengths. At the very shortest wavelengths accessible to reflecting optics, in the x-ray domain, the very low count fluxes of high energy photons place a premium on the collecting area. It is

  4. Fabrication

    NASA Technical Reports Server (NTRS)

    Angel, Roger; Helms, Richard; Bilbro, Jim; Brown, Norman; Eng, Sverre; Hinman, Steve; Hull-Allen, Greg; Jacobs, Stephen; Keim, Robert; Ulmer, Melville

    1992-01-01

    What aspects of optical fabrication technology need to be developed so as to facilitate existing planned missions, or enable new ones? Throughout the submillimeter to UV wavelengths, the common goal is to push technology to the limits to make the largest possible apertures that are diffraction limited. At any one wavelength, the accuracy of the surface must be better than lambda/30 (rms error). The wavelength range is huge, covering four orders of magnitude from 1 mm to 100 nm. At the longer wavelengths, diffraction limited surfaces can be shaped with relatively crude techniques. The challenge in their fabrication is to make as large as possible a reflector, given the weight and volume constraints of the launch vehicle. The limited cargo diameter of the shuttle has led in the past to emphasis on deployable or erectable concepts such as the Large Deployable Reflector (LDR), which was studied by NASA for a submillimeter astrophysics mission. Replication techniques that can be used to produce light, low-cost reflecting panels are of great interest for this class of mission. At shorter wavelengths, in the optical and ultraviolet, optical fabrication will tax to the limit the most refined polishing methods. Methods of mechanical and thermal stabilization of the substrate will be severely stressed. In the thermal infrared, the need for large aperture is tempered by the even stronger need to control the telescope's thermal emission by cooled or cryogenic operation. Thus, the SIRTF mirror at 1 meter is not large and does not require unusually high accuracy, but the fabrication process must produce a mirror that is the right shape at a temperature of 4 K. Future large cooled mirrors will present more severe problems, especially if they must also be accurate enough to work at optical wavelengths. At the very shortest wavelengths accessible to reflecting optics, in the x-ray domain, the very low count fluxes of high energy photons place a premium on the collecting area. It is

  5. Fabrication and Comparison of Fuels for Advanced Gas Reactor Irradiation Tests

    SciTech Connect

    Jeffrey Phillips; Charles Barnes; John Hunn

    2010-10-01

    As part of the program to demonstrate TRISO-coated fuel for the Next Generation Nuclear Plant, a series of irradiation tests of Advanced Gas Reactor (AGR) fuel are being performed in the Advanced Test Reactor (ATR) at the Idaho National Laboratory. In the first test, called “AGR-1,” graphite compacts containing approximately 300,000 coated particles were irradiated from December 2006 until November 2009. Development of AGR-1 fuel sought to replicate the properties of German TRISO-coated particles. No particle failures were seen in the nearly 3-year irradiation to a burn up of 19%. The AGR-1 particles were coated in a two-inch diameter coater. Following fabrication of AGR-1 fuel, process improvements and changes were made in each of the fabrication processes. Changes in the kernel fabrication process included replacing the carbon black powder feed with a surface-modified carbon slurry and shortening the sintering schedule. AGR-2 TRISO particles were produced in a six-inch diameter coater using a change size about twenty-one times that of the two-inch diameter coater used to coat AGR-1 particles. Changes were also made in the compacting process, including increasing the temperature and pressure of pressing and using a different type of press. Irradiation of AGR-2 fuel began in late spring 2010. Properties of AGR-2 fuel compare favorably with AGR-1 and historic German fuel. Kernels are more homogeneous in shape, chemistry and density. TRISO-particle sphericity, layer thickness standard deviations, and defect fractions are also comparable. In a sample of 317,000 particles from deconsolidated AGR-2 compacts, 3 exposed kernels were found in a leach test. No SiC defects were found in a sample of 250,000 deconsolidated particles, and no IPyC defects in a sample of 64,000 particles. The primary difference in properties between AGR-1 and AGR-2 compacts is that AGR-2 compacts have a higher matrix density, 1.6 g/cm3 compared to about 1.3 g/cm3 for AGR-1 compacts. Based on

  6. Optimised process for fabricating tapered long period gratings

    NASA Astrophysics Data System (ADS)

    Mullaney, K.; Staines, S. E.; James, S. W.; Tatam, R. P.

    2017-04-01

    The process of fabricating tapered long period gratings (TLPGs) using a CO2 laser is described. TLPGs with a period spacing of 378 μm, were fabricated by optimization of the taper waist diameter and careful control of the duty-cycle and its uniformity along the length of the grating. The 6-period TLPGs exhibited a pass-band insertion loss of 0.6 dB, resonance band extinction values of 3 dB and had a physical length of 2.27 mm.

  7. Fabrication of polycrystalline thin films by pulsed laser processing

    DOEpatents

    Mitlitsky, Fred; Truher, Joel B.; Kaschmitter, James L.; Colella, Nicholas J.

    1998-02-03

    A method for fabricating polycrystalline thin films on low-temperature (or high-temperature) substrates which uses processing temperatures that are low enough to avoid damage to the substrate, and then transiently heating select layers of the thin films with at least one pulse of a laser or other homogenized beam source. The pulse length is selected so that the layers of interest are transiently heated to a temperature which allows recrystallization and/or dopant activation while maintaining the substrate at a temperature which is sufficiently low to avoid damage to the substrate. This method is particularly applicable in the fabrication of solar cells.

  8. Fabrication of polycrystalline thin films by pulsed laser processing

    DOEpatents

    Mitlitsky, F.; Truher, J.B.; Kaschmitter, J.L.; Colella, N.J.

    1998-02-03

    A method is disclosed for fabricating polycrystalline thin films on low-temperature (or high-temperature) substrates which uses processing temperatures that are low enough to avoid damage to the substrate, and then transiently heating select layers of the thin films with at least one pulse of a laser or other homogenized beam source. The pulse length is selected so that the layers of interest are transiently heated to a temperature which allows recrystallization and/or dopant activation while maintaining the substrate at a temperature which is sufficiently low to avoid damage to the substrate. This method is particularly applicable in the fabrication of solar cells. 1 fig.

  9. Advanced CO2 removal process control and monitor instrumentation development

    NASA Technical Reports Server (NTRS)

    Heppner, D. B.; Dalhausen, M. J.; Klimes, R.

    1982-01-01

    A progam to evaluate, design and demonstrate major advances in control and monitor instrumentation was undertaken. A carbon dioxide removal process, one whose maturity level makes it a prime candidate for early flight demonstration was investigated. The instrumentation design incorporates features which are compatible with anticipated flight requirements. Current electronics technology and projected advances are included. In addition, the program established commonality of components for all advanced life support subsystems. It was concluded from the studies and design activities conducted under this program that the next generation of instrumentation will be greatly smaller than the prior one. Not only physical size but weight, power and heat rejection requirements were reduced in the range of 80 to 85% from the former level of research and development instrumentation. Using a microprocessor based computer, a standard computer bus structure and nonvolatile memory, improved fabrication techniques and aerospace packaging this instrumentation will greatly enhance overall reliability and total system availability.

  10. Flexible Fabrics with High Thermal Conductivity for Advanced Spacesuits

    NASA Technical Reports Server (NTRS)

    Trevino, Luis A.; Bue, Grant; Orndoff, Evelyne; Kesterson, Matt; Connel, John W.; Smith, Joseph G., Jr.; Southward, Robin E.; Working, Dennis; Watson, Kent A.; Delozier, Donovan M.

    2006-01-01

    This paper describes the effort and accomplishments for developing flexible fabrics with high thermal conductivity (FFHTC) for spacesuits to improve thermal performance, lower weight and reduce complexity. Commercial and additional space exploration applications that require substantial performance enhancements in removal and transport of heat away from equipment as well as from the human body can benefit from this technology. Improvements in thermal conductivity were achieved through the use of modified polymers containing thermally conductive additives. The objective of the FFHTC effort is to significantly improve the thermal conductivity of the liquid cooled ventilation garment by improving the thermal conductivity of the subcomponents (i.e., fabric and plastic tubes). This paper presents the initial system modeling studies, including a detailed liquid cooling garment model incorporated into the Wissler human thermal regulatory model, to quantify the necessary improvements in thermal conductivity and garment geometries needed to affect system performance. In addition, preliminary results of thermal conductivity improvements of the polymer components of the liquid cooled ventilation garment are presented. By improving thermal garment performance, major technology drivers will be addressed for lightweight, high thermal conductivity, flexible materials for spacesuits that are strategic technical challenges of the Exploration

  11. Flexible Fabrics with High Thermal Conductivity for Advanced Spacesuits

    NASA Technical Reports Server (NTRS)

    Trevino, Luis A.; Bue, Grant; Orndoff, Evelyne; Kesterson, Matt; Connel, John W.; Smith, Joseph G., Jr.; Southward, Robin E.; Working, Dennis; Watson, Kent A.; Delozier, Donovan M.

    2006-01-01

    This paper describes the effort and accomplishments for developing flexible fabrics with high thermal conductivity (FFHTC) for spacesuits to improve thermal performance, lower weight and reduce complexity. Commercial and additional space exploration applications that require substantial performance enhancements in removal and transport of heat away from equipment as well as from the human body can benefit from this technology. Improvements in thermal conductivity were achieved through the use of modified polymers containing thermally conductive additives. The objective of the FFHTC effort is to significantly improve the thermal conductivity of the liquid cooled ventilation garment by improving the thermal conductivity of the subcomponents (i.e., fabric and plastic tubes). This paper presents the initial system modeling studies, including a detailed liquid cooling garment model incorporated into the Wissler human thermal regulatory model, to quantify the necessary improvements in thermal conductivity and garment geometries needed to affect system performance. In addition, preliminary results of thermal conductivity improvements of the polymer components of the liquid cooled ventilation garment are presented. By improving thermal garment performance, major technology drivers will be addressed for lightweight, high thermal conductivity, flexible materials for spacesuits that are strategic technical challenges of the Exploration

  12. Low cost processes for fabricating silicon solar cells

    NASA Technical Reports Server (NTRS)

    Goldman, H.; Wolf, M.

    1980-01-01

    Solar cell fabrication processes, in particular junction formation and metallization, are evaluated in terms of cell efficiencies, process yields, module packing factors, and energy cost effectiveness. It is shown that for junction formation, the diffusion processes provide a relatively low-cost approach. The costs per unit cell area can be further reduced by increased wafer area and mechanized wafer handling. The costs for a large number of metallization processes, excluding the costs of the metal, are roughly comparable. However, their varying influence on cell performance leads to a significant spread in the allowable process costs.

  13. An Advanced Wafer Stepper For Sub-Micron Fabrication

    NASA Astrophysics Data System (ADS)

    Mayer, Herbert E.; Loebach, Ernst W.

    1987-09-01

    An advanced wafer stepper is presented addressing the specific problems involved by sub-micron lithography such as alignment and focusing to multilayer resist films. New sub-systems were developed while maintaining principles well proven in a previous design. The system is described emphasizing the new sub-systems, and performance data are presented.

  14. Fabrication of plasmonic crystals using programmable nanoreplica molding process

    NASA Astrophysics Data System (ADS)

    Liu, Longju; Badshah, Mohsin A.; Kim, Seok-min; Lu, Meng

    2016-03-01

    The development of many photonic devices, such as photonic integrated circuit, optical sensors, and photovoltaic devices, demands low-cost and reliable fabrication technologies to fabricate sub-wavelength features. Here, we report a programmable nanoreplica molding process, which is capable of producing photonic devices with a variety of submicrometer patterns. The process utilizes a stretchable plastic mold to generate the desired periodic pattern using a UVcurable polymer on plastic substrates. During the replica molding process, a uniaxial force is applied to the mold and results in changes of the periodic structure, which locates on the surface of the mold. The geometry of the replicated pattern, including the lattice constant and arrangement, is determined by the magnitude and direction of the force. As an example, we present a plasmonic crystal device with surface plasmon resonances carefully tuned by using the uniaxial force. This unique process offers an inexpensive route to generate various periodic nanostructures rapidly.

  15. Fabrication Process for Micro Thermoelectric Generators ( μTEGs)

    NASA Astrophysics Data System (ADS)

    Pelz, U.; Jaklin, J.; Rostek, R.; Thoma, F.; Kröner, M.; Woias, P.

    2016-03-01

    An innovative micro thermoelectric generator ( μTEG) fabrication process has been developed. Two selectively dissolvable photoresists and galvanostatic electrodeposition are used to grow p- and n-type thermoelectric materials as well as the upper and lower contacts of the μTEGs onto a single substrate. Two particular features of the process are the usage of a multilamination technique to create structures for legs and contacts, as well as an industrial pick and placer (P&P), which allows dispensing of a second, selectively dissolvable, photoresist to protect certain areas during material deposition. This allows sequential electrochemical deposition of two different thermoelectric materials on a single substrate, without further costly and time-consuming process steps. The process therefore provides a highly flexible fabrication platform for research and development.

  16. Thermoelectric microdevice fabricated by a MEMS-like electrochemical process

    NASA Technical Reports Server (NTRS)

    Snyder, G. Jeffrey; Lim, James R.; Huang, Chen-Kuo; Fleurial, Jean-Pierre

    2003-01-01

    Microelectromechanical systems (MEMS) are the basis of many rapidly growing technologies, because they combine miniature sensors and actuators with communications and electronics at low cost. Commercial MEMS fabrication processes are limited to silicon-based materials or two-dimensional structures. Here we show an inexpensive, electrochemical technique to build MEMS-like structures that contain several different metals and semiconductors with three-dimensional bridging structures. We demonstrate this technique by building a working microthermoelectric device. Using repeated exposure and development of multiple photoresist layers, several different metals and thermoelectric materials are fabricated in a three-dimensional structure. A device containing 126 n-type and p-type (Bi, Sb)2Te3 thermoelectric elements, 20 microm tall and 60 microm in diameter with bridging metal interconnects, was fabricated and cooling demonstrated. Such a device should be of technological importance for precise thermal control when operating as a cooler, and for portable power when operating as a micro power generator.

  17. Thermoelectric microdevice fabricated by a MEMS-like electrochemical process

    NASA Technical Reports Server (NTRS)

    Snyder, G. Jeffrey; Lim, James R.; Huang, Chen-Kuo; Fleurial, Jean-Pierre

    2003-01-01

    Microelectromechanical systems (MEMS) are the basis of many rapidly growing technologies, because they combine miniature sensors and actuators with communications and electronics at low cost. Commercial MEMS fabrication processes are limited to silicon-based materials or two-dimensional structures. Here we show an inexpensive, electrochemical technique to build MEMS-like structures that contain several different metals and semiconductors with three-dimensional bridging structures. We demonstrate this technique by building a working microthermoelectric device. Using repeated exposure and development of multiple photoresist layers, several different metals and thermoelectric materials are fabricated in a three-dimensional structure. A device containing 126 n-type and p-type (Bi, Sb)2Te3 thermoelectric elements, 20 microm tall and 60 microm in diameter with bridging metal interconnects, was fabricated and cooling demonstrated. Such a device should be of technological importance for precise thermal control when operating as a cooler, and for portable power when operating as a micro power generator.

  18. Thermoelectric microdevice fabricated by a MEMS-like electrochemical process.

    PubMed

    Snyder, G Jeffrey; Lim, James R; Huang, Chen-Kuo; Fleurial, Jean-Pierre

    2003-08-01

    Microelectromechanical systems (MEMS) are the basis of many rapidly growing technologies, because they combine miniature sensors and actuators with communications and electronics at low cost. Commercial MEMS fabrication processes are limited to silicon-based materials or two-dimensional structures. Here we show an inexpensive, electrochemical technique to build MEMS-like structures that contain several different metals and semiconductors with three-dimensional bridging structures. We demonstrate this technique by building a working microthermoelectric device. Using repeated exposure and development of multiple photoresist layers, several different metals and thermoelectric materials are fabricated in a three-dimensional structure. A device containing 126 n-type and p-type (Bi, Sb)2Te3 thermoelectric elements, 20 microm tall and 60 microm in diameter with bridging metal interconnects, was fabricated and cooling demonstrated. Such a device should be of technological importance for precise thermal control when operating as a cooler, and for portable power when operating as a micro power generator.

  19. Design, fabrication and test of graphite/polyimide composite joints and attachments for advanced aerospace vehicles

    NASA Technical Reports Server (NTRS)

    Koumal, D. E.

    1979-01-01

    The design and evaluation of built-up attachments and bonded joint concepts for use at elevated temperatures is documented. Joint concept screening, verification of GR/PI material, fabrication of design allowables panels, definition of test matrices, and analysis of bonded and bolted joints are among the tasks completed. The results provide data for the design and fabrication of lightly loaded components for advanced space transportation systems and high speed aircraft.

  20. Bulk heterojunction organic photovoltaics from water-processable nanomaterials and their facile fabrication approaches.

    PubMed

    Subianto, Surya; Dutta, Naba; Andersson, Mats; Choudhury, Namita Roy

    2016-09-01

    Organic thin film photovoltaics based on bulk-heterojunction donor-acceptor combinations have received significant interest due to their potential for low-cost, large-scale solution processing. However, current state-of-the-art cells utilise materials soluble mainly in halogenated solvents which pose processing challenges due to their toxicity and thus environmental hazards. In this contribution, we look at various nanomaterials, and alternative processing of these solar cells using environmentally friendly solvents, and review recently reported different strategies and approaches that are making inroads in this field. Specifically, we focus on the use of water-dispersible donors and acceptors, use of aqueous solvents for fabrication and discuss the merits of the two main approaches of water-processable solar cells; namely, through the use of water-soluble materials and the use of aqueous dispersion rather than a solution, as well as review some of the recent advances in alternative fabrication techniques.

  1. Drawing carbon nanotubes from liquid: a room temperature process for fabrication of CNT probes and wires

    NASA Astrophysics Data System (ADS)

    Tang, Jie; Geng, Huaizhi; Qiu, Qi; Go, Bao; Qin, Lu-Chang; Zhou, Otto

    2003-03-01

    Carbon nanotubes (CNTs) have unique material properties that are promising for a wide range of technological applications. Although advance has been made in synthesis of raw CNT materials, the lack of efficient processes for assembly and integration of the CNTs into functional forms has hindered the development of CNT-based devices. Electrophoresis is a high throughput process for deposition of micro- and nano-meter scale objects [1]. Here we report an efficient electrophoresis process to assemble pre-formed CNTs into probes and fibers. The advantage of this method is that it is a batch process that operates at room temperature and can be automated. The structure and morphology of the CNT structures thus fabricated will be presented and will be compared with those fabricated by other methods. [1] B. Gao et al., Adv. Mater, Vol. 13 (11), 816 (2001).

  2. Electron Beam Freeform Fabrication: A Fabrication Process that Revolutionizes Aircraft Structural Designs and Spacecraft Supportability

    NASA Technical Reports Server (NTRS)

    Taminger, Karen M.

    2008-01-01

    The technological inception and challenges, as well as current applications of the electron beam freeform fabrication (EBF3) process are outlined. The process was motivated by the need for a new metals technology that would be cost-effective, enable the production of new alloys and that would could be used for efficient, lightweight structures. EBF3 is a rapid metal fabrication, layer-additive process that uses no molds or tools and which yields properties equivalent to wrought. The benefits of EBF3 include it near-net shape which minimizes scrap and reduces part count; efficiency in design which allows for lighter weight and enhanced performance; and, its "green" manufacturing process which yields minimal waste products. EBF3 also has a high tensile strength, while a structural test comparison found that EBF3 panels performed 5% lower than machined panels. Technical challenges in the EBF3 process include a need for process control monitoring and an improvement in localized heat response. Currently, the EBF3 process can be used to add details onto forgings and to construct and form complex shapes. However, it has potential uses in a variety of industries including aerospace, automotive, sporting goods and medical implant devices. The novel structural design capabilities of EBF3 have the ability to yield curved stiffeners which may be optimized for performance, low weight, low noise and damage tolerance applications. EBF3 has also demonstrated its usefulness in 0-gravity environments for supportability in space applications.

  3. Fabrication of High Thermal Conductivity NARloy-Z-Diamond Composite Combustion Chamber Liner for Advanced Rocket Engines

    NASA Technical Reports Server (NTRS)

    Bhat, Biliyar N.; Greene, Sandra E.; Singh, Jogender

    2016-01-01

    This paper describes the process development for fabricating a high thermal conductivity NARloy-Z-Diamond composite (NARloy-Z-D) combustion chamber liner for application in advanced rocket engines. The fabrication process is challenging and this paper presents some details of these challenges and approaches used to address them. Prior research conducted at NASA-MSFC and Penn State had shown that NARloy-Z-40%D composite material has significantly higher thermal conductivity than the state of the art NARloy-Z alloy. Furthermore, NARloy-Z-40 %D is much lighter than NARloy-Z. These attributes help to improve the performance of the advanced rocket engines. Increased thermal conductivity will directly translate into increased turbopump power, increased chamber pressure for improved thrust and specific impulse. Early work on NARloy-Z-D composites used the Field Assisted Sintering Technology (FAST, Ref. 1, 2) for fabricating discs. NARloy-Z-D composites containing 10, 20 and 40vol% of high thermal conductivity diamond powder were investigated. Thermal conductivity (TC) data. TC increased with increasing diamond content and showed 50% improvement over pure copper at 40vol% diamond. This composition was selected for fabricating the combustion chamber liner using the FAST technique.

  4. Advanced planning for ISS payload ground processing

    NASA Astrophysics Data System (ADS)

    Page, Kimberly A.

    2000-01-01

    Ground processing at John F. Kennedy Space Center (KSC) is the concluding phase of the payload/flight hardware development process and is the final opportunity to ensure safe and successful recognition of mission objectives. Planning for the ground processing of on-orbit flight hardware elements and payloads for the International Space Station is a responsibility taken seriously at KSC. Realizing that entering into this operational environment can be an enormous undertaking for a payload customer, KSC continually works to improve this process by instituting new/improved services for payload developer/owner, applying state-of-the-art technologies to the advanced planning process, and incorporating lessons learned for payload ground processing planning to ensure complete customer satisfaction. This paper will present an overview of the KSC advanced planning activities for ISS hardware/payload ground processing. It will focus on when and how KSC begins to interact with the payload developer/owner, how that interaction changes (and grows) throughout the planning process, and how KSC ensures that advanced planning is successfully implemented at the launch site. It will also briefly consider the type of advance planning conducted by the launch site that is transparent to the payload user but essential to the successful processing of the payload (i.e. resource allocation, executing documentation, etc.) .

  5. Process for fabricating composite material having high thermal conductivity

    DOEpatents

    Colella, Nicholas J.; Davidson, Howard L.; Kerns, John A.; Makowiecki, Daniel M.

    2001-01-01

    A process for fabricating a composite material such as that having high thermal conductivity and having specific application as a heat sink or heat spreader for high density integrated circuits. The composite material produced by this process has a thermal conductivity between that of diamond and copper, and basically consists of coated diamond particles dispersed in a high conductivity metal, such as copper. The composite material can be fabricated in small or relatively large sizes using inexpensive materials. The process basically consists, for example, of sputter coating diamond powder with several elements, including a carbide forming element and a brazeable material, compacting them into a porous body, and infiltrating the porous body with a suitable braze material, such as copper-silver alloy, thereby producing a dense diamond-copper composite material with a thermal conductivity comparable to synthetic diamond films at a fraction of the cost.

  6. Advanced Processing and Characterization Technologies. Fabrication and Characterization of Semiconductor Optoelectronic Devices and Integrated Circuits Held in Clearwater, Florida on 8-10 May 1991. American Vacuum Society Series 10

    DTIC Science & Technology

    1992-07-01

    Confinement Effects in Ultra-Narrow lnGaAs/InP Quantum Well Wires ...................................... . 50 M. Notomi M. Naganuma H. Iwamura T... Quantum - Well AIGaAs Laser and Their Integration or More than 100 Lasers...................................... 160 S. Hirata, H. Nanui and Y Mori...Hu, P. Floyd, K-K Law, J.L. Merz and A.C Gossard Fabrication of GaAIAs/GaAs Single Quantum Well Gain-Coupled Distributed Feedback Lasers

  7. Advanced Digital Signal Processing for Hybrid Lidar

    DTIC Science & Technology

    2013-09-30

    Advanced Digital Signal Processing for Hybrid Lidar William D. Jemison Clarkson University [Technical Section Technical Objectives The technical...objective of this project is the development and evaluation of various digital signal processing (DSP) algorithms that will enhance hybrid lidar ...algorithm as shown in Figure 1. Hardware Platform for Algorithm Implementation + Underwater Channel Characteristics ^ Lidar DSP Algorithm Figure

  8. Fabrication of synthetic diffractive elements using advanced matrix laser lithography

    NASA Astrophysics Data System (ADS)

    Škereň, M.; Svoboda, J.; Květoň, M.; Fiala, P.

    2013-02-01

    In this paper we present a matrix laser writing device based on a demagnified projection of a micro-structure from a computer driven spatial light modulator. The device is capable of writing completely aperiodic micro-structures with resolution higher than 200 000 DPI. An optical system is combined with ultra high precision piezoelectric stages with an elementary step ~ 4 nm. The device operates in a normal environment, which significantly decreases the costs compared to competitive technologies. Simultaneously, large areas can be exposed up to 100 cm2. The capabilities of the constructed device will be demonstrated on particular elements fabricated for real applications. The optical document security is the first interesting field, where the synthetic image holograms are often combined with sophisticated aperiodic micro-structures. The proposed technology can easily write simple micro-gratings creating the color and kinetic visual effects, but also the diffractive cryptograms, waveguide couplers, and other structures recently used in the field of optical security. A general beam shaping elements and special photonic micro-structures are another important applications which will be discussed in this paper.

  9. MICRO-SEISMOMETERS VIA ADVANCED MESO-SCALE FABRICATION

    SciTech Connect

    Garcia, Caesar A; Onaran, Guclu; Avenson, Brad; Hall, Neal

    2014-11-07

    The Department of Energy (DOE) and the National Nuclear Security Administration (NNSA) seek revolutionary sensing innovations for the monitoring of nuclear detonations. Performance specifications are to be consistent with those obtainable by only an elite few products available today, but with orders of magnitude reduction in size, weight, power, and cost. The proposed commercial innovation calls upon several technologies including the combination of meso-scale fabrication and assembly, photonics-based displacement / motion detection methods, and the use of digital control electronics . Early Phase II development has demonstrated verified and repeatable sub 2ng noise floor from 3Hz to 100Hz, compact integration of 3-axis prototypes, and robust deployment exercises. Ongoing developments are focusing on low frequency challenges, low power consumption, ultra-miniature size, and low cross axis sensitivity. We are also addressing the rigorous set of specifications required for repeatable and reliable long-term explosion monitoring, including thermal stability, reduced recovery time from mass re-centering and large mechanical shocks, sensitivity stability, and transportability. Successful implementation will result in small, hand-held demonstration units with the ability to address national security needs of the DOE/NNSA. Additional applications envisioned include military/defense, scientific instrumentation, oil and gas exploration, inertial navigation, and civil infrastructure monitoring.

  10. Extra-terrestrial construction processes - Advancements, opportunities and challenges

    NASA Astrophysics Data System (ADS)

    Lim, Sungwoo; Prabhu, Vibha Levin; Anand, Mahesh; Taylor, Lawrence A.

    2017-10-01

    Government space agencies, including NASA and ESA, are conducting preliminary studies on building alternative space-habitat systems for deep-space exploration. Such studies include development of advanced technologies for planetary surface exploration, including an in-depth understanding of the use of local resources. Currently, NASA plans to land humans on Mars in the 2030s. Similarly, other space agencies from Europe (ESA), Canada (CSA), Russia (Roscosmos), India (ISRO), Japan (JAXA) and China (CNSA) have already initiated or announced their plans for launching a series of lunar missions over the next decade, ranging from orbiters, landers and rovers for extended stays on the lunar surface. As the Space Odyssey is one of humanity's oldest dreams, there has been a series of research works for establishing temporary or permanent settlement on other planetary bodies, including the Moon and Mars. This paper reviews current projects developing extra-terrestrial construction, broadly categorised as: (i) ISRU-based construction materials; (ii) fabrication methods; and (iii) construction processes. It also discusses four categories of challenges to developing an appropriate construction process: (i) lunar simulants; (ii) material fabrication and curing; (iii) microwave-sintering based fabrication; and (iv) fully autonomous and scaled-up construction processes.

  11. Fabrication process study for matrix silicon solar cells

    NASA Astrophysics Data System (ADS)

    Shepovalova, Olga V.

    2017-02-01

    The possibility of manufacturing silicon matrix solar cells (MSC) on the base of multi-layer epitaxial structures with electrically broken reverse-biased p-n junctions has been investigated. As a result of technological processes studies, experimental dependencies and theoretical expressions have been obtained to determine the values of electrical breakdown voltages applied in the course of MSC multi-layer epitaxial structure fabrication. The optimal technological conditions and parameters of the MSC fabrication process have been defined. Experimental samples of MSCs have been studied. The output voltage of experimental samples is 0.3V to 0.6V per one p-n junction wile the efficiency is from 8% to 8.6%, for MSCs with ten n-p junctions, and it ranges from 8.2% to 8.5%, for MSCs with twelve n-p junctions.

  12. Turbine component, turbine blade, and turbine component fabrication process

    DOEpatents

    Delvaux, John McConnell; Cairo, Ronald Ralph; Parolini, Jason Robert

    2017-05-30

    A turbine component, a turbine blade, and a turbine component fabrication process are disclosed. The turbine component includes ceramic matrix composite plies and a feature configured for preventing interlaminar tension of the ceramic matrix composite plies. The feature is selected from the group consisting of ceramic matrix composite tows or precast insert tows extending through at least a portion of the ceramic matrix composite plies, a woven fabric having fiber tows or a precast insert preventing contact between a first set of the ceramic matrix composite plies and a second set of the ceramic matrix composite plies, and combinations thereof. The process includes laying up ceramic matrix composite plies in a preselected arrangement and securing a feature configured for interlaminar tension.

  13. Evaluation of Double-Vacuum-Bag Process For Composite Fabrication

    NASA Technical Reports Server (NTRS)

    Hou, T. H.; Jensen, B. J.

    2004-01-01

    A non-autoclave vacuum bag process using atmospheric pressure alone that eliminates the need for external pressure normally supplied by an autoclave or a press is an attractive method for composite fabrication. This type of process does not require large capital expenditures for tooling and processing equipment. In the molding cycle (temperature/pressure profile) for a given composite system, the vacuum application point has to be carefully selected to achieve the final consolidated laminate net shape and resin content without excessive resin squeeze-out. The traditional single-vacuum- bag (SVB) process is best suited for molding epoxy matrix based composites because of their superior flow and the absence of reaction by-products or other volatiles. Other classes of materials, such as polyimides and phenolics, generate water during cure. In addition, these materials are commonly synthesized as oligomers using solvents to facilitate processability. Volatiles (solvents and reaction byproducts) management therefore becomes a critical issue. SVB molding, without additional pressure, normally fails to yield void-free quality composites for these classes of resin systems. A double-vacuum- bag (DVB) process for volatile management was envisioned, designed and built at the NASA Langley Research Center. This experimental DVB process affords superior volatiles management compared to the traditional SVB process. Void-free composites are consistently fabricated as measured by C-scan and optical photomicroscopy for high performance polyimide and phenolic resins.

  14. Wavelength dependence of silicon avalanche photodiode fabricated by CMOS process

    NASA Astrophysics Data System (ADS)

    Mohammed Napiah, Zul Atfyi Fauzan; Hishiki, Takuya; Iiyama, Koichi

    2017-07-01

    Avalanche photodiodes fabricated by CMOS process (CMOS-APDs) have features of high avalanche gain below 10 V, wide bandwidth over 5 GHz, and easy integration with electronic circuits. In CMOS-APDs, guard ring structure is introduced for high-speed operation by canceling photo-generated carriers in the substrate at the sacrifice of the responsivity. We describe here wavelength dependence of the responsivity and the bandwidth of the CMOS-APDs with shorted and opened guard ring structure.

  15. Computer-Aided Process Planning for the Layered Fabrication of Porous Scaffold Matrices

    NASA Astrophysics Data System (ADS)

    Starly, Binil

    Rapid Prototyping (RP) technology promises to have a tremendous impact on the design and fabrication of porous tissue replacement structures for applications in tissue engineering and regenerative medicine. The layer-by-layer fabrication technology enables the design of patient-specific medical implants and complex structures for diseased tissue replacement strategies. Combined with advancements in imaging modalities and bio-modeling software, physicians can engage themselves in advanced solutions for craniofacial and mandibular reconstruction. For example, prior to the advancement of RP technologies, solid titanium parts used as implants for mandibular reconstruction were fashioned out of molding or CNC-based machining processes (Fig. 3.1). Titanium implants built using this process are often heavy, leading to increased patient discomfort. In addition, the Young's modulus of titanium is almost five times that of healthy cortical bone resulting in stress shielding effects [1,2]. With the advent of CAD/CAM-based tools, the virtual reconstruction of the implants has resulted in significant design improvements. The new generation of implants can be porous, enabling the in-growth of healthy bone tissue for additional implant fixation and stabilization. Newer implants would conform to the external shape of the defect site that is intended to be filled in. More importantly, the effective elastic modulus of the implant can be designed to match that of surrounding tissue. Ideally, the weight of the implant can be designed to equal the weight of the tissue that is being replaced resulting in increased patient comfort. Currently, such porous structures for reconstruction can only be fabricated using RP-based metal fabrication technologies such as Electron Beam Melting (EBM), Selective Laser Sintering (SLS®), and 3D™ Printing processes.

  16. Development of Infrastructure Facilities for Superconducting RF Cavity Fabrication, Processing and 2 K Characterization at RRCAT

    NASA Astrophysics Data System (ADS)

    Joshi, S. C.; Raghavendra, S.; Jain, V. K.; Puntambekar, A.; Khare, P.; Dwivedi, J.; Mundra, G.; Kush, P. K.; Shrivastava, P.; Lad, M.; Gupta, P. D.

    2017-02-01

    An extensive infrastructure facility is being established at Raja Ramanna Centre for Advanced Technology (RRCAT) for a proposed 1 GeV, high intensity superconducting proton linac for Indian Spallation Neutron Source. The proton linac will comprise of a large number of superconducting Radio Frequency (SCRF) cavities ranging from low beta spoke resonators to medium and high beta multi-cell elliptical cavities at different RF frequencies. Infrastructure facilities for SCRF cavity fabrication, processing and performance characterization at 2 K are setup to take-up manufacturing of large number of cavities required for future projects of Department of Atomic Energy (DAE). RRCAT is also participating in a DAE’s approved mega project on “Physics and Advanced technology for High intensity Proton Accelerators” under Indian Institutions-Fermilab Collaboration (IIFC). In the R&D phase of IIFC program, a number of high beta, fully dressed multi-cell elliptical SCRF cavities will be developed in collaboration with Fermilab. A dedicated facility for SCRF cavity fabrication, tuning and processing is set up. SCRF cavities developed will be characterized at 2K using a vertical test stand facility, which is already commissioned. A Horizontal Test Stand facility has also been designed and under development for testing a dressed multi-cell SCRF cavity at 2K. The paper presents the infrastructure facilities setup at RRCAT for SCRF cavity fabrication, processing and testing at 2K.

  17. Processing and Characterization of PETI Composites Fabricated by High Temperature VARTM

    NASA Technical Reports Server (NTRS)

    Ghose, Sayata; Cano, Roberto J.; Watson, Kent A.; Britton, Sean M.; Jensen, Brian J.; Connell, John W.; Smith, Joseph G.; Loos, Alfred C.; Heider, Dirk

    2011-01-01

    The use of composites as primary structures on aerospace vehicles has increased dramatically over the past decade. As these advanced structures increase in size and complexity, their production costs have grown significantly. A major contributor to these manufacturing costs is the requirement of elevated processing pressures, during the thermal cure, to create fully consolidated composites. For certain composite parts, high temperature vacuum assisted resin transfer molding (HT-VARTM) can offer reduced fabrication costs compared to conventional autoclave techniques. The process has been successfully used with phenylethynyl terminated imide (PETI) resins developed by NASA LaRC. In the current study, two PETI resins, LARC(TradeMark) PETI-330 and LARC(TradeMark) PETI-8 have been used to make test specimens using HT-VARTM. Based on previous work at NASA LaRC, larger panels with a quasi-isotropic lay-up were fabricated. The resultant composite specimens exhibited void contents <3% by volume depending on the type of carbon fabric preform used. Mechanical properties of the panels were determined at both room and elevated temperatures. These included open-hole compressive (OHC) and short beam shear (SBS) properties. Limited process modeling efforts were carried out including infusion times, composite panel size limitations and fabric permeability characterization. Work has also been carried out to develop new PETI based resins specifically geared towards HT-VARTM. The results of this work are presented herein.

  18. Electron Beam Freeform Fabrication: A Rapid Metal Deposition Process

    NASA Technical Reports Server (NTRS)

    Taminger, Karen M. B.; Hafley, Robert A.

    2003-01-01

    Manufacturing of structural metal parts directly from computer aided design (CAD) data has been investigated by numerous researchers over the past decade. Researchers at NASA Langley REsearch Center are developing a new solid freeform fabrication process, electron beam freeform fabrication (EBF), as a rapid metal deposition process that works efficiently with a variety of weldable alloys. The EBF process introduces metal wire feedstock into a molten pool that is created and sustained using a focused electron beam in a vacuum environment. Thus far, this technique has been demonstrated on aluminum and titanium alloys of interest for aerospace structural applications nickel and ferrous based alloys are also planned. Deposits resulting from 2219 aluminum demonstrations have exhibited a range of grain morphologies depending upon the deposition parameters. These materials ave exhibited excellent tensile properties comparable to typical handbook data for wrought plate product after post-processing heat treatments. The EBF process is capable of bulk metal deposition at deposition rated in excess of 2500 cubic centimeters per hour (150 cubic inches per our) or finer detail at lower deposition rates, depending upon the desired application. This process offers the potential for rapidly adding structural details to simpler cast or forged structures rather than the conventional approach of machining large volumes of chips to produce a monolithic metallic structure. Selective addition of metal onto simpler blanks of material can have a significant effect on lead time reduction and lower material and machining costs.

  19. Technology advancement of the static feed water electrolysis process

    NASA Technical Reports Server (NTRS)

    Schubert, F. H.; Wynveen, R. A.

    1977-01-01

    A program to advance the technology of oxygen- and hydrogen-generating subsystems based on water electrolysis was studied. Major emphasis was placed on static feed water electrolysis, a concept characterized by low power consumption and high intrinsic reliability. The static feed based oxygen generation subsystem consists basically of three subassemblies: (1) a combined water electrolysis and product gas dehumidifier module; (2) a product gas pressure controller and; (3) a cyclically filled water feed tank. Development activities were completed at the subsystem as well as at the component level. An extensive test program including single cell, subsystem and integrated system testing was completed with the required test support accessories designed, fabricated, and assembled. Mini-product assurance activities were included throughout all phases of program activities. An extensive number of supporting technology studies were conducted to advance the technology base of the static feed water electrolysis process and to resolve problems.

  20. MONOLITHIC FUEL FABRICATION PROCESS DEVELOPMENT AT THE IDAHO NATIONAL LABORATORY

    SciTech Connect

    Glenn A. Moore; Francine J. Rice; Nicolas E. Woolstenhulme; W. David SwanK; DeLon C. Haggard; Jan-Fong Jue; Blair H. Park; Steven E. Steffler; N. Pat Hallinan; Michael D. Chapple; Douglas E. Burkes

    2008-10-01

    Within the Reduced Enrichment for Research and Test Reactors (RERTR) program directed by the US Department of Energy (DOE), UMo fuel-foils are being developed in an effort to realize high density monolithic fuel plates for use in high-flux research and test reactors. Namely, targeted are reactors that are not amenable to Low Enriched Uranium (LEU) fuel conversion via utilization of high density dispersion-based fuels, i.e. 8-9 gU/cc. LEU conversion of reactors having a need for >8-9 gU/cc fuel density will only be possible by way of monolithic fuel forms. The UMo fuel foils under development afford fuel meat density of ~16 gU/cc and thus have the potential to facilitate LEU conversions without any significant reactor-performance penalty. Two primary challenges have been established with respect to UMo monolithic fuel development; namely, fuel element fabrication and in-reactor fuel element performance. Both issues are being addressed concurrently at the Idaho National Laboratory. An overview is provided of the ongoing monolithic UMo fuel development effort at the Idaho National Laboratory (INL); including development of complex/graded fuel foils. Fabrication processes to be discussed include: UMo alloying and casting, foil fabrication via hot rolling, fuel-clad interlayer application via co-rolling and thermal spray processes, clad bonding via Hot Isostatic Pressing (HIP) and Friction Bonding (FB), and fuel plate finishing.

  1. A solar module fabrication process for HALE solar electric UAVs

    SciTech Connect

    Carey, P.G.; Aceves, R.C.; Colella, N.J.; Williams, K.A.; Sinton, R.A.; Glenn, G.S.

    1994-12-12

    We describe a fabrication process used to manufacture high power-to-weight-ratio flexible solar array modules for use on high-altitude-long-endurance (HALE) solar-electric unmanned air vehicles (UAVs). These modules have achieved power-to-weight ratios of 315 and 396 W/kg for 150{mu}m-thick monofacial and 110{mu}m-thick bifacial silicon solar cells, respectively. These calculations reflect average module efficiencies of 15.3% (150{mu}m) and 14.7% (110{mu}m) obtained from electrical tests performed by Spectrolab, Inc. under AMO global conditions at 25{degrees}C, and include weight contributions from all module components (solar cells, lamination material, bypass diodes, interconnect wires, and adhesive tape used to attach the modules to the wing). The fabrication, testing, and performance of 32 m{sup 2} of these modules will be described.

  2. One-step electrodeposition process to fabricate cathodic superhydrophobic surface

    NASA Astrophysics Data System (ADS)

    Chen, Zhi; Li, Feng; Hao, Limei; Chen, Anqi; Kong, Youchao

    2011-12-01

    In this work, a rapid one-step process is developed to fabricate superhydrophobic cathodic surface by electrodepositing copper plate in an electrolyte solution containing manganese chloride (MnCl2·4H2O), myristic acid (CH3(CH2)12COOH) and ethanol. The superhydrophobic surfaces were characterized by means of scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). The shortest electrolysis time for fabricating a superhydrophobic surface is about 1 min, the measured maximum contact angle is 163° and rolling angle is less than 3°. Furthermore, this method can be easily extended to other conductive materials. The approach is time-saving and cheap, and it is supposed to have a promising future in industrial fields.

