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Sample records for mixer overblow testing

  1. Pulse Jet Mixer Overblow Testing for Assessment of Loadings During Multiple Overblows

    SciTech Connect

    Pfund, David M.; Bontha, Jagannadha R.; Michener, Thomas E.; Nigl, Franz; Yokuda, Satoru T.; Leigh, Richard J.; Golovich, Elizabeth C.; Baumann, Aaron W.; Kurath, Dean E.; Hoza, Mark; Combs, William H.; Fort, James A.; Bredt, Ofelia P.

    2009-07-20

    The U.S. Department of Energy (DOE) Office of River Protection’s Waste Treatment Plant (WTP) is being designed and built to pretreat and then vitrify a large portion of the wastes in Hanford’s 177 underground waste storage tanks. The WTP consists of three primary facilities: pretreatment, low-activity waste (LAW) vitrification, and high-level waste (HLW) vitrification. The pretreatment facility will receive waste feed from the Hanford tank farms and separate it into 1) a high-volume, low-activity liquid stream stripped of most solids and radionuclides and 2) a much smaller volume of HLW slurry containing most of the solids and most of the radioactivity. Many of the vessels in the pretreatment facility will contain pulse jet mixers (PJMs) that will provide some or all of the mixing in the vessels. This technology was selected for use in so-called “black cell” regions of the WTP, where maintenance capability will not be available for the operating life of the WTP. PJM technology was selected for use in these regions because it has no moving mechanical parts that require maintenance. The vessels with the most concentrated slurries will also be mixed with air spargers and/or steady jets in addition to the mixing provided by the PJMs. This report contains the results of single and multiple PJM overblow tests conducted in a large, ~13 ft-diameter × 15-ft-tall tank located in the high bay of the Pacific Northwest National Laboratory (PNNL) 336 Building test facility. These single and multiple PJM overblow tests were conducted using water and a clay simulant to bound the lower and upper rheological properties of the waste streams anticipated to be processed in the WTP. Hydrodynamic pressures were measured at a number of locations in the test vessel using an array of nine pressure sensors and four hydrophones. These measurements were made under normal and limiting vessel operating conditions (i.e., maximum PJM fluid emptying velocity, maximum and minimum vessel

  2. Pulse Jet Mixer Overblow Testing for Assessment of Loadings During Multiple Overblows

    SciTech Connect

    Pfund, David M.; Bontha, Jagannadha R.; Michener, Thomas E.; Nigl, Franz; Yokuda, Satoru T.; Leigh, Richard J.; Golovich, Elizabeth C.; Baumann, Aaron W.; Kurath, Dean E.; Hoza, Mark; Combs, William H.; Fort, James A.; Bredt, Ofelia P.

    2008-03-03

    The U.S. Department of Energy (DOE) Office of River Protection’s Waste Treatment Plant (WTP) is being designed and built to pretreat and then vitrify a large portion of the wastes in Hanford’s 177 underground waste storage tanks. The WTP consists of three primary facilities: pretreatment, low-activity waste (LAW) vitrification, and high-level waste (HLW) vitrification. The pretreatment facility will receive waste feed from the Hanford tank farms and separate it into 1) a high-volume, low-activity liquid stream stripped of most solids and radionuclides and 2) a much smaller volume of HLW slurry containing most of the solids and most of the radioactivity. Many of the vessels in the pretreatment facility will contain pulse jet mixers (PJMs) that will provide some or all of the mixing in the vessels. This technology was selected for use in so-called “black cell” regions of the WTP, where maintenance capability will not be available for the operating life of the WTP. PJM technology was selected for use in these regions because it has no moving mechanical parts that require maintenance. The vessels with the most concentrated slurries will also be mixed with air spargers and/or steady jets in addition to the mixing provided by the PJMs. This report contains the results of single and multiple PJM overblow tests conducted in a large, ~13 ft-diameter × 15-ft-tall tank located in the high bay of the Pacific Northwest National Laboratory (PNNL) 336 Building test facility. These single and multiple PJM overblow tests were conducted using water and a clay simulant to bound the lower and upper rheological properties of the waste streams anticipated to be processed in the WTP. Hydrodynamic pressures were measured at a number of locations in the test vessel using an array of nine pressure sensors and four hydrophones. These measurements were made under normal and limiting vessel operating conditions (i.e., maximum PJM fluid emptying velocity, maximum and minimum vessel

  3. Mixer pump test plan for double shell tank AZ-101

    SciTech Connect

    STAEHR, T.W.

    1999-05-12

    Mixer pump systems have been chosen as the method for retrieval of tank wastes contained in double shell tanks at Hanford. This document describes the plan for testing and demonstrating the ability of two 300 hp mixer pumps to mobilize waste in tank AZ-101. The mixer pumps, equipment and instrumentation to monitor the test were installed by Project W-151.

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

    SciTech Connect

    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.

  5. Acceptance test report: Field test of mixer pump for 241-AN-107 caustic addition project

    SciTech Connect

    Leshikar, G.A.

    1997-05-16

    The field acceptance test of a 75 HP mixer pump (Hazleton serial number N-20801) installed in Tank 241-AN-107 was conducted from October 1995 thru February 1996. The objectives defined in the acceptance test were successfully met, with two exceptions recorded. The acceptance test encompassed field verification of mixer pump turntable rotation set-up and operation, verification that the pump instrumentation functions within established limits, facilitation of baseline data collection from the mixer pump mounted ultrasonic instrumentation, verification of mixer pump water flush system operation and validation of a procedure for its operation, and several brief test runs (bump) of the mixer pump.

  6. 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.

  7. SAFETY ANALYSIS FOR TANK 241-AZ-101 MIXER PUMP PROCESS TEST

    SciTech Connect

    HAMMOND DM; HARRIS JP; MOUETTE P

    1997-06-09

    This document contains the completed safety analysis which establishes the safety envelope for performing the mixer pump process test in Tank 241-AZ-101. This process test is described in TF-210-OTP-001. All equipment necessary for the mixer pump test has been installed by Project W-151. The purpose of this document is to describe and analyze the mixer pump test for Aging Waste Facility (AWF) Tank 241-AZ-101 and to address the 'yes/maybe' responses marked for evaluation questions identified in Unreviewed Safety Question Evaluation (USQE) TF-94-0266. The scope of this document is limited to the performance of the mixer pump test for Tank 241-AZ-101. Unreviewed Safety Question Determination (USQD) TF-96-0018 verified that the installation of two mixer pumps into Tank 241-AZ-101 was within the current Tank Waste Remediation System (TWRS) Authorization Basis. USQDs TF-96-0461, TF-96-0448, and TF-96-0805 verified that the installation of the in-tank video camera, thermocouples, and Ultrasonic Interface Level Analyzer (URSILLA), respectively, were within the current TWRS Authorization Basis. USQD TF-96-1041 verified that the checkout testing of the installed equipment was within the current TWRS Authorization Basis. Installation of the pumps and equipment has been completed. An evaluation of safety considerations associated with operation of the mixer pumps for the mixer pump test is provided in this document. This document augments the existing AWF authorization basis as defined in the Interim Safety Basis (Stahl 1997), and as such, will use the existing Interim Operational Safety Requirements (IOSRs) of Heubach 1996 to adequately control the mixer pump test. The hazard and accident analysis is limited to the scope and impact of the mixer pump test, and therefore does not address hazards already addressed by the current AWF authorization basis. This document does not evaluate removal of the mixer pumps. Safety considerations for removal of the pumps will be addressed by

  8. 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...

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. PJM Controller Testing with Prototypic PJM Nozzle Configuration

    SciTech Connect

    Bontha, Jagannadha R.; Nigl, Franz; Weier, Dennis R.; Leigh, Richard J.; Johnson, Eric D.; Wilcox, Wayne A.; Pfund, David M.; Baumann, Aaron W.; Wang, Yeefoo

    2009-08-21

    The U.S. Department of Energy (DOE) Office of River Protection’s Waste Treatment Plant (WTP) is being designed and built to pre-treat and then vitrify a large portion of the wastes in Hanford’s 177 underground waste storage tanks. The WTP consists of three primary facilities—pretreatment, low-activity waste (LAW) vitrification, and high-level waste (HLW) vitrification. The pretreatment facility will receive waste piped from the Hanford tank farms and separate it into a high-volume, low-activity liquid stream stripped of most solids and radionuclides and a much smaller volume of HLW slurry containing most of the solids and most of the radioactivity. Many of the vessels in the pretreatment facility will contain pulse jet mixers (PJM) that will provide some or all of the mixing in the vessels. Pulse jet mixer technology was selected for use in black cell regions of the WTP, where maintenance cannot be performed once hot testing and operations commence. The PJMs have no moving mechanical parts that require maintenance. The vessels with the most concentrated slurries will also be mixed with air spargers and/or steady jets in addition to the mixing provided by the PJMs. Pulse jet mixers are susceptible to overblows that can generate large hydrodynamic forces, forces that can damage mixing vessels or their internal parts. The probability of an overblow increases if a PJM does not fill completely. The purpose of the testing performed for this report was to determine how reliable and repeatable the primary and safety (or backup) PJM control systems are at detecting drive overblows (DOB) and charge vessel full (CVF) conditions. Testing was performed on the ABB 800xA and Triconex control systems. The controllers operated an array of four PJMs installed in an approximately 13 ft diameter × 15 ft tall tank located in the high bay of the Pacific Northwest National Laboratory (PNNL) 336 Building test facility. The PJMs were fitted with 4 inch diameter discharge nozzles

  14. Static jet noise test results of four 0.35 scale-model QCGAT mixer nozzles

    NASA Technical Reports Server (NTRS)

    Groesbeck, D. E.; Wasserbauer, C. A.

    1984-01-01

    As part of the NASA Quiet Clean General Aviation Turbofan (QCGAT) engine mixer-nozzle exhaust system program, static jet exhaust noise was recorded at microphone angles of 45 to 155 deg relative to the nozzle inlet for a conventional profile coaxial nozzle and three 12-lobed coaxial mixer nozzles. Both flows in all four nozzles are internally mixed before being discharged from a single exhaust nozzle. The conventional profile coaxial nozzle jet noise is compared to the current NASA Lewis coaxial jet noise prediction and after applying an adjustment to the predicted levels based on the ratio of the kinetic energy of the primary and secondary flows, the prediction is within a standard deviation of 0.9 dB of the measured data. The mass average (mixed flow) prediction is also compared to the noise data for the three mixer nozzles with a reasonably good fit after applying another kinetic energy ratio adjustment (standard deviation of 0.7 to 1.5 dB with the measured data). The tests included conditions for the full-scale engine at takeoff (T.O.), cutback (86% T.O.) and approach (67% T.O.).

  15. Evaluation of Flygt Mixers for Application in Savannah River Site Tank 19 Test Results from Phase A: Small-Scale Testing at ITT Flygt

    SciTech Connect

    Powell, M.R.; Farmer, J.R.; Gladki, H.; Hatchell, B.K.; Poirier, M.R.; Rodwell, P.O.

    1999-03-30

    The key findings of the small-scale Flygt mixer tests are provided in this section. Some of these findings may not apply in larger tanks, so these data must be applied carefully when making predictions for large tanks. Flygt mixer testing in larger tanks at PNNL and in a full-scale tank at the SRS will be used to determine the applicability of these findings. The principal objectives of the small-scale Flygt mixer tests were to measure the critical fluid velocities required for sludge mobilization and particle suspension, to evaluate the applicability of the Gladki (1997) method for predicting required mixer thrust, and to provide small-scale test results for comparison with larger-scale tests to observe the effects of scale-up. The tank profile and mixer orientation (i.e., stationary, horizontal mixers) were in the same configuration as the prototype system, however, available resources did not allow geometric, kinematic, and dynamic similitude to be achieved. The results of these tests will be used in conjunction with the results from similar tests using larger tanks and mixers (tank diameters of 1.8 and 5.7 m [Powell et al. 1999]) to evaluate the effects of scaling and to aid in developing a methodology for predicting performance at full scale.

  16. 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.

  17. Evaluation of Flygt Mixers for Application in Savannah River Site Tank 19 Test Results from Phase B: Mid-Scale Testing at PNNL

    SciTech Connect

    Powell, M.R.; Combs, W.H.; Farmer, J.R.; Gladki, H.; Hatchell, B.K.; Johnson, M.A.; Poirier, M.R.; Rodwell, P.O.

    1999-03-30

    Pacific Northwest National Laboratory (PNNL) performed mixer tests using 3-kW (4-hp) Flygt mixers in 1.8- and 5.7-m-diameter tanks at the 336 building facility in Richland, Washington to evaluate candidate scaling relationships for Flygt mixers used for sludge mobilization and particle suspension. These tests constituted the second phase of a three-phase test program involving representatives from ITT Flygt Corporation, the Savannah River Site (SRS), the Oak Ridge National Laboratory (ORNL), and PNNL. The results of the first phase of tests, which were conducted at ITT Flygt's facility in a 0.45-m-diameter tank, are documented in Powell et al. (1999). Although some of the Phase B tests were geometrically similar to selected Phase A tests (0.45-m tank), none of the Phase B tests were geometrically, cinematically, and/or dynamically similar to the planned Tank 19 mixing system. Therefore, the mixing observed during the Phase B tests is not directly indicative of the mixing expected in Tank 19 and some extrapolation of the data is required to make predictions for Tank 19 mixing. Of particular concern is the size of the mixer propellers used for the 5.7-m tank tests. These propellers were more than three times larger than required by geometric scaling of the Tank 19 mixers. The implications of the lack of geometric similarity, as well as other factors that complicate interpretation of the test results, are discussed in Section 5.4.

  18. Physical Properties of Kaolin/Sand Slurry Used During Submersible Mixer Pump Tests at TNX

    SciTech Connect

    HANSEN, ERICHK.

    2004-08-18

    The purpose of this task is to characterize the physical properties of kaolin/sand slurry used to test the performance of a new submersible mixer pump which is undergoing performance testing at the TNT Waste Tank mockup facility. Three different sample locations, the SMP cooling water exit, the SMP fluid flow field, and SMP effective cleaning radius were used for sampling over the seven day test. The physical properties determinations for the kaolin/sand slurry samples include rheology, weight percent total solids (wt TS), density, and particle size distribution were requested, though not all these determinations were performed on all the samples. The physical properties determinations are described in more detail in section 1.0. Measurements were performed at Savannah River National Laboratory in accordance with the Technical Assistance Request (TAR)1. The data, average of two measurements, is shown in the table below. This data clearly shows that the SMP-CWE samples contained more so lids than those at other sample locations for a given sample day. The SMP-FFF and SMP-ECR were similar in solids content. The rheology of the samples is dependent on the wt solids concentration and are all within the bounds stated in the TAR.

  19. Demystifying Mixers

    ERIC Educational Resources Information Center

    Thompson, Douglas Earl

    2012-01-01

    Using music technology is a daily reality for music educators. The task may be as simple as readying a CD player for use in an elementary classroom or as complex as setting up a complete sound system--including microphones, mixer, amplifier, and speakers--for a live music production. One piece of music technology music educators constantly…

  20. 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.

  1. 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

  2. Laser doppler velocimeter system for subsonic jet mixer nozzle testing at the NASA Lewis Aeroacoustic Propulsion Lab

    NASA Technical Reports Server (NTRS)

    Podboy, Gary G.; Bridges, James E.; Saiyed, Naseem H.; Krupar, Martin J.

    1995-01-01

    A laser Doppler velocimeter (LDV) system developed for the Aeroacoustic Propulsion Laboratory (APL) at the NASA Lewis Research Center is described. This system was developed to acquire detailed flow field data which could be used to quantify the effectiveness of internal exhaust gas mixers (IEGM's) and to verify and calibrate computational codes. The LDV was used as an orthogonal, three component system to measure the flow field downstream of the exit of a series of IEGM's and a reference axisymmetric splitter configuration. The LDV system was also used as a one component system to measure the internal axial flow within the nozzle tailpipe downstream of the mixers. These IEGM's were designed for low-bypass ratio turbofan engines. The data were obtained at a simulated low flight speed, high-power operating condition. The optical, seeding, and data acquisition systems of the LDV are described in detail. Sample flow field measurements are provided to illustrate the capabilities of the system at the time of this test, which represented the first use of LDV at the APL. A discussion of planned improvements to the LDV is also included.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  4. MM wave quasioptical SIS mixers

    SciTech Connect

    Hu, Qing; Mears, C.A.; Richards, P.L.; Lloyd, F.L.

    1988-08-01

    We have tested the performance of planar SIS mixers with log-periodic antennas at near millimeter and submillimeter wave frequencies from 90 to 360 GHz. The large ..omega..R/sub N/C product (/approximately/10 at 90 GHz) of our Nb/NbO/sub x//Pb-In-Au junctions requires an integrated inductive tuning element to resonate the junction capacitance at the operating frequencies. We have used two types of integrated tuning element, which were designed with the aid of measurements using a Fourier transform spectrometer. Preliminary results indicate that the tuning elements can give very good mixer performance up to at least 200 GHz. An inductive wire in parallel with a 5-junction array gives a minimum mixer noise temperature of 115K (DSB) at 90 GHz with a FWHM bandwidth of 8 GHz. An open-ended microstrip stub in parallel with a single junction, gives minimum mixer noise temperatures of 150 and 200K (DSB) near 90 and 180 GHz with FWHM bandwidths of 4 and 3 GHz, respectively. The relatively high mixer noise temperatures compared to those of waveguide SIS mixers in a similar frequency range are attributed mainly to the losses in our optical system, which is being improved. 13 refs., 6 figs., 1 tab.

  5. Cold Testing of a Russian Pulsating Mixer Pump at the Oak Ridge National Laboratory, Oak Ridge, Tennessee

    SciTech Connect

    Lewis, BE

    2002-01-29

    Russian pulsating mixer pump (PMP) technology was identified in FY 1996 during technical exchanges between the U.S. Department of Energy (DOE) Tanks Focus Area Retrieval and Closure program, the DOE Environmental Management International Programs, and delegates from Russia as a technology that could be implemented in tank waste retrieval operations in the United States. The PMP is basically a jet mixer powered by a pressure/vacuum supply system. A prototype PMP was provided by the Russian Mining and Chemical Combine and evaluated as a potential retrieval tool in FY 1997 at Pacific Northwest National Laboratory (PNNL). Based on this evaluation, Oak Ridge National Laboratory (ORNL) and DOE staff determined that a modified PMP would meet project needs for bulk mobilization of sludge from one or more of the Gunite and Associated Tanks (GAAT) at ORNL. In FY 1998, PMP technology was selected for deployment in one of the GAAT to mobilize settled solids. Deployment of the PMP was expected to reduce operation and maintenance costs required to utilize more expensive retrieval systems. The following series of cold tests and inspections were conducted on one of the three PMP units provided to verify the acceptability and readiness of the mixing system for operation in the GAATs at ORNL: (1) Inspections and measurements designed to evaluate the integrity of the equipment: Fabrication shop inspections, Equipment inspections, Vibration/oscillation measurements, Hydrostatic pressure tests. (2) Functionality of the system components: Tank riser interface functionality, Decontamination spray ring (DSR) functionality, Valves, actuator, sensors, and control system functionality, Support fixture tests; and Contamination control assessment. (3) Mixing and operational performance of the PMP system: DSR performance, PMP debris tolerance, PMP performance with water only, PMP cleaning radius determination, and PMP performance with sludge surrogates. The results from these tests indicate

  6. 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.

  7. Extended Cold Testing of a Russian Pulsating Mixer Pump at the Oak Ridge National Laboratory, Oak Ridge, Tennessee

    SciTech Connect

    Lewis, BE

    2002-12-23

    The effectiveness of a mixer is dependent on the size of the tank to be mixed, the characteristics of the waste, and the operating conditions. Waste tanks throughout the U.S. Department of Energy Complex require mixing and mobilization systems capable of (1) breaking up and suspending materials that are difficult to mix and pump, without introducing additional liquids into the tank; (2) complementing and augmenting the performance of other remotely operated and/or robotic waste retrieval systems; and (3) operating in tanks with various quantities of waste. The Oak Ridge Russian pulsating mixer pump (PMP) system was designed with the flexibility to permit deployment in a variety of cylindrical tanks. The PMP was installed at the Tanks Technology Cold Test Facility at the Oak Ridge National Laboratory (ORNL) to assess the performance of the system over an extended range of operating conditions, including supply pressures up to 175 psig. Previously conducted cold tests proved the applicability of the PMP for deployment in ORNL gunite tank TH-4. The previous testing and hot demonstrations had been limited to operating at air supply pressures of <100 psig. The extended cold testing of the Russian PMP system showed that the system was capable of mobilizing waste simulants in tanks in excess of 20-ft diam. The waste simulant used in these tests was medium-grain quartz sand. The system was successfully installed, checked out, and operated for 406 pulse discharge cycles. Only minor problems (i.e., a sticking air distributor valve and a few system lockups) were noted. Some improvements to the design of the air distributor valve may be needed to improve reliability. The air supply requirements of the PMP during the discharge cycle necessitated the operation of the system in single pulse discharge cycles to allow time for the air supply reservoir to recharge to the required pressure. During the test program, the system was operated with sand depths of 2, 4, and 4.5 in.; at

  8. Testing of In-Line Slurry Monitors and Pulsair Mixers with Radioactive Slurries

    SciTech Connect

    Hylton, T.D.; Bayne, C.K.

    1999-08-01

    Three in-line slurry monitoring instruments were demonstrated, tested, and evaluated for their capability to determine the transport properties of radioactive slurries. The instruments included the Endress + Hauser Promass 63M Coriolis meter for measuring density, the Lasentec M600P for measuring particle size distribution, and a prototype ultrasonic monitor that was developed by Argonne National Laboratory for measuring suspended solids concentration. In addition, the power consumption of the recirculation pump was monitored to determine whether this parameter could be used as a tool for in-line slurry monitoring. The Promass 63M and the M600P were also evaluated as potential indicators of suspended solids concentration. In order to use the Promass 63M as a suspended solids monitor, the densities of the fluid phase and the dry solid particle phase must be known. In addition, the fluid phase density and the dry solids density must remain constant, as any change will affect the correlation between the slurry density and the suspended solids concentration. For the M600P, the particle size distribution would need to remain relatively constant. These instruments were demonstrated and tested at the Gunite and Associated Tanks Remediation Project at the Oak Ridge National Laboratory. The testing of the instruments was conducted in parallel with the testing of a Pulsair mixing system, which was used to mix the contents of the selected tank. A total of six tests were performed. A submersible pump was positioned at two depths, while the Pulsair system was operated at three mixing rates.

  9. Evolution of Coextruded Structures in Static Mixers

    NASA Astrophysics Data System (ADS)

    Sollogoub, C.; Guinault, A.; Pedros, M.

    2007-04-01

    Coextrusion allows to combine two thermoplastics in different ways, creating structures with different cross-sectional geometries (side-by-side structure or concentric ring structure). We use static mixers after the feedblock, in order to homogenise these initial structures and obtain different blend morphologies. The control of these morphologies is of prime importance in order to predict the final properties of the polymer blends. The aim of this paper is to study the evolution of some initial coextruded structures in different static mixers. Different static mixers, with adjustable number of mixing elements, are tested. The experimental observations are confronted with numerical simulation results.

  10. Terahertz radiation mixer

    DOEpatents

    Wanke, Michael C.; Allen, S. James; Lee, Mark

    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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. Dayem bridge Josephson junctions. [for millimeter wave mixer

    NASA Technical Reports Server (NTRS)

    Barr, D. W.; Mattauch, R. J.

    1977-01-01

    The Josephson junction shows great promise as a millimeter wave mixer element. This paper discusses the physical mixing process from a first-order mathematical approach. Design and fabrication of such structures tailored for use in a 80-120 GHz mixer application is presented. Testing of the structures and a discussion of their interpretation is presented.

  16. 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.

  17. Introduction of electrodehydrators with built-in jet mixers

    SciTech Connect

    Gershuni, S.S.; Baimbetov, A.M.; Idrisova, T.S.; Makhov, A.F.

    1985-09-01

    This paper describes an effective technique of crude oil desalting which is recirculation of water within the electrodehydrator by means of built-in jet mixers. Vertical electrodehydrators with built-in jet mixers have been tested and approved at the Novo-Ufa refinery. Design and operation of the vessel is described. Results from analyses of the oil during the test period are summarized. Retrofitting of electrodehydrators with built-in jet mixers proved increased capacity and the consumption of water and electric power in desalting was cut in half while oil loss in the electric desalting units was reduced substantially.

  18. Design and performance of mass-produced sideband separating SIS mixers for ALMA band 4 receivers

    NASA Astrophysics Data System (ADS)

    Kojima, Takafumi; Kuroiwa, Koichi; Takahashi, Toshikazu; Fujii, Yumi; Uzawa, Yoshinori; Asayama, Shin'ichiro; Noguchi, Takashi

    2015-09-01

    We have designed and mass-produced low-noise sideband separating superconductor-insulator-superconductor (SIS) mixers for the Atacama Large Millimeter/submillimeter Array (ALMA) band 4 over the frequency range of 125-163 GHz. An integrated design was adopted for the band 4 sideband separating (2SB) mixer block because of the advantages it offers in terms of compactness, reduced testing time and lower cost. The mixer chip was designed to be robust for handling errors to avoid performance degradation caused by generation of the higher order mode in the mixer chip slot. Detailed analyses revealed its robustness and ability to ensure mass production of the 2SB mixers. Using the robust mixer design in addition to well-established waveguide technologies, all of the 2SB mixers met ALMA specifications for noise temperature and image rejection ratio.

  19. Chaotic mixer improves microarray hybridization.

    PubMed

    McQuain, Mark K; Seale, Kevin; Peek, Joel; Fisher, Timothy S; Levy, Shawn; Stremler, Mark A; Haselton, Frederick R

    2004-02-15

    Hybridization is an important aspect of microarray experimental design which influences array signal levels and the repeatability of data within an array and across different arrays. Current methods typically require 24h and use target inefficiently. In these studies, we compare hybridization signals obtained in conventional static hybridization, which depends on diffusional target delivery, with signals obtained in a dynamic hybridization chamber, which employs a fluid mixer based on chaotic advection theory to deliver targets across a conventional glass slide array. Microarrays were printed with a pattern of 102 identical probe spots containing a 65-mer oligonucleotide capture probe. Hybridization of a 725-bp fluorescently labeled target was used to measure average target hybridization levels, local signal-to-noise ratios, and array hybridization uniformity. Dynamic hybridization for 1h with 1 or 10ng of target DNA increased hybridization signal intensities approximately threefold over a 24-h static hybridization. Similarly, a 10- or 60-min dynamic hybridization of 10ng of target DNA increased hybridization signal intensities fourfold over a 24h static hybridization. In time course studies, static hybridization reached a maximum within 8 to 12h using either 1 or 10ng of target. In time course studies using the dynamic hybridization chamber, hybridization using 1ng of target increased to a maximum at 4h and that using 10ng of target did not vary over the time points tested. In comparison to static hybridization, dynamic hybridization reduced the signal-to-noise ratios threefold and reduced spot-to-spot variation twofold. Therefore, we conclude that dynamic hybridization based on a chaotic mixer design improves both the speed of hybridization and the maximum level of hybridization while increasing signal-to-noise ratios and reducing spot-to-spot variation.

  20. 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

  1. Design and development of liquid hydrogen mixer unit

    NASA Technical Reports Server (NTRS)

    Morgan, R. W.; Wuertz, K.; Rudich, R. R.

    1973-01-01

    A dc brushless motor driven mixer unit (a vaneaxial fan) was designed and evaluated for use in cryogenic fluids (liquids and gases). It was found to operate well in all fluids in which it was tested. The test fluids were liquid and gaseous helium, hydrogen in the liquid phase gas phase and mixtures of the two phases, and liquid nitrogen. It operated for over 100 hr at cryogenic temperatures without damage to the bearings and at the conclusion of testing the condition of the bearings was such that an operational life of 5000 hr appeared possible. The unit demonstrated that (with the brushless dc motor principle) useful pumping of cryogenic fluids could be accomplished with very small power inputs to the mixer motor. During test, the motor input power varied from approximately 0.5 W to 2.5 W, depending on fluid density. The high power input produced a mixer efficiency of over 49 percent. In an earlier program (see NASA Report CR-72365), a mixer using an ac induction motor demonstrated an efficiency of 17.7 percent under the same conditions, illustrating the advantage of the dc brushless motor driven unit. The mixer also demonstrated its ability to automatically vary speed as a function of the density of the fluid being pumped. This causes the unit to deliver higher volumetric flow rates as fluid density decreases.

  2. An Algorithm to Evaluate Imbalances of Quadrature Mixers

    NASA Astrophysics Data System (ADS)

    Asami, Koji; Arai, Michiaki

    It is essential, as bandwidths of wireless communications get wider, to evaluate the imbalances among quadrature mixer ports, in terms of carrier phase offset, IQ gain imbalance, and IQ skew. Because it is time consuming to separate skew, gain imbalance and carrier phase offset evaluation during test is often performed using a composite value, without separation of the imbalance factors. This paper describes an algorithm for enabling separation among quadrature mixer gain imbalance, carrier phase offset, and skew. Since the test time is reduced by the proposed method, it can be applied during high volume production testing.

  3. Mixer Assembly for a Gas Turbine Engine

    NASA Technical Reports Server (NTRS)

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

  4. Assessment of Differences in Phase 1 and Phase 2 Test Observations for Waste Treatment Plant Pulse Jet Mixer Tests with Non-Cohesive Solids

    SciTech Connect

    Meyer, Perry A.; Baer, Ellen BK; Bamberger, Judith A.; Fort, James A.; Minette, Michael J.

    2010-10-27

    The purpose of this work was to assess the apparent discrepancy in critical suspension velocity (UCS) between M3 Phase 1 (Meyer et al. 2009) and Phase 2 testing conducted by Energy Solutions (ES) at Mid-Columbia Engineering (MCE) and to address the applicability of Phase 1 scale-up laws to Phase 2 test results. Three Phase 2 test sequences were analyzed in detail. Several sources of discrepancy were identified including differences in nominal versus actual velocity, definition of model input parameters, and definition of UCS. A remaining discrepancy was shown to not be solely an artifact of Phase 1 data correlations, but was fundamental to the tests. The non-prototypic aspects of Phase 1 testing were reviewed and assessed. The effects of non-prototypic refill associated with the closed loop operation of the jets, previously known to affect cloud height, can be described in terms of a modified settling velocity. When the modified settling velocity is incorporated into the Phase 1 “new” physical model the adjusted new physical model does a better job of predicting the Phase 2 test results. The adjusted new physical model was bench marked with data taken during three prototypic drive tests. Scale-up behavior of the Phase 1 tests was reviewed. The applicability of the Phase 1 scale-up behavior to Phase 2 prototypic testing was analyzed. The effects of non-prototypic refill caused measured values of UCS to be somewhat reduced at larger scales. Hence the scale-up exponents are believed to be smaller than they would have been had there been prototypic refill. Estimated scale-up exponents for the Phase 2 testing are 0.40 for 8-tube tests and 0.36 for 12-tube tests.

  5. 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.

  6. Infrared hot carrier diode mixer.

    PubMed

    Aukerman, L W; Erler, J W

    1977-11-01

    Detection of a 54.3-GHz beatnote at 10.6 microm has been observed with a hot carrier diode mixer. The diode consists of a "cat whisker" antenna, which forms an ohmic point contact to n-InAs. The mechanism of this room-temperature detector is described as the "thermoelectric effect" of hot carriers.

  7. 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

  8. 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.

  9. 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.

  10. 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).

  11. 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.

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

    SciTech Connect

    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 wear 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.

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

    SciTech Connect

    Reigel, M.; Fowley, M.

    2013-09-23

    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 configuration 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 configured the

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. Wideband 3-mm SIS mixers operated with partial saturation

    NASA Astrophysics Data System (ADS)

    Engargiola, Greg; Plambeck, R. L.

    1998-07-01

    We built fixed-tuned SIS mixers for use between 70 and 115 GHz on the Berkeley-Illinois-Maryland Association (BIMA) array. The mixers are similar to 215 GHz SIS devices designed by R. Blundell et al. Our 1.4 X 1.4 micrometer Nb/Al-Al(subscript 2)O(subscript 3)/Nb junctions have extremely sharp I-V characteristics, with R(subscript sg)/R(subscript n) approximately 40, and (omega) RC approximately 2. Heterodyne tests were made with a temperature-regulated vane mounted in the input waveguide to the mixer block. With vane temperatures of 20 and 35 K, we measure double sideband receiver temperatures T(subscript rcvr) of 17 K from 80 to 115 GHz. Some gain compression occurs for input load temperatures greater than 50 K. Hence, with vane temperatures of 85 and 280 K we measure T(subscript rcvr) approximately 35 K. Similar noise temperatures are measured with 77 and 295 K loads mounted outside the dewar. Because the mixers are partially saturated, we bias the junctions approximately 0.1 mV above or below the gain maximum, where the receiver response is a nearly linear function of the input signal level. This yields T(subscript rcvr) of 35 - 40 K and makes it possible to calibrate the receivers on the telescopes using the standard chopper wheel method. With no LO power applied to the mixer, we observe a small IF signal which is proportional to the square of the input load temperature; we believe this is due to self-mixing of blackbody photons in the junction.

  19. 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.

  20. 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.

  1. 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.

  2. Modeling and Validation of a Propellant Mixer for Controller Design

    NASA Technical Reports Server (NTRS)

    Richter, Hanz; Barbieri, Enrique; Figueroa, Fernando

    2003-01-01

    A mixing chamber used in rocket engine testing at the NASA Stennis Space Center is modelled by a system of two nonlinear ordinary differential equations. 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. Mixer operation during a test requires the regulation of its internal pressure, exit mass flow, and exit temperature. A mathematical model is developed to facilitate subsequent controller designs. The model must be simple enough to lend itself to subsequent feedback controller design, yet its accuracy must be tested against real data. For this reason, the model includes function calls to thermodynamic property data. Some structural properties of the resulting model that pertain to controller design, such as uniqueness of the equilibrium point, feedback linearizability and local stability are shown to hold under conditions having direct physical interpretation. The existence of fixed valve positions that attain a desired operating condition is also shown. Validation of the model against real data is likewise provided.

  3. 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.

  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. 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.

  6. Electrochemical cell apparatus having an integrated reformer-mixer nozzle-mixer diffuser

    DOEpatents

    Shockling, Larry A.

    1991-01-01

    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), passes from the generator chamber (22) to combine with the fresh feed fuel inlet (28) to form a reformable mixture, where a reforming chamber (54) contains an outer portion containing reforming material (56), an inner portion preferably containing a mixer nozzle (50) and a mixer-diffuser (52), and a middle portion (64) for receiving spent fuel, where the mixer nozzle (50) and mixer-diffuser (52) are preferably both within the reforming chamber (54) and substantially exterior to the main portion of the apparatus, where the reformable mixture flows up and then backward before contacting the reforming material (56), and the mixer nozzle (50) can operate below 400.degree. C.

  7. Small Signal Modelling and Control of the Hydrogen Mixer for Facility E1

    NASA Technical Reports Server (NTRS)

    Barbieri, Enrique

    2003-01-01

    We have undertaken the theoretical modelling of an existing liquid hydrogen (LH2) and gas hydrogen (GH2) mixer subsystem of the E1 Ground Test Facility at NASA John C. Stennis Space Center. The E1 test facility carries out comprehensive ground-based testing and certification of various liquid rocket engines and their components. The mixer described in this work is responsible for combining high pressure LH2 and GH2 to produce a hydrogen flow that meets certain thermodynamic properties before it is fed into a test article. The desired properties are maintained by precise control of the mixture of LH2 and GH2 flows. The mixer is modelled as a general multi-flow lumped volume for single constituent fluids using density and internal energy as states. The set of nonlinear differential equations is linearized about an equilibrium point and the resulting two-state, 3-input linear model is analyzed as a possible candidate for control design.

  8. 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.

  9. Quantum limited quasiparticle mixers at 100 GHz

    SciTech Connect

    Mears, C.A; Hu, Qing; Richards, P.L. ); Worsham, A.H.; Prober, D.E. . Dept. of Applied Physics); Raeisaenen, A.V. . Radio Lab.)

    1990-09-01

    We have made accurate measurements of the noise and gain of superconducting-insulating-superconducting (SIS) mixers employing small area (1{mu}m{sup 2}) Ta/Ta{sub 2}O{sub 5}/Pb{sub 0.9}Bi{sub 0.1} tunnel junctions. We have measured an added mixer noise of 0.61 +/{minus} 0.31 quanta at 95.0 GHz, which is within 25 percent of the quantum limit of 0.5 quanta. We have carried out a detailed comparison between theoretical predictions of the quantum theory of mixing and experimentally measured noise and gain. We used the shapes of I-V curves pumped at the upper and lower sideband frequencies to deduce values of the embedding admittances at these frequencies. Using these admittances, the mixer noise and gain predicted by quantum theory are in excellent agreement with experiment. 21 refs., 9 figs.

  10. Heat Balance Study for Submersible Mixer Pump

    SciTech Connect

    Lee, S.Y.

    2003-07-21

    A transient heat balance model was developed to assess the impact of a Submersible Mixer Pump (SMP) on waste temperature during the process of waste mixing and removal for the Type-I SRS tanks. The model results will be mainly used to determine the SMP design impacts on the waste tank temperature during operations and to develop a specification for a new SMP design to replace existing long-shaft mixer pumps used during waste removal. The model will also be used to provide input to the operation planning. This planning will be used as input to pump run duration in order to maintain temperature requirements within the tank during SMP operation.

  11. 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".

  12. 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.

  13. 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.

  14. 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.

  15. Design of a TF34 turbofan mixer for reduction of flap impingement noise

    NASA Technical Reports Server (NTRS)

    Chamay, A.; Edkins, D. P.; Mishler, R. B.; Clapper, W. S.

    1972-01-01

    This portion of the TF-34 turbofan quiet engine studies has been devoted to the selection and design of a special mixer exhaust nozzle system to reduce the maximum 150 m (500 foot) sideline noise generated by the impingement of four engine exhausts on a STOL wing flap system to less than 92 PNdB. The design concept selected consists of a 12-lobe internal mixer and a 12-lobe external mixer mounted in series. The internal mixer reduces maximum exhaust velocities by mixing the fan and turbine streams. The external mixer is designed to reduce the velocity of the exhaust stream striking the wing flap surfaces. A ground test version of this concept has been designed to be installed and tested on an acoustically treated TF-34 engine nacelle, with flexibility to simulate a flight version of this concept which has also been defined. Estimated noise levels are 2 PNdB below the objective at approach and 2 PNdB above the objective at takeoff, with an uncertainty band of +3, -2 PNdB.

  16. 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...

  17. 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...

  18. 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...

  19. 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...

  20. 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...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5330 Breathing gas mixer. (a) Identification. A breathing gas mixer is a device intended for use in conjunction with a respiratory...

  1. 21 CFR 868.5330 - Breathing gas mixer.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Breathing gas mixer. 868.5330 Section 868.5330...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5330 Breathing gas mixer. (a) Identification. A breathing gas mixer is a device intended for use in conjunction with a respiratory...

  2. 21 CFR 868.5330 - Breathing gas mixer.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Breathing gas mixer. 868.5330 Section 868.5330...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5330 Breathing gas mixer. (a) Identification. A breathing gas mixer is a device intended for use in conjunction with a respiratory...

  3. 21 CFR 868.5330 - Breathing gas mixer.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Breathing gas mixer. 868.5330 Section 868.5330...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5330 Breathing gas mixer. (a) Identification. A breathing gas mixer is a device intended for use in conjunction with a respiratory...

  4. 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...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5330 Breathing gas mixer. (a) Identification. A breathing gas mixer is a device intended for use in conjunction with a respiratory...

  5. 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...

  6. NbN/MgO/NbN SIS tunnel junctions for submm wave mixers

    NASA Technical Reports Server (NTRS)

    Stern, J. A.; Hunt, B. D.; Leduc, H. G.; Judas, A.; Mcgrath, W. R.; Cypher, S. R.; Khanna, S. K.

