Sample records for advanced design mixer

  1. Design of a mixer for the thrust-vectoring system on the high-alpha research vehicle

    NASA Technical Reports Server (NTRS)

    Pahle, Joseph W.; Bundick, W. Thomas; Yeager, Jessie C.; Beissner, Fred L., Jr.

    1996-01-01

    One of the advanced control concepts being investigated on the High-Alpha Research Vehicle (HARV) is multi-axis thrust vectoring using an experimental thrust-vectoring (TV) system consisting of three hydraulically actuated vanes per engine. A mixer is used to translate the pitch-, roll-, and yaw-TV commands into the appropriate TV-vane commands for distribution to the vane actuators. A computer-aided optimization process was developed to perform the inversion of the thrust-vectoring effectiveness data for use by the mixer in performing this command translation. Using this process a new mixer was designed for the HARV and evaluated in simulation and flight. An important element of the Mixer is the priority logic, which determines priority among the pitch-, roll-, and yaw-TV commands.

  2. Recent advances in superconducting-mixer simulations

    NASA Technical Reports Server (NTRS)

    Withington, S.; Kennedy, P. R.

    1992-01-01

    Over the last few years, considerable progress have been made in the development of techniques for fabricating high-quality superconducting circuits, and this success, together with major advances in the theoretical understanding of quantum detection and mixing at millimeter and submillimeter wavelengths, has made the development of CAD techniques for superconducting nonlinear circuits an important new enterprise. For example, arrays of quasioptical mixers are now being manufactured, where the antennas, matching networks, filters and superconducting tunnel junctions are all fabricated by depositing niobium and a variety of oxides on a single quartz substrate. There are no adjustable tuning elements on these integrated circuits, and therefore, one must be able to predict their electrical behavior precisely. This requirement, together with a general interest in the generic behavior of devices such as direct detectors and harmonic mixers, has lead us to develop a range of CAD tools for simulating the large-signal, small-signal, and noise behavior of superconducting tunnel junction circuits.

  3. Lobed Mixer Optimization for Advanced Ejector Geometries

    NASA Technical Reports Server (NTRS)

    Waitz, Ian A.

    1996-01-01

    The overall objectives are: 1) to pursue analytical, computational, and experimental studies that enhance basic understanding of forced mixing phenomena relevant to supersonic jet noise reduction, and 2) to integrate this enhanced understanding (analytical, computational, and empirical) into a design-oriented model of a mixer-ejector noise suppression system. The work is focused on ejector geometries and flow conditions typical of those being investigated in the NASA High Speed Research Program (HSRP). The research will be carried out in collaboration with the NASA HSRP Nozzle Integrated Technology Development (ITD) Team, and will both contribute to, and benefit from, the results of other HSRP research. The noise suppressor system model that is being developed under this grant is distinct from analytical tools developed by industry because it directly links details of lobe geometry to mixer-ejector performance. In addition, the model provides a 'technology road map to define gaps in the current understanding of various phenomena related to mixer-ejector design and to help prioritize research areas. This report describes research completed in the past year, as well as work proposed for the following year.

  4. Quasi-optical antenna-mixer-array design for terahertz frequencies

    NASA Technical Reports Server (NTRS)

    Guo, Yong; Potter, Kent A.; Rutledge, David B.

    1992-01-01

    A new quasi-optical antenna-mixer-array design for terahertz frequencies is presented. In the design, antenna and mixer are combined into an entity, based on the technology in which millimeter-wave horn antenna arrays have been fabricated in silicon wafers. It consists of a set of forward- and backward-looking horns made with a set of silicon wafers. The front side is used to receive incoming signal, and the back side is used to feed local oscillator signal. Intermediate frequency is led out from the side of the array. Signal received by the horn array is picked up by antenna probes suspended on thin silicon-oxynitride membranes inside the horns. Mixer diodes will be located on the membranes inside the horns. Modeling of such an antenna-mixer-array design is done on a scaled model at microwave frequencies. The impedance matching, RF and LO isolation, and patterns of the array have been tested and analyzed.

  5. A Multidisciplinary Approach to Mixer-Ejector Analysis and Design

    NASA Technical Reports Server (NTRS)

    Hendricks, Eric, S.; Seidel, Jonathan, A.

    2012-01-01

    The design of an engine for a civil supersonic aircraft presents a difficult multidisciplinary problem to propulsion system engineers. There are numerous competing requirements for the engine, such as to be efficient during cruise while yet quiet enough at takeoff to meet airport noise regulations. The use of mixer-ejector nozzles presents one possible solution to this challenge. However, designing a mixer-ejector which will successfully address both of these concerns is a difficult proposition. Presented in this paper is an integrated multidisciplinary approach to the analysis and design of these systems. A process that uses several low-fidelity tools to evaluate both the performance and acoustics of mixer-ejectors nozzles is described. This process is further expanded to include system-level modeling of engines and aircraft to determine the effects on mission performance and noise near airports. The overall process is developed in the OpenMDAO framework currently being developed by NASA. From the developed process, sample results are given for a notional mixer-ejector design, thereby demonstrating the capabilities of the method.

  6. Design of Balanced Mixers for ALMA Band-10

    NASA Astrophysics Data System (ADS)

    Shitov, Sergey V.; Koryukin, Oleg V.; Uzawa, Yoshinori; Noguchi, Takashi; Uvarov, Andrey V.; Bukovski, Maksim A.; Cohn, Ilya A.

    2007-06-01

    Two variants of balanced mixer employing twin-SIS structure are under development for 787-950 GHz frequency range. Easy-to-use Geometry Transformation method for modeling of superconducting microstrips is developed, compared to referenced methods and used for design of the mixers. Lens-antenna mixer is based on cross-slot antenna; it does not need any intervening optics between its lens and sub-reflector of ALMA telescope; simple yet efficient composition of lens-antenna cartridge is suggested. Compact single-chamber balanced waveguide mixer employs two SIS chips and capacitive probe for LO injection; coupling above -3 dB and signal loss below -20 dB are expected. Need in shifting of resonance frequency of twin-SIS mixer towards top of the frequency band is predicted using Tucker's theory in large-signal approximation. TRX considerably below 200 K (DSB) is simulated using high-quality hybrid SIS junction for NbTiN/Nb - AlOx - Nb/Al for Jc = 12 kA/cm2.

  7. STME Hydrogen Mixer Study

    NASA Technical Reports Server (NTRS)

    Blumenthal, Rob; Kim, Dongmoon; Bache, George

    1992-01-01

    The hydrogen mixer for the Space Transportation Main Engine is used to mix cold hydrogen bypass flow with warm hydrogen coolant chamber gas, which is then fed to the injectors. It is very important to have a uniform fuel temperature at the injectors in order to minimize mixture ratio problems due to the fuel density variations. In addition, the fuel at the injector has certain total pressure requirements. In order to achieve these objectives, the hydrogen mixer must provide a thoroughly mixed fluid with a minimum pressure loss. The AEROVISC computational fluid dynamics (CFD) code was used to analyze the STME hydrogen mixer, and proved to be an effective tool in optimizing the mixer design. AEROVISC, which solves the Reynolds Stress-Averaged Navier-Stokes equations in primitive variable form, was used to assess the effectiveness of different mixer designs. Through a parametric study of mixer design variables, an optimal design was selected which minimized mixed fuel temperature variation and fuel mixer pressure loss. The use of CFD in the design process of the STME hydrogen mixer was effective in achieving an optimal mixer design while reducing the amount of hardware testing.

  8. Computer design of microfluidic mixers for protein/RNA folding studies.

    PubMed

    Inguva, Venkatesh; Kathuria, Sagar V; Bilsel, Osman; Perot, Blair James

    2018-01-01

    Kinetic studies of biological macromolecules increasingly use microfluidic mixers to initiate and monitor reaction progress. A motivation for using microfluidic mixers is to reduce sample consumption and decrease mixing time to microseconds. Some applications, such as small-angle x-ray scattering, also require large (>10 micron) sampling areas to ensure high signal-to-noise ratios and to minimize parasitic scattering. Chaotic to marginally turbulent mixers are well suited for these applications because this class of mixers provides a good middle ground between existing laminar and turbulent mixers. In this study, we model various chaotic to marginally turbulent mixing concepts such as flow turning, flow splitting, and vortex generation using computational fluid dynamics for optimization of mixing efficiency and observation volume. Design iterations show flow turning to be the best candidate for chaotic/marginally turbulent mixing. A qualitative experimental test is performed on the finalized design with mixing of 10 M urea and water to validate the flow turning unsteady mixing concept as a viable option for RNA and protein folding studies. A comparison of direct numerical simulations (DNS) and turbulence models suggests that the applicability of turbulence models to these flow regimes may be limited.

  9. A Matlab-Based Graphical User Interface for Simulation and Control Design of a Hydrogen Mixer

    NASA Technical Reports Server (NTRS)

    Richter, Hanz; Figueroa, Fernando

    2003-01-01

    A Graphical User Interface (GUI) that facilitates prediction and control design tasks for a propellant mixer is described. The Hydrogen mixer is used in rocket test stand operations at the NASA John C. Stennis Space Center. The mixer injects gaseous hydrogen (GH2) into a stream of liquid hydrogen (LH2) to obtain a combined flow with desired thermodynamic properties. The flows of GH2 and LH2 into the mixer are regulated by two control valves, and a third control valve is installed at the exit of the mixer to regulate the combined flow. The three valves may be simultaneously operated in order to achieve any desired combination of total flow, exit temperature and mixer pressure within the range of operation. The mixer, thus, constitutes a three-input, three-output system. A mathematical model of the mixer has been obtained and validated with experimental data. The GUI presented here uses the model to predict mixer response under diverse conditions.

  10. Review of mixer design for low voltage - low power applications

    NASA Astrophysics Data System (ADS)

    Nurulain, D.; Musa, F. A. S.; Isa, M. Mohamad; Ahmad, N.; Kasjoo, S. R.

    2017-09-01

    A mixer is used in almost all radio frequency (RF) or microwave systems for frequency translation. Nowadays, the increase market demand encouraged the industry to deliver circuit designs to create proficient and convenient equipment with very low power (LP) consumption and low voltage (LV) supply in both digital and analogue circuits. This paper focused on different Complementary Metal Oxide Semiconductor (CMOS) design topologies for LV and LP mixer design. Floating Gate Metal Oxide Semiconductor (FGMOS) is an alternative technology to replace CMOS due to their high ability for LV and LP applications. FGMOS only required a few transistors per gate and can have a shift in threshold voltage (VTH) to increase the LP and LV performances as compared to CMOS, which makes an attractive option to replace CMOS.

  11. QCGAT mixer compound exhaust system design and static big model test report

    NASA Technical Reports Server (NTRS)

    Blackmore, W. L.; Thompson, C. E.

    1978-01-01

    A mixer exhaust system was designed to meet the proposed performance and exhaust jet noise goals for the AiResearch QCGAT engine. Some 0.35 scale models of the various nozzles were fabricated and aerodynamically and acoustically tested. Preliminary optimization, engine cycle matching, model test data and analysis are presented. A final mixer exhaust system is selected for optimum performance for the overall flight regime.

  12. A compact design for the Josephson mixer: The lumped element circuit

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Pillet, J.-D.; Collège de France, 11 place Marcelin Berthelot, 75005 Paris; Flurin, E.

    2015-06-01

    We present a compact and efficient design in terms of gain, bandwidth, and dynamical range for the Josephson mixer, the superconducting circuit performing three-wave mixing at microwave frequencies. In an all lumped-element based circuit with galvanically coupled ports, we demonstrate nondegenerate amplification for microwave signals over a bandwidth up to 50 MHz for a power gain of 20 dB. The quantum efficiency of the mixer is shown to be about 70%, and its saturation power reaches −112 dBm.

  13. Energy Efficient Engine Exhaust Mixer Model Technology

    NASA Technical Reports Server (NTRS)

    Kozlowski, H.; Larkin, M.

    1981-01-01

    An exhaust mixer test program was conducted to define the technology required for the Energy Efficient Engine Program. The model configurations of 1/10 scale were tested in two phases. A parametric study of mixer design options, the impact of residual low pressure turbine swirl, and integration of the mixer with the structural pylon of the nacelle were investigated. The improvement of the mixer itself was also studied. Nozzle performance characteristics were obtained along with exit profiles and oil smear photographs. The sensitivity of nozzle performance to tailpipe length, lobe number, mixer penetration, and mixer modifications like scalloping and cutbacks were established. Residual turbine swirl was found detrimental to exhaust system performance and the low pressure turbine system for Energy Efficient Engine was designed so that no swirl would enter the mixer. The impact of mixer/plug gap was also established, along with importance of scalloping, cutbacks, hoods, and plug angles on high penetration mixers.

  14. Design of an Efficient Turbulent Micro-Mixer for Protein Folding Experiments

    NASA Astrophysics Data System (ADS)

    Inguva, Venkatesh; Perot, Blair

    2015-11-01

    Protein folding studies require the development of micro-mixers that require less sample, mix at faster rates, and still provide a high signal to noise ratio. Chaotic to marginally turbulent micro-mixers are promising candidates for this application. In this study, various turbulence and unsteadiness generation concepts are explored that avoid cavitation. The mixing enhancements include flow turning regions, flow splitters, and vortex shedding. The relative effectiveness of these different approaches for rapid micro-mixing is discussed. Simulations found that flow turning regions provided the best mixing profile. Experimental validation of the optimal design is verified through laser confocal microscopy experiments. This work is support by the National Science Foundation.

  15. Research of UHPC properties prepared with industrial mixer

    NASA Astrophysics Data System (ADS)

    Šerelis, E.; Vaitkevičius, V.; Kerševičius, V.

    2017-09-01

    Ultra-high performance concrete (UHPC) mixture with advanced mechanical and durability properties was created using decent Zyklos ZZ50HE mixer. Zyklos ZZ50HE rotating pan mixer is similar to mixer which has common concrete plants. In experiment UHPC was prepared with Zyklos ZZ50HE mixer and thereafter best composition was selected and prepared with industrial HPGM 1125 mixer. Experiment results revealed that UHPC with W/C=0.29 and advanced mechanical and durability properties can be prepared. In experiment tremendous amount of micro steel fibres (up to 147 kg/m3) were incorporated in UHPC. Concrete with excellent salt scaling resistance and great mechanical properties was obtained. Compressive strength was increased about 30 % from 116 MPa to 150 MPa and flexural strength was increased about 5 times from 6.7 to 36.2 MPa. Salt-scaling resistance at 40 cycles in 3 % NaCl solution varied from 0.006 kg/m2 to 0.197 kg/m2. There were a few attempts to create UHPC and UHPFRC with decent technology, however, unsuccessfully till now. In the world practice this new material is currently used in the construction of bridges and viaducts.

  16. Forced Mixer Nozzle Optimization

    NASA Technical Reports Server (NTRS)

    Sheoran, Yogi; Hoover, Robert; Schuster, William; Anderson, Morris; Weir, Donald S.

    1999-01-01

    Computational fluid dynamic (CFD) and computational acoustic analyses (CAA) were performed for a TFE731-40 compound nozzle, a TFE731-60 mixer nozzle and an Energy Efficient Engine (E(sup 3)) mixer nozzle for comparison with available data. The CFD analyses were performed with a three dimensional, Navier-Stokes solution of the flowfield on an unstructured grid using the RAMPANT program. The CAA analyses were performed with the NASA Glenn MGB program using a structured grid. A successful aerodynamic solution for the TFE731-40 compound nozzle operating statically was obtained, simulating an engine operating on a test stand. Analysis of the CFD results of the TFE731-40 with the MGB program produced predicted sound power levels that agree quite well with the measured data front full-scale static engine tests. Comparison of the predicted sound pressure with the data show good agreement near the jet axis, but the noise levels are overpredicted at angles closer to the inlet. The predicted sound power level for the TFE731-60 did not agree as well with measured static engine data as the TFE731-40. Although a reduction in the predicted noise level due to the mixed flow was observed, the reduction was not as significant as the measured data. The analysis of the V2 mixer from the E(sup 3) study showed that peak temperatures predicted in the mixer exit flowfield were within 5 percent of the values measured by the exit probes. The noise predictions of the V2 mixer nozzle tended to be 3-5 dB higher in peak noise level than the measurements. In addition, the maximum frequency of the noise was also overpredicted. An analysis of the 3 candidate mixer nozzle configurations demonstrated the feasibility of using centerbody lobes and porosity to improve mixing efficiency. A final configuration was designed with a predicted thermal mixing efficiency that was 5 percent higher than the 3 candidate mixers. The results of the MGB noise calculations show that the final design will exceed the

  17. Mixing monoclonal antibody formulations using bottom-mounted mixers: impact of mechanism and design on drug product quality.

    PubMed

    Gikanga, Benson; Chen, Yufei; Stauch, Oliver B; Maa, Yuh-Fun

    2015-01-01

    Using bottom-mounted mixers, particularly those that are magnetically driven, is becoming increasingly common during the mixing process in pharmaceutical and biotechnology manufacturing because of their associated low risk of contamination, ease of use, and ability to accommodate low minimum mixing volumes. Despite these benefits, the impact of bottom-mounted mixers on biologic drug product is not yet fully understood and is scarcely reported. This study evaluated four bottom-mounted mixers to assess their impact on monoclonal antibody formulations. Changes in product quality (size variants, particles, and turbidity) and impact on process performance (sterile filtration) were evaluated after mixing. The results suggested that mixers that are designed to function with no contact between the impeller and the drive unit are the most favorable and gentle to monoclonal antibody molecules. Designs with contact or a narrow clearance tended to shear and grind the protein and resulted in high particle count in the liquid, which would subsequently foul a filter membrane during sterile filtration using a 0.22 μm pore size filter. Despite particle formation, increases in turbidity of the protein solution and protein aggregation/fragmentation were not detected. Further particle analysis indicated particles in the range of 0.2-2 μm are responsible for filter fouling. A small-scale screening model was developed using two types of magnetic stir bars mimicking the presence or absence of contact between the impeller and drive unit in the bottom-mounted mixers. The model is capable of differentiating the sensitivity of monoclonal antibody formulations to bottom-mounted mixers with a small sample size. This study fills an important gap in understanding a critical bioprocess unit operation. Mixing is an important unit operation in drug product manufacturing for compounding (dilution, pooling, homogenization, etc.). The current trend in adopting disposable bottom-mounted mixers has

  18. Diffusion-Cooled Tantalum Hot-Electron Bolometer Mixers

    NASA Technical Reports Server (NTRS)

    Skalare, Anders; McGrath, William; Bumble, Bruce; LeDuc, Henry

    2004-01-01

    A batch of experimental diffusion-cooled hot-electron bolometers (HEBs), suitable for use as mixers having input frequencies in the terahertz range and output frequencies up to about a gigahertz, exploit the superconducting/normal-conducting transition in a thin strip of tantalum. The design and operation of these HEB mixers are based on mostly the same principles as those of a prior HEB mixer that exploited the superconducting/normal- conducting transition in a thin strip of niobium and that was described elsewhere.

  19. Terahertz radiation mixer

    DOEpatents

    Wanke, Michael C [Albuquerque, NM; Allen, S James [Santa Barbara, CA; Lee, Mark [Albuquerque, NM

    2008-05-20

    A terahertz radiation mixer comprises a heterodyned field-effect transistor (FET) having a high electron mobility heterostructure that provides a gatable two-dimensional electron gas in the channel region of the FET. The mixer can operate in either a broadband pinch-off mode or a narrowband resonant plasmon mode by changing a grating gate bias of the FET. The mixer can beat an RF signal frequency against a local oscillator frequency to generate an intermediate frequency difference signal in the microwave region. The mixer can have a low local oscillator power requirement and a large intermediate frequency bandwidth. The terahertz radiation mixer is particularly useful for terahertz applications requiring high resolution.

  20. Bluff Body Fuel Mixer

    NASA Technical Reports Server (NTRS)

    Cheung, Albert K. (Inventor); Hoke, James B. (Inventor); McKinney, Randal G. (Inventor)

    2017-01-01

    A combustor is provided. The combustor may include an axial fuel injection system, and a radial fuel injection system aft of the axial fuel injection system. The axial fuel injection system includes a mixer having a bluff body at an exit port of the mixer, and a fuel injector disposed within the mixer. A fuel and air mixer is also provided and comprises an outer housing with an exit port and a bluff body. The bluff body extends across the exit port of the outer housing. A fuel injection system is also provided. The systems comprise a mixer having a bluff body at an exit port of the mixer and a fuel injector disposed within the mixer.

  1. Acoustic and Laser Doppler Anemometer Results for Confluent, 22-Lobed, and Unique-Lobed Mixer Exhaust Systems for Subsonic Jet Noise Reduction

    NASA Technical Reports Server (NTRS)

    Salikuddin, M.; Martens, S.; Shin, H.; Majjigi, R. K.; Krejsa, Gene (Technical Monitor)

    2002-01-01

    The objective of this task was to develop a design methodology and noise reduction concepts for high bypass exhaust systems which could be applied to both existing production and new advanced engine designs. Special emphasis was given to engine cycles with bypass ratios in the range of 4:1 to 7:1, where jet mixing noise was a primary noise source at full power takeoff conditions. The goal of this effort was to develop the design methodology for mixed-flow exhaust systems and other novel noise reduction concepts that would yield 3 EPNdB noise reduction relative to 1992 baseline technology. Two multi-lobed mixers, a 22-lobed axisymmetric and a 21-lobed with a unique lobe, were designed. These mixers along with a confluent mixer were tested with several fan nozzles of different lengths with and without acoustic treatment in GEAE's Cell 41 under the current subtask (Subtask C). In addition to the acoustic and LDA tests for the model mixer exhaust systems, a semi-empirical noise prediction method for mixer exhaust system is developed. Effort was also made to implement flowfield data for noise prediction by utilizing MGB code. In general, this study established an aero and acoustic diagnostic database to calibrate and refine current aero and acoustic prediction tools.

  2. Embedding impedance approximations in the analysis of SIS mixers

    NASA Technical Reports Server (NTRS)

    Kerr, A. R.; Pan, S.-K.; Withington, S.

    1992-01-01

    Future millimeter-wave radio astronomy instruments will use arrays of many SIS receivers, either as focal plane arrays on individual radio telescopes, or as individual receivers on the many antennas of radio interferometers. Such applications will require broadband integrated mixers without mechanical tuners. To produce such mixers, it will be necessary to improve present mixer design techniques, most of which use the three-frequency approximation to Tucker's quantum mixer theory. This paper examines the adequacy of three approximations to Tucker's theory: (1) the usual three-frequency approximation which assumes a sinusoidal LO voltage at the junction, and a short-circuit at all frequencies above the upper sideband; (2) a five-frequency approximation which allows two LO voltage harmonics and five small-signal sidebands; and (3) a quasi five-frequency approximation in which five small-signal sidebands are allowed, but the LO voltage is assumed sinusoidal. These are compared with a full harmonic-Newton solution of Tucker's equations, including eight LO harmonics and their corresponding sidebands, for realistic SIS mixer circuits. It is shown that the accuracy of the three approximations depends strongly on the value of omega R(sub N)C for the SIS junctions used. For large omega R(sub N)C, all three approximations approach the eight-harmonic solution. For omega R(sub N)C values in the range 0.5 to 10, the range of most practical interest, the quasi five-frequency approximation is a considerable improvement over the three-frequency approximation, and should be suitable for much design work. For the realistic SIS mixers considered here, the five-frequency approximation gives results very close to those of the eight-harmonic solution. Use of these approximations, where appropriate, considerably reduces the computational effort needed to analyze an SIS mixer, and allows the design and optimization of mixers using a personal computer.

  3. Thrust Augmentation with Mixer/Ejector Systems

    NASA Technical Reports Server (NTRS)

    Presz, Walter M., Jr.; Reynolds, Gary; Hunter, Craig

    2002-01-01

    Older commercial aircraft often exceed FAA (Federal Aviation Administration) sideline noise regulations. The major problem is the jet noise associated with the high exhaust velocities of the low bypass ratio engines on such aircraft. Mixer/ejector exhaust systems can provide a simple means of reducing the jet noise on these aircraft by mixing cool ambient air with the high velocity engine gases before they are exhausted to ambient. This paper presents new information on thrust performance predictions, and thrust augmentation capabilities of mixer/ejectors. Results are presented from the recent development program of the patented Alternating Lobe Mixer Ejector Concept (ALMEC) suppressor system for the Gulfstream GII, GIIB and GIII aircraft. Mixer/ejector performance procedures are presented which include classical control volume analyses, compound compressible flow theory, lobed nozzle loss correlations and state of the art computational fluid dynamic predictions. The mixer/ejector thrust predictions are compared to subscale wind tunnel test model data and actual aircraft flight test measurements. The results demonstrate that a properly designed mixer/ejector noise suppressor can increase effective engine bypass ratio and generate large thrust gains at takeoff conditions with little or no thrust loss at cruise conditions. The cruise performance obtained for such noise suppressor systems is shown to be a strong function of installation effects on the aircraft.

  4. Planar Submillimeter-Wave Mixer Technology with Integrated Antenna

    NASA Technical Reports Server (NTRS)

    Chattopadhyay, Gautam; Mehdi, Imran; Gill, John J.; Lee, Choonsup; lombart, Muria L.; Thomas, Betrand

    2010-01-01

    High-performance mixers at terahertz frequencies require good matching between the coupling circuits such as antennas and local oscillators and the diode embedding impedance. With the availability of amplifiers at submillimeter wavelengths and the need to have multi-pixel imagers and cameras, planar mixer architecture is required to have an integrated system. An integrated mixer with planar antenna provides a compact and optimized design at terahertz frequencies. Moreover, it leads to a planar architecture that enables efficient interconnect with submillimeter-wave amplifiers. In this architecture, a planar slot antenna is designed on a thin gallium arsenide (GaAs) membrane in such a way that the beam on either side of the membrane is symmetric and has good beam profile with high coupling efficiency. A coplanar waveguide (CPW) coupled Schottky diode mixer is designed and integrated with the antenna. In this architecture, the local oscillator (LO) is coupled through one side of the antenna and the RF from the other side, without requiring any beam sp litters or diplexers. The intermediate frequency (IF) comes out on a 50-ohm CPW line at the edge of the mixer chip, which can be wire-bonded to external circuits. This unique terahertz mixer has an integrated single planar antenna for coupling both the radio frequency (RF) input and LO injection without any diplexer or beamsplitters. The design utilizes novel planar slot antenna architecture on a 3- mthick GaAs membrane. This work is required to enable future multi-pixel terahertz receivers for astrophysics missions, and lightweight and compact receivers for planetary missions to the outer planets in our solar system. Also, this technology can be used in tera hertz radar imaging applications as well as for testing of quantum cascade lasers (QCLs).

  5. Static Mixer for Heat Transfer Enhancement for Mold Cooling Application

    NASA Astrophysics Data System (ADS)

    Becerra, Rodolfo; Barbosa, Raul; Lee, Kye-Hwan; Park, Younggil

    Injection molding is the process by which a material is melted in a barrel and then it is injected through a nozzle in the mold cavity. When it cools down, the material solidifies into the shape of the cavity. Typical injection mold has cooling channels to maintain constant mold temperature during injection molding process. Even and constant temperature throughout the mold are very critical for a part quality and productivity. Conformal cooling improves the quality and productivity of injection molding process through the implementation of cooling channels that ``conform'' to the shape of the molded part. Recent years, the use of conformal cooling increases with advance of 3D printing technology such as Selective Laser Melting (SLM). Although it maximizes cooling, material and dimension limitations make SLM methods highly expensive. An alternative is the addition of static mixers in the molds with integrated cooling channels. A static mixer is a motionless mixing device that enhances heat transfer by producing improved flow mixing in the pipeline. In this study, the performance of the cooling channels will be evaluated with and without static mixers, by measuring temperature, pressure drop, and flow rate. The following question is addressed: Can a static mixer effectively enhance heat transfer for mold cooling application processes? This will provide insight on the development of design methods and guidelines that can be used to increase cooling efficiency at a lower cost.

  6. Lobed Mixer Design for Noise Suppression Acoustic and Aerodynamic Test Data Analysis

    NASA Technical Reports Server (NTRS)

    Mengle, Vinod G.; Dalton, William N.; Boyd, Kathleen (Technical Monitor); Bridges, James (Technical Monitor)

    2002-01-01

    A comprehensive database for the acoustic and aerodynamic characteristics of several model-scale lobe mixers of bypass ratio 5 to 6 has been created for mixed jet speeds up to 1080 ft/s at typical take-off (TO) conditions of small-to-medium turbofan engines. The flight effect was simulated for Mach numbers up to 0.3. The static thrust performance and plume data were also obtained at typical TO and cruise conditions. The tests were done at NASA Lewis anechoic dome and ASK's FluiDyne Laboratories. The effect of several lobe mixer and nozzle parameters, such as, lobe scalloping, lobe count, lobe penetration and nozzle length was examined in terms of flyover noise at constant altitude. Sound in the nozzle reference frame was analyzed to understand the source characteristics. Several new concepts, mechanisms and methods are reported for such lobed mixers, such as, "boomerang" scallops, "tongue" mixer, detection of "excess" internal noise sources, and extrapolation of flyover noise data from one flight speed to different flight speeds. Noise reduction of as much as 3 EPNdB was found with a deeply scalloped mixer compared to annular nozzle at net thrust levels of 9500 lb for a 29 in. diameter nozzle after optimizing the nozzle length.

  7. Design of an exhaust mixer nozzle for the Avco-Lycoming Quiet Clean General Aviation Turbofan (QCGAT)

    NASA Technical Reports Server (NTRS)

    Hurley, J. F.; Anson, L.; Wilson, C.

    1978-01-01

    This report describes the design configuration and method used to design the forced engine exhaust to bypass air mixing system for Lycoming's QCGAT engine. This mixer is an integral part of the total engine and nacelle system and was configured to reduce the propulsion system noise and fuel consumption levels.

  8. Flashback resistant pre-mixer assembly

    DOEpatents

    Laster, Walter R [Oviedo, FL; Gambacorta, Domenico [Oviedo, FL

    2012-02-14

    A pre-mixer assembly associated with a fuel supply system for mixing of air and fuel upstream from a main combustion zone in a gas turbine engine. The pre-mixer assembly includes a swirler assembly disposed about a fuel injector of the fuel supply system and a pre-mixer transition member. The swirler assembly includes a forward end defining an air inlet and an opposed aft end. The pre-mixer transition member has a forward end affixed to the aft end of the swirler assembly and an opposed aft end defining an outlet of the pre-mixer assembly. The aft end of the pre-mixer transition member is spaced from a base plate such that a gap is formed between the aft end of the pre-mixer transition member and the base plate for permitting a flow of purge air therethrough to increase a velocity of the air/fuel mixture exiting the pre-mixer assembly.

  9. A Dual Polarized Quasi-Optical SIS Mixer at 550-GHz

    NASA Technical Reports Server (NTRS)

    Chattopadhyay, Goutam; Miller, David; LeDuc, Henry G.; Zmuidzinas, Jonas

    2000-01-01

    We describe the design, fabrication, and the performance of a low-noise dual-polarized quasi-optical superconductor insulator superconductor (SIS) mixer at 550 GHz. The mixer utilizes a novel cross-slot antenna on a hyperhemispherical substrate lens, two junction tuning circuits, niobium trilayer junctions, and an IF circuit containing a lumped element 180 deg hybrid. The antenna consists of an orthogonal pair of twin-slot antennas, and has four feed points, two for each polarization. Each feed point is coupled to a two-junction SIS mixer. The 180 deg IF hybrid is implemented using a lumped element/microstrip circuit located inside the mixer block. Fourier transform spectrometer (FTS) measurements of the mixer frequency response show good agreement with computer simulations. The measured co-polarized and cross-polarized patterns for both polarizations also agree with the theoretical predictions. The noise performance of the dual-polarized mixer is excellent, giving uncorrected receiver noise temperature of better than 115 K (DSB) at 528 GHz for both the polarizations.

  10. A 30% bandwidth tunerless SIS mixer of quantum-limited sensitivity for Herschel / HIFI Band 1

    NASA Astrophysics Data System (ADS)

    Salez, Morvan; Delorme, Yan; Peron, I.; Lecomte, Benoit; Dauplay, Frederic; Boussaha, Faouzi; Spatazza, J.; Feret, A.; Krieg, J. M.; Schuster, Karl-Friedrich

    2003-02-01

    We report on the status of the development of a 30% bandwidth tunerless SIS double-sideband mixer for the "Band 1" (480 GHz-630 GHz) channel of the heterodyne instrument (HIFI) of ESA"s Herschel Space Observatory, scheduled for launch in 2007. After exposing the main features of our mixer design, we present the performance achieved by the demonstration mixer, measured via Fourier Transform Spectroscopy and heterodyne Y factor calibrations. We infer from a preliminary mixer analysis that the mixer has very low, quantum-limited noise and low conversion loss. We also report on some pre-qualification tests, as we currently start to manufacture the qualification models and design the last iteration of masks for SIS junction production.

  11. Noise and loss in balanced and subharmonically pumped mixers. I - Theory. II - Application

    NASA Technical Reports Server (NTRS)

    Kerr, A. R.

    1979-01-01

    The theory of noise and frequency conversion for two-diode balanced and subharmonically pumped mixers is presented. The analysis is based on the equivalent circuit of the Schottky diode, having nonlinear capacitance, series resistance, and shot and thermal noise. Expressions for the conversion loss, noise temperature, and input and output impedances are determined in a form suitable for numerical analysis. In Part II, the application of the theory to practical mixers is demonstrated, and the properties of some two-diode mixers are examined. The subharmonically pumped mixer is found to be much more strongly affected by the loop inductance than the balanced mixer, and the ideal two-diode mixer using exponential diodes has a multiport noise-equivalent network (attenuator) similar to that of the ideal single-diode mixer. It is concluded that the theory can be extended to mixers with more than two diodes and will be useful for their design and analysis, provided a suitable nonlinear analysis is available to determine the diode waveforms.

  12. Turbofan forced mixer lobe flow modeling. Part 3: Application to augment engines

    NASA Technical Reports Server (NTRS)

    Barber, T.; Moore, G. C.; Blatt, J. R.

    1988-01-01

    Military engines frequently need large quantities of thrust for short periods of time. The addition of an augmentor can provide such thrust increases but with a penalty of increased duct length and engine weight. The addition of a forced mixer to the augmentor improves performance and reduces the penalty, as well as providing a method for siting the required flame holders. In this report two augmentor concepts are investigated: a swirl-mixer augmentor and a mixer-flameholder augmentor. Several designs for each concept are included and an experimental assessment of one of the swirl-mixer augmentors is presented.

  13. Optimization of SIS mixer elements

    NASA Technical Reports Server (NTRS)

    Mattauch, Robert J.

    1985-01-01

    Superconductor-Insulator-Superconductor (SIS) quantum mixers provide an approach to millimeter wave mixing - potentially offering conversion gain, a low local oscillator power demand, and potential mixer noise temperatures near the quantum limit. The development of a reliable fabrication technology for producing such high quality SIS devices for mixer applications in radio astronomy is the focus of the work.

  14. Mixer assembly for a gas turbine engine having a pilot mixer with a corner flame stabilizing recirculation zone

    NASA Technical Reports Server (NTRS)

    Dai, Zhongtao (Inventor); Cohen, Jeffrey M. (Inventor); Fotache, Catalin G. (Inventor)

    2012-01-01

    A mixer assembly for a gas turbine engine is provided, including a main mixer, and a pilot mixer having an annular housing in which a corner is formed between an aft portion of the housing and a bulkhead wall in which a corner recirculation zone is located to stabilize and anchor the flame of the pilot mixer. The pilot mixer can further include features to cool the annular housing, including in the area of the corner recirculation zone.

  15. 670-GHz Schottky Diode-Based Subharmonic Mixer with CPW Circuits and 70-GHz IF

    NASA Technical Reports Server (NTRS)

    Chattopadhyay, Goutam; Schlecht, Erich T.; Lee, Choonsup; Lin, Robert H.; Gill, John J.; Mehdi, Imran; Sin, Seth; Deal, William; Loi, Kwok K.; Nam, Peta; hide

    2012-01-01

    GaAs-based, sub-harmonically pumped Schottky diode mixers offer a number of advantages for array implementation in a heterodyne receiver system. Since the radio frequency (RF) and local oscillator (LO) signals are far apart, system design becomes much simpler. A proprietary planar GaAs Schottky diode process was developed that results in very low parasitic anodes that have cutoff frequencies in the tens of terahertz. This technology enables robust implementation of monolithic mixer and frequency multiplier circuits well into the terahertz frequency range. Using optical and e-beam lithography, and conventional epitaxial layer design with innovative usage of GaAs membranes and metal beam leads, high-performance terahertz circuits can be designed with high fidelity. All of these mixers use metal waveguide structures for housing. Metal machined structures for RF and LO coupling hamper these mixers to be integrated in multi-pixel heterodyne array receivers for spectroscopic and imaging applications. Moreover, the recent developments of terahertz transistors on InP substrate provide an opportunity, for the first time, to have integrated amplifiers followed by Schottky diode mixers in a heterodyne receiver at these frequencies. Since the amplifiers are developed on a planar architecture to facilitate multi-pixel array implementation, it is quite important to find alternative architecture to waveguide-based mixers.

  16. New approach to the design of Schottky barrier diodes for THz mixers

    NASA Technical Reports Server (NTRS)

    Jelenski, A.; Grueb, A.; Krozer, V.; Hartnagel, H. L.

    1992-01-01

    Near-ideal GaAs Schottky barrier diodes especially designed for mixing applications in the THz frequency range are presented. A diode fabrication process for submicron diodes with near-ideal electrical and noise characteristics is described. This process is based on the electrolytic pulse etching of GaAs in combination with an in-situ platinum plating for the formation of the Schottky contacts. Schottky barrier diodes with a diameter of 1 micron fabricated by the process have already shown excellent results in a 650 GHz waveguide mixer at room temperature. A conversion loss of 7.5 dB and a mixer noise temperature of less than 2000 K have been obtained at an intermediate frequency of 4 GHz. The optimization of the diode structure and the technology was possible due to the development of a generalized Schottky barrier diode model which is valid also at high current densities. The common diode design and optimization is discussed on the basis of the classical theory. However, the conventional fomulas are valid only in a limited forward bias range corresponding to currents much smaller than the operating currents under submillimeter mixing conditions. The generalized new model takes into account not only the phenomena occurring at the junction such as current dependent recombination and drift/diffusion velocities, but also mobility and electron temperature variations in the undepleted epi-layer. Calculated diode I/V and noise characteristics are in excellent agreement with the measured values. Thus, the model offers the possibility of optimizing the diode structure and predicting the diode performance under mixing conditions at THz frequencies.

  17. A corner-reflector mixer mount for far infrared wavelengths.

    PubMed

    Zmuidzinas, J; Betz, A L; Boreiko, R T

    1989-01-01

    A new type of corner-reflector mixer mount, which has the advantages of ease of fabrication and assembly as well as frequency versatility, has been designed and constructed. The mixer works with arbitrary antenna lengths > or = 4 lambda with the reflector to antenna spacing adjusted to give a strong and symmetric central lobe. The predicted response patterns have been experimentally verified for various antenna lengths and operating frequencies between 800 and 2000 GHz. An important design feature is the incorporation of a microstrip matching network which eliminates IF impedance mismatch and provides mechanical isolation of the whisker antenna.

  18. Low-noise SIS mixer for far-infrared radio astronomy

    NASA Astrophysics Data System (ADS)

    Karpov, Alexandre; Miller, David; Rice, Frank R.; Stern, Jeffrey A.; Bumble, Bruce; LeDuc, Henry G.; Zmuidzinas, Jonas

    2004-10-01

    We present a low noise SIS mixer developed for the 1.2 THz band of the heterodyne spectrometer of the Herschel Space Observatory. With the launch of the Herschel SO in 2007, this device will be among the first SIS mixers flown in space. This SIS mixer has a quasi-optical design, with a double slot planar antenna and an extended spherical lens made of pure Si. The SIS junctions are Nb/AlN/NbTiN with a critical current density of about 30 KA/cm2 and with the junction area of a quarter of a micron square. Our mixer circuit uses two SIS junctions biased in parallel. To improve the simultaneous suppression of the Josephson current in each of them, we use diamond-shaped junctions. A low loss Nb/Au micro-strip transmission line is used for the first time in the mixer circuit well above the gap frequency of Nb. The minimum uncorrected Double Sideband receiver noise is 550 K (Y=1.34). The minimum receiver noise corrected for the local oscillator beam splitter and for the cryostat window is 340 K, about 6 hv/k, the lowest value achieved thus far in the THz frequencies range.

  19. A quasi-optical flight mixer. [Schottky diodes and wire grid lenses

    NASA Technical Reports Server (NTRS)

    1978-01-01

    A mechanically stable single block mixer design is described utilizing a recessed whisker and beamwidth equalization lens. A stripline I.F. matching section which is an integral part of the mixer is presented. Engineering measurements of wire grids and dielectric transmission loss near one millimeter wavelength are given and an anomolous I-V curve behavior observed during diode whiskering is discussed.

  20. Effect of Installation of Mixer/Ejector Nozzles on the Core Flow Exhaust of High-Bypass-Ratio Turbofan Engines

    NASA Technical Reports Server (NTRS)

    Harrington, Douglas E.

    1998-01-01

    The aerospace industry is currently investigating the effect of installing mixer/ejector nozzles on the core flow exhaust of high-bypass-ratio turbofan engines. This effort includes both full-scale engine tests at sea level conditions and subscale tests in static test facilities. Subscale model tests are to be conducted prior to full-scale testing. With this approach, model results can be analyzed and compared with analytical predications. Problem areas can then be identified and design changes made and verified in subscale prior to committing to any final design configurations for engine ground tests. One of the subscale model test programs for the integrated mixer/ejector development was a joint test conducted by the NASA Lewis Research Center and Pratt & Whitney Aircraft. This test was conducted to study various mixer/ejector nozzle configurations installed on the core flow exhaust of advanced, high-bypass-ratio turbofan engines for subsonic, commercial applications. The mixer/ejector concept involves the introduction of largescale, low-loss, streamwise vortices that entrain large amounts of secondary air and rapidly mix it with the primary stream. This results in increased ejector pumping relative to conventional ejectors and in more complete mixing within the ejector shroud. The latter improves thrust performance through the efficient energy exchange between the primary and secondary streams. This experimental program was completed in April 1997 in Lewis' CE-22 static test facility. Variables tested included the nozzle area ratio (A9/A8), which ranged from 1.6 to 3.0. This ratio was varied by increasing or decreasing the nozzle throat area, A8. Primary nozzles tested included both lobed mixers and conical primaries. These configurations were tested with and without an outer shroud, and the shroud position was varied by inserting spacers in it. In addition, data were acquired with and without secondary flow.

  1. The effect of fuel/air mixer design parameters on the continuous and discrete phase structure in the reaction-stabilizing region

    NASA Astrophysics Data System (ADS)

    Ateshkadi, Arash

    The demands on current and future aero gas turbine combustors are demanding a greater insight into the role of the injector/dome design on combustion performance. The structure of the two-phase flow and combustion performance associated with practical injector/dome hardware is thoroughly investigated. A spray injector with two radial inflow swirlers was custom-designed to maintain tight tolerances and strict assembly protocol to isolate the sensitivity of performance to hardware design. The custom set is a unique modular design that (1) accommodates parametric variation in geometry, (2) retains symmetry, and (3) maintains effective area. Swirl sense and presence of a venturi were found to be the most influential on fuel distribution and Lean Blowout. The venturi acts as a fuel-prefilming surface and constrains the highest fuel mass concentration to an annular ring near the centerline. Co-swirl enhances the radial dispersion of the continuous phase and counter-swirl increases the level of mixing that occurs in the downstream region of the mixer. The smallest drop size distributions were found to occur with the counter-swirl configuration with venturi. In the case of counter-swirl without venturi the high concentration of fluid mass is found in the center region of the flow. The Lean Blowout (LBO) equivalence ratio was lower for counter-swirl due to the coupling of the centerline recirculation zone with the location of high fuel concentration emanating from smaller droplets. In the co-swirl configuration a more intense reaction was found near the mixer exit leading to the lowest concentration of NOx, CO and UHC. An LBO model with good agreement to the measured values was developed that related, for the first time, specific hardware parameters and operating condition to stability performance. A semi-analytical model, which agreed best with co-swirl configurations, was modified and used to describe the axial velocity profile downstream of the mixer exit. The

  2. Scale model performance test investigation of exhaust system mixers for an Energy Efficient Engine /E3/ propulsion system

    NASA Technical Reports Server (NTRS)

    Kuchar, A. P.; Chamberlin, R.

    1980-01-01

    A scale model performance test was conducted as part of the NASA Energy Efficient Engine (E3) Program, to investigate the geometric variables that influence the aerodynamic design of exhaust system mixers for high-bypass, mixed-flow engines. Mixer configuration variables included lobe number, penetration and perimeter, as well as several cutback mixer geometries. Mixing effectiveness and mixer pressure loss were determined using measured thrust and nozzle exit total pressure and temperature surveys. Results provide a data base to aid the analysis and design development of the E3 mixed-flow exhaust system.

  3. 3D printed microfluidic mixer for point-of-care diagnosis of anemia.

    PubMed

    Plevniak, Kimberly; Campbell, Matthew; Mei He

    2016-08-01

    3D printing has been an emerging fabrication tool in prototyping and manufacturing. We demonstrated a 3D microfluidic simulation guided computer design and 3D printer prototyping for quick turnaround development of microfluidic 3D mixers, which allows fast self-mixing of reagents with blood through capillary force. Combined with smartphone, the point-of-care diagnosis of anemia from finger-prick blood has been successfully implemented and showed consistent results with clinical measurements. Capable of 3D fabrication flexibility and smartphone compatibility, this work presents a novel diagnostic strategy for advancing personalized medicine and mobile healthcare.

  4. Performance of all-NbN superconductive tunnel junctions as mixers at 205 GHz

    NASA Technical Reports Server (NTRS)

    Mcgrath, W. R.; Leduc, H. G.; Stern, J. A.

    1990-01-01

    Small-area (1x1 sq micron) high-current-density NbN-MgO-NbN tunnel junctions with I-V characteristics suitable for high frequency mixers were fabricated. These junctions are integrated with superconducting microstrip lines designed to resonate out the large junction capacitance. The mixer gain and noise performance were studied near 205 GHz as a function of the inductance provided by the microstrip. This has yielded values of junction capacitance of 85 fF/sq microns and magnetic penetration depth of 3800 angstroms. Mixer noise as low as 133 K has been obtained for properly tuned junctions. This is the best noise performance ever reported for an NbN SIS mixer.

  5. The development of mixer machine for organic animal feed production: Proposed study

    NASA Astrophysics Data System (ADS)

    Leman, A. M.; Wahab, R. Abdul; Zakaria, Supaat; Feriyanto, Dafit; Nor, M. I. F. Che Mohd; Muzarpar, Syafiq

    2017-09-01

    Mixer machine plays a major role in producing homogenous composition of animal feed. Long time production, inhomogeneous and minor agglomeration has been observed by existing mixer. Therefore, this paper proposed continuous mixer to enhance mixing efficiency with shorter time of mixing process in order to abbreviate the whole process in animal feed production. Through calculation of torque, torsion, bending, power and energy consumption will perform in mixer machine process. Proposed mixer machine is designed by two layer buckets with purpose for continuity of mixing process. Mixing process was performed by 4 blades which consists of various arm length such as 50, 100,150 and 225 mm in 60 rpm velocity clockwise rotation. Therefore by using this machine will produce the homogenous composition of animal feed through nutrition analysis and short operation time of mixing process approximately of 5 minutes. Therefore, the production of animal feed will suitable for various animals including poultry and aquatic fish. This mixer will available for various organic material in animal feed production. Therefore, this paper will highlights some areas such as continues animal feed supply chain and bio-based animal feed.

  6. Turbofan forced mixer lobe flow modeling. 2: Three-dimensional inviscid mixer analysis (FLOMIX)

    NASA Technical Reports Server (NTRS)

    Barber, T.

    1988-01-01

    A three-dimensional potential analysis (FLOMIX) was formulated and applied to the inviscid flow over a turbofan foced mixer. The method uses a small disturbance formulation to analytically uncouple the circumferential flow from the radial and axial flow problem, thereby reducing the analysis to the solution of a series of axisymmetric problems. These equations are discretized using a flux volume formulation along a Cartesian grid. The method extends earlier applications of the Cartesian method to complex cambered geometries. The effects of power addition are also included within the potential formulation. Good agreement is obtained with an alternate small disturbance analysis for a high penetration symmetric mixer in a planar duct. In addition, calculations showing pressure distributions and induced secondary vorticity fields are presented for practical trubofan mixer configurations, and where possible, comparison was made with available experimental data. A detailed description of the required data input and coordinate definition is presented along with a sample data set for a practical forced mixer configuration. A brief description of the program structure and subroutines is also provided.

  7. Mixing Study in a Multi-dimensional Motion Mixer

    NASA Astrophysics Data System (ADS)

    Shah, R.; Manickam, S. S.; Tomei, J.; Bergman, T. L.; Chaudhuri, B.

    2009-06-01

    Mixing is an important but poorly understood aspect in petrochemical, food, ceramics, fertilizer and pharmaceutical processing and manufacturing. Deliberate mixing of granular solids is an essential operation in the production of industrial powder products usually constituted from different ingredients. The knowledge of particle flow and mixing in a blender is critical to optimize the design and operation. Since performance of the product depends on blend homogeneity, the consequence of variability can be detrimental. A common approach to powder mixing is to use a tumbling blender, which is essentially a hollow vessel horizontally attached to a rotating shaft. This single axis rotary blender is one of the most common batch mixers among in industry, and also finds use in myriad of application as dryers, kilns, coaters, mills and granulators. In most of the rotary mixers the radial convection is faster than axial dispersion transport. This slow dispersive process hinders mixing performance in many blending, drying and coating applications. A double cone mixer is designed and fabricated which rotates around two axes, causing axial mixing competitive to its radial counterpart. Discrete Element Method (DEM) based numerical model is developed to simulate the granular flow within the mixer. Digitally recorded mixing states from experiments are used to fine tune the numerical model. Discrete pocket samplers are also used in the experiments to quantify the characteristics of mixing. A parametric study of the effect of vessel speeds, relative rotational speed (between two axes of rotation), on the granular mixing is investigated by experiments and numerical simulation. Incorporation of dual axis rotation enhances axial mixing by 60 to 85% in comparison to single axis rotation.

  8. Design of a Small-Scale Multi-Inlet Vortex Mixer for Scalable Nanoparticle Production and Application to the Encapsulation of Biologics by Inverse Flash NanoPrecipitation.

    PubMed

    Markwalter, Chester E; Prud'homme, Robert K

    2018-05-14

    Flash NanoPrecipitation (FNP) is a scalable approach to generate polymeric nanoparticles using rapid micromixing in specially-designed geometries such as a confined impinging jets (CIJ) mixer or a Multi-Inlet Vortex Mixer (MIVM). A major limitation of formulation screening using the MIVM is that a single run requires tens of milligrams of the therapeutic. To overcome this, we have developed a scaled-down version of the MIVM, requiring as little as 0.2 mg of therapeutic, for formulation screening. The redesigned mixer can then be attached to pumps for scale-up of the identified formulation. It was shown that Reynolds Number allowed accurate scaling between the two MIVM designs. The utility of the small-scale MIVM for formulation development was demonstrated through the encapsulation of a number of hydrophilic macromolecules using inverse Flash NanoPrecipitation with target loadings as high as 50% by mass. Copyright © 2018. Published by Elsevier Inc.

  9. The Optimization Design of An AC-Electroosmotic Micro mixer

    NASA Astrophysics Data System (ADS)

    Wang, Yangyang; Suh, Yongkweon; Kang, Sangmo

    2007-11-01

    We propose the optimization design of an AC-electroosmotic micro-mixer, which is composed of a channel and a series of pairs of electrodes attached on the bottom wall in zigzag patterns. The AC electric field is applied to the electrodes so that a fluid flow takes place around the electrodes across the channel, thus contributing to the mixing of the fluid within the channel. We have performed numerical simulations by using a commercial code (CFX 10) to optimize the shape and pattern of the electrodes via the concept of mixing index. It is found that the best combination of two kinds of electrodes, which leads to good mixing performance, is not simply harmonic one. When the length ratio of the two kinds of electrodes closes to 2:1, we can get the best mixing effect. Furthermore, we will visualize the flow pattern and measure the velocity field with a PTV technique to validate the numerical simulations. In addition, the mixing pattern will be visualized via the experiment.

  10. A micromechanical analogue mixer with dynamic displacement amplification

    NASA Astrophysics Data System (ADS)

    Erismis, M. A.

    2018-06-01

    A new micromechanical device is proposed which is capable of modulation, demodulation and filtering operations. The device uses a patented 3-mass coupled micromechanical resonator which dynamically amplifies the displacement within a frequency range of interest. Modulation can be obtained by exciting different masses of the resonator with the data and the carrier signals. Demodulation can be obtained similarly by exciting the actuator with the input and carrier signals at the same time. With the help of dynamic motion amplification, filtering and signal amplification can be achieved simultaneously. A generic design approach is introduced which can be applied from kHz to MHz regime frequencies of interest. A sample mixer design for an silicon on insulator-based process is provided. A SPICE (Simulation Program with Integrated Circuit Emphasis)-based electro-mechanical co-simulation platform is also developed and the proposed mixer is simulated.

  11. Alternate paddle configuration for improved wear resistance in the saltstone mixer

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Reigel, M.; Fowley, M.

    The Saltstone Production Facility has a 10-inch Readco-Kurimoto continuous mixer that mixes the premix dry feeds and low-level waste salt solution to make fresh (uncured) saltstone. Inspection of the mixer in January 2013 showed significant wear on the third, fourth and fifth paddle pairs after the conveying augers. A 2-inch Readco-Kurimoto continuous mixer was used to test alternate paddle configurations for use in the 10-inch mixer to decrease the wear rate on the paddles. Two wear tests were conducted to investigate a method of reducing wear on the mixer paddles. The first test (wear test 2a) had a paddle configurationmore » similar to the currently installed 10-inch mixer in the SPF. This test established baseline wear. The second test (wear test 2b) had a reconfigured paddle arrangement that replaced the flat paddles with helical paddles for paddle pairs 2 - 6 and aligned paddle pair 1 with the augers. The intent of the reconfiguration was to more effectively convey the partially wetted dry feeds through the transition region and into the liquid feed where paddle wear is reduced due to dry feeds and salt solution being mixed at the intended water to premix ratio. The design of the helical paddles provides conveyance through the transition region to the liquid feed inlet. The alignment with the auger is aimed to provide a smoother transition (minimizing the discontinuity between the auger and paddle pair 1) into the downstream paddles. A soft metal with low wear resistance (6000 series aluminum) was used for the wear testing paddles to determine wear patterns while minimizing run time and maximizing wear rate. For the two paddle configurations tested using the scaled 2-inch Readco-Kurimoto continuous mixer, with the first six paddles after the augers replaced by the wear paddles and the remaining paddles were stainless steel. Since the 10-inch SPF mixer is designed with the liquid inlet centered over paddle pairs 5 and 6, the scaled 2-inch mixer was

  12. Design of Interactively Time-Pulsed Microfluidic Mixers in Microchips using Numerical Simulation

    NASA Astrophysics Data System (ADS)

    Fu, Lung-Ming; Tsai, Chien-Hsiung

    2007-01-01

    In this paper, we propose a novel technique in which driving voltages are applied interactively to the respective inlet fluid flows of three configurations of a microfluidic device, namely T-shaped, double-T-shaped, and double-cross-shaped configurations, to induce electroosmotic flow (EOF) velocity variations in such a way as to develop a rapid mixing effect in the microchannel. In these configurations a microfluidic mixer apply only one electrokinetic driving force, which drives the sample fluids and simultaneously produces a periodic switching frequency. It requires no other external driving force to induce perturbations to the flow field. The effects of the main applied electric field, the interactive frequency, and the pullback electric field on the mixing performance are thoroughly examined numerically. The optimal interactive frequency range for a given set of micromixer parameters is identified for each type of control mode. The numerical results confirm that micromixers operating at an optimal interactive frequency are capable of delivering a significantly enhanced mixing performance. Furthermore, it is shown that the optimal interactive frequency depends upon the magnitude of the main applied electric field. The interactively pulsed mixers developed in this study have a strong potential for use in lab-on-a-chip systems. They involve a simpler fabrication process than either passive or active on-chip mixers and require less human intervention in operation than their bulky external counterparts.

  13. Mixer Assembly for a Gas Turbine Engine

    NASA Technical Reports Server (NTRS)

    Smith, Lance L. (Inventor); Fotache, Catalin G. (Inventor); Dai, Zhongtao (Inventor); Cohen, Jeffrey M. (Inventor); Hautman, Donald J. (Inventor)

    2015-01-01

    A mixer assembly for a gas turbine engine is provided, including a main mixer with fuel injection holes located between at least one radial swirler and at least one axial swirler, wherein the fuel injected into the main mixer is atomized and dispersed by the air flowing through the radial swirler and the axial swirler.

  14. Mixer Assembly for a Gas Turbine Engine

    NASA Technical Reports Server (NTRS)

    Dai, Zhongtao (Inventor); Cohen, Jeffrey M. (Inventor); Fotache, Catalin G. (Inventor); Hautman, Donald J. (Inventor); Smith, Lance L. (Inventor)

    2018-01-01

    A mixer assembly for a gas turbine engine is provided, including a main mixer with fuel injection holes located between at least one radial swirler and at least one axial swirler, wherein the fuel injected into the main mixer is atomized and dispersed by the air flowing through the radial swirler and the axial swirler.

  15. Electrochemical cell apparatus having an exterior fuel mixer nozzle

    DOEpatents

    Reichner, Philip; Doshi, Vinod B.

    1992-01-01

    An electrochemical apparatus (10) is made having a generator section (22) containing electrochemical cells (16), a fresh gaseous feed fuel inlet (28), a gaseous feed oxidant inlet (30), and at least one hot gaseous spent fuel recirculation channel (46), where the spent fuel recirculation channel (46), a portion of which is in contact with the outside of a mixer chamber (52), passes from the generator chamber (22) to combine with the fresh feed fuel inlet (28) at the entrance to the mixer chamber, and a mixer nozzle (50) is located at the entrance to the mixer chamber, where the mixer chamber (52) connects with the reforming chamber (54), and where the mixer-diffuser chamber (52) and mixer nozzle (50) are exterior to and spaced apart from the combustion chamber (24), and the generator chamber (22), and the mixer nozzle (50) can operate below 400.degree. C.

  16. Superconducting Nb DHEB Mixer Arrays for Far-Infrared Spectroscopy

    NASA Technical Reports Server (NTRS)

    Gerecht, E.; Reintsema, C. D.; Grossman, E. N.; Betz, A. L.; Boreiko, R. T.

    2001-01-01

    We are developing a heterodyne focal plane array with up to eight elements to study lines of the interstellar medium and planetary atmospheres with frequencies of 2 THz and above. Our fabrication process utilizes selective ion milling techniques to produce Nb Diffusion-Cooled Hot Electron Bolometric (DHEB) mixers from a bilayer thin film of Au/Nb deposited on a silicon substrate. A micro-bridge of 10 nm thick Nb forms the HEB device. The first generation of devices with lateral dimensions of 100 nm by 80 nm were fabricated at the feed of a broadband spiral antenna with a frequency response designed for up to 16 THz. Harmonic multiplier sources becoming available within the next few years should have sufficient power to provide a local-oscillator source for small-format, quasi-optically coupled arrays of these mixers. First generation devices measured at our laboratory have demonstrated a critical temperature (Tc) of 4.8 K with a 0.5 K transition width. These DHEB mixers are expected to have an optimum operational temperature of 1.8-2.0 K. The current four element array mixer block will ultimately be replaced by a dual polarization slot-ring array configuration with up to eight elements.

  17. Superconductive hot-electron-bolometer mixer receiver for 800-GHz operation

    NASA Astrophysics Data System (ADS)

    Kawamura, J.; Blundell, R.; Tong, C.-Y. E.; Papa, D. C.; Hunter, T. R.; Paine, S. N.; Patt, F.; Gol'Tsman, G.; Cherednichenko, S.; Voronov, B.; Gershenzon, E.

    2000-04-01

    In this paper, we describe a superconductive hot-electron-bolometer mixer receiver designed to operate in the partially transmissive 350-μm atmospheric window. The receiver employs an NbN thin-film microbridge as the mixer element, in which the main cooling mechanism of the hot electrons is through electron-phonon interaction. At a local-oscillator frequency of 808 GHz, the measured double-sideband receiver noise temperature is Trx=970 K, across a 1-GHz intermediate-frequency bandwidth centered at 1.8 GHz. We have measured the linearity of the receiver and the amount of local-oscillator power incident on the mixer for optimal operation, which is PLO ≈ 1 microwatt. This receiver was used in making observations as a facility instrument at the Heinrich Hertz Telescope, Mt. Graham, AZ, during the 1998-1999 winter observing season.

