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Sample records for advanced fabrication process

  1. Optimization of segmented alignment marks for advanced semiconductor fabrication processes

    NASA Astrophysics Data System (ADS)

    Wu, Qiang; Lu, Zhijian G.; Williams, Gary; Zach, Franz X.; Liegl, Bernhard

    2001-08-01

    The continued downscaling of semiconductor fabrication ground rule has imposed increasingly tighter overlay tolerances, which becomes very challenging at the 100 nm lithographic node. Such tight tolerances will require very high performance in alignment. Past experiences indicate that good alignment depends largely on alignment signal quality, which, however, can be strongly affected by chip design and various fabrication processes. Under some extreme circumstances, they can even be reduced to the non- usable limit. Therefore, a systematic understanding of alignment marks and a method to predict alignment performance based on mark design are necessary. Motivated by this, we have performed a detailed study of bright field segmented alignment marks that are used in current state-of- the-art fabrication processes. We find that alignment marks at different lithographic levels can be organized into four basic categories: trench mark, metal mark, damascene mark, and combo mark. The basic principles of these four types of marks turn out to be so similar that they can be characterized within the theoretical framework of a simple model based on optical gratings. An analytic expression has been developed for such model and it has been tested using computer simulation with the rigorous time-domain finite- difference (TD-FD) algorithm TEMPEST. Consistent results have been obtained; indicating that mark signal can be significantly improved through the optimization of mark lateral dimensions, such as segment pitch and segment width. We have also compared simulation studies against experimental data for alignment marks at one typical lithographic level and a good agreement is found.

  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. 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.

  6. 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.

    2016-03-01

    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.

  7. 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

  8. Advancements in fabrication process of microelectrode array for a retinal prosthesis using Liquid Crystal Polymer (LCP).

    PubMed

    Jeong, Joonsoo; Shin, Soowon; Lee, Geun Jae; Gwon, Tae Mok; Park, Jeong Hoan; Kim, Sung June

    2013-01-01

    Liquid Crystal Polymer (LCP) has been considered as an alternative biomaterial for implantable biomedical devices primarily for its low moisture absorption rate compared with conventional polymers such as polyimide, parylene and silicone elastomers. A novel retinal prosthetic device based on monolithic encapsulation of LCP is being developed in which entire neural stimulation circuitries are integrated into a thin and eye-conformable structure. Micromachining techniques for fabrication of a LCP retinal electrode array have been previously reported. In this research, however, for being used as a part of the LCP-based retinal implant, we developed advanced fabrication process of LCP retinal electrode through new approaches such as electroplating and laser-machining in order to achieve higher mechanical robustness, long-term reliability and flexibility. Thickened metal tracks could contribute to higher mechanical strength as well as higher long-term reliability when combined with laser-ablation process by allowing high-pressure lamination. Laser-thinning technique could improve the flexibility of LCP electrode. PMID:24110931

  9. 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.

  10. 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.

  11. 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

  12. Fabrication of advanced C/C composites by a hybrid process of CVI/liquid precursor impregnation

    SciTech Connect

    Ishizaki, Masato; Shioda, Muneyoshi; Miyahara, Kaoru; Sasa, Tadashi

    1995-10-01

    Fabrication processing of advanced C/C composites was developed by combining the CVI and liquid impregnation-pyrolysis processes. Time-controlled temperature-gradient (TC-TG) CVI processing was developed to accelerate the carbon matrix deposition in the C-fiber preform within relatively short process-time. The temperature gradient in the perform was changed according to a controlled program. The present TC-TG-CVI process gave twice as much weight gain as that of the conventional steady TG-CVI process. The CVI process, however, showed a limitation to fill up the large pores between the bundles. Liquid impregnation-pyrolysis was, therefore, carried out after the TC-TG-CVI process to improve the infiltration of these pores. Polycarbosilane (PCS) with the yield of about 50 wt% was used as the liquid precursor to form a SiC-rich matrix to improve the oxidation-resistance. SiC matrix was observed in the pores between bundles after pyrolysis of PCS. The weight gain after pyrolysis was found to be nearly saturated after 10 cycles of the impregnation-pyrolysis process.

  13. 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.

  14. 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.

  15. 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

  16. Advanced optic fabrication using ultrafast laser radiation

    NASA Astrophysics Data System (ADS)

    Taylor, Lauren L.; Qiao, Jun; Qiao, Jie

    2016-03-01

    Advanced fabrication and finishing techniques are desired for freeform optics and integrated photonics. Methods including grinding, polishing and magnetorheological finishing used for final figuring and polishing of such optics are time consuming, expensive, and may be unsuitable for complex surface features while common photonics fabrication techniques often limit devices to planar geometries. Laser processing has been investigated as an alternative method for optic forming, surface polishing, structure writing, and welding, as direct tuning of laser parameters and flexible beam delivery are advantageous for complex freeform or photonics elements and material-specific processing. Continuous wave and pulsed laser radiation down to the nanosecond regime have been implemented to achieve nanoscale surface finishes through localized material melting, but the temporal extent of the laser-material interaction often results in the formation of a sub-surface heat affected zone. The temporal brevity of ultrafast laser radiation can allow for the direct vaporization of rough surface asperities with minimal melting, offering the potential for smooth, final surface quality with negligible heat affected material. High intensities achieved in focused ultrafast laser radiation can easily induce phase changes in the bulk of materials for processing applications. We have experimentally tested the effectiveness of ultrafast laser radiation as an alternative laser source for surface processing of monocrystalline silicon. Simulation of material heating associated with ultrafast laser-material interaction has been performed and used to investigate optimized processing parameters including repetition rate. The parameter optimization process and results of experimental processing will be presented.

  17. 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.

  18. Process for fabrication of cermets

    DOEpatents

    Landingham, Richard L.

    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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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

  4. 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.

  5. 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.

  6. 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)

  7. 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.

  8. Advanced fabrication technologies for nano-electronics

    SciTech Connect

    Simmons, J.A.; Weckwerth, M.V.; Baca, W.E.

    1996-03-01

    Three novel fabrication technologies are presented which greatly increase the tools available for the realization of nano-electronic devices. First, a sub-micron area post structure descending from a metallic airbridge allows gating of regions as small as 0.1 {mu}m in diameter. This has enabled the study of such quantum phenomena as coupling of parallel quantum point contacts, and electron focusing around a tunable quantum antidot. We also describe two new techniques for backgating multiquantum well structures with submicron lateral resolution. These techniques enable separate ohmic contacts to individual quantum wells spaced as closely as 100 {Angstrom}, and thus allow the fabrication of novel quantum tunneling devices. The first technique uses regrowth over a patterned ion-implanted substrate. The second involves a novel epoxy-bond-and-stop-etch (EBASE) processing scheme, whereby the original substrate is etched away and the backside then patterned using conventional methods.

  9. Advanced detectors and signal processing

    NASA Technical Reports Server (NTRS)

    Greve, D. W.; Rasky, P. H. L.; Kryder, M. H.

    1986-01-01

    Continued progress is reported toward development of a silicon on garnet technology which would allow fabrication of advanced detection and signal processing circuits on bubble memories. The first integrated detectors and propagation patterns have been designed and incorporated on a new mask set. In addition, annealing studies on spacer layers are performed. Based on those studies, a new double layer spacer is proposed which should reduce contamination of the silicon originating in the substrate. Finally, the magnetic sensitivity of uncontaminated detectors from the last lot of wafers is measured. The measured sensitivity is lower than anticipated but still higher than present magnetoresistive detectors.

  10. Advanced signal processing

    NASA Astrophysics Data System (ADS)

    Creasey, D. J.

    1985-12-01

    A collection of papers on advanced signal processing in radar, sonar, and communications is presented. The topics addressed include: transmitter aerials, high-power amplifier design for active sonar, radar transmitters, receiver array technology for sonar, new underwater acoustic detectors, diversity techniques in communications receivers, GaAs IC amplifiers for radar and communication receivers, integrated optical techniques for acoustooptic receivers, logarithmic receivers, CCD processors for sonar, acoustooptic correlators, designing in silicon, very high performance integrated circuits, and digital filters. Also discussed are: display types, scan converters in sonar, display ergonomics, simulators, high throughput sonar processors, optical fiber systems for signal processing, satellite communications, VLSI array processor for image and signal processing, ADA, future of cryogenic devices for signal processing applications, advanced image understanding, and VLSI architectures for real-time image processing.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. Advanced soldering processes

    SciTech Connect

    Jellison, J.L.; Golden, J.; Frear, D.R.; Hosking, F.M.; Keicher, D.M.; Yost, F.G.

    1993-02-20

    Advanced soldering processes are discussed in a complete manner. The ability to meet the needs of electronic manufacturing, while addressing the environmental issues are challenging goals. Government regulations mandate the elimination of most solvents in solder flux removal. Alternative approaches to promoting wetting are discussed. Inert atmosphere soldering, acid vapor fluxless soldering, atomic and ionic hydrogen as reactive atmospheres, fluxless laser soldering in a controlled atmosphere are offered as soldering mechanisms for the future. Laser are discussed as alternate heat sources. Various types of lasers, advantages of lasers, and fiber optic beam delivery are considered.

  16. 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.

  17. 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

  18. Advances in speech processing

    NASA Astrophysics Data System (ADS)

    Ince, A. Nejat

    1992-10-01

    The field of speech processing is undergoing a rapid growth in terms of both performance and applications and this is fueled by the advances being made in the areas of microelectronics, computation, and algorithm design. The use of voice for civil and military communications is discussed considering advantages and disadvantages including the effects of environmental factors such as acoustic and electrical noise and interference and propagation. The structure of the existing NATO communications network and the evolving Integrated Services Digital Network (ISDN) concept are briefly reviewed to show how they meet the present and future requirements. The paper then deals with the fundamental subject of speech coding and compression. Recent advances in techniques and algorithms for speech coding now permit high quality voice reproduction at remarkably low bit rates. The subject of speech synthesis is next treated where the principle objective is to produce natural quality synthetic speech from unrestricted text input. Speech recognition where the ultimate objective is to produce a machine which would understand conversational speech with unrestricted vocabulary, from essentially any talker, is discussed. Algorithms for speech recognition can be characterized broadly as pattern recognition approaches and acoustic phonetic approaches. To date, the greatest degree of success in speech recognition has been obtained using pattern recognition paradigms. It is for this reason that the paper is concerned primarily with this technique.

  19. 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.

  20. 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.

  1. 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.

  2. Polymer micromold and fabrication process

    SciTech Connect

    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.

  3. Polymer micromold and fabrication process

    SciTech Connect

    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.

  4. 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

  5. Advanced Process Heater

    SciTech Connect

    Tom Briselden, Chris Parrish

    2005-03-07

    The Roadmap for Process Heating Technology (March 16, 2001), identified the following priority R&D needs: Improved performance of high temperature materials; Improved methods for stabilizing low emission flames; Heating technologies that simultaneously reduce emissions, increase efficiency, and increase heat transfer. This Category I award entitled ''Proof of Concept of an Advanced Process Heater (APH) for Steel, Aluminum, and Petroleum Industries of the Future'' met the technical feasibility goals of: (1) Doubling the heat transfer rates (2) Improving thermal efficiencies by 20%, (3) Improving temperature uniformity by 100 degrees F and (4) simultaneously reducing NOx and CO2 emissions. The APH address EERE's mission priority of increasing efficiency/reducing fuel usage in energy intensive industries. One component of the APH, the SpyroCorTM, was commercialized by STORM Development's partner, Spinworks LLC. Over 2000 SpyrCorsTM were sold in 2004 resulting in 480 million BTU's of energy savings, 20% reduction in NOx and CO2 levels, and 9 jobs in N.W. Pennsylvania. A second component, the HeatCorTM, a low-cost high-temperature heat exchanger will be demonstrated by Spinworks in 2005 in preparation for commercial sales in 2006. The project occurred in the 21st Congressional District of Pennsylvania. Once fully commercialized, the APH energy savings potential is 339 trillion BTUs annually in the U.S. and will process 1.5 million more tons annually without major capital equipment expenditures. Spinworks will commercialize the APH and add over 100 U.S. workers. To accomplish the objective, STORM Development LLC teamed with Penn State University, SyCore, Inc, Spinworks LLC, and Schunk-INEX, Inc. The project consisted of component engineering and integration of the APH followed by parametric testing. All components of the system were tested in a lab furnace that simulates a full scale industrial installation. The target areas for development include: (1) Scale up STORM

  6. Solid Freeform Fabrication Using the Wirefeed Process

    SciTech Connect

    Buchheit, T.E.; Crenshaw, T.B.; Ensz, M.T.; Greene, D.L.; Griffith, M.L.; Harwell, L.D.; Reckaway, D.E.; Romero, J.A.; Tikare, V.

    1999-07-22

    Direct metal deposition technologies produce complex, near net shape components from CAD solid models. Most of these techniques fabricate a component by melting powder in a laser weld pool, rastering this weld bead to form a layer, and additively constructing subsequent layers. This talk describes a new direct metal deposition process, known as WireFeed, whereby a small diameter wire is used instead of powder as the feed material to fabricate components. Currently, parts are being fabricated from stainless steel. Microscopy studies show the WireFeed parts to be fully dense with fine microstructural features. Initial mechanical tests show stainless steel parts to have good strength values with retained ductility.

  7. 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.

  8. Nano-fabrication processes for magnesium diboride

    NASA Astrophysics Data System (ADS)

    Shibata, Hiroyuki; Akazaki, Tatsushi; Tokura, Yasuhiro

    2010-12-01

    We compare the various nanowire fabrication processes for MgB 2 ultra-thin films: Ar ion beam milling with or without a protective layer (Au and SiO 2), an reactive ion etching (RIE) with fluorine-based gas, and a liftoff process using an Si/C bilayer mask. With Ar milling, we can fabricate nanowires down to 200 nm-wide, but the superconducting properties degrade as the width decreases further. MgB 2 can be etched by the fluorine-based RIE, but the etch rate is too slow for fabrication. The liftoff process gives the reliable and damage-free nanowires down to 100 nm-wide.

  9. Fabrication process of a high temperature polymer matrix engine duct

    NASA Technical Reports Server (NTRS)

    Pratt, R. D.; Wilson, A. J.

    1985-01-01

    The process that was used in the molding of an advanced composite outer by-pass duct planned for the F404 engine is discussed. This duct was developed as a potential replacement for the existing titanium duct in order to reduce both the weight and cost of the duct. The composite duct is now going into the manufacturing technology portion of the program. The duct is fabricated using graphite cloth impregnated with the PMR-15 matrix system.

  10. 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...

  11. 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.

  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. 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.

  14. 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.

  15. Advances in modeling of chemical vapor infiltration for tube fabrication

    SciTech Connect

    Starr, T.L.

    1998-04-01

    The forced flow/thermal gradient chemical vapor infiltration process (FCVI) can be used for fabrication of tube-shaped components of ceramic matrix composites. Recent experimental work at Oak Ridge National Laboratory (ORNL) includes process and materials development studies using a small tube reactor. Use of FCVI for this geometry involves significant changes in fixturing as compared to disk-shaped preforms previously fabricated. The authors have used their computer model of the CVI process to simulate tube densification and to identify process modifications that will decrease processing time. This report presents recent model developments and applications.

  16. Design, Fabrication and Certification of Advanced Modular PV Power Systems

    NASA Astrophysics Data System (ADS)

    Minyard, Glen E.; Lambarski, Timothy J.

    1997-02-01

    The Design, Fabrication and Certification of Advanced Modular PV Power Systems contract is a Photovoltaic Manufacturing Technology (PVMaT) cost-shared contract under Phase 4A1 for Product Driven Systems and Component Technologies. Phase 4A1 has the goals to improve the cost-effectiveness and manufacturing efficiency of PV end-products, optimize manufacturing and packaging methods, and generally improve balance-of-system performance, integration and manufacturing. This contract has the specific goal to reduce the installed PV system life cycle costs to the customer with the ultimate goal of increasing PV system marketability and customer acceptance. The specific objectives of the project are to develop certified, standardized, modular, pre-engineered products lines of our main stand-alone systems, the Modular Autonomous PV Power Supply (MAPPS) and PV-Generator Hybrid System (Photogenset). To date, we have designed a 200 W MAPPS and a 1 kW Photogenset and are in the process of having the MAPPS certified by Underwriters Laboratories (UL Listed) and approved for hazardous locations by Factory Mutual (FM). We have also developed a manufacturing plan for product line expansion for the MAPPS. The Photogenset will be fabricated in February 1997 and will also be UL Listed. Functionality testing will be performed at NREL and Sandia with the intentions of providing verification of performance and reliability and of developing test-based performance specifications. In addition to an expansion on the goals, objectives and status of the project, specific accomplishments and benefits are also presented in this paper.

  17. 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).

  18. Radiographic amplifier screens: Fabrication process and characteristics

    NASA Technical Reports Server (NTRS)

    Szepesi, Z. P.

    1977-01-01

    The fabrication process and transfer characteristics for solid state radiographic image transducers (radiographic amplifier screens) is described. These screens were developed for use in real time nondestructive evaluation procedures that require large format radiographic images with contrast and resolution capabilities unavailable with conventional fluoroscopic screens. This work was directed toward screens usable for inmotion, on-line radiographic inspection by means of closed circuit television.

  19. 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.

  20. ADVANCED OXIDATION PROCESS

    SciTech Connect

    Colin P. Horwitz; Terrence J. Collins

    2003-10-22

    The design of new, high efficiency and cleaner burning engines is strongly coupled with the removal of recalcitrant sulfur species, dibenzothiophene and its derivatives, from fuels. Oxidative desulfurization (ODS) wherein these dibenzothiophene derivatives are oxidized to their corresponding sulfoxides and sulfones is an approach that has gained significant attention. Fe-TAML{reg_sign} activators of hydrogen peroxide (TAML is Tetra-Amido-Macrocyclic-Ligand) convert in a catalytic process dibenzothiophene and its derivatives to the corresponding sulfoxides and sulfones rapidly at moderate temperatures (60 C) and ambient pressure. The reaction can be performed in both an aqueous system containing an alcohol (methanol, ethanol, or t-butanol) to solubilize the DBT and in a two-phase hydrocarbon/aqueous system where the alcohol is present in both phases and facilitates the oxidation. Under a consistent set of conditions using the FeBF{sub 2} TAML activator, the degree of conversion was found to be t-butanol > methanol > ethanol. In the cases of methanol and ethanol, both the sulfoxide and sulfone were observed while for t-butanol only the sulfone was detected. In the two-phase system, the alcohol may function as an inverse phase transfer agent. The oxidation was carried out using two different TAML activators. In homogeneous solution, approximately 90% oxidation of the DBT could be achieved using the prototype TAML activator, FeB*, by sonicating the solution at near room temperature. In bi-phasic systems conversions as high as 50% were achieved using the FeB* TAML activator and hydrogen peroxide at 100 C. The sonication method yielded only {approx}6% conversion but this may have been due to mixing.

  1. Design and fabrication of advanced EUV diffractive elements

    SciTech Connect

    Naulleau, Patrick P.; Liddle, J. Alexander; Salmassi, Farhad; Anderson, Erik H.; Gullikson, Eric M.

    2003-11-16

    As extreme ultraviolet (EUV) lithography approaches commercial reality, the development of EUV-compatible diffractive structures becomes increasingly important. Such devices are relevant to many aspects of EUV technology including interferometry, illumination, and spectral filtering. Moreover, the current scarcity of high power EUV sources makes the optical efficiency of these diffractive structures a paramount concern. This fact has led to a strong interest in phase-enhanced diffractive structures. Here we describe recent advancements made in the fabrication of such devices.

  2. 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.

  3. 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

  4. 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.

  5. 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.

  6. 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.

  7. Fabrication development for the Advanced Neutron Source Reactor

    SciTech Connect

    Pace, B.W.; Copeland, G.L.

    1995-08-01

    This report presents the fuel fabrication development for the Advanced Neutron Source (ANS) reactor. The fuel element is similar to that successfully fabricated and used in the High Flux Isotope Reactor (HFIR) for many years, but there are two significant differences that require some development. The fuel compound is U{sub 3}Si{sub 2} rather than U{sub 3}O{sub 8}, and the fuel is graded in the axial as well as the radial direction. Both of these changes can be accomplished with a straightforward extension of the HFIR technology. The ANS also requires some improvements in inspection technology and somewhat more stringent acceptance criteria. Early indications were that the fuel fabrication and inspection technology would produce a reactor core meeting the requirements of the ANS for the low volume fraction loadings needed for the highly enriched uranium design (up to 1.7 Mg U/m{sup 3}). Near the end of the development work, higher volume fractions were fabricated that would be required for a lower- enrichment uranium core. Again, results look encouraging for loadings up to {approx}3.5 Mg U/m{sup 3}; however, much less evaluation was done for the higher loadings.

  8. 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

  9. 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

  10. Ultrastructure processing of advanced ceramics

    SciTech Connect

    Mackenzie, J.D.; Ulrich, D.R.

    1988-01-01

    Experimental investigations and applications of advanced ceramics are discussed in reviews and reports presented at the Third International Conference on Ultrastructure Processing of Ceramics, Glasses, and Composites held in San Diego in February 1987. Sections are devoted to precursors and chemistry for ultrastructure processing; sol-gel science and technology; powders and colloids; advanced ceramics; and composites, new materials, and techniques. Particular attention is given to silicon oxynitride and sialon ceramics from organosilicon powders, fluoropolymer-modified silicate glasses, Raman and FTIR spectroscopy of rapid sol-gel processes, a low-temperature route to high-purity Ti/Zr/Hf diboride powders and films, and sol-gel methods for SiO2 optical-fiber coatings. Diagrams, drawings, graphs, micrographs, and tables of numerical data are included.

  11. 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.

  12. 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.

  13. Recent advantages in processing and fabrication of ceramic superconductors

    NASA Astrophysics Data System (ADS)

    Balachandran, U.; Poeppel, R. B.; Ferrando, W. A.; Karmarkar, S. D.; Kerr, J.; Hess, P. W.; Divecha, A. P.

    1991-08-01

    The properties of ceramic superconductors are greatly influenced by the temperature, heating rate, pressure, and gas atmosphere used during processing and fabrication. For example, transport critical current density decreases drastically in the presence of trace amounts of CO2 in the sintering atmosphere. The grain boundaries of samples sintered in O2 atmospheres containing various levels of CO2 have been thoroughly characterized by high-resolution electron microscopy. Reduced total pressure during binder removal and sintering was found to prevent decomposition of the superconductor. We have developed a low-oxygen-pressure technique for calcining precursors and sintering long lengths of wires and coils. Other advances include the improvement of critical current density and levitation force through melt-growth processing, incorporating of insulating coatings, and powder-in-tube processing of superconductors.

  14. 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.

  15. Advanced System for Process Engineering

    Energy Science and Technology Software Center (ESTSC)

    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 computationmore » 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.« less

  16. 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

  17. 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. PMID:26185244

  18. 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.

  19. 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.

  20. 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.

  1. 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

  2. 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. PMID:16003995

  3. 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).

  4. Advanced System for Process Engineering

    Energy Science and Technology Software Center (ESTSC)

    1998-09-14

    PRO ASPEN/PC1.0 (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 and has been ported to run on a PC. PRO ASPEN/PC1.0 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.more » 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 PRO ASPEN/PC1.0 Input Language is oriented towards process engineers.« less

  5. Progressive fabrication processes in aircraft-engine production

    NASA Astrophysics Data System (ADS)

    Vorobei, V. V.

    The papers presented in this volume provide an overview of some advanced fabrication processes that are currently used in the production of aircraft engines. In particular, attention is given to an analytical study of the bulk-abrasive machining of screw-shaped parts, exoemission diagnostics of the surface layer of gas turbine engine components following ion treatment, and calculation of the profile of a film deposited in a magnetron spraying system of the plane annular type. The discussion also covers an automated method for monitoring the shape and position of parts of complex configurations, automated measurement of shape deviations, and problems in the hardware and software support of computerized balancing. (For individual items see A93-31127 to A93-31139)

  6. 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,

  7. 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.

  8. 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

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. Virtual fabrication using directed self-assembly for process optimization in a 14nm DRAM

    NASA Astrophysics Data System (ADS)

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

    2016-03-01

    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 SAQP patterning with LiNe chemoepitaxy on a 14nm DRAM process. To quantify the impact of this module replacement, we investigate 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 LE4 patterning.

  15. 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.

  16. 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.

  17. 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.

  18. 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

  19. 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.

  20. 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.

  1. 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.

  2. 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

  3. 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.

  4. 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.

  5. 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.

  6. 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

  7. 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 %.

  8. 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.

  9. 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.

  10. Advanced beaded and tubular structural panels. Volume 2: Fabrication

    NASA Technical Reports Server (NTRS)

    Musgrove, M. D.; Northrop, R. F.