    1989-01-01

    The authors report on the fabrication and testing of all-refractory NbN/MgO/NbN SIS (superconductor-insulator-superconductor) tunnel junctions for use as high-frequency mixers. Progress in the development of techniques for the fabrication of submicron-area tunnel junctions is described. Junction structures which have been investigated include mesa, crossline, and edge geometries. Using reactive sputtering techniques, NbN tunnel junctions with critical currents in excess of 104 A/sq cm have been fabricated with Vm values as high as 65 mV and areas down to 0.1 sq micron. Specific capacitance measurements on NbN/MgO/NbN mesa-type tunnel junctions give values in the range 60-90 fF/sq micron. These SIS tunnel junctions have been integrated with antennas and coupling structures for mixer tests in a waveguide receiver at 207 GHz. Preliminary mixer results are reported.

  7. 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.; Ursic, J.

    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

  8. Internal Mixer Investigation for JT8D Engine Jet Noise Reduction. Volume 1 Results.

    DTIC Science & Technology

    1977-12-01

    were compared with~ re- suilts from other con tigurations. Scale Mo1 del Peru rmanc Tests Tlwo mixer". and the rt ference sytem were tested by thle...PN. curves in Vi,. uro 5.4’. Tite slort mixcr peroduccd about I P"NO1 1110K. 10is re. duction Mhan did the longs mixert &tInjakienwi takeoff and

  9. 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.

  10. Slot antenna SIS mixers for submillimeter wavelengths

    NASA Astrophysics Data System (ADS)

    Zmuidzinas, Jonas; Leduc, Henry G.; Stern, J. A.

    We are developing improved versions of a slot antenna SIS mixer which we have previously described. The initial work demonstrated a double sideband noise temperature of 420 K for a 500 GHz quasi-optical SIS mixer employing a twin-slot antenna on a quartz dielectric substrate. A quartz hyperhemispherical lens is used to focus the incoming radiation onto the twin-slot antenna. The advantages of a twin-slot antenna include a low impedance (35 omega) and a clean, symmetric beam pattern into the dielectric with a 70 percent efficiency. In our original mixer, the radiation was coupled from the two slot antennas onto superconducting microstrip lines which fed the SIS junction. By performing an impedance transformation using tapered lines and by feeding the radiation from the two slots to the junction in parallel, the effective (real) impedance seen by the junction was reduced to just 4 omega. This very low impedance allowed a junction area of 2.3 sq micron to be used at 500 GHz, which was manufactured using optical lithography. However, no attempt was made to tune out the junction capacitance. We estimate that this capacitance reduces the impedance coupling efficiency to eta(sub Z) approx. equals 0.23, for our junction with omega R(sub N) C = 5.3 at 500 GHz. The recent development of techniques using electron-beam lithography to manufacture junctions with very small areas (approx. equals 0.1 sq microns) now allows considerably more flexibility in the design of SIS mixer circuits. We have redesigned the slot-antenna mixer to take advantage of this possibility. In particular, we have included a novel circuit which allows the junction capacitance to be tune out over a broad bandwidth. For instance, mixers designed for 800 GHz using NbN/MgO/NbN junctions with realistic parameters achieve a 3 dB impedance bandwidth of nearly 400 GHz. Furthermore, our circuit uses only short lengths of microstrip and should be less sensitive to RF losses than other designs. The improved

  11. Modeling, Simulation and Control of a Propellant Mixer

    NASA Technical Reports Server (NTRS)

    Richter, Hanz; Barbieri, Enrique; Figueroa, Fernando

    2003-01-01

    This paper addresses some modeling and control issues for a mixing chamber used in rocket engine testing at NASA Stennis Space Center. The mixer must combine high pressure liquid hydrogen (LH2) and gaseous hydrogen (GH2) to produce and output flow that meets certain thermodynamic properties before it is fed into a test article. More precisely, this paper considers that the quantities to be tracked and/or regulated are mixer internal pressure, exit mass flow, and exit temperature. The available control inputs are given by three value positions, namely those of the GH2, LH2 and exit valves. The mixer is modelled by a system of two nonlinear ordinary differential equations having density and internal energy as states. The model must be simple enough to lend itself to subsequent feedback controller design, yet its accuracy must be tested against real data. For this reason, the model includes function calls to thermodynamic property data. Some structural properties of the resulting model that pertain to controller design, such as controllability and uniqueness of the equilibrium point are shown to hold. Validation of the model against real data is also provided. As a first control approach, a small-signal (linear) model is developed based on the nonlinear model and simulated as well. Pulse disturbances are introduced to the valve positions and the quality of the linear model is ascertained by comparing its behavior against the nonlinear model simulations. Valve control strategies that simulate an operator-in-the-loop scenario are then explored demonstrating the need for automatic feedback control. Classical optimal single-output and multi-output Proportional/Integral controllers are designed based on the linear model and applied to the nonlinear model with excellent results to track simultaneous, constant setpoint changes in desired exit flow, exit temperature, and mixer pressure, as well as to reject unmeasurable but bounded additive step perturbations in the valve

  12. 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

  13. 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.

  14. Improving performance of flat-plate photobioreactors by installation of novel internal mixers optimized with computational fluid dynamics.

    PubMed

    Huang, Jianke; Feng, Fei; Wan, Minxi; Ying, Jiangguo; Li, Yuanguang; Qu, Xiaoxing; Pan, Ronghua; Shen, Guomin; Li, Wei

    2015-04-01

    A novel mixer was developed to improve the performance of flat-plate photobioreactors (PBRs). The effects of mixer were theoretically evaluated using computational fluid dynamics (CFD) according to radial velocity of fluid and light/dark cycles within reactors. The structure parameters, including the riser width, top clearance, clearance between the baffles and walls, and number of the chambers were further optimized. The microalgae culture test aiming at validating the simulated results was conducted indoor. The results showed the maximum biomass concentrations in the optimized and archetype reactors were 32.8% (0.89 g L(-1)) and 19.4% (0.80 g L(-1)) higher than that in the control reactor (0.67 g L(-1)). Therefore, the novel mixer can significantly increase the fluid velocity along the light attenuation and light/dark cycles, thus further increased the maximum biomass concentration. The PBRs with novel mixers are greatly applicable for high-efficiency cultivation of microalgae.

  15. 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.

  16. Assessment of the relative performance of a confined impinging jets mixer and a multi-inlet vortex mixer for curcumin nanoparticle production.

    PubMed

    Chow, Shing Fung; Sun, Changquan Calvin; Chow, Albert Hee Lum

    2014-10-01

    The relative performance of two specially designed mixers for nanoparticle production, namely, two-stream confined impinging jets with dilution mixer (CIJ-D-M) and four-stream multi-inlet vortex mixer (MIVM), was evaluated using the model compound, curcumin (CUR), under defined conditions of varying mixing rate and organic solvent. In the absence of turbulent fluctuations, higher mixing rate tended to generate finer particles. Among the three water-miscible organic solvents tested, acetone afforded the smallest particle size and the narrowest particle size distribution. Both mixers were capable of reproducibly fabricating CUR nanoparticles with particle size below 100 nm and high encapsulation efficiency (>99.9%). Specifically, CIJ-D-M yielded nanoparticles with smaller size and polydispersity index while the particles obtained by the MIVM displayed better short-term stability. In addition, CIJ-D-M tended to produce a mixture of irregular nanoaggregates and primary nanoparticles while roughly spherical nanoparticles were generated with the MIVM. The observed particle size and morphological differences could be attributed to the differences in the configuration of the mixing chamber and the related mixing order.

  17. 241-SY-101 mixer pump lifetime expectancy. Final report

    SciTech Connect

    Shaw, C.P.

    1995-12-08

    The purpose of WHC-SD-WM-TI-726, Rev. 0 241-SY-101 Mixer Pump Lifetime Expectancy is to determine a best estimate of the mean lifetime of non-repairable (located in the waste) essential features of the hydrogen mitigation mixer pump presently installed in 101-SY. The estimated mean lifetime is 9.1 years. This report does not demonstrate operation of the entire pump assembly within the Tank Farm ``safety envelope``. It was recognized by the Defense Nuclear Facilities Safety Board (DNFSB) this test pump was not specifically designed for long term service in tank 101-SY. In June 95 the DNFSB visited Hanford and ask the question, ``how long will this test pump last and how will the essential features fail?`` During the 2 day meeting with the DNFSB it was discussed and defined within the meeting just exactly what essential features of the pump must operate. These essential features would allow the pump to operate for the purpose of extending the window for replacement. Operating with only essential features would definitely be outside the operating safety envelope and would require a waiver. There are three essential features: 1. The pump itself (i.e. the impeller and motor) must operate 2. Nozzles and discharges leg must remain unplugged 3. The pump can be re-aimed, new waste targeted, even if manually.

  18. Superconductor-Insulator-Superconductor Mixers for the 2 mm Band (129-174 GHz)

    NASA Astrophysics Data System (ADS)

    Navarrini, Alessandro; Fontana, Anne Laure; Maier, Doris; Serres, Patrice; Billon-Pierron, Dominique

    2014-07-01

    We present the design, construction and performance of backshort-tuned Single Side Band (SSB) and of fixed-tuned Double Side Band (DSB) Superconductor-Insulator-Superconductor (SIS) mixers covering the frequency range of 129-174 GHz (2 mm band). Receivers employing these SSB mixers have been continuously operated for astronomical observations on the six antennas of the IRAM Plateau de Bure Intereferometer (PdBI) since 2007 and on the IRAM 30 m Pico Veleta (PV) radio telescope since 2009. The DSB version of the mixer was employed in a prototype of a four-element focal plane array that was tested on the IRAM 30 m radio telescope. Both SSB and DSB mixers employ the same chip and are based on a wideband single ended probe transition from WR6 full-height waveguide to thin-film microstrip line and on a series array of two Nb/Al-AlOx/Nb junctions. The measured receiver noise for the four-element DSB mixer array pumped by a Gunn oscillator cascaded with a frequency doubler was in the range 25-35 K across the 135-168 GHz LO band. The PdBI and PV receivers equipped with the SSB mixers have measured noise temperatures in the range of 30 K to 60 K and an image sideband rejection below -10 dB over the 129-174 GHz RF band. The measurement results agree well with the predictions obtained through detailed simulations of the SIS receivers based on the standard theory of quantum mixing.

  19. Russian Pulsating Mixer Pump Deployment in the Gunite and Associated Tanks at ORNL

    SciTech Connect

    Hatchell, Brian K.; Lewis, Ben; Johnson, Marshall A.; Randolph, J. G.

    2001-03-01

    In FY 1998, Pulsating Mixer Pump (PMP) technology, consisting of a jet mixer powered by a reciprocating air supply, was selected for deployment in one of the Gunite and Associated Tanks at Oak Ridge National Laboratory (ORNL) to mobilize settled solids. The pulsating mixer pump technology was identified during FY 1996 and FY 1997 technical exchanges between the U.S. Department of Energy (DOE) Tanks Focus Area Retrieval and Closure program, the DOE Environmental Management International Programs, and delegates from Russia as a promising technology that could be implemented in the DOE complex. During FY 1997, the pulsating mixer pump technology, provided by the Russian Integrated Mining Chemical Company, was tested at Pacific Northwest National Laboratory (PNNL) to observe its ability to suspend settled solids. Based on the results of this demonstration, ORNL and DOE staff determined that a modified pulsating mixer pump would meet project needs for remote sludge mobilization of Gunite tank sludge and reduce the cost of operation and maintenance of more expensive mixing systems. The functions and requirements of the system were developed by combining the results and recommendations from the pulsating mixer pump demonstration at PNNL with the requirements identified by staff at ORNL involved with the remediation of the Gunite and Associated Tanks. The PMP is comprised of a pump chamber, check valve, a working gas supply pipe, a discharge manifold, and four jet nozzles. The pump uses two distinct cycles, fill and discharge, to perform its mixing action. During the fill cycle, vacuum is applied to the pump chamber by an eductor, which draws liquid into the pump. When the liquid level inside the chamber reaches a certain level, the chamber is pressurized with compressed air to discharge the liquid through the jet nozzles and back into the tank to mobilize sludge and settled solids.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. CMOS-MEMS Downconversion Mixer-Filters

    DTIC Science & Technology

    2005-12-01

    manufacturability by IC-compatible processes have promised the full-integration of RF-front ends. The pursuit of building a MEMS RF channel- select filter has...two-level reconfigurable radio architecture. Building an array of MEMS mixer-filters and integrating it with the neighboring circuits require a good...gives us the capability to build a resonator model from the atomic elements: beams, plates and gaps. NODAS uses the Verilog-A hardware modeling

  5. 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.

  6. Bubble-based acoustic micropropulsors: active surfaces and mixers.

    PubMed

    Bertin, Nicolas; Spelman, Tamsin A; Combriat, Thomas; Hue, Hervé; Stéphan, Olivier; Lauga, Eric; Marmottant, Philippe

    2017-04-11

    Acoustic micropropulsors present great potential for microfluidic applications. The propulsion is based on encapsulated 20 μm bubbles excited by a contacless ultrasonic transducer. The vibrating bubbles then generate a powerful streaming flow, with speeds 1-100 mm s(-1) in water, through the action of viscous stresses. In this paper we introduce a full toolbox of micropropulsors using a versatile three-dimensional (3D) microfabrication setup. Doublets and triplets of propulsors are introduced, and the flows they generate are predicted by a theoretical hydrodynamic model. We then introduce whole surfaces covered with propulsors, which we term active surfaces. These surfaces are excited by a single ultrasonic wave, can generate collective flows and may be harnessed for mixing purposes. Several patterns of propulsors are tested, and the flows produced by the two most efficient mixers are predicted by a simple theoretical model based on flow singularities. In particular, the vortices generated by the most efficient pattern, an L-shaped mixer, are analysed in detail.

  7. Microfluidic Mixers for Studying Protein Folding

    PubMed Central

    Waldauer, Steven A.; Wu, Ling; Yao, Shuhuai; Bakajin, Olgica; Lapidus, Lisa J.

    2012-01-01

    The process by which a protein folds into its native conformation is highly relevant to biology and human health yet still poorly understood. One reason for this is that folding takes place over a wide range of timescales, from nanoseconds to seconds or longer, depending on the protein1. Conventional stopped-flow mixers have allowed measurement of folding kinetics starting at about 1 ms. We have recently developed a microfluidic mixer that dilutes denaturant ~100-fold in ~8 μs2. Unlike a stopped-flow mixer, this mixer operates in the laminar flow regime in which turbulence does not occur. The absence of turbulence allows precise numeric simulation of all flows within the mixer with excellent agreement to experiment3-4. Laminar flow is achieved for Reynolds numbers Re ≤100. For aqueous solutions, this requires micron scale geometries. We use a hard substrate, such as silicon or fused silica, to make channels 5-10 μm wide and 10 μm deep (See Figure 1). The smallest dimensions, at the entrance to the mixing region, are on the order of 1 μm in size. The chip is sealed with a thin glass or fused silica coverslip for optical access. Typical total linear flow rates are ~1 m/s, yielding Re~10, but the protein consumption is only ~0.5 nL/s or 1.8 μL/hr. Protein concentration depends on the detection method: For tryptophan fluorescence the typical concentration is 100 μM (for 1 Trp/protein) and for FRET the typical concentration is ~100 nM. The folding process is initiated by rapid dilution of denaturant from 6 M to 0.06 M guanidine hydrochloride. The protein in high denaturant flows down a central channel and is met on either side at the mixing region by buffer without denaturant moving ~100 times faster (see Figure 2). This geometry causes rapid constriction of the protein flow into a narrow jet ~100 nm wide. Diffusion of the light denaturant molecules is very rapid, while diffusion of the heavy protein molecules is much slower, diffusing less than 1 μm in 1 ms

  8. Three-Dimensional CFD FLYGT Mixer Model and Results

    SciTech Connect

    Lee, S. Y.

    2002-04-16

    The main objectives of the present work are to examine detailed flow performance of the Tank 19 FLYGT mixer improved by the previous work, to conduct sensitivity analysis for a wide range of possible boundary conditions, and to investigate transient flow behavior and loading of the FLYGT mixer. For the present study, a flow simulation method is developed to calculate the flow around a marine-type propeller configuration of the FLYGT mixer.

  9. A practical guide to the staggered herringbone mixer

    PubMed Central

    Williams, Manda S.; Longmuir, Kenneth J.; Yager, Paul

    2009-01-01

    An analytical model of mixing in the staggered herringbone mixer (SHM) was derived to estimate mixing parameters and provide practical expressions to guide mixer design and operation for a wide range of possible solutes and flow conditions. Mixing in microfluidic systems has historically been characterized by the mixing of a specific solute system or by the redistribution of flow streams; this approach does not give any insight into the ideal operational parameters of the mixer with an arbitrary real system. For Stokes-flow mixers, mixing can be computed from a relationship between solute diffusivity, flow rate, and mixer length. Confocal microscopy and computational fluid dynamics (CFD) modeling were used to directly determine the extent of mixing for several solutes in the staggered herringbone mixer over a range of Reynolds numbers (Re) and Péclet numbers (Pe); the results were used to develop and evaluate an analytical model of its behavior. Mixing was found to be a function of only Pe and downstream position in the mixer. Required mixer length was proportional to Log(Pe); this analytical model matched well with the confocal data and CFD model for Pe < 5×104, at which point the experiments reached the limit of resolution. For particular solutes, required length and mixing time depend upon Re and diffusivity. This analytical model is applicable to other solute systems, and possibly to other embodiments of the mixer, to enable optimal design, operation, and estimation of performance. PMID:18584088

  10. Evaluation Of Saltstone Mixer Paddle Configuration For Improved Wear Resistance

    SciTech Connect

    Reigel, M. M.; Fowley, M. D.; Pickenheim, B. R.

    2012-09-27

    A soft metal with low wear resistance (6000 series aluminum), was used to minimize run time while maximizing wear rate. Two paddle configurations were tested, with the first four paddles after the augers replaced by the wear paddles. The first configuration was all flat paddles, with the first paddle not aligned with the augers and is consistent with present SPF mixer. The second configuration had helical paddles for the first three stages after the augers and a flat paddle at the fourth stage. The first helical paddle was aligned with the auger flight for the second configuration. The all flat paddle configuration wear rate was approximately double the wear rate of the helical paddles for the first two sets of paddles after the augers. For both configurations, there was little or no wear on the third and fourth paddle sets based on mass change, indicating that the fully wetted premix materials are much less abrasive than the un-wetted or partially wetted premix. Additionally, inspection of the wear surface of the paddles at higher magnification showed the flat paddles were worn much more than the helical and is consistent with the wear rates. Aligning the auger discharge flight with the first set of helical paddles was effective in reducing the wear rate as compared to the flat paddle configuration. Changing the paddle configuration from flat to helical resulted in a slight increase in rheological properties. Although, both tests produced grout-like material that is within the processing rage of the SPF, it should be noted that cement is not included in the premix and water was used rather than salt solution, which does affect the rheology of the fresh grout. The higher rheological properties from the helical wear test are most likely due to the reduced number of shearing paddles in the mixer. In addition, there is variation in the rheological data for each wear test. This is most likely due to the way that the dry feeds enter the mixer from the dry feeder. The

  11. Simulating the Resonant Acoustic Mixer

    DTIC Science & Technology

    2013-08-02

    12 3.1 Oxygen-Nitrogen Mixing ………………………………………………………..12 3.2 High Viscosity Mixing …………………………………………………………..15 4.0...up of the Oxygen-Nitrogen mixing test problem…………………………………...12 3 Slices of (a) vertical velocity and (b) vorticity magnitude for the Oxygen...Nitrogen mixing test case at 261.6 ms………………………………………………………………...13 4 Slices of (a) vertical velocity and (b) vorticity magnitude for the Oxygen-Nitrogen

  12. Using ionization response maps for SET characterisation in UHF mixers

    NASA Astrophysics Data System (ADS)

    Savchenkov, D. V.; Kuznetsov, A. G.

    2016-10-01

    SEE sensitivity of integrated circuits is characterized by their SEE cross-section vs. linear energy transfer dependences- σ(LET) which are obtained through ion tests. Often those σ(LET) dependencies have such few data points that it's much trouble to approximate them correctly. In those cases σ(LET) can be complemented with SEE cross-section vs. laser energy σ(J) obtained from laser tests. At the same time, σ(J) rarely follow exactly the shape of σ(LET) due to the metallization non-uniformly over chip area. Nevertheless, σ(J) can be corrected against this non-uniformity by examining the ionization response maps ΔU(x, y). In this work we demonstrate that such corrected σ(J) correlates better with σ(LET) by the example of single event transients (SET) in two types of UHF mixers.

  13. 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.

  14. 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

  15. 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

  16. PULSED MIXER-SETTLER SOLVENT EXTRACTION CONTACTORS

    DOEpatents

    Figg, W.S.

    1958-08-12

    A mixer-settler extractor is described for contacting immiscible liquids having different specific gravities in order to withdraw one or more components from one liquid with the aid of the other liquid. The extractor consists of a hollow column, a rotary drive shafi extending : through the column with a number of impellers spaced thereon, an equal nunnber of separator plate sets each consisting of one fluorothene and one stainless steel plate with peripheral recesses and flow slots mounted on the column, and a pulse generator. This apparatus is particularly useful in solvent extraction processes for recovering plutonium from aqueous acidic solutions of irradiated uranium.

  17. A scalable micro-mixer for biomedical applications

    NASA Astrophysics Data System (ADS)

    Cortelezzi, Luca; Ferrari, Simone; Dubini, Angelo

    2016-11-01

    Our study presents a geometrically scalable active micro-mixer suitable for biomedical/bioengineering applications and potentially assimilable in a Lab-on-Chip. We designed our micro-mixer with the goal of satisfying the following constraints: small dimensions, because the device must be able to process volumes of fluid in the range of 10-6 ÷10-9 liters; high mixing speed, because mixing should be obtained in the shortest possible time; constructive simplicity, to facilitate realizability, assimilability and reusability of the micro-mixer; and geometrical scalability, because the micro-mixer should be assimilable to microfluidic systems of different dimensions. We studied numerically the mixing performance of our micro-mixer both in two- and three-dimensions. We characterize the mixing performance in terms of Reynolds, Strouhal and Péclet numbers in order to establish a practical range of operating conditions for our micro-mixer. Finally, we show that our micro-mixer is geometrically scalable, ie., micro-mixers of different geometrical dimensions having the same nondimensional specifications produce nearly the same mixing performance.

  18. 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

  19. Does a fast mixer really exist?

    PubMed

    Liu, Weijiu

    2005-07-01

    In this paper, we are concerned about the limit behavior of the decay rate of variance of a passive and diffusive scalar in a flow field as the diffusivity of the scalar goes to zero. Motivated by the concept of the fast dynamo in the dynamo theory, we term a flow as fast mixer if the decay rate remains away from zero as the diffusivity goes to zero. We first repeat numerical simulations with flow maps and velocity fields used in the existing literature, including the lattice map, the 1D baker's map, and the sinusoidal shear flow. Our simulations shows that, in all cases, the decay rate tends to zero as the diffusivity goes to zero. For the closed flows in a bounded domain, we then theoretically proved this result under certain plausible conditions on the flows. For the open flows in the whole space, we show that the effective diffusivity matrix tends to zero in the limit without the conditions for the closed flow. In conclusion, although a fast mixer might exist, it could be very difficult to find one.

  20. 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.

  1. A simple confined impingement jets mixer for flash nanoprecipitation.

    PubMed

    Han, Jing; Zhu, Zhengxi; Qian, Haitao; Wohl, Adam R; Beaman, Charles J; Hoye, Thomas R; Macosko, Christopher W

    2012-10-01

    Johnson and Prud'homme (2003. AICHE J 49:2264-2282) introduced the confined impingement jets (CIJ) mixer to prepare nanoparticles loaded with hydrophobic compounds (e.g., drugs, inks, fragrances, or pheromones) via flash nanoprecipitation (FNP). We have modified the original CIJ design to allow hand operation, eliminating the need for a syringe pump, and we added a second antisolvent dilution stage. Impingement mixing requires equal flow momentum from two opposing jets, one containing the drug in organic solvent and the other containing an antisolvent, typically water. The subsequent dilution step in the new design allows rapid quenching with high antisolvent concentration that enhances nanoparticle stability. This new CIJ with dilution (CIJ-D) mixer is a simple, cheap, and efficient device to produce nanoparticles. We have made 55 nm diameter β-carotene nanoparticles using the CIJ-D mixer. They are stable and reproducible in terms of particle size and distribution. We have also compared the performance of our CIJ-D mixer with the vortex mixer, which can operate at unequal flow rates (Liu et al., 2008. Chem Eng Sci 63:2829-2842), to make β-carotene-containing particles over a series of turbulent conditions. On the basis of dynamic light scattering measurements, the new CIJ-D mixer produces stable particles of a size similar to the vortex mixer. Our CIJ-D design requires less volume and provides an easily operated and inexpensive tool to produce nanoparticles via FNP and to evaluate new nanoparticle formulation.

  2. Droplet mixers: Microfluidics, mixing measures and optimization

    NASA Astrophysics Data System (ADS)

    Stone, Zachary; Stone, Howard

    2003-11-01

    Rapid mixing is essential in a variety of microfluidic applications but is often difficult to achieve at low Reynolds numbers. Inspired by a recently developed microdevice that mixes reagents in droplets, which simply flow along a periodic serpentine channel (Song, Tice and Ismagilov, 2003), we investigate a model ``droplet mixer". The model consists of a spherical droplet immersed in a periodic sequence of distinct external flows, which are superpositions of uniform and shear flows. We label the fluid inside the droplet with two colors and visualize mixing with a method we call ``backtrace imaging", which allows us to render cross-sections of the droplet at arbitrary times during the mixing cycle. To analyze our results, we present a simple measure of mixing, which allows us to locate sets of parameters that optimize mixing over a small number of flow cycles. We also consider shear flows in multiple directions and the effect of random variations in the durations of external flows.

  3. 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.

  4. Static mixer retorting of oil shale

    SciTech Connect

    York, E.D.; Knepper, J.C.; Forgac, J.M.

    1988-11-22

    This patent describes a system for retorting oil shale, comprising: a static mixer having an upper free-fall section with a domed roof and a lower elongated deflector section. The deflector section having a greater diameter than the upper section, the static mixer having a vertical axis and having only stationary parts and components consisting of six vertically spaced tiers of triangular-shaped internals having upwardly pointing apexes in the deflector section, alternate tiers of the internals being spaced substantially parallel and at about right angles to adjacent tiers as viewed from the roof, the tiers extending substantially horizontally across the deflector section, the six tiers, as viewed from the roof, consisting of first and second tiers having only three triangular-shaped internals of substantially the same size, and third, fourth, fifth and sixth tiers positioned beneath the first and second tiers and having similarly sized triangular-shaped internals, the internals in the first and second tiers being smaller than the internals in the third through sixth tiers, the third and fourth tiers each having three triangular-shaped internals, the first through fourth tiers each having a center internal with an apex positioned substantially along the vertical axis, the first through fourth tiers each having outer internals with the apexes of the outer internals of the third and fourth tiers spaced laterally inwardly of the outer internals in the first and second tiers, the fifth and sixth tiers each having two intermediate triangular-shaped internals and two downwardly and inwardly sloping outer internals with the apexes of the intermediate internals being spaced outwardly and offset from the apexes of the center internals of the first through fourth tiers, the outer internals in the firth and sixth tiers being spaced outwardly from the outer internals in the third and fourth tiers.

  5. 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.

  6. Millimeter Wave Metal-Insulator-Metal Detector/Mixer Diode.

    DTIC Science & Technology

    1983-12-01

    AO-A138 391 MILLIMETER WAVE METAL-INSULATOR- METAL DETECTOR /MIXER 1/1 DIODE(VI NORTH CAROLIN A AGRICULTURAL A NO TECHNI CA L STATE UNIV GREENSRO. C TV...163-A I V AFWAL-TR-83-1179 MILLIMETER WAVE METAL-INSULATOR- METAL DETECTOR /MIXER DIODE CHUNG YU NORTH CAROLINA A&T STATE UNIVERSITY GREENSBORO, NORTH...TITLE (ad subsorle.I S. TYPE CrjflT&PEO OER MILLIMETER WAVE May, 1981--July, 1983 METAL-INSULATOR- METAL DETECTOR /MIXER G. PERFORMING ORG. REPORT

  7. 2.7 THz Balanced Waveguide HEB Mixer

    NASA Astrophysics Data System (ADS)

    Boussaha, Faouzi; Kawamura, Jonathan; Stern, Jeffery; Jung-Kubiak, Cecile

    2014-09-01

    We report on the development of a waveguide-based balanced superconducting mixer for operation near 2.7 THz. The mixer employs a pair of NbN hot-electron bolometers defined on 6 μm-thick silicon substrate that follows a 90° hybrid coupler. To produce the critical structures of the coupler and waveguide embedding circuit, we have utilized silicon micromachining techniques based on deep reactive ion etching. Operating near 4.2 K bath temperature, we have measured a minimum uncorrected DSB receiver noise temperature of less than 2000 K using Callen-Welton formula and local oscillator sideband noise rejection better than 13 3 dB at 2.74 THz. The concept is suitable for building arrays, readily scalable for higher frequencies up 5 THz, and could accommodate other mixer technologies, such as room-temperature Schottky diode mixers.

  8. Low Power Upconversion Mixer for Medical Remote Sensing

    PubMed Central

    Lioe, De Xing; Shafie, Suhaidi; Tan, Gim Heng

    2014-01-01

    This work presents the design of a low power upconversion mixer adapted in medical remote sensing such as wireless endoscopy application. The proposed upconversion mixer operates in ISM band of 433 MHz. With the carrier power of −5 dBm, the proposed mixer has an output inferred 1 dB compression point of −0.5 dBm with a corresponding output third-order intercept point (OIP3) of 7.1 dBm. The design of the upconversion mixer is realized on CMOS 0.13 μm platform, with a current consumption of 594 μA at supply voltage headroom of 1.2 V. PMID:25133266

  9. 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

  10. 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.

  11. 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.

  12. Sub-Micron Long HTS Ho Electron Mixers

    NASA Technical Reports Server (NTRS)

    Harnack, 0.; Karasik, B. S.; McGrath, W. R.; Kleinsasser, A. W.; Barner, J. B.

    2000-01-01

    The hot-electron bolometer mixer made from a high-T, superconductor (HTS) was introduced recently as an alternative to a Schottky mixer at THz frequencies. The performance of the mixer depends on the total thermal conductance for heat removal from the phonon sub-system due to either length-dependent phonon diffusion or phonon escape to the substrate. We have measured both the length and temperature dependencies of the IF bandwidth of the mixers fabricated from 25-35 mn thick YBCO films on MgO and sapphire substrates. The films were grown by a laser deposition technique and electron-beam lithography was used to define bridge lengths down to 50 nm. Mixer measurements were done using signal frequencies in the range of 1-100 GHz. For 50 nm and 400 nm long devices on MgO, the 3-dB bandwidth was about 100 MHz. At temperatures below 60 K, the hot-electron plateau was clearly seen starting around 2-3 GHz. At temperatures above 70 K, the flux-flow effects begin to dominate and the IF bandwidth increases to 1-8 GHz, while the conversion efficiency drops by several dB. This temperature dependence of the IF bandwidth can account for previously reported unexpectedly high bandwidth of HTS mixers.

  13. 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

  14. Biasable Subharmonic Membrane Mixer for 520 to 600 GHz

    NASA Technical Reports Server (NTRS)

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

    2009-01-01

    The figure shows a biasable subharmonic mixer designed to operate in the frequency range from 520 to 600 GHz. This mixer is a prototype of low-power mixers needed for development of wideband, high-resolution spectrometers for measuring spectra of molecules in the atmospheres of Earth, other planets, and comets in the frequency range of 400 to 700 GHz. Three considerations dictated the main features of the design: It is highly desirable to operate the spectrometers at or slightly below room temperature. This consideration is addressed by choosing Schottky diodes as the frequency-mixing circuit elements because of all mixer diodes, Schottky diodes are the best candidates for affording sufficient sensitivity at or slightly below room-temperature range. The short wavelengths in the intended operating-frequency range translate to stringent requirements for precision of fabrication and assembly of the circuits; these requirements are even more stringent for wide-bandwidth circuits. This consideration is addressed in two ways: (1) As much as possible of the mixer circuitry is fabricated in the form of a monolithic integrated circuit on a GaAs membrane, employing a modified version of a process used previously to fabricate a non-subharmonic mixer for a frequency of 2.5 THz and frequency multipliers for frequencies up to 2 THz. (2) The remainder of the circuitry is precision machined into a waveguide block that holds the GaAs integrated circuit.

  15. Static mixer improves crude-oil measurement

    SciTech Connect

    Graves, H.

    1987-03-09

    Water contamination in crude oil frequently hampers the accuracy of conventional sampling techniques for inline measurement. Installation of a static crude-oil mixer upstream of a sampling point has been shown to improve the accuracy of such measurement. Crude oil is sampled in pipelines to ensure that an agreed quality standard is obtained. Deviations from the standard, if undetected, can cost or save large sums of money. It is, therefore, necessary to achieve accurate and representative sampling. Discussion here is limited to representative sampling of oil flowing in a pipeline. In general, the oil industry is concerned with the measurement of crude-oil quality in two situations: Pipelines in which oil flows continuously with only small variations in flow and composition. Batch transfer operations, as in the unloading of tankers. In this case the following can be expected: 1. Start-up-low flow and high water content. 2. Normal conditions-high flow and medium or low water content. 3. Final phases of unloading and shutdown-decreasing flow and increasing water content. These two situations present different problems. In the case of the pipeline, it is usual for the pipe run prior to sampling to be very long, resulting in stratification of phases. Water will, in general, flow at the base of the pipe, although slugging can occur under certain conditions. In the case of batch transfer, the pipework is often tortuous, but flow rates can be low and at the same time water concentration varies.

  16. Evaluation of Static Mixer Flow Enhancements for Cryogenic Viscous Compressor Prototype for ITER Vacuum System

    SciTech Connect

    Duckworth, Robert C; Baylor, Larry R; Meitner, Steven J; Combs, Stephen Kirk; Ha, Tam T; Morrow, Michael; Biewer, Theodore M; Rasmussen, David A; Hechler, Michael P; Pearce, R.J.H.; Dremel, M.; Boissin, Jean Claude

    2014-01-01

    As part of the U.S. ITER contribution to the vacuum systems for the ITER fusion project, a cryogenic viscous compressor (CVC) is being designed and fabricated to cryopump hydrogenic gases in the torus and neutral beam exhaust streams and to regenerate the collected gases to controlled pressures such that they can be mechanically pumped with controlled flows to the tritium reprocessing facility. One critical element of the CVC design that required additional investigation was the determination of flow rates of the low pressure (50 to 1000 Pa) exhaust stream that would allow for complete pumping of hydrogenic gases while permitting trace levels of helium to pass through the CVC to be pumped by conventional vacuum pumps. A sub-scale prototype test facility was utilized to determine the effectiveness of a static mixer pump tube concept, which consisted of a series of rotated twisted elements brazed into a 2-mm thick, 5-cm diameter stainless steel tube. Cold helium gas flow provided by a dewar and helium transfer line was used to cool the exterior of the static mixer pump tube. Deuterium gas was mixed with helium gas through flow controllers at different concentrations while the composition of the exhaust gas was monitored with a Penning gauge and optical spectrometer to determine the effectiveness of the static mixer. It was found that with tube wall temperatures between 6 K and 9 K, the deuterium gas was completely cryopumped and only helium passed through the tube. These results have been used to design the cooling geometry and the static mixer pump tubes in the full-scale CVC prototype

  17. Evaluation of static mixer flow enhancements for cryogenic viscous compressor prototype for ITER vacuum system

    NASA Astrophysics Data System (ADS)

    Duckworth, Robert C.; Baylor, Larry R.; Meitner, Steven J.; Combs, Stephen K.; Ha, Tam; Morrow, Michael; Biewer, T.; Rasmussen, David A.; Hechler, Michael P.; Pearce, Robert J. H.; Dremel, Mattias; Boissin, J.-C.

    2014-01-01

    As part of the U.S. ITER contribution to the vacuum systems for the ITER fusion project, a cryogenic viscous compressor (CVC) is being designed and fabricated to cryopump hydrogenic gases in the torus and neutral beam exhaust streams and to regenerate the collected gases to controlled pressures such that they can be mechanically pumped with controlled flows to the tritium reprocessing facility. One critical element of the CVC design that required additional investigation was the determination of flow rates of the low pressure (up to 1000 Pa) exhaust stream that would allow for complete pumping of hydrogenic gases while permitting trace levels of helium to pass through the CVC to be pumped by conventional vacuum pumps. A sub-scale prototype test facility was utilized to determine the effectiveness of a static mixer pump tube concept, which consisted of a series of rotated twisted elements brazed into a 2-mm thick, 5-cm diameter stainless steel tube. Cold helium gas flow provided by a dewar and helium transfer line was used to cool the exterior of the static mixer pump tube. Deuterium gas was mixed with helium gas through flow controllers at different concentrations while the composition of the exhaust gas was monitored with a Penning gauge and optical spectrometer to determine the effectiveness of the static mixer. It was found that with tube wall temperatures between 6 K and 9 K, the deuterium gas was completely cryopumped and only helium passed through the tube. These results have been used to design the cooling geometry and the static mixer pump tubes in the full-scale CVC prototype.

  18. Evaluation of static mixer flow enhancements for cryogenic viscous compressor prototype for ITER vacuum system

    SciTech Connect

    Duckworth, Robert C.; Baylor, Larry R.; Meitner, Steven J.; Combs, Stephen K.; Ha, Tam; Morrow, Michael; Biewer, T.; Rasmussen, David A.; Hechler, Michael P.; Pearce, Robert J. H.; Dremel, Mattias; Boissin, J.-C.

    2014-01-29

    As part of the U.S. ITER contribution to the vacuum systems for the ITER fusion project, a cryogenic viscous compressor (CVC) is being designed and fabricated to cryopump hydrogenic gases in the torus and neutral beam exhaust streams and to regenerate the collected gases to controlled pressures such that they can be mechanically pumped with controlled flows to the tritium reprocessing facility. One critical element of the CVC design that required additional investigation was the determination of flow rates of the low pressure (up to 1000 Pa) exhaust stream that would allow for complete pumping of hydrogenic gases while permitting trace levels of helium to pass through the CVC to be pumped by conventional vacuum pumps. A sub-scale prototype test facility was utilized to determine the effectiveness of a static mixer pump tube concept, which consisted of a series of rotated twisted elements brazed into a 2-mm thick, 5-cm diameter stainless steel tube. Cold helium gas flow provided by a dewar and helium transfer line was used to cool the exterior of the static mixer pump tube. Deuterium gas was mixed with helium gas through flow controllers at different concentrations while the composition of the exhaust gas was monitored with a Penning gauge and optical spectrometer to determine the effectiveness of the static mixer. It was found that with tube wall temperatures between 6 K and 9 K, the deuterium gas was completely cryopumped and only helium passed through the tube. These results have been used to design the cooling geometry and the static mixer pump tubes in the full-scale CVC prototype.

  19. A new high-performance sideband-separating mixer for 650GHz

    NASA Astrophysics Data System (ADS)

    Hesper, R.; Khudchenko, A.; Baryshev, A. M.; Barkhof, J.; Mena, F. P.

    2016-07-01

    In the modular sideband-separating mixers that we built over the last years, we observe a clear anti-correlation between the image rejection ratio obtained with a certain block and its noise performance, as well as strong correlations between the image rejection and imbalances in the pumping of the mixer devices. We report on the mechanisms responsible for these effects, and conclude that the reduction of the image rejection is largely explained by the presence of standing waves. We demonstrate the rejection ratio to be very sensitive to those. In principle, all potential round-trip paths should be terminated in matched loads, so no standing waves can develop. In practice, the typical high reflections from the SIS mixers combined with imperfect loads and non-negligible input/output reflections of the other components give many opportunities for standing waves. Since most of the loss of image rejection can be attributed to standing waves, the anti-correlation with the noise temperature can be understood by considering any excess loss in the structure, as the waveguides start acting as distribured loads. This reduces the standing waves, and thereby improves the rejection ratio, at the expense of noise temperature. Based on these experiences, we designed a new waveguide structure, with a basic waveguide size of 400×200 μm and improved loads. Strong emphasis was placed on low input and output reflections of the waveguide components, in some places at the cost of phase or amplitude imbalance. For the latter there is ample margin not to impair the performance, however. Apart from further details of the design, we present the first results of the new mixers, tested in a modified production-level ALMA Band 9 receiver, and show that even in an unfinished state, it simultaneously meets requirements for image rejection and noise temperature.