  3. Microstructure fabrication process induced modulations in CVD graphene

    SciTech Connect

    Matsubayashi, Akitomo Zhang, Zhenjun; Lee, Ji Ung; LaBella, Vincent P.

    2014-12-15

    The systematic Raman spectroscopic study of a “mimicked” graphene device fabrication is presented. Upon photoresist baking, compressive stress is induced in the graphene which disappears after it is removed. The indirect irradiation from the electron beam (through the photoresist) does not significantly alter graphene characteristic Raman peaks indicating that graphene quality is preserved upon the exposure. The 2D peak shifts and the intensity ratio of 2D and G band, I(2D)/I(G), decreases upon direct metal deposition (Co and Py) suggesting that the electronic modulation occurs due to sp{sup 2} C-C bond weakening. In contrast, a thin metal oxide film deposited graphene does not show either the significant 2D and G peaks shift or I(2D)/I(G) decrease upon the metal deposition suggesting the oxide protect the graphene quality in the fabrication process.

  4. The role of rapid solidification processing in the fabrication of fiber reinforced metal matrix composites

    NASA Technical Reports Server (NTRS)

    Locci, Ivan E.; Noebe, Ronald D.

    1989-01-01

    Advanced composite processing techniques for fiber reinforced metal matrix composites require the flexibility to meet several widespread objectives. The development of uniquely desired matrix microstructures and uniformly arrayed fiber spacing with sufficient bonding between fiber and matrix to transmit load between them without degradation to the fiber or matrix are the minimum requirements necessary of any fabrication process. For most applications these criteria can be met by fabricating composite monotapes which are then consolidated into composite panels or more complicated components such as fiber reinforced turbine blades. Regardless of the end component, composite monotapes are the building blocks from which near net shape composite structures can be formed. The most common methods for forming composite monotapes are the powder cloth, foil/fiber, plasma spray, and arc spray processes. These practices, however, employ rapid solidification techniques in processing of the composite matrix phase. Consequently, rapid solidification processes play a vital and yet generally overlooked role in composite fabrication. The future potential of rapid solidification processing is discussed.

  5. Interior-architectured ZnO nanostructure for enhanced electrical conductivity via stepwise fabrication process

    PubMed Central

    2014-01-01

    Fabrication of ZnO nanostructure via direct patterning based on sol-gel process has advantages of low-cost, vacuum-free, and rapid process and producibility on flexible or non-uniform substrates. Recently, it has been applied in light-emitting devices and advanced nanopatterning. However, application as an electrically conducting layer processed at low temperature has been limited by its high resistivity due to interior structure. In this paper, we report interior-architecturing of sol-gel-based ZnO nanostructure for the enhanced electrical conductivity. Stepwise fabrication process combining the nanoimprint lithography (NIL) process with an additional growth process was newly applied. Changes in morphology, interior structure, and electrical characteristics of the fabricated ZnO nanolines were analyzed. It was shown that filling structural voids in ZnO nanolines with nanocrystalline ZnO contributed to reducing electrical resistivity. Both rigid and flexible substrates were adopted for the device implementation, and the robustness of ZnO nanostructure on flexible substrate was verified. Interior-architecturing of ZnO nanostructure lends itself well to the tunability of morphological, electrical, and optical characteristics of nanopatterned inorganic materials with the large-area, low-cost, and low-temperature producibility. PMID:25258595

  6. Degradation of formaldehyde by advanced oxidation processes.

    PubMed

    Guimarães, José Roberto; Farah, Carolina Rittes Turato; Maniero, Milena Guedes; Fadini, Pedro Sérgio

    2012-09-30

    The degradation of formaldehyde in an aqueous solution (400 mg L(-1)) was studied using photolysis, peroxidation and advanced oxidation processes (UV/H(2)O(2), Fenton and photo-Fenton). Photolysis was the only process tested that did not reduce formaldehyde concentration; however, only advanced oxidation processes (AOPs) significantly decreased dissolved organic carbon (DOC). UV/H(2)O(2) and photo-Fenton AOPs were used to degrade formaldehyde at the highest concentrations (1200-12,000 mg L(-1)); the processes were able to reduce CH(2)O by 98% and DOC by 65%. Peroxidation with ultraviolet light (UV/H(2)O(2)) improved the efficiency of treatment of effluent from an anatomy laboratory. The effluent's CH(2)O content was reduced by 91%, DOC by 48%, COD by 46% and BOD by 53% in 420 min of testing.

  7. HANDBOOK ON ADVANCED PHOTOCHEMICAL OXIDATION PROCESSES

    EPA Science Inventory

    This handbook summarizes commercial-scale system performance and cost data for advanced photochemical oxidation (APO) treatment of contaminated water, air, and solids. Similar information from pilot- and bench-scale evaluations of APO processes is also included to supplement the...

  8. HANDBOOK ON ADVANCED NONPHOTOCHEMICAL OXIDATION PROCESSES

    EPA Science Inventory

    The purpose of this handbook is to summarize commercial-scale system performance and cost data for advanced nonphotochemical oxidation (ANPO) treatment of contaminated water, air, and soil. Similar information from pilot-and bench-scale evaluations of ANPO processes is also inclu...

  9. HANDBOOK ON ADVANCED NONPHOTOCHEMICAL OXIDATION PROCESSES

    EPA Science Inventory

    The purpose of this handbook is to summarize commercial-scale system performance and cost data for advanced nonphotochemical oxidation (ANPO) treatment of contaminated water, air, and soil. Similar information from pilot-and bench-scale evaluations of ANPO processes is also inclu...

  10. HANDBOOK ON ADVANCED PHOTOCHEMICAL OXIDATION PROCESSES

    EPA Science Inventory

    This handbook summarizes commercial-scale system performance and cost data for advanced photochemical oxidation (APO) treatment of contaminated water, air, and solids. Similar information from pilot- and bench-scale evaluations of APO processes is also included to supplement the...

  11. Ion beam processing of advanced electronic materials

    SciTech Connect

    Cheung, N.W.; Marwick, A.D.; Roberto, J.B.; International Business Machines Corp., Yorktown Heights, NY . Thomas J. Watson Research Center; Oak Ridge National Lab., TN )

    1989-01-01

    This report contains research programs discussed at the materials research society symposia on ion beam processing of advanced electronic materials. Major topics include: shallow implantation and solid-phase epitaxy; damage effects; focused ion beams; MeV implantation; high-dose implantation; implantation in III-V materials and multilayers; and implantation in electronic materials. Individual projects are processed separately for the data bases. (CBS)

  12. Process simulation for advanced composites production

    SciTech Connect

    Allendorf, M.D.; Ferko, S.M.; Griffiths, S.

    1997-04-01

    The objective of this project is to improve the efficiency and lower the cost of chemical vapor deposition (CVD) processes used to manufacture advanced ceramics by providing the physical and chemical understanding necessary to optimize and control these processes. Project deliverables include: numerical process models; databases of thermodynamic and kinetic information related to the deposition process; and process sensors and software algorithms that can be used for process control. Target manufacturing techniques include CVD fiber coating technologies (used to deposit interfacial coatings on continuous fiber ceramic preforms), chemical vapor infiltration, thin-film deposition processes used in the glass industry, and coating techniques used to deposit wear-, abrasion-, and corrosion-resistant coatings for use in the pulp and paper, metals processing, and aluminum industries.

  13. Design and fabrication of an advanced, lightweight, high stiffness, railgun barrel concept

    SciTech Connect

    Vrable, D.L.; Rosenwasser, S.N.; Korican, J.A. )

    1991-01-01

    An advanced lightweight and high stiffness railgun barrel design and incorporates several new design features and advanced materials is being developed by SPARTA, Inc. The program is sponsored by the U.S. Army Armament Research, Development, and Engineering Center ARDEC and by the Defense Advanced Research Projects Agency (DARPA). The railgun is 7 m long and has a 90 mm round bore. It is designed to accommodate both solid and plasma armatures. Muzzle energies are expected in the range of 9 to 15 MJ. Analysis and final design has been completed and the barrel and other railgun subassemblies are in the fabrication stage at SPARTA, Inc. in San Diego, California. Initial testing will be conducted at Maxwell Laboratories Green Farm facility in September 1990 and will subsequently be shipped to the ARDEC Railgun Laboratory in October 1990 for full power operation and testing. This paper discusses the design features and fabrication approaches for this high performance, lightweight railgun barrel system.

  14. Advanced Laser Chemical Processing For Microelectronics and Integrated Optics

    DTIC Science & Technology

    1992-08-15

    Barbara, CA (June 25-27, 1990). 15. R.M. Osgood, Jr., " Laser - Fabrication for Integrated Electronics and Optics," OITDA Conference, Tokyo, Japan, (July 5...Society Meeting, Boston, MA, November 26 - December 3, 1990. 20. R.M. Osgood, Jr., "Advances in Laser Fabrication for Solid-State Electronics and...Thin, Excimer Laser-Deposited Cd Interlayers," J. Elec. Mat. 12, 1239 (July, 1990). 14. R.M. Osgood, Jr., " Laser - Fabrication for Solid State

  15. Amorphous In-Si-O Films Fabricated via Solution Processing

    NASA Astrophysics Data System (ADS)

    Jan, Hani Esmael; Hoang, Ha; Nakamura, Tsubasa; Koga, Tomoaki; Ina, Toshiaki; Uruga, Tomoya; Kizu, Takio; Tsukagoshi, Kazuhito; Nabatame, Toshihide; Fujiwara, Akihiko

    2017-06-01

    We report the characteristics of an amorphous oxide semiconductor In-Si-O fabricated via solution processing. In-Si-O thin films with nominal silicon concentration of 0 at.%, 1 at.%, 3 at.%, 5 at.%, 9 at.%, 50 at.%, and 100 at.% were fabricated via spin coating. The films were characterized via thermal desorption spectroscopy (TDS), x-ray reflectivity, x-ray diffraction (XRD), extended x-ray absorption fine structure (EXAFS), and electrical resistance measurements. TDS analysis suggested that organic residues, such as organic functional groups from raw materials and solvents, were almost completely desorbed from the films at approximately 400°C. The XRD and EXAFS analyses confirmed that pure In2O3 crystallizes at approximately 350°C and that the crystallization temperature increases with the silicon concentration. In-Si-O films with silicon concentration above 3 at.% exhibited high electrical resistance, indicating that films fabricated via spin coating contain few oxygen vacancies. These results suggest that In-Si-O thin films have significant potential for use as channels in field-effect transistors designed for next-generation flat-panel displays.

  16. Assessment of advanced coal gasification processes

    NASA Technical Reports Server (NTRS)

    Mccarthy, J.; Ferrall, J.; Charng, T.; Houseman, J.

    1981-01-01

    A technical assessment of the following advanced coal gasification processes is presented: high throughput gasification (HTG) process; single stage high mass flux (HMF) processes; (CS/R) hydrogasification process; and the catalytic coal gasification (CCG) process. Each process is evaluated for its potential to produce synthetic natural gas from a bituminous coal. Key similarities, differences, strengths, weaknesses, and potential improvements to each process are identified. The HTG and the HMF gasifiers share similarities with respect to: short residence time (SRT), high throughput rate, slagging, and syngas as the initial raw product gas. The CS/R hydrogasifier is also SRT, but is nonslagging and produces a raw gas high in methane content. The CCG gasifier is a long residence time, catalytic, fluidbed reactor producing all of the raw product methane in the gasifier.

  17. Optical microdevices fabricated using femtosecond laser processing (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Otuka, Adriano J. G.; Tomázio, Nathália B.; Tribuzi, Vinicius; Ferreira, Paulo Henrique D.; De Boni, Leonardo; Mendonça, Cleber R.

    2017-02-01

    Femtosecond laser processing techniques have been widely employed to produce micro or nanodevices with special features. These devices can be selectively doped with organic dyes, biological agents, nanoparticles or carbon nanotubes, increasing the range of applications. Acrylate polymers can be easily doped with various compounds, and therefore, they are interesting materials for laser fabrication techniques. In this work, we use multiphoton absorption polymerization (MAP) and laser ablation to fabricate polymeric microdevices for optical applications. The polymeric sample used in this work is composed in equal proportions of two three-acrylate monomers; while tris(2-hydroxyethyl)isocyanurate triacrylate gives hardness to the structure, the ethoxylated(6) trimethyl-lolpropane triacrylate reduces the shrinkage tensions upon polymerization. These monomers are mixed with a photoinitiator, the 2,4,6-trimetilbenzoiletoxifenil phosphine oxide, enabling the sample polymerization after laser irradiation. Using MAP, we fabricate three-dimensional structures doped with fluorescent dyes. These structures can be used in several optical applications, such as, RGB fluorescent microdevices or microresonators. Using azo compounds like dopant in the host resin, we can apply these structures in optical data storage devices. Using laser ablation technique, we can fabricate periodic microstructures inside polymeric bulks doped with xanthene dyes and single-walled carbon nanotubes, aiming applications in random laser experiments. In structured bulks we observed multi-narrow emission peaks over the xanthene fluorescence emission. Furthermore, in comparison with non-structured bulks, we observed that the periodic structure decreased the degree of randomness, reducing the number of peaks, but defining their position.

  18. Magnetic fabric and welding processes in high-grade tuffs

    NASA Astrophysics Data System (ADS)

    Pioli, L.; Ort, M.; Lanza, R.; Rosi, M.

    2003-04-01

    The welding fabric of tuffs is generally quantified through two main parameters: porosity and fiamme aspect ratio. However, these parameters are not useful for high-grade ignimbrites that display features indicating extensive rheomorphic flow, partial to complete obliteration of primary vitroclastic textures, and syn-depositional welding rather than load-related compaction. In this case, a 3D-microstructural characterization of the rock fabric is a fundamental proxy for the assessment of the dynamics and duration of welding processes. We have investigated the relations between magnetic fabric and welding textures in a rhyolitic, high-grade ignimbrite from the Sulcis volcanic District (SW Sardinia, Italy). The ignimbrite is characterized by dense welding throughout its preserved thickness and by regular lateral and vertical variations of welding, devitrification and vesiculation facies. Field and structural data indicate that syn-depositional welding and non-particulate (NP) flow were extensive and continuous during the emplacement of the ignimbrite. Paleomagnetic measurements of AMS, NRM, and AIRM of samples from the tuff indicate that the magnetic fabric is strain-sensitive and it is not significantly affected by post-depositional, static processes such as devitrification and vapor-phase alteration; in particular, magnetic susceptibility of the rock and the welding texture correlate well in terms of shape and orientation of the anisotropy ellipsoid. The direction of the K1 axis is indicative of the flow direction in the site of measurement. The anisotropy degree (P) increases with increasing welding and foliation (F) and lineation (L) are directly related to the strain facies. Onset of welding increased the degree of anisotropy and foliation; a non particulate, laminar flow stage further deformed the fabric stretching it along the flow direction and thus increasing L. The intensity of L is strictly related to the duration and the effect of simple shear (laminar

  19. Fabrication process for the PEP II RF cavities

    SciTech Connect

    Franks, R.M.; Rimmer, R.A.; Schwarz, H.

    1997-06-05

    This paper presents the major steps used in the fabrication of the 26 RF Cavities required for the PEP-II B-factory. Several unique applications of conventional processes have been developed and successfully implemented: electron beam welding (EBW), with minimal porosity, of .75 inch (19 mm) copper cross-sections; extensive 5-axis milling of water channels; electroplating of .37 inch (10 mm) thick OFE copper; tuning of the cavity by profiling beam noses prior to final joining with the cavity body; and machining of the cavity interior, are described here.

  20. Fabrication Processes for the PEP II RF Cavities

    SciTech Connect

    Franks, R.Mark; Rimmer, Robert A.; Schwarz, Heinz; /SLAC

    2011-09-01

    This paper presents the major steps used in the fabrication of the 26 RF Cavities required for the PEP-II B-factory. Several unique applications of conventional processes have been developed and successfully implemented: electron beam welding (EBW), with minimal porosity, of .75 inch (19 mm) copper cross-sections; extensive 5-axis milling of water channels; electroplating of .37 inch (10 mm) thick OFE copper; tuning of the cavity by profiling beam noses prior to final joining with the cavity body; and machining of the cavity interior, are described here.

  1. Assessment of Advanced Coal Gasification Processes

    NASA Technical Reports Server (NTRS)

    McCarthy, John; Ferrall, Joseph; Charng, Thomas; Houseman, John

    1981-01-01

    This report represents a technical assessment of the following advanced coal gasification processes: AVCO High Throughput Gasification (HTG) Process; Bell Single-Stage High Mass Flux (HMF) Process; Cities Service/Rockwell (CS/R) Hydrogasification Process; Exxon Catalytic Coal Gasification (CCG) Process. Each process is evaluated for its potential to produce SNG from a bituminous coal. In addition to identifying the new technology these processes represent, key similarities/differences, strengths/weaknesses, and potential improvements to each process are identified. The AVCO HTG and the Bell HMF gasifiers share similarities with respect to: short residence time (SRT), high throughput rate, slagging and syngas as the initial raw product gas. The CS/R Hydrogasifier is also SRT but is non-slagging and produces a raw gas high in methane content. The Exxon CCG gasifier is a long residence time, catalytic, fluidbed reactor producing all of the raw product methane in the gasifier. The report makes the following assessments: 1) while each process has significant potential as coal gasifiers, the CS/R and Exxon processes are better suited for SNG production; 2) the Exxon process is the closest to a commercial level for near-term SNG production; and 3) the SRT processes require significant development including scale-up and turndown demonstration, char processing and/or utilization demonstration, and reactor control and safety features development.

  2. Assessment of Advanced Coal Gasification Processes

    NASA Technical Reports Server (NTRS)

    McCarthy, John; Ferrall, Joseph; Charng, Thomas; Houseman, John

    1981-01-01

    This report represents a technical assessment of the following advanced coal gasification processes: AVCO High Throughput Gasification (HTG) Process; Bell Single-Stage High Mass Flux (HMF) Process; Cities Service/Rockwell (CS/R) Hydrogasification Process; Exxon Catalytic Coal Gasification (CCG) Process. Each process is evaluated for its potential to produce SNG from a bituminous coal. In addition to identifying the new technology these processes represent, key similarities/differences, strengths/weaknesses, and potential improvements to each process are identified. The AVCO HTG and the Bell HMF gasifiers share similarities with respect to: short residence time (SRT), high throughput rate, slagging and syngas as the initial raw product gas. The CS/R Hydrogasifier is also SRT but is non-slagging and produces a raw gas high in methane content. The Exxon CCG gasifier is a long residence time, catalytic, fluidbed reactor producing all of the raw product methane in the gasifier. The report makes the following assessments: 1) while each process has significant potential as coal gasifiers, the CS/R and Exxon processes are better suited for SNG production; 2) the Exxon process is the closest to a commercial level for near-term SNG production; and 3) the SRT processes require significant development including scale-up and turndown demonstration, char processing and/or utilization demonstration, and reactor control and safety features development.

  3. Silicon solar cell process development, fabrication and analysis

    NASA Technical Reports Server (NTRS)

    Yoo, H. I.; Iles, P. A.; Leung, D. C.

    1981-01-01

    Solar cells were fabricated from EFG ribbons dendritic webs, cast ingots by heat exchanger method, and cast ingots by ubiquitous crystallization process. Baseline and other process variations were applied to fabricate solar cells. EFG ribbons grown in a carbon-containing gas atmosphere showed significant improvement in silicon quality. Baseline solar cells from dendritic webs of various runs indicated that the quality of the webs under investigation was not as good as the conventional CZ silicon, showing an average minority carrier diffusion length of about 60 um versus 120 um of CZ wafers. Detail evaluation of large cast ingots by HEM showed ingot reproducibility problems from run to run and uniformity problems of sheet quality within an ingot. Initial evaluation of the wafers prepared from the cast polycrystalline ingots by UCP suggested that the quality of the wafers from this process is considerably lower than the conventional CZ wafers. Overall performance was relatively uniform, except for a few cells which showed shunting problems caused by inclusions.

  4. A New Process for Fabricating Random Silicon Nanotips

    NASA Technical Reports Server (NTRS)

    Manohara, Harish

    2004-01-01

    An improved process for the fabrication of random arrays of silicon nanotips has been demonstrated to be feasible. Relative to other such processes, this process offers advantages of low cost and simplicity. Moreover, this process can readily be combined with other processes used to fabricate integrated circuits and other monolithic silicon structures. Arrays of silicon nanotips are subjects of research and development efforts directed toward utilizing them as field emitters in flat-panel displays, vacuum microelectronics, and microwave devices. Other silicon-nanotip-fabrication processes developed thus far predominantly include lithography, etching, and/or elaborate deposition steps followed by oxide sharpening steps and are both process intensive as well as expensive. In addition to being cheaper and simpler, the present process can efficiently produce silicon nanotips that range in height from a few microns to several tens of microns and are distributed over large areas. The process mentioned here can be summarized as consisting of (1) the growth of micro-etch masks on a silicon substrate, followed by (2) etching away of the masks, along with some of the substrate, to make an array of sharp tips. In the first step of the process, a cleaned silicon substrate is subjected to reactive ion etching (RIE) in a certain mixture of oxygen and carbon tetrafluoride under radio-frequency excitation. This process step results in the growth of fluorine based compounds in the form of stumps randomly distributed on the substrate. These stumps are known in the art as polymer RIE grass. The dimensions of these stumps are of the order of hundreds of nanometers, the exact values depending on process time and gas composition. The areal density of the stumps decreases with increasing process time as they grow and merge with neighboring stumps. These stumps constitute the micro-etch masks for the next step of the process. In the second step of the process, the substrate covered with

  5. Silicon Solar Cell Process Development, Fabrication and Analysis, Phase 1

    NASA Technical Reports Server (NTRS)

    Yoo, H. I.; Iles, P. A.; Tanner, D. P.

    1979-01-01

    Solar cells from RTR ribbons, EFG (RF and RH) ribbons, dendritic webs, Silso wafers, cast silicon by HEM, silicon on ceramic, and continuous Czochralski ingots were fabricated using a standard process typical of those used currently in the silicon solar cell industry. Back surface field (BSF) processing and other process modifications were included to give preliminary indications of possible improved performance. The parameters measured included open circuit voltage, short circuit current, curve fill factor, and conversion efficiency (all taken under AM0 illumination). Also measured for typical cells were spectral response, dark I-V characteristics, minority carrier diffusion length, and photoresponse by fine light spot scanning. the results were compared to the properties of cells made from conventional single crystalline Czochralski silicon with an emphasis on statistical evaluation. Limited efforts were made to identify growth defects which will influence solar cell performance.

  6. Wrapping process for fabrication of A-15 superconducting composite wires

    DOEpatents

    Suenaga, M.; Klamut, C.J.; Luhman, T.S.

    1980-08-15

    A method for fabricating superconducting wires wherein a billet of copper containing filaments of niobium or vanadium is rolled to form a strip which is wrapped about a tin-alloy core to form a composite. The alloy is a tin-copper alloy for niobium filaments and a gallium-copper alloy for vanadium filaments. The composite is then drawn down to a desired wire size and heat treated. During the heat treatment process, the tin in the bronze reacts with the niobium to form the superconductor niobium tin. In the case where vanadium is used, the gallium in the gallium bronze reacts with the vanadium to form the superconductor vanadium gallium. This new process eliminates the costly annealing steps, external tin plating and drilling of bronze ingots required in a number of prior art processes.

  7. Process for the fabrication of ceramic fiber reinforced titanium aluminide

    SciTech Connect

    Horsfall, I.; Cundy, S.J.

    1992-10-01

    This paper describes initial work on a novel process for the production of titanium aluminide matrix composites reinforced with short alumina fibers. The processing route involves an adaption of existing metal matrix composite (MMC) fabrication technology used to produce hybrid particulate/short fiber composites. A preform is produced which contains alumina fibers and titanium metal powder with a fiber content of around 10 percent by volume and approximately 50 percent porosity. This preform is then infiltrated with pure aluminum by a squeeze casting process to produce a fully dense composite of titanium powder and alumina fibers in a metallic aluminum matrix. The composite is then heat treated in a hot isostatic press to react the aluminum and titanium to produce a titanium aluminide matrix. 9 refs.

  8. Composite monolayer fabrication by an arc-spray process

    NASA Technical Reports Server (NTRS)

    Westfall, Leonard J.

    1988-01-01

    A single layer (monotape) technique for fabricating complex high-temperature tungsten-fiber-reinforced superalloy composites is proposed. The fabrication of sheets of arc-sprayed monotape 38 cm wide and 122 cm long has been demonstrated. Composites fabricated using the method are shown to have equal tensile strength and a cleaner matrix than composites fabricated from powder metal cloth monotapes, and the present technique is less expensive than the powder metal fabrication techniques.

  9. 40 CFR 410.90 - Applicability; description of the felted fabric processing subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 30 2012-07-01 2012-07-01 false Applicability; description of the felted fabric processing subcategory. 410.90 Section 410.90 Protection of Environment ENVIRONMENTAL... Fabric Processing Subcategory § 410.90 Applicability; description of the felted fabric processing...

  10. 40 CFR 410.90 - Applicability; description of the felted fabric processing subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 28 2010-07-01 2010-07-01 true Applicability; description of the felted fabric processing subcategory. 410.90 Section 410.90 Protection of Environment ENVIRONMENTAL... Fabric Processing Subcategory § 410.90 Applicability; description of the felted fabric processing...

  11. Advancing the Assessment of Dynamic Psychological Processes

    PubMed Central

    Wright, Aidan G. C.; Hopwood, Christopher J.

    2016-01-01

    Most commonly used clinical assessment tools cannot fully capture the dynamic psychological processes often hypothesized as core mechanisms of psychopathology and psychotherapy. There is therefore a gap between our theories of problems and interventions for those problems and the tools we use to understand clients. The purpose of this special issue is to connect theory about clinical dynamics to practice by focusing on methods for collecting dynamic data, statistical models for analyzing dynamic data, and conceptual schemes for implementing dynamic data in applied settings. In this introductory article, we argue for the importance of assessing dynamic processes, highlight recent advances in assessment science that enable their measurement, review challenges in using these advances in applied practice, and adumbrate the articles in this issue. PMID:27313187

  12. Advancing the Assessment of Dynamic Psychological Processes.

    PubMed

    Wright, Aidan G C; Hopwood, Christopher J

    2016-08-01

    Most commonly used clinical assessment tools cannot fully capture the dynamic psychological processes often hypothesized as core mechanisms of psychopathology and psychotherapy. There is therefore a gap between our theories of problems and interventions for those problems and the tools we use to understand clients. The purpose of this special issue is to connect theory about clinical dynamics to practice by focusing on methods for collecting dynamic data, statistical models for analyzing dynamic data, and conceptual schemes for implementing dynamic data in applied settings. In this introductory article, we argue for the importance of assessing dynamic processes, highlight recent advances in assessment science that enable their measurement, review challenges in using these advances in applied practice, and adumbrate the articles in this issue.

  13. Processing Methods Established To Fabricate Porous Oxide Ceramic Spheres for Thermal Barrier Coating Applications

    NASA Technical Reports Server (NTRS)

    Dynys, Frederick W.

    2003-01-01

    As gas turbine technology advances, the demand for efficient engines and emission reduction requires a further increase in operating temperatures, but combustion temperatures are currently limited by the temperature capability of the engine components. The existing thermal barrier coating (TBC) technology does not provide sufficient thermal load reduction at a 3000 F (1649 C) operating condition. Advancement in thermal barrier coating technology is needed to meet this aggressive goal. One concept for improving thermal barrier coating effectiveness is to design coating systems that incorporate a layer that reflects or scatters photon radiation. This can be achieved by using porous structures. The refractive index mismatch between the solid and pore, the pore size, and the pore density can be engineered to efficiently scatter photon radiation. Under NASA s Ultra-Efficient Engine Technology (UEET) Program, processing methods to fabricate porous ceramic spheres suitable for scattering photon radiation at elevated temperatures have been established. A straightforward templating process was developed at the NASA Glenn Research Center that requires no special processing equipment. The template was used to define particle shape, particle size, and pore size. Spherical organic cation exchange resins were used as a structure-directing template. The cation exchange resins have dual template capabilities that can produce different pore architectures. This process can be used to fabricate both metal oxide and metal carbide spheres.

  14. Advanced oxidation process sanitization of eggshell surfaces.

    PubMed

    Gottselig, Steven M; Dunn-Horrocks, Sadie L; Woodring, Kristy S; Coufal, Craig D; Duong, Tri

    2016-06-01

    The microbial quality of eggs entering the hatchery represents an important critical control point for biosecurity and pathogen reduction programs in integrated poultry production. The development of safe and effective interventions to reduce microbial contamination on the surface of eggs will be important to improve the overall productivity and microbial food safety of poultry and poultry products. The hydrogen peroxide (H2O2) and ultraviolet (UV) light advanced oxidation process is a potentially important alternative to traditional sanitizers and disinfectants for egg sanitation. The H2O2/UV advanced oxidation process was demonstrated previously to be effective in reducing surface microbial contamination on eggs. In this study, we evaluated treatment conditions affecting the efficacy of H2O2/UV advanced oxidation in order to identify operational parameters for the practical application of this technology in egg sanitation. The effect of the number of application cycles, UV intensity, duration of UV exposure, and egg rotation on the recovery of total aerobic bacteria from the surface of eggs was evaluated. Of the conditions evaluated, we determined that reduction of total aerobic bacteria from naturally contaminated eggs was optimized when eggs were sanitized using 2 repeated application cycles with 5 s exposure to 14 mW cm(-2) UV light, and that rotation of the eggs between application cycles was unnecessary. Additionally, using these optimized conditions, the H2O2/UV process reduced Salmonella by greater than 5 log10 cfu egg(-1) on the surface of experimentally contaminated eggs. This study demonstrates the potential for practical application of the H2O2/UV advanced oxidation process in egg sanitation and its effectiveness in reducing Salmonella on eggshell surfaces.

  15. Advanced experimental applications for x-ray transmission gratings spectroscopy using a novel grating fabrication method

    NASA Astrophysics Data System (ADS)

    Hurvitz, G.; Ehrlich, Y.; Strum, G.; Shpilman, Z.; Levy, I.; Fraenkel, M.

    2012-08-01

    A novel fabrication method for soft x-ray transmission grating and other optical elements is presented. The method uses focused-ion-beam technology to fabricate high-quality free standing grating bars on transmission electron microscopy grids. High quality transmission gratings are obtained with superb accuracy and versatility. Using these gratings and back-illuminated CCD camera, absolutely calibrated x-ray spectra can be acquired for soft x-ray source diagnostics in the 100-3000 eV spectral range. Double grating combinations of identical or different parameters are easily fabricated, allowing advanced one-shot application of transmission grating spectroscopy. These applications include spectroscopy with different spectral resolutions, bandwidths, dynamic ranges, and may serve for identification of high-order contribution, and spectral calibrations of various x-ray optical elements.

  16. TOPICAL REVIEW: Recent advances in the fabrication and adhesion testing of biomimetic dry adhesives

    NASA Astrophysics Data System (ADS)

    Sameoto, D.; Menon, C.

    2010-10-01

    In the past two years, there have been a large number of publications on the topic of biomimetic dry adhesives from modeling, fabrication and testing perspectives. We review and compare the most recent advances in fabrication and testing of these materials. While there is increased convergence and consensus as to what makes a good dry adhesive, the fabrication of these materials is still challenging, particularly for anisotropic or hierarchal designs. Although qualitative comparisons between different adhesive designs can be made, quantifying the exact performance and rating each design is significantly hampered by the lack of standardized testing methods. Manufacturing dry adhesives, which can reliably adhere to rough surfaces, show directional and self-cleaning behavior and are relatively simple to manufacture, is still very challenging—great strides by multiple research groups have however made these goals appear achievable within the next few years.

  17. Computational design and fabrication of a novel bioresorbable cage for tibial tuberosity advancement application.

    PubMed

    Castilho, Miguel; Rodrigues, Jorge; Vorndran, Elke; Gbureck, Uwe; Quental, Carlos; Folgado, João; Fernandes, Paulo R

    2017-01-01

    Tibial tuberosity advancement (TTA) is a promising method for the treatment of cruciate ligament rupture in dogs that usually implies the implantation of a titanium cage as bone implant. This cage is non-biodegradable and fails in providing adequate implant-bone tissue integration. The objective of this work is to propose a new process chain for designing and manufacturing an alternative biodegradable cage that can fulfill specific patient requirements. A three-dimensional finite element model (3D FEM) of the TTA system was first created to evaluate the mechanical environment at cage domain during different stages of the dog walk. The cage microstructure was then optimized using a topology optimization tool, which addresses the accessed local mechanical requirements, and at same time ensures the maximum permeability to allow nutrient and oxygen supply to the implant core. The designed cage was then biofabricated by a 3D powder printing of tricalcium phosphate cement. This work demonstrates that the combination of a 3D FEM with a topology optimization approach enabled the design of a novel cage for TTA application with tailored permeability and mechanical properties, that can be successfully 3D printed in a biodegradable bioceramic material. These results support the potential of the design optimization strategy and fabrication method to the development of customized and bioresorbable implants for bone repair.

  18. Wafer-Level Membrane-Transfer Process for Fabricating MEMS

    NASA Technical Reports Server (NTRS)

    Yang, Eui-Hyeok; Wiberg, Dean

    2003-01-01

    A process for transferring an entire wafer-level micromachined silicon structure for mating with and bonding to another such structure has been devised. This process is intended especially for use in wafer-level integration of microelectromechanical systems (MEMS) that have been fabricated on dissimilar substrates. Unlike in some older membrane-transfer processes, there is no use of wax or epoxy during transfer. In this process, the substrate of a wafer-level structure to be transferred serves as a carrier, and is etched away once the transfer has been completed. Another important feature of this process is that two electrodes constitutes an electrostatic actuator array. An SOI wafer and a silicon wafer (see Figure 1) are used as the carrier and electrode wafers, respectively. After oxidation, both wafers are patterned and etched to define a corrugation profile and electrode array, respectively. The polysilicon layer is deposited on the SOI wafer. The carrier wafer is bonded to the electrode wafer by using evaporated indium bumps. The piston pressure of 4 kPa is applied at 156 C in a vacuum chamber to provide hermetic sealing. The substrate of the SOI wafer is etched in a 25 weight percent TMAH bath at 80 C. The exposed buried oxide is then removed by using 49 percent HF droplets after an oxygen plasma ashing. The SOI top silicon layer is etched away by using an SF6 plasma to define the corrugation profile, followed by the HF droplet etching of the remaining oxide. The SF6 plasma with a shadow mask selectively etches the polysilicon membrane, if the transferred membrane structure needs to be patterned. Electrostatic actuators with various electrode gaps have been fabricated by this transfer technique. The gap between the transferred membrane and electrode substrate is very uniform ( 0.1 m across a wafer diameter of 100 mm, provided by optimizing the bonding control). Figure 2 depicts the finished product.

  19. Fabrication Process of Silicone-based Dielectric Elastomer Actuators.

    PubMed

    Rosset, Samuel; Araromi, Oluwaseun A; Schlatter, Samuel; Shea, Herbert R

    2016-02-01

    This contribution demonstrates the fabrication process of dielectric elastomer transducers (DETs). DETs are stretchable capacitors consisting of an elastomeric dielectric membrane sandwiched between two compliant electrodes. The large actuation strains of these transducers when used as actuators (over 300% area strain) and their soft and compliant nature has been exploited for a wide range of applications, including electrically tunable optics, haptic feedback devices, wave-energy harvesting, deformable cell-culture devices, compliant grippers, and propulsion of a bio-inspired fish-like airship. In most cases, DETs are made with a commercial proprietary acrylic elastomer and with hand-applied electrodes of carbon powder or carbon grease. This combination leads to non-reproducible and slow actuators exhibiting viscoelastic creep and a short lifetime. We present here a complete process flow for the reproducible fabrication of DETs based on thin elastomeric silicone films, including casting of thin silicone membranes, membrane release and prestretching, patterning of robust compliant electrodes, assembly and testing. The membranes are cast on flexible polyethylene terephthalate (PET) substrates coated with a water-soluble sacrificial layer for ease of release. The electrodes consist of carbon black particles dispersed into a silicone matrix and patterned using a stamping technique, which leads to precisely-defined compliant electrodes that present a high adhesion to the dielectric membrane on which they are applied.

  20. Fabrication Process of Silicone-based Dielectric Elastomer Actuators

    PubMed Central

    Rosset, Samuel; Araromi, Oluwaseun A.; Schlatter, Samuel; Shea, Herbert R.

    2016-01-01

    This contribution demonstrates the fabrication process of dielectric elastomer transducers (DETs). DETs are stretchable capacitors consisting of an elastomeric dielectric membrane sandwiched between two compliant electrodes. The large actuation strains of these transducers when used as actuators (over 300% area strain) and their soft and compliant nature has been exploited for a wide range of applications, including electrically tunable optics, haptic feedback devices, wave-energy harvesting, deformable cell-culture devices, compliant grippers, and propulsion of a bio-inspired fish-like airship. In most cases, DETs are made with a commercial proprietary acrylic elastomer and with hand-applied electrodes of carbon powder or carbon grease. This combination leads to non-reproducible and slow actuators exhibiting viscoelastic creep and a short lifetime. We present here a complete process flow for the reproducible fabrication of DETs based on thin elastomeric silicone films, including casting of thin silicone membranes, membrane release and prestretching, patterning of robust compliant electrodes, assembly and testing. The membranes are cast on flexible polyethylene terephthalate (PET) substrates coated with a water-soluble sacrificial layer for ease of release. The electrodes consist of carbon black particles dispersed into a silicone matrix and patterned using a stamping technique, which leads to precisely-defined compliant electrodes that present a high adhesion to the dielectric membrane on which they are applied. PMID:26863283

  1. DESIGN, FABRICATION, AND TESTING OF AN ADVANCED, NON-POLLUTING TURBINE DRIVE GAS GENERATOR

    SciTech Connect

    Unknown

    2002-01-31

    The objective of this report period was to continue the development of the Gas Generator design, fabrication and test of the non-polluting unique power turbine drive Gas Generator. Focus during this past report period has been to continue completion the Gas Generator design, completing the brazing and bonding experiments to determine the best method and materials necessary to fabricate the Gas Generator hardware, continuing to making preparations for fabricating and testing this Gas Generator and commencing with the fabrication of the Gas Generator hardware and ancillary hardware. Designs have been completed sufficiently such that Long Lead Items [LLI] have been ordered and upon arrival will be readied for the fabrication process. The keys to this design are the platelet construction of the injectors that precisely measures/meters the flow of the propellants and water all throughout the steam generating process and the CES patented gas generating cycle. The Igniter Assembly injector platelets fabrication process has been completed and bonded to the Igniter Assembly and final machined. The Igniter Assembly is in final assembly and is being readied for testing in the October 2001 time frame. Test Plan dated August 2001, was revised and finalized, replacing Test Plan dated May 2001.

  2. Advanced miniature processing handware for ATR applications

    NASA Technical Reports Server (NTRS)

    Chao, Tien-Hsin (Inventor); Daud, Taher (Inventor); Thakoor, Anikumar (Inventor)

    2003-01-01

    A Hybrid Optoelectronic Neural Object Recognition System (HONORS), is disclosed, comprising two major building blocks: (1) an advanced grayscale optical correlator (OC) and (2) a massively parallel three-dimensional neural-processor. The optical correlator, with its inherent advantages in parallel processing and shift invariance, is used for target of interest (TOI) detection and segmentation. The three-dimensional neural-processor, with its robust neural learning capability, is used for target classification and identification. The hybrid optoelectronic neural object recognition system, with its powerful combination of optical processing and neural networks, enables real-time, large frame, automatic target recognition (ATR).

  3. Human factors challenges for advanced process control

    SciTech Connect

    Stubler, W.F.; O`Hara, J..M.

    1996-08-01

    New human-system interface technologies provide opportunities for improving operator and plant performance. However, if these technologies are not properly implemented, they may introduce new challenges to performance and safety. This paper reports the results from a survey of human factors considerations that arise in the implementation of advanced human-system interface technologies in process control and other complex systems. General trends were identified for several areas based on a review of technical literature and a combination of interviews and site visits with process control organizations. Human factors considerations are discussed for two of these areas, automation and controls.

  4. Technology advancement of the electrochemical CO2 concentrating process

    NASA Technical Reports Server (NTRS)

    Schubert, F. H.; Heppner, D. B.; Hallick, T. M.; Woods, R. R.

    1979-01-01

    Two multicell, liquid-cooled, advanced electrochemical depolarized carbon dioxide concentrator modules were fabricated. The cells utilized advanced, lightweight, plated anode current collectors, internal liquid cooling and lightweight cell frames. Both were designed to meet the carbon dioxide removal requirements of one-person, i.e., 1.0 kg/d (2.2 lb/d).

  5. Process for High-Rate Fabrication of Alumina Nanotemplates

    NASA Technical Reports Server (NTRS)

    Myung, Nosang; Fleurial, Jean-Pierre; Yun, Minhee; West, William; Choi, Daniel

    2007-01-01

    An anodizing process, at an early stage of development at the time of reporting the information for this article, has shown promise as a means of fabricating alumina nanotemplates integrated with silicon wafers. Alumina nanotemplates are basically layers of alumina, typically several microns thick, in which are formed approximately regular hexagonal arrays of holes having typical diameters of the order of 10 to 100 nm. Interest in alumina nanotemplates has grown in recent years because they have been found to be useful as templates in the fabrication of nanoscale magnetic, electronic, optoelectronic, and other devices. The present anodizing process is attractive for the fabrication of alumina nanotemplates integrated with silicon wafers in two respects: (1) the process involves self-ordering of the holes; that is, the holes as formed by the process are spontaneously arranged in approximately regular hexagonal arrays; and (2) the rates of growth (that is, elongation) of the holes are high enough to make the process compatible with other processes used in the mass production of integrated circuits. In preparation for fabrication of alumina nanotemplates in this process, one first uses electron-beam evaporation to deposit thin films of titanium, followed by thin films of aluminum, on silicon wafers. Then the alumina nanotemplates are formed by anodizing the aluminum layers, as described below. In experiments in which the process was partially developed, the titanium films were 200 A thick and the aluminum films were 5 m thick. The aluminum films were oxidized to alumina, and the arrays of holes were formed by anodizing the aluminum in aqueous solutions of sulfuric and/or oxalic acid at room temperature (see figure). The diameters, spacings, and rates of growth of the holes were found to depend, variously, on the composition of the anodizing solution, the applied current, or the applied potential, as follows: In galvanostatically controlled anodizing, regardless of the

  6. Computer-aided design tools for economical MEMS fabrication processes

    NASA Astrophysics Data System (ADS)

    Schneider, Christian; Priebe, Andreas; Brueck, Rainer; Hahn, Kai

    1999-03-01

    Since the early 70s when microsystem technology was first introduce an enormous market for MST-products has been developed. Airbag sensors, micro pumps, ink jet nozzles etc. and the market is just about to start up. Establishing these products for a reasonable price requires mass production. Meanwhile, also computer-based design-tools have been developed in order to reduce the expenses for MST-design. In contrast to other physical design processes like e.g. in micro electronics, MEMS physical design is characterized by the fact that each product requires a tailored sequence of fabrication steps, usually selected from a variety of processing alternatives. The selection from these alternatives is based on economical constraints. Therefore, the design has a strong influence on the money and time spent to take an MST-product to market.