    1974-01-01

    A study was conducted to exploit the efficiency of curved elements in the design of lightweight structural panels under combined loads of axial compression, inplane shear, and bending. A summary of the total program (analysis, fabrication and test) is presented in document NASA CR-2514. Detailed descriptions of the analysis effort and of the panel tests are contained in supplementary documents NASA CR-132460 and NASA-CR-132515 respectively. Data are also given on the development of economical fabrication techniques to minimize the effects of fabrication limitations on optimum panel designs.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  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. 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.

  20. 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.

  1. 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.

  2. 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.

  3. Application of foams to the processing of fabrics. Final report

    SciTech Connect

    Bedenbaugh, R.

    1984-06-01

    The overall accomplishments of this work were: commercialization of foam processing in textiles, especially foam finishing, was accelerated by about five years. Since 1979, about 3 billion yards of fabric have been finished by the U.M.M. or subsequently developed foam systems with a savings of about 1.5 to 2 trillion Btu. In 1984 about 15% of all domestic textile finishing was by a foam process. Foam processing of textiles is being practiced throughout the domestic and international textile industry. Foam dyeing is commercial in specialized areas of the textile industry such as carpet dyeing and the pigment dyeing of lightweight filament fabrics. Foam printing will increase with the development of rotary printing machines designed especially for foamed print colors. The use of foamed chemical systems for desizing, scouring and bleaching of fabrics, especially fabrics containing dyed yarns, is increasing. The development of equipment and chemical systems for foam sizing of fabrics was accelerated in 1983, and commercial equipment is expected to be available in 1984. The public disclosure of foam processing technology has led to the development of competitive foam systems as well as alternate low wet pick-up systems. An independent audit of outside (non-U.M. and M.) demonstration sites has unequivocally established the energy savings and economic advantages of foam processing.

  4. 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.

  5. 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.

  6. 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.

  7. Solidification process control for advanced superalloys

    NASA Technical Reports Server (NTRS)

    Gray, H. R.; Dreshfield, R. L.

    1982-01-01

    The importance of understanding and controlling the basic solidification process in high temperature alloy technology as applied to gas turbine engine production is discussed. Resultant tailoring of the superalloy macro- and microstructure offers significant potential for continued advances in superalloy use temperatures in turbine engines. Atomized superalloy powders, rapidly solidified superalloys, microstructural control, and advanced superalloys are discussed.

  8. DEVELOPMENT OF ADVANCED ESFF (ELECTRICAL STIMULATION OF FABRIC FILTRATION) TECHNOLOGY

    EPA Science Inventory

    The report summarizes work on electrical stimulation of fabric filtration (ESFF) with the major objectives of defining the role of some primary variables and understanding the mechanisms of electrostatic enhancement. It was concluded that the magnitude of particle charge has a st...

  9. 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.

  10. Fabrication and processing of iron aluminides

    SciTech Connect

    Sikka, V.K.; Viswanathan, S.

    1992-07-01

    The Fe{sub 3}Al-based alloys have been shown to exhibit room-temperature ductility values of 15 to 19% by the control of composition and thermomechanical processing steps. The scale-up of one of the compositions to 2270-kg (5000-lb) electroslag-remelted (ESR) round ingot and 3272-kg (7200-lb) vacuum-induction-melted (VIM) slab ingot is described. Microstructural and mechanical property data are presented on small pieces sectioned from these ingots. The effects of final rolling temperature and the final annealing treatment on room-temperature ductility were investigated for the ESR ingot. A study of iron-aluminide binary alloys revealed that the environmental effects on room-temperature ductility values were absent for {le}8.5 wt % Al. The increasing aluminum content and the development of ordered structure resulted in increased environmental effects. Applications and a brief description of their status are described. Based on the combined property and cost advantage, continued development of iron aluminide is recommended.

  11. Fabrication and processing of iron aluminides

    SciTech Connect

    Sikka, V.K.; Viswanathan, S.

    1992-01-01

    The Fe{sub 3}Al-based alloys have been shown to exhibit room-temperature ductility values of 15 to 19% by the control of composition and thermomechanical processing steps. The scale-up of one of the compositions to 2270-kg (5000-lb) electroslag-remelted (ESR) round ingot and 3272-kg (7200-lb) vacuum-induction-melted (VIM) slab ingot is described. Microstructural and mechanical property data are presented on small pieces sectioned from these ingots. The effects of final rolling temperature and the final annealing treatment on room-temperature ductility were investigated for the ESR ingot. A study of iron-aluminide binary alloys revealed that the environmental effects on room-temperature ductility values were absent for {le}8.5 wt % Al. The increasing aluminum content and the development of ordered structure resulted in increased environmental effects. Applications and a brief description of their status are described. Based on the combined property and cost advantage, continued development of iron aluminide is recommended.

  12. 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.

  13. 3D nanostructures fabricated by advanced stencil lithography.

    PubMed

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

    2016-03-01

    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. PMID:26884085

  14. 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.

  15. 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.

  16. Process of magnetite fabric development during granite deformation

    NASA Astrophysics Data System (ADS)

    Mamtani, Manish A.; Piazolo, Sandra; Greiling, Reinhard O.; Kontny, Agnes; Hrouda, František

    2011-08-01

    This study evaluates the fabric defined by magnetite grains in a syntectonically deformed granite and deciphers the processes that led to magnetite fabric development. Anisotropy of anhysteretic remanence magnetization (AARM) analysis is performed in samples taken from different parts of the granite to establish that the magnetite grains define a fabric. Along with microstructural studies, the AARM data help conclude that this fabric is on account of shape preferred orientation (SPO) of the magnetite grains. The intensity of magnetite fabric (degree of anisotropy of the AARM ellipsoid) is higher in the southern parts as compared to the north, which is inferred to indicate a strain gradient. Electron back scattered diffraction (EBSD) analyses of magnetite grains were performed to determine if there are intracrystalline deformation features that could have influenced magnetite shape and SPO, and thus AARM data. Detailed crystallographic orientation data coupled with orientation contrast imaging did not reveal any subgrains and/or significant variations in crystallographic orientations within magnetite grains. Instead, grains exhibit fractures and are in places associated with quartz pressure fringes. Hence, neither the SPO nor the variation in the magnetite fabric intensity in the granite can be attributed to intracrystalline deformation of magnetite by dislocation creep. It is concluded that the magnetite grains were rheologically rigid and there was relative movement between the magnetite and the matrix minerals (quartz, feldspar and biotite). These matrix minerals actually define the fabric attractor and the magnetite grains passively rotated to align with it. Thus it is demonstrated that the magnetite fabric in the granite stems from rigid body movement rather than dislocation creep.

  17. 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.

  18. Advanced technologies for fabrication and testing of large flat mirrors

    NASA Astrophysics Data System (ADS)

    Yellowhair, Julius Eldon

    Classical fabrication methods alone do not enable manufacturing of large flat mirrors that are much larger than 1 meter. This dissertation presents the development of enabling technologies for manufacturing large high performance flat mirrors and lays the foundation for manufacturing very large flat mirrors. The enabling fabrication and testing methods were developed during the manufacture of a 1.6 meter flat. The key advantage over classical methods is that our method is scalable to larger flat mirrors up to 8 m in diameter. Large tools were used during surface grinding and coarse polishing of the 1.6 m flat. During this stage, electronic levels provided efficient measurements on global surface changes in the mirror. The electronic levels measure surface inclination or slope very accurately. They measured slope changes across the mirror surface. From the slope information, we can obtain surface information. Over 2 m, the electronic levels can measure to 50 nm rms of low order aberrations that include power and astigmatism. The use of electronic levels for flatness measurements is analyzed in detail. Surface figuring was performed with smaller tools (size ranging from 15 cm to 40 cm in diameter). A radial stroker was developed and used to drive the smaller tools; the radial stroker provided variable tool stroke and rotation (up to 8 revolutions per minute). Polishing software, initially developed for stressed laps, enabled computer controlled polishing and was used to generate simulated removal profiles by optimizing tool stroke and dwell to reduce the high zones on the mirror surface. The resulting simulations from the polishing software were then applied to the real mirror. The scanning pentaprism and the 1 meter vibration insensitive Fizeau interferometer provided accurate and efficient surface testing to guide the remaining fabrication. The scanning pentaprism, another slope test, measured power to 9 nm rms over 2 meters. The Fizeau interferometer measured 1

  19. 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

  20. Adhesive coating eliminated in new honeycomb-core fabrication process

    NASA Technical Reports Server (NTRS)

    Batty, W. L.; Hayes, R. H.; Magee, F. S.

    1974-01-01

    Technique eliminates use of silicone-based adhesive material as bonding medium. Adhesive requires precise time-temperature cure. Prepreg resin is used as bonding medium, and each layer is laminated together to form honeycomb billet. Process can be used in any application where nonmetallic honeycomb core is being fabricated.

  1. 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

  2. Recent advances in the fabrication of nanostructured barrier films.

    PubMed

    Gokhale, Ankush A; Lee, Ilsoon

    2014-03-01

    The fabrication of barrier packaging films has gained significant momentum in recent years. Besides its dominance in the food industry as a means to extend the shelf-life of perishable goods and facilitate ease of handling and transportation, the use of barrier films to protect semiconductor and flexible electronics from dust, oxidation and moisture has generated considerable interest in recent years. This has ushered in new challenges for researchers to design and develop novel thin film barrier coatings that could be made available at a fraction of the cost. The emergence of the multidisciplinary field of nanotechnology has provided innovative solutions in the fields of medicine, catalysis and energy. In this review, we will be examining the integration of nanoscience driven techniques with barrier film technology with applications in both food and electronics industry. Details regarding permeation theory, some key parameters governing gas/moisture barrier properties and the market potential of nanostructured barrier films have been included. This review also explores several past and current examples of successful inclusion of functional nanostructured or colloidal materials to fabricate tailor-made barrier films. Finally a brief discussion regarding novel emerging trends for this industry has been included. PMID:24745209

  3. 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.

  4. 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.

  5. Fabrication and characterization of melt-processed YBCO

    SciTech Connect

    Sengupta, S.; Corpus, J.; Gaines, J.R. Jr.; Todt, V.R.; Zhang, X.F.; Miller, D.J.; Varanasi, C.; McGinn, P.J.

    1996-11-01

    Large domain YBCO are fabricated by using a melt processing technique for magnetic levitation applications. A Nd{sub 1+x}Ba{sub 2{minus}x}Cu{sub 3}O{sub y} seed is used to initiate grain growth and to control the orientation of YBCO grains. Samples as large as 2 inch have been fabricated by utilizing this method. Microstructural studies reveals two distinct regions in these levitators due to different growth mechanism along a/b and c axis. Some initial results on the mass production of these levitators are also reported.

  6. 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.

  7. Yield enhancement in micromechanical sensor fabrication using statistical process control

    NASA Astrophysics Data System (ADS)

    Borenstein, Jeffrey T.; Preble, Douglas M.

    1997-09-01

    Statistical process control (SPC) has gained wide acceptance in recent years as an essential tool for yield improvement in the microelectronics industry. In both manufacturing and research and development settings, statistical methods are extremely useful in process control and optimization. Here we describe the recent implementation of SPC in the micromachining fabrication process at Draper. A wide array of micromachined silicon sensors, including gyroscopes, accelerometers, and microphones, are routinely fabricated at Draper, often with rapidly changing designs and processes. In spite of Draper's requirements for rapid turnaround and relatively small, short production runs, SPC has turned out to be a critical component of the product development process. This paper describes the multipronged SPC approach we have developed and tailored to the particular requirements of an R & D micromachining process line. Standard tools such as Pareto charts, histograms, and cause-and-effect diagrams have been deployed to troubleshoot yield and performance problems in the micromachining process, and several examples of their use are described. More rigorous approaches, such as the use of control charts for variables and attributes, have been instituted with considerable success. The software package CornerstoneR was selected to handle the SPC program at Draper. We describe the highly automated process now in place for monitoring key processes, including diffusion, oxidation, photolithography, and etching. In addition to the process monitoring, gauge capability is applied to critical metrology tools on a regular basis. Applying these tools in the process line has resulted in sharply improved yields and shortened process cycles.

  8. 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.

  9. 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

  10. Design and fabrication of advanced hybrid circuits for high energy physics

    SciTech Connect

    Haller, G.M.; Moss, J.; Freytag, D.R.; Nelson, D.; Yim, A.; Lo, C.C.

    1987-10-01

    Current design and fabrication techniques of hybrid devices are explained for the Drift Chamber and the Liquid Argon Calorimeter for the Stanford Linear Collider Large Detector (SLD) at SLAC. Methods of developing layouts, ranging from hand-cut templates to advanced designs utilizing CAD tools with special hybrid design software were applied. Physical and electrical design rules for good yield and performance are discussed. Fabrication and assembly of the SLD hybrids are described. 7 refs., 10 figs.

  11. 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. PMID:27396690

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. Fabrication Of Micro-Nozzles Via {mu}-EDM Process

    SciTech Connect

    Modica, F.; Trotta, G.; Fassi, I.

    2011-01-17

    Since traditional handling mechanisms have an unpredictable behavior at micro scale, micro-assembly is a bottleneck in the development of hybrid micro-systems, and the development of new approaches is strongly demanded. In this paper, a recent study of the fabrication of a ceramics vacuum micro-gripper to handle parts in the range of hundreds of microns (300-1000) is presented. Among the possible micro manufacturing processes, micro-EDM has been selected as proving to be a very competitive fabrication technology for the manufacturing of ultra miniature components and micro sized features. The influence of the process parameters on the machining performance of interest is firstly investigated; then, the experimental results on machining the micro gripper are presented, finally concluding remarks are given.

  19. 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...

  20. 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...

  1. 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.

  2. 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)

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. Advances in the Fabrication of Toroidal Field Coil Prototypes*

    NASA Astrophysics Data System (ADS)

    Pizzuto, A.; Cucchiaro, A.; Frosi, R.; Ramogida, G.; Boert, F.; Wobker, H. G.; Bianchi, A.; Parodi, B.; Coppi, B.

    2006-10-01

    The Bitter-type Toroidal Field Coils (TFC) adopted for Ignitor consist of plates that are cooled down to 30 K by Helium gas. Copper OFHC has been selected for these plates, allowing for an Electron Beam (EB) welding solution of the cooling channels. Kabel Metal set up the welding parameters and qualified the process to achieve full joint penetration with acceptable metallurgical structure. The qualification covers both the welding of the cooling channels and the inlet/outlet tube made on two full size samples. A metallographic examination and vacuum and pressure tests have been preformed to validate the basic suitability of the EB welding process. *Sponsored in part by ENEA of Italy and by the U.S. DOE.

  8. 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.

  9. Large scale molecular dynamics modeling of materials fabrication processes

    SciTech Connect

    Belak, J.; Glosli, J.N.; Boercker, D.B.; Stowers, I.F.

    1994-02-01

    An atomistic molecular dynamics model of materials fabrication processes is presented. Several material removal processes are shown to be within the domain of this simulation method. Results are presented for orthogonal cutting of copper and silicon and for crack propagation in silica glass. Both copper and silicon show ductile behavior, but the atomistic mechanisms that allow this behavior are significantly different in the two cases. The copper chip remains crystalline while the silicon chip transforms into an amorphous state. The critical stress for crack propagation in silica glass was found to be in reasonable agreement with experiment and a novel stick-slip phenomenon was observed.

  10. 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.

  11. 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.

  12. Fabrication of ceramic components for advanced gas turbine engines

    NASA Technical Reports Server (NTRS)

    Liu, F.; Solidum, E.

    1985-01-01

    The AGT101 ceramic gas turbine engine feasibility study has made use of the slip casting of silicon or silicon nitride powders to produce either reaction-bonded or sintered components such as turbine rotors, turbine shrouds, and inner and outer diffusers. Attention is given to the effects of processing parameters on the microstructure and properties of the finished components; the parameters encompass powder particle size distribution, casting slip viscosity, pH, and solid content fraction. The green slip cast components were consolidated by nitriding, sintering, or sinter/HIPping.

  13. 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.

  14. A solar module fabrication process for HALE solar electric UAV's

    NASA Astrophysics Data System (ADS)

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

    1994-12-01

    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 (UAV's). These modules have achieved power-to-weight ratios of 315 and 396 W/kg for 150 micron-thick monofacial and 110 micron-thick bifacial silicon solar cells, respectively. These calculations reflect average module efficiencies of 15.3% (150 micron) and 14.7% (110 micron) obtained from electrical tests performed by Spectrolab, Inc. under AMO global conditions at 25 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 sq m of these modules is described.

  15. Fabrication of Spiral Micro-Coil Utilizing LIGA Process

    NASA Astrophysics Data System (ADS)

    Shimada, Osamu; Kusumi, Shinji; Mekaru, Harutaka; Sato, Noriaki; Shimizu, Masami; Yamashita, Michiru; Hattori, Tadashi

    We developed a method for fabricating a three-dimensional spiral micro-inductor with high inductance using the LIGA process. The spiral inductor created had a diameter of 0.5mm, and a length of 1mm. The width of the spiral line was 10µm, the pitch was 20µm, and the number of turns was 15. It was made of plated copper. The master was a brass round bar coated with PMMA resist. Deep X-ray lithography was employed to fabricate a master for a metallic mold at the NewSUBARU synchrotron radiation facility, University of Hyogo. The inductor core was made of resin by injection molding. It has a spiral micro flute on the surface. We chose the worm injection molding technique in order to avoid the parting line across the spiral line. The worm injection molding was the method─for demolding the work such as that used in loosening a screw.

  16. 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.

  17. Measuring DNA through a Nanopore Fabricated Using Plasma Processing Technology

    NASA Astrophysics Data System (ADS)

    Rossnagel, S. M.

    2009-10-01

    We have been developing a device based on a 2-3 nm diameter pore between two electrolyte volumes for the transit of DNA by means of a potential gradient. The nanopore is configured with 3 electrodes, each about 3 nm thick with 2-3nm dielectric spacers. The nanopore electrodes can be used to trap DNA in-transit, and ideally measure the impedance and hence the identity of each nucleotide as it passes through the nanopore, allowing real time sequencing of the DNA. The goal is to operate at megahertz, allowing sequencing of the entire genome within a few hours a fairly modest cost. This project has lead to numerous new developments in nanoscale fabrication, particularly for nanofluidics. The nanopore devices are fabricated using a number of critical plasma processing steps, both deposition and etch, in our 200mm pilot facility.

  18. 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.

  19. 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.

  20. Advances in resist technology and processing V

    SciTech Connect

    MacDonald, S.A.

    1988-01-01

    These proceedings discuss the technology and processing advances made in the resist materials. The topics included are: Mid-UV photoresists combining chemical amplification and dissolution inhibition; new photoactive compounds for deep-UV lithography; contrast-enhancement materials for mid-UV applications; materials for CMOS and bipolar circuits; effects of ion bombardment in oxygen plasma etching; silicone-based positive photoresist; and ion-etching properties of polysilane polysilane copolymers.

  1. 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. PMID:27030693

  2. 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. PMID:12883550

  3. A graphene superficial layer for the advanced electroforming process

    NASA Astrophysics Data System (ADS)

    Rho, Hokyun; Park, Mina; Lee, Seungmin; Bae, Sukang; Kim, Tae-Wook; Ha, Jun-Seok; Lee, Sang Hyun

    2016-06-01

    Advances in electroplating technology facilitate the progress of modern electronic devices, including computers, microprocessors and other microelectronic devices. Metal layers with high electrical and thermal conductivities are essential for high speed and high power devices. In this paper, we report an effective route to fabricate free-standing metal films using graphene as a superficial layer in the electroforming process. Chemical vapor deposition (CVD) graphene grown on a Cu foil was used as a template, which provides high electrical conductivity and low adhesive force with the template, thus enabling an effective electroforming process. The required force for delamination of the electroplated Cu layer from graphene is more than one order smaller than the force required for removing graphene from the Cu foil. We also demonstrated that the electroformed free-standing Cu thin films could be utilized for patterning microstructures and incorporated onto a flexible substrate for LEDs. This innovative process could be beneficial for the advancement of flexible electronics and optoelectronics, which require a wide range of mechanical and physical properties.Advances in electroplating technology facilitate the progress of modern electronic devices, including computers, microprocessors and other microelectronic devices. Metal layers with high electrical and thermal conductivities are essential for high speed and high power devices. In this paper, we report an effective route to fabricate free-standing metal films using graphene as a superficial layer in the electroforming process. Chemical vapor deposition (CVD) graphene grown on a Cu foil was used as a template, which provides high electrical conductivity and low adhesive force with the template, thus enabling an effective electroforming process. The required force for delamination of the electroplated Cu layer from graphene is more than one order smaller than the force required for removing graphene from the Cu foil

  4. 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.

  5. 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).

  6. 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.

  7. 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

  8. 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.

  9. 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.

  10. 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.

  11. Fabrication of the planar angular rotator using the CMOS process

    NASA Astrophysics Data System (ADS)

    Dai, Ching-Liang; Chang, Chien-Liu; Chen, Hung-Lin; Chang, Pei-Zen

    2002-05-01

    In this investigation we propose a novel planar angular rotator fabricated by the conventional complementary metal-oxide semiconductor (CMOS) process. Following the 0.6 μm single poly triple metal (SPTM) CMOS process, the device is completed by a simple maskless, post-process etching step. The rotor of the planar angular rotator rotates around its geometric center with electrostatic actuation. The proposed design adopts an intelligent mechanism including the slider-crank system to permit simultaneous motion. The CMOS planar angular rotator could be driven with driving voltages of around 40 V. The design proposed here has a shorter response time and longer life, without problems of friction and wear, compared to the more common planar angular micromotor.

  12. 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).

  13. A simple cost-effective and eco-friendly wet chemical process for the fabrication of superhydrophobic cotton fabrics

    NASA Astrophysics Data System (ADS)

    Richard, Edna; Lakshmi, R. V.; Aruna, S. T.; Basu, Bharathibai J.

    2013-07-01

    Superhydrophobic surfaces were created on hydrophilic cotton fabrics by a simple wet chemical process. The fabric was immersed in a colloidal suspension of zinc hydroxide followed by subsequent hydrophobization with stearic acid. The wettability of the modified cotton fabric sample was studied by water contact angle (WCA) and water shedding angle (WSA) measurements. The modified cotton fabrics exhibited superhydrophobicity with a WCA of 151° for 8 μL water droplet and a WSA of 5-10° for 40 μL water droplet. The superhydrophobic cotton sample was also characterized by field emission scanning electron microscopy (FESEM) and energy dispersive X-ray spectroscopy (EDX). The method is simple, eco-friendly and cost-effective and can be applied to large area of cotton fabric materials. It was shown that superhydrophobicity of the fabric was due to the combined effect of surface roughness imparted by zinc hydroxide and the low surface energy of stearic acid.

  14. Alternative fabrication process for edgeless detectors on 6 in. wafers

    NASA Astrophysics Data System (ADS)

    Kalliopuska, Juha; Eränen, Simo; Virolainen, Tuula

    2011-05-01

    VTT has developed a straightforward and fast process to fabricate edgeless (active edge) microstrip and pixel detectors on 6 in. (150 mm) wafers. The process avoids all slow process steps, such as polysilicon growth, planarization and additional ICP-etching. We have successfully fabricated 150 μm thick p-on-n and n-on-n prototypes of edgeless detectors having dead layers at the edge with a thickness below a micron. Fabrication was done on high resistivity n-type FZ-silicon wafers. The prototypes include 5×5 and 1×1 cm2 edgeless microstrip detectors with DC-, FOXFET- and PT-couplings. In addition 1.4×1.4 cm2 Medipix2 edgeless pixel detectors were also fabricated.This paper presents leakage current, capacitance and breakdown voltage measurements of different DC-coupled microstrip designs and compares them with respect to the active edge distance and polarity of the detector. The active edge distances were 20, 50 and 100 μm from the strips. Electrical characterization of these detectors on the wafer level gave promising results. A good uniformity in the measured parameters was observed for the inner strips. The parameters of the adjacent strip to the edge showed a dramatic dependence on the active edge distance. Leakage current and capacitance of the inner microstrips were 50-70 nA/cm2 and 580-660 pF/cm2 at, respectively, 40 V reverse bias for the p-on-n. For the n-on-n design these parameters were 116-118 nA/cm2 and 930-960 pF/cm2. The breakdown voltages were above 150 V for p-on-n prototypes and increased as a function of active edge distance. To fully deplete the p-on-n detectors required twice as much reverse bias as was needed for the n-on-n detectors, i.e. 13-28 V.

  15. 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.

  16. 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.