  20. Design of Novel Mixer and Applicator for Two-Component Surgical Adhesives

    PubMed Central

    Go, Kevin; Kim, Yeong; Lee, Andy H.; Staricha, Kelly; Messersmith, Phillip; Glucksberg, Matthew

    2015-01-01

    Current mixer and applicator devices on the market are not able to properly and efficiently mix two-component surgical adhesives in small volumes necessary to achieve economic viability. Furthermore, in these devices a significant amount of adhesive is wasted during the application process, as material within the dead space of the mixing chamber must be discarded. We have designed and demonstrated a new active mixer and applicator system capable of rapidly and efficiently mixing two components of an adhesive and applying it to the surgical site. Recently, Messersmith et al. have developed a tissue adhesive inspired by the mussel byssus and have shown that it is effective as a surgical sealant, and is especially suited for wet environments such as in fetal surgery. Like some other tissue sealants, this one requires that two components of differing viscosities be thoroughly mixed within a specified and short time period. Through a combination of compression and shear testing, we demonstrated that our device could effectively mix the adhesive developed by Messersmith et al. and improve its shear strength to significantly higher values than what has been reported for vortex mixing. Overall, our mixer and applicator system not only has potential applications in mixing and applying various adhesives in multiple surgical fields but also makes this particular adhesive viable for clinical use. PMID:26421090

  1. Reciprocating flow-based centrifugal microfluidics mixer

    NASA Astrophysics Data System (ADS)

    Noroozi, Zahra; Kido, Horacio; Micic, Miodrag; Pan, Hansheng; Bartolome, Christian; Princevac, Marko; Zoval, Jim; Madou, Marc

    2009-07-01

    Proper mixing of reagents is of paramount importance for an efficient chemical reaction. While on a large scale there are many good solutions for quantitative mixing of reagents, as of today, efficient and inexpensive fluid mixing in the nanoliter and microliter volume range is still a challenge. Complete, i.e., quantitative mixing is of special importance in any small-scale analytical application because the scarcity of analytes and the low volume of the reagents demand efficient utilization of all available reaction components. In this paper we demonstrate the design and fabrication of a novel centrifugal force-based unit for fast mixing of fluids in the nanoliter to microliter volume range. The device consists of a number of chambers (including two loading chambers, one pressure chamber, and one mixing chamber) that are connected through a network of microchannels, and is made by bonding a slab of polydimethylsiloxane (PDMS) to a glass slide. The PDMS slab was cast using a SU-8 master mold fabricated by a two-level photolithography process. This microfluidic mixer exploits centrifugal force and pneumatic pressure to reciprocate the flow of fluid samples in order to minimize the amount of sample and the time of mixing. The process of mixing was monitored by utilizing the planar laser induced fluorescence (PLIF) technique. A time series of high resolution images of the mixing chamber were analyzed for the spatial distribution of light intensities as the two fluids (suspension of red fluorescent particles and water) mixed. Histograms of the fluorescent emissions within the mixing chamber during different stages of the mixing process were created to quantify the level of mixing of the mixing fluids. The results suggest that quantitative mixing was achieved in less than 3 min. This device can be employed as a stand alone mixing unit or may be integrated into a disk-based microfluidic system where, in addition to mixing, several other sample preparation steps may be

  2. A Peristaltic Meso-Scale Mixer

    NASA Astrophysics Data System (ADS)

    Bau, Haim; Yi, Mingqiang; Hu, Howard H.

    2000-11-01

    In recent years, there has been a growing interest in developing minute laboratories on a "chip". Often, in order to facilitate chemical and biological reactions, one needs to mix various reagents and chemicals. Although the characteristic lengths associated with micro-devices are small, typically on the order of 100mm, in the case of large molecules, diffusion alone does not provide a sufficiently rapid means for mixing. Recent experimental[1] and theoretical[2] studies suggested the use of surface waves to induce peristaltic motion and enhance fluid stirring. We considered incompressible, viscous fluid confined in a rectangular cavity. One or two of the cavity walls were made of a thin membrane. Electric conductors were printed on the membrane. By passing appropriately phased alternating electric currents through these conductors in the presence of a magnetic field, relatively large amplitude travelling waves could be transmitted in cavity's walls and induce peristaltic motion. We describe the results of a theoretical study. We extended Selverov and Stone[2] theory to account for the presence of lateral boundaries. The induced velocity profiles were determined analytically for small amplitude waves (e) and numerically for waves of arbitrary amplitude. The effect of the peristaltic motion on the stretching and deformation of material lines were quantified. The work was supported, in part, by DARPA through grant N66001-97-1-8911 to the University of Pennsylvania. [1] Moroney, R. M., White, R., M., Howe, R., T., 1991, Ultrasonically Induced Microtransport, Proceedings IEEE Workshop Micro Electro Mechanical Systems, MEMS 95 Amsterdam, 277-282. [2] Selverov, K., and Stone, H., A., 2000, Peristaltically Driven Flows for Micro Mixers, to appear in Physics of Fluids.

  3. Study on velocity distribution in a pool by submersible mixers

    NASA Astrophysics Data System (ADS)

    Tian, F.; Shi, W. D.; Jiang, H.; Lu, X. N.; Chen, B.

    2012-11-01

    To study the distribution of submersible mixers and agitating effect in the sewage treatment pool, Pro/E software was utilized to build the three-dimensional model. Then, the large-scale computational fluid dynamics software FLUENT6.3 was used. ICEM software was used to build 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. The macro fluid field and each section velocity flow field distribution were analyzed to observe the efficiency of each submersible mixer. The average velocity and mixing area in the sewage pool were studied simultaneously. Results show that: the preferred project B, two submersible mixers speed is 980 r/min, and setting angles are all 30°. Fluid mixing area in the pool has reached more than 95%. Under the action of two mixers, the fluid in the sewage pool form a continuous circulating water flow. The fluid is mixed adequately and average velocity of fluid in the pool is at around 0.241m/s, which agreed with the work requirements. Consequently it can provide a reference basis for practical engineering application of submersible mixers by using this method.

  4. 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.

  5. Modeling viscoelastic flow in a multiflux static mixer

    NASA Astrophysics Data System (ADS)

    Köpplmayr, T.; Miethlinger, J.

    2014-05-01

    We present a numerical and experimental study of the polymer flow in a multiflux static mixer. Various geometrical configurations are compared in terms of layer homogeneity. To evaluate the layer-forming process in different geometries, we applied a general and precise approach based on trajectory calculations for a large set of material points, followed by a statistical analysis. A simulation of viscous flow using the Carreau-Yasuda constitutive equation produced results which deviated from our experimental findings. Therefore, we used the Giesekus constitutive equation, taking into account viscoelastic effects, such as extrudate swell and secondary motions inside the mixer. Parallel plate rheometry was employed to collect dynamic mechanical data in the linear viscoelastic flow regime. Weissenberg numbers were calculated, and the maximum relaxation time in the obtained spectrum was limited to avoid divergence issues. The results of our study provide deeper insights into the layerforming process of viscoelastic melts in a multiflux static mixer.

  6. An X-Band Mixer Engineered for 77 K Operation

    NASA Technical Reports Server (NTRS)

    Romanofsky, Robert R.

    1995-01-01

    An X-band Si-diode singly balanced mixer developed specifically for cryogenic operation is presented. In order to reduce thermal demands on a mechanical cooler, the mixer was designed to operate with a minimum of local oscillator (LO) power. That is, since the LO had to be cooled to reduce phase noise, it was desirable to minimize the LO drive. Novel embedding circuit strategy was responsible for nearly theoretical performance. The signal-matching circuit simultaneously provided a reactive termination to the image, sum, and first, second, and third LO harmonic frequencies. A conversion loss of 3.2 dB at 77 K with an LO drive of +1 dBm was measured. This loss included IF filter, dc block, and hybrid coupler losses. Mixer conversion loss is shown to be consistent with the theoretical performance limit expected from the intrinsic diode. The relationship among junction capacitance, flat-band potential, and conversion loss is examined.

  7. HTS step-edge Josephson junction terahertz harmonic mixer

    NASA Astrophysics Data System (ADS)

    Du, Jia; Weily, Andrew R.; Gao, Xiang; Zhang, Ting; Foley, Cathy P.; Guo, Yingjie Jay

    2017-02-01

    A high-temperature superconducting (HTS) terahertz (THz) frequency down-converter or mixer based on a thin-film ring-slot antenna coupled YBa2Cu3O7-x (YBCO)/MgO step-edge Josephson junction is reported. The frequency down-conversion was achieved using higher order harmonics of an applied lower frequency (19-40 GHz) local oscillator signal in the Josephson junction mixing with a THz signal of over 600 GHz, producing a 1-3 GHz intermediate frequency signal. Up to 31st order of harmonic mixing was obtained and the mixer operated stably at temperatures up to 77 K. The design details of the antenna, HTS Josephson junction mixer, the matching and isolation circuits, and the DC and RF performance evaluation are described in this paper.

  8. Femtomole Mixer for Microsecond Kinetic Studies of Protein Folding

    PubMed Central

    Hertzog, David E.; Michalet, Xavier; Jäger, Marcus; Kong, Xiangxu; Santiago, Juan G.; Weiss, Shimon; Bakajin, Olgica

    2005-01-01

    We have developed a microfluidic mixer for studying protein folding and other reactions with a mixing time of 8 μs and sample consumption of femtomoles. This device enables us to access conformational changes under conditions far from equilibrium and at previously inaccessible time scales. In this paper, we discuss the design and optimization of the mixer using modeling of convective diffusion phenomena and a characterization of the mixer performance using microparticle image velocimetry, dye quenching, and Förster resonance energy-transfer (FRET) measurements of single-stranded DNA. We also demonstrate the feasibility of measuring fast protein folding kinetics using FRET with acyl-CoA binding protein. PMID:15595857

  9. Stable Lobed Mixer With Combustion Demonstrated and Measured

    NASA Technical Reports Server (NTRS)

    1996-01-01

    The NASA Lewis Research Center collaborated with the Massachusetts Institute of Technology (MIT) on an experiment to study the use of lobed mixers to improve the fuel-air mixing process and increase combustion intensity in combustors with minimal pressure loss. This experiment is the first known stable combusting flow studied for this device, and the data show a much faster and much more uniform combustion process than for flat-plate mixers. Several potential benefits may be realized from this study in future combustors, including a reduction in NO_x emissions because of the more uniform temperature distribution. The experiment was done in Lewis' Planar Reacting Shear Layer facility, which was adapted to accept a lobed mixer in addition to the original planar tip. A graduate student at MIT provided the mixer design concept, and Lewis provided the engineering, operations, and research expertise. The experiment used hydrogen-nitrogen mixtures to react with vitiated hot air at 920 K. A flow speed of about 120 m/sec and a speed ratio of 0.5 were used. Flow diagnostics consisted of traversing fine-wire thermocouples and pitot probes for flow mapping. Supplementary fluorescence images were taken with a charged coupled device (CCD) camera to show the location and temporal behavior of the reaction zone. The data showed that the lobed mixer consumed the reactants between 3 to 10 times faster than a corresponding planar shear layer. The figure shows the dramatic difference in the measured temperature distribution with and without the lobed mixer. The increased mixing rate was due to a larger interfacial area as well as to the secondary flow from the streamwise vortices off the tips of the lobes. In addition, the fluorescence images showed that the lobes acted as flame stabilizers.

  10. Quasi-optical HEMT and MESFET self-oscillating mixers

    NASA Astrophysics Data System (ADS)

    Hwang, Vincent D.; Itoh, Tatsuo

    1988-12-01

    Planar quasi-optical receivers that compactly integrate a coupled slot antenna and a HEMT or MESFET balanced self-oscillating mixer on the same substrate for applications in microwave and millimeter-wave receiver arrays are discussed. Both the HEMT and the MESFET circuit are designed and demonstrated at X-band. The HEMT circuit exhibits an isotropic conversion gain of 4.5 dB and a noise figure of 6.5 dB. The isotropic conversion gain of the HEMT circuit is 7.5 dB higher than the mixer diode circuit previously reported.

  11. SIS quasiparticle mixers with bow-tie antennas

    NASA Astrophysics Data System (ADS)

    Li, Xizhi; Richards, P. L.; Lloyd, F. L.

    1988-02-01

    Planar lithographed W-band SIS mixers with bow-tie antennas and several different RF coupling structures have been designed. Single junctions with inductive microstrips and five-junction arrays with parallel wire inductors showed good coupling over bandwiths of about 5 and 25 percent, respectively. Good agreement is obtained between design calculations based on a simple equivalent circuit and measurements of the frequency dependence of the mixer gain. No systematic difference was noted in the performance of Pb-In-Au/Pb-Bi junctions and Nb/Pb-In-Au junctions with similar capacitance and resistance.

  12. 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.

  13. 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

  14. A Study of Microwave and Millimeter-Wave Quasi-Optical Planar Mixers.

    DTIC Science & Technology

    1983-08-31

    antenna and mixer using an simple planar antenna structure called a slot -ring antenna . The analysis ... Analysis . .... ..... ..... .... 49 Mixer Using the Slot -Ring Antenna .. ..... ..... .... 55 CHAPTER$6: SLOT RING MIXER EXPERIMENTS . . . . . . . .65...forward gain or low sidelobe levels . One way to retain a given forward gain while shrinking the anten- na is to reduce the wavelength of operation.

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

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 3 2014-01-01 2014-01-01 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...

  16. 7 CFR 58.228 - Dump hoppers, screens, mixers and conveyors.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 3 2012-01-01 2012-01-01 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...

  17. 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...

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

    SciTech Connect

    Wells, Beric E.; Bamberger, Judith A.; Recknagle, Kurtis P.; Enderlin, Carl W.; Minette, Michael J.; Holton, Langdon K.

    2015-12-07

    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 may 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 solids

  19. 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.

  20. A 640 GHz Planar-Diode Fundamental Mixer/Receiver

    NASA Technical Reports Server (NTRS)

    Siegel, P.; Mehdi, I.; Dengler, R.; Lee, T.; Humphrey, D.; Pease, A.

    1998-01-01

    The design and performance of a 640 GHz solid-state receiver using a fundamental planar-Schottky-diode mixer, InP Gunn diode oscillator, whisker-contacted Schottky-varactor-diode sextupler and folded-Fabry-Perot diplexer are reported.

  1. Commissioning and Operating Instructions of One Pint (US) Mixer

    DTIC Science & Technology

    1993-02-01

    computer keyboard, vi\\ the programmable logic controller , or from manual operation of a potentiometer on the control panel This signal inputs to the...with TV screen showing mixer bay. 13 3.12 Control System Programmable Logic Controller (PLC). Three units are used: (i) Toshiba EX40H PLC, for alarm

  2. Laminar-flow fluid mixer for fast fluorescence kinetics studies.

    PubMed Central

    Pabit, Suzette A; Hagen, Stephen J

    2002-01-01

    The ability to mix aqueous liquids on microsecond time scales, while consuming minimal amounts of sample and maintaining UV-visible optical access to the mixing region, is highly desirable for a range of biophysical studies of fast protein and nucleic acid interactions and folding. We have constructed a laminar coaxial jet mixer that allows the measurement of UV-excited fluorescence from nanoliter and microliter quantities of material, mixed at microsecond rates. The mixer injects a narrow cylindrical stream (radius a < 1 microm) of fluorescent sample into a larger flow of diluting buffer that moves through a capillary (100 microm i.d.) at a speed approximately 20 cm/s, under laminar flow conditions (Re approximately equal to 14). Construction from a fused silica capillary allows the laser excitation (at 266 nm) and detection (at 350 nm) of tryptophan fluorescence at reasonably low working concentrations, without interference from background fluorescence. Using this mixer we have measured sub-millisecond fluorescence quenching kinetics while consuming fluorescent sample at rates no greater than 6 nl/s. Consumption of the diluting buffer is also very modest (approximately 1-3 microl/s) in comparison with other rapid mixer designs. PMID:12414719

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

    SciTech Connect

    Zheleva, I.; Lecheva, A.

    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.

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

    NASA Astrophysics Data System (ADS)

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

    2001-12-01

    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.

  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. 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...

  7. Methodology, data collection, and data analysis for determination of water-mixing patterns induced by aerators and mixers

    USGS Publications Warehouse

    Johnson, Gary P.; Hornewer, N.J.; Robertson, D.M.; Olson, D.T.; Gioja, Josh

    2000-01-01

    The U.S. Geological Survey collected and analyzed data to describe mixing patterns induced by aerators and mixers to aid in the calibration and verification of a three-dimensional hydrodynamic model. During September 1995, three-dimensional water-velocity profiles were collected during the operation of fine-bubble and coarse-bubble aerators in a test tank at the U.S. Army Corps of Engineers Waterways Experiment Station. Three-dimensional water velocity, water-temperature, pH, dissolved oxygen concentration, and specific conductivity profiles were collected during operation of a coarse-bubble aerator in a reservoir in Schaumburg, Illinois, during summer 1996 and summer 1997, during strongly stratified and weakly stratified conditions. The effects of a submersible mixer alone and in combination with coarse-bubble aerators and a surface mixer alone also were investigated during summer 1997. The mixing patterns induced by the operation of aerators, submersible mixers, and surface mixers were described and compared with mixing patterns predicted by model simulations. Bubble-plume characteristics during tests in strongly stratified and weakly stratified conditions in the reservoir were documented and compared with characteristics simulated by different models. Lemckert and Imberger?s model simulates an entrainment rate similar to the rate measured during a test in the reservoir under strongly stratified conditions, whereas Schladow?s one-dimensional model appears to underestimate the total entrainment rate by about 50 percent. Schladow?s model was accurate during weak stratification but underestimated the radius of the plume during strong stratification. For 5 days during daylight hours, water temperature profiles were collected continuously during the operation of four aerators. Water temperatures in the reservoir were significantly affected by the operation of the aeration system. These changes were compared to simulations from a one-dimensional Dynamic Lake Model (DLM

  8. 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.

  9. An unsteady microfluidic T-form mixer perturbed by hydrodynamic pressure

    PubMed Central

    Ma, Yanbao; Sun, Chien-Pin; Fields, Michael; Li, Yang; Haake, David A; Churchill, Bernard M; Ho, Chih-Ming

    2009-01-01

    An unsteady microfluidic T-form mixer driven by pressure disturbances was designed and investigated. The performance of the mixer was examined both through numerical simulation and experimentation. Linear Stokes equations were used for these low Reynolds number flows. Unsteady mixing in a micro-channel of two aqueous solutions differing in concentrations of chemical species was described using a convection-dominated diffusion equation. The task was greatly simplified by employing linear superimposition of a velocity field for solving a scalar species concentration equation. Low-order-based numerical codes were found not to be suitable for simulation of a convection-dominated mixing process due to erroneous computational dissipation. The convection-dominated diffusion problem was addressed by designing a numerical algorithm with high numerical accuracy and computational-cost effectiveness. This numerical scheme was validated by examining a test case prior to being applied to the mixing simulation. Parametric analysis was performed using this newly developed numerical algorithm to determine the best mixing conditions. Numerical simulation identified the best mixing condition to have a Strouhal number (St)of 0.42. For a T-junction mixer (with channel width = 196 μm), about 75% mixing can be finished within a mixing distance of less than 3 mm (i.e. 15 channel width) at St = 0.42 for flow with a Reynolds number less than 0.24. Numerical results were validated experimentally by mixing two aqueous solutions containing yellow and blue dyes. Visualization of the flow field under the microscope revealed a high level of agreement between numerical simulation and experimental results. PMID:19177174

  10. 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

  11. Lobed Mixer Design for Noise Suppression: Plume, Aerodynamic and Acoustic Data. Volume 2

    NASA Technical Reports Server (NTRS)

    Mengle, Vinod G.; Baker, V. David; Dalton, William N.; 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 per 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 ASE'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 and also noise in the reference frame of the nozzle. This volume is divided into three parts: in the first two parts, we collate the plume survey data in graphical form (line, contour and surface plots) and analyze it; in part 3, we tabulate the aerodynamic data for the acoustics tests and the acoustic data in one-third octave band levels.

  12. Effects of Crust Ingestion on Mixer Pump Performance in Tank 241-SY-101: Workshop Results

    SciTech Connect

    Brennen, C.E.; Stewart, C.W.; Meyer, P.A.

    1999-10-20

    In August 1999, a workshop was held at Pacific Northwest National Laboratory to discuss the effects of crust ingestion on mixer pump performance in Hanford Waste Tank 241-SY-101. The main purpose of the workshop was to evaluate the potential for crust ingestion to degrade mixing and/or damage the mixer pump. The need for a previously determined 12-inch separation between the top of the mixer pump inlet and the crust base was evaluated. Participants included a representative from the pump manufacturer, an internationally known expert in centrifugal pump theory, Hanford scientists and engineers, and operational specialists representing relevant fields of expertise. The workshop focused on developing an understanding of the pump design, addressing the physics of entrainment of solids and gases into the pump, and assessing the effects of solids and gases on pump performance. The major conclusions are summarized as follows: (1) Entrainment of a moderate amount of solids or gas from the crust should not damage the pump or reduce its lifetime, though mixing effectiveness will be somewhat reduced. (2) Air binding should not damage the pump. Vibrations due to ingestion of gas, solids, and objects potentially could cause radial loads that might reduce the lifetime of bearings and seals. However, significant damage would require extreme conditions not associated with the small bubbles, fine solids, and chunks of relatively weak material typical of the crust. (3) The inlet duct extension opening, 235 inches from the tank bottom, should be considered the pump inlet, not the small gap at 262 inches. (4) A suction vortex exists at the inlet of all pumps. The characteristics of the inlet suction vortex in the mixer pump are very hard to predict, but its effects likely extend upward several feet. Because of this, the current 12-inch limit should be replaced with criteria based on actual monitored pump performance. The most obvious criterion (in addition to current operational

  13. A Novel Miniaturized Mixer Based on a Wankel Geometry

    NASA Astrophysics Data System (ADS)

    Kumar, Pankaj; Wan, Stephen

    2016-11-01

    Mixing in microfluidic systems is a challenge since the flow regime encountered in these systems is typically very low Reynolds number laminar flow, in which viscous forces dominate inertial forces, which precludes efficient turbulence-based mixing. Mixing based purely on diffusion is also not a practical alternative due to the long times required to achieve a sufficient level of mixing. The present study presents a pump based on Wankel geometry as a mixer for efficient mixing in a microfluidic system. Then, a novel modification to the internal geometry of the Wankel-pump-mixer is analyzed and is shown to enable robust mixing without the introduction of an additional system component and hence without the expense of undesirable dead volume. The Lagrangian Coherent Structures (LCS) calculated from the Finite-Time Lyapunov Exponent (FTLE) field with a mixing measure is used to quantify the mixing.

  14. 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.

  15. 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

  16. 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.

  17. Ionic electroactive polymer actuators as active microfluidic mixers

    SciTech Connect

    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 to be a useful alternative to other similar materials.

  18. Optimization of Integrated Impeller Mixer via Radiotracer Experiments

    PubMed Central

    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, Vdead (%), 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 Vdead (%) 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. PMID:24741344

  19. 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.

  20. Antimonide-based pN Terahertz Mixer Diodes

    DTIC Science & Technology

    2011-06-01

    are under development including the InAs channel high electron mobility transistors , the heterojunction bipolar transistors , the resonant tunneling...used to make high frequency mixer diodes. This article describes several features of the InGaSb/InAlAsSb pN diode that act to minimize the diffusion...for the collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data

  1. 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.

  2. 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.

  3. Low-noise THz MgB2 Josephson mixer

    NASA Astrophysics Data System (ADS)

    Cunnane, Daniel; Kawamura, Jonathan H.; Acharya, Narendra; Wolak, Matthäus A.; Xi, X. X.; Karasik, Boris S.

    2016-09-01

    The potential applications for high frequency operation of the Josephson effect in MgB2 include THz mixers, direct detectors, and digital circuits. Here we report on MgB2 weak links which exhibit the Josephson behavior up to almost 2 THz and using them for low-noise heterodyne detection of THz radiation. The devices are made from epitaxial film grown in the c-axis direction by the hybrid physical-chemical vapor deposition method. The current in the junctions travels parallel to the surface of the film, thus making possible a large contribution of the quasi-two-dimensional σ-gap in transport across the weak link. These devices are connected to a planar spiral antenna with a dielectric substrate lens to facilitate coupling to free-space radiation for use as a detector. The IcRn product of the junction is 5.25 mV, giving confirmation of a large gap parameter. The sensitivity of the mixer was measured from 0.6 THz to 1.9 THz. At a bath temperature of over 20 K, a mixer noise temperature less than 2000 K (DSB) was measured near 0.6 THz.

  4. A microfluidic mixer with self-excited 'turbulent' fluid motion for wide viscosity ratio applications.

    PubMed

    Xia, H M; Wang, Z P; Koh, Y X; May, K T

    2010-07-07

    In micromixer studies, compared with the design, modeling and characterization, the influence of the fluid properties on mixing has been less discussed. This topic is of practical significance as the properties of diverse biological and chemical liquids to be mixed have large variations. Here, we report a microfluidic mixer for mixing fluids with widely different viscosities. It contains an interconnected multi-channel network through which the bulk fluid volumes are divided into smaller ones and chaotically reorganized. Then, the multiple fluid streams are driven into an expansion chamber which triggers viscous flow instabilities. Experiments with the co-flow of glycerol and aqueous solutions show an automatic transition of the flow from a steady state to a 'turbulent' state, significantly enhancing the mixing. This observation is rather interesting considering that it occurs in a passive flow and the average Reynolds number involved is small. Further testing indicates that this mixer works well at viscosity ratio (chi) up to the order of 10(4).

  5. A high linearity dual-band mixer for IMT-A and UWB systems

    NASA Astrophysics Data System (ADS)

    Xusheng, Tang; Xiaoyu, Wang; Jiang, Yang; Xin, Tang; Fengyi, Huang

    2014-11-01

    The design and analysis of a reconfigurable dual-band down-conversion mixer for IMT-advanced (3.4-3.6 GHz) and UWB (4.2-4.8 GHz) applications are presented. Based on a folded double-balanced Gilbert cell, which is well known for its low voltage, simplicity and well balanced performance, the mixer adopts a capacitive cross-coupling technique for input matching and performance improvement. Switched capacitors and resistors are added to shift the working bands. Fabricated in a TSMC 0.13 μm process, the test results show flat conversion gains from 9.6 to 10.3 dB on the IMT-A band and from 9.7 to 10.4 dB on the UWB band, with a noise figure of about 15 dB on both bands. The input third-order intercept points (IIP3) are about 7.3 dBm on both of the frequency bands. The whole chip consumes 11 mW under 1.2 V supply and the total area of the layout is 0.76 × 0.65 mm2.

  6. Foaming/antifoaming in WTP Tanks Equipped with Pulse Jet Mixer and Air Spargers

    SciTech Connect

    HASSAN, NEGUIB

    2004-06-29

    The River Protection Project-Waste Treatment Plant (RPP-WTP) requested Savannah River National Laboratory (SRNL) to conduct small-scale foaming and antifoam testing using actual Hanford waste and simulants subjected to air sparging. The foaminess of Hanford tank waste solutions was previously demonstrated in SRNL during WTP evaporator foaming and ultrafiltration studies and commercial antifoam DOW Q2-3183A was recommended to mitigate the foam in the evaporators. Currently, WTP is planning to use air spargers in the HLW Lag Storage Vessels, HLW Concentrate Receipt Vessel, and the Ultrafiltration Vessels to assist the performance of the Jet Pulse Mixers (JPM). Sparging of air into WTP tanks will induce a foam layer within the process vessels. The air dispersion in the waste slurries and generated foams could present problems during plant operation. Foam in the tanks could also adversely impact hydrogen removal and mitigation. Antifoam (DOW Q2-3183A) will be used to control foaming in Hanford sparged waste processing tanks. These tanks will be mixed by a combination of pulse-jet mixers and air spargers. The percent allowable foaminess or freeboard in WTP tanks are shown in tables.

  7. Experimental Evaluation of Dual-Opposed Jet Mixer Pump Performance for Slurry Mixing

    SciTech Connect

    Bamberger, Judith A.; Enderlin, Carl W.

    2016-07-10

    Million-gallon double-shell tanks at Hanford are used to store transuranic, high-level, and low-level radioactive wastes. These wastes consist of a large volume of salt-laden solution covering a smaller volume of settled sludge primarily containing metal hydroxides. These wastes will be retrieved and processed into immobile waste forms suitable for permanent disposal. Retrieval is an important step in implementing these disposal scenarios. The retrieval concept evaluated is to use submerged dual-nozzle jet mixer pumps with horizontally oriented nozzles located near the tank floor that produce horizontal jets of fluid to mobilize the settled solids. The mixer pumps are oscillated through 180 about a vertical axis so the high velocity fluid jets sweep across the floor of the tank. After the solids are mobilized, the pumps will continue to operate at a reduced flow rate producing lower velocity jets sufficient to maintain the particles in a uniform suspension (concentration uniformity). Several types of waste and tank configurations exist at Hanford. The jet mixer pump systems and operating conditions required to mobilize sludge and maintain slurry uniformity will be a function of the waste type and tank configuration. The focus of this work was to conduct a 1/12-scale experiment to develop an analytical model to relate slurry uniformity to tank and mixer pump configurations, operating conditions, and sludge properties. This experimental study evaluated concentration uniformity in a 1/12-scale experiment varying the Reynolds number (Re), Froude number (Fr), and gravitational settling parameter (Gs) space. Simulant physical properties were chosen to obtain the required Re and Gs where Re and Gs were varied by adjusting the kinematic viscosity and mean particle diameter, respectively. Test conditions were achieved by scaling the jet nozzle exit velocity in a 75-in. diameter tank using a mock-up of a centrally located dual-opposed jet mixer pump located just above the

  8. 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.

  9. 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.

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

    SciTech Connect

    Cato, Jr., Joseph E.; Shearer, Paul M.; Rodwell, Philip O.

    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.

  11. Self-Anchoring Mast for Deploying a High-Speed Submersible Mixer in a Tank

    SciTech Connect

    Cato, Joseph E. Jr.; Shearer, Paul M.; Rodwell, Philip 0.

    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.

  12. An integrated membrane sub-harmonic Schottky diode mixers at 340GHz

    NASA Astrophysics Data System (ADS)

    Wang, Junlong; Yang, Dabao; Xing, Dong; Liang, Shixiong; Zhang, Lisen; Zhao, Xiangyang; Feng, Zhihong

    2015-11-01

    This paper presents a sub-harmonic mixer operating over the spectral band 332-348 GHz. The mixers employ integrated GaAs membrane Schottky diode technology. The simulated results show that the conversion loss of the mixer is below dB in the band from 333 GHz to 347 GHz with a local oscillator power requirement of 5mW.The minimum is 8.2dB at 344GHz.

  13. 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.

  14. 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.

  15. Scale model performance test investigation of mixed flow exhaust systems for an energy efficient engine /E3/ propulsion system

    NASA Technical Reports Server (NTRS)

    Kuchar, A. P.; Chamberlin, R.

    1983-01-01

    As part of the NASA Energy Efficient Engine program, scale-model performance tests of a mixed flow exhaust system were conducted. The tests were used to evaluate the performance of exhaust system mixers for high-bypass, mixed-flow turbofan engines. The tests indicated that: (1) mixer penetration has the most significant affect on both mixing effectiveness and mixer pressure loss; (2) mixing/tailpipe length improves mixing effectiveness; (3) gap reduction between the mixer and centerbody increases high mixing effectiveness; (4) mixer cross-sectional shape influences mixing effectiveness; (5) lobe number affects mixing degree; and (6) mixer aerodynamic pressure losses are a function of secondary flows inherent to the lobed mixer concept.

  16. DEVELOPMENT AND DEMONSTRATION OF POLYMER MICROENCAPSULATION OF MIXED WASTE USING KINETIC MIXER PROCESSING

    SciTech Connect

    LAGERAAEN,P.R.; KALB,P.D.; MILIAN,L.W.; ADAMS,J.W.

    1997-11-01

    Thermokinetic mixing was investigated as an alternative processing method for polyethylene microencapsulation, a technology well demonstrated for treatment of hazardous, low-level radioactive and low-level mixed wastes. Polyethylene encapsulation by extrusion has been previously shown to be applicable to a wide range of waste types but often pretreatment of the wastes is necessary due to process limitations regarding the maximum waste moisture content and particle size distribution. Development testing was conducted with kinetic mixing in order to demonstrate technology viability and show improved process applicability in these areas. Testing to establish process capabilities and relevant operating parameters was performed with waste surrogates including an aqueous evaporator concentrate and soil. Using a pilot-scale kinetic mixer which was installed and modified for this program, the maximum waste moisture content and particle size was determined. Following process development with surrogate wastes, the technology was successfully demonstrated at BNL using actual mixed waste.

  17. 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.

  18. Submillimeter-Wave Receiver Containing An SIS Mixer

    NASA Technical Reports Server (NTRS)

    Febvre, Pascal; Mcgrath, William R.; Batelaan, Paul D.; Leduc, Henry G.; Bumble, Bruce; Frerking, Margaret A.; Hernichel, Juergen

    1996-01-01

    Submillimeter-wave heterodyne receiver designed to operate at input frequencies in range of 480 to 650 GHz. Intended for use in radio astronomy at frequency of 547 or 626 GHz. Heart of receiver is waveguide mixer that includes adjustable backshort and electric-field-plane tuner. Mixing element high-current-density superconductor/insulator/superconductor (SIS) tunnel junction integrated with superconductive microstrip radio-frequency circuit that tunes out capacitance of junction; matching complex impedance of junction to available tuning range of waveguide mount.

  19. On the feasibility of constructing an imaging array of slot-antennas integrated with SIS mixers. [radio astronomy

    NASA Technical Reports Server (NTRS)

    Winkler, D.; Mcgrath, W. R.; Nilsson, B.; Claeson, T.; Johansson, J.; Kollberg, E.; Yngvesson, K. S.; Rudner, S.

    1986-01-01

    A prototype 700 GHz subharmonically pumped superconductor-insulator-superconductor (SIS) mixer integrated with a tapered slot antenna on a silicon substrate is described. Imaging using integrated SIS-mixer-antenna chips is discussed.

  20. 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.

  1. 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.

  2. 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

  3. A 100 GHz Josephson mixer using resistively-shunted Nb tunnel junctions

    NASA Technical Reports Server (NTRS)

    Schoelkopf, R. J.; Phillips, T. G.; Zmuidzinas, J.

    1993-01-01

    The authors describe preliminary mixer results using resistively shunted Nb/AlO(x)/Nb tunnel junctions in a 100-GHz waveguide mixer mount. The mixer utilizes robust, lithographically defined devices which have nonhysteretic I-V curves. A receiver temperature of 390 K (DSB) has been obtained with a conversion loss of -6.5 dB. The receiver's behavior agrees qualitatively with the behavior predicted by the resistively shunted junction model. Substantial improvements in performance are expected with the use of better-optimized shunted junctions, and numerical simulations suggest that, if devices with higher ICRN (critical current-normal state resistance) products can be obtained, Josephson effect mixers could be competitive with SIS mixers at high frequencies.

  4. Nonequilibrium single molecule protein folding in a coaxial mixer.

    PubMed

    Hamadani, Kambiz M; Weiss, Shimon

    2008-07-01

    We have developed a continuous-flow mixing device suitable for monitoring bioconformational reactions at the single-molecule level with a response time of approximately 10 ms under single-molecule flow conditions. Its coaxial geometry allows three-dimensional hydrodynamic focusing of sample fluids to diffraction-limited dimensions where diffusional mixing is rapid and efficient. The capillary-based design enables rapid in-lab construction of mixers without the need for expensive lithography-based microfabrication facilities. In-line filtering of sample fluids using granulated silica particles virtually eliminates clogging and extends the lifetime of each device to many months. In this article, to determine both the distance-to-time transfer function and the instrument response function of the device we characterize its fluid flow and mixing properties using both fluorescence cross-correlation spectroscopy velocimetry and finite element fluid dynamics simulations. We then apply the mixer to single molecule FRET protein folding studies of Chymotrypsin Inhibitor protein 2. By transiently populating the unfolded state of Chymotrypsin Inhibitor Protein 2 (CI2) under nonequilibrium in vitro refolding conditions, we spatially and temporally resolve the denaturant-dependent nonspecific collapse of the unfolded state from the barrier-limited folding transition of CI2. Our results are consistent with previous CI2 mixing results that found evidence for a heterogeneous unfolded state consisting of cis- and trans-proline conformers.

  5. 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...

  6. 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...

  7. 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...

  8. 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...

  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. Numerical analysis of a rapid magnetic microfluidic mixer.

    PubMed

    Wen, Chih-Yung; Liang, Kuok-Pong; Chen, Hua; Fu, Lung-Ming

    2011-11-01

    This paper presents a detailed numerical investigation of the novel active microfluidic mixer proposed by Wen et al. (Electrophoresis 2009, 30, 4179-4186). This mixer uses an electromagnet driven by DC or AC power to induce transient interactive flows between a water-based ferrofluid and DI water. Experimental results clearly demonstrate the mixing mechanism. In the presence of the electromagnet's magnetic field, the magnetic nanoparticles create a body force vector that acts on the mixed fluid. Numerical simulations show that this magnetic body force causes the ferrofluid to expand significantly and uniformly toward miscible water. The magnetic force also produces many extremely fine finger structures along the direction of local magnetic field lines at the interface in both upstream and downstream regions of the microchannel when the external steady magnetic strength (DC power actuation) exceeds 30  Oe (critical magnetic Peclet number Pe(m),cr = 2870). This study is the first to analyze these pronounced finger patterns numerically, and the results are in good agreement with the experimental visualization of Wen et al. (Electrophoresis 2009, 30, 4179-4186). The large interfacial area that accompanies these fine finger structures and the dominant diffusion effects occurring around the circumferential regions of fingers significantly enhance the mixing performance. The mixing ratio can be as high as 95% within 2.0  s. at a distance of 3.0  mm from the mixing channel inlet when the applied peak magnetic field supplied by the DC power source exceeds 60  Oe. This study also presents a sample implementation of AC power actuation in a numerical simulation, an experimental benchmark, and a simulation of DC power actuation with the same peak magnetic strength. The simulated flow structures of the AC power actuation agree well with the experimental visualization, and are similar to those produced by DC power. The AC and DC power actuated flow fields exhibited no

  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. Structural and functional imaging of 3D microfluidic mixers using optical coherence tomography.

    PubMed

    Xi, Chuanwu; Marks, Daniel L; Parikh, Devang S; Raskin, Lutgarde; Boppart, Stephen A

    2004-05-18

    To achieve high mixing efficiency in microfluidic devices, complex designs are often required. Microfluidic devices have been evaluated with light and confocal microscopy, but fluid-flow characteristics at different depths are difficult to separate from the en face images produced. By using optical coherence tomography (OCT), an imaging modality capable of imaging 3D microstructures at micrometer-scale resolutions over millimeter-size scales, we obtained 3D dynamic functional and structural data for three representative microfluidic mixers: a Y channel mixer, a 3D serpentine mixer, and a vortex mixer. In the serpentine mixer, OCT image analysis revealed that the mixing efficiency was linearly dependent on the Reynolds number, whereas it appeared to have exponential dependence when imaged with light microscopy. The visual overlap of fluid flows in light-microscopy images leads to an overestimation of the mixing efficiency, an effect that was eliminated with OCT imaging. Doppler OCT measurements determined velocity profiles at various points in the serpentine mixer. Mixing patterns in the vortex mixer were compared with light-microscopy and OCT image analysis. These results demonstrate that OCT can significantly improve the characterization of 3D microfluidic device structure and function.