  7. Monolithic high voltage nonlinear transmission line fabrication process

    DOEpatents

    Cooper, G.A.

    1994-10-04

    A process for fabricating sequential inductors and varistor diodes of a monolithic, high voltage, nonlinear, transmission line in GaAs is disclosed. An epitaxially grown laminate is produced by applying a low doped active n-type GaAs layer to an n-plus type GaAs substrate. A heavily doped p-type GaAs layer is applied to the active n-type layer and a heavily doped n-type GaAs layer is applied to the p-type layer. Ohmic contacts are applied to the heavily doped n-type layer where diodes are desired. Multiple layers are then either etched away or Oxygen ion implanted to isolate individual varistor diodes. An insulator is applied between the diodes and a conductive/inductive layer is thereafter applied on top of the insulator layer to complete the process. 6 figs.

  8. Monolithic high voltage nonlinear transmission line fabrication process

    DOEpatents

    Cooper, Gregory A.

    1994-01-01

    A process for fabricating sequential inductors and varactor diodes of a monolithic, high voltage, nonlinear, transmission line in GaAs is disclosed. An epitaxially grown laminate is produced by applying a low doped active n-type GaAs layer to an n-plus type GaAs substrate. A heavily doped p-type GaAs layer is applied to the active n-type layer and a heavily doped n-type GaAs layer is applied to the p-type layer. Ohmic contacts are applied to the heavily doped n-type layer where diodes are desired. Multiple layers are then either etched away or Oxygen ion implanted to isolate individual varactor diodes. An insulator is applied between the diodes and a conductive/inductive layer is thereafter applied on top of the insulator layer to complete the process.

  9. Flexible aerogel composite for mechanical stability and process of fabrication

    DOEpatents

    Coronado, Paul R.; Poco, John F.

    1999-01-01

    A flexible aerogel and process of fabrication. An aerogel solution is mixed with fibers in a mold and allowed to gel. The gel is then processed by supercritical extraction, or by air drying, to produce a flexible aerogel formed to the shape of the mold. The flexible aerogel has excellent thermal and acoustic properties, and can be utilized in numerous applications, such as for energy absorption, insulation (temperature and acoustic), to meet the contours of aircraft shapes, and where space is limited since an inch of aerogel is a 4-5 times better insulator than an inch of fiberglass. The flexible aerogel may be of an inorganic (silica) type or an organic (carbon) type, but containing fibers, such as glass or carbon fibers.

  10. Flexible aerogel composite for mechanical stability and process of fabrication

    DOEpatents

    Coronado, Paul R.; Poco, John F.

    2000-01-01

    A flexible aerogel and process of fabrication. An aerogel solution is mixed with fibers in a mold and allowed to gel. The gel is then processed by supercritical extraction, or by air drying, to produce a flexible aerogel formed to the shape of the mold. The flexible aerogel has excellent thermal and acoustic properties, and can be utilized in numerous applications, such as for energy absorption, insulation (temperature and acoustic), to meet the contours of aircraft shapes, and where space is limited since an inch of aerogel is a 4-5 times better insulator than an inch of fiberglass. The flexible aerogel may be of an inorganic (silica) type or an organic (carbon) type, but containing fibers, such as glass or carbon fibers.

  11. Fabricating binary optics: An overview of binary optics process technology

    NASA Technical Reports Server (NTRS)

    Stern, Margaret B.

    1993-01-01

    A review of binary optics processing technology is presented. Pattern replication techniques have been optimized to generate high-quality efficient microoptics in visible and infrared materials. High resolution optical photolithography and precision alignment is used to fabricate maximally efficient fused silica diffractive microlenses at lambda = 633 nm. The degradation in optical efficiency of four-phase-level fused silica microlenses resulting from an intentional 0.35 micron translational error has been systematically measured as a function of lens speed (F/2 - F/60). Novel processes necessary for high sag refractive IR microoptics arrays, including deep anisotropic Si-etching, planarization of deep topography and multilayer resist techniques, are described. Initial results are presented for monolithic integration of photonic and microoptic systems.

  12. Process for fabricating ribbed electrode substrates and other articles

    DOEpatents

    Goller, Glen J.; Breault, Richard D.; Smith, J. Harold

    1984-01-01

    A process for fabricating a resin bonded carbon fiber article, and in particular electrochemical cell electrode substrates and the like requiring different mean pore sizes in different areas, involves simultaneously heating and compacting different mixtures of carbon fibers and resin in different areas of an article forming mold, wherein the carbon fibers in each of the different mixtures have different, known bulk densities. The different bulk densities of the carbon fibers in the mixtures are chosen to yield the desired mean pore sizes and other properties in the article after heating and compacting the mixtures. Preferably, the different bulk densities are obtained using different carbon fiber lengths in the molding mixtures. The process is well suited to forming ribbed electrode substrates with preselected optimum mean pore sizes, porosities, and densities in the ribs, the webs connecting the ribs, and in the edge seals.

  13. Micro-structured fiber Bragg gratings: optimization of the fabrication process.

    PubMed

    Iadicicco, A; Campopiano, S; Paladino, D; Cutolo, A; Cusano, A

    2007-11-12

    This work has been devoted to present and demonstrate a novel approach for the fabrication of micro-structured fiber Bragg gratings (MSFBGs) with enhanced control of the geometric features and thus of the spectral properties of the final device. The investigated structure relies on the localized stripping of the cladding layer in a well defined region in the middle of the grating structure leading to the formation of a defect state in the spectral response. In order to fully explore the versatility of MSFBGs for sensing and communications applications, a technological assessment of the fabrication process aimed to provide high control of the geometrical features is required. To this aim, here, we demonstrate that the optimization of this device is possible by adopting a fabrication process based on polymeric coatings patterned by high resolution UV laser micromachining tools. The function of the polymeric coating is to act as mask for the HF based chemical etching process responsible for the cladding stripping. Whereas, UV laser micromachining provides a valuable method to accurately pattern the polymeric coating and thus obtain a selective stripping along the grating structure. Here, we experimentally demonstrate the potentiality of the proposed approach to realize reliable and cost efficient MSFBGs enabling the prototyping of advanced photonics devices based on this technology.

  14. Advanced Photonic Processes for Photovoltaic and Energy Storage Systems.

    PubMed

    Sygletou, Maria; Petridis, Constantinos; Kymakis, Emmanuel; Stratakis, Emmanuel

    2017-08-24

    Solar-energy harvesting through photovoltaic (PV) conversion is the most promising technology for long-term renewable energy production. At the same time, significant progress has been made in the development of energy-storage (ES) systems, which are essential components within the cycle of energy generation, transmission, and usage. Toward commercial applications, the enhancement of the performance and competitiveness of PV and ES systems requires the adoption of precise, but simple and low-cost manufacturing solutions, compatible with large-scale and high-throughput production lines. Photonic processes enable cost-efficient, noncontact, highly precise, and selective engineering of materials via photothermal, photochemical, or photophysical routes. Laser-based processes, in particular, provide access to a plethora of processing parameters that can be tuned with a remarkably high degree of precision to enable innovative processing routes that cannot be attained by conventional approaches. The focus here is on the application of advanced light-driven approaches for the fabrication, as well as the synthesis, of materials and components relevant to PV and ES systems. Besides presenting recent advances on recent achievements, the existing limitations are outlined and future possibilities and emerging prospects discussed. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Green, scalable, binderless fabrication of a single-walled carbon nanotube nonwoven fabric based on an ancient Japanese paper process.

    PubMed

    Kobashi, Kazufumi; Hirabayashi, Tatsuya; Ata, Seisuke; Yamada, Takeo; Futaba, Don N; Hata, Kenji

    2013-12-11

    We propose a fabrication method for carbon nanotube (CNT) nonwoven fabrics based on an ancient Japanese papermaking process where paper is made from natural plant fibers. In our method, CNT nonwoven fabrics are made by a scalable process of filtering binder-free, aqueous suspensions of CNTs. The aqueous suspension of these entangled single-walled carbon nanotube (SWNT) aggregates enabled smooth filtration through a cellulose filter with large pores (8 μm). The "wet SWNT cakes," which were composed solely of SWNT and water and obtained after filtration, were press-dried to fabricate an SWNT nonwoven fabric. This environmentally friendly process employs water and the raw CNT material alone. Moreover, the scalability of this process was demonstrated by manufacturing a large area (A3, 30 × 42 cm; thickness: 40-150 μm), self-supporting SWNT nonwoven fabric with a density of 0.4 g/cm(3), a basis weight of 0.2 g/m(2) , a porosity of 63%, and a specific surface area of 740 m(2)/g. This SWNT nonwoven fabric is anticipated to find application as functional particle-supported sheets, electrode materials, and filters.

  16. Recent advances in high-temperature superconductor wire fabrication and applications development

    SciTech Connect

    Hull, J.R.; Uherka, K.L.

    1992-01-01

    In this paper, recent advances in fabrication of HTS wires are summarized, and detailed discussion is provided for developments in near- and intermediate-term applications. Near-term applications, using presently obtainable current densities, include: liquid-nitrogen depth sensors, cryostat current leads, and magnetic bearings. Intermediate-term applications, using current densities expected to be available in the near future include fault-current limiters and short transmission lines. 25 refs.

  17. Recent advances in high-temperature superconductor wire fabrication and applications development

    SciTech Connect

    Hull, J.R.; Uherka, K.L.

    1992-08-01

    In this paper, recent advances in fabrication of HTS wires are summarized, and detailed discussion is provided for developments in near- and intermediate-term applications. Near-term applications, using presently obtainable current densities, include: liquid-nitrogen depth sensors, cryostat current leads, and magnetic bearings. Intermediate-term applications, using current densities expected to be available in the near future include fault-current limiters and short transmission lines. 25 refs.

  18. ASPEN. Advanced System for Process Engineering

    SciTech Connect

    Bajura, R.A.

    1985-10-01

    ASPEN (Advanced System for Process Engineering) is a state of the art process simulator and economic evaluation package which was designed for use in engineering fossil energy conversion processes. ASPEN can represent multiphase streams including solids, and handle complex substances such as coal. The system can perform steady state material and energy balances, determine equipment size and cost, and carry out preliminary economic evaluations. It is supported by a comprehensive physical property system for computation of major properties such as enthalpy, entropy, free energy, molar volume, equilibrium ratio, fugacity coefficient, viscosity, thermal conductivity, and diffusion coefficient for specified phase conditions; vapor, liquid, or solid. The properties may be computed for pure components, mixtures, or components in a mixture, as appropriate. The ASPEN Input Language is oriented towards process engineers.

  19. Computer-assisted virtual planning and surgical template fabrication for frontoorbital advancement.

    PubMed

    Soleman, Jehuda; Thieringer, Florian; Beinemann, Joerg; Kunz, Christoph; Guzman, Raphael

    2015-05-01

    OBJECT The authors describe a novel technique using computer-assisted design (CAD) and computed-assisted manufacturing (CAM) for the fabrication of individualized 3D printed surgical templates for frontoorbital advancement surgery. METHODS Two patients underwent frontoorbital advancement surgery for unilateral coronal synostosis. Virtual surgical planning (SurgiCase-CMF, version 5.0, Materialise) was done by virtual mirroring techniques and superposition of an age-matched normative 3D pediatric skull model. Based on these measurements, surgical templates were fabricated using a 3D printer. Bifrontal craniotomy and the osteotomies for the orbital bandeau were performed based on the sterilized 3D templates. The remodeling was then done placing the bone plates within the negative 3D templates and fixing them using absorbable poly-dl-lactic acid plates and screws. RESULTS Both patients exhibited a satisfying head shape postoperatively and at follow-up. No surgery-related complications occurred. The cutting and positioning of the 3D surgical templates proved to be very accurate and easy to use as well as reproducible and efficient. CONCLUSIONS Computer-assisted virtual planning and 3D template fabrication for frontoorbital advancement surgery leads to reconstructions based on standardizedmeasurements, precludes subjective remodeling, and seems to be overall safe and feasible. A larger series of patients with long-term follow-up is needed for further evaluation of this novel technique.

  20. Advanced PPA Reactor and Process Development

    NASA Technical Reports Server (NTRS)

    Wheeler, Raymond; Aske, James; Abney, Morgan B.; Miller, Lee A.; Greenwood, Zachary

    2012-01-01

    Design and development of a second generation Plasma Pyrolysis Assembly (PPA) reactor is currently underway as part of NASA s Atmosphere Revitalization Resource Recovery effort. By recovering up to 75% of the hydrogen currently lost as methane in the Sabatier reactor effluent, the PPA helps to minimize life support resupply costs for extended duration missions. To date, second generation PPA development has demonstrated significant technology advancements over the first generation device by doubling the methane processing rate while, at the same time, more than halving the required power. One development area of particular interest to NASA system engineers is fouling of the PPA reactor with carbonaceous products. As a mitigation plan, NASA MSFC has explored the feasibility of using an oxidative plasma based upon metabolic CO2 to regenerate the reactor window and gas inlet ports. The results and implications of this testing are addressed along with the advanced PPA reactor development work.

  1. Fabrication of a Flexible Amperometric Glucose Sensor Using Additive Processes.

    PubMed

    Du, Xiaosong; Durgan, Christopher J; Matthews, David J; Motley, Joshua R; Tan, Xuebin; Pholsena, Kovit; Árnadóttir, Líney; Castle, Jessica R; Jacobs, Peter G; Cargill, Robert S; Ward, W Kenneth; Conley, John F; Herman, Gregory S

    This study details the use of printing and other additive processes to fabricate a novel amperometric glucose sensor. The sensor was fabricated using a Au coated 12.7 μm thick polyimide substrate as a starting material, where micro-contact printing, electrochemical plating, chloridization, electrohydrodynamic jet (e-jet) printing, and spin coating were used to pattern, deposit, chloridize, print, and coat functional materials, respectively. We have found that e-jet printing was effective for the deposition and patterning of glucose oxidase inks with lateral feature sizes between ~5 to 1000 μm in width, and that the glucose oxidase was still active after printing. The thickness of the permselective layer was optimized to obtain a linear response for glucose concentrations up to 32 mM and no response to acetaminophen, a common interfering compound, was observed. The use of such thin polyimide substrates allow wrapping of the sensors around catheters with high radius of curvature ~250 μm, where additive and microfabrication methods may allow significant cost reductions.

  2. Fabrication of a Flexible Amperometric Glucose Sensor Using Additive Processes

    PubMed Central

    Du, Xiaosong; Durgan, Christopher J.; Matthews, David J.; Motley, Joshua R.; Tan, Xuebin; Pholsena, Kovit; Árnadóttir, Líney; Castle, Jessica R.; Jacobs, Peter G.; Cargill, Robert S.; Ward, W. Kenneth; Conley, John F.; Herman, Gregory S.

    2015-01-01

    This study details the use of printing and other additive processes to fabricate a novel amperometric glucose sensor. The sensor was fabricated using a Au coated 12.7 μm thick polyimide substrate as a starting material, where micro-contact printing, electrochemical plating, chloridization, electrohydrodynamic jet (e-jet) printing, and spin coating were used to pattern, deposit, chloridize, print, and coat functional materials, respectively. We have found that e-jet printing was effective for the deposition and patterning of glucose oxidase inks with lateral feature sizes between ~5 to 1000 μm in width, and that the glucose oxidase was still active after printing. The thickness of the permselective layer was optimized to obtain a linear response for glucose concentrations up to 32 mM and no response to acetaminophen, a common interfering compound, was observed. The use of such thin polyimide substrates allow wrapping of the sensors around catheters with high radius of curvature ~250 μm, where additive and microfabrication methods may allow significant cost reductions. PMID:26634186

  3. A microelectromechanical accelerometer fabricated using printed circuit processing techniques

    NASA Astrophysics Data System (ADS)

    Rogers, J. E.; Ramadoss, R.; Ozmun, P. M.; Dean, R. N.

    2008-01-01

    A microelectromechanical systems (MEMS) capacitive-type accelerometer fabricated using printed circuit processing techniques is presented. A Kapton polymide film is used as the structural layer for fabricating the MEMS accelerometer. The accelerometer proof mass along with four suspension beams is defined in the Kapton polyimide film. The proof mass is suspended above a Teflon substrate using a spacer. The deflection of the proof mass is detected using a pair of capacitive sensing electrodes. The top electrode of the accelerometer is defined on the top surface of the Kapton film. The bottom electrode is defined in the metallization on the Teflon substrate. The initial gap height is determined by the distance between the bottom electrode and the Kapton film. For an applied external acceleration (normal to the proof mass), the proof mass deflects toward or away from the fixed bottom electrode due to inertial force. This deflection causes either a decrease or increase in the air-gap height thereby either increasing or decreasing the capacitance between the top and the bottom electrodes. An example PCB MEMS accelerometer with a square proof mass of membrane area 6.4 mm × 6.4 mm is reported. The measured resonant frequency is 375 Hz and the Q-factor in air is 0.52.

  4. Advanced Manufacturing Processes Laboratory Building 878 hazards assessment document

    SciTech Connect

    Wood, C.; Thornton, W.; Swihart, A.; Gilman, T.

    1994-07-01

    The introduction of the hazards assessment process is to document the impact of the release of hazards at the Advanced Manufacturing Processes Laboratory (AMPL) that are significant enough to warrant consideration in Sandia National Laboratories` operational emergency management program. This hazards assessment is prepared in accordance with the Department of Energy Order 5500.3A requirement that facility-specific hazards assessments be prepared, maintained, and used for emergency planning purposes. This hazards assessment provides an analysis of the potential airborne release of chemicals associated with the operations and processes at the AMPL. This research and development laboratory develops advanced manufacturing technologies, practices, and unique equipment and provides the fabrication of prototype hardware to meet the needs of Sandia National Laboratories, Albuquerque, New Mexico (SNL/NM). The focus of the hazards assessment is the airborne release of materials because this requires the most rapid, coordinated emergency response on the part of the AMPL, SNL/NM, collocated facilities, and surrounding jurisdiction to protect workers, the public, and the environment.

  5. Needs for Process Control in Advanced Processing of Materials

    NASA Astrophysics Data System (ADS)

    Mehrabian, Robert; Wadley, Haydn N. G.

    1985-02-01

    Recent advances in the synthesis of new materials with complex microstructures, coupled with an improved understanding of process/microtructure/property relationships, has created a new challenge for NDE—the redirection of a technology originally conceived for flaw detection/characterization to the nondestructive measurement of process and microstructure variables during materials processing. This review shows how NDE techniques could play the sensor role in automated process control. The techniques, originally developed for detecting cracks, show merit in monitoring solidification. Other ultrasonic techniques show promise in characterizing temperature distributions and porosity. Problems include: the need for inverse modeling/calibration/high speed data acquisition and reconstruction; and display and hardware able to survive the harsh processing environment. Feedback systems based on artificial intelligence combine heuristic and mathematical predictions with developing sensor technologies to drive process development.

  6. Electrically conductive articles and processes for their fabrication

    SciTech Connect

    Mir, J.M.; Hung, L.S.

    1991-01-29

    This patent describes a electrically conductive articles and processes for their fabrication. They comprise a refractory substrate, a flexible electrically conductive crystalline cuprate layer, a release layer interposed between the flexible conductive cuprate layer and the substrate, the release layer being comprised of at least on of the metals of groups 8 to 11 and periods 5 and 6 of the periodic table of elements, a flexible organic film, and means for adhesively bonding the flexible organic film to the flexible conductive cuprate layer, so that the release layer, the flexible conductive cuprate layer, the adhesive bonding means and the flexible organic film can be stripped from the refractory substrate to form a flexible electrically conductive article.

  7. Fabrication process for combustion chamber/nozzle assembly

    NASA Technical Reports Server (NTRS)

    Myers, W. Neill (Inventor); Cornelius, Charles S. (Inventor)

    2001-01-01

    An integral, lightweight combustion chamber/nozzle assembly for a rocket engine has a refractory metal shell defining a chamber of generally frusto-conical contour. The shell communicates at its smaller end with a rocket body, and terminates at its larger end in a generally contact contour, which is open at its terminus and which serves as a nozzle for the rocket engine. The entire inner surface of the refractory metal shell has a thermal and oxidation barrier layer applied thereto. An ablative silica phenolic insert is bonded to the exposed surface of the thermal and oxidation barrier layer. The ablative phenolic insert provides a chosen inner contour for the combustion chamber and has a taper toward the open terminus of the nozzle. A process for fabricating the integral, lightweight combustion chamber/nozzle assembly is simple and efficient, and results in economy in respect of both resources and time.

  8. Combustion Chamber/Nozzle Assembly and Fabrication Process Therefor

    NASA Technical Reports Server (NTRS)

    Myers, W. Neill (Inventor); Cornelius, Charles S. (Inventor)

    2000-01-01

    An integral lightweight combustion chamber/nozzle assembly for a rocket engine has a refractory metal shell defining a chamber of generally frusto-conical contour. The shell communicates at its larger end with a rocket body, and terminates at its smaller end in a tube of generally cylindrical contour, which is open at its terminus and which serves as a nozzle for the rocket engine. The entire inner surface of the refractory metal shell has a thermal and oxidation barrier layer applied thereto. An ablative silica phenolic insert is bonded to the exposed surface of the thermal and oxidation barrier layer. The ablative phenolic insert provides a chosen inner contour for the combustion chamber and has a taper toward the open terminus of the nozzle. A process for fabricating the integral, lightweight combustion chamber/nozzle assembly is simple and efficient, and results in economy in respect of both resources and time.

  9. Environmental assessment for radioisotope heat source fuel processing and fabrication

    SciTech Connect

    Not Available

    1991-07-01

    DOE has prepared an Environmental Assessment (EA) for radioisotope heat source fuel processing and fabrication involving existing facilities at the Savannah River Site (SRS) near Aiken, South Carolina and the Los Alamos National Laboratory (LANL) near Los Alamos, New Mexico. The proposed action is needed to provide Radioisotope Thermoelectric Generators (RTG) to support the National Aeronautics and Space Administration's (NASA) CRAF and Cassini Missions. Based on the analysis in the EA, DOE has determined that the proposed action does not constitute a major Federal action significantly affecting the quality of the human environment within the meaning of the National Environmental Policy Act (NEPA) of 1969. Therefore, an Environmental Impact Statement is not required. 30 refs., 5 figs.

  10. MONOLITHIC FUEL FABRICATION PROCESS DEVELOPMENT AT THE IDAHO NATIONAL LABORATORY_

    SciTech Connect

    G. A. Moore; F. J. Rice; N. E. Woolstenhulme; J-F. Jue; B. H. Park; S. E. Steffler; N. P. Hallinan; M. D. Chapple; M. C. Marshall; B. L. Mackowiak; C. R. Clark; B. H. Rabin

    2009-11-01

    Full-size/prototypic U10Mo monolithic fuel-foils and aluminum clad fuel plates are being developed at the Idaho National Laboratory’s (INL) Materials and Fuels Complex (MFC). These efforts are focused on realizing Low Enriched Uranium (LEU) high density monolithic fuel plates for use in High Performance Research and Test Reactors. The U10Mo fuel foils under development afford a fuel meat density of ~16 gU/cc and thus have the potential to facilitate LEU conversions without any significant reactor-performance penalty. An overview is provided of the ongoing monolithic UMo fuel development effort, including application of a zirconium barrier layer on fuel foils, fabrication scale-up efforts, and development of complex/graded fuel foils. Fuel plate clad bonding processes to be discussed include: Hot Isostatic Pressing (HIP) and Friction Bonding (FB).

  11. Pultrusion Process for Fabrication of Tethers (preliminary Concepts)

    NASA Technical Reports Server (NTRS)

    Macconochie, I. O.; Wilson, M. L.

    1985-01-01

    Three composite materials were manufactured by the pultrusion process, coiled on 24 inch diameter spools for a period of two months, uncoiled and evaluated for memory recall. These materials were pultruded to lengths of approximately 150 feet and cross section profiles were maintained at 0.143 inch in thickness by 0.566 inch in width. Mechanical properties were studied and results compared. The reinforcement material volume percent of each was identical. Of the three systems, the Kevlar reinforced composite had the highest specific strength, the lowest flexural modulus, and the lowest memory recall. Further evaluations of materials and fabrication technology of pultrusion should be conducted to address some problem areas encountered in this preliminary concept. Areas for further study are suggested.

  12. Advanced Digital Signal Processing for Hybrid Lidar

    DTIC Science & Technology

    2012-03-30

    Progress Report (1/1/2012- 3 /30/2012) This document provides a progress report on the project "Advanced JDigital Signal Processing" covering the...period of 1/1/2012- 3 /30/2012. XCiV’So3>oTu^lDM William D. Jemison, Professor and Chair, PO Box 5720, Clarkson University, Potsdam, NY 13699-5720 315...z + Az. t) S/jY(z,t) d) Az ■^ Souri^f^) Figura 1, Single delay line canceter When applying this filtering approach to a turbid underwater

  13. Advanced Digital Signal Processing for Hybrid Lidar

    DTIC Science & Technology

    2013-03-31

    project "Advanced Digital Signal Processing for Hybrid Lidar " covering the period of 1/1/2013-3/31/2013. 9LO\\SO^O’IH^’?’ William D. Jemison...Chaotic LIDAR for Naval Applications This document contains a Progress Summary for FY13 Q2 and a Short Work Statement for FY13 Progress Summary for...This technique has the potential to increase the unambiguous range of hybrid lidar -radar while maintaining reasonable range resolution. Proof-of

  14. Processing and properties of advanced metallic foams

    NASA Astrophysics Data System (ADS)

    Brothers, Alan Harold

    Since the development of the first aluminum foams in the middle of the 20th century [178], great advances have been made in the processing and fundamental understanding of metallic foams. As a result of these advances, metallic foams are now penetrating a number of applications where their unique suite of properties makes them superior to solid materials, such as lightweight structures, packaging and impact protection, and filtration and catalysis [3]. The purpose of this work is to extend the use of metallic foams in such applications by expanding their processing to include more sophisticated base alloys and architectures. The first four chapters discuss replacement of conventional crystalline metal foams with ones made from high-strength, low-melting amorphous metals, a substitution that offers potential for achieving mechanical properties superior to those of the best crystalline metal foams, without sacrificing the simplicity of processing methods made for low-melting crystalline alloys. Three different amorphous metal foams are developed in these chapters, and their structures and properties characterized. It is shown for the first time that amorphous metal foams, due to stabilization of shear bands during bending of their small strut-like features, are capable of compressive ductility comparable to that of ductile crystalline metal foams. A two-fold improvement in mechanical energy absorption relative to crystalline aluminum foams is shown experimentally to result from this stabilization. The last two chapters discuss modifications in foam processing that are designed to introduce controllable and continuous gradients in local foam density, which should improve mass efficiency by mimicking the optimized structures found in natural cellular materials [64], as well as facilitate the bonding and joining of foams with solid materials in higher-order structures. Two new processing methods are developed, one based on replication of nonuniformly-compressed polymer

  15. Design, fabrication and test of graphite/polyimide composite joints and attachments for advanced aerospace vehicles

    NASA Technical Reports Server (NTRS)

    1981-01-01

    The development of several types of graphite/polyimide (GR/PI) bonded and bolted joints is reported. The program consists of two concurrent tasks: (1) design and test of specific built up attachments; and (2) evaluation of standard advanced bonded joint concepts. A data base for the design and analysis of advanced composite joints for use at elevated temperatures (561K (550 deg F)) to design concepts for specific joining applications, and the fundamental parameters controlling the static strength characteristics of such joints are evaluated. Data for design and build GR/PI of lightly loaded flight components for advanced space transportation systems and high speed aircraft are presented. Results for compression and interlaminar shear strengths of Celion 6000/PMR-15 laminates are given. Static discriminator test results for type 3 and type 4 bonded and bolted joints and final joint designs for TASK 1.4 scale up fabrication and testing are presented.

  16. Lead-free piezoelectric ceramic coatings fabricated by thermal spray process.

    PubMed

    Yao, Kui; Chen, Shuting; Guo, Kun; Tan, Chee Kiang Ivan; Mirshekarloo, Meysam Sharifzadeh; Tay, Francis Eng Hock

    2017-09-04

    The paper starts from a review on the progress in fabrication of piezoelectric ceramic coatings by thermal spray method. For our experimental work, two types of lead-free piezoelectric ceramic coatings, including potassium sodium niobate (KNN)-based and bismuth sodium titanate (BNT)-based, are fabricated by thermal spray process, and their structure, morphology and piezoelectric properties are characterized. Our obtained lead-free ceramic coatings exhibit single phase of perovskite structure, relatively dense morphology, and competitive piezoelectric coefficients. The mechanism of forming the piezoelectric perovskite crystalline phase by thermal spray involving melting-recrystallization process is analyzed in comparison to that of ceramic synthesis through solid state reaction. Suppression of volatile loss and decomposition at high temperature due to the extremely high melting and cooling rate in the thermal spray process, and the impact on the resulting structure are discussed. Significant advantages of the thermal spray method over alternative processing methods for forming piezoelectric ceramic coatings are summarized. The combination of environmentally friendly lead-free compositions and the scalable thermal spray processing method will promote more applications of piezoelectric ceramic coatings for producing distributive sensors and transducers, and forming advanced smart structures and systems.

  17. Understanding the Critical Parameters of the PAMS Mandrel Fabrication Process

    SciTech Connect

    Bhandarkar, Suhas; Paguio, Reny; Elsner, Fred; Hoover, Denise

    2016-07-05

    As a part of an effort to continually better the roundness and roughness of ablator capsules, we looked at improving the same for the poly(alphamethylstyrene) or PAMS mandrels used to make the plastic capsules. The importance of this work is based on the fact that the surface properties of the mandrels set the lower limit for the ultimate attributes of the ablator capsule. These mandrels are made using an elegant double-emulsion process that uses the isotropic forces brought about by hydrostatic pressure and interfacial tension to seek sphericity. This paper describes the reasoning that led to investigating the so-called curing process where a solid PAMS shell is generated from a solution phase for achieving this goal. Using modeling to account for the mass transfer of the fluorobenzene solvent phase, we demonstrate that it is the control of the conditions through the percolation point of the system that leads to better mandrels. These concepts were implemented into the fabrication process to demonstrate significant improvements of the roundness of the mandrels.

  18. Understanding the Critical Parameters of the PAMS Mandrel Fabrication Process

    DOE PAGES

    Bhandarkar, Suhas; Paguio, Reny; Elsner, Fred; ...

    2016-07-05

    As a part of an effort to continually better the roundness and roughness of ablator capsules, we looked at improving the same for the poly(alphamethylstyrene) or PAMS mandrels used to make the plastic capsules. The importance of this work is based on the fact that the surface properties of the mandrels set the lower limit for the ultimate attributes of the ablator capsule. These mandrels are made using an elegant double-emulsion process that uses the isotropic forces brought about by hydrostatic pressure and interfacial tension to seek sphericity. This paper describes the reasoning that led to investigating the so-called curingmore » process where a solid PAMS shell is generated from a solution phase for achieving this goal. Using modeling to account for the mass transfer of the fluorobenzene solvent phase, we demonstrate that it is the control of the conditions through the percolation point of the system that leads to better mandrels. These concepts were implemented into the fabrication process to demonstrate significant improvements of the roundness of the mandrels.« less

  19. Understanding the Critical Parameters of the PAMS Mandrel Fabrication Process

    SciTech Connect

    Bhandarkar, Suhas; Paguio, Reny; Elsner, Fred; Hoover, Denise

    2016-07-05

    As a part of an effort to continually better the roundness and roughness of ablator capsules, we looked at improving the same for the poly(alphamethylstyrene) or PAMS mandrels used to make the plastic capsules. The importance of this work is based on the fact that the surface properties of the mandrels set the lower limit for the ultimate attributes of the ablator capsule. These mandrels are made using an elegant double-emulsion process that uses the isotropic forces brought about by hydrostatic pressure and interfacial tension to seek sphericity. This paper describes the reasoning that led to investigating the so-called curing process where a solid PAMS shell is generated from a solution phase for achieving this goal. Using modeling to account for the mass transfer of the fluorobenzene solvent phase, we demonstrate that it is the control of the conditions through the percolation point of the system that leads to better mandrels. These concepts were implemented into the fabrication process to demonstrate significant improvements of the roundness of the mandrels.

  20. Apparatus and process for freeform fabrication of composite reinforcement preforms

    NASA Technical Reports Server (NTRS)

    Yang, Junsheng (Inventor); Wu, Liangwei (Inventor); Liu, Junhai (Inventor); Jang, Bor Z. (Inventor)

    2001-01-01

    A solid freeform fabrication process and apparatus for making a three-dimensional reinforcement shape. The process comprises the steps of (1) operating a multiple-channel material deposition device for dispensing a liquid adhesive composition and selected reinforcement materials at predetermined proportions onto a work surface; (2) during the material deposition process, moving the deposition device and the work surface relative to each other in an X-Y plane defined by first and second directions and in a Z direction orthogonal to the X-Y plane so that the materials are deposited to form a first layer of the shape; (3) repeating these steps to deposit multiple layers for forming a three-dimensional preform shape; and (4) periodically hardening the adhesive to rigidize individual layers of the preform. These steps are preferably executed under the control of a computer system by taking additional steps of (5) creating a geometry of the shape on the computer with the geometry including a plurality of segments defining the preform shape and each segment being preferably coded with a reinforcement composition defining a specific proportion of different reinforcement materials; (6) generating programmed signals corresponding to each of the segments in a predetermined sequence; and (7) moving the deposition device and the work surface relative to each other in response to these programmed signals. Preferably, the system is also operated to generate a support structure for any un-supported feature of the 3-D preform shape.

  1. A thermal microprobe fabricated with wafer-stage processing

    NASA Astrophysics Data System (ADS)

    Zhang, Yongxia; Zhang, Yanwei; Blaser, Juliana; Sriram, T. S.; Enver, Ahsan; Marcus, R. B.

    1998-05-01

    A thermal microprobe has been designed and built for high resolution temperature sensing. The thermal sensor is a thin-film thermocouple junction at the tip of an atomic force microprobe (AFM) silicon probe needle. Only wafer-stage processing steps are used for the fabrication. For high resolution temperature sensing it is essential that the junction be confined to a short distance at the AFM tip. This confinement is achieved by a controlled photoresist coating process. Experiment prototypes have been made with an Au/Pd junction confined to within 0.5 μm of the tip, with the two metals separated elsewhere by a thin insulating oxide layer. Processing begins with double-polished, n-type, 4 in. diameter, 300-μm-thick silicon wafers. Atomically sharp probe tips are formed by a combination of dry and wet chemical etching, and oxidation sharpening. The metal layers are sputtering deposited and the cantilevers are released by a combination of KOH and dry etching. A resistively heated calibration device was made for temperature calibration of the thermal microprobe over the temperature range 25-110 °C. Over this range the thermal outputs of two microprobes are 4.5 and 5.6 μV/K and is linear. Thermal and topographical images are also obtained from a heated tungsten thin film fuse.

  2. Advanced systems for shuttle launch processing

    NASA Technical Reports Server (NTRS)

    Perez, Rafael A.

    1995-01-01

    Four advanced technologies that could be used in a new shuttle launch processing center are described. The latest methods for high capacity data storage technology, disk arrays and magneto optical disks, are described and their advantages and disadvantages compared. A 3-D protein based optical memory, now being researched, is also described as a possible future technology for data storage. An overview of neural network technology is presented together with several commercial software development options now available for neural network applications. The feasibility of Asynchronous Data Transfer technology as the networking technology to integrate video, voice, and data in a new launch processing center is also considered. Different applications of expert system technology at KSC are enumerated together with a number of commercial expert systems development packages presently available.

  3. Smart Pixels for Optical Processing and Communications: Design, Models, Fabrication and Test

    DTIC Science & Technology

    1998-06-01

    examined. In particular, the report investigates the monolithic integration of field effect transistors with lasers, optical quenched lasers...lasers, fabrication, transistors, monolithically integrated , optoelectronic integrated circuits (OEICs) 17. SECURITY CLASSIFICATION OF REPORT...assisted with the investigation of the monolithic integration of FETs and Lasers. Capt. Kirnmet advanced many of the fabrication procedures. The

  4. Optimal fabrication processes for unidirectional metal-matrix composites - A computational simulation

    NASA Technical Reports Server (NTRS)

    Saravanos, D. A.; Murthy, P. L. N.; Morel, M.

    1990-01-01

    A method is proposed for optimizing the fabrication process of unidirectional metal matrix composites. The temperature and pressure histories are optimized such that the residual microstresses of the composite at the end of the fabrication process are minimized and the material integrity throughout the process is ensured. The response of the composite during the fabrication is simulated based on a nonlinear micromechanics theory. The optimal fabrication problem is formulated and solved with nonlinear programming. Application cases regarding the optimization of the fabrication cool-down phases of unidirectional ultra-high modulus graphite/copper and silicon carbide/titanium composites are presented.

  5. Optimal fabrication processes for unidirectional metal-matrix composites: A computational simulation

    NASA Technical Reports Server (NTRS)

    Saravanos, D. A.; Murthy, P. L. N.; Morel, M.

    1990-01-01

    A method is proposed for optimizing the fabrication process of unidirectional metal matrix composites. The temperature and pressure histories are optimized such that the residual microstresses of the composite at the end of the fabrication process are minimized and the material integrity throughout the process is ensured. The response of the composite during the fabrication is simulated based on a nonlinear micromechanics theory. The optimal fabrication problem is formulated and solved with non-linear programming. Application cases regarding the optimization of the fabrication cool-down phases of unidirectional ultra-high modulus graphite/copper and silicon carbide/titanium composites are presented.

  6. Development of Impregnated Agglomerate Pelletization (IAP) process for fabrication of (Th,U)O 2 mixed oxide pellets

    NASA Astrophysics Data System (ADS)

    Khot, P. M.; Nehete, Y. G.; Fulzele, A. K.; Baghra, Chetan; Mishra, A. K.; Afzal, Mohd.; Panakkal, J. P.; Kamath, H. S.

    2012-01-01

    Impregnated Agglomerate Pelletization (IAP) technique has been developed at Advanced Fuel Fabrication Facility (AFFF), BARC, Tarapur, for manufacturing (Th, 233U)O 2 mixed oxide fuel pellets, which are remotely fabricated in hot cell or shielded glove box facilities to reduce man-rem problem associated with 232U daughter radionuclides. This technique is being investigated to fabricate the fuel for Indian Advanced Heavy Water Reactor (AHWR). In the IAP process, ThO 2 is converted to free flowing spheroids by powder extrusion route in an unshielded facility which are then coated with uranyl nitrate solution in a shielded facility. The dried coated agglomerate is finally compacted and then sintered in oxidizing/reducing atmosphere to obtain high density (Th,U)O 2 pellets. In this study, fabrication of (Th,U)O 2 mixed oxide pellets containing 3-5 wt.% UO 2 was carried out by IAP process. The pellets obtained were characterized using optical microscopy, XRD and alpha autoradiography. The results obtained were compared with the results for the pellets fabricated by other routes such as Coated Agglomerate Pelletization (CAP) and Powder Oxide Pelletization (POP) route.

  7. Electromagnetic levitation coil fabrication technique for MSFC containerless processing facilities

    NASA Technical Reports Server (NTRS)

    Ethridge, E. C.; Theiss, J.; Curreri, P. A.; Abbaschian, G. J.

    1983-01-01

    A technique is described for more reproducible fabrication of electromagnetic levitation coils. A split mandrel was developed upon which the coil is wound. After fabrication the mandrel can be disassembled to remove it from the coil. Previously, a full day was required to fabricate a levitation coil and the success rate for a functional coil was only 50 percent. About eight coils may be completed in one day using the technique developed and 95 percent of them are good levitation coils.

  8. Scalable, Economical Fabrication Processes for Ultra-Compact Warm-White LEDs

    SciTech Connect

    Lowes, Ted

    2016-01-31

    Conventional warm-white LED component fabrication consists of a large number of sequential steps which are required to incorporate electrical, mechanical, and optical functionality into the component. Each of these steps presents cost and yield challenges which multiply throughout the entire process. Although there has been significant progress in LED fabrication over the last decade, significant advances are needed to enable further reductions in cost per lumen while not sacrificing efficacy or color quality. Cree conducted a focused 18-month program to develop a new low-cost, high-efficiency light emitting diode (LED) architecture enabled by novel large-area parallel processing technologies, reduced number of fabrication steps, and minimized raw materials use. This new scheme is expected to enable ultra-compact LED components exhibiting simultaneously high efficacy and high color quality. By the end of the program, Cree fabricated warm-white LEDs with a room-temperature “instant on” efficacy of >135 lm/W at ~3500K and 90 CRI (when driven at the DOE baseline current density of 35 A/cm2). Cree modified the conventional LED fabrication process flow in a manner that is expected to translate into simultaneously high throughput and yield for ultra-compact packages. Building on its deep expertise in LED wafer fabrication, Cree developed these ultra-compact LEDs to have no compromises in color quality or efficacy compared to their conventional counterparts. Despite their very small size, the LEDs will also be robustly electrically integrated into luminaire systems with the same attach yield as conventional packages. The versatility of the prototype high-efficacy LED architecture will likely benefit solid-state lighting (SSL) luminaire platforms ranging from bulbs to troffers. We anticipate that the prototype LEDs will particularly benefit luminaires with large numbers of distributed compact packages, such as linear and area luminaires (e.g. troffers). The fraction of

  9. Precision tuning of silicon nanophotonic devices through post-fabrication processes

    NASA Astrophysics Data System (ADS)

    Chen, Charlton J.