  17. Advances in freeform optics fabrication for conformal window and dome applications

    NASA Astrophysics Data System (ADS)

    DeGroote Nelson, Jessica; Gould, Alan; Smith, Nathan; Medicus, Kate; Mandina, Michael

    2013-06-01

    Freeform optical shapes or optical surfaces that are designed with non-symmetric features are gaining popularity with lens designers and optical system integrators. This enabling technology allows for conformal sensor windows and domes that provide enhanced aerodynamic properties as well as environmental and ballistic protection. In order to provide ballistic and environmental protection, these conformal windows and domes are typically fabricated from hard ceramic materials. Hard ceramic conformal windows and domes provide two challenges to the optical fabricator. The material hardness, polycrystalline nature and non-traditional shape demand creative optical fabrication techniques to produce these types of optics cost-effectively. This paper will overview a complete freeform optical fabrication process that includes ultrasonic generation of hard ceramic surfaces, high speed VIBE polishing, sub-aperture figure correction of polycrystalline materials and final testing of freeform surfaces. This paper will highlight the progress made to each of the processes as well as the challenges associated with each of them.

  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. A wide spectral range single-photon avalanche diode fabricated in an advanced 180 nm CMOS technology.

    PubMed

    Mandai, Shingo; Fishburn, Matthew W; Maruyama, Yuki; Charbon, Edoardo

    2012-03-12

    We present a single-photon avalanche diode (SPAD) with a wide spectral range fabricated in an advanced 180 nm CMOS process. The realized SPAD achieves 20 % photon detection probability (PDP) for wavelengths ranging from 440 nm to 820 nm at an excess bias of 4 V, with 30 % PDP at wavelengths from 520 nm to 720 nm. Dark count rates (DCR) are at most 5 kHz, which is 30 Hz/μm2, at an excess bias of 4V when we measure 10 μm diameter active area structure. Afterpulsing probability, timing jitter, and temperature effects on DCR are also presented. PMID:22418462

  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. Fabrication Process of Silicone-based Dielectric Elastomer Actuators.

    PubMed

    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

  2. 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.

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

    PubMed

    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. PMID:22938276

  4. 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.

  5. Testing of advanced ceramic fabric heat pipe for a Stirling engine

    SciTech Connect

    Antoniak, Z.I.; Webb, B.J.; Bates, J.M.

    1991-09-01

    The development and application of Stirling engines for space power production requires concomitant development of an advanced heat rejection system. We are currently involved in the design, development, and testing of advanced ceramic fabric (ACF) water heat pipes for optimal heat rejection from the Stirling cycle without the use of hazardous working fluids such as mercury. Our testing to-date has been with a 200-{mu}m thick titanium heat pipe utilizing Nextel {trademark} fabric as both the outer structural component and as a wick. This heat pipe has been successfully started up from a frozen condition against a negative 4 degree tilt (i.e., fluid return to evaporator was against gravity), with 75 W heat input, in ambient air. In a horizontal orientation, up to 100 W heat input was tolerated without experiencing dryout. 7 refs., 5 figs., 2 tabs.

  6. 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.

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

    SciTech Connect

    Coronado, P.R.; Poco, J.F.

    1999-10-26

    A flexible aerogel and process of fabrication are disclosed. 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.

  8. 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.

  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. 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.

  11. 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.

  12. 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

  13. 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.

  14. 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.

  15. 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.

  16. Advanced microlithography process with chemical shrink technology

    NASA Astrophysics Data System (ADS)

    Kanda, Takashi; Tanaka, Hatsuyuki; Kinoshita, Yoshiaki; Watase, Natsuo; Eakin, Ronald J.; Ishibashi, Takeo; Toyoshima, Toshiyuki; Yasuda, Naoki; Tanaka, Mikihiro

    2000-06-01

    Mitsubishi Electric Corporation (MELCO) has developed an advanced microlithographic process for producing 0.1 micrometer contact holes (CH). A chemical shrink technology, RELACSTM (Resolution Enhancement Lithography Assisted by Chemical Shrink), utilizes the crosslinking reaction catalyzed by the acid component existing in a predefined resist pattern. This 'RELACSTM' process is a hole shrinking procedure that includes simple coating, baking, and rinse steps applied after conventional photolithography. This paper examines the process parameters affecting shrinkage of CH size. We subsequently evaluated the dependency of CH shrinkage on resist formulation. We conducted investigations of shrink magnitude dependency on each process parameter. (1) Photoresist lithography process: CH size, exposure dose, post development bake temperature. (2) AZR R200 [a product of Clariant, Japan) K.K.] RELACSTM process: Soft bake temperature, film thickness, mixing bake temperature (diffusion bake temperature), etc. We found that the mixing bake condition (diffusion bake temperature) is one of most critical parameters to affect the amount of CH shrink. Additionally, the structural influence of photoacid generators on shrinkage performance was also investigated in both high and low activation energy resist systems. The shrinkage behavior by the photoacid generator of the resist is considered in terms of the structure (molecular volume) of the photogenerated acid and its acidity (pKa). The results of these studies are discussed in terms of base polymer influence on shrinkage performance and tendency. Process impact of the structure and acidity of the photogenerated acid is explored. Though the experimental acetal type KrF positive resist (low activation energy system) can achieve around 0.1 micrometer CH after RELACSTM processing under the optimized condition, the experimental acrylate type positive resist (high activation energy system) showed less shrinkage under the same process

  17. 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.

  18. A graphene superficial layer for the advanced electroforming process.

    PubMed

    Rho, Hokyun; Park, Mina; Lee, Seungmin; Bae, Sukang; Kim, Tae-Wook; Ha, Jun-Seok; Lee, Sang Hyun

    2016-07-01

    Advances in electroplating technology facilitate the progress of modern electronic devices, including computers, microprocessors and other microelectronic devices. Metal layers with high electrical and thermal conductivities are essential for high speed and high power devices. In this paper, we report an effective route to fabricate free-standing metal films using graphene as a superficial layer in the electroforming process. Chemical vapor deposition (CVD) graphene grown on a Cu foil was used as a template, which provides high electrical conductivity and low adhesive force with the template, thus enabling an effective electroforming process. The required force for delamination of the electroplated Cu layer from graphene is more than one order smaller than the force required for removing graphene from the Cu foil. We also demonstrated that the electroformed free-standing Cu thin films could be utilized for patterning microstructures and incorporated onto a flexible substrate for LEDs. This innovative process could be beneficial for the advancement of flexible electronics and optoelectronics, which require a wide range of mechanical and physical properties. PMID:26949072

  19. 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. PMID:24221814

  20. 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

  1. Fabrication of the helical field coil components for the advanced toroidal facility

    SciTech Connect

    Cole, M.J.; Whitson, J.C.; Banks, B.J.

    1987-01-01

    The fabrication techniques used to manufacture the major components of the helical field (HF) coil segments for the Advanced Toroidal Facility (ATF) are described. The major components of an HF coil segment are 14 water-cooled, copper conductors and a T-shaped stainless steel support member (or ''tee''). Twenty-four of these segments were used in the fabrication of two coils for the ATF experiment. The helical shape, accurate position requirements, large size, and potential for high cost required unique approaches to the fabrication of these components. One method of fabrication was to use 44-mm-thick (standard size) plate to form the base and leg of the tee and to join the sections by welding. Because of the tolerance requirements, a thicker plate (70 mm) was used and then contour machined to the final shape. The second approach, conducted in parallel with the first, was to cast the tee as a single piece. The first attempts were to make the casting larger than required, then machine it to final size and shape. The cost of machining either the welded tee or the cast tee was extremely high, so several prototypes were fabricated until a cast tee that required no contour machining was produced. The shape and positional requirements were also the major problems in fabricating the copper conductors, or turns. The approach taken was to make an accurate fixture and position the turns in the fixture, then anneal to remove residual stresses and form the copper turns to the shape of the fixture. The lessons learned in pursuing these fabrication methods are presented. 5 refs., 3 figs.

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

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 30 2013-07-01 2012-07-01 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...

  4. 40 CFR 410.90 - Applicability; description of the felted fabric processing subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 29 2011-07-01 2009-07-01 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...

  5. 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...

  6. 40 CFR 410.90 - Applicability; description of the felted fabric processing subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 29 2014-07-01 2012-07-01 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...

  7. 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...

  8. 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.

  9. 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.

  10. 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.

  11. 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).

  12. 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.

  13. 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.

  14. Fabrication of TI/SIC Surface Nano-Composite Layer by Friction Stir Processing

    NASA Astrophysics Data System (ADS)

    Shamsipur, Ali; Kashani-Bozorg, Seyed Farshid; Zareie-Hanzaki, Abbas

    In the present investigation, novel Ti/SiC surface nano-composite layer was successfully fabricated by dispersing nano-sized SiC particles into commercially pure titanium plates employing friction stir processing technique. The process parameters such as tool rotation and advancing speeds were adjusted to produce defect-free surface composite layer, however, uniform distribution of the nano-size SiC particles in a matrix of titanium was achieved after the second pass. The micro hardness value of the Ti/SiC nano-composite surface layer was found to be 534 HV; this is 3.3 times higher than that of the commercially pure titanium substrate. No reaction was detected between SiC powders and the titanium matrix after friction stir processing.

  15. 75 FR 66319 - State Systems Advance Planning Document (APD) Process

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-28

    ... HUMAN SERVICES 45 CFR Part 95 RIN 0970-AC33 State Systems Advance Planning Document (APD) Process AGENCY... Health and Human Services (HHS). ACTION: Final rule. SUMMARY: The Advance Planning Document (APD) process... support programs for children and families. The Advance Planning Document (APD) process governs...

  16. 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.

  17. 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. PMID:21726140

  18. More than monitoring: advanced lithographic process tuning

    NASA Astrophysics Data System (ADS)

    Cantrell, G. R.; Dumaya, Jo Alvin; Bürgel, Christian; Feicke, Axel; Häcker, Martin; Utzny, Clemens

    2011-11-01

    Critical dimensions (CD) measured in resist are key to understanding the CD distribution on photomasks. Vital to this understanding is the separation of spatially random and systematic contributions to the CD distribution. Random contributions will not appear in post etch CD measurements (final) whereas systematic contributions will strongly impact final CDs. Resist CD signatures and their variations drive final CD distributions, thus an understanding of the mechanisms influencing the resist CD signature and its variation play a pivotal role in CD distribution improvements. Current technological demands require strict control of reticle critical dimension uniformity (CDU) and the Advanced Mask Technology Center (AMTC) has found significant reductions in reticle CDU are enabled through the statistical analysis of large data sets. To this end, we employ Principle Component Analysis (PCA) - a methodology well established at the AMTC1- to show how different portions of the lithographic process contribute to CD variations. These portions include photomask blank preparation as well as a correction parameter in the front end process. CD variations were markedly changed by modulating these two lithographic portions, leading to improved final CDU on test reticles in two different chemically amplified resist (CAR) processes.

  19. 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.

  20. 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

  1. 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

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. Recent advances in the welding technology on the fabrication of jackup drilling rig

    SciTech Connect

    Akahide, K.; Hashimoto, O.; Kikukawa, S.; Shimizu, T.

    1983-05-01

    This paper presents new techniques in the fabrication of rig components that satisfy various requirements for use in cold and/or deep waters such as the North Sea. Details discussed include: improving the toughness of heavy-walled HSLA steel pipes (700-800 MPa class) for the chords and legs of rigs, method of controlling welding deformation in the fabrication of chords, and the effect of post weld heat treatment (PWHT) on the toughness of welded joints. Data are presented from both field operations and laboratory tests of actual size specimens manufactured by industrial processes.

  8. 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

  9. 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.

  10. 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.

  11. Induced effects of advanced oxidation processes

    PubMed Central

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

    2014-01-01

    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. PMID:24503715

  12. 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

  13. 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

  14. 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%.

  15. Advanced ceramic fabric body mounted radiator for Space Station Freedom Phase O design

    SciTech Connect

    Webb, B.J.; Antoniak, Z.I.; Pauley, K.A.

    1990-06-01

    A body mounted radiator concept constructed of advanced ceramic fabric materials for use with the Phase 0 design of Space Station Freedom is described. The radiator is expected to weigh between 1.4 and 3.5 kg/m{sup 2} of single sided radiating surface, use ammonia working fluid, be highly deployable, and exhibit good reliability characteristics. This compares well with the 11.8 kg/m{sup 2} for two sided radiators proposed for the current space station design.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. Noninvasive sensors for in-situ process monitoring and control in advanced microelectronics manufacturing

    NASA Astrophysics Data System (ADS)

    Moslehi, Mehrdad M.

    1991-04-01

    The combination of noninvasive in-situ monitoring sensors single-wafer processing modules vacuum-integrated cluster tools and computer-integrated manufacturing (CIM) can provide a suitable fabrication environment for flexible and high-yield advanced semiconductor device manufacturing. The use of in-situ sensors for monitoring of equipment process and wafer parameters results in increased equipment/process up-time reduced process and device parameter spread improved cluster tool reliability and functionality and reduced overall device manufacturing cycle time. This paper will present an overview of the main features and impact of noninvasive in-situ monitoring sensors for semiconductor device manufacturing applications. Specific examples will be presented for the use of critical sensors in conjunction with cluster tools for advanced CMOS device processing. A noninvasive temperature sensor will be presented which can monitor true wafer temperature via infrared (5. 35 jtm) pyrometery and laser-assisted real-time spectral wafer emissivity measurements. This sensor design eliminates any. temperature measurement errors caused by the heating lamp radiation and wafer emissivity variations. 1. SENSORS: MOTIVATIONS AND IMPACT Semiconductor chip manufacturing factories usually employ well-established statistical process control (SPC) techniques to minimize the process parameter deviations and to increase the device fabrication yield. The conventional fabrication environments rely on controlling a limited set of critical equipment and process parameters (e. g. process pressure gas flow rates substrate temperature RF power etc. ) however most of the significant wafer process and equipment parameters of interest are not monitored in real

  1. Sampling for advanced overlay process control

    NASA Astrophysics Data System (ADS)

    Choi, DongSub; Izikson, Pavel; Sutherland, Doug; Sherman, Kara; Manka, Jim; Robinson, John C.

    2008-03-01

    Overlay metrology and control have been critical for successful advanced microlithography for many years, and are taking on an even more important role as time goes on. Due to throughput constraints it is necessary to sample only a small subset of overlay metrology marks, and typical sample plans are static over time. Standard production monitoring and control involves measuring sufficient samples to calculate up to 6 linear correctables. As design rules shrink and processing becomes more complex, however, it is necessary to consider higher order modeled terms for control, fault detection, and disposition. This in turn, requires a higher level of sampling. Due to throughput concerns, however, careful consideration is needed to establish a base-line sampling, and higher levels of sampling can be considered on an exception-basis based on automated trigger mechanisms. The goal is improved scanner control and lithographic cost of ownership. This study addresses tools for establishing baseline sampling as well as motivation and initial results for dynamic sampling for application to higher order modeling.

  2. Sampling for advanced overlay process control

    NASA Astrophysics Data System (ADS)

    Kato, Cindy; Kurita, Hiroyuki; Izikson, Pavel; Robinson, John C.

    2009-03-01

    Overlay metrology and control have been critical for successful advanced microlithography for many years, and are taking on an even more important role as time goes on. Due to throughput constraints it is necessary to sample only a small subset of overlay metrology marks, and typical sample plans are static over time. Standard production monitoring and control involves measuring sufficient samples to calculate up to 6 linear correctables. As design rules shrink and processing becomes more complex, however, it is necessary to consider higher order models with additional degrees of freedom for control, fault detection, and disposition. This in turn, requires a higher level of sampling and a careful consideration of flyer removal. Due to throughput concerns, however, careful consideration is needed to establish a baseline sampling plan using rigorous statistical methods. This study focuses on establishing a 3x nm node immersion lithography production-worthy sampling plan for 3rd order modeling, verification of the accuracy, and proof of robustness of the sampling. In addition we discuss motivation for dynamic sampling for application to higher order modeling.

  3. 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.

  4. 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.

  5. 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.

  6. 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

  7. 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

    2015-10-01

    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

  8. 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.

  9. 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.

  10. Integrated porous-silicon light-emitting diodes: A fabrication process using graded doping profiles

    SciTech Connect

    Barillaro, G.; Diligenti, A.; Pieri, F.; Fuso, F.; Allegrini, M.

    2001-06-25

    A fabrication process, compatible with an industrial bipolar+complementary metal{endash}oxide{endash}semiconductor (MOS)+diffusion MOS technology, has been developed for the fabrication of efficient porous-silicon-based light-emitting diodes. The electrical contact is fabricated with a double n{sup +}/p doping, achieving a high current injection efficiency and thus lower biasing voltages. The anodization is performed as the last step of the process, thus reducing potential incompatibilities with industrial processes. The fabricated devices show yellow-orange electroluminescence, visible with the naked eye in room lighting. A spectral characterization of light emission is presented and briefly discussed. {copyright} 2001 American Institute of Physics.

  11. 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.

  12. Fabrication of Compound Refractive X-ray Lenses Using LIGA Process and Performance Tests

    SciTech Connect

    Lee, Jin Pyoung; Kim, Guk Bae; Kim, Jong Hyun; Chang, Suk Sang; Lee, Sang Joon

    2007-01-19

    Recent advances of X-ray microscopy technology enable the visualization of some micro/nano-scale objects which optical microscopy and electron microscopy cannot be used to observe. The X-ray microscopy can be applied to observe the internal structure of a thicker sample than the electron microscopy can, and its spatial resolution is higher than that of the optical microscopy. Moreover, it has a powerful element specific imaging ability. For further improving the X-ray microscope, it is indispensable to make X-ray optics for focusing X-rays more effectively. Recently, various X-ray lenses such as diffraction lenses of FZP(Fresnel zone plate) and spatter-sliced FZT, total reflection lenses of K-B(Kirkpatrick-Baez) mirror and Wolter mirror, and refractive lens of CRL(compound refractive lens) were introduced. Compared with the other types of lenses, CRL is easy to fabricate and handle. In this study, we designed and fabricated various types of CRLs using LIGA(LIthographie, Galvanoformung, Abformtechnik) process, and used PMMA(Poly(methyl methacrylate)) material as the material of CRL. Their performances are tested with varying parameters such as parabolic/kinoform shape, radius of curvature, wall thickness between adjacent lenses, and width of lenses. The performance tests were carried out by using a simple synchrotron X-ray imaging method. The tests results revealed that hard x-rays could be condensed well by the CRL of PMMA material at the focal point we expect We captured sample images one-dimensionally magnified by CRLs. Furthermore, we found which parameter is more effective for enhancing focus efficiency and which parameter should be considered more carefully in the fabrication process of LIGA.

  13. 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.

  14. 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.

  15. 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)

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

    DOE PAGESBeta

    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. 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)

    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.

  20. 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.

  1. 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

  2. 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.

  3. 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.

  4. 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. PMID:27415640

  5. Recent advances in design and fabrication of on-chip micro-supercapacitors

    NASA Astrophysics Data System (ADS)

    Beidaghi, Majid; Wang, Chunlei

    2012-06-01

    Recent development in miniaturized electronic devices has increased the demand for power sources that are sufficiently compact and can potentially be integrated on a chip with other electronic components. Miniaturized electrochemical capacitors (EC) or micro-supercapacitors have great potential to complement or replace batteries and electrolytic capacitors in a variety of applications. Recently, we have developed several types of micro-supercapacitors with different structural designs and active materials. Carbon-Microelectromechanical Systems (C-MEMS) with three dimensional (3D) interdigital structures are employed both as electrode material for electric double layer capacitor (EDLC) or as three dimensional (3D) current collectors of pseudo-capacitive materials. More recently, we have also developed microsupercapacitor based on hybrid graphene and carbon nanotube interdigital structures. In this paper, the recent advances in design and fabrication of on-chip micro-supercapacitors are reviewed.

  6. Fabrication of copper nanoparticles: advances in synthesis, morphology control, and chemical stability.

    PubMed

    Benavente, Eglantina; Lozano, Harold; González, Guillermo

    2013-06-01

    Metal nanoparticles have attracted great interest particularly because of the size dependence of physical and chemical properties and its enormous technological potential. Although most pioneering advancements refers to gold and silver, more recently there is growing interest in nanoparticles of copper, mostly due to its relatively low cost, which could allow the use of these small metal objects in large-scale nanotechnology applications, for example, antiseptics materials and metallic inks. However, the manufacture of copper nanoparticles stable in air with controlled size and shape has been a major challenge because of the relatively high reactivity of this element. Great efforts in getting the basic knowledge and synthesis know-how has gone into finding better ways to produce particles protected against oxidation and selfaggregation under normal conditions. In this review article, we briefly discuss a number of selected papers and recent patents on procedures and other issues related to the fabrication of copper nanoparticles. PMID:22974429

  7. 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.

  8. 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.

  9. 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

    2013-05-01

    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. PMID:24104441

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  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. 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. PMID:26257367

  16. 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.

  17. 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.

  18. A Blueprint for GNEP Advanced Burner Reactor Startup Fuel Fabrication Facility

    SciTech Connect

    S. Khericha

    2010-12-01

    The purpose of this article is to identify the requirements and issues associated with design of GNEP Advanced Burner Reactor Fuel Facility. The report was prepared in support of providing 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 was 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 was 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 was 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 was assumed to 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) was being considered for fabrication of WG Pu fuel for the ABR. It was estimated that the facility will provide the startup fuel for 10-15 years and would take 3 to 5 years to construct.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. Fabrication and processing of high-strength densely packed carbon nanotube yarns without solution processes.

    PubMed

    Liu, Kai; Zhu, Feng; Liu, Liang; Sun, Yinghui; Fan, Shoushan; Jiang, Kaili

    2012-06-01

    Defects of carbon nanotubes, weak tube-tube interactions, and weak carbon nanotube joints are bottlenecks for obtaining high-strength carbon nanotube yarns. Some solution processes are usually required to overcome these drawbacks. Here we fabricate ultra-long and densely packed pure carbon nanotube yarns by a two-rotator twisting setup with the aid of some tensioning rods. The densely packed structure enhances the tube-tube interactions, thus making high tensile strengths of carbon nanotube yarns up to 1.6 GPa. We further use a sweeping laser to thermally treat as-produced yarns for recovering defects of carbon nanotubes and possibly welding carbon nanotube joints, which improves their Young's modulus by up to ∼70%. The spinning and laser sweeping processes are solution-free and capable of being assembled together to produce high-strength yarns continuously as desired. PMID:22538869

  4. Fabrication and processing of high-strength densely packed carbon nanotube yarns without solution processes

    NASA Astrophysics Data System (ADS)

    Liu, Kai; Zhu, Feng; Liu, Liang; Sun, Yinghui; Fan, Shoushan; Jiang, Kaili

    2012-05-01

    Defects of carbon nanotubes, weak tube-tube interactions, and weak carbon nanotube joints are bottlenecks for obtaining high-strength carbon nanotube yarns. Some solution processes are usually required to overcome these drawbacks. Here we fabricate ultra-long and densely packed pure carbon nanotube yarns by a two-rotator twisting setup with the aid of some tensioning rods. The densely packed structure enhances the tube-tube interactions, thus making high tensile strengths of carbon nanotube yarns up to 1.6 GPa. We further use a sweeping laser to thermally treat as-produced yarns for recovering defects of carbon nanotubes and possibly welding carbon nanotube joints, which improves their Young's modulus by up to ~70%. The spinning and laser sweeping processes are solution-free and capable of being assembled together to produce high-strength yarns continuously as desired.

  5. ADVANCED CONCEPTS: SO2 REMOVAL PROCESS IMPROVEMENTS

    EPA Science Inventory

    The report gives results of a study of a potassium scrubbing system that recovers useful forms of sulfur from pollutants while using a low-energy process to regenerate the absorbing medium. The report also describes two versions of a new, regenerable process for SO2 scrubbing tha...

  6. 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.

  7. 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.

  8. 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.

  9. 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

  10. 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. PMID:27408708

  11. 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.

  12. 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.

  13. Recent advances in process assessment and optimisation.

    PubMed

    Van Loey, A; Hendrickx, M; Smout, C; Haentjens, T; Tobback, P

    1996-01-01

    After stating the general principle of food preservation, this paper focuses on currently available methods to evaluate quantitatively the integrated time temperature impact during and/or after a thermal preservation process. In this context, both the physical-mathematical approach and the use of time temperature integrators are briefly reviewed and recent evolutions are indicated. Also new trends with regard to thermal process optimisation are highlighted. PMID:22060643

  14. 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.

  15. 10 CFR 140.13a - Amount of financial protection required for plutonium processing and fuel fabrication plants.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... plutonium processing and fuel fabrication plant is required to have and maintain financial protection in the... use plutonium at two or more plutonium processing and fuel fabrication plants at the same location... protection covers all such plants at the location....

  16. 10 CFR 140.13a - Amount of financial protection required for plutonium processing and fuel fabrication plants.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... plutonium processing and fuel fabrication plant is required to have and maintain financial protection in the... use plutonium at two or more plutonium processing and fuel fabrication plants at the same location... protection covers all such plants at the location....