  18. The Strength Analysis of Differential Planetary Gears of Gearbox for Concrete Mixer Truck

    NASA Astrophysics Data System (ADS)

    Bae, M. H.; Bae, T. Y.; Kim, D. J.

    2018-03-01

    The power train of mixer gearbox for concrete mixer truck includes differential planetary gears to get large reduction ratio for operating mixer a drum and simple structure. The planetary gears are very important part of a mixer gearbox where strength problems namely gear bending stress, gear compressive stress and scoring failure are the main concern. In the present study, calculating specifications of the differential planetary gears and analyzing the gear bending and compressive stresses as well as scoring factor of the differential planetary gears gearbox for an optimal design of the mixer gearbox in respect to cost and reliability are investigated. The analyses of actual gear bending and compressive stresses of the differential planetary gears using Lewes & Hertz equation and verifications of the calculated specifications of the differential planetary gears evaluate the results with the data of allowable bending and compressive stress from the Stress-No. of cycles curves of gears. In addition, we also analyze actual gear scoring factor as well as evaluate the possibility of scoring failure of the differential planetary gear.

  19. Planar doped barrier subharmonic mixers

    NASA Technical Reports Server (NTRS)

    Lee, T. H.; East, J. R.; Haddad, G. I.

    1992-01-01

    The Planar Doped Barrier (PDB) diode is a device consisting of a p(+) doping spike between two intrinsic layers and n(+) ohmic contacts. This device has the advantages of controllable barrier height, diode capacitance and forward to reverse current ratio. A symmetrically designed PDB has an anti-symmetric current vs. voltage characteristic and is ideal for use as millimeter wave subharmonic mixers. We have fabricated such devices with barrier heights of 0.3, 0.5 and 0.7 volts from GaAs and InGaAs using a multijunction honeycomb structure with junction diameters between one and ten microns. Initial RF measurements are encouraging. The 0.7 volt barrier height 4 micron GaAs devices were tested as subharmonic mixers at 202 GHz with an IF frequency of 1 GHz and had 18 dB of conversion loss. The estimated mismatch loss was 7 dB and was due to higher diode capacitance. The LO frequency was 100.5 GHz and the pump power was 8 mW.

  20. Oxide_Oxide Ceramic Matrix Composite (CMC) Exhaust Mixer Development in the NASA Environmentally Responsible Aviation (ERA) Project

    NASA Technical Reports Server (NTRS)

    Kiser, James D.; Bansal, Narottam P.; Szelagowski, J.; Sokhey, J.; Heffernan, T.; Clegg, J.; Pierluissi, A.; Riedell, J.; Atmur, S.; Wyen, T.; hide

    2015-01-01

    Rolls-Royce North American Technologies, Inc. (LibertyWorksLW) began considering the development of CMC exhaust forced mixers in 2008, as a means of obtaining reduced weight and hotter operating temperature capability, while minimizing shape distortion during operation, which would improve mixing efficiency and reduce fuel burn. Increased component durability, enhanced ability to fabricate complex-shaped components, and engine noise reduction are other potential advantages of CMC mixers (compared to metallic mixers). In 2010, NASA was pursuing the reduction of NOx emissions, fuel burn, and noise from turbine engines in Phase I of the Environmentally Responsible Aviation (ERA) Project. ERA subtasks, including those focused on CMC components, were formulated with the goal of maturing technology from proof of concept validation (TRL 3) to a systemsubsystem or prototype demonstration in a relevant environment (TRL 6). In April 2010, the NASA Glenn Research Center (GRC) and LibertyWorks jointly initiated a CMC Exhaust System Validation Program within the ERA Project, teaming on CMC exhaust mixer development for subsonic jet engines capable of operating with increased performance. Our initial focus was on designing, fabricating, and characterizing the thrust and acoustic performance of a roughly quarter-scale 16-lobe oxide oxide CMC mixer and tail cone along with a conventional low bypass exhaust nozzle. Support Services, LLC (Allendale, MI) and ATK COI Ceramics, Inc. (COIC, in San Diego, CA) supported the design of a subscale nozzle assembly that consisted of an oxide oxide CMC mixer and center body, with each component mounted on a metallic attachment ring. That design was based upon the operating conditions a mixer would experience in a turbofan engine. Validation of the aerodynamic and acoustic performance of the subscale mixer via testing and the achievement of TRL 4 encouraged the NASALWCOIC team to move to the next phase where a full scale CMC mixer sized for a RR

  1. Fabrication and characterization of 8.87 THz schottky barrier mixer diodes for mixer

    NASA Astrophysics Data System (ADS)

    Wang, Wenjie; Li, Qian; An, Ning; Tong, Xiaodong; Zeng, Jianping

    2018-04-01

    In this paper we report on the fabrication and characterization of GaAs-based THz schottky barrier mixer diodes. Considering the analyzed results as well as fabrication cost and complexity, a group of trade-off parameters was determined. Electron-beam lithography and air-bridge technique have been used to obtain schottky diodes with a cut off frequency of 8.87 THz. Equivalent values of series resistance, ideal factor and junction capacitance of 10.2 (1) Ω, 1.14 (0.03) and 1.76(0.03) respectively have been measured for 0.7um diameter anode devices by DC and RF measurements. The schottky barrier diodes fabrication process is fully planar and very suitable for integration in THz frequency multiplier and mixer circuits. THz Schottky barrier diodes based on such technology with 2 μm diameter anodes have been tested at 1.6 THz in a sub-harmonic mixer.

  2. EHF Test-Bed Subharmonic Mixer.

    DTIC Science & Technology

    1981-07-14

    work undertaken between June 1979 and April 1981 to develop a low noise, subharmonically pumped mixer f or a satel- lite receiver. A further objective is...waveguide with LO filter, of structure in Fig. 7a. 27 LO( J FILTER VRF TWT - Cj C10 RF SOURCE Fig. 8. Mixer equivalent circuit at RP. zo 9 VRF j Fig. 9

  3. HgCdTe Photoconductive Mixers for 2-8 THz

    NASA Technical Reports Server (NTRS)

    Betz, A. L.; Boreiko, R. T.; Sivananthan, S.; Ashokan, R.

    2001-01-01

    Heterodyne spectroscopy has been taken to wavelengths as short as 63 micrometers with Schottky-diode mixers. Schottkys, however, are relatively insensitive compared to superconducting mixers such as the hot-electron microbolometer (HEB), which has an effective quantum efficiency of 3% at 120 micrometers (2.5 THz). Although HEB sensitivities are bound to improve, there will always be losses associated with antenna coupling of radiation into sub-micron size devices. Another approach to far infrared (FIR) mixer design is to use a photoconductive device which can be made much larger than a wavelength, and thus act as its own antenna. For example, HgCdTe photodiodes have been used as mixers in the lambda = 10 micrometers band for over 25 years, with sensitivities now only a factor of 2 from the quantum-noise-limit. HgCdTe can also be applied at FIR wavelengths, but surprisingly little work has been done to date. The exception is the pioneering work of Spears and Kostiuk and Spears, who developed HgCdTe photomixers for the 20-120 micrometer region. The spectral versatility of the HgCdTe alloy is well recognized for wavelengths as long as 8-20 micrometers. What is not so recognized, however, is that theoretically there is no long wavelength limit for appropriately composited HgCdTe. Although Spears successfully demonstrated a photoconductive response from HgCdTe at 120 micrometers, this initial effort was apparently never followed up, in part because of the difficulty of controlling the HgCdTe alloy composition with liquid-phase-epitaxy (LPE) techniques. With the availability of precise molecular-beam-epitaxy (MBE) since the early 1990's, it is now appropriate to reconsider HgCdTe for detector applications longward of lambda = 20 micrometers. We recently initiated an effort to fabricate detectors and mixers using II-VI materials for FIR wavelengths. Of particular interest are device structures called superlattices, which offer a number of advantages for high sensitivity

  4. A general numerical analysis of the superconducting quasiparticle mixer

    NASA Technical Reports Server (NTRS)

    Hicks, R. G.; Feldman, M. J.; Kerr, A. R.

    1985-01-01

    For very low noise millimeter-wave receivers, the superconductor-insulator-superconductor (SIS) quasiparticle mixer is now competitive with conventional Schottky mixers. Tucker (1979, 1980) has developed a quantum theory of mixing which has provided a basis for the rapid improvement in SIS mixer performance. The present paper is concerned with a general method of numerical analysis for SIS mixers which allows arbitrary terminating impedances for all the harmonic frequencies. This analysis provides an approach for an examination of the range of validity of the three-frequency results of the quantum mixer theory. The new method has been implemented with the aid of a Fortran computer program.

  5. Planar doped barrier devices for subharmonic mixers

    NASA Technical Reports Server (NTRS)

    Lee, T. H.; East, J. R.; Haddad, G. I.

    1991-01-01

    An overview is given of planar doped barrier (PDB) devices for subharmonic mixer applications. A simplified description is given of PDB characteristics along with a more complete numerical analysis of the current versus voltage characteristics of typical structures. The analysis points out the tradeoffs between the device structure and the resulting characteristics that are important for mixer performance. Preliminary low-frequency characterization results are given for the device structures, and a computer analysis of subharmonic mixer parameters and performance is presented.

  6. Energy Efficient Engine exhaust mixer model technology report addendum; phase 3 test program

    NASA Technical Reports Server (NTRS)

    Larkin, M. J.; Blatt, J. R.

    1984-01-01

    The Phase 3 exhaust mixer test program was conducted to explore the trends established during previous Phases 1 and 2. Combinations of mixer design parameters were tested. Phase 3 testing showed that the best performance achievable within tailpipe length and diameter constraints is 2.55 percent better than an optimized separate flow base line. A reduced penetration design achieved about the same overall performance level at a substantially lower level of excess pressure loss but with a small reduction in mixing. To improve reliability of the data, the hot and cold flow thrust coefficient analysis used in Phases 1 and 2 was augmented by calculating percent mixing from traverse data. Relative change in percent mixing between configurations was determined from thrust and flow coefficient increments. The calculation procedure developed was found to be a useful tool in assessing mixer performance. Detailed flow field data were obtained to facilitate calibration of computer codes.

  7. Quantum noise in SIS mixers

    NASA Astrophysics Data System (ADS)

    Zorin, A. B.

    1985-03-01

    In the present, quantum-statistical analysis of SIS heterodyne mixer performance, the conventional three-port model of the mixer circuit and the microscopic theory of superconducting tunnel junctions are used to derive a general expression for a noise parameter previously used for the case of parametric amplifiers. This expression is numerically evaluated for various quasiparticle current step widths, dc bias voltages, local oscillator powers, signal frequencies, signal source admittances, and operation temperatures.

  8. Space Station galley design

    NASA Technical Reports Server (NTRS)

    Trabanino, Rudy; Murphy, George L.; Yakut, M. M.

    1986-01-01

    An Advanced Food Hardware System galley for the initial operating capability (IOC) Space Station is discussed. Space Station will employ food hardware items that have never been flown in space, such as a dishwasher, microwave oven, blender/mixer, bulk food and beverage dispensers, automated food inventory management, a trash compactor, and an advanced technology refrigerator/freezer. These new technologies and designs are described and the trades, design, development, and testing associated with each are summarized.

  9. Gen 2.0 Mixer/Ejector Nozzle Test at LSAF June 1995 to July 1996

    NASA Technical Reports Server (NTRS)

    Arney, L. D.; Sandquist, D. L.; Forsyth, D. W.; Lidstone, G. L.; Long-Davis, Mary Jo (Technical Monitor)

    2005-01-01

    Testing of the HSCT Generation 2.0 nozzle model hardware was conducted at the Boeing Low Speed Aeroacoustic Facility, LSAF. Concurrent measurements of noise and thrust were made at critical takeoff design conditions for a variety of mixer/ejector model hardware. Design variables such as suppressor area ratio, mixer area ratio, liner type and thickness, ejector length, lobe penetration, and mixer chute shape were tested. Parallel testing was conducted at G.E.'s Cell 41 acoustic free jet facility to augment the LSAF test. The results from the Gen 2.0 testing are being used to help shape the current nozzle baseline configuration and guide the efforts in the upcoming Generation 2.5 and 3.0 nozzle tests. The Gen 2.0 results have been included in the total airplane system studies conducted at MDC and Boeing to provide updated noise and thrust performance estimates.

  10. 21 CFR 888.4210 - Cement mixer for clinical use.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cement mixer for clinical use. 888.4210 Section... (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Surgical Devices § 888.4210 Cement mixer for clinical use. (a) Identification. A cement mixer for clinical use is a device consisting of a container intended for use in mixing...

  11. 21 CFR 888.4210 - Cement mixer for clinical use.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Cement mixer for clinical use. 888.4210 Section... (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Surgical Devices § 888.4210 Cement mixer for clinical use. (a) Identification. A cement mixer for clinical use is a device consisting of a container intended for use in mixing...

  12. 21 CFR 888.4210 - Cement mixer for clinical use.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Cement mixer for clinical use. 888.4210 Section... (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Surgical Devices § 888.4210 Cement mixer for clinical use. (a) Identification. A cement mixer for clinical use is a device consisting of a container intended for use in mixing...

  13. 21 CFR 888.4210 - Cement mixer for clinical use.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Cement mixer for clinical use. 888.4210 Section... (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Surgical Devices § 888.4210 Cement mixer for clinical use. (a) Identification. A cement mixer for clinical use is a device consisting of a container intended for use in mixing...

  14. 21 CFR 888.4210 - Cement mixer for clinical use.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Cement mixer for clinical use. 888.4210 Section... (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Surgical Devices § 888.4210 Cement mixer for clinical use. (a) Identification. A cement mixer for clinical use is a device consisting of a container intended for use in mixing...

  15. 21 CFR 868.5330 - Breathing gas mixer.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Breathing gas mixer. 868.5330 Section 868.5330 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5330 Breathing gas mixer. (a...

  16. 21 CFR 868.5330 - Breathing gas mixer.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Breathing gas mixer. 868.5330 Section 868.5330 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5330 Breathing gas mixer. (a...

  17. Symmetric Gain Optoelectronic Mixers for LADAR

    DTIC Science & Technology

    2008-12-01

    photodetector in the receiver is used as an optoelectronic mixer (OEM). Adding gain to the optoelectronic mixer allows the following transimpedance ...output is the low frequency difference signal, several orders of magnitude lower than the LO signal. Therefore, the gain of the transimpedance ... amplifier (TZA) following the photodetector can be increased, improving LADAR range. The metal-semiconductor- metal (MSM) Schottky detector is such a

  18. 670-GHz Down- and Up-Converting HEMT-Based Mixers

    NASA Technical Reports Server (NTRS)

    Schlecht, Enrich T.; Chattopadhyay, Goutam; Lin, Robert H.; Sin, Seth; Deal, William; Rodriquez, Bryan; Bayuk, Brian; Leong, Kevin; Mei, Gerry

    2012-01-01

    A large category of scientific investigation takes advantage of the interactions of signals in the frequency range from 300 to 1,000 GHz and higher. This includes astronomy and atmospheric science, where spectral observations in this frequency range give information about molecular abundances, pressures, and temperatures of small-sized molecules such as water. Additionally, there is a minimum in the atmospheric absorption at around 670 GHz that makes this frequency useful for terrestrial imaging, radar, and possibly communications purposes. This is because 670 GHz is a good compromise for imaging and radar applications between spatial resolution (for a given antenna size) that favors higher frequencies, and atmospheric losses that favor lower frequencies. A similar trade-off applies to communications link budgets: higher frequencies allow smaller antennas, but incur a higher loss. All of these applications usually require converting the RF (radio frequency) signal at 670 GHz to a lower IF (intermediate frequency) for processing. Further, transmitting for communication and radar generally requires up-conversion from IF to the RF. The current state-of-the-art device for performing the frequency conversion is based on Schottky diode mixers for both up and down conversion in this frequency range for room-temperature operation. Devices that can operate at room temperature are generally required for terrestrial, military, and planetary applications that cannot tolerate the mass, bulk, and power consumption of cryogenic cooling. The technology has recently advanced to the point that amplifiers in the region up to nearly 1,000 GHz are feasible. Almost all of these have been based on indium phosphide pseudomorphic high-electron mobility transistors (pHEMTs), in the form of monolithic microwave integrated circuits (MMICs). Since the processing of HEMT amplifiers is quite differ en t from that of Schottky diodes, use of Schottky mixers requires separate MMICs for the mixers

  19. Acoustic Characteristics of Various Treatment Panel Designs Specific to HSCT Mixer-Ejector Application

    NASA Technical Reports Server (NTRS)

    Salikuddin, M.; Kinzie, K.; Vu, D. D.; Langenbrunner, L. E.; Szczepkowski, G. T.

    2006-01-01

    The development process of liner design methodology is described in several reports. The results of the initial effort of concept development, screening, laboratory testing of various liner concepts, and preliminary correlation (generic data) are presented in a report Acoustic Characteristics of Various Treatment Panel Designs for HSCT Ejector Liner Acoustic Technology Development Program. The second phase of laboratory test results of more practical concepts and their data correlations are presented in this report (product specific). In particular, this report contains normal incidence impedance measurements of several liner types in both a static rig and in a high temperature flow duct rig. The flow duct rig allows for temperatures up to 400 F with a grazing flow up to Mach 0.8. Measurements of impedance, DC flow resistance, and in the flow rig cases, impact of the liner on boundary layer profiles are documented. In addition to liner rig tests, a limited number of tests were made on liners installed in a mixer-Ejector nozzle to confirm the performance of the liner prediction in an installed configuration.

  20. A Planar Microfluidic Mixer Based on Logarithmic Spirals

    PubMed Central

    Scherr, Thomas; Quitadamo, Christian; Tesvich, Preston; Park, Daniel Sang-Won; Tiersch, Terrence; Hayes, Daniel; Choi, Jin-Woo; Nandakumar, Krishnaswamy

    2013-01-01

    A passive, planar micromixer design based on logarithmic spirals is presented. The device was fabricated using polydimethylsiloxane soft photolithography techniques, and mixing performance was characterized via numerical simulation and fluorescent microscopy. Mixing efficiency initially declined as Reynolds number increased, and this trend continued until a Reynolds number of 15 where a minimum was reached at 53%. Mixing efficiency then began to increase reaching a maximum mixing efficiency of 86% at Re = 67. Three-dimensional simulations of fluid mixing in this design were compared to other planar geometries such as the Archimedes spiral and Meandering-S mixers. The implementation of logarithmic curvature offers several unique advantages that enhance mixing, namely a variable cross-sectional area and a logarithmically varying radius of curvature that creates 3-D Dean vortices. These flow phenomena were observed in simulations with multilayered fluid folding and validated with confocal microscopy. This design provides improved mixing performance over a broader range of Reynolds numbers than other reported planar mixers, all while avoiding external force fields, more complicated fabrication processes, and the introduction of flow obstructions or cavities that may unintentionally affect sensitive or particulate-containing samples. Due to the planar design requiring only single-step lithographic features, this compact geometry could be easily implemented into existing micro-total analysis systems requiring effective rapid mixing. PMID:23956497

  1. A planar microfluidic mixer based on logarithmic spirals

    NASA Astrophysics Data System (ADS)

    Scherr, Thomas; Quitadamo, Christian; Tesvich, Preston; Sang-Won Park, Daniel; Tiersch, Terrence; Hayes, Daniel; Choi, Jin-Woo; Nandakumar, Krishnaswamy; Monroe, W. Todd

    2012-05-01

    A passive, planar micromixer design based on logarithmic spirals is presented. The device was fabricated using polydimethylsiloxane soft photolithography techniques, and mixing performance was characterized via numerical simulation and fluorescent microscopy. Mixing efficiency initially declined as the Reynolds number increased, and this trend continued until a Reynolds number of 15 where a minimum was reached at 53%. Mixing efficiency then began to increase reaching a maximum mixing efficiency of 86% at Re = 67. Three-dimensional (3D) simulations of fluid mixing in this design were compared to other planar geometries such as the Archimedes spiral and Meandering-S mixers. The implementation of logarithmic curvature offers several unique advantages that enhance mixing, namely a variable cross-sectional area and a logarithmically varying radius of curvature that creates 3D Dean vortices. These flow phenomena were observed in simulations with multilayered fluid folding and validated with confocal microscopy. This design provides improved mixing performance over a broader range of Reynolds numbers than other reported planar mixers, all while avoiding external force fields, more complicated fabrication processes and the introduction of flow obstructions or cavities that may unintentionally affect sensitive or particulate-containing samples. Due to the planar design requiring only single-step lithographic features, this compact geometry could be easily implemented into existing micro-total analysis systems requiring effective rapid mixing.

  2. Development of Submillimeter SIS Mixers and Broadband HEMT Amplifiers

    NASA Technical Reports Server (NTRS)

    Zmuidzinas, J.

    2004-01-01

    This is the final technical report for NASA grant NAG5-9493. entitled "Development of Submillimeter SIS Mixers and Broadband HEMT Amplifiers". The goal of this project was to develop and demonstrate a new generation of superconducting tunnel junction (SIS) receivers with extremely wide instantaneous (intermediate-frequency, or IF) bandwidths. of order 12 GHz. along with the wideband low-noise microwave HEMT (high electron mobility transistor) amplifiers which follow the SIS mixer. These wideband SIS/HEMT receivers would allow rapid submillimeter wavelength spectral line surveys to be carried out, for instance with the NASA airborne observatory SOFIA. and could potentially be useful for future submillimeter space missions such as SAFIR. In addition, there are potential NASA earth science applications. such as the monitoring of the distribution of chemical species in the stratosphere and troposphere using the limb-sounding technique. The overall goals of this project have been achieved: a broadband 200-300 SIS receiver was designed and constructed, and was demonstrated in the field through a test run at the Caltech Submillimeter Observatory on Mauna Kea. HI. The technical details are described in the appendices. which are primarily conference publications. but Appendix A also includes an unpublished summary of the latest results. The work on the SIS mixer design are described in the conference publications (appendices B and C). The "Supermix" software package that was developed at Caltech and used for the SIS design is also described in two conference papers, but has been substantially revised, debugged. and extended as part of the work completed for this grant. The Supermix package is made available to the community at no charge. The electromagnetic design of a radial waveguide probe similar to the one used in this work is described in a journal publication. Details of the novel fabrication procedure used for producing the SIS devices at JPL are also given in an

  3. Convex Grooves in Staggered Herringbone Mixer Improve Mixing Efficiency of Laminar Flow in Microchannel.

    PubMed

    Kwak, Tae Joon; Nam, Young Gyu; Najera, Maria Alejandra; Lee, Sang Woo; Strickler, J Rudi; Chang, Woo-Jin

    2016-01-01

    The liquid streams in a microchannel are hardly mixed to form laminar flow, and the mixing issue is well described by a low Reynolds number scheme. The staggered herringbone mixer (SHM) using repeated patterns of grooves in the microchannel have been proved to be an efficient passive micro-mixer. However, only a negative pattern of the staggered herringbone mixer has been used so far after it was first suggested, to the best of our knowledge. In this study, the mixing efficiencies from negative and positive staggered herringbone mixer patterns as well as from opposite flow directions were tested to investigate the effect of the micro-structure geometry on the surrounding laminar flow. The positive herringbone pattern showed better mixing efficiency than the conventionally used negative pattern. Also, generally used forward flow gives better mixing efficiency than reverse flow. The mixing was completed after two cycles of staggered herringbone mixer with both forward and reverse flow in a positive pattern. The traditional negative pattern showed complete mixing after four and five cycles in forward and reverse flow direction, respectively. The mixing effect in all geometries was numerically simulated, and the results confirmed more efficient mixing in the positive pattern than the negative. The results can further enable the design of a more efficient microfluidic mixer, as well as in depth understanding of the phenomena of positive and negative patterns existing in nature with regards to the surrounding fluids.

  4. Convex Grooves in Staggered Herringbone Mixer Improve Mixing Efficiency of Laminar Flow in Microchannel

    PubMed Central

    Nam, Young Gyu; Najera, Maria Alejandra; Lee, Sang Woo; Strickler, J. Rudi; Chang, Woo-Jin

    2016-01-01

    The liquid streams in a microchannel are hardly mixed to form laminar flow, and the mixing issue is well described by a low Reynolds number scheme. The staggered herringbone mixer (SHM) using repeated patterns of grooves in the microchannel have been proved to be an efficient passive micro-mixer. However, only a negative pattern of the staggered herringbone mixer has been used so far after it was first suggested, to the best of our knowledge. In this study, the mixing efficiencies from negative and positive staggered herringbone mixer patterns as well as from opposite flow directions were tested to investigate the effect of the micro-structure geometry on the surrounding laminar flow. The positive herringbone pattern showed better mixing efficiency than the conventionally used negative pattern. Also, generally used forward flow gives better mixing efficiency than reverse flow. The mixing was completed after two cycles of staggered herringbone mixer with both forward and reverse flow in a positive pattern. The traditional negative pattern showed complete mixing after four and five cycles in forward and reverse flow direction, respectively. The mixing effect in all geometries was numerically simulated, and the results confirmed more efficient mixing in the positive pattern than the negative. The results can further enable the design of a more efficient microfluidic mixer, as well as in depth understanding of the phenomena of positive and negative patterns existing in nature with regards to the surrounding fluids. PMID:27814386

  5. Low-noise submillimeter-wave NbTiN superconducting tunnel junction mixers

    NASA Astrophysics Data System (ADS)

    Kawamura, Jonathan; Chen, Jian; Miller, David; Kooi, Jacob; Zmuidzinas, Jonas; Bumble, Bruce; LeDuc, Henry G.; Stern, Jeff A.

    1999-12-01

    We have developed a low-noise 850 GHz superconductor-insulator-superconductor quasiparticle mixer with NbTiN thin-film microstrip tuning circuits and hybrid Nb/AlN/NbTiN tunnel junctions. The mixer uses a quasioptical configuration with a planar twin-slot antenna feeding a two-junction tuning circuit. At 798 GHz, we measured an uncorrected double-sideband receiver noise temperature of TRX=260 K at 4.2 K bath temperature. This mixer outperforms current Nb SIS mixers by a factor of nearly 2 near 800 GHz. The high-gap frequency and low loss at 800 GHz make NbTiN an attractive material with which to fabricate tuning circuits for SIS mixers. NbTiN mixers can potentially operate up to the gap frequency, 2Δ/h˜1.2 THz.

  6. Experimental evaluation of exhaust mixers for an Energy Efficient Engine

    NASA Technical Reports Server (NTRS)

    Kozlowski, H.; Kraft, G.

    1980-01-01

    Static scale model tests were conducted to evaluate exhaust system mixers for a high bypass ratio engine as part of the NASA sponsored Energy Efficient program. Gross thrust coefficients were measured for a series of mixer configurations which included variations in the number of mixer lobes, tailpipe length, mixer penetration, and length. All of these parameters have a significant impact on exhaust system performance. In addition, flow visualization pictures and pressure/temperature traverses were obtained for selected configurations. Parametric performance trends are discussed and the results considered relative to the Energy Efficient Engine program goals.

  7. Submillimeter SIS Mixers Using High Current Density Nb/AIN/Nb Tunnel Junctions and NbTiN Films

    NASA Astrophysics Data System (ADS)

    Kawamura, J.; Miller, D.; Chen, J.; Kooi, J.; Zmuidzinas, J.; Bumble, B.; Leduc, H.; Stern, J.

    1999-03-01

    We are currently exploring ways to improve the performance of SIS mixers above 700 GHz. One approach is to use NbTiN in place of Nb for all or some of the mixer circuitry. With its high gap frequency and low losses demonstrated up to 800 GHz, it should be possible to fabricate an all-NbTiN SIS mixer with near quantum-limited noise performance up to 1.2 THz. Using a quasioptical twin-slot two-junction mixer with NbTiN ground plane and wiring and hybrid Nb/A1N/NbTiN junctions, we measured an uncorrected receiver noise temperature of TRx ~ 500 K across 790-850 GHz at 4.2 K bath temperature. Our second approach is to reduce the RC product of the mixer by employing very high current density Nb/A1N/Nb junctions. By using these we will greatly relax the requirement on tuning circuits, which is where substantial losses occur in mixers operating above the Nb gap frequency. These junctions have resistance-area products of R_N*A ~ 5.6 Ohm um2, good subgap to normal resistance ratios, R_sg/R_N ~ 10, and good run-to-run reproducibility. From FTS measurements we infer that omega*R_N*C = 1 at 270 GHz in these junctions. This is a substantial improvement over that available using Nb/Al0x/Nb technology. The sensitivity of a receiver incorporating these high current density mixers is T_Rx = 110 K at 533 GHz using a design for lower J_c mixers, which is close to the best we have measured with lower J_c Nb/Al0x/Nb mixers.

  8. 7 CFR 58.228 - Dump hoppers, screens, mixers and conveyors.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 3 2011-01-01 2011-01-01 false Dump hoppers, screens, mixers and conveyors. 58.228... Service 1 Equipment and Utensils § 58.228 Dump hoppers, screens, mixers and conveyors. The product contact surfaces of dump hoppers, screens, mixers and conveyors which are used in the process of transferring dry...

  9. Acoustic characteristics of externally blown flap systems with mixer nozzles

    NASA Technical Reports Server (NTRS)

    Goodykoontz, J. H.; Dorsch, R. G.; Wagner, J. M.

    1974-01-01

    Noise tests were conducted on a large scale, cold flow model of an engine-under-the-wing externally blown flap lift augmentation system employing a mixer nozzle. The mixer nozzle was used to reduce the flap impingement velocity and, consequently, try to attenuate the additional noise caused by the interaction between the jet exhaust and the wing flap. Results from the mixer nozzle tests are summarized and compared with the results for a conical nozzle. The comparison showed that with the mixer nozzle, less noise was generated when the trailing flap was in a typical landing setting (e.g., 60 deg). However, for a takeoff flap setting (20 deg), there was little or no difference in the acoustic characteristics when either the mixer or conical nozzle was used.

  10. A 220-GHz SIS Mixer Tightly Integrated With a Sub-Hundred-Microwatt SiGe IF Amplifier

    NASA Astrophysics Data System (ADS)

    Montazeri, Shirin; Grimes, Paul K.; Tong, Cheuk-Yu Edward; Bardin, Joseph C.

    2016-01-01

    Future kilopixel-scale heterodyne focal plane arrays based on superconductor-insulator-superconductor (SIS) mixers will require submilliwatt power consumption low-noise amplifiers (LNAs) which are tightly integrated with the mixers. In this paper, an LNA that is optimized for direct connection to a 220-GHz SIS mixer chip and requires less than 100 μW of dc power is reported. The amplifier design process is described, and measurement results are presented. It is shown that, when pumped at local oscillator frequencies between 214 and 226 GHz, the mixer/amplifier module achieves a double-sideband system noise temperature between 35 and 50 K over the 3.3-6 GHz IF frequency range while requiring just 90 μW of dc power. Moreover, the potential to further reduce the power consumption is explored and successful operation is demonstrated for LNA power consumption as low as 60 μW.

  11. Credit BG. This view looks northwest (290°) in the mixer ...

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

    Credit BG. This view looks northwest (290°) in the mixer room at the 30-gallon Baker-Perkins model 121/2 PVM mixer and its associated equipment. The hopper in the left background feeds ingredients to the mixing pot when the hopper is mounted on the mixer frame; the hoist overhead is used to mount the hopper. The mixing pot is in its lowered position beneath the mixer blades. The pot is normally raised and secured to the upper half of the mixer, and a vacuum is applied during mixing operations to prevent the entrainment of air bubbles in the mix. A second mixing pot appears in the right background, and a pot vacuum lid appears in the extreme right foreground. The equipment on the palette in the left foreground is not related to the mixer. Note the explosion-proof fluorescent lighting fixtures suspended from the ceiling. The floor has an electrically conductive coating to dissipate static electrical charges - Jet Propulsion Laboratory Edwards Facility, Mixer & Casting Building, Edwards Air Force Base, Boron, Kern County, CA

  12. Concrete Mixing Methods and Concrete Mixers: State of the Art

    PubMed Central

    Ferraris, Chiara F.

    2001-01-01

    As for all materials, the performance of concrete is determined by its microstructure. Its microstructure is determined by its composition, its curing conditions, and also by the mixing method and mixer conditions used to process the concrete. This paper gives an overview of the various types of mixing methods and concrete mixers commercially available used by the concrete industry. There are two main types of mixers used: batch mixers and continuous mixers. Batch mixers are the most common. To determine the mixing method best suited for a specific application, factors to be considered include: location of the construction site (distance from the batching plant), the amount of concrete needed, the construction schedule (volume of concrete needed per hour), and the cost. Ultimately, the quality of the concrete produced determines its performance after placement. An important measure of the quality is the homogeneity of the material after mixing. This paper will review mixing methods in regards to the quality of the concrete produced. Some procedures used to determine the effectiveness of the mixing will be examined. PMID:27500029

  13. Low-Noise Submillimeter-Wave NbTiN Superconducting Tunnel Junction Mixers

    NASA Technical Reports Server (NTRS)

    Kawamura, J.; Chen, J.; Miller, D.; Kooi, J.; Zmuidzinas, J.; Bumble, B.; LeDuc, H. G.; Stern, J. A.

    1999-01-01

    We have developed a low-noise 850 GHz superconductor-insulator-superconductor (SIS) quasi-particle mixer with NbTiN thin-film microstrip tuning circuits and hybrid Nb/AlN/NbTiN tunnel junctions. The mixer uses a quasioptical configuration with a planar twin-slot antenna feeding a two-junction tuning circuit. At 798 GHz, we measured an uncorrected double-sideband receiver noise temperature of T(sub RX) = 260 K at 4.2 K bath temperature. This mixer outperforms current Nb SIS mixers by a factor of nearly 2 near 800 GHz. The high gap frequency and low loss at 800 GHz make NbTiN an attractive material with which to fabricate tuning circuits for SIS mixers. NbTiN mixers can potentially operate up to the gap frequency, 2(delta)/h is approximately 1.2THz.

  14. Noise tests of a mixer nozzle-externally blown flap system

    NASA Technical Reports Server (NTRS)

    Goodykoontz, J. H.; Dorsch, R. G.; Groesbeck, D. E.

    1973-01-01

    Noise tests were conducted on a large scale model of an externally blown flap lift augmentation system, employing a mixer nozzle. The mixer nozzle consisted of seven flow passages with a total equivalent diameter of 40 centimeters. With the flaps in the 30 - 60 deg setting, the noise level below the wing was less with the mixer nozzle than when a standard circular nozzle was used. At the 10 - 20 deg flap setting, the noise levels were about the same when either nozzle was used. With retracted flaps, the noise level was higher when the mixer nozzle was used.

  15. Development of Balanced SIS Mixers for ALMA Band-10

    NASA Astrophysics Data System (ADS)

    Shitov, Sergey V.; Koryukin, Oleg V.; Uzawa, Yoshinory; Noguchi, Takashi; Uvarov, Andrey V.; Cohn, Ilya A.

    2006-05-01

    A few concepts of a wide-band balanced SIS mixer employing submicron-sized SIS junctions are under development for 787-950 GHz frequency range. A quasioptical DSB balanced mixer with integrated cross-slot antenna is considered as the less laborious and cheaper option. The silicon lens-antenna beam efficiency is expected above 80 % across the whole band with first-order sidelobe below -16 dB. To use the conservative horn antenna solution, a single chamber waveguide DSB balanced mixer is developed. Two equal probe-type SIS chips are inserted into a full-height waveguide through its opposite broad walls; these two mixers are driven by the signal waveguide in series. The LO current is transferred to the mixers in parallel via a capacitive probe inserted through the narrow wall of the signal waveguide from the neighboring LO waveguide. The HFSS model demonstrated the LO power coupling efficiency above -3 dB, almost perfect signal transfer and the LO cross talk below -30 dB that take into account misalignment (misbalance) of the chips. It is demonstrated numerically using Tucker's 3-port model that unequal pump of junctions of a twin-SIS mixer can lead, in spite of the perfect signal coupling, to degradation of the gain performance up to -3 dB, especially at the top of the ALMA Band-10.

  16. Nonlinear Modeling and Control of a Propellant Mixer

    NASA Technical Reports Server (NTRS)

    Barbieri, Enrique; Richter, Hanz; Figueroa, Fernando

    2003-01-01

    A mixing chamber used in rocket engine combustion testing at NASA Stennis Space Center is modeled by a second order nonlinear MIMO system. The mixer is used to condition the thermodynamic properties of cryogenic liquid propellant by controlled injection of the same substance in the gaseous phase. The three inputs of the mixer are the positions of the valves regulating the liquid and gas flows at the inlets, and the position of the exit valve regulating the flow of conditioned propellant. The outputs to be tracked and/or regulated are mixer internal pressure, exit mass flow, and exit temperature. The outputs must conform to test specifications dictated by the type of rocket engine or component being tested downstream of the mixer. Feedback linearization is used to achieve tracking and regulation of the outputs. It is shown that the system is minimum-phase provided certain conditions on the parameters are satisfied. The conditions are shown to have physical interpretation.

  17. An Integrated 520-600 GHz Sub-Harmonic Mixer and Tripler Combination Based on GaAs MMIC Membrane Planar Schottky Diodes

    NASA Technical Reports Server (NTRS)

    Thomas, B.; Gill, J.; Maestrini, A.; Lee, C.; Lin, R.; Sin, S.; Peralta, A.; Mehdi, I.

    2011-01-01

    We present here the design, development and test of an integrated sub-millimeter front-end featuring a 520-600 GHz sub-harmonic mixer and a 260-300 GHz frequency tripler in a single cavity. Both devices used GaAs MMIC membrane planar Schottky diode technology. The sub-harmonic mixer/tripler circuit has been tested using conventional machined as well as silicon micro-machined blocks. Measurement results on the metal block give best DSB mixer noise temperature of 2360 K and conversion losses of 7.7 dB at 520 GHz. Preliminary results on the silicon micro-machined blocks give a DSB mixer noise temperature of 4860 K and conversion losses of 12.16 dB at 540 GHz. The LO input power required to pump the integrated tripler/sub-harmonic mixer for both packages is between 30 and 50 mW

  18. An Integrated 520-600 GHz Sub-Harmonic Mixer and Tripler Combination Based on GaAs MMIC Membrane Planar Schottky Diodes

    NASA Technical Reports Server (NTRS)

    Thomas, B.; Gill, J.; Maestrini, A.; Lee, C.; Lin, R.; Sin, S.; Peralta, A.; Mehdi, I.

    2010-01-01

    We present here the design, development and test of an integrated sub-millimeter front-end featuring a 520-600 GHz sub-harmonic mixer and a 260-300 GHz frequency tripler in a single cavity. Both devices used GaAs MMIC membrane planar Schottky diode technology. The sub-harmonic mixer/tripler circuit has been tested using conventional machined as well as silicon micro-machined blocks. Measurement results on the metal block give best DSB mixer noise temperature of 2360 K and conversion losses of 7.7 dB at 520 GHz. Preliminary results on the silicon micro-machined blocks give a DSB mixer noise temperature of 4860 K and conversion losses of 12.16 dB at 540 GHz. The LO input power required to pump the integrated tripler/sub-harmonic mixer for both packages is between 30 and 50 mW.

  19. Hot-electron bolometer terahertz mixers for the Herschel Space Observatory.

    PubMed

    Cherednichenko, Sergey; Drakinskiy, Vladimir; Berg, Therese; Khosropanah, Pourya; Kollberg, Erik

    2008-03-01

    We report on low noise terahertz mixers (1.4-1.9 THz) developed for the heterodyne spectrometer onboard the Herschel Space Observatory. The mixers employ double slot antenna integrated superconducting hot-electron bolometers (HEBs) made of thin NbN films. The mixer performance was characterized in terms of detection sensitivity across the entire rf band by using a Fourier transform spectrometer (from 0.5 to 2.5 THz, with 30 GHz resolution) and also by measuring the mixer noise temperature at a limited number of discrete frequencies. The lowest mixer noise temperature recorded was 750 K [double sideband (DSB)] at 1.6 THz and 950 K DSB at 1.9 THz local oscillator (LO) frequencies. Averaged across the intermediate frequency band of 2.4-4.8 GHz, the mixer noise temperature was 1100 K DSB at 1.6 THz and 1450 K DSB at 1.9 THz LO frequencies. The HEB heterodyne receiver stability has been analyzed and compared to the HEB stability in the direct detection mode. The optimal local oscillator power was determined and found to be in a 200-500 nW range.

  20. High-k Scattering Receiver Mixer Performance for NSTX-U

    NASA Astrophysics Data System (ADS)

    Barchfeld, Robert; Riemenschneider, Paul; Domier, Calvin; Luhmann, Neville; Ren, Yang; Kaita, Robert

    2016-10-01

    The High-k Scattering system detects primarily electron-scale turbulence k θ spectra for studying electron thermal transport in NSTX-U. A 100 mW, 693 GHz probe beam passes through plasma, and scattered power is detected by a 4-pixel quasi optical, mixer array. Remotely controlled receiving optics allows the scattering volume to be located from core to edge with a k θ span of 7 to 40 cm-1. The receiver array features 4 RF diagonal input horns, where the electric field polarization is aligned along the diagonal of a square cross section horn, at 30 mm channel spacing. The local oscillator is provided by a 14.4 GHz source followed by a x48 multiplier chain, giving an intermediate frequency of 1 GHz. The receiver optics receive 4 discreet scattering angles simultaneously, and then focus the signals as 4 parallel signals to their respective horns. A combination of a steerable probe beam, and translating receiver, allows for upward or downward scattering which together can provide information about 2D turbulence wavenumber spectrum. IF signals are digitized and stored for later computer analysis. The performance of the receiver mixers is discussed, along with optical design features to enhance the tuning and performance of the mixers. Work supported in part by U.S. DOE Grant DE-FG02-99ER54518 and DE-AC02-09CH1146.

  1. Methodology for calculating power consumption of planetary mixers

    NASA Astrophysics Data System (ADS)

    Antsiferov, S. I.; Voronov, V. P.; Evtushenko, E. I.; Yakovlev, E. A.

    2018-03-01

    The paper presents the methodology and equations for calculating the power consumption necessary to overcome the resistance of a dry mixture caused by the movement of cylindrical rods in the body of a planetary mixer, as well as the calculation of the power consumed by idling mixers of this type. The equations take into account the size and physico-mechanical properties of mixing material, the size and shape of the mixer's working elements and the kinematics of its movement. The dependence of the power consumption on the angle of rotation in the plane perpendicular to the axis of rotation of the working member is presented.

  2. Micromechanical Waveguide Mounts for Hot Electron Bolometer Terahertz Mixers

    NASA Astrophysics Data System (ADS)

    Brandt, Michael; Jacobs, Karl; Honingh, C. E.; Stodolka, Jörg

    The superior beam matching of waveguide horn antennas to a telescope suggests using waveguide mounts even at THz-frequencies. In contrast to the more common quasi-optical (substrate lens) designs, the exceedingly small dimensions of the waveguide require novel micro-mechanical fabrication technologies. We will present a novel fabrication scheme for 1.9 THz waveguide mixers for SOFIA. Hot Electron Bolometer devices (HEB) are fabricated on 2 μm thick Si3N4 membrane strips. The strips are robust enough to be mounted on a separately fabricated Si support frame using an adapted flip-chip technology. Mounted onto the frame, the devices can be easily positioned and glued into a copper waveguide mount. Further developments regarding micro-mechanical processes to fabricate this copper waveguide mount and the receiving horn antenna will be presented, as well as the KOSMA Micro Assembly Station and its capabilities to handle mixer substrates.

  3. A Low-Noise NbTiN Hot Electron Bolometer Mixer

    NASA Technical Reports Server (NTRS)

    Tong, C. Edward; Stern, Jeffrey; Megerian, Krikor; LeDuc, Henry; Sridharan, T. K.; Gibson, Hugh; Blundell, Raymond

    2001-01-01

    Hot electron bolometer (HEB) mixer elements, based on niobium titanium nitride (NbTiN) thin film technology, have been fabricated on crystalline quartz substrates over a 20 nm thick AlN buffer layer. The film was patterned by optical lithography, yielding bolometer elements that measure about 1 micrometer long and between 2 and 12 micrometers wide. These mixer chips were mounted in a fixed-tuned waveguide mixer block, and tested in the 600 and 800 GHz frequency range. The 3-dB output bandwidth of these mixers was determined to be about 2.5 GHz and we measured a receiver noise temperature of 270 K at 630 GHz using an intermediate frequency of 1.5 GHz. The receiver has excellent amplitude stability and the noise temperature measurements are highly repeatable. An 800 GHz receiver incorporating one of these mixer chips has recently been installed at the Sub-Millimeter Telescope in Arizona for field test and for astronomical observations.

  4. Detailed evaluation of the performance of microfluidic T mixers using fluorescence and ultraviolet resonance Raman spectroscopy

    NASA Astrophysics Data System (ADS)

    Masca, Sergiu I.; Rodriguez-Mendieta, Iñigo R.; Friel, Claire T.; Radford, Sheena E.; Smith, D. Alastair

    2006-05-01

    A reliable device that produces efficient mixing with a short dead time has enormous utility in the kinetic analysis of biochemical and chemical processes. We have designed two different T mixers that use moderate flow rates (0.2-0.4ml/s), can monitor reactions up to several milliseconds, and achieve mixing times as low as 20μs. The two mixers are easy to build and dismantle, reliable, and can perform hundreds of experiments without blocking. The first mixer comprises a stainless steel block, containing a microchannel, glued to a quartz cuvette, containing a 200×200μm2 observation channel defining a conventional T mixer. The reactions are monitored by imaging the length of the observation channel onto a charge-coupled device camera. In the second mixer the entire T (200×200μm2 internal cross section) is contained within a 40-mm-long quartz cuvette. We have adopted a novel approach to controlling the entrance channel bore by inserting a stainless steel wire in order to increase the linear speed of the impinging fluids. Using a dye to visualize the flow profile inside the second T mixer, it was shown that in this T geometry segregation of the reactants is observed in the junction between the inlet channels and the observation channel (T junction) and mixing occurs entirely in the observation channel. We thoroughly tested the two mixers through several kinetic reactions using both fluorescence and ultraviolet resonance Raman spectroscopy measurements. We show that both mixers provide efficient mixing with nominal dead times (using 1:10 v /v dilution), calculated using the quenching of the fluorescence of N-acetyl-L-tryptophanamide by N-bromosuccinimide, of 200±20 and 100±10μs, for each mixer, respectively. However, the ability to monitor within the inlet channels and the entire observation channel of the second mixer shows that this standard approach to estimating the dead time is artifactual, since it relies on assuming a constant flow speed throughout the

  5. A picoliter-volume mixer for microfluidic analytical systems.

    PubMed

    He, B; Burke, B J; Zhang, X; Zhang, R; Regnier, F E

    2001-05-01

    Mixing confluent liquid streams is an important, but difficult operation in microfluidic systems. This paper reports the construction and characterization of a 100-pL mixer for liquids transported by electroosmotic flow. Mixing was achieved in a microfabricated device with multiple intersecting channels of varying lengths and a bimodal width distribution. All channels running parallel to the direction of flow were 5 microm in width whereas larger 27-microm-width channels ran back and forth through the parallel channel network at a 45 degrees angle. The channel network composing the mixer was approximately 10 microm deep. It was observed that little mixing of the confluent solvent streams occurred in the 100-microm-wide, 300-microm-long mixer inlet channel where mixing would be achieved almost exclusively by diffusion. In contrast, after passage through the channel network in the approximately 200-microm-length static mixer bed, mixing was complete as determined by confocal microscopy and CCD detection. Theoretical simulations were also performed in an attempt to describe the extent of mixing in microfabricated systems.

  6. 11. VIEW OF HORIZONTAL MIXER (GedgeGray Co., Lockland, Ohio), LOCATED ...

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

    11. VIEW OF HORIZONTAL MIXER (Gedge-Gray Co., Lockland, Ohio), LOCATED IN THE BASEMENT, MIXED ANIMAL FEED TO ORDER. THE WATER-POWERED MIXER WAS SUPERSEDED BY TWO ELECTRIC-POWERED VERTICAL MIXERS, ADDED IN THE 1940S. Photographer: Louise Taft Cawood, July 1986 - Alexander's Grist Mill, Lock 37 on Ohio & Erie Canal, South of Cleveland, Valley View, Cuyahoga County, OH

  7. Alternative Fuels Data Center: Ozinga Adds 14 Natural Gas Concrete Mixers

    Science.gov Websites

    to Its Fleet Ozinga Adds 14 Natural Gas Concrete Mixers to Its Fleet to someone by E-mail Share Alternative Fuels Data Center: Ozinga Adds 14 Natural Gas Concrete Mixers to Its Fleet on Facebook Tweet about Alternative Fuels Data Center: Ozinga Adds 14 Natural Gas Concrete Mixers to Its Fleet on Twitter Bookmark

  8. A User's Guide for the Differential Reduced Ejector/Mixer Analysis "DREA" Program. 1.0

    NASA Technical Reports Server (NTRS)

    DeChant, Lawrence J.; Nadell, Shari-Beth

    1999-01-01

    A system of analytical and numerical two-dimensional mixer/ejector nozzle models that require minimal empirical input has been developed and programmed for use in conceptual and preliminary design. This report contains a user's guide describing the operation of the computer code, DREA (Differential Reduced Ejector/mixer Analysis), that contains these mathematical models. This program is currently being adopted by the Propulsion Systems Analysis Office at the NASA Glenn Research Center. A brief summary of the DREA method is provided, followed by detailed descriptions of the program input and output files. Sample cases demonstrating the application of the program are presented.

  9. High-pressure liquid chromatographic gradient mixer

    DOEpatents

    Daughton, C.G.; Sakaji, R.H.

    1982-09-08

    A gradient mixer effects the continuous mixing of any two miscible solvents without excessive decay or dispersion of the resultant isocratic effluent or of a linear or exponential gradient. The two solvents are fed under low or high pressure by means of two high performance liquid chromatographic pumps. The mixer comprises a series of ultra-low dead volume stainless steel tubes and low dead volume chambers. The two solvent streams impinge head-on at high fluxes. This initial nonhomogeneous mixture is then passed through a chamber packed with spirally-wound wires which cause turbulent mixing thereby homogenizing the mixture with minimum band-broadening.

  10. Flow regimes in a T-mixer operating with a binary mixture

    NASA Astrophysics Data System (ADS)

    Camarri, Simone; Siconolfi, Lorenzo; Galletti, Chiara; Salvetti, Maria Vittoria

    2015-11-01

    Efficient mixing in small volumes is a key target in many processes. Among the most common micro-devices, passive T-shaped micro-mixers are widely used. For this reason, T-mixers have been studied in the literature and its working flow regimes have been identified. However, in most of the available theoretical studies it is assumed that only one working fluid is used, i.e. that the same fluid at the same thermodynamic conditions is entering the two inlet conduits of the mixer. Conversely, the practical use of micro-devices often involves the mixing of two different fluids or of the same fluid at different thermodynamic conditions. In this case flow regimes significantly different than those observed for a single working fluid may occur. The present work aims at investigating the flow regimes in a T-mixers when water at two different temperatures, i.e. having different viscosity and density, is entering the mixer. The effect of the temperature difference on the flow regimes in a 3D T-mixer is investigated by DNS and stability analysis and the results are compared to the case in which a single working fluid is employed.

  11. Split-Waveguide Mounts For Submillimeter-Wave Multipliers And Harmonic Mixers

    NASA Technical Reports Server (NTRS)

    Raisanen, Antti; Choudhury, Debabani; Dengler, Robert J.; Oswald, John E.; Siegel, Peter H.

    1996-01-01

    Novel variation of split-waveguide mount for millimeter-and submillimeter-wavelength frequency multipliers and harmonic mixers developed. Designed to offer wide range of available matching impedances, while maintaining relatively simple fabrication sequence. Wide tuning range achieved with separate series and parallel elements, consisting of two pairs of noncontacting sliding backshorts, at fundamental and harmonic frequencies. Advantages include ease of fabrication, reliability, and tunability.

  12. GUI for Computational Simulation of a Propellant Mixer

    NASA Technical Reports Server (NTRS)

    Figueroa, Fernando; Richter, Hanz; Barbieri, Enrique; Granger, Jamie

    2005-01-01

    Control Panel is a computer program that generates a graphical user interface (GUI) for computational simulation of a rocket-test-stand propellant mixer in which gaseous hydrogen (GH2) is injected into flowing liquid hydrogen (LH2) to obtain a combined flow having desired thermodynamic properties. The GUI is used in conjunction with software that models the mixer as a system having three inputs (the positions of the GH2 and LH2 inlet valves and an outlet valve) and three outputs (the pressure inside the mixer and the outlet flow temperature and flow rate). The user can specify valve characteristics and thermodynamic properties of the input fluids via userfriendly dialog boxes. The user can enter temporally varying input values or temporally varying desired output values. The GUI provides (1) a set-point calculator function for determining fixed valve positions that yield desired output values and (2) simulation functions that predict the response of the mixer to variations in the properties of the LH2 and GH2 and manual- or feedback-control variations in valve positions. The GUI enables scheduling of a sequence of operations that includes switching from manual to feedback control when a certain event occurs.

  13. Turbofan forced mixer-nozzle internal flowfield. Volume 3: A computer code for 3-D mixing in axisymmetric nozzles

    NASA Technical Reports Server (NTRS)

    Kreskovsky, J. P.; Briley, W. R.; Mcdonald, H.

    1982-01-01

    A finite difference method is developed for making detailed predictions of three dimensional subsonic turbulent flow in turbofan lobe mixers. The governing equations are solved by a forward-marching solution procedure which corrects an inviscid potential flow solution for viscous and thermal effects, secondary flows, total pressure distortion and losses, internal flow blockage and pressure drop. Test calculations for a turbulent coaxial jet flow verify that the turbulence model performs satisfactorily for this relatively simple flow. Lobe mixer flows are presented for two geometries typical of current mixer design. These calculations included both hot and cold flow conditions, and both matched and mismatched Mach number and total pressure in the fan and turbine streams.

  14. INTERIOR VIEW OF MIXER LOCATED ON SECOND FLOOR OF BATCH ...

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

    INTERIOR VIEW OF MIXER LOCATED ON SECOND FLOOR OF BATCH PLANT. RECENTLY PURCHASED TO REPLACE OLD MIXER. USED TO MIX THE BATCH - Chambers-McKee Window Glass Company, Batch Plant, Clay Avenue Extension, Jeannette, Westmoreland County, PA

  15. High pressure liquid chromatographic gradient mixer

    DOEpatents

    Daughton, Christian G.; Sakaji, Richard H.

    1985-01-01

    A gradient mixer which effects the continuous mixing of any two miscible solvents without excessive decay or dispersion of the resultant isocratic effluent or of a linear or exponential gradient. The two solvents are fed under low or high pressure by means of two high performance liquid chromatographic pumps. The mixer comprises a series of ultra-low dead volume stainless steel tubes and low dead volume chambers. The two solvent streams impinge head-on at high fluxes. This initial nonhomogeneous mixture is then passed through a chamber packed with spirally-wound wires which cause turbulent mixing thereby homogenizing the mixture with minimum "band-broadening".

  16. 30 GHz monolithic balanced mixers using an ion-implanted FET-compatible 3-inch GaAs wafer process technology

    NASA Technical Reports Server (NTRS)

    Bauhahn, P.; Contolatis, A.; Sokolov, V.; Chao, C.

    1986-01-01

    An all ion-implanted Schottky barrier mixer diode which has a cutoff frequency greater than 1000 GHz has been developed. This new device is planar and FET-compatible and employs a projection lithography 3-inch wafer process. A Ka-band monolithic balanced mixer based on this device has been designed, fabricated and tested. A conversion loss of 8 dB has been measured with a LO drive of 10 dBm at 30 GHz.

  17. Conceptual design study of advanced acoustic-composite nacelles

    NASA Technical Reports Server (NTRS)

    Nordstrom, K. E.; Marsh, A. H.; Sargisson, D. F.

    1975-01-01

    Conceptual studies were conducted to assess the impact of incorporating advanced technologies in the nacelles of a current wide-bodied transport and an advanced technology transport. The improvement possible in the areas of fuel consumption, flyover noise levels, airplane weight, manufacturing costs, and airplane operating cost were evaluated for short and long-duct nacelles. Use of composite structures for acoustic duct linings in the fan inlet and exhaust ducts was considered as well as for other nacelle components. For the wide-bodied transport, the use of a long-duct nacelle with an internal mixer nozzle in the primary exhaust showed significant improvement in installed specific fuel consumption and airplane direct operating costs compared to the current short-duct nacelle. The long-duct mixed-flow nacelle is expected to achieve significant reductions in jet noise during takeoff and in turbo-machinery noise during landing approach. Recommendations were made of the technology development needed to achieve the potential fuel conservation and noise reduction benefits.

  18. A Novel Split-Waveguide Mount Design For MM and SubMM wave frequency multipliers and Harmonic Mixers

    NASA Technical Reports Server (NTRS)

    Raisanen, Anti V.; Choudhury, Debabani; Dengler, Robert J.; Oswald, John E.; Siegel, Peter H.

    1993-01-01

    A novel split-waveguide mount for millimeter and submillimeter wave frequency multipliers and harmonic mixers is presented. It consists of only two pieces, block halves, which are mirror images of each other.

  19. Liquid/Gas Flow Mixers

    NASA Technical Reports Server (NTRS)

    Fabris, Gracio

    1994-01-01

    Improved devices mix gases and liquids into bubbly or foamy flows. Generates flowing, homogeneous foams or homogeneous dispersions of small, noncoalescing bubbles entrained in flowing liquids. Mixers useful in liquid-metal magnetohydrodynamic electric-power generator, froth flotation in mining industry, wastewater treatment, aerobic digestion, and stripping hydrocarbon contaminants from ground water.

  20. Experimental Investigation of a Broadband High-Temperature Superconducting Terahertz Mixer Operating at Temperatures Between 40 and 77 K

    NASA Astrophysics Data System (ADS)

    Gao, Xiang; Du, Jia; Zhang, Ting; Jay Guo, Y.; Foley, Cathy P.

    2017-11-01

    This paper presents a systematic investigation of a broadband thin-film antenna-coupled high-temperature superconducting (HTS) terahertz (THz) harmonic mixer at relatively high operating temperature from 40 to 77 K. The mixer device chip was fabricated using the CSIRO established step-edge YBa2Cu3O7-x (YBCO) Josephson junction technology, packaged in a well-designed module and cooled in a temperature adjustable cryocooler. Detailed experimental characterizations were carried out for the broadband HTS mixer at both the 200 and 600 GHz bands in harmonic mixing mode. The DC current-voltage characteristics (IVCs), bias current condition, local oscillator (LO) power requirement, frequency response, as well as conversion efficiency under different bath temperatures were thoroughly investigated for demonstrating the frequency down-conversion performance.

  1. Applying Hanford Tank Mixing Data to Define Pulse Jet Mixer Operation

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Wells, Beric E.; Bamberger, Judith A.; Recknagle, Kurtis P.

    Pulse jet mixed (PJM) process vessels are being developed for storing, blending, and chemical processing of nuclear waste slurries at the Waste Treatment and Immobilization Plant (WTP) to be built at Hanford, Washington. These waste slurries exhibit variable process feed characteristics including Newtonian to non-Newtonian rheologies over a range of solids loadings. Waste feed to the WTP from the Hanford Tank Farms will be accomplished via the Waste Feed Delivery (WFD) system which includes million-gallon underground storage double-shell tanks (DSTs) with dual-opposed jet mixer pumps. Experience using WFD type jet mixer pumps to mobilize actual Hanford waste in DSTs maymore » be used to establish design threshold criteria of interest to pulse jet mixed process vessel operation. This paper describes a method to evaluate the pulse jet mixed vessel capability to process waste based on information obtained during mobilizing and suspending waste by the WFD system jet mixer pumps in a DST. Calculations of jet velocity and wall shear stress in a specific pulse jet mixed process vessel were performed using a commercial computational fluid dynamics (CFD) code. The CFD-modelled process vessel consists of a 4.9-m- (16-ft-) diameter tank with a 2:1 semi-elliptical head, a single, 10-cm (4-in.) downward facing 60-degree conical nozzle, and a 0.61-m (24-in.) inside diameter PJM. The PJM is located at 70% of the vessel radius with the nozzle stand-off-distance 14 cm (6 in.) above the vessel head. The CFD modeled fluid velocity and wall shear stress can be used to estimate vessel waste-processing performance by comparison to available actual WFD system process data. Test data from the operation of jet mixer pumps in the 23-m (75-ft) diameter DSTs have demonstrated mobilization, solid particles in a sediment matrix were moved from their initial location, and suspension, mobilized solid particles were moved to a higher elevation in the vessel than their initial location, of waste

  2. Modeling emulsification processes in rotary-disk mixers

    NASA Astrophysics Data System (ADS)

    Laponov, S. V.; Shulaev, N. S.; Ivanov, S. P.; Bondar', K. E.; Suleimanov, D. F.