  13. Sandwich-format 3D printed microfluidic mixers: a flexible platform for multi-probe analysis

    PubMed Central

    Kise, Drew P; Reddish, Michael J; Dyer, R Brian

    2015-01-01

    We report on a microfluidic mixer fabrication platform that increases the versatility and flexibility of mixers for biomolecular applications. A sandwich-format design allows the application of multiple spectroscopic probes to the same mixer. A polymer spacer is ‘sandwiched’ between two transparent windows, creating a closed microfluidic system. The channels of the mixer are defined by regions in the polymer spacer that lack material and therefore the polymer need not be transparent in the spectral region of interest. Suitable window materials such as CaF2 make the device accessible to a wide range of optical probe wavelengths, from the deep UV to the mid-IR. In this study, we use a commercially available 3D printer to print the polymer spacers to apply three different channel designs into the passive, continuous-flow mixer, and integrated them with three different spectroscopic probes. All three spectroscopic probes are applicable to each mixer without further changes. The sandwich-format mixer coupled with cost-effective 3D printed fabrication techniques could increase the applicability and accessibility of microfluidic mixing to intricate kinetic schemes and monitoring chemical synthesis in cases where only one probe technique proves insufficient. PMID:26855478

  14. Design sensitivity and mixing uniformity of a micro-fluidic mixer

    NASA Astrophysics Data System (ADS)

    Ivorra, Benjamin; López Redondo, Juana; Ramos, Angel M.; Santiago, Juan G.

    2016-01-01

    We consider a particular hydrodynamic focusing microfluidic mixer used to initiate the folding process of individual proteins, which has been designed in a previous work and exhibited a mixing time of 0.1 μs. The aim of the current paper is twofold. First, we explore the sensitivity of mixing time to key geometric and flow parameters. In particular, we study the angle between inlets, the shape of the channel intersections, channel widths, mixer depth, mixer symmetry, inlet velocities, working fluid physical properties, and denaturant concentration thresholds. Second, we analyze the uniformity of mixing times as a function of inlet flow streamlines. We find the shape of the intersection, channel width, inlet velocity ratio, and asymmetries have strong effects on mixing time; while inlet angles, mixer depth, fluid properties, and concentration thresholds have weaker effects. Also, the uniformity of the mixing time is preserved for most of the inlet flow and distances of down to within about 0.4 μm of the mixer wall. We offer these analyses of sensitivities to imperfections in mixer geometry and flow conditions as a guide to experimental efforts which aim to fabricate and use these types of mixers. Our study also highlights key issues and provides a guide to the optimization and practical design of other microfluidic devices dependent on both geometry and flow conditions.

  15. Design Of Dual Polarisation Sideband Separation Mixer For ALMA Band 5

    NASA Astrophysics Data System (ADS)

    Billade, Bhushan

    2009-09-01

    This licentiate is focused on the design and development of Superconductor-Insulator-Superconductor (SIS) junction mixer for ALMA Band 5, one of the ten frequency bands of the Atacama Large Millimeter Array (ALMA) project. ALMA Band 5 is a dual polarisation sideband separation heterodyne receiver covering radio frequencies (RF) from 163 GHz to 211 GHz, with 4-8 GHz intermediate frequency (IF). Amongst the other ALMA bands, Band 5 is the lowest frequency band, which uses all-cold optics. That puts strong constrains on the dimensions of all the receiver components. For the SIS mixer, we employ a MMIC-like approach where most of the DSB mixer components, including LO injection circuitry with novel directional coupler, are integrated on the same crystal quartz substrate. The mixer uses a lumped filter technique to extract the IF frequencies, which is non-traditional for SIS mixers. A custom made superconducting Lange coupler with suspended air bridges to connect the fingers of Lange coupler is used. Experimental measurements of the double sideband mixer show state of the art performance with the receiver noise temperature below 30 Kelvin across the entire band. The noise temperature for sideband separation mixer is below 60 Kelvin with sideband rejection better than 12 dB over most of the band.

  16. Retrieval Pump Flexible Suction Hose Dynamic Response Induced by Impact of a Mixer Pump Jet

    SciTech Connect

    Enderlin, C.W.; Terrones, G.; Bamberger, J.A.; White, M.; Combs, W.H.

    1999-10-07

    Experiments were conducted to investigate whether it may be feasible to simultaneously mix and retrieve radioactive waste slurries that are stored in million-gallon, double-shell tanks at the Hanford Site in Richland, Washington. Oscillating mixer pumps, located near the floor of these tanks, are used to mobilize and mix the slurry prior to retrieval. Operational scenarios that may be beneficial for retrieval may require simultaneous operation of a decant/transfer pump and the jet mixer pumps. The effects of jet-induced agitation and jet impingement upon the decant/transfer pump's flexible suction hose have not previously been experimentally evaluated. Possible effects of the jet impacting the hose include hose fatigue, hose collision or entanglement with other structures, and induced static and dynamic loads on the decant/transfer pump equipment. The objective of this work was to create operating conditions in a test tank that produce a dynamic response (in the flexible suction hose upon impingement from an above-floor jet) that is similar to that anticipated in the actual tank. A scaling analysis was conducted to define the interactions between the jet, the tank floor and the suction hose. The complexity of scaling the multi-layer flexible hose (matching its hydroelastic parameters at full and 1/4-scale) led to an alternate approach, that of matching the expected full-scale forces on the full-scale hose in the scaled tank. Two types of tests were conducted: characterization of the jet velocity profile in the test tank at two axial locations from the nozzle and observation of the motion induced in the flexible retrieval hose from impact by the jet. The velocity profile of the jet in the test tank was measured to compare the measured profiles with profile predictions for an above-floor jet. These data were used to obtain a refined estimate of the velocity profile and therefore, the force acting upon the test article at a particular location in the tank. The hose

  17. A 230-GHz radiometer system employing a second-harmonic mixer

    NASA Technical Reports Server (NTRS)

    Goldsmith, P. F.; Plambeck, R. L.

    1976-01-01

    A radiometer system for use in the 1.3 mm region has been constructed and used for radio astronomical observations. A second-harmonic mixer employing a single Schottky diode downconverts the incident power to an IF frequency of about 1400 MHz. The measured double-sideband system noise temperature is 6000 K (noise figure = 13 dB) and the double-sideband mixer conversion loss is calculated to be 10 dB. The mixer is tunable over a range of at least 15 GHz.

  18. 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.

  19. Fluid flow structure around the mixer in a reactor with mechanical mixing

    SciTech Connect

    Lecheva, A.; Zheleva, I.

    2015-10-28

    Fluid flow structure around the mixer in a cylindrical reactor with mechanical mixing is studied and numerical results are presented in this article. The model area is complex because of the presence of convex corners of the mixer in the fluid flow. Proper boundary conditions for the vorticity calculated on the base of the stream function values near solid boundaries of the examined area are presented. The boundary value problem of motion of swirling incompressible viscous fluid in a vertical tank reactor with a mixer is solved numerically. The calculations are made by a computer code, written in MATLAB. The complex structure of the flow around the mixing disk is described and commented.

  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; Ursic, Joseph

    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. 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.

  2. The design and development of a mixer compound exhaust system for a quiet clean general aviation turbofan

    NASA Technical Reports Server (NTRS)

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

    1981-01-01

    Lower engine fuel consumption has become a dominant factor in turbofan engine design due to rapidly increasing fuel costs. One engine component with a large impact on engine performance is the exhaust system. Previous exhaust system studies have demonstrated the significant exhaust system efficiency gains available through mixing of the core and bypass flows. Typically, a large, costly rig and engine program are required to develop and optimize these gains. The purpose of this paper is to present the results of the low-cost design system used for the quiet, clean general aviation turbofan mixer nozzle design and development. The scale model and full-scale engine test results confirm the predicted 3 to 5% reduction in cruise fuel consumption. This unique design system, which is based on integrating advanced three-dimensional viscous numerical methods with empirical optimization techniques, is summarized and detailed comparisons with test data are presented. The ability to accurately predict relative performance of mixer systems with substantially reduced development time and cost savings is demonstrated.

  3. Low-noise integrated balanced SIS mixer for 787-950 GHz

    NASA Astrophysics Data System (ADS)

    Fujii, Yasunori; Kojima, Takafumi; Gonzalez, Alvaro; Asayama, Shin'ichiro; Kroug, Matthias; Kaneko, Keiko; Ogawa, Hideo; Uzawa, Yoshinori

    2017-02-01

    We developed a low-noise, compact, balanced superconductor-insulator-superconductor (SIS) mixer, operating in the 787-950 GHz radio frequency range. A waveguide mixer block was designed to integrate all the key components, such as a radio frequency (RF) 90° hybrid coupler, two identical SIS mixer chips, bias-tees, and an intermediate frequency power-combiner. The RF waveguide 90° hybrid coupler consists of branch lines with wide slots optimized by numerical simulation, for ease of fabrication. The balanced mixer was installed into a cartridge type receiver, originally developed for the Atacama Large Millimeter/submillimeter Array Band 10 (787-950 GHz). The receiver demonstrated double sideband noise temperatures of approximately 200 K for most of the band, without any correction for loss in front of the receiver. The local oscillator noise rejection ratio was estimated to be more than 15 dB within the measured frequency range.

  4. Terahertz Sub-harmonic Mixer Using Discrete Schottky Diode for Planetary Science and Remote Sensing

    NASA Astrophysics Data System (ADS)

    Yang, F.; Meng, H. F.; Duo, W. B.; Sun, Z. L.

    2017-01-01

    Sub-harmonic mixers are the core element of terahertz room temperature, high spectral resolution heterodyne receivers for planetary science, and remote sensing. Here, terahertz sub-harmonic mixer up to 400 GHz using discrete Schottky diode is presented. Measured performance is in agreement with results from the linear and nonlinear co-simulations, and this methodology shows its practicability for the discrete planar GaAs Schottky diode-based terahertz core circuit design.

  5. Development of novel micro swirl mixer for producing fine metal oxide nanoparticles by continuous supercritical hydrothermal method.

    PubMed

    Kawasaki, Shin-ichiro; Sue, Kiwamu; Ookawara, Ryuto; Wakashima, Yuichiro; Suzuki, Akira

    2010-01-01

    Novel micro swirl mixers were developed to synthesize nanoparticles, and the effect of their mixing performance on the characteristics of the synthesized nanoparticles was determined. The results were compared with those obtained using simple T-shaped mixers under the same reaction conditions. The synthesis of NiO, whose characteristics depend on the mixing performance of the mixer, was chosen as a model reaction. Initial investigations highlighted that the average particle size decreased from 32 to 23 to 20 nm as the inner diameter of the swirl mixers was decreased from 3.2 mm (Swirl mixer, SM-3.2) to 0.8 mm (Micro swirl mixer, MSM-0.8) to 0.5 mm (Micro swirl mixer, MSM-0.5), respectively. On the other hand, a similar decrease in the average particle size from 34 to 20 nm was observed with a decrease in the inner diameter of the T-shaped mixers from 1.3 mm (Tee union, T-1.3) to 0.3 mm (Micro tee union, T-0.3), respectively. Further, narrow particle size distributions were observed with a decrease in the inner diameter of each mixer. Furthermore, a computational fluid dynamics (CFD) simulation indicated an excellent mixing mechanism, which contributed to the improvement in the heating rate and the formation of nanoparticles of smaller size with a narrow particle size distribution. The result presented here indicates that the micro swirl mixers produce high-quality metal oxide nanoparticles. The size of the obtained particles with improved size distributions was comparable to that of the particles obtained using the T-shaped mixers, although the inner diameter of the swirl mixers was larger. Therefore, preliminary evidence suggests that the swirl flow mixers have the ability to produce rapid and homogeneous fluid mixing, thus controlling the particle size.

  6. 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.

  7. 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.

  8. 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; Rodriguez, Bryan

    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.

  9. Sandwich mixer-reactor: influence of the diffusion coefficient and flow rate ratios.

    PubMed

    Abonnenc, Mélanie; Josserand, Jacques; Girault, Hubert H

    2009-02-07

    A sandwich mixer consists of mixing two solutions in a channel, one central laminar flow being sandwiched between two outer flow solutions. The present numerical study considers the convection-diffusion of two reacting species A and B, provided respectively by the two incoming solutions. The simulations show how the diffusion coefficient, flow rate and species concentration ratios influence, via the transversal diffusion length and reaction kinetics, the reaction extent at the end of the sandwich mixer. First, this extent can be enhanced up to 60% if the species with the lowest diffusion coefficient is located in the outer solutions where the flow velocity is small compared to that of the central part (higher residence time). Secondly, decreasing the outer flow rates (to confine the reaction close to the walls) and increasing the local concentration to keep the same flux ratio improve the extent by 300%. Comparison with a bi-lamination passive mixer, with an ideal mixer and an electro-osmotic driven flow mixer is presented. These conclusions are also demonstrated for consecutive reactions, showing an amplification of the effects described above. The results are also presented versus the residence time in the mixer-reactor to show the time window for which the gain is appreciable.

  10. Theoretical SIS mixer research. Final technical report, 1 June 1990-30 November 1992. [SIS (superconductor-insulator-superconductor)

    SciTech Connect

    Feldman, M.J.

    1993-06-01

    Theoretical research has been conducted to elucidate the basic physics behind the properties of superconductor-insulator-superconductor (SIS) tunnel junction receiving devices. The properties of SIS mixers using nonideal junctions and finite LO power, were determined by analytic expansion of the equations of the quantum theory of mixing, and also by computer simulations of SIS receivers over the entire range of experimental parameters. The result is a new coherent and intuitive picture of SIS mixer behavior. Many of the outstanding mysteries and questions about SIS receivers are resolved, and this contributes greatly to the design and interpretation of SIS mixer experiments. Other calculations show how to achieve sub-quantum noise temperatures in the phase sensitive SIS mixer, an important step towards realization of ultra-low-noise detectors. A simplified model casts doubt on the superlative experimental results reported for the rf-series dc-parallel biased array SIS mixer. Superconductivity; SIS mixer; Submillimeter-wave detection.

  11. 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.

  12. 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.

  13. Active micro-mixers using surface acoustic waves on Y-cut 128° LiNbO3

    NASA Astrophysics Data System (ADS)

    Tseng, Wei-Kuo, Jr.; Lin, Lung; Sung, Wang-Chou; Chen, Shu-Hui; Lee, Gwo-Bin

    2006-03-01

    This study presents an active method for micro-mixers using surface acoustic waves (SAW) to rapidly mix co-fluent fluids. Mixing is challenging work in microfluidic systems due to their low-Reynolds-number flow conditions. SAW devices were fabricated on 128° Y-cut lithium niobate (LiNbO3). The micro-mixers are these piezoelectric actuators integrated with polydimethylsiloxane microchannels. The effects of the applied voltages on interdigitated transducers (IDTs) and two layouts, parallel- and transversal-type, of micro-mixers on the mixing performance were experimentally explored. The experimental results revealed that the parallel-type mixer achieved a higher mixing effect. Meanwhile, a higher applied voltage on the IDTs led to a significant improvement in the mixing performance of the active micro-mixer. Typical temperature effects associated with the applied voltages on the IDTs were also investigated. Finally, a digestion reaction between a protein (hemoglobin) and an enzyme (trypsin) was performed to verify the capability of the micro-mixers. The protein-enzyme mixture was qualitatively analyzed using mass spectrometry. Using these SAW-based mixers, the amount of digested peptides increased. Additionally, the protein-enzyme mixture was also quantitatively analyzed using high-performance liquid chromatography. Experimental data showed that the amount of digested peptides increased 21.1% using the active mixer. Therefore, the developed micro-mixers can be applied in microfluidic systems for improving mixing efficiency and thus enhancing the bio-reaction.

  14. 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.

  15. 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.

  16. Safety basis for the 241-AN-107 mixer pump installation and caustic addition

    SciTech Connect

    Van Vleet, R.J.

    1994-10-05

    This safety Basis was prepared to determine whether or not the proposed activities of installing a 76 HP jet mixer pump and the addition of approximately 50,000 gallons of 19 M (50:50 wt %) aqueous caustic are within the safety envelope as described by Tank Farms (chapter six of WHC-SD-WM-ISB-001, Rev. 0). The safety basis covers the components, structures and systems for the caustic addition and mixer pump installation. These include: installation of the mixer pump and monitoring equipment; operation of the mixer pump, process monitoring equipment and caustic addition; the pump stand, caustic addition skid, the electrical skid, the video camera system and the two densitometers. Also covered is the removal and decontamination of the mixer pump and process monitoring system. Authority for this safety basis is WHC-IP-0842 (Waste Tank Administration). Section 15.9, Rev. 2 (Unreviewed Safety Questions) of WHC-IP-0842 requires that an evaluation be performed for all physical modifications.

  17. Design of turbulent tangential micro-mixers that mix liquids on the nanosecond time scale.

    PubMed

    Mitic, Sandra; van Nieuwkasteele, Jan W; van den Berg, Albert; de Vries, Simon

    2015-01-15

    Unravelling (bio)chemical reaction mechanisms and macromolecular folding pathways on the (sub)microsecond time scale is limited by the time resolution of kinetic instruments for mixing reactants and observation of the progress of the reaction. To improve the mixing time resolution, turbulent four- and two-jet tangential micro-mixers were designed and characterized for their mixing and (unwanted) premixing performances employing acid-base reactions monitored by a pH-sensitive fluorescent dye. The mixing performances of the micro-mixers were determined after the mixing chamber in a free-flowing jet. The premixing behavior in the vortex chamber was assessed in an optically transparent glass-silicon replica of a previously well-characterized stainless-steel four-jet tangential micro-mixer. At the highest flow rates, complete mixing was achieved in 160ns with only approximately 9% premixing of the reactants. The mixing time of 160ns is at least 50 times shorter than estimated for other fast mixing devices. Key aspects to the design of ultrafast turbulent micro-mixers are discussed. The integration of these micro-mixers with an optical flow cell would enable the study of the very onset of chemical reactions in general and of enzyme catalytic reactions in particular.

  18. Performance of NbN superconductive tunnel junctions as SIS mixers at 205 GHz

    SciTech Connect

    McGrath, W.R.; Stern, J.A.; Javadi, H.H.S.; Cypher, S.R.; Hunt, B.D.; LeDuc, H.G. )

    1991-03-01

    This paper reports on the performance of NbN superconductive tunnel junctions as SIS mixers at 205 GHz. The authors have fabricated small area ({le}1 {mu}{sup 2}) high current density NbN/MgO/NbN tunnel junctions with I- V characteristics suitable for high frequency mixers. Mesa- geometry junctions with an area of about 1 {mu}{sup 2} and critical current density of 5-10kA/cm{sup 2} are integrated with superconducting microstrip lines designed to resonate out the junction capacitance. Accurate values of junction capacitance and magnetic-penetration depth are required for the proper design of the microstrip. The authors studied the mixer gain and noise performance near 205 GHz as a function of the inductance provided by the microstrip line.

  19. Fabrication of high-Tc superconducting hot electron bolometers for terahertz mixer applications

    NASA Astrophysics Data System (ADS)

    Villegier, Jean-Claude; Degardin, Annick F.; Guillet, Bruno; Houze, Frederic; Kreisler, Alain J.; Chaubet, Michel

    2005-03-01

    Superconducting Hot Electron Bolometer (HEB) mixers are a competitive alternative to Schottky diode mixers or other conventional superconducting receiver technologies in the terahertz frequency range because of their ultrawide bandwidth (from millimeter waves to the visible), high conversion gain, and low intrinsic noise level, even at 77 K. A new technological process has been developed to realize HEB mixers based on high temperature superconducting materials, using 15 to 40 nm thick layers of YBa2Cu3O7-δ (YBCO), sputtered on MgO (100) substrates by hollow cathode magnetron sputtering. Critical temperature values of YBCO films were found in the 85 to 91 K range. Sub-micron HEB bridges (0.8 μm x 0.8 μm) were obtained by combining electronic and UV lithography followed by selective etching techniques. Realization of YBCO HEB coupling to planar integrated gold antennas was also considered.

  20. The evaluation of a metered mixer for RTV silicone for RSRM nozzle backfill operations

    NASA Technical Reports Server (NTRS)

    Wardell, T. C.

    1989-01-01

    Metered mixing specifically for the RSRM backfill operation was investigated. Projected advantages were the elimination of waste RTV silicone produced in the operation and the elimination of entrapped air during the mix. Although metered mixing proved to be a viable method for mixing the Dow Corning DC 90-0006 rubber with its catalyst, applying the technology to the RSRM backfill operation has several disadvantages that are decisive. Use of a metered mixer would increase the amount of material that was being scraped for each backfill and increase the amount of time required to clean up the equipment after each operation. Therefore, use of metered static mixers is not recommended for use in the RSRM nozzle backfill operations. Because metered mixers proved to have significant disadvantages other methods of mixing and dispensing the RTV during the backfill operation are being investigated, and will be reported in a separate document.

  1. Noise performance of phase-insensitive frequency multicasting in parametric mixer with finite dispersion.

    PubMed

    Tong, Zhi; Wiberg, Andreas O J; Myslivets, Evgeny; Huynh, Chris K; Kuo, Bill P P; Alic, Nikola; Radic, Stojan

    2013-07-29

    Noise performance of dual-pump, multi-sideband parametric mixer operated in phase-insensitive mode is investigated theoretically and experimentally. It is shown that, in case when a large number of multicasting idlers are generated, the noise performance is strictly dictated by the dispersion characteristics of the mixer. We find that the sideband noise performance is significantly degraded in anomalous dispersion region permitting nonlinear noise amplification. In contrast, in normal dispersion region, the noise performance converges to the level of four-sideband parametric process, rather than deteriorates with increased sideband creation. Low noise generation mandates precise dispersion-induced phase mismatch among pump and sideband waves in order to control the noise coupling. We measure the noise performance improvement for a many-sideband, multi-stage mixer by incorporating new design technique.

  2. Quantum-limited operation of balanced mixer homodyne and heterodyne receivers

    NASA Astrophysics Data System (ADS)

    Machida, Susumu; Yamamoto, Yoshihisa

    1986-05-01

    In the GaAs semiconductor laser balanced mixer heterodyne receiver of Abbas and Chan (1983), the photocurrent fluctuation due to local oscillator wave intensity noise was suppressed, but the absolute quantum noise level calibration was not clarified. In this paper, the results of experimental calibration of the quantum noise level were obtained using two different methods: photocurrent spectral density measurement and photoelectron counting. The noise of a balanced mixer operation was confirmed to be truly quantum limited; the photocurrent fluctuation spectral density measured with a spectrum analyzer agreed with the quantum noise spectral density. The deviations from the absolute quantum noise level were within + or -0.02 dB. Complete suppression of local oscillator excess noise was demonstrated in the 0-1.5 GHz frequency region. Uses of balanced mixers for observing the squeezing phenomenon and quantum nondemolition measurement is mentioned.

  3. 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.

  4. Design and simulation of a mixer and phase difference measuring circuitry for laser range finding systems

    NASA Astrophysics Data System (ADS)

    Liu, Guili; Wang, Yanlin; Liu, Gang

    2006-11-01

    This article focuses on the circuit implementation of a mixer and phase difference measurement for laser range finding systems. It will introduce simply the principle of the laser range finding system, which is the basis of the electronic circuitry design. The modulated laser lights of two different frequencies are mixed and the phase difference is detected in order to measure the range. The method of measuring the range is to use the mixer and the phase difference detector. The new and high precision IC that has a high quality makes the circuit simple and reliable. The circuit of the mixer and the phase difference detector for laser range finding systems is designed using AD608 and AD8302 chips.

  5. Vortical and turbulent structure of planar and lobed mixer free-shear layers

    NASA Astrophysics Data System (ADS)

    McCormick, Duane Clark

    A comprehensive experimental investigation of the free-shear layer vortical and turbulent structure downstream of a lobed mixer has been conducted. Pulsed-laser flow visualization with smoke and three-dimensional velocity measurements with triple-sensor hot film anemometry were obtained for two lobed mixer configurations (symmetric and unsymmetric waveforms) and a baseline, planar configuration. Both laminar and turbulent initial boundary layer conditions were documented for each of the three configurations. The main result of this investigation is that a new vortex structure was found to exist for the lobed mixers in addition to the well-known streamwise vortex array. The normal vortex (due to the Kelvin-Helmholtz instability) sheds periodically from the convoluted trailing edge of the lobed mixer and plays a major part in the enhanced mixing process in combination with the streamwise vorticity. The streamwise vorticity deforms the normal vortex into a pinched-off structure that creates intense turbulence and mixing. The scale of the normal vortex was approximately one fourth that of the planar case, thereby introducing a small-scale turbulence over a large cross-stream area of the flow that dominates the near-field Reynolds shear stress distribution. Thus, the lobed mixer free-shear layer provides enhanced mixing down to the molecular scale. The shear layer growth rate for the first 5-6 lobe heights was substantially greater than the planar free-shear layer due to the normal and streamwise vortex interaction. Downstream of six lobe heights, the growth rate slowed considerably to a rate below that of the planar configuration due to the reduced turbulent kinetic energy of a double-layered shear layer structure. The streamwise and normal vorticity were completely dissipated by 5-6 lobe heights. Also, the lobe mixer development was found to be surprisingly insensitive to initial laminar and turbulent boundary layer conditions (unlike the planar case).

  6. Vortical and Turbulent Structure of Planar and Lobed Mixer Free-Shear Layers

    NASA Astrophysics Data System (ADS)

    McCormick, Duane Clark

    A comprehensive experimental investigation of the free-shear layer vortical and turbulent structure downstream of a lobed mixer has been conducted. Pulsed-laser flow visualization with smoke and three-dimensional velocity measurements with triple-sensor hot film anemometry were obtained for two lobed mixer configurations (symmetric and unsymmetric waveforms) and a baseline, planar configuration. Both laminar and turbulent initial boundary layer conditions were documented for each of the three configurations. The main result of this investigation is that a new vortex structure was found to exist for the lobed mixers in addition to the well-known streamwise vortex array. The normal vortex (due to the Kelvin-Helmholtz instability) sheds periodically from the convoluted trailing edge of the lobed mixer and plays a major part in the enhanced mixing process in combination with the streamwise vorticity. The streamwise vorticity deforms the normal vortex into a pinched -off structure that creates intense turbulence and mixing. The scale of the normal vortex was approximately one fourth that of the planar case, thereby introducing a small-scale turbulence over a large cross-stream area of the flow that dominates the near-field Reynolds shear stress distribution. Thus, the lobed mixer free-shear layer provides enhanced mixing down to the molecular scale. The shear layer growth rate for the first 5-6 lobe heights was substantially greater than the planar free-shear layer due to the normal and streamwise vortex interaction. Downstream of six lobe heights, the growth rate slowed considerably to a rate below that of the planar configuration due to the reduced turbulent kinetic energy of a double-layered shear layer structure. The streamwise and normal vorticity were completely dissipated by 5-6 lobe heights. Also, the lobed mixer development was found to be surprisingly insensitive to initial laminar and turbulent boundary layer conditions (unlike the planar case).

  7. 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.

  8. Packaging design criteria, transfer and disposal of 102-AP mixer pump

    SciTech Connect

    Carlstrom, R.F.

    1994-11-23

    A mixer pump installed in storage tank 241-AP-102 (102-AP) has failed. This pump is referred to as the 102-AP mixer pump (APMP). The APMP will be removed from 102-AP 1 and a new pump will be installed. The main purpose of the Packaging Design Criteria (PDC) is to establish criteria necessary to design and fabricate a shipping container for the transfer and storage of the APMP from 102-AP. The PDC will be used as a guide to develop a Safety Evaluation for Packaging (SEP).

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

    SciTech Connect

    Pillet, J.-D.; Flurin, E.; Mallet, F. Huard, B.

    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.

  10. Fabrication of an Aluminum Based Hot Electron Mixer for Terahertz Applications

    NASA Technical Reports Server (NTRS)

    Echternach, P. M.; LeDuc, H. G.; Skalare, A.; McGrath, W. R.

    2000-01-01

    Aluminum based diffusion cooled hot electron bolometers (HEB) mixers, predicted to have better noise, bandwidth and to require less LO power than Nb based diffusion cooled HEBs, have been fabricated. Preliminary DC tests were performed. The bolometer elements consisted of short (0.1 to 0.3 micron), narrow (0.08 to 0. 15 micron) and thin (11 nm) aluminum wires connected to large contact pads consisting of a novel trilayer Al/Ti/Au. The patterns were defined by electron beam lithography and the metal deposition involved a double angle process, the Aluminum wires being deposited straight on and the pads being deposited at a 45 degree angle without breaking vacuum. The Al/Ti/Au trilayer was developed to provide a way of making contact between the aluminum wire and the gold antenna. The Titanium layer acts as a diffusion barrier to avoid damage of the Aluminum contact and bolometer wire and to lower the transition temperature of the pads to below that of the bolometer wire. The Au layer avoids the formation of an oxide on the Ti layer and provides good electrical contact to the IF/antenna structure. The resistance of the bolometers as a function of temperature was measured. It is clear that below the transition temperature of the wire (1.8K) but above the transition temperature of the contact pads (0.6K), the proximity effect drives most of the bolometer wire normal, causing a very broad transition. This effect should not affect the performance of the bolometers since they will be operated at a temperature below the TC of the pads. This is evident from the IV characteristics measured at 0.3K. RF characterization tests will begin shortly.

  11. Engineering scale mixing system tests for MWTF title II design

    SciTech Connect

    Chang, S.C.

    1994-10-10

    Mixing tests for the Multifunction Waste Tank Facility (MWTF) were conducted in 1/25 and 1/10 scale test tanks with different slurry levels, solids concentrations, different jet mixers and with simulated in-tank structures. The same test procedure was used as in the Title I program, documented in WHC-SD-W236A-ER-005. The test results support the scaling correlation derived previously in the Title I program. The tests also concluded that a partially filled tank requires less mixing power, and horizontal and angled jets in combination (H/A mixer) are significantly more effective than the two horizontal jet mixers (H/H mixer) when used for mixing slurry with a high solids concentrations.

  12. 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.

  13. INTERIOR VIEW WITH MIXER TO LADLE TRANSFER. CRANE OPERATOR, M.L. ...

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

    INTERIOR VIEW WITH MIXER TO LADLE TRANSFER. CRANE OPERATOR, M.L. BROWN; SWITCHER, BILL CLARK; DESULPHUR OPERATORS, CHARLIE WILLIAMS AND TIM BUSH. - U.S. Steel, Fairfield Works, Q-Bop Furnace, North of Valley Road & West of Ensley, Pleasant Grove Road, Fairfield, Jefferson County, AL

  14. INTERIOR VIEW WITH MIXER TO LADLE TRANSFER. CRANE OPERATOR, M.L. ...

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

    INTERIOR VIEW WITH MIXER TO LADLE TRANSFER. CRANE OPERATOR, M.L. BROWN; SWITCHER, BILL CLARK; DESULPHUR OPERATORS, CHARLIE WILLIAMS AND TIM BUSH - U.S. Steel, Fairfield Works, Q-Bop Furnace, North of Valley Road & West of Ensley, Pleasant Grove Road, Fairfield, Jefferson County, AL

  15. A Low-Noise Terahertz SIS Mixer Incorporating a Waveguide Directional Coupler for LO Injection

    NASA Astrophysics Data System (ADS)

    Kojima, Takafumi; Kuroiwa, Kouichi; Uzawa, Yoshinori; Kroug, Matthias; Takeda, Masanori; Fujii, Yasunori; Kaneko, Keiko; Miyachi, Akihira; Wang, Zhen; Ogawa, Hideo

    2010-11-01

    We have developed a low-noise heterodyne waveguide Superconductor-Insulator-Superconductor (SIS) mixer with a novel local oscillator (LO) injection scheme for the Atacama Large Millimeter/submillimeter Array (ALMA) band 10, over the frequency range 0.78-0.95 THz. The SIS mixer uses radio frequency (RF) and LO receiving horns separately and a waveguide 10 dB LO coupler integrated in the mixer block. The insertion loss of the waveguide and coupling factor of the coupler were evaluated at terahertz frequencies at both room and cryogenic temperatures. The double-sideband (DSB) receiver noise temperatures were below 330 K (7.5 hf/ k B) at LO frequencies in the range 0.801-0.945 THz. The minimum temperature was 221 K at 0.873 THz over the intermediate frequency range of 4-12 GHz at an operating temperature of 4 K. This waveguide heterodyne SIS mixer exhibits great potential for practical applications, such as high-frequency receivers of the ALMA.

  16. 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.

  17. A reconfigurable passive mixer for multimode multistandard receivers in 0.18 μm CMOS

    NASA Astrophysics Data System (ADS)

    Xiangning, Fan; Jian, Tao; Kuan, Bao; Zhigong, Wang

    2016-08-01

    This paper presents a reconfigurable quadrature passive mixer for multimode multistandard receivers. By using controllable transconductor and transimpedance-amplifier stages, the voltage conversion gain of the mixer is reconfigured according to the requirement of the selected communication standard Other characteristics such as noises figure, linearity and power consumption are also reconfigured consequently. The design concept is verified by implementing a quadrature passive mixer in 0.18 μm CMOS technology. On wafer measurement results show that, with the input radio frequency ranges from 700 MHz to 2.3 GHz, the mixer achieves a controllable voltage conversion gain from 4 to 22 dB with a step size of 6 dB. The measured maximum IIP3 is 8.5 dBm and the minimum noise figure is 8.0 dB. The consumed current for a single branch (I or Q) ranges from 3.1 to 5.6 mA from a 1.8 V supply voltage. The chip occupies an area of 0.71 mm2 including pads. Project supported by the State Key Development Program for Basic Research of China (No. 2010CB327404).

  18. 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.

  19. Nanosizing of poorly water soluble compounds using rotation/revolution mixer.

    PubMed

    Takatsuka, Takayuki; Endo, Tomoko; Jianguo, Yao; Yuminoki, Kayo; Hashimoto, Naofumi

    2009-10-01

    In this study, nanoparticles of various poorly water soluble compounds were prepared by wet milling that was carried out using a rotation/revolution mixer and zirconia balls. To be compared with Beads mill, rotation/revolution mixer has superior in very quick process (5 min) and needs very few amounts of zirconia balls (2.4 g) for pulverizing drugs to nanometer range. Phenytoin, indomethacin, nifedipine, danazol, and naproxen were selected as the standard poorly water soluble compounds. Various parameters of the rotation/revolution mixer were studied to decide the optimal pulverization conditions for the production of nanoparticles of the abovementioned compounds. The rotation/revolution speed, shape of the mixing vessel, amount of zirconia balls, and volume of the vehicle (methylcellulose solution) mainly affected the pulverization of the compounds. Using the mixer, phenytoin could be pulverized to nanoparticles within a few minutes. The particle size was confirmed by using a scanning electron microscope and a particle size analyzer. The crystallinity of the pulverized phenytoin particles was confirmed by X-ray diffractometry (XRD) and differential scanning calorimetry (DSC). It was observed that the pulverized phenytoin particles retained their crystallinity, and amorphous phenytoin was not detected. Particles of other poorly water soluble compounds were also reduced to the nanometer range by using this method.

  20. 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...

  1. 7 CFR 58.228 - Dump hoppers, screens, mixers and conveyors.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 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...

  2. Structural evaluation of mixer pump installed in Tank 241-AN-107 for caustic addition project

    SciTech Connect

    Leshikar, G.A.

    1995-06-16

    This report documents the structural analysis and evaluation of a mixer pump and caustic addition system to be used in Tank 107-AN. This pump will be installed in the central pump pit of this double- shell tank for the purpose of bringing the hydroxide ion concentration into compliance with Tank Farm operating specifications.

  3. 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

  4. Computational fluid dynamics analysis and noise modeling of jets with internal forced mixers

    NASA Astrophysics Data System (ADS)

    Garrison, Loren Armstrong

    The goal of the current research work is to develop a stand-alone jet noise prediction methodology. The current project is focused on jets with internal forced mixers, which are used in regional jet aircraft. In the current approach a two-step method is adopted. First, the turbulence properties in the jet plume are determined from Computational Fluid Dynamics (CFD) analysis using the Reynolds Averaged Navier-Stokes (BANS) equations with a two-equation turbulence model. Second, the far-field noise spectrum is predicted using a noise model based on the combination of simple single stream jet components taken from an existing experimental database. The results of this study show that the CFD predictions of the mean velocity field in the jet plume are in good agreement with experimental particle image velocimetry data. It is also observed that the CFD analysis over-predicts the turbulence levels in a simple single jet shear layer. However, it is determined that the CFD analysis under-predicts the enhancement of the shear layer turbulence levels for the forced mixers. Despite this deficiency, it is seen that the trends in the peak turbulence levels for various mixer geometries are correctly predicted by the CFD analysis. In the current study the far-field noise spectra are predicted using a noise model based on the combination of simple single stream jet components. It is found that the CFD-based two-source model noise predictions are under-predicted when compared to experimental acoustic data. This under-prediction appears to result from the under-prediction of the enhanced turbulence levels in the plume of the jets with forced mixers. In addition to the two-source noise model, a new multi-source model is proposed and evaluated. This model, which has a more general form, takes into account additional mean flow information from the jet plume. As a result, this model should be applicable to a wider range of geometric configurations. The results using this new multi

  5. 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

  6. 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.

  7. Microwave-assisted Measurement of the Frequency Response of Terahertz HEB mixers with a Fourier Transform Spectrometer

    NASA Astrophysics Data System (ADS)

    Lobanov, Y. V.; Tong, Cheuk-Yu E.; Hedden, A. S.; Blundell, R.; Gol'tsman, G. N.

    2010-03-01

    We describe a novel method of operation of the HEB direct detector for use with a Fourier Transform Spectrometer. Instead of elevating the bath temperature, we have measured the RF response of waveguide HEB mixers by applying microwave radiation to select appropriate bias conditions. In our experiment, a microwave signal is injected in to the HEB mixer via its IF port. By choosing an appropriate injection level, the device can be operated close to the desired operating point. Furthermore, we have shown that both thermal biasing and microwave injection can reproduce the same spectral response of the HEB mixer. However, with the use of microwave injection, there is no need to wait for the mixer to reach thermal equilibrium, so characterisation can be done in less time. Also, the liquid helium consumption for our wet cryostat is also reduced. We have demonstrated that the signal-to-noise ratio of the FTS measurements can be improved with microwave injection.

  8. 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.

  9. 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.

  10. Broadband MgB2 Hot-Electron Bolometer THz Mixers Operating up to 20 K

    NASA Astrophysics Data System (ADS)

    Novoselov, Evgenii; Cherednichenko, Sergey

    2017-01-01

    We discuss performance of submicron size hot-electron bolometer mixers made from thin MgB2 superconducting films. With a superconducting transition temperature of ∼30 K, such terahertz (THz) mixers can operate with high sensitivity at temperatures up to 20 K. Due to very small dimensions local oscillator power requirements are rather low. In the intermediate frequency band of 1-3 GHz, the double sideband receiver noise temperature is 1600 K at 10 K operation temperature, 2000 K at 15 K, 2500-3000 K at 20 K. The gain bandwidth of such devices is 6 GHz and the noise bandwidth is estimated to be 6-8 GHz.

  11. Feasibility Study on Using Two Mixer Pumps for Tank 241-AY-102 Waste Mixing

    SciTech Connect

    Onishi, Yasuo; Wells, Beric E.

    2004-08-30

    The current waste retrieval plan at Hanford calls for using two mixer pumps to mix the waste stored in double-shell Tank 214-AY-102. The objective of this evaluation was to determine whether two rotating 300-hp mixer pumps placed 22 ft (6.7 m) off-center in the tank could adequately mix the AY-102 waste. The tank currently contains high-level waste that is 248 inches (6.3 m) deep, comprising 62 inches (1.58 m) of sludge and 186 inches (4.72 m) of supernatant liquid (Galbraith et al. 2002). Based on the available data, AY-102 waste properties were determined, including the densities of liquid and agglomerated settled solids and crystals, the volume fraction of settled solids, the solid particle size distribution, the liquid and slurry viscosities, and the yield stress in shear (shear strength) of the settled solids layer. To evaluate the likely and bounding cases of AY-102 waste mixing, sludge erosion modeling was performed with a median value of 1,090 Pa (likely condition) and a conservative (more difficult to erode) 97.5 percentile value of 2,230 Pa for shear strength. According to model predictions, the two rotating mixer pumps would erode 89% of the sludge with shear strength of 1,090 Pa. They would erode sludge up to 41 ft (12.5 m) away from the mixer pumps but would not mobilize the bottom 2.5 inches (0.06-m) of sludge or sludge in the areas next to the tank wall, more than 26 ft (7.9 m) away. Once the sludge is mobilized, the solids were predicted to be uniformly suspended within the tank within a 1-vol% concentration variation except those in few inches at the bottom. With shear strength of 2,230 Pa, the two pumps would erode 85% of the sludge, slightly less than the 1,090-Pa shear strength case. In this case, the pump jets would mobilize the sludge up to 38 ft (11.6 m), except the bottom 2.5 inches of sludge. The mixer pumps would also leave the sludge at the tank wall, which is 20 ft or more from the pumps. Similar to the 1,090 Pa case, the solids were

  12. A Mixer-Receiver for the Parametric Acoustic Receiving Array (PARRAY)

    DTIC Science & Technology

    1978-09-18

    oo NuMSIS _______ SEP05! I4 _ T~y~~~~f .~ ~ MIXER-BECEIVER FOR THE PARAMETRIC ACOUSTIC K ~~~~~ hnica l P.cP.rL) )RECEIVING ARRAY ( PARRAY ) ~~. I...ic receiver B PARRAY nonlinear acoustics $~~~~~~~t 5AC T ~CnntInu. on ,.v ~~.. •ld~ U n.c. .•I.y and Id.nSE~~ Ay bh~rA nu~~ba r) — — (U) A...receiver for a Parametric Acoustic Receiving Array ( PARRAY ’~ based on a high performance mixer appears to be well suited to the requirements of some PARRAY

  13. Microfluidic mixers for the investigation of rapid protein folding kinetics using synchrotron radiation circular dichroism spectroscopy.