  17. 10 CFR 140.13a - Amount of financial protection required for plutonium processing and fuel fabrication plants.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... plutonium processing and fuel fabrication plant is required to have and maintain financial protection in the... use plutonium at two or more plutonium processing and fuel fabrication plants at the same location... protection covers all such plants at the location....

  18. 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

  19. 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

  20. 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.

  1. 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.

  2. Advances in iridium alloy processing in 1987

    SciTech Connect

    Heestand, R.L.; Ohriner, E.K.; Roche, T.K.

    1988-08-01

    A new process for the production of DOP-26 iridium alloy blanks is being evaluated and optimized. The alloy is prepared by electron-beam (EB) melting of Ir-0.3% W powder compacts followed by doping with aluminum and thorium by arc melting. Drop-cast alloy rod segments are EB welded to produce an electrode that is consumable arc melted to produce an ingot for extrusion and subsequent rolling. Initial results showed rejections for ultrasonic indications of alloy blanks produced by this process to be very low. Subsequently, some ingots have exhibited delaminations in the sheet, leading to rejection rates similar to that obtained in the standard process. The increase in delaminations is related to near-surface porosity in the consumable arc-melted ingot. A number of modifications to the arc-melting process and plans for further experimental work are described. In addition, the tensile properties of the DOP-26 iridium alloys have been measured over a range of test temperatures and strain rates. A laboratory evaluation of alternative cleaning procedures indicates that electrolytic dissolution of DOP-26 iridium alloy in an HCl solution is a potential substitute to the KCN process now in use. 7 refs., 13 figs., 6 tabs.

  3. Self-Assembling Process for Fabricating Tailored Thin Films

    ScienceCinema

    Sandia

    2009-09-01

    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)

  4. Self-Assembling Process for Fabricating Tailored Thin Films

    ScienceCinema

    None

    2010-01-08

    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)

  5. 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)

  6. 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.

  7. 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.

  8. ADVANCED OXIDATION PROCESSES (AOP'S FOR THE TREATMENT OF CCL CHEMICALS

    EPA Science Inventory

    Research on treatment of Contaminant Candidate List (CCL) chemicals is being conducted. Specific groups of contaminants on the CCL will be evaluated using numerous advanced oxidation processes (AOPs). Initially, these CCL contaminants will be evaluated in groups based on chemical...

  9. Process Technology and Advanced Concepts: Organic Solar Cells (Fact Sheet)

    SciTech Connect

    Not Available

    2011-06-01

    Capabilities fact sheet for the National Center for Photovoltaics: Process Technology and Advanced Concepts: Organic Solar Cell that includes scope, core competencies and capabilities, and contact/web information.

  10. Cold plasma processing technology makes advances

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  11. Photonics in advanced process control applications

    NASA Astrophysics Data System (ADS)

    Lundqvist, Stefan H.; Andersson, Torbjoern; Grimbrandt, Jan

    1999-02-01

    A measurement system optimized for process control in the industrial environment has been developed and successfully commercialized. The system comprises a central unit, which contains all sensitive electronic and electro-optic parts. Fiber optics is used to transport the probing laser light to the measuring points in the process. Extremely rugged sensor heads are used to interface to the harsh industrial environment. Adaptation to the different applications is solely made up by changing the type of sensor head used. Six different process control applications will be presented. Ammonia slip monitoring in the NO(subscript x4/ reduction process in power stations, waste incinerators and heavy-duty diesel engines. Measurement of water vapor and oxygen in municipal waste to energy plants. Monitoring of oxygen and the thermodynamic gas temperature in steel pellets manufacturing. Monitoring HF reduction in a dry scrubber and HF emission from a pot room. Experiences of CO emission peak monitoring to protect electro filter in a chemical waste incinerator. Finally, we will describe measurements of HCI in the raw gas to access the calorific value of waste and to optimize bag-house filter operation.

  12. Fabrication of silica integrated waveguide circuits for quantum enhanced sensing, quantum information processing and number resolving detection

    NASA Astrophysics Data System (ADS)

    Smith, Peter G. R.; Gates, James C.; Holmes, Christopher; Gawith, Corin B. E.; Carpenter, Lewis G.; Mennea, Paolo L.; Posner, Matthew T.; Cooper, Peter A.; Lynch, Stephen G.

    2015-01-01

    Integrated optics is becoming increasingly important for applications in quantum information processing, quantum sensing and for advanced measurement. Intrinsically stable and low-loss it provides essential routing and coupling for quantum optical experiments offering functions such as interconnects, couplers, phase delays and routing. Silica-onsilicon has particular attractions, and in this work the fabrication approaches and advantages of the technique will be explored. In particular, UV direct writing of waveguides and Bragg gratings proves useful for its rapid-prototyping capability and its ability to provide grating for characterization of components for loss, birefringence and coupling ratio. This review concentrates on the fabrication of planar waveguide devices, and ways in which direct UV writing provides important functionality. Examples of applications of silica-on-silicon waveguides include quantum enhanced interferometry, teleportation, boson sampling as well as hybrid operation for single photon detection with transition edge sensors directly placed onto waveguide devices.

  13. 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.

  14. 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.

  15. Advances in the shell coal gasification process

    SciTech Connect

    Doering, E.L.; Cremer, G.A.

    1995-12-31

    The Shell Coal Gasification Process (SCGP) is a dry-feed, oxygen-blown, entrained flow coal gasification process which has the capability to convert virtually any coal or petroleum coke into a clean medium Btu synthesis gas, or syngas, consisting predominantly of carbon monoxide and hydrogen. In SCGP, high pressure nitrogen or recycled syngas is used to pneumatically convey dried, pulverized coal to the gasifier. The coal enters the gasifier through diametrically opposed burners where it reacts with oxygen at temperatures in excess of 2500{degrees}F. The gasification temperature is maintained to ensure that the mineral matter in the coal is molten and will flow smoothly down the gasifier wall and out the slag tap. Gasification conditions are optimized, depending on coal properties, to achieve the highest coal to gas conversion efficiency, with minimum formation of undesirable byproducts.

  16. 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.

  17. Advanced processes for metallurgical coke. Appendices

    SciTech Connect

    Straus, R.W.; Carsey, J.N.; von Bismarck, G.; Fujishima, C.

    1980-12-01

    Material collected in a survey of German coking plants (some in German, some in English) is presented: Ancit hot briquetting (including blast furnace tests), by-products of Ancit process, coal preparation, high volatile coking coals, preheating, briquetting blending, compacting and preheating, short coking time, wet charges, temperature control and heat consumption, supplies of coke, Solmer coke oven complex at Fos-sur-Mer, etc. (LTN)

  18. Advanced materials and electrochemical processes in high-temperature solid electrolytes

    SciTech Connect

    Bates, J.L.; Chick, L.A.; Youngblood, G.E.; Weber, W.J.

    1990-10-01

    Fuel cells for the direct conversion of fossil fuels to electric energy necessitates the use of high-temperature solid electrodes. This study has included: (1) determination of electrical transport, thermal and electrical properties to illucidate the effects of microstructure, phase equilibria, oxygen partial pressure, additives, synthesis and fabrication on these properties; (2) investigation of synthesis and fabrication of advanced oxide materials, such as La{sub 0.9}Sn{sub 0.1}MnO{sub 3}; and (3) application of new analytical techniques using complex impedance coupled with conventional electrochemical methods to study the electrochemical processes and behavior of materials for solid oxide fuel cells and other high-temperature electrolyte electrochemical process. 15 refs., 10 figs., 2 tabs. (BM)

  19. 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

  20. 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. PMID:24580644

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

    PubMed

    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

  2. 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

  3. 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.

  4. 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.

  5. Long-length contaminated equipment burial containers fabrication process procedures

    SciTech Connect

    McCormick, W.A., Fluor Daniel Hanford

    1997-03-11

    These special process procedures cover the detailed step-by-step procedures required by the supplier who will manufacture the Long-Length Contaminated Equipment (LLCE) Burial Container design. Also included are detailed step-by-step procedures required by the disposal process for completion of the LLCE Burial Containers at Hanford.

  6. 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…

  7. Improved epitaxial process for fabricating silicon carbide semiconductor devices

    NASA Technical Reports Server (NTRS)

    Will, H. A.; Powell, J. A.

    1974-01-01

    Process of growing expitaxial silicon carbide (SiC) layers on SiC substrates so that epitaxial growth is perpendicular to c-axis by chemical vapor deposition process at temperatures of 1590 to 1660 K minimizes variations in stacking sequence and problems associated with high temperatures.

  8. 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.

  9. 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.

  10. Digraph reliability model processing advances and applications

    NASA Technical Reports Server (NTRS)

    Iverson, D. L.; Patterson-Hine, F. A.

    1993-01-01

    This paper describes a new algorithm, called SourceDoubls, which efficiently solves for singletons and doubletons of a digraph reliability model. Compared with previous methods, the SourceDoubls algorithm provides up to a two order of magnitude reduction in the amount of time required to solve large digraph models. This significant increase in model solution speed allows complex digraphs containing thousands of nodes to be used as knowledge bases for real time automated monitoring and diagnosis applications. Currently, an application to provide monitoring and diagnosis of the Space Station Freedom Data Management System is under development at NASA/Ames Research Center and NASA/Johnson Space Center. This paper contains an overview of this system and provides details of how it will use digraph models processed by the SourceDoubls algorithm to accomplish its task.

  11. 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.

  12. 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.

  13. 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.

  14. Integration of advanced nuclear materials separation processes

    SciTech Connect

    Jarvinen, G.D.; Worl, L.A.; Padilla, D.D.; Berg, J.M.; Neu, M.P.; Reilly, S.D.; Buelow, S.

    1998-12-31

    This is the final report of a two-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). This project has examined the fundamental chemistry of plutonium that affects the integration of hydrothermal technology into nuclear materials processing operations. Chemical reactions in high temperature water allow new avenues for waste treatment and radionuclide separation.Successful implementation of hydrothermal technology offers the potential to effective treat many types of radioactive waste, reduce the storage hazards and disposal costs, and minimize the generation of secondary waste streams. The focus has been on the chemistry of plutonium(VI) in solution with carbonate since these are expected to be important species in the effluent from hydrothermal oxidation of Pu-containing organic wastes. The authors investigated the structure, solubility, and stability of the key plutonium complexes. Installation and testing of flow and batch hydrothermal reactors in the Plutonium Facility was accomplished. Preliminary testing with Pu-contaminated organic solutions gave effluent solutions that readily met discard requirements. A new effort in FY 1998 will build on these promising initial results.

  15. 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. PMID:19473926

  16. 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.

  17. Fabrication of a Wrinkled Surface on Poly(dimethylsiloxane) Using a Thermal Curing Process

    NASA Astrophysics Data System (ADS)

    Lee, Dong Guk; Jeong, Ok Chan

    2013-06-01

    We describe the fabrication of a spontaneous wrinkled surface on poly(dimethylsiloxane) (PDMS). The wrinkled surface on an elastic PDMS substrate was fabricated by thermally shrinking liquid PDMS coated on a cured PDMS layer during a simple thermal curing process. Optical and atomic force microscopy, deflections of PDMS cantilever beams on the wrinkled surface, and contact angles of water droplets on the wrinkled surface were used to quantitatively investigate the wrinkled patterns on the PDMS layer. The morphology of cells seeded on the fabricated wrinkled surface was observed.

  18. 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. PMID:26218024

  19. 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.

  20. Fabrication of low cost cutting wheel via thermal spray process

    NASA Astrophysics Data System (ADS)

    Anasyida, A. S.; Nurulakmal, M. S.

    2012-09-01

    The present study is mainly focused on development of metal cutting wheel. The process involved hard particles (abrasives) being bonded on the wheel to enhance the cutting capability by thermal spraying process and followed by polymer bonding. The purpose of this work is to produce low cost cutting wheel and study the performance of cutting behavior. Two different types of powders; silicon carbide (SiC) as bonding agent and chromium carbide (Cr3C2) as abrasives were used. Wear loss and depth of cut as function of load, cutting time and cutting speed were evaluated. The results showed that the speed and load were the main factors that affected the cutting efficiency and the optimum cutting process can be performed at low cutting speed and high load or at high cutting speed and low load.

  1. 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.

  2. 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.

  3. 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.

  4. 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)

  5. 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.

  6. 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. PMID:24804662

  7. 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.

  8. 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.

  9. 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.

  10. Processing and fabrication of high temperature oxide superconductors

    NASA Astrophysics Data System (ADS)

    Johnson, Sylvia M.; Gusman, Michael I.

    1992-11-01

    Synthesis of YBa2Cu3O7-a superconductor powders by freeze-drying was developed. The freeze-drying process consists of forming a solution of Y and Cu nitrates and Ba acetate, freezing, sublimating the water and calcination. The effect of processing variables on the powder characteristics, including surface area, size, stoichiometry, agglomeration, were investigated. Stoichiometry control requires control of the chemistry of the system, and careful analysis of starting solutions is required to prepare powders of the desired composition. Powders were sintered into pellets and the superconducting behavior was evaluated. Stanford University served as a subcontractor and was responsible for most of the critical transition temperature and critical current measurements.

  11. 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.

  12. 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.

  13. Advanced computational research in materials processing for design and manufacturing

    SciTech Connect

    Zacharia, T.

    1995-04-01

    Advanced mathematical techniques and computer simulation play a major role in providing enhanced understanding of conventional and advanced materials processing operations. Development and application of mathematical models and computer simulation techniques can provide a quantitative understanding of materials processes and will minimize the need for expensive and time consuming trial- and error-based product development. As computer simulations and materials databases grow in complexity, high performance computing and simulation are expected to play a key role in supporting the improvements required in advanced material syntheses and processing by lessening the dependence on expensive prototyping and re-tooling. Many of these numerical models are highly compute-intensive. It is not unusual for an analysis to require several hours of computational time on current supercomputers despite the simplicity of the models being studied. For example, to accurately simulate the heat transfer in a 1-m{sup 3} block using a simple computational method requires 10`2 arithmetic operations per second of simulated time. For a computer to do the simulation in real time would require a sustained computation rate 1000 times faster than that achievable by current supercomputers. Massively parallel computer systems, which combine several thousand processors able to operate concurrently on a problem are expected to provide orders of magnitude increase in performance. This paper briefly describes advanced computational research in materials processing at ORNL. Continued development of computational techniques and algorithms utilizing the massively parallel computers will allow the simulation of conventional and advanced materials processes in sufficient generality.

  14. 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.

  15. Advanced simulation technology for etching process design for CMOS device applications

    NASA Astrophysics Data System (ADS)

    Kuboi, Nobuyuki; Fukasawa, Masanaga; Tatsumi, Tetsuya

    2016-07-01

    Plasma etching is a critical process for the realization of high performance in the next generation of CMOS devices. To predict and control fluctuations in the etching properties accurately during mass production, it is essential that etching process simulation technology considers fluctuations in the plasma chamber wall conditions, the effects of by-products on the critical dimensions, the Si recess dependence on the wafer open area ratio and local pattern structure, and the time-dependent plasma-induced damage distribution associated with the three-dimensional feature scale profile at the 100 nm level. This consideration can overcome the issues with conventional simulations performed under the assumed ideal conditions, which are not accurate enough for practical process design. In this article, these advanced process simulation technologies are reviewed, and, from the results of suitable process simulations, a new etching system that automatically controls the etching properties is proposed to enable stable CMOS device fabrication with high yields.

  16. 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.

  17. 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.

  18. 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

  19. 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.

  20. Advanced information processing system for advanced launch system: Hardware technology survey and projections

    NASA Technical Reports Server (NTRS)

    Cole, Richard

    1991-01-01

    The major goals of this effort are as follows: (1) to examine technology insertion options to optimize Advanced Information Processing System (AIPS) performance in the Advanced Launch System (ALS) environment; (2) to examine the AIPS concepts to ensure that valuable new technologies are not excluded from the AIPS/ALS implementations; (3) to examine advanced microprocessors applicable to AIPS/ALS, (4) to examine radiation hardening technologies applicable to AIPS/ALS; (5) to reach conclusions on AIPS hardware building blocks implementation technologies; and (6) reach conclusions on appropriate architectural improvements. The hardware building blocks are the Fault-Tolerant Processor, the Input/Output Sequencers (IOS), and the Intercomputer Interface Sequencers (ICIS).

  1. 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.

  2. 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

  3. 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.

  4. 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.

  5. Advanced Process Technology: Combi Materials Science and Atmospheric Processing (Fact Sheet)

    SciTech Connect

    Not Available

    2011-06-01

    Capabilities fact sheet for the National Center for Photovoltaics: Process Technology and Advanced Concepts -- High-Throughput Combi Material Science and Atmospheric Processing that includes scope, core competencies and capabilities, and contact/web information.

  6. GEOTECHNICAL/GEOCHEMICAL CHARACTERIZATION OF ADVANCED COAL PROCESS WASTE STREAMS

    SciTech Connect

    Edwin S. Olson; Charles J. Moretti

    1999-11-01

    Thirteen solid wastes, six coals and one unreacted sorbent produced from seven advanced coal utilization processes were characterized for task three of this project. The advanced processes from which samples were obtained included a gas-reburning sorbent injection process, a pressurized fluidized-bed coal combustion process, a coal-reburning process, a SO{sub x}, NO{sub x}, RO{sub x}, BOX process, an advanced flue desulfurization process, and an advanced coal cleaning process. The waste samples ranged from coarse materials, such as bottom ashes and spent bed materials, to fine materials such as fly ashes and cyclone ashes. Based on the results of the waste characterizations, an analysis of appropriate waste management practices for the advanced process wastes was done. The analysis indicated that using conventional waste management technology should be possible for disposal of all the advanced process wastes studied for task three. However, some wastes did possess properties that could present special problems for conventional waste management systems. Several task three wastes were self-hardening materials and one was self-heating. Self-hardening is caused by cementitious and pozzolanic reactions that occur when water is added to the waste. All of the self-hardening wastes setup slowly (in a matter of hours or days rather than minutes). Thus these wastes can still be handled with conventional management systems if care is taken not to allow them to setup in storage bins or transport vehicles. Waste self-heating is caused by the exothermic hydration of lime when the waste is mixed with conditioning water. If enough lime is present, the temperature of the waste will rise until steam is produced. It is recommended that self-heating wastes be conditioned in a controlled manner so that the heat will be safely dissipated before the material is transported to an ultimate disposal site. Waste utilization is important because an advanced process waste will not require

  7. Advanced processing for high-bandwidth sensor systems

    NASA Astrophysics Data System (ADS)

    Szymanski, John J.; Blain, Phil C.; Bloch, Jeffrey J.; Brislawn, Christopher M.; Brumby, Steven P.; Cafferty, Maureen M.; Dunham, Mark E.; Frigo, Janette R.; Gokhale, Maya; Harvey, Neal R.; Kenyon, Garrett; Kim, Won-Ha; Layne, J.; Lavenier, Dominique D.; McCabe, Kevin P.; Mitchell, Melanie; Moore, Kurt R.; Perkins, Simon J.; Porter, Reid B.; Robinson, S.; Salazar, Alfonso; Theiler, James P.; Young, Aaron C.

    2000-11-01

    Compute performance and algorithm design are key problems of image processing and scientific computing in general. For example, imaging spectrometers are capable of producing data in hundreds of spectral bands with millions of pixels. These data sets show great promise for remote sensing applications, but require new and computationally intensive processing. The goal of the Deployable Adaptive Processing Systems (DAPS) project at Los Alamos National Laboratory is to develop advanced processing hardware and algorithms for high-bandwidth sensor applications. The project has produced electronics for processing multi- and hyper-spectral sensor data, as well as LIDAR data, while employing processing elements using a variety of technologies. The project team is currently working on reconfigurable computing technology and advanced feature extraction techniques, with an emphasis on their application to image and RF signal processing. This paper presents reconfigurable computing technology and advanced feature extraction algorithm work and their application to multi- and hyperspectral image processing. Related projects on genetic algorithms as applied to image processing will be introduced, as will the collaboration between the DAPS project and the DARPA Adaptive Computing Systems program. Further details are presented in other talks during this conference and in other conferences taking place during this symposium.

  8. Development of an indirect solid freeform fabrication process based on microstereolithography for 3D porous scaffolds

    NASA Astrophysics Data System (ADS)

    Kang, Hyun-Wook; Seol, Young-Joon; Cho, Dong-Woo

    2009-01-01

    Scaffold fabrication using solid freeform fabrication (SFF) technology is a hot topic in tissue engineering. Here, we present a new indirect SFF technology based on microstereolithography (MSTL), which has the highest resolution of all SFF methods, to construct a three-dimensional (3D) porous scaffold by combining SFF with molding technology. To realize this indirect method, we investigated and modified a water-soluble photopolymer. We used MSTL technology to fabricate a high-resolution 3D porous mold composed of the modified polymer. The mold can be removed using an appropriate solvent. We tested two materials, polycaprolactone and calcium sulfate hemihydrate, using the molding process, and developed a lost-mold shape forming process by dissolving the mold. This procedure demonstrated that the proposed method can yield scaffold pore sizes as small as 60-70 µm. In addition, cytotoxicity test results indicated that the proposed process is feasible for producing 3D porous scaffolds.

  9. Program to investigate advanced laser processing of materials

    NASA Astrophysics Data System (ADS)

    Breinan, E. M.; Snow, D. B.; Brown, C. O.

    1981-01-01

    This program included two major areas of research. In the processing area, a LAYERGLAZE (trade name) apparatus using a powder feed was developed and used to produce a 13.2 cm diameter by 3 cm thick cylindrical blank which was used as a preform for a scale model gas turbine disk. In addition to demonstrating that the process was capable of fabricating model size parts, mechanical testing and microstructural analysis of LAYERGLAZED material indicated that LAYERGLAZED parts exhibit good structural integrity and that the process produces no sizable or serious fabrication flaws provided that the alloy has adequate 'weldability' at high cooling rates. In a second major area, design of a LAYERGLAZE-processable superalloy was undertaken. With the system Ni-Al-Mo - X, numerous processable compositions were found, however, these compositions were characterized by embrittling phase transformations in the 600-800 deg temperature range. The research efforts in the alloy design area aimed at understanding and controlling this instability produced several alloys in the Ni-Al-Mo + X family which appeared to demonstrate the necessary characteristics of processability and phase stability. The mechanical properties of these alloys are being evaluated under an additional program. In addition to alloys from the above system, a number of additional alloys with high strength potentials have been developed based on other systems.

  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. 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.

  12. 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.

  13. Micropen direct-write technique for fabrication of advanced electroceramic and optical materials

    NASA Astrophysics Data System (ADS)

    Sun, Jingjing

    Direct-write technologies, a subset of the rapid prototyping, have been applied for many applications including electronics, photonics and biomedical engineering. Among them, Micropen(TM) is a promising technique, providing precision deposition of materials with various viscosities, on-line design changes and writing on nonplanar substrates. The objective of this project was to directly write two- and three-dimensional novel structures by Micropen(TM) for potential optical and transducer applications. First, to gain a basic understanding of Micropen(TM) operation, poly(methyl methacrylate) (PMMA) solutions were developed as a model system. The effects of solution rheological properties on deposition conditions were investigated. Secondly, PMMA/SiO2 hybrids were developed using sol-gel process. The effects of organic/inorganic ratios on thermal stability, microstructure and optical properties were studied. The solution with 80 wt% PMMA loading was chosen to deposit lines for optical applications. Another application was the direct-write of lead zirconate titanate (PZT) thick films (6-70 mum) for MEMS or high frequency medical imaging applications. Pastes consisting of 15-30 vol% ceramic loading in a sol-gel solution were prepared for the deposition of films on various substrates. The PZT sol was used as a binder as well as to achieve low temperature heat treatment of the films. Using the 15 vol% paste with a 250-mum pen tip, a four-layer film was deposited on a silicon substrate. This 16-mum film with 1 cm 2 area had K of 870, tandelta of 4.1%, Pr of 12.2 muC/cm 2 and Ec of 27 kV/cm. Furthermore, Micropen(TM) was utilized for the direct-write of ceramic skeletal structures to develop PZT ceramic/polymer composites with 2-2 connectivity for medical ultrasound transducers. Ceramic/binder based pastes were developed as writing materials. The 35 vol% paste exhibited shear thinning with a viscosity of 45 Pa˙s at lower shear rate and 3 Pa˙s at higher shear rate. Using a

  14. 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

    2016-01-01

    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

  15. 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.

  16. Advanced solidification processing of an industrial gas turbine engine component

    NASA Astrophysics Data System (ADS)

    Clemens, Mei Ling; Price, Allen; Bellows, Richard S.