    2017-10-01

    This article presents the experimental studies results of emulsification processes in liquid-liquid systems in rotary-disk mixers, allowing regulating the distribution of dispersed particles by changing the process conditions and the ratio of the dispersed phase. It is shown that with the increase of mixer’s revolutions per minute (RPM), both the size of dispersed particles and the deviation of dispersed particles sizes from the average decrease. The increase of the dispersed particles part results in the increase of particles average sizes at the current energy consumption. Discovered relationships can be used in the design of industrial equipment and laboratory research.

  3. Low-noise and wideband hot-electron superconductive mixer for terahertz frequencies

    NASA Astrophysics Data System (ADS)

    Karasik, Boris S.; Skalare, Anders; McGrath, William R.; Bumble, Bruce; Leduc, Henry G.; Barner, J. B.; Kleinsasser, Alan W.; Burke, P. J.; Schoelkopf, Robert J.; Prober, Daniel E.

    1998-11-01

    Superconductive hot-electron bolometer (HEB) mixers have been built and tested in the frequency range from 1.1 THz to 2.5 THz. The mixer device is a 0.15 - 0.3 micrometer microbridge made from a 10 nm thick Nb film. This device employs diffusion as a cooling mechanism for hot electrons. The double sideband noise temperature was measured to be less than or equal to 3000 K at 2.5 THz and the mixer IF bandwidth is expected to be at least 10 GHz for a 0.1 micrometer long device. The local oscillator (LO) power dissipated in the HEB microbridge was 20 - 100 nW. Further improvement of the mixer characteristics can be potentially achieved by using Al microbridges. The advantages and parameters of such devices are evaluated. The HEB mixer is a primary candidate for ground based, airborne and spaceborne heterodyne instruments at THz frequencies. HEB receivers are planned for use on the NASA Stratospheric Observatory for Infrared Astronomy (SOFIA) and the ESA Far Infrared and Submillimeter Space Telescope (FIRST). The prospects of a submicron-size YBa2Cu3O7-(delta ) (YBCO) HEB are discussed. The expected LO power of 1 - 10 (mu) W and SSB noise temperature of approximately equals 2000 K may make this mixer attractive for various remote sensing applications.

  4. The spurious response of microwave photonic mixer

    NASA Astrophysics Data System (ADS)

    Xiao, Yongchuan; Zhong, Guoshun; Qu, Pengfei; Sun, Lijun

    2018-02-01

    Microwave photonic mixer is a potential solution for wideband information systems due to the ultra-wide operating bandwidth, high LO-to-RF isolation, the intrinsic immunity to electromagnetic interference, and the compatibility with exsiting microwave photonic transmission systems. The spurious response of microwave photonic mixer cascading in series a pair of Mach-Zehnder interferometric intensity modulators has been simulated and analyzed in this paper. The low order spurious products caused by the nonlinearity of modulators are non-negligible, and the proper IF frequency and accurate bias-controlling are of great importance to mitigate the impact of spurious products.

  5. Axial static mixer

    DOEpatents

    Sandrock, H.E.

    1982-05-06

    Static axial mixing apparatus includes a plurality of channels, forming flow paths of different dimensions. The axial mixer includes a flow adjusting device for adjustable selective control of flow resistance of various flow paths in order to provide substantially identical flows through the various channels, thereby reducing nonuniform coating of interior surfaces of the channels. The flow adjusting device may include diaphragm valves, and may further include a pressure regulating system therefor.

  6. Sound suppression mixer

    NASA Technical Reports Server (NTRS)

    Brown, William H. (Inventor)

    1994-01-01

    A gas turbine engine flow mixer includes at least one chute having first and second spaced apart sidewalls joined together at a leading edge, with the sidewalls having first and second trailing edges defining therebetween a chute outlet. The first trailing edge is spaced longitudinally downstream from the second trailing edge for defining a septum in the first sidewall extending downstream from the second trailing edge. The septum includes a plurality of noise attenuating apertures.

  7. Improvement of mass transfer characteristics and productivities of inclined tubular photobioreactors by installation of internal static mixers.

    PubMed

    Ugwu, C U; Ogbonna, J C; Tanaka, H

    2002-04-01

    The feasibility of improving mass transfer characteristics of inclined tubular photobioreactors by installation of static mixers was investigated. The mass transfer characteristics of the tubular photobioreactor varied depending on the type (shape) and the number of static mixers. The volumetric oxygen transfer coefficient ( k(L)a) and gas hold up of the photobioreactor with internal static mixers were significantly higher than those of the photobioreactor without static mixers. The k(L)a and gas hold up increased with the number of static mixers but the mixing time became longer due to restricted liquid flow through the static mixers. By installing the static mixers, the liquid flow changed from plug flow to turbulent mixing so that cells were moved between the surface and bottom of the photobioreactor. In outdoor culture of Chlorella sorokiniana, the photobioreactor with static mixers gave higher biomass productivities irrespective of the standing biomass concentration and solar radiation. The effectiveness of the static mixers (average percentage increase in the productivities of the photobioreactor with static mixers over the productivities obtained without static mixers) was higher at higher standing biomass concentrations and on cloudy days (solar radiation below 6 MJ m(-2) day(-1)).

  8. Numerical Investigation on Aerodynamic and Combustion Performance of Chevron Mixer Inside an Afterburner.

    PubMed

    Yong, Shan; JingZhou, Zhang; Yameng, Wang

    2014-11-01

    To improve the performance of the afterburner for the turbofan engine, an innovative type of mixer, namely, the chevron mixer, was considered to enhance the mixture between the core flow and the bypass flow. Computational fluid dynamics (CFD) simulations investigated the aerodynamic performances and combustion characteristics of the chevron mixer inside a typical afterburner. Three types of mixer, namely, CC (chevrons tilted into core flow), CB (chevrons tilted into bypass flow), and CA (chevrons tilted into core flow and bypass flow alternately), respectively, were studied on the aerodynamic performances of mixing process. The chevrons arrangement has significant effect on the mixing characteristics and the CA mode seems to be advantageous for the generation of the stronger streamwise vortices with lower aerodynamic loss. Further investigations on combustion characteristics for CA mode were performed. Calculation results reveal that the local temperature distribution at the leading edge section of flame holder is improved under the action of streamwise vortices shedding from chevron mixers. Consequently, the combustion efficiency increased by 3.5% compared with confluent mixer under the same fuel supply scheme.

  9. Topics in the optimization of millimeter-wave mixers

    NASA Technical Reports Server (NTRS)

    Siegel, P. H.; Kerr, A. R.; Hwang, W.

    1984-01-01

    A user oriented computer program for the analysis of single-ended Schottky diode mixers is described. The program is used to compute the performance of a 140 to 220 GHz mixer and excellent agreement with measurements at 150 and 180 GHz is obtained. A sensitivity analysis indicates the importance of various diode and mount characteristics on the mixer performance. A computer program for the analysis of varactor diode multipliers is described. The diode operates in either the reverse biased varactor mode or with substantial forward current flow where the conversion mechanism is predominantly resistive. A description and analysis of a new H-plane rectangular waveguide transformer is reported. The transformer is made quickly and easily in split-block waveguide using a standard slitting saw. It is particularly suited for use in the millimeter-wave band, replacing conventional electroformed stepped transformers. A theoretical analysis of the transformer is given and good agreement is obtained with measurements made at X-band.

  10. Superconducting terahertz mixer using a transition-edge microbolometer

    NASA Technical Reports Server (NTRS)

    Prober, D. E.

    1993-01-01

    We present a new device concept for a mixer element for THz frequencies. This uses a superconducting transition-edge microbridge biased at the center of its superconducting transition near 4.2 K. It is fed from an antenna or waveguide structure. Power from a local oscillator and an RF signal produce a temperature and resulting resistance variation at the difference frequency. The new aspect is the use of a very short bridge in which rapid (less than 0.1 ns) outdiffusion of hot electrons occurs. This gives large intermediate frequency (IF) response. The mixer offers about 4 GHz IF bandwidth, about 80 ohm RF resistive impedance, good match to the IF amplifier, and requires only 1-20 nW of local oscillator power. The upper RF frequency is determined by antenna or waveguide properties. Predicted mixer conversion efficiency is 1/8, and predicted double-sideband receiver noise temperatures are 260 and 90 K for transition widths of 0.1 and 0.5 Tc, respectively.

  11. Qualification test of the Ross Double Planetary Mixer

    NASA Technical Reports Server (NTRS)

    Lueders, Kurt F.

    1993-01-01

    This test report describes the qualification test of the Ross Double Planetary Mixer used to mix room temperature vulcanized (RTV) silicone (Dow Corning 90-006-2) for the redesigned solid rocket motor (RSRM) nozzle joints. Testing was completed 18 June 1993 in the M-113A Nozzle Fabrication Facility at Thiokol Corporation, Space Operations, Brigham City, Utah. The Ross mixer provides better mixing and better control on temperature and humidity, resulting in better quality RTV and a longer usable pot life. The test began on 3 May 1993 and was stopped due to operator error during the tensile strength and elongation testing. Specimens were ruined without gathering any useful data. A 'no test' was declared, the problem was remedied, and the test was re-run with MSFC approval. The test was run and all pass/fail criteria were met, most with a considerable margin. The Ross Double Planetary Mixer met all certification objectives and is recommended for immediate use for mixing RTV silicone for RSRM nozzle joints.

  12. Wide-band operation of quasi-optical distributed superconductor/insulator/superconductor mixers with epitaxial NbN/AlN/NbN junctions

    NASA Astrophysics Data System (ADS)

    Kohjiro, S.; Shitov, S. V.; Wang, Z.; Uzawa, Y.; Miki, S.; Kawakami, A.; Shoji, A.

    2004-05-01

    For the optimum design of integrated receivers operating above the gap frequency of Nb, we have designed, fabricated and tested NbN-based quasi-optical superconductor/insulator/superconductor (SIS) mixers. The mixer chip incorporates a resonant half-wavelength epitaxial NbN/AlN/NbN junction, a twin-slot antenna and their coupling circuits. We adopted two kinds of coupling circuit between the antenna and the SIS junction: one is an in-phase feed with a length of 95 µm and the other is an anti-phase feed of 30 µm length. It was found that the anti-phase mixer reveals a 3 dB bandwidth of 43% of the centre frequency; the uncorrected double-sideband receiver noise temperature TRX = 691 K at 0.91 THz and TRX = 844 K at 0.80 THz, while 17% and TRX = 1250 K at 0.79 THz for the in-phase version. Possible reasons for this difference are discussed, which could be transmission loss and its robustness with respect to the variation of junction parameters. These experimental results suggest the NbN-based distributed mixer with the anti-phase feed is a better candidate for wide-band integrated receivers operating above 0.7 THz.

  13. Airfoil-shaped micro-mixers for reducing fouling on membrane surfaces

    DOEpatents

    Ho, Clifford K; Altman, Susan J; Clem, Paul G; Hibbs, Michael; Cook, Adam W

    2012-10-23

    An array of airfoil-shaped micro-mixers that enhances fluid mixing within permeable membrane channels, such as used in reverse-osmosis filtration units, while minimizing additional pressure drop. The enhanced mixing reduces fouling of the membrane surfaces. The airfoil-shaped micro-mixer can also be coated with or comprised of biofouling-resistant (biocidal/germicidal) ingredients.

  14. A novel in-plane passive microfluidic mixer with modified Tesla structures.

    PubMed

    Hong, Chien-Chong; Choi, Jin-Woo; Ahn, Chong H

    2004-04-01

    An innovative in-plane passive micromixer using modified Tesla structures, which are used as passive valves, has been designed, simulated, fabricated and successfully characterized in this paper. Simulation and experimental results of the developed novel micromixer have shown excellent mixing performance over a wide range of flow conditions in the micro scale. The micromixer realized in this work has achieved even better mixing performance at a higher flow rate, and its pressure drop is less than 10 KPa at the flow rate of 100 microl min(-1). This micromixer shows characteristics similar to Taylor dispersion, with contributions from both diffusion and convection. The mixer has a diffusion domain region at low flow rate, but it moves to a convection domain region at high flow rate. Due to the simple in-plane structure of the novel micromixer explored in this work, the mixer can be easily realized and integrated with on-chip microfluidic devices and micro total analysis systems (micro-TAS).

  15. Reduced T(sub c) Niobium Superconducting HEB Mixers

    NASA Technical Reports Server (NTRS)

    Siddiqi, I.; Prober, D. E.; Bumble, B.; LeDuc, H. G.

    2001-01-01

    A reduction in the mixer noise is expected when using superconductors with a lower transition temperature (T(sub c)) since the thermal noise components of the mixer noise should scale with T(sub c). Also, the local oscillator (LO) power required for a diffusion-cooled device should decrease as T(sub c) when T(sub bath) << T(sub c). We previously studied mixing in aluminum based hot-electron bolometers (HEBs) at microwave frequencies (approximately 30 GHz), and observed a significant improvement in noise performance, and a reduction in LO power as predicted. However, the bias voltage range over which good mixer performance was observed was approximately 5 - 10 microV. These devices are thus susceptible to saturation effects, in particular output saturation. In the present work, we have investigated Nb HEBs whose T(sub c) is lowered by applying a magnetic field. The goal is to study a case intermediate between Nb and Al, and hopefully to find properties that will allow use in practical receivers. A 15 kOe perpendicular magnetic field was applied to a Nb HEB (L = 0.16 micrometers, W = 0.08 micrometers, R(sub N) = 90 ohms) to reduce T(sub c) from 5.2 K to 2.4 K. The mixer noise, as inferred from the output noise and the conversion efficiency, decreased from 390 K, DSB to 171 K, DSB. The LO power required for near optimum mixer conversion efficiency (eta(sub mixer) = -9 dB in this device) was 8 nW in zero field, and approximately 2 nW when T(sub c) was reduced to 2.4 K. T(sub bath) = 0.22 K. The conversion bandwidth was previously measured to be 2.4 GHz and the same bandwidth was observed in the presence of a magnetic field. By lowering T(sub c), the voltage range over which good mixing was observed also decreased. However, even with T(sub c) reduced to 2.4 K, the conversion efficiency dropped by 3 dB from its maximum value only when the bias voltage was changed by approximately 90 microV. Saturation effects should thus be much less of a concern in these devices than in

  16. Conversion loss and noise of microwave and millimeter-wave mixers. I - Theory. II - Experiment

    NASA Technical Reports Server (NTRS)

    Held, D. N.; Kerr, A. R.

    1978-01-01

    The conversion loss and noise of microwave and millimeter-wave mixers are analyzed. Nonlinear capacitance, arbitrary embedding impedances, as well as shot, thermal and scattering noise arising in the diode, figure in the analysis. The anomalous mixer noise noted in millimeter-wave mixers by Kerr (1975) is shown to be explainable in terms of the correlation of down-converted components of the time-varying shot noise. A digital computer analysis of the conversion loss, noise, and output impedance of an 80-120-GHz mixer is also conducted.

  17. Quasi-Optical SIS Mixer Development

    NASA Technical Reports Server (NTRS)

    Zmuidzinas, J.

    1997-01-01

    This grant supported our ongoing development of sensitive quasi-optical SIS mixers for the submillimeter band. The technology developed under this grant is now being applied to NASA missions, including the NASA/USRA SOFIA airborne observatory and and the ESA/NASA FIRST/Herschel space astronomy mission.

  18. Matlab GUI for a Fluid Mixer

    NASA Technical Reports Server (NTRS)

    Barbieri, Enrique

    2005-01-01

    The Test and Engineering Directorate at NASA John C. Stennis Space Center developed an interest to study the modeling, evaluation, and control of a liquid hydrogen (LH2) and gas hydrogen (GH2) mixer subsystem of a ground test facility. This facility carries out comprehensive ground-based testing and certification of liquid rocket engines including the Space Shuttle Main engine. A software simulation environment developed in MATLAB/SIMULINK (M/S) will allow NASA engineers to test rocket engine systems at relatively no cost. In the progress report submitted in February 2004, we described the development of two foundation programs, a reverse look-up application using various interpolation algorithms, a variety of search and return methods, and self-checking methods to reduce the error in returned search results to increase the functionality of the program. The results showed that these efforts were successful. To transfer this technology to engineers who are not familiar with the M/S environment, a four-module GUI was implemented allowing the user to evaluate the mixer model under open-loop and closed-loop conditions. The progress report was based on an udergraduate Honors Thesis by Ms. Jamie Granger Austin in the Department of Electrical Engineering and Computer Science at Tulane University, during January-May 2003, and her continued efforts during August-December 2003. In collaboration with Dr. Hanz Richter and Dr. Fernando Figueroa we published these results in a NASA Tech Brief due to appear this year. Although the original proposal in 2003 did not address other components of the test facility, we decided in the last few months to extend our research and consider a related pressurization tank component as well. This report summarizes the results obtained towards a Graphical User Interface (GUI) for the evaluation and control of the hydrogen mixer subsystem model and for the pressurization tank each taken individually. Further research would combine the two

  19. Noise Reduction with Lobed Mixers: Nozzle-Length and Free-Jet Speed Effects

    NASA Technical Reports Server (NTRS)

    Mengle, Vinod G.; Dalton, William N.; Bridges, James C.; Boyd, Kathy C.

    1997-01-01

    Acoustic test results are presented for 1/4th-scaled nozzles with internal lobed mixers used for reduction of subsonic jet noise of turbofan engines with bypass ratio above 5 and jet speeds up to 830 ft/s. One coaxial and three forced lobe mixers were tested with variations in lobe penetration, cut-outs in lobe-sidewall, lobe number and nozzle-length. Measured exit flow profiles and thrusts are used to assist the inferences from acoustic data. It is observed that lobed mixers reduce the low-frequency noise due to more uniformly mixed exit flow; but they may also increase the high-frequency noise at peak perceived noise (PNL) angle and angles upstream of it due to enhanced mixing inside the nozzle. Cut-outs and low lobe penetration reduce the annoying portion of the spectrum but lead to less uniform exit flow. Due to the dominance of internal duct noise in unscalloped, high-penetration mixers their noise is not reduced as much with increase in free-jet speed as that of coaxial or cut-out lobed mixers. The latter two mixers also show no change in PNL over the wide range of nozzle-lengths tested because most of their noise sources are outside the nozzle; whereas, the former show an increase in noise with decrease in nozzle-length.

  20. Development of a Liner Design Methodology and Relevant Results of Acoustic Suppression in the Farfield for Mixer-Ejector Nozzles

    NASA Technical Reports Server (NTRS)

    Salikuddin, M.

    2006-01-01

    We have developed a process to predict noise field interior to the ejector and in the farfield for any liner design for a mixer-ejector of arbitrary scale factor. However, a number of assumptions, not verified for the current application, utilized in this process, introduce uncertainties in the final result, especially, on a quantitative basis. The normal impedance model for bulk with perforated facesheet is based on homogeneous foam materials of low resistivity. The impact of flow conditions for HSCT application as well as the impact of perforated facesheet on predicted impedance is not properly accounted. Based on the measured normal impedance for deeper bulk samples (i.e., 2.0 in.) the predicted reactance is much higher compared to the data at frequencies above 2 kHz for T-foam and 200 ppi SiC. The resistance is under predicted at lower frequencies (below 4 kHz) for these samples. Thus, the use of such predicted data in acoustic suppression is likely to introduce inaccuracies. It should be noted that the impedance prediction methods developed recently under liner technology program are not utilized in the studies described in this report due to the program closeout. Acoustic suppression prediction is based on the uniform flow and temperature conditions in a two-sided treated constant area rectangular duct. In addition, assumptions of equal energy per mode noise field and interaction of all frequencies with the treated surface for the entire ejector length may not be accurate. While, the use of acoustic transfer factor minimizes the inaccuracies associated with the prediction for a known test case, the assumption of the same factor for other liner designs and with different linear scale factor ejectors seems to be very optimistic. As illustrated in appendix D that the predicted noise suppression for LSM-1 is lower compared to the measured data is an indication of the above argument. However, the process seems to be more reliable when used for the same scale

  1. Complex modeling of technological processes in pneumatic mixers for production of dry construction mixtures

    NASA Astrophysics Data System (ADS)

    Orekhova, T. N.; Nosov, O. A.; Prokopenko, V. S.; Kachaev, A. E.

    2018-03-01

    The improvement of the design of the pneumatic mixers aimed at the possibility of obtaining homogeneous disperse systems, while the resource and energy saving issues play an important role in the conditions of enterprises that use this type of equipment in their technological chain, is described in the article.

  2. Self-anchoring mast for deploying a high-speed submersible mixer in a tank

    DOEpatents

    Cato, Jr., Joseph E.; Shearer, Paul M [Aiken, SC; Rodwell, Philip O [Evans, GA

    2004-10-12

    A self-anchoring mast for deploying a high-speed submersible mixer in a tank includes operably connected first and second mast members (20, 22) and a foot member 46 operably connected to the second mast member for supporting the mast in a tank. The second mast member includes a track (36, 38) for slidably receiving a bearing of the mixer to change the orientation of the mixer in the tank.

  3. Compact terahertz passive spectrometer with wideband superconductor-insulator-superconductor mixer.

    PubMed

    Kikuchi, K; Kohjiro, S; Yamada, T; Shimizu, N; Wakatsuki, A

    2012-02-01

    We developed a compact terahertz (THz) spectrometer with a superconductor-insulator-superconductor (SIS) mixer, aiming to realize a portable and highly sensitive spectrometer to detect dangerous gases at disaster sites. The receiver cryostat which incorporates the SIS mixer and a small cryocooler except for a helium compressor has a weight of 27 kg and dimensions of 200 mm × 270 mm × 690 mm. In spite of the small cooling capacity of the cryocooler, the SIS mixer is successfully cooled lower than 4 K, and the temperature variation is suppressed for the sensitive measurement. By adopting a frequency sweeping system using photonic local oscillator, we demonstrated a spectroscopic measurement of CH(3)CN gas in 0.2-0.5 THz range.

  4. Tank 241-AZ-101 Mixer Pump Test Vapor Sampling and Analysis Plan

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    TEMPLETON, A.M.

    2000-03-06

    This sampling and analysis plan (SAP) identifies characterization objectives pertaining to sample collection, laboratory analytical evaluation, and reporting requirements for vapor samples obtained during the operation of mixer pumps in tank 241-AZ-101. The primary purpose of the mixer pump test (MPT) is to demonstrate that the two 300 horsepower mixer pumps installed in tank 241-AZ-101 can mobilize the settled sludge so that it can be retrieved for treatment and vitrification. Sampling will be performed in accordance with Tank 241-AZ-101 Mixer Pump Test Data Quality Objective (Banning 1999) and Data Quality Objectives for Regulatory Requirements for Hazardous and Radioactive Air Emissionsmore » Sampling and Analysis (Mulkey 1999). The sampling will verify if current air emission estimates used in the permit application are correct and provide information for future air permit applications.« less

  5. Tank 241-AZ-101 Mixer Pump Test Vapor Sampling and Analysis Plan

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    TEMPLETON, A.M.

    2000-01-31

    This sampling and analysis plan (SAP) identifies characterization objectives pertaining to sample collection, laboratory analytical evaluation, and reporting requirements for vapor samples obtained during the operation of mixer pumps in tank 241-AZ-101. The primary purpose of the mixer pump test (MPT) is to demonstrate that the two 300 horsepower mixer pumps installed in tank 241-AZ-101 can mobilize the settled sludge so that it can be retrieved for treatment and vitrification Sampling will be performed in accordance with Tank 241-AZ-101 Mixer Pump Test Data Quality Objective (Banning 1999) and Data Quality Objectives for Regulatory Requirements for Hazardous and Radioactive Air Emissionsmore » Sampling and Analysis (Mulkey 1999). The sampling will verify if current air emission estimates used in the permit application are correct and provide information for future air permit applications.« less

  6. Tank 241-AZ-101 Mixer Pump Test Vapor Sampling and Analysis Plan

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    TEMPLETON, A.M.

    2000-04-10

    This sampling and analysis plan (SAP) identifies characterization objectives pertaining to sample collection, laboratory analytical evaluation, and reporting requirements for vapor samples obtained during the operation of mixer pumps in tank 241-AZ-101. The primary purpose of the mixer pump test (MPT) is to demonstrate that the two 300 horsepower mixer pumps installed in tank 241-AZ-101 can mobilize the settled sludge so that it can be retrieved for treatment and vitrification. Sampling will be performed in accordance with Tank 241-AZ-101 Mixer Pump Test Data Quality Objective (Banning 1999) and Data Quality Objectives for Regulatory Requirements for Hazardous and Radioactive Air Emissionsmore » Sampling and Analysis (Mulkey 1999). The sampling will verify if current air emission estimates used in the permit application are correct and provide information for future air permit applications.« less

  7. 180-GHz I-Q Second Harmonic Resistive Mixer MMIC

    NASA Technical Reports Server (NTRS)

    Kangaslahti, Pekka P.; Lai, Richard; Mei, Xiaobing

    2010-01-01

    An indium phosphide MMIC (monolithic microwave integrated circuit) mixer was developed, processed, and tested in the NGC 35-nm-gate-length HEMT (high electron mobility transistor) process. This innovation is very compact in size and operates with very low LO power. Because it is a resistive mixer, this innovation does not require DC power. This is an enabling technology for the miniature receiver modules for the GeoSTAR instrument, which is the only viable option for the NRC decadal study mission PATH.

  8. Low Noise in a Diffusion-Cooled Hot-Electron Mixer at 2.5 THz

    NASA Technical Reports Server (NTRS)

    Karasik, B. S.; Gaidis, M. C.; McGrath, W. R.; Bumble, B.; LeDuc, H. G.

    1997-01-01

    The noise performance of a Nb hot-electron bolometer mixer at 2.5 THz has been investigated. The devices are fabricated from a 12-nm-thick Nb film, and have a 0.30 micrometer x 0.15 micrometer in-plane size, thus exploiting diffusion as the electron cooling mechanism. The rf coupling was provided by a twin-slot planar antenna on an elliptical Si lens. The experimentally measured double sideband noise temperature of the receiver was as low as 2750 +/- 250 K with an estimated mixer noise temperature of approximately equal 900 K. The mixer bandwidth derived from both noise bandwidth and IF impedance measurements was approximately equal 1.4 GHz. These results demonstrate the low-noise operation of the diffusion-cooled bolometer mixer above 2 THz.

  9. BIB mixers

    NASA Technical Reports Server (NTRS)

    1995-01-01

    We have determined that the multi-pin 'microprocessor style' packages in which current Blocked Impurity Band (BIB) devices are mounted will not meet our IF bandwidth spec of greater than 2 GHz for a practical mixer. Hence we have started to repackage the Ga:Ge BIB devices in new microwave compatible packages. The smaller size of the microwave package mount necessitates cutting the BIB array down to include only the 3 smallest detectors: 0.2, 0.4, and 0.6 mm sq. A FIR beam incident at f/1.5 can be focussed on the smallest element for wavelengths shorter than 100 microns. A more typical (easier) beam convergence of f/3 will require 0.4 mm elements at 100 microns and 0.6 mm elements at 170 microns wavelength. Since the device capacitance (parasitic loss) scales with detector size, there is a tradeoff of speed of response and optical convenience. Our existing optics produce only the slower convergence beam, so we need to redesign the optical layout and are looking at long focal length all-reflective microscope objectives. BIB detectors and the edge-coupled microbolometers have restricted IF bandwidths, an order of magnitude less than what is possible with the Schottky-diode mixers we currently use for astronomical observations. Consequently the frequencies of the FIR laser lines must be close to the astronomical line of interest to be an effective Local Oscillator (LO). We have therefore begun a coordinated effort to discover and measure new FIR laser transition lines in close frequency coincidence with important astrophysical lines. Most of this effort involves pumping isotopic variants of known good laser molecules with laser lines from isotopic variants of CO2. We have been most successful in detecting new FIR lines in deuterated ammonia. One line in particular is very close to the frequency of HD rotational line at 2675 GHz.

  10. Submersible canned motor mixer pump

    DOEpatents

    Guardiani, Richard F.; Pollick, Richard D.

    1997-01-01

    A mixer pump used in a waste tank for mobilizing high-level radioactive liquid waste having a column assembly containing power cables, a motor housing with electric motor means which includes a stator can of a stator assembly and a rotor can of a rotor assembly, and an impeller assembly with an impeller connected to a shaft of the rotor assembly. The column assembly locates the motor housing with the electric motor means adjacent to the impeller which creates an hydraulic head, and which forces the liquid waste into the motor housing to cool the electric motor means and to lubricate radial and thrust bearing assemblies. Hard-on-hard bearing surfaces of the bearing assemblies and a ring assembly between the impeller and electric motor means act to grind down large particles in the liquid waste flow. These larger particles are received in slots in the static bearing members of the radial bearing assemblies. Only solid waste particles smaller than the clearances in the system can pass therethrough, thereby resisting damage to and the interruption of the operation of the mixer pump.

  11. Superconducting Mixers for Far-Infrared Spectroscopy

    NASA Technical Reports Server (NTRS)

    Betz, A. L.; Boreiko, R. T.; Grossman, E. R.; Reintsema, C. D.; Ono, R. H.; Gerecht, E.

    2002-01-01

    The goal of this project was to fabricate and test planar arrays of superconducting mixers for the 2-6 THz band. The technology is intended for multi-beam receivers aboard Explorer-class missions and the SOFIA Airborne Observatory. The mixer technology is the superconducting transition-edge microbolometer, which is more commonly known as the Hot-Electron micro-Bolometer (HEB). As originally proposed, two superconducting technologies were to be developed: (1) low-Tc niobium HEBs which could approach quantum-noise-limited sensitivities but require cooling to 2- 4 K, and (2) high-Tc YBCO HEBs with sensitivities 10 times worse but with a relaxed cooling requirement of 30-60 K. The low-Tc devices would be best for astronomy applications on SOFIA, whereas the high-Tc devices would be more suitable for planetary missions using systems without stored cryogens. The work plan called for planar micro-fabrication and initial testing of HEB devices at the NIST Boulder clean-room facility. Subsequent assembly and RF testing of selected devices would be done at the CASA laboratory at U. Colorado. Approximately 1-year after work began on this project, Dr. Eyal Gerecht joined the NIST group, and assumed day-to-day responsibility for Nb-HEB development at NIST outside of micro-fabrication. The YBCO-HEB work was to be guided by Dr. Ron Ono, who was the NIST expert in YBCO technology. Unfortunately, recurrent health problems limited the time Ron could devote to the project in its first year. These problems became aggravated in early 2001, and sadly led to Ron's death in October, 2001. His loss was not only a blow to his friends and associates at NIST, but was mounted by the US superconductivity community at large. With his passing, work on high-Tc HEBs ceased at NIST. There was no one to replace him or his expertise. Our work subsequently shifted solely to Nb-HEB devices. In the sections which follow, our progress in the development of diffusion-cooled Nb-HEB mixers is detailed. To

  12. A microfluidic chaotic mixer platform for cancer stem cell immunocapture and release

    NASA Astrophysics Data System (ADS)

    Shaner, Sebastian Wesley

    Isolation of exceedingly rare and ambiguous cells, like cancer stem cells (CSCs), from a pool of other abundant cells is a daunting task primarily due to the inadequately defined properties of such cells. With phenotypes of different CSCs fairly well-defined, immunocapturing of CSCs is a desirable cell-specific capture technique. A microfluidic device is a proven candidate that offers the platform for user-constrained microenvironments that can be optimized for small-scale volumetric flow experimentation. In this study, we show how a well-known passive micromixer design (staggered herringbone mixer - SHM) can be optimized to induce maximum chaotic mixing within antibody-laced microchannels and, ultimately, promote CSC capture. The device's (Cancer Stem Cell Capture Chip - CSC3 (TM)) principle design configuration is called: Single-Walled Staggered Herringbone (SWaSH). The CSC3 (TM) was constructed of a polydimethylsiloxane (PDMS) foundation and thinly coated with an alginate hydrogel derivatized with streptavidin. The results of our work showed that the non-stickiness of alginate and antigen-specific antibodies allowed for superb target-specific cell isolation and negligible non-specific cell binding. Future engineering design directions include developing new configurations (e.g. Staggered High-Low Herringbone (SHiLoH) and offset SHiLoH) to optimize microvortex generation within the microchannels. This study's qualitative and quantitative results can help stimulate progress into refinements in device design and prospective advancements in cancer stem cell isolation and more comprehensive single-cell and cluster analysis.

  13. AZ-101 Mixer Pump Test Qualification Test Procedures (QTP)

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    THOMAS, W.K.

    2000-01-10

    Describes the Qualification test procedure for the AZ-101 Mixer Pump Data Acquisition System (DAS). The purpose of this Qualification Test Procedure (QTP) is to confirm that the AZ-101 Mixer Pump System has been properly programmed and hardware configured correctly. This QTP will test the software setpoints for the alarms and also check the wiring configuration from the SIMcart to the HMI. An Acceptance Test Procedure (ATP), similar to this QTP will be performed to test field devices and connections from the field.

  14. Turbofan forced mixer-nozzle internal flowfield. Volume 1: A benchmark experimental study

    NASA Technical Reports Server (NTRS)

    Paterson, R. W.

    1982-01-01

    An experimental investigation of the flow field within a model turbofan forced mixer nozzle is described. Velocity and thermodynamic state variable data for use in assessing the accuracy and assisting the further development of computational procedures for predicting the flow field within mixer nozzles are provided. Velocity and temperature data suggested that the nozzle mixing process was dominated by circulations (secondary flows) of a length scale on the order the lobe dimensions which were associated with strong radial velocities observed near the lobe exit plane. The 'benchmark' model mixer experiment conducted for code assessment purposes is discussed.

  15. Comparison of measured and predicted performance of a SIS waveguide mixer at 345 GHz

    NASA Technical Reports Server (NTRS)

    Honingh, C. E.; Delange, G.; Dierichs, M. M. T. M.; Schaeffer, H. H. A.; Wezelman, J.; Vandekuur, J.; Degraauw, T.; Klapwijk, T. M.

    1992-01-01

    The measured gain and noise of a SIS waveguide mixer at 345 GHz have been compared with theoretical values, calculated from the quantum mixer theory using a three port model. As a mixing element, we use a series array of two Nb-Al2O3-Nb SIS junctions. The area of each junction is 0.8 sq microns and the normal state resistance is 52 omega. The embedding impedance of the mixer has been determined from the pumped DC-IV curves of the junction and is compared to results from scale model measurements (105 x). Good agreement was obtained. The measured mixer gain, however, is a factor of 0.45 plus or minus 0.5 lower than the theoretical predicted gain. The measured mixer noise temperature is a factor of 4-5 higher than the calculated one. These discrepancies are independent on pump power and are valid for a broad range of tuning conditions.

  16. Influence of Geometry and Flow Variations on NO Formation in the Quick Mixer of a Staged Combustor

    NASA Technical Reports Server (NTRS)

    Hatch, M. S.; Sowa, W. A.; Samuelsen, G. S.; Holdeman, J. D.

    1995-01-01

    Staged combustion, such as Rich-Burn/Quick-Mix/Lean-Burn (RQL), is a viable strategy to meet nitric oxide (NO) emission goals for both stationary and propulsion gas turbine engines. A critical element of the design is the quick mixer section where the potential for NO production is high. While numerical calculations of the quick mixer under reacting conditions have been conducted, the hostile environment and lack of appropriate diagnostics have, to date, precluded experimental probing of the reacting case. As an alternative to understanding the effect of geometry and flow variations on the production of NO in the quick mixer, the present paper presents (1) a series of non-reacting parametric studies, and (2) a computational method to extrapolate the results of the non-reacting experiments to reacting conditions. The results show that the rate of NO production is highest in the immediate vicinity of the injection plane. For a given momentum flux ratio between the jets and mainstream, the most effective mixing geometry is that which mixes effectively in both (1) the plane of injection, and (2) the wall regions downstream of the plan of injection. The tailoring of the mixing is key to minimize the NO formed. As a result, the best overall mixer with respect to the minimization of NO production may depend on the system specific characteristics of the particular application.

  17. Development of SIS Mixers for 1 THz

    NASA Technical Reports Server (NTRS)

    Zmuidzinas, J.; Kooi, J.; Chattopadhyay, G.; Bumble, B.; LeDuc, H. G.; Stern, J. A.

    1998-01-01

    SIS heterodyne mixer technology based on niobium tunnel junctions has now been pushed to frequencies over 1 THz, clearly demonstrating that the SIS junctions are capable of mixing at frequencies up to twice the energy gap frequency (4 Delta/h). However, the performance degrades rapidly above the gap frequency of niobium (2 Delta/h approx. 700 GHz) due to substantial ohmic losses in the on-chip tuning circuit. To solve this problem, the tuning circuit should be fabricated using a superconducting film with a larger energy gap, such as NbN; unfortunately, NbN films often have a substantial excess surface resistance in the submillimeter band. In contrast, the SIS mixer measurements we present in this paper indicate that the losses for NbTiN thin films can be quite low.

  18. Making Wide-IF SIS Mixers with Suspended Metal-Beam Leads

    NASA Technical Reports Server (NTRS)

    Kaul, Anupama; Bumble, Bruce; Lee, Karen; LeDuc, Henry; Rice, Frank; Zmuidzinas, Jonas

    2005-01-01

    A process that employs silicon-on-insulator (SOI) substrates and silicon (Si) micromachining has been devised for fabricating wide-intermediate-frequency-band (wide-IF) superconductor/insulator/superconductor (SIS) mixer devices that result in suspended gold beam leads used for radio-frequency grounding. The mixers are formed on 25- m-thick silicon membranes. They are designed to operate in the 200 to 300 GHz frequency band, wherein wide-IF receivers for tropospheric- chemistry and astrophysical investigations are necessary. The fabrication process can be divided into three sections: 1. The front-side process, in which SIS devices with beam leads are formed on a SOI wafer; 2. The backside process, in which the SOI wafer is wax-mounted onto a carrier wafer, then thinned, then partitioned into individual devices; and 3. The release process, in which the individual devices are separated using a lithographic dicing technique. The total thickness of the starting 4-in. (10.16-cm)-diameter SOI wafer includes 25 m for the Si device layer, 0.5 m for the buried oxide (BOX) layer, and 350 m the for Si-handle layer. The front-side process begins with deposition of an etch-stop layer of SiO2 or AlN(x), followed by deposition of a Nb/Al- AlN(x) /Nb trilayer in a load-locked DC magnetron sputtering system. The lithography for four of a total of five layers is performed in a commercial wafer-stepping apparatus. Diagnostic test dies are patterned concurrently at certain locations on the wafer, alongside the mixer devices, using a different mask set. The conventional, self-aligned lift-off process is used to pattern the SIS devices up to the wire level.

  19. Turbofan forced mixer lobe flow modeling. 1: Experimental and analytical assessment

    NASA Technical Reports Server (NTRS)

    Barber, T.; Paterson, R. W.; Skebe, S. A.

    1988-01-01

    A joint analytical and experimental investigation of three-dimensional flowfield development within the lobe region of turbofan forced mixer nozzles is described. The objective was to develop a method for predicting the lobe exit flowfield. In the analytical approach, a linearized inviscid aerodynamical theory was used for representing the axial and secondary flows within the three-dimensional convoluted mixer lobes and three-dimensional boundary layer analysis was applied thereafter to account for viscous effects. The experimental phase of the program employed three planar mixer lobe models having different waveform shapes and lobe heights for which detailed measurements were made of the three-dimensional velocity field and total pressure field at the lobe exit plane. Velocity data was obtained using Laser Doppler Velocimetry (LDV) and total pressure probing and hot wire anemometry were employed to define exit plane total pressure and boundary layer development. Comparison of data and analysis was performed to assess analytical model prediction accuracy. As a result of this study a planar mixed geometry analysis was developed. A principal conclusion is that the global mixer lobe flowfield is inviscid and can be predicted from an inviscid analysis and Kutta condition.

  20. Implementation of an optimized microfluidic mixer in alumina employing femtosecond laser ablation

    NASA Astrophysics Data System (ADS)

    Juodėnas, M.; Tamulevičius, T.; Ulčinas, O.; Tamulevičius, S.

    2018-01-01

    Manipulation of liquids at the lowest levels of volume and dimension is at the forefront of materials science, chemistry and medicine, offering important time and resource saving applications. However, manipulation by mixing is troublesome at the microliter and lower scales. One approach to overcome this problem is to use passive mixers, which exploit structural obstacles within microfluidic channels or the geometry of channels themselves to enforce and enhance fluid mixing. Some applications require the manipulation and mixing of aggressive substances, which makes conventional microfluidic materials, along with their fabrication methods, inappropriate. In this work, implementation of an optimized full scale three port microfluidic mixer is presented in a slide of a material that is very hard to process but possesses extreme chemical and physical resistance—alumina. The viability of the selected femtosecond laser fabrication method as an alternative to conventional lithography methods, which are unable to process this material, is demonstrated. For the validation and optimization of the microfluidic mixer, a finite element method (FEM) based numerical modeling of the influence of the mixer geometry on its mixing performance is completed. Experimental investigation of the laminar flow geometry demonstrated very good agreement with the numerical simulation results. Such a laser ablation microfabricated passive mixer structure is intended for use in a capillary force assisted nanoparticle assembly setup (CAPA).

  1. A wideband current-commutating passive mixer for multi-standard receivers in a 0.18 μm CMOS

    NASA Astrophysics Data System (ADS)

    Kuan, Bao; Xiangning, Fan; Wei, Li; Zhigong, Wang

    2013-01-01

    This paper reports a wideband passive mixer for direct conversion multi-standard receivers. A brief comparison between current-commutating passive mixers and active mixers is presented. The effect of source and load impedance on the linearity of a mixer is analyzed. Specially, the impact of the input impedance of the transimpedance amplifier (TIA), which acts as the load impedance of a mixer, is investigated in detail. The analysis is verified by a passive mixer implemented with 0.18 μm CMOS technology. The circuit is inductorless and can operate over a broad frequency range. On wafer measurements show that, with radio frequency (RF) ranges from 700 MHz to 2.3 GHz, the mixer achieves 21 dB of conversion voltage gain with a -1 dB intermediate frequency (IF) bandwidth of 10 MHz. The measured IIP3 is 9 dBm and the measured double-sideband noise figure (NF) is 10.6 dB at 10 MHz output. The chip occupies an area of 0.19 mm2 and drains a current of 5.5 mA from a 1.8 V supply.

  2. The role of Mixer in patterning the early Xenopus embryo.

    PubMed

    Kofron, Matt; Wylie, Chris; Heasman, Janet

    2004-05-01

    The transcription factor VegT, is required in early Xenopus embryos for the formation of both the mesoderm and endoderm germ layers. Inherited as a maternal mRNA localized only in vegetal cells, VegT activates the transcription of a large number of transcription factors, as well as signaling ligands that induce cells in the vegetal mass to form endoderm, and the marginal zone to form mesoderm. It is important now to understand the extent to which transcription factors downstream of VegT play individual, or overlapping, roles in the specification and patterning of the endoderm and mesoderm. In addition, it is important to understand the mechanism that specifies the boundary between endoderm and mesoderm. One of the downstream targets of VegT, the homeodomain protein Mixer, is expressed at high levels at the mesoderm/endoderm boundary at the late blastula stage. We therefore examined its functions by blocking its translation using morpholino oligos. In Mixer-depleted embryos, the expression of many signaling ligands and transcription factors was affected. In particular, we found that the expression of several genes, including several normally expressed in mesoderm, was upregulated. Functional assays of Mixer-depleted vegetal cells showed that they have increased mesoderm-inducing activity. This demonstrates that Mixer plays an essential role in controlling the amount of mesoderm induction by the vegetal cells.

  3. Submersible canned motor mixer pump

    DOEpatents

    Guardiani, R.F.; Pollick, R.D.

    1997-10-07

    A mixer pump is described used in a waste tank for mobilizing high-level radioactive liquid waste having a column assembly containing power cables, a motor housing with electric motor means which includes a stator can of a stator assembly and a rotor can of a rotor assembly, and an impeller assembly with an impeller connected to a shaft of the rotor assembly. The column assembly locates the motor housing with the electric motor means adjacent to the impeller which creates an hydraulic head, and which forces the liquid waste into the motor housing to cool the electric motor means and to lubricate radial and thrust bearing assemblies. Hard-on-hard bearing surfaces of the bearing assemblies and a ring assembly between the impeller and electric motor means act to grind down large particles in the liquid waste flow. These larger particles are received in slots in the static bearing members of the radial bearing assemblies. Only solid waste particles smaller than the clearances in the system can pass there through, thereby resisting damage to and the interruption of the operation of the mixer pump. 10 figs.

  4. Analysis of Fuel Vaporization, Fuel-Air Mixing, and Combustion in Integrated Mixer-Flame Holders

    NASA Technical Reports Server (NTRS)

    Deur, J. M.; Cline, M. C.

    2004-01-01

    Requirements to limit pollutant emissions from the gas turbine engines for the future High-Speed Civil Transport (HSCT) have led to consideration of various low-emission combustor concepts. One such concept is the Integrated Mixer-Flame Holder (IMFH). This report describes a series of IMFH analyses performed with KIVA-II, a multi-dimensional CFD code for problems involving sprays, turbulence, and combustion. To meet the needs of this study, KIVA-II's boundary condition and chemistry treatments are modified. The study itself examines the relationships between fuel vaporization, fuel-air mixing, and combustion. Parameters being considered include: mixer tube diameter, mixer tube length, mixer tube geometry (converging-diverging versus straight walls), air inlet velocity, air inlet swirl angle, secondary air injection (dilution holes), fuel injection velocity, fuel injection angle, number of fuel injection ports, fuel spray cone angle, and fuel droplet size. Cases are run with and without combustion to examine the variations in fuel-air mixing and potential for flashback due to the above parameters. The degree of fuel-air mixing is judged by comparing average, minimum, and maximum fuel/air ratios at the exit of the mixer tube, while flame stability is monitored by following the location of the flame front as the solution progresses from ignition to steady state. Results indicate that fuel-air mixing can be enhanced by a variety of means, the best being a combination of air inlet swirl and a converging-diverging mixer tube geometry. With the IMFH configuration utilized in the present study, flashback becomes more common as the mixer tube diameter is increased and is instigated by disturbances associated with the dilution hole flow.

  5. AlGaAs/GaAs quasi-bulk effect mixers: Analysis and experiments

    NASA Technical Reports Server (NTRS)

    Yngvesson, K. S.; Yang, J.-X.; Agahi, F.; Dai, D.; Musante, C.; Grammer, W.; Lau, K. M.

    1992-01-01

    The lowest noise temperature for any receiver in the 0.5 to 1 THz range has been achieved with the bulk InSb hot electron mixer, which unfortunately suffers from the problem of having a very narrow bandwidth (1-2 MHz). We have demonstrated a three order of magnitude improvement in the bandwidth of hot electron mixers, by using the two-dimensional electron gas (2DEG) medium at the hetero-interface between AlGaAs and GaAs. We have tested both inhouse MOCVD-grown material, and MBE materials, with similar results. The conversion loss (L(sub c)) at 94 GHz is presently 18 dB for a mixer operating at 20 K, and calculations indicate that L(sub c) can be decreased to about 10 dB in future devices. Calculated and measured curves of L(sub c), versus PLO and IDC, respectively, agree well. We argue that there are several different configurations of hot electron mixers, which will also show wide bandwidth, and that these devices are likely to become important as low-noise THz receivers in the future.

  6. Efficient gas-liquid contact using microfluidic membrane devices with staggered herringbone mixers.

    PubMed

    Femmer, Tim; Eggersdorfer, Max L; Kuehne, Alexander J C; Wessling, Matthias

    2015-08-07

    We describe a novel membrane based gas-liquid-contacting device with increased mass transport and reduced pressure loss by combining a membrane with a staggered herringbone static mixer. Herringbone structures are imposed on the microfluidic channel geometry via soft lithography, acting as mixers which introduce secondary flows at the membrane interface. Such flows include Dean vortices and Taylor flows generating effective mixing while improving mass transport and preventing concentration polarization in microfluidic channels. Furthermore, our static herringbone mixer membranes effectively reduce pressure losses leading to devices with enhanced transfer properties for microfluidic gas-liquid contact. We investigate the red blood cell distribution to tailor our devices towards miniaturised extracorporeal membrane oxygenation and improved comfort of patients with lung insufficiencies.

  7. A compact D-band monolithic APDP-based sub-harmonic mixer

    NASA Astrophysics Data System (ADS)

    Zhang, Shengzhou; Sun, Lingling; Wang, Xiang; Wen, Jincai; Liu, Jun

    2017-11-01

    The paper presents a compact D-band monolithic sub-harmonic mixer (SHM) with 3 μm planar hyperabrupt schottky-varactor diodes offered by 70 nm GaAs mHEMT technology. According to empirical equivalent-circuit models, a wide-band large signal equivalent circuit model of the diode is proposed. Based on the extracted model, the mixer is implemented and optimized with a shunt-mounted anti-parallel diode pair (APDP) to fulfill the sub-harmonic mixing mechanism. Furthermore, a modified asymmetric three-transmission-line coupler is devised to achieve high-level coupling and minimize the chip size. The measured results show that the conversion gain varies between -13.9 dB and -17.5 dB from 110 GHz to 145 GHz, with a local oscillator (LO) power level of 14 dBm and an intermediate frequency (IF) of 1 GHz. The total chip size including probe GSG pads is 0.57 × 0.68mm2. In conclusion, the mixer exhibits outstanding figure-of-merits.

  8. 3D-printed conductive static mixers enable all-vanadium redox flow battery using slurry electrodes

    NASA Astrophysics Data System (ADS)

    Percin, Korcan; Rommerskirchen, Alexandra; Sengpiel, Robert; Gendel, Youri; Wessling, Matthias

    2018-03-01

    State-of-the-art all-vanadium redox flow batteries employ porous carbonaceous materials as electrodes. The battery cells possess non-scalable fixed electrodes inserted into a cell stack. In contrast, a conductive particle network dispersed in the electrolyte, known as slurry electrode, may be beneficial for a scalable redox flow battery. In this work, slurry electrodes are successfully introduced to an all-vanadium redox flow battery. Activated carbon and graphite powder particles are dispersed up to 20 wt% in the vanadium electrolyte and charge-discharge behavior is inspected via polarization studies. Graphite powder slurry is superior over activated carbon with a polarization behavior closer to the standard graphite felt electrodes. 3D-printed conductive static mixers introduced to the slurry channel improve the charge transfer via intensified slurry mixing and increased surface area. Consequently, a significant increase in the coulombic efficiency up to 95% and energy efficiency up to 65% is obtained. Our results show that slurry electrodes supported by conductive static mixers can be competitive to state-of-the-art electrodes yielding an additional degree of freedom in battery design. Research into carbon properties (particle size, internal surface area, pore size distribution) tailored to the electrolyte system and optimization of the mixer geometry may yield even better battery properties.

  9. SIS Mixer Design for a Broadband Millimeter Spectrometer Suitable for Rapid Line Surveys and Redshift Determinations

    NASA Technical Reports Server (NTRS)

    Rice, F.; Sumner, M.; Zmuidzinas, J.; Hu, R.; LeDuc, H.; Harris, A.; Miller, D.

    2004-01-01

    We present some detail of the waveguide probe and SIS mixer chip designs for a low-noise 180-300 GHz double- sideband receiver with an instantaneous RF bandwidth of 24 GHz. The receiver's single SIS junction is excited by a broadband, fixed-tuned waveguide probe on a silicon substrate. The IF output is coupled to a 6-18 GHz MMIC low- noise preamplifier. Following further amplification, the output is processed by an array of 4 GHz, 128-channel analog autocorrelation spectrometers (WASP 11). The single-sideband receiver noise temperature goal of 70 Kelvin will provide a prototype instrument capable of rapid line surveys and of relatively efficient carbon monoxide (CO) emission line searches of distant, dusty galaxies. The latter application's goal is to determine redshifts by measuring the frequencies of CO line emissions from the star-forming regions dominating the submillimeter brightness of these galaxies. Construction of the receiver has begun; lab testing should begin in the fall. Demonstration of the receiver on the Caltech Submillimeter Observatory (CSO) telescope should begin in spring 2003.

  10. On the Relationship Between Schottky Barrier Capacitance and Mixer Performance at Cryogenic Temperatures

    NASA Technical Reports Server (NTRS)

    Romanofsky, Robert R.

    1996-01-01

    The flat-band voltage is the Schottky junction voltage required to shrink the depletion width to zero. At cryogenic temperatures, mixer diodes are generally biased and/or pumped beyond the flat-band condition to minimize conversion loss and noise figure. This occurs despite the presumed sharp increase in junction capacitance near flat-band, which should instead limit mixer performance. Past moderate forward bias, the diode C-V relationship is difficult to measure. A simple analytic expression for C(V) is usually used to model and predict mixer performance. This letter provides experimental data on C(V) at 77 K based on a microwave measurement and modeling technique. Data is also provided on the conversion loss of a singly balanced mixer optimized for 77 K operation. The connection between junction capacitance, flat-band potential, and conversion loss is examined. It is shown that the analytic expression greatly overestimates the junction capacitance that occurs as flat-band is approached.

  11. Advanced turbocharger design study program

    NASA Technical Reports Server (NTRS)

    Culy, D. G.; Heldenbrand, R. W.; Richardson, N. R.

    1984-01-01

    The advanced Turbocharger Design Study consisted of: (1) the evaluation of three advanced engine designs to determine their turbocharging requirements, and of technologies applicable to advanced turbocharger designs; (2) trade-off studies to define a turbocharger conceptual design and select the engine with the most representative requirements for turbocharging; (3) the preparation of a turbocharger conceptual design for the Curtiss Wright RC2-32 engine selected in the trade-off studies; and (4) the assessment of market impact and the preparation of a technology demonstration plan for the advanced turbocharger.

  12. Ionic electroactive polymer actuators as active microfluidic mixers

    DOE PAGES

    Meis, Catherine; Montazami, Reza; Hashemi, Nastaran

    2015-11-06

    On-chip sample processing is integral to the continued development of lab-on-a-chip devices for various applications. An active microfluidic mixer prototype is proposed using ionic electroactive polymer actuators (IEAPAs) as artificial cilia. A proof-of-concept experiment was performed in which the actuators were shown to produce localized flow pattern disruptions in the laminar flow regime. Suggestions for further engineering and optimization of a scaled-down, complete device are provided. Furthermore, the device in its current state of development necessitates further engineering, the use of IEAPAs addresses issues currently associated with the use of electromechanical actuators as active microfluidic mixers and may prove tomore » be a useful alternative to other similar materials.« less

  13. EVALUATION AND RECOMMENDATION OF SALTSTONE MIXER AUGER/PADDLES MATERIALS OF CONSTRUCTION FOR IMPROVED WEAR RESISTANCE

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Mickalonis, J.; Torres, R.

    2012-08-15

    Wear and corrosion testing were conducted to evaluate alternate materials of construction for the Saltstone mixer auger and paddles. These components have been degraded by wear from the slurry processed in the mixer. Material test options included PVD coatings (TiN, TiCN, and ZrN), weld overlays (Stellite 12 and Ultimet) and higher hardness steels and carbides (D2 and tungsten carbide). The corrosion testing demonstrated that the slurry is not detrimental to the current materials of construction or the new candidates. The ASTM G75 Miller wear test showed that the high hardness materials and the Stellite 12 weld overlay provide superior wearmore » relative to the Astralloy and CF8M stainless steel, which are the current materials of construction, as well as the PVD coatings and Ultimet. The following recommendations are made for selecting new material options and improving the overall wear resistance of the Saltstone mixer components: A Stellite 12 weld overlay or higher hardness steel (with toughness equivalent to Astralloy) be used to improve the wear resistance of the Saltstone mixer paddles; other manufacturing specifications for the mixer need to be considered in this selection. The current use of the Stellite 12 weld overlay be evaluated so that coverage of the 316 auger can be optimized for improved wear resistance of the auger. The wear surfaces of the Saltstone mixer auger and paddles be evaluated so that laboratory data can be better correlated to actual service. The 2-inch Saltstone mixer prototype be used to verify material performance.« less

  14. Accurate experimental and theoretical comparisons between superconductor-insulator-superconductor mixers showing weak and strong quantum effects

    NASA Technical Reports Server (NTRS)

    Mcgrath, W. R.; Richards, P. L.; Face, D. W.; Prober, D. E.; Lloyd, F. L.

    1988-01-01

    A systematic study of the gain and noise in superconductor-insulator-superconductor mixers employing Ta based, Nb based, and Pb-alloy based tunnel junctions was made. These junctions displayed both weak and strong quantum effects at a signal frequency of 33 GHz. The effects of energy gap sharpness and subgap current were investigated and are quantitatively related to mixer performance. Detailed comparisons are made of the mixing results with the predictions of a three-port model approximation to the Tucker theory. Mixer performance was measured with a novel test apparatus which is accurate enough to allow for the first quantitative tests of theoretical noise predictions. It is found that the three-port model of the Tucker theory underestimates the mixer noise temperature by a factor of about 2 for all of the mixers. In addition, predicted values of available mixer gain are in reasonable agreement with experiment when quantum effects are weak. However, as quantum effects become strong, the predicted available gain diverges to infinity, which is in sharp contrast to the experimental results. Predictions of coupled gain do not always show such divergences.

  15. Study on installation of the submersible mixer

    NASA Astrophysics Data System (ADS)

    Tian, F.; Shi, W. D.; He, X. H.; Jiang, H.; Xu, Y. H.

    2013-12-01

    Study on installation of the submersible mixer for sewage treatment has been limited. In this article, large-scale computational fluid dynamics software FLUENT6.3 was adopted. ICEM software was used to build an unstructured grid of sewage treatment pool. After that, the sewage treatment pool was numerically simulated by dynamic coordinate system technology and RNG k-ε turbulent model and PIOS algorithm. Agitation pools on four different installation location cases were simulated respectively, and the external characteristic of the submersible mixer and the velocity cloud of the axial section were respectively comparatively analyzed. The best stirring effect can be reached by the installation location of case C, which is near the bottom of the pool 600 mm and blade distance the bottom at least for 200 mm wide and wide edge and narrow edge distance by 4:3. The conclusion can guide the engineering practice.

  16. Phased-Array Study of Dual-Flow Jet Noise: Effect of Nozzles and Mixers

    NASA Technical Reports Server (NTRS)

    Soo Lee, Sang; Bridges, James

    2006-01-01

    A 16-microphone linear phased-array installed parallel to the jet axis and a 32-microphone azimuthal phased-array installed in the nozzle exit plane have been applied to identify the noise source distributions of nozzle exhaust systems with various internal mixers (lobed and axisymmetric) and nozzles (three different lengths). Measurements of velocity were also obtained using cross-stream stereo particle image velocimetry (PIV). Among the three nozzle lengths tested, the medium length nozzle was the quietest for all mixers at high frequency on the highest speed flow condition. Large differences in source strength distributions between nozzles and mixers occurred at or near the nozzle exit for this flow condition. The beamforming analyses from the azimuthal array for the 12-lobed mixer on the highest flow condition showed that the core flow and the lobe area were strong noise sources for the long and short nozzles. The 12 noisy spots associated with the lobe locations of the 12-lobed mixer with the long nozzle were very well detected for the frequencies 5 KHz and higher. Meanwhile, maps of the source strength of the axisymmetric splitter show that the outer shear layer was the most important noise source at most flow conditions. In general, there was a good correlation between the high turbulence regions from the PIV tests and the high noise source regions from the phased-array measurements.

  17. Highly efficient evaluation of a gas mixer using a hollow waveguide based laser spectral sensor.

    PubMed

    Du, Z; Yang, X; Li, J; Yang, Y; Qiao, C

    2017-05-01

    This paper aims to provide a fast, sensitive, and accurate characterization of a Mass Flow Controller (MFC) based gas mixer. The gas mixer was evaluated by using a hollow waveguide based laser spectral sensor with high efficiency. Benefiting from the sensor's fast response, high sensitivity and continuous operation, multiple key parameters of the mixer, including mixing uncertainty, linearity, and response time, were acquired by a one-round test. The test results show that the mixer can blend multi-compound gases quite efficiently with an uncertainty of 1.44% occurring at a flow rate of 500 ml/min, with the linearity of 0.998 43 and the response time of 92.6 s. The results' reliability was confirmed by the relative measurement of gas concentration, in which the isolation of the sensor's uncertainty was conducted. The measured uncertainty has shown well coincidence with the theoretical uncertainties of the mixer, which proves the method to be a reliable characterization. Consequently, this sort of laser based characterization's wide appliance on gas analyzer's evaluations is demonstrated.

  18. Highly efficient evaluation of a gas mixer using a hollow waveguide based laser spectral sensor

    NASA Astrophysics Data System (ADS)

    Du, Z.; Yang, X.; Li, J.; Yang, Y.; Qiao, C.