    In recent years, silicon photonics has begun to transition from research to commercialization. Decades of relentless advances in the field of computing have led to fundamental bottlenecks in the design of computers, especially in interconnect bandwidth density. For IBM, silicon photonics has become a potential technological solution for enabling the future of server systems and cutting-edge supercomputers. For Intel, silicon photonics has become a cost-effective solution for supplying the necessary bandwidth needed by future generations of consumer computing products. While the field of silicon photonics is now advancing at a rapid pace there is still a great deal of research to be done. This thesis investigates ways of improving the performance of fundamental silicon nanophotonic devices through post-fabrication processes. These devices include numerous optical resonator designs as well as slow-light waveguides. Optical resonators are used to confine photons both spatially and temporally. In recent years, there has been much research, both theoretical and experimental, into improving the design of optical resonators. Improving these devices through fabrication processes has generally been less studied. Optical waveguides are used to guide the flow of photons over chip-level distances. Slow-light waveguides have also been studied by many research groups in recent years and can be applied to an increasingly wide-range of applications. The work can be divided into several parts: Chapter 1 is an introduction to the field of silicon photonics as well as an overview of the fabrication, experimental and computational techniques used throughout this work. Chapters 2, 3 and 4 describe our investigations into the precision tuning of nanophotonic devices using laser-assisted thermal oxidation and atomic layer deposition. Chapters 5 and 6 describe our investigations into improving the sidewall roughness of silicon photonic devices using hydrogen annealing and excimer laser

  10. Concurrent tailoring of fabrication process and interphase layer to reduce residual stresses in metal matrix composites

    NASA Technical Reports Server (NTRS)

    Saravanos, D. A.; Chamis, C. C.; Morel, M.

    1991-01-01

    A methodology is presented to reduce the residual matrix stresses in continuous fiber metal matrix composites (MMC) by optimizing the fabrication process and interphase layer characteristics. The response of the fabricated MMC was simulated based on nonlinear micromechanics. Application cases include fabrication tailoring, interphase tailoring, and concurrent fabrication-interphase optimization. Two composite systems, silicon carbide/titanium and graphite/copper, are considered. Results illustrate the merits of each approach, indicate that concurrent fabrication/interphase optimization produces significant reductions in the matrix residual stresses and demonstrate the strong coupling between fabrication and interphase tailoring.

  11. Fabrication of Glassy and Crystalline Ferroelectric Oxide by Containerless Processing

    NASA Astrophysics Data System (ADS)

    Yoda, Shinichi

    1. Instruction Much effort has been devoted to forming bulk glass from the melt of ferroelectric crystalline materials without adding any network-forming oxides such as SiO2 due to the potential for producing transparent glass ceramics with high dielectric constant and enhanced piezoelectric, pyroelectric and electro-optic effects. However, they require a higher cooling rate than glass formed by conventional techniques. Therefore, only amorphous thin-films have been formed, using rapid quenching with a cooling rate >105 K/s. The containerless processing is an attractive synthesis technique as it can prevent melt contamination, minimize heterogeneous nucleation, and allow melt to achieve deep undercooling for forming metastable phase and glassy material. Recently a new ferroelectric materiel, monoclinic BaTi2 O5 , with Currie temperature as 747 K was reported. In this study, we fabricated a bulk BaTi2 O5 glass from melt using containerless processing to study the phase relations and ferroelectric properties of BaTi2 O5 . To our knowledge, this was the first time that a bulk glass of ferroelectric material was fabricated from melt without adding any network-forming oxide. 2. Experiments BaTi2 O5 sphere glass with 2mm diameter was fabricated using containerless processing in an Aerodynamic Levitation Furnace (ALF). The containerless processing allowed the melt to achieve deep undercooling for glass forming. High purity commercial BaTiO3 and TiO2 powders were mixed with a mole ratio of 1:1 and compressed into rods and then sintered at 1427 K for 10 h. Bulk samples with a mass of about 20 mg were cut from the rod, levitated with the ALF, and then melted by a CO2 laser beam. After quenching with a cooling rate of about 1000 K/s, 2 mm diameter sphere glass could be obtained. To analyze the glass structure, a high-energy x-ray diffraction experiment was performed using an incident photon energy of 113.5 keV at the high-energy x-ray diffraction beamline BL04B2 of SPring-8

  12. Cell culture process development: advances in process engineering.

    PubMed

    Heath, Carole; Kiss, Robert

    2007-01-01

    Representatives from the cell culture process development community met on September 11 and 12, 2006 at the ACS National Meeting in San Francisco to discuss "Cell Culture Process Development: Advances in Process Engineering". This oral session was held as part of the Division of Biochemical Technology (BIOT) program. The presentations addressed the very small scale (less than 1 mL) to the very large scale (20,000 L). The topics covered included development of high throughput cell culture screening systems, modeling and characterization of bioreactor environments from mixing and shear perspectives at both small and large scales, systematic approaches for improving scale-up and scale-down activities, development of disposable bioreactor technologies, and novel perfusion culture approaches. All told, this well-attended session resulted in a valuable exchange of technical information and demonstrated a high level of interest within the process development community.

  13. Design and fabrication of brazed Rene 41 honeycomb sandwich structural panels for advanced space transportation systems

    NASA Technical Reports Server (NTRS)

    Hepler, A. K.; Swegle, A. R.

    1981-01-01

    The design and fabrication of two large brazed Rene 41 honeycomb panels, the establishment of a test plan, the design and fabrication of a test fixture to subject the panels to cyclic thermal gradients and mechanical loads equivalent to those imposed on an advanced space transportation vehicle during its boost and entry trajectories are discussed. The panels will be supported at four points, creating three spans. The outer spans are 45.7 cm (18 in.) and the center span 76.2 cm (30 in). Specimen width is 30.5 cm (12 in.). The panels were primarily designed by boost conditions simulated by subjecting the panels to liquid nitrogen, 77K (-320 F) on one side and 455K (360 F) on the other side and by mechanically imposing loads representing vehicle fuel pressure loads. Entry conditions were simulated by radiant heating to 1034K (1400 F). The test program subjected the panels to 500 boost thermal conditions. Results are presented.

  14. Advanced printing and deposition methodologies for the fabrication of biosensors and biodevices.

    PubMed

    Gonzalez-Macia, Laura; Morrin, Aoife; Smyth, Malcolm R; Killard, Anthony J

    2010-05-01

    Advanced printing and deposition methodologies are revolutionising the way biological molecules are deposited and leading to changes in the mass production of biosensors and biodevices. This revolution is being delivered principally through adaptations of printing technologies to device fabrication, increasing throughputs, decreasing feature sizes and driving production costs downwards. This review looks at several of the most relevant deposition and patterning methodologies that are emerging, either for their high production yield, their ability to reach micro- and nano-dimensions, or both. We look at inkjet, screen, microcontact, gravure and flexographic printing as well as lithographies such as scanning probe, photo- and e-beam lithographies and laser printing. We also take a look at the emerging technique of plasma modification and assess the usefulness of these for the deposition of biomolecules and other materials associated with biodevice fabrication.

  15. Process for fabricating a wraparound contact solar cell

    SciTech Connect

    Minahan, J.A.; Ralph, E.L.; Dill, H.G.

    1986-09-09

    A process is described for fabricating a wraparound contact solar cell comprising: (a) providing a silicon substrate of a chosen size and shape having first and second opposed major surfaces, (b) forming openings in the substrate and extending through the substrate form the first major surface thereof to the second major surface and spaced apart by a desired lateral dimension of a solar cell, (c) processing the substrate to form a p-n junction therein and between the openings, whereby the vertical walls of the substrate defining the openings are exposed for oxidation, photolithography, and junction-forming steps, (d) utilizing these steps in paragraph (c) above to also form p-region and n-region contacts on the major surfaces of the substrate and extending to a single one of the first and second major surfaces thereof through the openings where they are electrically isolated for bonding to a common solar cell support member, and (e) forming grid lines on one major surface of the substrate for interconnection to one of the p- or n-region contacts for deriving a solar cell output voltage resulting from charge carriers generated at the p-n junction.

  16. Advances in CO2 laser fabrication for high power fibre laser devices

    NASA Astrophysics Data System (ADS)

    Boyd, Keiron; Rees, Simon; Simakov, Nikita; Daniel, Jae M. O.; Swain, Robert; Mies, Eric; Hemming, Alexander; Clarkson, W. A.; Haub, John

    2016-03-01

    CO2 laser processing facilitates contamination free, rapid, precise and reproducible fabrication of devices for high power fibre laser applications. We present recent progress in fibre end-face preparation and cladding surface modification techniques. We demonstrate a fine feature CO2 laser process that yields topography significantly smaller than that achieved with typical mechanical cleaving processes. We also investigate the side processing of optical fibres for the fabrication of all-glass cladding light strippers and demonstrate extremely efficient cladding mode removal. We apply both techniques to fibres with complex designs containing multiple layers of doped and un-doped silica as well as shaped and circularly symmetric structures. Finally, we discuss the challenges and approaches to working with various fibre and glass-types.

  17. Finite Element Models for Electron Beam Freeform Fabrication Process

    NASA Technical Reports Server (NTRS)

    Chandra, Umesh

    2012-01-01

    Electron beam freeform fabrication (EBF3) is a member of an emerging class of direct manufacturing processes known as solid freeform fabrication (SFF); another member of the class is the laser deposition process. Successful application of the EBF3 process requires precise control of a number of process parameters such as the EB power, speed, and metal feed rate in order to ensure thermal management; good fusion between the substrate and the first layer and between successive layers; minimize part distortion and residual stresses; and control the microstructure of the finished product. This is the only effort thus far that has addressed computer simulation of the EBF3 process. The models developed in this effort can assist in reducing the number of trials in the laboratory or on the shop floor while making high-quality parts. With some modifications, their use can be further extended to the simulation of laser, TIG (tungsten inert gas), and other deposition processes. A solid mechanics-based finite element code, ABAQUS, was chosen as the primary engine in developing these models whereas a computational fluid dynamics (CFD) code, Fluent, was used in a support role. Several innovative concepts were developed, some of which are highlighted below. These concepts were implemented in a number of new computer models either in the form of stand-alone programs or as user subroutines for ABAQUS and Fluent codes. A database of thermo-physical, mechanical, fluid, and metallurgical properties of stainless steel 304 was developed. Computing models for Gaussian and raster modes of the electron beam heat input were developed. Also, new schemes were devised to account for the heat sink effect during the deposition process. These innovations, and others, lead to improved models for thermal management and prediction of transient/residual stresses and distortions. Two approaches for the prediction of microstructure were pursued. The first was an empirical approach involving the

  18. Development and fabrication of a solar cell junction processing system

    NASA Technical Reports Server (NTRS)

    Kiesling, R.

    1981-01-01

    The major component fabrication program was completed. Assembly and system testing of the pulsed electron beam annealing machine are described. The design program for the transport reached completion, and the detailed drawings were released for fabrication and procurement of the long lead time components.

  19. Investigation of mechanical properties for open cellular structure CoCrMo alloy fabricated by selective laser melting process

    NASA Astrophysics Data System (ADS)

    Azidin, A.; Taib, Z. A. M.; Harun, W. S. W.; Che Ghani, S. A.; Faisae, M. F.; Omar, M. A.; Ramli, H.

    2015-12-01

    Orthodontic implants have been a major focus through mechanical and biological performance in advance to fabricate shape of complex anatomical. Designing the part with a complex mechanism is one of the challenging process and addition to achieve the balance and desired mechanical performance brought to the right manufacture technique to fabricate. Metal additive manufacturing (MAM) is brought forward to the newest fabrication technology in this field. In this study, selective laser melting (SLM) process was utilized on a medical grade cobalt-chrome molybdenum (CoCrMo) alloy. The work has focused on mechanical properties of the CoCrMo open cellular structures samples with 60%, 70%, and 80% designed volume porosity that could potentially emulate the properties of human bone. It was observed that hardness values decreased as the soaking time increases except for bottom face. For compression test, 60% designed volume porosity demonstrated highest ultimate compressive strength compared to 70% and 80%.

  20. An Advanced Electrospinning Method of Fabricating Nanofibrous Patterned Architectures with Controlled Deposition and Desired Alignment

    NASA Astrophysics Data System (ADS)

    Rasel, Sheikh Md

    We introduce a versatile advanced method of electrospinning for fabricating various kinds of nanofibrous patterns along with desired alignment, controlled amount of deposition and locally variable density into the architectures. In this method, we employed multiple electrodes whose potentials have been altered in milliseconds with the help of microprocessor based control system. Therefore, key success of this method was that the electrical field as well as charge carrying fibers could be switched shortly from one electrode's location to another, as a result, electrospun fibers could be deposited on the designated areas with desired alignment. A wide range of nanofibrous patterned architectures were constructed using proper arrangement of multiple electrodes. By controlling the concurrent activation time of two adjacent electrodes, we demonstrated that amount of fibers going into the pattern can be adjusted and desired alignment in electrospun fibers can be obtained. We also revealed that the deposition density of electrospun fibers in different areas of patterned architectures can be varied. We showed that by controlling the deposition time between two adjacent electrodes, a number of functionally graded patterns can be generated with uniaxial alignment. We also demonstrated that this handy method was capable of producing random, aligned, and multidirectional nanofibrous mats by engaging a number of electrodes and switching them in desired patterns. A comprehensive study using finite element method was carried out to understand the effects of electrical field. Simulation results revealed that electrical field strength alters shortly based on electrode control switch patterns. Nanofibrous polyvinyl alcohol (PVA) scaffolds and its composite reinforced with wollastonite and wood flour were fabricated using rotating drum electrospinning technique. Morphological, mechanical, and thermal, properties were characterized on PVA/wollastonite and PVA/wood flour nanocomposites

  1. Design, Fabrication, and Characterization of Carbon Nanotube Field Emission Devices for Advanced Applications

    NASA Astrophysics Data System (ADS)

    Radauscher, Erich Justin

    Carbon nanotubes (CNTs) have recently emerged as promising candidates for electron field emission (FE) cathodes in integrated FE devices. These nanostructured carbon materials possess exceptional properties and their synthesis can be thoroughly controlled. Their integration into advanced electronic devices, including not only FE cathodes, but sensors, energy storage devices, and circuit components, has seen rapid growth in recent years. The results of the studies presented here demonstrate that the CNT field emitter is an excellent candidate for next generation vacuum microelectronics and related electron emission devices in several advanced applications. The work presented in this study addresses determining factors that currently confine the performance and application of CNT-FE devices. Characterization studies and improvements to the FE properties of CNTs, along with Micro-Electro-Mechanical Systems (MEMS) design and fabrication, were utilized in achieving these goals. Important performance limiting parameters, including emitter lifetime and failure from poor substrate adhesion, are examined. The compatibility and integration of CNT emitters with the governing MEMS substrate (i.e., polycrystalline silicon), and its impact on these performance limiting parameters, are reported. CNT growth mechanisms and kinetics were investigated and compared to silicon (100) to improve the design of CNT emitter integrated MEMS based electronic devices, specifically in vacuum microelectronic device (VMD) applications. Improved growth allowed for design and development of novel cold-cathode FE devices utilizing CNT field emitters. A chemical ionization (CI) source based on a CNT-FE electron source was developed and evaluated in a commercial desktop mass spectrometer for explosives trace detection. This work demonstrated the first reported use of a CNT-based ion source capable of collecting CI mass spectra. The CNT-FE source demonstrated low power requirements, pulsing

  2. Fabrication and assembly of a superconducting undulator for the advanced photon source

    SciTech Connect

    Hasse, Quentin; Fuerst, J. D.; Ivanyushenkov, Y.; Doose, C.; Kasa, M.; Shiroyanagi, Y.; Trakhtenberg, E. M.; Skiadopoulos, D.

    2014-01-29

    A prototype superconducting undulator magnet (SCU0) has been built at the Advanced Photon Source (APS) of Argonne National Laboratory (ANL) and has successfully completed both cryogenic performance and magnetic measurement test programs. The SCU0 closed loop, zero-boil-off cryogenic system incorporates high temperature superconducting (HTS) current leads, cryocoolers, a LHe reservoir supplying dual magnetic cores, and an integrated cooled beam chamber. This system presented numerous challenges in the design, fabrication, and assembly of the device. Aspects of this R and D relating to both the cryogenic and overall assembly of the device are presented here. The SCU0 magnet has been installed in the APS storage ring.

  3. Advanced ceramic-to-metal joining process

    SciTech Connect

    Deluca, M.A.; Swain, J.W. Jr.; Swank, L.R.

    1987-08-01

    One of the major problems in the use of ceramics as components of turbochargers, gas turbines, diesel engines, and other heat engine applications is the joining of ceramics to metals. A new advanced process for achieving strong bonds which utilizes ceramic surface modification and a high-strength direct bonding of metal coating to ceramic is discussed in this paper. Also discussed are the requirements of braze materials for a successful bond and the engineering design of a successful attachment. The tensile and fatigue tests conducted to verify the bonds are discussed. Tests conducted on a simulated turbocharger rotor-to-shaft attachment show good results at temperatures as high as 650 C. 8 references.

  4. Advancements in MEMS materials and processing technology

    NASA Astrophysics Data System (ADS)

    Olivas, John D.; Bolin, Stephen

    1998-01-01

    From achievements in display imaging to air bag deployment, microelectromechanical systems are becoming more commonplace in everyday life. With an abundance of opportunities for innovative R&D in the field, the research trends are not only directed toward novel sensor and actuator development, but also toward further miniaturization, specifically achieving micro- and nanoscaled integrated systems. R&D efforts in space, military, and commercial applications are directing specific research programs focused on the area of materials science as an enabling technology to be exploited by researchers and to further push the envelope of micrometerscaled device technology. These endeavors are making significant progress in bringing this aspect of the microelectro-mechanical field to maturation through advances in materials and processing technologies.

  5. Processing and analyzing advanced hyperspectral imagery data

    NASA Astrophysics Data System (ADS)

    El-Nahry, A. H.

    2006-09-01

    The main objective of the current work is to recognize the dominant and predominant clay minerals of South Port Said plain soils, Egypt using the high advanced remote sensing techniques of hyperspectral data. Spectral analyses as one of the most advanced remote sensing techniques were used for the aforementioned purpose. Different spectral processes have been used to execute the prospective spectral analyses. These processes include 1-The reflectance calibration of hyperspectral data belonging to the studied area, 2- Using the minimum noise fraction (MNF) transformation. 3 -Creating the pixel purity index (PPI) which used as a mean of finding the most "spectrally pure", extreme, pixel in hyperspectral images. Making conjunction between the Minimum Noise Fraction Transform (MNF) and Pixel Purity Index (PPI) tools through 3-D visualization offered capabilities to locate, identify, and cluster the purest pixels and most extreme spectral responses in a data set. To identify the clay minerals of the studied area the extracted unknown spectra of the purest pixels was matched to pre-defined (library) spectra providing score with respect to the library spectra. Three methods namely, Spectral Feature Fitting (SFF),Spectral Angle Mapper (SAM) and Binary Encoding (BE) were used to produce score between 0 and 1, where the value of I equal a perfect match showing exactly the mineral type. In the investigated area four clay minerals could be identified i.e. Vermiculite, Kaolinite, Montmorillinite, and Illite recording different scores related to their abundance in the soils. In order to check the validity and accuracy of the obtained results, X-ray diffraction analysis was applied on surface soil samples covering the same locations of the end-members that derived from hyperspectral image. Highly correlated and significant results were obtained using the two approaches (spectral signatures and x-ray diffraction).

  6. Novel imazethapyr detoxification applying advanced oxidation processes.

    PubMed

    Stathis, Ioannis; Hela, Dimitra G; Scrano, Laura; Lelario, Filomena; Emanuele, Lucia; Bufo, Sabino A

    2011-01-01

    Different degradation methods have been applied to assess the suitability of advanced oxidation process (AOPs) to promote mineralization of imazethapyr [(RS)-5-ethyl-2-(4-isopropyl-4-methyl-5-oxo-2-imidazolin-2-yl)nicotinic acid], a widely used imidazolinone class herbicide, the persistence of which has been demonstrated in surface and ground waters destined to human uses. Independent of the oxidation process assessed, the decomposition of imazethapyr always followed a pseudo-first order kinetic. The direct UV-irradiation (UV) of the herbicide as well as its oxidation with ozone (O₃), and hydrogen peroxide tied to UV-irradiation (H₂O₂/UV) were sufficiently slow to permit the identification of intermediate products, the formation pathway of which has been proposed. Ozonation joined to UV-irradiation (O₃/UV), ozonation joined to titanium dioxide photo-catalysis (TiO₂/UV+O₃), sole photo-catalysis (TiO₂/UV), and photo-catalysis reinforced with hydrogen peroxide-oxidation (TiO₂/UV+H₂O₂) were characterized by a faster degradation and rapid formation of a lot of small molecules, which were quickly degraded to complete mineralization. The most effective oxidation methods were those using titanium dioxide photo-catalysis enhanced either by ozonation or hydrogen peroxide. Most of all, these last processes were useful to avoid the development of dangerous by-products.

  7. Process for fabricating device structures for real-time process control of silicon doping

    DOEpatents

    Weiner, Kurt H.

    2001-01-01

    Silicon device structures designed to allow measurement of important doping process parameters immediately after the doping step has occurred. The test structures are processed through contact formation using standard semiconductor fabrication techniques. After the contacts have been formed, the structures are covered by an oxide layer and an aluminum layer. The aluminum layer is then patterned to expose the contact pads and selected regions of the silicon to be doped. Doping is then performed, and the whole structure is annealed with a pulsed excimer laser. But laser annealing, unlike standard annealing techniques, does not effect the aluminum contacts because the laser light is reflected by the aluminum. Once the annealing process is complete, the structures can be probed, using standard techniques, to ascertain data about the doping step. Analysis of the data can be used to determine probable yield reductions due to improper execution of the doping step and thus provide real-time feedback during integrated circuit fabrication.

  8. Processing and fabrication of mixed uranium/refractory metal carbide fuels with liquid-phase sintering

    NASA Astrophysics Data System (ADS)

    Knight, Travis W.; Anghaie, Samim

    2002-11-01

    Optimization of powder processing techniques were sought for the fabrication of single-phase, solid-solution mixed uranium/refractory metal carbide nuclear fuels - namely (U, Zr, Nb)C. These advanced, ultra-high temperature nuclear fuels have great potential for improved performance over graphite matrix, dispersed fuels tested in the Rover/NERVA program of the 1960s and early 1970s. Hypostoichiometric fuel samples with carbon-to-metal ratios of 0.98, uranium metal mole fractions of 5% and 10%, and porosities less than 5% were fabricated. These qualities should provide for the longest life and highest performance capability for these fuels. Study and optimization of processing methods were necessary to provide the quality assurance of samples for meaningful testing and assessment of performance for nuclear thermal propulsion applications. The processing parameters and benefits of enhanced sintering by uranium carbide liquid-phase sintering were established for the rapid and effective consolidation and formation of a solid-solution mixed carbide nuclear fuel.

  9. Technology advancement of the electrochemical CO2 concentrating process

    NASA Technical Reports Server (NTRS)

    Schubert, F. H.; Woods, R. R.; Hallick, T. M.; Heppner, D. B.

    1977-01-01

    A five-cell, liquid-cooled advanced electrochemical depolarized carbon dioxide concentrator module was fabricated. The cells utilized the advanced, lightweight, plated anode current collector concept and internal liquid-cooling. The five cell module was designed to meet the carbon dioxide removal requirements of one man and was assembled using plexiglass endplates. This one-man module was tested as part of an integrated oxygen generation and recovery subsystem.

  10. Silver-clad ? superconducting tapes fabricated by different mechanical processing

    NASA Astrophysics Data System (ADS)

    Guo, Y. C.; Liu, H. K.; Dou, S. X.; Kuroda, T.; Tanaka, Y.

    1998-10-01

    0953-2048/11/10/032/img10/silver composites were fabricated by drawing a silver tube packed with precursor powders into round wire and deforming the round wire into flat tapes by longitudinal rolling, transverse rolling and uniaxial pressing respectively. The resultant tapes were observed by optical microscopy to examine the superconductor core/silver interface. Short pieces were cut from the tapes and heat-treated by a thermomechanical process consisting of alternate sintering and intermediate mechanical deformation. Intermediate deformation was carried out for each tape using the method by which the tape was formed. The effect of different deformations on the microstructure and transport property of the final tapes was investigated. It was found that deformation method affected the core/silver interface of tapes significantly. Pressing produced a wavier core/silver interface (sausaging) and more cracks than longitudinal and transverse rolling. As for critical current density, pressing yielded the highest value, due to the higher density and better grain alignment in the pressed tapes than in the longitudinal and transverse rolled ones.

  11. Fabrication and quality assurance processes for superhybrid composite fan blades

    NASA Technical Reports Server (NTRS)

    Lark, R. F.; Chamis, C. C.

    1986-01-01

    The feasibility of fabricating full-scale fan blades from superhybrid composites (SHC) for use large, commercial gas turbine engines was evaluated. The type of blade construction selected was a metal-spar/SHC-shell configuration, in which the outer shell was adhesively bonded to a short, internal, titanium spar. Various aspects of blade fabrication, inspection, and quality assurance procedures developed in the investigation are described. It is concluded that the SHC concept is feasible for the fabrication of prototype, full-scale, metal-spar/SHC-shell fan blades that have good structural properties and meet dimensional requirements.

  12. Fabrication and quality assurance processes for superhybrid composite fan blades

    NASA Technical Reports Server (NTRS)

    Lark, R. F.; Chamis, C. C.

    1983-01-01

    The feasibility of fabricating full-scale fan blades from superhybrid composites (SHC) for use large, commercial gas turbine engines was evaluated. The type of blade construction selected was a metal-spar/SHC-shell configuration, in which the outer shell was adhesively bonded to a short, internal, titanium spar. Various aspects of blade fabrication, inspection, and quality assurance procedures developed in the investigation are described. It is concluded that the SHC concept is feasible for the fabrication of prototype, full-scale, metal-spar/SHC-shell fan blades that have good structural properties and meet dimensional requirements.

  13. Advances in excimer laser processing of materials

    SciTech Connect

    Jervis, T.R.; Nastasi, M.; Hirvonen, J.-P.

    1996-08-01

    The use of pulsed excimer lasers to surface processing of materials hinges on an understanding of the nature of the interaction between the laser energy and the material. The application of this understanding of the laser materials interaction to surface modification must also recognize the existence of thermodynamic driving forces and kinetic limitations in light of the short duration of a single pulse event. For species that have higher solubility in the liquid than in the solid phase, segregation by ``zone refinement`` from multiple passes by a solidification front to the surface results in surface enrichment of those species. The most obvious applications for surface processing occur where the bulk properties of a component are not commensurate with the needed surface properties. Improvements in surface mechanical properties have been observed in a number of metal and ceramic alloys. In the microelectronics industry, apart from micromachining or material removal applications, for which excimers are indeed well suited, the same features of the laser-materials interaction that are used to modify the mechanical or electrochemical properties of a surface can be used to advantage. Further advances, such as those demonstrated in microelectronics, await application-specific developments. 22 refs., 1 fig.

  14. Induced effects of advanced oxidation processes.

    PubMed

    Liu, Peng; Li, Chaolin; Zhao, Zhuanjun; Lu, Gang; Cui, Haibo; Zhang, Wenfang

    2014-02-07

    Hazardous organic wastes from industrial, military, and commercial activities represent one of the greatest challenges to human beings. Advanced oxidation processes (AOPs) are alternatives to the degradation of those organic wastes. However, the knowledge about the exact mechanisms of AOPs is still incomplete. Here we report a phenomenon in the AOPs: induced effects, which is a common property of combustion reaction. Through analysis EDTA oxidation processes by Fenton and UV-Fenton system, the results indicate that, just like combustion, AOPs are typical induction reactions. One most compelling example is that pre-feeding easily oxidizable organic matter can promote the oxidation of refractory organic compound when it was treated by AOPs. Connecting AOPs to combustion, it is possible to achieve some helpful enlightenment from combustion to analyze, predict and understand AOPs. In addition, we assume that maybe other oxidation reactions also have induced effects, such as corrosion, aging and passivation. Muchmore research is necessary to reveal the possibilities of induced effects in those fields.

  15. Induced effects of advanced oxidation processes

    NASA Astrophysics Data System (ADS)

    Liu, Peng; Li, Chaolin; Zhao, Zhuanjun; Lu, Gang; Cui, Haibo; Zhang, Wenfang

    2014-02-01

    Hazardous organic wastes from industrial, military, and commercial activities represent one of the greatest challenges to human beings. Advanced oxidation processes (AOPs) are alternatives to the degradation of those organic wastes. However, the knowledge about the exact mechanisms of AOPs is still incomplete. Here we report a phenomenon in the AOPs: induced effects, which is a common property of combustion reaction. Through analysis EDTA oxidation processes by Fenton and UV-Fenton system, the results indicate that, just like combustion, AOPs are typical induction reactions. One most compelling example is that pre-feeding easily oxidizable organic matter can promote the oxidation of refractory organic compound when it was treated by AOPs. Connecting AOPs to combustion, it is possible to achieve some helpful enlightenment from combustion to analyze, predict and understand AOPs. In addition, we assume that maybe other oxidation reactions also have induced effects, such as corrosion, aging and passivation. Muchmore research is necessary to reveal the possibilities of induced effects in those fields.

  16. Fabrication of conductive polymer nanofibers through SWNT supramolecular functionalization and aqueous solution processing.

    PubMed

    Naeem, Fahim; Prestayko, Rachel; Saem, Sokunthearath; Nowicki, Lauren; Imit, Mokhtar; Adronov, Alex; Moran-Mirabal, Jose M

    2015-10-02

    Polymeric thin films and nanostructured composites with excellent electrical properties are required for the development of advanced optoelectronic devices, flexible electronics, wearable sensors, and tissue engineering scaffolds. Because most polymers available for fabrication are insulating, one of the biggest challenges remains the preparation of inexpensive polymer composites with good electrical conductivity. Among the nanomaterials used to enhance composite performance, single walled carbon nanotubes (SWNTs) are ideal due to their unique physical and electrical properties. Yet, a barrier to their widespread application is that they do not readily disperse in solvents traditionally used for polymer processing. In this study, we employed supramolecular functionalization of SWNTs with a conjugated polyelectrolyte as a simple approach to produce stable aqueous nanotube suspensions, that could be effortlessly blended with the polymer poly(ethyleneoxide) (PEO). The homogeneous SWNT:PEO mixtures were used to fabricate conductive thin films and nanofibers with improved conductivities through drop casting and electrospinning. The physical characterization of electrospun nanofibers through Raman spectroscopy and SEM revealed that the SWNTs were uniformly incorporated throughout the composites. The electrical characterization of SWNT:PEO thin films allowed us to assess their conductivity and establish a percolation threshold of 0.1 wt% SWNT. Similarly, measurement of the nanofiber conductivity showed that the electrospinning process improved the contact between nanotube complexes, resulting in conductivities in the S m(-1) range with much lower weight loading of SWNTs than their thin film counterparts. The methods reported for the fabrication of conductive nanofibers are simple, inexpensive, and enable SWNT processing in aqueous solutions, and offer great potential for nanofiber use in applications involving flexible electronics, sensing devices, and tissue engineering

  17. Fabrication of conductive polymer nanofibers through SWNT supramolecular functionalization and aqueous solution processing

    NASA Astrophysics Data System (ADS)

    Naeem, Fahim; Prestayko, Rachel; Saem, Sokunthearath; Nowicki, Lauren; Imit, Mokhtar; Adronov, Alex; Moran-Mirabal, Jose M.

    2015-10-01

    Polymeric thin films and nanostructured composites with excellent electrical properties are required for the development of advanced optoelectronic devices, flexible electronics, wearable sensors, and tissue engineering scaffolds. Because most polymers available for fabrication are insulating, one of the biggest challenges remains the preparation of inexpensive polymer composites with good electrical conductivity. Among the nanomaterials used to enhance composite performance, single walled carbon nanotubes (SWNTs) are ideal due to their unique physical and electrical properties. Yet, a barrier to their widespread application is that they do not readily disperse in solvents traditionally used for polymer processing. In this study, we employed supramolecular functionalization of SWNTs with a conjugated polyelectrolyte as a simple approach to produce stable aqueous nanotube suspensions, that could be effortlessly blended with the polymer poly(ethyleneoxide) (PEO). The homogeneous SWNT:PEO mixtures were used to fabricate conductive thin films and nanofibers with improved conductivities through drop casting and electrospinning. The physical characterization of electrospun nanofibers through Raman spectroscopy and SEM revealed that the SWNTs were uniformly incorporated throughout the composites. The electrical characterization of SWNT:PEO thin films allowed us to assess their conductivity and establish a percolation threshold of 0.1 wt% SWNT. Similarly, measurement of the nanofiber conductivity showed that the electrospinning process improved the contact between nanotube complexes, resulting in conductivities in the S m-1 range with much lower weight loading of SWNTs than their thin film counterparts. The methods reported for the fabrication of conductive nanofibers are simple, inexpensive, and enable SWNT processing in aqueous solutions, and offer great potential for nanofiber use in applications involving flexible electronics, sensing devices, and tissue engineering

  18. Microwave processing of silicon nitride for advanced gas turbine applications

    SciTech Connect

    Tiegs, T.N.; Kiggans, J.O.

    1993-04-01

    Results from previous studies on microwave processing of silicon nitride-based ceramics are reviewed to ascertain the application of this technology to advanced gas turbine (AGT) materials. Areas of microwave processing that have been examined in the past are (1) sintering of powder compacts; (2) heat treatment of dense materials; and (3) nitridation of Si for reactionbonded silicon nitride. The sintering of Si{sub 3}N{sub 4} powder compacts showed improved densification and enhanced grain growth. However, the high additive levels required to produce crack-free parts generally limit these materials to low temperature applications. Improved high-temperature creep resistance has been observed for microwave heat-treated materials and therefore has application to materials used in highly demanding service conditions. In contrast to Si{sub 3}N{sub 4}, Si couples well in the microwave and sintered reaction-bonded silicon nitride materials have been fabricated in a one-step process with cost-effective raw materials. However, these materials are also limited to lower temperature applications, under about 1000{degrees}C.

  19. Microwave processing of silicon nitride for advanced gas turbine applications

    SciTech Connect

    Tiegs, T.N.; Kiggans, J.O.

    1993-01-01

    Results from previous studies on microwave processing of silicon nitride-based ceramics are reviewed to ascertain the application of this technology to advanced gas turbine (AGT) materials. Areas of microwave processing that have been examined in the past are (1) sintering of powder compacts; (2) heat treatment of dense materials; and (3) nitridation of Si for reactionbonded silicon nitride. The sintering of Si[sub 3]N[sub 4] powder compacts showed improved densification and enhanced grain growth. However, the high additive levels required to produce crack-free parts generally limit these materials to low temperature applications. Improved high-temperature creep resistance has been observed for microwave heat-treated materials and therefore has application to materials used in highly demanding service conditions. In contrast to Si[sub 3]N[sub 4], Si couples well in the microwave and sintered reaction-bonded silicon nitride materials have been fabricated in a one-step process with cost-effective raw materials. However, these materials are also limited to lower temperature applications, under about 1000[degrees]C.

  20. Process development and fabrication of application-specific microvalves

    NASA Astrophysics Data System (ADS)

    Xu, Bai; Castracane, James; Geer, Robert E.; Yao, Yahong; Altemus, Bruce

    2000-08-01

    MEMS promise to revolutionize nearly every product category by bringing together silicon-based microelectronics fabrication with silicon micromachining technology, thereby, making possible the realizing of complete systems-on-a-chip.

  1. Thin resist performance comparison for advanced e-beam reticle fabrication

    NASA Astrophysics Data System (ADS)

    Kobayashi, Hideo; Higuchi, Takao; Asakawa, Keishi; Yokoya, Yasunori; Yamashiro, Kazuhide

    1997-07-01

    There seem to be much activities, in the mask-making industry at present, in re-establishing a new proces technique and condition for conventional high-molecular polymer resists such as EBR-9TM series rather than in seeking an alternative. This is because of infeasibility of an alternative such as DNQ-Novolak or chemical amplified resist. And 'thin resist' is a promising option for advanced e-beam reticle fabrication. We had investigated optimum coating thickness as thin resist, baking condition and exposure dose firstly on PBS and ZEP- 7000TM, and reported the results and its efficacy in pattering performance at 16th BACUS annual symposium in '96. This time, we tried to determine the optimum coating conditions for EBR-9, EBR-9 HS31TM and ZEP-810TM, and evaluated patterning performance, by which all major five resists to be covered for a comparison. We examined pre-baking latitude, coating thickness latitude, exposure dose latitude, develop latitude, and pattern linearity and fidelity, under the optimum conditions, in order to see advantages and disadvantages of thin resist coating on each individual resist. This paper describes our investigation results on the optimum condition in coating thickness, pre-baking and exposure dose, as well as comparison results on patterning performance of thin resist coating between major five conventional resists, PBSTM, EBR-9, EBR-9 HS31, ZEP-810 and ZEP-7000, for advanced e-beam reticle fabrication.

  2. Virtual fabrication using directed self-assembly for process optimization in a 14-nm dynamic random access memory

    NASA Astrophysics Data System (ADS)

    Kamon, Mattan; Akbulut, Mustafa; Yan, Yiguang; Faken, Daniel; Pap, Andras; Allampalli, Vasanth; Greiner, Ken; Fried, David

    2016-07-01

    For directed self-assembly (DSA) to be deployed in advanced semiconductor technologies, it must reliably integrate into a full process flow. We present a methodology for using virtual fabrication software, including predictive DSA process models, to develop and analyze the replacement of self-aligned quadruple patterning with Liu-Nealey chemoepitaxy on a 14-nm dynamic random access memory (DRAM) process. To quantify the impact of this module replacement, we investigated a key process yield metric for DRAM, interface area between the capacitor contacts and transistor source/drain. Additionally, we demonstrate virtual fabrication of the DRAM cell's hexagonally packed capacitors patterned with an array of diblock copolymer cylinders in place of fourfold litho-etch (LE4) patterning.

  3. Bioinspired superhydrophobic surfaces, fabricated through simple and scalable roll-to-roll processing

    NASA Astrophysics Data System (ADS)

    Park, Sung-Hoon; Lee, Sangeui; Moreira, David; Bandaru, Prabhakar R.; Han, Intaek; Yun, Dong-Jin

    2015-10-01

    A simple, scalable, non-lithographic, technique for fabricating durable superhydrophobic (SH) surfaces, based on the fingering instabilities associated with non-Newtonian flow and shear tearing, has been developed. The high viscosity of the nanotube/elastomer paste has been exploited for the fabrication. The fabricated SH surfaces had the appearance of bristled shark skin and were robust with respect to mechanical forces. While flow instability is regarded as adverse to roll-coating processes for fabricating uniform films, we especially use the effect to create the SH surface. Along with their durability and self-cleaning capabilities, we have demonstrated drag reduction effects of the fabricated films through dynamic flow measurements.

  4. Multi-Step Deep Reactive Ion Etching Fabrication Process for Silicon-Based Terahertz Components

    NASA Technical Reports Server (NTRS)

    Jung-Kubiak, Cecile (Inventor); Reck, Theodore (Inventor); Chattopadhyay, Goutam (Inventor); Perez, Jose Vicente Siles (Inventor); Lin, Robert H. (Inventor); Mehdi, Imran (Inventor); Lee, Choonsup (Inventor); Cooper, Ken B. (Inventor); Peralta, Alejandro (Inventor)

    2016-01-01

    A multi-step silicon etching process has been developed to fabricate silicon-based terahertz (THz) waveguide components. This technique provides precise dimensional control across multiple etch depths with batch processing capabilities. Nonlinear and passive components such as mixers and multipliers waveguides, hybrids, OMTs and twists have been fabricated and integrated into a small silicon package. This fabrication technique enables a wafer-stacking architecture to provide ultra-compact multi-pixel receiver front-ends in the THz range.

  5. Application of foams to the processing of fabrics. Final report, October 1, 1977-September 30, 1981

    SciTech Connect

    Namboodri, C.G.

    1981-10-01

    The primary objective of this project was to reduce the energy consumed in the wet processing of fabrics where wet processing encompasses those processes used to convert loomstate (greige) goods to finished textile products. This includes desizing, scouring, bleaching, dyeing, printing, and finishing of fabrics. The energy intensive step in most of these processes is drying the fabric. By having less water on the fabric as it enters a drying oven, proportionately less energy is consumed in drying the fabric. The specific route used in this project to accomplish this objective has been to use air to distribute the finish, dye or printing ink onto the fabric. Rather than saturating the fabric with a dilute finish formulation, a concentrated formulation is mechanically foamed, air serving as the diluting medium and the foam applied to the fabric. In this manner, the water content of the fabric as it enters the drying oven is reduced by as much as 80% thereby leading to a corresponding reduction in the energy required to dry the fabric. Details on the procedure are presented and experimental results are discussed. (MCW)

  6. Cost-Benefit Analysis for the Advanced Near Net Shape Technology (ANNST) Method for Fabricating Stiffened Cylinders

    NASA Technical Reports Server (NTRS)

    Stoner, Mary Cecilia; Hehir, Austin R.; Ivanco, Marie L.; Domack, Marcia S.

    2016-01-01

    This cost-benefit analysis assesses the benefits of the Advanced Near Net Shape Technology (ANNST) manufacturing process for fabricating integrally stiffened cylinders. These preliminary, rough order-of-magnitude results report a 46 to 58 percent reduction in production costs and a 7-percent reduction in weight over the conventional metallic manufacturing technique used in this study for comparison. Production cost savings of 35 to 58 percent were reported over the composite manufacturing technique used in this study for comparison; however, the ANNST concept was heavier. In this study, the predicted return on investment of equipment required for the ANNST method was ten cryogenic tank barrels when compared with conventional metallic manufacturing. The ANNST method was compared with the conventional multi-piece metallic construction and composite processes for fabricating integrally stiffened cylinders. A case study compared these three alternatives for manufacturing a cylinder of specified geometry, with particular focus placed on production costs and process complexity, with cost analyses performed by the analogy and parametric methods. Furthermore, a scalability study was conducted for three tank diameters to assess the highest potential payoff of the ANNST process for manufacture of large-diameter cryogenic tanks. The analytical hierarchy process (AHP) was subsequently used with a group of selected subject matter experts to assess the value of the various benefits achieved by the ANNST method for potential stakeholders. The AHP study results revealed that decreased final cylinder mass and quality assurance were the most valued benefits of cylinder manufacturing methods, therefore emphasizing the relevance of the benefits achieved with the ANNST process for future projects.

  7. Natural language processing and advanced information management

    NASA Technical Reports Server (NTRS)

    Hoard, James E.

    1989-01-01

    Integrating diverse information sources and application software in a principled and general manner will require a very capable advanced information management (AIM) system. In particular, such a system will need a comprehensive addressing scheme to locate the material in its docuverse. It will also need a natural language processing (NLP) system of great sophistication. It seems that the NLP system must serve three functions. First, it provides an natural language interface (NLI) for the users. Second, it serves as the core component that understands and makes use of the real-world interpretations (RWIs) contained in the docuverse. Third, it enables the reasoning specialists (RSs) to arrive at conclusions that can be transformed into procedures that will satisfy the users' requests. The best candidate for an intelligent agent that can satisfactorily make use of RSs and transform documents (TDs) appears to be an object oriented data base (OODB). OODBs have, apparently, an inherent capacity to use the large numbers of RSs and TDs that will be required by an AIM system and an inherent capacity to use them in an effective way.