    2003-03-01

    This paper will describe the efforts of the Advanced Turbine Airfoil Manufacturing Technology Program sponsored by the U.S. Department of Energy through the Oak Ridge National Laboratory and Howmet Research Corporation. The purpose of the program is to develop single-crystal and directionally solidified casting technologies to benefit Advanced Turbine Systems (ATS) industrial and utility gas turbine engines. The focus is on defining and implementing advanced Vacuum Induction Melting (VIM) furnace enhancements that provide precise control of mold temperatures during solidification. Emphasis was placed on increasing the total magnitude of thermal gradients while minimizing the difference in maximum and minimum gradients produced during the solidification process. Advanced VIM casting techniques were applied to Solar Turbines Incorporated’s Titan 130 First Stage High Pressure Turbine Blade under the ATS program. A comparison of the advanced VIM casting process to the conventional Bridgeman casting process will be presented as it pertains to the thermal gradients achieved during solidification, microstructure, elemental partitioning characterization, and solution heat treat response.

  17. 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.

  18. Two step process for the fabrication of diffraction limited concave microlens arrays.

    PubMed

    Ruffieux, Patrick; Scharf, Toralf; Philipoussis, Irène; Herzig, Hans Peter; Voelkel, Reinhard; Weible, Kenneth J

    2008-11-24

    A two step process has been developed for the fabrication of diffraction limited concave microlens arrays. The process is based on the photoresist filling of melted holes obtained by a preliminary photolithography step. The quality of these microlenses has been tested in a Mach-Zehnder interferometer. The method allows the fabrication of concave microlens arrays with diffraction limited optical performance. Concave microlenses with diameters ranging between 30 microm to 230 microm and numerical apertures up to 0.25 have been demonstrated. As an example, we present the realization of diffusers obtained with random sizes and locations of concave shapes. PMID:19030040

  19. A sacrificial process for fabrication of biodegradable polymer membranes with submicron thickness.

    PubMed

    Beardslee, Luke A; Stolwijk, Judith; Khaladj, Dimitrius A; Trebak, Mohamed; Halman, Justin; Torrejon, Karen Y; Niamsiri, Nuttawee; Bergkvist, Magnus

    2016-08-01

    A new sacrificial molding process using a single mask has been developed to fabricate ultrathin 2-dimensional membranes from several biocompatible polymeric materials. The fabrication process is similar to a sacrificial microelectromechanical systems (MEMS) process flow, where a mold is created from a material that can be coated with a biodegradable polymer and subsequently etched away, leaving behind a very thin polymer membrane. In this work, two different sacrificial mold materials, silicon dioxide (SiO2 ) and Liftoff Resist (LOR) were used. Three different biodegradable materials; polycaprolactone (PCL), poly(lactic-co-glycolic acid) (PLGA), and polyglycidyl methacrylate (PGMA), were chosen as model polymers. We demonstrate that this process is capable of fabricating 200-500 nm thin, through-hole polymer membranes with various geometries, pore-sizes and spatial features approaching 2.5 µm using a mold fabricated via a single contact photolithography exposure. In addition, the membranes can be mounted to support rings made from either SU8 or PCL for easy handling after release. Cell culture compatibility of the fabricated membranes was evaluated with human dermal microvascular endothelial cells (HDMECs) seeded onto the ultrathin porous membranes, where the cells grew and formed confluent layers with well-established cell-cell contacts. Furthermore, human trabecular meshwork cells (HTMCs) cultured on these scaffolds showed similar proliferation as on flat PCL substrates, further validating its compatibility. All together, these results demonstrated the feasibility of our sacrificial fabrication process to produce biocompatible, ultra-thin membranes with defined microstructures (i.e., pores) with the potential to be used as substrates for tissue engineering applications. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 1192-1201, 2016. PMID:26079689

  20. Fabricating superhydrophilic wool fabrics.

    PubMed

    Chen, Dong; Tan, Longfei; Liu, Huiyu; Hu, Junyan; Li, Yi; Tang, Fangqiong

    2010-04-01

    A simple method for fabricating environmentally stable superhydrophilic wool fabrics is reported here. An ultrathin silica layer coated on the wool altered both the surface roughness and the surface energy of the fiber and endowed the wool fabrics with excellent water absorption. The process of coating silica sols was dependent on an acid solution of low pH, which influenced the electrostatic interactions between nanoparticles and wool fibers. The morphology and composition of silica-sol-coated wool fabrics were characterized by a combination of SEM, TEM, EDX, FTIR, and XPS measurements. The possible mechanism and size effect of silica nanoparticles on the hydrophilic property of wool fabric were discussed. The washing fastness of the superhydrophilic wool fabrics in perchlorethylene and water was also evaluated. This study shows that wool fabrics modified by optical transparence, chemical stability, and nontoxic silica sols are promising in constructing smart textiles. PMID:19908843

  1. Fabrication and nondestructive examination development for advanced components and materials for the SP-100 space reactor

    NASA Astrophysics Data System (ADS)

    Ring, Peter J.; Dobrzynski, Walter J.

    1993-01-01

    Significant progress has now been made in the development of fabrication and Nondestructive Examination techniques for the SP-100 Space Reactor. All major fabrication challenges have been faced and overcome. Methods are in place for the fabrication and inspection of composite fuel cladding, the reactor honeycomb core, cold forging of the core support nozzle course, and electron beam welding of the auxiliary cooling loop system. Specifications and procedures have been developed and proven on actual hardware for electron beam welding, gas tungsten arc welding, heat treatment, solvent cleaning, chemical cleaning, ultrasonic inspection, helium leak testing, dye penetrant and microfocus rod anode radiography. Signicant work remains to be done but no problems have been identified which would prevent fabrication of the high temperature SP-100 Space Reactor.

  2. 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.

    1978-01-01

    The overall objectives of the present program are to: (1) improve the performance of the electrochemical CO2 removal technique by increasing CO2 removal efficiencies at pCO2 levels below 400 Pa, increasing cell power output and broadening the tolerance of electrochemical cells for operation over wide ranges of cabin relative humidity; (2) design, fabricate, and assemble development hardware to continue the evolution of the electrochemical concentrating technique from the existing level to an advanced level able to efficiently meet the CO2 removal needs of a spacecraft air revitalization system (ARS); (3) develop and incorporate into the EDC the components and concepts that allow for the efficient integration of the electrochemical technique with other subsystems to form a spacecraft ARS; (4) combine ARS functions to enable the elimination of subsystem components and interfaces; and (5) demonstrate the integration concepts through actual operation of a functionally integrated ARS.

  3. Development of processing techniques for advanced thermal protection materials

    NASA Technical Reports Server (NTRS)

    Selvaduray, Guna S.

    1994-01-01

    The effort, which was focused on the research and development of advanced materials for use in Thermal Protection Systems (TPS), has involved chemical and physical testing of refractory ceramic tiles, fabrics, threads and fibers. This testing has included determination of the optical properties, thermal shock resistance, high temperature dimensional stability, and tolerance to environmental stresses. Materials have also been tested in the Arc Jet 2 x 9 Turbulent Duct Facility (TDF), the 1 atmosphere Radiant Heat Cycler, and the Mini-Wind Tunnel Facility (MWTF). A significant part of the effort hitherto has gone towards modifying and upgrading the test facilities so that meaningful tests can be carried out. Another important effort during this period has been the creation of a materials database. Computer systems administration and support have also been provided. These are described in greater detail below.

  4. Microwave systems for the processing of advanced ceramics

    SciTech Connect

    Wilson, O. Jr.; Carmel, Y.; Lloyd, I.

    1999-07-01

    Microwave processing systems are continually evolving to incorporate more unique capabilities and design features. These new developments are instrumental in expanding the scope of microwave systems for studying complex phenomena in materials synthesis and processing. On a more fundamental level, questions concerning the nature of interactions between microwaves and ceramic materials systems can be addressed to provide direct impact on processing strategies for advanced ceramic materials. A novel microwave processing system is being developed to study fundamental issues in the sintering of advanced ceramic materials with enhanced dielectric, thermal, optical, and mechanical properties for applications in microelectronics, biomaterials, and structural applications. The system consists of a single and dual frequency microwave furnace that operates at 2.45 and 28 GHz, an optical pyrometric temperature measuring system, and an optical, non-invasive, non-contact, extensometer for measuring sintering shrinkage and kinetics. The additional ability to process at 28 GHz provides opportunities to sinter a wider range of ceramic materials by direct coupling. An even more exciting benefit of the dual frequency system is the potential to process ceramics at two frequencies simultaneously. This capability can provide a unique way to tailor the microstructure of advanced ceramics by controlling the extent of both volumetric and surface heating. Experimental results for microwave sintering studies involving ZnO, hydroxyapatite, AlN-SiC composites, and alumina composites will be presented, with an emphasis on the processing of nanograin ceramics. In particular, the role of surface modification and microwave field intensification effects will be discussed.

  5. Develop and demonstrate manufacturing processes for fabricating graphite filament reinforced polymide (Gr/PI) composite structural elements

    NASA Technical Reports Server (NTRS)

    Chase, V. A.; Harrison, E. S.

    1985-01-01

    A study was conducted to assess the merits of using graphite/polyimide, NR-150B2 resin, for structural applications on advanced space launch vehicles. The program was divided into two phases: (1) Fabrication Process Development; and (2) Demonstration Components. The first phase of the program involved the selection of a graphite fiber, quality assurance of the NR-150B2 polyimide resin, and the quality assurance of the graphite/polyimide prepreg. In the second phase of the program, a limited number of components were fabricated before the NR-150B2 resin system was removed from the market by the supplier, Du Pont. The advancement of the NR-150B2 polyimide resin binder was found to vary significantly based on previous time and temperature history during the prepregging operation. Strength retention at 316C (600F) was found to be 50% that of room temperature strength. However, the composite would retain its initial strength after 200 hours exposure at 316C (600F). Basic chemistry studies are required for determining NR-150B2 resin binder quality assurance parameters. Graphite fibers are available that can withstand high temperature cure and postcure cycles.

  6. Literature on fabrication of tungsten for application in pyrochemical processing of spent nuclear fuels

    SciTech Connect

    Edstrom, C.M.; Phillips, A.G.; Johnson, L.D.; Corle, R.R.

    1980-10-11

    The pyrochemical processing of nuclear fuels requires crucibles, stirrers, and transfer tubing that will withstand the temperature and the chemical attack from molten salts and metals used in the process. This report summarizes the literature that pertains to fabrication (joining, chemical vapor deposition, plasma spraying, forming, and spinning) is the main theme. This report also summarizes a sampling of literature on molbdenum and the work previously performed at Argonne National Laboratory on other container materials used for pyrochemical processing of spent nuclear fuels.

  7. Advancement in conductive cotton fabrics through in situ polymerization of polypyrrole-nanocellulose composites.

    PubMed

    Hebeish, A; Farag, S; Sharaf, S; Shaheen, Th I

    2016-10-20

    Current research was undertaking with a view to innovate a new approach for development of conductive - coated textile materials through coating cotton fabrics with nanocellulose/polypyrrole composites. The study was designed in order to have a clear understanding of the role of nanocellulose as well as modified composite thereof under investigation. It is anticipated that incorporation of nanocellulose in the pyrrole/cotton fabrics/FeCl3/H2O system would form an integral part of the composites with mechanical, electrical or both properties. Three different nanocellulosic substrates are involved in the oxidation polymerization reaction of polypyrrole (Ppy) in presence of cotton fabrics. Polymerization was subsequently carried out by admixing at various ratios of FeCl3 and pyrrole viz. Ppy1, Ppy2 and pp3. The conductive, mechanical and thermal properties of cotton fabrics coated independently with different nanocellulose/polypyrrole were investigated. FTIR, TGA, XRD, SEM and EDX were also used for further characterization. Results signify that, the conductivity of cotton fabrics increases exponentially with increasing the dose of pyrrole and oxidant irrespective of nanocellulose substrate used. While, the mechanical properties of cotton fabrics are not significantly affected by the oxidant treatment. PMID:27474547

  8. Microeconomics of advanced process window control for 50-nm gates

    NASA Astrophysics Data System (ADS)

    Monahan, Kevin M.; Chen, Xuemei; Falessi, Georges; Garvin, Craig; Hankinson, Matt; Lev, Amir; Levy, Ady; Slessor, Michael D.

    2002-07-01

    Fundamentally, advanced process control enables accelerated design-rule reduction, but simple microeconomic models that directly link the effects of advanced process control to profitability are rare or non-existent. In this work, we derive these links using a simplified model for the rate of profit generated by the semiconductor manufacturing process. We use it to explain why and how microprocessor manufacturers strive to avoid commoditization by producing only the number of dies required to satisfy the time-varying demand in each performance segment. This strategy is realized using the tactic known as speed binning, the deliberate creation of an unnatural distribution of microprocessor performance that varies according to market demand. We show that the ability of APC to achieve these economic objectives may be limited by variability in the larger manufacturing context, including measurement delays and process window variation.

  9. Advanced Instruction: Facilitation of Individual Learning Processes in Large Groups

    ERIC Educational Resources Information Center

    Putz, Claus; Intveen, Geesche

    2009-01-01

    By supplying various combinations of advanced instructions and different forms of exercises individual learning processes within the impartation of basic knowledge can be activated and supported at best. The fundamentals of our class "Introduction to spatial-geometric cognition using CAD" are constructional inputs, which systematically induce the…

  10. Adding Structure to the Transition Process to Advanced Mathematical Activity

    ERIC Educational Resources Information Center

    Engelbrecht, Johann

    2010-01-01

    The transition process to advanced mathematical thinking is experienced as traumatic by many students. Experiences that students had of school mathematics differ greatly to what is expected from them at university. Success in school mathematics meant application of different methods to get an answer. Students are not familiar with logical…

  11. Data Processing (Advanced Business Programming) Volume II. Instructor's Guide.

    ERIC Educational Resources Information Center

    Litecky, Charles R.; Lamkin, Tim

    This curriculum guide for an advanced course in data processing is for use as a companion publication to a textbook or textbooks; references to appropriate textbooks are given in most units. Student completion of assignments in Volume I, available separately (see ED 220 604), is a prerequisite. Topics covered in the 18 units are introduction,…

  12. Advanced potato breeding clones: storage and processing evaluation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The accumulation of reducing sugars during cold storage of potato tubers is a serious and costly problem for producers and processors. The degree to which cultivars accumulate reducing sugars during storage determines their processing and market potential. Cultivars or advanced breeding lines with...

  13. Optimization of lithography process for the fabrication of Micro-Faraday cup array

    NASA Astrophysics Data System (ADS)

    Arab, J. M.; Brahmankar, P. K.; Pawade, R. S.; Srivastava, A. K.

    2016-05-01

    Micro-faraday cup array detector (MFCAD) is used for the detection of charge of incoming ions in mass spectrometry. The optimization of complete lithography process for the fabrication of Micro-Faraday cup array detector structure in photoresist (AZ4903) on silicon substrate is reported in this work. An UV-LED based exposure system is designed for the transfer of micro-faraday cup structure on to the photoresist. The assembly consists of exposure system, collimating lens and mask/substrate holder. The fabrication process consists of coating of photoresist on Silicon substrate, designing and printing the photo mask and finally the UV lithography. These fabricated structures are characterized using optical microscope. The dimensions achieved are found to be similar as compared to the photo mask.

  14. Scalable shape-controlled fabrication of curved microstructures using a femtosecond laser wet-etching process.

    PubMed

    Bian, Hao; Yang, Qing; Chen, Feng; Liu, Hewei; Du, Guangqing; Deng, Zefang; Si, Jinhai; Yun, Feng; Hou, Xun

    2013-07-01

    Materials with curvilinear surface microstructures are highly desirable for micro-optical and biomedical devices. However, realization of such devices efficiently remains technically challenging. This paper demonstrates a facile and flexible method to fabricate curvilinear microstructures with controllable shapes and dimensions. The method composes of femtosecond laser exposures and chemical etching process with the hydrofluoric acid solutions. By fixed-point and step-in laser irradiations followed by the chemical treatments, concave microstructures with different profiles such as spherical, conical, bell-like and parabola were fabricated on silica glasses. The convex structures were replicated on polymers by the casting replication process. In this work, we used this technique to fabricate high-quality microlens arrays and high-aspect-ratio microwells which can be used in 3D cell culture. This approach offers several advantages such as high-efficient, scalable shape-controllable and easy manipulations. PMID:23623098

  15. Fabrication and characterization of groove-gate MOSFETs based on a self-aligned CMOS process

    NASA Astrophysics Data System (ADS)

    Ma, Xiao-Hua; Hao, Yue; Sun, Bao-Gang; Gao, Hai-Xia; Ren, Hong-Xia; Zhang, Jin-Cheng; Zhang, Jin-Feng; Zhang, Xiao-Ju; Zhang, Wei-Dong

    2006-01-01

    N and P-channel groove-gate MOSFETs based on a self-aligned CMOS process have been fabricated and characterized. For the devices with channel length of 140nm, the measured drain induced barrier lowering (DIBL) was 66mV/V for n-MOSFETs and 82mV/V for p-MOSFETs. The substrate current of a groove-gate n-MOSFET was 150 times less than that of a conventional planar n-MOSFET. These results demonstrate that groove-gate MOSFETs have excellent capabilities in suppressing short-channel effects. It is worth emphasizing that our groove-gate MOSFET devices are fabricated by using a simple process flow, with the potential of fabricating devices in the sub-100nm range.

  16. Fabrication of Nanostructure 1050/6061 Complex Al Alloy by Accumulative Roll-Bonding Process.

    PubMed

    Lee, Seong-Hee; Kim, Jung Han

    2015-01-01

    A nanostructure AA1050/AA6061 complex aluminum alloy was successfully fabricated by the accumulative roll-bonding (ARB) process. The ARB process was performed up to 5 cycles without a lubricant at ambient temperature. The samples fabricated by the ARB were the multi-layer complex aluminum alloys in which AA1050 and AA6061 layers are alternately stacked. The tensile strength of the samples increased with proceeding of the ARB, it reached about 300 MPa which is about twice that of the as-received AA6061. The grain size was greatly reduced to submicron order during the ARB, the efficiency of grain refinement was greater in AA6061 than AA1050. The tensile fracture surfaces showed a mixed morphology of brittle and ductile fracture. It was also found that a nanostructure multi-layer AA1050/AA6061 alloy fabricated by the ARB exhibited very complex microstructure and texture. PMID:26328381

  17. Progress in the Development of Direct Osmotic Concentration Wastewater Recovery Process for Advanced Life Support Systems

    NASA Technical Reports Server (NTRS)

    Cath, Tzahi Y.; Adams, Dean V.; Childress, Amy; Gormly, Sherwin; Flynn, Michael

    2005-01-01

    Direct osmotic concentration (DOC) has been identified as a high potential technology for recycling of wastewater to drinking water in advanced life support (ALS) systems. As a result the DOC process has been selected for a NASA Rapid Technology Development Team (RTDT) effort. The existing prototype system has been developed to a Technology Readiness Level (TRL) 3. The current project focuses on advancing the development of this technology from TRL 3 to TRL 6 (appropriate for human rated testing). A new prototype of a DOC system is been designed and fabricated that addresses the deficiencies encountered during the testing of the original system and allowing the new prototype to achieve TRL 6. Background information is provided about the technologies investigated and their capabilities, results from preliminary tests, and the milestones plan and activities for the RTDT program intended to develop a second generation prototype of the DOC system.

  18. A Highly Controllable Electrochemical Anodization Process to Fabricate Porous Anodic Aluminum Oxide Membranes

    NASA Astrophysics Data System (ADS)

    Lin, Yuanjing; Lin, Qingfeng; Liu, Xue; Gao, Yuan; He, Jin; Wang, Wenli; Fan, Zhiyong

    2015-12-01

    Due to the broad applications of porous alumina nanostructures, research on fabrication of anodized aluminum oxide (AAO) with nanoporous structure has triggered enormous attention. While fabrication of highly ordered nanoporous AAO with tunable geometric features has been widely reported, it is known that its growth rate can be easily affected by the fluctuation of process conditions such as acid concentration and temperature during electrochemical anodization process. To fabricate AAO with various geometric parameters, particularly, to realize precise control over pore depth for scientific research and commercial applications, a controllable fabrication process is essential. In this work, we revealed a linear correlation between the integrated electric charge flow throughout the circuit in the stable anodization process and the growth thickness of AAO membranes. With this understanding, we developed a facile approach to precisely control the growth process of the membranes. It was found that this approach is applicable in a large voltage range, and it may be extended to anodization of other metal materials such as Ti as well.

  19. A Highly Controllable Electrochemical Anodization Process to Fabricate Porous Anodic Aluminum Oxide Membranes.

    PubMed

    Lin, Yuanjing; Lin, Qingfeng; Liu, Xue; Gao, Yuan; He, Jin; Wang, Wenli; Fan, Zhiyong

    2015-12-01

    Due to the broad applications of porous alumina nanostructures, research on fabrication of anodized aluminum oxide (AAO) with nanoporous structure has triggered enormous attention. While fabrication of highly ordered nanoporous AAO with tunable geometric features has been widely reported, it is known that its growth rate can be easily affected by the fluctuation of process conditions such as acid concentration and temperature during electrochemical anodization process. To fabricate AAO with various geometric parameters, particularly, to realize precise control over pore depth for scientific research and commercial applications, a controllable fabrication process is essential. In this work, we revealed a linear correlation between the integrated electric charge flow throughout the circuit in the stable anodization process and the growth thickness of AAO membranes. With this understanding, we developed a facile approach to precisely control the growth process of the membranes. It was found that this approach is applicable in a large voltage range, and it may be extended to anodization of other metal materials such as Ti as well. PMID:26706687

  20. Evaluation of advanced oxidation process for the treatment of groundwater

    SciTech Connect

    Garland, S.B. II ); Peyton, G.R. ); Rice, L.E. . Kansas City Div.)

    1990-01-01

    An advanced oxidation process utilizing ozone, ultraviolet radiation, and hydrogen peroxide was selected for the removal of chlorinated hydrocarbons, particularly trichlorethene and 1,2-dichlorethene, from groundwater underlying the US Department of Energy Kansas City Plant. Since the performance of this process for the removal of organics from groundwater is not well-documented, an evaluation was initiated to determine the performance of the treatment plant, document the operation and maintenance costs experience, and evaluate contaminant removal mechanisms. 11 refs., 3 figs.

  1. Advanced aerial film processing system for long range reconnaissance

    NASA Astrophysics Data System (ADS)

    Ryman, I. G.

    1980-01-01

    An introduction is given to the system features and development histories of continuous aerial film processing equipment. The advantages and disadvantages of (1) deep tank, full immersion processing, (2) spray processing, and (3) viscous processing are enumerated, with respect to load end, supply accumulator, spray cabinet, squeegee section, dryer, film take-up section and film transport system functions. Future research efforts are recommended toward the incorporation of water regeneration, pollution control, and pH monitoring and control systems, and the greater use of computer technology to prevent operator errors and permit the handling of thinner, advanced films.

  2. Advances in iridium alloy processing in FY 1988

    SciTech Connect

    Ohriner, E.K.; Heestand, R.L.

    1989-12-01

    A new process for the production of DOP-26 iridium alloy blanks is being evaluated and optimized. The alloy is prepared by electron-beam (EB) melting of Ir-0.3% W powder compacts followed by doping with aluminum and thorium by arc melting. Drop-cast alloy rod segments are EB welded together into an electrode that is arc melted to produce an ingot for extrusion and subsequent sheet rolling and blanking. Initial results showed rejections for ultrasonic indications for alloy blanks fabricated by this process to be very low. Subsequently, some ingots have exhibited delaminations in the sheet, leading to blank rejection rates similar to that obtained in the standard process. The occurrence of ultrasonic indications in the blanks are now shown to be associated with the presence of subsurface flaws in the arc-melted ingot that are not healed during extrusion or the subsequent rolling of the sheet. There is substantial evidence indicating that the occurrence of surface and subsurface flaws in the ingots are exacerbated by the relatively small clearances between the electrode and the side wall of the 51-mm-diam mold. These results obtained from experimental melts, with both stainless steel and scrap iridium alloy materials, have led to a recommendation for arc melting in a large 63-mm-diam mold. The fabrication of blanks from this larger diameter ingot is under way. The efficiency of iridium material utilization in the new process is also discussed. 2 refs., 23 figs., 12 tabs.

  3. Design, fabrication, and calibration of curved integral coils for measuring transfer function, uniformity, and effective length of LBL ALS (Lawrence Berkeley Laboratory Advanced Light Source) Booster Dipole Magnets

    SciTech Connect

    Green, M.I.; Nelson, D.; Marks, S.; Gee, B.; Wong, W.; Meneghetti, J.

    1989-03-01

    A matched pair of curved integral coils has been designed, fabricated and calibrated at Lawrence Berkeley Laboratory for measuring Advanced Light Source (ALS) Booster Dipole Magnets. Distinctive fabrication and calibration techniques are described. The use of multifilar magnet wire in fabrication integral search coils is described. Procedures used and results of AC and DC measurements of transfer function, effective length and uniformity of the prototype booster dipole magnet are presented in companion papers. 8 refs.