    2017-05-01

    This paper aims to provide a fast, sensitive, and accurate characterization of a Mass Flow Controller (MFC) based gas mixer. The gas mixer was evaluated by using a hollow waveguide based laser spectral sensor with high efficiency. Benefiting from the sensor's fast response, high sensitivity and continuous operation, multiple key parameters of the mixer, including mixing uncertainty, linearity, and response time, were acquired by a one-round test. The test results show that the mixer can blend multi-compound gases quite efficiently with an uncertainty of 1.44% occurring at a flow rate of 500 ml/min, with the linearity of 0.998 43 and the response time of 92.6 s. The results' reliability was confirmed by the relative measurement of gas concentration, in which the isolation of the sensor's uncertainty was conducted. The measured uncertainty has shown well coincidence with the theoretical uncertainties of the mixer, which proves the method to be a reliable characterization. Consequently, this sort of laser based characterization's wide appliance on gas analyzer's evaluations is demonstrated.

  19. Results of Aero/Acoustic Tests and Analytical Studies of a Two-Dimensional Eight-Lobe Mixer-Ejector Exhaust Nozzle at Takeoff Conditions

    NASA Technical Reports Server (NTRS)

    Harrington, Douglas (Technical Monitor); Schweiger, P.; Stern, A.; Gamble, E.; Barber, T.; Chiappetta, L.; LaBarre, R.; Salikuddin, M.; Shin, H.; Majjigi, R.

    2005-01-01

    Hot flow aero-acoustic tests were conducted with Pratt & Whitney's High-Speed Civil Transport (HSCT) Mixer-Ejector Exhaust Nozzles by General Electric Aircraft Engines (GEAE) in the GEAE Anechoic Freejet Noise Facility (Cell 41) located in Evendale, Ohio. The tests evaluated the impact of various geometric and design parameters on the noise generated by a two-dimensional (2-D) shrouded, 8-lobed, mixer-ejector exhaust nozzle. The shrouded mixer-ejector provides noise suppression by mixing relatively low energy ambient air with the hot, high-speed primary exhaust jet. Additional attenuation was obtained by lining the shroud internal walls with acoustic panels, which absorb acoustic energy generated during the mixing process. Two mixer designs were investigated, the high mixing "vortical" and aligned flow "axial", along with variations in the shroud internal mixing area ratios and shroud length. The shrouds were tested as hardwall or lined with acoustic panels packed with a bulk absorber. A total of 21 model configurations at 1:11.47 scale were tested. The models were tested over a range of primary nozzle pressure ratios and primary exhaust temperatures representative of typical HSCT aero thermodynamic cycles. Static as well as flight simulated data were acquired during testing. A round convergent unshrouded nozzle was tested to provide an acoustic baseline for comparison to the test configurations. Comparisons were made to previous test results obtained with this hardware at NASA Glenn's 9- by 15-foot low-speed wind tunnel (LSWT). Laser velocimetry was used to investigate external as well as ejector internal velocity profiles for comparison to computational predictions. Ejector interior wall static pressure data were also obtained. A significant reduction in exhaust system noise was demonstrated with the 2-D shrouded nozzle designs.

  20. A general numerical analysis program for the superconducting quasiparticle mixer

    NASA Technical Reports Server (NTRS)

    Hicks, R. G.; Feldman, M. J.; Kerr, A. R.

    1986-01-01

    A user-oriented computer program SISCAP (SIS Computer Analysis Program) for analyzing SIS mixers is described. The program allows arbitrary impedance terminations to be specified at all LO harmonics and sideband frequencies. It is therefore able to treat a much more general class of SIS mixers than the widely used three-frequency analysis, for which the harmonics are assumed to be short-circuited. An additional program, GETCHI, provides the necessary input data to program SISCAP. The SISCAP program performs a nonlinear analysis to determine the SIS junction voltage waveform produced by the local oscillator. The quantum theory of mixing is used in its most general form, treating the large signal properties of the mixer in the time domain. A small signal linear analysis is then used to find the conversion loss and port impedances. The noise analysis includes thermal noise from the termination resistances and shot noise from the periodic LO current. Quantum noise is not considered. Many aspects of the program have been adequately verified and found accurate.

  1. Linear Quadratic Tracking Design for a Generic Transport Aircraft with Structural Load Constraints

    NASA Technical Reports Server (NTRS)

    Burken, John J.; Frost, Susan A.; Taylor, Brian R.

    2011-01-01

    When designing control laws for systems with constraints added to the tracking performance, control allocation methods can be utilized. Control allocations methods are used when there are more command inputs than controlled variables. Constraints that require allocators are such task as; surface saturation limits, structural load limits, drag reduction constraints or actuator failures. Most transport aircraft have many actuated surfaces compared to the three controlled variables (such as angle of attack, roll rate & angle of side slip). To distribute the control effort among the redundant set of actuators a fixed mixer approach can be utilized or online control allocation techniques. The benefit of an online allocator is that constraints can be considered in the design whereas the fixed mixer cannot. However, an online control allocator mixer has a disadvantage of not guaranteeing a surface schedule, which can then produce ill defined loads on the aircraft. The load uncertainty and complexity has prevented some controller designs from using advanced allocation techniques. This paper considers actuator redundancy management for a class of over actuated systems with real-time structural load limits using linear quadratic tracking applied to the generic transport model. A roll maneuver example of an artificial load limit constraint is shown and compared to the same no load limitation maneuver.

  2. Optimizing micromixer design for enhancing dielectrophoretic microconcentrator performance.

    PubMed

    Lee, Hsu-Yi; Voldman, Joel

    2007-03-01

    We present an investigation into optimizing micromixer design for enhancing dielectrophoretic (DEP) microconcentrator performance. DEP-based microconcentrators use the dielectrophoretic force to collect particles on electrodes. Because the DEP force generated by electrodes decays rapidly away from the electrodes, DEP-based microconcentrators are only effective at capturing particles from a limited cross section of the input liquid stream. Adding a mixer can circulate the input liquid, increasing the probability that particles will drift near the electrodes for capture. Because mixers for DEP-based microconcentrators aim to circulate particles, rather than mix two species, design specifications for such mixers may be significantly different from that for conventional mixers. Here we investigated the performance of patterned-groove micromixers on particle trapping efficiency in DEP-based microconcentrators numerically and experimentally. We used modeling software to simulate the particle motion due to various forces on the particle (DEP, hydrodynamic, etc.), allowing us to predict trapping efficiency. We also conducted trapping experiments and measured the capture efficiency of different micromixer configurations, including the slanted groove, staggered herringbone, and herringbone mixers. Finally, we used these analyses to illustrate the design principles of mixers for DEP-based concentrators.

  3. Factors which influence the behavior of turbofan forced mixer nozzles

    NASA Technical Reports Server (NTRS)

    Anderson, B. H.; Povinelli, L. A.

    1981-01-01

    A finite difference procedure was used to compute the mixing for three experimentally tested mixer geometries. Good agreement was obtained between analysis and experiment when the mechanisms responsible for secondary flow generation were properly modeled. Vorticity generation due to flow turning and vorticity generated within the centerbody lobe passage were found to be important. Results are presented for two different temperature ratios between fan and core streams and for two different free stream turbulence levels. It was concluded that the dominant mechanisms in turbofan mixers is associated with the secondary flows arising within the lobe region and their development within the mixing section.

  4. Influence of pressure driven secondary flows on the behavior of turbofan forced mixers

    NASA Technical Reports Server (NTRS)

    Anderson, B.; Povinelli, L.; Gerstenmaier, W.

    1980-01-01

    A finite difference procedure was developed to analyze the three dimensional subsonic turbulent flows in turbofan forced mixer nozzles. The method is based on a decomposition of the velocity field into primary and secondary flow components which are determined by solution of the equations governing primary momentum, secondary vorticity, thermal energy, and continuity. Experimentally, a strong secondary flow pattern was identified which is associated with the radial inflow and outflow characteristics of the core and fan streams and forms a very strong vortex system aligned with the radial interface between the core and fan regions. A procedure was developed to generate a similar generic secondary flow pattern in terms of two constants representing the average radial outflow or inflow in the core and fan streams as a percentage of the local streamwise velocity. This description of the initial secondary flow gave excellent agreement with experimental data. By identifying the nature of large scale secondary flow structure and associating it with characteristic mixer nozzle behavior, it is felt that the cause and effect relationship between lobe design and nozzle performance can be understood.

  5. Scalar transport in inline mixers with spatially periodic flows

    NASA Astrophysics Data System (ADS)

    Baskan, Ozge; Rajaei, Hadi; Speetjens, Michel F. M.; Clercx, Herman J. H.

    2017-01-01

    Spatially persisting patterns form during the downstream evolution of passive scalars in three-dimensional (3D) spatially periodic flows due to the coupled effect of stretching and folding mechanisms of the flow field. This has been investigated in many computational and theoretical studies of 2D time-periodic and 3D spatially periodic flow fields. However, experimental studies, to date, have mainly focused on flow visualization with streaks of dye rather than fully 3D scalar field measurements. Our study employs 3D particle tracking velocimetry and 3D laser-induced fluorescence to analyze the evolution of 3D flow and scalar fields and the correlation between the coherent flow/scalar field structures in a representative inline mixer, the Quatro static mixer. For this purpose an experimental setup that consists of an optically accessible test section with transparent internal elements accommodating a pressure-driven pipe flow has been built. The flow and scalar fields clearly underline the complementarity of the experimental results with numerical simulations and provide validation of the periodicity assumption needed in numerical studies. The experimental procedure employed in this investigation, which allows studying the scalar transport in the advective limit, demonstrates the suitability of the present method for exploratory mixing studies of a variety of mixing devices, beyond the Quatro static mixer.

  6. Muller Mixer Fire - Lessons Learned

    DTIC Science & Technology

    1986-08-01

    wheel National Engineering stainless steel Special Simpson Porto Muller equipped with two-200 pound muller wheels plus an inside and outside plow...The mixer wheels /plows revolve at approximately 18 RPM and are driven by an 1800 RPM 3 H.P. motor through a double belt sheave and gear box. The bowl...diameter is approximately 39 inches and 12 inches deep with the mulling wheels /plows geared to move in a counterclockwise rotation. All bays are

  7. Advanced Technologies For Heterodyne Radio Astronomy Instrumentation - Part1 By A. Pavolotsky, And Advanced Technologies For Heterodyne Radio Astronomy Instrumentation - Part2 By V. Desmaris

    NASA Astrophysics Data System (ADS)

    Pavolotsky, Alexey

    2018-01-01

    Modern and future heterodyne radio astronomy instrumentation critically depends on availability of advanced fabrication technologies and components. In Part1 of the Poster, we present the thin film fabrication process for SIS mixer receivers, utilizing either AlOx, or AlN barrier superconducting tunnel junctions developed and supported by GARD. The summary of the process design rules is presented. It is well known that performance of waveguide mixer components critically depends on accuracy of their geometrical dimensions. At GARD, all critical mechanical parts are 3D-mapped with a sub-um accuracy. Further progress of heterodyne instrumentation requires new efficient and compact sources of LO signal. We present SIS-based frequency multiplier, which could become a new option for LO source. Future radio astronomy THz receivers will need waveguide components, which fabricating due to their tiny dimensions is not feasible by traditional mechanical machining. We present the alternative micromachining technique for fabricating waveguide component for up 5 THz band and probably beyond.

  8. Optimization of integrated impeller mixer via radiotracer experiments.

    PubMed

    Othman, N; Kamarudin, S K; Takriff, M S; Rosli, M I; Engku Chik, E M F; Adnan, M A K

    2014-01-01

    Radiotracer experiments are carried out in order to determine the mean residence time (MRT) as well as percentage of dead zone, V dead (%), in an integrated mixer consisting of Rushton and pitched blade turbine (PBT). Conventionally, optimization was performed by varying one parameter and others were held constant (OFAT) which lead to enormous number of experiments. Thus, in this study, a 4-factor 3-level Taguchi L9 orthogonal array was introduced to obtain an accurate optimization of mixing efficiency with minimal number of experiments. This paper describes the optimal conditions of four process parameters, namely, impeller speed, impeller clearance, type of impeller, and sampling time, in obtaining MRT and V dead (%) using radiotracer experiments. The optimum conditions for the experiments were 100 rpm impeller speed, 50 mm impeller clearance, Type A mixer, and 900 s sampling time to reach optimization.

  9. 670 GHz Schottky Diode Based Subharmonic Mixer with CPW Circuits and 70 GHz IF

    NASA Technical Reports Server (NTRS)

    Chattopadhyay, Goutam (Inventor); Schlecht, Erich T. (Inventor); Lee, Choonsup (Inventor); Lin, Robert H. (Inventor); Gill, John J. (Inventor); Sin, Seth (Inventor); Mehdi, Imran (Inventor)

    2014-01-01

    A coplanar waveguide (CPW) based subharmonic mixer working at 670 GHz using GaAs Schottky diodes. One example of the mixer has a LO input, an RF input and an IF output. Another possible mixer has a LO input, and IF input and an RF output. Each input or output is connected to a coplanar waveguide with a matching network. A pair of antiparallel diodes provides a signal at twice the LO frequency, which is then mixed with a second signal to provide signals having sum and difference frequencies. The output signal of interest is received after passing through a bandpass filter tuned to the frequency range of interest.

  10. CHEMICAL INDUCTION MIXER VERIFICATION - ENVIRONMENTAL TECHNOLOGY VERIFICATION PROGRAM

    EPA Science Inventory

    The Wet-Weather Flow Technologies Pilot of the Environmental Technology Verification (ETV) Program, which is supported by the U.S. Environmental Protection Agency and facilitated by NSF International, has recently evaluated the performance of chemical induction mixers used for di...

  11. 26 CFR 48.4061-1 - Temporary regulations with respect to floor stock refunds or credits on cement mixers.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... stock refunds or credits on cement mixers. 48.4061-1 Section 48.4061-1 Internal Revenue INTERNAL REVENUE... § 48.4061-1 Temporary regulations with respect to floor stock refunds or credits on cement mixers. (a... of tax on motor vehicles) on the sale of a cement mixer after June 30, 1968, and before January 1...

  12. 26 CFR 48.4061-1 - Temporary regulations with respect to floor stock refunds or credits on cement mixers.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... stock refunds or credits on cement mixers. 48.4061-1 Section 48.4061-1 Internal Revenue INTERNAL REVENUE... § 48.4061-1 Temporary regulations with respect to floor stock refunds or credits on cement mixers. (a... of tax on motor vehicles) on the sale of a cement mixer after June 30, 1968, and before January 1...

  13. 26 CFR 48.4061-1 - Temporary regulations with respect to floor stock refunds or credits on cement mixers.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... stock refunds or credits on cement mixers. 48.4061-1 Section 48.4061-1 Internal Revenue INTERNAL REVENUE... § 48.4061-1 Temporary regulations with respect to floor stock refunds or credits on cement mixers. (a... of tax on motor vehicles) on the sale of a cement mixer after June 30, 1968, and before January 1...

  14. 26 CFR 48.4061-1 - Temporary regulations with respect to floor stock refunds or credits on cement mixers.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... stock refunds or credits on cement mixers. 48.4061-1 Section 48.4061-1 Internal Revenue INTERNAL REVENUE... § 48.4061-1 Temporary regulations with respect to floor stock refunds or credits on cement mixers. (a... of tax on motor vehicles) on the sale of a cement mixer after June 30, 1968, and before January 1...

  15. Frequency mixer having ferromagnetic film

    DOEpatents

    Khitun, Alexander; Roshchin, Igor V.; Galatsis, Kosmas; Bao, Mingqiang; Wang, Kang L.

    2016-03-29

    A frequency conversion device, which may include a radiofrequency (RF) mixer device, includes a substrate and a ferromagnetic film disposed over a surface of the substrate. An insulator is disposed over the ferromagnetic film and at least one microstrip antenna is disposed over the insulator. The ferromagnetic film provides a non-linear response to the frequency conversion device. The frequency conversion device may be used for signal mixing and amplification. The frequency conversion device may also be used in data encryption applications.

  16. Drug residues recovered in feed after various feedlot mixer truck cleanout procedures.

    PubMed

    Van Donkersgoed, Joyce; Sit, Dan; Gibbons, Nicole; Ramogida, Caterina; Hendrick, Steve

    2010-01-01

    A study was conducted to determine the effectiveness of two methods of equipment cleanout, sequencing or flushing, for reducing drug carryover in feedlot mixer trucks. Feed samples were collected from total mixed rations before and after various feed mixer equipment cleanout procedures. Medicated rations contained either 11 ppm of tylosin or 166 or 331 ppm of chlortetracycline. There were no differences between sequencing and flushing or between flushing with dry barley and flushing with barley silage in the median proportion of drug recovered in the next ration. A larger drug reduction was achieved using flush material at a volume of 10 versus 5% of the mixer capacity and mixing the flush material for 3 versus 4 min. Regardless of the drug or prescription concentrations in the total mixed rations or the equipment cleanout procedure used, concentrations of chlortetracycline and tylosin recovered were very low.

  17. Performance and Uniformity of Mass-Produced SIS Mixers for ALMA Band 8 Receiver Cartridges

    NASA Astrophysics Data System (ADS)

    Tomura, Tomonuri; Noguchi, Takashi; Sekimoto, Yutaro; Shan, Wenlei; Sato, Naohisa; Iizuka, Yoshizo; Kumagai, Kazuyoshi; Niizeki, Yasuaki; Iwakuni, Mikio; Ito, Tetsuya

    2015-05-01

    The Atacama large millimeter/submillimeter array (ALMA), which was jointly built in Chile by Europe, North America and East Asia, has an observational band from 30 to 950 GHz [1], [2]. We developed receiver cartridges for ALMA Band 8 (385-500 GHz) [3]-[5] which is one of ALMA 10 frequency bands. The Band 8 receiver cartridges were produced as 73 cartridges, and 292 SIS mixers were installed in their cartridges. Also, their all cartridges were required to meet following ALMA specifications: 1. The noise temperature is less than 196 K over 80% of the frequency range and less than 292 K at any frequency from 385 to 500 GHz. 2. The image rejection ratio is larger than 10 dB over 90% of the frequency range. 3. The IF output power variation is less than 7.0 dB peak-to-peak in the 4-8 GHz band. 4. The gain compression to RF load temperatures between 77 and 373 K is less than 5%. 5. The Allan variance of the IF output power is less than 4.0×10-7 in the time scale of 0.05 s≤T≤100 s and 3.0×10-6 at 300 s. To meet these specifications, the performance and uniformity of the SIS mixers are crucial. The SIS mixers with Nb/Al-AlOx/Nb superconductor-insulator-superconductor (SIS) tunnel junctions were fabricated in a clean room of National Astronomical Observatory of Japan and over 1000 mixer chips were mass-produced. After screening these mixers, 73 Band 8 receivers were assembled and tested. We report the test results of the mass-produced mixers and the receiver cartridges in detail from a statistical point of view.

  18. Development of hot-electron THz bolometric mixers using MgB2 thin films

    NASA Astrophysics Data System (ADS)

    Cunnane, Daniel; Kawamura, Jonathan; Karasik, Boris S.; Wolak, Matthaeus A.; Xi, X. X.

    2014-07-01

    Terahertz high-resolution spectroscopy of interstellar molecular clouds greatly relies on hot-electron superconducting bolometric (HEB) mixers. Current state-of-the-art receivers use mixer devices made from ultrathin (~ 3-5 nm) films of NbN with critical temperature ~ 9-11 K. Such mixers have been deployed on a number of groundbased, suborbital, and orbital platforms including the HIFI instrument on the Hershel Space Observatory. Despite its good sensitivity and well-established fabrication process, the NbN HEB mixer suffers from the narrow intermediate frequency (IF) bandwidth ~ 2-3 GHz and is limited to operation at liquid Helium temperature. As the heterodyne receivers are now trending towards "high THz" frequencies, the need in a larger IF bandwidth becomes more pressing since the same velocity resolution for a Doppler shifted line at 5 THz requires a 5-times greater IF bandwidth than at 1 THz. Our work is focusing on the realization of practical HEB mixers using ultrathin (10-20 nm) MgB2 films. They are prepared using a Hybrid Physical-Chemical Vapor Deposition (HPCVD) process yielding ultrathin films with critical temperature ~ 37-39 K. The expectation is that the combination of small thickness, high acoustic phonon transparency at the interface with the substrate, and very short electron-phonon relaxation time may lead to IF bandwidth ~ 10 GHz or even higher. SiC continues to be the most favorable substrate for MgB2 growth and as a result, a study has been conducted on the transparency of SiC at THz frequencies. FTIR measurements show that semi-insulating SiC substrates are at least as transparent as Si up to 2.5 THz. Currently films are passivated using a thin (10 nm) SiO2 layer which is deposited ex-situ via RF magnetron sputtering. Micron-sized spiral antenna-coupled HEB mixers have been fabricated using MgB2 films as thin as 10 nm. Fabrication was done using contact UV lithography and Ar Ion milling, with E-beam evaporated Au films deposited for the

  19. Mechanical Mixer for Rudder/Braking Wedge

    NASA Technical Reports Server (NTRS)

    Grimm, D.

    1985-01-01

    Right and left rudder panels moved separately. Mechanical mixer enables panels of two-panel rudder to rotate in same direction for steering or in opposite directions for dynamic braking. Steering and braking inputs separate so any combination of steering and braking motions executed simultaneously. Developed for aerodynamic braking of Space Shuttle orbiter, steering/braking drive train and rudder arrangement used for similar purposes on aircraft, thereby reducing sizes of thrust reversers.

  20. A three-dimensional turbulent compressible flow model for ejector and fluted mixers

    NASA Technical Reports Server (NTRS)

    Rushmore, W. L.; Zelazny, S. W.

    1978-01-01

    A three dimensional finite element computer code was developed to analyze ejector and axisymmetric fluted mixer systems whose flow fields are not significantly influenced by streamwise diffusion effects. A two equation turbulence model was used to make comparisons between theory and data for various flow fields which are components of the ejector system, i.e., (1) turbulent boundary layer in a duct; (2) rectangular nozzle (free jet); (3) axisymmetric nozzle (free jet); (4) hypermixing nozzle (free jet); and (5) plane wall jet. Likewise, comparisons of the code with analytical results and/or other numerical solutions were made for components of the axisymmetric fluted mixer system. These included: (1) developing pipe flow; (2) developing flow in an annular pipe; (3) developing flow in an axisymmetric pipe with conical center body and no fluting and (4) developing fluted pipe flow. Finally, two demonstration cases are presented which show the code's ability to analyze both the ejector and axisymmetric fluted mixers.

  1. High linearity current communicating passive mixer employing a simple resistor bias

    NASA Astrophysics Data System (ADS)

    Rongjiang, Liu; Guiliang, Guo; Yuepeng, Yan

    2013-03-01

    A high linearity current communicating passive mixer including the mixing cell and transimpedance amplifier (TIA) is introduced. It employs the resistor in the TIA to reduce the source voltage and the gate voltage of the mixing cell. The optimum linearity and the maximum symmetric switching operation are obtained at the same time. The mixer is implemented in a 0.25 μm CMOS process. The test shows that it achieves an input third-order intercept point of 13.32 dBm, conversion gain of 5.52 dB, and a single sideband noise figure of 20 dB.

  2. Biasable, Balanced, Fundamental Submillimeter Monolithic Membrane Mixer

    NASA Technical Reports Server (NTRS)

    Siegel, Peter; Schlecht, Erich; Mehdi, Imran; Gill, John; Velebir, James; Tsang, Raymond; Dengler, Robert; Lin, Robert

    2010-01-01

    This device is a biasable, submillimeter-wave, balanced mixer fabricated using JPL s monolithic membrane process a simplified version of planar membrane technology. The primary target application is instrumentation used for analysis of atmospheric constituents, pressure, temperature, winds, and other physical and chemical properties of the atmospheres of planets and comets. Other applications include high-sensitivity gas detection and analysis. This innovation uses a balanced configuration of two diodes allowing the radio frequency (RF) signal and local oscillator (LO) inputs to be separated. This removes the need for external diplexers that are inherently narrowband, bulky, and require mechanical tuning to change frequency. Additionally, this mixer uses DC bias-ability to improve its performance and versatility. In order to solve problems relating to circuit size, the GaAs membrane process was created. As much of the circuitry as possible is fabricated on-chip, making the circuit monolithic. The remainder of the circuitry is precision-machined into a waveguide block that holds the GaAs circuit. The most critical alignments are performed using micron-scale semiconductor technology, enabling wide bandwidth and high operating frequencies. The balanced mixer gets superior performance with less than 2 mW of LO power. This can be provided by a simple two-stage multiplier chain following an amplifier at around 90 GHz. Further, the diodes are arranged so that they can be biased. Biasing pushes the diodes closer to their switching voltage, so that less LO power is required to switch the diodes on and off. In the photo, the diodes are at the right end of the circuit. The LO comes from the waveguide at the right into a reduced-height section containing the diodes. Because the diodes are in series to the LO signal, they are both turned on and off simultaneously once per LO cycle. Conversely, the RF signal is picked up from the RF waveguide by the probe at the left, and flows

  3. 100-GHz Phase Switch/Mixer Containing a Slot-Line Transition

    NASA Technical Reports Server (NTRS)

    Gaier, Todd; Wells, Mary; Dawson, Douglas

    2009-01-01

    A circuit that can function as a phase switch, frequency mixer, or frequency multiplier operates over a broad frequency range in the vicinity of 100 GHz. Among the most notable features of this circuit is a grounded uniplanar transition (in effect, a balun) between a slot line and one of two coplanar waveguides (CPWs). The design of this circuit is well suited to integration of the circuit into a microwave monolithic integrated circuit (MMIC) package. One CPW is located at the input end and one at the output end of the top side of a substrate on which the circuit is fabricated (see Figure 1). The input CPW feeds the input signal to antiparallel flip-chip Schottky diodes connected to the edges of the slot line. Phase switching is effected by the combination of (1) the abrupt transition from the input CPW to the slot line and (2) CPW ground tuning effected by switching of the bias on the diodes. Grounding of the slot metal to the bottom metal gives rise to a frequency cutoff in the slot. This cutoff is valuable for separating different frequency components when the circuit is used as a mixer or multiplier. Proceeding along the slot line toward the output end, one encounters the aforementioned transition, which couples the slot line to the output CPW. Impedance tuning of the transition is accomplished by use of a high-impedance section immediately before the transition.

  4. The Study of 0.34 THz Monolithically Integrated Fourth Subharmonic Mixer Using Planar Schottky Barrier Diode

    NASA Astrophysics Data System (ADS)

    Tong, Xiaodong; Li, Qian; An, Ning; Wang, Wenjie; Deng, Xiaodong; Zhang, Liang; Liu, Haitao; Zeng, Jianping; Li, Zhiqiang; Tang, Hailing; Xiong, Yong-Zhong

    2015-11-01

    A planar Schottky barrier diode with the designed Schottky contact area of approximately 3 μm2 is developed on gallium arsenide (GaAs) material. The measurements of the developed planar Schottky barrier diode indicate that the zero-biased junction capacitance Cj0 is 11.0 fF, the parasitic series resistance RS is 3.0 Ω, and the cut off frequency fT is 4.8 THz. A monolithically integrated fourth subharmonic mixer with this diode operating at the radio frequency (RF) signal frequency of 0.34 THz with the chip area of 0.6 mm2 is implemented. The intermediate frequency (IF) bandwidth is from DC to 40 GHz. The local oscillator (LO) bandwidth is 37 GHz from 60 to 97 GHz. The RF bandwidth is determined by the bandwidth of the on chip antenna, which is 28 GHz from 322 to 350 GHz. The measurements of the mixer demonstrated a conversion loss of approximately 51 dB.

  5. An inductorless active mixer using stacked nMOS/pMOS configuration and LO shaping technique

    NASA Astrophysics Data System (ADS)

    Guo, Benqing; Chen, Jun; Wang, Xuebing; Chen, Hongpeng

    2018-04-01

    In this paper, a CMOS active down-conversion mixer is presented for wideband applications. Specifically, a LO generation chain is suggested to convert AC LO signal to shaped trapezoid burst, which reduces the sinusoidal LO power level requirement by the mixer. The current-reuse technique by stacked nMOS/pMOS architecture is used to save the power consumption of the circuit. Moreover, this complementary configuration is also employed to compensate second-order nonlinearity of the circuit. Implemented in a 0.18-μm CMOS process, post-simulations show that, driven by only ‑10 dBm sinusoidal LO signal, the proposed inductorless mixer provides a maximal conversion gain of 15.7 dB and a noise figure (NF) of 9.1-12 dB across RF input frequency range 0.5-1.6 GHz. The IIP3 and IP1dB of 3.5 dBm and ‑4.8 dBm are obtained, respectively. The mixer core only consumes 3.6 mW from a 1.8-V supply.

  6. Low-Noise Wide Bandwith, Hot Electron Bolometer Mixers for Submillimeter Wavelengths

    NASA Technical Reports Server (NTRS)

    McGrath, W. R.

    1995-01-01

    Recently a novel superconductive hot-electron micro-bolometer has been proposed which is both fast and sensitive (D. E. Prober, Appl. Phys. Lett. 62, 2119, 1993). This device has several important properties which make it useful as a heterodyne sensor for radioastronomy applications at frequencies above 1 THz. The thermal response time of the device is fast enough, several 10's of picoseconds, to allow for IF's of several GHz. This bolometer mixer should operate well up to at least 10 THz. There is no energy gap limitation as in an SIS mixer, since the mixing process relies on heating of the electron gas. In fact, rf power is absorbed more uniformly above the gap frequency. The mixer noise should be near quantum-limited, and the local oscillator (LO) power requirement is very low: / 10 nW for a Nb device. One of the unique features of this device is that it employs rapid electron diffusion into a normal metal, rather than phonon emission, as the thermal conductance that cools the heated electrons. In order for diffusion to dominate over phonon emission, the device must be short, less than 0.5.

  7. Influence of melt mixer on injection molding of thermoset elastomers

    NASA Astrophysics Data System (ADS)

    Rochman, Arif; Zahra, Keith

    2016-10-01

    One of the drawbacks in injection molding is that the plasticizing screw is short such that polymers having high concentrations of additives, such as thermoset elastomers, might not mix homogeneously within the short period of time during the plasticizing stage. In this study, various melt mixers inside the nozzle chamber, together forming a mixing nozzle, were developed. Three different materials were investigated, namely nitrile butadiene rubber (NBR), ethylene propylene-diene monomer (EPDM) and fluorocarbon (FKM). The use of these melt mixers resulted in better homogeneity and properties of the molded parts despite a curing time reduction of 10 s. This was due to the increase in mixing and shearing introduced a higher rate of crosslinking formation in the molded parts.

  8. Wide-bandwidth electron bolometric mixers - A 2DEG prototype and potential for low-noise THz receivers

    NASA Technical Reports Server (NTRS)

    Yang, Jian-Xun; Agahi, Farid; Dai, Dong; Musante, Charles F.; Grammer, Wes; Lau, Kei M.; Yngvesson, K. S.

    1993-01-01

    This paper presents a new type of electron bolometric ('hot electron') mixer. We have demonstrated a 3 order-of-magnitude improvement in the bandwidth compared with previously known types of electron bolometric mixers, by using the two-dimensional electron gas (2DEG) medium at the heterointerface between AlGaAs and GaAs. We have tested both in-house MOCVD-grown material and MBE material, with similar results. The conversion loss (Lc) at 94 GHz is presently 18 dB for a mixer operating at 20 K, and calculations indicate that Lc can be decreased to about 10 dB in future devices. Calculated and measured curves of Lc versus P(LO), and I(DC), respectively, agree well. We argue that there are several different configurations of electron bolometric mixers, which will all show wide bandwidth, and that these devices are likely to become important as low-noise THz receivers in the future.

  9. A Low Power 2.4 GHz CMOS Mixer Using Forward Body Bias Technique for Wireless Sensor Network

    NASA Astrophysics Data System (ADS)

    Yin, C. J.; Murad, S. A. Z.; Harun, A.; Ramli, M. M.; Zulkifli, T. Z. A.; Karim, J.

    2018-03-01

    Wireless sensor network (WSN) is a highly-demanded application since the evolution of wireless generation which is often used in recent communication technology. A radio frequency (RF) transceiver in WSN should have a low power consumption to support long operating times of mobile devices. A down-conversion mixer is responsible for frequency translation in a receiver. By operating a down-conversion mixer at a low supply voltage, the power consumed by WSN receiver can be greatly reduced. This paper presents a development of low power CMOS mixer using forward body bias technique for wireless sensor network. The proposed mixer is implemented using CMOS 0.13 μm Silterra technology. The forward body bias technique is adopted to obtain low power consumption. The simulation results indicate that a low power consumption of 0.91 mW is achieved at 1.6 V supply voltage. Moreover, the conversion gain (CG) of 21.83 dB, the noise figure (NF) of 16.51 dB and the input-referred third-order intercept point (IIP3) of 8.0 dB at 2.4 GHz are obtained. The proposed mixer is suitable for wireless sensor network.

  10. 41. JL photographer, summer 1978, view of chemical mixer from ...

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

    41. JL photographer, summer 1978, view of chemical mixer from atop chemical spray nozzels. - Division Avenue Pumping Station & Filtration Plant, West 45th Street and Division Avenue, Cleveland, Cuyahoga County, OH

  11. A "twisted" microfluidic mixer suitable for a wide range of flow rate applications.

    PubMed

    Sivashankar, Shilpa; Agambayev, Sumeyra; Mashraei, Yousof; Li, Er Qiang; Thoroddsen, Sigurdur T; Salama, Khaled Nabil

    2016-05-01

    This paper proposes a new "twisted" 3D microfluidic mixer fabricated by a laser writing/microfabrication technique. Effective and efficient mixing using the twisted micromixers can be obtained by combining two general chaotic mixing mechanisms: splitting/recombining and chaotic advection. The lamination of mixer units provides the splitting and recombination mechanism when the quadrant of circles is arranged in a two-layered serial arrangement of mixing units. The overall 3D path of the microchannel introduces the advection. An experimental investigation using chemical solutions revealed that these novel 3D passive microfluidic mixers were stable and could be operated at a wide range of flow rates. This micromixer finds application in the manipulation of tiny volumes of liquids that are crucial in diagnostics. The mixing performance was evaluated by dye visualization, and using a pH test that determined the chemical reaction of the solutions. A comparison of the tornado-mixer with this twisted micromixer was made to evaluate the efficiency of mixing. The efficiency of mixing was calculated within the channel by acquiring intensities using ImageJ software. Results suggested that efficient mixing can be obtained when more than 3 units were consecutively placed. The geometry of the device, which has a length of 30 mm, enables the device to be integrated with micro total analysis systems and other lab-on-chip devices.

  12. Energy efficient engine preliminary design and integration study

    NASA Technical Reports Server (NTRS)

    Gray, D. E.

    1978-01-01

    The technology and configurational requirements of an all new 1990's energy efficient turbofan engine having a twin spool arrangement with a directly coupled fan and low-pressure turbine, a mixed exhaust nacelle, and a high 38.6:1 overall pressure ratio were studied. Major advanced technology design features required to provide the overall benefits were a high pressure ratio compression system, a thermally actuated advanced clearance control system, lightweight shroudless fan blades, a low maintenance cost one-stage high pressure turbine, a short efficient mixer and structurally integrated engine and nacelle. A conceptual design analysis was followed by integration and performance analyses of geared and direct-drive fan engines with separate or mixed exhaust nacelles to refine previously designed engine cycles. Preliminary design and more detailed engine-aircraft integration analysis were then conducted on the more promising configurations. Engine and aircraft sizing, fuel burned, and airframe noise studies on projected 1990's domestic and international aircraft produced sufficient definition of configurational and advanced technology requirements to allow immediate initiation of component technology development.

  13. Subsonic Jet Noise Reduced With Improved Internal Exhaust Gas Mixers

    NASA Technical Reports Server (NTRS)

    1996-01-01

    Aircraft noise pollution is becoming a major environmental concern for the world community. The Federal Aviation Administration (FAA) is responding to this concern by imposing more stringent noise restrictions for aircraft certification then ever before to keep the U.S. industry competitive with the rest of the world. At the NASA Lewis Research Center, attempts are underway to develop noise-reduction technology for newer engines and for retrofitting existing engines so that they are as quiet as (or quieter than) required. Lewis conducted acoustic and Laser Doppler Velocimetry (LDV) tests using Pratt & Whitney's Internal Exhaust Gas Mixers (IEGM). The IEGM's mix the core flow with the fan flow prior to their common exhaust. All tests were conducted in Lewis' Aero-Acoustic Propulsion Laboratory--a semihemispheric dome open to the ambient atmosphere. This was the first time Laser Doppler Velocimetry was used in such a facility at Lewis. Jet exhaust velocity and turbulence and the internal velocity fields were detailed. Far-field acoustics were also measured. Pratt & Whitney provided 1/7th scale model test hardware (a 12-lobe mixer, a 20-lobe mixer, and a splitter) for 1.7 bypass ratio engines, and NASA provided the research engineers, test facility, and test time. The Pratt & Whitney JT8D-200 engine power conditions were used for all tests.

  14. FRONT (SOUTH) ELEVATION, MIXER RUINS (CENTER) WITH STACKS (LEFT) AND ...

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

    FRONT (SOUTH) ELEVATION, MIXER RUINS (CENTER) WITH STACKS (LEFT) AND POWER HOUSE (RIGHT). - Tennessee Coal & Iron Company, Ensley Works, Open Hearth Furnace (Ruins), West of Ensley commercial & residential districts, Birmingham, Jefferson County, AL

  15. FRONT (SOUTH) ELEVATION, MIXER RUINS (CENTER) WITH STACKS (LEFT) AND ...

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

    FRONT (SOUTH) ELEVATION, MIXER RUINS (CENTER) WITH STACKS (LEFT) AND POWER HOUSE (RIGHT - Tennessee Coal & Iron Company, Ensley Works, Open Hearth Furnace (Ruins), West of Ensley commercial & residential districts, Birmingham, Jefferson County, AL

  16. Optimal Elevation and Configuration of Hanford's Double-Shell Tank Waste Mixer Pumps

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Onishi, Yasuo; Yokuda, Satoru T.; Majumder, Catherine A.

    The objective of this study was to compare the mixing performance of the Lawrence pump, which has injection nozzles at the top, with an alternative pump that has injection nozzles at the bottom, and to determine the optimal elevation for the alternative pump. Sixteen cases were evaluated: two sludge thicknesses at eight levels. A two-step evaluation approach was used: Step 1 to evaluate all 16 cases with the non-rotating mixer pump model and Step 2 to further evaluate four of those cases with the more realistic rotating mixer pump model. The TEMPEST code was used.

  17. A user oriented computer program for the analysis of microwave mixers, and a study of the effects of the series inductance and diode capacitance on the performance of some simple mixers

    NASA Technical Reports Server (NTRS)

    Siegel, P. H.; Kerr, A. R.

    1979-01-01

    A user oriented computer program for analyzing microwave and millimeter wave mixers with a single Schottky barrier diode of known I-V and C-V characteristics is described. The program first performs a nonlinear analysis to determine the diode conductance and capacitance waveforms produced by the local oscillator. A small signal linear analysis is then used to find the conversion loss, port impedances, and input noise temperature of the mixer. Thermal noise from the series resistance of the diode and shot noise from the periodically pumped current in the diode conductance are considered. The effects of the series inductance and diode capacitance on the performance of some simple mixer circuits using a conventional Schottky diode, a Schottky diode in which there is no capacitance variation, and a Mott diode are studied. It is shown that the parametric effects of the voltage dependent capacitance of a conventional Schottky diode may be either detrimental or beneficial depending on the diode and circuit parameters.

  18. Combined Numerical/Analytical Perturbation Solutions of the Navier-Stokes Equations for Aerodynamic Ejector/Mixer Nozzle Flows

    NASA Technical Reports Server (NTRS)

    DeChant, Lawrence Justin

    1998-01-01

    In spite of rapid advances in both scalar and parallel computational tools, the large number of variables involved in both design and inverse problems make the use of sophisticated fluid flow models impractical, With this restriction, it is concluded that an important family of methods for mathematical/computational development are reduced or approximate fluid flow models. In this study a combined perturbation/numerical modeling methodology is developed which provides a rigorously derived family of solutions. The mathematical model is computationally more efficient than classical boundary layer but provides important two-dimensional information not available using quasi-1-d approaches. An additional strength of the current methodology is its ability to locally predict static pressure fields in a manner analogous to more sophisticated parabolized Navier Stokes (PNS) formulations. To resolve singular behavior, the model utilizes classical analytical solution techniques. Hence, analytical methods have been combined with efficient numerical methods to yield an efficient hybrid fluid flow model. In particular, the main objective of this research has been to develop a system of analytical and numerical ejector/mixer nozzle models, which require minimal empirical input. A computer code, DREA Differential Reduced Ejector/mixer Analysis has been developed with the ability to run sufficiently fast so that it may be used either as a subroutine or called by an design optimization routine. Models are of direct use to the High Speed Civil Transport Program (a joint government/industry project seeking to develop an economically.viable U.S. commercial supersonic transport vehicle) and are currently being adopted by both NASA and industry. Experimental validation of these models is provided by comparison to results obtained from open literature and Limited Exclusive Right Distribution (LERD) sources, as well as dedicated experiments performed at Texas A&M. These experiments have

  19. Shot-noise in resistive-diode mixers and the attenuator noise model

    NASA Technical Reports Server (NTRS)

    Kerr, A. R.

    1979-01-01

    The representation of a pumped exponential diode, operating as a mixer, by an equivalent lossy network, is reexamined. It is shown that the model is correct provided the network has ports for all sideband frequencies at which (real) power flow can occur between the diode and its embedding. The temperature of the equivalent network is eta/2 times the physical temperature of the diode. The model is valid only if the series resistance and nonlinear capacitance of the diode are negligible. Expressions are derived for the input and output noise temperature and the noise-temperature ratio of ideal mixers. Some common beliefs concerning noise-figure and noise-temperature ratio are shown to be incorrect.

  20. Classical and low-light-level detection and pulse characterization using optical-frequency mixers

    NASA Astrophysics Data System (ADS)

    Langrock, Carsten

    2007-12-01

    Classical all-optical signal processing for telecommunication applications greatly benefits from the availability of highly efficient optical frequency (OF) mixers, the optical analogue of radio-frequency mixers used in RF signal processing. The OF mixers presented in this dissertation are based on reverse-proton-exchange (RPE) periodically-poled lithium niobate (PPLN) waveguides, one of the most efficient and versatile material systems in the field of nonlinear optics to date. Taking advantage of fabrication technologies developed in Prof. Martin Fejer's group over the past two decades, we expand the range of applications for these OF mixers to low-light-level signal detection and pulse characterization. We demonstrate high-speed high-efficiency single-photon counting at telecommunication wavelengths, used for the implementation of record-breaking quantum-key distribution systems, which allow unconditionally secure data transfer. In collaboration with researchers at the MIT Lincoln Laboratory, we also show that the very same technology can be used to achieve an order of magnitude improvement in the sensitivity of classical few-photon free-space communication links based on pulse-position modulation. These extremely sensitive receivers (1 photon/bit) are being developed to facilitate deep-space communication over several hundred million kilometers between Mars and Earth. OF mixers can also be used to fully characterize, potentially weak, ultrashort pulses, as well as time-magnify segments of ultra-high-speed data streams to be detected in real time by conventional streak cameras and oscilloscopes. We will present a novel implementation of both collinear autocorrelation as well as parametric temporal imaging (in collaboration with the Lawrence Livermore National Laboratory) based on mode-multiplexing in integrated asymmetric Y-junctions in combination with linearly-chirped apodized quasi-phasematching gratings. For the first time, background-free autocorrelation

  1. Intermediate/Advanced Research Design and Statistics

    NASA Technical Reports Server (NTRS)

    Ploutz-Snyder, Robert

    2009-01-01

    The purpose of this module is To provide Institutional Researchers (IRs) with an understanding of the principles of advanced research design and the intermediate/advanced statistical procedures consistent with such designs

  2. Characterization of Viscoelastic Materials Through an Active Mixer by Direct-Ink Writing

    NASA Astrophysics Data System (ADS)

    Drake, Eric

    The goal of this thesis is two-fold: First, to determine mixing effectiveness of an active mixer attachment to a three-dimensional (3D) printer by characterizing actively-mixed, three-dimensionally printed silicone elastomers. Second, to understand mechanical properties of a printed lattice structure with varying geometry and composition. Ober et al defines mixing effectiveness as a measureable quantity characterized by two key variables: (i) a dimensionless impeller parameter (O ) that depends on mixer geometry as well as Peclet number (Pe) and (ii) a coefficient of variation (COV) that describes the mixer effectiveness based upon image intensity. The first objective utilizes tungsten tracer particles distributed throughout a batch of Dow Corning SE1700 (two parts silicone) - ink "A". Ink "B" is made from pure SE1700. Using the in-site active mixer, both ink "A" and "B" coalesce to form a hybrid ink just before extrusion. Two samples of varying mixer speeds and composition ratios are printed and analyzed by microcomputed tomography (MicroCT). A continuous stirred tank reactor (CSTR) model is applied to better understand mixing behavior. Results are then compared with computer models to verify the hypothesis. Data suggests good mixing for the sample with higher impeller speed. A Radial Distrubtion Function (RDF) macro is used to provide further qualitative analysis of mixing efficiency. The second objective of this thesis utilized three-dimensionally printed samples of varying geometry and composition to ascertain mechanical properties. Samples were printed using SE1700 provided by Lawrence Livermore National Laboratory with a face-centered tetragonal (FCT) structure. Hardness testing is conducted using a Shore OO durometer guided by a computer-controlled, three-axis translation stage to provide precise movements. Data is collected across an 'x-y' plane of the specimen. To explain the data, a simply supported beam model is applied to a single unit cell which yields

  3. Usefulness of a rotation-revolution mixer for mixing powder-liquid reline material.

    PubMed

    Yamaga, Yoshio; Kanatani, Mitsugu; Nomura, Shuichi

    2015-01-01

    The purpose of this study was to evaluate the distribution of bubbles, degree of mixing, flowability and mechanical strength of powder-liquid reline material by manually and with a rotation-revolution (planetary) mixer, and to determine the usefulness of a rotation-revolution mixer for this application. Powder-liquid reline material (Mild Rebaron, GC, Tokyo, Japan) was mixed with a powder to liquid ratio of 1:0.62 according to the manufacturer's instruction. Two methods were used to mix it: mixed by manually ("manual-mixing") and automatically with a rotation-revolution mixer (Super Rakuneru Fine, GC, Tokyo, Japan; "automatic-mixing"). Disc-shaped specimens, 30 mm in diameter and 1.0mm in thickness, were used to observe the distribution of bubbles in at 10× magnifications. Flowability tests were carried out according to the JIS T6521 for denture base hard reline materials. A three point bending test was carried out by a universal testing machine. Elastic modulus and flexural stress at the proportional limit were calculated. A median of 4 bubbles and inhomogeneous were observed in manual-mixed specimens. However, no bubbles and homogeneous were observed in automatic-mixed specimens. Flowability was within the JIS range in all mixing conditions and did not differ significantly across conditions. The elastic modulus was the same for manual-mixed and automatic-mixed specimens. On the other hand, the flexural stress at the proportional limit differed significantly between manual-mixed and automatic-mixed specimens. The results confirm that rotation-revolution mixer is useful for mixing powder-liquid reline material. Automatic-mixing may be recommended for clinical practice. Copyright © 2014 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

  4. Soft Mixer Assignment in a Hierarchical Generative Model of Natural Scene Statistics

    PubMed Central

    Schwartz, Odelia; Sejnowski, Terrence J.; Dayan, Peter

    2010-01-01

    Gaussian scale mixture models offer a top-down description of signal generation that captures key bottom-up statistical characteristics of filter responses to images. However, the pattern of dependence among the filters for this class of models is prespecified. We propose a novel extension to the gaussian scale mixture model that learns the pattern of dependence from observed inputs and thereby induces a hierarchical representation of these inputs. Specifically, we propose that inputs are generated by gaussian variables (modeling local filter structure), multiplied by a mixer variable that is assigned probabilistically to each input from a set of possible mixers. We demonstrate inference of both components of the generative model, for synthesized data and for different classes of natural images, such as a generic ensemble and faces. For natural images, the mixer variable assignments show invariances resembling those of complex cells in visual cortex; the statistics of the gaussian components of the model are in accord with the outputs of divisive normalization models. We also show how our model helps interrelate a wide range of models of image statistics and cortical processing. PMID:16999575

  5. A “twisted” microfluidic mixer suitable for a wide range of flow rate applications

    PubMed Central

    Sivashankar, Shilpa; Agambayev, Sumeyra; Mashraei, Yousof; Li, Er Qiang; Thoroddsen, Sigurdur T.; Salama, Khaled Nabil

    2016-01-01

    This paper proposes a new “twisted” 3D microfluidic mixer fabricated by a laser writing/microfabrication technique. Effective and efficient mixing using the twisted micromixers can be obtained by combining two general chaotic mixing mechanisms: splitting/recombining and chaotic advection. The lamination of mixer units provides the splitting and recombination mechanism when the quadrant of circles is arranged in a two-layered serial arrangement of mixing units. The overall 3D path of the microchannel introduces the advection. An experimental investigation using chemical solutions revealed that these novel 3D passive microfluidic mixers were stable and could be operated at a wide range of flow rates. This micromixer finds application in the manipulation of tiny volumes of liquids that are crucial in diagnostics. The mixing performance was evaluated by dye visualization, and using a pH test that determined the chemical reaction of the solutions. A comparison of the tornado-mixer with this twisted micromixer was made to evaluate the efficiency of mixing. The efficiency of mixing was calculated within the channel by acquiring intensities using ImageJ software. Results suggested that efficient mixing can be obtained when more than 3 units were consecutively placed. The geometry of the device, which has a length of 30 mm, enables the device to be integrated with micro total analysis systems and other lab-on-chip devices. PMID:27453767

  6. Observational demonstration of a high image rejection SIS mixer receiver using a new waveguide filter at 230 GHz

    NASA Astrophysics Data System (ADS)

    Hasegawa, Yutaka; Asayama, Shinichiro; Harada, Ryohei; Tokuda, Kazuki; Kimura, Kimihiro; Ogawa, Hideo; Onishi, Toshikazu

    2017-12-01

    A new sideband separation method was developed for use in millimeter-/submillimeter-band radio receivers using a novel waveguide frequency separation filter (FSF), which consists of two branch line hybrid couplers and two waveguide high-pass filters. The FSF was designed to allow the radio frequency (RF) signal to pass through to an output port when the frequency is higher than a certain value (225 GHz), and to reflect the RF signal back to another output port when the frequency is lower. The FSF is connected to two double sideband superconductor-insulator-superconductor (SIS) mixers, and an image rejection ratio (IRR) is determined by the FSF characteristics. With this new sideband separation method, we can achieve good and stable IRR without the balancing two SIS mixers such as is necessary for conventional sideband-separating SIS mixers. To demonstrate the applicability of this method, we designed and developed an FSF for simultaneous observations of the J = 2-1 rotational transition lines of three CO isotopes (12CO, 13CO, and C18O): the 12CO line is in the upper sideband and the others are in the lower sideband with an intermediate-frequency range of 4-8 GHz at the radio frequency of 220/230 GHz. This FSF was then installed in the receiver system of the 1.85 m radio telescope of Osaka Prefecture University, and was used during the 2014 observation season. The observation results indicate that the IRR of the proposed receiver is 25 dB or higher for the 12CO line, and no significant fluctuation larger than 1 dB in the IRR was observed throughout the season. These results demonstrate the practical utility of the FSF receiver for observations like extensive molecular cloud surveys in specified lines with a fixed frequency setting.

  7. 16. VIEW OF THE CONCRETE MIXER THAT WAS USED AT ...

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

    16. VIEW OF THE CONCRETE MIXER THAT WAS USED AT THE MERCER MUSEUM AND ON THE INDIAN HOUSE TOWER. - Moravian Pottery & Tile Works, Southwest side of State Route 313 (Swamp Road), Northwest of East Court Street, Doylestown, Bucks County, PA

  8. Evaluation of dispersive mixing, extension rate and bubble size distribution using numerical simulation of a non-Newtonian fluid in a twin-screw mixer

    NASA Astrophysics Data System (ADS)

    Rathod, Maureen L.

    a larger impact. Examination of maximum stable bubble diameter through the mixer predicted areas of higher bubble dispersion based on flow type. This research has advanced simulation of non-Newtonian fluid and shown that direct calculation of extension rate is possible, demonstrating the effect of extension rate on bubble break-up.

  9. Electrokinetically driven active micro-mixers utilizing zeta potential variation induced by field effect

    NASA Astrophysics Data System (ADS)

    Lee, Chia-Yen; Lee, Gwo-Bin; Fu, Lung-Ming; Lee, Kuo-Hoong; Yang, Ruey-Jen

    2004-10-01

    This paper presents a new electrokinetically driven active micro-mixer which uses localized capacitance effects to induce zeta potential variations along the surface of silica-based microchannels. The mixer is fabricated by etching bulk flow and shielding electrode channels into glass substrates and then depositing Au/Cr thin films within the latter to form capacitor electrodes, which establish localized zeta potential variations near the electrical double layer (EDL) region of the electroosmotic flow (EOF) within the microchannels. The potential variations induce flow velocity changes within a homogeneous fluid and a rapid mixing effect if an alternating electric field is provided. The current experimental data confirm that the fluid velocity can be actively controlled by using the capacitance effect of the buried shielding electrodes to vary the zeta potential along the channel walls. While compared with commonly used planar electrodes across the microchannels, the buried shielding electrodes prevent current leakage caused by bad bonding and allow direct optical observation during operation. It also shows that the buried shielding electrodes can significantly induce the field effect, resulting in higher variations of zeta potential. Computational fluid dynamic simulations are also used to study the fluid characteristics of the developed active mixers. The numerical and experimental results demonstrate that the developed microfluidic device permits a high degree of control over the fluid flow and an efficient mixing effect. Moreover, the developed device could be used as a pumping device as well. The development of the active electrokinetically driven micro-mixer could be crucial for micro-total-analysis-systems.

  10. Effect of mixing time and speed on experimental baking and dough testing with a 200g pin-mixer

    USDA-ARS?s Scientific Manuscript database

    Under mixing or over mixing the dough results in varied experimental loaf volumes. Bread preparation requires a trained baker to evaluate dough development and determine stop points of mixer. Instrumentation and electronic control of the dough mixer would allow for automatic mixing. This study us...

  11. Can fractal objects operate as efficient inline mixers?

    NASA Astrophysics Data System (ADS)

    Laizet, Sylvain; Vassilicos, John; Turbulence, Mixing; Flow Control Group Team

    2011-11-01

    Recently, Hurst & Vassilicos, PoF 2007, Seoud & Vassilicos, PoF 2007, Mazellier & Vassilicos, PoF, 2010 used different multiscale grids to generate turbulence in a wind tunnel and have shown that complex multiscale boundary/initial conditions can drastically influence the behaviour of a turbulent flow, but that the detailled specific nature of the multiscale geometry matters too. Multiscale (fractal) objects can be designed to be immersed in any fluid flow where there is a need to control and design the turbulence generated by the object. Different types of multiscale objects can be designed as different types of energy-efficient mixers with varying degrees of high turbulent intensities, small pressure drop and downstream distance from the grid where the turbulence is most vigorous. Here, we present a 3D DNS study of the stirring and mixing of a passive scalar by turbulence generated with either a fractal square grid or a regular grid in the presence of a mean scalar gradient. The results show that: (1) there is a linear increase for the passive scalar variance for both grids, (2) the passive scalar variance is ten times bigger for the fractal grid, (3) the passive scalar flux is constant after the production region for both grids, (4) the passive scalar flux is enhanced by an order of magnitude for the fractal grid. We acknowledge support from EPSRC, UK.

  12. Frequency-Domain Analysis of Diffusion-Cooled Hot-Electron Bolometer Mixers

    NASA Technical Reports Server (NTRS)

    Skalare, A.; McGrath, W. R.; Bumble, B.; LeDuc, H. G.

    1998-01-01

    A new theoretical model is introduced to describe heterodyne mixer conversion efficiency and noise (from thermal fluctuation effects) in diffusion-cooled superconducting hot-electron bolometers. The model takes into account the non-uniform internal electron temperature distribution generated by Wiedemann-Franz heat conduction, and accepts for input an arbitrary (analytical or experimental) superconducting resistance-versus- temperature curve. A non-linear large-signal solution is solved iteratively to calculate the temperature distribution, and a linear frequency-domain small-signal formulation is used to calculate conversion efficiency and noise. In the small-signal solution the device is discretized into segments, and matrix algebra is used to relate the heating modulation in the segments to temperature and resistance modulations. Matrix expressions are derived that allow single-sideband mixer conversion efficiency and coupled noise power to be directly calculated. The model accounts for self-heating and electrothermal feedback from the surrounding bias circuit.

  13. Simulator design for advanced ISDN satellite design and experiments

    NASA Technical Reports Server (NTRS)

    Pepin, Gerald R.

    1992-01-01

    This simulation design task completion report documents the simulation techniques associated with the network models of both the Interim Service ISDN (integrated services digital network) Satellite (ISIS) and the Full Service ISDN Satellite (FSIS) architectures. The ISIS network model design represents satellite systems like the Advanced Communication Technology Satellite (ACTS) orbiting switch. The FSIS architecture, the ultimate aim of this element of the Satellite Communications Applications Research (SCAR) program, moves all control and switching functions on-board the next generation ISDN communication satellite. The technical and operational parameters for the advanced ISDN communications satellite design will be obtained from the simulation of ISIS and FSIS engineering software models for their major subsystems. Discrete events simulation experiments will be performed with these models using various traffic scenarios, design parameters and operational procedures. The data from these simulations will be used to determine the engineering parameters for the advanced ISDN communications satellite.

  14. 88. VIEW OF THE CONCRETE MIXER THAT WAS USED AT ...

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

    88. VIEW OF THE CONCRETE MIXER THAT WAS USED AT THE MERCER MUSEUM AND ON THE INDIAN HOUSE TOWER. SAME VIEW AS PA-107-16. - Moravian Pottery & Tile Works, Southwest side of State Route 313 (Swamp Road), Northwest of East Court Street, Doylestown, Bucks County, PA

  15. 7 CFR 58.228 - Dump hoppers, screens, mixers and conveyors.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... AND STANDARDS UNDER THE AGRICULTURAL MARKETING ACT OF 1946 AND THE EGG PRODUCTS INSPECTION ACT... DAIRY PRODUCTS 1 General Specifications for Dairy Plants Approved for USDA Inspection and Grading Service 1 Equipment and Utensils § 58.228 Dump hoppers, screens, mixers and conveyors. The product contact...

  16. VERIFICATION TESTING OF HIGH-RATE MECHANICAL INDUCTION MIXERS FOR CHEMICAL DISINFECTANTS

    EPA Science Inventory

    This paper describes the results of verification testing of mechanical induction mixers for dispersion of chemical disinfectants in wet-weather flow (WWF) conducted under the U.S. Environmental Protection Agency's Environmental Technology Verification (ETV) WWF Pilot Program. Th...

  17. Very high-current-density Nb/AlN/Nb tunnel junctions for low-noise submillimeter mixers

    NASA Astrophysics Data System (ADS)

    Kawamura, Jonathan; Miller, David; Chen, Jian; Zmuidzinas, Jonas; Bumble, Bruce; LeDuc, Henry G.; Stern, Jeff A.

    2000-04-01

    We have fabricated and tested submillimeter-wave superconductor-insulator-superconductor (SIS) mixers using very high-current-density Nb/AlN/Nb tunnel junctions (Jc≈30 kA cm-2). The junctions have low-resistance-area products (RNA≈5.6 Ω μm2), good subgap-to-normal resistance ratios Rsg/RN≈10, and good run-to-run reproducibility. From Fourier transform spectrometer measurements, we infer that ωRNC=1 at 270 GHz. This is a factor of 2.5 improvement over what is generally available with Nb/AlOx/Nb junctions suitable for low-noise mixers. The AlN-barrier junctions are indeed capable of low-noise operation: we measure an uncorrected double-sideband receiver noise temperature of TRX=110 K at 533 GHz for an unoptimized device. In addition to providing wider bandwidth operation at lower frequencies, the AlN-barrier junctions will considerably improve the performance of THz SIS mixers by reducing rf loss in the tuning circuits.

  18. Full-scale altitude engine test of a turbofan exhaust-gas-forced mixer to reduce thrust specific fuel consumption

    NASA Technical Reports Server (NTRS)

    Cullom, R. R.; Johnson, R. L.

    1977-01-01

    The specific fuel consumption of a low-bypass-ratio, confluent-flow, turbofan engine was measured with and without a mixer installed. Tests were conducted for flight Mach numbers from 0.3 to 1.4 and altitudes from 10,670 to 14,630 meters (35,000 to 48,000 ft) for core-stream-to-fan-stream temperature ratios of 2.0 and 2.5 and mixing-length-to-diameter ratios of 0.95 and 1.74. For these test conditions, the reduction in specific fuel consumption varied from 2.5 percent to 4.0 percent. Pressure loss measurements as well as temperature and pressure surveys at the mixer inlet, the mixer exit, and the nozzle inlet were made.