    PubMed

    Kane, Avinash S; Hoffmann, Armin; Baumgärtel, Peter; Seckler, Robert; Reichardt, Gerd; Horsley, David A; Schuler, Benjamin; Bakajin, Olgica

    2008-12-15

    We have developed a microfluidic mixer optimized for rapid measurements of protein folding kinetics using synchrotron radiation circular dichroism (SRCD) spectroscopy. The combination of fabrication in fused silica and synchrotron radiation allows measurements at wavelengths below 220 nm, the typical limit of commercial instrumentation. At these wavelengths, the discrimination between the different types of protein secondary structure increases sharply. The device was optimized for rapid mixing at moderate sample consumption by employing a serpentine channel design, resulting in a dead time of less than 200 micros. Here, we discuss the design and fabrication of the mixer and quantify the mixing efficiency using wide-field and confocal epi-fluorescence microscopy. We demonstrate the performance of the device in SRCD measurements of the folding kinetics of cytochrome c, a small, fast-folding protein. Our results show that the combination of SRCD with microfluidic mixing opens new possibilities for investigating rapid conformational changes in biological macromolecules that have previously been inaccessible.

  14. Submicron area NbN/MgO/NbN tunnel junctions for SIS mixer applications

    NASA Technical Reports Server (NTRS)

    Leduc, H. G.; Judas, A.; Cypher, S. R.; Bumble, B.; Hunt, B. D.

    1991-01-01

    The development of submicron area mixer elements for operation in the submillimeter wave range is discussed. High-current-density NbN/MgO/NbN tunnel junctions with areas down to 0.1 sq microns have been fabricated in both planar and edge geometries. The planar junctions were fabricated from in situ deposited trilayers using electron-beam lithography to pattern submicron area mesas. Modifications of fabrication techniques used in larger-area NbN tunnel junctions are required and are discussed. The NbN/MgO/NbN edge junction process using sapphire substrates has been transferred to technologically important quartz substrates using MgO buffer layers to minimize substrate interactions. The two junction geometries are compared and contrasted in the context of submillimeter wave mixer applications.

  15. Test report for run-in acceptance testing of Project W-151 300 HP mixing pumps

    SciTech Connect

    Berglin, B.G.

    1998-01-29

    This report documents the results of a performance demonstration and operational checkout of three 300 HP mixer pumps in accordance with WHC-SD-WI51-TS-001 ``Mixer Pump Test Specification for Project W-151`` and Statement of Work 8K520-EMN-95-004 ``Mixer Pump Performance Demonstration at MASF`` in the 400 Area Maintenance and Storage Facility (MASF) building. Testing of the pumps was performed by Fast Flux Test Facility (FFTF) Engineering and funded by the Tank Waste Remediation System (TWRS) Project W-151. Testing began with the first pump on 04-01-95 and ended with the third pump on 11-01-96. Prior to testing, the MASF was modified and prepared to meet the pump testing requirements set forth by the Test Specification and the Statement of Work.

  16. Test report for run-in acceptance testing of hydrogen mitigation test pump-2

    SciTech Connect

    Brewer, A.K.; Kolowith, R.

    1995-01-01

    This document provides the results of the run-in test of the replacement mixer pump for the Tank 241-SY-101. The test was conducted at the 400 Area MASF facility between August 12 and September 29, 1994. The report includes findings, analysis, recommendations, and corrective actions taken.

  17. 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.

  18. Study of Asphaltic Concrete Produced in Dryer Drum Mixers for Airport Pavements.

    DTIC Science & Technology

    1976-10-01

    STWDARDS-163- w S 4 -- , ,a, i I Report No-c FAA-RD-76-165 STUDY OF ASPHALTIC CONCRETE PRODUCED IN DRYER DRUM MIXERS FOR AIRPORT PAVEMENTS 0 E. T...PREFACE This study was supported by the Systems Research and Development Service of the Federal Aviation Administration. This is a final report presenting...the asphaltic concrete . In September, 1976 the Alaskan Region of FAA reported that the runway pavement had transverse thermal cracks approximately 200

  19. 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.

  20. Developing a fast and tunable micro-mixer using induced vortices around a conductive flexible link

    NASA Astrophysics Data System (ADS)

    Azimi, Shahriar; Nazari, Mohsen; Daghighi, Yasaman

    2017-03-01

    This paper presents a numerical study of a micro-mixer based on the continuous deformation of a conducting flexible link. The induced vortices around the link enhance the mixing process. This micro-mixer consists of one straight microchannel and one conductive flexible link. One end of the link is fixed on the upper wall of the channel and the other end can move freely due to the fluid-solid interactions. Since this link is conductive, vortices form around the link (once the electric field is applied). Applying a time-varying DC electric field causes variation in the applied forces to the link; thus, the link will swipe the channel and acts as a micro-stirrer to enhance mixing results. The presented results show that there is a direct relationship between mixing efficiency and the length of the link, as well as the amplitude of time-varying DC electric field. The effects of Young's modulus, the average of applied electric field, and link position are also studied. Link with lower Young's modulus swipes larger area inside the channel and enhances the mixing efficiency. By increasing the length of the conductive link, large vortices will be induced around it and mixing efficiency enhances. Our numerical results show that average mixing efficiency of link with a length of L = 0.625 W = 156.25 μm is about 90%. The proposed micro-mixer is simple to be fabricated and mixes the fluid streams in a short period of time with high efficiency. Such micro-mixers can be used in various microfluidics, biomedical, or chemical applications.

  1. Safety Evaluation for Packaging 101-SY Hydrogen Mitigation Mixer Pump package

    SciTech Connect

    Carlstrom, R.F.

    1994-10-05

    This Safety Evaluation for Packaging (SEP) provides analysis and considered necessary to approve a one-time transfer of the 101-SY Hydrogen Mitigation Mixer Pump (HMMP). This SEP will demonstrate that the transfer of the HMMP in a new shipping container will provide an equivalent degree of safety as would be provided by packages meeting US Department of Transportation (DOT)/US Nuclear Regulatory Commission (NRC) requirements. This fulfills onsite, transportation requirements implemented by WHC-CM-2-14.

  2. Status of the RBCC Direct-Connect Mixer Combustor Experiment

    NASA Technical Reports Server (NTRS)

    Walker, James F.; Kamhawi, Hani; Krivanek, Thomas M.; Thomas, Scott R.; Smith, Timothy D.

    2002-01-01

    The NASA Glenn Research Center is developing hydrogen based combined cycle propulsion technology for a single-stage-to-orbit launch vehicle application under a project called GTX. Rocket Based Combined Cycle (RBCC) propulsion systems incorporate one or more rocket engines into an airbreathing flow path to increase specific impulse as compared to an all rocket-powered vehicle. In support of this effort, an RBCC direct-connect test capability was established at the Engine Components Research Laboratory to investigate low speed, ejector ramjet, and initial ramjet operations and performance. The facility and test article enables the evaluation of two candidate low speed operating schemes; the simultaneous mixing and combustion (SMC) and independent ramjet stream (IRS). The SMC operating scheme is based on the fuel rich operations of the rocket where performance depends upon mixing between the rocket plume and airstream. In contrast, the IRS scheme fuels the airstream separately and uses the rocket plume to ignite the fuel-air mixture. This paper describes the test hardware and facility upgrades installed to support the RBCC tests. It also defines and discusses low speed technical challenges being addressed by the experiments. Finally, preliminary test results, including rocket risk mitigating tests, unfueled airflow tests, and the integrated system hot fire test will be presented.

  3. 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.

  4. The Increasing of Air and Biogas Mixer Instrument for Generating Friendly Environmental Electricity Power

    NASA Astrophysics Data System (ADS)

    Ketut Lasmi, Ni; Singarimbun, Alamta; Srigutomo, Wahyu

    2016-08-01

    The abolition of BBM Subsidize by the government causes increasing of its price, so a solution is necessary to find an alternative energy that is relatively cheap, environmentally friendly and affordable by all layers of society. Biogas is one of the renewable energy resources that are potential to be developed, especially in a farming area, because up until now, animal's excrement is not yet optimally used and it causes problem to environment. In response to this, one innovation to do is to make an instrument which is able to mix biogas and air by venture pipe using the basic theory of fluid mechanic, in order to raise the use of biogas as electricity source. Biogas conversion is done by changing fuel in benzene 5 kilowatt genset to biogas so it becomes a biogas genset. The biogas pressure is controlled when it enters the mixer instrument so that the velocity of biogas when it enters and it comes out the mixer is the same, and it will gain different pressure between biogas and air. By the pressure difference between biogas in the mixer instrument, biogas goes to the burning room so that the conversion of mechanical energy biogas to electricity will happen, and it will be applied as light and society's needs.

  5. Chaotic mixer using electro-osmosis at finite Péclet number

    NASA Astrophysics Data System (ADS)

    Sugioka, Hideyuki

    2010-03-01

    Two pressure-driven streams of two miscible liquids can only mix by diffusion in microfluidic channels because of the low Reynolds number. We present an idea to generate mixing by “chaotic advection” in microscale geometries. That is, we consider using induced-charge electro-osmosis to generate a second flow and then modulate between the pressure-driven and induced-charge flows. By using the combined method consisting of the boundary element method, the Lagrangian particle tracking method, and the random-walk method, we analyze mixing efficiency, mixing time, and mixing length, with the effects of modulation frequency and molecular diffusivity, and compare our proposed mixer with other mixers. By this analysis, we find that chaotic mixing can be produced efficiently in a microfluidic channel by switching between pressure-driven and induced-charge flows in a wide range of Péclet number under the specific condition of Strouhal number. By using our proposed mixer, we can expect to realize efficient chaotic mixing with minimum voltage in an ordinary flow channel with a simple structure without an oblique electric field even at large Péclet number.

  6. Performance comparison of a lobed-daisy mixer nozzle with a convergent nozzle at subsonic speeds

    NASA Technical Reports Server (NTRS)

    Maiden, D. L.

    1973-01-01

    An investigation to determine the performance, in terms of thrust minus nozzle axial force, of a lobed-daisy mixer nozzle has been conducted in a 16-foot transonic tunnel at static conditions and at Mach numbers from 0.40 to 0.90 at angles of attack from 4 minus to 8. Jet-total-pressure ratio was varied from about 1.2 to 2.0. The performance of a reference convergent nozzle with a similar nozzle throat area and length was used as a base line to evaluate the performance of the lobed-daisy mixer nozzle. The results of this investigation indicate that with no external airflow (Mach number M of 0), and at values of jet-total-pressure ratio between 1.2 and 2.0, the static thrust exerted by the lobed-daisy mixer nozzle is less than that of the convergent nozzle by about 10 percent of ideal gross thrust. About 3.4 percent of the thrust loss was attributed to an unintentional internal area expansion in the fan passage.

  7. 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.

  8. 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

  9. The Mixer: Introducing the Concept of Factor Analysis

    ERIC Educational Resources Information Center

    Segrist, Dan J.; Pawlow, Laura A.

    2007-01-01

    This study entailed the development and implementation of a classroom activity designed to introduce students to the concept of factor analysis. We implemented the activity in both a personality theories course and a tests and measurements course. Data suggest that students learned about factor analysis from this activity, while enjoying it.…

  10. A 700 GHz unilateral finline SIS mixer fed by a multi-flare angle smooth-walled horn

    NASA Astrophysics Data System (ADS)

    Tan, Boon-Kok; Yassin, Ghassan; Grimes, Paul; Leech, Jamie; Jacobs, Karl; Withington, Stafford; Tacon, Mike; Groppi, Christopher

    2010-07-01

    We present the design of a broadband superconductor-insulator-superconductor (SIS) mixer operating near 700 GHz. A key feature of our design is the utilisation of a new type of waveguide to planar circuit transition comprising a unilateral finline taper. This transition is markedly easier to design, simulate and fabricate than the antipodal finline we employed previously. The finline taper and the superconducting circuitry are deposited on a 15 μm thick silicon substrate. The employment of the very thin substrate, achieved using Silicon-On-Insulator (SOI) technology, makes it easy to match the incoming signal to the loaded waveguide. The lightweight mixer chip is held in the E-plane of the waveguide using gold beam leads, avoiding the need for deep grooves in the waveguide wall. This new design yields a significantly shorter chip, free of serrations and a wider RF bandwidth. Since tuning and all other circuits are integrated on the mixer chip, the mixer block is extremely simple, comprising a feed horn and a waveguide section without any complicated mechanical features. We employ a new type of smooth-walled horn which exhibits excellent beam circularity and low cross polarisation, comparable to the conventional corrugated horn, and yet is easier to fabricate. The horn is machined by standard milling with a drill tool shaped into the horn profile. In this paper, we describe the detailed design of the mixer chip including electromagnetic simulations, and the mixer performance obtained with SuperMix simulations. We also present the preliminary measurements of the smooth-walled horn radiation patterns near the mixer operating frequencies.

  11. JT8D Engine Internal Exhaust Mixer Technology Program.

    DTIC Science & Technology

    1980-04-01

    fabricability and cost considerations. In addition, this material has excellent repairability properties for service usage. The aluminum fan duct fairing...this period. (3) Along with noise and performance, ambient air temperature, rela- tive humidity, barometric pressure, and wind velocity were re- corded...at each test condition. Neither noise nor performance were recorded when the wind speed exceeded 8 knots or when the crosswind component exceeded 5

  12. A 2 to 5GHz-Band Self Frequency Dividing Quadrature Mixer Using Current Re-Use Configuration

    NASA Astrophysics Data System (ADS)

    Taniguchi, Eiji; Shimozawa, Mitsuhiro; Suematsu, Noriharu

    A 2 to 5GHz-band self frequency dividing quadrature mixer utilizing current re-use configuration with small size and broad band operation is proposed for a direct conversion receiver and a low-IF receiver of cognitive radio. The proposed mixer operates at twice the LO frequency by directly using a static type flip-flop frequency divider as the LO switching circuit for quadrature signal generation. The current re-use configuration is realized because the dc current of the frequency divider and the RF common-emitter amplifier share the same current flow path. Simulations and experiments verify that the proposed mixer offers broad band operation, miniaturization, and low power consumption. The mixer IC fabricated by 0.35μm SiGe-BiCMOS technology achieved the conversion gain of 20.6dB, noise figure of 11.9dB and EVM for π/4-shift QPSK signal of 4.4% at 2.1GHz with power consumption of 15mW and size of 0.22×0.31mm2. For the confirmation of broad band operation, the characteristics of conversion gain and noise figure were measured at 5.2GHz. The proposed mixer could operate at 5.2GHz with enough conversion gain, but the noise figure was inferior to that of 2.1GHz. Therefore the further investigation and improvement about the noise figure will be needed for higher frequency.

  13. Comparison of scaled model data to full size energy efficient engine test results

    NASA Technical Reports Server (NTRS)

    Lavin, S. P.; Ho, P. Y.; Chamberlin, R.

    1984-01-01

    Acoustic tests of a subscale fan and a subscale mixer nozzle were conducted in anechoic chambers over a variety of operating conditions. The subscale fan test was an investigation into the effects of vane/blade ratio and spacing on fan generated noise. A turbulence control structure (TCS) was used to simulate the 'turbulence-free' condition in flight. The subscale mixer nozzle test investigated the acoustic properties of several different forced mixer designs. A tertiary flow was utilized on the mixer model to simulate the forward velocity effects on the jet. The results were scaled up to full size conditions and compared with measured engine data. The comparisons showed good agreement between the component scaled model results and the full scale engine data.

  14. 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.

  15. 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.

  16. Effects of molecular confinement and crowding on horseradish peroxidase kinetics using a nanofluidic gradient mixer.

    PubMed

    Wichert, William R A; Han, Donghoon; Bohn, Paul W

    2016-03-07

    The effects of molecular confinement and crowding on enzyme kinetics were studied at length scales and under conditions similar to those found in biological cells. These experiments were carried out using a nanofluidic network of channels constituting a nanofluidic gradient mixer, providing the basis for measuring multiple experimental conditions simultaneously. The 100 nm × 40 μm nanochannels were wet etched directly into borosilicate glass, then annealed and characterized with fluorescein emission prior to kinetic measurements. The nanofluidic gradient mixer was then used to measure the kinetics of the conversion of the horseradish peroxidase (HRP)-catalyzed conversion of non-fluorescent Amplex Red (AR) to the fluorescent product resorufin in the presence of hydrogen peroxide (H2O2). The design of the gradient mixer allows reaction kinetics to be studied under multiple (five) unique solution compositions in a single experiment. To characterize the efficiency of the device the effects of confinement on HRP-catalyzed AR conversion kinetics were studied by varying the starting ratio of AR : H2O2. Equimolar concentrations of Amplex Red and H2O2 yielded the highest reaction rates followed by 2 : 1, 1 : 2, 5 : 1, and finally 1 : 5 [AR] : [H2O2]. Under all conditions, initial reaction velocities were decreased by excess H2O2. Crowding effects on kinetics were studied by increasing solution viscosity in the nanochannels in the range 1.0-1.6 cP with sucrose. Increasing the solution viscosities in these confined geometries decreases the initial reaction velocity at the highest concentration from 3.79 μM min(-1) at 1.00 cP to 0.192 μM min(-1) at 1.59 cP. Variations in reaction velocity are interpreted in the context of models for HRP catalysis and for molecular crowding.

  17. Radiometers based on SIS mixers to measure SZ effect from galaxy clusters

    NASA Astrophysics Data System (ADS)

    Gervasi, M.; Banfi, S.; Boella, G.; Passerini, A.; Natale, V.; Sironi, G.; Tartari, A.; Zannoni, M.

    2007-03-01

    We present a project to realize radiometers devoted to the observation of the Sunyaev-Zeldovich effect towards galaxy clusters. Radiometers are based on SIS mixers and are working at three frequency bands (around 94, 240 and 345 GHz) covering both the positive and negative part of the spectral displacement. The radiometers have been developed to be used at a telescope of 3 m class, like MITO. The observation program would be completed performing low frequency measurements first at the Noto radiotelescope (at 43 GHz) and then at SRT (at 40 and 90 GHz).

  18. 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.

  19. 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.

  20. High-T{sub c} superconducting Josephson mixers for terahertz heterodyne detection

    SciTech Connect

    Malnou, M.; Feuillet-Palma, C.; Olanier, L.; Lesueur, J.; Bergeal, N.; Ulysse, C.; Faini, G.; Febvre, P.; Sirena, M.

    2014-08-21

    We report on an experimental and theoretical study of the high-frequency mixing properties of ion-irradiated YBa{sub 2}Cu{sub 3}O{sub 7} Josephson junctions embedded in THz antennas. We investigated the influence of the local oscillator power and frequency on the device performances. The experimental data are compared with theoretical predictions of the general three-port model for mixers in which the junction is described by the resistively shunted junction model. A good agreement is obtained for the conversion efficiency in different frequency ranges, spanning above and below the characteristic frequencies f{sub c} of the junctions.

  1. Computation of three-dimensional flow in turbofan mixers and comparison with experimental data

    NASA Technical Reports Server (NTRS)

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

    1980-01-01

    A three dimensional, viscous computer code was used to calculate the mixing downstream of a typical turbofan mixer geometry. Experimental data obtained using pressure and temperature rakes at the lobe and nozzle exit stations were used to validate the computer results. The relative importance of turbulence in the mixing phenomenon as compared with the streamwise vorticity set up by the secondary flows was determined. The observations suggest that the generation of streamwise vorticity plays a significant role in determining the temperature distribution at the nozzle exit plane.

  2. 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.

  3. Rapid prototyping of three-dimensional microfluidic mixers in glass by femtosecond laser direct writing.

    PubMed

    Liao, Yang; Song, Jiangxin; Li, En; Luo, Yong; Shen, Yinglong; Chen, Danping; Cheng, Ya; Xu, Zhizhan; Sugioka, Koji; Midorikawa, Katsumi

    2012-02-21

    The creation of complex three-dimensional (3D) microfluidic systems has attracted significant attention from both scientific and applied research communities. However, it is still a formidable challenge to build 3D microfluidic structures with arbitrary configurations using conventional planar lithographic fabrication methods. Here, we demonstrate rapid fabrication of high-aspect-ratio microfluidic channels with various 3D configurations in glass substrates by femtosecond laser direct writing. Based on this approach, we demonstrate a 3D passive microfluidic mixer and characterize its functionalities. This technology will enable rapid construction of complex 3D microfluidic devices for a wide array of lab-on-a-chip applications.

  4. Development of horn antenna mixer array with internal local oscillator module for microwave imaging diagnostics

    NASA Astrophysics Data System (ADS)

    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.

  5. Mixer-settler counter-current chromatography with a barricaded spiral disk assembly with glass beads.

    PubMed

    Ito, Yoichiro; Qi, Lin; Powell, Jimmie; Sharpnack, Frank; Metger, Howard; Yost, James; Cao, Xue-Li; Dong, Yin-Mao; Huo, Liang-Sheng; Zhu, Xiao-Ping; Li, Ting

    2007-06-01

    A novel spiral disk is designed by placing barricades at 6 mm intervals in the middle of the spiral channel to divide the channel into multiple sections. Glass beads are placed in every other section so that the planetary motion produces repetitive mixing and settling of polymer phase systems. Performance of this mixer-settler spiral disk assembly was examined for separation of lysozyme and myoglobin with a polymer phase system. The best results were obtained with a spiral disk equipped with barricades with openings ranging from 1.2 to 0.4 mm on each side at a high revolution speed up to 1200 rpm.

  6. Development of horn antenna mixer array with internal local oscillator module for microwave imaging diagnostics

    SciTech Connect

    Kuwahara, D.; Ito, N.; Nagayama, Y.; Yoshinaga, T.; Yamaguchi, S.; Yoshikawa, M.; Kohagura, J.; Sugito, S.; Kogi, Y.; Mase, A.

    2014-11-15

    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.

  7. Forward flight effects on mixer nozzle design and noise considerations for STOL externally blown flap systems

    NASA Technical Reports Server (NTRS)

    Vonglahn, U. H.; Sekas, N.; Groesbeck, D. E.; Huff, R. G.

    1972-01-01

    Experimental data of the peak axial-velocity decay in a moving airstream are presented for several types of nozzles. The nozzles include a six-tube mixer nozzle of a type considered for reduction of jet-flap interaction noise for externally-blown-flap STOL aircraft. The effect of secondary flow on the core flow velocity decay of a bypass nozzle is also discussed. Tentative correlation equations are suggested for the configurations evaluated. Recommendations for minimizing forward velocity effects on velocity decay and jet-flap interaction noise are made.

  8. Forward flight effects on mixer nozzle design and noise considerations for STOL externally blown flap systems.

    NASA Technical Reports Server (NTRS)

    Vonglahn, U. H.; Sekas, N.; Groesbeck, D. E.; Huff, R. G.

    1972-01-01

    Experimental data of the peak axial-velocity decay in a moving airstream are presented for several types of nozzles. The nozzles include a six-tube mixer nozzle of a type considered for reduction of jet-flap interaction noise for externally-blown-flap STOL aircraft. The effect of secondary flow on the core flow velocity decay of a bypass nozzle is also discussed. Tentative correlation equations are suggested for the configurations evaluated. Recommendations for minimizing forward velocity effects on velocity decay and jet-flap interaction noise are made.

  9. Low-noise room-temperature and cryogenic mixers for 80-120 GHz. [design for use on radio telescope

    NASA Technical Reports Server (NTRS)

    Kerr, A. R.

    1975-01-01

    A description is given of two new mixers designed to operate in the 80-120-GHz range on 36-ft radio telescope. It is shown that for a hard-driven diode the parasitic resistance and capacitance are the primary factors influencing the design of the diode mount. A room-temperature mixer is described which achieves a single-sideband (SSB) conversion loss (L) of 5.5 dB, and a SSB noise temperature (Tm) of 500 K (excluding the IF contribution) with a 1.4-GHz IF. A cryogenically cooled version, using a quartz structure to support the diode chip and contact whisker, achieves values of L = 5.8 dB and Tm = 300 K with a 4.75-GHz IF. The mixers use high-quality Schottky-barrier diodes in a one-quarter-height waveguide mount.

  10. The 0.9 and 1.3 THz Superconducting HEB Mixer Receiver for the ASTE 10 m Telescope

    NASA Astrophysics Data System (ADS)

    Shiino, T.; Furuya, R.; Soma, T.; Sakai, T.; Watanabe, Y.; Sakai, N.; Jiang, L.; Ohguchi, O.; Maezawa, H.; Yamakura, T.; Yamamoto, S.

    2013-10-01

    We have developed low-noise waveguide-type superconducting hot electron bolometer (HEB) mixers for astronomical observations in the 0.8-1.0 and 1.3-1.5 THz bands, by using a relatively thick NbTiN superconducting film (10.8 nm). The receiver noise temperature of 350 K (DSB) at 0.81 THz and 490 K at 1.475 THz has been achieved. We have built the 0.8-1.0/1.3-1.5 THz dual band heterodyne receiver using these low noise HEB mixers, and have installed it on the ASTE (Atacama Submillimeter Telescope Experiment) 10 m telescope in Chile in 2011. The 13CO emission (J = 8-7 : 0.8813 THz) has successfully been detected toward the Orion A molecular cloud with our HEB mixer receiver.

  11. Comparison between hot spot modeling and measurement of a superconducting hot electron bolometer mixer at submillimeter wavelengths

    NASA Astrophysics Data System (ADS)

    Miao, Wei; Delorme, Yan; Feret, Alexandre; Lefevre, Rolland; Lecomte, Benoit; Dauplay, Fred; Krieg, Jean-Michel; Beaudin, Gerard; Zhang, Wen; Ren, Yuan; Shi, Sheng-Cai

    2009-11-01

    This paper presents the modeling and measurement of a quasioptical niobium nitride superconducting hot electron bolometer mixer at submillimeter wavelengths. The modeling is performed with a distributed hot spot model which is based on solving a heat balance equation for electron temperature along the superconducting microbridge. Particular care has been taken during the modeling concerning the temperature-dependent resistance and the bias current dependence of the critical temperature of the device. The dc and mixing characteristics of this mixer have been computed and we have observed a quite good match between the predicted and the measured results for both dc characteristics and mixing performances at submillimeter wavelengths.

  12. Suspended Solids Profiler Shop Test Report

    SciTech Connect

    STAEHR, T.W.

    2000-01-19

    The Suspended Solids Profiler (SSP) Instrument is planned to be installed in the AZ-101 tank to measure suspended solids concentrations during mixer pump testing. The SSP sensor uses a reflectance measurement principle to determine the suspended solids concentrations. The purpose of this test is to provide a documented means of verifying that the functional components of the SSP operate properly.

  13. Hanford high level waste (HLW) tank mixer pump safe operating envelope reliability assessment

    SciTech Connect

    Fischer, S.R.; Clark, J.

    1993-10-01

    The US Department of Energy and its contractor, Westinghouse Corp., are responsible for the management and safe storage of waste accumulated from processing defense reactor irradiated fuels for plutonium recovery at the Hanford Site. These wastes, which consist of liquids and precipitated solids, are stored in underground storage tanks pending final disposition. Currently, 23 waste tanks have been placed on a safety watch list because of their potential for generating, storing, and periodically releasing various quantities of hydrogen and other gases. Tank 101-SY in the Hanford SY Tank Farm has been found to release hydrogen concentrations greater than the lower flammable limit (LFL) during periodic gas release events. In the unlikely event that an ignition source is present during a hydrogen release, a hydrogen burn could occur with a potential to release nuclear waste materials. To mitigate the periodic gas releases occurring from Tank 101-SY, a large mixer pump currently is being installed in the tank to promote a sustained release of hydrogen gas to the tank dome space. An extensive safety analysis (SA) effort was undertaken and documented to ensure the safe operation of the mixer pump after it is installed in Tank 101-SY.1 The SA identified a need for detailed operating, alarm, and abort limits to ensure that analyzed safety limits were not exceeded during pump operations.

  14. YBCO microwave grain boundary mixer using a SrTiO[sub 3] bicrystal substrate

    SciTech Connect

    Seed, R.G.; Dorsey, P.C.; How, H.; Widom, A.; Vittoria, C. )

    1993-11-01

    A microwave mixer was patterned on a microstrip transmission line of superconducting YBCO (YBa[sub 2]Cu[sub 3]O[sub 7[minus]x]). The YBCO film was epitaxially laser deposited on a SrTiO[sub 3] bicrystal substrate. A weak link was constructed by patterning a microbridge In the microstrip at the bicrystal boundary. Two microwave signals were applied at the input of the microstrip line, one signal at 9.000 GM and the other signal at 9.941 GHz. An output intermediate frequency signal was observed at 941 MHz and was detected as the transmitted signal. The microbridge junction, which behaved as a resistively shunted Josephson junction (RSJ), was current biased slightly above the critical current I[sub c]. The mixer conversion loss was measured at the input and output ports of the device package. With these measurements, the mixing efficiency was determined at the device junction, and this measured efficiency was compared with the calculated efficiency. The calculated efficiency was determined by numerical solution of the Josephson equation for the weak link junction.

  15. 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.

  16. 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.

  17. High speed velocimetry and concentration measurements in a microfluidic mixer using fluorescence confocal microscopy

    NASA Astrophysics Data System (ADS)

    Inguva, Venkatesh; Perot, Blair; Kathuria, Sagar; Rothstein, Jonathan; Bilsel, Osman

    2016-11-01

    This work experimentally examines the performance of a quasi-turbulent micro-mixer that was designed to produce rapid mixing for protein-folding experiments. The original design of the mixer was performed using Direct Numerical Simulation (DNS) of the flow field and LES of the high Sc number scalar field representing the protein. The experimental work is designed to validate the DNS results. Both the velocity field and the protein concentration require validation. Different experiments were carried out to measure these two quantities. Concentration measurements are performed using a 488nm continuous wave laser coupled with a confocal microscope to measure fluorescence intensity during mixing. This is calibrated using the case where no mixing occurs. The velocity measurements use a novel high speed velocimetry technique capable of measuring speeds on the order of 10 m/s in a micro channel. The technique involves creating a pulsed confocal volume from a Ti-Sapphire laser with a pulse width of 260ns and observing the decay of fluorescence due to the fluid motion. Results from both experiments will be presented along with a comparison to the DNS results. The work is supported by NSF IDBR Award No. 1353942.

  18. Laser direct writing 3D structures for microfluidic channels: flow meter and mixer

    NASA Astrophysics Data System (ADS)

    Lin, Chih-Lang; Liu, Yi-Jui; Lin, Zheng-Da; Wu, Bo-Long; Lee, Yi-Hsiung; Shin, Chow-Shing; Baldeck, Patrice L.

    2015-03-01

    The 3D laser direct-writing technology is aimed at the modeling of arbitrary three-dimensional (3D) complex microstructures by scanning a laser-focusing point along predetermined trajectories. Through the perspective technique, the details of designed 3D structures can be properly fabricated in a microchannel. This study introduces a direct reading flow meter and a 3D passive mixer fabricated by laser direct writing for microfluidic applications. The flow meter consists of two rod-shaped springs, a pillar, an anchor, and a wedge-shaped indicator, installed inside a microfluidic channel. The indicator is deflected by the flowing fluid while restrained by the spring to establish an equilibrium indication according to the flow rate. The measurement is readily carried out by optical microscopy observation. The 3D passive Archimedes-screw-shaped mixer is designed to disturb the laminar flow 3D direction for enhancing the mixing efficiency. The simulation results indicate that the screw provides 3D disturbance of streamlines in the microchannel. The mixing demonstration for fluids flowing in the micrchannel approximately agrees with the simulation result. Thanks to the advantage of the laser direct writing technology, this study performs the ingenious applications of 3D structures for microchannels.

  19. Structural design and analysis of a mixer pump for beyond-design- basis load

    SciTech Connect

    Rezvani, M.A.; Strehlow, J.P.; Baliga, R.; Kok, S.B.

    1994-03-01

    This paper presents the results of the structural evaluation of a mixer pump for a postulated drop accident. The mixer pump will be installed in a double-shell tank at the Hanford Site, near Richland, Washington. This tank has a 1,000,000-gallon (3,785,000 liter) capacity and is used to store radioactive waste before final disposal. The beyond-design-basis load case presented here is a postmulated drop of the pump during installation or removal. It is assumed that the pump assembly might be dropped approximateely 140 ft (15 m) from a height at which the bottom of the pump assembly is slightly above the top of the access riser to the bottom of the tank. The acceptance criterion for this load case is that the pump assembly shall not penetrate the primary tank liner. To ensure the integrity of the liner, the kinetic energy (developed in the pump drop) must be absorbed by some means to limit the impact force on the tank dome and thereby keep the pump from contacting the bottom of the tank. The limited clearance near the mounting assembly warranted an innovative two-step design of the energy absorbing system to limit the impact force on the tank dome to an acceptable value. This innovative design incorporates two energy absorbers in a unique series arrangement, one with the pump assembly and tile other in the pump pit.

  20. 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.

  1. 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.

  2. 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.

  3. Nanopatterning and Hot Spot Modeling of YBCO Ultrathin Film Constrictions for THz Mixers

    NASA Astrophysics Data System (ADS)

    Ladret, Romain G.; Degardin, Annick F.; Kreisler, Alain J.

    2013-06-01

    High-TC hot electron bolometers (HEB) are promising THz mixers due to their expected wide bandwidth, large mixing gain, and low intrinsic noise. To achieve this goal, 0.6-μm-size constrictions were patterned on YBaCuO-based, 10-40-nm-thick films grown on (100) MgO substrates, which as previously reported, exhibited good DC superconducting properties. In this paper, we have simulated the DC and mixer characteristics of YBaCuO HEBs with a hot spot model usually dedicated to low-TC devices. For a 100 nm × 100 nm × 10 nm constriction, the expected double sideband noise temperature TN is 2000 K for 5 μW local oscillator (LO) power (G = -13.5 dB conversion gain). For a larger (but more realistic according to YBaCuO aging effects) 600 nm × 1000 nm × 35 nm constriction, TN = 1300 K at 200 μW LO power (G = -12 dB). This approach is expected to allow optimizing the operation of the HEB constriction coupled to a THz planar antenna.

  4. 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.

  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. Numerical study of a novel induced-charge electrokinetic micro-mixer.

    PubMed

    Daghighi, Yasaman; Li, Dongqing

    2013-02-06

    A novel micro-mixer based on the induced-charge electrokinetic motion of an electrically conducting particle is proposed and numerically demonstrated in this paper. For most microfluidic applications, it is desired to mix different streams of solutions rapidly in a continuous flow mode. Therefore, in this work, we consider a mixing chamber containing an electrically conducting particle and the mixing chamber is located in the middle of a microchannel. Vortices are generated around the electrically conducting particle in an aqueous solution due to the interaction of the applied electric field and the induced surface charge on the particle. These vortices will enhance significantly the mixing of different solutions around the particle. The effectiveness of mixing the two streams entering the mixing chamber is numerically studied as functions of the applied electric field. Excellent mixing can be achieved in this system under two perpendicularly applied electric fields. The proposed micro-mixer is simple and easy to be fabricated for lab-on-a-chip applications.

  7. 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...

  8. 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…

  9. 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.

  10. 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.

  11. 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

  12. Superconducting Hot-Electron Bolometric Mixer Receivers, and Evolution of Ionized Nebulae

    NASA Astrophysics Data System (ADS)

    Kawamura, Hiroyuki Jonathan

    Receivers incorporating niobium nitride phonon-cooled hot-electron bolometric mixers have been constructed and characterized. The mixer elements are thin-film NbN microbridges with dimensions of ~4 nm thickness, 1-20 μm width and 1.5-4 μm length. These are incorporated in waveguide receivers operating at 200 GHz, 450 GHz, 660 GHz, and 900 GHz. Operating at 4.2 K, the double-sideband receiver noise temperatures in each frequency band were 750 K at 244 GHz, 410 K at 430 GHz, 483 K at 606 GHz, and 1150 K at 800 GHz, a an intermediate frequency of 1.4 GHz and 200 MHz bandwidth. The receiver noise temperature is generally less than 3 GHz K-1 for mixers most recently fabricated. The intermediate frequency bandwidth exceeds 2 GHz, and the local oscillator power for optimal mixing is ~1μW. In addition, the time-evolution of ionized nebulae was studied using difference maps generated by combining new high sensitivity Very Large Array radio interferometrer observations with archived data, separated by a time baseline of ~10 yr. The distances to two bright planetary nebulae are determined by detecting their expansion parallax: the distance to BD +30o3639 is 1.5 ± 0.4 kpc, and to NGC 6572 is 1.2 ± 0.4 kpc. These distances incorporate a new correction term, and are considerably more accurate than those reported previously. The difference mapping technique is for the first time used to study another class of objects, and applied to observe changes in two bright, well-studied compact H scII regions, W 3(OH) and NGC 7538. W 3(OH) is observed to expand at a rate of 3 km s-1, which although significantly smaller than the plasma sound speed, implies an age of ~3×103 yr. This measurement has important consequences for modeling evolution of compact H scII regions. In contrast NGC 7538 exhibits significant changes in the structure whose interpretation is difficult, but nevertheless suggest that structures observed in compact H scII regions are not static.

  13. Hybrid Lattice Boltzmann Method for the Simulation of Blending Process in Static Mixers

    NASA Astrophysics Data System (ADS)

    Latt, Jonas; Kontaxakis, Dimitrios; Chatagny, Laurent; Muggli, Felix; Chopard, Bastien

    2013-12-01

    A lattice Boltzmann method is proposed to simulate the blending of two fluids in static, laminar mixers. The method uses a mesh-based algorithm to solve for the fluid flow, and a meshless technique to trace the interface between the blended fluids. This hybrid approach is highly accurate, because the position of the interface can be traced beyond the resolution of the grid. The numerical diffusion is negligible in this model, and it is possible to reproduce mixing patterns that contain more than one hundred striations with high fidelity. The implementation of this method in the massively parallel library Palabos is presented, and simulation results are compared with experimental data to emphasize the accuracy of the results.

  14. Scalable ionic gelation synthesis of chitosan nanoparticles for drug delivery in static mixers.

    PubMed

    Dong, Yuancai; Ng, Wai Kiong; Shen, Shoucang; Kim, Sanggu; Tan, Reginald B H

    2013-05-15

    The purpose of this study is to synthesize chitosan (CS) nanoparticles (NPs) by ionic gelation with tripolyphosphate (TPP) as crossslinker in static mixers. The proposed static mixing technique showed good control over the ionic gelation process and 152-376 nm CS NPs were achieved in a continuous and scalable mode. Increasing the flow rates of CS:TPP solution streams, decreasing the CS concentration or reducing the CS:TPP solution volume ratio led to the smaller particles. Sylicylic acid (SA) was used as a model drug and successfully loaded into the CS NPs during the fabrication process. Our work demonstrates that ionic gelation-static mixing is a robust platform for continuous and large scale production of CS NPs for drug delivery.

  15. 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.