  4. Dispersing perylene diimide/SWCNT hybrids: structural insights at the molecular level and fabricating advanced materials.

    PubMed

    Tsarfati, Yael; Strauss, Volker; Kuhri, Susanne; Krieg, Elisha; Weissman, Haim; Shimoni, Eyal; Baram, Jonathan; Guldi, Dirk M; Rybtchinski, Boris

    2015-06-17

    The unique properties of carbon nanotubes (CNT) are advantageous for emerging applications. Yet, the CNT insolubility hampers their potential. Approaches based on covalent and noncovalent methodologies have been tested to realize stable dispersions of CNTs. Noncovalent approaches are of particular interest as they preserve the CNT's structures and properties. We report on hybrids, in which perylene diimide (PDI) amphiphiles are noncovalently immobilized onto single wall carbon nanotubes (SWCNT). The resulting hybrids were dispersed and exfoliated both in water and organic solvents in the presence of two different PDI derivatives, PP2b and PP3a. The dispersions were investigated using cryogenic transmission electron microscopy (cryo-TEM), providing unique structural insights into the exfoliation. A helical arrangement of PP2b assemblies on SWCNTs dominates in aqueous dispersions, while a single layer of PP2b and PP3a was found on SWCNTs in organic dispersions. The dispersions were probed by steady-state and time-resolved spectroscopies, revealing appreciable charge redistribution in the ground state, and an efficient electron transfer from SWCNTs to PDIs in the excited state. We also fabricated hybrid materials from the PP2b/SWCNT dispersions. A supramolecular membrane was prepared from aqueous dispersions and used for size-selective separation of gold nanoparticles. Hybrid buckypaper films were prepared from the organic dispersions. In the latter, high conductivity results from enhanced electronic communication and favorable morphology within the hybrid material. Our findings shed light onto SWCNT/dispersant molecular interactions, and introduce a versatile approach toward universal solution processing of SWCNT-based materials. PMID:25977989

  5. Rapid fabrication of graphene on dielectric substrates via solid-phase processes

    NASA Astrophysics Data System (ADS)

    Xiong, W.; Zhou, Y. S.; Hou, W. J.; Lu, Y. F.

    2015-03-01

    To unleash the full potential of graphene in functional devices, high-quality graphene sheets and patterns are frequently required to be deposited on dielectric substrates. However, it generally calls for post-growth catalyst etching and graphene transfer steps in currently existing approaches, which are very time consuming and costly for fabricating functional graphene devices. We developed a rapid and cost-effective growth method to achieve the graphene formation directly on various kinds of dielectric substrates via a novel solid-phase transformation mechanism based on Ni/C thin films. High-quality graphene was obtained uniformly on whole surface of wafers with a controlled number of graphene layers. The monolayer graphene, as obtained, exhibits a low sheet resistance of about 50 Ω/sq and a high optical transmittance of 95.8% at 550 nm. Graphene patterns were successfully fabricated simply by either conventional photolithography or laser direct writing techniques. Various graphene patterns, including texts, spirals, line arrays, and even large-scale integrated circuit patterns, with a feature line width of 800 nm and a low sheet resistance of 205 ohm/sq, were achieved. The developed method provides a facile and cost-effective way to fabricate complex and high-quality graphene patterns directly on target substrates, which opens a door for fabricating various advanced optoelectronic devices.

  6. Mutual diffusion process for continuous fabrication of graded-index plastic rod lenses

    NASA Astrophysics Data System (ADS)

    Uozu, Yoshihiro; Horie, Kazuyuki

    2003-11-01

    We propose a new process for fabrication of plastic rod lenses based on the traditional method of fiber extrusion. The process consists of the following steps: multilayer conjugate extrusion, monomer diffusion between adjacent layers, and photopolymerization of an uncured strand fiber. We call this process a mutual diffusion process for continuous plastic rod lens fabrication. Characteristics of this process are as follows: fast production speed (~100 cm/min), precision control of refractive-index distribution, high angular aperture, and long-term reliability. The optical resolution of the rod-lens array is 300 dpi, which is high enough for application to G3 facsimiles with transmission time of less than 1 min and monochromatic scanners.

  7. Processing and Characterization of Peti Composites Fabricated by High Temperature Vartm (Section)

    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., Jr.; 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, but so have the production costs associated with their fabrication. For certain composites, 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 Langley Research Center (LaRC). In the current study, three PETI resins 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 of 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. Fabric permeability characterizations and limited process modeling efforts were carried out to determine infusion times and composite panel size limitations. In addition, new PETI based resins were synthesized specifically for HT-VARTM.

  8. Fabrication of long REBCO coated conductors by PLD process in China

    NASA Astrophysics Data System (ADS)

    Li, Yijie; Liu, Linfei; Wu, Xiang

    2015-11-01

    In China, the First National Key Project on CC Program started in 2009, which was focused on developing hundred meter long class CC tapes based on PLD/RABiTS processes. In this project, SJTU mainly worked on all of functional layer deposition process development. Northwest Institute for Non-ferrous Metal Research worked on RABiTS tape fabrication. At the end of the project in 2011, SJTU successfully fabricated hundred meter long CC tapes with over 300 A/cm (at 77 K, self field) on RABiTS tapes. To develop high performance CC tapes by PLD/IBAD-MgO processes, a pilot CC fabrication line was set up at Shanghai Superconductor Technology Corporation, Ltd. in 2013. High quality long REBCO coated conductors have been successfully fabricated on flexible polycrystalline metal tapes by PLD plus magnetron sputter and IBAD processes. Under optimized conditions, the IBAD-MgO layers showed pure (0 0 1) orientation and excellent in-plane texture. The in-plane phi-scan rocking curve is 4-6 degrees. AFM observation showed MgO layer had very smooth surface. The RMS is less 1 nm. On the textured MgO layer, sputter deposited single cerium oxide cap-layer showed pure (0 0 1) orientation and excellent in-plane texture of 4-6 degree. Reel-to-reel PLD process with high deposition rate was already scaled up to 100 m/h tape speed. Hundred meters long coated conductor tapes with over 500 A/cm performance have been routinely fabricated. And now, the process optimization for kilometer long coated conductor tapes is underway.

  9. Advanced Reactors Thermal Energy Transport for Process Industries

    SciTech Connect

    P. Sabharwall; S.J. Yoon; M.G. McKellar; C. Stoots; George Griffith

    2014-07-01

    The operation temperature of advanced nuclear reactors is generally higher than commercial light water reactors and thermal energy from advanced nuclear reactor can be used for various purposes such as liquid fuel production, district heating, desalination, hydrogen production, and other process heat applications, etc. Some of the major technology challenges that must be overcome before the advanced reactors could be licensed on the reactor side are qualification of next generation of nuclear fuel, materials that can withstand higher temperature, improvement in power cycle thermal efficiency by going to combined cycles, SCO2 cycles, successful demonstration of advanced compact heat exchangers in the prototypical conditions, and from the process side application the challenge is to transport the thermal energy from the reactor to the process plant with maximum efficiency (i.e., with minimum temperature drop). The main focus of this study is on doing a parametric study of efficient heat transport system, with different coolants (mainly, water, He, and molten salts) to determine maximum possible distance that can be achieved.

  10. Solar Energy: Materials, Materials Handling, and Fabrication Processes: Student Material. First Edition.

    ERIC Educational Resources Information Center

    Bolin, William Everet; Orsak, Charles G., Jr.

    Designed for student use in "Materials, Materials Handling, and Fabrication Processes," one of 11 courses in a 2-year associate degree program in solar technology, this manual provides readings, exercises, worksheets, bibliographies, and illustrations for 13 course modules. The manual, which corresponds to an instructor guide for the same course,…

  11. Differential scanning calorimetry investigation on vinyl ester resin curing process for polymer nanocomposite fabrication.

    PubMed

    Guo, Zhanhu; Ng, Ho Wai; Yee, Gary L; Hahn, H Thomas

    2009-05-01

    Two different ceramic (cerium oxide and titanium oxide) nanoparticles were introduced into vinyl ester resin for nanocomposite fabrication. The curing process of the vinyl ester resin was investigated by a differential scanning calorimetery (DSC). The incorporation of nanoparticles in the resin affects the curing process due to the physicochemical interaction between the nanoparticles and the polymer matrix. The particle loading has a significant effect on the initial and peak curing temperatures, reaction heat and curing extent. The fully cured vinyl ester resin nanocomposites reinforced with cerium oxide nanoparticles were fabricated after a 24-hour room temperature curing and a one-hour postcuring at 85 degrees C. Particle functionalization favors the composite fabrication with a higher curing extent after room-temperature curing as compared to the as-received nanoparticle filled vinyl ester resin nanocomposites. The nanofiller materials were observed to significantly affect the curing process. In comparison to cerium oxide nanoparticles, titanium oxide nanoparticles prohibit the curing process with a much higher initiating curing temperatures. The fully cured nanocomposites reinforced with titanium oxide nanoparticles were fabricated by one-hour postcuring at 85 degrees C. PMID:19453004

  12. Fabrication process scale-up and optimization for a boron-aluminum composite radiator

    NASA Technical Reports Server (NTRS)

    Okelly, K. P.

    1973-01-01

    Design approaches to a practical utilization of a boron-aluminum radiator for the space shuttle orbiter are presented. The program includes studies of laboratory composite material processes to determine the feasibility of a structural and functional composite radiator panel, and to estimate the cost of its fabrication. The objective is the incorporation of boron-aluminum modulator radiator on the space shuttle.

  13. Recent advances in processing and characterization of edgeless detectors

    NASA Astrophysics Data System (ADS)

    Wu, X.; Kalliopuska, J.; Eränen, S.; Virolainen, T.

    2012-02-01

    During past five years VTT has actively developed edgeless detector fabrication process. The straightforward and high yield process relies on ion-implantation to activate the edges of the detector. A recent fabrication process was performed at VTT to provide p-on-n edgeless detectors. The layout contained DC- and AC-coupled strip detector and pixel detectors for Medipix/Timepix readouts. The fabricated detector thicknesses were 50, 100 and 150 μm. Electrical characterization was done for 5 × 5 mm2 edgeless diodes on wafer level. All measured electrical parameters showed a dramatic dependence on the diode thickness. Leakage current was measured below 10 nA/cm2 at full depletion. Calculation using a theoretical approximation indicates the diode surface generation current of less than 300 pA. The breakdown voltages were measured to be above 140 V and increased as a function of diode thickness. Reverse bias of 10 V is enough to fully deplete designed edgeless diodes. Leakage current dependence of temperature was investigated for both p-on-n and previous n-on-n edgeless detectors and results show that the leakage current doubles for every 8.5 degree Celsius rise in temperature. TCAD device simulations reveal that breakdown occurs at the lateral p-n junction where the electric field reaches its highest value. Thick edgeless diodes have wider bulk space that allows electric potential to drop and causes smaller curvature of the equipotential lines. This releases the accumulation of electric field at the corner of anode and increases the breakdown voltage. A good match of the simulated and the measured capacitance-voltage curves enables identification of proper parameters used in the simulation.

  14. Research on chemical vapor deposition processes for advanced ceramic coatings

    NASA Technical Reports Server (NTRS)

    Rosner, Daniel E.

    1993-01-01

    Our interdisciplinary background and fundamentally-oriented studies of the laws governing multi-component chemical vapor deposition (VD), particle deposition (PD), and their interactions, put the Yale University HTCRE Laboratory in a unique position to significantly advance the 'state-of-the-art' of chemical vapor deposition (CVD) R&D. With NASA-Lewis RC financial support, we initiated a program in March of 1988 that has led to the advances described in this report (Section 2) in predicting chemical vapor transport in high temperature systems relevant to the fabrication of refractory ceramic coatings for turbine engine components. This Final Report covers our principal results and activities for the total NASA grant of $190,000. over the 4.67 year period: 1 March 1988-1 November 1992. Since our methods and the technical details are contained in the publications listed (9 Abstracts are given as Appendices) our emphasis here is on broad conclusions/implications and administrative data, including personnel, talks, interactions with industry, and some known applications of our work.

  15. Advanced titanium alloys and processes for minimally invasive surgery

    NASA Astrophysics Data System (ADS)

    Rack, H. J.; Qazi, Javaid

    2005-11-01

    Major advances continue to be made in enhancing patient care while at the same time attempting to slow ever-rising health costs. Among the most innovative of these advances are minimally invasive surgical techniques, which allow patients to undergo life-saving and quality-of-life enhancing surgery with minimized risk and substantially reduced hospital stays. Recently this approach was introduced for orthopedic procedures (e.g., during total hip replacement surgery). In this instance, the implantable devices will bear the same loads and will therefore be subject to higher stress. This paper provides a brief overview of several potential approaches for developing new advanced titanium alloys and processes that should provide substantial benefit for this application in minimally invasive devices.

  16. Fabrication of Antireflective Subwavelength Structure on Spherical Glass Surface Using Imprinting Process

    NASA Astrophysics Data System (ADS)

    Tamura, Takamasa; Umetani, Makoto; Yamada, Kazuhiro; Tanaka, Yasuhiro; Kintaka, Kenji; Kasa, Haruya; Nishii, Junji

    2010-11-01

    For the first time, an antireflective structure (ARS) on a convex spherical glass surface was fabricated using an imprinting process. The inverted pattern of the ARS with a 250-nm period was fabricated on a SiC mold with a concave surface using electron beam (EB) direct writing and reactive ion etching. The sample surface height was adjusted to the EB focal position along the mold curvature during the step-and-repeat EB lithography. The imprinted lens with the ARS exhibited surface reflectance of 0.2% at a wavelength of 530 nm and a spherical error magnitude of less than 500 nm.

  17. Fabrication process of carbon nanotube field effect transistors using atomic layer deposition passivation for biosensors.

    PubMed

    Nakashima, Yasuhiro; Ohno, Yutaka; Kishimoto, Shigeru; Okochi, Mina; Honda, Hiroyuki; Mizutani, Takashi

    2010-06-01

    Fabrication process of the carbon nanotube (CNT) field effect transistors (FETs) for biosensors was studied. Atomic layer deposition (ALD) of HfO2 was applied to the deposition of the passivation/gate insulator film. The CNT-FETs did not show the drain current degradation after ALD passivation even though the passivation by Si3N4 deposited by plasma-enhanced chemical vapor deposition (PECVD) resulted in a significant drain current decrease. This indicates the advantage of the present ALD technique in terms of the damage suppression. The biosensing operation was confirmed using thus fabricated CNT-FETs. PMID:20355371

  18. Near net shape processing for solar thermal propulsion hardware using directed light fabrication

    SciTech Connect

    Milewski, J.O.; Fonseca, J.C.; Lewis, G.K.

    1998-12-01

    Directed light fabrication (DLF) is a direct metal deposition process that fuses gas delivered powder, in the focal zone of a high powered laser beam to form fully fused near net shaped components. The near net shape processing of rhenium, tungsten, iridium and other high temperature materials may offer significant cost savings compared with conventional processing. This paper describes a 3D parametric solid model, integrated with a manufacturing model, and creating a control field which runs on the DLF machine directly depositing a fully dense, solid metal, near net shaped, nozzle component. Examples of DLF deposited rhenium, iridium and tantalum, from previous work, show a continuously solidified microstructure in rod and tube shapes. Entrapped porosity indicates the required direction for continued process development. These combined results demonstrate the potential for a new method to fabricate complex near net shaped components using materials of interest to the space and aerospace industries.

  19. Investigation of etching techniques for superconductive Nb/Al-Al2O3/Nb fabrication processes

    NASA Technical Reports Server (NTRS)

    Lichtenberger, A. W.; Lea, D. M.; Lloyd, F. L.

    1993-01-01

    Wet etching, CF4 and SF6 reactive ion etching (RIE), RIE/wet hybrid etching, Cl-based RIE, ion milling, and liftoff techniques have been investigated for use in superconductive Nb/Al-Al2O3/Nb fabrication processes. High-quality superconductor-insulator-superconductor (SIS) junctions have been fabricated using a variety of these etching methods; however, each technique offers distinct tradeoffs for a given process an wafer design. In particular, it was shown that SF6 provides an excellent RIE chemistry for low-voltage anisotropic etching of Nb with high selectivity to Al. The SF6 tool has greatly improved the trilevel resist junction insulation process. Excellent repeatability, selectivity with respect to quartz, and submicron resolution make Cl2 + BCl3 + CHCl3 RIE a very attractive process for trilayer patterning.

  20. Development of Advanced Conformal Ablative TPS Fabricated from Rayon- and PAN-Based Carbon Felts

    NASA Technical Reports Server (NTRS)

    Gasch, Matthew; Stackpoole, Margaret; White, Susan; Boghozian, Tane

    2016-01-01

    The conformal ablative TPS first developed under NASA's Hypersonics Project in the early 2000's demonstrated very low through the thickness conductivity compared to state-ofthe- art PICA. However, in initial arcjet testing of Conformal-1, surface recession rates were 2x higher than PICA. Because commercial carbon felts are currently available as very thin substrates, this was a concern if conformal TPS were to be considered for a mission that required thicker material. Discussed in this paper are the results of the development of an Advanced Conformal TPS derived from thicker, higher density carbon felt. Two substrate systems were evaluated, the first material was a needled rayon-based carbon felt and the other a needled PAN-based carbon felt. Both substrates were impregnated with phenolic resin following the PICA/CPICA process to add a low density phenolic matrix to the system prior to aerothermal screening at the LaRC HyMETS facility and larger scale testing in the NASA ARC Interaction Heating Facility (IHF) at heating fluxes ranging from 250-1700 W/cm2.

  1. Sensor-model prediction, monitoring and in-situ control of liquid RTM advanced fiber architecture composite processing

    NASA Astrophysics Data System (ADS)

    Kranbuehl, D.; Kingsley, P.; Hart, S.; Loos, A.; Hasko, G.; Dexter, B.

    In-situ frequency dependent electromagnetic sensors (FDEMS) and the Loos resin transfer model have been used to select and control the processing properties of an epoxy resin during liquid pressure RTM impregnation and cure. Once correlated with viscosity and degree of cure the FDEMS sensor monitors and the RTM processing model predicts the reaction advancement of the resin, viscosity and the impregnation of the fabric. This provides a direct means for predicting, monitoring, and controlling the liquid RTM process in-situ in the mold throughout the fabrication process and the effects of time, temperature, vacuum and pressure. Most importantly, the FDEMS-sensor model system has been developed to make intelligent decisions, thereby automating the liquid RTM process and removing the need for operator direction.

  2. Sensor-model prediction, monitoring and in-situ control of liquid RTM advanced fiber architecture composite processing

    NASA Technical Reports Server (NTRS)

    Kranbuehl, D.; Kingsley, P.; Hart, S.; Loos, A.; Hasko, G.; Dexter, B.

    1992-01-01

    In-situ frequency dependent electromagnetic sensors (FDEMS) and the Loos resin transfer model have been used to select and control the processing properties of an epoxy resin during liquid pressure RTM impregnation and cure. Once correlated with viscosity and degree of cure the FDEMS sensor monitors and the RTM processing model predicts the reaction advancement of the resin, viscosity and the impregnation of the fabric. This provides a direct means for predicting, monitoring, and controlling the liquid RTM process in-situ in the mold throughout the fabrication process and the effects of time, temperature, vacuum and pressure. Most importantly, the FDEMS-sensor model system has been developed to make intelligent decisions, thereby automating the liquid RTM process and removing the need for operator direction.

  3. AFIP-4 Fabrication Summary Report

    SciTech Connect

    Glenn A. Moore

    2010-02-01

    The AFIP-4 (ATR Full –size-plate In center flux trap Position) experiment was designed to evaluate the performance of monolithic fuels at a scale prototypic of research reactor fuel plates. Twelve qualified fueled plates were fabricated for the AFIP-4 experiment; to be irradiated in the INL Advanced Test Reactor (ATR). This report provides details of the fuel fabrication efforts; including material selection, fabrication processes, and fuel plate qualification.

  4. AFIP-2 Fabrication Summary Report

    SciTech Connect

    Glenn Moore

    2010-02-01

    The Advanced Test Reactor (ATR) Full-size Plate In Center Flux Trap Position (AFIP)-2 experiment was designed to evaluate the performance of monolithic fuels at a scale prototypic of research reactor fuel plates. Two qualified fueled plates were fabricated for the AFIP 2 experiment to be irradiated in the Idaho National Laboratory ATR. This report provides details of the fuel fabrication efforts, including material selection, fabrication processes, and fuel plate qualification.

  5. AFIP-6 Fabrication Summary Report

    SciTech Connect

    Glenn A. Moore; M. Craig Marshall

    2011-09-01

    The AFIP-6 (ATR Full-size plate In center flux trap Position) experiment was designed to evaluate the performance of monolithic fuels at a scale prototypic of research reactor fuel plates. Two qualified fueled plates were fabricated for the AFIP-6 experiment; to be irradiated in the INL Advanced Test Reactor (ATR). This report provides details of the fuel fabrication efforts, including material selection, fabrication processes, and fuel plate qualification.

  6. Development of a method for fabricating metallic matrix composite shapes by a continuous mechanical process

    NASA Technical Reports Server (NTRS)

    Divecha, A. P.

    1974-01-01

    Attempts made to develop processes capable of producing metal composites in structural shapes and sizes suitable for space applications are described. The processes must be continuous and promise to lower fabrication costs. Special attention was given to the aluminum boride (Al/b) composite system. Results show that despite adequate temperature control, the consolidation characteristics did not improve as expected. Inadequate binder removal was identified as the cause responsible. An Al/c (aluminum-graphite) composite was also examined.

  7. High-performance self-aligned graphene transistors fabricated using contamination- and defect-free process

    NASA Astrophysics Data System (ADS)

    Park, Goon-Ho; Kim, Kwan-Soo; Fukidome, Hirokazu; Suemitsu, Tetsuya; Otsuji, Taiichi; Cho, Won-Ju; Suemitsu, Maki

    2016-06-01

    A contamination- and defect-free process is proposed for self-aligned graphene field-effect transistor (GFET) fabrication using a protective gold layer and by its etching. The gold layer serves as an electrode metal for both the source and drain. GFETs fabricated by this method exhibit superior electrical characteristics, such as an intrinsic carrier mobility of 8900 cm2 V‑1 s‑1 and a series resistance of 1520 Ω µm, which is ascribed to the effective blocking of unwanted contamination and defect formation as well as to the reduction in access length due to the self-aligned configuration. Our approach is quite promising as a device fabrication method for high-performance GFETs.

  8. Advances in biologically inspired on/near sensor processing

    NASA Astrophysics Data System (ADS)

    McCarley, Paul L.

    1999-07-01

    As electro-optic sensors increase in size and frame rate, the data transfer and digital processing resource requirements also increase. In many missions, the spatial area of interest is but a small fraction of the available field of view. Choosing the right region of interest, however, is a challenge and still requires an enormous amount of downstream digital processing resources. In order to filter this ever-increasing amount of data, we look at how nature solves the problem. The Advanced Guidance Division of the Munitions Directorate, Air Force Research Laboratory at Elgin AFB, Florida, has been pursuing research in the are of advanced sensor and image processing concepts based on biologically inspired sensory information processing. A summary of two 'neuromorphic' processing efforts will be presented along with a seeker system concept utilizing this innovative technology. The Neuroseek program is developing a 256 X 256 2-color dual band IRFPA coupled to an optimized silicon CMOS read-out and processing integrated circuit that provides simultaneous full-frame imaging in MWIR/LWIR wavebands along with built-in biologically inspired sensor image processing functions. Concepts and requirements for future such efforts will also be discussed.

  9. RCE-DR, a novel process for coated conductor fabrication with high performance

    NASA Astrophysics Data System (ADS)

    Lee, Jae-Hun; Lee, Hunju; Lee, Jung-Woo; Choi, Soon-Mi; Yoo, Sang-Im; Moon, Seung-Hyun

    2014-04-01

    We report in detail on SuNAM’s reactive co-evaporation by deposition and reaction (RCE-DR) process. We have successfully fabricated a high performance GdBCO coated conductor (CC) with high throughput by the RCE-DR process, that consists of two steps for the deposition of elemental metal oxides and the conversion of cation oxides into the GdBCO superconducting phase. Constituting metals such as Gd, Ba and Cu were first deposited on LaMnO3 (LMO)-buffered IBAD-MgO templates at low temperatures and low pressures followed by a high temperature treatment step under high oxygen partial pressure for fast phase conversion. GdBCO CCs fabricated by RCE-DR showed excellent transport properties such as a critical current of 794 A cm-1 width at 77 K in self-field. With the RCE-DR process, we have achieved an overall processing speed of more than 120 m h-1 (in terms of a real process linear tape speed equivalent). SuNAM’s RCE-DR technique showed great potential as the highest throughput fabrication process compared with other methods developed previously for second generation high temperature superconducting wires, meeting the current and future need of industry in terms of price and production speed.