  19. FDC Mentor-Mentee Mixer Breaks the Ice Between Investigators and Trainees | Poster

    Cancer.gov

    The Frederick Diversity Committee’s mentor-mentee mixer gave research trainees, senior investigators, scientists, and administrative staff a chance to meet and mingle over refreshments and games following the Spring Research Festival.

  20. 50 MHz-10 GHz low-power resistive feedback current-reuse mixer with inductive peaking for cognitive radio receiver.

    PubMed

    Vitee, Nandini; Ramiah, Harikrishnan; Chong, Wei-Keat; Tan, Gim-Heng; Kanesan, Jeevan; Reza, Ahmed Wasif

    2014-01-01

    A low-power wideband mixer is designed and implemented in 0.13 µm standard CMOS technology based on resistive feedback current-reuse (RFCR) configuration for the application of cognitive radio receiver. The proposed RFCR architecture incorporates an inductive peaking technique to compensate for gain roll-off at high frequency while enhancing the bandwidth. A complementary current-reuse technique is used between transconductance and IF stages to boost the conversion gain without additional power consumption by reusing the DC bias current of the LO stage. This downconversion double-balanced mixer exhibits a high and flat conversion gain (CG) of 14.9 ± 1.4 dB and a noise figure (NF) better than 12.8 dB. The maximum input 1-dB compression point (P1dB) and maximum input third-order intercept point (IIP3) are -13.6 dBm and -4.5 dBm, respectively, over the desired frequency ranging from 50 MHz to 10 GHz. The proposed circuit operates down to a supply headroom of 1 V with a low-power consumption of 3.5 mW.

  1. An inverted micro-mixer based on a magnetically-actuated cilium made of Fe doped PDMS

    NASA Astrophysics Data System (ADS)

    Liu, Fengli; Zhang, Jun; Alici, Gursel; Yan, Sheng; Mutlu, Rahim; Li, Weihua; Yan, Tianhong

    2016-09-01

    In this paper, we report a new micromixer based on a flexible artificial cilium activated by an external magnetic field. The cilium is fabricated from Polydimethylsiloxane doped with Fe microparticles. The fabrication method is based on the standard sacrificial layer technology. The cilium was built on a glass slide, and then was bonded on the top of the micro-mixer chamber in a microfluidic chip. This fabrication process for the miniaturized active mixers is simple and cost effective. An electromagnetic system was used to drive the cilium and induce strong convective flows of the fluid in the chamber. In the presence of an alternating magnetic field, the cilium applied a corresponding alternating force on the surrounding fluids. The performance of the electromagnetically activated cilium was quantified and optimized in order to obtain maximum mixing performance. In addition, the mixing performance of the cilium in a circular micro-chamber was compared with pure diffusion. Up to 80% of a 60 ul liquid in the chamber can be fully mixed after 2 min using a cilium mixer under a magnetic flux density of 22 mT in contrast to the 20 min which were needed to obtain the same mixing percentage under pure diffusion. Furthermore, for a mixing degree of 80%, the mixing speed for the cilia micromixer proposed in this study was 9 times faster than that of the diffusion-based micro-mixers reported in the literature.

  2. Hot-Electron Bolometer Mixers on Silicon-on-Insulator Substrates for Terahertz Frequencies

    NASA Technical Reports Server (NTRS)

    Skalare, Anders; Stern, Jeffrey; Bumble, Bruce; Maiwald, Frank

    2005-01-01

    A terahertz Hot-Electron Bolometer (HEB) mixer design using device substrates based on Silicon-On-Insulator (SOI) technology is described. This substrate technology allows very thin chips (6 pm) with almost arbitrary shape to be manufactured, so that they can be tightly fitted into a waveguide structure and operated at very high frequencies with only low risk for power leakages and resonance modes. The NbTiN-based bolometers are contacted by gold beam-leads, while other beamleads are used to hold the chip in place in the waveguide test fixture. The initial tests yielded an equivalent receiver noise temperature of 3460 K double-sideband at a local oscillator frequency of 1.462 THz and an intermediate frequency of 1.4 GHz.

  3. All-optical, ultra-wideband microwave I/Q mixer and image-reject frequency down-converter.

    PubMed

    Gao, Yongsheng; Wen, Aijun; Chen, Wei; Li, Xiaoyan

    2017-03-15

    An all-optical and ultra-wideband microwave in-phase/quadrature (I/Q) mixer, based on a dual-parallel Mach-Zehnder modulator and a wavelength division multiplexer, is proposed. Due to the simultaneous frequency down-conversion and 360-deg tunable phase shifting in the optical domain, the proposed I/Q mixer has the advantages of high conversion gain and excellent quadrature phase balance (<±1.3 deg⁡) with a wide operating frequency from 10 to 40 GHz. Assisted by an analog or digital intermediate-frequency quadrature coupler, an image-reject frequency down-converter is then implemented, with an image rejection exceeding 50 dB over the working band.

  4. Modeling and Optimization of a High-Tc Hot-Electron Superconducting Mixer for Terahertz Applicaitons

    NASA Technical Reports Server (NTRS)

    Karasik, B. S.; McGrath, W. R.; Gaidis, M. C.; Burns, M. J.; Kleinsasser, A. W.; Delin, K. A.; Vasquez, R. P.

    1996-01-01

    The development of a YBa(sub 2)Cu(sub 3)O(sub 7-(kronecker delta))(YBCO) hot-electron bolometer (HEB) quasioptical mixer for a 2.5 heterodyne receiver is discussed. The modeled device is a submicron bridge made from a 10 nm thick film on a high thermal conductance substrate. The mixer performance expected for this device is analyzed in the framework of a two-temperature model which includes heating both of the electrons and the lattice. Also, the contribution of heat diffusion from the film through the substrate and from the film to the normal metal contacts is evaluated....a single sideband temperature of less than 2000k is predicted.

  5. Very High Current Density Nb/AlN/Nb Tunnel Junctions for Low-Noise Submillimeter Mixers

    NASA Technical Reports Server (NTRS)

    Kawamura, Jonathan; Miller, David; Chen, Jian; Zmuidzinas, Jonas; Bumble, Bruce; LeDuc, Henry G.; Stern, Jeff A.

    2000-01-01

    We have fabricated and tested submillimeter-wave superconductor-insulator-superconductor (SIS) mixers using very high current density Nb/AlN/Nb tunnel junctions (J(sub c) approximately equal 30 kA/sq cm) . The junctions have low resistance-area products (R(sub N)A approximately 5.6 Omega.sq micron), good subgap to normal resistance ratios R(sub sg)/R(sub N) approximately equal 10, and good run-to-run reproducibility. From Fourier transform spectrometer measurements, we infer that omega.R(sub N)C = 1 at 270 GHz. This is a factor of 2.5 improvement over what is generally available with Nb/AlO(x)/Nb junctions suitable for low-noise mixers. The AlN-barrier junctions are indeed capable of low-noise operation: we measure an uncorrected receiver noise temperature of T(sub RX) = 110 K (DSB) at 533 GHz for an unoptimized device. In addition to providing wider bandwidth operation at lower frequencies, the AlN-barrier junctions will considerably improve the performance of THz SIS mixers by reducing RF loss in the tuning circuits.

  6. ENVIRONMENTAL TECHNOLOGY VERIFICATION JOINT (NSF-EPA) VERIFICATION STATEMENT AND REPORT PERFORMANCE OF INDUCTION MIXERS FOR DISINFECTION OF WET WEATHER FLOWS, GAS MASTRRR SERIES 32 SUBMERSIBLE CHEMICAL INDUCTION MIXERS

    EPA Science Inventory

    The Wet-Weather Flow Technologies Pilot of the EPA's Environmental Technology Verification (ETV) Program under a partnership with NSF International has verified the performance of the GAS MASTRRR Series 32 Submersible Chemical Induction Mixers used for disinfection of wet-weather...

  7. VERIFICATION TESTING OF HIGH-RATE MECHANICAL INDUCTION MIXERS FOR CHEMICAL DISINFECTANTS, Oregon

    EPA Science Inventory

    This paper describes the results of verification testing of mechanical induction mixers for dispersion of chemical disinfectants in wet-weather flow (WWF) conducted under the U.S. Environmental Protection Agency's Environmental Technology Verification (ETV) WWF Pilot Program. Th...

  8. Building Better: Advanced Energy Design Guides - Continuum Magazine |

    Science.gov Websites

    NREL Building Better: Advanced Energy Design Guides Building Better: Advanced Energy Design Greensburg be constructed to meet Leadership in Energy and Environmental Design (LEED) Platinum ratings from design needs to incorporate a number of recommendations for achieving energy savings over the minimum

  9. Noise and Bandwidth Measurements of Diffusion-Cooled Nb Hot-Electron Bolometer Mixers at Frequencies Above the Superconductive Energy Gap

    NASA Technical Reports Server (NTRS)

    Wyss, R. A.; Karasik, B. S.; McGrath, W. R.; Bumble, B.; LeDuc, H.

    1999-01-01

    Diffusion-cooled Nb hot-electron bolometer (HEB) mixers have the potential to simultaneously achieve high intermediate frequency (IF) bandwidths and low mixer noise temperatures for operation at THz frequencies (above the superconductive gap energy). We have measured the IF signal bandwidth at 630 GHz of Nb devices with lengths L = 0.3, 0.2, and 0.1 micrometer in a quasioptical mixer configuration employing twin-slot antennas. The 3-dB EF bandwidth increased from 1.2 GHz for the 0.3 gm long device to 9.2 GHz for the 0.1 gm long device. These results demonstrate the expected 1/L squared dependence of the IF bandwidth at submillimeter wave frequencies for the first time, as well as the largest EF bandwidth obtained to date. For the 0.1 gm device, which had the largest bandwidth, the double sideband (DSB) noise temperature of the receiver was 320-470 K at 630 GHz with an absorbed LO power of 35 nW, estimated using the isothermal method. A version of this mixer with the antenna length scaled for operation at 2.5 THz has also been tested. A DSB receiver noise temperature of 1800 plus or minus 100 K was achieved, which is about 1,000 K lower than our previously reported results. These results demonstrate that large EF bandwidth and low-noise operation of a diffusion-cooled HEB mixer is possible at THz frequencies with the same device geometry.

  10. Receiver System Analysis and Optimization

    DTIC Science & Technology

    2013-01-01

    designers to make best use of advanced silicon processes (scale, fast devices) while minimizing the disadvantages (low-Q passives, low transimpedance ). A...components such as amplifiers , filters, mixers, oscillators, etc. Specifications for the components are then passed on to design teams. The digital and...cascade connection of an LNA, Mixer, Voltage Controlled Oscillator [VCO], Amplifier and Analog to Digital Converter [ADC] as well as appropriate

  11. Advanced wind turbine design

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Jamieson, P.M.; Jaffrey, A.

    1995-09-01

    Garrad Hassan have a project in progress funded by the UK Department of Trade and Industry (DTI) to assess the prospects and cost benefits of advanced wind turbine design. In the course of this work, a new concept, the coned rotor design, has been developed. This enables a wind turbine system to operate in effect with variable rotor diameter augmenting energy capture in light winds and shedding loads in storm conditions. Comparisons with conventional design suggest that a major benefit in reduced cost of wind generated electricity may be possible.

  12. Advanced wind turbine design

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Jamieson, P.M.; Jaffrey, A.

    1997-11-01

    Garrad Hassan have a project in progress funded by the U.K. Department of Trade and Industry (DTI) to assess the prospects and cost benefits of advanced wind turbine design. In the course of this work, a new concept, the coned rotor design, has been developed. This enables a wind turbine system to operate in effect with variable rotor diameter augmenting energy capture in light winds and shedding loads in storm conditions. Comparisons with conventional design suggest that a major benefit in reduced cost of wind-generated electricity may be possible.

  13. The aerodynamic design of an advanced rotor airfoil

    NASA Technical Reports Server (NTRS)

    Blackwell, J. A., Jr.; Hinson, B. L.

    1978-01-01

    An advanced rotor airfoil, designed utilizing supercritical airfoil technology and advanced design and analysis methodology is described. The airfoil was designed subject to stringent aerodynamic design criteria for improving the performance over the entire rotor operating regime. The design criteria are discussed. The design was accomplished using a physical plane, viscous, transonic inverse design procedure, and a constrained function minimization technique for optimizing the airfoil leading edge shape. The aerodynamic performance objectives of the airfoil are discussed.

  14. Microfluidic T-form mixer utilizing switching electroosmotic flow.

    PubMed

    Lin, Che-Hsin; Fu, Lung-Ming; Chien, Yu-Sheng

    2004-09-15

    This paper presents a microfluidic T-form mixer utilizing alternatively switching electroosmotic flow. The microfluidic device is fabricated on low-cost glass slides using a simple and reliable fabrication process. A switching DC field is used to generate an electroosmotic force which simultaneously drives and mixes the fluid samples. The proposed design eliminates the requirements for moving parts within the microfluidic device and delicate external control systems. Two operation modes, namely, a conventional switching mode and a novel pinched switching mode, are presented. Computer simulation is employed to predict the mixing performance attainable in both operation modes. The simulation results are then compared to those obtained experimentally. It is shown that a mixing performance as high as 97% can be achieved within a mixing distance of 1 mm downstream from the T-junction when a 60 V/cm driving voltage and a 2-Hz switching frequency are applied in the pinched switching operation mode. This study demonstrates how the driving voltage and switching frequency can be optimized to yield an enhanced mixing performance. The novel methods presented in this study provide a simple solution to mixing problems in the micro-total-analysis-systems field.

  15. Numerical study of fluid motion in bioreactor with two mixers

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Zheleva, I., E-mail: izheleva@uni-ruse.bg; Lecheva, A., E-mail: alecheva@uni-ruse.bg

    2015-10-28

    Numerical study of hydrodynamic laminar behavior of a viscous fluid in bioreactor with multiple mixers is provided in the present paper. The reactor is equipped with two disk impellers. The fluid motion is studied in stream function-vorticity formulation. The calculations are made by a computer program, written in MATLAB. The fluid structure is described and numerical results are graphically presented and commented.

  16. Advanced Beamline Design for Fermilab's Advanced Superconducting Test Accelerator

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Prokop, Christopher

    2014-01-01

    The Advanced Superconducting Test Accelerator (ASTA) at Fermilab is a new electron accelerator currently in the commissioning stage. In addition to testing superconducting accelerating cavities for future accelerators, it is foreseen to support a variety of Advanced Accelerator R&D (AARD) experiments. Producing the required electron bunches with the expected flexibility is challenging. The goal of this dissertation is to explore via numerical simulations new accelerator beamlines that can enable the advanced manipulation of electron bunches. The work especially includes the design of a low-energy bunch compressor and a study of transverse-to-longitudinal phase space exchangers.

  17. A Low-noise Micromachined Millimeter-Wave Heterodyne Mixer using Nb Superconducting Tunnel Junctions

    NASA Technical Reports Server (NTRS)

    DeLange, Gert; Jacobson, Brian R.; Hu, Qing

    1996-01-01

    A heterodyne mixer with a micromachined horn antenna and a superconductor-insulator-superconductor (SIS) tunnel junction as mixing element is tested in the W-band (75-115 GHz) frequency range. Micromachined integrated horn antennas consist of a dipole antenna suspended on a thin Si3N4 dielectric membrane inside a pyramidal cavity etched in silicon. The mixer performance is optimized by using a backing plane behind the dipole antenna to tune out the capacitance of the tunnel junction. The lowest receiver noise temperature of 30 +/- 3 K (without any correction) is measured at 106 GHz with a 3-dB bandwidth of 8 GHz. This sensitivity is comparable to the state-of-the-art waveguide and quasi-optical SIS receivers, showing the potential use of micromachined horn antennas in imaging arrays.

  18. Full Navier-Stokes analysis of a two-dimensional mixer/ejector nozzle for noise suppression

    NASA Technical Reports Server (NTRS)

    Debonis, James R.

    1992-01-01

    A three-dimensional full Navier-Stokes (FNS) analysis was performed on a mixer/ejector nozzle designed to reduce the jet noise created at takeoff by a future supersonic transport. The PARC3D computational fluid dynamics (CFD) code was used to study the flow field of the nozzle. The grid that was used in the analysis consisted of approximately 900,000 node points contained in eight grid blocks. Two nozzle configurations were studied: a constant area mixing section and a diverging mixing section. Data are presented for predictions of pressure, velocity, and total temperature distributions and for evaluations of internal performance and mixing effectiveness. The analysis provided good insight into the behavior of the flow.

  19. A novel microfluidic mixer based on dual-hydrodynamic focusing for interrogating the kinetics of DNA-protein interaction.

    PubMed

    Li, Ying; Xu, Fei; Liu, Chao; Xu, Youzhi; Feng, Xiaojun; Liu, Bi-Feng

    2013-08-21

    Kinetic measurement of biomacromolecular interaction plays a significant role in revealing the underlying mechanisms of cellular activities. Due to the small diffusion coefficient of biomacromolecules, it is difficult to resolve the rapid kinetic process with traditional analytical methods such as stopped-flow or laminar mixers. Here, we demonstrated a unique continuous-flow laminar mixer based on microfluidic dual-hydrodynamic focusing to characterize the kinetics of DNA-protein interactions. The time window of this mixer for kinetics observation could cover from sub-milliseconds to seconds, which made it possible to capture the folding process with a wide dynamic range. Moreover, the sample consumption was remarkably reduced to <0.55 μL min⁻¹, over 1000-fold saving in comparison to those reported previously. We further interrogated the interaction kinetics of G-quadruplex and the single-stranded DNA binding protein, indicating that this novel micromixer would be a useful approach for analyzing the interaction kinetics of biomacromolecules.

  20. Fabrication of High-T(sub c) Hot-Electron Bolometric Mixers for Terahertz Applications

    NASA Technical Reports Server (NTRS)

    Burns, M. J.; Kleinsasser, A. W.; Delin, K. A.; Vasquez, R. P.; Karasik, B. S.; McGrath, W. R.; Gaidis, M. C.

    1996-01-01

    Superocnducting hot-electron bolometers (HEB) represent a promising candidate for heterodyne mixing at frequencies exceeding 1 THz. Nb HEB mixers offer performance competitive with tunnel junctions without the frequency limit imposed by the superconducting energy gap.

  1. Analysis of a High-Tc Hot-Electron Superconducting Mixer for Terahertz Applications

    NASA Technical Reports Server (NTRS)

    Karasik, B. S.; McGrath, W. R.; Gaidis, M. C.

    1996-01-01

    The prospects of a YBa2Cu3O7(delta)(YBCO) hot-electron bolometer (HEB) mixer for a THz heterodyne receiver is discussed. The modeled device is a submicron bridge made from a 10 nm thick film on a high thermal conductance substrate.

  2. Proceedings of the Ninth Annual Summer Conference: NASA/USRA University Advanced Aeronautics Design Program and Advanced Space Design Program

    NASA Technical Reports Server (NTRS)

    1993-01-01

    The NASA/USRA University Advanced Design Program was established in 1984 as an attempt to add more and better design education to primarily undergraduate engineering programs. The original focus of the pilot program encompassing nine universities and five NASA centers was on space design. Two years later, the program was expanded to include aeronautics design with six universities and three NASA centers participating. This year marks the last of a three-year cycle of participation by forty-one universities, eight NASA centers, and one industry participant. The Advanced Space Design Program offers universities an opportunity to plan and design missions and hardware that would be of usc in the future as NASA enters a new era of exploration and discovery, while the Advanced Aeronautics Design Program generally offers opportunities for study of design problems closer to the present time, ranging from small, slow-speed vehicles to large, supersonic and hypersonic passenger transports. The systems approach to the design problem is emphasized in both the space and aeronautics projects. The student teams pursue the chosen problem during their senior year in a one- or two-semester capstone design course and submit a comprehensive written report at the conclusion of the project. Finally, student representatives from each of the universities summarize their work in oral presentations at the Annual Summer Conference, sponsored by one of the NASA centers and attended by the university faculty, NASA and USRA personnel and aerospace industry representatives. As the Advanced Design Program has grown in size, it has also matured in terms of the quality of the student projects. The present volume represents the student work accomplished during the 1992-1993 academic year reported at the Ninth Annual Summer Conference hosted by NASA Lyndon B. Johnson Space Center, June 14-18, 1993.

  3. Desire to Drink Alcohol is Enhanced with High Caffeine Energy Drink Mixers.

    PubMed

    Marczinski, Cecile A; Fillmore, Mark T; Stamates, Amy L; Maloney, Sarah F

    2016-09-01

    Consumption of alcohol mixed with energy drinks (AmED) has been associated with a variety of risks beyond that observed with alcohol alone. Consumers of AmED beverages are more likely to engage in heavy episodic (binge) drinking. This study was to investigate whether the consumption of high caffeine energy drink mixers with alcohol would increase the desire to drink alcohol compared to the same amount of alcohol alone using a double-blind, within-subjects, placebo-controlled study design. Participants (n = 26) of equal gender who were social drinkers attended 6 double-blind dose administration sessions that involved consumption of alcohol and energy drinks, alone and in combination. On each test day, participants received 1 of 6 possible doses: (i) 1.21 ml/kg vodka + 3.63 ml/kg decaffeinated soft drink, (ii) 1.21 ml/kg vodka + 3.63 ml/kg energy drink, (iii) 1.21 ml/kg vodka + 6.05 ml/kg energy drink, (iv) 3.63 ml/kg decaffeinated soft drink, (v) 3.63 ml/kg energy drink, and (vi) 6.05 ml/kg energy drink. Following dose administration, participants repeatedly completed self-reported ratings on the Desire-for-Drug questionnaire and provided breath alcohol readings. Alcohol alone increased the subjective ratings of "desire for more alcohol" compared to placebo doses. Energy drink mixers with the alcohol increased desire for more alcohol ratings beyond that observed with alcohol alone. This study provides laboratory evidence that AmED beverages lead to greater desire to drink alcohol versus the same amount of alcohol consumed alone. The findings are consistent with results from animal studies indicating that caffeine increases the rewarding and reinforcing properties of alcohol. Copyright © 2016 by the Research Society on Alcoholism.

  4. Systematic analysis of CMOS-micromachined inductors with application to mixer matching circuits

    NASA Astrophysics Data System (ADS)

    Wu, Jerry Chun-Li

    The growing demand for consumer voice and data communication systems and military communication applications has created a need for low-power, low-cost, high-performance radio-frequency (RF) front-end. To achieve this goal, bringing passive components, especially inductors, to silicon is imperative. On-chip passive components such as inductors and capacitors generally enhance the reliability and efficiency of silicon-integrated RF cells. They can provide circuit solutions with superior performance and contribute to a higher level of integration. With passive components on chip, there is a great opportunity to have transformers, filters, and matching networks on chip. However, inductors on silicon have a low quality factor (Q) due to both substrate and metal loss. This dissertation demonstrates the systematic analysis of inductors fabricated using standard complementary metal-oxide-semiconductor (CMOS) and micro-electro-mechanical (MEMS) system technologies. We report system-on-chip inductor modeling, simulation, and measurements of effective inductance and quality factors. In this analysis methodology, a number of systematic simulations are performed on regular and micromachined inductors with different parameters such as spiral topology, number of turns, outer diameter, thickness, and percentage of substrate removed by using micromachining technologies. Three different novel support structures of the micromachined spiral inductor are proposed, analyzed, and implemented for larger size suspended inductors. The sensitivity of the structure support and different degree of substrate etching by post-processing is illustrated. The results provide guidelines for the selection of inductor parameters, post-processing methodologies, and its spiral supports to meet the RF design specifications and the stability requirements for mobile communication. The proposed CMOS-micromachined inductor is used in a low cost-effective double-balanced Gilbert mixer with on-chip matching

  5. Aeroacoustic Characteristics of a Rectangular Multi-Element Supersonic Jet Mixer-Ejector Nozzle

    NASA Technical Reports Server (NTRS)

    Raman, Ganesh; Taghavi, Ray

    1996-01-01

    This paper provides a unique, detailed evaluation of the acoustics and aerodynamics of a rectangular multi-element supersonic jet mixer-ejector noise suppressor. The performance of such mixer-ejectors is important in aircraft engine application for noise suppression and thrust augmentation. In contrast to most prior experimental studies on ejectors that reported either aerodynamic or acoustic data, our work documents both types of data. We present information on the mixing, pumping, ejector wall pressure distribution, thrust augmentation and noise suppression characteristics of four simple, multi-element, jet mixer-ejector configurations. The four configurations included the effect of ejector area ratio (AR = ejector area/primary jet area) and the effect of non-parallel ejector walls. We also studied in detail the configuration that produced the best noise suppression characteristics. Our results show that ejector configurations that produced the maximum maximum pumping (entrained flow per secondary inlet area) also exhibited the lowest wall pressures in the inlet region, and the maximum thrust augmentation. When cases having the same total mass flow were compared, we found that noise suppression trends corresponded with those for pumping. Surprisingly, the mixing (quantified by the peak Mach number, and flow uniformity) at the ejector exit exhibited no relationship to the noise suppression at moderate primary jet fully expanded Mach numbers (Mj is less than 1.4). However, the noise suppression dependence on the mixing was apparent at higher Mj. The above observations are justified by noting that the mixing at the ejector exit is ot a strong factor in determining the radiated noise when noise produced internal to the ejector dominates the noise field outside the ejector.

  6. 5 Gbps wireless transmission link with an optically pumped uni-traveling carrier photodiode mixer at the receiver.

    PubMed

    Mohammad, Ahmad W; Shams, Haymen; Balakier, Katarzyna; Graham, Chris; Natrella, Michele; Seeds, Alwyn J; Renaud, Cyril C

    2018-02-05

    We report the first demonstration of a uni-traveling carrier photodiode (UTC-PD) used as a 5 Gbps wireless receiver. In this experiment, a 35.1 GHz carrier was electrically modulated with 5 Gbps non-return with zero on-off keying (NRZ-OOK) data and transmitted wirelessly over a distance of 1.3 m. At the receiver, a UTC-PD was used as an optically pumped mixer (OPM) to down-convert the received radio frequency (RF) signal to an intermediate frequency (IF) of 11.7 GHz, before it was down-converted to the baseband using an electronic mixer. The recovered data show a clear eye diagram, and a bit error rate (BER) of less than 10 -8 was measured. The conversion loss of the UTC-PD optoelectronic mixer has been measured at 22 dB. The frequency of the local oscillator (LO) used for the UTC-PD is defined by the frequency spacing between the two optical tones, which can be broadly tuneable offering the frequency agility of this photodiode-based receiver.

  7. Thermal Analysis and Design of an Advanced Space Suit

    NASA Technical Reports Server (NTRS)

    Lin, Chin H.; Campbell, Anthony B.; French, Jonathan D.; French, D.; Nair, Satish S.; Miles, John B.

    2000-01-01

    The thermal dynamics and design of an Advanced Space Suit are considered. A transient model of the Advanced Space Suit has been developed and implemented using MATLAB/Simulink to help with sizing, with design evaluation, and with the development of an automatic thermal comfort control strategy. The model is described and the thermal characteristics of the Advanced Space suit are investigated including various parametric design studies. The steady state performance envelope for the Advanced Space Suit is defined in terms of the thermal environment and human metabolic rate and the transient response of the human-suit-MPLSS system is analyzed.

  8. A millimeter wave Josephson mixer employing a high-T(c) GdBaCuO point contact

    NASA Technical Reports Server (NTRS)

    Olsson, H. K.; Claeson, T.; Eriksson, S.; Johansson, L.-G.; Mcgrath, W. R.

    1987-01-01

    A Josephson effect heterodyne mixer for the millimeter wave band was investigated employing high-T(c) GdBaCuO point contacts. Mixer performance was in qualitative agreement with theory. A mixing response was observed up to 55 K, the highest operating temperature achieved for such a device to date. The voltage separation of RF-induced steps gave a value of h/2e = 2.08 x 10 to the -15th V s, which is in excellent agreement with the value expected for Cooper pairs. In addition, the temperature dependence of the I(0)R product was found to agree with Bardeen-Cooper-Schrieffer theory in the weak coupling limit.

  9. Advanced Subsonic Airplane Design and Economic Studies

    NASA Technical Reports Server (NTRS)

    Liebeck, Robert H.; Andrastek, Donald A.; Chau, Johnny; Girvin, Raquel; Lyon, Roger; Rawdon, Blaine K.; Scott, Paul W.; Wright, Robert A.

    1995-01-01

    A study was made to examine the effect of advanced technology engines on the performance of subsonic airplanes and provide a vision of the potential which these advanced engines offered. The year 2005 was selected as the entry-into-service (EIS) date for engine/airframe combination. A set of four airplane classes (passenger and design range combinations) that were envisioned to span the needs for the 2005 EIS period were defined. The airframes for all classes were designed and sized using 2005 EIS advanced technology. Two airplanes were designed and sized for each class: one using current technology (1995) engines to provide a baseline, and one using advanced technology (2005) engines. The resulting engine/airframe combinations were compared and evaluated on the basis on sensitivity to basic engine performance parameters (e.g. SFC and engine weight) as well as DOC+I. The advanced technology engines provided significant reductions in fuel burn, weight, and wing area. Average values were as follows: reduction in fuel burn = 18%, reduction in wing area = 7%, and reduction in TOGW = 9%. Average DOC+I reduction was 3.5% using the pricing model based on payload-range index and 5% using the pricing model based on airframe weight. Noise and emissions were not considered.

  10. Cross-Stream PIV Measurements of Jets With Internal Lobed Mixers

    NASA Technical Reports Server (NTRS)

    Bridges, James; Wernet, Mark P.

    2004-01-01

    With emphasis being placed on enhanced mixing of jet plumes for noise reduction and on predictions of jet noise based upon turbulent kinetic energy, unsteady measurements of jet plumes are a very important part of jet noise studies. Given that hot flows are of most practical interest, optical techniques such as Particle Image Velocimetry (PIV) are applicable. When the flow has strong azimuthal features, such as those generated by chevrons or lobed mixers, traditional PIV, which aligns the measurement plane parallel to the dominant flow direction is very inefficient, requiring many planes of data to be acquired and stacked up to produce the desired flow cross-sections. This paper presents PIV data acquired in a plane normal to the jet axis, directly measuring the cross-stream gradients and features of an internally mixed nozzle operating at aircraft engine flow conditions. These nozzle systems included variations in lobed mixer penetration, lobe count, lobe scalloping, and nozzle length. Several cases validating the accuracy of the PIV data are examined along with examples of its use in answering questions about the jet noise generation processes in these nozzles. Of most interest is the relationship of low frequency aft-directed noise with turbulence kinetic energy and mean velocity.

  11. Conversion gain and noise of niobium superconducting hot-electron-mixers

    NASA Technical Reports Server (NTRS)

    Ekstrom, Hans; Karasik, Boris S.; Kollberg, Erik L.; Yngvesson, Sigfrid

    1995-01-01

    A study has been done of microwave mixing at 20 GHz using the nonlinear (power dependent) resistance of thin niobium strips in the resistive state. Our experiments give evidence that electron-heating is the main cause of the nonlinear phenomenon. Also a detailed phenomenological theory for the determination of conversion properties is presented. This theory is capable of predicting the frequency-conversion loss rather accurately for arbitrary bias by examining the I-V-characteristic. Knowing the electron temperature relaxation time, and using parameters derived from the I-V-characteristic also allows us to predict the -3 dB IF bandwidth. Experimental results are in excellent agreement with the theoretical predictions. The requirements on the mode of operation and on the film parameters for minimizing the conversion loss (and even achieving conversion gain) are discussed in some detail. Our measurements demonstrate an intrinsic conversion loss as low as 1 dB. The maximum IF frequency defined for -3 dB drop in conversion gain, is about 80 MHz. Noise measurements indicate a device output noise temperature of about 50 K and SSB mixer noise temperature below 250 K. This type of mixer is considered very promising for use in low-noise heterodyne receivers at THz frequencies.

  12. Advances in Antibody Design

    PubMed Central

    Tiller, Kathryn E.; Tessier, Peter M.

    2017-01-01

    The use of monoclonal antibodies as therapeutics requires optimizing several of their key attributes. These include binding affinity and specificity, folding stability, solubility, pharmacokinetics, effector functions, and compatibility with the attachment of additional antibody domains (bispecific antibodies) and cytotoxic drugs (antibody–drug conjugates). Addressing these and other challenges requires the use of systematic design methods that complement powerful immunization and in vitro screening methods. We review advances in designing the binding loops, scaffolds, domain interfaces, constant regions, post-translational and chemical modifications, and bispecific architectures of antibodies and fragments thereof to improve their bioactivity. We also highlight unmet challenges in antibody design that must be overcome to generate potent antibody therapeutics. PMID:26274600

  13. Terahertz Heterodyne Receiver with an Electron-Heating Mixer and a Heterodyne Based on the Quantum-Cascade Laser

    NASA Astrophysics Data System (ADS)

    Seliverstov, S. V.; Anfertyev, V. A.; Tretyakov, I. V.; Ozheredov, I. A.; Solyankin, P. M.; Revin, L. S.; Vaks, V. L.; Rusova, A. A.; Goltsman, G. N.; Shkurinov, A. P.

    2017-12-01

    We study characteristics of the laboratory prototype of a terahertz heterodyne receiver with an electron-heating mixer and a heterodyne based on the quantum-cascade laser. The results obtained demonstrate the possibility to use this receiver as a basis for creation of a high-sensitivity terahertz spectrometer, which can be used in many basic and practical applications. A significant advantage of this receiver will be the possibility of placing the mixer and heterodyne in the same cryostat, which will reduce the device dimensions considerably. The obtained experimental results are analyzed, and methods of optimizing the parameters of the receiver are proposed.

  14. Design and simulation of the micromixer with chaotic advection in twisted microchannels.

    PubMed

    Jen, Chun-Ping; Wu, Chung-Yi; Lin, Yu-Cheng; Wu, Ching-Yi

    2003-05-01

    Chaotic mixers with twisted microchannels were designed and simulated numerically in the present study. The phenomenon whereby a simple Eulerian velocity field may generate a chaotic response in the distribution of a Lagrangian marker is termed chaotic advection. Dynamic system theory indicates that chaotic particle motion can occur when a velocity field is either two-dimensional and time-dependent, or three-dimensional. In the present study, micromixers with three-dimensional structures of the twisted microchannel were designed in order to induce chaotic mixing. In addition to the basic T-mixer, three types of micromixers with inclined, oblique and wavelike microchannels were investigated. In the design of each twisted microchannel, the angle of the channels' bottoms alternates in each subsection. When the fluids enter the twisted microchannels, the flow sways around the varying structures within the microchannels. The designs of the twisted microchannels provide a third degree of freedom to the flow field in the microchannel. Therefore, chaotic regimes that lead to chaotic mixing may arise. The numerical results indicate that mixing occurs in the main channel and progressively larger mixing lengths are required as the Peclet number increased. The swaying of the flow in the twisted microchannel causes chaotic advection. Among the four micromixer designs, the micromixer with the inclined channel most improved mixing. Furthermore, using the inclined mixer with six subsections yielded optimum performance, decreasing the mixing length by up to 31% from that of the basic T-mixer.

  15. Experimental Investigation of Spatially-Periodic Scalar Patterns in an Inline Mixer

    NASA Astrophysics Data System (ADS)

    Baskan, Ozge; Speetjens, Michel F. M.; Clercx, Herman J. H.

    2015-11-01

    Spatially persisting patterns with exponentially decaying intensities form during the downstream evolution of passive scalars in three-dimensional (3D) spatially periodic flows due to the coupled effect of the chaotic nature of the flow and the diffusivity of the material. This has been investigated in many computational and theoretical studies on 3D spatially-periodic flow fields. However, in the limit of zero-diffusivity, the evolution of the scalar fields results in more detailed structures that can only be captured by experiments due to limitations in the computational tools. Our study employs the-state-of-the-art experimental methods to analyze the evolution of 3D advective scalar field in a representative inline mixer, called Quatro static mixer. The experimental setup consists of an optically accessible test section with transparent internal elements, accommodating a pressure-driven pipe flow and equipped with 3D Laser-Induced Fluorescence. The results reveal that the continuous process of stretching and folding of material creates finer structures as the flow progresses, which is an indicator of chaotic advection and the experiments outperform the simulations by revealing far greater level of detail.

  16. Noise Temperature and IF Bandwidth of a 530 GHz Heterodyne Receiver Employing a Diffusion-Cooled Superconducting Hot-Electron Mixer

    NASA Technical Reports Server (NTRS)

    Skalare, A.; McGrath, W. R.; Bumble, B.; LeDuc, H. G.; Burke, P. J.; Verheijen, A. A.; Prober, D. E.

    1995-01-01

    We report on the first heterodyne measurements with a diffusion-cooled hot-electron bolometer mixer in the submillimeter wave band, using a waveguide mixer cooled to 2.2 K. The best receiver noise temperature at a local oscillator frequency of 533 GHz and an intermediate frequency of 1.4 GHz was 650 K (double sideband). The 3 dB IF roll-off frequency was around 1.7 to 1.9 GHz, with a weak dependence on the device bias conditions.

  17. Designing Design into an Advanced Desktop Publishing Course (A Teaching Tip).

    ERIC Educational Resources Information Center

    Guthrie, Jim

    1995-01-01

    Describes an advanced desktop publishing course that combines instruction in a few advanced techniques for using software with extensive discussion of such design principles as consistency, proportion, asymmetry, appropriateness, contrast, and color. Describes computer hardware and software, class assignments, problems, and the rationale for such…

  18. Effect of zeta potential on the performance of a ring-type electroosmotic mixer.

    PubMed

    Kim, T A; Koo, K H; Kim, Y J

    2009-12-01

    In order to achieve faster mixing, a new type of electrokinetic mixer with a T-type channel is introduced. The proposed mixer takes two fluids from different inlets and combines them into a single channel. The fluids then enter a mixing chamber with different inner and outer radii. Four microelectrodes are positioned on the outer wall of the mixing chamber. The electric potentials on the four microelectrodes are sinusoidal with respect to time and have various maximum voltages, zeta potentials and frequency values. The working fluid is water and each inlet has a different initial concentration values. The incompressible Navier-Stokes equation is solved in the channel, with a slip boundary condition on the inner and outer walls of the mixing chamber. The convection-diffusion equation is used to describe the concentration of the dissolved substances in the fluid. The pressure, concentration and flow fields in the channel are calculated and the results are graphically depicted for various flow and electric conditions.

  19. Magnetic suspension and balance system advanced study, 1989 design

    NASA Technical Reports Server (NTRS)

    Boom, Roger W.; Eyssa, Y. M.; Abdelsalam, Moustafa K.; Mcintosh, Glen E.

    1991-01-01

    The objectives are to experimentally confirm several advanced design concepts on the Magnetic Suspension and Balance Systems (MSBS). The advanced design concepts were identified as potential improvements by Madison Magnetics, Inc. (MMI) during 1984 and 1985 studies of an MSBS utilizing 14 external superconductive coils and a superconductive solenoid in an airplane test model suspended in a wind tunnel. This study confirmed several advanced design concepts on magnetic suspension and balance systems. The 1989 MSBS redesign is based on the results of these experiments. Savings of up to 30 percent in supporting magnet ampere meters and 50 percent in energy stored over the 1985 design were achieved.

  20. Advanced heat receiver conceptual design study

    NASA Technical Reports Server (NTRS)

    Kesseli, James; Saunders, Roger; Batchelder, Gary

    1988-01-01

    Solar Dynamic space power systems are candidate electrical power generating systems for future NASA missions. One of the key components of the solar dynamic power system is the solar receiver/thermal energy storage (TES) subsystem. Receiver development was conducted by NASA in the late 1960's and since then a very limited amount of work has been done in this area. Consequently the state of the art (SOA) receivers designed for the IOC space station are large and massive. The objective of the Advanced Heat Receiver Conceptual Design Study is to conceive and analyze advanced high temperature solar dynamic Brayton and Stirling receivers. The goal is to generate innovative receiver concepts that are half of the mass, smaller, and more efficient than the SOA. It is also necessary that these innovative receivers offer ease of manufacturing, less structural complexity and fewer thermal stress problems. Advanced Brayton and Stirling receiver storage units are proposed and analyzed in this study which can potentially meet these goals.

  1. The Desire to Drink Alcohol is Enhanced with High Caffeine Energy Drink Mixers

    PubMed Central

    Marczinski, Cecile A.; Fillmore, Mark T.; Stamates, Amy L.; Maloney, Sarah F.

    2017-01-01

    Background Consumption of alcohol mixed with energy drinks (AmED) has been associated with a variety of risks beyond that observed with alcohol alone. Consumers of AmED beverages are more likely to engage in heavy episodic (binge) drinking. The purpose of this study was to investigate whether the consumption of high caffeine energy drink mixers with alcohol would increase the desire to drink alcohol compared to the same amount of alcohol alone using a double-blind, within-subjects, placebo-controlled study design. Methods Participants (n = 26) of equal gender who were social drinkers attended 6 double-blind dose administration sessions that involved consumption of alcohol and energy drinks, alone and in combination. On each test day, participants received 1 of 6 possible doses: 1) 1.21 ml/kg vodka + 3.63 ml/kg decaffeinated soft drink, 2) 1.21 ml/kg vodka + 3.63 ml/kg energy drink, 3) 1.21 ml/kg vodka + 6.05 ml/kg energy drink, 4) 3.36 ml/kg decaffeinated soft drink, 5) 3.36 ml/kg energy drink, and 6) 6.05 ml/kg energy drink. Following dose administration, participants repeatedly completed self-reported ratings on the Desire for Drug questionnaire and provided breath alcohol readings. Results Alcohol alone increased the subjective ratings of “desire for more alcohol” compared to placebo doses. Energy drink mixers with the alcohol increased desire for more alcohol ratings beyond that observed with alcohol alone. Conclusions This study provides laboratory evidence that AmED beverages lead to greater desire to drink alcohol versus the same amount of alcohol consumed alone. The findings are consistent with results from animal studies indicating that caffeine increases the rewarding and reinforcing properties of alcohol. PMID:27419377

  2. Preparation and characterization of CNTs/UHMWPE nanocomposites via a novel mixer under synergy of ultrasonic wave and extensional deformation.

    PubMed

    Yin, Xiaochun; Li, Sai; He, Guangjian; Feng, Yanhong; Wen, Jingsong

    2018-05-01

    In this work, design and development of a new melt mixing method and corresponding mixer for polymer materials were reported. Effects of ultrasonic power and sonication time on the carbon nanotubes (CNTs) filled ultra high molecular weight polyethylene (UHMWPE) nanocomposites were experimentally studied. Transmission Electron Microscopy images showed that homogeneous dispersion of CNTs in intractable UHMWPE matrix is successfully realized due to the synergetic effect of ultrasonic wave and extensional deformation without any aid of other additives or solvents. Differential scanning calorimetry results revealed an increase in crystallinity and crystallization rate due to the finer dispersion of the CNTs in the matrix which act as nucleating point. Composites' complex viscosity and storage modulus decreased sharply at first and then leveled off with the increase of sonication time or the ultrasonic power. The thermal stability and the tensile strength of the CNTs/UHMWPE nanocomposites improved by using this novel mixing method. This is the first method that combined the ultrasonic wave and the extensional deformation in which the elongation rate, sonication time and ultrasonic power can be adjusted simultaneously during mixing. The novel mixer offers several advantages such as environment-friendly, high mixing efficiency, self-cleaning and wide adaptability to materials. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. ESD protection design for advanced CMOS

    NASA Astrophysics Data System (ADS)

    Huang, Jin B.; Wang, Gewen

    2001-10-01

    ESD effects in integrated circuits have become a major concern as today's technologies shrink to sub-micron/deep- sub-micron dimensions. The thinner gate oxide and shallower junction depth used in the advanced technologies make them very vulnerable to ESD damages. The advanced techniques like silicidation and STI (shallow trench insulation) used for improving other device performances make ESD design even more challenging. For non-silicided technologies, a certain DCGS (drain contact to gate edge spacing) is needed to achieve ESD hardness for nMOS output drivers and nMOS protection transistors. The typical DCGS values are 4-5um and 2-3um for 0.5um and 0.25um CMOS, respectively. The silicidation reduces the ballast resistance provided by DCGS with at least a factor of 10. As a result, scaling of the ESD performance with device width is lost and even zero ESD performance is reported for standard silicided devices. The device level ESD design is focused in this paper, which includes GGNMOS (gate grounded NMOS) and GCNMOS (gate coupled NMOS). The device level ESD testing including TLP (transmission line pulse) is given. Several ESD issues caused by advanced technologies have been pointed out. The possible solutions have been developed and summarized including silicide blocking, process optimization, back-end ballasting, and new protection scheme, dummy gate/n-well resistor ballsting, etc. Some of them require process cost increase, and others provide novel, compact, and simple design but involving royalty/IP (intellectual property) issue. Circuit level ESD design and layout design considerations are covered. The top-level ESD protection strategies are also given.

  4. Advanced Solar Panel Designs

    NASA Technical Reports Server (NTRS)

    Ralph, E. L.; Linder, E. B.

    1995-01-01

    Solar panel designs that utilize new high-efficiency solar cells and lightweight rigid panel technologies are described. The resulting designs increase the specific power (W/kg) achievable in the near-term and are well suited to meet the demands of higher performance small satellites (smallsats). Advanced solar panel designs have been developed and demonstrated on two NASA SBIR contracts at Applied Solar. The first used 19% efficient, large area (5.5 cm x 6.5 cm) GaAs/Ge solar cells with a lightweight rigid graphite epoxy isogrid substrate configuration. A 1,445 sq cm coupon was fabricated and tested to demonstrate 60 W/kg with a high potential of achieving 80 W/kg. The second panel design used new 22% efficiency, dual-junction GaInP2/GaAs/Ge solar cells combined with a lightweight aluminum core/graphite fiber mesh facesheet substrate. A 1,445 sq cm coupon was fabricated and tested to demonstrate 105 W/kg with the potential of achieving 115 W/kg.

  5. Parametric Study of a Mixer/Ejector Nozzle with Mixing Enhancement Devices

    NASA Technical Reports Server (NTRS)

    DalBello, T.; Steffen, C. J., Jr.

    2001-01-01

    A numerical study employing a simplified model of the High Speed Civil Transport mixer/ejector nozzle has been conducted to investigate the effect of tabs (vortex generators) on the mixing process. More complete mixing of the primary and secondary flows within the confined ejector lowers peak exit velocity resulting in reduced jet noise. Tabs were modeled as vortex pairs and inserted into the computational model. The location, size, and number of tabs were varied and its effect on the mixing process is presented here both quantitatively and qualitatively. A baseline case (no tabs) along with six other cases involving two different vortex strengths at three different orientations have been computed and analyzed. The case with the highest vorticity (six vortices representing large tabs) gives the best mixing. It is shown that the influence of the vorticity acts primarily in the forward or middle portions of the duct, significantly alters the flow structure, and promotes some mixing in the lateral direction. Unmixed pockets were found at the top and bottom of the lobe, and more clever placement of tabs improved mixing in the vertical direction. The technique of replacing tabs with vortices shows promise as an efficient tool for quickly optimizing tab placement in lobed mixers.

  6. Measurement and Computation of Supersonic Flow in a Lobed Diffuser-Mixer for Trapped Vortex Combustors

    NASA Technical Reports Server (NTRS)

    Brankovic, Andreja; Ryder, Robert C., Jr.; Hendricks, Robert C.; Liu, Nan-Suey; Gallagher, John R.; Shouse, Dale T.; Roquemore, W. Melvyn; Cooper, Clayton S.; Burrus, David L.; Hendricks, John A.

    2002-01-01

    The trapped vortex combustor (TVC) pioneered by Air Force Research Laboratories (AFRL) is under consideration as an alternative to conventional gas turbine combustors. The TVC has demonstrated excellent operational characteristics such as high combustion efficiency, low NO(x) emissions, effective flame stabilization, excellent high-altitude relight capability, and operation in the lean-burn or rich burn-quick quench-lean burn (RQL) modes of combustion. It also has excellent potential for lowering the engine combustor weight. This performance at low to moderate combustor mach numbers has stimulated interest in its ability to operate at higher combustion mach number, and for aerospace, this implies potentially higher flight mach numbers. To this end, a lobed diffuser-mixer that enhances the fuel-air mixing in the TVC combustor core was designed and evaluated, with special attention paid to the potential shock system entering the combustor core. For the present investigation, the lobed diffuser-mixer combustor rig is in a full annular configuration featuring sixfold symmetry among the lobes, symmetry within each lobe, and plain parallel, symmetric incident flow. During hardware cold-flow testing, significant discrepancies were found between computed and measured values for the pitot-probe-averaged static pressure profiles at the lobe exit plane. Computational fluid dynamics (CFD) simulations were initiated to determine whether the static pressure probe was causing high local flow-field disturbances in the supersonic flow exiting the diffuser-mixer and whether shock wave impingement on the pitot probe tip, pressure ports, or surface was the cause of the discrepancies. Simulations were performed with and without the pitot probe present in the modeling. A comparison of static pressure profiles without the probe showed that static pressure was off by nearly a factor of 2 over much of the radial profile, even when taking into account potential axial displacement of the

  7. Design of the advanced regional aircraft, the DART-75

    NASA Technical Reports Server (NTRS)

    Elliott, Steve; Gislason, Jason; Huffstetler, Mark; Mann, Jon; Withers, Ashley; Zimmerman, Mark

    1992-01-01

    This design analysis is intended to show the capabilities of the DART-75, a 75 passenger medium-range regional transport. Included are the detailed descriptions of the structures, performance, stability and control, weight and balance, and engine design. The design should allow for the DART to become the premier regional aircraft of the future due to some advanced features like the canard, semi-composite construction, and advanced engines.

  8. Biosensing enhancement of dengue virus using microballoon mixers on centrifugal microfluidic platforms.

    PubMed

    Aeinehvand, Mohammad Mahdi; Ibrahim, Fatimah; Harun, Sulaiman Wadi; Djordjevic, Ivan; Hosseini, Samira; Rothan, Hussin A; Yusof, Rohana; Madou, Marc J

    2015-05-15

    Dengue is the current leading cause of death among children in several Latin American and Asian countries. Due to poverty in areas where the disease is prevalent and the high cost of conventional diagnostic systems, low cost devices are needed to reduce the burden caused by dengue infection. Centrifugal microfluidic platforms are an alternative solution to reduce costs and increase the availability of a rapid diagnostic system. The rate of chemical reactions in such devices often depends on the efficiency of the mixing techniques employed in their microfluidic networks. This paper introduces a micromixer that operates by the expansion and contraction of a microballoon to produce a consistent periodical 3D reciprocating flow. We established that microballoons reduced mixing time of 12 μl liquids from 170 min, for diffusional mixing, to less than 23 s. We have also tested the effect of the microballoon mixers on the detection of the dengue virus. The results indicate that employing a microballoon mixer enhances the detection sensitivity of the dengue virus by nearly one order of magnitude compared to the conventional ELISA method. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. Modelling and performance of Nb SIS mixers in the 1.3 mm and 0.8 mm bands

    NASA Technical Reports Server (NTRS)

    Karpov, A.; Carter, M.; Lazareff, B.; Billon-Pierron, D.; Gundlach, K. H.

    1992-01-01

    We describe the modeling and subsequent improvements of SIS waveguide mixers for the 200-270 and 330-370 GHz bands (Blundell, Carter, and Gundlach 1988, Carter et al 1991). These mixers are constructed for use in receivers on IRAM radiotelescopes on Pico Veleta (Spain, Sierra Nevada) and Plateau de Bure (French Alps), and must meet specific requirements. The standard reduced height waveguide structure with suspended stripline is first analyzed and a model is validated through comparison with scale model and working scale measurements. In the first step, the intrinsic limitations of the standard mixer structure are identified, and the parameters are optimized bearing in mind the radioastronomical applications. In the second step, inductive tuning of the junctions is introduced and optimized for minimum noise and maximum bandwidth. In the 1.3 mm band, a DSB receiver temperature of less than 110 K (minimum 80 K) is measured from 180 through 260 GHz. In the 0.8 mm band, a DSB receiver temperature of less than 250 K (minimum 175 K) is obtained between 325 and 355 GHz. All these results are obtained with room-temperature optics and a 4 GHz IF chain having a 500 MHz bandwidth and a noise temperature of 14 K.

  10. Cost/benefit studies of advanced materials technologies for future aircraft turbine engines: Materials for advanced turbine engines

    NASA Technical Reports Server (NTRS)

    Stearns, M.; Wilbers, L.

    1982-01-01

    Cost benefit studies were conducted on six advanced materials and processes technologies applicable to commercial engines planned for production in the 1985 to 1990 time frame. These technologies consisted of thermal barrier coatings for combustor and high pressure turbine airfoils, directionally solidified eutectic high pressure turbine blades, (both cast and fabricated), and mixers, tail cones, and piping made of titanium-aluminum alloys. A fabricated titanium fan blisk, an advanced turbine disk alloy with improved low cycle fatigue life, and a long-life high pressure turbine blade abrasive tip and ceramic shroud system were also analyzed. Technologies showing considerable promise as to benefits, low development costs, and high probability of success were thermal barrier coating, directionally solidified eutectic turbine blades, and abrasive-tip blades/ceramic-shroud turbine systems.

  11. Microfluidic active mixers employing ultra-high aspect-ratio rare-earth magnetic nano-composite polymer artificial cilia

    NASA Astrophysics Data System (ADS)

    Rahbar, Mona; Shannon, Lesley; Gray, Bonnie L.

    2014-02-01

    We present a new micromixer based on highly magnetic, flexible, high aspect-ratio, artificial cilia that are fabricated as individual micromixer elements or in arrays for improved mixing performance. These new cilia enable high efficiency, fast mixing in a microchamber, and are controlled by small electromagnetic fields. The artificial cilia are fabricated using a new micromolding process for nano-composite polymers. Cilia fibers with aspect-ratios as high as 8:0.13 demonstrate the fabrication technique's capability in creating ultra-high aspect-ratio microstructures. Cilia, which are realized in polydimethylsiloxane doped with rare-earth magnetic powder, are magnetized to produce permanent magnetic structures with bidirectional deflection capabilities, making them highly suitable as mixers controlled by electromagnetic fields. Due to the high magnetization level of the polarized nano-composite polymer, we are able to use miniature electromagnets providing relatively small magnetic fields of 1.1 to 7 mT to actuate the cilia microstructures over a very wide motion range. Mixing performances of a single cilium, as well as different arrays of multiple cilia ranging from 2 to 8 per reaction chamber, are characterized and compared with passive diffusion mixing performance. The mixer cilia are actuated at different amplitudes and frequencies to optimize mixing performance. We demonstrate that more than 85% of the total volume of the reaction chamber is fully mixed after 3.5 min using a single cilium mixer at 7 mT compared with only 20% of the total volume mixed with passive diffusion. The time to achieve over 85% mixing is further reduced to 70 s using an array of eight cilia microstructures. The novel microfabrication technique and use of rare-earth permanently-magnetizable nano-composite polymers in mixer applications has not been reported elsewhere by other researchers. We further demonstrate improved mixing over other cilia micromixers as enabled by the high aspect

  12. HYBRID SILICON-ON-SAPPHIRE/SCALED CMOS INTERFERENCE MITIGATION FRONT END BASED ON SIMULTANEOUS NOISE CANCELLATION, ACTIVE-INTERFERENCE CANCELLATION AND N-PATH-MIXER FILTERING

    DTIC Science & Technology

    2017-04-01

    INTERFERENCE-CANCELLATION AND N-PATH-MIXER FILTERING Harish Krishnaswamy, Negar Reiskarimian, and Linxiao Zhang Columbia University APRIL 2017 Final...INTERFERENCE-CANCELLATION AND N- PATH-MIXER FILTERING 5a. CONTRACT NUMBER FA8650-14-1-7414 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 61101E/62716E 6...techniques for developing interference mitigation technology (IMT) enabling frequency-agile, reconfigurable filter -less receivers. Wideband noise

  13. Nb/Al-AlOx/Nb Edge Junctions for Distributed Mixers

    NASA Astrophysics Data System (ADS)

    Amos, R. S.; Lichtenberger, A. W.; Tong, C. E.; Blundell, R.; Pan, S.-K.; Kerr, A. R.

    We have fabricated high quality Nb/Al-oxide/Al/Nb edge junctions using a Nb/SiO/sub 2/ bi-layer film as the base electrode, suitable for use as traveling wave mixers. An edge is cut in the bi-layer with an ion gun at a 45 degree angle using a photoresist mask. The wafer is then cleaned in-situ with a physical ion gun clean followed by the deposition of a thin Al (a1) film, which is then thermally oxidized, an optional second Al (a2) layer, and a Nb counter electrode. It was found that devices with an a2 layer resulted in superior electrical characteristics, though proximity effects increased strongly with a2 thickness. The counter electrode is defined with an SF/sub 6/+N/sub 2/ reactive ion etch, using the Al barrier layer as an etch stop. The Al barrier layer is then either removed with an Al wet etch to isolate the individual devices, or the devices are separated with an anodization process. Various ion gun cleaning conditions have been examined; in addition, both wet and plasma etch bi-layer edge surface pre-treatments were investigated. It was found that edge junctions with large widths (i.e., those more suitable for traveling wave mixers) typically benefited more from such treatments. Initial receiver results at 260 GHz have yielded a DSB noise temperature of 60 K.

  14. Sonic Fatigue Design Techniques for Advanced Composite Aircraft Structures

    DTIC Science & Technology

    1980-04-01

    AFWAL-TR-80.3019 AD A 090553 SONIC FATIGUE DESIGN TECHNIQUES FOR ADVANCED COMPOSITE AIRCRAFT STRUCTURES FINAL REPORT Ian Holehouse Rohr Industries...5 2. General Sonic Fatigue Theory .... ....... 7 3. Composite Laminate Analysis .. ....... ... 10 4. Preliminary Sonic Fatigue...overall sonic fatigue design guides. These existing desiyn methcds have been developed for metal structures. However, recent advanced composite

  15. Aerodynamic Design Study of Advanced Multistage Axial Compressor

    NASA Technical Reports Server (NTRS)

    Larosiliere, Louis M.; Wood, Jerry R.; Hathaway, Michael D.; Medd, Adam J.; Dang, Thong Q.

    2002-01-01

    As a direct response to the need for further performance gains from current multistage axial compressors, an investigation of advanced aerodynamic design concepts that will lead to compact, high-efficiency, and wide-operability configurations is being pursued. Part I of this report describes the projected level of technical advancement relative to the state of the art and quantifies it in terms of basic aerodynamic technology elements of current design systems. A rational enhancement of these elements is shown to lead to a substantial expansion of the design and operability space. Aerodynamic design considerations for a four-stage core compressor intended to serve as a vehicle to develop, integrate, and demonstrate aerotechnology advancements are discussed. This design is biased toward high efficiency at high loading. Three-dimensional blading and spanwise tailoring of vector diagrams guided by computational fluid dynamics (CFD) are used to manage the aerodynamics of the high-loaded endwall regions. Certain deleterious flow features, such as leakage-vortex-dominated endwall flow and strong shock-boundary-layer interactions, were identified and targeted for improvement. However, the preliminary results were encouraging and the front two stages were extracted for further aerodynamic trimming using a three-dimensional inverse design method described in part II of this report. The benefits of the inverse design method are illustrated by developing an appropriate pressure-loading strategy for transonic blading and applying it to reblade the rotors in the front two stages of the four-stage configuration. Multistage CFD simulations based on the average passage formulation indicated an overall efficiency potential far exceeding current practice for the front two stages. Results of the CFD simulation at the aerodynamic design point are interrogated to identify areas requiring additional development. In spite of the significantly higher aerodynamic loadings, advanced CFD

  16. Reconfigurable Control Design for the Full X-33 Flight Envelope

    NASA Technical Reports Server (NTRS)

    Cotting, M. Christopher; Burken, John J.

    2001-01-01

    A reconfigurable control law for the full X-33 flight envelope has been designed to accommodate a failed control surface and redistribute the control effort among the remaining working surfaces to retain satisfactory stability and performance. An offline nonlinear constrained optimization approach has been used for the X-33 reconfigurable control design method. Using a nonlinear, six-degree-of-freedom simulation, three example failures are evaluated: ascent with a left body flap jammed at maximum deflection; entry with a right inboard elevon jammed at maximum deflection; and landing with a left rudder jammed at maximum deflection. Failure detection and identification are accomplished in the actuator controller. Failure response comparisons between the nominal control mixer and the reconfigurable control subsystem (mixer) show the benefits of reconfiguration. Single aerosurface jamming failures are considered. The cases evaluated are representative of the study conducted to prove the adequate and safe performance of the reconfigurable control mixer throughout the full flight envelope. The X-33 flight control system incorporates reconfigurable flight control in the existing baseline system.

  17. 50% Advanced Energy Design Guides: Preprint

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Bonnema, E.; Leach, M.; Pless, S.