  16. Mixer-settler counter-current chromatography with multiple spiral disk assembly.

    PubMed

    Ito, Yoichiro; Clary, Robert; Sharpnak, Frank; Metger, Howard; Powell, Jimmie

    2007-11-23

    A novel system for performing high-speed counter-current chromatography has been developed for separation of biopolymers using polymer phase systems. The spiral disk assembly consisting of eight units, each equipped with over 300 mixer-settler sets, was constructed and performance evaluated in terms of retention of the stationary phase and separation efficiency. A series of experiments was performed with a polymer phase system composed of polyethylene glycol 1000 (12.5%, w/w) and dibasic potassium phosphate (12.5%, w/w) using two stable protein samples of myoglobin and lysozyme at various experimental conditions of flow rates and revolution speeds. The best results were obtained with revolution speeds of 800-1000rpm at flow rates of 0.25-0.5ml/min where the partition efficiency of several 100 theoretical plates was achieved with over 50% stationary phase retention.

  17. 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.

  18. Test Procedure - pumping system for caustic addition project

    SciTech Connect

    Leshikar, G.A.

    1994-10-01

    This test procedure provides the requirements for sub-system testing and integrated operational testing of the submersible mixer pump and caustic addition equipment by WHC and Kaiser personnel at the Rotating Equipment Shop run-in pit (Bldg. 272E).

  19. A high linearity current mode second IF CMOS mixer for a DRM/DAB receiver

    NASA Astrophysics Data System (ADS)

    Jian, Xu; Zheng, Zhou; Yiqiang, Wu; Zhigong, Wang; Jianping, Chen

    2015-05-01

    A passive current switch mixer was designed for the second IF down-conversion in a DRM/DAB receiver. The circuit consists of an input transconductance stage, a passive current switching stage, and a current amplifier stage. The input transconductance stage employs a self-biasing current reusing technique, with a resistor shunt feedback to increase the gain and output impedance. A dynamic bias technique is used in the switching stage to ensure the stability of the overdrive voltage versus the PVT variations. A current shunt feedback is introduced to the conventional low-voltage second-generation fully balanced multi-output current converter (FBMOCCII), which provides very low input impedance and high output impedance. With the circuit working in current mode, the linearity is effectively improved with low supply voltages. Especially, the transimpedance stage can be removed, which simplifies the design considerably. The design is verified with a SMIC 0.18 μm RF CMOS process. The measurement results show that the voltage conversation gain is 1.407 dB, the NF is 16.22 dB, and the IIP3 is 4.5 dBm, respectively. The current consumption is 9.30 mA with a supply voltage of 1.8 V. This exhibits a good compromise among the gain, noise, and linearity for the second IF mixer in DRM/DAB receivers. Project supported by the National Natural Science Foundation of China (No. 61306069), and the National High Technology Research and Development Program of China (No. 2011AA010301).

  20. Artificial sweeteners versus regular mixers increase breath alcohol concentrations in male and female social drinkers

    PubMed Central

    Marczinski, Cecile A.; Stamates, Amy L.

    2012-01-01

    Background Limited research suggests that alcohol consumed with an artificially sweetened mixer (e.g., diet soft drink) results in higher breath alcohol concentrations (BrACs) compared to the same amount of alcohol consumed with a similar beverage containing sugar. The purpose of this study was to determine the reliability of this effect in both male and female social drinkers and to determine if there are measureable objective and subjective differences when alcohol is consumed with an artificially-sweetened versus sugar-sweetened mixer. Methods Participants (n = 16) of equal gender attended three sessions where they received one of 3 doses (1.97 ml/kg vodka mixed with 3.94 ml/kg Squirt, 1.97 ml/kg vodka mixed with 3.94 ml/kg diet Squirt, and a placebo beverage) in random order. BrACs were recorded, as was self-reported ratings of subjective intoxication, fatigue, impairment and willingness to drive. Objective performance was assessed using a cued go/no-go reaction time task. Results BrACs were significantly higher in the alcohol + diet beverage condition compared with the alcohol + regular beverage condition. The mean peak BrAC was .091 g/210 L in the alcohol + diet condition compared to .077 g/210 L in the alcohol + regular condition. Cued go/no-go task performance indicated the greatest impairment for the alcohol + diet beverage condition. Subjective measures indicated that participants appeared unaware of any differences in the two alcohol conditions, given that no significant differences in subjective ratings were observed for the two alcohol conditions. No gender differences were observed for BrACs, objective and subjective measures. Conclusions Mixing alcohol with a diet soft drink resulted in elevated BrACs, as compared to the same amount of alcohol mixed with a sugar sweetened beverage. Individuals were unaware of these differences, a factor that may increase the safety risks associated with drinking alcohol. PMID:23216417

  1. 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.

  2. A fully integrated folded mixer in CMOS 0.35 µm technology for 802.11a WIFI applications

    NASA Astrophysics Data System (ADS)

    del Pino, J.; Díaz, R.; Afonso, M.; Cabrera, F.; Iturri, A.; Khemchandani, S. L.

    2007-05-01

    In the last years, Wireless market has shown an incredible growth, exceeding expectations. This paper presents a fully integrated folded mixer in a BiCMOS 0.35 μm technology for the 5 GHz band, according to the IEEE 802.11a WIFI standard. To make possible a comparison, two designs are presented: a folded mixer, and a classical Gilbert cell. In both designs all passives devices are on chip, including integrated inductors which have been designed by electromagnetic simulations. This work demonstrates the improvement in gain and linearity of a folded mixer comparing to a classical Gilbert topology, at expense of a little increase in power consumption. This implies that, unlike the Gilbert mixer, in a low voltage application, the folded topology would present still good performance.

  3. A Comparative Study of Fiber Break-up During Compounding of Glass Fiber-Reinforced Polyamide in Batch and Continuous Mixers

    NASA Astrophysics Data System (ADS)

    Inceoglu, Funda; Ville, Julien; Ghamri, Nessim; Durin, Audrey; De Micheli, Pascal; Valette, Rudy; Vergnes, Bruno

    2010-06-01

    Glass fiber breakage during compounding was determined for both batch and continuous mixers including an internal mixer and two different co-rotating twin screw extruders; of laboratory and industrial scales. The effect of processing conditions such as screw speed, feed rate and screw profiles on fiber damage was investigated. Finally, the results of experimental studies were discussed, compared and interpreted using a model for fiber breakage.

  4. 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

  5. InAs nanowire MOSFETs in three-transistor configurations: single balanced RF down-conversion mixers.

    PubMed

    Berg, Martin; Persson, Karl-Magnus; Wu, Jun; Lind, Erik; Sjöland, Henrik; Wernersson, Lars-Erik

    2014-12-05

    Integration of III-V semiconductors on Si substrates allows for the realization of high-performance, low power III-V electronics on the Si-platform. In this work, we demonstrate the implementation of single balanced down-conversion mixer circuits, fabricated using vertically aligned InAs nanowire devices on Si. A thin, highly doped InAs buffer layer has been introduced to reduce the access resistance and serve as a bottom electrode. Low-frequency voltage conversion gain is measured up to 7 dB for a supply voltage of 1.5V. Operation of these mixers extends into the GHz regime with a -3 dB cut-off frequency of 2 GHz, limited by the optical lithography system used. The circuit dc power consumption is measured at 3.9 mW.

  6. Low noise terahertz MgB2 hot-electron bolometer mixers with an 11 GHz bandwidth

    NASA Astrophysics Data System (ADS)

    Novoselov, E.; Cherednichenko, S.

    2017-01-01

    Terahertz (THz) hot-electron bolometer mixers reach a unique combination of low noise, wide noise bandwidth, and high operation temperature when 6 nm thick superconducting MgB2 films are used. We obtained a noise bandwidth of 11 GHz with a minimum receiver noise temperature of 930 K with a 1.63 THz Local Oscillator (LO), and a 5 K operation temperature. At 15 K and 20 K, the noise temperature is 1100 K and 1600 K, respectively. From 0.69 THz to 1.63 THz, the receiver noise increases by only 12%. Device current-voltage characteristics are identical when pumped with LOs from 0.69 THz up to 2.56 THz, and match well with IVs at elevated temperatures. Therefore, the effect of the THz waves on the mixer is totally thermal, due to absorption in the π conduction band of MgB2.

  7. Ultra-high throughput synthesis of nanoparticles with homogeneous size distribution using a coaxial turbulent jet mixer.

    PubMed

    Lim, Jong-Min; Swami, Archana; Gilson, Laura M; Chopra, Sunandini; Choi, Sungyoung; Wu, Jun; Langer, Robert; Karnik, Rohit; Farokhzad, Omid C

    2014-06-24

    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.

  8. 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.

  9. 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.

  10. A simple three-dimensional-focusing, continuous-flow mixer for the study of fast protein dynamics

    PubMed Central

    Burke, Kelly S.; Parul, Dzmitry; Reddish, Michael J.; Dyer, R. Brian

    2013-01-01

    We present a simple, yet flexible microfluidic mixer with a demonstrated mixing time as short as 80 µs that is widely accessible because it is made of commercially available parts. To simplify the study of fast protein dynamics, we have developed an inexpensive continuous-flow microfluidic mixer, requiring no specialized equipment or techniques. The mixer uses three-dimensional, hydrodynamic focusing of a protein sample stream by a surrounding sheath solution to achieve rapid diffusional mixing between the sample and sheath. Mixing initiates the reaction of interest. Reactions can be spatially observed by fluorescence or absorbance spectroscopy. We characterized the pixel-to-time calibration and diffusional mixing experimentally. We achieved a mixing time as short as 80 µs. We studied the kinetics of horse apomyoglobin (apoMb) unfolding from the intermediate (I) state to its completely unfolded (U) state, induced by a pH jump from the initial pH of 4.5 in the sample stream to a final pH of 2.0 in the sheath solution. The reaction time was probed using the fluorescence of 1-anilinonapthalene-8-sulfonate (1,8-ANS) bound to the folded protein. We observed unfolding of apoMb within 760 µs, without populating additional intermediate states under these conditions. We also studied the reaction kinetics of the conversion of pyruvate to lactate catalyzed by lactate dehydrogenase using the intrinsic tryptophan emission of the enzyme. We observe sub-millisecond kinetics that we attribute to Michaelis complex formation and loop domain closure. These results demonstrate the utility of the three-dimensional focusing mixer for biophysical studies of protein dynamics. PMID:23760106

  11. Quarterly review of 241-SY-101 mixer pump data: January - March 1999

    SciTech Connect

    CONNER, J.M.

    1999-07-22

    This report presents data obtained on 241-SY-101 pump performance. The period covered is January 1 through March 31, 1999. During the quarter: There were changes in pumping parameters. Both the pump volute pressure and amperage decreased during the quarter. It is not clear whether this was due to changes in waste properties (due to less solids or more entrained gas) or due to degradation of the pump. There was an indication of a 7.5-inch increase in the waste level at riser 1 A, and an average growth rate of 0.082 inches per day. There was an indication of a 5.7-inch increase in the waste level at riser 1C. This riser was flushed with water several times, which would lower the level of the crust at this location. Gases continued to be released at less than the pre-pump installation baseline rate, indicating a decrease in the gas generation rate, or an increase in gas retention, or both. The release rate was about 78 percent of the rate in the previous few quarters, and only 34 percent of the generation rate calculated prior to mixer pump installation in 1993. Key controls exist for waste temperature, gas concentration, pump parameters, and long-term waste behavior associated with the safe operation of the mixer pump that mitigates the buoyant displacement gas release event behavior of 241-SY-101. Table 1-1 compares the key controls and the current state of the waste as of March 3 1. 1999. The pump was run 28 times between January 1 and March 31, 1999. All of the pump runs were intended to be normal 25-minute, 1000-rpm excavation runs performed to mix the waste and release gas. Because of the pump oil often reached the high temperature alarm setpoint of 190 F, many of the runs were shortened (by as many as 8 minutes). This phenomenon was identified in November 1998, but got progressively worse over the quarter. The pump schedule was nominally three runs per week. However, core sampling activities interrupted the usual pump schedule several times during the quarter

  12. 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.

  13. DESIGN OF 2.4 GHZ CMOS DIRECT CONVERSION LNA AND MIXER COMBINATION FOR WIRLESS DATA LINK TRANSCEIVER.

    SciTech Connect

    ZHAO, D.; OCONNOR, P.

    2002-04-10

    Three LNA and mixer combinations in 0.6{micro}m and 0.4{micro}m standard CMOS processes for direct-conversion receiver of 2.4GHz ISM band short-range wireless data-link applications are described in this paper. Taking low power dissipation as first consideration, these designs, employing differential common-source LNA and double balanced mixer architectures, achieve total conversion gain as high as 42.4dB, DSB noise figure as low as 9.5dB, output-referred IP3 as high as of 21.3dBm at about 4mA DC current consumption. This proves it is possible to apply standard CMOS process to implement receiver front-end with low power dissipation for this kind of application, but gain changeable LNA is needed to combat the dominant flicker noise of the mixer in order to achieve acceptable sensitivity and dynamic range at the same time.

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

    NASA Astrophysics Data System (ADS)

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

    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.

  15. Design and analysis of In 0.53Ga 0.47As/InP symmetric gain optoelectronic mixers

    NASA Astrophysics Data System (ADS)

    Zhang, Wang; Emanetoglu, Nuri W.; Bambha, Neal; Bickford, Justin R.

    2010-12-01

    A symmetric gain optoelectronic mixer based on an indium gallium arsenide (In 0.53Ga 0.47As)/indium phosphide (InP) symmetric heterojunction phototransistor structure is being investigated for chirped-AM laser detection and ranging (LADAR) systems operating in the "eye-safe" 1.55 μm wavelength range. Signal processing of a chirped-AM LADAR system is simplified if the photodetector in the receiver is used as an optoelectronic mixer (OEM). Adding gain to the OEM allows the following transimpedance amplifier's gain to be reduced, increasing bandwidth and improving the system's noise performance. A symmetric gain optoelectronic mixer based on a symmetric phototransistor structure using an indium gallium arsenide narrow bandgap base and indium phosphide emitter/collector layers is proposed. The devices are simulated with the Synopsis TCAD Sentaurus tools. The effects of base-emitter interface layers, base thickness and the doping densities of the base and emitters on the device performance are investigated. AC and DC simulation results are compared with a device model. Improved responsivity and lower dark current are predicted for the optimized InGaAs/InP device over previously reported devices with indium aluminum arsenide emitter/collector layers.

  16. 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.

  17. Using a modified shepards method for optimization of a nanoparticulate cyclosporine a formulation prepared by a static mixer technique.

    PubMed

    Douroumis, Dionysios; Scheler, Stefan; Fahr, Alfred

    2008-02-01

    An innovative methodology has been used for the formulation development of Cyclosporine A (CyA) nanoparticles. In the present study the static mixer technique, which is a novel method for producing nanoparticles, was employed. The formulation optimum was calculated by the modified Shepard's method (MSM), an advanced data analysis technique not adopted so far in pharmaceutical applications. Controlled precipitation was achieved injecting the organic CyA solution rapidly into an aqueous protective solution by means of a static mixer. Furthermore the computer based MSM was implemented for data analysis, visualization, and application development. For the optimization studies, the gelatin/lipoid S75 amounts and the organic/aqueous phase were selected as independent variables while the obtained particle size as a dependent variable. The optimum predicted formulation was characterized by cryo-TEM microscopy, particle size measurements, stability, and in vitro release. The produced nanoparticles contain drug in amorphous state and decreased amounts of stabilizing agents. The dissolution rate of the lyophilized powder was significantly enhanced in the first 2 h. MSM was proved capable to interpret in detail and to predict with high accuracy the optimum formulation. The mixer technique was proved capable to develop CyA nanoparticulate formulations.

  18. Interferometric source of multi-color, multi-beam entangled photons with mirror and mixer

    DOEpatents

    Dress, William B.; Kisner, Roger A.; Richards, Roger K.

    2004-06-01

    53 Systems and methods are described for an interferometric source of multi-color, multi-beam entangled photons. An apparatus includes: a multi-refringent device optically coupled to a source of coherent energy, the multi-refringent device providing a beam of multi-color entangled photons; a condenser device optically coupled to the multi-refringent device, the condenser device i) including a mirror and a mixer and ii) converging two spatially resolved portions of the beam of multi-color entangled photons into a converged multi-color entangled photon beam; a tunable phase adjuster optically coupled to the condenser device, the tunable phase adjuster changing a phase of at least a portion of the converged multi-color entangled photon beam to generate a first interferometeric multi-color entangled photon beam; and a beam splitter optically coupled to the condenser device, the beam splitter combining the first interferometeric multi-color entangled photon beam with a second interferometric multi-color entangled photon beam.

  19. Bioactive insulin microparticles produced by supercritical fluid assisted atomization with an enhanced mixer.

    PubMed

    Du, Zhe; Tang, Chuan; Guan, Yi-Xin; Yao, Shan-Jing; Zhu, Zi-Qiang

    2013-09-15

    Supercritical fluid assisted atomization introduced by a hydrodynamic cavitation mixer (SAA-HCM) was used to micronize insulin from aqueous solution without use of any organic solvents. Insulin microparticles produced under different operating conditions including solution type, solution concentration and precipitator temperature presented distinct morphologies such as highly folded, partly deflated, corrugated or smooth hollow spherical shape. Solution concentration had a striking influence on particle size, and insulin microparticles produced from acidic solution had mean diameters increasing from 1.4 μm to 2.7 μm when protein concentration increased from 3g/L to 50 g/L. HPLC chromatograms showed no degradation of insulin after SAA-HCM processing and FTIR, CD and fluorescence data further confirmed the structural stability. TGA analysis revealed that insulin microparticles remained moderate moisture content compared with raw material. In vivo study showed that insulin processed by SAA-HCM from acidic solution retained identical bioactivity. SAA-HCM is demonstrated to be a very promising process for insulin inhaled formulation development.

  20. Analysis of a laminar-flow diffusional mixer for directed self-assembly of liposomes.

    PubMed

    Kennedy, Matthew J; Ladouceur, Harold D; Moeller, Tiffany; Kirui, Dickson; Batt, Carl A

    2012-01-01

    The present work describes the operation and simulation of a microfluidic laminar-flow mixer. Diffusive mixing takes place between a core solution containing lipids in ethanol and a sheath solution containing aqueous buffer, leading to self assembly of liposomes. Present device architecture hydrodynamically focuses the lipid solution into a cylindrical core positioned at the center of a microfluidic channel of 125 × 125-μm(2) cross-section. Use of the device produces liposomes in the size range of 100-300 nm, with larger liposomes forming at greater ionic strength in the sheath solution and at lower lipid concentration in the core solution. Finite element simulations compute the concentration distributions of solutes at axial distances of greater than 100 channel widths. These simulations reduce computation time and enable computation at long axial distances by utilizing long hexahedral elements in the axial flow region and fine tetrahedral elements in the hydrodynamic focusing region. Present meshing technique is generally useful for simulation of long microfluidic channels and is fully implementable using comsol Multiphysics. Confocal microscopy provides experimental validation of the simulations using fluorescent solutions containing fluorescein or enhanced green fluorescent protein.

  1. Physical-chemical properties of furosemide nanocrystals developed using rotation revolution mixer.

    PubMed

    Barbosa, Sávio Fujita; Takatsuka, Takayuki; Tavares, Guilherme Diniz; Araújo, Gabriel Lima Barros; Wang, Hui; Vehring, Reinhard; Löbenberg, Raimar; Bou-Chacra, Nádia Araci

    2016-11-01

    Recently, several approaches have been reported to improve the dissolution rate and bioavailability of furosemide, a class IV drug. However, to the best of our knowledge, none of them proposed nanocrystals. In the last decade, nanocrystals successfully addressed solubility issues by increasing surface area and saturation solubility, both leading to an increase in the dissolution rate of poor water soluble drugs. The preparation of furosemide nanocrystals was by a rotation revolution mixer method. Size distribution and morphology were performed using laser diffraction and scanning electron microscopy, respectively. In addition, differential scanning calorimetry, thermogravimetry, X-ray powder diffraction (XRD) and low frequency shift-Raman spectroscopy allowed investigating the thermal properties and crystalline state. Solubility saturation and intrinsic dissolution rate (IDR) studies were conducted. The thermal analysis revealed lower melting range for the nanocrystals comparing to furosemide. Moreover, a slight crystalline structure change to the amorphous state was observed by XRD and confirmed by low frequency shift Raman. The particle size was reduced to 231 nm with a polydispersity index of 0.232, a 30-fold reduction from the original powder. Finally, the saturation solubility and IDR showed a significant increase. Furosemide nanocrystals showed potential for development of innovative formulations as an alternative to the commercial products.

  2. Analysis of a laminar-flow diffusional mixer for directed self-assembly of liposomes

    PubMed Central

    Kennedy, Matthew J.; Ladouceur, Harold D.; Moeller, Tiffany; Kirui, Dickson; Batt, Carl A.

    2012-01-01

    The present work describes the operation and simulation of a microfluidic laminar-flow mixer. Diffusive mixing takes place between a core solution containing lipids in ethanol and a sheath solution containing aqueous buffer, leading to self assembly of liposomes. Present device architecture hydrodynamically focuses the lipid solution into a cylindrical core positioned at the center of a microfluidic channel of 125 × 125-μm2 cross-section. Use of the device produces liposomes in the size range of 100–300 nm, with larger liposomes forming at greater ionic strength in the sheath solution and at lower lipid concentration in the core solution. Finite element simulations compute the concentration distributions of solutes at axial distances of greater than 100 channel widths. These simulations reduce computation time and enable computation at long axial distances by utilizing long hexahedral elements in the axial flow region and fine tetrahedral elements in the hydrodynamic focusing region. Present meshing technique is generally useful for simulation of long microfluidic channels and is fully implementable using comsol Multiphysics. Confocal microscopy provides experimental validation of the simulations using fluorescent solutions containing fluorescein or enhanced green fluorescent protein. PMID:24348890

  3. 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.

  4. Quarterly review of 241-SY-101 mixer pump data: October - December, 1998

    SciTech Connect

    CONNER, J.M.

    1999-05-11

    This report presents data obtained on 241-SY-101 pump performance. The period covered is October 1 through December 31, 1998. During the quarter: (1) There was an indication of a 7.0-inch increase in the waste level at riser lA, and an average growth rate of 0.076 inches per day. (2) There was an indication of a 2.3-inch increase in the waste level at riser 1C. This riser was flushed with water several times, which would lower the level of the crust at this location. (3) Gases continued to be released at less than the pre-pump installation baseline rate, indicating a decrease in the gas generation rate, or an increase in gas retention, or both. The release rate was about 60 percent of the rate in the previous few quarters, and only 44 percent of the pre-pump release rate. (4) There was no change in the parameters that monitor pump performance. Key controls exist for waste temperature, gas concentration, pump parameters, and long-term waste behavior associated with the safe operation of the mixer pump that mitigates the buoyant displacement gas release event behavior of 241-SY-101. Table 1-1 compares the key controls and the current state of the waste as of December 31, 1998.

  5. Influence of Geometry and Flow Variation on Jet Mixing and NO Formation in a Model Staged Combustor Mixer with Eight Orifices

    NASA Technical Reports Server (NTRS)

    Samuelsen, G. S.; Sowa, W. A.; Hatch, M. S.

    1996-01-01

    A series of non-reacting parametric experiments was conducted to investigate the effect of geometric and flow variations on mixing of cold jets in an axis-symmetric, heated cross flow. The confined, cylindrical geometries tested represent the quick mix region of a Rich-Burn/Quick-Mix/Lean-Burn (RQL) combustor. The experiments show that orifice geometry and jet to mainstream momentum-flux ratio significantly impact the mixing characteristic of jets in a cylindrical cross stream. A computational code was used to extrapolate the results of the non-reacting experiments to reacting conditions in order to examine the nitric oxide (NO) formation potential of the configurations examined. The results show that the rate of NO formation is highest immediately downstream of the injection plane. For a given momentum-flux ratio, the orifice geometry that mixes effectively in both the immediate vicinity of the injection plane, and in the wall regions at downstream locations, has the potential to produce the lowest NO emissions. The results suggest that further study may not necessarily lead to a universal guideline for designing a low NO mixer. Instead, an assessment of each application may be required to determine the optimum combination of momentum-flux ratio and orifice geometry to minimize NO formation. Experiments at reacting conditions are needed to verify the present results.

  6. Fiscal year 1993 1/25-scale sludge mobilization testing

    SciTech Connect

    Powell, M.R.; Golcar, G.R.; Hymas, C.R.; McKay, R.L.

    1995-04-01

    Sixteen 1/25-scale sludge mobilization experiments were conducted in fiscal year (FY) 1993. The results of this testing are presented in this document. The ability of a single, centrally-located, scale model mixer pump to resuspend a layer of simulated tank sludge was evaluated for five different simulant types. The resistance of these simulants to the mobilizing action of the mixer pump jets was not found to adequately correlate with simulant vane shear strength. The data indicate that the simulant cohesion, as quantified by tensile strength, may provide a good measure of mobilization resistance. A single test was done to evaluate whether indexed mixer pump rotation is significantly more effective than the planned continuous oscillation. No significant difference was found in the sludge mobilization caused by these two modes of operation. Two tests were conducted using a clay-based sludge simulant that contained approximately 5 wt% soluble solids. The distance to which the mixer pump jets were effective for this simulant was approximately 50% greater than on similar simulants that did not contain soluble solids. The implication is that sludge dissolution effects may significantly enhance the performance of mixer pumps in some tanks. The development of a means to correlate the magnitude of this effect with waste properties is a direction for future work. Two tests were performed with the goal of determining whether the 1/25-scale sludge mobilization data can be scaled linearly to 1/12-scale. The two 1/25-scale tests were conducted using the same simulant recipe as had been used in previous 1/12-scale tests. The difficulty of matching the 1/25-scale simulants, with those used previously is thought to have adversely affected the results. Further tests are needed to determine whether the data from sludge mobilization tests can be linearly scaled.

  7. Ultrasonic interface level analyzer shop test procedure

    SciTech Connect

    STAEHR, T.W.

    1999-05-24

    The Royce Instrument Corporation Model 2511 Interface Level Analyzer (URSILLA) system uses an ultrasonic ranging technique (SONAR) to measure sludge depths in holding tanks. Three URSILLA instrument assemblies provided by the W-151 project are planned to be used during mixer pump testing to provide data for determining sludge mobilization effectiveness of the mixer pumps and sludge settling rates. The purpose of this test is to provide a documented means of verifying that the functional components of the three URSILLA instruments operate properly. Successful completion of this Shop Test Procedure (STP) is a prerequisite for installation in the AZ-101 tank. The objective of the test is to verify the operation of the URSILLA instruments and to verify data collection using a stand alone software program.

  8. 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.

  9. 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

  10. A handheld LED coloured-light mixer for students to learn collaboratively the primary colours of light

    NASA Astrophysics Data System (ADS)

    Nopparatjamjomras, Suchai; Chitaree, Ratchapak; Panijpan, Bhinyo

    2009-03-01

    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 light-emitting diodes (LEDs) producing primary colours are combined with green intensity varying circuitry to generate the standard colour-triangle secondary colours and various shades ranging from yellow to orange and pale blue to cyan. In the laboratory, students worked collaboratively, predicting, observing and explaining, and finally discussing until there was a consensus.

  11. Simulated performance of SIS and SIN junctions as heterodyne receivers in waveguide and open antenna mixer mounts

    NASA Astrophysics Data System (ADS)

    Davies, S. R.; Shafiee, R.; Little, L. T.

    1990-02-01

    Tucker's quantum theory of mixing (in the 3-port approximation) is employed to calculate the gain over a wide range of frequencies of model mixers employing SIS and SIN junctions with both real and ideal I V characteristics. A comparison is made between the performance of junctions in waveguide and open antenna mounts. It is concluded that ideal junctions give gain 1.5 to 2 times higher than real ones, SIS junctions have gain approximately three times greater than otherwise similar SIN junctions, and that junction areas need to be typically three times smaller in open antenna structures to provide comparable gain to those in waveguide mounts.

  12. 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.

  13. 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.

  14. 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.

  15. Novel flat-plate photobioreactors for microalgae cultivation with special mixers to promote mixing along the light gradient.

    PubMed

    Huang, Jianke; Li, Yuanguang; Wan, Minxi; Yan, Yi; Feng, Fei; Qu, Xiaoxing; Wang, Jun; Shen, Guomin; Li, Wei; Fan, Jianhua; Wang, Weiliang

    2014-05-01

    Novel flat-plate photobioreactors (PBRs) with special mixers (type-a, type-b, and type-c) were designed based on increased mixing degree along the light gradient. The hydrodynamic and light regime characteristic of the novel PBRs were investigated through computational fluid dynamics. Compared with the control reactor without mixer, the novel reactors can effectively increase liquid velocity along the light gradient, the frequency of light/dark (L/D) cycles, and the algal growth rates of Chlorella pyrenoidosa. The maximum biomass concentrations in type-a, type-b, and type-c reactors were 42.9% (1.3 g L(-1)), 31.9% (1.2 g L(-1)), and 20.9% (1.1 g L(-1)) higher than that in the control reactor (0.91 g L(-1)), respectively, at an aeration rate of 1.0 vvm. Correlation analysis of algal growth rate with the characteristics of mixing and light regime shows the key factors affecting algal photoautotrophic growth are liquid velocity along the light gradient and L/D cycles rather than the macro-mixing degree.

  16. Noise temperature and beam pattern of an NbN hot electron bolometer mixer at 5.25 THz

    NASA Astrophysics Data System (ADS)

    Zhang, W.; Khosropanah, P.; Gao, J. R.; Bansal, T.; Klapwijk, T. M.; Miao, W.; Shi, S. C.

    2010-11-01

    We report the measured sensitivities of a superconducting NbN hot electron bolometer (HEB) heterodyne receiver at 5.25 THz. Terahertz (THz) radiation is quasioptically coupled to a HEB mixer with a lens and a spiral antenna. Using a measurement setup with black body calibration sources and a beam splitter in vacuo, and an antireflection coated Si lens, we obtained a double sideband (DSB) receiver noise temperature (TrecDSB) of 1150 K, which is nine times hν/2k, where h is the Planck constant, ν the frequency, and k the Boltzmann constant. In addition, the measured far field beam patterns of the integrated lens antenna show nearly collimated beams from 2.5 to 5.3 THz that allow reliable measurement of TrecDSB using the vacuum setup. Our experimental results in combination with an antenna-to-bolometer coupling simulation suggest that the HEB mixer can work well at least up to 6 THz, making it suitable for next generation of high-resolution spectroscopic space telescopes and, in particular, for the detection of the neutral atomic oxygen line at 4.7 THz.

  17. 50 MHz–10 GHz Low-Power Resistive Feedback Current-Reuse Mixer with Inductive Peaking for Cognitive Radio Receiver

    PubMed Central

    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. PMID:25133252

  18. 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…

  19. Further development of a method for computing three-dimensional subsonic viscous flows in turbofan lobe mixers

    NASA Technical Reports Server (NTRS)

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

    1983-01-01

    Procedure for computing subsonic, turbulent flow in turbofan lobe mixers was extended to allow consideration of flow fields in which a swirl component of velocity may be present. Additional, an optional k-lambda turbulence model was added to the procedure. The method of specifying the initial flow field was also modified, allowing parametric specification or radial secondary flow velocities, and making it possible to consider initial flow fields which have significant inlet secondary flow vorticity. A series of example calculations was performed which demonstrate the various capabilities of the modified code. These calculations demonstrate the effects of initial secondary flows of various magnitudes, the effects of swirl, and the effects of turbulence model on the mixing process. The results of these calculations indicate that the initial secondary flows, presumed to be generated within the lobes, play a dominant role in the mixing process, and that the predicted results are relatively insensitive to the turbulence model used.

  20. 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.

  1. Coupling of a microfluidic mixer to a Fourier-transform infrared spectrometer for protein-conformation studies.

    PubMed

    Prim, Denis; Crelier, Simon; Segura, Jean-Manuel

    2011-01-01

    The biological properties of a protein critically depend on its conformation, which can vary as a result of changes in conditions such as pH or following the addition of various substances. Being able to reliably assess the quality of protein structures under various conditions is therefore of crucial importance. Infrared (IR) spectroscopy of the Amide I band of proteins is a powerful method for the determination of protein conformations and further allows the analysis of continuously flowing solutions of the target molecule. Here, a commercial Fourier-transform infrared spectrometer was coupled to a microfluidic mixer to allow the on-line monitoring of protein conformation under varying conditions. The validity of the concept was demonstrated by continuously recording the variations of the IR spectrum of poly-L-lysine resulting from repetitive, pH-induced conformational changes.

  2. Analysis of continuous solvent extraction of nickel from spent electroless nickel plating baths by a mixer-settler.

    PubMed

    Huang, Ying; Tanaka, Mikiya

    2009-05-30

    It is urgent to develop an effective technique to treat the large amount of spent electroless nickel plating bath and recycle the high concentration nickel. In our previous study, high recycling efficiency of nickel from the model spent bath was obtained by continuous solvent extraction with 2-hydroxy-5-nonylacetophenone oxime (LIX84I) as the extractant and 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester (PC88A) as the accelerator using a mixer-settler extractor. It was observed that the extraction efficiency was affected by the operation parameters such as the flow rates of the aqueous and organic phases and the total stage number. In the present study, the effects of the operation parameters on the extraction efficiency were quantitatively studied on the basis of the pseudo-first-order interfacial extraction rate equation together with the hydrodynamic properties in the mixer. The organic phase holdup, measured under varying conditions of the flow rates of both phases, was analyzed by the Takahashi-Takeuchi holdup model in order to estimate the specific interfacial area. The overall extraction rate coefficients defined by the product of the interfacial extraction rate constant and the specific interfacial area were evaluated using the experimental data and ranged from 3.5 x 10(-3) to 6.7 x 10(-3)s(-1), which was close to the value of 3.4 x 10(-3)s(-1) obtained by batch extraction. Finally, an engineering simulation method was established for assessing the extraction efficiency of nickel during a multistage operation.

  3. Modeling and Simulation of a Nuclear Fuel Element Test Section

    NASA Technical Reports Server (NTRS)

    Moran, Robert P.; Emrich, William

    2011-01-01

    "The Nuclear Thermal Rocket Element Environmental Simulator" test section closely simulates the internal operating conditions of a thermal nuclear rocket. The purpose of testing is to determine the ideal fuel rod characteristics for optimum thermal heat transfer to their hydrogen cooling/working fluid while still maintaining fuel rod structural integrity. Working fluid exhaust temperatures of up to 5,000 degrees Fahrenheit can be encountered. The exhaust gas is rendered inert and massively reduced in temperature for analysis using a combination of water cooling channels and cool N2 gas injectors in the H2-N2 mixer portion of the test section. An extensive thermal fluid analysis was performed in support of the engineering design of the H2-N2 mixer in order to determine the maximum "mass flow rate"-"operating temperature" curve of the fuel elements hydrogen exhaust gas based on the test facilities available cooling N2 mass flow rate as the limiting factor.

  4. Multi-stage mixer-settler planet centrifuge. Preliminary studies on partition of macromolecules with organic-aqueous and aqueous-aqueous two-phase solvent systems.

    PubMed

    Ito, Y; Zhang, T Y

    1988-03-11

    A rotary-seal-free planetary centrifuge holds a separation column which consists of multiple partition units (ca. 200) connected in series with transfer tubes. In the cavity of each partition unit the transfer tube extends to form a mixer which vibrates to stir the contents under an oscillating force field generated by the planetary motion of the centrifuge. Consequently, solutes locally introduced at the inlet of the column are subjected to an efficient partition process in each partition unit and separated according to their partition coefficients. The mixer tube equipped with a flexible silicone rubber joint was found to produce excellent results for partition with viscous polymer phase systems. The capability of the method was demonstrated on separation of cytochrome c and lysozyme using a PEG-aqueous dibasic potassium phosphate-aqueous two-phase solvent system.

  5. 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

  6. New approach to evaluate the lubrication process in various granule filling levels and rotating mixer sizes using a thermal effusivity sensor.

    PubMed

    Uchiyama, Jumpei; Aoki, Shigeru; Uemoto, Yoshifumi

    2015-01-01

    The principles of thermal effusivity are applied to an understanding of the detailed mechanisms of the lubrication process in a rotating mixer. The relationships and impact of the lubrication process by the pattern of powder flow, the filling level, and the rotating mixer size were investigated. Thermal effusivity profiles of the lubrication process, as obtained, indicate that lubrication is a two-phase process. The intersection point of the first and second phases (IPFS) is influenced by changing the filling level, thus changing the resulting number of avalanche flows created. The slope of the second phase (SSP) is influenced by the relationship between the number and the length of avalanche flows. Understanding this difference between the first and second phases is important to successfully evaluate the impact of proposed changes in the lubrication process. From this knowledge, a predictive model of the lubrication profile can be generated to allow an evaluation of proposed changes to the lubrication process. This model allows estimation of the lubrication profile at different filling levels and in different rotating mixer sizes. In this study, the actual lubrication profile almost coincides with the model predicted lubrication profile. Based on these findings, it is assumed that lubrication profiles at a commercial scale can be predicted from data generated at the laboratory scale. Further, it is assumed that changes in the filling level can also be estimated from the laboratory or current data.

  7. Randomised controlled trial of thermostatic mixer valves in reducing bath hot tap water temperature in families with young children in social housing: A protocol

    PubMed Central

    Kendrick, Denise; Stewart, Jane; Coupland, Carol; Hayes, Michael; Hopkins, Nick; McCabe, Debbie; Murphy, Robert; O'Donnell, George; Phillips, Ceri; Radford, David; Ryan, Jackie; Smith, Sherie; Groom, Lindsay; Towner, Elizabeth

    2008-01-01

    Background Each year in the UK 2000 children attend emergency departments and 500 are admitted to hospital following a bath water scald. The long term effects can include disability, disfigurement or psychological harm and repeated skin grafts may be required as the child grows. The costs of treating a severe scald are estimated at 250,000 GBP. Children living in the most deprived wards are at greatest risk of thermal injuries; hospital admission rates are three times that for children living in the least deprived wards. Domestic hot water, which is usually stored at around 60 degrees Celsius, can result in a second-degree burn after 3 seconds and a third-degree burn after 5 seconds. Educational strategies to encourage testing of tap water temperature and reduction of hot water thermostat settings have largely proved unsuccessful. Legislation in the USA mandating pre-setting hot water heater thermostats at 49 degrees Celsius was effective in reducing scald injuries, suggesting passive measures may have a greater impact. Thermostatic mixer valves (TMVs), recently developed for the domestic market, fitted across the hot and cold water supply pipes of the bath, allow delivery of water set at a fixed temperature from the hot bath tap. These valves therefore offer the potential to reduce scald injuries. Design/Methods A pragmatic, randomised controlled trial to assess the effectiveness of TMVs in reducing bath hot tap water temperatures in the homes of families with young children in rented social housing. Two parallel arms include an intervention group and a control group where the intervention will be deferred. The intervention will consist of fitting a TMV (set at 44 degrees Celsius) by a qualified plumber and provision of educational materials. The control arm will not receive a TMV or the educational materials for the study duration but will be offered the intervention after collection of follow-up data 12 months post randomisation. The primary outcome measure will

  8. Thermodynamic Vent System Test in a Low Earth Orbit Simulation

    NASA Technical Reports Server (NTRS)

    VanOverbeke, Thomas J.

    2004-01-01

    A thermodynamic vent system for a cryogenic nitrogen tank was tested in a vacuum chamber simulating oxygen storage in low earth orbit. The nitrogen tank was surrounded by a cryo-shroud at -40 F. The tank was insulated with two layers of multi-layer insulation. Heat transfer into cryogenic tanks causes phase change and increases tank pressure which must be controlled. A thermodynamic vent system was used to control pressure as the location of vapor is unknown in low gravity and direct venting would be wasteful. The thermodynamic vent system consists of a Joule-Thomson valve and heat exchanger installed on the inlet side of the tank mixer-pump. The combination is used to extract thermal energy from the tank fluid, reducing temperature and ullage pressure. The system was sized so that the tank mixer-pump operated a small fraction of the time to limit motor heating. Initially the mixer used sub-cooled liquid to cool the liquid-vapor interface inducing condensation and pressure reduction. Later, the thermodynamic vent system was used. Pressure cycles were performed until steady-state operation was demonstrated. Three test runs were conducted at tank fills of 97, 80, and 63 percent. Each test was begun with a boil-off test to determine heat transfer into the tank. The lower tank fills had time averaged vent rates very close to steady-state boil-off rates showing the thermodynamic vent system was nearly as efficient as direct venting in normal gravity.