  10. Advanced Process Model for Polymer Pyrolysis and Uranium Ceramic Material Processing

    SciTech Connect

    Wang, Xiaolin; Zunjarrao, Suraj C.; Zhang, Hui; Singh, Raman P.

    2006-07-01

    Silicon carbide (SiC) based uranium ceramic material can be fabricated as hosts for ultra high temperature applications, such as gas-cooled fast reactor fuels and in-core materials. A pyrolysis-based material processing technique allows for the fabrication of SiC based uranium ceramic materials at a lower temperature compared to sintering route. Modeling of the process is considered important for optimizing the fabrication and producing material with high uniformity. This study presents a process model describing polymer pyrolysis and uranium ceramic material processing, including heat transfer, polymer pyrolysis, SiC crystallization, chemical reactions, and species transport of a porous uranium oxide mixed polymer. Three key reactions for polymer pyrolysis and one key reaction for uranium oxide polymer interaction are established for the processing. Included in the model formulation are the effects of transport processes such as heat-up, polymer decomposition, and volatiles escape. The model is capable of accurately predicting the polymer pyrolysis and chemical reactions of the source material. Processing of a sample with certain geometry is simulated. The effects of heating rate, particle size and volume ratio of uranium oxide and polymer on porosity evolution, species uniformity, reaction rate are investigated. (authors)

  11. Mechanical Behavior of Cu/Al multilayers fabricated by Accumulative Roll-Bonding (ARB) processing

    NASA Astrophysics Data System (ADS)

    Zhang, Qiwei

    For many years, there have been long-standing interests in studying multilayer metals. And many kinds of multilayers are fabricated via a variety of methods. Recently, in an effort to obtain ultrafine grains, a novel technique, namely, accumulative roll-bonding (ARB) is created, which is a kind of severe plastic deformation (SPD) process [1]. Via this technique extremely high strain can be obtained when metal materials are processed; and the properties of original metals can also be largely changed. However, ARB process is rarely applied to multilayer fabrication, especially the fabrication of multilayer bimetals. This thesis focuses on how to obtain Al/Cu multilayers via ARB process, and also examines the microstructure evolution with the increasing number of layers, and the metal properties of the obtained multilayers. This thesis first reviews the development and mechanism of rolling, one of the most important metal forming processes, and the application of rolling in metal fabrication in recent years. Then the formation and the development of ARB process are introduced, followed by current studies on ARB process. Among all the methods of fabricating multilayers, ARB process features high efficiency and continuous production of sheet materials, etc., because it is based on the rolling principle. This thesis examines a mass of unique metal properties and the microstructure of the products that experienced ARB process. In this research, a great numbers of conditions for the roll-bonding of aluminum and copper sheets were studied. Besides, aluminum and copper sheets were rolled to 1.1 mm, 0.8 mm, 0.58 mm and 0.5 mm thick as initial samples. Then the Al/Cu multilayer sheets experienced ARB process for up to 10 cycles at most, at various heat treatment temperatures under various annealing conditions, with various reductions in thickness per cycles and different thickness ratio of aluminum and copper layers. Altogether 11 groups were obtained. In this thesis, the

  12. Improvement of process control using wafer geometry for enhanced manufacturability of advanced semiconductor devices

    NASA Astrophysics Data System (ADS)

    Lee, Honggoo; Lee, Jongsu; Kim, Sang Min; Lee, Changhwan; Han, Sangjun; Kim, Myoungsoo; Kwon, Wontaik; Park, Sung-Ki; Vukkadala, Pradeep; Awasthi, Amartya; Kim, J. H.; Veeraraghavan, Sathish; Choi, DongSub; Huang, Kevin; Dighe, Prasanna; Lee, Cheouljung; Byeon, Jungho; Dey, Soham; Sinha, Jaydeep

    2015-03-01

    Aggressive advancements in semiconductor technology have resulted in integrated chip (IC) manufacturing capability at sub-20nm half-pitch nodes. With this, lithography overlay error budgets are becoming increasingly stringent. The delay in EUV lithography readiness for high volume manufacturing (HVM) and the need for multiple-patterning lithography with 193i technology has further amplified the overlay issue. Thus there exists a need for technologies that can improve overlay errors in HVM. The traditional method for reducing overlay errors predominantly focused on improving lithography scanner printability performance. However, processes outside of the lithography sector known as processinduced overlay errors can contribute significantly to the total overlay at the current requirements. Monitoring and characterizing process-induced overlay has become critical for advanced node patterning. Recently a relatively new technique for overlay control that uses high-resolution wafer geometry measurements has gained significance. In this work we present the implementation of this technique in an IC fabrication environment to monitor wafer geometry changes induced across several points in the process flow, of multiple product layers with critical overlay performance requirement. Several production wafer lots were measured and analyzed on a patterned wafer geometry tool. Changes induced in wafer geometry as a result of wafer processing were related to down-stream overlay error contribution using the analytical in-plane distortion (IPD) calculation model. Through this segmentation, process steps that are major contributors to down-stream overlay were identified. Subsequent process optimization was then isolated to those process steps where maximum benefit might be realized. Root-cause for the within-wafer, wafer-to-wafer, tool-to-tool, and station-to-station variations observed were further investigated using local shape curvature changes - which is directly related to

  13. Field study of disposed wastes from advanced coal processes

    SciTech Connect

    Not Available

    1990-01-01

    The objective of this research is to develop information to be used by private industry and government agencies for planning waste disposal practices associated with advanced coal processes. DOE has contracted Radian Corporation and the North Dakota Energy Environmental Research Center (EERC) to design, construct and monitor a limited number of field disposal tests with advanced coal process wastes. These field tests will be monitored over a three year period with the emphasis on collecting data on the field disposal of these wastes. This report discusses waste composition from fluidized bed coal combustion. Also presented is analytical data from the leaching of waste sampled from storage soils and of soil samples collected. 6 figs., 13 tabs.

  14. Explosive Indentation Study of B4C-TiAlx Composites Fabricated by the Dipping Exothermic Reaction Process

    NASA Astrophysics Data System (ADS)

    Kim, Jong Ho; Ansari, Haris Masood; Kim, Haneul; Kim, Do Kyung; Chang, Soon Nam

    The aim of this study is to fabricate a high volume fraction B4C-reinforced intermetallic matrix composite by the dipping exothermic reaction process and investigate the shock impact damage response of composites by explosive indentation experiment. It has been shown that the final microstructure of the dipping exothermic reaction process-fabricated composite can be tailored by treatment of the constituent powders and post heat treatment. The hardness and impact damage resistance of the fabricated composites were evaluated.

  15. Recent advances in natural language processing for biomedical applications.

    PubMed

    Collier, Nigel; Nazarenko, Adeline; Baud, Robert; Ruch, Patrick

    2006-06-01

    We survey a set a recent advances in natural language processing applied to biomedical applications, which were presented in Geneva, Switzerland, in 2004 at an international workshop. While text mining applied to molecular biology and biomedical literature can report several interesting achievements, we observe that studies applied to clinical contents are still rare. In general, we argue that clinical corpora, including electronic patient records, must be made available to fill the gap between bioinformatics and medical informatics. PMID:16139564

  16. Advanced information processing system: Input/output network management software

    NASA Technical Reports Server (NTRS)

    Nagle, Gail; Alger, Linda; Kemp, Alexander

    1988-01-01

    The purpose of this document is to provide the software requirements and specifications for the Input/Output Network Management Services for the Advanced Information Processing System. This introduction and overview section is provided to briefly outline the overall architecture and software requirements of the AIPS system before discussing the details of the design requirements and specifications of the AIPS I/O Network Management software. A brief overview of the AIPS architecture followed by a more detailed description of the network architecture.

  17. Composite material having high thermal conductivity and process for fabricating same

    DOEpatents

    Colella, N.J.; Davidson, H.L.; Kerns, J.A.; Makowiecki, D.M.

    1998-07-21

    A process is disclosed 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. 7 figs.

  18. Composite material having high thermal conductivity and process for fabricating same

    DOEpatents

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

    1998-01-01

    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.

  19. Integratible Process for Fabrication of Fluidic Microduct Networks on a Single Wafer

    SciTech Connect

    Matzke, C.M.; Ashby, C.I.; Bridges, M.M.; Griego, L.; Wong, C.C.

    1999-09-07

    We present a microelectronics fabrication compatible process that comprises photolithography and a key room temperature SiON thin film plasma deposition to define and seal a fluidic microduct network. Our single wafer process is independent of thermo-mechanical material properties, particulate cleaning, global flatness, assembly alignment, and glue medium application, which are crucial for wafer fusion bonding or sealing techniques using a glue medium. From our preliminary experiments, we have identified a processing window to fabricate channels on silicon, glass and quartz substrates. Channels with a radius of curvature between 8 and 50 {micro}m, are uniform along channel lengths of several inches and repeatable across the wafer surfaces. To further develop this technology, we have begun characterizing the SiON film properties such as elastic modulus using nanoindentation, and chemical bonding compatibility with other microelectronic materials.

  20. Characterization and optimization of residual layer thickness during UV imprint process for singlemode waveguide fabrication

    NASA Astrophysics Data System (ADS)

    An, Shinmo; Lee, Hyun-Shik; Park, Se-Guen; O, Beom-Hoan; Lee, Seung-Gol; Lee, El-Hang

    2009-02-01

    We report on the fabrication and characterization of a residual layer resulting from UV imprinting of singlemode optical waveguide. We have measured the residual thickness formed from the imprinting process for several-um-size singlemode waveguide fabrication using the parameters of the imprinting pressure, dropped volume, and viscosity of the used polymer. We found that the residual layer thickness is dependent on both the initial polymer volume and process pressure and the initial polymer volume is more critical than process pressure. Viscosity of polymer also affects the residual layer thickness, the lowest residual layer thickness of 29nm is achieved with nano-imprinting resin, 0.3uL volume, and imprint pressure more than 20bar. Even with optical resin, the residual layer thickness of 60nm is achieved with 0.3uL volume and imprinting pressure of 30bar.

  1. Advanced technology development for image gathering, coding, and processing

    NASA Technical Reports Server (NTRS)

    Huck, Friedrich O.

    1990-01-01

    Three overlapping areas of research activities are presented: (1) Information theory and optimal filtering are extended to visual information acquisition and processing. The goal is to provide a comprehensive methodology for quantitatively assessing the end-to-end performance of image gathering, coding, and processing. (2) Focal-plane processing techniques and technology are developed to combine effectively image gathering with coding. The emphasis is on low-level vision processing akin to the retinal processing in human vision. (3) A breadboard adaptive image-coding system is being assembled. This system will be used to develop and evaluate a number of advanced image-coding technologies and techniques as well as research the concept of adaptive image coding.

  2. Silicon solar-cell process: development, fabrication, and analysis. Tenth quarterly report, 1 July 1981-30 September 1981

    SciTech Connect

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

    1981-01-01

    Work has progressed in fabrication and characterization of solar cells from 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 SJ, BSF, and 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% AM1 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% AM1 with 13.4% AM1 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.

  3. Advanced metal mirror processing for tactical ISR systems

    NASA Astrophysics Data System (ADS)

    Schaefer, John P.

    2013-05-01

    Using its patented VQ™ finishing process, Raytheon EO Innovations has been producing low-scatter, low-figure and affordable aluminum 6061-based mirrors for long stand-off intelligence, surveillance and reconnaissance (ISR) systems in production since 2005. These common aperture multispectral systems require λ/30 root mean square (RMS) surface figure and sub-20Å RMS finishes for optimal visible imaging performance. This paper discusses the process results, scatter performance, and fabrication capabilities of Multispectral Reflective Lightweight Optics Technology (MeRLOT™), a new lightweight substrate material. This new technology enables lightweight, common-aperture, broadband performance that can be put in the hands of the warfighter for precision targeting and surveillance operations.

  4. Holographic femtosecond laser manipulation for advanced material processing

    NASA Astrophysics Data System (ADS)

    Hasegawa, Satoshi; Hayasaki, Yoshio

    2016-02-01

    Parallel femtosecond laser processing using a computer-generated hologram displayed on a spatial light modulator, known as holographic femtosecond laser processing, provides the advantages of high throughput and high-energy use efficiency. Therefore, it has been widely used in many applications, including laser material processing, two-photon polymerization, two-photon microscopy, and optical manipulation of biological cells. In this paper, we review the development of holographic femtosecond laser processing over the past few years from the perspective of wavefront and polarization modulation. In particular, line-shaped and vector-wave femtosecond laser processing are addressed. These beam-shaping techniques are useful for performing large-area machining in laser cutting, peeling, and grooving of materials and for high-speed fabrication of the complex nanostructures that are applied to material-surface texturing to control tribological properties, wettability, reflectance, and retardance. Furthermore, issues related to the nonuniformity of diffraction light intensity in optical reconstruction and wavelength dispersion from a computer-generated hologram are addressed. As a result, large-scale holographic femtosecond laser processing over 1000 diffraction spots was successfully demonstrated on a glass sample.

  5. High-performance thin-film transistors fabricated using excimer laser processing and grain engineering

    SciTech Connect

    Giust, G.K.; Sigmon, T.W.

    1998-04-01

    High-performance polysilicon thin-film transistors (TFT`s) are fabricated using an excimer laser to recrystallize the undoped channel and dope the source-drain regions. Using a technique the authors call grain engineering they are able to control grain microstructure using laser parameters. Resulting polysilicon films are obtained with average grain sizes of {approximately}4--9 {micro}m in sub-100 nm thick polysilicon films without substrate heating during the laser recrystallization process. Using a simple four-mask self-aligned aluminum top-gate structure, they fabricate TFT`s in these films. By combining the grain-engineered channel polysilicon regions with laser-doped source-drain regions, TFT`s are fabricated with electron mobilities up to 260 cm{sup 2}/Vs and on/off current ratios greater than 10{sup 7} To their knowledge, these devices represent the highest performance laser-processed TFT`s reported to date fabricated without substrate heating or hydrogenation.

  6. A basic experimental study of ultrasonic assisted hot embossing process for rapid fabrication of microlens arrays

    NASA Astrophysics Data System (ADS)

    Chang, Chih-Yuan; Yu, Che-Hao

    2015-02-01

    This paper reports a highly effective technique for rapid fabrication of microlens arrays based on an ultrasonic assisted hot embossing process. In this method, a thin stainless steel mold with micro-holes array is fabricated by a photolithography and wet etching process. Then, the thin stainless steel mold with micro-holes array is placed on top of a plastic substrate (PMMA plate) and the stack is placed in an ultrasonic vibration embossing machine. During ultrasonic assisted hot embossing operation, the surface of the stainless steel mold with micro-holes array presses against the thermoplastic PMMA substrate. Under proper ultrasonic vibration time, embossing pressure and hold time, the softened polymer will just partially fill the circular holes and due to surface tension, form a convex lens surface. After the stainless steel mold is removed, the microlens array patterns on the surface of plastic substrate can be obtained. The total cycle time is less than 10 s. Finally, geometrical and optical properties of the fabricated plastic microlens arrays were measured and proved satisfactory. This technique shows great potential for fabricating microlens array on plastic substrates with high productivity and low cost.

  7. Characterization of the interactions within fine particle mixtures in highly concentrated suspensions for advanced particle processing.

    PubMed

    Otsuki, Akira; Bryant, Gary

    2015-12-01

    This paper aims to summarize recent investigations into the dispersion of fine particles, and the characterization of their interactions, in concentrated suspensions. This summary will provide a better understanding of the current status of this research, and will provide useful feedback for advanced particle processing. Such processes include the fabrication of functional nanostructures and the sustainable beneficiation of complex ores. For example, there has been increasing demand for complex ore utilization due to the noticeable decrease in the accessibility of high grade and easily extractable ores. In order to maintain the sustainable use of mineral resources, the effective beneficiation of complex ores is urgently required. It can be successfully achieved only with selective particle/mineral dispersion/liberation and the assistance of mineralogical and particle characterization. PMID:26298173

  8. Process development status report for advanced manufacturing projects

    SciTech Connect

    Brinkman, J.R.; Homan, D.A.

    1990-03-30

    This is the final status report for the approved Advanced Manufacturing Projects for FY 1989. Five of the projects were begun in FY 1987, one in FY 1988, and one in FY 1989. The approved projects cover technology areas in welding, explosive material processing and evaluation, ion implantation, and automated manufacturing. It is expected that the successful completion of these projects well result in improved quality and/or reduced cost for components produced by Mound. Those projects not brought to completion will be continued under Process development in FY 1990.

  9. Advanced biologically plausible algorithms for low-level image processing

    NASA Astrophysics Data System (ADS)

    Gusakova, Valentina I.; Podladchikova, Lubov N.; Shaposhnikov, Dmitry G.; Markin, Sergey N.; Golovan, Alexander V.; Lee, Seong-Whan

    1999-08-01

    At present, in computer vision, the approach based on modeling the biological vision mechanisms is extensively developed. However, up to now, real world image processing has no effective solution in frameworks of both biologically inspired and conventional approaches. Evidently, new algorithms and system architectures based on advanced biological motivation should be developed for solution of computational problems related to this visual task. Basic problems that should be solved for creation of effective artificial visual system to process real world imags are a search for new algorithms of low-level image processing that, in a great extent, determine system performance. In the present paper, the result of psychophysical experiments and several advanced biologically motivated algorithms for low-level processing are presented. These algorithms are based on local space-variant filter, context encoding visual information presented in the center of input window, and automatic detection of perceptually important image fragments. The core of latter algorithm are using local feature conjunctions such as noncolinear oriented segment and composite feature map formation. Developed algorithms were integrated into foveal active vision model, the MARR. It is supposed that proposed algorithms may significantly improve model performance while real world image processing during memorizing, search, and recognition.

  10. Fabrication of Hybrid Nanostructures via Nanoscale Laser-Induced Reshaping for Advanced Light Manipulation.

    PubMed

    Zuev, Dmitry A; Makarov, Sergey V; Mukhin, Ivan S; Milichko, Valentin A; Starikov, Sergey V; Morozov, Ivan A; Shishkin, Ivan I; Krasnok, Alexander E; Belov, Pavel A

    2016-04-01

    Ordered hybrid nanostructures for nanophotonics applications are fabricated by a novel approach via femtosecond laser melting of asymmetric metal-dielectric (Au/Si) nanoparticles created by lithographical methods. The approach allows selective reshaping of the metal components of the hybrid nanoparticles without affecting the dielectric ones and is applied for tuning of the scattering properties of the hybrid nanostructures in the visible range. PMID:26901635

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

    NASA Technical Reports Server (NTRS)

    1980-01-01

    Principal program activities dealt with the literature survey, design of joint concepts, assessment of GR/PI material quality, fabrication of test panels and specimens, and small specimen testing. Bonded and bolted designs are presented for each of the four major attachment types. Quality control data are presented for prepreg Lots 2W4651 and 3W2020. Preliminary design allowables test results for tension tests and compression tests of laminates are also presented.

  12. SOI waveguide fabrication process development using star coupler scattering loss measurements

    NASA Astrophysics Data System (ADS)

    Yap, K. P.; Lapointe, J.; Lamontagne, B.; Delâge, A.; Bogdanov, A.; Janz, S.; Syrett, B.

    2007-12-01

    We show that integrated optical star couplers can be useful characterization devices to measure the sidewall roughness-induced scattering losses of planar waveguides. We describe the detailed fabrication processes of these star couplers on the silicon-on-insulator (SOI) platform and the process improvements implemented to reduce the waveguide sidewall roughness and scattering loss. We report the main process challenges, particularly to assure a clear gap between any adjacent waveguides of the dense and closely spaced output waveguide array. These challenges are addressed by optimizing the exposure dose of the resist and adding an oxygen ashing treatment to eliminate waveguide footings. We demonstrate further improvement on the waveguide profile and sidewall roughness through the use of a thin Cr hardmask for the dry plasma etching. This optimized fabrication process is capable of producing approximately a 3 nm root-mean-square sidewall roughness, measured using both scanning electron microscopy (SEM) and atomic force microscopy (AFM). Using the fabricated star couplers, we manage to measure the relative scattering losses of various waveguides with the width varying from 0.2 to 2.0 μm in a single measurement, and show that the measured losses agree with the measured sidewall roughness.

  13. Integrated Seismic Event Detection and Location by Advanced Array Processing

    SciTech Connect

    Kvaerna, T; Gibbons, S J; Ringdal, F; Harris, D B

    2007-02-09

    The principal objective of this two-year study is to develop and test a new advanced, automatic approach to seismic detection/location using array processing. We address a strategy to obtain significantly improved precision in the location of low-magnitude events compared with current fully-automatic approaches, combined with a low false alarm rate. We have developed and evaluated a prototype automatic system which uses as a basis regional array processing with fixed, carefully calibrated, site-specific parameters in conjuction with improved automatic phase onset time estimation. We have in parallel developed tools for Matched Field Processing for optimized detection and source-region identification of seismic signals. This narrow-band procedure aims to mitigate some of the causes of difficulty encountered using the standard array processing system, specifically complicated source-time histories of seismic events and shortcomings in the plane-wave approximation for seismic phase arrivals at regional arrays.

  14. Advances in process intensification through multifunctional reactor engineering

    SciTech Connect

    O'Hern, T. J.

    2012-03-01

    This project was designed to advance the art of process intensification leading to a new generation of multifunctional chemical reactors. Experimental testing was performed in order to fully characterize the hydrodynamic operating regimes critical to process intensification and implementation in commercial applications. Physics of the heat and mass transfer and chemical kinetics and how these processes are ultimately scaled were investigated. Specifically, we progressed the knowledge and tools required to scale a multifunctional reactor for acid-catalyzed C4 paraffin/olefin alkylation to industrial dimensions. Understanding such process intensification strategies is crucial to improving the energy efficiency and profitability of multifunctional reactors, resulting in a projected energy savings of 100 trillion BTU/yr by 2020 and a substantial reduction in the accompanying emissions.

  15. Thermal Skin fabrication technology

    NASA Technical Reports Server (NTRS)

    Milam, T. B.

    1972-01-01

    Advanced fabrication techniques applicable to Thermal Skin structures were investigated, including: (1) chemical machining; (2) braze bonding; (3) diffusion bonding; and (4) electron beam welding. Materials investigated were nickel and nickel alloys. Sample Thermal Skin panels were manufactured using the advanced fabrication techniques studied and were structurally tested. Results of the program included: (1) development of improved chemical machining processes for nickel and several nickel alloys; (2) identification of design geometry limits; (3) identification of diffusion bonding requirements; (4) development of a unique diffusion bonding tool; (5) identification of electron beam welding limits; and (6) identification of structural properties of Thermal Skin material.

  16. A process for fabrication submicron all-refractory Josephson tunnel junction circuits

    SciTech Connect

    Dang, H.; Radpervar, M. )

    1991-03-01

    This paper describes a process for fabricating submicron Josephson junctions suitable for integration in small and medium scale integrated circuits. This junction process utilizes a double layer SiO{sub 2} lift-off process in a cross-type geometry to define Josephson junctions. A photoresist strip with an arbitrary length and a fixed width defines the length of the junction. Its width is defined simultaneously with the metallization strip that crosses the first strip. The double layer SiO{sub 2} insures a pinhole- free oxide and yields excellent insulating properties suitable for medium scale circuit applications.

  17. Enhanced performance of wearable piezoelectric nanogenerator fabricated by two-step hydrothermal process

    NASA Astrophysics Data System (ADS)

    Qiu, Yu; Lei, Jixue; Yang, Dechao; Yin, Bing; Zhang, Heqiu; Bian, Jiming; Ji, Jiuyu; Liu, Yanhong; Zhao, Yu; Luo, Yingmin; Hu, Lizhong

    2014-03-01

    A simple two-step hydrothermal process was proposed for enhancing the performance of the nanogenerator on flexible and wearable terylene-fabric substrate. With this method, a significant enhancement in output voltage of the nanogenerator from ˜10 mV to 7 V was achieved, comparing with the one by conventional one-step process. In addition, another advantage with the devices synthesized by two-step hydrothermal process was that their output voltages are only sensitive to strain rather than strain rate. The devices with a high output voltage have the ability to power common electric devices and will have important applications in flexible electronics and wearable devices.

  18. Rapid Fabrication of Lightweight SiC Optics using Reactive Atom Plasma (RAP) Processing

    NASA Technical Reports Server (NTRS)

    Fiske, Peter S.

    2006-01-01

    Reactive Atom Plasma (RAP) processing is a non-contact, plasma-based processing technology that can be used to generate damage-free optical surfaces. We have developed tools and processes using RAP that allow us to shape extremely lightweight mirror Surfaces made from extremely hard-to-machine materials (e.g. SiC). We will describe our latest results using RAP in combination with other technologies to produce finished lightweight SiC mirrors and also discuss applications for RAP in the rapid fabrication of mirror segments for reflective and grazing incidence telescopes.