    2012-07-01

    This paper presents the process, methodology, and assumptions for the development of the 50% Energy Savings Advanced Energy Design Guides (AEDGs), a design guidance document that provides specific recommendations for achieving 50% energy savings above the requirements of ANSI/ASHRAE/IESNA Standard 90.1-2004 in four building types: (1) Small to medium office buildings, (2) K-12 school buildings, (3) Medium to big box retail buildings, (4) Large hospital buildings.

  18. Advanced technologies impact on compressor design and development: A perspective

    NASA Technical Reports Server (NTRS)

    Ball, Calvin L.

    1989-01-01

    A historical perspective of the impact of advanced technologies on compression system design and development for aircraft gas turbine applications is presented. A bright view of the future is projected in which further advancements in compression system technologies will be made. These advancements will have a significant impact on the ability to meet the ever-more-demanding requirements being imposed on the propulsion system for advanced aircraft. Examples are presented of advanced compression system concepts now being studied. The status and potential impact of transitioning from an empirically derived design system to a computationally oriented system are highlighted. A current NASA Lewis Research Center program to enhance this transitioning is described.

  19. Design and implementation of a low-power SOI CMOS receiver

    NASA Astrophysics Data System (ADS)

    Zencir, Ertan

    There is a strong demand for wireless communications in civilian and military applications, and space explorations. This work attempts to implement a low-power, high-performance fully-integrated receiver for deep space communications using Silicon on Insulator (SOI) CMOS technology. Design and implementation of a UHF low-IF receiver front-end in a 0.35-mum SOI CMOS technology are presented. Problems and challenges in implementing a highly integrated receiver at UHF are identified. Low-IF architecture, suitable for low-power design, has been adopted to mitigate the noise at the baseband. Design issues of the receiver building blocks including single-ended and differential LNA's, passive and active mixers, and variable gain/bandwidth complex filters are discussed. The receiver is designed to have a variable conversion gain of more than 100 dB with a 70 dB image rejection and a power dissipation of 45 mW from a 2.5-V supply. Design and measured performance of the LNA's, and the mixer are presented. Measurement results of RF front-end blocks including a single-ended LNA, a differential LNA, and a double-balanced mixer demonstrate the low power realizability of RF front-end circuits in SOI CMOS technology. We also report on the design and simulation of the image-rejecting complex IF filter and the full receiver circuit. Gain, noise, and linearity performance of the receiver components prove the viability of fully integrated low-power receivers in SOI CMOS technology.

  20. A low-noise double-dipole antenna SIS mixer at 1 THz

    NASA Astrophysics Data System (ADS)

    Shitov, S. V.; Jackson, B. D.; Baryshev, A. M.; Markov, A. V.; Iosad, N. N.; Gao, J.-R.; Klapwijk, T. M.

    2002-08-01

    A quasi-optical mixer employing a Nb/Al/AlO x/Nb twin-SIS junction with a NbTiN/SiO 2/Al microstrip coupling circuit is tested at 800-1000 GHz. The receiver noise temperature TRX=250 K (DSB) is measured at 935 GHz for the bath temperature 2 K at IF=1.5 GHz; TRX remains below 350 K within the frequency range 850-1000 GHz. The integrated lens-antenna demonstrated good beam symmetry with sidelobes below -16 dB.

  1. A 1.5 THz hot-electron bolometer mixer operated by a planar diode based local oscillator

    NASA Technical Reports Server (NTRS)

    Tong, C. Y. E.; Meledin, D.; Blundell, R.; Erickson, N.; Mehdi, I.; Goltsman, G.

    2003-01-01

    We have developed a 1.5 THz superconducting NbN Hot-Electron Bolometer mixer. It is oprated by an all-solid-state Local Oscillator comprising of a cascade of 4 planar doublers following an MMIC based W-band power amplifier.

  2. Developments at the Advanced Design Technologies Testbed

    NASA Technical Reports Server (NTRS)

    VanDalsem, William R.; Livingston, Mary E.; Melton, John E.; Torres, Francisco J.; Stremel, Paul M.

    2003-01-01

    A report presents background and historical information, as of August 1998, on the Advanced Design Technologies Testbed (ADTT) at Ames Research Center. The ADTT is characterized as an activity initiated to facilitate improvements in aerospace design processes; provide a proving ground for product-development methods and computational software and hardware; develop bridging methods, software, and hardware that can facilitate integrated solutions to design problems; and disseminate lessons learned to the aerospace and information technology communities.

  3. Ultra-High Throughput Synthesis of Nanoparticles with Homogeneous Size Distribution Using a Coaxial Turbulent Jet Mixer

    PubMed Central

    2015-01-01

    High-throughput production of nanoparticles (NPs) with controlled quality is critical for their clinical translation into effective nanomedicines for diagnostics and therapeutics. Here we report a simple and versatile coaxial turbulent jet mixer that can synthesize a variety of NPs at high throughput up to 3 kg/d, while maintaining the advantages of homogeneity, reproducibility, and tunability that are normally accessible only in specialized microscale mixing devices. The device fabrication does not require specialized machining and is easy to operate. As one example, we show reproducible, high-throughput formulation of siRNA-polyelectrolyte polyplex NPs that exhibit effective gene knockdown but exhibit significant dependence on batch size when formulated using conventional methods. The coaxial turbulent jet mixer can accelerate the development of nanomedicines by providing a robust and versatile platform for preparation of NPs at throughputs suitable for in vivo studies, clinical trials, and industrial-scale production. PMID:24824296

  4. Hydrodynamics of CNT dispersion in high shear dispersion mixers

    NASA Astrophysics Data System (ADS)

    Park, Young Min; Lee, Dong Hyun; Hwang, Wook Ryol; Lee, Sang Bok; Jung, Seung-Il

    2014-11-01

    In this work, we investigate the carbon nanotube (CNT) fragmentation mechanism and dispersion in high shear homogenizers as a plausible dispersion technique, correlating with device geometries and processing conditions, for mass production of CNT-aluminum composites for automobile industries. A CNT dispersion model has been established in a turbulent flow regime and an experimental method in characterizing the critical yield stress of CNT flocs are presented. Considering CNT dispersion in ethanol as a model system, we tested two different geometries of high shear mixers — blade-stirrer type and rotor-stator type homogenizers — and reported the particle size distributions in time and the comparison has been made with the modeling approach and partly with the computational results.

  5. Advances in Ureteral Stent Design

    NASA Astrophysics Data System (ADS)

    Denstedt, John D.

    2007-04-01

    Ureteral stents are commonly used in urolithiasis patients for relief of obstruction or in association with stone treatments such as ureteroscopy and extracorporeal shock wave lithotripsy. There are currently many different bulk materials and coatings available for the manufacture of ureteral stents, however the ideal material has yet to be discovered. All potential biomaterials must undergo rigorous physical and biocompatibility testing before commercialization and use in humans. Despite significant advances in basic science research involving biocompatibility issues and biofilm formation, infection and encrustation remain associated with the use of biomaterials in the urinary tract. There have been many significant advances in the design of ureteral stents in recent years and these will be highlighted along with a discussion of future aspects of biomaterials and use of stents in association with urolithiasis.

  6. Advanced Aerospace Materials by Design

    NASA Technical Reports Server (NTRS)

    Srivastava, Deepak; Djomehri, Jahed; Wei, Chen-Yu

    2004-01-01

    The advances in the emerging field of nanophase thermal and structural composite materials; materials with embedded sensors and actuators for morphing structures; light-weight composite materials for energy and power storage; and large surface area materials for in-situ resource generation and waste recycling, are expected to :revolutionize the capabilities of virtually every system comprising of future robotic and :human moon and mars exploration missions. A high-performance multiscale simulation platform, including the computational capabilities and resources of Columbia - the new supercomputer, is being developed to discover, validate, and prototype next generation (of such advanced materials. This exhibit will describe the porting and scaling of multiscale 'physics based core computer simulation codes for discovering and designing carbon nanotube-polymer composite materials for light-weight load bearing structural and 'thermal protection applications.

  7. Altitude engine test of a turbofan exhaust gas mixer to conserve fuel

    NASA Technical Reports Server (NTRS)

    Cullom, R. R.; Johnsen, R. L.

    1977-01-01

    A comparison of the specific fuel consumption was made with and without an internal mixer installed in a low bypass ratio, confluent flow turbofan engine. Tests were conducted at several Mach numbers and altitudes for core to fan stream total temperature ratios of 2.0 and 2.5 and mixing lengths of L/D = 0.95 and 1.74. For these test conditions, the specific fuel consumption improvement varied from 2.5 to 4.0 percent.

  8. Improving the Efficiency of 3-D Hydrogeological Mixers: Dilution Enhancement Via Coupled Engineering-Induced Transient Flows and Spatial Heterogeneity

    NASA Astrophysics Data System (ADS)

    Di Dato, Mariaines; de Barros, Felipe P. J.; Fiori, Aldo; Bellin, Alberto

    2018-03-01

    Natural attenuation and in situ oxidation are commonly considered as low-cost alternatives to ex situ remediation. The efficiency of such remediation techniques is hindered by difficulties in obtaining good dilution and mixing of the contaminant, in particular if the plume deformation is physically constrained by an array of wells, which serves as a containment system. In that case, dilution may be enhanced by inducing an engineered sequence of injections and extractions from such pumping system, which also works as a hydraulic barrier. This way, the aquifer acts as a natural mixer, in a manner similar to the industrialized engineered mixers. Improving the efficiency of hydrogeological mixers is a challenging task, owing to the need to use a 3-D setup while relieving the computational burden. Analytical solutions, though approximated, are a suitable and efficient tool to seek the optimum solution among all possible flow configurations. Here we develop a novel physically based model to demonstrate how the combined spatiotemporal fluctuations of the water fluxes control solute trajectories and residence time distributions and therefore, the effectiveness of contaminant plume dilution and mixing. Our results show how external forcing configurations are capable of inducing distinct time-varying groundwater flow patterns which will yield different solute dilution rates.

  9. Advanced solar panel designs

    NASA Technical Reports Server (NTRS)

    Ralph, E. L.; Linder, E.

    1995-01-01

    This paper describes solar cell panel designs that utilize new hgih efficiency solar cells along with lightweight rigid panel technology. The resulting designs push the W/kg and W/sq m parameters to new high levels. These new designs are well suited to meet the demand for higher performance small satellites. This paper reports on progress made on two SBIR Phase 1 contracts. One panel design involved the use of large area (5.5 cm x 6.5 cm) GaAs/Ge solar cells of 19% efficiency combined with a lightweight rigid graphite fiber epoxy isogrid substrate configuration. A coupon (38 cm x 38 cm) was fabricated and tested which demonstrated an array specific power level of 60 W/kg with a potential of reaching 80 W/kg. The second panel design involved the use of newly developed high efficiency (22%) dual junction GaInP2/GaAs/Ge solar cells combined with an advanced lightweight rigid substrate using aluminum honeycomb core with high strength graphite fiber mesh facesheets. A coupon (38 cm x 38 cm) was fabricated and tested which demonstrated an array specific power of 105 W/kg and 230 W/sq m. This paper will address the construction details of the panels and an a analysis of the component weights. A strawman array design suitable for a typical small-sat mission is described for each of the two panel design technologies being studied. Benefits in respect to weight reduction, area reduction, and system cost reduction are analyzed and compared to conventional arrays.

  10. Design of an advanced flight planning system

    NASA Technical Reports Server (NTRS)

    Sorensen, J. A.; Goka, T.

    1985-01-01

    The demand for both fuel conservation and four-dimensional traffic management require that the preflight planning process be designed to account for advances in airborne flight management and weather forecasting. The steps and issues in designing such an advanced flight planning system are presented. Focus is placed on the different optimization options for generating the three-dimensional reference path. For the cruise phase, one can use predefined jet routes, direct routes based on a network of evenly spaced grid points, or a network where the grid points are existing navaid locations. Each choice has its own problem in determining an optimum solution. Finding the reference path is further complicated by choice of cruise altitude levels, use of a time-varying weather field, and requiring a fixed time-of-arrival (four-dimensional problem).

  11. PARC Analysis of the NASA/GE 2D NRA Mixer/Ejector Nozzle

    NASA Technical Reports Server (NTRS)

    DeBonis, J. R.

    1999-01-01

    Interest in developing a new generation supersonic transport has increased in the past several years. Current projections indicate this aircraft would cruise at approximately Mach 2.4, have a range of 5000 nautical miles and carry at least 250 passengers. A large market for such an aircraft will exist in the next century due to a predicted doubling of the demand for long range air transportation by the end of the century and the growing influence of the Pacific Rim nations. Such a proposed aircraft could more than halve the flying time from Los Angeles to Tokyo. However, before a new economically feasible supersonic transport can be built, many key technologies must be developed. Among these technologies is noise suppression. Propulsion systems for a supersonic transport using current technology would exceed acceptable noise levels. All new aircraft must satisfy FAR 36 Stage III noise regulations. The largest area of concern is the noise generated during takeoff. A concerted effort under NASA's High Speed Research (HSR) program has begun to address the problem of noise suppression. One of the most promising concepts being studied in the area of noise suppression is the mixer/ejector nozzle. This study analyzes a typical noise suppressing mixer ejector nozzle at take off conditions, using a Full Navier-Stokes (FNS) computational fluid dynamics (CFD) code.

  12. Advanced ISDN satellite designs and experiments

    NASA Technical Reports Server (NTRS)

    Pepin, Gerard R.

    1992-01-01

    The research performed by GTE Government Systems and the University of Colorado in support of the NASA Satellite Communications Applications Research (SCAR) Program is summarized. Two levels of research were undertaken. The first dealt with providing interim services Integrated Services Digital Network (ISDN) satellite (ISIS) capabilities that accented basic rate ISDN with a ground control similar to that of the Advanced Communications Technology Satellite (ACTS). The ISIS Network Model development represents satellite systems like the ACTS orbiting switch. The ultimate aim is to move these ACTS ground control functions on-board the next generation of ISDN communications satellite to provide full-service ISDN satellite (FSIS) capabilities. The technical and operational parameters for the advanced ISDN communications satellite design are obtainable from the simulation of ISIS and FSIS engineering software models of the major subsystems of the ISDN communications satellite architecture. Discrete event simulation experiments would generate data for analysis against NASA SCAR performance measure and the data obtained from the ISDN satellite terminal adapter hardware (ISTA) experiments, also developed in the program. The Basic and Option 1 phases of the program are also described and include the following: literature search, traffic mode, network model, scenario specifications, performance measures definitions, hardware experiment design, hardware experiment development, simulator design, and simulator development.

  13. Test model designs for advanced refractory ceramic materials

    NASA Technical Reports Server (NTRS)

    Tran, Huy Kim

    1993-01-01

    The next generation of space vehicles will be subjected to severe aerothermal loads and will require an improved thermal protection system (TPS) and other advanced vehicle components. In order to ensure the satisfactory performance system (TPS) and other advanced vehicle materials and components, testing is to be performed in environments similar to space flight. The design and fabrication of the test models should be fairly simple but still accomplish test objectives. In the Advanced Refractory Ceramic Materials test series, the models and model holders will need to withstand the required heat fluxes of 340 to 817 W/sq cm or surface temperatures in the range of 2700 K to 3000 K. The model holders should provide one dimensional (1-D) heat transfer to the samples and the appropriate flow field without compromising the primary test objectives. The optical properties such as the effective emissivity, catalytic efficiency coefficients, thermal properties, and mass loss measurements are also taken into consideration in the design process. Therefore, it is the intent of this paper to demonstrate the design schemes for different models and model holders that would accommodate these test requirements and ensure the safe operation in a typical arc jet facility.

  14. Turbofan forced mixer-nozzle internal flowfield. Volume 2: Computational fluid dynamic predictions

    NASA Technical Reports Server (NTRS)

    Werle, M. J.; Vasta, V. N.

    1982-01-01

    A general program was conducted to develop and assess a computational method for predicting the flow properties in a turbofan forced mixed duct. The detail assessment of the resulting computer code is presented. It was found that the code provided excellent predictions of the kinematics of the mixing process throughout the entire length of the mixer nozzle. The thermal mixing process between the hot core and cold fan flows was found to be well represented in the low speed portion of the flowfield.

  15. Silicon Carbide Mixers Demonstrated to Improve the Interference Immunity of Radio-Based Aircraft Avionics

    NASA Technical Reports Server (NTRS)

    Neudeck, Philip G.

    1998-01-01

    Concern over the interference of stray radiofrequency (RF) emissions with key aircraft avionics is evident during takeoff and landing of every commercial flight when the flight attendant requests that all portable electronics be switched off. The operation of key radio-based avionics (such as glide-slope and localizer approach instruments) depends on the ability of front-end RF receivers to detect and amplify desired information signals while rejecting interference from undesired RF sources both inside and outside the aircraft. Incidents where key navigation and approach avionics malfunction because of RF interference clearly represent an increasing threat to flight safety as the radio spectrum becomes more crowded. In an initial feasibility experiment, the U.S. Army Research Laboratory and the NASA Lewis Research Center recently demonstrated the strategic use of silicon carbide (SiC) semiconductor components to significantly reduce the susceptibility of an RF receiver circuit to undesired RF interference. A pair of silicon carbide mixer diodes successfully reduced RF interference (intermodulation distortion) in a prototype receiver circuit by a factor of 10 (20 dB) in comparison to a pair of commercial silicon-based mixer diodes.

  16. Advanced EVA system design requirements study

    NASA Technical Reports Server (NTRS)

    1986-01-01

    Design requirements and criteria for the Space Station Advanced Extravehicular Activity System (EVAS) including crew enclosures, portable life support systems, maneuvering propulsion systems, and related extravehicular activity (EVA) support equipment were defined and established. The EVA mission requirements, environments, and medical and physiological requirements, as well as opertional, procedures, and training issues were considered.

  17. Advanced Control Considerations for Turbofan Engine Design

    NASA Technical Reports Server (NTRS)

    Connolly, Joseph W.; Csank, Jeffrey T.; Chicatelli, Amy

    2016-01-01

    This paper covers the application of a model-based engine control (MBEC) methodology featuring a self tuning on-board model for an aircraft turbofan engine simulation. The nonlinear engine model is capable of modeling realistic engine performance, allowing for a verification of the advanced control methodology over a wide range of operating points and life cycle conditions. The on-board model is a piece-wise linear model derived from the nonlinear engine model and updated using an optimal tuner Kalman Filter estimation routine, which enables the on-board model to self-tune to account for engine performance variations. MBEC is used here to show how advanced control architectures can improve efficiency during the design phase of a turbofan engine by reducing conservative operability margins. The operability margins that can be reduced, such as stall margin, can expand the engine design space and offer potential for efficiency improvements. Application of MBEC architecture to a nonlinear engine simulation is shown to reduce the thrust specific fuel consumption by approximately 1% over the baseline design, while maintaining safe operation of the engine across the flight envelope.

  18. Various advanced design projects promoting engineering education

    NASA Technical Reports Server (NTRS)

    1994-01-01

    The Universities Space Research Association (USRA) Advanced Design Program (ADP) program promotes engineering education in the field of design by presenting students with challenging design projects drawn from actual NASA interests. In doing so, the program yields two very positive results. Firstly, the students gain a valuable experience that will prepare them for design problems with which they will be faced in their professional careers. Secondly, NASA is able to use the work done by students as an additional resource in meeting its own design objectives. The 1994 projects include: Universal Test Facility; Automated Protein Crystal Growth Facility; Stiffening of the ACES Deployable Space Boom; Launch System Design for Access to Space; LH2 Fuel Tank Design for SSTO Vehicle; and Feed System Design for a Reduced Pressure Tank.

  19. Advanced stratified charge rotary aircraft engine design study

    NASA Technical Reports Server (NTRS)

    Badgley, P.; Berkowitz, M.; Jones, C.; Myers, D.; Norwood, E.; Pratt, W. B.; Ellis, D. R.; Huggins, G.; Mueller, A.; Hembrey, J. H.

    1982-01-01

    A technology base of new developments which offered potential benefits to a general aviation engine was compiled and ranked. Using design approaches selected from the ranked list, conceptual design studies were performed of an advanced and a highly advanced engine sized to provide 186/250 shaft Kw/HP under cruise conditions at 7620/25,000 m/ft altitude. These are turbocharged, direct-injected stratified charge engines intended for commercial introduction in the early 1990's. The engine descriptive data includes tables, curves, and drawings depicting configuration, performance, weights and sizes, heat rejection, ignition and fuel injection system descriptions, maintenance requirements, and scaling data for varying power. An engine-airframe integration study of the resulting engines in advanced airframes was performed on a comparative basis with current production type engines. The results show airplane performance, costs, noise & installation factors. The rotary-engined airplanes display substantial improvements over the baseline, including 30 to 35% lower fuel usage.

  20. C-130 Advanced Technology Center wing box conceptual design/cost study

    NASA Technical Reports Server (NTRS)

    Whitehead, R. S.; Foreman, C. R.; Silva, K.

    1992-01-01

    A conceptual design was developed by Northrop/LTV for an advanced C-130 Center Wing Box (CWB) which could meet the severe mission requirements of the SOF C-130 aircraft. The goals for the advanced technology CWB relative to the current C-130H CWB were: (1) the same acquisition cost; (2) lower operating support costs; (3) equal or lower weight; (4) a 30,000 hour service life for the SOF mission; and (5) minimum impact on the current maintenance concept. Initially, the structural arrangement, weight, external and internal loads, fatigue spectrum, flutter envelope and design criteria for the SOF C-130 aircraft CWB were developed. An advanced materials assessment was then conducted to determine the suitability of advanced materials for a 1994 production availability and detailed trade studies were performed on candidate CWB conceptual designs. Finally, a life-cycle cost analysis was performed on the advanced CWB. The study results showed that a hybrid composite/metallic CWB could meet the severe SOF design requirements, reduce the CWB weight by 14 pct., and was cost effective relative to an all metal beefed up C-130H CWB.

  1. Technical Workshop: Advanced Helicopter Cockpit Design

    NASA Technical Reports Server (NTRS)

    Hemingway, J. C. (Editor); Callas, G. P. (Editor)

    1984-01-01

    Information processing demands on both civilian and military aircrews have increased enormously as rotorcraft have come to be used for adverse weather, day/night, and remote area missions. Applied psychology, engineering, or operational research for future helicopter cockpit design criteria were identified. Three areas were addressed: (1) operational requirements, (2) advanced avionics, and (3) man-system integration.

  2. Cost and accuracy of advanced breeding trial designs in apple

    PubMed Central

    Harshman, Julia M; Evans, Kate M; Hardner, Craig M

    2016-01-01

    Trialing advanced candidates in tree fruit crops is expensive due to the long-term nature of the planting and labor-intensive evaluations required to make selection decisions. How closely the trait evaluations approximate the true trait value needs balancing with the cost of the program. Designs of field trials of advanced apple candidates in which reduced number of locations, the number of years and the number of harvests per year were modeled to investigate the effect on the cost and accuracy in an operational breeding program. The aim was to find designs that would allow evaluation of the most additional candidates while sacrificing the least accuracy. Critical percentage difference, response to selection, and correlated response were used to examine changes in accuracy of trait evaluations. For the quality traits evaluated, accuracy and response to selection were not substantially reduced for most trial designs. Risk management influences the decision to change trial design, and some designs had greater risk associated with them. Balancing cost and accuracy with risk yields valuable insight into advanced breeding trial design. The methods outlined in this analysis would be well suited to other horticultural crop breeding programs. PMID:27019717

  3. Directed molecular evolution to design advanced red fluorescent proteins.

    PubMed

    Subach, Fedor V; Piatkevich, Kiryl D; Verkhusha, Vladislav V

    2011-11-29

    Fluorescent proteins have become indispensable imaging tools for biomedical research. Continuing progress in fluorescence imaging, however, requires probes with additional colors and properties optimized for emerging techniques. Here we summarize strategies for development of red-shifted fluorescent proteins. We discuss possibilities for knowledge-based rational design based on the photochemistry of fluorescent proteins and the position of the chromophore in protein structure. We consider advances in library design by mutagenesis, protein expression systems and instrumentation for high-throughput screening that should yield improved fluorescent proteins for advanced imaging applications.

  4. Advanced Energy Design Guide K-12: Next Generation of School Design and Operation

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Torcellini, Paul A; Pless, Shanti

    Driven by energy efficiency advances and renewable energy cost reductions, zero energy buildings are popping up all around the country. Although zero energy represents a bold paradigm shift - from buildings that consume energy to buildings that produce enough energy to meet their energy needs on an annual basis - it isn't a sudden shift. Zero energy buildings are the result of steady, incremental progress by researchers and building professionals working together to improve building energy performance. ASHRAE is taking the lead by publishing - in partnership with the American Institute of Architects (AIA), the Illuminating Engineering Society (IES), themore » U.S. Green Building Council (USGBC), and the U.S. Department of Energy (DOE) - a new series of advanced energy design guides (AEDGs) focused on zero energy buildings. The recently completed Advanced Energy Design Guide for K-12 School Buildings: Achieving Zero Energy (K-12 ZE AEDG) is the first in this series.« less

  5. A Handheld LED Coloured-Light Mixer for Students to Learn Collaboratively the Primary Colours of Light

    ERIC Educational Resources Information Center

    Nopparatjamjomras, Suchai; Chitaree, Ratchapak; Panijpan, Bhinyo

    2009-01-01

    To overcome students' inaccurate prior knowledge on primary additive colours, a coloured-light mixer has been constructed to enable students to observe directly the colours produced and reach the conclusion by themselves that the three primary colours of light are red, green, and blue (NOT red, yellow, and blue). Three closely packed tiny…

  6. T-mixer operating with water at different temperatures: Simulation and stability analysis

    NASA Astrophysics Data System (ADS)

    Siconolfi, L.; Camarri, S.; Salvetti, M. V.

    2018-03-01

    In this paper we investigate the transition from the vortex to the engulfment regime in a T-mixer when the two entering flows have different viscosity. In particular we consider as working fluid water entering the two inlet channels of the mixer at two different temperatures. Contrary to the isothermal case, at low Reynolds numbers the vortex regime shows only a single reflectional symmetry, due to the nonhomogeneous distribution of the viscosity. Increasing the Reynolds number, a symmetry-breaking bifurcation drives the system to a new steady flow configuration, usually called the engulfment regime, similar to what it is possible to observe in an isothermal case. This flow regime is associated with an increase of the mixing between the two inlet streams. It is shown by direct numerical simulation (DNS) and by stability analysis that the engulfment regime is promoted by the temperature difference. Starting from the DNSs, the resulting flow fields are analyzed in detail considering different temperature jumps between the two inlet boundaries. Furthermore, dedicated linear stability analyses are carried out to investigate the instability mechanism associated with the occurrence of the engulfment regime. In particular, similarly to the case without temperature differences, the onset of engulfment is driven by the momentum equation, and the temperature field does not lead to any additional instability mechanism. However, the existence of a temperature field leads to quantitative changes of the stability characteristics and of the resulting flow fields via a variation of the viscosity coefficient.

  7. Synthetic biology: advancing the design of diverse genetic systems

    PubMed Central

    Wang, Yen-Hsiang; Wei, Kathy Y.; Smolke, Christina D.

    2013-01-01

    A main objective of synthetic biology is to make the process of designing genetically-encoded biological systems more systematic, predictable, robust, scalable, and efficient. The examples of genetic systems in the field vary widely in terms of operating hosts, compositional approaches, and network complexity, ranging from a simple genetic switch to search-and-destroy systems. While significant advances in synthesis capabilities support the potential for the implementation of pathway- and genome-scale programs, several design challenges currently restrict the scale of systems that can be reasonably designed and implemented. Synthetic biology offers much promise in developing systems to address challenges faced in manufacturing, the environment and sustainability, and health and medicine, but the realization of this potential is currently limited by the diversity of available parts and effective design frameworks. As researchers make progress in bridging this design gap, advances in the field hint at ever more diverse applications for biological systems. PMID:23413816

  8. Designing a Robust Micromixer Based on Fluid Stretching

    NASA Astrophysics Data System (ADS)

    Mott, David; Gautam, Dipesh; Voth, Greg; Oran, Elaine

    2010-11-01

    A metric for measuring fluid stretching based on finite-time Lyapunov exponents is described, and the use of this metric for optimizing mixing in microfluidic components is explored. The metric is implemented within an automated design approach called the Computational Toolbox (CTB). The CTB designs components by adding geometric features, such a grooves of various shapes, to a microchannel. The transport produced by each of these features in isolation was pre-computed and stored as an "advection map" for that feature, and the flow through a composite geometry that combines these features is calculated rapidly by applying the corresponding maps in sequence. A genetic algorithm search then chooses the feature combination that optimizes a user-specified metric. Metrics based on the variance of concentration generally require the user to specify the fluid distributions at inflow, which leads to different mixer designs for different inflow arrangements. The stretching metric is independent of the fluid arrangement at inflow. Mixers designed using the stretching metric are compared to those designed using a variance of concentration metric and show excellent performance across a variety of inflow distributions and diffusivities.

  9. Experimental investigation of wing installation effects on a two-dimensional mixer/ejector nozzle for supersonic transport aircraft

    NASA Technical Reports Server (NTRS)

    Anderson, David J.; Lambert, Heather H.; Mizukami, Masashi

    1992-01-01

    Experimental results from a wind tunnel test conducted to investigate propulsion/airframe integration (PAI) effects are presented. The objectives of the test were to examine rough order-of-magnitude changes in the acoustic characteristics of a mixer/ejector nozzle due to the presence of a wing and to obtain limited wing and nozzle flow-field measurements. A simple representative supersonic transport wing planform, with deflecting flaps, was installed above a two-dimensional mixer/ejector nozzle that was supplied with high-pressure heated air. Various configurations and wing positions with respect to the nozzle were studied. Because of hardware problems, no acoustics and only a limited set of flow-field data were obtained. For most hardware configurations tested, no significant propulsion/airframe integration effects were identified. Significant effects were seen for extreme flap deflections. The combination of the exploratory nature of the test and the limited flow-field instrumentation made it impossible to identify definitive propulsion/airframe integration effects.

  10. Design of the advanced regional aircraft, the DART-75

    NASA Technical Reports Server (NTRS)

    Elliot, Steve; Gislason, Jason; Huffstetler, Mark; Mann, Jon; Withers, Ashley; Zimmerman, Mark

    1992-01-01

    The need for regional aircraft stems from the problem of hub airport congestion. Regional travel will allow a passenger to commute from one spoke city to another spoke city without entering the congested hub airport. In addition, those people traveling longer routes may begin the flight at home instead of traveling to the hub airport. At this time, there is no American aerospace company that produces a regional transport for under 100 passengers. The intention of the Developmental Advanced Regional Transport (DART-75) is to fill this void with a modern, efficient regional aircraft. This design achieves the efficiency through a number of advanced features including three lifting surfaces, partial composite construction, and an advanced engine design. Efficiency is not the only consideration. Structural integrity, fatigue life, ease of maintenance, passenger comfort and convenience, and environmental aspects must all be considered. These factors force the design team to face many tradeoffs that are studied to find the best solution. The final consideration that cannot be overlooked is that of cost. The DART-75 is a 75-passenger medium-range regional transport intended for spoke-to-spoke, spoke-to-hub, and some hub-to-hub operations. Included are the general descriptions of the structures, weight and balance, stability and control, performance, and engine design.

  11. Simulation and measurement of a Ka-band HTS MMIC Josephson junction mixer

    NASA Astrophysics Data System (ADS)

    Zhang, Ting; Pegrum, Colin; Du, Jia; Guo, Yingjie Jay

    2017-01-01

    We report modeling and simulation results for a Ka band high-temperature superconducting (HTS) monolithic microwave integrated circuit (MMIC) Josephson junction mixer. A Verilog-A model of a Josephson junction is established and imported into the system simulator to realize a full HTS MMIC circuit simulation containing the HTS passive circuit models. Impedance matching optimization between the junction and passive devices is investigated. Junction DC I-V characteristics, current and local oscillator bias conditions and mixing performance are simulated and compared with the experimental results. Good agreement is obtained between the simulation and measurement results.

  12. Design of a rapid magnetic microfluidic mixer

    NASA Astrophysics Data System (ADS)

    Ballard, Matthew; Owen, Drew; Mills, Zachary Grant; Hanasoge, Srinivas; Hesketh, Peter; Alexeev, Alexander

    2015-11-01

    Using three-dimensional simulations and experiments, we demonstrate rapid mixing of fluid streams in a microchannel using orbiting magnetic microbeads. We use a lattice Boltzmann model coupled to a Brownian dynamics model to perform numerical simulations that study in depth the effect of system parameters such as channel configuration and fluid and bead velocities. We use our findings to aid the design of an experimental micromixer. Using this experimental device, we demonstrate rapid microfluidic mixing over a compact channel length, and validate our numerical simulation results. Finally, we use numerical simulations to study the physical mechanisms leading to microfluidic mixing in our system. Our findings demonstrate a promising method of rapid microfluidic mixing over a short distance, with applications in lab-on-a-chip sample testing.

  13. AZ-101 Mixer Pump Demonstration Data Acquisition System and Gamma Cart Data Acquisition Control System Software Configuration Management Plan

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    WHITE, D.A.

    1999-12-29

    This Software Configuration Management Plan (SCMP) provides the instructions for change control of the AZ1101 Mixer Pump Demonstration Data Acquisition System (DAS) and the Sludge Mobilization Cart (Gamma Cart) Data Acquisition and Control System (DACS).

  14. Designing an Advanced Instructional Design Advisor: Principles of Instructional Design. Volume 2

    DTIC Science & Technology

    1991-05-01

    ones contained in this paper would comprise a substantial part of the knowledge base for the AIDA . 14. SUBJECT TERMS IS.NUMBER OF PAGES ucigoirlive...the classroom (e.g., computer simulations models can be used to enhance CBI). The Advanced Instructional Design Advisor is a project aimed at providing... model shares with its variations. Tennyson then identifies research- based prescriptions from the cognitive sciences which should become part of ISD in

  15. A Design Heritage-Based Forecasting Methodology for Risk Informed Management of Advanced Systems

    NASA Technical Reports Server (NTRS)

    Maggio, Gaspare; Fragola, Joseph R.

    1999-01-01

    The development of next generation systems often carries with it the promise of improved performance, greater reliability, and reduced operational costs. These expectations arise from the use of novel designs, new materials, advanced integration and production technologies intended for functionality replacing the previous generation. However, the novelty of these nascent technologies is accompanied by lack of operational experience and, in many cases, no actual testing as well. Therefore some of the enthusiasm surrounding most new technologies may be due to inflated aspirations from lack of knowledge rather than actual future expectations. This paper proposes a design heritage approach for improved reliability forecasting of advanced system components. The basis of the design heritage approach is to relate advanced system components to similar designs currently in operation. The demonstrated performance of these components could then be used to forecast the expected performance and reliability of comparable advanced technology components. In this approach the greater the divergence of the advanced component designs from the current systems the higher the uncertainty that accompanies the associated failure estimates. Designers of advanced systems are faced with many difficult decisions. One of the most common and more difficult types of these decisions are those related to the choice between design alternatives. In the past decision-makers have found these decisions to be extremely difficult to make because they often involve the trade-off between a known performing fielded design and a promising paper design. When it comes to expected reliability performance the paper design always looks better because it is on paper and it addresses all the know failure modes of the fielded design. On the other hand there is a long, and sometimes very difficult road, between the promise of a paper design and its fulfillment; with the possibility that sometimes the reliability

  16. Advanced solar panel designs

    NASA Technical Reports Server (NTRS)

    Ralph, E. L.; Linder, E. B.

    1996-01-01

    Solar panel designs that utilize new high-efficiency solar cells and lightweight rigid panel technologies are described. The resulting designs increase the specific power (W/kg) achievable in the near-term and are well suited to meet the demands of higher performance small satellites (smallsats). Advanced solar panel designs have been developed and demonstrated on two NASA SBIR contracts at Applied Solar. The first used 19% efficient, large area (5.5 cm x 6.5 cm) GaAs/Ge solar cells with a lightweight rigid graphite epoxy isogrid substrate configuration. A 1,445 cm(exp 2) coupon was fabricated and tested to demonstrate 60 W/kg with a high potential of achieving 80 W/kg. The second panel design used new 22% efficiency, dual junction GaInP2/GaAs/Ge solar cells combined with a lightweight aluminum core/graphite fiber mesh facesheet substrate. A 1,445 cm(exp 2) coupon was fabricated and tested to demonstrate 105 W/kg with the potential of achieving 115 W/kg. This paper will address the construction details for the GaAs/isogrid and dual-junction GaAs/carbon mesh panel configurations. These are ultimately sized to provide 75 Watts and 119 Watts respectively for smallsats or may be used as modular building blocks for larger systems. GaAs/isogrid and dual-junction GaAs/carbon mesh coupons have been fabricated and tested to successfully demonstrate critical performance parameters and results are also provided here.

  17. Advanced designs for IPV nickel-hydrogen cells

    NASA Technical Reports Server (NTRS)

    Smithrick, J. J.; Manzo, M. A.; Gonzalez-Sanabria, O. D.

    1984-01-01

    Advanced designs for individual pressure vessel nickel-hydrogen cells have been concieved which should improve the cycle life at deep depths-of-discharge. Features of the designs which are new and not incorporated in either of the contemporary cells (Air Force/Hughes, Comsat) are: (1) use of alternate methods of oxygen recombination, (2) use of serrated edge separators to facilitate movement of gas within the cell while still maintaining required physical contact with the wall wick, and (3) use of an expandable stack to accommodate some of the nickel electrode expansion. The designs also consider electrolyte volume requirements over the life of the cells, and are fully compatible with the Air Force/Hughes design.

  18. A 0.2-0.5 THz single-band heterodyne receiver based on a photonic local oscillator and a superconductor-insulator-superconductor mixer

    NASA Astrophysics Data System (ADS)

    Kohjiro, Satoshi; Kikuchi, Kenichi; Maezawa, Masaaki; Furuta, Tomofumi; Wakatsuki, Atsushi; Ito, Hiroshi; Shimizu, Naofumi; Nagatsuma, Tadao; Kado, Yuichi

    2008-09-01

    We have demonstrated that a superconductor-insulator-superconductor (SIS) mixer pumped by a photonic local oscillator (LO) covers the whole frequency range of 0.2-0.5THz. In the bandwidth of 74% of the center frequency, this single-band receiver exhibits noise temperature of TRX⩽20hf/kB, where h is Planck's constant, f is the frequency, and kB is Boltzmann's constant. Resultant TRX is almost equal to TRX of the identical SIS mixer pumped by three conventional frequency-multiplier-based LOs which share the 0.2-0.5THz band. This technique will contribute to simple, wide-band, and low-noise heterodyne receivers in the terahertz region.

  19. Mechanism of amorphisation of micro-particles of griseofulvin during powder flow in a mixer.

    PubMed

    Pazesh, Samaneh; Höckerfelt, Mina Heidarian; Berggren, Jonas; Bramer, Tobias; Alderborn, Göran

    2013-11-01

    The purpose of the research was to investigate the degree of solid-state amorphisation during powder flow and to propose a mechanism for this transformation. Micro-particles of griseofulvin (about 2 μm in diameter) were mixed in a shear mixer under different conditions to influence the inter-particulate collisions during flow, and the degree of amorphisation was determined by micro-calorimeter. The amorphisation of griseofulvin particles (GPs) during repeated compaction was also determined. The GPs generally became disordered during mixing in a range from about 6% to about 86%. The degree of amorphisation increased with increased mixing time and increased batch size of the mixer, whereas the addition of a lubricant to the blend reduced the degree of amorphisation. Repeated compaction using the press with ejection mode gave limited amorphisation, whereas repeated compaction without an ejection process gave minute amorphisation. It is concluded that during powder flow, the most important inter-particulate contact process that cause the transformation of a crystalline solid into an amorphous state is sliding. On the molecular scale, this amorphisation is proposed to be caused by vitrification, that is the melting of a solid because of the generation of heat during sliding followed by solidification into an amorphous phase. © 2013 Wiley Periodicals, Inc. and the American Pharmacists Association.

  20. Oxide_Oxide Ceramic Matrix Composite (CMC) Exhaust Mixer Development in the NASA Environmentally Responsible Aviation (ERA) Project

    NASA Technical Reports Server (NTRS)

    Kiser, J. Douglas; Bansal, Narottam P.; Szelagowski, James; Sokhey, Jagdish; Heffernan, Tab; Clegg, Joseph; Pierluissi, Anthony; Riedell, Jim; Wyen, Travis; Atmur, Steven; hide

    2015-01-01

    LibertyWorks®, a subsidiary of Rolls-Royce Corporation, first studied CMC (ceramic matrix composite) exhaust mixers for potential weight benefits in 2008. Oxide CMC potentially offered weight reduction, higher temperature capability, and the ability to fabricate complex-shapes for increased mixing and noise suppression. In 2010, NASA was pursuing the reduction of NOx emissions, fuel burn, and noise from turbine engines in Phase I of the Environmentally Responsible Aviation (ERA) Project (within the Integrated Systems Research Program). ERA subtasks, including those focused on CMC components, were being formulated with the goal of maturing technology from Proof of Concept Validation (Technology Readiness Level 3 (TRL 3)) to System/Subsystem or Prototype Demonstration in a Relevant Environment (TRL 6). LibertyWorks®, a subsidiary of Rolls-Royce Corporation, first studied CMC (ceramic matrix composite) exhaust mixers for potential weight benefits in 2008. Oxide CMC potentially offered weight reduction, higher temperature capability, and the ability to fabricate complex-shapes for increased mixing and noise suppression. In 2010, NASA was pursuing the reduction of NOx emissions, fuel burn, and noise from turbine engines in Phase I of the Environmentally Responsible Aviation (ERA) Project (within the Integrated Systems Research Program). ERA subtasks, including those focused on CMC components, were being formulated with the goal of maturing technology from Proof of Concept Validation (Technology Readiness Level 3 (TRL 3)) to System/Subsystem or Prototype Demonstration in a Relevant Environment (TRL 6). Oxide CMC component at both room and elevated temperatures. A TRL˜5 (Component Validation in a Relevant Environment) was attained and the CMC mixer was cleared for ground testing on a Rolls-Royce AE3007 engine for performance evaluation to achieve TRL 6.

  1. Numerical Simulation of the Oscillations in a Mixer: An Internal Aeroacoustic Feedback System

    NASA Technical Reports Server (NTRS)

    Jorgenson, Philip C. E.; Loh, Ching Y.

    2004-01-01

    The space-time conservation element and solution element method is employed to numerically study the acoustic feedback system in a high temperature, high speed wind tunnel mixer. The computation captures the self-sustained feedback loop between reflecting Mach waves and the shear layer. This feedback loop results in violent instabilities that are suspected of causing damage to some tunnel components. The computed frequency is in good agreement with the available experimental data. The physical phenomena are explained based on the numerical results.

  2. Advanced Technology Spark-Ignition Aircraft Piston Engine Design Study

    NASA Technical Reports Server (NTRS)

    Stuckas, K. J.

    1980-01-01

    The advanced technology, spark ignition, aircraft piston engine design study was conducted to determine the improvements that could be made by taking advantage of technology that could reasonably be expected to be made available for an engine intended for production by January 1, 1990. Two engines were proposed to account for levels of technology considered to be moderate risk and high risk. The moderate risk technology engine is a homogeneous charge engine operating on avgas and offers a 40% improvement in transportation efficiency over present designs. The high risk technology engine, with a stratified charge combustion system using kerosene-based jet fuel, projects a 65% improvement in transportation efficiency. Technology enablement program plans are proposed herein to set a timetable for the successful integration of each item of required advanced technology into the engine design.

  3. Preliminary design and analysis of an advanced rotorcraft transmission

    NASA Technical Reports Server (NTRS)

    Henry, Z. S.

    1990-01-01

    Future rotorcraft transmissions of the 1990s and beyond the year 2000 require the incorporation of key emerging material and component technologies using advanced and innovative design practices in order to meet the requirements for a reduced weight-to-power ratio, a decreased noise level, and a substantially increased reliability. The specific goals for future rotocraft transmissions when compared with current state-of-the-art transmissions are a 25 percent weight reduction, a 10-dB reduction in the transmitted noise level, and a system reliability of 5000 hours mean-time-between-removal for the transmission. This paper presents the results of the design studies conducted to meet the stated goals for an advanced rotorcraft transmission. These design studies include system configuration, planetary gear train selection, and reliability prediction methods.

  4. Design of an advanced 500-HP helicopter transmission

    NASA Technical Reports Server (NTRS)

    Braddock, C. E.

    1982-01-01

    A 500-hp Advanced Technology Demonstrator helicopter transmission was designed by an American aerospace company under a NASA contract. The project was mainly concerned with designing a 500-hp version of the OH-58C 317-hp transmission which would have the capabilities for a long, quiet life at a minimum increase in cost, weight, and space, which usually increase along with power increases. This objective was accomplished by implementing advanced technology which has been developed during the last decade and by making improvements dictated by field experience. The improvements are related to bearings made of cleaner gear steels, spiral bevel gears made of cleaner gear steels, high contact ratio spur gear teeth in the planetary which will reduce noise level and increase gear life, and modifications concerning the sun gear.

  5. NASA/USRA University Advanced Design Program Fifth Annual Summer Conference

    NASA Technical Reports Server (NTRS)

    1989-01-01

    The NASA/USRA University Advanced Design Program is a unique program that brings together NASA engineers, students, and faculty from United States engineering schools by integrating current and future NASA space/aeronautics engineering design projects into the university curriculum. The Program was conceived in the fall of 1984 as a pilot project to foster engineering design education in the universities and to supplement NASA's in-house efforts in advanced planning for space and aeronautics design. Nine universities and five NASA centers participated in the first year of the pilot project. Close cooperation between the NASA centers and the universities, the careful selection of design topics, and the enthusiasm of the students has resulted in a very successful program than now includes forty universities and eight NASA centers. The study topics cover a broad range of potential space and aeronautics projects.

  6. Progress on a Multichannel, Dual-Mixer Stability Analyzer

    NASA Technical Reports Server (NTRS)

    Kirk, Albert; Cole, Steven; Stevens, Gary; Tucker, Blake; Greenhall, Charles

    2005-01-01

    Several documents describe aspects of the continuing development of a multichannel, dual-mixer system for simultaneous characterization of the instabilities of multiple precise, low-noise oscillators. One of the oscillators would be deemed to be a reference oscillator, its frequency would be offset by an amount (100 Hz) much greater than the desired data rate, and each of the other oscillators would be compared with the frequency-offset signal by operation of a combination of hardware and software. A high-rate time-tag counter would collect zero-crossing times of the approximately equal 100-Hz beat notes. The system would effect a combination of interpolation and averaging to process the time tags into low-rate phase residuals at the desired grid times. Circuitry that has been developed since the cited prior article includes an eight-channel timer board to replace an obsolete commercial time-tag counter, plus a custom offset generator, cleanup loop, distribution amplifier, zero-crossing detector, and frequency divider.

  7. Passive Solar still: Recent advancement in design and related Performance.

    PubMed

    Awasthi, Anuradha; Kumari, Kanchan; Panchal, Hitesh; Sathyamurthy, Ravishankar

    2018-05-31

    Present review paper mainly focuses on different varieties of solar stills and highlights mostly the passive solar still with advanced modifications in the design and development of material, single and multi-effect solar still with augmentation of different materials, energy absorbing, insulators, mechanisms of heat and mass transfer to improve the loss of heat and enhance the productivity of solar still. The cost-benefit analysis along with the progressive advancement for solar stills is the major highlights of this review. To increase the output of solar still nowadays, applications of advance modifications is one of the promising tools, and it is anticipated that shortly more vigor will be added in this area with the modifications in designs of solar stills.

  8. A 1/10 Scale Model Test of a Fixed Chute Mixer-Ejector Nozzle in Unsuppressed Model. Part 1; Test Overview

    NASA Technical Reports Server (NTRS)

    Wolter, John D.

    2007-01-01

    This paper discusses a test of a nozzle concept for a high-speed commercial aircraft. While a great deal of effort has been expended to und erstand the noise-suppressed, take-off performance of mixer-ejector n ozzles, little has been done to assess their performance in unsuppressed mode at other flight conditions. To address this, a 1/10th scale m odel mixer-ejector nozzle in unsuppressed mode was tested at conditio ns representing transonic acceleration, supersonic cruise, subsonic cruise, and approach. Various configurations were tested to understand the effects of acoustic liners and several geometric parameters, such as throat area, expansion ratio, and nozzle length on nozzle performance. Thrust, flow, and internal pressures were measured. A statistica l model of the peak thrust coefficient results is presented and discussed.

  9. Advanced radial inflow turbine rotor program: Design and dynamic testing

    NASA Technical Reports Server (NTRS)

    Rodgers, C.

    1976-01-01

    The advancement of small, cooled, radial inflow turbine technology in the area of operation at higher turbine inlet temperature is discussed. The first step was accomplished by designing, fabricating, and subjecting to limited mechanical testing an advanced gas generator rotating assembly comprising a radial inflow turbine and two-stage centrifugal compressor. The radial inflow turbine and second-stage compressor were designed as an integrally machined monorotor with turbine cooling taking place basically by conduction to the compressor. Design turbine inlet rotor gas temperature, rotational speed, and overall gas generator compressor pressure ratio were 1422 K (2560 R), 71,222 rpm, and 10/1 respectively. Mechanical testing on a fabricated rotating assembly and bearing system covered 1,000 cold start/stop cycles and three spins to 120 percent design speed (85,466 rpm).

  10. Advances in Experiment Design for High Performance Aircraft

    NASA Technical Reports Server (NTRS)

    Morelli, Engene A.

    1998-01-01

    A general overview and summary of recent advances in experiment design for high performance aircraft is presented, along with results from flight tests. General theoretical background is included, with some discussion of various approaches to maneuver design. Flight test examples from the F-18 High Alpha Research Vehicle (HARV) are used to illustrate applications of the theory. Input forms are compared using Cramer-Rao bounds for the standard errors of estimated model parameters. Directions for future research in experiment design for high performance aircraft are identified.

  11. Digital Baseband Architecture For Transponder

    NASA Technical Reports Server (NTRS)

    Nguyen, Tien M.; Yeh, Hen-Geul

    1995-01-01

    Proposed advanced transponder for long-distance radio communication system with turnaround ranging contains carrier-signal-tracking loop including baseband digital "front end." For reduced cost, transponder includes analog intermediate-frequency (IF) section and analog automatic gain control (AGC) loop at first of two IF mixers. However, second IF mixer redesigned to ease digitization of baseband functions. To conserve power and provide for simpler and smaller transponder hardware, baseband digital signal-processing circuits designed to implement undersampling scheme. Furthermore, sampling scheme and sampling frequency chosen so redesign involves minimum modification of command-detector unit (CDU).

  12. Co-Simulation for Advanced Process Design and Optimization

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Stephen E. Zitney

    2009-01-01

    Meeting the increasing demand for clean, affordable, and secure energy is arguably the most important challenge facing the world today. Fossil fuels can play a central role in a portfolio of carbon-neutral energy options provided CO{sub 2} emissions can be dramatically reduced by capturing CO{sub 2} and storing it safely and effectively. Fossil energy industry faces the challenge of meeting aggressive design goals for next-generation power plants with CCS. Process designs will involve large, highly-integrated, and multipurpose systems with advanced equipment items with complex geometries and multiphysics. APECS is enabling software to facilitate effective integration, solution, and analysis of high-fidelitymore » process/equipment (CFD) co-simulations. APECS helps to optimize fluid flow and related phenomena that impact overall power plant performance. APECS offers many advanced capabilities including ROMs, design optimization, parallel execution, stochastic analysis, and virtual plant co-simulations. NETL and its collaborative R&D partners are using APECS to reduce the time, cost, and technical risk of developing high-efficiency, zero-emission power plants with CCS.« less

  13. NASA/USRA University advanced design program

    NASA Technical Reports Server (NTRS)

    Lembeck, Michael F.; Prussing, John

    1989-01-01

    The participation of the University of Illinois at Urbana-Champaign in the NASA/USRA University Advanced Design Program for the 1988 to 1989 academic year is reviewed. The University's design project was the Logistics Resupply and Emergency Crew Return System for Space Station Freedom. Sixty-one students divided into eight groups, participated in the spring 1989 semester. A presentation prepared by three students and a graduate teaching assistant for the program's summer conference summarized the project results. Teamed with the NASA Marshall Space Flight Center (MSFC), the University received support in the form of remote telecon lectures, reference material, and previously acquired applications software. In addition, a graduate teaching assistant was awarded a summer 1989 internship at MSFC.

  14. Advanced Solid Rocket Motor case design status

    NASA Technical Reports Server (NTRS)

    Palmer, G. L.; Cash, S. F.; Beck, J. P.

    1993-01-01

    The Advanced Solid Rocket Motor (ASRM) case design aimed at achieving a safer and more reliable solid rocket motor for the Space Shuttle system is considered. The ASRM case has a 150.0 inch diameter, three equal length segment, and 9Ni-4CO-0.3C steel alloy. The major design features include bolted casebolted case joints which close during pressurization, plasma arc welded factory joints, integral stiffener for splash down and recovery, and integral External Tank attachment rings. Each mechanical joint has redundant and verifiable o-ring seals.

  15. Preliminary design studies of an advanced general aviation aircraft

    NASA Technical Reports Server (NTRS)

    Barrett, Ron; Demoss, Shane; Dirkzwager, AB; Evans, Darryl; Gomer, Charles; Keiter, Jerry; Knipp, Darren; Seier, Glen; Smith, Steve; Wenninger, ED

    1991-01-01

    The preliminary design results are presented of the advanced aircraft design project. The goal was to take a revolutionary look into the design of a general aviation aircraft. Phase 1 of the project included the preliminary design of two configurations, a pusher, and a tractor. Phase 2 included the selection of only one configuration for further study. The pusher configuration was selected on the basis of performance characteristics, cabin noise, natural laminar flow, and system layouts. The design was then iterated to achieve higher levels of performance.

  16. Lubricant based determination of design space for continuously manufactured high dose paracetamol tablets.

    PubMed

    Taipale-Kovalainen, Krista; Karttunen, Anssi-Pekka; Ketolainen, Jarkko; Korhonen, Ossi

    2018-03-30

    The objective of this study was to devise robust and stable continuous manufacturing process settings, by exploring the design space after an investigation of the lubrication-based parameters influencing the continuous direct compression tableting of high dose paracetamol tablets. Experimental design was used to generate a structured study plan which involved 19 runs. The formulation variables studied were the type of lubricant (magnesium stearate or stearic acid) and its concentration (0.5, 1.0 and 1.5%). Process variables were total production feed rate (5, 10.5 and 16kg/h), mixer speed rpm (500, 850 and 1200rpm), and mixer inlet port for lubricant (A or B). The continuous direct compression tableting line consisted of loss-in-weight feeders, a continuous mixer and a tablet press. The Quality Target Product Profile (QTPP) was defined for the final product, as the flowability of powder blends (2.5s), tablet strength (147N), dissolution in 2.5min (90%) and ejection force (425N). A design space was identified which fulfilled all the requirements of QTPP. The type and concentration of lubricant exerted the greatest influence on the design space. For example, stearic acid increased the tablet strength. Interestingly, the studied process parameters had only a very minor effect on the quality of the final product and the design space. It is concluded that the continuous direct compression tableting process itself is insensitive and can cope with changes in lubrication, whereas formulation parameters exert a major influence on the end product quality. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. The Design and Testing of the LSSIF Advanced Thermal Control System

    NASA Technical Reports Server (NTRS)

    Henson, Robert A.; Keller, John R.

    1995-01-01

    The Life Support Systems Integration Facility (LSSIF) provides a platform to design and evaluate advanced manned space systems at NASA Johnson Space Center (JSC). The LSSIF Early Human Testing Initiative requires the integration of such subsystems to enable human occupancy of the 6 meter chamber for a 90 day closed volume test. The Advanced Thermal Control System (TCS) is an important component of the integrated system by supplying coolant to the subsystems within the chamber, such as the Air Revitalization System. The TCS incorporates an advanced high efficiency, heat pump to reject waste heat from the chamber to an external sink or 'lift' temperature that emulates a Lunar environment. The heat pump is the High Lift Heat Pump, developed by Foster-Miller, Inc., and is the main test article of the TCS. The heat pump prototype utilizes a non-CFC refrigerant in a design where the thermal requirements exceed existing terrestrial technology. These operating requirements provide a unique opportunity to design and test an advanced integrated thermal system and the associated controls. The design, control, and systems integration of the heat pump and the TCS also have terrestrial technology application. This paper addresses the design of the TCS and the heat pump, along with the control scheme to fully test the heat pump. Design approaches utilized in the LSSIF TCS are promoted for implementation in terrestrial thermal systems. The results of the preliminary thermal and fluid analyses used to develop the control of the thermal systems will also be discussed. The paper includes objectives for the 90 day human test and the test setup. Finally, conclusions will be drawn and recommendations for Earth design application are submitted.

  18. Spectrometric Analysis for Pulse Jet Mixer Testing

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    ZEIGLER, KRISTINE

    2004-07-12

    The Analytical Development Section (ADS) was tasked with providing support for a Hanford River Protection Program-Waste Treatment Program (RPP-WTP) project test involving absorption analysis for non-Newtonian pulse jet mixer testing for small scale (PJM) and prototype (CRV) tanks with sparging. Tanks filled with clay were mixed with various amounts of powdered dye as a tracer. The objective of the entire project was to determine the best mixing protocol (nozzle velocity, number of spargers used, total air flow, etc.) by determining the percent mixed volume through the use of an ultraviolet-visible (UV-Vis) spectrometer. The dye concentration within the sample could bemore » correlated to the volume fraction mixed in the tank. Samples were received in vials, a series of dilutions were generated from the clay, allowed to equilibrate, then centrifuged and siphoned for the supernate liquid to analyze by absorption spectroscopy. Equilibration of the samples and thorough mixing of the samples were a continuous issue with dilution curves being difficult to obtain. Despite these technical issues, useful data was obtained for evaluation of various mix conditions.« less

  19. Advanced Free Flight Planner and Dispatcher's Workstation: Preliminary Design Specification

    NASA Technical Reports Server (NTRS)

    Wilson, J.; Wright, C.; Couluris, G. J.

    1997-01-01

    The National Aeronautics and Space Administration (NASA) has implemented the Advanced Air Transportation Technology (AATT) program to investigate future improvements to the national and international air traffic management systems. This research, as part of the AATT program, developed preliminary design requirements for an advanced Airline Operations Control (AOC) dispatcher's workstation, with emphasis on flight planning. This design will support the implementation of an experimental workstation in NASA laboratories that would emulate AOC dispatch operations. The work developed an airline flight plan data base and specified requirements for: a computer tool for generation and evaluation of free flight, user preferred trajectories (UPT); the kernel of an advanced flight planning system to be incorporated into the UPT-generation tool; and an AOC workstation to house the UPT-generation tool and to provide a real-time testing environment. A prototype for the advanced flight plan optimization kernel was developed and demonstrated. The flight planner uses dynamic programming to search a four-dimensional wind and temperature grid to identify the optimal route, altitude and speed for successive segments of a flight. An iterative process is employed in which a series of trajectories are successively refined until the LTPT is identified. The flight planner is designed to function in the current operational environment as well as in free flight. The free flight environment would enable greater flexibility in UPT selection based on alleviation of current procedural constraints. The prototype also takes advantage of advanced computer processing capabilities to implement more powerful optimization routines than would be possible with older computer systems.

  20. Control Design for an Advanced Geared Turbofan Engine

    NASA Technical Reports Server (NTRS)

    Chapman, Jeffryes W.; Litt, Jonathan S.

    2017-01-01

    This paper describes the design process for the control system of an advanced geared turbofan engine. This process is applied to a simulation that is representative of a 30,000 pound-force thrust class concept engine with two main spools, ultra-high bypass ratio, and a variable area fan nozzle. Control system requirements constrain the non-linear engine model as it operates throughout its flight envelope of sea level to 40,000 feet and from 0 to 0.8 Mach. The purpose of this paper is to review the engine control design process for an advanced turbofan engine configuration. The control architecture selected for this project was developed from literature and reflects a configuration that utilizes a proportional integral controller with sets of limiters that enable the engine to operate safely throughout its flight envelope. Simulation results show the overall system meets performance requirements without exceeding operational limits.

  1. Advanced Control Design for Wind Turbines; Part I: Control Design, Implementation, and Initial Tests

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Wright, A. D.; Fingersh, L. J.

    The purpose of this report is to give wind turbine engineers information and examples of the design, testing through simulation, field implementation, and field testing of advanced wind turbine controls.

  2. Advanced control design for hybrid turboelectric vehicle

    NASA Technical Reports Server (NTRS)

    Abban, Joseph; Norvell, Johnesta; Momoh, James A.

    1995-01-01

    The new environment standards are a challenge and opportunity for industry and government who manufacture and operate urban mass transient vehicles. A research investigation to provide control scheme for efficient power management of the vehicle is in progress. Different design requirements using functional analysis and trade studies of alternate power sources and controls have been performed. The design issues include portability, weight and emission/fuel efficiency of induction motor, permanent magnet and battery. A strategic design scheme to manage power requirements using advanced control systems is presented. It exploits fuzzy logic, technology and rule based decision support scheme. The benefits of our study will enhance the economic and technical feasibility of technological needs to provide low emission/fuel efficient urban mass transit bus. The design team includes undergraduate researchers in our department. Sample results using NASA HTEV simulation tool are presented.