  9. High-Tc micro and nano-constrictions modeling: hot spot approach for DC characteristics and HEB THz mixer performance

    NASA Astrophysics Data System (ADS)

    Ladret, Romain G.; Dégardin, Annick F.; Kreisler, Alain J.

    2014-05-01

    High-TC hot electron bolometers (HEB) are promising THz mixers due to their expected wide bandwidth, large mixing gain, and low intrinsic noise. We have simulated the characteristics of YBaCuO HEBs with a hot spot model usually dedicated to low-TC phonon cooled devices. With respect to e.g., NbN, the high-TC specificities are mainly arising from the large values of YBaCuO phonon thermal conductivity, and the film to MgO substrate phonon escape time. The consequent effects on the electron temperature profiles along the YBaCuO constriction and the current voltage DC characteristics are considered. The conversion gain G and noise temperature TN were computed for two constriction dimensions. For a 100 nm long × 100 nm wide × 10 nm thick constriction at 9 microwatt local oscillator (LO) power, the expected double sideband (DSB) TN = 1520 K (G = -13.7 dB). For a larger (but more realistic according to YBaCuO aging effects) 400 nm long × 400 nm wide × 35 nm thick constriction, minimum TN = 1210 K DSB at 35 microwatt LO power (G = -13.1 dB).

  10. Concurrent 2,4-D and triclopyr biomonitoring of backpack applicators, mixer/loader and field supervisor in forestry.

    PubMed

    Zhang, Xiaofei; Acevedo, Sandra; Chao, Yingfu; Chen, Zhenshan; Dinoff, Travis; Driver, Jeffrey; Ross, John; Williams, Ryan; Krieger, Robert

    2011-01-01

    Two herbicides, 2,4-D and triclopyr esters (application ratio 1.6:1 acid equivalents) were applied as a tank mix by a crew of 8 backpack sprayer applicators, a mixer/loader, and a field supervisor. The crew was employed in a conifer release program in northern California during the summer of 2002. Biomonitoring (urine, 24 h) utilized 2,4-D and triclopyr (a.e.) as rapidly excreted exposure biomarkers. The absorbed dosages of 2,4-D and triclopyr were calculated based upon cotton whole body suits and biomonitoring. Dosages based upon accumulation of the herbicides on body suits averaged 42.6 μg (a.e.) 2,4-D/kg-d and 8.0 μg (a.e.) triclopyr/kg-d. Six consecutive days of concurrent urine collections showed that backpack applicators excreted an average of 11.0 μg (a.e.) 2,4-D/kg-d and 18.9 μg (a.e.) triclopyr/kg-d. Estimates based upon curve fitting were 17.1 and 29.3 μg (a.e.)/kg-d, respectively. Results suggest that passive dosimetry for 2,4-D consistently overestimated the dosage measured using biomonitoring by a factor of 2-3 fold, while for triclopyr, passive dosimetry underestimated the absorbed dose based on biomonitoring by a factor of 2-4 fold.

  11. Predicting optimal wet granulation parameters for extrusion-spheronisation of pharmaceutical pellets using a mixer torque rheometer.

    PubMed

    Kuhs, Manuel; Moore, John; Kollamaram, Gayathri; Walker, Gavin; Croker, Denise

    2017-01-30

    Mixer torque rheometry (MTR) was evaluated as a pre-production (pre-formulation and optimization) tool for predicting ideal liquid-to-solid ratios (L/S) for extrusion-spheronisation of a wide range of APIs using 10g formulations. APIs of low, medium and high solubility were formulated at low and high loadings (15 and 40% w/w, respectively) with PVP as binder (5%) and MCC as the major excipient. L/S corresponding to the maximum torque produced during wet massing in the MTR, L/S(maxT), was 0.8 for the low solubility APIs, which decreased to 0.6 for some of the more soluble APIs, especially at high loadings. Formulations extruded-spheronised at L/SmaxT) produced pellets of acceptable size (between 900 and 1400um) for all formulations, but mostly of unacceptable shape (dumb-bells of aspect ratio 1.2). Increasing L/S by 25% successfully produced spherical or near-spherical (aspect ratio 1.1) pellets for all formulations except one of the highly soluble APIs (piracetam) at high loading. Overall, MTR was demonstrated to be a useful pre-formulation and optimization tool in extrusion-spheronisation.

  12. System design description for SY-101 hydrogen mitigation test project data acquisition and control system (DACS-1)

    SciTech Connect

    Truitt, R.W.; Pounds, T.S.; Smith, S.O.

    1994-08-24

    This document describes the hardware subsystems of the data acquisition and control system (DACS) used in mitigation tests conducted on waste tank SY-101 at the Hanford Nuclear Reservation. The system was designed and implemented by Los Alamos National Laboratory (LANL) and supplied to Westinghouse Hanford Company (WHC). The mitigation testing uses a pump immersed in the waste tank, directed at certain angles and operated at different speeds and time durations. The SY-101 tank has experienced recurrent periodic gas releases of hydrogen, nitrous oxide, ammonia, and (recently discovered) methane. The hydrogen gas represents a danger, as some of the releases are in amounts above the lower flammability limit (LFL). These large gas releases must be mitigated. Several instruments have been added to the tank to monitor the gas compositions, the tank level, the tank temperature, and other parameters. A mixer pump has been developed to stir the tank waste to cause the gases to be released at a slow rate. It is the function of the DACS to monitor those instruments and to control the mixer pump in a safe manner. During FY93 and FY94 the mixer pump was installed with associated testing operations support equipment and a mitigation test project plan was implemented. These activities successfully demonstrated the mixer pump`s ability to mitigate the SY-101 tank hydrogen gas hazard.

  13. 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.

    Initially 3D FEM simulation of a simplified mixer was used to examine the effect of mixer configuration and operating conditions on dispersive mixing of a non-Newtonian fluid. Horizontal and vertical velocity magnitudes increased with increasing mixer speed, while maximum axial velocity and shear rate were greater with staggered paddles. In contrast, parallel paddles produced an area of efficient dispersive mixing between the center of the paddle and the barrel wall. This study was expanded to encompass the complete nine-paddle mixing section using power-law and Bird-Carreau fluid models. In the center of the mixer, simple shear flow was seen, corresponding with high [special character omitted]. Efficient dispersive mixing appeared near the barrel wall at all flow rates and near the barrel center with parallel paddles. Areas of backflow, improving fluid retention time, occurred with staggered paddles. The Bird-Carreau fluid showed greater influence of paddle motion under the same operating conditions due to the inelastic nature of the fluid. Shear-thinning behavior also resulted in greater maximum shear rate as shearing became easier with decreasing fluid viscosity. Shear rate distributions are frequently calculated, but extension rate calculations have not been made in a complex geometry since Debbaut and Crochet (1988) defined extension rate as the ratio of the third to the second invariant of the strain rate tensor. Extension rate was assumed to be negligible in most studies, but here extension rate is shown to be significant. It is possible to calculate maximum stable bubble diameter from capillary number if shear and extension rates in a flow field are known. Extension rate distributions were calculated for Newtonian and non-Newtonian fluids. High extension and shear rates were found in the intermeshing region. Extension is the major influence on critical capillary number and maximum stable bubble diameter, but when extension rate values are low shear rate has

  14. The simultaneous role of an alveolus as flow mixer and flow feeder for the deposition of inhaled submicron particles.

    PubMed

    Henry, F S; Haber, S; Haberthür, D; Filipovic, N; Milasinovic, D; Schittny, J C; Tsuda, A

    2012-12-01

    In an effort to understand the fate of inhaled submicron particles in the small sacs, or alveoli, comprising the gas-exchange region of the lung, we calculated the flow in three-dimensional (3D) rhythmically expanding models of alveolated ducts. Since convection toward the alveolar walls is a precursor to particle deposition, it was the goal of this paper to investigate the streamline maps' dependence upon alveoli location along the acinar tree. On the alveolar midplane, the recirculating flow pattern exhibited closed streamlines with a stagnation saddle point. Off the midplane we found no closed streamlines but nested, funnel-like, spiral, structures (reminiscent of Russian nesting dolls) that were directed towards the expanding walls in inspiration, and away from the contracting walls in expiration. These nested, funnel-like, structures were surrounded by air that flowed into the cavity from the central channel over inspiration and flowed from the cavity to the central channel over expiration. We also found that fluid particle tracks exhibited similar nested funnel-like spiral structures. We conclude that these unique alveolar flow structures may be of importance in enhancing deposition. In addition, due to inertia, the nested, funnel-like, structures change shape and position slightly during a breathing cycle, resulting in flow mixing. Also, each inspiration feeds a fresh supply of particle-laden air from the central channel to the region surrounding the mixing region. Thus, this combination of flow mixer and flow feeder makes each individual alveolus an effective mixing unit, which is likely to play an important role in determining the overall efficiency of convective mixing in the acinus.

  15. Low-noise 1.5 THz waveguide-type hot-electron bolometer mixers using relatively thick NbTiN superconducting film

    NASA Astrophysics Data System (ADS)

    Shiino, Tatsuya; Furuya, Ryuta; Soma, Tatsuya; Watanabe, Yoshimasa; Sakai, Takeshi; Jiang, Ling; Maezawa, Hiroyuki; Yamakura, Tetsuya; Sakai, Nami; Yamamoto, Satoshi

    2015-03-01

    We have developed waveguide-type low-noise superconducting hot-electron bolometer (HEB) mixers for astronomical observations in the 1.3-1.5 THz region by using a relatively thick NbTiN superconducting film (10.8 nm). We have achieved a receiver noise temperature of 490 K (DSB: double side band) at 1.475 THz. This noise temperature corresponds to seven times the quantum noise. According to gain bandwidth measurements, the contribution of diffusion cooling is found to be responsible for such a good noise performance.

  16. Chlorhexidine-calcium phosphate nanoparticles - Polymer mixer based wound healing cream and their applications.

    PubMed

    Viswanathan, Kaliyaperumal; Monisha, P; Srinivasan, M; Swathi, D; Raman, M; Dhinakar Raj, G

    2016-10-01

    In this work, we developed a wound healing cream composed of two different polymers, namely chitosan and gelatin with chlorhexidine along with calcium phosphate nanoparticles. The physicochemical properties of the prepared cream were investigated based on SEM, EDX, Raman, FTIR and the results indicated that the cream contained gelatin, chitosan, calcium phosphate nanoparticles and chlorhexidine. The maximum swelling ratio studies indicated that the ratio was around of 52±2.2 at pH7.4 and the value was increased in acidic and alkaline pH. The antimicrobial activity was tested against bacteria and the results indicated that, both chlorhexidine and the hybrid cream devoid of chlorhexidine exhibited antimicrobial activity but the chlorhexidine impregnated cream showed three fold higher antimicrobial activity than without chlorhexidine. In vivo wound healing promoting activities of hybrid cream containing 0.4mg/L chlorhexidine were evaluated on surgically induced dermal wounds in mice. The results indicated that the cream with incorporated chlorhexidine significantly enhanced healing compared with the control samples. For the field validations, the veterinary clinical animals were treated with the cream and showed enhanced healing capacity. In conclusion, a simple and efficient method for design of a novel wound healing cream has been developed for veterinary applications.

  17. Low Emissions RQL Flametube Combustor Component Test Results

    NASA Technical Reports Server (NTRS)

    Holdeman, James D.; Chang, Clarence T.

    2001-01-01

    This report describes and summarizes elements of the High Speed Research (HSR) Low Emissions Rich burn/Quick mix/Lean burn (RQL) flame tube combustor test program. This test program was performed at NASA Glenn Research Center circa 1992. The overall objective of this test program was to demonstrate and evaluate the capability of the RQL combustor concept for High Speed Civil Transport (HSCT) applications with the goal of achieving NOx emission index levels of 5 g/kg-fuel at representative HSCT supersonic cruise conditions. The specific objectives of the tests reported herein were to investigate component performance of the RQL combustor concept for use in the evolution of ultra-low NOx combustor design tools. Test results indicated that the RQL combustor emissions and performance at simulated supersonic cruise conditions were predominantly sensitive to the quick mixer subcomponent performance and not sensitive to fuel injector performance. Test results also indicated the mixing section configuration employing a single row of circular holes was the lowest NOx mixer tested probably due to the initial fast mixing characteristics of this mixing section. However, other quick mix orifice configurations such as the slanted slot mixer produced substantially lower levels of carbon monoxide emissions most likely due to the enhanced circumferential dispersion of the air addition. Test results also suggested that an optimum momentum-flux ratio exists for a given quick mix configuration. This would cause undesirable jet under- or over-penetration for test conditions with momentum-flux ratios below or above the optimum value. Tests conducted to assess the effect of quick mix flow area indicated that reduction in the quick mix flow area produced lower NOx emissions at reduced residence time, but this had no effect on NOx emissions measured at similar residence time for the configurations tested.

  18. EVALUATION OF FOAMING/ANTIFOAMING IN WTP TANKS EQUIPPED WITH PULSE JET MIXERS AND AIR SPARGERS

    SciTech Connect

    JONES, TIMOTHYM.

    2004-09-01

    has no significant effect on pH or chemical composition of the slurry. The rheology is also not impacted by air sparging. The primary effect of air sparging is the removal of water by the dry air passing through the column and exiting in a saturated condition. This effect can be mitigated by adding water back to the column or vessel during sparging. Therefore, an initial charge of 350 mg/L antifoam (Dow Q2-3183A) followed by small batch additions of 70 mg/LQ2-3183A every 24 hours is recommended for use in WTP tanks equipped with air spargers and pulse jets based upon the testing done in this study. However, this recommendation is based upon a limited set of antifoam degradation data developed for the WTP evaporator R and T program. Therefore, additional investigation into refining the kinetic behavior of Q2 antifoam under radiation dose is recommended.

  19. A novel microfluidic mixer-based approach for determining inactivation kinetics of Escherichia coli O157:H7 in chlorine solutions.

    PubMed

    Zhang, Boce; Luo, Yaguang; Zhou, Bin; Wang, Qin; Millner, Patricia D

    2015-08-01

    Determination of the minimum free chlorine concentration needed to prevent pathogen survival/cross-contamination during produce washing is essential for the development of science-based food safety regulations and practices. Although the trend of chlorine concentration-contact time on pathogen inactivation is generally understood, specific information on chlorine and the kinetics of pathogen inactivation at less than 1.00 s is urgently needed by the produce processing industry. However, conventional approaches to obtain this critical data have been unable to adequately measure very rapid responses. This paper reports our development, fabrication, and test of a novel microfluidic device, and its application to obtain the necessary data on pathogen inactivation by free chlorine in produce wash solution in times as short as 0.10 s. A novel microfluidic mixer with the capability to accurately determine the reaction time and control the chlorine concentration was designed with three inlets for bacterial, chlorine and dechlorinating solutions, and one outlet for effluent collection. The master mold was fabricated on a silicon wafer with microchannels via photopolymerization. Polydimethylsiloxane replicas with patterned microchannels were prototyped via soft lithography. The replicas were further assembled into the micromixer on glass via O2 plasma treatment, and the inlets were connected to a syringe pump for solution delivery. To determine the kinetics of free chlorine on pathogen inactivation, chlorine solutions of varying concentrations were first pumped into the micromixer, together with the addition of bacterial suspension of Escherichia coli O157:H7 through a separate inlet. This was followed by injection of dechlorinating solution to stop the chlorine-pathogen reaction. The effluent was collected and the surviving bacteria cells were enumerated using a modified 'Most Probable Number' method. Free chlorine concentration was determined using a standard colorimetric

  20. 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.

  1. GMAG Jobs Mixer

    NASA Astrophysics Data System (ADS)

    This event is open to the members of the magnetism community, especially postdocs and students, who are interested in jobs in industry, national labs, and academia, or have a job opportunity to offer. Refreshments will be served

  2. ENVIRONMENTAL TECHNOLOGY VERIFICATION JOINT (NSF-EPA) VERIFICATION STATEMENT AND REPORT, PERFORMANCE OF INDUCTION MIXERS FOR DISINFECTION OF WET WEATHER FLOWS, US FILTER/STRANCO PRODUCTS WATER CHAMP R F SERIES CHEMICAL INDUCTION SYSTEM

    EPA Science Inventory

    The Wet-Weather Flow Technologies Pilot of the EPA's Technology Verification (ETV) Program under a partnership with NSF International has verified the performawnce of the USFilter/Stranco Products chemical induction mixer used for disinfection of wet-weather flows. The USFilter t...

  3. Full scale technology demonstration of a modern counterrotating unducted fan engine concept: Component test

    NASA Technical Reports Server (NTRS)

    1987-01-01

    The UDF trademark (Unducted Fan) engine is a new aircraft engine concept based on an ungeared, counterrotating, unducted, ultra-high-bypass turbofan configuration. This engine is being developed to provide a high thrust-to-weight ratio powerplant with exceptional fuel efficiency for subsonic aircraft application. This report covers the testing of pertinent components of this engine such as the fan blades, control and actuation system, turbine blades and spools, seals, and mixer frame.

  4. Optical multidimensional multiple access(O-MDMA): a new concept for free-space laser communication based on photonic mixer devices

    NASA Astrophysics Data System (ADS)

    Hess, Holger; Albrecht, Martin; Grothof, Markus; Hussmann, Stephan; Schwarte, Rudolf

    2004-01-01

    Working on optical distance measurement a new optical correlator was developed at the Institute for Data Processing of the University of Siegen in the last years. The so called Photonic Mixer Device (PMD), to be meant originally for laser ranging systems, offers a lot of advantages for wireless optical data communication like high speed spatial light demodulation up to the GHz range and inherent backlight suppression. This contribution describes the application of such PMDs in a free space interconnect based on the principle of Multi Dimensional Multiple Access (MDMA) and the advantages of this new approach, starting from the MDMA principle and followed by the fundamental functionality of PMDs. After that an Optical MDMA (O-MDMA) demonstrator and first measurement results will be presented.

  5. POC-Scale Testing of Oil Agglomeration Techniques and Equipment for Fine Coal Processing

    SciTech Connect

    1998-11-12

    The objective of this project is to develop and demonstrate a Proof-of-Concept (POC) scale oil agglomeration technology capable of increasing the recovery and improving the quality of fine coal strearrts. Two distinct agglomeration devices will be tested, namely, a conventional high shear mixer and a jet processor. To meet the overall objective an eleven task work plan has been designed. The work ranges from batch and continuous bench-scale testing through the design, commissioning and field testing of POC-scale agglomeration equipment.

  6. Mixing studies in modular intermeshing co-rotating twin screw extruder, modular counter-rotating twin screw extruder, Buss Kneader, and Kobelco Nex-T Continuous Mixer

    NASA Astrophysics Data System (ADS)

    Shon, Keungjin

    In this dissertation, we investigated dispersive different mixing processes in various continuous mixing machines. This includes the Buss Kneader, a modular intermeshing co-rotating and intermeshing counter-rotating twin screw extruder, and a Farrel type Continuous Mixer. The systems investigated were (i) damage to glass fibers, (ii) calcium carbonate (CaCO 3) agglomerate breakup of solid particles, and (iii) polymer blend dispersion (polyamide 6). These all occurred in the matrix of a polypropylene melt. The residence time distribution was examined to understand the flow characteristics of these mixing machines. We considered the morphology changes in terms of average size and size decrease rate for dispersed and distributed minor phase. Comparisons were made of different mixing machines and systems. The Buss Kneader exhibited the broadest residence time distribution relatively less fiber breakage inferior dispersion of solid particulates, while it showed finer droplet size for polymer melt blending system. The intermeshing counter-rotating twin screw extruder showed both the lowest residence time and narrowest residence time distribution. Among the different mixing machines, it performed as the best dispersive mixing machine when it was configured with suitable mixing elements. It also gave the most severe breakage of glass fibers. Based on our experimental investigations, fiber breakage and calcium carbonate agglomerate breakdown and dispersed phase polymer melts, dispersive mixing was modeled. Rate constants for (i) glass fiber breakage, (ii) agglomerate breakup of calcium carbonate, and (iii) droplet size decrease of minor phase into polymer melt were determined for various modular elements.

  7. Self-assembling process of flash nanoprecipitation in a multi-inlet vortex mixer to produce drug-loaded polymeric nanoparticles

    NASA Astrophysics Data System (ADS)

    Shen, Hao; Hong, Seungpyo; Prud'homme, Robert K.; Liu, Ying

    2011-09-01

    We present an experimental study of self-assembled polymeric nanoparticles in the process of flash nanoprecipitation using a multi-inlet vortex mixer (MIVM). β-Carotene and polyethyleneimine (PEI) are used as a model drug and a macromolecule, respectively, and encapsulated in diblock copolymers. Flow patterns in the MIVM are microscopically visualized by mixing iron nitrate (Fe(NO3)3) and potassium thiocyanate (KSCN) to precipitate Fe(SCN) x (3- x)+ . Effects of physical parameters, including Reynolds number, supersaturation rate, interaction force, and drug-loading rate, on size distribution of the nanoparticle suspensions are investigated. It is critical for the nanoprecipitation process to have a short mixing time, so that the solvent replacement starts homogeneously in the reactor. The properties of the nanoparticles depend on the competitive kinetics of polymer aggregation and organic solute nucleation and growth. We report the existence of a threshold Reynolds number over which nanoparticle sizes become independent of mixing. A similar value of the threshold Reynolds number is confirmed by independent measurements of particle size, flow-pattern visualization, and our previous numerical simulation along with experimental study of competitive reactions in the MIVM.

  8. Altitude test of several afterburner configurations on a turbofan engine with a hydrogen heater to simulate an elevated turbine discharge temperature

    NASA Technical Reports Server (NTRS)

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

    1977-01-01

    A performance test of several experimental afterburner configurations was conducted with a mixed-flow turbofan engine in an altitude facility. The simulated flight conditions were for Mach 1.4 at two altitudes, 12,190 and 14,630 meters. Turbine discharge temperatures of 889 and 1056 K were used. A production afterburner was tested for comparison. The research afterburners included partial forced mixers with V-gutter flameholders, a carburetted V-gutter flameholder, and a triple ring V-gutter flameholder with four swirl-can fuel mixers. Fuel injection variations were included. Performance data shown include augmented thrust ratio, thrust specific fuel consumption, combustion efficiency, and total pressure drop across the afterburner.

  9. 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.

  10. Testing the Effects of Helium Pressurant on Thermodynamic Vent System Performance with Liquid Hydrogen

    NASA Technical Reports Server (NTRS)

    Flachbart, R. H.; Hastings, L. J.; Hedayat, A.; Nelson, S.; Tucker, S.

    2006-01-01

    In support of the development of a zero gravity pressure control capability for liquid hydrogen, testing was conducted at the Marshall Space Flight Center using the Multipurpose Hydrogen Test Bed (MHTB) to evaluate the effects of helium pressurant on the performance of a spray bar thermodynamic vent system (TVS). Fourteen days of testing was performed in August - September 2005, with an ambient heat leak of about 70-80 watts and tank fill levels of 90%, 50%, and 25%. The TVS successfully controlled the tank pressure within a +/- 3.45 kPa (+/- 0.5 psi) band with various helium concentration levels in the ullage. Relative to pressure control with an "all hydrogen" ullage, the helium presence resulted in 10 to 30 per cent longer pressure reduction durations, depending on the fill level, during the mixing/venting phase of the control cycle. Additionally, the automated control cycle was based on mixing alone for pressure reduction until the pressure versus time slope became positive, at which time the Joule-Thomson vent was opened. Testing was also conducted to evaluate thermodynamic venting without the mixer operating, first with liquid then with vapor at the recirculation line inlet. Although ullage stratification was present, the ullage pressure was successfully controlled without the mixer operating. Thus, if vapor surrounded the pump inlet in a reduced gravity situation, the ullage pressure can still be controlled by venting through the TVS Joule Thomson valve and heat exchanger. It was evident that the spray bar configuration, which extends almost the entire length of the tank, enabled significant thermal energy removal from the ullage even without the mixer operating. Details regarding the test setup and procedures are presented in the paper. 1

  11. 40 CFR 61.355 - Test methods, procedures, and compliance provisions.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... to sampling. (B) A static mixer shall be installed in the process line or in a by-pass line unless the owner or operator demonstrates that installation of a static mixer in the line is not necessary to... within two pipe diameters of the static mixer outlet. (D) Prior to the initiation of sampling,...

  12. TEST PLAN CHARACTERIZATION OF JET FORCES UPON WASTE TANK COMPONENTS

    SciTech Connect

    Bamberger, J. A.

    1992-01-01

    Westinghouse Hanford Company plans to install mixer pumps in double-shell waste tanks to mobilize and suspend settled sludge to allow eventual retrieval for treatment and permanent storage. The mixer pumps produce high momentum, horizontally directed jets that impact and mobilize the sludge and mix it into slurry for removal. There is concern that the force of the jet may damage tank internal components in its path. This test plan describes scaled experiments designed to characterize the velocity profiles of a near floor jet and to quantify the impact farces and drag coefficients of three tank components: radiation dry well, airlift circulator, and steam coil. The experiments will be conducted in water, at approximately 1/6-scale, using one stationary nozzle to simulate the jet. To measure and confirm the velocity profile of the free, submerged jet, the horizontal and vertical velocity profiles will be measured at several distances from the nozzle. The profile will also be measured after the jet impinges upon the tank floor to determine the·extent of the change in the profile caused by impingement. The jet forces upon the test articles will be measured at a maximum of four velocities and a variety of test article orientations. Each orientation will represent a unique position of the test article relative to the jet and the tank floor. In addition, the steam coil will be tested in three rotational orientations because it is not symmetric. The highest jet velocity will be selected so that the Reynolds number of the test article in the model will match that of the prototype when operating at design conditions. The forces measured upon the model components will be used to calculate the force on the prototype components using geometric scaling factors. In addition, the model force measurements will be used to calculate the component's drag coefficient as a function of the component Reynolds number.

  13. Level maintenance for Tank 101-SY mitigation-by-mixing test

    SciTech Connect

    Sobocinski, R.G.

    1994-11-16

    This document provides the procedure to be followed to implement the requirements of the Mixer Pump Long-Term Operations Plan for Tank 241-SY-101 Mitigation, WHC-SD-WM-PLN-081. The test is divided into 2 distinct sequences, named Single Position Pump Run and Tank Sweep. Instructions for all sequences are defined within the procedure. All safety requirements as defined in LA-UR-92-3196, A Safety Assessment for Proposed Mixing Operations to Mitigate Episodic Gas Releases in Tank 241-101-SY have been implemented into this procedure.

  14. Liquid Oxygen Thermodynamic Vent System Testing with Helium Pressurization

    NASA Technical Reports Server (NTRS)

    VanDresar, Neil T.

    2014-01-01

    This report presents the results of several thermodynamic vent system (TVS) tests with liquid oxygen plus a test with liquid nitrogen. In all tests, the liquid was heated above its normal boiling point to 111 K for oxygen and 100 K for nitrogen. The elevated temperature was representative of tank conditions for a candidate lunar lander ascent stage. An initial test series was conducted with saturated oxygen liquid and vapor at 0.6 MPa. The initial series was followed by tests where the test tank was pressurized with gaseous helium to 1.4 to 1.6 MPa. For these tests, the helium mole fraction in the ullage was quite high, about 0.57 to 0.62. TVS behavior is different when helium is present than when helium is absent. The tank pressure becomes the sum of the vapor pressure and the partial pressure of helium. Therefore, tank pressure depends not only on temperature, as is the case for a pure liquid-vapor system, but also on helium density (i.e., the mass of helium divided by the ullage volume). Thus, properly controlling TVS operation is more challenging with helium pressurization than without helium pressurization. When helium was present, the liquid temperature would rise with each successive TVS cycle if tank pressure was kept within a constant control band. Alternatively, if the liquid temperature was maintained within a constant TVS control band, the tank pressure would drop with each TVS cycle. The final test series, which was conducted with liquid nitrogen pressurized with helium, demonstrated simultaneous pressure and temperature control during TVS operation. The simultaneous control was achieved by systematic injection of additional helium during each TVS cycle. Adding helium maintained the helium partial pressure as the liquid volume decreased because of TVS operation. The TVS demonstrations with liquid oxygen pressurized with helium were conducted with three different fluid-mixer configurations-a submerged axial jet mixer, a pair of spray hoops in the tank

  15. Topological Optimization of Rod Mixers

    NASA Astrophysics Data System (ADS)

    Finn, Matthew D.; Thiffeault, Jean-Luc

    2006-11-01

    Stirring of fluid with moving rods is necessary in many practical applications to achieve homogeneity. These rods are topological obstacles that force stretching of fluid elements. The resulting stretching and folding is commonly observed as filaments and striations, and is a precursor to mixing. In a space-time diagram, the trajectories of the rods form a braid [1], and the properties of this braid impose a minimal complexity in the flow. We discuss how optimal mixing protocols can be obtained by a judicious choice of braid, and how these protocols can be implemented using simple gearing [2].[12pt] [1] P. L. Boyland, H. Aref, and M. A. Stremler, JFM 403, 277 (2000).[8pt] [2] J.-L. Thiffeault and M. D. Finn, http://arxiv.org/nlin/0603003

  16. Radial flow pulse jet mixer

    DOEpatents

    VanOsdol, John G.

    2013-06-25

    The disclosure provides a pulse jet mixing vessel for mixing a plurality of solid particles. The pulse jet mixing vessel is comprised of a sludge basin, a flow surface surrounding the sludge basin, and a downcoming flow annulus between the flow surface and an inner shroud. The pulse jet mixing vessel is additionally comprised of an upper vessel pressurization volume in fluid communication with the downcoming flow annulus, and an inner shroud surge volume separated from the downcoming flow annulus by the inner shroud. When the solid particles are resting on the sludge basin and a fluid such as water is atop the particles and extending into the downcoming flow annulus and the inner shroud surge volume, mixing occurs by pressurization of the upper vessel pressurization volume, generating an inward radial flow over the flow surface and an upwash jet at the center of the sludge basin.

  17. Magnetohydrodynamic (MHD) driven droplet mixer

    DOEpatents

    Lee, Abraham P.; Lemoff, Asuncion V.; Miles, Robin R.

    2004-05-11

    A magnetohydrodynamic fluidic system mixes a first substance and a second substance. A first substrate section includes a first flow channel and a first plurality of pairs of spaced electrodes operatively connected to the first flow channel. A second substrate section includes a second flow channel and a second plurality of pairs of spaced electrodes operatively connected to the second flow channel. A third substrate section includes a third flow channel and a third plurality of pairs of spaced electrodes operatively connected to the third flow channel. A magnetic section and a control section are operatively connected to the spaced electrodes. The first substrate section, the second substrate section, the third substrate section, the first plurality of pairs of spaced electrodes, the second plurality of pairs of spaced electrodes, the third plurality of pairs of spaced electrodes, the magnetic section, and the control section are operated to move the first substance through the first flow channel, the second substance through the second flow channel, and both the first substance and the second substance into the third flow channel where they are mixed.

  18. Level maintenance for Tank 101-SY mitigation-by-mixing test. Revision 2

    SciTech Connect

    Larsen, D.C.

    1994-09-28

    The Phase A, Phase B and Full Scale testing portions of the Mitigation-By-Mixing Test have demonstrated the effectiveness of the Mixer Pump to maintain the waste in tank 101-SY in the desired mitigated state. The operation of the 101-SY Mixer Pump for short periods of time results in a controlled release of hydrogen gas in concentrations well below the established safety limits. Additionally, it has been shown that operation of the pump on a regular schedule minimizes the historical generation rate of hydrogen inventory in the waste. Generation of hydrogen inventory is exhibited by waste level growth. The primary objective of this procedure is to maintain the waste level in tank 241-SY-101 within the safe operating range as defined by the Safety Assessment and the Test Plan. The secondary objective is to operate the pump on a schedule that maximizes its useful lifespan and prevents the formation of obstructions in the normal flow path of the pump.

  19. Computational fluid dynamics (CFD) tools for investigating flow and mixing in industrial systems: The Koch-Glitsch SMX(RTM) static mixer and a three Rushton turbine stirred tank

    NASA Astrophysics Data System (ADS)

    Zalc, Jeffrey Michael

    2000-11-01

    A suite of numerical tools, encompassing both commercial software and algorithms developed over the course of this dissertation research, is implemented for a detailed analysis of laminar flow and mixing in two industrial systems. A four element SMX static mixer geometry and a batch stirred tank equipped with three Rushton turbines are considered. Computational fluid dynamics (CFD) is used to compute the fully three-dimensional flow fields over tine unstructured tetrahedral meshes; at least ten flow conditions are considered for each system. Particle tracking routines are then employed to characterize the velocity components, pressure fields, and local mixing rates. Lagrangian mixing analysis is based on the dispersion of tracer particles. The stretching of fluid elements is used to quantify mixing performance. In the SMX static mixer, CFD results are validated through comparison of computed pressure drops with experimental results reported in the literature. Flow behavior is characterized by contour plots and probability density functions of velocity components and the magnitude of the deformation tensor. It is found that the flow in the static mixer is essentially independent of flow rate up through a Reynolds number of 1, beyond which inertial effects become significant and substantial differences in the nature of the flow are observed. Computed mixing patterns exhibit self-similarity and asymptotic directionality, which are fingerprints of chaotic behavior. Statistical characterization of the partially mixed structures reveals an exponential decay of the coefficient of variance with increasing axial distance. In the three Rushton turbine stirred tank, planar velocity vectors extracted from the CFD results are compared with experimental results obtained from particle imaging velocimetry (PIV). Planar laser-induced fluorescence (PLIF) and Poincare sections are both used to expose persistent poor-mixing regions, whose sizes and shapes depend strongly on the

  20. POC-scale testing of oil agglomeration techniques and equipment for fine coal processing

    SciTech Connect

    W. Pawlak; K. Szymocha

    1998-08-01

    This report covers the technical progress achieved from April 1, 1998 to June 30, 1998 on the POC-Scale Testing of Oil Agglomeration Techniques and Equipment for Fine Coal Processing. Continuous bench-scale runs were carried out with Luscar Mine coal. The main objectives were to optimize process conditions for a proposed jet processor and to compare its performance with a standard high-shear mixer. A total of three runs consisted of 15 testing periods was carried out. Both conditioning devices performed very well with combustible matter recovery exceeding 96%. Slightly higher coal recovery was observed for high-shear mixer, while lower ash contents were achieved when jet processor was used for coal conditioning. During the current reporting period work has been continued and completed on the engineering and design package of a 3 t/h POC-scale agglomeration unit. Preliminary design package prepared by Thermo Design Engineering, a subcontractor to this project, was submitted to DOE for revision and approval.

  1. Test results after refurbish of cryogenic system for smiles

    NASA Astrophysics Data System (ADS)

    Otsuka, Kiyomi; Tsunematsu, Shoji; Okabayashi, Akinobu; Narasaki, Katsuhiro; Satoh, Ryota

    2010-09-01

    Superconducting Sub-millimeter-wave Limb-Emission Sounder (SMILES) is to be operated aboard the Japanese Experiment Module (JEM) of the International Space Station (ISS) in 2009. SMILES uses two superconductor-insulator-superconductor (SIS) mixers for sub-millimeter-wave atmospheric observation and they are cooled to 4 K levels by a cryogenic system with a two-stage Stirling cooler, a Joule-Thomson (JT) cycle cooler and a cryostat composed of three stages. Two-stage Stirling cooler precools the JT circuit and also cools radiation shields in the cryostat. JT circuit has three tube-in-tube type heat exchangers and an orifice for JT expansion in the cryostat. The cryogenic system is built, tested and delivered.

  2. ELAWD GROUT HOPPER MOCK-UP TESTING

    SciTech Connect

    Pickenheim, B.; Hansen, E.; Leishear, R.; Marzolf, A.; Reigel, M.

    2011-10-27

    A 10-inch READCO mixer is used for mixing the premix (45 (wt%) fly ash, 45 wt% slag, and 10 wt% portland cement) with salt solution in the Saltstone Production Facility (SPF). The Saltstone grout free falls into the grout hopper which feeds the suction line leading to the Watson SPX 100 duplex hose pump. The Watson SPX 100 pumps the grout through approximately 1500 feet of piping prior to being discharged into the Saltstone Disposal Facility (SDF) vaults. The existing grout hopper has been identified by the Saltstone Enhanced Low Activity Waste Disposal (ELAWD) project for re-design. The current nominal working volume of this hopper is 12 gallons and does not permit handling an inadvertent addition of excess dry feeds. Saltstone Engineering has proposed a new hopper tank that will have a nominal working volume of 300 gallons and is agitated with a mechanical agitator. The larger volume hopper is designed to handle variability in the output of the READCO mixer and process upsets without entering set back during processing. The objectives of this task involve scaling the proposed hopper design and testing the scaled hopper for the following processing issues: (1) The effect of agitation on radar measurement. Formation of a vortex may affect the ability to accurately measure the tank level. The agitator was run at varying speeds and with varying grout viscosities to determine what parameters cause vortex formation and whether measurement accuracy is affected. (2) A dry feeds over addition. Engineering Calculating X-ESR-Z-00017 1 showed that an additional 300 pounds of dry premix added to a 300 gallon working volume would lower the water to premix ratio (W/P) from the nominal 0.60 to 0.53 based on a Salt Waste Processing Facility (SWPF) salt simulant. A grout with a W/P of 0.53 represents the upper bound of grout rheology that could be processed at the facility. A scaled amount of dry feeds will be added into the hopper to verify that this is a recoverable situation

  3. Idaho Chemical Processing Plant Liquid Effluent Treatment and Disposal Facility hot test report

    SciTech Connect

    Hastings, R.L.

    1993-09-01

    Prior to initial operation with radioactive feed or ``hot`` operation, the Liquid Effluent Treatment and Disposal (LET&D) Facility underwent extensive testing. This report provides a detailed description and analysis of this testing. Testing has determined that LET&D is capable of processing radioactive solutions between the design flowrates of 275 gph to 550 gph. Modifications made to prevent condensation on the off-gas HEPA filters, to the process vacuum control, bottoms cooler rupture disks, and feed control system operation were successful. Unfortunately, two mixers failed prior to ``hot`` testing due to manufacturer`s error which limited operation of the PEW Evaporator System and sampling was not able to prove that design removal efficiencies for Mercury, Cadmium, Plutonium, and Non-Volatile Radionuclides.

  4. Results of an Advanced Development Zero Boil-Off Cryogenic Propellant Storage Test

    NASA Technical Reports Server (NTRS)

    Plachta, David

    2004-01-01

    A zero boil-off (ZBO) cryogenic propellant storage concept was recently tested in a thermally relevant low-earth orbit environment, an important development in the effort to apply this concept to flight projects. Previous efforts documented the benefits of ZBO for launch vehicle upper stages in a low-earth orbit (LEO). Central to that analysis is a ZBO Cryogenic Analysis Tool that estimates the performance of each component and the ZBO system. This test is essential to the validation of that tool, and was the first flight representative configuration tested in a thermally representative environment. The test article was comprised of a spherical 1.4 m diameter insulated propellant tank, with a submerged mixer, a cryogenic heat pipe, flight design cryocooler, and a radiator. All were enclosed in a thermal shroud and inserted into and tested in a vacuum chamber that simulated an LEO thermal environment. Thermal and pressure control tests were performed at sub-critical LN2 temperatures and approximately 2 atmospheres pressure. The cold side of the ZBO system performed well. In particular, the heat pipe performed better than expected, which suggests that the cryocooler could be located further from the tank than anticipated, i.e. on a spacecraft bus, while maintaining the desired efficiency. Also, the mixer added less heat than expected. The tank heating rate through the insulation was higher than expected; also the temperatures on the cryocooler hot side were higher than planned. This precluded the cryocooler from eliminating the boil-off. The results show the cryocooler was successful at removing 6.8 W of heat at approximately 75 K and 150 W of input power, with a heat rejection temperature of 311 K. The data generated on the ZBO components is essential for the upgrade of the ZBO Cryogenic Analysis Tool to more accurately apply the concept to future missions.