  8. Advanced Coal Conversion Process Demonstration Project

    SciTech Connect

    Not Available

    1992-04-01

    Western Energy Company (WECO) was selected by the Department of Energy (DOE) to demonstrate the Advanced Coal Conversion Process (ACCP) which upgrades low rank coals into high Btu, low sulfur, synthetic bituminous coal. As specified in the Corporate Agreement, RSCP is required to develop an Environmental Monitoring Plan (EMP) which describes in detail the environmental monitoring activities to be performed during the project execution. The purpose of the EMP is to: (1) identify monitoring activities that will be undertaken to show compliance to applicable regulations, (2) confirm the specific environmental impacts predicted in the National Environmental Policy Act documentation, and (3) establish an information base of the assessment of the environmental performance of the technology demonstrated by the project. The EMP specifies the streams to be monitored (e.g. gaseous, aqueous, and solid waste), the parameters to be measured (e.g. temperature, pressure, flow rate), and the species to be analyzed (e.g. sulfur compounds, nitrogen compounds, trace elements) as well as human health and safety exposure levels. The operation and frequency of the monitoring activities is specified, as well as the timing for the monitoring activities related to project phase (e.g. preconstruction, construction, commissioning, operational, post-operational). The EMP is designed to assess the environmental impacts and the environmental improvements resulting from construction and operation of the project.

  9. Advanced information processing system: Local system services

    NASA Technical Reports Server (NTRS)

    Burkhardt, Laura; Alger, Linda; Whittredge, Roy; Stasiowski, Peter

    1989-01-01

    The Advanced Information Processing System (AIPS) is a multi-computer architecture composed of hardware and software building blocks that can be configured to meet a broad range of application requirements. The hardware building blocks are fault-tolerant, general-purpose computers, fault-and damage-tolerant networks (both computer and input/output), and interfaces between the networks and the computers. The software building blocks are the major software functions: local system services, input/output, system services, inter-computer system services, and the system manager. The foundation of the local system services is an operating system with the functions required for a traditional real-time multi-tasking computer, such as task scheduling, inter-task communication, memory management, interrupt handling, and time maintenance. Resting on this foundation are the redundancy management functions necessary in a redundant computer and the status reporting functions required for an operator interface. The functional requirements, functional design and detailed specifications for all the local system services are documented.

  10. Advanced processing architectures that accommodate autonomy

    NASA Astrophysics Data System (ADS)

    Daley, Philip C.

    1992-03-01

    This paper surveys past architectures accommodating autonomy and projects future directions in these architectures. In recent years research toward autonomous systems has been stimulated by Space Station Freedom, SDI, and DARPA's Strategic Computing Initiative. More recently, the Mars Rover studies and the Human Exploration Initiative are driving the needs for onboard computer systems which provide either autonomous or supervised autonomous operations. While early work focussed on defining functional requirements for such systems and the development of algorithms for each functional element, current research focuses on integrated sensori-motor control and techniques to assure that the processing architectures to execute these onboard functions will respect well-defined volume, weight, and power budgets. The success of programs which demonstrate autonomous systems such as the Martin Marietta Autonomous Land Vehicle, as well as large scale laboratory demonstrations of supervised autonomy, show this can be done. Integration requires many disciplines to be jointly considered: vision, planning, control, computer systems, and platform management. The system engineering discipline to balance the design imperatives of each within a well- engineered solution must advance as well. One of the intriguing aspects of this problem is that the approach and resulting architecture must accommodate changes to the mission and associated key mission timing parameters. Therefore, the ease of evolving both the architecture and mission contribute design imperatives of their own. This paper discusses processing architectures for autonomy and lessons learned in our past work, the impact of emerging techniques such as neural networks, and our recent work to exploit custom hardware to accommodate the increased number and complexity of onboard functions required for autonomous platforms while respecting stringent volume, weight, and power considerations.

  11. In-Process Thermal Imaging of the Electron Beam Freeform Fabrication Process

    NASA Technical Reports Server (NTRS)

    Taminger, Karen M.; Domack, Christopher S.; Zalameda, Joseph N.; Taminger, Brian L.; Hafley, Robert A.; Burke, Eric R.

    2016-01-01

    Researchers at NASA Langley Research Center have been developing the Electron Beam Freeform Fabrication (EBF3) metal additive manufacturing process for the past 15 years. In this process, an electron beam is used as a heat source to create a small molten pool on a substrate into which wire is fed. The electron beam and wire feed assembly are translated with respect to the substrate to follow a predetermined tool path. This process is repeated in a layer-wise fashion to fabricate metal structural components. In-process imaging has been integrated into the EBF3 system using a near-infrared (NIR) camera. The images are processed to provide thermal and spatial measurements that have been incorporated into a closed-loop control system to maintain consistent thermal conditions throughout the build. Other information in the thermal images is being used to assess quality in real time by detecting flaws in prior layers of the deposit. NIR camera incorporation into the system has improved the consistency of the deposited material and provides the potential for real-time flaw detection which, ultimately, could lead to the manufacture of better, more reliable components using this additive manufacturing process.

  12. In-process thermal imaging of the electron beam freeform fabrication process

    NASA Astrophysics Data System (ADS)

    Taminger, Karen M.; Domack, Christopher S.; Zalameda, Joseph N.; Taminger, Brian L.; Hafley, Robert A.; Burke, Eric R.

    2016-05-01

    Researchers at NASA Langley Research Center have been developing the Electron Beam Freeform Fabrication (EBF3) metal additive manufacturing process for the past 15 years. In this process, an electron beam is used as a heat source to create a small molten pool on a substrate into which wire is fed. The electron beam and wire feed assembly are translated with respect to the substrate to follow a predetermined tool path. This process is repeated in a layer-wise fashion to fabricate metal structural components. In-process imaging has been integrated into the EBF3 system using a near-infrared (NIR) camera. The images are processed to provide thermal and spatial measurements that have been incorporated into a closed-loop control system to maintain consistent thermal conditions throughout the build. Other information in the thermal images is being used to assess quality in real time by detecting flaws in prior layers of the deposit. NIR camera incorporation into the system has improved the consistency of the deposited material and provides the potential for real-time flaw detection which, ultimately, could lead to the manufacture of better, more reliable components using this additive manufacturing process.

  13. A fabrication process for integrating polysilicon microstructures with post-processed CMOS circuits

    NASA Astrophysics Data System (ADS)

    Gianchandani, Y. B.; Kim, H.; Shinn, M.; Ha, B.; Lee, B.; Najafi, K.; Song, C.

    2000-09-01

    A MEMS-first fabrication process for integrating CMOS circuits with polysilicon micromechanical structures is described in detail. The overall process uses 18 masks (22 lithography steps) to merge a p-well LOCOS CMOS process that has one metal and two polysilicon layers with a surface micromachining process that has three layers of polysilicon. The microstructures are formed within recesses on the surface of silicon wafers such that their uppermost surfaces are coplanar with the remainder of the substrate. No special planarization technique, such as chemical-mechanical polishing, is used in the work described here. Special aspects of the process include provisions to improve lithography within the recesses, to protect the microstructures during the circuit fabrication, and to implement an effective lead transfer between the microstructures and the on-chip circuitry. The process is validated using a test vehicle that includes accelerometers and gyroscopes interfaced with sensing circuits. Measured transistor parameters match those obtained in standard CMOS, with NMOS and PMOS thresholds at 0.76 V and -0.96 V, respectively.

  14. 2D all-solid state fabric supercapacitor fabricated via an all solution process for use in smart textiles

    NASA Astrophysics Data System (ADS)

    Jang, Yunseok; Jo, Jeongdai; Woo, Kyoohee; Lee, Seung-Hyun; Kwon, Sin; Kim, Kwang-Young; Kang, Dongwoo

    2017-05-01

    We propose a method to fabricate a supercapacitor for smart textiles using silver (Ag) nanoparticle (NP) ink, simple spray patterning systems, and intense pulsed light (IPL) sintering systems. The Ag NP current collectors provided as high conductivity as the metal current collectors. The spray patterning technique is useful for fabricating supercapacitors because it is simple, fast, and cheap. IPL systems reduced the sintering temperature of Ag NPs and prevented thermal damage to the textiles during the Ag NP sintering process. The two-dimensional (2D) all-solid state fabric supercapacitor with an interdigitated configuration, developed here, exhibited a specific capacitance of 25.7 F/g and an energy density of 1.5 Wh/kg at a power density of 64.3 W/kg. These results support the utility of our proposed method in the development of energy textiles.

  15. Fabrication of advanced organic-inorganic nanocomposite coatings for biomedical applications by electrodeposition

    NASA Astrophysics Data System (ADS)

    Pang, Xin

    Novel electrodeposition strategies have been developed for the fabrication of thick adherent zirconia ceramic and composite coatings for biomedical applications. The new method is based on the electrophoretic deposition (EPD) of polyelectrolyte additives combined with the cathodic precipitation of zirconia. The method enables the room-temperature electrosynthesis of crystalline zirconia nanoparticles in the polymer matrix. Adherent crack-free coatings up to several microns thick were obtained. The deposits were studied by thermogravimetric and differential thermal analysis, X-ray diffraction analysis, scanning and transmission electron microscopy, and atomic force microscopy. Obtained results pave the way for electrodeposition of other ceramic-polymer composites. Novel advanced nanocomposite coatings based on bioceramic hydroxyapatite (HA) have been developed for the surface modification of orthopaedic and dental implant metals. HA nanopartic1es prepared by a chemical precipitation method were used for the fabrication of novel HA-chitosan nanocomposite coatings. The use of chitosan enables room-temperature fabrication of the composite coatings. The problems related to the sintering of HA can be avoided. A new electrodeposition strategy, based on the EPD of HA nanoparticles and electrochemical deposition of chitosan macromolecules, has been developed. The method enabled the formation of dense, adherent and uniform coatings of various thicknesses in the range of up to 60 mum. Bioactive composite coatings containing 40.9-89.8 wt% HA were obtained. The deposit composition and microstructure can be tailored by varying the chitosan and HA concentrations in the deposition bath. A mathematical model describing the formation of the HA-chitosan composite deposit has been developed. X-ray studies revealed preferred orientation of HA nanoparticles in the nanocomposites. Obtained coatings provide corrosion protection of the substrates and can be utilized for the fabrication of

  16. Foreword: Additive Manufacturing: Interrelationships of Fabrication, Constitutive Relationships Targeting Performance, and Feedback to Process Control

    DOE PAGES

    Carpenter, John S.; Beese, Allison M.; Bourell, David L.; ...

    2015-06-26

    Additive manufacturing (AM) offers distinct advantages over conventional manufacturing processes including the capability to both build and repair complex part shapes; to integrate and consolidate parts and thus overcome joining concerns; and to locally tailor material compositions as well as properties. Moreover, a variety of fields such as aerospace, military, automotive, and biomedical are employing this manufacturing technique as a way to decrease costs, increase manufacturing agility, and explore novel geometry/functionalities. In order to increase acceptance of AM as a viable processing method, pathways for qualifying both the material and the process need to be developed and, perhaps, standardized. Thismore » symposium was designed to serve as a venue for the international AM community—including government, academia, and industry—to define the fundamental interrelationships between feedstock, processing, microstructure, shape, mechanical behavior/materials properties, and function/performance. Eventually, insight into the connections between processing, microstructure, property, and performance will be achieved through experimental observations, theoretical advances, and computational modeling of physical processes. Finally, once this insight matures, AM will be able to move from the realm of making parts to making qualified materials that are certified for use with minimal need for post-fabrication characterization.« less

  17. Foreword: Additive Manufacturing: Interrelationships of Fabrication, Constitutive Relationships Targeting Performance, and Feedback to Process Control

    SciTech Connect

    Carpenter, John S.; Beese, Allison M.; Bourell, David L.; Hamilton, Reginald F.; Mishra, Rajiv; Sears, James

    2015-06-26

    Additive manufacturing (AM) offers distinct advantages over conventional manufacturing processes including the capability to both build and repair complex part shapes; to integrate and consolidate parts and thus overcome joining concerns; and to locally tailor material compositions as well as properties. Moreover, a variety of fields such as aerospace, military, automotive, and biomedical are employing this manufacturing technique as a way to decrease costs, increase manufacturing agility, and explore novel geometry/functionalities. In order to increase acceptance of AM as a viable processing method, pathways for qualifying both the material and the process need to be developed and, perhaps, standardized. This symposium was designed to serve as a venue for the international AM community—including government, academia, and industry—to define the fundamental interrelationships between feedstock, processing, microstructure, shape, mechanical behavior/materials properties, and function/performance. Eventually, insight into the connections between processing, microstructure, property, and performance will be achieved through experimental observations, theoretical advances, and computational modeling of physical processes. Finally, once this insight matures, AM will be able to move from the realm of making parts to making qualified materials that are certified for use with minimal need for post-fabrication characterization.

  18. Advanced Materials and Fabrication Techniques for the Orion Attitude Control Motor

    NASA Technical Reports Server (NTRS)

    Gorti, Sridhar; Holmes, Richard; O'Dell, John; McKechnie, Timothy; Shchetkovskiy, Anatoliy

    2013-01-01

    Rhenium, with its high melting temperature, excellent elevated temperature properties, and lack of a ductile-to-brittle transition temperature (DBTT), is ideally suited for the hot gas components of the ACM (Attitude Control Motor), and other high-temperature applications. However, the high cost of rhenium makes fabricating these components using conventional fabrication techniques prohibitive. Therefore, near-net-shape forming techniques were investigated for producing cost-effective rhenium and rhenium alloy components for the ACM and other propulsion applications. During this investigation, electrochemical forming (EL-Form ) techniques were evaluated for producing the hot gas components. The investigation focused on demonstrating that EL-Form processing techniques could be used to produce the ACM flow distributor. Once the EL-Form processing techniques were established, a representative rhenium flow distributor was fabricated, and samples were harvested for material properties testing at both room and elevated temperatures. As a lower cost and lighter weight alternative to an all-rhenium component, rhenium- coated graphite and carbon-carbon were also evaluated. The rhenium-coated components were thermal-cycle tested to verify that they could withstand the expected thermal loads during service. High-temperature electroforming is based on electrochemical deposition of compact layers of metals onto a mandrel of the desired shape. Mandrels used for electro-deposition of near-net shaped parts are generally fabricated from high-density graphite. The graphite mandrel is easily machined and does not react with the molten electrolyte. For near-net shape components, the inner surface of the electroformed part replicates the polished graphite mandrel. During processing, the mandrel itself becomes the cathode, and scrap or refined refractory metal is the anode. Refractory metal atoms from the anode material are ionized in the molten electrolytic solution, and are deposited

  19. Silicon solar cell process development, fabrication and analysis

    NASA Technical Reports Server (NTRS)

    Minahan, J. A.

    1981-01-01

    The fabrication of solar cells from several unconventional silicon materials is described, and cell performance measured and analyzed. Unconventional materials evaluated are edge defined film fed grown (EFG), heat exchanger method (HEM), dendritic web grown, and continuous CZ silicons. Resistivity, current voltage, and spectral sensitivity of the cells were measured. Current voltage was measured under AM0 and AM1 conditions. Maximum conversion efficiencies of cells fabricated from these and other unconventional silicons were compared and test results analyzed. The HEM and continuous CZ silicon were found to be superior to silicon materials considered previously.

  20. Development and demonstration of manufacturing processes for fabricating graphite/LARC 160 polyimide structural elements

    NASA Technical Reports Server (NTRS)

    Frost, R. K.; Jones, J. S.; Dynes, P. J.; Wykes, D. H.

    1981-01-01

    The development and demonstration of manufacturing technologies for the structural application of Celion graphite/LARC-160 polyimide composite material is discussed. Process development and fabrication of demonstration components are discussed. Process development included establishing quality assurance of the basic composite material and processing, nondestructive inspection of fabricated components, developing processes for specific structural forms, and qualification of processes through mechanical testing. Demonstration components were fabricated. The demonstration components consisted of flat laminates, skin/stringer panels, honeycomb panels, chopped fiber compression moldings, and a technology demonstrator segment (TDS) representative of the space shuttle aft body flap.

  1. Silicon solar cell process development, fabrication and analysis

    NASA Technical Reports Server (NTRS)

    Iles, P. A.; Leung, D. C.

    1982-01-01

    For UCP Si, randomly selected wafers and wafers cut from two specific ingots were studied. For the randomly selected wafers, a moderate gettering diffusion had little effect. Moreover, an efficiency up to 14% AMI was achieved with advanced processes. For the two specific UCP ingots, ingot #5848-13C displayed severe impurity effects as shown by lower 3sc in the middle of the ingot and low CFF in the top of the ingot. Also the middle portions of this ingot responded to a series of progressively more severe gettering diffusion. Unexplained was the fact that severely gettered samples of this ingot displayed a negative light biased effect on the minority carrier diffusion length while the nongettered or moderately gettered ones had the more conventional positive light biased effect on diffusion length. On the other hand, ingot C-4-21A did not have the problem of ingot 5848-13C and behaved like to the randomly selected wafers. The top half of the ingot was shown to be slightly superior to the bottom half, but moderate gettering helped to narrow the gap.

  2. Fabrication of advanced fiber Bragg gratings by use of sequential writing with a continuous-wave ultraviolet laser source.

    PubMed

    Petermann, Ingemar; Sahlgren, Bengt; Helmfrid, Sten; Friberg, Ari T; Fonjallaz, Pierre-Yves

    2002-02-20

    We present a novel scheme based on sequential writing for fabrication of advanced fiber Bragg gratings. As opposed to earlier sequential methods this technique uses a cw UV laser source and allows for very precise control and repetitivity of the formation of the gratings. Furthermore it is possible to use high average irradiances without destroying the fiber, resulting in considerable reduction in fabrication time for complex gratings. The method has been applied to several test gratings, which proved its versatility and quality.

  3. Plan for advanced microelectronics processing technology application

    SciTech Connect

    Goland, A.N.

    1990-10-01

    The ultimate objective of the tasks described in the research agreement was to identify resources primarily, but not exclusively, within New York State that are available for the development of a Center for Advanced Microelectronics Processing (CAMP). Identification of those resources would enable Brookhaven National Laboratory to prepare a program plan for the CAMP. In order to achieve the stated goal, the principal investigators undertook to meet the key personnel in relevant NYS industrial and academic organizations to discuss the potential for economic development that could accompany such a Center and to gauge the extent of participation that could be expected from each interested party. Integrated of these discussions was to be achieved through a workshop convened in the summer of 1990. The culmination of this workshop was to be a report (the final report) outlining a plan for implementing a Center in the state. As events unfolded, it became possible to identify the elements of a major center for x-ray lithography on Lone Island at Brookhaven National Laboratory. The principal investigators were than advised to substitute a working document based upon that concept in place of a report based upon the more general CAMP workshop originally envisioned. Following that suggestion from the New York State Science and Technology Foundation, the principals established a working group consisting of representatives of the Grumman Corporation, Columbia University, the State University of New York at Stony Brook, and Brookhaven National Laboratory. Regular meetings and additional communications between these collaborators have produced a preproposal that constitutes the main body of the final report required by the contract. Other components of this final report include the interim report and a brief description of the activities which followed the establishment of the X-ray Lithography Center working group.

  4. New Advanced Fabrication Technique for Millimeter-Wave Planar Components based on Fluororesin Substrates using Graft Polymerization

    NASA Astrophysics Data System (ADS)

    Ito, Naoki; Mase, Atsushi; Kogi, Yuichiro; Seko, Noriaki; Tamada, Masao; Sakata, Eiji

    2008-06-01

    As the importance of advanced millimeter-wave diagnostics increases, a reliable and accurate fabrication technique for high-performance devices and relevant components is essential. We describe a new improved fabrication technique for millimeter-wave planar components, such as antennas using low-loss fluororesin substrates. A fragile adhesion between the copper foil and fluororesin substrate and the accuracy of the device pattern using conventional fabrication techniques have been prime suspects in the failure of the devices. In order to solve these problems, surface treatment of fluororesin films and a fabrication method using electro-fine-forming (EF2) are proposed. The peel adhesion strength between the metal and fluororesin films and the value of the dielectric constant of the fluororesin films before and after grafting are reported. A prototype antenna using conventional fluororesin substrates and grafted-poly(tetrafluoroethylene) (PTFE) films produced using the EF2 fabrication technique are also introduced.

  5. Advanced Fabrication Method for the Preparation of MOF Thin Films: Liquid-Phase Epitaxy Approach Meets Spin Coating Method.

    PubMed

    Chernikova, Valeriya; Shekhah, Osama; Eddaoudi, Mohamed

    2016-08-10

    Here, we report a new and advanced method for the fabrication of highly oriented/polycrystalline metal-organic framework (MOF) thin films. Building on the attractive features of the liquid-phase epitaxy (LPE) approach, a facile spin coating method was implemented to generate MOF thin films in a high-throughput fashion. Advantageously, this approach offers a great prospective to cost-effectively construct thin-films with a significantly shortened preparation time and a lessened chemicals and solvents consumption, as compared to the conventional LPE-process. Certainly, this new spin-coating approach has been implemented successfully to construct various MOF thin films, ranging in thickness from a few micrometers down to the nanometer scale, spanning 2-D and 3-D benchmark MOF materials including Cu2(bdc)2·xH2O, Zn2(bdc)2·xH2O, HKUST-1, and ZIF-8. This method was appraised and proved effective on a variety of substrates comprising functionalized gold, silicon, glass, porous stainless steel, and aluminum oxide. The facile, high-throughput and cost-effective nature of this approach, coupled with the successful thin film growth and substrate versatility, represents the next generation of methods for MOF thin film fabrication. Therefore, paving the way for these unique MOF materials to address a wide range of challenges in the areas of sensing devices and membrane technology.

  6. 3D template fabrication process for the dual damascene NIL approach

    NASA Astrophysics Data System (ADS)

    Butschke, Joerg; Irmscher, Mathias; Resnick, Douglas; Sailer, Holger; Thompson, Ecron

    2007-05-01

    NIL technique enables an easy replication of three dimensional patterns. Combined with a UV printable low-k material the NIL lithography can dramatically simplify the dual damascene process. Goal of this work was to develop a template process scheme which enables the generation of high resolution pillars on top of corresponding lines for direct printing of later vias and metal lines. The process flow is based on conventional 6025 photomask blanks. Exposure was done on a variable shaped e-beam writer Vistec SB350 using a sample of an advanced negative tone CAR and Fujifilm pCAR FEP171 for the first and the second layer, respectively. Chrome and quartz etching was accomplished in an Oerlikon mask etcher Gen III and Gen IV. Assessment of the developed template process was done in terms of overlay accuracy, feature profile and resolution capability depending on aspect ratio and line duty cycle. Finally the printability of 3D templates fabricated according the developed process scheme was proved.

  7. Automated spray coating process for the fabrication of large-area artificial opals on textured substrates.

    PubMed

    Sprafke, Alexander N; Schneevoigt, Daniela; Seidel, Sophie; Schweizer, Stefan L; Wehrspohn, Ralf B

    2013-05-06

    3D photonic crystals, such as opals, have been shown to have a high potential to increase the efficiency of solar cells by enabling advanced light management concepts. However, methods which comply with the demands of the photovoltaic industry for integration of these structures, i. e. the fabrication in a low-cost, fast, and large-scale manner, are missing up to now. In this work, we present the spray coating of a colloidal suspension on textured substrates and subsequent drying. We fabricated opaline films of much larger lateral dimensions and in much shorter times than what is possible using conventional opal fabrication methods.

  8. Investigation of the Thermomechanical Behavior of a 2 × 2 TWILL Weave Fabric Advanced Textile Composite

    NASA Astrophysics Data System (ADS)

    Dixit, A.; Mali, H. S.; Misra, R. K.

    2015-05-01

    The thermomechanical performance of a 2 × 2 twill weave fabric advanced textile composite was evaluated. The tensile, compressive, and flexural properties of flat beam specimens of the composite were tested at room temperature, in water (24.9 to 96.7°C), and in liquid nitrogen (-96.9 to 99.4°C) by using a high-precision instrument called the dynamic mechanical analyzer (DMA). The storage modulus and tanδ of the carbonfiber-reinforced plastic (CFRP) specimens at various temperatures were evaluated. The scanning electron micrograph (SEMs) of deformed composite specimens revealed their failure mode (fiber pull-out, debonding, crack propagation, delamination, matrix cracking, and kinking of fibers).

  9. Fabrication technologies and sensing applications of graphene-based composite films: Advances and challenges.

    PubMed

    Yu, Xiaoqing; Zhang, Wensi; Zhang, Panpan; Su, Zhiqiang

    2017-03-15

    Graphene (G)-based composite materials have been widely explored for the sensing applications ascribing to their atom-thick two-dimensional conjugated structures, high conductivity, large specific surface areas and controlled modification. With the enormous advantages of film structure, G-based composite films (GCFs), prepared by combining G with different functional nanomaterials (noble metals, metal compounds, carbon materials, polymer materials, etc.), show unique optical, mechanical, electrical, chemical, and catalytic properties. Therefore, great quantities of sensors with high sensitivity, selectivity, and stability have been created in recent years. In this review, we focus on the recent advances in the fabrication technologies of GCFs and their specific sensing applications. In addition, the relationship between the properties of GCFs and sensing performance is concentrated on. Finally, the personal perspectives and key challenges of GCFs are mentioned in the hope to shed a light on their potential future research directions.

  10. Recent advances in graphene-based nanomaterials for fabricating electrochemical hydrogen peroxide sensors.

    PubMed

    Zhang, Ruizhong; Chen, Wei

    2017-03-15

    Due to the large specific surface area, extraordinary mechanical flexibility, chemical stability, and superior electrical and thermal conductivities, graphene (G)-based materials have recently opened up an exciting field in the science and technology of two-dimensional (2D) nanomaterials with continuously growing academic and technological impetus. In the past several years, graphene-based materials have been well designed, synthesized, and investigated for sensing applications. In this review, we discuss the synthesis and application of graphene-based 2D nanomaterials for the fabrication of hydrogen peroxide (H2O2) electrochemical sensors. In particular, graphene-based nanomaterials as immobilization matrix of heme proteins for the fabrication of enzymatic H2O2 electrochemical biosensors is first summarized. Then, the application of graphene-based electrocatalysts (metal-free, noble-metals and non-noble metals) in constructing non-enzymatic H2O2 electrochemical sensors is discussed in detail. We hope that this review is helpful to push forward the advancement of this academic issue (189 references).

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

    PubMed

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

    2012-02-01

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

  12. PRELIMINARY DATA CALL REPORT ADVANCED BURNER REACTOR START UP FUEL FABRICATION FACILITY

    SciTech Connect

    S. T. Khericha

    2007-04-01

    The purpose of this report is to provide data for preparation of a NEPA Environmental Impact Statement in support the U. S. Department of Energy (DOE) Global Nuclear Energy Partnership (GNEP). One of the GNEP objectives is to reduce the inventory of long lived actinide from the light water reactor (LWR) spent fuel. The LWR spent fuel contains Plutonium (Pu) -239 and other transuranics (TRU) such as Americium-241. One of the options is to transmute or burn these actinides in fast neutron spectra as well as generate the electricity. A sodium-cooled Advanced Recycling Reactor (ARR) concept has been proposed to achieve this goal. However, fuel with relatively high TRU content has not been used in the fast reactor. To demonstrate the utilization of TRU fuel in a fast reactor, an Advanced Burner Reactor (ABR) prototype of ARR is proposed, which would necessarily be started up using weapons grade (WG) Pu fuel. The WG Pu is distinguished by relatively highest proportions of Pu-239 and lesser amount of other actinides. The WG Pu will be used as the startup fuel along with TRU fuel in lead test assemblies. Because such fuel is not currently being produced in the US, a new facility (or new capability in an existing facility) is being considered for fabrication of WG Pu fuel for the ABR. This report is provided in response to ‘Data Call’ for the construction of startup fuel fabrication facility. It is anticipated that the facility will provide the startup fuel for 10-15 years and will take to 3 to 5 years to construct.

  13. High-performance and high-reliability SOT-6 packaged diplexer based on advanced IPD fabrication techniques

    NASA Astrophysics Data System (ADS)

    Qiang, Tian; Wang, Cong; Kim, Nam-Young

    2017-08-01

    A diplexer offering the advantages of compact size, high performance, and high reliability is proposed on the basis of advanced integrated passive device (IPD) fabrication techniques. The proposed diplexer is developed by combining a third-order low-pass filter (LPF) and a third-order high-pass filter (HPF), which are designed on the basis of the elliptic function prototype low-pass filter. Primary components, such as inductors and capacitors, are designed and fabricated with high Q-factor and appropriate values, and they are subsequently used to construct a compact diplexer having a chip area of 900 μm × 1100 μm (0.009 λ0 × 0.011 λ0, where λ0 is the guided wavelength). In addition, a small-outline transistor (SOT-6) packaging method is adopted, and reliability tests (including temperature, humidity, vibration, and pressure) are conducted to guarantee long-term stability and commercial success. The packaged measurement results indicate excellent RF performance with insertion losses of 1.39 dB and 0.75 dB at operation bands of 0.9 GHz and 1.8 GHz, respectively. The return loss is lower than 10 dB from 0.5 GHz to 4.0 GHz, while the isolation is higher than 15 dB from 0.5 GHz to 3.0 GHz. Thus, it can be concluded that the proposed SOT-6 packaged diplexer is a promising candidate for GSM/CDMA applications. Synthetic solution of diplexer design, RF performance optimization, fabrication process, packaging, RF response measurement, and reliability test is particularly explained and analyzed in this work.

  14. Challenges and Opportunities in Reactive Processing and Applications of Advanced Ceramic Materials

    NASA Technical Reports Server (NTRS)

    Singh, Mrityunjay

    2003-01-01

    Recently, there has been a great deal of interest in the research, development, and commercialization of innovative synthesis and processing technologies for advanced ceramics and composite materials. Reactive processing approaches have been actively considered due to their robustness, flexibility, and affordability. A wide variety of silicon carbide-based advanced ceramics and composites are currently being fabricated using the processing approaches involving reactive infiltration of liquid and gaseous species into engineered fibrous or microporous carbon performs. The microporous carbon performs have been fabricated using the temperature induced phase separation and pyrolysis of two phase organic (resin-pore former) mixtures and fiber reinforcement of carbon and ceramic particulate bodies. In addition, pyrolyzed native plant cellulose tissues also provide unique carbon templates for manufacturing of non-oxide and oxide ceramics. In spite of great interest in this technology due to their affordability and robustness, there is a lack of scientific basis for process understanding and many technical challenges still remain. The influence of perform properties and other parameters on the resulting microstructure and properties of final material is not well understood. In this presentation, mechanism of silicon-carbon reaction in various systems and the effect of perform microstructure on the mechanical properties of advanced silicon carbide based materials will be discussed. Various examples of applications of reactively processed advanced silicon carbide ceramics and composite materials will be presented.

  15. Challenges and Opportunities in Reactive Processing and Applications of Advanced Ceramic Materials

    NASA Technical Reports Server (NTRS)

    Singh, Mrityunjay

    2003-01-01

    Recently, there has been a great deal of interest in the research, development, and commercialization of innovative synthesis and processing technologies for advanced ceramics and composite materials. Reactive processing approaches have been actively considered due to their robustness, flexibility, and affordability. A wide variety of silicon carbide-based advanced ceramics and composites are currently being fabricated using the processing approaches involving reactive infiltration of liquid and gaseous species into engineered fibrous or microporous carbon performs. The microporous carbon performs have been fabricated using the temperature induced phase separation and pyrolysis of two phase organic (resin-pore former) mixtures and fiber reinforcement of carbon and ceramic particulate bodies. In addition, pyrolyzed native plant cellulose tissues also provide unique carbon templates for manufacturing of non-oxide and oxide ceramics. In spite of great interest in this technology due to their affordability and robustness, there is a lack of scientific basis for process understanding and many technical challenges still remain. The influence of perform properties and other parameters on the resulting microstructure and properties of final material is not well understood. In this presentation, mechanism of silicon-carbon reaction in various systems and the effect of perform microstructure on the mechanical properties of advanced silicon carbide based materials will be discussed. Various examples of applications of reactively processed advanced silicon carbide ceramics and composite materials will be presented.

  16. Fabrication and physical testing of graphite composite panels utilizing woven graphite fabric with current and advanced state-of-the-art resin systems

    NASA Technical Reports Server (NTRS)

    Lee, S. C. S.

    1979-01-01

    Three weaves were evaluated; a balanced plain weave, a balanced 8-harness satin weave, and a semiunidirectional crowfoot satin weave. The current state-of-the-art resin system selected was Fiberite's 934 Epoxy; the advanced resin systems evaluated were Phenolic, Phenolic/Novolac, Benzyl and Bismaleimide. The panels were fabricated for testing on NASA/Ames Research Center's Composites Modification Program. Room temperature mechanical tests only were performed by Hitco; the results are presented.

  17. A new fabrication process for the SOI-based miniature electric field sensor

    NASA Astrophysics Data System (ADS)

    Wei, Liu; Pengfei, Yang; Chunrong, Peng; Dongming, Fang; Shanhong, Xia

    2013-08-01

    This paper presents a new fabrication process for the SOI-based novel miniature electric field sensor. This new process uses polyimide film to release the SiO2 layer. Compared with the CO2 critical point release method, it significantly improves the device surface cleanliness and shortens the process flow. The impurity on the base layer is analyzed. The problem of peak and butterfly-type contamination occurring on the base layer of the SOI wafer during the DRIE process is discussed and solved by thickening the photoresist layer and coating with polyimide film twice. This new process could fabricate MEMS sensors and actuators such as SOI-based electric field sensors, gyroscopes, and micro mirrors and can be an alternative fabrication process compared to commercial SOIMUMPS fabrication processes.

  18. Manufacturing processes for fabricating graphite/PMR 15 polyimide structural elements

    NASA Technical Reports Server (NTRS)

    Sheppard, C. H.; Hoggatt, J. T.; Symonds, W. A.

    1979-01-01

    Investigations were conducted to obtain commercially available graphite/PMR-15 polyimide prepreg, develop an autoclave manufacturing process, and demonstrate the process by manufacturing structural elements. Controls were established on polymer, prepreg, composite fabrication, and quality assurance, Successful material quality control and processes were demonstrated by fabricating major structural elements including flat laminates, hat sections, I beam sections, honeycomb sandwich structures, and molded graphite reinforced fittings. Successful fabrication of structural elements and simulated section of the space shuttle aft body flap shows that the graphite/PMR-15 polyimide system and the developed processes are ready for further evaluation in flight test hardware.

  19. Advanced Reduction Processes: A New Class of Treatment Processes

    PubMed Central

    Vellanki, Bhanu Prakash; Batchelor, Bill; Abdel-Wahab, Ahmed

    2013-01-01

    Abstract A new class of treatment processes called advanced reduction processes (ARPs) is proposed. ARPs combine activation methods and reducing agents to form highly reactive reducing radicals that degrade oxidized contaminants. Batch screening experiments were conducted to identify effective ARPs by applying several combinations of activation methods (ultraviolet light, ultrasound, electron beam, and microwaves) and reducing agents (dithionite, sulfite, ferrous iron, and sulfide) to degradation of four target contaminants (perchlorate, nitrate, perfluorooctanoic acid, and 2,4 dichlorophenol) at three pH-levels (2.4, 7.0, and 11.2). These experiments identified the combination of sulfite activated by ultraviolet light produced by a low-pressure mercury vapor lamp (UV-L) as an effective ARP. More detailed kinetic experiments were conducted with nitrate and perchlorate as target compounds, and nitrate was found to degrade more rapidly than perchlorate. Effectiveness of the UV-L/sulfite treatment process improved with increasing pH for both perchlorate and nitrate. We present the theory behind ARPs, identify potential ARPs, demonstrate their effectiveness against a wide range of contaminants, and provide basic experimental evidence in support of the fundamental hypothesis for ARP, namely, that activation methods can be applied to reductants to form reducing radicals that degrade oxidized contaminants. This article provides an introduction to ARPs along with sufficient data to identify potentially effective ARPs and the target compounds these ARPs will be most effective in destroying. Further research will provide a detailed analysis of degradation kinetics and the mechanisms of contaminant destruction in an ARP. PMID:23840160

  20. Method for Fabricating Composite Structures Including Continuous Press Forming and Pultrusion Processing

    NASA Technical Reports Server (NTRS)

    Farley, Gary L. (Inventor)

    1995-01-01

    A method for fabricating composite structures at a low-cost, moderate-to-high production rate is disclosed. A first embodiment of the method includes employing a continuous press forming fabrication process. A second embodiment of the method includes employing a pultrusion process for obtaining composite structures. The methods include coating yarns with matrix material, weaving the yarn into fabric to produce a continuous fabric supply, and feeding multiple layers of net-shaped fabrics having optimally oriented fibers into a debulking tool to form an undebulked preform. The continuous press forming fabrication process includes partially debulking the preform, cutting the partially debulked preform, and debulking the partially debulked preform to form a netshape. An electron-beam or similar technique then cures the structure. The pultrusion fabric process includes feeding the undebulked preform into a heated die and gradually debulking the undebulked preform. The undebulked preform in the heated die changes dimension until a desired cross-sectional dimension is achieved. This process further includes obtaining a net-shaped infiltrated uncured preform, cutting the uncured preform to a desired length, and electron-beam curing (or similar technique) the uncured preform. These fabrication methods produce superior structures formed at higher production rates, resulting in lower cost and high structural performance.

  1. Advances in mask fabrication and alignment for masked ion-beam lithography

    NASA Astrophysics Data System (ADS)

    Stumbo, David P.; Damm, George A.; Engler, D. W.; Fong, F. O.; Sen, S.; Wolfe, John C.; Randall, John N.; Mauger, Phillip E.; Shimkunas, Alex R.; Loeschne, Hans

    1990-05-01

    This paper describes recent developments in three areas ofmasked ion beam lithography (MIBL). These are 1) fabrication oflarge area, low distortion, silicon stencilmasks for demagnifying ion projection lithography, 2) fabrication ofstencil masks with nanometer scale resolution for 1:1 proximity printing, and 3) development of a direct method of alignment using the ion beam induced fluorescence of Si02. These topics are discussed below. Demagnifying ion projection masks: We describe the fabrication of stencil masks in large area, low stress (10 MPa), n-type silicon membranes. The projection masks have a silicon foil area 95 mm in diameter, thicknesses between 1.5-5 and resolution of0.6um. Measured distortion (3a) in the IPL masks ranges between 0.23gm and 0.65,um, with an experimental error of 0.20 1um. Proximity printing masks: A process is described for fabricating stencil masks with 50 nm resolution in low stress, n-type silicon membranes. Membranes less than 0.5 ,ttm thick are shown to be free of the sidewall taper that limits resolution in thicker masks. These thin membranes show a slightly flared profile due to the imperfectly collimated etching ions. Alignment: A direct method of alignment is being developed which uses the ion beam induced fluorescence of Si02 marks. Fluorescence yield is characterized as a function of ion energy and resist coating thickness. The yield for Si02 is in the range between 0.1-1.0 photons/proton, while the yields for Si, Al, and photoresist are negligibly small. Thus, a simple alignment technique can be implemented where registration of a grating in the mask with a corresponding oxide pattern is detected as a fluorescence maximum. A simple model predicts that 50 nm alignment can be accomplished, following a 1 im prealignment, in 2 seconds.

  2. Silicon solar cell process development, fabrication, and analysis

    NASA Technical Reports Server (NTRS)

    Yoo, H. I.; Iles, P. A.; Leung, D. C.

    1980-01-01

    Solar cells from HEM, Dendritic Webs, and EFG ribbons were fabricated and characterized. The HEM solar cells showed only slight enhancement in cell performance after gettering steps (diffusion glass) were added. Dendritic webs from various growth runs indicated that performance of solar cells made from the webs was not as good as that of the conventional CZ cells. The EFG ribbons grown in CO ambient showed significant improvement in silicon quality.

  3. Design and fabrication of a 30 T superconducting solenoid using overpressure processed Bi2212 round wire

    SciTech Connect

    Flanagan, Gene; Johnson, Rolland

    2016-02-18

    High field superconducting magnets are used in particle colliders, fusion energy devices, and spectrometers for medical imaging and advanced materials research. Magnets capable of generating fields of 20-30 T are needed by future accelerator facilities. A 20-30 T magnet will require the use of high-temperature superconductors (HTS) and therefore the challenges of high field HTS magnet development need to be addressed. Superconducting Bi2Sr2CaCu2Ox (Bi2212) conductors fabricated by the oxide-powder-in-tube (OPIT) technique have demonstrated the capability to carry large critical current density of 105 A/cm2 at 4.2 K and in magnetic fields up to 45 T. Available in round wire multi-filamentary form, Bi2212 may allow fabrication of 20-50 T superconducting magnets. Until recently the performance of Bi2212 has been limited by challenges in realizing high current densities (Jc ) in long lengths. This problem now is solved by the National High Magnetic Field Lab using an overpressure (OP) processing technique, which uses external pressure to process the conductor. OP processing also helps remove the ceramic leakage that results when Bi-2212 liquid leaks out from the sheath material and reacts with insulation, coil forms, and flanges. Significant advances have also been achieved in developing novel insulation materials (TiO2 coating) and Ag-Al sheath materials that have higher mechanical strengths than Ag-0.2wt.% Mg, developing heat treatment approaches to broadening the maximum process temperature window, and developing high-strength, mechanical reinforced Bi-2212 cables. In the Phase I work, we leveraged these new opportunities to prototype overpressure processed solenoids and test them in background fields of up to 14 T. Additionally a design of a fully superconducting 30 T solenoid was produced. This work in conjunction with the future path outlined in the Phase II proposal would

  4. Novel magnetic wire fabrication process by way of nanoimprint lithography for current induced magnetization switching

    NASA Astrophysics Data System (ADS)

    Asari, Tsukasa; Shibata, Ryosuke; Awano, Hiroyuki

    2017-05-01

    Nanoimprint lithography (NIL) is an effective method to fabricate nanowire because it does not need expensive systems and this process is easier than conventional processes. In this letter, we report the Current Induced Magnetization Switching (CIMS) in perpendicularly magnetized Tb-Co alloy nanowire fabricated by NIL. The CIMS in Tb-Co alloy wire was observed by using current pulse under in-plane external magnetic field (HL). We successfully observed the CIMS in Tb-Co wire fabricated by NIL. Additionally, we found that the critical current density (Jc) for the CIMS in the Tb-Co wire fabricated by NIL is 4 times smaller than that fabricated by conventional lift-off process under HL = 200Oe. These results indicate that the NIL is effective method for the CIMS.