  3. Conceptual design study for an advanced cab and visual system, volume 2

    NASA Technical Reports Server (NTRS)

    Rue, R. J.; Cyrus, M. L.; Garnett, T. A.; Nachbor, J. W.; Seery, J. A.; Starr, R. L.

    1980-01-01

    The performance, design, construction and testing requirements are defined for developing an advanced cab and visual system. The rotorcraft system integration simulator is composed of the advanced cab and visual system and the rotorcraft system motion generator, and is part of an existing simulation facility. User's applications for the simulator include rotorcraft design development, product improvement, threat assessment, and accident investigation.

  4. Maintenance Free Fluidic Transfer and Mixing Devices for Highly Radioactive Applications - Design, Development, Deployment and Operational Experience

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Phillips, C.; Richardson, J. E.; Fallows, P.

    2006-07-01

    Power Fluidics is the generic name for a range of maintenance-free fluid transfer and mixing devices, capable of handling a wide range of highly radioactive fluids, jointly developed by British Nuclear Group, its US-based subsidiary BNG America, and AEA Technology. Power Fluidic devices include Reverse Flow Diverters (RFDs), Vacuum Operated Slug Lifts (VOSLs), and Air Lifts, all of which have an excellent proven record for pumping radioactive liquids and sludges. Variants of the RFD, termed Pulse Jet Mixers (PJMs) are used to agitate and mix tank contents, where maintenance-free equipment is desirable, and where a high degree of homogenization ismore » necessary. The equipment is designed around the common principle of using compressed air to provide the motive force to transfer liquids and sludges. These devices have no moving parts in contact with the radioactive medium and therefore require no maintenance in radioactive areas of processing plants. Once commissioned, Power Fluidic equipment has been demonstrated to operate for the life of the facility. Over 800 fluidic devices continue to operate safely and reliably in British Nuclear Group's nuclear facilities at the Sellafield site in the United Kingdom, and some of these have done so for almost 40 years. More than 400 devices are being supplied by AEA Technology and BNG America for the Waste Treatment Plant (WTP) at the Hanford Site in southeastern Washington State, USA. This paper discusses: - Principles of operation of fluidic pumps and mixers. - Selection criteria and design of fluidic pumps and mixers. - Operational experience of fluidic pumps and mixers in the United Kingdom. - Applications of fluidic pumps and mixers at the U.S. Department of Energy nuclear sites. (authors)« less

  5. Leveraging advances in biology to design biomaterials

    NASA Astrophysics Data System (ADS)

    Darnell, Max; Mooney, David J.

    2017-12-01

    Biomaterials have dramatically increased in functionality and complexity, allowing unprecedented control over the cells that interact with them. From these engineering advances arises the prospect of improved biomaterial-based therapies, yet practical constraints favour simplicity. Tools from the biology community are enabling high-resolution and high-throughput bioassays that, if incorporated into a biomaterial design framework, could help achieve unprecedented functionality while minimizing the complexity of designs by identifying the most important material parameters and biological outputs. However, to avoid data explosions and to effectively match the information content of an assay with the goal of the experiment, material screens and bioassays must be arranged in specific ways. By borrowing methods to design experiments and workflows from the bioprocess engineering community, we outline a framework for the incorporation of next-generation bioassays into biomaterials design to effectively optimize function while minimizing complexity. This framework can inspire biomaterials designs that maximize functionality and translatability.

  6. Advanced tracking systems design and analysis

    NASA Technical Reports Server (NTRS)

    Potash, R.; Floyd, L.; Jacobsen, A.; Cunningham, K.; Kapoor, A.; Kwadrat, C.; Radel, J.; Mccarthy, J.

    1989-01-01

    The results of an assessment of several types of high-accuracy tracking systems proposed to track the spacecraft in the National Aeronautics and Space Administration (NASA) Advanced Tracking and Data Relay Satellite System (ATDRSS) are summarized. Tracking systems based on the use of interferometry and ranging are investigated. For each system, the top-level system design and operations concept are provided. A comparative system assessment is presented in terms of orbit determination performance, ATDRSS impacts, life-cycle cost, and technological risk.

  7. Dynamics and Control of Orbiting Space Structures NASA Advanced Design Program (ADP)

    NASA Technical Reports Server (NTRS)

    Cruse, T. A.

    1996-01-01

    The report summarizes the advanced design program in the mechanical engineering department at Vanderbilt University for the academic years 1994-1995 and 1995-1996. Approximately 100 students participated in the two years of the subject grant funding. The NASA-oriented design projects that were selected included lightweight hydrogen propellant tank for the reusable launch vehicle, a thermal barrier coating test facility, a piezoelectric motor for space antenna control, and a lightweight satellite for automated materials processing. The NASA supported advanced design program (ADP) has been a success and a number of graduates are working in aerospace and are doing design.

  8. [An object-oriented intelligent engineering design approach for lake pollution control].

    PubMed

    Zou, Rui; Zhou, Jing; Liu, Yong; Zhu, Xiang; Zhao, Lei; Yang, Ping-Jian; Guo, Huai-Cheng

    2013-03-01

    Regarding the shortage and deficiency of traditional lake pollution control engineering techniques, a new lake pollution control engineering approach was proposed in this study, based on object-oriented intelligent design (OOID) from the perspective of intelligence. It can provide a new methodology and framework for effectively controlling lake pollution and improving water quality. The differences between the traditional engineering techniques and the OOID approach were compared. The key points for OOID were described as object perspective, cause and effect foundation, set points into surface, and temporal and spatial optimization. The blue algae control in lake was taken as an example in this study. The effect of algae control and water quality improvement were analyzed in details from the perspective of object-oriented intelligent design based on two engineering techniques (vertical hydrodynamic mixer and pumping algaecide recharge). The modeling results showed that the traditional engineering design paradigm cannot provide scientific and effective guidance for engineering design and decision-making regarding lake pollution. Intelligent design approach is based on the object perspective and quantitative causal analysis in this case. This approach identified that the efficiency of mixers was much higher than pumps in achieving the goal of low to moderate water quality improvement. However, when the objective of water quality exceeded a certain value (such as the control objective of peak Chla concentration exceeded 100 microg x L(-1) in this experimental water), the mixer cannot achieve this goal. The pump technique can achieve the goal but with higher cost. The efficiency of combining the two techniques was higher than using one of the two techniques alone. Moreover, the quantitative scale control of the two engineering techniques has a significant impact on the actual project benefits and costs.

  9. Design and demonstration of ultra-fast W-band photonic transmitter-mixer and detectors for 25 Gbits/sec error-free wireless linking.

    PubMed

    Chen, Nan-Wei; Shi, Jin-Wei; Tsai, Hsuan-Ju; Wun, Jhih-Min; Kuo, Fong-Ming; Hesler, Jeffery; Crowe, Thomas W; Bowers, John E

    2012-09-10

    A 25 Gbits/s error-free on-off-keying (OOK) wireless link between an ultra high-speed W-band photonic transmitter-mixer (PTM) and a fast W-band envelope detector is demonstrated. At the transmission end, the high-speed PTM is developed with an active near-ballistic uni-traveling carrier photodiode (NBUTC-PD) integrated with broadband front-end circuitry via the flip-chip bonding technique. Compared to our previous work, the wireless data rate is significantly increased through the improvement on the bandwidth of the front-end circuitry together with the reduction of the intermediate-frequency (IF) driving voltage of the active NBUTC-PD. The demonstrated PTM has a record-wide IF modulation (DC-25 GHz) and optical-to-electrical fractional bandwidths (68-128 GHz, ~67%). At the receiver end, the demodulation is realized with an ultra-fast W-band envelope detector built with a zero-bias Schottky barrier diode with a record wide video bandwidth (37 GHz) and excellent sensitivity. The demonstrated PTM is expected to find applications in multi-gigabit short-range wireless communication.

  10. An advanced Ni-Cd battery cell design

    NASA Technical Reports Server (NTRS)

    Miller, L.

    1986-01-01

    The evolution of an advanced Ni-Cd space battery cell design continues to prove very promising. High oxygen/hydrogen gas recombination rates (currently up to a C/5 charge rate) and increased electrolyte activation level tolerance (currently up to 5.6 grams Ah of positive capacity) were demonstrated by test. A superior performance, extended life battery cell offering advantages should soon be available for mission applications

  11. Forest fire advanced system technology (FFAST) conceptual design study

    NASA Technical Reports Server (NTRS)

    Nichols, J. David; Warren, John R.

    1987-01-01

    The National Aeronautics and Space Administration's Jet Propulsion Laboratory (JPL) and the U.S. Department of Agriculture (USDA) Forest Service completed a conceptual design study that defined an integrated forest fire detection and mapping system that will be based upon technology available in the 1990s. Potential system configuration options in emerging and advanced technologies related to the conceptual design were identified and recommended for inclusion as preferred system components. System component technologies identified for an end-to-end system include airborne mounted, thermal infrared (IR) linear array detectors, automatic onboard georeferencing and signal processing, geosynchronous satellite communications links, and advanced data integration and display. Potential system configuration options were developed and examined for possible inclusion in the preferred system configuration. The preferred system configuration will provide increased performance and be cost effective over the system currently in use. Forest fire management user requirements and the system component emerging technologies were the basis for the system configuration design. The conceptual design study defined the preferred system configuration that warrants continued refinement and development, examined economic aspects of the current and preferred system, and provided preliminary cost estimates for follow-on system prototype development.

  12. Soft computing in design and manufacturing of advanced materials

    NASA Technical Reports Server (NTRS)

    Cios, Krzysztof J.; Baaklini, George Y; Vary, Alex

    1993-01-01

    The potential of fuzzy sets and neural networks, often referred to as soft computing, for aiding in all aspects of manufacturing of advanced materials like ceramics is addressed. In design and manufacturing of advanced materials, it is desirable to find which of the many processing variables contribute most to the desired properties of the material. There is also interest in real time quality control of parameters that govern material properties during processing stages. The concepts of fuzzy sets and neural networks are briefly introduced and it is shown how they can be used in the design and manufacturing processes. These two computational methods are alternatives to other methods such as the Taguchi method. The two methods are demonstrated by using data collected at NASA Lewis Research Center. Future research directions are also discussed.

  13. Robust flight design for an advanced launch system vehicle

    NASA Astrophysics Data System (ADS)

    Dhand, Sanjeev K.; Wong, Kelvin K.

    Current launch vehicle trajectory design philosophies are generally based on maximizing payload capability. This approach results in an expensive trajectory design process for each mission. Two concepts of robust flight design have been developed to significantly reduce this cost: Standardized Trajectories and Command Multiplier Steering (CMS). These concepts were analyzed for an Advanced Launch System (ALS) vehicle, although their applicability is not restricted to any particular vehicle. Preliminary analysis has demonstrated the feasibility of these concepts at minimal loss in payload capability.

  14. Results From a Parametric Acoustic Liner Experiment Using P and W GEN1 HSR Mixer/Ejector Model

    NASA Technical Reports Server (NTRS)

    Boyd, Kathleen C.; Wolter, John D.

    2004-01-01

    This report documents the results of an acoustic liner test performed using a Gen 1 HSR mixer/ejector model installed on the Jet Exit Rig in the Nozzle Acoustic Test Rig in the Aeroacoustic Propulsion Laboratory or NASA Glenn Research Center. Acoustic liner effectiveness and single-component thrust performance results are discussed. Results from 26 different types of single-degree-of-freedom and bulk material liners are compared with each other and against a hardwall baseline. Design parameters involving all aspects of the facesheet, the backing cavity, and the type of bulk material were varied in order to study the effects of these design features on the acoustic impedance, acoustic effectiveness and on nozzle thrust performance. Overall, the bulk absorber liners are more effective at reducing the jet noise than the single-degree-of-freedom liners. Many of the design parameters had little effect on acoustic effectiveness, such as facesheeet hole diameter and honeycomb cell size. A relatively large variation in the impedance of the bulk absorber in a bulk liner is required to have a significant impact on the noise reduction. The thrust results exhibit a number of consistent trends, supporting the validity of this new addition to the facility. In general, the thrust results indicate that thrust performance benefits from increased facesheet thickness and decreased facesheet porosity.

  15. Proceedings of the Seventh Annual Summer Conference. NASA/USRA: University Advanced Design Program

    NASA Technical Reports Server (NTRS)

    1991-01-01

    The Advanced Design Program (ADP) is a unique program that brings together students and faculty from U.S. engineering schools with engineers from the NASA centers through integration of current and future NASA space and aeronautics projects into university engineering design curriculum. The Advanced Space Design Program study topics cover a broad range of projects that could be undertaken during a 20-30 year period beginning with the deployment of the Space Station Freedom. The Advanced Aeronautics Design Program study topics typically focus on nearer-term projects of interest to NASA, covering from small, slow-speed vehicles through large, supersonic passenger transports and on through hypersonic research vehicles. Student work accomplished during the 1990-91 academic year and reported at the 7th Annual Summer Conference is presented.

  16. Phase locking of 2.324 and 2.959 terahertz quantum cascade lasers using a Schottky diode harmonic mixer.

    PubMed

    Danylov, Andriy; Erickson, Neal; Light, Alexander; Waldman, Jerry

    2015-11-01

    The 23rd and 31st harmonics of a microwave signal generated in a novel THz balanced Schottky diode mixer were used as a frequency stable reference source to phase lock solid-nitrogen-cooled 2.324 and 2.959 THz quantum cascade lasers. Hertz-level frequency stability was achieved, which was maintained for several hours.

  17. Advanced EVA system design requirements study, executive summary

    NASA Technical Reports Server (NTRS)

    1986-01-01

    Design requirements and criteria for the space station advanced Extravehicular Activity System (EVAS) including crew enclosures, portable life support systems, maneuvering propulsion systems, and related EVA support equipment were established. The EVA mission requirements, environments, and medical and physiological requirements, as well as operational, procedures and training issues were considered.

  18. TMF design considerations in turbine airfoils of advanced turbine engines

    NASA Astrophysics Data System (ADS)

    Date, C. G.; Zamrik, S. Y.; Adams, J. H.; Frani, N. E.

    A review of thermal-mechanicalfatigue (TMF) in advanced turbine engines is presented. The review includes examples of typical thermal-mechnical loadings encountered in the design of hot section blades and vanes. Specific issues related to TMF behavior are presented and the associated impact on component life analysis and design is discussed.

  19. Advanced surface design for logistics analysis

    NASA Astrophysics Data System (ADS)

    Brown, Tim R.; Hansen, Scott D.

    The development of anthropometric arm/hand and tool models and their manipulation in a large system model for maintenance simulation are discussed. The use of Advanced Surface Design and s-fig technology in anthropometrics, and three-dimensional graphics simulation tools, are found to achieve a good balance between model manipulation speed and model accuracy. The present second generation models are shown to be twice as fast to manipulate as the first generation b-surf models, to be easier to manipulate into various configurations, and to more closely approximate human contours.

  20. Advanced Extravehicular Mobility Unit Informatics Software Design

    NASA Technical Reports Server (NTRS)

    Wright, Theodore

    2014-01-01

    This is a description of the software design for the 2013 edition of the Advanced Extravehicular Mobility Unit (AEMU) Informatics computer assembly. The Informatics system is an optional part of the space suit assembly. It adds a graphical interface for displaying suit status, timelines, procedures, and caution and warning information. In the future it will display maps with GPS position data, and video and still images captured by the astronaut.

  1. The 13.9 GHz short pulse radar noise figure measurements utilizing silicon and gallium-arsenide mixer diodes

    NASA Technical Reports Server (NTRS)

    Dombrowski, M.

    1977-01-01

    An analysis was made on two commercially available silicon and gallium arsenide Schottky barrier diodes. These diodes were selected because of their particularly low noise figure in the frequency range of interest. The specified noise figure for the silicon and gallium arsenide diodes were 6.3 db and 5.3 db respectively when functioning as mixers in the 13.6 GHz region with optimum local oscillator drive.

  2. Test Method Designed to Evaluate Cylinder Liner-Piston Ring Coatings for Advanced Heat Engines

    NASA Technical Reports Server (NTRS)

    Radil, Kevin C.

    1997-01-01

    Research on advanced heat engine concepts, such as the low-heat-rejection engine, have shown the potential for increased thermal efficiency, reduced emissions, lighter weight, simpler design, and longer life in comparison to current diesel engine designs. A major obstacle in the development of a functional advanced heat engine is overcoming the problems caused by the high combustion temperatures at the piston ring/cylinder liner interface, specifically at top ring reversal (TRR). Therefore, advanced cylinder liner and piston ring materials are needed that can survive under these extreme conditions. To address this need, researchers at the NASA Lewis Research Center have designed a tribological test method to help evaluate candidate piston ring and cylinder liner materials for advanced diesel engines.

  3. Low-Loss NbTiN Films for THz SIS Mixer Tuning Circuits

    NASA Technical Reports Server (NTRS)

    Kooi, J. W.; Stern, J. A.; Chattopadhyay, G.; LeDuc, H. G.; Bumble, B.; Zmuidzinas, J.

    1998-01-01

    Recent results at 1 THz using normal-metal tuning circuits have shown that SIS mixers can work well up to twice the gap frequency of the junction material (niobium). However, the performance at 1 THz is limited by the substantial loss in the normal metal films. For better performance superconducting films with a higher gap frequency than niobium and with low RF loss are needed. Niobium nitride has long been considered a good candidate material, but typical NbN films suffer from high RF loss. To circumvent this problem we are currently investigating the RF loss in NbTiN films, a 15 K Tc compound superconductor, by incorporating them into quasi-optical slot antenna SIS devices.

  4. Advanced Antenna Design for NASA's EcoSAR Instrument

    NASA Technical Reports Server (NTRS)

    Du Toit, Cornelis F.; Deshpande, Manohar; Rincon, Rafael F.

    2016-01-01

    Advanced antenna arrays were designed for NASA's EcoSAR airborne radar instrument. EcoSAR is a beamforming synthetic aperture radar instrument designed to make polarimetric and "single pass" interferometric measurements of Earth surface parameters. EcoSAR's operational requirements of a 435MHz center frequency with up to 200MHz bandwidth, dual polarization, high cross-polarization isolation (> 30 dB), +/- 45deg beam scan range and antenna form-factor constraints imposed stringent requirements on the antenna design. The EcoSAR project successfully developed, characterized, and tested two array antennas in an anechoic chamber. EcoSAR's first airborne campaign conducted in the spring of 2014 generated rich data sets of scientific and engineering value, demonstrating the successful operation of the antennas.

  5. Pesticide Safety for Non-Certified Mixers, Loaders and Applicators = Uso Seguro de Pesticidas para Mezcladores, Cargadores y Aplicadores no Certificados.

    ERIC Educational Resources Information Center

    Poli, Bonnie; Fluker, Sam S.

    Written in English and Spanish and completely illustrated, this manual provides basic safety information for pesticide workers. Mixers, loaders, and applicators work with pesticides at their greatest strength and have the highest risk of poisoning. Understanding the pesticide label is the first step to pesticide safety. The words…

  6. Effect of NASA advanced designs on thermal behavior of Ni-H2 cells

    NASA Technical Reports Server (NTRS)

    Gonzalez-Sanabria, Olga D.

    1987-01-01

    As part of an overall effort to advance the technology of nickel-hydrogen batteries for low Earth orbit (LEO) applications, advanced designs for individual pressure vessel (IPV) nickel-hydrogen cells have been conceived. These designs incorporate alternative methods of oxygen recombination which affect the thermal behavior of the cells. The effect of these oxygen recombination methods on the cell temperature profiles is examined.

  7. Interim Service ISDN Satellite (ISIS) network model for advanced satellite designs and experiments

    NASA Technical Reports Server (NTRS)

    Pepin, Gerard R.; Hager, E. Paul

    1991-01-01

    The Interim Service Integrated Services Digital Network (ISDN) Satellite (ISIS) Network Model for Advanced Satellite Designs and Experiments describes a model suitable for discrete event simulations. A top-down model design uses the Advanced Communications Technology Satellite (ACTS) as its basis. The ISDN modeling abstractions are added to permit the determination and performance for the NASA Satellite Communications Research (SCAR) Program.

  8. Analog CMOS design for optical coherence tomography signal detection and processing.

    PubMed

    Xu, Wei; Mathine, David L; Barton, Jennifer K

    2008-02-01

    A CMOS circuit was designed and fabricated for optical coherence tomography (OCT) signal detection and processing. The circuit includes a photoreceiver, differential gain stage and lock-in amplifier based demodulator. The photoreceiver consists of a CMOS photodetector and low noise differential transimpedance amplifier which converts the optical interference signal into a voltage. The differential gain stage further amplifies the signal. The in-phase and quadrature channels of the lock-in amplifier each include an analog mixer and switched-capacitor low-pass filter with an external mixer reference signal. The interferogram envelope and phase can be extracted with this configuration, enabling Doppler OCT measurements. A sensitivity of -80 dB is achieved with faithful reproduction of the interferometric signal envelope. A sample image of finger tip is presented.

  9. Advanced photovoltaic solar array design assessment

    NASA Technical Reports Server (NTRS)

    Stella, Paul; Scott-Monck, John

    1987-01-01

    The Advanced Photovoltaic Solar Array (APSA) program seeks to bring to flight readiness a solar array that effectively doubles the specific power of the Solar Array Flight Experiment/Solar Electric Propulsion (SAFE/SEP) design that was successfully demonstrated during the Shuttle 41-D mission. APSA is a critical intermediate milestone in the effort to demonstrate solar array technologies capable of 300 W/kg and 300 W/square m at beginning of life (BOL). It is not unreasonable to anticipate the development of solar array designs capable of 300 W/kg at BOL for operational power levels approx. greater than 25 kW sub e. It is also quite reasonable to expect that high performance solar arrays capable of providing at least 200 W/kg at end of life for most orbits now being considered by mission planners will be realized in the next decade.

  10. Acoustic flight testing of advanced design propellers on a JetStar aircraft

    NASA Technical Reports Server (NTRS)

    Lasagna, P.; Mackall, K.

    1981-01-01

    Advanced turboprop-powered aircraft have the potential to reduce fuel consumption by 15 to 30 percent as compared with an equivalent technology turbofan-powered aircraft. An important obstacle to the use of advanced design propellers is the cabin noise generated at Mach numbers up to .8 and at altitudes up to 35,000 feet. As part of the NASA Aircraft Energy Efficiency Program, the near-field acoustic characteristics on a series of advanced design propellers are investigated. Currently, Dryden Flight Research Center is flight testing a series of propellers on a JetStar airplane. The propellers used in the flight test were previously tested in wind tunnels at the Lewis Research Center. Data are presented showing the narrow band spectra, acoustic wave form, and acoustic contours on the fuselage surface. Additional flights with the SR-3 propeller and other advanced propellers are planned in the future.

  11. Design and implementation of a laboratory-based drug design and synthesis advanced pharmacy practice experience.

    PubMed

    Philip, Ashok; Stephens, Mark; Mitchell, Sheila L; Watkins, E Blake

    2015-04-25

    To provide students with an opportunity to participate in medicinal chemistry research within the doctor of pharmacy (PharmD) curriculum. We designed and implemented a 3-course sequence in drug design or drug synthesis for pharmacy students consisting of a 1-month advanced elective followed by two 1-month research advanced pharmacy practice experiences (APPEs). To maximize student involvement, this 3-course sequence was offered to third-year and fourth-year students twice per calendar year. Students were evaluated based on their commitment to the project's success, productivity, and professionalism. Students also evaluated the course sequence using a 14-item course evaluation rubric. Student feedback was overwhelmingly positive. Students found the experience to be a valuable component of their pharmacy curriculum. We successfully designed and implemented a 3-course research sequence that allows PharmD students in the traditional 4-year program to participate in drug design and synthesis research. Students report the sequence enhanced their critical-thinking and problem-solving skills and helped them develop as independent learners. Based on the success achieved with this sequence, efforts are underway to develop research APPEs in other areas of the pharmaceutical sciences.

  12. Effect of NASA advanced designs on thermal behavior of Ni-H2 cells

    NASA Technical Reports Server (NTRS)

    Gonzalez-Sanabria, Olga D.

    1988-01-01

    As part of an overall effort to advance the technology of nickel-hydrogen batteries for low earth orbit (LEO) applications, advanced designs for individual pressure vessel (IPV) nickel-hydrogen cells have been conceived. These designs incorporate alternative methods of oxygen recombination which affect the thermal behavior of the cells. The effect of these oxygen recombination methods on the cell temperature profiles will be examined.

  13. Launch Vehicle Design and Optimization Methods and Priority for the Advanced Engineering Environment

    NASA Technical Reports Server (NTRS)

    Rowell, Lawrence F.; Korte, John J.

    2003-01-01

    NASA's Advanced Engineering Environment (AEE) is a research and development program that will improve collaboration among design engineers for launch vehicle conceptual design and provide the infrastructure (methods and framework) necessary to enable that environment. In this paper, three major technical challenges facing the AEE program are identified, and three specific design problems are selected to demonstrate how advanced methods can improve current design activities. References are made to studies that demonstrate these design problems and methods, and these studies will provide the detailed information and check cases to support incorporation of these methods into the AEE. This paper provides background and terminology for discussing the launch vehicle conceptual design problem so that the diverse AEE user community can participate in prioritizing the AEE development effort.

  14. The Design and Transfer of Advanced Command and Control (C2) Computer-Based Systems

    DTIC Science & Technology

    1980-03-31

    TECHNICAL REPORT 80-02 QUARTERLY TECHNICAL REPORT: THE DESIGN AND TRANSFER OF ADVANCED COMMAND AND CONTROL (C 2 ) COMPUTER-BASED SYSTEMS ARPA...The Tasks/Objectives and/or Purposes of the overall project are connected with the design , development, demonstration and transfer of advanced...command and control (C2 ) computer-based systems; this report covers work in the computer-based design and transfer areas only. The Technical Problems thus

  15. Advanced photovoltaic solar array - Design and performance

    NASA Technical Reports Server (NTRS)

    Kurland, Richard; Stella, Paul

    1992-01-01

    This paper reports on the development of an ultralightweight flexible blanket, flatpack, foldout solar array design that can provide 3- to 4-fold improvement on specific power performance of current rigid panel arrays and a factor of two improvement over a first-generation flexible blanket array developed as a forerunner to the Space Station Freedom array. To date a prototype wing has been built with a projected specific power performance of about 138 W/kg at beginning-of-life (BOL) and 93 W/kg end-of-life (EOL) at 12 kW (BOL) for a 10-year geosynchronous (GEO) mission. The prototype wing hardware has been subjected to a series of system-level tests to demonstrate design feasibility. The design of the array is summarized. The major trade studies that led to the selection of the baseline design are discussed. Key system-level and component-level testing are described. Array-level performance projections are presented as a function of existing and advanced solar array component technology for various mission applications.

  16. DAWN (Design Assistant Workstation) for advanced physical-chemical life support systems

    NASA Technical Reports Server (NTRS)

    Rudokas, Mary R.; Cantwell, Elizabeth R.; Robinson, Peter I.; Shenk, Timothy W.

    1989-01-01

    This paper reports the results of a project supported by the National Aeronautics and Space Administration, Office of Aeronautics and Space Technology (NASA-OAST) under the Advanced Life Support Development Program. It is an initial attempt to integrate artificial intelligence techniques (via expert systems) with conventional quantitative modeling tools for advanced physical-chemical life support systems. The addition of artificial intelligence techniques will assist the designer in the definition and simulation of loosely/well-defined life support processes/problems as well as assist in the capture of design knowledge, both quantitative and qualitative. Expert system and conventional modeling tools are integrated to provide a design workstation that assists the engineer/scientist in creating, evaluating, documenting and optimizing physical-chemical life support systems for short-term and extended duration missions.

  17. Recent Advances and Current Trends in Metamaterial-by-Design

    NASA Astrophysics Data System (ADS)

    Anselmi, N.; Gottardi, G.

    2018-02-01

    Thanks to their potential applications in several engineering areas, metamaterials gained much of attentions among different research communities, leading to the development of several analysis and synthesis tools. In this context, the metamaterial-by-design (MbD) paradigm has been recently introduced as a powerful tool for the design of complex metamaterials-based structures. In this work a review of the state-of-art, as well as the recent advancements of MbD-based methods are presented.

  18. Combined Numerical/Analytical Perturbation Solutions of the Navier-Stokes Equations for Aerodynamic (Ejector Nozzle) Flows

    NASA Technical Reports Server (NTRS)

    DeChant, Lawrence J.

    1997-01-01

    In spite of the rapid advances in both scalar and parallel computational tools, the large number and breadth of variables involved in aerodynamic systems make the use of parabolized or even boundary layer fluid flow models impractical for both preliminary design and inverse design problems. Given this restriction, we have concluded that reduced or approximate models are an important family of tools for design purposes. This study of a combined perturbation/numerical modeling methodology with an application to ejector-mixer nozzles (shown schematically in the following figure) is nearing completion. The work is being funded by a grant from the NASA Lewis Research Center to Texas A&M University. These ejector-mixer nozzle models are designed to be of use to the High Speed Civil Transport Program and may be adopted by both NASA and industry. A computer code incorporating the ejector-mixer models is under development. This code, the Differential Reduced Ejector/Mixer Analysis (DREA), can be run fast enough to be used as a subroutine or to be called by a design optimization routine. Simplified conservation equations--x-momentum, energy, and mass conservation--are used to define the model. Unlike other preliminary design models, DREA requires minimal empirical input and includes vortical mixing and a fully compressible formulation among other features. DREA is being validated by comparing it with results obtained from open literature and proprietary industry data. Preliminary results for a subsonic ejector and a supersonic ejector are shown. In addition, dedicated experiments have been performed at Texas A&M. These experiments use a hydraulic/gas flow analog to provide information about the inviscid mixing interface structure. Final validation and documentation of this work is expected by May of 1997. However, preliminary versions of DREA can be expected in early 1997. In summary, DREA provides a sufficiently detailed and realistic ejector-mixer nozzle model at a

  19. Toward a Psychological Science of Advanced Technology Design for Older Adults

    PubMed Central

    Fisk, Arthur D.

    2010-01-01

    Objectives. Technology represents advances in knowledge that change the way humans perform tasks. Ideally, technology will make the task easier, more efficient, safer, or perhaps more pleasurable. Unfortunately, new technologies can sometimes make a task more difficult, slower, dangerous, or perhaps more frustrating. Older adults interact with a variety of technologies in the course of their daily activities and thus products should be designed to be used by people of varying ages. Methods. In this article, we provide an overview of what psychology has to offer to the design of technology—from understanding what people need, to identifying their preferences for design characteristics, and to defining their capabilities and limitations that will influence technology interactions. Results. We identify how research in the field of psychology and aging has advanced understanding of technology interactions and how research on technology interactions can inform theories of aging. Discussion. Design for aging involves understanding the unique capabilities and limitations of older adults; identifying their needs, preferences, and desires for technology in their lives; and involving them in the design process. PMID:20833690

  20. Conceptual design study: Forest Fire Advanced System Technology (FFAST)

    NASA Technical Reports Server (NTRS)

    Nichols, J. D.; Warren, J. R.

    1986-01-01

    An integrated forest fire detection and mapping system that will be based upon technology available in the 1990s was defined. Uncertainties in emerging and advanced technologies related to the conceptual design were identified and recommended for inclusion as preferred system components. System component technologies identified for an end-to-end system include thermal infrared, linear array detectors, automatic georeferencing and signal processing, geosynchronous satellite communication links, and advanced data integration and display. Potential system configuration options were developed and examined for possible inclusion in the preferred system configuration. The preferred system configuration will provide increased performance and be cost effective over the system currently in use. Forest fire management user requirements and the system component emerging technologies were the basis for the system configuration design. A preferred system configuration was defined that warrants continued refinement and development, examined economic aspects of the current and preferred system, and provided preliminary cost estimates for follow-on system prototype development.

  1. Validation test of 125 Ah advanced design IPV nickel-hydrogen flight cells

    NASA Technical Reports Server (NTRS)

    Smithrick, John J.; Hall, Stephen W.

    1993-01-01

    An update of validation test results confirming the advanced design nickel-hydrogen cell is presented. An advanced 125 Ah individual pressure vessel Ni-H cell was designed. The primary function of the advanced cell is to store and deliver energy for long-term LEO spacecraft missions. The new features of this design are: (1) use of 26 percent rather than 31 percent KOH electrolyte; (2) use of a patented catalyzed wall wick; (3) use of serrated-edge separators to facilitate gaseous O and H flow within the cell, while maintaining physical contact with the wall wick for electrolyte management; and (4) use of a floating rather than a fixed stack to accommodate Ni electrode expansion due to charge/discharge cycling. The significant improvements resulting from these innovations are extended cycle life; enhanced thermal, electrolyte, and oxygen management; and accommodation of Ni electrode expansion. Six 125 Ah flight cells based on this design were fabricated; the catalyzed wall wick cells have been cycled for over 19,000 cycles with no cell failures in the continuing test. Two of the noncatalyzed wall wick cells failed (cycles 9588 and 13,900).

  2. An airline study of advanced technology requirements for advanced high speed commercial transport engines. 2: Engine preliminary design assessment

    NASA Technical Reports Server (NTRS)

    Sallee, G. P.

    1973-01-01

    The advanced technology requirements for an advanced high speed commercial transport engine are presented. The results of the phase 2 study effort cover the following areas: (1) general review of preliminary engine designs suggested for a future aircraft, (2) presentation of a long range view of airline propulsion system objectives and the research programs in noise, pollution, and design which must be undertaken to achieve the goals presented, (3) review of the impact of propulsion system unreliability and unscheduled maintenance on cost of operation, (4) discussion of the reliability and maintainability requirements and guarantees for future engines.

  3. Updated Assessment of an Open Rotor Airplane Using an Advanced Blade Design

    NASA Technical Reports Server (NTRS)

    Hendricks, Eric S.; Berton, Jeffrey J.; Haller, William J.; Tong, Michael T.; Guynn, Mark D.

    2013-01-01

    Application of open rotor propulsion systems (historically referred to as "advanced turboprops" or "propfans") to subsonic transport aircraft received significant attention and research in the 1970s and 1980s when fuel efficiency was the driving focus of aeronautical research. Recent volatility in fuel prices and concern for aviation's environmental impact have renewed interest in open rotor propulsion, and revived research by NASA and a number of engine manufacturers. Over the last few years, NASA has revived and developed analysis capabilities to assess aircraft designs with open rotor propulsion systems. These efforts have been described in several previous papers along with initial results from applying these capabilities. The initial results indicated that open rotor engines have the potential to provide large reductions in fuel consumption and emissions. Initial noise analysis indicated that current noise regulations can be met with modern baseline blade designs. Improved blades incorporating low-noise features are expected to result in even lower noise levels. This paper describes improvements to the initial assessment, plus a follow-on study using a more advanced open rotor blade design to power the advanced singleaisle transport. The predicted performance and environmental results of these two advanced open rotor concepts are presented and compared.

  4. Advanced Technology Display House. Volume 2: Energy system design concepts

    NASA Technical Reports Server (NTRS)

    Maund, D. H.

    1981-01-01

    The preliminary design concept for the energy systems in the Advanced Technology Display House is analyzed. Residential energy demand, energy conservation, and energy concepts are included. Photovoltaic arrays and REDOX (reduction oxidation) sizes are discussed.

  5. Mixing of low-dose cohesive drug and overcoming of pre-blending step using a new gentle-wing high-shear mixer granulator.

    PubMed

    Alsulays, Bader B; Fayed, Mohamed H; Alalaiwe, Ahmed; Alshahrani, Saad M; Alshetaili, Abdullah S; Alshehri, Sultan M; Alanazi, Fars K

    2018-05-16

    The objective of this study was to examine the influence of drug amount and mixing time on the homogeneity and content uniformity of a low-dose drug formulation during the dry mixing step using a new gentle-wing high-shear mixer. Moreover, the study investigated the influence of drug incorporation mode on the content uniformity of tablets manufactured by different methods. Albuterol sulfate was selected as a model drug and was blended with the other excipients at two different levels, 1% w/w and 5% w/w at impeller speed of 300 rpm and chopper speed of 3000 rpm for 30 min. Utilizing a 1 ml unit side-sampling thief probe, triplicate samples were taken from nine different positions in the mixer bowl at selected time points. Two methods were used for manufacturing of tablets, direct compression and wet granulation. The produced tablets were sampled at the beginning, middle, and end of the compression cycle. An analysis of variance analysis indicated the significant effect (p < .05) of drug amount on the content uniformity of the powder blend and the corresponding tablets. For 1% w/w and 5% w/w formulations, incorporation of the drug in the granulating fluid provided tablets with excellent content uniformity and very low relative standard deviation (∼0.61%) during the whole tableting cycle compared to direct compression and granulation method with dry incorporation mode of the drug. Overall, gentle-wing mixer is a good candidate for mixing of low-dose cohesive drug and provides tablets with acceptable content uniformity with no need for pre-blending step.

  6. Validation test of 125 Ah advanced design IPV nickel-hydrogen flight cells

    NASA Technical Reports Server (NTRS)

    Smithrick, John J.; Hall, Stephen W.

    1993-01-01

    An update of validation test results confirming the advanced design nickel-hydrogen cell is presented. An advanced 125 Ah individual pressure vessel (IPV) nickel-hydrogen cell was designed. The primary function of the advanced cell is to store and deliver energy for long-term, Low-Earth-Orbit (LEO) spacecraft missions. The new features of this design, which are not incorporated in state-of-the-art design cells, are: (1) use of 26 percent rather than 31 percent potassium hydroxide (KOH) electrolyte; (2) use of a patented catalyzed wall wick; (3) use of serrated-edge separators to facilitate gaseous oxygen and hydrogen flow within the cell, while still maintaining physical contact with the wall wick for electrolyte management; and (4) use of a floating rather than a fixed stack (state-of-the-art) to accommodate nickel electrode expansion due to charge/discharge cycling. The significant improvements resulting from these innovations are extended cycle life; enhanced thermal, electrolyte, and oxygen management; and accommodation of nickel electrode expansion. Six 125 Ah flight cells based on this design were fabricated by Eagle-Picher. Three of the cells contain all of the advanced features (test cells) and three are the same as the test cells except they do not have catalyst on the wall wick (control cells). All six cells are in the process of being evaluated in a LEO cycle life test at the Naval Weapons Support Center, Crane, IN, under a NASA Lewis Research Center contract. The catalyzed wall wick cells have been cycled for over 19000 cycles with no cell failures in the continuing test. Two of the noncatalyzed wall wick cells failed (cycles 9588 and 13,900).

  7. Wind-tunnel evaluation of an advanced main-rotor blade design for a utility-class helicopter

    NASA Technical Reports Server (NTRS)

    Yeager, William T., Jr.; Mantay, Wayne R.; Wilbur, Matthew L.; Cramer, Robert G., Jr.; Singleton, Jeffrey D.

    1987-01-01

    An investigation was conducted in the Langley Transonic Dynamics Tunnel to evaluate differences between an existing utility-class main-rotor blade and an advanced-design main-rotor blade. The two rotor blade designs were compared with regard to rotor performance oscillatory pitch-link loads, and 4-per-rev vertical fixed-system loads. Tests were conducted in hover and over a range of simulated full-scale gross weights and density altitude conditions at advance ratios from 0.15 to 0.40. Results indicate that the advanced blade design offers performance improvements over the baseline blade in both hover and forward flight. Pitch-link oscillatory loads for the baseline rotor were more sensitive to the test conditions than those of the advanced rotor. The 4-per-rev vertical fixed-system load produced by the advanced blade was larger than that produced by the baseline blade at all test conditions.

  8. Innovations in Science and Mathematics Education: Advanced Designs for Technologies of Learning.

    ERIC Educational Resources Information Center

    Jacobson, Michael J., Ed.; Kozma, Robert B., Ed.

    This collection of essays consists of current work that addresses the challenge not just to put the newest technologies in schools, but to identify advanced ways to design and use these new technologies to advance learning. These essays are intended for science and mathematics educators, educational and cognitive researchers, instructional…

  9. Application of acoustic surface wave filter-beam lead component technology to deep space multimission hardware design

    NASA Technical Reports Server (NTRS)

    Kermode, A. W.; Boreham, J. F.

    1974-01-01

    This paper discusses the utilization of acoustic surface wave filters, beam lead components, and thin film metallized ceramic substrate technology as applied to the design of deep space, long-life, multimission transponder. The specific design to be presented is for a second mixer local oscillator module, operating at frequencies as high as 249 MHz.

  10. Studio in Advertising Design, Fashion Design and Illustration, Product Design, Stage Design. Volume 3: Advanced Elective Courses in Art for Grades 10, 11, or 12.

    ERIC Educational Resources Information Center

    New York State Education Dept., Albany. Bureau of Secondary Curriculum Development.

    The document provides teaching guidelines and information on advance elective courses in a studio art program for grades 10, 11, and 12. The courses are presented in four sections: (1) studio in advertising design--advertising and production, lettering, illustrating, and color reproduction; (2) studio in fashion design and illustration--elements…

  11. Design of Digital Phase-Locked Loops For Advanced Digital Transponders

    NASA Technical Reports Server (NTRS)

    Nguyen, Tien M.

    1994-01-01

    For advanced digital space transponders, the Digital Phased-Locked Loops (DPLLs) can be designed using the available analog loops. DPLLs considered in this paper are derived from the Analog Phase-Locked Loop (APLL) using S-domain mapping techniques.

  12. Interim Service ISDN Satellite (ISIS) simulator development for advanced satellite designs and experiments

    NASA Technical Reports Server (NTRS)

    Pepin, Gerard R.

    1992-01-01

    The simulation development associated with the network models of both the Interim Service Integrated Services Digital Network (ISDN) Satellite (ISIS) and the Full Service ISDN Satellite (FSIS) architectures is documented. The ISIS Network Model design represents satellite systems like the Advanced Communications Technology Satellite (ACTS) orbiting switch. The FSIS architecture, the ultimate aim of this element of the Satellite Communications Applications Research (SCAR) Program, moves all control and switching functions on-board the next generation ISDN communications satellite. The technical and operational parameters for the advanced ISDN communications satellite design will be obtained from the simulation of ISIS and FSIS engineering software models for their major subsystems. Discrete event simulation experiments will be performed with these models using various traffic scenarios, design parameters, and operational procedures. The data from these simulations will be used to determine the engineering parameters for the advanced ISDN communications satellite.

  13. System design impacts on optimization of the advanced radioisotope power system (ARPS) AMTEC cell

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hendricks, T.J.; Huang, C.

    1998-07-01

    Several NASA deep space missions require Advanced Radioisotope Power Systems (ARPS) to supply spacecraft power for various internal functions and mission instruments and experiments. AMTEC (Alkali-Metal Thermal-Electric Conversion) power conversion is the DOE-selected technology for an advanced, next- generation RPS to power these spacecraft. Advanced Modular Power Systems, Inc. (AMPS) has begun investigating the design of an AMTEC-based ARPS using the General Purpose Heat Source (GPHS) and the latest PX-5 AMTEC cell technology with refractory materials in critical components. This paper presents and discusses the system design methodology, and results of important system design tradeoffs and system design impacts onmore » the ARPS AMTEC cell design. This work investigated dual 2-GPHS system configurations and 4-GPHS system configurations with 16 side-mounted AMTEC cells operating at beginning-of-mission (BOM) and end-of-mission (EOM) GPHS heat dissipation conditions. Current design studies indicate using a refractory material AMTEC cell with 8-BASE tubes, 5.0 inches long, and 1.75 inches diameter in the 4-GPHS system configuration is the strongest design candidate to satisfy system performance requirements.« less

  14. Design and analysis of an energy-efficient O-QPSK coherent IR-UWB transceiver with a 0.52° RMS phase-noise fractional synthesizer

    NASA Astrophysics Data System (ADS)

    Ying, Yutong; Lin, Fujiang; Bai, Xuefei

    2018-03-01

    This paper explores an energy-efficient pulsed ultra-wideband (UWB) radio-frequency (RF) front-end chip fabricated in 0.18-μm CMOS technology, including a transmitter, receiver, and fractional synthesizer. The transmitter adopts a digital offset quadrature phase-shift keying (O-QPSK) modulator and passive direct-phase multiplexing technology, which are energy- and hardware-efficient, to enhance the data rate for a given spectrum. A passive mixer and a capacitor cross-coupled (CCC) source-follower driving amplifier (DA) are also designed for the transmitter to further reduce the low power consumption. For the receiver, a power-aware low-noise amplifier (LNA) and a quadrature mixer are applied. The LNA adopts a CCC boost common-gate amplifier as the input stage, and its current is reused for the second stage to save power. The mixer uses a shared amplification stage for the following passive IQ mixer. Phase noise suppression of the phase-locked loop (PLL) is achieved by utilizing an even-harmonics-nulled series-coupled quadrature oscillator (QVCO) and an in-band noise-aware charge pump (CP) design. The transceiver achieves a measured data rate of 0.8 Gbps with power consumption of 16 mW and 31.5 mW for the transmitter and the receiver, respectively. The optimized integrated phase noise of the PLL is 0.52° at 4.025 GHz. Project supported by the National Science and Technology Major Project of China (No. 2011ZX03004-002-01).

  15. Timing noise measurement of 320 GHz optical pulses using an improved optoelectronic harmonic mixer.

    PubMed

    Tsuchida, Hidemi

    2006-03-01

    An improved optoelectronic harmonic mixer (OEHM) has been employed for measuring the timing noise of 320 GHz optical pulses that are generated from a 160 GHz mode-locked laser diode by the temporal Talbot effect. The OEHM makes use of a low-drive voltage LiNbO3 modulator and a W-band unitraveling carrier photodiode for converting the 320 GHz pulse intensity into a low-frequency electrical signal. The time domain demodulation technique has been used for the precise evaluation of phase noise power spectral density. The rms timing jitter has been estimated to be 311 fs for the 10 Hz-18.6 MHz bandwidth.

  16. Advanced Low-Noise Research Fan Stage Design

    NASA Technical Reports Server (NTRS)

    Neubert, Robert; Bock, Larry; Malmborg, Eric; Owen-Peer, William

    1997-01-01

    This report describes the design of the Advanced Low-Noise Research Fan stage. The fan is a variable pitch design, which is designed at the cruise pitch condition. Relative to the cruise setting, the blade is closed at takeoff and opened for reverse thrust operation. The fan stage is a split flow design with fan exit guide vanes (FEGVs) and core stators. The fan stage design is combined with a nacelle and engine core duct to form a powered fan/nacelle subscale model. This model is intended for use in combined aerodynamic, acoustic, and structural testing in a wind tunnel. The fan has an outer diameter of 22 in. and a hub-to-tip of 0.426 in., which allows the use of existing NASA fan and cowl force balance and rig drive systems. The design parameters were selected to permit valid acoustic and aerodynamic comparisons with the Pratt & Whitney (P&W) 17- and 22-in. rigs previously tested under NASA contract. The fan stage design is described in detail. The results of the design axisymmetric and Navier-Stokes aerodynamic analysis are presented at the critical design conditions. The structural analysis of the fan rotor and attachment is included. The blade and attachment are predicted to have adequate low-cycle fatigue life and an acceptable operating range without resonant stress or flutter. The stage was acoustically designed with airfoil counts in the FEGV and core stator to minimize noise. A fan/FEGV tone analysis developed separately under NASA contract was used to determine the optimum airfoil counts. The fan stage was matched to the existing nacelle, designed under the previous P&W low-noise contract, to form a fan/nacelle model for wind tunnel testing. It is an axisymmetric nacelle for convenience in testing and analysis. Previous testing confirmed that the nacelle performed as required at various aircraft operating conditions.

  17. Interim Service ISDN Satellite (ISIS) hardware experiment design for advanced ISDN satellite design and experiments

    NASA Technical Reports Server (NTRS)

    Pepin, Gerard R.

    1992-01-01

    The Interim Service Integrated Services Digital Network (ISDN) Satellite (ISIS) Hardware Experiment Design for Advanced Satellite Designs describes the design of the ISDN Satellite Terminal Adapter (ISTA) capable of translating ISDN protocol traffic into time division multiple access (TDMA) signals for use by a communications satellite. The ISTA connects the Type 1 Network Termination (NT1) via the U-interface on the line termination side of the CPE to the V.35 interface for satellite uplink. The same ISTA converts in the opposite direction the V.35 to U-interface data with a simple switch setting.

  18. Cam Design Projects in an Advanced CAD Course for Mechanical Engineers

    ERIC Educational Resources Information Center

    Ault, H. K.

    2009-01-01

    The objective of this paper is to present applications of solid modeling aimed at modeling of complex geometries such as splines and blended surfaces in advanced CAD courses. These projects, in CAD-based Mechanical Engineering courses, are focused on the use of the CAD system to solve design problems for applications in machine design, namely the…

  19. Remotely powered distributed microfluidic pumps and mixers based on miniature diodes.

    PubMed

    Chang, Suk Tai; Beaumont, Erin; Petsev, Dimiter N; Velev, Orlin D

    2008-01-01

    We demonstrate new principles of microfluidic pumping and mixing by electronic components integrated into a microfluidic chip. The miniature diodes embedded into the microchannel walls rectify the voltage induced between their electrodes from an external alternating electric field. The resulting electroosmotic flows, developed in the vicinity of the diode surfaces, were utilized for pumping or mixing of the fluid in the microfluidic channel. The flow velocity of liquid pumped by the diodes facing in the same direction linearly increased with the magnitude of the applied voltage and the pumping direction could be controlled by the pH of the solutions. The transverse flow driven by the localized electroosmotic flux between diodes oriented oppositely on the microchannel was used in microfluidic mixers. The experimental results were interpreted by numerical simulations of the electrohydrodynamic flows. The techniques may be used in novel actively controlled microfluidic-electronic chips.

  20. Development of horn antenna mixer array with internal local oscillator module for microwave imaging diagnostics

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kuwahara, D., E-mail: dkuwahar@cc.tuat.ac.jp; Ito, N.; Nagayama, Y.

    A new antenna array is proposed in order to improve the sensitivity and complexity of microwave imaging diagnostics systems such as a microwave imaging reflectometry, a microwave imaging interferometer, and an electron cyclotron emission imaging. The antenna array consists of five elements: a horn antenna, a waveguide-to-microstrip line transition, a mixer, a local oscillation (LO) module, and an intermediate frequency amplifier. By using an LO module, the LO optics can be removed, and the supplied LO power to each element can be equalized. We report details of the antenna array and characteristics of a prototype antenna array.

  1. Development of horn antenna mixer array with internal local oscillator module for microwave imaging diagnostics.

    PubMed

    Kuwahara, D; Ito, N; Nagayama, Y; Yoshinaga, T; Yamaguchi, S; Yoshikawa, M; Kohagura, J; Sugito, S; Kogi, Y; Mase, A

    2014-11-01

    A new antenna array is proposed in order to improve the sensitivity and complexity of microwave imaging diagnostics systems such as a microwave imaging reflectometry, a microwave imaging interferometer, and an electron cyclotron emission imaging. The antenna array consists of five elements: a horn antenna, a waveguide-to-microstrip line transition, a mixer, a local oscillation (LO) module, and an intermediate frequency amplifier. By using an LO module, the LO optics can be removed, and the supplied LO power to each element can be equalized. We report details of the antenna array and characteristics of a prototype antenna array.

  2. AGBT Advanced Counter-Rotating Gearbox Detailed Design Report

    NASA Technical Reports Server (NTRS)

    Howe, D. C.; Sundt, C. V.; Mckibbon, A. H.

    1988-01-01

    An Advanced Counter-Rotating (CR) Gearbox was designed and fabricated to evaluate gearbox efficiency, durability and weight characteristics for emerging propfan-powered airplanes. Component scavenge tests showed that a constant volume collector had high scavenge effectiveness, which was uneffected by added airflow. Lubrication tests showed that gearbox losses could be reduced by controlling the air/oil mixture and by directing the oil jets radially, with a slight axial component, into the sun/planet gears.

  3. 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.

  4. Team Expo: A State-of-the-Art JSC Advanced Design Team

    NASA Technical Reports Server (NTRS)

    Tripathi, Abhishek

    2001-01-01

    In concert with the NASA-wide Intelligent Synthesis Environment Program, the Exploration Office at the Johnson Space Center has assembled an Advanced Design Team. The purpose of this team is two-fold. The first is to identify, use, and develop software applications, tools, and design processes that streamline and enhance a collaborative engineering environment. The second is to use this collaborative engineering environment to produce conceptual, system-level-of-detail designs in a relatively short turnaround time, using a standing team of systems and integration experts. This includes running rapid trade studies on varying mission architectures, as well as producing vehicle and/or subsystem designs. The standing core team is made up of experts from all of the relevant engineering divisions (e.g. Power, Thermal, Structures, etc.) as well as representatives from Risk and Safety, Mission Operations, and Crew Life Sciences among others. The Team works together during 2- hour sessions in the same specially enhanced room to ensure real-time integration/identification of cross-disciplinary issues and solutions. All subsystem designs are collectively reviewed and approved during these same sessions. In addition there is an Information sub-team that captures and formats all data and makes it accessible for use by the following day. The result is Team Expo: an Advanced Design Team that is leading the change from a philosophy of "over the fence" design to one of collaborative engineering that pushes the envelope to achieve the next-generation analysis and design environment.

  5. Full Service ISDN Satellite (FSIS) network model for advanced ISDN satellite design and experiments

    NASA Technical Reports Server (NTRS)

    Pepin, Gerard R.

    1992-01-01

    The Full Service Integrated Services Digital Network (FSIS) network model for advanced satellite designs describes a model suitable for discrete event simulations. A top down model design uses the Advanced Communications Technology Satellite (ACTS) as its basis. The ACTS and the Interim Service ISDN Satellite (ISIS) perform ISDN protocol analyses and switching decisions in the terrestrial domain, whereas FSIS makes all its analyses and decisions on-board the ISDN satellite.

  6. Studying enzymatic bioreactions in a millisecond microfluidic flow mixer

    PubMed Central

    Buchegger, Wolfgang; Haller, Anna; van den Driesche, Sander; Kraft, Martin; Lendl, Bernhard; Vellekoop, Michael

    2012-01-01

    In this study, the pre-steady state development of enzymatic bioreactions using a microfluidic mixer is presented. To follow such reactions fast mixing of reagents (enzyme and substrate) is crucial. By using a highly efficient passive micromixer based on multilaminar flow, mixing times in the low millisecond range are reached. Four lamination layers in a shallow channel reduce the diffusion lengths to a few micrometers only, enabling very fast mixing. This was proven by confocal fluorescence measurements in the channel’s cross sectional area. Adjusting the overall flow rate in the 200 μm wide and 900 μm long mixing and observation channel makes it possible to investigate enzyme reactions over several seconds. Further, the device enables changing the enzyme/substrate ratio from 1:1 up to 3:1, while still providing high mixing efficiency, as shown for the enzymatic hydrolysis using β-galactosidase. This way, the early kinetics of the enzyme reaction at multiple enzyme/substrate concentrations can be collected in a very short time (minutes). The fast and easy handling of the mixing device makes it a very powerful and convenient instrument for millisecond temporal analysis of bioreactions. PMID:22662071

  7. Advance Approach to Concept and Design Studies for Space Missions

    NASA Technical Reports Server (NTRS)

    Deutsch, M.; Nichols, J.

    1999-01-01

    Recent automated and advanced techniques developed at JPL have created a streamlined and fast-track approach to initial mission conceptualization and system architecture design, answering the need for rapid turnaround of trade studies for potential proposers, as well as mission and instrument study groups.

  8. An integrated modeling and design tool for advanced optical spacecraft

    NASA Technical Reports Server (NTRS)

    Briggs, Hugh C.

    1992-01-01

    Consideration is given to the design and status of the Integrated Modeling of Optical Systems (IMOS) tool and to critical design issues. A multidisciplinary spacecraft design and analysis tool with support for structural dynamics, controls, thermal analysis, and optics, IMOS provides rapid and accurate end-to-end performance analysis, simulations, and optimization of advanced space-based optical systems. The requirements for IMOS-supported numerical arrays, user defined data structures, and a hierarchical data base are outlined, and initial experience with the tool is summarized. A simulation of a flexible telescope illustrates the integrated nature of the tools.

  9. Design and construction of a prototype ACTS propagation terminal

    NASA Technical Reports Server (NTRS)

    Stutzman, Warren; Pratt, Tim; Nunnally, Charles; Nealy, Randall; Remaklus, Will; Sylvester, Bill; Predoehl, Andrew; Gaff, Doug

    1993-01-01

    The launch schedule for the Advanced Communication Technology Satellite (ACTS) spacecraft did not leave sufficient time for completion of the prototype ACTS Propagation Terminals (APT) prior to initiation of the APT production phase. In fact, the approach used was to construct and test all subassemblies of the terminal with special emphasis on the technically challenging portions. These include the RF front end that uses a state-of-the-art down converter which integrates a low noise amplifier, mixer, post amplifier, filter, and local oscillator port frequency doubler into a single small package. In addition, a new digital receiver that uses the latest DSP technology was developed. Both of these subassemblies were thoroughly tested. The highest risk technology in the APT program was the digital receiver. Several candidate algorithms and DSP chips were investigated early on, primarily under JPL sponsorship. A receiver was constructed based on Texas Instruments chip. The final prototype digital receiver was one based on an Analog Devices chip. The design and test results are documented in a report prepared for this grant. A Primary Design Review (PDR) was conducted 30 May 1991, and a Critical Design Review was held 7 Jul. 1992. Final complete documentation of the APT's will appear in the form of three reports: a hardware description report, a report on the data collection code (ACTS VIEW), and a report on the preprocessing code.

  10. Design of an AdvancedTCA board management controller (IPMC)

    NASA Astrophysics Data System (ADS)

    Mendez, J.; Bobillier, V.; Haas, S.; Joos, M.; Mico, S.; Vasey, F.

    2017-03-01

    The AdvancedTCA (ATCA) standard has been selected as the hardware platform for the upgrade of the back-end electronics of the CMS and ATLAS experiments of the Large Hadron Collider (LHC) . In this context, the electronic systems for experiments group at CERN is running a project to evaluate, specify, design and support xTCA equipment. As part of this project, an Intelligent Platform Management Controller (IPMC) for ATCA blades, based on a commercial solution, has been designed to be used on existing and future ATCA blades. This paper reports on the status of this project presenting the hardware and software developments.

  11. Refined Exploration of Turbofan Design Options for an Advanced Single-Aisle Transport

    NASA Technical Reports Server (NTRS)

    Guynn, Mark D.; Berton, Jeffrey J.; Fisher, Kenneth L.; Haller, William J.; Tong, Michael T.; Thurman, Douglas R.

    2011-01-01

    A comprehensive exploration of the turbofan engine design space for an advanced technology single-aisle transport (737/A320 class aircraft) was conducted previously by the authors and is documented in a prior report. Through the course of that study and in a subsequent evaluation of the approach and results, a number of enhancements to the engine design ground rules and assumptions were identified. A follow-on effort was initiated to investigate the impacts of these changes on the original study results. The fundamental conclusions of the prior study were found to still be valid with the revised engine designs. The most significant impact of the design changes was a reduction in the aircraft weight and block fuel penalties incurred with low fan pressure ratio, ultra-high bypass ratio designs. This enables lower noise levels to be pursued (through lower fan pressure ratio) with minor negative impacts on aircraft weight and fuel efficiency. Regardless of the engine design selected, the results of this study indicate the potential for the advanced aircraft to realize substantial improvements in fuel efficiency, emissions, and noise compared to the current vehicles in this size class.

  12. Initial performance of advanced designs for IPV nickel-hydrogen cells

    NASA Technical Reports Server (NTRS)

    Smithrick, John J.

    1986-01-01

    Advanced designs for individual pressure vessel nickel-hydrogen cells have been conceived which should improve the cycle life at deep depths-of-discharge and improve thermal management. Features of the designs which are new and not incorporated in either of the contemporary cells (Air Force/Hughes, Comsat) are: (1) use of alternate methods of oxygen recombination, (2) use of serrated edge separators to facilitate movement of gas within the cell while still maintaining required physical contact with the wall wick, and (3) use of an expandable stack to accommodate some of the nickel electrode expansion. The designs also consider electrolyte volume requirements over the life of the cells, and are fully compatible with the Air Force/Hughes design.

  13. Preliminary design study of advanced multistage axial flow core compressors

    NASA Technical Reports Server (NTRS)

    Wisler, D. C.; Koch, C. C.; Smith, L. H., Jr.