  5. Test Architecture, Test Retrofit

    ERIC Educational Resources Information Center

    Fulcher, Glenn; Davidson, Fred

    2009-01-01

    Just like buildings, tests are designed and built for specific purposes, people, and uses. However, both buildings and tests grow and change over time as the needs of their users change. Sometimes, they are also both used for purposes other than those intended in the original designs. This paper explores architecture as a metaphor for language…

  6. An integrated practical implementation of continuous aqueous two-phase systems for the recovery of human IgG: From the microdevice to a multistage bench-scale mixer-settler device.

    PubMed

    Espitia-Saloma, Edith; Vâzquez-Villegas, Patricia; Rito-Palomares, Marco; Aguilar, Oscar

    2016-05-01

    Aqueous two-phase systems (ATPS) are a liquid-liquid extraction technology with clear process benefits; however, its lack of industrial embracement is still a challenge to overcome. Antibodies are a potential product to be recovered by ATPS in a commercial context. The objective of this work is to present a more integral approach of the different isolated strategies that have arisen in order to enable a practical, generic implementation of ATPS, using human immunoglobulin G (IgG) as experimental model. A microfluidic device is used for ATPS parameters preselection for product recovery. ATPS were continuously operated in a mixer-settler device in one stage, multistage and multistage with recirculation configuration. Single-stage pure IgG extraction with a polyethylene glycol (PEG) 3350-phophates ATPS within continuous operation allowed a 65% recovery. Further implementation of a multistage platform promoted a higher particle partitioning reaching a 90% recovery. The processing of IgG from a cell supernatant culture harvest in a multistage system with top phase recirculation resulted in 78% IgG recovery in bottom phase. This work conjugates three not widely spread methodologies for ATPS: microfluidics, continuous and multistage operation.

  7. The Brain As a Mixer, I. Preliminary Literature Review: Auditory Integration. Studies in Language and Language Behavior, Progress Report Number VII.

    ERIC Educational Resources Information Center

    Semmel, Melvyn I.; And Others

    Methods to evaluate central hearing deficiencies and to localize brain damage are reviewed beginning with Bocca who showed that patients with temporal lobe tumors made significantly lower discrimination scores in the ear opposite the tumor when speech signals were distorted. Tests were devised to attempt to pinpoint brain damage on the basis of…

  8. Test plan :

    SciTech Connect

    Dwyer, Stephen F.

    2013-05-01

    This test plan is a document that provides a systematic approach to the planned testing of rooftop structures to determine their actual load carrying capacity. This document identifies typical tests to be performed, the responsible parties for testing, the general feature of the tests, the testing approach, test deliverables, testing schedule, monitoring requirements, and environmental and safety compliance.

  9. Pinworm test

    MedlinePlus

    Oxyuriasis test; Enterobiasis test; Tape test ... diagnose this infection is to do a tape test. The best time to do this is in ... lay their eggs at night. Steps for the test are: Firmly press the sticky side of a ...

  10. Thyroid Tests

    MedlinePlus

    ... calories and how fast your heart beats. Thyroid tests check how well your thyroid is working. They ... thyroid diseases such as hyperthyroidism and hypothyroidism. Thyroid tests include blood tests and imaging tests. Blood tests ...

  11. Susceptibility Testing

    MedlinePlus

    ... Also known as: Sensitivity Testing; Drug Resistance Testing; Culture and Sensitivity; C & S; Antimicrobial Susceptibility Formal name: Bacterial and Fungal Susceptibility Testing Related tests: Urine Culture ; Blood Culture ; Bacterial Wound Culture ; AFB Testing ; MRSA ; ...

  12. Acoustic and Laser Doppler Anemometer Results for Confluent and 12-Lobed E(exp 3) Mixer Exhaust Systems for Subsonic Jet Noise Reduction

    NASA Technical Reports Server (NTRS)

    Salikuddin, M.; Babbit, R. R.; Shin, H.; Wisler, S.; Janardan, B. A.; Majjigi, R. K.; Bridges, James (Technical Monitor)

    2002-01-01

    The research described in this report has been funded by NASA Glenn Research Center as part of the Advanced Subsonic Technologies (AST) initiative. The program operates under the Large Engine Technologies (LET) as Task Order #3 1. Task Order 31 is a three year research program divided into three subtasks. Subtask A develops the experimental acoustic and aerodynamic subsonic mixed flow exhaust system databases. Subtask B seeks to develop and assess CFD-based aero-acoustic methods for subsonic mixed flow exhaust systems. Subtask B relies on the data obtained from Subtask A to direct and calibrate the aero-acoustic methods development. Subtask C then seeks to utilize both the aero-acoustic data bases developed in Subtask A and the analytical methods developed in Subtask B to define improved subsonic mixed-flow exhaust systems. The mixed flow systems defined in Subtask C will be experimentally demonstrated for improved noise reduction in a scale model aero-acoustic test conducted similarly to the test performed in Subtask A. The overall object of this Task Order is to develop and demonstrate the technology to define a -3EPNdB exhaust system relative to 1992 exhaust system technology.

  13. Pharmacogenomic Testing

    MedlinePlus

    ... Primary care providers Specialists Getting covered Research Basic science research Research in people ... screening Diagnostic testing Direct-to-consumer genetic testing Newborn screening Pharmacogenomic testing ...

  14. Predictive Testing

    MedlinePlus

    ... Primary care providers Specialists Getting covered Research Basic science research Research in people ... screening Diagnostic testing Direct-to-consumer genetic testing Newborn screening Pharmacogenomic testing ...

  15. Pregnancy Tests

    MedlinePlus

    ... Us Home A-Z Health Topics Pregnancy tests Pregnancy tests > A-Z Health Topics Pregnancy test fact ... To receive Publications email updates Enter email Submit Pregnancy tests If you think you may be pregnant , ...

  16. VDRL test

    MedlinePlus

    ... The VDRL test is a screening test for syphilis. It measures substances (proteins), called antibodies, that your ... come in contact with the bacteria that cause syphilis. How the Test is Performed The test is ...

  17. Coombs test

    MedlinePlus

    Direct antiglobulin test; Indirect antiglobulin test; Anemia - hemolytic ... No special preparation is necessary for this test. ... There are 2 types of the Coombs test: Direct Indirect The direct ... that are stuck to the surface of red blood cells. Many diseases ...

  18. Ham test

    MedlinePlus

    Acid hemolysin test; Paroxysmal nocturnal hemoglobinuria - Ham test; PNH - Ham test ... BJ. In: Chernecky CC, Berger BJ, eds. Laboratory Tests and Diagnostic Procedures . 6th ed. Philadelphia, PA: Elsevier ...

  19. Trichomonas Testing

    MedlinePlus

    ... Trichomonas vaginalis by Amplified Detection; Trichomonas vaginalis by Direct Fluorescent Antibody (DFA) Related tests: Pap Test , Chlamydia ... by one of the following methods: Molecular testing, direct DNA probes, or nucleic acid amplification tests (NAATs)— ...

  20. Research in millimeter wave techniques

    NASA Technical Reports Server (NTRS)

    Forsythe, R. E.

    1982-01-01

    Subharmonically pumped mixers were ascended and tested. A computerized version of the automatic noise figure measurement system was developed. Impedance matching techniques suitable for these types of mixers were investigated. Narrow and broadband (one octave) matching networks for the subharmonic mixers were designed. The automatic mixer noise figure test facility was completed. Subharmonic mixers and the systems that use them at 183 and 220 GHz were evaluated and characterized.

  1. CFD simulation and experimental analysis of erosion in a slurry tank test rig

    NASA Astrophysics Data System (ADS)

    Azimian, Mehdi; Bart, Hans-Jörg

    2013-04-01

    Erosion occurring in equipment dealing with liquid-solid mixtures such as pipeline parts, slurry pumps, liquid-solid stirred reactors and slurry mixers in various industrial applications results in operational failure and economic costs. A slurry erosion tank test rig is designed and was built to investigate the erosion rates of materials and the influencing parameters such as flow velocity and turbulence, flow angle, solid particle concentration, particles size distribution, hardness and target material properties on the material loss and erosion profiles. In the present study, a computational fluid dynamics (CFD) tool is used to simulate the erosion rate of sample plates in the liquid-solid slurry mixture in a cylindrical tank. The predictions were made in a steady state and also transient manner, applying the flow at the room temperature and using water and sand as liquid and solid phases, respectively. The multiple reference frame method (MRF) is applied to simulate the flow behavior and liquid-solid interactions in the slurry tank test rig. The MRF method is used since it is less demanding than sliding mesh method (SM) and gives satisfactory results. The computational domain is divided into three regions: a rotational or MRF zone containing the mixer, a rotational zone (MRF) containing the erosion plates and a static zone (outer liquid zone). It is observed that changing the MRF zone diameter and height causes a very low impact on the results. The simulated results were obtained for two kinds of hard metals namely stainless steel and ST-50 under some various operating conditions and are found in good agreement with the experimental results.

  2. POC-scale testing of oil agglomeration techniques and equipment for fine coal processing: technical progress report no. 3--January 1, 1996-March 31, 1996

    SciTech Connect

    1996-10-01

    The objective of this project is to develop and demonstrate a Proof-of-Concept (POC) scale oil agglomeration technology capable of increasing the recovery and improving the quality of fine coal streams. Two distinct agglomeration devices will be tested, namely, a conventional high shear mixer and a tubular (jet) processor. To meet the overall objective an 11 task work plan has been designed. The work will range from batch and continuous bench-scale testing through the design, commissioning and field testing of POC-scale agglomeration equipment. During the reporting period there were activities under the following tasks: project planning and management; host site selection and plan formulation; preliminary engineering and design of POC equipment; coal characterization and laboratory (batch) and bench-scale testing; and process evaluation. The work on the remaining tasks is scheduled for the next months.

  3. Thyroid Tests

    MedlinePlus

    ... the thyroid, a computerized tomography (CT) scan, or nuclear medicine tests, to diagnose and find the cause ... is having the scan for other health problems. Nuclear medicine tests. Nuclear medicine tests of the thyroid ...

  4. Laboratory Tests

    MedlinePlus

    Laboratory tests check a sample of your blood, urine, or body tissues. A technician or your doctor ... compare your results to results from previous tests. Laboratory tests are often part of a routine checkup ...

  5. Lipase Test

    MedlinePlus

    ... known as: LPS Formal name: Lipase Related tests: Amylase , Trypsin , Trypsinogen At a Glance Test Sample The ... lipase is most often used, along with an amylase test , to help diagnose and monitor acute pancreatitis . ...

  6. IQ testing

    MedlinePlus

    IQ (intelligence quotient) testing is a series of exams used to determine your general intelligence in relation ... Many IQ tests are used today. Whether they measure actual intelligence or simply certain abilities is controversial. IQ tests ...

  7. Test Madness

    ERIC Educational Resources Information Center

    Hedrick, Wanda B., Ed.

    2007-01-01

    There's accountability and then there's the testing craze an iatrogenic practice that undermines real learning. Hedrick documents the negative effects of testing, giving teachers another weapon in their arsenal against mindless preparation for high-stakes tests.

  8. Chlamydia Testing

    MedlinePlus

    ... of testing for chlamydia. NAAT is a molecular test that detects the genetic material ( DNA ) of Chlamydia trachomatis . It is generally more sensitive and specific than other chlamydia tests and can be performed on a vaginal swab ...

  9. Testing Services

    NASA Technical Reports Server (NTRS)

    1993-01-01

    Trace Laboratories is an independent testing laboratory specializing in testing printed circuit boards, automotive products and military hardware. Technical information from NASA Tech Briefs and two subsequent JPL Technical Support packages have assisted Trace in testing surface insulation resistance on printed circuit board materials. Testing time was reduced and customer service was improved because of Jet Propulsion Laboratory technical support packages.

  10. RPR test

    MedlinePlus

    ... more specific test for syphilis, such as FTA-ABS . The FTA-ABS test will help distinguish between syphilis and other ... Elsevier Saunders; 2015:chap 239. Read More FTA-ABS test VDRL test Review Date 9/10/2015 ...

  11. Composite Testing

    DTIC Science & Technology

    2007-01-01

    Impact Test Matrix for Each Team Impact Tests Qty. Reqd. Per Team Dimensions Steel- GFRP Hybrid Specimen 3 40” x 12” GFRP Control...5: Tension Test Specimen Details Table 2: Tension Test Matrix for Each Team Tension Tests Qty. Reqd. Per Team Dimensions Steel- GFRP Hybrid...Specimen 6 12” L x 1-2” W GFRP Control Specimen 3 12” L x 1-2” W Numerical Modelling A detailed numerical model

  12. SIS (Superconductor-Insulator-Superconductor) Mixer Research.

    DTIC Science & Technology

    1987-03-17

    in linear amplifiers. 2. Arrays: Little has been accomplished on this topic, but preparations are being made for future research. A new graduate...termination impedance. This appears to violate the assumptions of the most widely quoted theory C.M. Caves.- Phys. Rev. D26, 1817 (1982)1 of quantum noise

  13. SIS (Superconductor-Insulator-Superconductor) Mixer Research

    DTIC Science & Technology

    1989-07-01

    in linear amplifiers. The calculation performed in this work was unique in that it employed the complete equations of the quantum theory of mixing in...termination impedance. This appears to violate the assumptions of the most widely quoted theory [C.M. Caves, Phys. Rev. D26, 1817 (1982)] of quantum noise

  14. Topological chaos in inviscid and viscous mixers

    NASA Astrophysics Data System (ADS)

    Finn, M. D.; Cox, S. M.; Byrne, H. M.

    2003-10-01

    Topological chaos may be used to generate highly effective laminar mixing in a simple batch stirring device. Boyland, Aref & Stremler (2000) have computed a material stretch rate that holds in a chaotic flow, provided it has appropriate topological properties, irrespective of the details of the flow. Their theoretical approach, while widely applicable, cannot predict the size of the region in which this stretch rate is achieved. Here, we present numerical simulations to support the observation of Boyland et al. that the region of high stretch is comparable with that through which the stirring elements move during operation of the device. We describe a fast technique for computing the velocity field for either inviscid, irrotational or highly viscous flow, which enables accurate numerical simulation of dye advection. We calculate material stretch rates, and find close agreement with those of Boyland et al., irrespective of whether the fluid is modelled as inviscid or viscous, even though there are significant differences between the flow fields generated in the two cases.

  15. 7 CFR 58.515 - Mixers.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) REGULATIONS AND STANDARDS UNDER THE AGRICULTURAL MARKETING ACT OF 1946 AND THE EGG PRODUCTS INSPECTION ACT (CONTINUED) GRADING AND INSPECTION,...

  16. SIS (Superconductor-Insulator-Superconductor) Mixer Research.

    DTIC Science & Technology

    1988-02-01

    presently equipping a CF 4 plasma etcher for the CHF 3 process. In order to more reproducibly fabricate these junctions, we have installed a variable...evaluate plasma -etched NbN edge junctions to study the mechanisms of oxide growth on a shaped NbN surface. ,-,",, iM. Status of the Research Several...have appeared in print [9], but many aspects warrant further research and a final publication is still in preparation [141. 4. Plasma -etched NbN edge

  17. Antimonide-based Diodes for Terahertz Mixers

    DTIC Science & Technology

    2008-06-01

    different analysis by Sheinman and Ritter.6 The layer structure presented in Fig. 2 is for a diode that has been successfully grown on both semi-insultating...6B. Sheinman and D. Ritter, IEEE Trans. Electron Devices 50, 1075 2003. 7R. Magno, E. R. Glaser, B. P. Tinkham, J. G. Champlain, J. B. Boos, M. G

  18. 7 CFR 58.515 - Mixers.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... MARKETING ACT OF 1946 AND THE EGG PRODUCTS INSPECTION ACT (CONTINUED) GRADING AND INSPECTION, GENERAL SPECIFICATIONS FOR APPROVED PLANTS AND STANDARDS FOR GRADES OF DAIRY PRODUCTS 1 General Specifications for Dairy... the wall of the tank below the level of the product, they shall be equipped with proper seals...

  19. Ultrafast active mixer using polyelectrolytic ion extractor.

    PubMed

    Chun, Honggu; Kim, Hee Chan; Chung, Taek Dong

    2008-05-01

    We report on a low voltage, straight/smooth surface, and efficient active micromixer. The mixing principle is based on alternative ion depletion-enrichment using a pair of positively charged polyelectrolytic gel electrodes (pPGEs), which face each other joined by a microchannel. This system has an external AC signal source electrically connected to the pPGEs via the respective 1 M KCl solutions and Ag/AgCl electrodes. When an electric bias is applied between the two pPGEs, anions are extracted through one of the pPGEs to create a local ion-deficient region. Simultaneously, an ion-rich area appears near the other pPGE due to an inward anionic flux. As the direction of the charge flow is periodically reversed by the AC signal source, the ion depletion-enrichment regions are alternately swapped with each other on the 'push-pull' basis. The turmoil between the pPGEs quickly mixes the solutions in the microchannel without any mechanical moving part or specially machined structures. In the proposed system, both AC frequency and current density can be easily and finely controlled so that one can quickly find the optimal conditions for a given sample. The micromixer as made showed a mixing efficiency higher than 90% for sample solutions of 1 mM Rhodamine 6G and PBS at pH 7.4 when the flow rate was under 6 mm s(-1). In addition to the solution-solution mixing, the micromixer can effectively mix suspended microparticles with solution. As a representative example, rapid and efficient lysis of human red blood cells was demonstrated allowing minimal damage of the white blood cells.

  20. Scaling Relationships Based on Scaled Tank Mixing and Transfer Test Results

    SciTech Connect

    Piepel, Gregory F.; Holmes, Aimee E.; Heredia-Langner, Alejandro; Lee, Kearn P.; Kelly, Steven E.

    2014-01-01

    This report documents the statistical analyses performed (by Pacific Northwest National Laboratory for Washington River Protection Solutions) on data from 26 tests conducted using two scaled tanks (43 and 120 inches) in the Small Scale Mixing Demonstration platform. The 26 tests varied several test parameters, including mixer-jet nozzle velocity, base simulant, supernatant viscosity, and capture velocity. For each test, samples were taken pre-transfer and during five batch transfers. The samples were analyzed for the concentrations (lbs/gal slurry) of four primary components in the base simulants (gibbsite, stainless steel, sand, and ZrO2). The statistical analyses including modeling the component concentrations as functions of test parameters using stepwise regression with two different model forms. The resulting models were used in an equivalent performance approach to calculate values of scaling exponents (for a simple geometric scaling relationship) as functions of the parameters in the component concentration models. The resulting models and scaling exponents are displayed in tables and graphically. The sensitivities of component concentrations and scaling exponents to the test parameters are presented graphically. These results will serve as inputs to subsequent work by other researchers to develop scaling relationships that are applicable to full-scale tanks.

  1. Scaling Relationships Based on Scaled Tank Mixing and Transfer Test Results

    SciTech Connect

    Piepel, Gregory F.; Holmes, Aimee E.; Heredia-Langner, Alejandro

    2013-09-18

    This report documents the statistical analyses performed (by Pacific Northwest National Laboratory for Washington River Protection Solutions) on data from 26 tests conducted using two scaled tanks (43 and 120 inches) in the Small Scale Mixing Demonstration platform. The 26 tests varied several test parameters, including mixer-jet nozzle velocity, base simulant, supernatant viscosity, and capture velocity. For each test, samples were taken pre-transfer and during five batch transfers. The samples were analyzed for the concentrations (lbs/gal slurry) of four primary components in the base simulants (gibbsite, stainless steel, sand, and ZrO2). The statistical analyses including modeling the component concentrations as functions of test parameters using stepwise regression with two different model forms. The resulting models were used in an equivalent performance approach to calculate values of scaling exponents (for a simple geometric scaling relationship) as functions of the parameters in the component concentration models. The resulting models and scaling exponents are displayed in tables and graphically. The sensitivities of component concentrations and scaling exponents to the test parameters are presented graphically. These results will serve as inputs to subsequent work by other researchers to develop scaling relationships that are applicable to full-scale tanks.

  2. Design of a Mach-3 Nozzle for TBCC Testing in the NASA LaRC 8-ft High Temperature Tunnel

    NASA Technical Reports Server (NTRS)

    Gaffney, Richard L., Jr.; Norris, Andrew T.

    2008-01-01

    A new nozzle is being constructed for the NASA Langley Research Center 8-Foot High Temperature Tunnel. The axisymmetric nozzle was designed with a Mach-3 exit flow for testing Turbine-Based Combined-Cycle engines at a Mach number in the vicinity of the transition from turbojet to ramjet operation. The nozzle contour was designed using the NASA Langley IMOCND computer program which solves the potential equation using the classical method of characteristics. To include viscous effects, the design procedure iterated the MOC contour generation with CFD Navier-Stokes calculations, adjusting MOC input parameters until target nozzle-exit conditions were achieved in the Navier-Stokes calculations. The design process was complicated by a requirement to use the final 29.5 inches of an existing 54.5-inch exit-diameter Mach-5 nozzle contour. This was accomplished by generating a Mach-3 contour that matched the radius of the Mach-5 contour at the match point and using a 3rd order polynomial to create a smooth transition between the two contours. During the final evaluation of the design it was realized that the throat diameter is more than half that of the upstream mixing chamber. This led to the concern that large vortical structures generated in the mixer would persist downstream, affecting nozzle-exit flow. This concern was addressed by analyzing the results of three-dimensional, viscous, numerical simulations of the entire flowfield, from the exit of the facility combustor to the nozzle exit. An analysis of the solution indicated that large scale structures do not pass through the throat and that both the total temperature and species (CO2) are well mixed in the mixer, providing uniform flow to the nozzle and subsequently the test cabin.

  3. Pregnancy test

    MedlinePlus

    ... eds. Henry's Clinical Diagnosis and Management by Laboratory Methods . 22nd ed. Philadelphia, PA: Elsevier Saunders; 2011:chap 25. Read More Ectopic pregnancy HCG blood test - qualitative HCG blood test - quantitative HCG in urine Miscarriage ...

  4. Prenatal Tests

    MedlinePlus

    ... may recommend you have an invasive test, like amniocentesis , to confirm the results. Chorionic villus sampling (also ... done at 15 to 22 weeks of pregnancy. Amniocentesis (also called amnio). Tests the amniotic fluid from ...

  5. Procalcitonin Test

    MedlinePlus

    ... Tests Online. AACC is a not-for-profit organization and does not endorse non-AACC products and services. Advertising & ... Complete Blood Count , Blood Culture , CSF Analysis All content on Lab Tests Online ...

  6. HPV Test

    MedlinePlus

    ... test for wider range of HPV types. 2009 Mar 13. US Food and Drug Administration. Available online ... approves two DNA tests to detect HPV. 2009 Mar 17. Infectious Disease News. Available online at http:// ...

  7. Potassium test

    MedlinePlus

    ... this page: //medlineplus.gov/ency/article/003484.htm Potassium test To use the sharing features on this ... enable JavaScript. This test measures the amount of potassium in the fluid portion (serum) of the blood. ...

  8. Kidney Tests

    MedlinePlus

    ... taking out waste products and making urine. Kidney tests check to see how well your kidneys are working. They include blood, urine, and imaging tests. Early kidney disease usually does not have signs ...

  9. Urodynamic Testing

    MedlinePlus

    ... the ability or inability to stop the urine flow in midstream. For precise measurements, imaging equipment takes pictures of the bladder filling ... postvoid residual measurement cystometric test leak point pressure measurement pressure flow ... urodynamic tests Uroflowmetry Uroflowmetry is ...

  10. Pertussis Tests

    MedlinePlus

    ... as: Whooping Cough Tests Formal name: Bordetella pertussis Culture; Bordetella pertussis by PCR; Bordetella pertussis Antibodies (IgA, ... outbreak, at least one case be confirmed using culture. Culture – this test was the "gold standard" for ...

  11. Syphilis Test

    MedlinePlus

    ... been developed, making them convenient for screening purposes. Direct detection of bacteria —these tests are less commonly ... highly sensitive; can be used to exclude neurosyphilis. Direct detection tests (much less common): Microscopic Exam, Darkfield ...

  12. Seismic testing

    SciTech Connect

    Knott, S.

    1981-10-01

    Electric Power Research Institute (EPRI) research programs in seismic testing to improve earthquake design guidelines lowers the safety-design costs of nuclear power plants. Explosive tests that simulate earthquakes help to determine how structures respond to ground motion and how these are related to soil and geologic conditions at a specific site. Explosive tests develop data for simulation using several computer codes. Photographs illustrate testing techniques. 6 references. (DCK)

  13. Tested Demonstrations.

    ERIC Educational Resources Information Center

    Gilbert, George L., Ed.

    1988-01-01

    Describes three flame test demonstrations including "Student-Presented Demonstrations on the Colors of Transition Metal Complexes,""A Flame Test Demonstration Device," and "Vivid Flame Tests." Preparation and procedures are discussed. Included in the first demonstration is an evaluation scheme for grading student…

  14. Teacher Testing.

    ERIC Educational Resources Information Center

    Dunn, Judy; And Others

    1987-01-01

    A one-page introduction is followed by summaries of articles and documents on teacher competency testing. George F. Madaus argues that, although tests serve some useful functions, treating them as a major mechanism for reforming education is questionable. Peter A. Garcia examines the negative impact of testing on minority teachers and minorities…

  15. Fiscal year 1994 1/25-scale sludge mobilization testing

    SciTech Connect

    Powell, M.R.; Gates, C.M.; Hymas, C.R.; Sprecher, M.A.; Morter, N.J.

    1995-07-01

    There are 28 one-million-gallon double-shell radioactive waste tanks on the Hanford Reservation in southeastern Washington State. The waste in these tanks was generated during processing of nuclear materials. Solids-laden slurries were placed into many of the tanks. Over time, the waste solids have settled to form a layer of sludge in the bottom of these tanks. The sludge layer thickness varies from tank to tank with some having only a few centimeters or no sludge up to some tanks which have about 4.5 m (15 ft) of sludge. It is planned that the waste will be removed from these tanks as part of the overall Hanford site cleanup efforts. Jet mixer pumps are to be placed into the tanks to stir up (mobilize) the sludge and form a uniform slurry suitable for pumping to downstream processing facilities. These mixer pumps use powerful jets of tank fluid directed horizontally out of two, diametrically opposed nozzles near the tank bottom. These fluid jets impinge upon the sludge and stir it up. The amount of sludge mobilized by the mixer pump jets depends not only on the jet properties, but also on the ability of the sludge to resist the jets. It is the goal of the work described in this document to develop the ability to predict how much sludge will be mobilized by the mixer pumps based on the size and velocity of the mixer pump jets and the physical and chemical properties of the tank sludge.

  16. Analytical testing

    NASA Technical Reports Server (NTRS)

    Flannelly, W. G.; Fabunmi, J. A.; Nagy, E. J.

    1981-01-01

    Analytical methods for combining flight acceleration and strain data with shake test mobility data to predict the effects of structural changes on flight vibrations and strains are presented. This integration of structural dynamic analysis with flight performance is referred to as analytical testing. The objective of this methodology is to analytically estimate the results of flight testing contemplated structural changes with minimum flying and change trials. The category of changes to the aircraft includes mass, stiffness, absorbers, isolators, and active suppressors. Examples of applying the analytical testing methodology using flight test and shake test data measured on an AH-1G helicopter are included. The techniques and procedures for vibration testing and modal analysis are also described.

  17. Mitigation of tank 241-SY-101 by pump mixing: Results of full-scale testing

    SciTech Connect

    Stewart, C.W.; Hudson, J.D.; Friley, J.R.; Panisko, F.E.; Antoniak, Z.I.; Irwin, J.J.; Fadeff, J.G.; Efferding, L.F.; Michener, T.E.; Kirch, N.W.

    1994-06-01

    The Full-Scale Mixer Pump Test Program was performed in Hanford Tank 241-SY-101 from February 4 to April 13, 1994, to confirm the long-term operational strategy for flammable gas mitigation and to demonstrate that mixing can control the gas release and waste level. Since its installation on July 3, 1993, the current pump, operating only a few hours per week, has proved capable of mixing the waste sufficiently to release gas continuously instead of in large episodic events. The results of Full-Scale Testing demonstrated that the pump can control gas release and waste level for long-term mitigation, and the four test sequences formed the basis for the long-term operating schedule. The last test sequence, jet penetration tests, showed that the current pump jet creates flow near the tank wall and that it can excavate portions of the bottom sludge layer if run at maximum power. Pump mixing has altered the {open_quote}normal{close_quote} configuration of the waste; most of the original nonconvective sludge has been mixed with the supernatant liquid into a mobile convective slurry that has since been maintained by gentle pump operation and does not readily return to sludge.

  18. Testing Relativity

    NASA Astrophysics Data System (ADS)

    Hentschel, Klaus

    in chapter 7 of this book, Klaus Hentschel first reviews Einstein's general attitude towards experiments, much more positive than generally believed, then reviews experimental tests of both special and general relativity, focussing on tests during Einstein's lifetime, incl. gravitational redshift, light deflection, perihelion motion. Among the non-standard tests, time-delay measurements, gyroscope experiments, the Nordtvedt effect, and gravitational waves are also discussed.

  19. Performance tests.

    PubMed Central

    Wetherell, A

    1996-01-01

    This paper discusses the use of psychological performance tests to assess the effects of environmental stressors. The large number and the variety of performance tests are illustrated, and the differences between performance tests and other psychological tests are described in terms of their design, construction, use, and purpose. The stressor emphasis is on the effects of drugs since that is where most performance tests have found their main application, although other stressors, e.g., fatigue, toxic chemicals, are mentioned where appropriate. Diazepam is used as an example. There is no particular performance emphasis since the tests are intended to have wide applicability. However, vehicle-driving performance is discussed because it has been the subject of a great deal of research and is probably one of the most important areas of application. Performance tests are discussed in terms of the four main underlying models--factor analysis, general information processing, multiple resource and strategy models, and processing-stage models--and in terms of their psychometric properties--sensitivity, reliability, and content, criterion, construct, and face validity. Some test taxonomies are presented. Standardization is also discussed with reference to the reaction time, mathematical processing, memory search, spatial processing, unstable tracking, verbal processing, and dual task tests used in the AGARD STRES battery. Some comments on measurement strengths and appropriate study designs and methods are included. PMID:9182033

  20. Rubella Test

    MedlinePlus

    ... be limited. Home Visit Global Sites Search Help? Advertisement Proceeds from website advertising help sustain Lab Tests ... for trustworthy health information. Verify Compliance . Produced by Advertisement

  1. Malnutrition Tests

    MedlinePlus

    ... be limited. Home Visit Global Sites Search Help? Advertisement Proceeds from website advertising help sustain Lab Tests ... for trustworthy health information. Verify Compliance . Produced by Advertisement

  2. RSV Test

    MedlinePlus

    ... be limited. Home Visit Global Sites Search Help? Advertisement Proceeds from website advertising help sustain Lab Tests ... for trustworthy health information. Verify Compliance . Produced by Advertisement

  3. PTH Test

    MedlinePlus

    ... be limited. Home Visit Global Sites Search Help? Advertisement Proceeds from website advertising help sustain Lab Tests ... for trustworthy health information. Verify Compliance . Produced by Advertisement

  4. Progesterone Test

    MedlinePlus

    ... be limited. Home Visit Global Sites Search Help? Advertisement Proceeds from website advertising help sustain Lab Tests ... for trustworthy health information. Verify Compliance . Produced by Advertisement

  5. RF and Data Acquisition Systems for Fermilab's ILC SRF Cavity Vertical Test Stand

    SciTech Connect

    Joseph P. Ozelis; Roger Nehring; Christiana Grenoble; Thomas J. Powers

    2007-06-01

    Fermilab is developing a facility for vertical testing of SRF cavities as part of a program to improve cavity performance reproducibility for the ILC. The RF system for this facility, using the classic combination of oscillator, phase detector/mixer, and loop amplifier to detect the resonant cavity frequency and lock onto the cavity, is based on the proven production cavity test systems used at Jefferson Lab for CEBAF and SNS cavity testing. The design approach is modular in nature, using commercial-off-the-shelf (COTS) components. This yields a system that can be easily debugged and modified, and with ready availability of spares. Data acquisition and control is provided by a PXI-based hardware platform in conjunction with software developed in the LabView programming environment. This software provides for amplitude and phase adjustment of incident RF power, and measures all relevant cavity power levels, cavity thermal environment parameters, as well as field emission-produced radiation. It also calculates the various cavity performance parameters and their associated errors. Performance during system commissioning and initial cavity tests will be presented.

  6. Jet noise results from static, wind tunnel, and flight tests of conical and mechanical suppressor nozzles

    NASA Technical Reports Server (NTRS)

    Mckinnon, R. A.; Johnson, E. S.; Atencio, A., Jr.

    1981-01-01

    Results of jet noise suppression tests conducted on a Rolls-Royce Viper 601 turbojet engine are reported. Seven exhaust nozzle configurations are tested, including two conical nozzles, two suppressor mixers, and three treated ejector configurations with different ejector inlets. Tests are conducted at the NASA Ames outdoor static test facility and the 40- by 80-ft wind tunnel facility at minimum tunnel flow velocity and normal flow velocities of 230 and 290 ft/sec. Near-field multiple sideline noise levels are projected to the far fields to compare far-field fixed microphone outdoor static noise levels, and wind tunnel near-field noise data are projected to the far field and flight distances to compare with noise levels recorded from an Hs-125 aircraft. Near-field outdoor noise data duplicate the far-field data recorded from fixed microphones within 2 PNdB, and the Douglas mechanical jet noise suppressor/treated ejector exhaust system achieves a noise reduction of 12 EPNdB relative to a conic reference nozzle at equal thrust in flight.

  7. Rapid inoculum standardization system: a novel device for standardization of inocula in antimicrobial susceptibility testing.

    PubMed Central

    Wicks, J H; Nelson, R L; Krejcarek, G E

    1983-01-01

    A rapid inoculum standardization system for antimicrobial susceptibility testing without incubation or the conventional turbidity adjustment has been developed. The rapid inoculum standardization system consists of a plastic rod with cross-hatched grooves on one end and a specific nutrient medium in a vial. The crosshatched grooves are designed to pick up and release a known number of viable microorganisms. In use, the end of the rod is touched to five colonies 1 to 2 mm in diameter from a primary agar plate, thus filling the grooves with bacteria. The rod is placed into the vial, and the bacteria are suspended in the medium by agitation with a Vortex Genie Mixer. The resulting suspension contains 5 X 10(7) to 5 X 10(8) CFU/ml for most gram-negative bacilli and gram-positive cocci. Microorganisms such as streptococci that have colonies less than 1 mm in diameter require as many as 10 colonies for an adequate inoculum suspension. Ninety-five commonly encountered bacterial isolates were tested in triplicate by agar plate counts. The resulting overall geometric mean of the agar plate counts was 1.52 X 10(8) CFU/ml for the species tested. We have found that the rapid inoculum standardization system provides a consistent and reproducible method for the standardization of inoculum for antimicrobial susceptibility testing without the incubation period and turbidity adjustment. Images PMID:6874902

  8. Testing Speaking.

    ERIC Educational Resources Information Center

    Kitao, S. Kathleen; Kitao, Kenji

    Speaking a second language is probably the most difficult skill to test in that it involves a combination of skills that may have no correlation with each other, and which do not lend themselves to objective testing. In addition, what can be understood is a function of the listener's background and ability as well as those of the speaker. Another…

  9. Microalbumin Test

    MedlinePlus

    ... test to detect very small levels of a blood protein (albumin) in your urine. A microalbumin test is used ... kidney disease. Healthy kidneys filter waste from your blood and hang on to the healthy components, including proteins such as albumin. Kidney damage can cause proteins to leak through ...

  10. Testing Behavior.

    ERIC Educational Resources Information Center

    Zirkel, Perry A.

    2003-01-01

    Analyzes Georgia high-stakes testing case involving administrative law judge's recommendation (subsequently approved) that fifth-grade science teacher's teaching certificate be suspended for giving his students pretest copies of the Iowa Tests of Basic Skills. Suggests No Child Left Behind Act will spawn similar litigation in the future. (PKP)

  11. Strength Testing.

    ERIC Educational Resources Information Center

    Londeree, Ben R.

    1981-01-01

    Postural deviations resulting from strength and flexibility imbalances include swayback, scoliosis, and rounded shoulders. Screening tests are one method for identifying strength problems. Tests for the evaluation of postural problems are described, and exercises are presented for the strengthening of muscles. (JN)

  12. Optical testing

    NASA Technical Reports Server (NTRS)

    Wyant, James; Hochberg, Eric; Breault, Robert; Greivenkamp, John; Hunt, Gary; Mason, Pete; Mcguire, James; Meinel, Aden; Morris, Mike; Scherr, Larry

    1992-01-01

    Optical testing is one of the most vital elements in the process of preparing an optical instrument for launch. Without well understood, well controlled, and well documented test procedures, current and future mission goals will be jeopardized. We should keep in mind that the reason we test is to provide an opportunity to catch errors, oversights, and problems on the ground, where solutions are possible and difficulties can be rectified. Consequently, it is necessary to create tractable test procedures that truly provide a measure of the performance of all optical elements and systems under conditions which are close to those expected in space. Where testing is not feasible, accurate experiments are required in order to perfect models that can exactly predict the optical performance. As we stretch the boundaries of technology to perform more complex space and planetary investigations, we must expand the technology required to test the optical components and systems which we send into space. As we expand the observational wavelength ranges, so must we expand our range of optical sources and detectors. As we increase resolution and sensitivity, our understanding of optical surfaces to accommodate more stringent figure and scatter requirements must expand. Only with research and development in these areas can we hope to achieve success in the ever increasing demands made on optical testing by the highly sophisticated missions anticipated over the next two decades. Technology assessment and development plan for surface figure, surface roughness, alignment, image quality, radiometric quantities, and stray light measurement are presented.

  13. Patch tests*

    PubMed Central

    Lazzarini, Rosana; Duarte, Ida; Ferreira, Alessandra Lindmayer

    2013-01-01

    Patch tests were introduced as a diagnostic tool in the late nineteenth century. Since then, they have improved considerably becoming what they are today. Patch tests are used in the diagnostic investigation of contact dermatitis worldwide. Batteries or series previously studied and standardized should be used in patch testing. The methodology is simple, but it requires adequate training for the results to be correctly interpreted and used. Despite having been used for over a century, it needs improvement like all other diagnostic techniques in the medical field. PMID:24474094

  14. Misconceptions Tests or Misconceived Tests?

    ERIC Educational Resources Information Center

    Griggs, Richard A.; Ransdell, Sarah E.

    1987-01-01

    States that taking a high school psychology course did not improve the performance of college students in an introductory psychology class on a modified version of Vaughan's misconceptions test (Test of Common Beliefs). Concludes that while college experience did lead to some improvement, comparison with other studies indicates that perhaps the…

  15. Cholesterol Test

    MedlinePlus

    ... AACC products and services. Advertising & Sponsorship: Policy | Opportunities Cholesterol Share this page: Was this page helpful? Also known as: Blood Cholesterol Formal name: Total Cholesterol Related tests: HDL Cholesterol , ...

  16. VMA Test

    MedlinePlus

    ... is primarily used to detect and rule out neuroblastomas in children with an abdominal mass or other ... homovanillic acid (HVA) test to help diagnose a neuroblastoma, to monitor the effectiveness of treatment, and to ...

  17. Neuropathy Tests

    MedlinePlus

    ... strength and tone, and the ability to sense vibration, light touch, body position, temperature, and pain. Depending ... tests that record the ability to sense touch, vibration, cooling, and heat Nerve biopsy – to evaluate damage ...

  18. Runflat Testing

    DTIC Science & Technology

    2015-09-09

    tire assembly tread life combat flat central tire inflation system (CTIS) 16. SECURITY CLASSIFICATION OF: 17. LIMITATION...2 2. FACILITIES AND INSTRUMENTATION ......................... 2 2.1 Facilities...2 2.2 Instrumentation ...................................................................... 3 3. REQUIRED TEST

  19. Iron Test

    MedlinePlus

    ... detect and help diagnose iron deficiency or iron overload. In people with anemia , these tests can help ... also be ordered when iron deficiency or iron overload is suspected. Early iron deficiency often goes unnoticed. ...

  20. Albumin Test

    MedlinePlus

    ... may also be ordered to evaluate a person's nutritional status. ^ Back to top When is it ordered? An ... albumin test to check or monitor a person's nutritional status. However, since albumin concentrations respond to a variety ...