  5. Concurrent micromechanical tailoring and fabrication process optimization for metal-matrix composites

    NASA Technical Reports Server (NTRS)

    Morel, M.; Saravanos, D. A.; Chamis, Christos C.

    1990-01-01

    A method is presented to minimize the residual matrix stresses in metal matrix composites. Fabrication parameters such as temperature and consolidation pressure are optimized concurrently with the characteristics (i.e., modulus, coefficient of thermal expansion, strength, and interphase thickness) of a fiber-matrix interphase. By including the interphase properties in the fabrication process, lower residual stresses are achievable. Results for an ultra-high modulus graphite (P100)/copper composite show a reduction of 21 percent for the maximum matrix microstress when optimizing the fabrication process alone. Concurrent optimization of the fabrication process and interphase properties show a 41 percent decrease in the maximum microstress. Therefore, this optimization method demonstrates the capability of reducing residual microstresses by altering the temperature and consolidation pressure histories and tailoring the interphase properties for an improved composite material. In addition, the results indicate that the consolidation pressures are the most important fabrication parameters, and the coefficient of thermal expansion is the most critical interphase property.

  6. Combined micromechanical and fabrication process optimization for metal-matrix composites

    NASA Technical Reports Server (NTRS)

    Morel, M.; Saravanos, D. A.; Chamis, C. C.

    1991-01-01

    A method is presented to minimize the residual matrix stresses in metal matrix composites. Fabrication parameters such as temperature and consolidation pressure are optimized concurrently with the characteristics (i.e., modulus, coefficient of thermal expansion, strength, and interphase thickness) of a fiber-matrix interphase. By including the interphase properties in the fabrication process, lower residual stresses are achievable. Results for an ultra-high modulus graphite (P100)/copper composite show a reduction of 21 percent for the maximum matrix microstress when optimizing the fabrication process alone. Concurrent optimization of the fabrication process and interphase properties show a 41 percent decrease in the maximum microstress. Therefore, this optimization method demonstrates the capability of reducing residual microstresses by altering the temperature and consolidation pressure histories and tailoring the interphase properties for an improved composite material. In addition, the results indicate that the consolidation pressures are the most important fabrication parameters, and the coefficient of thermal expansion is the most critical interphase property.

  7. Hydrothermal fabrication of selectively doped organic assisted advanced ZnO nanomaterial for solar driven photocatalysis.

    PubMed

    Namratha, K; Byrappa, K; Byrappa, S; Venkateswarlu, P; Rajasekhar, D; Deepthi, B K

    2015-08-01

    Hydrothermal fabrication of selectively doped (Ag(+)+Pd(3+)) advanced ZnO nanomaterial has been carried out under mild pressure temperature conditions (autogeneous; 150°C). Gluconic acid has been used as a surface modifier to effectively control the particle size and morphology of these ZnO nanoparticles. The experimental parameters were tuned to achieve optimum conditions for the synthesis of selectively doped ZnO nanomaterials with an experimental duration of 4 hr. These selectively doped ZnO nanoparticles were characterized using powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), UV-Vis spectroscopy and scanning electron microscopy (SEM). The solar driven photocatalytic studies have been carried out for organic dyes, i.e., Procion MX-5B dye, Cibacron Brilliant Yellow dye, Indigo Carmine dye, separately and all three mixed, by using gluconic acid modified selectively doped advanced ZnO nanomaterial. The influence of catalyst, its concentration and initial dye concentration resulted in the photocatalytic efficiency of 89% under daylight. Copyright © 2015. Published by Elsevier B.V.

  8. Process development and fabrication for sphere-pac fuel rods. [PWR; BWR

    SciTech Connect

    Welty, R.K.; Campbell, M.H.

    1981-06-01

    Uranium fuel rods containing sphere-pac fuel have been fabricated for in-reactor tests and demonstrations. A process for the development, qualification, and fabrication of acceptable sphere-pac fuel rods is described. Special equipment to control fuel contamination with moisture or air and the equipment layout needed for rod fabrication is described and tests for assuring the uniformity of the fuel column are discussed. Fuel retainers required for sphere-pac fuel column stability and instrumentation to measure fuel column smear density are described. Results of sphere-pac fuel rod fabrication campaigns are reviewed and recommended improvements for high throughput production are noted.

  9. High performance mask fabrication process for the next-generation mask production

    NASA Astrophysics Data System (ADS)

    Yagawa, Keisuke; Ugajin, Kunihiro; Suenaga, Machiko; Kobayashi, Yoshihito; Motokawa, Takeharu; Hagihara, Kazuki; Saito, Masato; Itoh, Masamitsu

    2014-07-01

    ArF immersion lithography combined with double patterning has been used for fabricating below half pitch 40nm devices. However, when pattern size shrinks below 20nm, we must use new technology like quadruple patterning process or next generation lithography (NGL) solutions. Moreover, with change in lithography tool, next generation mask production will be needed. According to ITRS 2013, fabrication of finer patterns less than 15nm will be required on mask plate in NGL mask production 5 years later [1]. In order to fabricate finer patterns on mask, higher resolution EB mask writer and high performance fabrication process will be required. In a previous study, we investigated a potential of mask fabrication process for finer patterning and achieved 17nm dense line pattern on mask plate by using VSB (Variable Shaped Beam) type EB mask writer and chemically amplified resist [2][3]. After a further investigation, we constructed higher performance mask process by using new EB mask writer EBM9000. EBM9000 is the equipment supporting hp16nm generation's photomask production and has high accuracy and high throughput. As a result, we achieved 15.5nm pattern on mask with high productivity. Moreover, from evaluation of isolated pattern, we proved that current mask process has the capability for sub-10nm pattern. These results show that the performance of current mask fabrication process have the potential to fabricate the next-generation mask.

  10. New structure and fabrication process for thermal-type microsensors

    NASA Astrophysics Data System (ADS)

    Ji-song, Han; Kadowaki, Tadashi; Sato, Kazuo; Shikida, Mitsuhiro

    2001-09-01

    We describe the structure and fabrication of a one- dimensionally arrayed high density thermal-type micro fingerprint sensor. To provide thermal isolation, we designed and fabricated two sets of insulation cavities for each heater element, one for reducing the heat-transfer from the heater to the substrate, and the other one for that of heat to the wiring. The first set of cavities were etched under each heater bridge, leaving an SiO2 diaphragm with the heater bridge on it, and laterally penetrating with the cavities of neighboring heater bridges. The second ones were etched at the both ends of each heater element, leaving a set of SiO2- wiring bridges. This SiO2-wiring bridge structure was used as a thermal isolator when performing a metal-film wiring. The wiring (an electrical feed-through) was formed by a lift-off method, and runs on the SiO2 insulation surface from the heater element to the bonding pad through the SiO2-wiring bridges. The fabricated sensor device was made on a (100) SOI (silicon-on-insulator) wafer. Each heater element was 5 X 17 X 50 (micrometer3) with a pitch of 80 micrometer. Because of its small thermal capacity and effective thermal isolation, the sensor element was very sensitive. When a 0.4- V/20-microsecond pulse-voltage was applied to the heater elements, their resistance reached a steady maximum value in about 4 to approximately 5 microseconds. This level of sensitivity will be useful in variety of thermal sensors, such as micro temperature sensors and micro flow sensors, in addition to the thermal-type fingerprint sensors.

  11. Polymer laser fabricated by a simple micromolding process

    NASA Astrophysics Data System (ADS)

    Lawrence, Justin R.; Turnbull, Graham A.; Samuel, Ifor D. W.

    2003-06-01

    We report polymer distributed feedback lasers fabricated using solvent-assisted microcontact molding. The poly[2-methoxy-5-(3,7-dimethyloctyloxy) paraphenylenevinylene] film is patterned by placing it in conformal contact with an elastomeric mould inked with a suitable solvent. When the resulting microstructured film is pumped with the 532 nm pulsed output of a microchip laser, we observe lasing above a threshold pump energy of 225 nJ. Above threshold the emission narrows to a linewidth of less than 0.6 nm at a wavelength of 638 nm. This micromolding technique may find application to a wide range of wavelength-scale microstructured organic photonic devices.

  12. Development and fabrication of a solar cell junction processing system

    NASA Technical Reports Server (NTRS)

    Giesling, R.

    1981-01-01

    Modifications to the ground plane, to insure a good electrical return path during the pulse discharge, were made using a ring of beryllium copper finger stock attached to the underside of the aluminum ground plate. Experiments on annealing of wafers with ion implantation damage continued. The entire surface of 100 mm diameter wafers were annealed by one pulse for the standard implant (10 keV, phosphorus, 2x10 to the 15th power ions/sq cm). While samples are being fabricated into solar cells for electrical characterization, work is continuing on improvement of the electron beam uniformity and the optimization of the diode parameters. The engineering design was completed and the manufacturing detail drawings were released for fabrication. Assembly of the subcomponents for the exit and entrance locks is almost complete. These components include the cassettes, the indexing mechanisms, main doors, and wafer carrier transfer modules. The 'Y' track and three phase transition track sections are under final assembly and test.

  13. Development and fabrication of a solar cell junction processing system

    NASA Astrophysics Data System (ADS)

    Giesling, R.

    1981-07-01

    Modifications to the ground plane, to insure a good electrical return path during the pulse discharge, were made using a ring of beryllium copper finger stock attached to the underside of the aluminum ground plate. Experiments on annealing of wafers with ion implantation damage continued. The entire surface of 100 mm diameter wafers were annealed by one pulse for the standard implant (10 keV, phosphorus, 2x10 to the 15th power ions/sq cm). While samples are being fabricated into solar cells for electrical characterization, work is continuing on improvement of the electron beam uniformity and the optimization of the diode parameters. The engineering design was completed and the manufacturing detail drawings were released for fabrication. Assembly of the subcomponents for the exit and entrance locks is almost complete. These components include the cassettes, the indexing mechanisms, main doors, and wafer carrier transfer modules. The 'Y' track and three phase transition track sections are under final assembly and test.

  14. Project T.E.A.M. (Technical Education Advancement Modules). Advanced Statistical Process Control.

    ERIC Educational Resources Information Center

    Dunlap, Dale

    This instructional guide, one of a series developed by the Technical Education Advancement Modules (TEAM) project, is a 20-hour advanced statistical process control (SPC) and quality improvement course designed to develop the following competencies: (1) understanding quality systems; (2) knowing the process; (3) solving quality problems; and (4)…

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

    NASA Technical Reports Server (NTRS)

    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.

  16. Advanced fabrication techniques for hydrogen-cooled engine structures. Final report, October 1975-June 1982

    SciTech Connect

    Buchmann, O.A.; Arefian, V.V.; Warren, H.A.; Vuigner, A.A.; Pohlman, M.J.

    1985-11-01

    Described is a program for development of coolant passage geometries, material systems, and joining processes that will produce long-life hydrogen-cooled structures for scramjet applications. Tests were performed to establish basic material properties, and samples constructed and evaluated to substantiate fabrication processes and inspection techniques. Results of the study show that the basic goal of increasing the life of hydrogen-cooled structures two orders of magnitude relative to that of the Hypersonic Research Engine can be reached with available means. Estimated life is 19000 cycles for the channels and 16000 cycles for pin-fin coolant passage configurations using Nickel 201. Additional research is required to establish the fatigue characteristics of dissimilar-metal coolant passages (Nickel 201/Inconel 718) and to investigate the embrittling effects of the hydrogen coolant.

  17. Self-aligned single-mask fabrication process for electro-thermal microactuators using ICP-RIE

    NASA Astrophysics Data System (ADS)

    Alamin Dow, Ali B.; Gougam, Adel; Kherani, Nazir P.; Rangelow, I. W.

    2013-05-01

    Advances in the miniaturization of semiconductor devices have been made possible by new methods of microfabrication techniques . These advances have stimulated the birth of Micro Electro Mechanical Systems (MEMS) technology which enable the fabrication of a wide variety of sensing and actuating devices of microscopic dimensions . Of particular interest are thermal microactuators which provide large deflections and are compatible with existing IC technologies. In MEMS technology, a well controlled etching process is critical for the fabrication of structures with specific geometry and properties. Increasing demand for intricate semiconductor devices has fueled and motivated researches to develop high precision micromachining techniques . Inductively coupled plasma- Reactive ion etching (ICP-RIE) is capable of producing features with high aspect ratio as high as 90:1. Taking advantage of the notching effect when making a structure from silicon on insulator (SOI), structure release without the use of HF acid has been demonstrated. We report on the development of a self-aligned single-mask process for the fabrication of released and movable MEMS devices. ICP-RIE was used to realize the structures directly out of single crystal silicon. Applying side wall passivation, controlling the ratio of ion flux and radical flux, smooth etching profile can be obtained with high aspect ratio. No wet etching process is required to release the structures as is the case with SOI wafers. This approach overcomes the stiction limitation associated with wet etching and yields good thickness uniformity over the entire structure. Electrothermal microactuators with integrated microgrippers were designed, fabricated and characterized. harvesters.

  18. The multiphysics analysis of the metallic bipolar plate by the electrochemical micro-machining fabrication process

    NASA Astrophysics Data System (ADS)

    Lee, Yu-Ming; Lee, Shuo-Jen; Lee, Chi-Yuan; Chang, Dar-Yuan

    In this study, the flow channels of a PEM fuel cell are fabricated by the EMM process. The parametric effects of the process are studied by both numerical simulation and experimental tests. For the numerical simulation, the multiphysics model, consisting of electrical field, convection, and diffusion phenomena is applied using COMSOL software. COMSOL software is used to predict the parametric effects of the channel fabrication accuracy such as pulse rate, pulse duty cycle, inter-electrode gap and electrolytic inflow velocity. The proper experimental parameters and the relationship between the parameters and the distribution of metal removal are established from the simulated results. The experimental fabrication tests showed that a shorter pulse rate and a higher pulse current improved the fabrication accuracy, and is consistent with the numerical simulation results. The proposed simulation model could be employed as a predictive tool to provide optimal parameters for better machining accuracy and process stability of the EMM process.

  19. Recent advances in fabrication of high-T{sub c} superconductors for electric power applications.

    SciTech Connect

    Balachandran, U.

    1998-03-25

    The U.S. Department of Energy (DOE) supports an applied superconductivity program entitled ''Superconductivity Program for Electric Power Systems.'' Activities within this program contribute to development of the high-temperature superconductor (HTS) technology needed for industry to proceed with the commercial development of electric power applications such as motors, generators, transformers, transmission cables, and current limiters. Research is conducted in three categories: wire development, systems technology development, and Superconductivity Partnership Initiative (SPI). Wire development activities are devoted to improving the critical current density (J{sub c}) of short-length HTS wires, whereas systems technology development focuses on fabrication of long-length wires, coils, and on magnets. The SPI activities are aimed at development of prototype products. Significant progress has been made in the development of (HTSs) for various applications: some applications have already made significant strides in the marketplace, while others are still in the developmental stages. For successful electric power applications, it is very important that the HTS be fabricated into long-length conductors that exhibit desired superconducting and mechanical properties. Several parameters of the PIT technique must be carefully controlled to obtain the desired properties. Long lengths of Bi-2223 tapes with respectable superconducting properties have been fabricated by a carefully designed thermomechanical treatment process. A 1-MVA capacity fault current limiter, a 286-hp motor, and 630-kVA transformers, and a 50-m-long conductor, all using HTSs, have already been demonstrated. While the use of HTS devices in the electric utility area has clear advantages, impediments to successful commercialization remain. Issues such as AC losses, conductor cost, and reliable superconducting joints must be addressed. The cost of HTS conductors are still quite high, and significant R and D

  20. FABRICATE AND TEST AN ADVANCED NON-POLLUTING TURBINE DRIVE GAS GENERATOR

    SciTech Connect

    Eugene Baxter; Roger E. Anderson; Stephen E. Doyle

    2003-06-01

    In September 2000 the Department of Energy's National Energy Technology Laboratory (DOE/NETL) contracted with Clean Energy Systems, Inc. (CES) of Sacramento, California to design, fabricate, and test a 20 MW{sub t} (10 MW{sub e}) gas generator. Program goals were to demonstrate a non-polluting gas generator at temperatures up to 3000 F at 1500 psi, and to demonstrate resulting drive gas composition, comprising steam and carbon dioxide substantially free of pollutants. Following hardware design and fabrication, testing, originally planned to begin in the summer of 2001, was delayed by unavailability of the contracted test facility. CES designed, fabricated, and tested the proposed gas generator as originally agreed. The CES process for producing near-zero-emissions power from fossil fuels is based on the near-stoichiometric combustion of a clean gaseous fuel with oxygen in the presence of recycled water, to produce a high-temperature, high-pressure turbine drive fluid comprising steam and carbon dioxide. Tests demonstrated igniter operation over the prescribed ranges of pressure and mixture ratios. Ignition was repeatable and reliable through more than 100 ignitions. Injector design ''A'' was operated successfully at both low power ({approx}20% of rated power) and at rated power ({approx}20 MW{sub t}) in more than 95 tests. The uncooled gas generator configuration (no diluent injectors or cooldown chambers installed) produced drive gases at temperatures approaching 3000 F and at pressures greater than 1550 psia. The fully cooled gas generator configuration, with cooldown chambers and injector ''A'', operated consistently at pressures from 1100 to 1540 psia and produced high pressure, steam-rich turbine drive gases at temperatures ranging from {approx}3000 to as low as 600 F. This report includes description of the intended next steps in the gas generator technology demonstration and traces the anticipated pathway to commercialization for the gas generator technology

  1. Final Report - ADVANCED LASER-BASED SENSORS FOR INDUSTRIAL PROCESS CONTROL

    SciTech Connect

    Gupta, Manish; Baer, Douglas

    2013-09-30

    The objective of this work is to capture the potential of real-time monitoring and overcome the challenges of harsh industrial environments, Los Gatos Research (LGR) is fabricating, deploying, and commercializing advanced laser-based gas sensors for process control monitoring in industrial furnaces (e.g. electric arc furnaces). These sensors can achieve improvements in process control, leading to enhanced productivity, improved product quality, and reduced energy consumption and emissions. The first sensor will utilize both mid-infrared and near-infrared lasers to make rapid in-situ measurements of industrial gases and associated temperatures in the furnace off-gas. The second sensor will make extractive measurements of process gases. During the course of this DOE project, Los Gatos Research (LGR) fabricated, tested, and deployed both in-situ tunable diode laser absorption spectrometry (TDLAS) analyzers and extractive Off-Axis Integrated Cavity Output Spectroscopy (Off-Axis ICOS) analyzers.

  2. A novel fabrication process for out-of-plane microneedle sheets of biocompatible polymer

    NASA Astrophysics Data System (ADS)

    Han, Manhee; Hyun, Dong-Hun; Park, Hyoun-Hyang; Lee, Seung S.; Kim, Chang-Hyeon; Kim, Changgyou

    2007-06-01

    This paper presents a novel process for fabricating out-of-plane microneedle sheets of biocompatible polymer using in-plane microneedles. This process comprises four steps: (1) fabrication of in-plane microneedles using inclined UV lithography and electroforming, (2) conversion of the in-plane microneedles to an out-of-plane microneedle array, (3) fabrication of a negative PDMS mold and (4) fabrication of out-of-plane microneedle sheets of biocompatible polymer by hot embossing. The in-plane microneedles are fabricated with a sharp tip for low insertion forces and are made long to ensure sufficient penetration depth. The in-plane microneedles are converted into an out-of-plane microneedle array to increase the needle density. The negative mold is fabricated for mass-production using a polymer molding technique. The final out-of-plane microneedle sheets are produced using polycarbonate for biocompatibility by employing the hot embossing process. The height of the fabricated needles ranges from 500 to 1500 µm, and the distance between the needles is 500 to 2000 µm. The radii of curvature are approximately 2 µm, while the tip angles are in the range of 39-56°. Most of the geometrical characteristics of the out-of-plane microneedles can be freely controlled for real life applications such as drug delivery, cosmetic delivery and mesotherapy. Since it is also possible to mass-produce the microneedles, this novel process holds sufficient potential for applications in industrial fields.

  3. Advanced materials for geothermal energy processes

    SciTech Connect

    Kukacka, L.E.

    1985-08-01

    The primary goal of the geothermal materials program is to ensure that the private sector development of geothermal energy resources is not constrained by the availability of technologically and economically viable materials of construction. This requires the performance of long-term high risk GHTD-sponsored materials R and D. Ongoing programs described include high temperature elastomers for dynamic sealing applications, advanced materials for lost circulation control, waste utilization and disposal, corrosion resistant elastomeric liners for well casing, and non-metallic heat exchangers. 9 refs.

  4. Silicon Web Process Development. [for solar cell fabrication

    NASA Technical Reports Server (NTRS)

    Duncan, C. S.; Seidensticker, R. G.; Hopkins, R. H.; Mchugh, J. P.; Hill, F. E.; Heimlich, M. E.; Driggers, J. M.

    1979-01-01

    Silicon dendritic web, ribbon form of silicon and capable of fabrication into solar cells with greater than 15% AMl conversion efficiency, was produced from the melt without die shaping. Improvements were made both in the width of the web ribbons grown and in the techniques to replenish the liquid silicon as it is transformed to web. Through means of improved thermal shielding stress was reduced sufficiently so that web crystals nearly 4.5 cm wide were grown. The development of two subsystems, a silicon feeder and a melt level sensor, necessary to achieve an operational melt replenishment system, is described. A gas flow management technique is discussed and a laser reflection method to sense and control the melt level as silicon is replenished is examined.

  5. A batch process micromachined thermoelectric energy harvester: fabrication and characterization

    NASA Astrophysics Data System (ADS)

    Su, J.; Leonov, V.; Goedbloed, M.; van Andel, Y.; de Nooijer, M. C.; Elfrink, R.; Wang, Z.; Vullers, R. J. M.

    2010-10-01

    Micromachined thermopiles are considered as a cost-effective solution for energy harvesters working at a small temperature difference and weak heat flows typical for, e.g., the human body. They can be used for powering autonomous wireless sensor nodes in a body area network. In this paper, a micromachined thermoelectric energy harvester with 6 µm high polycrystalline silicon germanium (poly-SiGe) thermocouples fabricated on a 6 inch wafer is presented. An open circuit voltage of 1.49 V and an output power of 0.4 µW can be generated with 3.5 K temperature difference in a model of a wearable micromachined energy harvester of the discussed design, which has a die size of 1.0 mm × 2.5 mm inside a watch-size generator.

  6. Chemical mechanical polishing: An enabling fabrication process for surface micromachining technologies

    SciTech Connect

    Sniegowski, J.J.

    1998-08-01

    Chemical-mechanical polishing (CMP), once it is set-up and developed in a fabrication line can be readily adapted as a planarization technique for use in polysilicon surface micromachining technology. Although the planarization is a conceptually simple step, the benefit of its inclusion in the overall fabrication process is immense. Manufacturing impediments are removed while novel, expanded processes and designs become possible. The authors anticipate that CMP planarization, in the near future, will become a standard within the MEMS community for polysilicon surface micromachining. In addition, other MEMS fabrication technologies such as bulk micromachining and LIGA can potentially benefit from CMP.

  7. Improved transfer process for fabrication of cantilever with precise air-gap formation

    NASA Astrophysics Data System (ADS)

    Kanazawa, Shusuke; Kusaka, Yasuyuki; Yamamoto, Noritaka; Ushijima, Hirobumi

    2017-05-01

    In this paper, an improved transfer process to fabricate a cantilever structure with a precise air gap is reported. For this fabrication, a planar imprinting method was used and the drying conditions of the cantilever precursor ink were controlled. The air gap between the cantilevered top and bottom electrodes was formed with an estimated error of less than 3%. An operational force gauge with a changeable capacitance was obtained by applying a force to the cantilevered top electrode. This process can facilitate the eco-friendly fabrication of micro-devices with three-dimensional structures.

  8. Development and demonstration of manufacturing processes for fabricating graphite/PMR-15 polyimide structures

    NASA Technical Reports Server (NTRS)

    Sheppard, C. H.; Hoggatt, J. T.; Hunter, A. B.

    1979-01-01

    The work included establishing controls on the polymer, the prepreg, composite fabrication, and quality assurance, as well as fabrication of structural elements to demonstrate the developed materials and processes. The fabricated structures were hat sections, I-beam sections, honeycomb sandwich structures, and molded graphite-reinforced fittings. The graphite/PMR-15 polyimide system was shown to be well suited for use in the 550-600 F temperature range; the processing techniques developed were proved and found potentially useful for other commercially available systems.

  9. Direct coupled microwave thermal processing for photovoltaic device fabrication

    NASA Astrophysics Data System (ADS)

    Guidici, D. C.

    A microwave thermal processing technology has been developed which reduces cycle time and energy requirements for solar cell manufacture through the direct coupling of a tuned microwave field to the material processed. The microwave processing is shown to be feasible for both junction formation and metallization sintering; cells produced have an efficiency of 8%. Diffusion throughput is satisfactory if multiple wafer processing (coin stacks) is used. Metallization sintering throughput is, however, limited by the single wafer process capability, and another form of applicator would be necessary to make microwave heating economically attractive for this process.

  10. Advances in processing nuclear waste glasses

    SciTech Connect

    Plodinec, M J

    1988-01-01

    The vitrification of nuclear waste glasses is presenting unique challenges to glass technologists. On the one hand, the composition of the most important constituent of the glass batch/--/the waste/--/may vary widely. On the other hand, the vitrification process itself must be tightly controlled to ensure product quality, public safety, and process reliability. This has led to several important developments in waste vitrification technology, all aimed at improving process control. These include use of process models, use of artificial intelligence techniques, and improved control and measurement of glass redox. 19 refs., 2 figs., 2 tabs.

  11. Cost-Benefit Analysis for the Advanced Near Net Shape Technology (ANNST) Method for Fabricating Stiffened Cylinders

    NASA Technical Reports Server (NTRS)

    Ivanco, Marie L.; Domack, Marcia S.; Stoner, Mary Cecilia; Hehir, Austin R.

    2016-01-01

    Low Technology Readiness Levels (TRLs) and high levels of uncertainty make it challenging to develop cost estimates of new technologies in the R&D phase. It is however essential for NASA to understand the costs and benefits associated with novel concepts, in order to prioritize research investments and evaluate the potential for technology transfer and commercialization. This paper proposes a framework to perform a cost-benefit analysis of a technology in the R&D phase. This framework was developed and used to assess the Advanced Near Net Shape Technology (ANNST) manufacturing process for fabricating integrally stiffened cylinders. The ANNST method was compared with the conventional multi-piece metallic construction and composite processes for fabricating integrally stiffened cylinders. Following the definition of a case study for a cryogenic tank cylinder of specified geometry, data was gathered through interviews with Subject Matter Experts (SMEs), with particular focus placed on production costs and process complexity. This data served as the basis to produce process flowcharts and timelines, mass estimates, and rough order-of-magnitude cost and schedule estimates. The scalability of the results was subsequently investigated to understand the variability of the results based on tank size. Lastly, once costs and benefits were identified, the Analytic Hierarchy Process (AHP) was used to assess the relative value of these achieved benefits for potential stakeholders. These preliminary, rough order-of-magnitude results predict a 46 to 58 percent reduction in production costs and a 7-percent reduction in weight over the conventional metallic manufacturing technique used in this study for comparison. Compared to the composite manufacturing technique, these results predict cost savings of 35 to 58 percent; however, the ANNST concept was heavier. In this study, the predicted return on investment of equipment required for the ANNST method was ten cryogenic tank barrels

  12. Advanced fabrication of single-crystalline silver nanopillar on SiO{sub 2} substrate

    SciTech Connect

    Mori, Tomohiro E-mail: kenzo@eng.kagawa-u.ac.jp; Tanaka, Yasuhiro; Suzaki, Yoshifumi; Yamaguchi, Kenzo E-mail: kenzo@eng.kagawa-u.ac.jp

    2016-01-25

    Nanoscale crystallographic textures have received very little attention in research on surface plasmons using metallic nanostructures. A single-crystalline metallic nanostructure with a controlled crystallographic texture is expected to reduce optical losses. We elucidated the grain growth mechanism in silver thin films deposited on a highly transparent SiO{sub 2} substrate by electron backscatter diffraction methods with nanoscale resolution. At higher substrate temperatures, the grain growth was facilitated but the preferred orientation was not achieved. Moreover, we fabricated a single-crystalline silver nanopillar in a (111)-oriented large growing grain, which was controlled by varying the substrate temperature during film deposition by focused ion-beam milling. Furthermore, the light intensity of the scattering spectrum was measured for a single-crystalline silver nanopillar (undersurface diameter: 200 nm) for which surface plasmon resonance was observed. The single-crystalline silver nanopillar exhibits a stronger and sharper spectrum than the polycrystalline silver nanopillar. These results can be applied to the direct fabrication of a single-crystalline silver nanopillar using only physical processing.

  13. A fabrication process for a 580ps 4 Kbit Josephson non-destructive read-out RAM

    SciTech Connect

    Ishida, I.; Tahara, S.; Hidaka, M.; Nagasawa, S.; Tsuchida, S.; Wada, Y. )

    1991-03-01

    This paper reports on the development of a 4 Kbit Josephson non-destructive read-out (NDRO) random access memory (RAM). A process for fabricating the 580 ps 4 Kbit Josephson NDRO RAM is described that is based primarily on the use of Nb/AlOx/Nb technology and state-of-the-art planarization. The process has evolved from 1 Kbit Josephson NDRO RAM previously reported, with changes having occurred in a memory cell structure, a multilevel construction, layer planarization and minimum design rules. Advanced memory cells having 2 stacked superconducting, layer planarization and minimum design rules. Advanced memory cells having 2 stacked superconducting loops on which control lines are prepared are formed on ground plane insulation layers.

  14. Self-Assembling Process for Fabricating Tailored Thin Films

    ScienceCinema

    Sandia

    2016-07-12

    A simple, economical nanotechnology coating process that enables the development of nanoparticle thin films with architectures and properties unattainable by any other processing method. 2007 R&D 100 winner (SAND2007-1878P)

  15. Self-Assembling Process for Fabricating Tailored Thin Films

    SciTech Connect

    2008-07-31

    A simple, economical nanotechnology coating process that enables the development of nanoparticle thin films with architectures and properties unattainable by any other processing method. 2007 R&D 100 winner (SAND2007-1878P)

  16. Advanced algorithms and architectures for signal processing III

    SciTech Connect

    Luk, F.T.

    1988-01-01

    This book covers proceedings on advanced algorithms and architectures for signal processing III. Topics covered include: Fast QR-based array-processing algorithm; Model for the analysis of fault-tolerant signal processing architecture; Parallel VLSI direction finding algorithm; and Self-calibration techniques for high-resolution array processing.

  17. Improved Design of Optical MEMS Using the SUMMiT Fabrication Process

    SciTech Connect

    Michalicek, M.A.; Comtois, J.H.; Barron, C.C.

    1997-12-31

    This paper describes the design and fabrication of optical Microelectromechanical Systems (MEMS) devices using the Sandia Ultra planar Multilevel MEMS Technology (SUMMiT) fabrication process. This state of the art process, offered by Sandia National Laboratories, provides unique and very advantageous features which make it ideal for optical devices. This enabling process permits the development of micromirror devices with near ideal characteristics which have previously been unrealizable in standard polysilicon processes. This paper describes such characteristics as elevated address electrodes, individual address wiring beneath the device, planarized mirror surfaces, unique post-process metallization, and the best active surface area to date.

  18. Fabrication of the Advanced X-ray Astrophysics Facility (AXAF) Optics: A Deterministic, Precision Engineering Approach to Optical Fabrication

    NASA Technical Reports Server (NTRS)

    Gordon, T. E.

    1995-01-01

    The mirror assembly of the AXAF observatory consists of four concentric, confocal, Wolter type 1 telescopes. Each telescope includes two conical grazing incidence mirrors, a paraboloid followed by a hyperboloid. Fabrication of these state-or-the-art optics is now complete, with predicted performance that surpasses the goals of the program. The fabrication of these optics, whose size and requirements exceed those of any previous x-ray mirrors, presented a challenging task requiring the use of precision engineering in many different forms. Virtually all of the equipment used for this effort required precision engineering. Accurate metrology required deterministic support of the mirrors in order to model the gravity distortions which will not be present on orbit. The primary axial instrument, known as the Precision Metrology Station (PMS), was a unique scanning Fizeau interferometer. After metrology was complete, the optics were placed in specially designed Glass Support Fixtures (GSF's) for installation on the Automated Cylindrical Grinder/Polishers (ACG/P's). The GSF's were custom molded for each mirror element to match the shape of the outer surface to minimize distortions of the inner surface. The final performance of the telescope is expected to far exceed the original goals and expectations of the program.

  19. Recent advances in imaging subcellular processes

    PubMed Central

    Myers, Kenneth A.; Janetopoulos, Christopher

    2016-01-01

    Cell biology came about with the ability to first visualize cells. As microscopy techniques advanced, the early microscopists became the first cell biologists to observe the inner workings and subcellular structures that control life. This ability to see organelles within a cell provided scientists with the first understanding of how cells function. The visualization of the dynamic architecture of subcellular structures now often drives questions as researchers seek to understand the intricacies of the cell. With the advent of fluorescent labeling techniques, better and new optical techniques, and more sensitive and faster cameras, a whole array of questions can now be asked. There has been an explosion of new light microscopic techniques, and the race is on to build better and more powerful imaging systems so that we can further our understanding of the spatial and temporal mechanisms controlling molecular cell biology. PMID:27408708

  20. Recent advances in imaging subcellular processes.

    PubMed

    Myers, Kenneth A; Janetopoulos, Christopher

    2016-01-01

    Cell biology came about with the ability to first visualize cells. As microscopy techniques advanced, the early microscopists became the first cell biologists to observe the inner workings and subcellular structures that control life. This ability to see organelles within a cell provided scientists with the first understanding of how cells function. The visualization of the dynamic architecture of subcellular structures now often drives questions as researchers seek to understand the intricacies of the cell. With the advent of fluorescent labeling techniques, better and new optical techniques, and more sensitive and faster cameras, a whole array of questions can now be asked. There has been an explosion of new light microscopic techniques, and the race is on to build better and more powerful imaging systems so that we can further our understanding of the spatial and temporal mechanisms controlling molecular cell biology.

  1. Site-controlled and advanced epitaxial Ge/Si quantum dots: fabrication, properties, and applications

    NASA Astrophysics Data System (ADS)

    Brehm, Moritz; Grydlik, Martyna

    2017-09-01

    In this review, we report on fabrication paths, challenges, and emerging solutions to integrate group-IV epitaxial quantum dots (QDs) as active light emitters into the existing standard Si technology. Their potential as laser gain material for the use of optical intra- and inter-chip interconnects as well as possibilities to combine a single-photon-source-based quantum cryptographic means with Si technology will be discussed. We propose that the mandatory addressability of the light emitters can be achieved by a combination of organized QD growth assisted by templated self-assembly, and advanced inter-QD defect engineering to boost the optical emissivity of group-IV QDs at room-temperature. Those two main parts, the site-controlled growth and the light emission enhancement in QDs through the introduction of single defects build the main body of the review. This leads us to a roadmap for the necessary further development of this emerging field of CMOS-compatible group-IV QD light emitters for on-chip applications.

  2. Design, fabrication and test of graphite/polyimide composite joints and attachments for advanced aerospace vehicles

    NASA Technical Reports Server (NTRS)

    Barclay, D. L.

    1980-01-01

    Results of an experimental program to develop several types of graphite/polyimide (GR/PI) bonded and bolted joints for lightly loaded flight components for advanced space transportation systems and high speed aircraft are presented. Tasks accomplished include: a literature survey; design of static discriminator specimens; design allowables testing; fabrication of test panels and specimens; small specimen testing; and standard joint testing. Detail designs of static discriminator specimens for each of the four major attachment types are presented. Test results are given for the following: (1) transverse tension of Celion 3000/PMR-15 laminate; (2) net tension of a laminate for both a loaded and unloaded bolt hole; (3) comparative testing of bonded and co-cured doublers along with pull-off tests of single and double bonded angles; (4) single lap shear tests, transverse tension and coefficient of thermal expansion tests of A7F (LARC-13 amide-imide modified) adhesive; and (5) tension tests of standard single lap, double lap, and symmetric step lap bonded joints. Also, included are results of a finite element analysis of a single lap bonded composite joint.

  3. CARs blanks feasibility study results for advanced EB reticle fabrication: III

    NASA Astrophysics Data System (ADS)

    Hashimoto, Masahiro; Ohta, Fumiko; Yokoya, Yasunori; Kobayashi, Hideo

    2001-09-01

    For advanced EB reticle fabrication with CAR blanks, we have been trying blanks life improvement and resolution enhancement. This paper describes several options to extend CAR blanks life by shipping package and storage manners. Dry-N2 purged shipping package and desiccant showed efficiency for PCD improvement. However, desiccant is not available for products since it is not investigated yet if particle contamination could be happened. To extend blanks life after blanks package opened, we blanks maker really recommend the fresh dry-N2 purged box (overflowed) as an ideal storage manner, or regular shipping box storage at least. We tried a BARC as isolator and thinning CAR for resolution enhancement, and found that a neutral-BARC showed an improvement. However, we needs further study about its feasibility, especially for coating uniformity and defect quality control. Thin resist showed almost no improvement for CAR resolution enhancement. To improve CAR performance further, we continuously need the resist-makers cooperation to design and develop a CAR that provides us footing-less pattern profile and long-life after coating.

  4. Site-controlled and advanced epitaxial Ge/Si quantum dots: fabrication, properties, and applications.

    PubMed

    Brehm, Moritz; Grydlik, Martyna

    2017-09-29

    In this review, we report on fabrication paths, challenges, and emerging solutions to integrate group-IV epitaxial quantum dots (QDs) as active light emitters into the existing standard Si technology. Their potential as laser gain material for the use of optical intra- and inter-chip interconnects as well as possibilities to combine a single-photon-source-based quantum cryptographic means with Si technology will be discussed. We propose that the mandatory addressability of the light emitters can be achieved by a combination of organized QD growth assisted by templated self-assembly, and advanced inter-QD defect engineering to boost the optical emissivity of group-IV QDs at room-temperature. Those two main parts, the site-controlled growth and the light emission enhancement in QDs through the introduction of single defects build the main body of the review. This leads us to a roadmap for the necessary further development of this emerging field of CMOS-compatible group-IV QD light emitters for on-chip applications.

  5. Modeling and Advanced Control for Sustainable Process ...

    EPA Pesticide Factsheets

    This book chapter introduces a novel process systems engineering framework that integrates process control with sustainability assessment tools for the simultaneous evaluation and optimization of process operations. The implemented control strategy consists of a biologically-inspired, multi-agent-based method. The sustainability and performance assessment of process operating points is carried out using the U.S. E.P.A.’s GREENSCOPE assessment tool that provides scores for the selected economic, material management, environmental and energy indicators. The indicator results supply information on whether the implementation of the controller is moving the process towards a more sustainable operation. The effectiveness of the proposed framework is illustrated through a case study of a continuous bioethanol fermentation process whose dynamics are characterized by steady-state multiplicity and oscillatory behavior. This book chapter contribution demonstrates the application of novel process control strategies for sustainability by increasing material management, energy efficiency, and pollution prevention, as needed for SHC Sustainable Uses of Wastes and Materials Management.

  6. Bioinspired superhydrophobic surfaces, fabricated through simple and scalable roll-to-roll processing

    PubMed Central

    Park, Sung-Hoon; Lee, Sangeui; Moreira, David; Bandaru, Prabhakar R.; Han, InTaek; Yun, Dong-Jin

    2015-01-01

    A simple, scalable, non-lithographic, technique for fabricating durable superhydrophobic (SH) surfaces, based on the fingering instabilities associated with non-Newtonian flow and shear tearing, has been developed. The high viscosity of the nanotube/elastomer paste has been exploited for the fabrication. The fabricated SH surfaces had the appearance of bristled shark skin and were robust with respect to mechanical forces. While flow instability is regarded as adverse to roll-coating processes for fabricating uniform films, we especially use the effect to create the SH surface. Along with their durability and self-cleaning capabilities, we have demonstrated drag reduction effects of the fabricated films through dynamic flow measurements. PMID:26490133

  7. The effects of process parameters on injection-molded PZT ceramics part fabrication- compounding process rheology.

    SciTech Connect

    Halbleib, Laura L.; Yang, Pin; Mondy, Lisa Ann; Burns, George Robert

    2005-05-01

    Solid solutions of lead-based perovskites are the backbone materials of the piezoelectric components for transducer, actuator, and resonator applications. These components, typically small in size, are fabricated from large sintered ceramic slugs using grinding and lapping processes. These operations increase manufacturing costs and produce a large hazardous waste stream, especially when component size decreases. To reduce costs and hazardous wastes associated with the production of these components, an injection molding technique is being investigated to replace the machining processes. The first step in the new technique is to compound an organic carrier with a ceramic powder. The organic carrier is a thermoplastic based system composed of a main carrier, a binder, and a surfactant. Understanding the rheology of the compounded material is necessary to minimize the creation of defects such as voids or cavities during the injection-molding process. An experiment was performed to model the effects of changes in the composition and processing of the material on the rheological behavior. Factors studied included: the surfactant of the organic carrier system, the solid loading of the compounded material, and compounding time. The effects of these factors on the viscosity of the material were investigated.

  8. Challenge to advanced materials processing with lasers in Japan

    NASA Astrophysics Data System (ADS)

    Miyamoto, Isamu

    2003-02-01

    Japan is one of the most advanced countries in manufacturing technology, and lasers have been playing an important role for advancement of manufacturing technology in a variety of industrial fields. Contribution of laser materials processing to Japanese industry is significant for both macroprocessing and microprocessing. The present paper describes recent trend and topics of industrial applications in terms of the hardware and the software to show how Japanese industry challenges to advanced materials processing using lasers, and national products related to laser materials processing are also briefly introduced.

  9. DESIGN, FABRICATION, AND TESTING OF AN ADVANCED, NON-POLLUTING TURBINE DRIVE GAS GENERATOR

    SciTech Connect

    Unknown

    2001-10-30

    The objectives of this report period were to continue the development of the Gas Generator design, to complete the hardware and ancillary hardware fabrication, and commence the Test Preparations for the testing of the non-polluting unique power turbine drive gas generator. Focus during this report period has been on testing the Gas Generator. Because of unacceptable delays encountered in a previously competitively selected test site, CES initiated a re-competition of our testing program and selected an alternate test site. Following that selection, CES used all available resources to make preparations for testing the 10 Mw Gas Generator at the new testing site facilities of NTS at Saugus, CA. A substantial portion of this report period was devoted to Testing Preparations, i.e. test facility development, cold- flow testing, calibration testing, performing igniter ignition testing, and then commencement of the completely assembled Gas Generator Assembly Testing, in process at this writing.