    1977-01-01

    A preliminary design study was conducted to identify an advanced core compressor for use in new high-bypass-ratio turbofan engines to be introduced into commercial service in the 1980's. An evaluation of anticipated compressor and related component 1985 state-of-the-art technology was conducted. A parametric screening study covering a large number of compressor designs was conducted to determine the influence of the major compressor design features on efficiency, weight, cost, blade life, aircraft direct operating cost, and fuel usage. The trends observed in the parametric screening study were used to develop three high-efficiency, high-economic-payoff compressor designs. These three compressors were studied in greater detail to better evaluate their aerodynamic and mechanical feasibility.

  14. Initial performance of advanced designs for IPV nickel-hydrogen cells

    NASA Technical Reports Server (NTRS)

    Smithrick, J. J.

    1985-01-01

    Advanced designs for individual pressure vessel nickel hydrogen cells were conceived which should improve the life cycle at deep depths of discharge and improve thermal management. Features of the designs which are new and not incorporated in either of the contemporary cells (Air Force/Hughes, Comsat) are: (1) the use of alternate methods of oxygen recombination, (2) use of serrated edge separators to facilitate movement of gas within the cell while still maintaining required physical contact with the wall wick, and (3) use of an expandable stack to accommodate some of the nickel electrode expansion. The designs also consider electrolyte volume requirements over the life of the cells, and are fully compatible with the Air Force/Hughes design.

  15. ASDA - Advanced Suit Design Analyzer computer program

    NASA Technical Reports Server (NTRS)

    Bue, Grant C.; Conger, Bruce C.; Iovine, John V.; Chang, Chi-Min

    1992-01-01

    An ASDA model developed to evaluate the heat and mass transfer characteristics of advanced pressurized suit design concepts for low pressure or vacuum planetary applications is presented. The model is based on a generalized 3-layer suit that uses the Systems Integrated Numerical Differencing Analyzer '85 in conjunction with a 41-node FORTRAN routine. The latter simulates the transient heat transfer and respiratory processes of a human body in a suited environment. The user options for the suit encompass a liquid cooled garment, a removable jacket, a CO2/H2O permeable layer, and a phase change layer.

  16. Preliminary aerodynamic design considerations for advanced laminar flow aircraft configurations

    NASA Technical Reports Server (NTRS)

    Johnson, Joseph L., Jr.; Yip, Long P.; Jordan, Frank L., Jr.

    1986-01-01

    Modern composite manufacturing methods have provided the opportunity for smooth surfaces that can sustain large regions of natural laminar flow (NLF) boundary layer behavior and have stimulated interest in developing advanced NLF airfoils and improved aircraft designs. Some of the preliminary results obtained in exploratory research investigations on advanced aircraft configurations at the NASA Langley Research Center are discussed. Results of the initial studies have shown that the aerodynamic effects of configuration variables such as canard/wing arrangements, airfoils, and pusher-type and tractor-type propeller installations can be particularly significant at high angles of attack. Flow field interactions between aircraft components were shown to produce undesirable aerodynamic effects on a wing behind a heavily loaded canard, and the use of properly designed wing leading-edge modifications, such as a leading-edge droop, offset the undesirable aerodynamic effects by delaying wing stall and providing increased stall/spin resistance with minimum degradation of laminar flow behavior.

  17. Aerodynamic optimization by simultaneously updating flow variables and design parameters with application to advanced propeller designs

    NASA Technical Reports Server (NTRS)

    Rizk, Magdi H.

    1988-01-01

    A scheme is developed for solving constrained optimization problems in which the objective function and the constraint function are dependent on the solution of the nonlinear flow equations. The scheme updates the design parameter iterative solutions and the flow variable iterative solutions simultaneously. It is applied to an advanced propeller design problem with the Euler equations used as the flow governing equations. The scheme's accuracy, efficiency and sensitivity to the computational parameters are tested.

  18. Polymer planar lightwave circuit based hybrid-integrated coherent receiver for advanced modulation signals

    NASA Astrophysics Data System (ADS)

    Wang, Jin; Han, Yang; Liang, Zhongcheng; Chen, Yongjin

    2012-11-01

    Applying coherent detection technique to advanced modulation formats makes it possible to electronically compensate the signal impairments. A key issue for a successful deployment of coherent detection technique is the availability of cost-efficient and compact integrated receivers, which are composed of an optical 90° hybrid mixer and four photodiodes (PDs). In this work, three different types of optical hybrids are fabricated with polymer planar lightwave circuit (PLC), and hybridly integrated with four vertical backside illuminated III-V PDs. Their performances, such as the insertion loss, the transmission imbalance, the polarization dependence and the phase deviation of 90° hybrid will be discussed.

  19. Advanced composites: Design and application. Proceedings of the meeting of the Mechanical Failures Prevention Group

    NASA Technical Reports Server (NTRS)

    Shives, T. R.; Willard, W. A.

    1979-01-01

    The design and application of advanced composites is discussed with emphasis on aerospace, aircraft, automotive, marine, and industrial applications. Failure modes in advanced composites are also discussed.

  20. Spacecraft Conceptual Design for the 8-Meter Advanced Technology Large Aperture Space Telescope (ATLAST)

    NASA Technical Reports Server (NTRS)

    Hopkins, Randall C.; Capizzo, Peter; Fincher, Sharon; Hornsby, Linda S.; Jones, David

    2010-01-01

    The Advanced Concepts Office at Marshall Space Flight Center completed a brief spacecraft design study for the 8-meter monolithic Advanced Technology Large Aperture Space Telescope (ATLAST-8m). This spacecraft concept provides all power, communication, telemetry, avionics, guidance and control, and thermal control for the observatory, and inserts the observatory into a halo orbit about the second Sun-Earth Lagrange point. The multidisciplinary design team created a simple spacecraft design that enables component and science instrument servicing, employs articulating solar panels for help with momentum management, and provides precise pointing control while at the same time fast slewing for the observatory.

  1. Quadrant CFD Analysis of a Mixer-Ejector Nozzle for HSCT Applications

    NASA Technical Reports Server (NTRS)

    Yoder, Dennis A.; Georgiadis, Nicholas J.; Wolter, John D.

    2005-01-01

    This study investigates the sidewall effect on flow within the mixing duct downstream of a lobed mixer-ejector nozzle. Simulations which model only one half-chute width of the ejector array are compared with those which model one complete quadrant of the nozzle geometry and with available experimental data. These solutions demonstrate the applicability of the half-chute technique to model the flowfield far away from the sidewall and the necessity of a full-quadrant simulation to predict the formation of a low-energy flow region near the sidewall. The quadrant solutions are further examined to determine the cause of this low-energy region, which reduces the amount of mixing and lowers the thrust of the nozzle. Grid resolution and different grid topologies are also examined. Finally, an assessment of the half-chute and quadrant approaches is made to determine the ability of these simulations to provide qualitative and/or quantitative predictions for this type of complex flowfield.

  2. Instructional Design Theory: Advancements from Cognitive Science and Instructional Technology.

    ERIC Educational Resources Information Center

    Tennyson, Robert D.

    Scientific advancements in cognitive science and instructional technology extend the behaviorally-oriented learning paradigm of instructional design and management in three major areas: (1) analysis of information-to-be-learned; (2) means of evaluating learners; and (3) linkage of learning theory to instructional prescriptions. The two basic types…

  3. Summary of the Advanced Reactor Design Criteria (ARDC) Phase 2 Activities

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Holbrook, Mark Raymond

    This report provides an end-of-year summary reflecting the progress and status of proposed regulatory design criteria for advanced non-LWR designs in accordance with the Level 3 milestone in M3AT-15IN2001017 in work package AT-15IN200101. These criteria have been designated as ARDC, and they provide guidance to future applicants for addressing the GDC that are currently applied specifically to LWR designs. The report provides a summary of Phase 2 activities related to the various tasks associated with ARDC development and the subsequent development of example adaptations of ARDC for Sodium Fast Reactor (SFR) and modular High Temperature Gas-cooled Reactor (HTGR) designs.

  4. Sandia Advanced MEMS Design Tools v. 3.0

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Yarberry, Victor R.; Allen, James J.; Lantz, Jeffrey W.

    This is a major revision to the Sandia Advanced MEMS Design Tools. It replaces all previous versions. New features in this version: Revised to support AutoCAD 2014 and 2015 This CD contains an integrated set of electronic files that: a) Describe the SUMMiT V fabrication process b) Provide enabling educational information (including pictures, videos, technical information) c) Facilitate the process of designing MEMS with the SUMMiT process (prototype file, Design Rule Checker, Standard Parts Library) d) Facilitate the process of having MEMS fabricated at Sandia National Laboratories e) Facilitate the process of having post-fabrication services performed. While there exists somemore » files on the CD that are used in conjunction with software package AutoCAD, these files are not intended for use independent of the CD. Note that the customer must purchase his/her own copy of AutoCAD to use with these files.« less

  5. Effects of an Advanced Reactor’s Design, Use of Automation, and Mission on Human Operators

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Jeffrey C. Joe; Johanna H. Oxstrand

    The roles, functions, and tasks of the human operator in existing light water nuclear power plants (NPPs) are based on sound nuclear and human factors engineering (HFE) principles, are well defined by the plant’s conduct of operations, and have been validated by years of operating experience. However, advanced NPPs whose engineering designs differ from existing light-water reactors (LWRs) will impose changes on the roles, functions, and tasks of the human operators. The plans to increase the use of automation, reduce staffing levels, and add to the mission of these advanced NPPs will also affect the operator’s roles, functions, and tasks.more » We assert that these factors, which do not appear to have received a lot of attention by the design engineers of advanced NPPs relative to the attention given to conceptual design of these reactors, can have significant risk implications for the operators and overall plant safety if not mitigated appropriately. This paper presents a high-level analysis of a specific advanced NPP and how its engineered design, its plan to use greater levels of automation, and its expanded mission have risk significant implications on operator performance and overall plant safety.« less

  6. Circuit design advances for ultra-low power sensing platforms

    NASA Astrophysics Data System (ADS)

    Wieckowski, Michael; Dreslinski, Ronald G.; Mudge, Trevor; Blaauw, David; Sylvester, Dennis

    2010-04-01

    This paper explores the recent advances in circuit structures and design methodologies that have enabled ultra-low power sensing platforms and opened up a host of new applications. Central to this theme is the development of Near Threshold Computing (NTC) as a viable design space for low power sensing platforms. In this paradigm, the system's supply voltage is approximately equal to the threshold voltage of its transistors. Operating in this "near-threshold" region provides much of the energy savings previously demonstrated for subthreshold operation while offering more favorable performance and variability characteristics. This makes NTC applicable to a broad range of power-constrained computing segments including energy constrained sensing platforms. This paper explores the barriers to the adoption of NTC and describes current work aimed at overcoming these obstacles in the circuit design space.

  7. The design of components for an advanced Rankine cycle test facility.

    NASA Technical Reports Server (NTRS)

    Bond, J. A.

    1972-01-01

    The design of a facility for testing components of an advanced Rankine cycle power system is summarized. The facility is a three-loop system in which lithium, potassium and NaK-78 are the working fluids of the primary, secondary and heat-rejection loops, respectively. Design bases and performance predictions for the major loop components, including the lithium heater and the potassium boiler, condenser and preheater, are outlined.

  8. Advanced Wet Tantalum Capacitors: Design, Specifications and Performance

    NASA Technical Reports Server (NTRS)

    Teverovsky, Alexander

    2016-01-01

    Insertion of new types of commercial, high volumetric efficiency wet tantalum capacitors in space systems requires reassessment of the existing quality assurance approaches that have been developed for capacitors manufactured to MIL-PRF-39006 requirements. The specifics of wet electrolytic capacitors is that leakage currents flowing through electrolyte can cause gas generation resulting in building up of internal gas pressure and rupture of the case. The risk associated with excessive leakage currents and increased pressure is greater for high value advanced wet tantalum capacitors, but it has not been properly evaluated yet. This presentation gives a review of specifics of the design, performance, and potential reliability risks associated with advanced wet tantalum capacitors. Problems related to setting adequate requirements for DPA, leakage currents, hermeticity, stability at low and high temperatures, ripple currents for parts operating in vacuum, and random vibration testing are discussed. Recommendations for screening and qualification to reduce risks of failures have been suggested.

  9. Advanced Wet Tantalum Capacitors: Design, Specifications and Performance

    NASA Technical Reports Server (NTRS)

    Teverovsky, Alexander

    2017-01-01

    Insertion of new types of commercial, high volumetric efficiency wet tantalum capacitors in space systems requires reassessment of the existing quality assurance approaches that have been developed for capacitors manufactured to MIL-PRF-39006 requirements. The specifics of wet electrolytic capacitors is that leakage currents flowing through electrolyte can cause gas generation resulting in building up of internal gas pressure and rupture of the case. The risk associated with excessive leakage currents and increased pressure is greater for high value advanced wet tantalum capacitors, but it has not been properly evaluated yet. This presentation gives a review of specifics of the design, performance, and potential reliability risks associated with advanced wet tantalum capacitors. Problems related to setting adequate requirements for DPA, leakage currents, hermeticity, stability at low and high temperatures, ripple currents for parts operating in vacuum, and random vibration testing are discussed. Recommendations for screening and qualification to reduce risks of failures have been suggested.

  10. Single stage, low noise, advanced technology fan. Volume 1: Aerodynamic design

    NASA Technical Reports Server (NTRS)

    Sullivan, T. J.; Younghans, J. L.; Little, D. R.

    1976-01-01

    The aerodynamic design for a half-scale fan vehicle, which would have application on an advanced transport aircraft, is described. The single stage advanced technology fan was designed to a pressure ratio of 1.8 at a tip speed of 503 m/sec 11,650 ft/sec). The fan and booster components are designed in a scale model flow size convenient for testing with existing facility and vehicle hardware. The design corrected flow per unit annulus area at the fan face is 215 kg/sec sq m (44.0 lb m/sec sq ft) with a hub-tip ratio of 0.38 at the leading edge of the fan rotor. This results in an inlet corrected airflow of 117.9 kg/sec (259.9 lb m/sec) for the selected rotor tip diameter if 90.37 cm (35.58 in.). The variable geometry inlet is designed utilizing a combination of high throat Mach number and acoustic treatment in the inlet diffuser for noise suppression (hybrid inlet). A variable fan exhaust nozzle was assumed in conjunction with the variable inlet throat area to limit the required area change of the inlet throat at approach and hence limit the overall diffusion and inlet length. The fan exit duct design was primarily influenced by acoustic requirements, including length of suppressor wall treatment; length, thickness and position on a duct splitter for additional suppressor treatment; and duct surface Mach numbers.

  11. GeMS: an advanced software package for designing synthetic genes.

    PubMed

    Jayaraj, Sebastian; Reid, Ralph; Santi, Daniel V

    2005-01-01

    A user-friendly, advanced software package for gene design is described. The software comprises an integrated suite of programs-also provided as stand-alone tools-that automatically performs the following tasks in gene design: restriction site prediction, codon optimization for any expression host, restriction site inclusion and exclusion, separation of long sequences into synthesizable fragments, T(m) and stem-loop determinations, optimal oligonucleotide component design and design verification/error-checking. The output is a complete design report and a list of optimized oligonucleotides to be prepared for subsequent gene synthesis. The user interface accommodates both inexperienced and experienced users. For inexperienced users, explanatory notes are provided such that detailed instructions are not necessary; for experienced users, a streamlined interface is provided without such notes. The software has been extensively tested in the design and successful synthesis of over 400 kb of genes, many of which exceeded 5 kb in length.

  12. High sensitive THz superconducting hot electron bolometer mixers and transition edge sensors

    NASA Astrophysics Data System (ADS)

    Zhang, W.; Miao, W.; Zhou, K. M.; Guo, X. H.; Zhong, J. Q.; Shi, S. C.

    2016-11-01

    Terahertz band, which is roughly defined as 0.1 THz to 10 THz, is an interesting frequency region of the electromagnetic spectrum to be fully explored in astronomy. THz observations play key roles in astrophysics and cosmology. High sensitive heterodyne and direct detectors are the main tools for the detection of molecular spectral lines and fine atomic structure spectral lines, which are very important tracers for probing the physical and chemical properties and dynamic processes of objects such as star and planetary systems. China is planning to build an THz telescope at Dome A, Antarctica, a unique site for ground-based THz observations. We are developing THz superconducting hot electron bolometer (HEB) mixers and transition edge sensors (TES), which are quantum limited and back-ground limited detectors, respectively. Here we first introduce the working principles of superconducting HEB and TES, and then mainly present the results achieved at Purple mountain Observatory.

  13. Performance analysis of vortex based mixers for confined flows

    NASA Astrophysics Data System (ADS)

    Buschhagen, Timo

    The hybrid rocket is still sparsely employed within major space or defense projects due to their relatively poor combustion efficiency and low fuel grain regression rate. Although hybrid rockets can claim advantages in safety, environmental and performance aspects against established solid and liquid propellant systems, the boundary layer combustion process and the diffusion based mixing within a hybrid rocket grain port leaves the core flow unmixed and limits the system performance. One principle used to enhance the mixing of gaseous flows is to induce streamwise vorticity. The counter-rotating vortex pair (CVP) mixer utilizes this principle and introduces two vortices into a confined flow, generating a stirring motion in order to transport near wall media towards the core and vice versa. Recent studies investigated the velocity field introduced by this type of swirler. The current work is evaluating the mixing performance of the CVP concept, by using an experimental setup to simulate an axial primary pipe flow with a radially entering secondary flow. Hereby the primary flow is altered by the CVP swirler unit. The resulting setup therefore emulates a hybrid rocket motor with a cylindrical single port grain. In order to evaluate the mixing performance the secondary flow concentration at the pipe assembly exit is measured, utilizing a pressure-sensitive paint based procedure.

  14. Twin Screw Extruders as Continuous Mixers for Thermal Processing: a Technical and Historical Perspective.

    PubMed

    Martin, Charlie

    2016-02-01

    Developed approximately 100 years ago for natural rubber/plastics applications, processes via twin screw extrusion (TSE) now generate some of the most cutting-edge drug delivery systems available. After 25 or so years of usage in pharmaceutical environments, it has become evident why TSE processing offers significant advantages as compared to other manufacturing techniques. The well-characterized nature of the TSE process lends itself to ease of scale-up and process optimization while also affording the benefits of continuous manufacturing. Interestingly, the evolution of twin screw extrusion for pharmaceutical products has followed a similar path as previously trodden by plastics processing pioneers. Almost every plastic has been processed at some stage in the manufacturing train on a twin screw extruder, which is utilized to mix materials together to impart desired properties into a final part. The evolution of processing via TSEs since the early/mid 1900s is recounted for plastics and also for pharmaceuticals from the late 1980s until today. The similarities are apparent. The basic theory and development of continuous mixing via corotating and counterrotating TSEs for plastics and drug is also described. The similarities between plastics and pharmaceutical applications are striking. The superior mixing characteristics inherent with a TSE have allowed this device to dominate other continuous mixers and spurred intensive development efforts and experimentation that spawned highly engineered formulations for the commodity and high-tech plastic products we use every day. Today, twin screw extrusion is a battle hardened, well-proven, manufacturing process that has been validated in 24-h/day industrial settings. The same thing is happening today with new extrusion technologies being applied to advanced drug delivery systems to facilitate commodity, targeted, and alternative delivery systems. It seems that the "extrusion evolution" will continue for wide

  15. Effect of Processing Variables on Tensile Modulus and Morphology of Polyethylene/Clay Nanocomposites Prepared in an Internal Mixer

    NASA Astrophysics Data System (ADS)

    Ujianto, O.; Jollands, M.; Kao, N.

    2018-03-01

    A comparative study on effect of internal mixer on high density Polyethylene (HDPE)/clay nanocomposites preparation was done. Effect of temperature, rotor rotation (rpm), and mixing time, as well as rotor type (Roller and Banbury) on mechanical properties and morphology of HDPE/clay nanocomposites were studied using Box-Behnken experimental design. The model was developed according to secant modulus and confirmed to morphology analysis using Transmission Electron Microscopy (TEM). The finding suggests that there is different mechanisms occurred in each rotor to improve the mechanical properties. The mechanism in Roller is medium shear and medium diffusion, while Banbury is high shear and low diffusion. The difference in mechanism to disperse the clay particles attribute to the different optimum processing conditions in each rotor. The settings for roller samples are predicted around mid temperature, mid speed, and mid mixing time. There is no optimum setting for Banbury within the processing boundaries. The best settings for Banbury are at low, high, low settings. The morphology results showed a hybrid composite structure, with some exfoliations and some intercalations. There was a correlation between better mechanical properties and morphology with more exfoliation and thinner intercalated particles.

  16. Large-Scale Advanced Prop-Fan (LAP) pitch change actuator and control design report

    NASA Technical Reports Server (NTRS)

    Schwartz, R. A.; Carvalho, P.; Cutler, M. J.

    1986-01-01

    In recent years, considerable attention has been directed toward improving aircraft fuel consumption. Studies have shown that the high inherent efficiency previously demonstrated by low speed turboprop propulsion systems may now be extended to today's higher speed aircraft if advanced high-speed propeller blades having thin airfoils and aerodynamic sweep are utilized. Hamilton Standard has designed a 9-foot diameter single-rotation Large-Scale Advanced Prop-Fan (LAP) which will be tested on a static test stand, in a high speed wind tunnel and on a research aircraft. The major objective of this testing is to establish the structural integrity of large-scale Prop-Fans of advanced construction in addition to the evaluation of aerodynamic performance and aeroacoustic design. This report describes the operation, design features and actual hardware of the (LAP) Prop-Fan pitch control system. The pitch control system which controls blade angle and propeller speed consists of two separate assemblies. The first is the control unit which provides the hydraulic supply, speed governing and feather function for the system. The second unit is the hydro-mechanical pitch change actuator which directly changes blade angle (pitch) as scheduled by the control.

  17. Recent advances in metal oxide-based electrode architecture design for electrochemical energy storage.

    PubMed

    Jiang, Jian; Li, Yuanyuan; Liu, Jinping; Huang, Xintang; Yuan, Changzhou; Lou, Xiong Wen David

    2012-10-02

    Metal oxide nanostructures are promising electrode materials for lithium-ion batteries and supercapacitors because of their high specific capacity/capacitance, typically 2-3 times higher than that of the carbon/graphite-based materials. However, their cycling stability and rate performance still can not meet the requirements of practical applications. It is therefore urgent to improve their overall device performance, which depends on not only the development of advanced electrode materials but also in a large part "how to design superior electrode architectures". In the article, we will review recent advances in strategies for advanced metal oxide-based hybrid nanostructure design, with the focus on the binder-free film/array electrodes. These binder-free electrodes, with the integration of unique merits of each component, can provide larger electrochemically active surface area, faster electron transport and superior ion diffusion, thus leading to substantially improved cycling and rate performance. Several recently emerged concepts of using ordered nanostructure arrays, synergetic core-shell structures, nanostructured current collectors, and flexible paper/textile electrodes will be highlighted, pointing out advantages and challenges where appropriate. Some future electrode design trends and directions are also discussed. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Proceedings of the 6th Annual Summer Conference: NASA/USRA University Advanced Design Program

    NASA Technical Reports Server (NTRS)

    1990-01-01

    The NASA/USRA University Advanced Design Program is a unique program that brings together NASA engineers, students, and faculty from United States engineering schools by integrating current and future NASA space/aeronautics engineering design projects into the university curriculum. The Program was conceived in the fall of 1984 as a pilot project to foster engineering design education in the universities and to supplement NASA's in-house efforts in advanced planning for space and aeronautics design. Nine universities and five NASA centers participated in the first year of the pilot project. The study topics cover a broad range of potential space and aeronautics projects that could be undertaken during a 20 to 30 year period beginning with the deployment of the Space Station Freedom scheduled for the mid-1990s. Both manned and unmanned endeavors are embraced, and the systems approach to the design problem is emphasized.

  19. Three-dimensional viscous design methodology for advanced technology aircraft supersonic inlet systems

    NASA Technical Reports Server (NTRS)

    Anderson, B. H.

    1983-01-01

    A broad program to develop advanced, reliable, and user oriented three-dimensional viscous design techniques for supersonic inlet systems, and encourage their transfer into the general user community is discussed. Features of the program include: (1) develop effective methods of computing three-dimensional flows within a zonal modeling methodology; (2) ensure reasonable agreement between said analysis and selective sets of benchmark validation data; (3) develop user orientation into said analysis; and (4) explore and develop advanced numerical methodology.

  20. Computer aided design of monolithic microwave and millimeter wave integrated circuits and subsystems

    NASA Astrophysics Data System (ADS)

    Ku, Walter H.; Gang, Guan-Wan; He, J. Q.; Ichitsubo, I.

    1988-05-01

    This final technical report presents results on the computer aided design of monolithic microwave and millimeter wave integrated circuits and subsystems. New results include analytical and computer aided device models of GaAs MESFETs and HEMTs or MODFETs, new synthesis techniques for monolithic feedback and distributed amplifiers and a new nonlinear CAD program for MIMIC called CADNON. This program incorporates the new MESFET and HEMT model and has been successfully applied to the design of monolithic millimeter-wave mixers.

  1. Advanced Propfan Engine Technology (APET) definition study, single and counter-rotation gearbox/pitch change mechanism design

    NASA Technical Reports Server (NTRS)

    Anderson, R. D.

    1985-01-01

    Single-rotation propfan-powered regional transport aircraft were studied to identify key technology development issues and programs. The need for improved thrust specific fuel consumption to reduce fuel burned and aircraft direct operating cost is the dominant factor. Typical cycle trends for minimizing fuel consumption are reviewed, and two 10,000 shp class engine configurations for propfan propulsion systems for the 1990's are presented. Recommended engine configurations are both three-spool design with dual spool compressors and free power turbines. The benefits of these new propulsion system concepts were evaluated using an advanced airframe, and results are compared for single-rotation propfan and turbofan advanced technology propulsion systems. The single-rotation gearbox is compared to a similar design with current technology to establish the benefits of the advanced gearbox technology. The conceptual design of the advanced pitch change mechanism identified a high pressure hydraulic system that is superior to the other contenders and completely external to the gearboxes.

  2. Characterization of mixing in an electroosmotically stirred continuous micro mixer

    NASA Astrophysics Data System (ADS)

    Beskok, Ali

    2005-11-01

    We present theoretical and numerical studies of mixing in a straight micro channel with zeta potential patterned surfaces. A steady pressure driven flow is maintained in the channel in addition to a time dependent electroosmotic flow, generated by a stream-wise AC electric field. The zeta potential patterns are placed critically in the channel to achieve spatially asymmetric time-dependent flow patterns that lead to chaotic stirring. Fixing the geometry, we performed parametric studies of passive particle motion that led to generation of Poincare sections and characterization of chaotic strength by finite time Lyapunov exponents. The parametric studies were performed as a function of the Womersley number (normalized AC frequency) and the ratio of Poiseuille flow and electroosmotic velocities. After determining the non-dimensional parameters that led to high chaotic strength, we performed spectral element simulations of species transport and mixing at high Peclet numbers, and characterized mixing efficiency using the Mixing Index inverse. Mixing lengths proportional to the natural logarithm of the Peclet number are reported. Using the optimum non-dimensional parameters and the typical magnitudes involved in electroosmotic flows, we were able to determine the physical dimensions and operation conditions for a prototype micro-mixer.

  3. Cold Aero Performance of a Two-Dimensional Mixer Ejector Nozzle

    NASA Technical Reports Server (NTRS)

    Balan, C.

    2005-01-01

    Since 1986, NASA and the U.S. aerospace industry have been assessing the economic viability and environmental acceptability of a second-generation supersonic civil transport, or High Speed Civil Transport (HSCT). Environmental acceptability in terms of airport community noise and economic viability are critical elements in this endeavor. Development of a propulsion system that satisfies strict airport noise regulations (FAR36 Stage III levels), at acceptable performance and weight, is critical to the success of any HSCT program. Two-dimensional mixer-ejector (2DME) exhaust systems are one approach in achieving this goal. In support of HSCT development, GEAE (GE Aircraft Engines), under contract to the NASA Glenn Research Center, conducted this test program at the NASA Langley 16 ft transonic wind tunnel to evaluate the cold aerodynamic performance aspects of the 2DME exhaust system concept. The effects of SAR (SAR, suppressor area ratio, = mixed-flow area/primary nozzle throat area), MAR (MAR = overall exhaust system exit/mixing-plane area), flap length, CER (suppressor chute expansion ratio), chute alignment, and free stream Mach number were investigated on a 1/11th cold aerodynamic scale model of a 2DME exhaust system.

  4. An airline study of advanced technology requirements for advanced high speed commercial transport engines. 1: Engine design study assessment

    NASA Technical Reports Server (NTRS)

    Sallee, G. P.

    1973-01-01

    The advanced technology requirements for an advanced high speed commercial tranport engine are presented. The results of the phase 1 study effort cover the following areas: (1) statement of an airline's major objectives for future transport engines, (2) airline's method of evaluating engine proposals, (3) description of an optimum engine for a long range subsonic commercial transport including installation and critical design features, (4) discussion of engine performance problems and experience with performance degradation, (5) trends in engine and pod prices with increasing technology and objectives for the future, (6) discussion of the research objectives for composites, reversers, advanced components, engine control systems, and devices to reduce the impact of engine stall, and (7) discussion of the airline objectives for noise and pollution reduction.

  5. Analysis of Advanced Fuel Assemblies and Core Designs for the Current and Next Generations of LWRs

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ragusa, Jean; Vierow, Karen

    2011-09-01

    The objective of the project is to design and analyze advanced fuel assemblies for use in current and future light water reactors and to assess their ability to reduce the inventory of transuranic elements, while preserving operational safety. The reprocessing of spent nuclear fuel can delay or avoid the need for a second geological repository in the US. Current light water reactor fuel assembly designs under investigation could reduce the plutonium inventory of reprocessed fuel. Nevertheless, these designs are not effective in stabilizing or reducing the inventory of minor actinides. In the course of this project, we developed and analyzedmore » advanced fuel assembly designs with improved thermal transmutation capability regarding transuranic elements and especially minor actinides. These designs will be intended for use in thermal spectrum (e.g., current and future fleet of light water reactors in the US). We investigated various fuel types, namely high burn-up advanced mixed oxides and inert matrix fuels, in various geometrical designs that are compliant with the core internals of current and future light water reactors. Neutronic/thermal hydraulic effects were included. Transmutation efficiency and safety parameters were used to rank and down-select the various designs.« less

  6. Measuring and Advancing Experimental Design Ability in an Introductory Course without Altering Existing Lab Curriculum.

    PubMed

    Shanks, Ryan A; Robertson, Chuck L; Haygood, Christian S; Herdliksa, Anna M; Herdliska, Heather R; Lloyd, Steven A

    2017-01-01

    Introductory biology courses provide an important opportunity to prepare students for future courses, yet existing cookbook labs, although important in their own way, fail to provide many of the advantages of semester-long research experiences. Engaging, authentic research experiences aid biology students in meeting many learning goals. Therefore, overlaying a research experience onto the existing lab structure allows faculty to overcome barriers involving curricular change. Here we propose a working model for this overlay design in an introductory biology course and detail a means to conduct this lab with minimal increases in student and faculty workloads. Furthermore, we conducted exploratory factor analysis of the Experimental Design Ability Test (EDAT) and uncovered two latent factors which provide valid means to assess this overlay model's ability to increase advanced experimental design abilities. In a pre-test/post-test design, we demonstrate significant increases in both basic and advanced experimental design abilities in an experimental and comparison group. We measured significantly higher gains in advanced experimental design understanding in students in the experimental group. We believe this overlay model and EDAT factor analysis contribute a novel means to conduct and assess the effectiveness of authentic research experiences in an introductory course without major changes to the course curriculum and with minimal increases in faculty and student workloads.

  7. Improved silicon carbide for advanced heat engines

    NASA Technical Reports Server (NTRS)

    Whalen, Thomas J.

    1989-01-01

    The development of high strength, high reliability silicon carbide parts with complex shapes suitable for use in advanced heat engines is studied. Injection molding was the forming method selected for the program because it is capable of forming complex parts adaptable for mass production on an economically sound basis. The goals were to reach a Weibull characteristic strength of 550 MPa (80 ksi) and a Weibull modulus of 16 for bars tested in four-point loading. Statistically designed experiments were performed throughout the program and a fluid mixing process employing an attritor mixer was developed. Compositional improvements in the amounts and sources of boron and carbon used and a pressureless sintering cycle were developed which provided samples of about 99 percent of theoretical density. Strengths were found to improve significantly by annealing in air. Strengths in excess of 550 MPa (80 ksi) with Weibull modulus of about 9 were obtained. Further improvements in Weibull modulus to about 16 were realized by proof testing. This is an increase of 86 percent in strength and 100 percent in Weibull modulus over the baseline data generated at the beginning of the program. Molding yields were improved and flaw distributions were observed to follow a Poisson process. Magic angle spinning nuclear magnetic resonance spectra were found to be useful in characterizing the SiC powder and the sintered samples. Turbocharger rotors were molded and examined as an indication of the moldability of the mixes which were developed in this program.

  8. Phase 1 Development Testing of the Advanced Manufacturing Demonstrator Engine

    NASA Technical Reports Server (NTRS)

    Case, Nicholas L.; Eddleman, David E.; Calvert, Marty R.; Bullard, David B.; Martin, Michael A.; Wall, Thomas R.

    2016-01-01

    The Additive Manufacturing Development Breadboard Engine (BBE) is a pressure-fed liquid oxygen/pump-fed liquid hydrogen (LOX/LH2) expander cycle engine that was built and operated by NASA at Marshall Space Flight Center's East Test Area. The breadboard engine was conceived as a technology demonstrator for the additive manufacturing technologies for an advanced upper stage prototype engine. The components tested on the breadboard engine included an ablative chamber, injector, main fuel valve, turbine bypass valve, a main oxidizer valve, a mixer and the fuel turbopump. All parts minus the ablative chamber were additively manufactured. The BBE was successfully hot fire tested seven times. Data collected from the test series will be used for follow on demonstration tests with a liquid oxygen turbopump and a regeneratively cooled chamber and nozzle.

  9. Innovative designs for the smart ICU: Part 3: Advanced ICU informatics.

    PubMed

    Halpern, Neil A

    2014-04-01

    This third and final installment of this series on innovative designs for the smart ICU addresses the steps involved in conceptualizing, actualizing, using, and maintaining the advanced ICU informatics infrastructure and systems. The smart ICU comprehensively and electronically integrates the patient in the ICU with all aspects of care, displays data in a variety of formats, converts data to actionable information, uses data proactively to enhance patient safety, and monitors the ICU environment to facilitate patient care and ICU management. The keys to success in this complex informatics design process include an understanding of advanced informatics concepts, sophisticated planning, installation of a robust infrastructure capable of both connectivity and interoperability, and implementation of middleware solutions that provide value. Although new technologies commonly appear compelling, they are also complicated and challenging to incorporate within existing or evolving hospital informatics systems. Therefore, careful analysis, deliberate testing, and a phased approach to the implementation of innovative technologies are necessary to achieve the multilevel solutions of the smart ICU.

  10. Noise measurements for various configurations of a model of a mixer nozzle externally blown flap system

    NASA Technical Reports Server (NTRS)

    Goodykoontz, J. H.; Wagner, J. M.; Sargent, N. B.

    1973-01-01

    Noise data were taken for variations to a large scale model of an externally blown flap lift augmentation system. The variations included two different mixer nozzles (7 and 8 lobes), two different wing models (2 and 3 flaps), and different lateral distances between the wing chord line and the nozzle centerline. When the seven lobe was used with the trailing flap in the 60 deg position, increasing the wing to nozzle distance had no effect on the sound level. When the eight lobe nozzle was used there was a decrease in sound level. With the 20 deg flap setting the noise level decreased when the distance was increased using either nozzle.

  11. Piloted Evaluation of a UH-60 Mixer Equivalent Turbulence Simulation Model

    NASA Technical Reports Server (NTRS)

    Lusardi, Jeff A.; Blanken, Chris L.; Tischeler, Mark B.

    2002-01-01

    A simulation study of a recently developed hover/low speed Mixer Equivalent Turbulence Simulation (METS) model for the UH-60 Black Hawk helicopter was conducted in the NASA Ames Research Center Vertical Motion Simulator (VMS). The experiment was a continuation of previous work to develop a simple, but validated, turbulence model for hovering rotorcraft. To validate the METS model, two experienced test pilots replicated precision hover tasks that had been conducted in an instrumented UH-60 helicopter in turbulence. Objective simulation data were collected for comparison with flight test data, and subjective data were collected that included handling qualities ratings and pilot comments for increasing levels of turbulence. Analyses of the simulation results show good analytic agreement between the METS model and flight test data, with favorable pilot perception of the simulated turbulence. Precision hover tasks were also repeated using the more complex rotating-frame SORBET (Simulation Of Rotor Blade Element Turbulence) model to generate turbulence. Comparisons of the empirically derived METS model with the theoretical SORBET model show good agreement providing validation of the more complex blade element method of simulating turbulence.

  12. Drug-beta-cyclodextrin containing pellets prepared with a high-shear mixer.

    PubMed

    Gainotti, Alessandro; Bettini, Ruggero; Gazzaniga, Andrea; Colombo, Paolo; Giordano, Ferdinando

    2004-01-01

    This work was aimed at investigating the preparation of beta-cyclodextrin-microcrystalline cellulose pellets by means of a high-shear mixer, both in the absence or in the presence of ibuprofen as model drug. Drug loading of pellets was accomplished by means of two alternative techniques: 1) solution layering or 2) powder layering. The prepared pellets were characterised in terms of size distribution, shape factor, friability and dissolution rate. The interaction between ibuprofen and beta-cyclodextrin was monitored by Differential Scanning Calorimetry (DSC). Micro Fourier Transform Infrared spectroscopy (MicroFTIR) was applied to determine the distribution of components within each pellet on a micro scale. Pellets with narrow size distribution and containing up to about 90% of BCD were prepared using water as binder. The process yield resulted around 84 and 63% for drug-free and medicate pellets respectively. Drug loaded pellets with favourable technological and biopharmaceutical characteristics can be obtained both by powder or solution layering techniques. The latter proved to be more suitable for producing pellets with high drug contents, reduced friability and high drug dissolution rates.

  13. Design of advanced beams considering elasto-plastic behaviour of material

    NASA Astrophysics Data System (ADS)

    Tolun, S.

    1992-10-01

    The paper proposes a computational procedure for precise calculation of limit and ultimate or design loads, which must be carried by an advanced aviation beam, without permanent distortion and without rupture. Among several stress-strain curve representations, one that is suitable for a particular material is chosen for applied loads, yield, and failure load calculations, and then nonlinear analysis is performed.

  14. A low noise 410-495 heterodyne two tuner mixer, using submicron Nb/Al2O3/Nb tunneljunctions

    NASA Technical Reports Server (NTRS)

    Delange, G.; Honingh, C. E.; Dierichs, M. M. T. M.; Panhuyzen, R. A.; Schaeffer, H. H. A.; Klapwijk, T. M.; Vandestadt, H.; Degraauw, M. W. M.

    1992-01-01

    A 410-495 GHz heterodyne receiver, with an array of two Nb/Al2O3/Nb tunneljunctions as mixing element is described. The noise temperature of this receiver is below 230 K (DSB) over the whole frequency range, and has lowest values of 160 K in the 435-460 GHz range. The calculated DSB mixergain over the whole frequency range varies from -11.9 plus or minus 0.6 dB to -12.6 plus or minus 0.6 dB and the mixer noise is 90 plus or minus 30 K.

  15. Toward Realization of 2.4 GHz Balunless Narrowband Receiver Front-End for Short Range Wireless Applications.

    PubMed

    El-Desouki, Munir M; Qasim, Syed Manzoor; BenSaleh, Mohammed S; Deen, M Jamal

    2015-05-07

    The demand for radio frequency (RF) transceivers operating at 2.4 GHz band has attracted considerable research interest due to the advancement in short range wireless technologies. The performance of RF transceivers depends heavily on the transmitter and receiver front-ends. The receiver front-end is comprised of a low-noise amplifier (LNA) and a downconversion mixer. There are very few designs that focus on connecting the single-ended output LNA to a double-balanced mixer without the use of on-chip transformer, also known as a balun. The objective of designing such a receiver front-end is to achieve high integration and low power consumption. To meet these requirements, we present the design of fully-integrated 2.4 GHz receiver front-end, consisting of a narrow-band LNA and a double balanced mixer without using a balun. Here, the single-ended RF output signal of the LNA is translated into differential signal using an NMOS-PMOS (n-channel metal-oxide-semiconductor, p-channel metal-oxide-semiconductor) transistor differential pair instead of the conventional NMOS-NMOS transistor configuration, for the RF amplification stage of the double-balanced mixer. The proposed receiver circuit fabricated using TSMC 0.18 µm CMOS technology operates at 2.4 GHz and produces an output signal at 300 MHz. The fabricated receiver achieves a gain of 16.3 dB and consumes only 6.74 mW operating at 1.5 V, while utilizing 2.08 mm2 of chip area. Measurement results demonstrate the effectiveness and suitability of the proposed receiver for short-range wireless applications, such as in wireless sensor network (WSN).

  16. Environmental performance evaluation of an advanced-design solid-state television camera

    NASA Technical Reports Server (NTRS)

    1979-01-01

    The development of an advanced-design black-and-white solid-state television camera which can survive exposure to space environmental conditions was undertaken. A 380 x 488 element buried-channel CCD is utilized as the image sensor to ensure compatibility with 525-line transmission and display equipment. Specific camera design approaches selected for study and analysis included: (1) component and circuit sensitivity to temperature; (2) circuit board thermal and mechanical design; and (3) CCD temperature control. Preferred approaches were determined and integrated into the final design for two deliverable solid-state TV cameras. One of these cameras was subjected to environmental tests to determine stress limits for exposure to vibration, shock, acceleration, and temperature-vacuum conditions. These tests indicate performance at the design goal limits can be achieved for most of the specified conditions.

  17. Advanced Design and Implementation of a Control Architecture for Long Range Autonomous Planetary Rovers

    NASA Technical Reports Server (NTRS)

    Martin-Alvarez, A.; Hayati, S.; Volpe, R.; Petras, R.

    1999-01-01

    An advanced design and implementation of a Control Architecture for Long Range Autonomous Planetary Rovers is presented using a hierarchical top-down task decomposition, and the common structure of each design is presented based on feedback control theory. Graphical programming is presented as a common intuitive language for the design when a large design team is composed of managers, architecture designers, engineers, programmers, and maintenance personnel. The whole design of the control architecture consists in the classic control concepts of cyclic data processing and event-driven reaction to achieve all the reasoning and behaviors needed. For this purpose, a commercial graphical tool is presented that includes the mentioned control capabilities. Messages queues are used for inter-communication among control functions, allowing Artificial Intelligence (AI) reasoning techniques based on queue manipulation. Experimental results show a highly autonomous control system running in real time on top the JPL micro-rover Rocky 7 controlling simultaneously several robotic devices. This paper validates the sinergy between Artificial Intelligence and classic control concepts in having in advanced Control Architecture for Long Range Autonomous Planetary Rovers.

  18. Advanced Space Suit Portable Life Support Subsystem Packaging Design

    NASA Technical Reports Server (NTRS)

    Howe, Robert; Diep, Chuong; Barnett, Bob; Thomas, Gretchen; Rouen, Michael; Kobus, Jack

    2006-01-01

    This paper discusses the Portable Life Support Subsystem (PLSS) packaging design work done by the NASA and Hamilton Sundstrand in support of the 3 future space missions; Lunar, Mars and zero-g. The goal is to seek ways to reduce the weight of PLSS packaging, and at the same time, develop a packaging scheme that would make PLSS technology changes less costly than the current packaging methods. This study builds on the results of NASA s in-house 1998 study, which resulted in the "Flex PLSS" concept. For this study the present EMU schematic (low earth orbit) was used so that the work team could concentrate on the packaging. The Flex PLSS packaging is required to: protect, connect, and hold the PLSS and its components together internally and externally while providing access to PLSS components internally for maintenance and for technology change without extensive redesign impact. The goal of this study was two fold: 1. Bring the advanced space suit integrated Flex PLSS concept from its current state of development to a preliminary design level and build a proof of concept mockup of the proposed design, and; 2. "Design" a Design Process, which accommodates both the initial Flex PLSS design and the package modifications, required to accommodate new technology.

  19. Optimal design application on the advanced aeroelastic rotor blade

    NASA Technical Reports Server (NTRS)

    Wei, F. S.; Jones, R.

    1985-01-01

    The vibration and performance optimization procedure using regression analysis was successfully applied to an advanced aeroelastic blade design study. The major advantage of this regression technique is that multiple optimizations can be performed to evaluate the effects of various objective functions and constraint functions. The data bases obtained from the rotorcraft flight simulation program C81 and Myklestad mode shape program are analytically determined as a function of each design variable. This approach has been verified for various blade radial ballast weight locations and blade planforms. This method can also be utilized to ascertain the effect of a particular cost function which is composed of several objective functions with different weighting factors for various mission requirements without any additional effort.

  20. Mask manufacturing of advanced technology designs using multi-beam lithography (part 2)

    NASA Astrophysics Data System (ADS)

    Green, Michael; Ham, Young; Dillon, Brian; Kasprowicz, Bryan; Hur, Ik Boum; Park, Joong Hee; Choi, Yohan; McMurran, Jeff; Kamberian, Henry; Chalom, Daniel; Klikovits, Jan; Jurkovic, Michal; Hudek, Peter

    2016-09-01

    As optical lithography is extended into 10nm and below nodes, advanced designs are becoming a key challenge for mask manufacturers. Techniques including advanced optical proximity correction (OPC) and Inverse Lithography Technology (ILT) result in structures that pose a range of issues across the mask manufacturing process. Among the new challenges are continued shrinking sub-resolution assist features (SRAFs), curvilinear SRAFs, and other complex mask geometries that are counter-intuitive relative to the desired wafer pattern. Considerable capability improvements over current mask making methods are necessary to meet the new requirements particularly regarding minimum feature resolution and pattern fidelity. Advanced processes using the IMS Multi-beam Mask Writer (MBMW) are feasible solutions to these coming challenges. In this paper, Part 2 of our study, we further characterize an MBMW process for 10nm and below logic node mask manufacturing including advanced pattern analysis and write time demonstration.

  1. Transonic Resonance Demonstrated To Be a Source of Internal Noise From Mixer-Ejector Nozzles

    NASA Technical Reports Server (NTRS)

    Zaman, Khairul B.

    2002-01-01

    During noise field studies with mixer-ejector nozzles in NASA's High-Speed Research program, tones were often encountered. The tones would persist in the simulated "cutback" condition (shortly after takeoff). Unfortunately, we did not understand their origin and, thus, could not develop a logical approach for suppressing them. We naturally questioned whether or not some of those tones were due to the transonic resonance. This was studied with a 1/13th scale model of the High-Speed Civil Transport nozzle. The first objective was to determine if indeed tones could be detected in the radiated noise. The next objective was to diagnose if those tones were due to the transonic resonance. Agreement of the frequencies with the correlation equation and the effect of boundary layer tripping were to be used in the diagnosis.

  2. The F-12 series aircraft approach to design for control system reliability

    NASA Technical Reports Server (NTRS)

    Schenk, F. L.; Mcmaster, J. R.

    1976-01-01

    The F-12 series aircraft control system design philosophy is reviewed as it pertains to functional reliability. The basic control system, i.e., cables, mixer, feel system, trim devices, and hydraulic systems are described and discussed. In addition, the implementation of the redundant stability augmentation system in the F-12 aircraft is described. Finally, the functional reliability record that has been achieved is presented.

  3. Design of a 12-GHz multicarrier earth-terminal for satellite-CATV interconnection

    NASA Technical Reports Server (NTRS)

    Newman, B. A.; Singh, J. P.; Rosenbaum, F. J.

    1971-01-01

    The design and development of the front-end for a multi-carrier system that allows multiplex signal transmission from satellite-borne transponders is described. Detailed systems analyses provided down-converter specifications. The 12 GHz carrier down-converter uses waveguide, coaxial, and microstrip transmission line elements in its implementation. Mixing is accomplished in a single-ended coaxial mixer employing a field-replacable cartridge style diode.

  4. Orbit transfer vehicle advanced expander cycle engine point design study. Volume 2: Study results

    NASA Technical Reports Server (NTRS)

    Diem, H. G.

    1980-01-01

    The design characteristics of the baseline engine configuration of the advanced expander cycle engine are described. Several aspects of engine optimization are considered which directly impact the design of the baseline thrust chamber. Four major areas of the power cycle optimization are emphasized: main turbine arrangement; cycle engine source; high pressure pump design; and boost pump drive.

  5. Traffic model for advanced satellite designs and experiments for ISDN services

    NASA Technical Reports Server (NTRS)

    Pepin, Gerard R.; Hager, E. Paul

    1991-01-01

    The data base structure and fields for categorizing and storing Integrated Services Digital Network (ISDN) user characteristics is outlined. This traffic model data base will be used to exercise models of the ISDN Advanced Communication Satellite to determine design parameters and performance for the NASA Satellite Communications Applications Research (SCAR) Program.

  6. Measuring and Advancing Experimental Design Ability in an Introductory Course without Altering Existing Lab Curriculum†

    PubMed Central

    Shanks, Ryan A.; Robertson, Chuck L.; Haygood, Christian S.; Herdliksa, Anna M.; Herdliska, Heather R.; Lloyd, Steven A.

    2017-01-01

    Introductory biology courses provide an important opportunity to prepare students for future courses, yet existing cookbook labs, although important in their own way, fail to provide many of the advantages of semester-long research experiences. Engaging, authentic research experiences aid biology students in meeting many learning goals. Therefore, overlaying a research experience onto the existing lab structure allows faculty to overcome barriers involving curricular change. Here we propose a working model for this overlay design in an introductory biology course and detail a means to conduct this lab with minimal increases in student and faculty workloads. Furthermore, we conducted exploratory factor analysis of the Experimental Design Ability Test (EDAT) and uncovered two latent factors which provide valid means to assess this overlay model’s ability to increase advanced experimental design abilities. In a pre-test/post-test design, we demonstrate significant increases in both basic and advanced experimental design abilities in an experimental and comparison group. We measured significantly higher gains in advanced experimental design understanding in students in the experimental group. We believe this overlay model and EDAT factor analysis contribute a novel means to conduct and assess the effectiveness of authentic research experiences in an introductory course without major changes to the course curriculum and with minimal increases in faculty and student workloads. PMID:28904647

  7. Rapid three-dimensional microfluidic mixer for high viscosity solutions to unravel earlier folding kinetics of G-quadruplex under molecular crowding conditions.

    PubMed

    Liu, Chao; Li, Ying; Li, Yiwei; Chen, Peng; Feng, Xiaojun; Du, Wei; Liu, Bi-Feng

    2016-01-01

    Rapid mixing of highly viscous solutions is a great challenge, which helps to analyze the reaction kinetics in viscous liquid phase, particularly to discover the folding kinetics of macromolecules under molecular crowding conditions mimicking the conditions inside cells. Here, we demonstrated a novel microfluidic mixer based on Dean flows with three-dimensional (3D) microchannel configuration for fast mixing of high-viscosity fluids. The main structure contained three consecutive subunits, each consisting of a "U"-type channel followed by a chamber with different width and height. Thus, the two solutions injected from the two inlets would undergo a mixing in the first "U"-type channel due to the Dean flow effect, and simultaneous vortices expansions in both horizontal and vertical directions in the following chamber. Numerical simulations and experimental characterizations confirmed that the micromixer could achieve a mixing time of 122.4μs for solutions with viscosities about 33.6 times that of pure water. It was the fastest micromixer for high viscosity solutions compared with previous reports. With this highly efficient 3D microfluidic mixer, we further characterized the early folding kinetics of human telomere G-quadruplex under molecular crowding conditions, and unravelled a new folding process within 550μs. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. Design Study of an MBA Lattice for the Advanced Photon Source

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Decker, Glenn

    2014-11-02

    Recent interest in ultra-low-emittance designs for storage-ring-based synchrotron light sources has spurred a focused design effort on a multi-bend achromat (MBA) storage ring replacement for the Advanced Photon Source (APS). The APS is relatively large (1104 m circumference) and, as such, an upgrade to a fourth-generation storage ring holds the potential for a two to three order of magnitude enhancement of X-ray brightness due to the approximate inverse cubic scaling of emittance with the number of dipole bend magnets.

  9. Experimental Design for Evaluating the Safety Benefits of Railroad Advance Warning Signs

    DOT National Transportation Integrated Search

    1979-04-01

    The report presents the findings and conclusions of a study to develop an experimental design and analysis plan for field testing and evaluation of the accident reduction potential of a proposed new railroad grade crossing advance warning sign. Sever...

  10. Innovative grinding wheel design for cost-effective machining of advanced ceramics

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Licht, R.H.; Kuo, P.; Liu, S.

    2000-05-01

    This Final Report covers the Phase II Innovative Grinding Wheel (IGW) program in which Norton Company successfully developed a novel grinding wheel for cost-effective cylindrical grinding of advanced ceramics. In 1995, Norton Company successfully completed the 16-month Phase I technical effort to define requirements, design, develop, and evaluate a next-generation grinding wheel for cost-effective cylindrical grinding of advanced ceramics using small prototype wheels. The Phase II program was initiated to scale-up the new superabrasive wheel specification to larger diameters, 305-mm to 406-mm, required for most production grinding of cylindrical ceramic parts, and to perform in-house and independent validation grinding tests.

  11. In-flight acoustic test results for the SR-2 and SR-3 advanced-design propellers

    NASA Technical Reports Server (NTRS)

    Lasagna, P. L.; Mackall, K. G.; Cohn, R. B.

    1983-01-01

    Several advanced-design propellers, previously tested in the wind tunnel at the Lewis Research Center, have been tested in flight at the Dryden Flight Research Facility. The flight-test propellers were mounted on a pylon on the top of the fuselage of a JetStar airplane. Acoustic data for the advanced-design SR-2 and SR-3 propellers at Mach numbers to 0.8 and helical-tip Mach numbers to 1.15 are presented; maximum blade-passage frequency sound-pressure levels are also compared.

  12. 10 CFR Appendix A to Part 52 - Design Certification Rule for the U.S. Advanced Boiling Water Reactor

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Water Reactor A Appendix A to Part 52 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSES... Rule for the U.S. Advanced Boiling Water Reactor I. Introduction Appendix A constitutes the standard design certification for the U.S. Advanced Boiling Water Reactor (ABWR) design, in accordance with 10 CFR...

  13. 10 CFR Appendix A to Part 52 - Design Certification Rule for the U.S. Advanced Boiling Water Reactor

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Water Reactor A Appendix A to Part 52 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSES... Rule for the U.S. Advanced Boiling Water Reactor I. Introduction Appendix A constitutes the standard design certification for the U.S. Advanced Boiling Water Reactor (ABWR) design, in accordance with 10 CFR...

  14. Advanced Spacesuit Informatics Software Design for Power, Avionics and Software Version 2.0

    NASA Technical Reports Server (NTRS)

    Wright, Theodore W.

    2016-01-01

    A description of the software design for the 2016 edition of the Informatics computer assembly of the NASAs Advanced Extravehicular Mobility Unit (AEMU), also called the Advanced Spacesuit. The Informatics system is an optional part of the spacesuit assembly. It adds a graphical interface for displaying suit status, timelines, procedures, and warning information. It also provides an interface to the suit mounted camera for recording still images, video, and audio field notes.

  15. ITER structural design criteria and their extension to advanced reactor blankets*1

    NASA Astrophysics Data System (ADS)

    Majumdar, S.; Kalinin, G.

    2000-12-01

    Applications of the recent ITER structural design criteria (ISDC) are illustrated by two components. First, the low-temperature-design rules are applied to copper alloys that are particularly prone to irradiation embrittlement at relatively low fluences at certain temperatures. Allowable stresses are derived and the impact of the embrittlement on allowable surface heat flux of a simple first-wall/limiter design is demonstrated. Next, the high-temperature-design rules of ISDC are applied to evaporation of lithium and vapor extraction (EVOLVE), a blanket design concept currently being investigated under the US Advanced Power Extraction (APEX) program. A single tungsten first-wall tube is considered for thermal and stress analyses by finite-element method.

  16. 77 FR 56241 - Notice of Withdrawal of Final Design Approval; Westinghouse Electric Company; Advanced Passive 1000

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-12

    ... NUCLEAR REGULATORY COMMISSION [NRC-2010-0131] Notice of Withdrawal of Final Design Approval... final design approval (FDA) for the Advanced Passive 1000 (AP1000) design upon the completion of rulemaking for the amendment to the AP1000 design and the issuance of the amended AP1000 design certification...

  17. Structural characteristics of a gas-liquid flow in a microchannel with a T-shaped mixer

    NASA Astrophysics Data System (ADS)

    Kuznetsov, V. V.; Kozulin, I. A.

    2017-11-01

    The results of experimental studies of the structural characteristics of a nitrogen-water mixture flow in a horizontal microchannel provided with a T-shaped mixer are presented. The experiments are performed in a channel with a rectangular cross section of 250 × 315 μm under the conditions of a dominating influence of capillary forces. Structural characteristics of the flow are determined using the two-beam laser scanning and high-speed video capture at a distance of 500 calibers from the inlet in a wide range of reduced gas- and liquid-flow rates. A new method for the identification of flow regimes is proposed based on the statistical treatment of the laser-scanning data, and a map of flow patterns is constructed.

  18. Design of Test Support Hardware for Advanced Space Suits

    NASA Technical Reports Server (NTRS)

    Watters, Jeffrey A.; Rhodes, Richard

    2013-01-01

    As a member of the Space Suit Assembly Development Engineering Team, I designed and built test equipment systems to support the development of the next generation of advanced space suits. During space suit testing it is critical to supply the subject with two functions: (1) cooling to remove metabolic heat, and (2) breathing air to pressurize the space suit. The objective of my first project was to design, build, and certify an improved Space Suit Cooling System for manned testing in a 1-G environment. This design had to be portable and supply a minimum cooling rate of 2500 BTU/hr. The Space Suit Cooling System is a robust, portable system that supports very high metabolic rates. It has a highly adjustable cool rate and is equipped with digital instrumentation to monitor the flowrate and critical temperatures. It can supply a variable water temperature down to 34 deg., and it can generate a maximum water flowrate of 2.5 LPM. My next project was to design and build a Breathing Air System that was capable of supply facility air to subjects wearing the Z-2 space suit. The system intakes 150 PSIG breathing air and regulates it to two operating pressures: 4.3 and 8.3 PSIG. It can also provide structural capabilities at 1.5x operating pressure: 6.6 and 13.2 PSIG, respectively. It has instrumentation to monitor flowrate, as well as inlet and outlet pressures. The system has a series of relief valves to fully protect itself in case of regulator failure. Both projects followed a similar design methodology. The first task was to perform research on existing concepts to develop a sufficient background knowledge. Then mathematical models were developed to size components and simulate system performance. Next, mechanical and electrical schematics were generated and presented at Design Reviews. After the systems were approved by the suit team, all the hardware components were specified and procured. The systems were then packaged, fabricated, and thoroughly tested. The next step

  19. Design and analysis of advanced flight planning concepts

    NASA Technical Reports Server (NTRS)

    Sorensen, John A.

    1987-01-01

    The objectives of this continuing effort are to develop and evaluate new algorithms and advanced concepts for flight management and flight planning. This includes the minimization of fuel or direct operating costs, the integration of the airborne flight management and ground-based flight planning processes, and the enhancement of future traffic management systems design. Flight management (FMS) concepts are for on-board profile computation and steering of transport aircraft in the vertical plane between a city pair and along a given horizontal path. Flight planning (FPS) concepts are for the pre-flight ground based computation of the three-dimensional reference trajectory that connects the city pair and specifies the horizontal path, fuel load, and weather profiles for initializing the FMS. As part of these objectives, a new computer program called EFPLAN has been developed and utilized to study advanced flight planning concepts. EFPLAN represents an experimental version of an FPS. It has been developed to generate reference flight plans compatible as input to an FMS and to provide various options for flight planning research. This report describes EFPLAN and the associated research conducted in its development.

  20. Recent advances in automated protein design and its future challenges.

    PubMed

    Setiawan, Dani; Brender, Jeffrey; Zhang, Yang

    2018-04-25

    Protein function is determined by protein structure which is in turn determined by the corresponding protein sequence. If the rules that cause a protein to adopt a particular structure are understood, it should be possible to refine or even redefine the function of a protein by working backwards from the desired structure to the sequence. Automated protein design attempts to calculate the effects of mutations computationally with the goal of more radical or complex transformations than are accessible by experimental techniques. Areas covered: The authors give a brief overview of the recent methodological advances in computer-aided protein design, showing how methodological choices affect final design and how automated protein design can be used to address problems considered beyond traditional protein engineering, including the creation of novel protein scaffolds for drug development. Also, the authors address specifically the future challenges in the development of automated protein design. Expert opinion: Automated protein design holds potential as a protein engineering technique, particularly in cases where screening by combinatorial mutagenesis is problematic. Considering solubility and immunogenicity issues, automated protein design is initially more likely to make an impact as a research tool for exploring basic biology in drug discovery than in the design of protein biologics.