  19. Practical use of hard mask process to fabricate fine photomasks for 45nm node and beyond

    NASA Astrophysics Data System (ADS)

    Kushida, Yasuyuki; Handa, Hitoshi; Maruyama, Hiroshi; Abe, Yuuki; Fujimura, Yukihiro; Yokoyama, Toshifumi

    2007-10-01

    New process with hard-mask (HM) blanks was evaluated as one of candidates for photomasks beyond 45nm-node. Through the fabrication of gate-layer photomasks, aptitude of the HM process for practical use was confirmed from the view of controllability on CDs and defects. Although conventional process for attenuated PSM was shown to have critical CD error which belongs to the "patterns" in bright-field masks, experimental data proved effectiveness of the HM process to control CDs after process optimization. With the HM blanks, remarkable reduction of CD error more than 80% of conventional process was confirmed. In this report, peculiar opaque defects are also shown to be a critical issue on the HM process. From results of design of experiment (DOE), combining the proper means to prepare the HM blanks with the optimized HM etching condition, these defects were proved to be controlled within the tolerance for production. Through the investigations, validity of the HM process on practical use for mask fabrication of 45nm-node and beyond is considered as conclusions.

  20. Fabrication process development for high-purity germanium radiation detectors with amorphous semiconductor contacts

    NASA Astrophysics Data System (ADS)

    Looker, Quinn

    High-purity germanium (HPGe) radiation detectors are well established as a valuable tool in nuclear science, astrophysics, and nuclear security applications. HPGe detectors excel in gamma-ray spectroscopy, offering excellent energy resolution with large detector sizes for high radiation detection efficiency. Although a robust fabrication process has been developed, improvement is needed, especially in developing electrical contact and surface passivation technology for position-sensitive detectors. A systematic study is needed to understand how the detector fabrication process impacts detector performance and reliability. In order to provide position sensitivity, the electrical contacts are segmented to form multiple electrodes. This segmentation creates new challenges in the fabrication process and warrants consideration of additional detector effects related to the segmentation. A key area of development is the creation of the electrical contacts in a way that enables reliable operation, provides low electronic noise, and allows fine segmentation of electrodes, giving position sensitivity for radiation interactions in the detector. Amorphous semiconductor contacts have great potential to facilitate new HPGe detector designs by providing a thin, high-resistivity surface coating that is the basis for electrical contacts that block both electrons and holes and can easily be finely segmented. Additionally, amorphous semiconductor coatings form a suitable passivation layer to protect the HPGe crystal surface from contamination. This versatility allows a simple fabrication process for fully passivated, finely segmented detectors. However, the fabrication process for detectors with amorphous semiconductors is not as highly developed as for conventional technologies. The amorphous semiconductor layer properties can vary widely based on how they are created and these can translate into varying performance of HPGe detectors with these contacts. Some key challenges include

  1. A novel fabrication process to realize a valveless micropump on a flexible substrate

    NASA Astrophysics Data System (ADS)

    Wei, Yang; Torah, Russel; Yang, Kai; Beeby, Steve; Tudor, John

    2014-02-01

    This paper reports, for the first time, on the design, fabrication and testing of a planar valveless micropump, entirely screen printed onto a flexible polyimide (Kapton) substrate using sacrificial, structural, conductive and piezoelectric layers. The sacrificial layer, used to achieve a pump chamber and inlet/outlet channels, is removed using water followed by a 140 ° C heat treatment to evaporate the water from the structure. The fabrication process is analogous to a standard silicon based micro-electro-mechanical system sacrificial process. Applying a sinusoidal AC voltage to the piezoelectric layer drives a flexible membrane which pumps a liquid through the chamber. A maximum flow rate of 38 μl min-1 was achieved using a drive frequency of 3 kHz.

  2. Evaluation of Schottky barrier diodes fabricated directly on processed 4H-SiC(0001) surfaces.

    PubMed

    Sano, Yasuhisa; Shirasawa, Yuki; Okamoto, Takeshi; Yamauchi, Kazuto

    2011-04-01

    Silicon carbide (SiC) is a suitable substrate for low-power-consumption power devices and high-temperature applications. However, this material is difficult to machine because of its hardness and chemical inertness, and many machining methods have been studied intensively in recent years. In this paper, we present a simple method to evaluate the electrical properties of the processed surface using the ideal factor n of a Schottky barrier diode (SBD) fabricated directly on the processed surface. Upon comparing the values of n for SBDs fabricated on a damaged SiC surface and a non-damaged SiC surface, we found that there is a significant difference in the dispersion and magnitude of n. Furthermore, by combining this technique with slope etching, we were able to estimate the thickness of the damaged sub-surface layer. PMID:21776636

  3. Update On Monolithic Fuel Fabrication Development

    SciTech Connect

    C. R Clark; J. M. Wight; G. C. Knighton; G. A. Moore; J. F. Jue

    2005-11-01

    Efforts to develop a viable monolithic research reactor fuel plate have continued at Idaho National Laboratory. These efforts have concentrated on both fabrication process refinement and scale-up to produce full sized fuel plates. Advancements have been made in the production of U-Mo foil including full sized foils. Progress has also been made in the friction stir welding and transient liquid phase bonding fabrication processes resulting in better bonding, more stable processes and the ability to fabricate larger fuel plates.

  4. A fast prototyping process for fabrication of microfluidic systems on soda-lime glass

    NASA Astrophysics Data System (ADS)

    Lin, Che-Hsin; Lee, Gwo-Bin; Lin, Yen-Heng; Chang, Guan-Liang

    2001-11-01

    This paper describes a fast, low-cost but reliable process for the fabrication of microfluidic systems on soda-lime glass substrates. Instead of using an expensive metal or polisilicon/nitride layer as an etch mask, a thin layer of AZ 4620 positive photoresist (PR) is used for buffered oxide etching (BOE) of soda-lime glass. A novel two-step baking process prolongs the survival time of the PR mask in the etchant, which avoids serious peeling problems of the PR. A new process to remove precipitated particles generated during the etching process is also reported in which the glass substrate is dipped into a 1 M hydrochloride solution. A microfluidic channel with a depth of 35.95±0.39 µm is formed after 40 min BOE in an ultrasonic bath. The resulting channel has a smooth profile with a surface roughness of less than 45.95±7.96 Å. Glass chips with microfluidic channels are then bonded at 580 °C for 20 min to seal the channel while a slight pressure is applied. A new bonding process has been developed such that the whole process can be finished within 10 h. To our knowledge, this is the shortest processing time that has ever been reported. In the present study, an innovative microfluidic device, a `micro flow-through sampling chip', has been demonstrated using the fabrication method. Successful sampling and separation of Cy5-labelled bovine serum albumin (BSA) and anti-BSA has been achieved. This simple fabrication process is suitable for fast prototyping and mass production of microfluidic systems.

  5. Bridging Microstructure, Properties and Processing of Polymer Based Advanced Materials

    SciTech Connect

    Li, Dongsheng; Ahzi, Said; Khaleel, Mohammad A.

    2012-01-01

    This is a guest editorial for a special issue in Journal of Engineering Materials and Technology. The papers collected in this special issue emphasize significant challenges, current approaches and future strategies necessary to advance the development of polymer-based materials. They were partly presented at the symposium of 'Bridging microstructure, properties and processing of polymer based advanced materials' in the TMS 2011 annual conference meeting, which was held in San Diego, US, on Feb 28 to March 3, 2011. This symposium was organized by the Pacific Northwest National Laboratory (USA) and the Institute of Mechanics of Fluids and Solids of the University of Strasbourg (France). The organizers were D.S. Li, S. Ahzi, and M. Khaleel.

  6. Advanced Plasma Pyrolysis Assembly (PPA) Reactor and Process Development

    NASA Technical Reports Server (NTRS)

    Wheeler, Richard R., Jr.; Hadley, Neal M.; Dahl, Roger W.; Abney, Morgan B.; Greenwood, Zachary; Miller, Lee; Medlen, Amber

    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.

  7. Virus Reduction during Advanced Bardenpho and Conventional Wastewater Treatment Processes.

    PubMed

    Schmitz, Bradley W; Kitajima, Masaaki; Campillo, Maria E; Gerba, Charles P; Pepper, Ian L

    2016-09-01

    The present study investigated wastewater treatment for the removal of 11 different virus types (pepper mild mottle virus; Aichi virus; genogroup I, II, and IV noroviruses; enterovirus; sapovirus; group-A rotavirus; adenovirus; and JC and BK polyomaviruses) by two wastewater treatment facilities utilizing advanced Bardenpho technology and compared the results with conventional treatment processes. To our knowledge, this is the first study comparing full-scale treatment processes that all received sewage influent from the same region. The incidence of viruses in wastewater was assessed with respect to absolute abundance, occurrence, and reduction in monthly samples collected throughout a 12 month period in southern Arizona. Samples were concentrated via an electronegative filter method and quantified using TaqMan-based quantitative polymerase chain reaction (qPCR). Results suggest that Plant D, utilizing an advanced Bardenpho process as secondary treatment, effectively reduced pathogenic viruses better than facilities using conventional processes. However, the absence of cell-culture assays did not allow an accurate assessment of infective viruses. On the basis of these data, the Aichi virus is suggested as a conservative viral marker for adequate wastewater treatment, as it most often showed the best correlation coefficients to viral pathogens, was always detected at higher concentrations, and may overestimate the potential virus risk. PMID:27447291

  8. Advanced materials and biochemical processes for geothermal applications

    SciTech Connect

    Kukacka, L.E.; van Rooyen, D.; Premuzic, E.T.

    1987-04-01

    Two Geothermal Technology Division (GTD)-sponsored programs: (1) Geothermal Materials Development, and (2) Advanced Biochemical Processes for Geothermal Brines, are described. In the former, work in the following tasks is in progress: (1) high temperature elastomeric materials for dynamic sealing applications, (2) advanced high temperature (300/sup 0/C) lightweight (1.1 g/cc) well cementing materials, (3) thermally conductive composites for heat exchanger tubing, (4) corrosion rates for metals in brine-contaminated binary plant working fluids, and (5) elastomeric liners for well casing. Methods for the utilization and/or the low cost environmentally acceptable disposal of toxic geothermal residues are being developed in the second program. This work is performed in two tasks. In one, microorganisms that can interact with toxic metals found in geothermal residues to convert them into soluble species for subsequent reinjection back into the reservoir or to concentrate them for removal by conventional processes are being identified. In the second task, process conditions are being defined for the encapsulation of untreated or partially biochemically treated residues in Portland cement-based formulations and the subsequent utilization of the waste fractions in building materials. Both processing methods yield materials which appear to meet disposal criteria for non-toxic solid waste, and their technical and economic feasibilities have been established.

  9. Graphene resist interlacing process for versatile fabrication of free-standing graphene

    NASA Astrophysics Data System (ADS)

    Kumar, S.; Rezvani, E.; Nicolosi, V.; Duesberg, G. S.

    2012-04-01

    We present a graphene resist interlacing process (GRIP) to sandwich graphene between polymer lines in a cloth-like fashion, making it more accessible for experiments and applications. We demonstrate the handling of large-area graphene in this way. Here, GRIP is used to fabricate supports for transmission electron microscopy. These supports improve the imaging quality of nanoparticles, as we show by comparison to imaging on standard lacey carbon supports.

  10. The pultrusion process for structures on advanced aerospace transportation systems

    NASA Technical Reports Server (NTRS)

    Wilson, Maywood L.; Macconochie, Ian O.; Johnson, Gary S.

    1986-01-01

    The pultrusion process, which has the potential for use in the manufacture of structures for aerospace hardware, is described. In this process, reinforcing fibers are pulled continuously through a resin system for wetting and subsequently through a heated die for polymerization. By using this process, fabrication of very long lengths of high strength, lightweight structures with consistently high quality for aerospace applications is possible. The more conventional processes involve hand lay-up, vacuum bagging, autoclaving or oven curing techniques such that lengths of structural elements produced are limited by the lengths of autoclaves or curing ovens. Several types of developmental structural elements are described in which fiberglass, aramid, graphite, and hybrid fiber systems have been used as reinforcements in an epoxy matrix and their flexural properties compared. Reinforcement fibers having tailor-made orientations which achieve tailor-made strength in the pultrusions are described. The potential aerospace applications for the pultruded products are described with advantages cited over conventional hand lay-up methods.

  11. Investigation on fabrication process of dissolving microneedle arrays to improve effective needle drug distribution.

    PubMed

    Wang, Qingqing; Yao, Gangtao; Dong, Pin; Gong, Zihua; Li, Ge; Zhang, Kejian; Wu, Chuanbin

    2015-01-23

    The dissolving microneedle array (DMNA) offers a novel potential approach for transdermal delivery of biological macromolecular drugs and vaccines, because it can be as efficient as hypodermic injection and as safe and patient compliant as conventional transdermal delivery. However, effective needle drug distribution is the main challenge for clinical application of DMNA. This study focused on the mechanism and control of drug diffusion inside DMNA during the fabrication process in order to improve the drug delivery efficiency. The needle drug loading proportion (NDP) in DMNAs was measured to determine the influences of drug concentration gradient, needle drying step, excipients, and solvent of the base solution on drug diffusion and distribution. The results showed that the evaporation of base solvent was the key factor determining NDP. Slow evaporation of water from the base led to gradual increase of viscosity, and an approximate drug concentration equilibrium was built between the needle and base portions, resulting in NDP as low as about 6%. When highly volatile ethanol was used as the base solvent, the viscosity in the base rose quickly, resulting in NDP more than 90%. Ethanol as base solvent did not impact the insertion capability of DMNAs, but greatly increased the in vitro drug release and transdermal delivery from DMNAs. Furthermore, the drug diffusion process during DMNA fabrication was thoroughly investigated for the first time, and the outcomes can be applied to most two-step molding processes and optimization of the DMNA fabrication. PMID:25446513

  12. Functionally Graded Aluminum Foam Fabricated by Friction Powder Sintering Process with Traversing Tool

    NASA Astrophysics Data System (ADS)

    Hangai, Yoshihiko; Morita, Tomoaki; Koyama, Shinji; Kuwazuru, Osamu; Yoshikawa, Nobuhiro

    2016-07-01

    Functionally graded aluminum foam (FG Al foam) is a new class of Al foam in which the pore structure varies over the foam, resulting in corresponding variations in the mechanical properties of the foam. In this study, FG Al foam plates were fabricated by a friction powder sintering (FPS) process with a traversing tool that is based on a previously developed sintering and dissolution process. The variation of the mechanical properties was realized by setting the volume fraction φ of NaCl in the mixture to 60, 70, and 80%. Long FG Al foam plates were fabricated with a length equal to the tool traversing length with φ varying in the tool traversing direction. From x-ray computed tomography observation, it was shown that the density of the Al foam decreased with increasing φ. In contrast, almost uniform pore structures were obtained in each area. According to the results of compression tests on each area, the plateau stress and energy absorption tended to decrease with increasing φ. Therefore, it was shown that FG Al foam plates with varying mechanical properties can be fabricated by the FPS process with the traversing tool.

  13. Semiellipsoid microlens fabrication method using the lift-off and alignment exposure processes

    NASA Astrophysics Data System (ADS)

    Hung, Chien-Hsin; Hung, Shih-Yu; Shen, Ming-Ho; Yang, Hsiharng

    2012-10-01

    We present a new semiellipsoid microlens fabrication method using the lift-off and alignment exposure processes. The lift-off method is used to create an elliptical base before the thermal reflow process. During the photoresist thermal reflow process, the elliptical base can precisely define the bottom shape of the liquid photoresist, and fabricate the semiellipsoid microlens array with a large height and small radius of curvature. The prolate spheroid approximation method is developed to estimate the thickness of the elliptic photoresist column required by the semiellipsoid microlens of a certain height, with the error being controlled within ±3%. Electroforming technology is then used to convert the photoresist patterns into a metallic mold for a PDMS ellipsoidal microlens. The experiment results show that the geometries of a semiellipsoid microlens can be accurately defined by three parameters: the length of the major axis of the elliptical base, the length of the minor axis of the elliptical base and the thickness of the elliptical photoresist column. The proposed fabrication method facilitates mass production to achieve a high-yield and high-coupling semiellipsoid microlens that is suitable for use in commercial fiber transmission systems

  14. Characterization of high-purity niobium structures fabricated using the electron beam melting process

    NASA Astrophysics Data System (ADS)

    Terrazas Najera, Cesar Adrian

    Additive Manufacturing (AM) refers to the varied set of technologies utilized for the fabrication of complex 3D components from digital data in a layer-by-layer fashion. The use of these technologies promises to revolutionize the manufacturing industry. The electron beam melting (EBM) process has been utilized for the fabrication of fully dense near-net-shape components from various metallic materials. This process, catalogued as a powder bed fusion technology, consists of the deposition of thin layers (50 - 120microm) of metallic powder particles which are fused by the use of a high energy electron beam and has been commercialized by Swedish company Arcam AB. Superconducting radio frequency (SRF) cavities are key components that are used in linear accelerators and other light sources for studies of elemental physics. Currently, cavity fabrication is done by employing different forming processes including deep-drawing and spinning. In both of the latter techniques, a feedstock high-purity niobium sheet with a thickness ranging from 3-4 mm is mechanically deformed and shaped into the desired geometry. In this manner, half cavities are formed that are later joined by electron beam welding (EBW). The welding step causes variability in the shape of the cavity and can also introduce impurities at the surface of the weld interface. The processing route and the purity of niobium are also of utmost importance since the presence of impurities such as inclusions or defects can be detrimental for the SRF properties of cavities. The focus of this research was the use of the EBM process in the manufacture of high purity niobium parts with potential SRF applications. Reactor grade niobium was plasma atomized and used as the precursor material for fabrication using EBM. An Arcam A2 system was utilized for the fabrication. The system had all internal components of the fabrication chamber replaced and was cleaned to prevent contamination of niobium powder. A mini-vat, developed at

  15. High-power ultrasonic processing: Recent developments and prospective advances

    NASA Astrophysics Data System (ADS)

    Gallego-Juarez, Juan A.

    2010-01-01

    Although the application of ultrasonic energy to produce or to enhance a wide variety of processes have been explored since about the middle of the 20th century, only a reduced number of ultrasonic processes have been established at industrial level. However, during the last ten years the interest in ultrasonic processing has revived particularly in industrial sectors where the ultrasonic technology may represent a clean and efficient tool to improve classical existing processes or an innovation alternative for the development of new processes. Such seems to be the case of relevant sectors such as food industry, environment, pharmaceuticals and chemicals manufacture, machinery, mining, etc where power ultrasound is becoming an emerging technology for process development. The possible major problem in the application of high-intensity ultrasound on industrial processing is the design and development of efficient power ultrasonic systems (generators and reactors) capable of large scale successful operation specifically adapted to each individual process. In the area of ultrasonic processing in fluid media and more specifically in gases, the development of the steppedplate transducers and other power ge with extensive radiating surface has strongly contributed to the implementation at semi-industrial and industrial stage of several commercial applications, in sectors such as food and beverage industry (defoaming, drying, extraction, etc), environment (air cleaning, sludge filtration, etc...), machinery and process for manufacturing (textile washing, paint manufacture, etc). The development of different cavitational reactors for liquid treatment in continuous flow is helping to introduce into industry the wide potential of the area of sonochemistry. Processes such as water and effluent treatment, crystallization, soil remediation, etc have been already implemented at semi-industrial and/or industrial stage. Other single advances in sectors like mining or energy have

  16. Nanorods of Co/Pd multilayers fabricated by glancing angle deposition for advanced media

    NASA Astrophysics Data System (ADS)

    Su, Hao; Natarajarathinam, Anusha; Gupta, Subhadra

    2013-05-01

    Perpendicular anisotropy magnetic nanorods composed of Co/Pd multilayers have been successfully fabricated by glancing angle deposition (GLAD) in a planetary sputtering system. Co and Pd layer thickness, ratio, and bilayer number were optimized for both normal and GLAD depositions. Scanning electron micrographs estimated the nanorods to be about 12 nm in diameter. M-H loops showed that the coercivity for the GLAD nanorods increased from 1.3 kOe for the normally deposited continuous films to 2.9 kOe for the GLAD nanorod array, a 123% increase.

  17. Nanorods of Co/Pd multilayers fabricated by glancing angle deposition for advanced media

    SciTech Connect

    Su, Hao; Gupta, Subhadra; Natarajarathinam, Anusha

    2013-05-28

    Perpendicular anisotropy magnetic nanorods composed of Co/Pd multilayers have been successfully fabricated by glancing angle deposition (GLAD) in a planetary sputtering system. Co and Pd layer thickness, ratio, and bilayer number were optimized for both normal and GLAD depositions. Scanning electron micrographs estimated the nanorods to be about 12 nm in diameter. M-H loops showed that the coercivity for the GLAD nanorods increased from 1.3 kOe for the normally deposited continuous films to 2.9 kOe for the GLAD nanorod array, a 123% increase.

  18. Feasibility study of applying an advanced composite structure technique to the fabrication of helicopter rotor blades

    NASA Technical Reports Server (NTRS)

    Gleich, D.

    1972-01-01

    The fabrication of helicopter rotary wings from composite materials is discussed. Two composite spar specimens consisting of compressively prestressed stainless steel liner over-wrapped with pretensioned fiberglass were constructed. High liner strength and toughness together with the prescribed prestresses and final sizing of the part are achieved by means of cryogenic stretch forming of the fiber wrapped composite spar at minus 320 F, followed by release of the forming pressure and warm up to room temperature. The prestresses are chosen to provide residual compression in the metal liner under operating loads.

  19. Advanced automation for in-space vehicle processing

    NASA Technical Reports Server (NTRS)

    Sklar, Michael; Wegerif, D.

    1990-01-01

    The primary objective of this 3-year planned study is to assure that the fully evolved Space Station Freedom (SSF) can support automated processing of exploratory mission vehicles. Current study assessments show that required extravehicular activity (EVA) and to some extent intravehicular activity (IVA) manpower requirements for required processing tasks far exceeds the available manpower. Furthermore, many processing tasks are either hazardous operations or they exceed EVA capability. Thus, automation is essential for SSF transportation node functionality. Here, advanced automation represents the replacement of human performed tasks beyond the planned baseline automated tasks. Both physical tasks such as manipulation, assembly and actuation, and cognitive tasks such as visual inspection, monitoring and diagnosis, and task planning are considered. During this first year of activity both the Phobos/Gateway Mars Expedition and Lunar Evolution missions proposed by the Office of Exploration have been evaluated. A methodology for choosing optimal tasks to be automated has been developed. Processing tasks for both missions have been ranked on the basis of automation potential. The underlying concept in evaluating and describing processing tasks has been the use of a common set of 'Primitive' task descriptions. Primitive or standard tasks have been developed both for manual or crew processing and automated machine processing.

  20. Development of advanced hot-gas desulfurization processes

    SciTech Connect

    Jothimurugesan, K.

    1999-10-14

    Advanced integrated gasification combined cycle (IGCC) power plants nearing completion, such as Sierra-Pacific, employ a circulating fluidized-bed (transport) reactor hot-gas desulfurization (HGD) process that uses 70-180 {micro}m average particle size (aps) zinc-based mixed-metal oxide sorbent for removing H{sub 2}S from coal gas down to less than 20 ppmv. The sorbent undergoes cycles of absorption (sulfidation) and air regeneration. The key barrier issues associated with a fluidized-bed HGD process are chemical degradation, physical attrition, high regeneration light-off (initiation) temperature, and high cost of the sorbent. Another inherent complication in all air-regeneration-based HGD processes is the disposal of the problematic dilute SO{sub 2} containing regeneration tail-gas. Direct Sulfur Recovery Process (DSRP), a leading first generation technology, efficiently reduces this SO{sub 2} to desirable elemental sulfur, but requires the use of 1-3 % of the coal gas, thus resulting in an energy penalty to the plant. Advanced second-generation processes are under development that can reduce this energy penalty by modifying the sorbent so that it could be directly regenerated to elemental sulfur. The objective of this research is to support the near and long term DOE efforts to commercialize the IGCC-HGD process technology. Specifically we aim to develop: optimized low-cost sorbent materials with 70-80 {micro}m average aps meeting all Sierra specs; attrition resistant sorbents with 170 {micro}m aps that allow greater flexibility in the choice of the type of fluidized-bed reactor e.g. they allow increased throughput in a bubbling-bed reactor; and modified fluidizable sorbent materials that can be regenerated to produce elemental sulfur directly with minimal or no use of coal gas The effort during the reporting period has been devoted to development of an advanced hot-gas process that can eliminate the problematic SO{sub 2} tail gas and yield elemental sulfur