  10. Understanding anisotropic plasma etching of two-dimensional polystyrene opals for advanced materials fabrication.

    PubMed

    Akinoglu, Eser M; Morfa, Anthony J; Giersig, Michael

    2014-10-21

    Anisotropic deformation of polystyrene particles in an oxygenated (O2/Ar) plasma is observed for radio frequency (rf) plasma and inductively coupled plasma (ICP). A facile model based on a ratio of completely isotropic and completely anisotropic etching is presented to describe the anisotropy of the etching process and is implemented to determine the height of the spheroid-shaped polystyrene particles. In our systems, we find the plasma etching to be 54% isotropic in the rf plasma and 79% isotropic in the ICP. With this model, the maximum material deposition thickness for nanofabrication with plasma-etched nanosphere lithography or colloid lithography can be predicted. Moreover, the etching of polystyrene particles in an oxygenated plasma is investigated versus the etching time, gas flow, gas composition, temperature, substrate material, and particle size. The results of this study allow precise shape tuning during the fabrication of nanostructured surfaces with size-dependent properties for bionic, medical, and photonic applications.

  11. Screen printing of a capacitive cantilever-based motion sensor on fabric using a novel sacrificial layer process for smart fabric applications

    NASA Astrophysics Data System (ADS)

    Wei, Yang; Torah, Russel; Yang, Kai; Beeby, Steve; Tudor, John

    2013-07-01

    Free-standing cantilevers have been fabricated by screen printing sacrificial and structural layers onto a standard polyester cotton fabric. By printing additional conductive layers, a complete capacitive motion sensor on fabric using only screen printing has been fabricated. This type of free-standing structure cannot currently be fabricated using conventional fabric manufacturing processes. In addition, compared to conventional smart fabric fabrication processes (e.g. weaving and knitting), screen printing offers the advantages of geometric design flexibility and the ability to simultaneously print multiple devices of the same or different designs. Furthermore, a range of active inks exists from the printed electronics industry which can potentially be applied to create many types of smart fabric. Four cantilevers with different lengths have been printed on fabric using a five-layer structure with a sacrificial material underneath the cantilever. The sacrificial layer is subsequently removed at 160 °C for 30 min to achieve a freestanding cantilever above the fabric. Two silver electrodes, one on top of the cantilever and the other on top of the fabric, are used to capacitively detect the movement of the cantilever. In this way, an entirely printed motion sensor is produced on a standard fabric. The motion sensor was initially tested on an electromechanical shaker rig at a low frequency range to examine the linearity and the sensitivity of each design. Then, these sensors were individually attached to a moving human forearm to evaluate more representative results. A commercial accelerometer (Microstrain G-link) was mounted alongside for comparison. The printed sensors have a similar motion response to the commercial accelerometer, demonstrating the potential of a printed smart fabric motion sensor for use in intelligent clothing applications.

  12. The National Shipbuilding Research Program. Automated Process Application in Steel Fabrication and Subassembly Facilities; Phase I (Process Analysis)

    DTIC Science & Technology

    1999-05-01

    6 Automated Process Application in Steel Fabrication and Subassembly Facilities; Phase I ( Process Analysis ) U.S. DEPARTMENT OF THE NAVY CARDEROCK...Subassembly Facilities; Phase I ( Process Analysis ) 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e

  13. Electrokinetic soil remediation: Advances and process enhancement

    SciTech Connect

    Hodko, D.; Franaszczuk, K.; Rogers, T.D.

    1995-12-31

    Electrokinetic remediation is an in situ emerging technology that offers potential cost and process benefits for contaminated soil treatment. The innovative approach under development at Lynntech, Inc. is based on the application of nonhomogeneous pulsed DC or AC electric fields with the objective to maximize rates of contaminant removal. The process combines several DC and AC electrokinetic phenomena occurring in soil when pulsed electric fields are applied across the electrodes positioned in the soil and utilize them for an enhanced contaminant removal from soil. Removal of contaminants is achieved by: (i) electroosmotic pore fluid flow; (ii) electromigration of anionic and cationic contaminants towards electrode wells, where they can be removed by electrodeposition, and, (iii) dielectrophoretically induced pore fluid flow and migration of charged and noncharged contaminants through the soil. Successful combination of DC and AC electrokinetic phenomena in soil presents a basis for an enhanced electrokinetic process for removal of both charged and noncharged contaminants from soil. The process utilizes an electrochemically produced acid in the anode well which propagates through the soil and solubilizes heavy metal ions in the pore fluid. An appropriate leachant. which depends on the type of soil and heavy metal contaminant, is electrokinetically delivered and distributed in soil to further enhance solubilization and mobilization of heavy metal contaminants through the soil. It can be efficiently combined with other existing in situ contaminated soil treatment processes, e.g. bioremediation, soil extraction and soil washing. A field scale study is initiated in 1995 and preliminary results will be described.

  14. A Course on Plasma Processing in Integrated Circuit Fabrication.

    ERIC Educational Resources Information Center

    Sawin, Herbert H.; Reif, Rafael

    1983-01-01

    Describes a course, taught jointly by electrical/chemical engineering departments at the Massachusetts Institute of Technology, designed to teach the fundamental science of plasma processing as well as to give an overview of the present state of industrial processes. Provides rationale for course development, texts used, class composition, and…

  15. A Course on Plasma Processing in Integrated Circuit Fabrication.

    ERIC Educational Resources Information Center

    Sawin, Herbert H.; Reif, Rafael

    1983-01-01

    Describes a course, taught jointly by electrical/chemical engineering departments at the Massachusetts Institute of Technology, designed to teach the fundamental science of plasma processing as well as to give an overview of the present state of industrial processes. Provides rationale for course development, texts used, class composition, and…

  16. Primary processes in sensory cells: current advances.

    PubMed

    Frings, Stephan

    2009-01-01

    In the course of evolution, the strong and unremitting selective pressure on sensory performance has driven the acuity of sensory organs to its physical limits. As a consequence, the study of primary sensory processes illustrates impressively how far a physiological function can be improved if the survival of a species depends on it. Sensory cells that detect single-photons, single molecules, mechanical motions on a nanometer scale, or incredibly small fluctuations of electromagnetic fields have fascinated physiologists for a long time. It is a great challenge to understand the primary sensory processes on a molecular level. This review points out some important recent developments in the search for primary processes in sensory cells that mediate touch perception, hearing, vision, taste, olfaction, as well as the analysis of light polarization and the orientation in the Earth's magnetic field. The data are screened for common transduction strategies and common transduction molecules, an aspect that may be helpful for researchers in the field.

  17. Fabrication of Bacteria Environment Cubes with Dry Lift-Off Fabrication Process for Enhanced Nitrification

    PubMed Central

    Pishko, Michael; Kameoka, Jun

    2016-01-01

    We have developed a 3D dry lift-off process to localize multiple types of nitrifying bacteria in polyethylene glycol diacrylate (PEGDA) cubes for enhanced nitrification, a two-step biological process that converts ammonium to nitrite and then to nitrate. Ammonia-oxidizing bacteria (AOB) is responsible for converting ammonia into nitrite, and nitrite-oxidizing bacteria (NOB) is responsible for converting nitrite to nitrate. Successful nitrification is often challenging to accomplish, in part because AOB and NOB are slow growers and highly susceptible to many organic and inorganic chemicals in wastewater. Most importantly, the transportation of chemicals among scattered bacteria is extremely inefficient and can be problematic. For example, nitrite, produced from ammonia oxidation, is toxic to AOB and can lead to the failure of nitrification. To address these challenges, we closely localize AOB and NOB in PEGDA cubes as microenvironment modules to promote synergetic interactions. The AOB is first localized in the vicinity of the surface of the PEGDA cubes that enable AOB to efficiently uptake ammonia from a liquid medium and convert it into nitrite. The produced nitrite is then efficiently transported to the NOB localized at the center of the PEGDA particle and converted into non-toxic nitrate. Additionally, the nanoscale PEGDA fibrous structures offer a protective environment for these strains, defending them from sudden toxic chemical shocks and immobilize in cubes. This engineered microenvironment cube significantly enhances nitrification and improves the overall ammonia removal rate per single AOB cell. This approach—encapsulation of multiple strains at close range in cube in order to control their interactions—not only offers a new strategy for enhancing nitrification, but also can be adapted to improve the production of fermentation products and biofuel, because microbial processes require synergetic reactions among multiple species. PMID:27812154

  18. Fabrication of Bacteria Environment Cubes with Dry Lift-Off Fabrication Process for Enhanced Nitrification.

    PubMed

    Samarasinghe, S A P L; Shao, Yiru; Huang, Po-Jung; Pishko, Michael; Chu, Kung-Hui; Kameoka, Jun

    2016-01-01

    We have developed a 3D dry lift-off process to localize multiple types of nitrifying bacteria in polyethylene glycol diacrylate (PEGDA) cubes for enhanced nitrification, a two-step biological process that converts ammonium to nitrite and then to nitrate. Ammonia-oxidizing bacteria (AOB) is responsible for converting ammonia into nitrite, and nitrite-oxidizing bacteria (NOB) is responsible for converting nitrite to nitrate. Successful nitrification is often challenging to accomplish, in part because AOB and NOB are slow growers and highly susceptible to many organic and inorganic chemicals in wastewater. Most importantly, the transportation of chemicals among scattered bacteria is extremely inefficient and can be problematic. For example, nitrite, produced from ammonia oxidation, is toxic to AOB and can lead to the failure of nitrification. To address these challenges, we closely localize AOB and NOB in PEGDA cubes as microenvironment modules to promote synergetic interactions. The AOB is first localized in the vicinity of the surface of the PEGDA cubes that enable AOB to efficiently uptake ammonia from a liquid medium and convert it into nitrite. The produced nitrite is then efficiently transported to the NOB localized at the center of the PEGDA particle and converted into non-toxic nitrate. Additionally, the nanoscale PEGDA fibrous structures offer a protective environment for these strains, defending them from sudden toxic chemical shocks and immobilize in cubes. This engineered microenvironment cube significantly enhances nitrification and improves the overall ammonia removal rate per single AOB cell. This approach-encapsulation of multiple strains at close range in cube in order to control their interactions-not only offers a new strategy for enhancing nitrification, but also can be adapted to improve the production of fermentation products and biofuel, because microbial processes require synergetic reactions among multiple species.

  19. Advanced processes for metallurgical coke. [Comparative evaluations

    SciTech Connect

    Straus, R.W.; Carsey, J.N.; von Bismarck, G.; Fujishima, C.

    1980-12-01

    This contract required Galaxy to examine overseas coking processes which can reduce the cost of metallurgical coke, while meeting pollution standards of the US. To approach this task properly, it was necessary to begin with a review of the basic data on the US steel industry. Experts tell Galaxy that over half of the US coke oven capacity is over or near retirement. This means replacement which has to be done in the face of a depressed industry. But it is necessary to compete with foreign steel producers who are going ahead with improvements. Thus, without new and more energy effective coke processes, which can cut cost, the US steel industry faces further recessions in the years ahead. The Japanese, the Germans, the French, and the Russians, as well as the US, are all conducting research on improved processes in the following categories: those which can use lower grades and cheaper coals as feedstocks; those which obtain higher energy efficiencies by recapturing heat now lost; those that will meet the increasingly stringent pollution control standards in the US; or processes, or combinations thereof, which reduce the coke rate per ton of steel. The advantages of the overseas processes are shown by the rather spectacular rise in US imports of coke which in less than a decade have risen from less than 200,000 tons to almost 4 million tons per year. The report details what the major countries, Japan, Germany, and France are doing, their expectations for reducing costs, using less costly coals, cutting emissions and developing auxiliary processes. Our experts agree that progress is evolutionary rather than revolutionary.

  20. Study on advanced information processing system

    NASA Technical Reports Server (NTRS)

    Shin, Kang G.; Liu, Jyh-Charn

    1992-01-01

    Issues related to the reliability of a redundant system with large main memory are addressed. In particular, the Fault-Tolerant Processor (FTP) for Advanced Launch System (ALS) is used as a basis for our presentation. When the system is free of latent faults, the probability of system crash due to nearly-coincident channel faults is shown to be insignificant even when the outputs of computing channels are infrequently voted on. In particular, using channel error maskers (CEMs) is shown to improve reliability more effectively than increasing the number of channels for applications with long mission times. Even without using a voter, most memory errors can be immediately corrected by CEMs implemented with conventional coding techniques. In addition to their ability to enhance system reliability, CEMs--with a low hardware overhead--can be used to reduce not only the need of memory realignment, but also the time required to realign channel memories in case, albeit rare, such a need arises. Using CEMs, we have developed two schemes, called Scheme 1 and Scheme 2, to solve the memory realignment problem. In both schemes, most errors are corrected by CEMs, and the remaining errors are masked by a voter.

  1. Advanced processing and properties of superhard materials

    SciTech Connect

    Narayan, J.

    1995-06-01

    The author reviews fundamental aspects of Superhard Materials with hardness close to that of diamond. These materials include cubic boron nitride (c-BN), carbon nitride ({beta}-C{sub 3}N{sub 4}) and diamondlike carbon. Since these materials are metastable at normal temperatures and pressures, novel methods of synthesis and processing of these materials are required. This review focuses on synthesis and processing, detailed materials characterization and properties of c-BN and {beta}C{sub 3}N{sub 4} and diamondlike carbon films.

  2. Advanced Digital Signal Processing for Hybrid Lidar

    DTIC Science & Technology

    2014-10-30

    microcontroller board is used to control a laser scanner. A MATLAB program collects data at each pixel and constructs both amplitude and range images...development of signed processing algorithms for hybrid lidar- radar designed to improve detection performance. 15. SUBJECT TERMS Hybrid Lidar - Radar 16...hardware implementation and underwater channel characteristics. Tecfinical Approach A significant challenge in hybrid lidar- radar is optical

  3. Cold plasma processing technology makes advances

    USDA-ARS?s Scientific Manuscript database

    Cold plasma (AKA nonthermal plasma, cool plasma, gas plasma, etc.) is a rapidly maturing antimicrobial process being developed for applications in the food industry. A wide array of devices can be used to create cold plasma, but the defining characteristic is that they operate at or near room temper...

  4. Advanced Fuels and Combustion Processes for Propulsion

    DTIC Science & Technology

    2010-09-01

    production from biomass steam reforming – Conduct a feasibility analysis of the proposed integrated process Energia Technologies - D. Nguyen & K. Parimi...strength foam material development by Ultramet – Combustion experiments performed U. Of Alabama – End-user input provided by Solar Turbines Major

  5. [Cerebellar contribution to cognitive process: current advances].

    PubMed

    Tirapu-Ustarroz, J; Luna-Lario, P; Iglesias-Fernandez, M D; Hernaez-Goni, P

    2011-09-01

    The cerebellum has traditionally been considered a neuronal system which is an essential part of coordination and motor control. However, in recent decades the idea of the cerebellum as an organ related to high level cognitive processes has gained strength, a claim supported by studies carried out on animals and humans with cerebellar lesions such as the contribution of modern neuroimaging techniques. The contribution of the cerebellum is reviewed in different cognitive functions such as the regulation of motor functions, attention, language, visuoconstructional skills, learning, memory and executive functions. The results of said review produce, as the most clarifying data, the influence of the cerebellum on processes such as attention, working memory (covert articulation) and verbal fluency as well as procedural learning. The results found regarding the cerebellum and the executive functions are not conclusive. We consider it necessary to systematize the table that has already been outlined. This will enable us to answer not only the question of whether the cerebellum plays a role in human cognition but which is its role. Perhaps the basis for understanding the cognitive functions of the cerebellum are not found in the fact that the cerebellum contains functions but that it relates the intention to the action in the emotional as well as the behavioural cognitive plane although the role of 'interface' is found closer to the output processes than processing of functions with a motor component.

  6. Advances in Neural Information Processing Systems

    NASA Astrophysics Data System (ADS)

    Jordan, Michael I.; Lecun, Yann; Solla, Sara A.

    2001-11-01

    The annual conference on Neural Information Processing Systems (NIPS) is the flagship conference on neural computation. The conference is interdisciplinary, with contributions in algorithms, learning theory, cognitive science, neuroscience, vision, speech and signal processing, reinforcement learning and control, implementations, and diverse applications. Only about 30 percent of the papers submitted are accepted for presentation at NIPS, so the quality is exceptionally high. This CD-ROM contains the entire proceedings of the twelve Neural Information Processing Systems conferences from 1988 to 1999. The files are available in the DjVu image format developed by Yann LeCun and his group at AT&T Labs. The CD-ROM includes free browsers for all major platforms. Michael I. Jordan is Professor of Computer Science and of Statistics at the University of California, Berkeley. Yann LeCun is Head of the Image Processing Research Department at AT&T Labs-Research. Sara A. Solla is Professor of Physics and of Physiology at Northwestern University.

  7. Fabricating capacitive micromachined ultrasonic transducers with a novel silicon-nitride-based wafer bonding process.

    PubMed

    Logan, Andrew; Yeow, John T W

    2009-05-01

    We report the fabrication and experimental testing of 1-D 23-element capacitive micromachined ultrasonic transducer (CMUT) arrays that have been fabricated using a novel wafer-bonding process whereby the membrane and the insulation layer are both silicon nitride. The membrane and cell cavities are deposited and patterned on separate wafers and fusion-bonded in a vacuum environment to create CMUT cells. A user-grown silicon-nitride membrane layer avoids the need for expensive silicon-on-insulator (SOI) wafers, reduces parasitic capacitance, and reduces dielectric charging. It allows more freedom in selecting the membrane thickness while also providing the benefits of wafer-bonding fabrication such as excellent fill factor, ease of vacuum sealing, and a simplified fabrication process when compared with the more standard sacrificial release process. The devices fabricated have a cell diameter of 22 microm, a membrane thickness of 400 nm, a gap depth of 150 nm, and an insulation thickness of 250 nm. The resonant frequency of the CMUT in air is 17 MHz and has an attenuation compensated center frequency of approximately 9 MHz in immersion with a -6 dB fractional bandwidth of 123%. This paper presents the fabrication process and some characterization results.

  8. Computer Aided Design of Integrated Circuit Fabrication Processes for VLSI Devices

    DTIC Science & Technology

    1981-07-01

    pressure oxidation . Improvement on these IC processing factors, time and temperature, are important prerequisites for development of VLSI technology ...goals of the present program is the development of an advanced process modeling capability. This requires the investigation of the latest technological ... advances and their incorporation in the present process modeling program. For high pressure oxidation , the kinetics of oxide growth in dry 02 and

  9. Optical Multiple Access Network (OMAN) for advanced processing satellite applications

    NASA Technical Reports Server (NTRS)

    Mendez, Antonio J.; Gagliardi, Robert M.; Park, Eugene; Ivancic, William D.; Sherman, Bradley D.

    1991-01-01

    An OMAN breadboard for exploring advanced processing satellite circuit switch applications is introduced. Network architecture, hardware trade offs, and multiple user interference issues are presented. The breadboard test set up and experimental results are discussed.

  10. Fabrication of flexible ultraviolet photodetectors using an all-spray-coating process

    NASA Astrophysics Data System (ADS)

    Han, Junebeom; Lee, Jonghun; Ju, Sanghyun

    2016-04-01

    We report on a flexible ultraviolet (UV) photodetector fabricated using an all-spray-coating process. Two spray coating units were utilized to deposit semiconducting tin oxide nanowires as an active channel layer and metallic silver nanowires as an electrode layer. The device was mounted on the back of a human hand, and the UV intensities in sunlight were monitored over time. The fabricated flexible UV photodetector showed highly sensitive, stable, and reproducible detection properties. The main advantage of the proposed fabrication method is the extension of the integration environment by allowing direct application on various substrates, such as clothes and human skin, with varying device size and shape.

  11. Preliminary Evaluation of Mechanical Properties of Co-Cr Alloys Fabricated by Three New Manufacturing Processes.

    PubMed

    Jang, Seong-Ho; Lee, Dae-Ho; Ha, Jung-Yun; Hanawa, Takao; Kim, Kyo-Han; Kwon, Tae-Yub

    2015-01-01

    A preliminary tensile test was performed to evaluate the mechanical properties of cobalt-chromium (Co-Cr) alloys fabricated by three new manufacturing processes: metal milling, milling for soft metal, and rapid prototyping (n=6). For comparison, the three alloy materials were also used to fabricate specimens by a casting procedure. In all groups tested, the proof strength and elongation were over 500 MPa and 2%, respectively. The milled soft alloy in particular showed a substantially greater elongation, whereas the alloy fabricated by rapid prototyping exhibited a higher proof strength.

  12. Fabrication of FeSe superconducting films with chemical transport deposition process

    NASA Astrophysics Data System (ADS)

    Feng, J. Q.; Zhang, S. N.; Liu, J. X.; Hao, Q. B.; Li, C. S.; Zhang, P. X.

    2017-07-01

    FeSe Superconducting films were fabricated with a chemical transport deposition process. During the fabrication process, Fe foils were adopted as substrates and Se powders were put at one end of the tube furnace. During the heating process, Se powders were vaporized, and vaporized atoms were carried by Ar flow and deposited on the Fe substrates. With a heat treatment process under proper temperature, superconducting tetragonal β-FeSe phase can be obtained. The effects of key parameters, including the sintering temperatures and the distances between Fe substrates and Se source on the phase composition and morphology of the obtained films were systematically investigated. The superconducting transition temperature of 7.8 K was obtained on the optimized film. By further optimization of the heat treatment process, it is promising to fabricate FeSe films with higher superconducting phase content and better superconducting properties.

  13. Advanced Drying Process for Lower Manufacturing Cost of Electrodes

    SciTech Connect

    Ahmad, Iftikhar; Zhang, Pu

    2016-11-30

    For this Vehicle Technologies Incubator/Energy Storage R&D topic, Lambda Technologies teamed with Navitas Systems and proposed a new advanced drying process that promised a 5X reduction in electrode drying time and significant reduction in the cost of large format lithium batteries used in PEV's. The operating principle of the proposed process was to use penetrating radiant energy source Variable Frequency Microwaves (VFM), that are selectively absorbed by the polar water or solvent molecules instantly in the entire volume of the electrode. The solvent molecules are thus driven out of the electrode thickness making the process more efficient and much faster than convective drying method. To evaluate the Advanced Drying Process (ADP) a hybrid prototype system utilizing VFM and hot air flow was designed and fabricated. While VFM drives the solvent out of the electrode thickness, the hot air flow exhausts the solvent vapors out of the chamber. The drying results from this prototype were very encouraging. For water based anodes there is a 5X drying advantage (time & length of oven) in using ADP over standard drying system and for the NMP based cathodes the reduction in drying time has 3X benefit. For energy savings the power consumption measurements were performed to ADP prototype and compared with the convection standard drying oven. The data collected demonstrated over 40% saving in power consumption with ADP as compared to the convection drying systems. The energy savings are one of the operational cost benefits possible with ADP. To further speed up the drying process, the ADP prototype was explored as a booster module before the convection oven and for the electrode material being evaluated it was possible to increase the drying speed by a factor of 4, which could not be accomplished with the standard dryer without surface defects and cracks. The instantaneous penetration of microwave in the entire slurry thickness showed a major advantage in rapid drying of the

  14. Advanced Development Strategies for Biopharmaceutical Cell Culture Processes.

    PubMed

    Zalai, Denes; Golabgir, Aydin; Wechselberger, Patrick; Putics, Akos; Herwig, Christoph

    2015-01-01

    The shift from empirical to science-based process development is considered to be a key factor to increase bioprocess performance and to reduce time to market for biopharmaceutical products in the near future. In the last decade, expanding knowledge in systems biology and bioprocess technology has delivered the foundation of the scientific understanding of relationships between process input parameters and process output features. Based on this knowledge, advanced process development approaches can be applied to maximize process performance and to generate process understanding. This review focuses on tools which enable the integration of physiological knowledge into cell culture process development. As a structured approach, the availability and the proposed benefit of the application of these tools are discussed for the subsequent stages of process development. The ultimate aim is to deliver a comprehensive overview of the current role of physiological understanding during cell culture process development from clone selection to the scale-up of advanced control strategies for ensuring process robustness.

  15. Advanced photomask fabrication by e-beam lithography for mask aligner applications

    NASA Astrophysics Data System (ADS)

    Weichelt, T.; Bourgin, Y.; Banasch, M.; Zeitner, U. D.

    2016-10-01

    Photomasks contain geometric information that will be transferred to substrates or pre-structured surfaces. Conventional mask aligner lithography in the sense of shadow printing of the photomask suffers from limited achievable resolution. Photomask and substrate are typically separated by an air gap causing diffraction effects and hence affecting the minimum structure size. Even though contact lithography offers a resolution in the wavelengthscale, yield problems and contamination of the photomask are its drawbacks. Using proximity lithography, these problems can be avoided since it profits from a contact-free exposure process. To overcome the resolution limitation of the shadow printing mode more advanced diffraction based photo masks need to be used.

  16. A Fully Contained Resin Infusion Process for Fiber-Reinforced Polymer Composite Fabrication and Repair

    DTIC Science & Technology

    2013-01-01

    Assisted Resin Transfer Molding ( VARTM ) process is applicable for fiber-reinforced polymer (FRP) composite fabrication and repair. However, VARTM in...scenario is a fully enclosed VARTM system that limits the need for laboratory or manufacturing equipment. The Bladder-Bag VARTM (BBVARTM) technique...composite fabrication, VARTM , composite repair, in-field repair 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT UU 18. NUMBER

  17. Fabrication of lightweight ceramic mirrors by means of a chemical vapor deposition process

    NASA Technical Reports Server (NTRS)

    Goela, Jitendra S. (Inventor); Taylor, Raymond L. (Inventor)

    1991-01-01

    A process to fabricate lightweigth ceramic mirrors, and in particular, silicon/silicon carbide mirrors, involves three chemical vapor deposition steps: one to produce the mirror faceplate, the second to form the lightweight backstructure which is deposited integral to the faceplate, and the third and final step which results in the deposition of a layer of optical grade material, for example, silicon, onto the front surface of the faceplate. The mirror figure and finish are fabricated into this latter material.

  18. Fabrication Process of Fine Electrodes Using Shadow Mask Evaporation and Tip-Induced Local Oxidation

    NASA Astrophysics Data System (ADS)

    Akai, Tomonori; Abe, Takumi; Ishibashi, Masayoshi; Kato, Midori; Heike, Seiji; Shimomura, Takeshi; Okai, Makoto; Hashizume, Tomihiro; Ito, Kohzo

    2002-07-01

    We report on a simple process for fabricating fine electrodes by using shadow mask evaporation and tip-induced local oxidation. A set of electrodes for four-term resistance measurement has been fabricated. The gap width between the fine electrode was 150 nm and the roughness of the electrode surface was less than 0.5 nm. We were able to use the electrodes to measure the conductivity of a multiwalled carbon nanotube (MWNT).

  19. Femtosecond laser processing of transparent materials for assembly-free fabrication of photonic microsensors

    NASA Astrophysics Data System (ADS)

    Yuan, Lei; Zhang, Yinan; Huang, Jie; Liu, Jie; Song, Yang; Zhang, Qi; Lei, Jincheng; Xiao, Hai

    2016-03-01

    In this paper, we summarize our recent research progresses on the understanding, design, fabrication, characterization of various photonic sensors for energy, defense, environmental, biomedical and industry applications. Femtosecond laser processing/ablation of various glass materials (fused silica, doped silica, sapphire, etc.) will be discussed towards the goal of one-step fabrication of novel photonic sensors and new enabling photonic devices. A number of new photonic devices and sensors will be presented.

  20. Report on Development of Concepts for the Advanced Casting System in Support of the Deployment of a Remotely Operable Research Scale Fuel Fabrication Facility for Metal Fuel

    SciTech Connect

    Ken Marsden

    2007-03-01

    Demonstration of recycle processes with low transuranic losses is key to the successful implementation of the Global Nuclear Energy Partnership strategy to manage spent fuel. It is probable that these recycle processes will include remote fuel fabrication. This report outlines the strategy to develop and implement a remote metal fuel casting process with minimal transuranic losses. The approach includes a bench-scale casting system to develop materials, methods, and perform tests with transuranics, and an engineering-scale casting system to demonstrate scalability and remote operability. These systems will be built as flexible test beds allowing exploration of multiple fuel casting approaches. The final component of the remote fuel fabrication demonstration culminates in the installation of an advanced casting system in a hot cell to provide integrated remote operation experience with low transuranic loss. Design efforts and technology planning have begun for the bench-scale casting system, and this will become operational in fiscal year 2008, assuming appropriate funding. Installation of the engineering-scale system will follow in late fiscal year 2008, and utilize materials and process knowledge gained in the bench-scale system. Assuming appropriate funding, the advanced casting system will be installed in a remote hot cell at the end of fiscal year 2009.

  1. Advanced plasma diagnostics for plasma processing

    NASA Astrophysics Data System (ADS)

    Malyshev, Mikhail Victorovich

    1999-10-01

    A new, non-intrusive, non-perturbing diagnostic method was developed that can be broadly applied to low pressure, weakly ionized plasmas and glow discharges-trace rare gases optical emission spectroscopy (TRG-OES). The method is based on a comparison of intensities of atomic emission from trace amounts of inert gases (He, Ne, Ar, Kr, and Xe) that are added to the discharge to intensities calculated from the theoretical model. The model assumes a Maxwellian electron energy distribution function (EEDF), computes the population of emitting levels both from the ground state and the metastable states of rare gases, and from the best fit between theory and experiment determines electron temperature (Te). Subject to conditions, TRG-OES can also yield electron density or its upper or lower limit. From the comparison of the emission from levels excited predominantly by high energy electrons to that excited by low energy electrons, information about the EEDF can be obtained. The use of TRG-OES also allows a traditionally qualitative actinometry technique (determination of concentration of radical species in plasma through optical emission) to become a precise quantitative method by including Te and rare gases metastables effects. A combination of TRG-OES, advanced actinometry, and Langmuir probe measurements was applied to several different plasma reactors and regimes of operation. Te measurements and experiments to correct excitation cross section were conducted in a laboratory helical resonator. Two chamber configuration of a commercial (Lam Research) metal etcher were studied to determine the effects of plasma parameters on plasma-induced damage. Two different methods (RF inductive coupling and ultra-high frequency coupling) for generating a plasma in a prototype reactor were also studied. Pulsed plasmas, a potential candidate to eliminate the plasma-induced damage to microelectronics devices that occurs in manufacturing due to differential charging of the wafer, have

  2. Liquid crystal gratings for advanced control of polarized light propagation fabricated by one-step multiple beam holographic photoalignment

    NASA Astrophysics Data System (ADS)

    Kawai, K.; Sakamoto, M.; Noda, K.; Sasaki, T.; Kawatsuki, N.; Ono, H.

    2017-02-01

    Liquid crystal grating with three-dimensionally modulated anisotropic structure is fabricated by one-step exposure of an empty glass cell whose inner walls are coated with photocrosslinkable polymer liquid crystals to four-beam polarization interference UV beams. The diffraction properties were probed with a 633 nm wavelength laser and a 532 nm wavelength laser which were the coaxial incident. The novel properties, which diffraction directions are threedimensionally different depending on the wavelengths, are realized by the resultant liquid crystal grating. Furthermore, the resultant liquid crystal grating can be also applied to an advanced polarizing beam splitter which opposite circular polarization and linear polarizations are diffracted simultaneously. These diffraction properties were well-explained by Jones calculus. The resultant liquid crystal grating has the plural of the functions of optical elements such as wave plates, polarization beam splitter, dichroic beam splitter, Wollaston/Rochon prism, and tunable wavelength filter. Therefore, the resultant liquid crystal grating can contribute to miniaturization, sophistication, and cost reduction of optical systems using for, such as optical measurement, communication, and information processing.

  3. Advanced alarm systems: Display and processing issues

    SciTech Connect

    O`Hara, J.M.; Wachtel, J.; Perensky, J.

    1995-05-01

    This paper describes a research program sponsored by the US Nuclear Regulatory Commission to address the human factors engineering (HFE) deficiencies associated with nuclear power plant alarm systems. The overall objective of the study is to develop HFE review guidance for alarm systems. In support of this objective, human performance issues needing additional research were identified. Among the important issues were alarm processing strategies and alarm display techniques. This paper will discuss these issues and briefly describe our current research plan to address them.

  4. Advanced Digital Signal Processing for Hybrid Lidar

    DTIC Science & Technology

    2014-03-31

    on a multimeter to ensure that the PMT remained within its linear operating regime. The AC-coupTed signal was demodulated and digitized in the SDR ...receiver. The I and Q samples obtained by"" the SDR are transferred over an Ethernet cable to a PC, where the data are processed in a custom LabVIEW...Q samples are generated by the SDR receiver and used to compute range on a PC. Ranging results from the FDR experiments and RangeFinder simulations

  5. Technology advances for Space Shuttle processing

    NASA Technical Reports Server (NTRS)

    Wiskerchen, M. J.; Mollakarimi, C. L.

    1988-01-01

    One of the major initial tasks of the Space Systems Integration and Operations Research Applications (SIORA) Program was the application of automation and robotics technology to all aspects of the Shuttle tile processing and inspection system. The SIORA Program selected a nonlinear systems engineering methodology which emphasizes a team approach for defining, developing, and evaluating new concepts and technologies for the operational system. This is achieved by utilizing rapid prototyping testbeds whereby the concepts and technologies can be iteratively tested and evaluated by the team. The present methodology has clear advantages for the design of large complex systems as well as for the upgrading and evolution of existing systems.

  6. Advanced communications technologies for image processing

    NASA Technical Reports Server (NTRS)

    Likens, W. C.; Jones, H. W.; Shameson, L.

    1984-01-01

    It is essential for image analysts to have the capability to link to remote facilities as a means of accessing both data bases and high-speed processors. This can increase productivity through enhanced data access and minimization of delays. New technology is emerging to provide the high communication data rates needed in image processing. These developments include multi-user sharing of high bandwidth (60 megabits per second) Time Division Multiple Access (TDMA) satellite links, low-cost satellite ground stations, and high speed adaptive quadrature modems that allow 9600 bit per second communications over voice-grade telephone lines.

  7. Low cost processes for silicon. [fabricated for solar cells

    NASA Technical Reports Server (NTRS)

    Lutwack, R.

    1979-01-01

    The paper describes the multiple process development of low cost processes for manufacture of silicon. A support program includes subtasks for the modeling of reactions and reactors, chemical engineering and solid-state physics studies, and development of impurity concentration measurement procedures. The preliminary economic analyses indicate total product costs ranging from $5.00 to $8.73/kg based on 1000 MT/yr plants. In the studies of impurity effects, a model which considers that degradations of solar cell performance by impurities are primarily due to decreases in base diffusion length was constructed from experimental data.

  8. More steps towards process automation for optical fabrication

    NASA Astrophysics Data System (ADS)

    Walker, David; Yu, Guoyu; Beaucamp, Anthony; Bibby, Matt; Li, Hongyu; McCluskey, Lee; Petrovic, Sanja; Reynolds, Christina

    2017-06-01

    In the context of Industrie 4.0, we have previously described the roles of robots in optical processing, and their complementarity with classical CNC machines, providing both processing and automation functions. After having demonstrated robotic moving of parts between a CNC polisher and metrology station, and auto-fringe-acquisition, we have moved on to automate the wash-down operation. This is part of a wider strategy we describe in this paper, leading towards automating the decision-making operations required before and throughout an optical manufacturing cycle.

  9. Advances in Processing of Bulk Ferroelectric Materials

    NASA Astrophysics Data System (ADS)

    Galassi, Carmen

    The development of ferroelectric bulk materials is still under extensive investigation, as new and challenging issues are growing in relation to their widespread applications. Progress in understanding the fundamental aspects requires adequate technological tools. This would enable controlling and tuning the material properties as well as fully exploiting them into the scale production. Apart from the growing number of new compositions, interest in the first ferroelectrics like BaTiO3 or PZT materials is far from dropping. The need to find new lead-free materials, with as high performance as PZT ceramics, is pushing towards a full exploitation of bariumbased compositions. However, lead-based materials remain the best performing at reasonably low production costs. Therefore, the main trends are towards nano-size effects and miniaturisation, multifunctional materials, integration, and enhancement of the processing ability in powder synthesis. Also, in control of dispersion and packing, to let densification occur in milder conditions. In this chapter, after a general review of the composition and main properties of the principal ferroelectric materials, methods of synthesis are analysed with emphasis on recent results from chemical routes and cold consolidation methods based on the colloidal processing.

  10. Advances in the electrospark deposition coating process

    SciTech Connect

    Johnson, R.N.; Sheldon, G.L.

    1986-11-01

    Electrospark deposition (ESD) is a pulsed-arc microwelding process using short-duration, high-current electrical pulses to deposit an electrode material on a metallic substrate. It is one of the few methods available by which a fused, metallurgically bonded coating can be applied with such a low total heat input that the bulk substrate material remains at or near ambient temperatures. The short duration of the electrical pulse allows an extremely rapid solidification of the deposited material and results in an exceptionally fine-grained, homogeneous coating that approaches (and with some materials, actually is) an amorphous structure. This structure is believed to contribute to the good tribological and corrosion performance observed for hardsurfacing materials used in the demanding environments of high temperatures, liquid metals, and neutron irradiation. A brief historical review of the process is provided, followed by descriptions of the present state of the art and of the performance and applications of electrospark deposition coating in liquid--metal-cooled nuclear reactors.

  11. Advanced colour processing for mobile devices

    NASA Astrophysics Data System (ADS)

    Gillich, Eugen; Dörksen, Helene; Lohweg, Volker

    2015-02-01

    Mobile devices such as smartphones are going to play an important role in professionally image processing tasks. However, mobile systems were not designed for such applications, especially in terms of image processing requirements like stability and robustness. One major drawback is the automatic white balance, which comes with the devices. It is necessary for many applications, but of no use when applied to shiny surfaces. Such an issue appears when image acquisition takes place in differently coloured illuminations caused by different environments. This results in inhomogeneous appearances of the same subject. In our paper we show a new approach for handling the complex task of generating a low-noise and sharp image without spatial filtering. Our method is based on the fact that we analyze the spectral and saturation distribution of the channels. Furthermore, the RGB space is transformed into a more convenient space, a particular HSI space. We generate the greyscale image by a control procedure that takes into account the colour channels. This leads in an adaptive colour mixing model with reduced noise. The results of the optimized images are used to show how, e. g., image classification benefits from our colour adaptation approach.

  12. Design & fabrication of two seated aircraft with an advanced rotating leading edge wing

    NASA Astrophysics Data System (ADS)

    Al Ahmari, Saeed Abdullah Saeed

    The title of this thesis is "Design & Fabrication of two Seated Aircraft with an Advanced Rotating Leading Edge Wing", this gives almost a good description of the work has been done. In this research, the moving surface boundary-layer control (MSBC) concept was investigated and implemented. An experimental model was constructed and tested in wind tunnel to determine the aerodynamic characteristics using the leading edge moving surface of modified semi-symmetric airfoil NACA1214. The moving surface is provided by a high speed rotating cylinder, which replaces the leading edge of the airfoil. The angle of attack, the cylinder surfaces velocity ratio Uc/U, and the flap deflection angle effects on the lift and drag coefficients and the stall angle of attack were investigated. This new technology was applied to a 2-seat light-sport aircraft that is designed and built in the Aerospace Engineering Department at KFUPM. The project team is led by the aerospace department chairman Dr. Ahmed Z. AL-Garni and Dr. Wael G. Abdelrahman and includes graduate and under graduate student. The wing was modified to include a rotating cylinder along the leading edge of the flap portion. This produced very promising results such as the increase of the maximum lift coefficient at Uc/U=3 by 82% when flaps up and 111% when flaps down at 40° and stall was delayed by 8degrees in both cases. The laboratory results also showed that the effective range of the leading-edge rotating cylinder is at low angles of attack which reduce the need for higher angles of attack for STOL aircraft.

  13. Silicon Solar Cell Process Development, Fabrication and Analysis

    NASA Technical Reports Server (NTRS)

    Yoo, H. I.; Iles, P. A.; Tanner, D. P.

    1978-01-01

    Ribbon to Ribbon (RTR) solar cells processed from polycrystalline feedstock showed maximum AMO efficiency of 5.6%. Solar cells from single crystalline feedstock showed slightly higher efficiency than those from polycrystalline feedstock, indicating maximum efficiency of about 6.6% with SiO AR coating. Single crystalline control cells gave 11-12% AMO efficiencies demonstrating that the poor performance of the RTR solar was due to the low quality of material itself. Dendritic web solar cells from the standard process showed maximum AMO efficiency of 9.8% while efficiency of control solar cells were around 11-12%. Web solar cells from back surface field (BSF) process indicated maximum AMO efficiency of 10.9%. Some improvement in open circuit voltage was noticed from the BSF process. Small light spot scanning experiments were carried out on the solar cells from Wacker Silso, EFG, RTR, and dendritic web ribbons. Photoresponse results provided information on localized cell performance and grain size in polycrystalline material, and agreed quite well with the cell performance data, such as efficiency, minority carrier diffusion length, and spectral response.

  14. Advances in crystal growth, device fabrication and characterization of thallium bromide detectors for room temperature applications

    NASA Astrophysics Data System (ADS)

    Datta, Amlan; Moed, Demi; Becla, Piotr; Overholt, Matthew; Motakef, Shariar

    2016-10-01

    Thallium bromide (TlBr) is a promising room-temperature radiation detector candidate with excellent charge transport properties. However, several critical issues need to be addressed before deployment of this material for long-term field applications can be realized. In this paper, progress made towards solving some of these challenges is discussed. The most significant factors for achieving long-term performance stability for TlBr devices include residual stress as generated during crystal growth and fabrication processes, surface conditions, and the choice of contact metal. Modifications to the commonly used traveling molten zone growth technique for TlBr crystals can significantly minimize the stresses generated by large temperature gradients near the melt-solid interface of the growing crystal. Plasma processing techniques were introduced for the first time to modify the Br-etched TlBr surfaces, which resulted in improvements to the surface conditions, and consequently the spectroscopic response of the detectors. Palladium electrodes resulted a 20-fold improvement in the room-temperature device lifetime when compared to its Br-etched Pt counterpart.

  15. Advanced engineering tools for design and fabrication of a custom nasal prosthesis

    NASA Astrophysics Data System (ADS)

    Oliveira, Inês; Leal, Nuno; Silva, Pedro; da Costa Ferreira, A.; Neto, Rui J.; Lino, F. Jorge; Reis, Ana

    2012-09-01

    Unexpected external defects resulting from neoplasms, burns, congenital malformations, trauma or other diseases, particularly when involving partial or total loss of an external organ, can be emotionally devastating. These defects can be restored with prosthesis, obtained by different techniques, materials and methods. The increase of patient numbers and cost constraints lead to the need of exploring new techniques that can increase efficiency. The main goal of this project was to develop a full engineering-based manufacturing process to obtain soft-tissue prosthesis that could provide faster and less expensive options in the manufacturing of customized prosthesis, and at the same time being able to reproduce the highest degree of details, with the maximum comfort for the patient. Design/methodology/approach - This case report describes treatment using silicone prosthesis with an anatomic retention for an 80-years-old woman with a rhinectomy. The proposed methodology integrates non-contact structured light scanning, CT and reverse engineering with CAD/CAM and additive manufacturing technology. Findings - The proposed protocol showed encouraging results since reveals being a better solution for fabricating custom-made facial prostheses for asymmetrical organs than conventional approaches. The process allows the attainment of prosthesis with the minimum contact and discomfort for the patient, disclosing excellent results in terms of aesthetic, prosthesis retention and in terms of time and resources consumed.

  16. 3D MEMS in Standard Processes: Fabrication, Quality Assurance, and Novel Measurement Microstructures

    NASA Technical Reports Server (NTRS)

    Lin, Gisela; Lawton, Russell A.

    2000-01-01

    Three-dimensional MEMS microsystems that are commercially fabricated require minimal post-processing and are easily integrated with CMOS signal processing electronics. Measurements to evaluate the fabrication process (such as cross-sectional imaging and device performance characterization) provide much needed feedback in terms of reliability and quality assurance. MEMS technology is bringing a new class of microscale measurements to fruition. The relatively small size of MEMS microsystems offers the potential for higher fidelity recordings compared to macrosize counterparts, as illustrated in the measurement of muscle cell forces.

  17. Carbon nanotube thin film transistors fabricated by an etching based manufacturing compatible process.

    PubMed

    Tian, Boyuan; Liang, Xuelei; Xia, Jiye; Zhang, Han; Dong, Guodong; Huang, Qi; Peng, Lianmao; Xie, Sishen

    2017-03-17

    Carbon nanotube thin film transistors (CNT-TFTs) have been regarded as strong competitors to currently commercialized TFT technologies. Though much progress has been achieved recently, CNT-TFT research is still in the stage of laboratory research. One critical challenge for commercializing CNT-TFT technology is that the commonly used device fabrication method is a lift-off based process, which is not suitable for mass production. In this paper, we report an etching based fabrication process for CNT-TFTs, which is fully manufacturing compatible. In our process, the CNT thin film channel was patterned by dry etching, while wet etching was used for patterning the layers of metal and insulator. The CNT-TFTs were successfully fabricated on a 4 inch wafer in both top-gate and buried-gate geometries with low Schottky barrier contact and pretty uniform performance. High output current (>1.2 μA μm(-1)), high on/off current ratio (>10(5)) and high mobility (>30 cm(2) V(-1) s(-1)) were obtained. Though the fabrication process still needs to be optimized, we believe our research on the etching fabrication process pushes CNT-TFT technology a step forward towards real applications in the near future.

  18. Optical metrology for advanced process control: full module metrology solutions

    NASA Astrophysics Data System (ADS)

    Bozdog, Cornel; Turovets, Igor

    2016-03-01

    Optical metrology is the workhorse metrology in manufacturing and key enabler to patterning process control. Recent advances in device architecture are gradually shifting the need for process control from the lithography module to other patterning processes (etch, trim, clean, LER/LWR treatments, etc..). Complex multi-patterning integration solutions, where the final pattern is the result of multiple process steps require a step-by-step holistic process control and a uniformly accurate holistic metrology solution for pattern transfer for the entire module. For effective process control, more process "knobs" are needed, and a tighter integration of metrology with process architecture.

  19. Advanced information processing system for advanced launch system: Avionics architecture synthesis

    NASA Technical Reports Server (NTRS)

    Lala, Jaynarayan H.; Harper, Richard E.; Jaskowiak, Kenneth R.; Rosch, Gene; Alger, Linda S.; Schor, Andrei L.

    1991-01-01

    The Advanced Information Processing System (AIPS) is a fault-tolerant distributed computer system architecture that was developed to meet the real time computational needs of advanced aerospace vehicles. One such vehicle is the Advanced Launch System (ALS) being developed jointly by NASA and the Department of Defense to launch heavy payloads into low earth orbit at one tenth the cost (per pound of payload) of the current launch vehicles. An avionics architecture that utilizes the AIPS hardware and software building blocks was synthesized for ALS. The AIPS for ALS architecture synthesis process starting with the ALS mission requirements and ending with an analysis of the candidate ALS avionics architecture is described.

  20. Qualification of local advanced cryogenic cleaning technology for 14nm photomask fabrication

    NASA Astrophysics Data System (ADS)

    Taumer, Ralf; Krome, Thorsten; Bowers, Chuck; Varghese, Ivin; Hopkins, Tyler; White, Roy; Brunner, Martin; Yi, Daniel

    2014-10-01

    The march toward tighter design rules, and thus smaller defects, implies stronger surface adhesion between defects and the photomask surface compared to past generations, thereby resulting in increased difficulty in photomask cleaning. Current state-of-the-art wet clean technologies utilize functional water and various energies in an attempt to produce similar yield to the acid cleans of previous generations, but without some of the negative side effects. Still, wet cleans have continued to be plagued with issues such as persistent particles and contaminations, SRAF and feature damages, leaving contaminants behind that accelerate photo-induced defect growth, and others. This paper details work done through a design of experiments (DOE) utilized to qualify an improved cryogenic cleaning technology for production in the Advanced Mask Technology Center (AMTC) advanced production lines for 20 and 14 nm processing. All work was conducted at the AMTC facility in Dresden, Germany utilizing technology developed by Eco-Snow Systems and RAVE LLC for their cryogenic local cleaning VC1200F platform. This system uses a newly designed nozzle, improved gaseous CO2 delivery, extensive filtration to remove hydrocarbons and minimize particle adders, and other process improvements to overcome the limitations of the previous generation local cleaning tool. AMTC has successfully qualified this cryogenic cleaning technology and is currently using it regularly to enhance production yields even at the most challenging technology nodes.

  1. Process for fabricating ZnO-based varistors

    DOEpatents

    Lauf, Robert J.

    1985-01-01

    The invention is a process for producing ZnO-based varistors incorporating a metal oxide dopant. In one form, the invention comprises providing a varistor powder mix of colloidal particles of ZnO and metal-oxide dopants including Bi.sub.2 O.sub.3. The mix is hot-pressed to form a compact at temperatures below 850.degree. C. and under conditions effecting reduction of the ZnO to sub-stoichiometric oxide. This promotes densification while restricting liquid formation and grain growth. The compact then is heated under conditions restoring the zinc oxide to stoichiometric composition, thus improving the varistor properties of the compact. The process produces fine-grain varistors characterized by a high actual breakdown voltage and a high average breakdown voltage per individual grain boundary.

  2. Process for fabricating ZnO-based varistors

    DOEpatents

    Lauf, R.J.

    The invention is a process for producing ZnO-based varistors incorporating a metal oxide dopant. In one form, the invention comprises providing a varistor powder mix of colloidal particles of ZnO and metal-oxide dopants including Bi/sub 2/O/sub 3/. The mix is hot-pressed to form a compact at temperatures below 850/sup 0/C and under conditions effecting reduction of the ZnO to sub-stoichiometric oxide. This promotes densification while restricting liquid formation and grain growth. The compact then is heated under conditions restoring the zinc oxide to stoichiometric composition, thus improving the varistor properties of the compact. The process produces fine-grain varistors characterized by a high actual breakdown voltage and a high average breakdown voltage per individual grain boundary.

  3. Development and fabrication of a solar cell junction processing system

    NASA Technical Reports Server (NTRS)

    1984-01-01

    A processing system capable of producing solar cell junctions by ion implantation followed by pulsed electron beam annealing was developed and constructed. The machine was to be capable of processing 4-inch diameter single-crystal wafers at a rate of 10(7) wafers per year. A microcomputer-controlled pulsed electron beam annealer with a vacuum interlocked wafer transport system was designed, built and demonstrated to produce solar cell junctions on 4-inch wafers with an AMI efficiency of 12%. Experiments showed that a non-mass-analyzed (NMA) ion beam could implant 10 keV phosphorous dopant to form solar cell junctions which were equivalent to mass-analyzed implants. A NMA ion implanter, compatible with the pulsed electron beam annealer and wafer transport system was designed in detail but was not built because of program termination.

  4. Silicon Solar Cell Process Development, Fabrication and Analysis

    NASA Technical Reports Server (NTRS)

    Minahan, J. A.

    1979-01-01

    Solar cells were constructed from polycrystalline silicon sheet material (10 cm x 10 cm). These cells were made using conventional aerospace methods and serve as the so-called baseline cell for analysis and comparison with cells to be made from similar material, but using optimized processing techniques. Before and during the processing of the baseline cells in a cleaned diffusion tube, control cells were built using the baseline method. All cells were measured on a solar simulator at air mass zero and 28 C. Average efficiency for the baseline cells was 9.5%. Efficiency was found to vary with location in the sheet. Center regions had higher efficiencies whereas corner and edge regions had lower efficiencies. In general, the efficiency falls off with distance from the center of the sheet.

  5. Processing, Fabrication and Demonstration of HTS Integrated Microwave CIrcuits

    DTIC Science & Technology

    1993-04-25

    reason. Another potential backup was explored by purchasing commercially available 2-inch diameter wafers coated with YBCO on one side from Conductus ...Measurements of Rs with a 2" end-wall replacement cavity showed that the Conductus films meet the program requirements. Although Conductus deposits a...film on only one side of a wafer, our processing time could be cut in half by having to grow YBCO on just the second side. The Conductus films received

  6. Advance care planning in CKD/ESRD: an evolving process.

    PubMed

    Holley, Jean L

    2012-06-01

    Advance care planning was historically considered to be simply the completion of a proxy (health care surrogate designation) or instruction (living will) directive that resulted from a conversation between a patient and his or her physician. We now know that advance care planning is a much more comprehensive and dynamic patient-centered process used by patients and families to strengthen relationships, achieve control over medical care, prepare for death, and clarify goals of care. Some advance directives, notably designated health care proxy documents, remain appropriate expressions of advance care planning. Moreover, although physician orders, such as do-not-resuscitate orders and Physician Orders for Life-Sustaining Treatment, may not be strictly defined as advance directives, their completion, when appropriate, is an integral component of advance care planning. The changing health circumstances and illness trajectory characteristic of ESRD mandate that advance care planning discussions adapt to a patient's situation and therefore must be readdressed at appropriate times and intervals. The options of withholding and withdrawing dialysis add ESRD-specific issues to advance care planning in this population and are events each nephrologist will at some time confront. Advance care planning is important throughout the spectrum of ESRD and is a part of nephrology practice that can be rewarding to nephrologists and beneficial to patients and their families.

  7. TOWARD LOW-COST FABRICATION OF MICROCHANNEL PROCESS TECHNOLOGIES - COST MODELING FOR MANUFACTURING DEVELOPMENT

    SciTech Connect

    Leith, Steven D.; King, Dale A.; Paul, Brian

    2010-11-07

    Chemical and energy conversion systems based on microchannel process technology (MPT) demonstrate high performance in applications in which rates are controlled by diffusive heat and mass transfer flux. The performance of MPT-based heat exchangers, absorbers/desorbers and chemical reactors all benefit from process intensification and have been used in a variety of mobile energy conversion systems including fuel reformers/converters, heat pumps and waste heat scavenging technologies. The service environments typical of MPTs often require the devices to be fabricated from metals such as aluminum, titanium, stainless steel or high temperature super alloys. Flow channels and associated critical dimensions in these devices can be as small as 50 um, but generally range from 100 to 1000 um in width and height with characteristic flow channel lengths normally in the mm to cm range. High surface area architectures (e.g. wicks or textured surfaces) are often included in the flow channels as well for enhanced mass transfer and/or catalytic functionality. Fabrication of MPT devices has historically been performed using a stacked-shim approach in which individual metal sheets are first patterned with micro- and meso-scale flow channels and subsequently bonded in a stack to create an array of miniaturized, parallel flow paths. Typical proof-of-concept fabrication efforts have utilized photo chemical machining (PCM) for shim patterning and diffusion bonding or diffusion brazing for joining of shim stacks. While flexible and capable of supporting technology demonstration, however, these techniques can be expensive at prototyping volumes. The high fabrication cost associated with these prototyping processes has contributed to a perception that MPT technology is expensive and will be relegated to a small application space. Recent work at the Microproducts Breakthrough Institute (MBI) has focused on exploring the cost structure of high volume manufacturing of MPT devices in effort to

  8. Process Development for the Fabrication of Spheroidal Microdevice Packages Utilizing MEMS Technologies

    DTIC Science & Technology

    2014-03-27

    providing an efficient method of data collection. A method of performing sophisticated wafer alignment and photolithography processes by leveraging... wafers using a chrome mask and photoresist. Modified from [33]. ............................................................................... 30...process; (a) hexsil cap is fabricated on “donor” wafer and aligned with MEMS wafer , (b) the two wafers are brought together and bonded, and (c) the

  9. Design and fabrication of advanced materials from Illinois coal wastes. [Quarterly] technical report, September 1--November 30, 1994

    SciTech Connect

    Malhotra, V.M.; Wright, M.A.

    1994-12-31

    The main goal of this project is to develop a bench-scale procedure to design and fabricate advanced brake and structural composite materials from Illinois coal combustion residues. During the first quarter of the project, the thrust of the work was directed towards setting up the experimental facilities and undertaking preliminary tests to gauge the ability of coal tar derived binder in fabricating the brake skeletons. In addition systematic scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and differential thermal analysis (DTA) were conducted on PCC fly ash (Baldwin), fly ash (ADM), FBC fly ash, FBC spent bed bottom ash, bottom ash (ADM), and scrubber sludge residues to characterize their geometrical shape and thermal stability. The PCC fly ash particles being highly spherical in shape and thermally inert up to 1100{degrees}C will make an excellent raw material for our composites. This is born out by fabricating brake skeletons from PCC fly ash colloids. Unlike the PCC fly ash and FBC fly ash, the scrubber sludge particles are not suitable hosts for our brake lining materials because of a whisker-like particle structure. Six different compositions of various combustion residues were tested in the fabrication of brake skeletons, and our tar derived binder shows great promise in the fabrication of composite materials.

  10. Automated catalyst processing for cloud electrode fabrication for fuel cells

    DOEpatents

    Goller, Glen J.; Breault, Richard D.

    1980-01-01

    A process for making dry carbon/polytetrafluoroethylene floc material, particularly useful in the manufacture of fuel cell electrodes, comprises of the steps of floccing a co-suspension of carbon particles and polytetrafluoroethylene particles, filtering excess liquids from the co-suspension, molding pellet shapes from the remaining wet floc solids without using significant pressure during the molding, drying the wet floc pellet shapes within the mold at temperatures no greater than about 150.degree. F., and removing the dry pellets from the mold.

  11. DESIGN, FABRICATION, AND TESTING OF AN ADVANCED, NON-POLLUTING TURBINE DRIVE GAS GENERATOR

    SciTech Connect

    Unknown

    2002-03-31

    The objectives of this report period were to complete the development of the Gas Generator design, which was done; fabricate and test of the non-polluting unique power turbine drive gas Gas Generator, which has been postponed. Focus during this report period has been to complete the brazing and bonding necessary to fabricate the Gas Generator hardware, continue making preparations for fabricating and testing the Gas Generator, and continuing the fabrication of the Gas Generator hardware and ancillary hardware in preparation for the test program. Fabrication is more than 95% complete and is expected to conclude in early May 2002. the test schedule was affected by relocation of the testing to another test supplier. The target test date for hot fire testing is now not earlier than June 15, 2002.

  12. Technology for Fabrication of Nanostructures by Standard Cleanroom Processing and Nanoimprint Lithography

    NASA Astrophysics Data System (ADS)

    Bilenberg, Brian; Jacobsen, Søren; Pastore, Carine; Nielsen, Theodor; Enghoff, Simon Riis; Jeppesen, Claus; Larsen, Asger Vig; Kristensen, Anders

    2005-07-01

    Sub-micron structures are routinely fabricated by electron beam lithography (EBL). However EBL is a time consuming and costly technology. We present a technology for fabrication of nanostructures by standard UV-lithography and thermal nanoimprint lithography (NIL). NIL-stamps with sub-30 nm patterns are fabricated by standard micrometer resolution cleanroom processing, i.e. UV-lithography, reactive ion etching and thermal oxidation, and the pattern is transferred to a polymer thin film on a substrate by NIL. Subsequently the patterned polymer film is used either as a direct etching mask to transfer the pattern to the substrate or as a metal lift-off mask. This way we have demonstrated the fabrication of sub-100 nm nanochannels in silicon oxide and sub-50 nm gold lines on silicon.

  13. Fabrication processes for MEMS deformable mirrors in the next generation telescope instruments

    NASA Astrophysics Data System (ADS)

    Diouf, Alioune

    This dissertation advances three critical technology areas at the frontier of research for micro electro-mechanical systems (MEMS) deformable minors (DMs) needed for next generation telescopes (NGTs). High actuator-count MEMS deformable minors are needed for future ground-based large astronomical telescopes. Scaling up the current MEMS DMs to unprecedented numbers of independent actuators---up to 10,000 on a single DM---will require new electrical connection architecture for the actuators in order to replace the wire-bonded scheme that has been used to date. A through-wafer via interconnection fabrication process for MEMS DMs is developed to offer a path to transform the frontier of high actuator count MEMS micromirrors. In a class of NGTs instrument known as the Multi-Object Adaptive Optics (MOAO), the correction made by the DM of the wavefront phase error over the entire telescope field view is not accessible to the sensing unit. To achieve compensation, precise, single step "open-loop" commands must be developed for the DM. Due to the nonlinear relationship between applied voltage and actuation displacement at each actuator, and the mechanical coupling among actuators through the mirror membrane, such open-loop control is a formidable task. A combination of mirror surface modeling and sparse actuator empirical calibration is used to demonstrate open-loop control of MEMS deformable minors to the accuracy of closed-loop control over the entire available DM stroke. Shapes at the limit of achievable minor spatial frequencies with up to 2.5microm amplitudes have been achieved within 20nm RMS error accuracy of closed-loop control. The calibration of a single actuator to be used for predicting shapes results in an additional 14nm RMS surface error compared to parallel calibration of all actuators in the deformable minor. The ubiquitous reflective coatings for MEMS deformable minors are gold and aluminum. Emerging adaptive optics application require broadband optical

  14. In-process fault detection for textile fabric production: onloom imaging

    NASA Astrophysics Data System (ADS)

    Neumann, Florian; Holtermann, Timm; Schneider, Dorian; Kulczycki, Ashley; Gries, Thomas; Aach, Til

    2011-05-01

    Constant and traceable high fabric quality is of high importance both for technical and for high-quality conventional fabrics. Usually, quality inspection is carried out by trained personal, whose detection rate and maximum period of concentration are limited. Low resolution automated fabric inspection machines using texture analysis were developed. Since 2003, systems for the in-process inspection on weaving machines ("onloom") are commercially available. With these defects can be detected, but not measured quantitative precisely. Most systems are also prone to inevitable machine vibrations. Feedback loops for fault prevention are not established. Technology has evolved since 2003: Camera and computer prices dropped, resolutions were enhanced, recording speeds increased. These are the preconditions for real-time processing of high-resolution images. So far, these new technological achievements are not used in textile fabric production. For efficient use, a measurement system must be integrated into the weaving process; new algorithms for defect detection and measurement must be developed. The goal of the joint project is the development of a modern machine vision system for nondestructive onloom fabric inspection. The system consists of a vibration-resistant machine integration, a high-resolution machine vision system, and new, reliable, and robust algorithms with quality database for defect documentation. The system is meant to detect, measure, and classify at least 80 % of economically relevant defects. Concepts for feedback loops into the weaving process will be pointed out.

  15. Process system and method for fabricating submicron field emission cathodes

    DOEpatents

    Jankowski, A.F.; Hayes, J.P.

    1998-05-05

    A process method and system for making field emission cathodes exists. The deposition source divergence is controlled to produce field emission cathodes with height-to-base aspect ratios that are uniform over large substrate surface areas while using very short source-to-substrate distances. The rate of hole closure is controlled from the cone source. The substrate surface is coated in well defined increments. The deposition source is apertured to coat pixel areas on the substrate. The entire substrate is coated using a manipulator to incrementally move the whole substrate surface past the deposition source. Either collimated sputtering or evaporative deposition sources can be used. The position of the aperture and its size and shape are used to control the field emission cathode size and shape. 3 figs.

  16. Process system and method for fabricating submicron field emission cathodes

    DOEpatents

    Jankowski, Alan F.; Hayes, Jeffrey P.

    1998-01-01

    A process method and system for making field emission cathodes exists. The deposition source divergence is controlled to produce field emission cathodes with height-to-base aspect ratios that are uniform over large substrate surface areas while using very short source-to-substrate distances. The rate of hole closure is controlled from the cone source. The substrate surface is coated in well defined increments. The deposition source is apertured to coat pixel areas on the substrate. The entire substrate is coated using a manipulator to incrementally move the whole substrate surface past the deposition source. Either collimated sputtering or evaporative deposition sources can be used. The position of the aperture and its size and shape are used to control the field emission cathode size and shape.

  17. Equalizing Si photodetectors fabricated in standard CMOS processes

    NASA Astrophysics Data System (ADS)

    Guerrero, E.; Aguirre, J.; Sánchez-Azqueta, C.; Royo, G.; Gimeno, C.; Celma, S.

    2017-05-01

    This work presents a new continuous-time equalization approach to overcome the limited bandwidth of integrated CMOS photodetectors. It is based on a split-path topology that features completely decoupled controls for boosting and gain; this capability allows a better tuning of the equalizer in comparison with other architectures based on the degenerated differential pair, which is particularly helpful to achieve a proper calibration of the system. The equalizer is intended to enhance the bandwidth of CMOS standard n-well/p-bulk differential photodiodes (DPDs), which falls below 10MHz representing a bottleneck in fully integrated optoelectronic interfaces to fulfill the low-cost requirements of modern smart sensors. The proposed equalizer has been simulated in a 65nm CMOS process and biased with a single supply voltage of 1V, where the bandwidth of the DPD has been increased up to 3 GHz.

  18. Hydrocarbon Processing`s Advanced control and information systems `95

    SciTech Connect

    1995-09-01

    This special report presents control strategies and information systems for most hydrocarbon processes and plants. Each summary (76 in all) contains information on application, control strategy, economics, commercial installations, and licensor. The processes include NGL recovery, alkylation, blending, catalytic reforming, caustic treating, cryogenic separation, delayed coking, fractionation, hydrocracking, hydrogen production, isomerization, lube oil extraction, oil transport and storage, pipeline management, information management, sulfur recovery, waste water treatments, and others.

  19. Advanced Manufacturing Systems in Food Processing and Packaging Industry

    NASA Astrophysics Data System (ADS)

    Shafie Sani, Mohd; Aziz, Faieza Abdul

    2013-06-01

    In this paper, several advanced manufacturing systems in food processing and packaging industry are reviewed, including: biodegradable smart packaging and Nano composites, advanced automation control system consists of fieldbus technology, distributed control system and food safety inspection features. The main purpose of current technology in food processing and packaging industry is discussed due to major concern on efficiency of the plant process, productivity, quality, as well as safety. These application were chosen because they are robust, flexible, reconfigurable, preserve the quality of the food, and efficient.

  20. Recent advances in processing and applications of microwave ferrites

    NASA Astrophysics Data System (ADS)

    Harris, Vincent G.; Geiler, Anton; Chen, Yajie; Yoon, Soack Dae; Wu, Mingzhong; Yang, Aria; Chen, Zhaohui; He, Peng; Parimi, Patanjali V.; Zuo, Xu; Patton, Carl E.; Abe, Manasori; Acher, Olivier; Vittoria, Carmine

    2009-07-01

    Next generation magnetic microwave devices will be planar, smaller, weigh less, and perform well beyond the present state-of-the-art. For this to become a reality advances in ferrite materials must first be realized. These advances include self-bias magnetization, tunability of the magnetic anisotropy, low microwave loss, and volumetric and weight reduction. To achieve these goals one must turn to novel materials processing methods. Here, we review recent advances in the processing of microwave ferrites. Attention is paid to the processing of ferrite films by pulsed laser deposition, liquid phase epitaxy, spin spray ferrite plating, screen printing, and compaction of quasi-single crystals. Conventional and novel applications of ferrite materials, including microwave non-reciprocal passive devices, microwave signal processing, negative index metamaterial-based electronics, and electromagnetic interference suppression are discussed.

  1. A Reverse Osmosis System for an Advanced Separation Process Laboratory.

    ERIC Educational Resources Information Center

    Slater, C. S.; Paccione, J. D.

    1987-01-01

    Focuses on the development of a pilot unit for use in an advanced separations process laboratory in an effort to develop experiments on such processes as reverse osmosis, ultrafiltration, adsorption, and chromatography. Discusses reverse osmosis principles, the experimental system design, and some experimental studies. (TW)

  2. A Reverse Osmosis System for an Advanced Separation Process Laboratory.

    ERIC Educational Resources Information Center

    Slater, C. S.; Paccione, J. D.

    1987-01-01

    Focuses on the development of a pilot unit for use in an advanced separations process laboratory in an effort to develop experiments on such processes as reverse osmosis, ultrafiltration, adsorption, and chromatography. Discusses reverse osmosis principles, the experimental system design, and some experimental studies. (TW)

  3. TECHNOLOGY SUMMARY ADVANCING TANK WASTE RETRIEVAL AND PROCESSING

    SciTech Connect

    SAMS TL; MENDOZA RE

    2010-08-11

    This technology overview provides a high-level summary of technologies being investigated and developed by Washington River Protection Solutions (WRPS) to advance Hanford Site tank waste retrieval and processing. Technology solutions are outlined, along with processes and priorities for selecting and developing them.

  4. Advanced oxidation processes with coke plant wastewater treatment.

    PubMed

    Krzywicka, A; Kwarciak-Kozłowska, A

    2014-01-01

    The aim of this study was to determine the most efficient method of coke wastewater treatment. This research examined two processes - advanced oxidation with Fenton and photo-Fenton reaction. It was observed that the use of ultraviolet radiation with Fenton process had a better result in removal of impurities.

  5. TECHNOLOGY SUMMARY ADVANCING TANK WASTE RETREIVAL AND PROCESSING

    SciTech Connect

    SAMS TL

    2010-07-07

    This technology overview provides a high-level summary of technologies being investigated and developed by Washington River Protection Solutions (WRPS) to advance Hanford Site tank waste retrieval and processing. Technology solutions are outlined, along with processes and priorities for selecting and developing them.

  6. The design, fabrication, and test of a new VLSI hybrid analog-digital neural processing element

    NASA Technical Reports Server (NTRS)

    Deyong, Mark R.; Findley, Randall L.; Fields, Chris

    1992-01-01

    A hybrid analog-digital neural processing element with the time-dependent behavior of biological neurons has been developed. The hybrid processing element is designed for VLSI implementation and offers the best attributes of both analog and digital computation. Custom VLSI layout reduces the layout area of the processing element, which in turn increases the expected network density. The hybrid processing element operates at the nanosecond time scale, which enables it to produce real-time solutions to complex spatiotemporal problems found in high-speed signal processing applications. VLSI prototype chips have been designed, fabricated, and tested with encouraging results. Systems utilizing the time-dependent behavior of the hybrid processing element have been simulated and are currently in the fabrication process. Future applications are also discussed.

  7. The design, fabrication, and test of a new VLSI hybrid analog-digital neural processing element

    NASA Technical Reports Server (NTRS)

    Deyong, Mark R.; Findley, Randall L.; Fields, Chris

    1992-01-01

    A hybrid analog-digital neural processing element with the time-dependent behavior of biological neurons has been developed. The hybrid processing element is designed for VLSI implementation and offers the best attributes of both analog and digital computation. Custom VLSI layout reduces the layout area of the processing element, which in turn increases the expected network density. The hybrid processing element operates at the nanosecond time scale, which enables it to produce real-time solutions to complex spatiotemporal problems found in high-speed signal processing applications. VLSI prototype chips have been designed, fabricated, and tested with encouraging results. Systems utilizing the time-dependent behavior of the hybrid processing element have been simulated and are currently in the fabrication process. Future applications are also discussed.

  8. Primary fabric ellipsoids in sandstones: implications for depositional processes and strain analysis

    NASA Astrophysics Data System (ADS)

    Paterson, Scott R.; Yu, Hao

    1994-04-01

    matrix cements also argue against significant compaction during burial in these clast-supported, sand-rich units and instead suggest that the primary fabrics largely reflect grain packing processes during deposition, and/or slumping and packing in the case of the Pigeon Point samples.

  9. Evaluation of the fabricability of advanced iron aluminide-clad austenitic stainless steel tubing

    SciTech Connect

    Mohn, W.R.; Topolski, M.J.

    1993-07-01

    Researchers at Babcock & Wilcox Alliance Research Center have investigated methods to produce bimetallic tubing consisting of iron aluminide-clad austenitic stainless steel for practical use in fossil fueled energy equipment. In the course of this work, the compatibility of iron aluminide with four candidate austenitic stainless steel substrates was first evaluated using diffusion couples. Based on these results, a combination of iron aluminide and 304 stainless steel was selected for further development. Two composite billets of this combination were then prepared and extruded in separate trails at 2200F and 2000F. Both extrusions yielded 2-inch OD clad tubes, each approximately 18 feet long. Results of the evaluation show that the tube extruded at 2000F had a sound, integrally bonded clad layer throughout its entire length. However, the tube extruded at 2200F exhibited regions of disbonding between the clad layer and the substrate. In supplement to this work, an assessment of the technical and economic merits of iron aluminide-clad austenitic stainless steel components in power generation systems was conducted by B&W Fossil Power Division. Future activities should include an investigation of lower extrusion processing temperatures to optimize the fabrication of high quality iron-aluminide clad tubing.

  10. An advanced low-fluorine solution route for fabrication of high-performance YBCO superconducting films

    NASA Astrophysics Data System (ADS)

    Chen, Yuanqing; Wu, Chuanbao; Zhao, Gaoyang; You, Caiyin

    2012-06-01

    We have developed a new low-fluorine solution consisting of non-fluorine (F-free) barium and copper salts, and fluorine-containing yttrium trifluoroacetate. Using this new low-fluorine solution, the BaCO3 phase was avoided in the pyrolyzed precursor films. Instead, CuO, Y and Ba fluorides (YF3 and BaF2) were formed in the precursor films pyrolyzed at 450 °C, which was the same as when an All-TFA solution (prepared using Y, Ba, Cu trifluoroacetates as precursors) or other fluorine-reduced solutions were used. This new kind of low-fluorine solution has only 23% of the fluorine content in an All-TFA solution, and the fluorine content was lower than any other fluorine-reduced solution. Thus, rapid production of YBa2Cu3O7-x (YBCO) films can be easily realized. Using a heating rate of 10 °C min-1 in the pyrolysis process, a high critical current density (Jc) of 5 MA cm-2 (at 77 K, 0 T) was obtained in YBCO films fabricated on LaAlO3 (LAO) single crystal substrates from the new starting solution.

  11. Development of processing procedures for advanced silicon solar cells. [antireflection coatings and short circuit currents

    NASA Technical Reports Server (NTRS)

    Scott-Monck, J. A.; Stella, P. M.; Avery, J. E.

    1975-01-01

    Ten ohm-cm silicon solar cells, 0.2 mm thick, were produced with short circuit current efficiencies up to thirteen percent and using a combination of recent technical advances. The cells were fabricated in conventional and wraparound contact configurations. Improvement in cell collection efficiency from both the short and long wavelengths region of the solar spectrum was obtained by coupling a shallow junction and an optically transparent antireflection coating with back surface field technology. Both boron diffusion and aluminum alloying techniques were evaluated for forming back surface field cells. The latter method is less complicated and is compatible with wraparound cell processing.

  12. Development and demonstration of manufacturing processes for fabricating graphite/LARC-160 polyimide structural elements, part 4, paragraph B

    NASA Technical Reports Server (NTRS)

    1980-01-01

    A quality assurance program was developed which included specifications for celion/LARC-160 polyimide materials and quality control of materials and processes. The effects of monomers and/or polymer variables and prepeg variables on the processibility of celion/LARC prepeg were included. Processes for fabricating laminates, honeycomb core panels, and chopped fiber moldings were developed. Specimens and conduct tests were fabricated to qualify the processes for fabrication of demonstration components.

  13. Welding process selection for fabrication of a superconducting magnet structure

    SciTech Connect

    Goodwin, G.M.

    1985-08-01

    The magnets that will provide containment of the intensely hot plasma in fusion reactors must be wound with superconductors to enable these reactors to produce more energy than they consume (Ref. 1). With current superconductor technology, this requires the use of liquid helium at its boiling point (about 4 K, or -269/sup 0/C) as a coolant. At this temperature, all other known materials are solid. Austenitic stainless steels are the most widely used alloys for structural applications below 77 K (-196/sup 0/C) (Ref. 2). Their physical properties offer advantages over those of competing materials; the elastic modulus is high, and the thermal expansion, magnetic permeability, and electrical and thermal conductivities are low. Their mechanical properties, including strength, ductility and fracture toughness, are generally adequate to withstand the large forces imposed on magnet structures reliably. A possible exception to this statement arises in the case of weldments; the limited 4 K (-269/sup 0/C) fracture toughness data for austenitic stainless steel weld metal show a wide range of values, with no obvious explanation for the large differences. This report summarizes the data available in the literature, contributes new data for three different welding processes - gas tungsten arc (GTAW), shielded metal arc (SMAW) and flux cored arc (FCAW) - and offers some observations of the fracture morphology.

  14. Novel printing process for the fabrication of cantilever structures by the partially controlled sintering of ink

    NASA Astrophysics Data System (ADS)

    Kanazawa, Shusuke; Kusaka, Yasuyuki; Yamamoto, Noritaka; Ushijima, Hirobumi

    2017-01-01

    We present a novel process for manufacturing cantilever structures by the additive stacking of ink layers. The three-dimensional transfer of printed mechanical parts was achieved by optimizing the ink-sintering conditions to guarantee the structural integrity of the printed parts and provide adequate differences in adhesion strengths between the receiver and donor interfaces. A metal-insulator-metal cantilever structure with a bottom electrode, air insulator, and cantilevered top electrode was fabricated on a flexible film, forming a successful capacitive bending sensor for use on human bodies. This process allows highly efficient device fabrication in the MEMS field.

  15. Comb/serpentine/cross-bridge test structure for fabrication process evaluation

    NASA Technical Reports Server (NTRS)

    Sayah, Hoshyar R.; Buehler, Martin G.

    1988-01-01

    The comb/serpentine/cross-bridge structure was developed to monitor and evaluate same layer shorts and step coverage problems (open and high-resistance wire over steps) for integrated circuit fabrication processes. The cross-bridge provides local measurements of wire sheet resistance and wirewidth. These local parametric measurements are used in the analysis of the serpentine wire, which identifies step coverage problems. The comb/serpentine/cross-bridge structure was fabricated with 3 microns CMOS/bulk p-well process and tested using a computer-controlled parametric test system.

  16. Advancing MEMS Technology Usage through the MUMPS (Multi-User MEMS Processes) Program

    NASA Technical Reports Server (NTRS)

    Koester, D. A.; Markus, K. W.; Dhuler, V.; Mahadevan, R.; Cowen, A.

    1995-01-01

    In order to help provide access to advanced micro-electro-mechanical systems (MEMS) technologies and lower the barriers for both industry and academia, the Microelectronic Center of North Carolina (MCNC) and ARPA have developed a program which provides users with access to both MEMS processes and advanced electronic integration techniques. The four distinct aspects of this program, the multi-user MEMS processes (MUMP's), the consolidated micro-mechanical element library, smart MEMS, and the MEMS technology network are described in this paper. MUMP's is an ARPA-supported program created to provide inexpensive access to MEMS technology in a multi-user environment. It is both a proof-of-concept and educational tool that aids in the development of MEMS in the domestic community. MUMP's technologies currently include a 3-layer poly-silicon surface micromachining process and LIGA (lithography, electroforming, and injection molding) processes that provide reasonable design flexibility within set guidelines. The consolidated micromechanical element library (CaMEL) is a library of active and passive MEMS structures that can be downloaded by the MEMS community via the internet. Smart MEMS is the development of advanced electronics integration techniques for MEMS through the application of flip chip technology. The MEMS technology network (TechNet) is a menu of standard substrates and MEMS fabrication processes that can be purchased and combined to create unique process flows. TechNet provides the MEMS community greater flexibility and enhanced technology accessibility.

  17. Fabrication of Fully Solution Processed Inorganic Nanocrystal Photovoltaic Devices.

    PubMed

    Townsend, Troy K; Durastanti, Dario; Heuer, William B; Foos, Edward E; Yoon, Woojun; Tischler, Joseph G

    2016-07-08

    We demonstrate a method for the preparation of fully solution processed inorganic solar cells from a spin and spray coating deposition of nanocrystal inks. For the photoactive absorber layer, colloidal CdTe and CdSe nanocrystals (3-5 nm) are synthesized using an inert hot injection technique and cleaned with precipitations to remove excess starting reagents. Similarly, gold nanocrystals (3-5 nm) are synthesized under ambient conditions and dissolved in organic solvents. In addition, precursor solutions for transparent conductive indium tin oxide (ITO) films are prepared from solutions of indium and tin salts paired with a reactive oxidizer. Layer-by-layer, these solutions are deposited onto a glass substrate following annealing (200-400 °C) to build the nanocrystal solar cell (glass/ITO/CdSe/CdTe/Au). Pre-annealing ligand exchange is required for CdSe and CdTe nanocrystals where films are dipped in NH4Cl:methanol to replace long-chain native ligands with small inorganic Cl(-) anions. NH4Cl(s) was found to act as a catalyst for the sintering reaction (as a non-toxic alternative to the conventional CdCl2(s) treatment) leading to grain growth (136±39 nm) during heating. The thickness and roughness of the prepared films are characterized with SEM and optical profilometry. FTIR is used to determine the degree of ligand exchange prior to sintering, and XRD is used to verify the crystallinity and phase of each material. UV/Vis spectra show high visible light transmission through the ITO layer and a red shift in the absorbance of the cadmium chalcogenide nanocrystals after thermal annealing. Current-voltage curves of completed devices are measured under simulated one sun illumination. Small differences in deposition techniques and reagents employed during ligand exchange have been shown to have a profound influence on the device properties. Here, we examine the effects of chemical (sintering and ligand exchange agents) and physical treatments (solution concentration

  18. Advanced materials: The fabrication, characterization and study of novel ceramics and composites

    NASA Astrophysics Data System (ADS)

    Pitcher, Michael W.

    As advances in technology prompt demands for materials with specific and wide ranges of properties, traditional materials have often not been able to meet these more challenging needs. There is also an exigency to process these materials with minimal consumption of energy at low cost. To address these needs there has been a considerable impetus to develop new materials, new processing strategies and/or new synthetic strategies. This thesis focuses on the synthesis, characterization, and manipulation of a variety of new and advanced materials. The two main topics of this thesis are, firstly, a composite system where the growth of an inorganic phase takes place within a polymer film. Composite films of CdS in PEO were formed by an in situ reaction of CdCl2/PEO composite films with an octane solution of hexamethyldisilathiane [S(TMS) 2]. Organized crystallization of the product was found only to occur in thin films (<300nm) in the presence of surfactant. Crystals were found to be uniform in size, shape, phase and crystallographic orientation. The principles of this system have been further developed and used to produce novel phases of lead sulfides at room temperature and pressure, and the first known synthesis of single crystals of Lithium Niobate at room temperature and pressure. The second part of this thesis deals with the synthesis and characterization of poly(methyl)silyne (PMSy), a polymer precursor to silicon carbide (SiC). The synthesis of PMSy is both cheap and simple. The polymer is non-pyrophoric which is unique among current SiC preceramic polymers. The pyrolysis of PMSy results in a ceramic of unrivaled purity, it is the only perfectly stoichiometric SiC than has been obtained from any polymeric precursor. Ceramic films have also been produced from PMSy, and are the smoothest, the most continuous, the most perfect and defect free that have ever been reported.

  19. Recent advances in ultrasonic-assisted machining for the fabrication of micro/nano-textured surfaces

    NASA Astrophysics Data System (ADS)

    Xu, Shaolin; Kuriyagawa, Tsunemoto; Shimada, Keita; Mizutani, Masayoshi

    2017-03-01

    In this paper, the state of art of ultrasonic-assisted machining technologies used for fabrication of micro/nano-textured surfaces is reviewed. Diamond machining is the most widely used method in industry for manufacturing precision parts. For fabrication of fine structures on surfaces, conventional diamond machining methods are competitive by considering the precision of structures, but have limitations at machinable structures and machining efficiency, which have been proved to be partly solved by the integration of ultrasonic vibration motion. In this paper, existing ultrasonic-assisted machining methods for fabricating fine surface structures are reviewed and classified, and a rotary ultrasonic texturing (RUT) technology is mainly introduced by presenting the construction of vibration spindles, the texturing principles, and the applications of textured surfaces. Some new ideas and experimental results are presented. Finally, the challenges in using the RUT method to fabricate micro/ nano-textured surfaces are discussed with respect to texturing strategies, machinable structures, and tool wear.

  20. Recent advances in ultrasonic-assisted machining for the fabrication of micro/nano-textured surfaces

    NASA Astrophysics Data System (ADS)

    Xu, Shaolin; Kuriyagawa, Tsunemoto; Shimada, Keita; Mizutani, Masayoshi

    2017-02-01

    In this paper, the state of art of ultrasonicassisted machining technologies used for fabrication of micro/nano-textured surfaces is reviewed. Diamond machining is the most widely used method in industry for manufacturing precision parts. For fabrication of fine structures on surfaces, conventional diamond machining methods are competitive by considering the precision of structures, but have limitations at machinable structures and machining efficiency, which have been proved to be partly solved by the integration of ultrasonic vibration motion. In this paper, existing ultrasonic-assisted machining methods for fabricating fine surface structures are reviewed and classified, and a rotary ultrasonic texturing (RUT) technology is mainly introduced by presenting the construction of vibration spindles, the texturing principles, and the applications of textured surfaces. Some new ideas and experimental results are presented. Finally, the challenges in using the RUT method to fabricate micro/ nano-textured surfaces are discussed with respect to texturing strategies, machinable structures, and tool wear.